CN119199895A - Laser radar and its detection method - Google Patents
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Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
- G01S17/88—Lidar systems specially adapted for specific applications
- G01S17/93—Lidar systems specially adapted for specific applications for anti-collision purposes
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
- G01S17/02—Systems using the reflection of electromagnetic waves other than radio waves
- G01S17/06—Systems determining position data of a target
- G01S17/08—Systems determining position data of a target for measuring distance only
- G01S17/10—Systems determining position data of a target for measuring distance only using transmission of interrupted, pulse-modulated waves
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
- G01S17/88—Lidar systems specially adapted for specific applications
- G01S17/89—Lidar systems specially adapted for specific applications for mapping or imaging
- G01S17/894—3D imaging with simultaneous measurement of time-of-flight at a 2D array of receiver pixels, e.g. time-of-flight cameras or flash lidar
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
- G01S7/483—Details of pulse systems
- G01S7/484—Transmitters
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
- G01S7/483—Details of pulse systems
- G01S7/486—Receivers
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
- G01S7/483—Details of pulse systems
- G01S7/486—Receivers
- G01S7/4865—Time delay measurement, e.g. time-of-flight measurement, time of arrival measurement or determining the exact position of a peak
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
- G01S7/497—Means for monitoring or calibrating
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- Computer Networks & Wireless Communication (AREA)
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- Optical Radar Systems And Details Thereof (AREA)
Abstract
The invention provides a laser radar which comprises a transmitting device, a detecting device and a data processing device, wherein the transmitting device comprises at least one light emitting unit, the light emitting unit is configured to emit a plurality of detection pulses for detecting an obstacle in a detection process, the detecting device comprises at least one detection unit, each detection unit comprises a pixel array, the pixel array can respond to echoes reflected by the detection pulses on the obstacle and generate detection data, the data processing device is coupled with the detecting device and is configured to acquire the detection data, the data processing device comprises a feedback processing module, the feedback processing module is coupled with the transmitting device, the transmitting device firstly transmits a first group of detection pulses in the detection process, the first group of detection pulses comprise one or more detection pulses, the data processing device acquires the first group of detection data, and the first group of detection data is the detection data generated after the pixel array responds to echoes reflected by the first group of detection pulses on the obstacle, and the feedback processing module is configured to determine a subsequent transmission strategy of the transmitting device according to the first group of detection data. The laser radar of the invention determines the subsequent transmitting strategy of the transmitting device through the feedback mechanism, thereby effectively reducing the system power consumption of the laser radar.
Description
Technical Field
The present invention relates generally to the field of lidar, and more particularly, to a lidar and a method for detecting the lidar.
Background
The laser radar is a radar system for detecting the position, speed and other characteristic quantities of a target by emitting laser beams, and is an advanced detection mode combining laser technology and photoelectric detection technology. The laser radar is widely applied to the fields of automatic driving, traffic communication, unmanned aerial vehicle, intelligent robot, resource exploration and the like due to the advantages of high resolution, good concealment, strong active interference resistance, good low-altitude detection performance, small volume, light weight and the like.
Some laser radars adopt detectors similar to single photon avalanche diodes (Single Photon Avalanche Diode, SPAD) for detection, the SPAD has strong sensitivity, can be triggered and responded by single photons and is easily influenced by ambient light noise, and on the other hand, the SPAD has lower photon detection efficiency (Photon Detection Efficiency, PDE) for the common detection light wave band of the laser radars, so the signal intensity obtained by single detection of the SPAD is weaker, and the distance measuring capability of the laser radars is limited. In one detection scan, SPAD may only trigger several times in the detection time window, so it is difficult to distinguish whether the detected optical signal is echo signal or ambient light noise, and the signal-to-noise ratio is low, which affects the accuracy of the detection result.
In order to improve the ranging performance of the laser radar and reduce the influence of noise, the laser radar can perform repeated measurement in one detection process when detecting an obstacle in the same field of view, wherein one measurement is also called one scan (sweep), that is, one laser can perform multiple light emission (that is, emit multiple detection pulses) in the light emission time of the laser, each light emission is called one scan, and each scan emits 1 detection pulse (the number of repeated measurement can reach 400-500 times, even thousands of times, or more or less). As shown in fig. 1a, the lidar performs, for example, 400 scans in a single detection process. As shown in fig. 1b, during each scanning process, echoes generated by the detection pulse emitted by the lidar through the reflection of the obstacle, ambient light noise, and the like trigger different numbers of SPADs at different moments (the abscissa in fig. 1b is time, and the ordinate is the number of SPADs triggered). The result of only 1 scan (i.e. the histogram in the upper right corner in fig. 1 b) cannot effectively distinguish the echo signal from the noise signal, so that the result of the 2 nd scan can be accumulated on the basis of the result of the 1 st scan, so that a higher amount of the echo signal is accumulated in time corresponding to the echo signal, and so on until the result of 400 scans is accumulated (assuming that the total number of scans is 400), a histogram (refer to the histogram in the lower right corner in fig. 1 b) is obtained, and a stronger peak value is accumulated in time corresponding to the obstacle, so that the echo signal and the noise signal are effectively distinguished, and the distance of the obstacle is measured at this time, so as to obtain a point in the laser radar point cloud. The method for acquiring the obstacle information according to the accumulated results of the multiple scans can effectively improve the detection performance of the laser radar which adopts SPAD as a detector in some cases. But limited by the number of light emissions, the signal-to-noise ratio of the weak echo signal is relatively low, especially for echo signals of long-distance, low-reflectivity targets, the ability to trigger the detector is poor, and thus the pulse peak obtained after limited times of accumulation may still be low, and the signal-to-noise ratio is low.
In order to improve the signal-to-noise ratio, some lidars adopt a convolution processing scheme, namely, convoluting the electric signal output by each detection unit, so that the signal-to-noise ratio can be effectively improved, and the method is very beneficial to actual measurement of the lidars, but in the existing scheme, most lidars adopt convolution kernels with the same size and the same convolution step length in the convolution processing process, so that the calculation consumption is larger, and the adjustment capability is weaker. In addition, in the one-time detection process, the number of light emission times of each laser of the laser radar is the same, and each detection unit corresponding to the laser radar also responds corresponding to the number of light emission times, so that the power consumption of the laser radar system is high.
Therefore, how to reduce the calculation consumption and the power consumption of the laser radar system, and simultaneously, keep the laser radar with better detection performance (such as higher signal-to-noise ratio, remote measurement performance, accuracy of detection results, dynamic adjustment capability, and the like), is a continuous improvement requirement in the laser radar field.
The matters in the background section are only those known to the inventors and do not, of course, represent prior art in the field.
Disclosure of Invention
Aiming at one or more of the problems in the prior art, the invention provides a laser radar, which firstly transmits a first group of detection pulses in a one-time detection process, carries out feedback processing based on detection data of the first group of detection pulses, determines a subsequent transmission strategy of a transmitting device, and can realize at least one of detection performances such as reducing calculation consumption, reducing system power consumption, keeping higher signal-to-noise ratio, measuring remote performance, accuracy of detection results, dynamic adjustment capability and the like.
The laser radar includes:
a transmitting device including at least one light emitting unit configured to transmit a plurality of detection pulses for detecting an obstacle in one detection process;
A detection device comprising at least one detection unit, wherein each detection unit comprises an array of pixels, wherein the array of pixels is responsive to echoes of the detection pulses reflected on an obstacle and generates detection data, and
A data processing device coupled to the detection device and configured to acquire the detection data;
the data processing device comprises a feedback processing module, and the feedback processing module is coupled with the transmitting device;
Wherein during a detection process, the transmitting means first transmits a first set of detection pulses, wherein the first set of detection pulses comprises one or more detection pulses;
the data processing device acquires a first group of detection data, wherein the first group of detection data is generated after the pixel array responds to an echo reflected by the first group of detection pulses on an obstacle;
The feedback processing module is configured to determine a subsequent transmission strategy of the transmitting device based on the first set of probe data.
According to one aspect of the invention, wherein the feedback processing module is configured to:
performing a first convolution process on the first set of detection data to obtain a first recombined pixel array, and
Determining a subsequent emission strategy of the emission device according to the first recombined pixel array.
According to one aspect of the invention, wherein the feedback processing module is configured to:
counting the data of the reorganized pixels in the first reorganized pixel array, and
And determining the subsequent transmission strategy of the transmitting device according to the statistical result.
According to one aspect of the invention, wherein the feedback processing module is configured to:
Counting whether threshold crossing pulses exist in the data of the recombined pixels in the first recombined pixel array and obtaining a pulse counting result, wherein the threshold crossing pulses are pulses exceeding a first intensity threshold;
and determining a subsequent transmission strategy of the transmitting device according to the pulse statistical result.
According to one aspect of the invention, wherein the feedback processing module is configured to:
when the threshold crossing pulse exists in the data of the recombined pixels in the first recombined pixel array, one or more of the following parameters, namely the intensity of each threshold crossing pulse, the obstacle distance corresponding to each threshold crossing pulse, the number of the recombined pixels with the threshold crossing pulse and the proportion of the recombined pixels with the threshold crossing pulse to all the recombined pixels in the first recombined pixel array are further counted;
and determining a subsequent transmission strategy of the transmitting device according to the result of the further statistics.
According to one aspect of the invention, wherein the feedback processing module is configured to ambient light compensate data of at least part of the rebinned pixels in the first rebinned pixel array.
According to one aspect of the invention, wherein the transmission strategy comprises one of:
continuing to transmit a second set of detection pulses, wherein the second set of detection pulses comprises one or more detection pulses, and
And stopping transmitting the detection pulse, and ending the detection.
According to one aspect of the invention, wherein said continuing to transmit the second set of probe pulses comprises:
continuing to transmit the second set of detection pulses at a reduced transmission intensity, or
The second set of detection pulses continues to be transmitted at a constant transmission intensity.
According to one aspect of the invention, wherein the feedback processing module is configured to:
And stopping transmitting the detection pulse when the obstacle is detected based on a preset standard through the first group of detection data, and otherwise, continuing transmitting the second group of detection pulse.
According to one aspect of the invention, wherein the feedback processing module is configured to feedback the transmission strategy to the transmitting device, the transmitting device being configured to execute the transmission strategy.
According to one aspect of the invention, during a detection process, when the transmitting device continues to transmit a second set of detection pulses, the data processing device is configured to acquire a second set of detection data, the second set of detection data being detection data generated by the pixel array in response to echoes reflected by the obstacle by the second set of detection pulses, and the feedback processing module is configured to determine a subsequent transmission strategy of the transmitting device according to the second set of detection data.
According to one aspect of the invention, the data processing device further comprises an output processing module, the output processing module is coupled with the feedback processing module, when the feedback processing module determines that the transmitting strategy is to stop transmitting the detection pulse, the output processing module is configured to perform second convolution processing on the detection data generated according to at least one group of detection pulses transmitted by the transmitting device to obtain a second recombinant pixel array, and generate a laser radar point cloud according to the second recombinant pixel array, wherein the detection data generated according to at least one group of detection pulses comprises the first group of detection data.
According to one aspect of the invention, the second convolution processing comprises the step of carrying out convolution processing on the detection data by adopting a plurality of convolution kernels with different sizes respectively to obtain a plurality of second recombinant pixel arrays, and generating a laser radar point cloud according to the plurality of second recombinant pixel arrays.
According to one aspect of the invention, wherein the output processing module is configured to ambient light compensate at least part of the reconstructed pixel data in the second reconstructed pixel array.
According to one aspect of the invention, the output processing module is configured to determine a final rebinned pixel array from the state of rebinned pixel data in the plurality of second rebinned pixel arrays and generate a lidar point cloud from the final rebinned pixel array.
According to one aspect of the invention, wherein the output processing module is configured to determine the final recombined pixel array based on pulse threshold crossing states of adjacent recombined pixels in at least two of the second recombined pixel arrays.
According to one aspect of the invention, wherein the output processing means is configured to determine the manner of computation of the intermediate rebinned pixel data based on the threshold state of pulse crossing of at least two adjacent rebinned pixel data in the second rebinned pixel array.
According to one aspect of the invention, the output processing means is configured to determine the manner of calculation of the intermediate rebinned pixel data based on the pulse threshold state of the at least two adjacent rebinned pixel data and the distance and/or reflectivity of its corresponding obstacle.
According to one aspect of the invention, the calculation mode of the intermediate rebinned pixel data comprises one of interpolation calculation of the intermediate rebinned pixel, single-point calculation of the intermediate rebinned pixel and convolution calculation of the intermediate pixel.
The invention also provides a detection method of the laser radar, the laser radar comprises a transmitting device and a detection device, the transmitting device comprises at least one light emitting unit, wherein the light emitting unit transmits a plurality of detection pulses in one detection process, the detection device comprises at least one detection unit, each detection unit comprises a pixel array, and the detection method comprises the following steps of in one detection process,
S11, firstly, transmitting a first group of detection pulses, wherein the first group of detection pulses comprises one or more detection pulses;
s12, responding to the echoes reflected by the obstacle by the first group of detection pulses by the pixel array of the detection unit and generating a first group of detection data, and
And S13, determining a subsequent transmission strategy according to the first group of detection data.
According to one aspect of the invention, wherein said step S13 comprises:
performing a first convolution process on the first set of detection data to obtain a first recombined pixel array, and
Determining a subsequent emission strategy of the emission device according to the first recombined pixel array.
According to one aspect of the invention, wherein said step S13 comprises:
counting the data of the reorganized pixels in the first reorganized pixel array, and
And determining the subsequent transmission strategy of the transmitting device according to the statistical result.
According to one aspect of the invention, the step of counting the data of the rebinned pixels in the first rebinned pixel array comprises:
Counting whether threshold crossing pulses exist in the data of the recombined pixels in the first recombined pixel array and obtaining a pulse counting result, wherein the threshold crossing pulses are pulses exceeding a first intensity threshold;
and determining a subsequent transmission strategy of the transmitting device according to the pulse statistical result.
According to one aspect of the invention, when the threshold crossing pulse is present in the data of the rebinned pixels in the first rebinned pixel array, the step of counting the data of the rebinned pixels in the first rebinned pixel array further comprises:
further counting one or more of the intensity of each of said threshold crossing pulses, the distance of the obstacle to which each of said threshold crossing pulses corresponds, the number of rebinned pixels in which said threshold crossing pulse is present, and the ratio of rebinned pixels in which said threshold crossing pulse is present to all rebinned pixels in said first array of rebinned pixels;
and determining a subsequent transmission strategy of the transmitting device according to the result of the further statistics.
According to one aspect of the invention, wherein said step S13 comprises ambient light compensation of at least part of the recombined pixel data in said first recombined pixel array.
According to one aspect of the invention, wherein the transmission strategy comprises one of:
continuing to transmit a second set of detection pulses, wherein the second set of detection pulses comprises one or more detection pulses, and
And stopping transmitting the detection pulse, and ending the detection.
According to one aspect of the invention, wherein the step of continuing to transmit the second set of probe pulses comprises:
continuing to transmit the second set of detection pulses at a reduced transmission intensity, or
The second set of detection pulses continues to be transmitted at a constant transmission intensity.
According to one aspect of the invention, wherein said step S13 comprises:
And stopping transmitting the detection pulse when the obstacle is detected based on a preset standard through the first group of detection data, and otherwise, continuing transmitting the second group of detection pulse.
According to one aspect of the present invention, further comprising:
Feeding back the transmission strategy to the transmitting device, and
And controlling the transmitting device to execute the fed-back transmitting strategy.
According to one aspect of the invention, during a detection, when the second set of detection pulses continues to be transmitted, the detection method further comprises:
Acquiring a second set of detection data generated by the pixel array in response to echoes of the second set of detection pulses reflected on the obstacle, and
The subsequent transmission strategy is determined from the second set of probe data.
According to one aspect of the invention, when the emission strategy is determined to stop emitting detection pulses, the detection method further comprises performing second convolution processing on detection data generated according to at least one group of detection pulses emitted by the emission device, obtaining a second recombinant pixel array, and generating a laser radar point cloud according to the second recombinant pixel array, wherein the detection data generated according to the at least one group of detection pulses comprises the first group of detection data.
According to one aspect of the invention, the step of performing second convolution processing on the detection data generated according to at least one group of detection pulses transmitted by the transmitting device comprises the step of performing convolution processing on the detection data by using a plurality of convolution kernels with different sizes respectively to obtain a plurality of second recombinant pixel arrays, and generating a laser radar point cloud according to the plurality of second recombinant pixel arrays.
According to one aspect of the invention, ambient light compensation is also included for at least a portion of the reconstructed pixel data in the second reconstructed pixel array.
According to one aspect of the invention, the method further comprises determining a final reorganized pixel array according to the state of reorganized pixel data in the plurality of second reorganized pixel arrays, and generating a laser radar point cloud according to the final reorganized pixel array.
According to one aspect of the invention, wherein the step of determining a final recombined pixel array from the state of recombined pixel data in a plurality of second recombined pixel arrays comprises determining the final recombined pixel array from pulse threshold crossing states of neighboring recombined pixels in at least two of the second recombined pixel arrays.
According to one aspect of the invention, wherein the step of determining the final rebinned pixel array based on the state of rebinned pixel data in the plurality of second rebinned pixel arrays further comprises determining a manner of calculating intermediate rebinned pixel data based on the threshold state of pulse crossing of at least two adjacent rebinned pixel data in the second rebinned pixel array.
According to one aspect of the invention, wherein the step of determining the final rebinned pixel array based on the state of the rebinned pixel data in the plurality of second rebinned pixel arrays further comprises determining a manner of calculating the intermediate rebinned pixel data based on the pulse threshold state of the at least two rebinned pixel data and the distance and/or reflectivity of its corresponding obstacle.
According to one aspect of the invention, the method for calculating the intermediate rebinned pixel data comprises one of interpolating the intermediate pixel, performing a single point calculation on the intermediate pixel, and performing a convolution calculation on the intermediate pixel.
In summary, the scheme of the invention is described in detail, the laser radar of the invention works based on a feedback mechanism, and in a detection process, the transmitting device firstly transmits a first group of detection pulses, and the feedback processing module determines a subsequent transmission strategy of the transmitting device according to the first group of detection data. The subsequent emission strategy may be to stop the emission of light, or to continue to emit probe pulses at a reduced emission intensity, or to continue to emit probe pulses at a constant emission intensity. Therefore, the integral scanning times can be reduced, and the system power consumption of the laser radar is greatly saved. Meanwhile, each light-emitting unit in the plurality of light-emitting units can decide the corresponding total scanning times of the light-emitting units according to the real-time detection result, so that the self-adaptive adjustment of the quantity of emitted detection pulses is realized, and the system power consumption is reduced while the higher detection accuracy in the whole view field range is ensured.
Further, the feedback processing module performs the first convolution processing by adopting a larger step size and a smaller convolution check on the first group of detection data, so that the calculated amount of the first convolution processing is lower, the calculation speed is higher, and the system power consumption of the laser radar can be reduced.
Further, in the second convolution processing process, compared with the convolution step length in the first convolution processing, the output processing module preferentially adopts smaller convolution step length to carry out the second convolution processing, and through a mode of firstly thickening and then thinning, the calculation amount can be reduced, the system power consumption of the laser radar is reduced, and meanwhile, the fine calculation result can be finally obtained.
Further, the feedback processing module/output processing module can reduce interference of ambient light by performing ambient light compensation on the data of at least part of the recombined pixels in the first/second recombined pixel arrays, so that the result is more accurate.
In addition, the total luminous times can be adjusted through a feedback mechanism according to different detection targets, fewer luminous times are adopted for a near-distance high-reflectivity (strong echo signal) area, and more luminous times are adopted for a far-distance low-reflectivity (weak echo signal) area, so that the luminous times can be adjusted in a self-adaptive mode according to real-time echo signals, and the system power consumption of the whole laser radar is reduced.
In addition, the laser radar can realize the adjustment of spatial resolution and signal-to-noise ratio, can realize high spatial resolution for the targets with short distance and high reflectivity, can keep high signal-to-noise ratio for the targets with long distance and weak reflectivity, can realize farther detection capability, can also relieve the problem of expansion of the objects with high reflectivity and the problem of false targets, is beneficial to improving the accuracy of detection results, and enables the laser radar to dynamically keep better detection performance in the whole field of view.
Drawings
The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate the invention and together with the embodiments of the invention, serve to explain the invention. In the drawings:
FIG. 1a shows a schematic diagram of a laser radar making multiple measurements in one probe;
FIG. 1b shows a schematic diagram of a histogram accumulated from a plurality of measurements;
FIG. 2 shows a schematic diagram of a lidar according to an embodiment of the invention;
FIG. 3 shows a schematic diagram of a detection device according to one embodiment of the invention;
Fig. 4 shows a schematic view of a detection device according to another preferred embodiment of the invention;
Fig. 5 shows an enlarged view of a detection unit according to a preferred embodiment of the invention;
FIG. 6 is a schematic diagram of a feedback processing module performing a first convolution process on a first set of probe data in accordance with a preferred embodiment of the present invention;
FIG. 7 shows a schematic diagram of a lidar according to a preferred embodiment of the present invention;
FIGS. 8-10 are diagrams illustrating a second convolution process performed on a first set of probe data by an output processing module according to some preferred embodiments of the present invention;
FIG. 11 is a schematic diagram showing the positional relationship between adjacent and intermediate reorganized pixels, and
Fig. 12 shows a flowchart of a detection method of a lidar according to an embodiment of the present invention.
Detailed Description
Hereinafter, only certain exemplary embodiments are briefly described. As will be recognized by those of skill in the pertinent art, the described embodiments may be modified in various different ways without departing from the spirit or scope of the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature and not as restrictive.
In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more of the described features. In the description of the present invention, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.
In the description of the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected, mechanically connected, electrically connected, or communicable with each other, directly connected, indirectly connected via an intermediary, or in communication between two elements or in an interaction relationship between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.
In the present invention, unless expressly stated or limited otherwise, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, as well as the first and second features not being in direct contact but being in contact with each other through additional features therebetween. Moreover, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly under and obliquely below the second feature, or simply means that the first feature is less level than the second feature.
The following disclosure provides many different embodiments, or examples, for implementing different features of the invention. In order to simplify the present disclosure, components and arrangements of specific examples are described below. They are, of course, merely examples and are not intended to limit the invention. Furthermore, the present invention may repeat reference numerals and/or letters in the various examples, which are for the purpose of brevity and clarity, and which do not themselves indicate the relationship between the various embodiments and/or arrangements discussed. In addition, the present invention provides examples of various specific processes and materials, but one of ordinary skill in the art will recognize the application of other processes and/or the use of other materials.
The preferred embodiments of the present invention will be described below with reference to the accompanying drawings, it being understood that the preferred embodiments described herein are for illustration and explanation of the present invention only, and are not intended to limit the present invention.
The present invention provides a lidar, fig. 2 shows a schematic diagram of a lidar 100 according to an embodiment of the present invention, and as shown in fig. 2, the lidar 100 comprises a transmitting device 110, a detecting device 120 and a data processing device 130. Wherein the transmitting means 110 comprises at least one light emitting unit 111 (fig. 2 schematically shows one light emitting unit 111), the light emitting unit 111 being configured to emit a plurality of detection pulses L for detecting an obstacle OB during a detection, wherein the detecting means 120 comprises at least one detection unit 121 (fig. 2 schematically shows one of the detection units 121), wherein each detection unit 121 comprises a pixel array (fig. 2 schematically shows an 8 x 16 pixel array) which is responsive to echoes L' of the detection pulses L reflected on the obstacle OB and generates detection data, wherein the data processing means 130 is coupled to the detecting means 120 and configured to acquire detection data, wherein the data processing means 130 comprises a feedback processing module 131 coupled to the transmitting means 110, wherein during a detection the transmitting means 110 first transmits a first set of detection pulses comprising one or more detection pulses L, wherein the data processing means 130 acquires a first set of detection data which is the response of the pixel array to echoes of the first set of detection pulses reflected on the obstacle OB, wherein the data processing means 130 is configured to subsequently determine the transmission strategy of the first set of detection data based on the feedback processing module 131. The laser radar of the invention determines the subsequent transmitting strategy of the transmitting device through the feedback mechanism, thereby determining the quantity of transmitting detection pulses according to the real-time detection result, effectively reducing the total quantity of detection pulses and reducing the system power consumption of the laser radar. For example, when the detected data generated from the echoes generated from the first set of detected pulses is sufficient to accurately calculate the obstacle information, the transmission of the remaining detected pulses in the detection process may be selected to be stopped, and when the detected data generated from the echoes generated from the first set of detected pulses is insufficient to accurately calculate the obstacle information, the transmission of further detected pulses may be selected to be continued, and the detected data may be generated from the further detected results. As described in detail below.
Fig. 3 shows a schematic diagram of a detection device 120 according to a preferred embodiment of the present invention, as shown in fig. 3, the detection device 120 includes a plurality of detection units, for example, N detection units R 1、R2、R3、…、RN, where N is an integer greater than 1, and the plurality of detection units are arranged in a one-dimensional linear array along a vertical direction, covering a vertical field of view of the lidar, and further implementing scanning detection of a three-dimensional scene by mechanically rotating a transceiver device of the lidar or by rotating a scanning mirror.
Fig. 4 shows a schematic diagram of a detecting device 120 according to another preferred embodiment of the present invention, as shown in fig. 4, the detecting device 120 includes a plurality of detecting units R 11、R21、…、RM1、…、R1N、R2N、…、RMN, which may be arranged in a two-dimensional area array to form an n×m detecting unit array, i.e., an N-row and M-column detecting unit array, where N and M are integers greater than 1, and the present invention is not limited with respect to the size relationship between N and M.
Fig. 5 shows an enlarged view of one detection unit 121 according to a preferred embodiment of the present invention, as shown in fig. 5, the detection unit 121 includes a pixel array, each pixel array including a plurality of pixels arranged in an array, for example, 8×16=128 pixels exemplarily shown in the figure, each pixel may include one or more single photon avalanche diodes (Single Photon Avalanche Diode, SPAD), each single photon avalanche diode being individually gated and addressable, and data in one or more SPADs in each pixel being accumulated to form data for the pixel. It will be appreciated that the data for each SPAD can also be output and read independently.
The above embodiments describe the detection device of the present invention in detail, and it should be noted that, regarding the number and arrangement of the detection units in the detection device, the number and arrangement of the pixels in each detection unit, and the number and arrangement of SPADs in each pixel, the present invention is not limited, and in practical application, the present invention can be flexibly set according to requirements.
According to a preferred embodiment of the present invention, the emitting device 110 includes at least one light emitting unit 111, each light emitting unit 111 corresponding to at least one detecting unit 121. The echoes of the probe beam emitted by each light emitting unit 111 on the obstacle will be received and converted by the corresponding probe unit 121. On the one hand, the light emitting units 111 can be paired with the detecting units 121 one by one, that is, the number of the light emitting units 111 is equal to that of the detecting units 121, and the echo generated by the detecting light beams emitted by each light emitting unit 111 on the obstacle is received and converted by the detecting units 121 paired with the light emitting units, on the other hand, the echo generated by the detecting light beams emitted by the plurality of light emitting units 111 on the obstacle can also be received and converted by one detecting unit 121, and in addition, the detecting light beams emitted by one light emitting unit 111 can be subdivided into a plurality of light beams, or the detecting light beams can be collected to a plurality of detecting units 121 by means of uniform light and the like.
Preferably, the light emitting unit 111 may employ a Vertical-Cavity Surface-emitting laser (Vertical-Cavity Surface-EMITTING LASER, VCSEL) or an edge-emitting laser (EDGE EMITTING LASER, EEL). When the emitting device 110 includes a plurality of light emitting units 111, the plurality of light emitting units 111 may be arranged in a one-dimensional linear array or a two-dimensional area array according to the arrangement manner of the detecting units 121, which is within the scope of the present invention.
According to an embodiment of the present invention, during the detection process of the lidar, the detection light beam L emitted by the light emitting unit 111 may be deflected by a scanning device (such as a turning mirror), or the emitting device 110 may poll and emit the detection light beam L at intervals of a certain horizontal angle (such as 0.05 °), under the driving of the rotor, the pixel array of the detection unit 121 corresponding to the detection light beam L may respond to the echo L 'reflected by the obstacle OB by the detection light beam L and convert the echo L' into an electrical signal, and through the movement of the field of view, the lidar may complete the scanning of the whole scene of the surrounding environment, thereby implementing the detection within a certain horizontal field of view range, and the data processing device 130 may obtain the three-dimensional point cloud of the surrounding environment by stitching the three-dimensional point cloud of each field of view area. However, the laser radar of the present invention is not limited to the mechanical rotary laser radar or the scanning laser radar described above, and may be a solid-state laser radar, that is, a plane array arrangement of the transmitting device and the detecting device may be used without any mechanical rotary structure, and may cover a certain spatial field of view.
In some lidars, each light emitting unit executes the same emission strategy in the process of detecting multiple times, that is, emits the same number of detection pulses for detecting the obstacle, and the pixel array of the corresponding detection unit also responds for corresponding times, so that the system power consumption of the lidar is larger and the self-adaptive adjustment capability is poor. The invention improves this, in a detection process, the light emitting unit 111 firstly emits a first group of detection pulses, the pixel array of the corresponding detection unit 121 responds to the echo reflected by the obstacle by the first group of detection pulses and generates a first group of detection data, the data processing device 130 obtains the first group of detection data, and the feedback processing module 131 determines the subsequent emission strategy of the emission device 110 according to the first group of detection data. Specifically, in one detection process, assuming that the total number of light emission times of each light emitting unit 111 is Nsweep times (for example, 400 times), each light emitting unit 111 first emits a first set of detection pulses, for example, 1, 50, 100, etc., denoted as N1, where N1< Nsweep, the pixel array of the detection unit 121 corresponding thereto responds to the echoes reflected by the first set of detection pulses on the obstacle and generates a first set of detection data. The first set of detection data may be histogram data obtained by accumulating echo response signals of N1 scans. The data processing device 130 may collect the electrical signals (such as echo waveforms, or the triggering number of SPADs, triggering time, etc.) output by each pixel in the pixel array in parallel, and obtain a first set of detection data after N1 times of accumulation, and the feedback processing module 131 determines a subsequent transmission strategy of the transmitting device 110 according to the first set of detection data.
According to a preferred embodiment of the present invention, the subsequent transmission strategy of the transmitting means 110 comprises one of continuing to transmit a second set of probing pulses, wherein said second set of probing pulses comprises one or more probing pulses, denoted N2, wherein N1+N2.ltoreq. Nsweep, and stopping transmitting probing pulses, ending the present probing. How the feedback processing module 131 determines a subsequent transmission strategy of the transmitting device 110 based on the first set of probe data is described below.
According to an embodiment of the invention, wherein the feedback processing module 131 is configured to determine a subsequent transmission strategy of the transmitting device 110 based on the first set of probe data, for example, it may be determined whether there is a threshold crossing pulse directly based on the first set of probe data or the signal to noise ratio is high enough to decide whether to continue transmitting the second set of probe pulses subsequently. In particular, the feedback processing module 131 may be configured to count whether a threshold crossing pulse is present in the first set of probe data and obtain a pulse count result, and determine a subsequent transmission strategy of the transmitting device 110 based on the pulse count result, wherein the threshold crossing pulse is a pulse exceeding a first intensity threshold. According to a preferred embodiment of the invention, when there are over-threshold pulses in the first set of detection data, the feedback processing module 131 is further configured to further count one or more of the following parameters, namely the intensity of each over-threshold pulse, the distance of the obstacle corresponding to each over-threshold pulse (calculated from the over-threshold pulse), the number of over-threshold pulses, the proportion of over-threshold pulses in the first set of detection data, and to determine the subsequent transmission strategy of said transmitting means 110 based on the result of the further counting. Additionally or alternatively, the feedback processing module 131 may determine a subsequent transmission strategy of the transmitting device 110 based on the signal-to-noise ratio of the first set of probe data. According to a preferred embodiment of the present invention, the feedback processing module 131 is configured to perform a first convolution process on the first set of detection data to obtain a first reorganized pixel array, and determine a subsequent emission strategy of the emission device 110 according to the first reorganized pixel array. In the first convolution processing of the first set of detection data, it is preferable that a smaller-sized convolution kernel conv and a larger convolution step size stride be employed. The convolution kernel may also be referred to as a convolution window or an accumulation window, where the size of the convolution kernel is p×q (a matrix form of P rows and Q columns) and may cover p×q pixels, where P, Q is an integer greater than or equal to 1, and the two may be equal or unequal, and the minimum size of the convolution kernel is a size of one pixel, i.e., conv=1×1.
Fig. 6 shows a schematic diagram of a first convolution process on a first set of probe data according to a preferred embodiment of the present invention. As shown in fig. 6, in this embodiment, in the first convolution process, the convolution kernel conv=1×1 and the convolution step size stride=3, the convolution kernel conv=1×1 is moved gradually in a preset direction (for example, from left to right and from top to bottom) with the convolution step size stride=3 as a unit, and each movement, the electrical signals (for example, echo waveforms) output by all the pixels (1 pixel) covered by the convolution kernel are accumulated once, so as to obtain one recombined pixel, and the pixel array 8×16 of the entire detection unit is traversed, so as to obtain a recombined pixel array (first recombined pixel array) of 3×6, where one dark grid represents one recombined pixel, and referring to fig. 6, a dashed box shows one recombined pixel and a corresponding single pixel (original pixel) thereof, and the lower right part of fig. 6 shows the signal waveform of one recombined pixel (original pixel). The feedback processing module 131 performs the first convolution processing on the first group of detection data by adopting the convolution kernel conv with a smaller size and the convolution step stride with a larger size, so that the first reorganized pixel array can be obtained based on part of the first group of detection data, thereby reducing the calculated amount, improving the calculation speed and saving the system power consumption. Although the present embodiment is described with reference to the convolution kernel having a size conv=1×1 and a convolution step size stride=3, the present invention is not limited thereto, and the convolution kernel may have other sizes and the convolution step size may be other steps in the first convolution process. Preferably, the convolution step length is greater than the side length of the convolution kernel. In the first convolution processing process, the feedback processing module 131 can obtain the first reorganized pixel array based on part or all of the first group of detection data, so that whether the current detection result can detect the obstacle accurately enough can be quickly determined, and the feedback processing module 131 adopts a convolution processing mode to achieve the effects of reducing calculation consumption, saving system power consumption and improving the signal-to-noise ratio of the detection data.
A preferred embodiment of how the feedback processing module 131 determines the subsequent emission strategy of the emission device 110 from the first recombined pixel array is described in detail below.
According to a preferred embodiment of the present invention, the feedback processing module 131 is configured to count the data of the rebinned pixels in the first rebinned pixel array, and determine the subsequent emission strategy of the emission device 110 according to the result of the statistics. Specifically, the feedback processing module 131 is configured to count whether there is a threshold crossing pulse in the data of the rebinned pixels in the first rebinned pixel array and obtain a pulse count result, and determine a subsequent transmission strategy of the transmitting device 110 according to the pulse count result, wherein the threshold crossing pulse is a pulse exceeding the first intensity threshold.
According to a preferred embodiment of the invention, when said threshold crossing pulse is present in the data of the rebinned pixels in the first rebinned pixel array, the feedback processing module 131 is further configured to further count one or more of the following parameters, the intensity of each threshold crossing pulse, the obstacle distance corresponding to each threshold crossing pulse (calculated from the threshold crossing pulse), the number of rebinned pixels with threshold crossing pulses, the ratio of the rebinned pixels with threshold crossing pulses to all rebinned pixels in said first rebinned pixel array, and to determine the subsequent emission strategy of said emission means 110 based on the result of the further counting.
Specifically, the feedback processing module 131 is configured to determine whether the result of the further statistics meets a preset standard, where the preset standard may be one or more of an intensity of the threshold crossing pulse being greater than or equal to a second intensity threshold, where the second intensity threshold is greater than or equal to the first intensity threshold, an obstacle distance corresponding to the threshold crossing pulse being less than a distance threshold, a number of recombining pixels having the threshold crossing pulse reaching a number threshold, and a ratio of recombining pixels having the threshold crossing pulse to all recombining pixels in the first array of recombining pixels reaching a ratio threshold. For example, when the intensity of the over-threshold pulse reaches the second intensity threshold and the ratio of the re-combination pixels in which the over-threshold pulse is present to all of the re-combination pixels in the first array of re-combination pixels reaches a ratio threshold (e.g., 90%), or the number of re-combination pixels in which the over-threshold pulse is present reaches a number threshold and the distance of the obstacle corresponding to the over-threshold pulse is less than a distance threshold, it is indicated that the further statistical result meets a preset criterion. It should be noted that the preset criteria are not limited to the above-mentioned case, but may include other preset criteria, which are all within the scope of the present invention.
When the further statistical result meets the preset standard, it indicates that the signal intensity of the data of the reorganized pixels in the first reorganized pixel array is stronger, the signal to noise ratio is higher, and the feedback processing module 131 can detect the obstacle and accurately calculate the obstacle information through the first group of detection data based on the preset standard. The feedback processing module 131 is configured to determine, when it is determined that an obstacle is detected based on a preset criterion by the first set of detection data, that the subsequent transmission strategy of the transmitting device 110 is to stop transmitting the detection pulse and end the detection. The feedback processing module 131 feeds back the transmission strategy to the transmitting device 110, the transmitting device 110 being configured to execute the transmission strategy.
On the contrary, when the result of the further statistics does not meet the preset standard, it indicates that the signal strength of the data of the reorganized pixels in the first group of pixel arrays is weak, the signal to noise ratio is low, and the feedback processing module 131 can not accurately detect the obstacle through the first group of detection data based on the preset standard. The feedback processing module 131 is configured to determine a subsequent transmission strategy of the transmitting device 110 to continue transmitting the second set of detection pulses when it is determined that the obstacle cannot be detected with sufficient accuracy based on the preset criteria by the first set of detection data. Likewise, the feedback processing module 131 feeds back the transmission strategy to the transmitting device 110, the transmitting device 110 being configured to execute the transmission strategy.
According to another preferred embodiment of the present invention, when there is no threshold crossing pulse in the data of the rebinned pixels in the first rebinned pixel array, it is indicated that the signal strength of the data of the rebinned pixels in the first rebinned pixel array is weak, the signal to noise ratio is low, and the feedback processing module 131 cannot detect the obstacle with sufficient accuracy through the first set of detection data. At this point, the feedback processing module 131 determines a subsequent transmission strategy of the transmitting device 110 to continue transmitting the second set of sounding pulses. Likewise, the feedback processing module 131 feeds back the transmission strategy to the transmitting device 110, the transmitting device 110 being configured to execute the transmission strategy.
The above embodiments describe the specific procedure by which the feedback processing module 131 determines the subsequent transmission strategy of the transmitting device 110 based on the first set of probe data. The feedback processing module 131 is configured to count whether there is a threshold crossing pulse in the data of the rebinned pixels in the first rebinned pixel array, and further count whether the threshold crossing pulse meets a preset criterion when there is a threshold crossing pulse in the data of the rebinned pixels in the first rebinned pixel array, and if the threshold crossing pulse meets the preset criterion, it indicates that the obstacle is sufficiently detected according to the first group of detection data, the feedback processing module 131 determines a subsequent transmission strategy of the transmitting device 110 to stop transmitting the detection pulse and end the detection. At this time, the transmitting device 110 does not need to continuously transmit the detection pulse, and it is not necessary to completely transmit Nsweep detection pulses capable of being transmitted by the light emitting unit 111, so as to reduce the actual transmission times of the light emitting unit 111 and the actual response times of the pixel array of the corresponding detection unit 121, thereby greatly saving the system power consumption of the laser radar. Conversely, if the predetermined criteria is not met or when no threshold crossing pulse is present in the data of the rebinned pixels in the first rebinned pixel array, indicating that an obstacle is not detected with sufficient accuracy based on the first set of detection data, the feedback processing module 131 determines a subsequent firing strategy of the emitting device 110 to continue emitting the second set of detection pulses. At this time, the transmitting device 110 continues to transmit the second set of detection pulses for detection. Based on a feedback mechanism, the dynamic adjustment capability of the laser radar is greatly improved.
During a probing process, when the transmitting device 110 needs to continue transmitting the second set of probing pulses, the transmitting device 110 may continue transmitting the second set of probing pulses with a reduced transmission intensity. Alternatively, the transmitting device 110 may continue to transmit the second set of probe pulses at a constant transmission intensity. According to a preferred embodiment of the present invention, when there is a threshold crossing pulse in the data of the reorganized pixels in the first reorganized pixel array, but the threshold crossing pulse does not meet the preset standard, the transmitting device 110 may continue to transmit the second set of detection pulses with the reduced transmission intensity for performing the supplementary detection, so as to avoid generating an erroneous determination on the obstacle, and simultaneously, reducing the light intensity may also save power consumption. According to another preferred embodiment of the present invention, when it is determined that the distance of the obstacle is relatively long based on the data of the rebinned pixels in the first rebinned pixel array, but the number and/or intensity of the threshold crossing pulses is high, there may be an obstacle with high reflectivity, and the transmitting device 110 may continue to transmit the second set of detection pulses with reduced transmission intensity for complementary detection, so as to reduce the expansion of the high reflectivity object, and achieve more accurate detection. It should be noted that, regarding the specific implementation manner of reducing the emission intensity, the present invention is not limited, and may be implemented by reducing the current or reducing the voltage, for example. According to another preferred embodiment of the present invention, the transmitting means 110 may continue to transmit the second set of detection pulses with a constant transmission intensity when no threshold crossing pulse is present in the data of the rebinned pixels in the first rebinned pixel array.
During a detection process, when the transmitting device 110 continues to transmit the second set of detection pulses, the data processing device 130 is configured to acquire the second set of detection data, where the second set of detection data is the detection data generated by the pixel array after responding to the echo reflected by the obstacle by the second set of detection pulses, and the feedback processing module 131 is configured to determine a subsequent transmission strategy of the transmitting device 110 according to the second set of detection data. Specifically, the second set of detection pulses includes one or more detection pulses, denoted as N2, and the data processing device 130 may collect and accumulate signals generated by the pixel array after responding to echoes reflected by the N2 detection pulses on the obstacle to generate second set of detection data, and may accumulate the second set of detection data with the first set of detection data to obtain accumulated data, and determine a subsequent emission strategy of the emission device 110 according to the accumulated data in a manner of determining the subsequent emission strategy of the emission device 110 according to the first set of detection data, and cycle through so as to determine that the subsequent emission strategy of the emission device 110 is to stop emitting the detection pulses, or end the detection until the total number of emission detection pulses reaches Nsweep.
According to a preferred embodiment of the present invention, the feedback operation of the feedback processing module 131 may be performed a plurality of times during a detection process, for example, each time the transmitting device transmits a set (or a certain number) of detection pulses, the feedback processing module 131 determines the transmission strategy of the transmitting device 110 according to the detection data of the set of detection pulses, and performs a feedback operation. The feedback processing module 131 can determine the subsequent transmitting strategy of the transmitting device 110 for multiple times by executing multiple feedback operations, and the transmitting device 110 can execute the transmitting strategy for multiple times, so that not only can the system power consumption of the laser radar be effectively reduced and the dynamic adjustment capability of the laser radar be improved, but also the balance among various detection performances such as the signal-to-noise ratio, the accuracy, the remote measurement capability, the system power consumption and the like of the laser radar can be facilitated, and the self-adaptive capability of the laser radar can be improved.
In order to more accurately determine the emission strategy of the emission device 110, according to a preferred embodiment of the present invention, the feedback processing module 131 is configured to ambient light compensate the data of at least part of the rebinned pixels in the first rebinned pixel array. Specifically, the feedback processing module 131 may perform pulse detection on the data of the first rebinned pixel, detect whether there is a pulse exceeding the first intensity threshold in the data of the first rebinned pixel, and perform ambient light compensation on the pulse data exceeding the first intensity threshold if there is a pulse exceeding the first intensity threshold. Or the feedback processing module 131 may perform ambient light compensation on the pulse data of the first recombinant pixel, and then detect whether the compensated pulse exceeds the first threshold value in the data, which is not limited by the present invention regarding the sequence of threshold pulse detection and ambient light compensation. In particular implementations, the ambient light compensation data may be determined by the feedback processing module 131 collecting baseline data, or may be determined by other ambient light collection devices (not shown). After the ambient light compensation data is determined, the feedback processing module 131 compensates the ambient light compensation data to a pulse peak exceeding the first intensity threshold, or may also compensate the ambient light compensation data to the first intensity threshold. The feedback processing module 131 can reduce the influence of the ambient light on the data of the recombined pixels in the first recombined pixel array by performing ambient light compensation on the data of at least part of the recombined pixels in the first recombined pixel array, so that the data of the recombined pixels in the first recombined pixel array is more accurate, and therefore, the feedback processing module 131 can also perform statistics on the data of the recombined pixels in the first recombined pixel array after the ambient light compensation so as to obtain more accurate statistical results, thereby determining the subsequent transmitting strategy of the transmitting device 110 more accurately, taking into account the reduction of the power consumption and the improvement of the accuracy of the laser radar system, and being beneficial to further improving the detection performance of the laser radar.
The above embodiments describe how the feedback processing module 131 determines the subsequent emission strategy of the emission device according to the first set of detection data, that is, performs the first convolution processing on the first set of detection data to obtain the first reorganized pixel array, determines the subsequent emission strategy of the emission device according to the pulse statistics result of the reorganized pixel data in the first reorganized pixel array, and if the obstacle is detected accurately enough according to the current scanning result, can stop continuously emitting the detection pulse and end the detection, thereby implementing the preliminary determination based on the scanning result of a small number of times, so as to reduce the total light emitting times of the emission device and the total response times of the detection device, and greatly save the system power consumption of the laser radar. Otherwise, if the current scanning result is insufficient to accurately detect the obstacle, continuing to transmit a second group of detection pulses, performing feedback judgment based on the accumulated result of the second group of detection data and the first group of detection data, and if the obstacle is detected accurately enough based on the accumulated result, stopping to continuously transmit the detection pulses, and ending the detection; if the accumulation result is still insufficient to accurately detect the obstacle, continuing to transmit the third group of detection pulses, performing feedback judgment based on the accumulation result of the third group of detection data and the first two groups of detection data, stopping to transmit the detection pulses and ending the detection if the accumulation result is insufficient to accurately detect the obstacle, continuing to transmit the fourth group of detection pulses if the accumulation result is insufficient to accurately detect the obstacle, accumulating the group of detection data and the first several groups of detection data every time one group of detection pulses is transmitted, performing feedback judgment based on the accumulation result of the group of detection data and the first several groups of detection data, performing feedback judgment repeatedly for a plurality of times until the accumulation result is sufficient to accurately detect the obstacle, or the total number of the transmission detection pulses reaches Nsweep, determining that the subsequent transmission strategy of the transmitting device 110 is to stop transmitting the detection pulses and ending the detection, thereby reducing the system power consumption of the whole radar, and each light emitting unit can realize self-adaptive adjustment of the total number of the emission decision-making pulses according to the total number of the detection results of the light emitting units, the system power consumption is reduced, and meanwhile, higher detection accuracy in the whole view field range can be ensured.
Fig. 7 shows a schematic diagram of a lidar 200 according to a preferred embodiment of the present invention, as shown in fig. 7, the lidar 200 comprises a transmitting means 110, a detecting means 120, a data processing means 130 and a storing means 140. Wherein the storage means 140 is coupled to the data processing means 130 for storing the probe data. According to a preferred embodiment of the present invention, the data processing device 130 is further configured to store the detection data in the storage device 140 and read the detection data in the storage device 140, where the storage device 140 includes a plurality of storage units (not shown in the figure), each storage unit corresponds to the detection data of a different pixel at a different time, and the data processing device 130 may accumulate the electrical signal output by each pixel according to the trigger time and store the accumulated electrical signal in the corresponding storage unit. The detection data outputted from the detection means 120, the first rebinned pixel array generated from the first set of detection data, and the second rebinned pixel array (to be described in detail later) may all be stored in the storage means 140.
Referring to fig. 7, according to a preferred embodiment of the present invention, wherein the data processing apparatus 130 further includes an output processing module 132, the output processing module 132 may be directly or indirectly coupled to and in communication with the feedback processing module 131. The output processing module 132 and the feedback processing module 131 may be integrated in the same chip, for example, a DSP chip, or may be formed of two independent chips (not shown in the figure) to perform different functions.
According to a preferred embodiment of the present invention, when the feedback processing module 131 determines that the emission strategy is to stop emitting detection pulses, the output processing module 132 is configured to perform a second convolution process on detection data generated according to at least one set of detection pulses emitted by the emitting device 110, to obtain a second recombinant pixel array, and generate a laser radar point cloud according to the second recombinant pixel array, wherein the detection data generated according to at least one set of detection pulses includes the first set of detection data, and if detection pulses of other sets continue to be emitted after the first set of detection pulses, the detection data generated according to at least one set of detection pulses further includes detection data generated by other sets of detection pulses. Specifically, when the feedback processing module 131 determines that the emission strategy is to stop emitting the detection pulse according to the first recombinant pixel array, the output processing module 132 is configured to perform a second convolution process on the first set of detection data to obtain a second recombinant pixel array, and generate a laser radar point cloud according to the second recombinant pixel array. In contrast, when the feedback processing module 131 determines that the emission strategy is to continue to emit the second set of detection pulses according to the first recombinant pixel array, and determines that the emission strategy is to stop emitting the detection pulses according to the accumulation result of the second set of detection data and the first set of detection data, the output processing module 132 is configured to perform a second convolution process on the accumulation result of the second set of detection data and the first set of detection data, to obtain a second recombinant pixel array, and generate the laser radar point cloud according to the second recombinant pixel array. When the feedback processing module 131 determines that the emission strategy is to continue to emit the third group of detection pulses according to the accumulation result of the second group of detection data and the first group of detection data, and determines that the emission strategy is to stop emitting the detection pulses according to the accumulation result of the third group of detection data and the first two groups of detection data, the output processing module 132 is configured to perform a second convolution process on the accumulation result of the third group of detection data and the first two groups of detection data, to obtain a second recombinant pixel array, and generate a laser radar point cloud according to the second recombinant pixel array.
The following describes in detail the case that the feedback processing module 131 determines, according to the first recombinant pixel array, that the emission strategy is to stop emitting the detection pulse, and the output processing module 132 is configured to perform the second convolution processing on the first set of detection data to obtain a second recombinant pixel array, and generate the laser radar point cloud according to the second recombinant pixel array. The processing is similar for the case where the transmitting device 110 transmits multiple sets of probe pulses.
According to one embodiment of the present invention, when the feedback processing module 131 determines that the emission strategy is to stop emitting the detection pulse according to the first recombined pixel array, the output processing module 132 is configured to perform a second convolution process on the first set of detection data, where the second convolution process includes performing a single second convolution process on the first set of detection data with a convolution kernel and a convolution step size with a certain size, to obtain a second recombined pixel array, and generating a lidar point cloud according to the second recombined pixel array. Specifically, in this embodiment, the detection unit includes an 8×16 pixel array, the convolution kernel has a size conv=3×3, the convolution step size stride=1, the pixels of 2 columns and 2 rows may be respectively expanded on the right side and the lower side of the detection unit, the data processing device 130 performs the second convolution processing according to the expanded pixel array, and it may be understood that the second convolution processing may be performed only according to the pixel array in the detection unit without expansion. In the second convolution processing, the convolution kernel conv=3×3 moves gradually in a preset direction (for example, from left to right and from top to bottom) with the convolution step size stride=1 as a unit, and each time the convolution kernel moves, the electrical signals (for example, echo waveforms) output by all the pixels (9 pixels) covered by the convolution kernel are accumulated once, so as to obtain a recombined pixel, and the pixel array 8×16 of the whole detection unit is traversed, so that a second recombined pixel array can be obtained. The output processing module 132 generates and outputs a laser radar point cloud according to the obtained second recombinant pixel array. Those skilled in the art will readily appreciate that the output processing module 132 may also perform the second convolution process on the first set of probe data using a single convolution kernel of other sizes, such as 2 x2, 4 x 4, or 5x 5, and the like, and a convolution step size of 2 or other values, which are within the scope of the present invention. It should be understood that if the second convolution process is to use the same convolution kernel size and convolution step size as the first convolution process, for example, convolution kernel conv=1×1 and convolution step size stride=3, in this case, the output processing module 132 may also generate and output a lidar point cloud directly based on the 3×6 first rebinned pixel array in the foregoing embodiment of fig. 6 without performing the operation of the second convolution process. Preferably, the second convolution process uses a convolution kernel size and a convolution step size different from those of the first convolution process, in which, for example, the size conv=1×1 of the convolution kernel and the convolution step size stride=3 (refer to fig. 6), and in the second convolution process, for example, the size conv=3×3 of the convolution kernel and the convolution step size stride=1, by performing the second convolution process with a smaller convolution step size than that of the first convolution process, a higher spatial resolution can be obtained, and by performing the second convolution process with a larger convolution kernel than that of the first convolution process, the signal-to-noise ratio can be improved, and in a specific implementation, can be flexibly set as needed.
According to a preferred embodiment of the present invention, when the feedback processing module 131 determines that the emission strategy is to stop emitting the detection pulse according to the first recombined pixel array, the output processing module 132 is configured to perform a second convolution process on the first set of detection data, where the second convolution process further includes performing the convolution process on the first set of detection data by using a plurality of convolution kernels with different sizes, so as to obtain a plurality of second recombined pixel arrays, and generating a lidar point cloud according to the plurality of second recombined pixel arrays. Wherein the plurality of different sizes are at least two different sizes, for example conv=1×1 (refer to fig. 8), conv=3×3 (refer to fig. 9), conv=5×5 (refer to fig. 10), conv=3×2 (not shown), and the like.
Since the convolution kernel has a certain size, the convolution operation of the detection unit boundary region may be affected. In view of this problem, the pixel data of the boundary area of the detection unit may be expanded by the data processing apparatus 130, that is, the data processing apparatus 130 collects not only the electrical signals output by the 8×16 pixel array of the detection unit, but also the electrical signals output by some pixels of other detection units adjacent thereto, so that the number of pixels corresponding to the actually collected data is greater than 8×16, so that the convolution kernel can cover some pixels of the boundary area of the detection unit and some pixels of the boundary area of the adjacent detection unit, thereby obtaining a plurality of second recombinant pixel arrays with the same arrangement, and facilitating the subsequent processing. In the following, a specific description will be given of an example of performing a second convolution process on the first set of detection data by using three convolution kernels with different sizes, where the sizes of the convolution kernels are conv=1×1 (refer to fig. 8), conv=3×3 (refer to fig. 9), and conv=5×5 (refer to fig. 10), respectively.
Referring to fig. 8, in the present embodiment, the detection unit includes an 8×16 pixel array, the size conv=1×1 of the convolution kernel, and the convolution step size stride=2. In the second convolution process, the convolution kernel conv=1×1 moves gradually in a preset direction (for example, from left to right and from top to bottom) with the convolution step size stride=2 as a unit, and each time the convolution kernel moves, the electric signals (for example, echo waveforms) output by all the pixels (1 pixel) covered by the convolution kernel are accumulated once, so as to obtain a recombined pixel, the 8×16 pixel array of the whole detection unit is traversed, so that a 4×8 recombined pixel array (second recombined pixel array) can be obtained, one dark grid represents one recombined pixel, a dashed frame in fig. 8 shows one recombined pixel and a single pixel (original pixel) corresponding to the one recombined pixel, and the lower right part in fig. 8 shows the signal waveform of one recombined pixel (original pixel).
Referring to fig. 9, in the present embodiment, the detection unit includes an 8×16 pixel array, the size conv=3×3 of the convolution kernel, and the convolution step size stride=2. The data processing device 130 may extend 1 column and 1 row of pixels on the right and lower sides of the detection unit, respectively. In the second convolution processing process, the convolution kernel conv=3×3 moves gradually in a preset direction (for example, from left to right and from top to bottom) with the convolution step size stride=2 as a unit, and each time the convolution kernel moves, the electric signals (for example, echo waveforms) output by all the pixels (9 pixels) covered by the convolution kernel are accumulated once to obtain a recombined pixel, the 8×16 pixel array of the whole detection unit is traversed, and a 4×8 recombined pixel array (second recombined pixel array) can also be obtained, wherein one dark grid represents one recombined pixel, the dashed box of fig. 9 shows the signal waveforms of one recombined pixel and the 9 pixels (original pixels) corresponding to the recombined pixel, and the lower right part of fig. 9 shows the signal waveforms of one recombined pixel and a single pixel.
Referring to fig. 10, in the present embodiment, the detection unit includes an 8×16 pixel array, the size conv=5×5 of the convolution kernel, and the convolution step size stride=2. The data processing means 130 may extend the pixels of 3 columns and 3 rows on the right and lower side of the detection unit, respectively. In the second convolution processing process, the convolution kernel conv=5×5 moves gradually in a preset direction (for example, from left to right and from top to bottom) with the convolution step size stride=2 as a unit, and for each movement, the electric signals (for example, echo waveforms) output by all the pixels (25 pixels) covered by the convolution kernel are accumulated once to obtain a recombined pixel, the 8×16 pixel array of the whole detection unit is traversed, and a 4×8 recombined pixel array (second recombined pixel array) can also be obtained, wherein one dark grid represents one recombined pixel, the dashed box of fig. 10 shows one recombined pixel and the corresponding 25 pixels (original pixels) thereof, and the lower right part of fig. 10 shows the comparison of the signal waveforms of one recombined pixel and a single pixel, so that the signal intensity of the recombined pixel is stronger and the signal to noise ratio is higher. And the signal strength of the rebinned pixel in the embodiment of fig. 10 is stronger and the signal-to-noise ratio is higher than that of the rebinned pixel in the embodiment of fig. 9.
The above embodiment describes a detailed process of performing the second convolution processing on the first set of detection data by the output processing module 132, where the processing module 132 may perform the second convolution processing by using a single-size convolution check on the first set of detection data, or may perform the second convolution processing by using a plurality of convolution checks on the first set of detection data with different sizes, and the size and the convolution step size of the convolution kernel may be flexibly set according to the actual situation, which is beneficial to improving the dynamic adjustment capability of the laser radar. Preferably, the output processing module 132 may preferentially use a smaller convolution step size in the second convolution process than the convolution step size in the first convolution process, so as to improve the spatial resolution, and finally, can obtain a fine calculation result.
According to a preferred embodiment of the present invention, after the second convolution process is finished, the output processing module 132 is further configured to perform ambient light compensation on at least a portion of the data of the pixels in the second array of pixels to reduce the influence of the ambient light on the data of the pixels in the second array of pixels, so that the data of the pixels in the second array of pixels is more accurate. The operation of the output processing module 132 to perform ambient light compensation on at least a portion of the recombined pixel data in the second recombined pixel array is similar to that of the feedback processing module 131 to perform ambient light compensation on at least a portion of the recombined pixel data in the first recombined pixel array, and will not be described herein.
According to a preferred embodiment of the present invention, the output processing module 132 is configured to select an optimal one of the plurality of second recombinant pixel arrays to generate a lidar point cloud.
Assuming that the convolution kernels are P x P in size, and that echoes within the field of view covered by the convolution kernels correspond to the same obstacle and are uniformly distributed, the signal-to-noise ratio of the reconstructed pixels resulting from the different sizes of convolution kernels can be expressed as:
SNR=P×SNR0
Where SNR 0 is the signal-to-noise ratio of a single original pixel, SNR is the signal-to-noise ratio of a reconstructed pixel. It can be seen that the larger the size of the convolution kernel, the stronger the signal intensity of the rebinned pixel obtained after convolution processing, and the higher the signal-to-noise ratio, i.e. the signal-to-noise ratio (or signal intensity) of the rebinned pixel is positively correlated with the size of the convolution kernel.
Therefore, in the actual detection process of the laser radar, in order to improve the signal-to-noise ratio, obtain better remote measurement performance and more accurate detection results, the electric signals output by the pixel array of the detection unit can be subjected to convolution processing by utilizing the convolution check with larger size, and the method is particularly beneficial to detection of long-distance and weak targets.
In the embodiments of fig. 8 to 10, the data processing apparatus 130 expands the pixel data of the boundary area of the detection unit, and the output processing module 132 performs the second convolution processing with the same convolution step size by using a plurality of convolution kernels with different sizes, so that a plurality of second recombinant pixel arrays with consistent sizes can be obtained, which effectively relieves the influence of the size of the convolution kernels on the convolution operation of the boundary area of the detection unit, and each of the recombinant pixels at the same position has a plurality of data values. Specifically, referring to fig. 8 to 10, for example, each of the rebuilt pixels at the same position has 3 data values, including 1×1 convolution data, 3×3 convolution data, and 5×5 convolution data, so that each of the rebuilt pixels at the same position has waveform data with different characteristics, and further, the plurality of rebuilt pixel arrays have waveform data with different characteristics, such as different resolution, signal-to-noise ratio, echo pulse intensity, and the like, and the output processing module 132 may select an optimal rebuilt pixel array according to the waveform data of the plurality of rebuilt pixel arrays, and generate a laser radar point cloud according to the selected optimal rebuilt pixel array, which is favorable for further improving the adaptive capacity and dynamic range of the laser radar and improving the detection performance of the laser radar. According to a preferred embodiment of the invention, the waveform data comprises a signal-to-noise ratio (Signal to Noise Ratio, SNR). The output processing module 132 is configured to determine a signal-to-noise ratio for each of the plurality of second recombinant pixel arrays and select one of the plurality of second recombinant pixel arrays having a signal-to-noise ratio greater than a signal-to-noise ratio threshold T SNR, and select the second recombinant pixel array having the smallest convolution kernel size when the signal-to-noise ratio of the plurality of second recombinant pixel arrays is greater than the signal-to-noise ratio threshold T SNR. specifically, for example, in fig. 8, 9 and 10, convolution processing is performed by using convolution kernels with sizes of 1×1,3×3 and 5×5, and signal-to-noise ratios of signal waveforms of three second recombinant pixel arrays obtained after the convolution processing are T1, T3, The method comprises the steps of selecting a convolution result (a second array of reconstruction pixels) obtained by a convolution kernel of 5×5 to generate a laser radar point cloud if T1< T SNR,T3<TSNR,T5>TSNR, calculating obstacle information according to the convolution result of the convolution kernel of 5×5, selecting a convolution result obtained by a convolution kernel of 3×3 to generate the laser radar point cloud if T1< T SNR,T3>TSNR,T5>TSNR, calculating the obstacle information according to the convolution result of the convolution kernel of 3×3, selecting a convolution result (namely an original pixel array) obtained by the convolution kernel of 1×1 to generate the laser radar point cloud if T1> T SNR,T3>TSNR,T5>TSNR, calculating the obstacle information according to the convolution result (namely an original single pixel) of the convolution kernel of 1×1, and if T1< T SNR,T3<TSNR,T5<TSNR, indicating that the signal to noise ratio of a signal is too low and no target is detected, not generating the laser radar point cloud.
Therefore, when processing the detection data outputted from the plurality of pixels in the detection unit, convolution processing is performed with convolution kernels of side lengths n0, n1, n2, and..once again, the convolution kernels are convolved (where n0< n1< n2 <..once again), assuming that the signal-to-noise ratios of the echo signals of the plurality of second recombinant pixel arrays obtained are SNR (n 0), SNR (n 1), SNR (n 2) &..and so on, setting the signal-to-noise ratio threshold to T SNR, the final selected convolution kernel size is:
n=argmin(SNR(ni)>TSNR)
That is, the minimum convolution kernel size with a signal-to-noise ratio exceeding the threshold T SNR is selected as the final selected convolution kernel size, and a lidar point cloud is generated from the second array of pixels resulting from the convolution kernel of the selected size.
According to another preferred embodiment of the invention, the waveform data further comprises pulse intensity. The output processing module 132 is configured to determine a pulse intensity for each second recombinant pixel array and select a second recombinant pixel array from the plurality of second recombinant pixel arrays having a pulse intensity greater than the pulse intensity threshold T PS. When the pulse intensity of the plurality of second recombinant pixel arrays is higher than the pulse intensity threshold T PS, a second recombinant pixel array in which the convolution kernel size is the smallest is selected. Specifically, for example, convolution kernels with sizes of 1×1,3×3, and 5×5 are used to perform convolution processing, pulse intensities of signal waveforms of three second recombinant pixel arrays obtained after the convolution processing are P1, P3, and P5, respectively, if P1< T PS,P3<TPS,P5>TPS, a convolution result (second recombinant pixel array) obtained by the convolution kernel of 5×5 is selected to generate a laser radar point cloud, obstacle information is calculated according to the convolution result of the convolution kernel of 5×5, if P1< T PS,P3>TPS,P5>TPS, a convolution result (second recombinant pixel array) obtained by the convolution kernel of 3×3 is selected to generate a laser radar point cloud, and according to the convolution result (i.e., original pixel array) obtained by the convolution kernel of 3×3 is selected to generate a laser radar point cloud, if P1> T PS,P3>TPS,P5>TPS, obstacle information is calculated according to the convolution result of the convolution kernel of 1×1, and if P1< T PS,P3<TPS,P5<TPS, no laser radar point cloud is generated.
Therefore, when processing the detection data output from the plurality of pixels in the detection unit, convolution processing is performed on convolution kernels having side lengths of n0, n1, n2, respectively,..the convolution kernels are convolved (where n0< n1< n2 >,) and assuming that the pulse intensities of the echo signals of the obtained recombined pixels are PS (n 0), PS (n 1), PS (n 2), respectively, and the like, the pulse intensity threshold is set to T PS, the finally selected convolution kernel size is:
n=argmin(PS(ni)>TPS)
that is, the minimum convolution kernel size with pulse intensity exceeding the threshold T PS is selected as the final selected convolution kernel size, and a lidar point cloud is generated from the second array of pixels resulting from the convolution kernel of the selected size.
According to a further preferred embodiment of the invention, the size of the convolution kernel may also be determined from a combination of the signal-to-noise ratio and the pulse intensity of the second recombinant pixel array.
Specifically, for example, a minimum convolution kernel size that the signal-to-noise ratio exceeds the threshold T SNR and the pulse intensity exceeds the threshold T PS is selected as the final selected convolution kernel size, as follows:
n=argmin(SNR(ni)>TSNR&PS(ni)>TPS)
Also for example, a minimum convolution kernel size that either has a signal-to-noise ratio exceeding the threshold T SNR or a pulse intensity exceeding the threshold T PS is selected as the final selected convolution kernel size, as follows:
n=argmin(SNR(ni)>TSNR|PS(ni)>TPS)
In the embodiments of fig. 8 to 10, the convolution kernel sizes are 1×1, 3×3, and 5×5, and the convolution step size is stride=2, but the invention is not limited thereto, and the convolution kernel size may be other sizes, for example, conv=3×2, and the convolution step size may be other convolution step sizes, for example stride=1, and the like.
Since the arrangement of the plurality of second recombinant pixel arrays described above with reference to fig. 8, 9, and 10 is the same, each recombinant pixel has a plurality of data values (at least two). Referring to fig. 8, 9, and 10, for example, each reorganized pixel has 3 data values including 1×1 convolution data, 3×3 convolution data, and 5×5 convolution data. Similarly, for the reconstructed pixel data value obtained by performing the second convolution processing with the convolution kernel of other sizes, assuming that the size of the convolution kernel is p×q, the reconstructed pixel data value is p×q convolution data, and so on, where P and Q are integers greater than or equal to 1, and P and Q may be the same or different.
According to a preferred embodiment of the present invention, the output processing module 132 is further configured to determine a status of each of the plurality of second recombinant pixel arrays. Preferably, the state comprises a pulse-through threshold state. In this embodiment, the threshold value refers to a value of the data of the recombined pixel exceeding a third intensity threshold value, and the present invention is not limited to the magnitude relation between the third intensity threshold value and the first and second intensity threshold values. Specifically, the output processing module 132 may perform pulse detection on the data (e.g., echo waveforms) of the pixels in the second plurality of pixel arrays, and determine the state of each pixel data based on the pulse detection result. More specifically, referring to fig. 8, 9, and 10, the output processing module 132 may detect whether the 1×1 convolution data (i.e., single point data), the 3×3 convolution data, and the 5×5 convolution data of each of the reorganized pixel data are threshold-crossing, respectively, to determine a state of each of the reorganized pixel data (referred to as a pulse-crossing threshold state, for short). For example, a state of one rebuilt pixel data is single point detection thresholded, a state of one rebuilt pixel data is convolution detection thresholded, a state of one rebuilt pixel data is 3×3 convolution data and/or 5×5 convolution data is thresholded, and a state of one rebuilt pixel data is non-thresholded if none of the 1×1 convolution data, the 3×3 convolution data, and the 5×5 convolution data of the one rebuilt pixel data is thresholded. Thus, the state of the rebinned pixel data (pulse over threshold state) may include single point detection over threshold, convolution detection over threshold, no over threshold, or also include single point detection over threshold, 3x 3 convolution detection over threshold, 5 x 5 convolution detection over threshold, no over threshold. Preferably, the output processing module 132 may also perform a classification of the labels for each rebinned pixel based on the state of each rebinned pixel data, e.g., labeled as single point detected threshold, convolution detected threshold, non-threshold, for a total of 3 classes, or labeled as single point detected threshold, 3x 3 convolution detected threshold, 5 x 5 convolution detected threshold, non-threshold, for a total of 4 classes, facilitating subsequent processing.
As shown in fig. 8, 9 and 10, the first group of detection data has a dimension of 8×16, and the second group of reconstruction pixel array has a dimension of 4×8, and by performing the second convolution processing with a larger convolution step, a plurality of discrete reconstruction pixels can be obtained to construct the second group of reconstruction pixel array, whereby the calculation amount can be reduced, the calculation speed can be increased, and the system power consumption can be saved. To improve resolution, it is preferable that the final rebinned pixel array be determined by calculating blank pixels among the discrete rebinned pixels from the discrete rebinned pixels, and the lidar point cloud be generated from the final rebinned pixel array. As described in detail below.
According to a preferred embodiment of the present invention, the output processing module 132 is configured to determine a final reorganized pixel array according to the status of reorganized pixel data in the plurality of second reorganized pixel arrays, and generate a lidar point cloud according to the final reorganized pixel array. Preferably, the output processing module 132 is configured to determine the final recombined pixel array based on pulse threshold crossing states of adjacent recombined pixels in at least two of the second recombined pixel arrays. Wherein the adjacent recombined pixels comprise vertically adjacent, laterally adjacent or diagonally adjacent recombined pixels. Referring to fig. 11, it is exemplarily shown that the recombinant pixels 1 and 2 are the recombinant pixels adjacent to the middle recombinant pixel C1 from the left to the right, the recombinant pixels 3 and 4 are the recombinant pixels adjacent to the middle recombinant pixel C4 from the left to the right, the recombinant pixels 1 and 3 are the recombinant pixels adjacent to the middle recombinant pixel C2 from the top to the bottom, the recombinant pixels 2 and 4 are the recombinant pixels adjacent to the middle recombinant pixel C3 from the top to the bottom, the recombinant pixels 1 and 4 are the recombinant pixels adjacent to the middle recombinant pixel C5 from the diagonal, and the recombinant pixels 2 and 3 are the recombinant pixels adjacent to the middle recombinant pixel C5 from the diagonal. In fig. 11, for example, the darkest color recombined pixels 1,2, 3, and 4 are pixels obtained by the second convolution process, and the middle recombined pixels C1, C2, C3, C4, and C5 are pixels (blank pixels) which have not undergone the second convolution process.
To determine the final rebinned pixel array, according to a preferred embodiment of the present invention, the output processing module 132 is configured to determine the manner in which the intermediate rebinned pixel data is calculated based on the threshold states of pulses of at least two adjacent rebinned pixel data in the second rebinned pixel array. Wherein an intermediate rebinned pixel exists between every two adjacent rebinned pixels. Referring to fig. 11, it is exemplarily shown that an intermediate recombinant pixel C2 exists between the vertically adjacent recombinant pixel 1 and the recombinant pixel 3, an intermediate recombinant pixel C3 exists between the vertically adjacent recombinant pixel 2 and the recombinant pixel 4, an intermediate recombinant pixel C1 exists between the horizontally adjacent recombinant pixel 1 and the recombinant pixel 2, an intermediate recombinant pixel C4 exists between the horizontally adjacent recombinant pixel 3 and the recombinant pixel 4, and an intermediate recombinant pixel C5 exists between the diagonally adjacent recombinant pixel 1 and the recombinant pixel 4 (or the recombinant pixel 2 and the recombinant pixel 3). Thus, the output processing module 132 may determine the manner in which the intermediate rebinned pixel data is calculated based on the pulse threshold state of at least two adjacent rebinned pixel data, and thus determine the final rebinned pixel array. According to a preferred embodiment of the present invention, the output processing module 132 is configured to determine the manner of calculation of the intermediate rebinned pixel data based on the pulse threshold state of at least two adjacent rebinned pixel data and the distance and/or reflectivity of their corresponding obstacles. The calculation mode of the intermediate recombined pixel data comprises one of interpolation calculation of the intermediate recombined pixel, single-point calculation of the intermediate recombined pixel and convolution calculation of the intermediate pixel.
The calculation method for determining the data of the intermediate rebinned pixel C1 based on the threshold state of the pulses of the adjacent rebinned pixel 1 and the rebinned pixel 2 will be described as an example. It will be appreciated that the intermediate rebinned pixel data is determined in a similar manner for pulse threshold states employing a greater number of adjacent rebinned pixels.
Referring to fig. 11, assuming that the pulse threshold passing states of the rebinned pixel 1 and the rebinned pixel 2 are both single-point detection threshold passing states, in this case, it is indicated that the echo pulse intensities of the two rebinned pixels are stronger, but the two adjacent rebinned pixels may or may not correspond to the same obstacle, for which, the output processing module 132 may determine the distances and/or reflectances of the obstacles corresponding to the two rebinned pixels, respectively, and determine the distances and/or reflectances using the first determination condition, so as to avoid or reduce obtaining false targets, so that the result is more accurate. If the difference value of the distances and/or the reflectances of the obstacles corresponding to the two recombined pixels is smaller than the preset value, the recombined pixel 1 and the recombined pixel 2 are considered to be in accordance with the first judging condition, the data of the recombined pixel 1 and/or the recombined pixel 2 can be adopted for interpolation calculation of the middle pixel C1 at the moment, otherwise, if the difference value of the distances and/or the reflectances of the obstacles corresponding to the two recombined pixels is not smaller than the preset value, the recombined pixel 1 and the recombined pixel 2 are considered to be not in accordance with the first judging condition, and the two obstacles corresponding to the two obstacles are not the same, at the moment, the data of the corresponding position in the first group of detection data are used as the data of the middle recombined pixel C1, so that high-resolution detection can be realized, the problem of target expansion can be reduced or even avoided, the calculated amount can be reduced, the power consumption of a laser radar system can be saved, the accuracy of a detection result can be considered, and the method is particularly suitable for detection of a near-distance or a strong-reflectivity target.
Referring to fig. 11, assuming that the pulse threshold crossing state of the rebuilt pixel 1 is a single point detection threshold and the pulse threshold crossing state of the rebuilt pixel 2 is a convolution detection threshold, the output processing module 132 may determine the distances and/or reflectances of the obstacles corresponding to the two rebuilt pixels, respectively, and determine the distances and/or reflectances using a second determination condition, and if the second determination condition is met, perform interpolation calculation on the data of the middle pixel C1 using the rebuilt pixel 1 and/or the rebuilt pixel 2, and if the second determination condition is not met, perform single point calculation on the middle rebuilt pixel C1, that is, use the data of the corresponding positions in the first set of detection data as the data of the middle rebuilt pixel C1. It should be appreciated that the aforementioned first determination condition may be more severe than the second determination condition (i.e., the determination is also made by the difference in distance and/or reflectance of the obstacle corresponding to the two reorganized pixels, but the preset value adopted in the first determination condition is smaller), and it is understood that the two may be equal.
Referring to fig. 11, assuming that the pulse threshold crossing state of the rebinned pixel 1 is a single-point detection threshold crossing state and the pulse threshold crossing state of the rebinned pixel 2 is a non-threshold crossing state, the output processing module 132 may perform a single-point calculation, i.e., a1×1 convolution calculation, on the middle rebinned pixel C1 to obtain data of the middle rebinned pixel C1.
For weaker targets, referring to fig. 11, assuming that the pulse threshold passing states of the rebuilt pixel 1 and the rebuilt pixel 2 are convolution detection threshold, the output processing module 132 may determine the distance and/or the reflectivity of the obstacle corresponding to the rebuilt pixel respectively, determine the distance and/or the reflectivity by using a third determination condition, if the third determination condition is met, that is, the distance and/or the reflectivity of the two differ less, the output processing module 132 performs interpolation calculation on the data (for example, 3×3 convolution data or 5×5 convolution data) of the rebuilt pixel 1 and/or the rebuilt pixel 2 by using the middle pixel C1, and if the third determination condition is not met, that is, the distance and/or the reflectivity of the two differ more, the data of the middle pixel C1 outputs 0. The third determination condition may be the same as or different from the first determination condition and/or the second determination condition.
Referring to fig. 11, assuming that the pulse threshold crossing state of the rebuilt pixel 1 is the convolution detection threshold and the pulse threshold crossing state of the rebuilt pixel 2 is the non-threshold, in this case, the signal intensity of the target echo is weaker, the output processing module 132 may perform convolution calculation on the middle pixel C1 with a convolution kernel of a large size, for example, a convolution calculation with a convolution kernel of 5×5, to obtain data on the middle pixel C1, or may use the convolution data of the convolution kernel of the large size of the rebuilt pixel 1 as the data of the middle pixel C1, so that the signal intensity of the middle pixel C1 may be enhanced by performing convolution calculation with a convolution kernel of a large size for the weaker echo signal, thereby achieving enhancement of the signal-to-noise ratio of the weak target echo signal.
Referring to fig. 11, assuming that the pulse threshold states of the recombinant pixels 1 and 2 are all non-threshold, in this case, indicating that no obstacle is detected, the data of the intermediate pixel C1 is output 0.
The above embodiment describes how to determine the calculation of the data of the intermediate rebinned pixel C1 based on the threshold state of the pulses of the neighboring rebinned pixels 1 and 2. Similarly, for the middle rebinned pixel C2 data, it may be determined based on the threshold state of the pulses of the neighboring rebinned pixels 1 and 3, for the middle rebinned pixel C3 data, it may be determined based on the threshold state of the pulses of the neighboring rebinned pixels 2 and 4, for the middle rebinned pixel C4 data, it may be determined based on the threshold state of the pulses of the neighboring rebinned pixels 3 and 4, and for the middle rebinned pixel C5 data, it may be determined based on the threshold state of the pulses of the neighboring rebinned pixels 1,2,3, 4. In summary, the intermediate rebinned pixel data may be determined according to the threshold state of the pulses of at least two neighboring rebinned pixels, thereby determining a final rebinned pixel array, and generating a lidar point cloud according to the final rebinned pixel array. Meanwhile, based on the judgment of the distance and/or the reflectivity, the problems of expansion and the like of a high-reflectivity object can be weakened, compared with the convolution kernel with the same size, the convolution computation is carried out on each middle recombinant pixel, the obtained middle recombinant pixel and the final recombinant pixel array have better resolution, distance and reflectivity precision, and meanwhile, the resolution and signal-to-noise ratio of the final recombinant pixel array of the whole detection unit can be dynamically distributed according to the signal intensity, so that the laser radar can dynamically maintain better detection performance in the whole field of view.
In addition, it should be noted that, in the present invention, the feedback processing module 131 is used to implement the feedback operation for the purpose of reducing the power consumption of the laser radar system. In some cases, especially in the case where there is a larger margin in the power of the lidar, the feedback operation of the feedback processing module 131 may be skipped, that is, the preset total scan times Nsweep are continuously performed, and then the probe data obtained according to Nsweep scans are performed, and the output processing module 132 performs the subsequent data processing operation. For example, for some lidars dedicated to measuring short-range obstacles, the power required for each detection is low, so that the feedback operation described above can be skipped or omitted, the detection pulse of Nsweep times is directly transmitted, and the relevant information of the obstacle is calculated according to the detection result of Nsweep times.
The laser radar of the invention can realize the dynamic resolution and signal-to-noise ratio of the whole field of view. The method has higher spatial resolution for the strong echo signal region, higher signal-to-noise ratio and stronger distance measurement capability for the weak echo signal region, not only can be used for detecting long-distance, low-reflectivity and small target signals, but also can be used for keeping the detection of short-distance and strong-echo (high-reflectivity) targets to have higher spatial resolution, and can be used for weakening the expansion problem of high-reflectivity objects, thereby being beneficial to improving the accuracy of detection results and enabling the laser radar to dynamically keep better detection performance in the whole field of view.
The invention also provides a detection method 10 of the laser radar 100, and the laser radar 100 comprises a transmitting device 110 and a detecting device 120 referring to fig. 2 and fig. 2, wherein the transmitting device 110 comprises at least one light emitting unit 111, the light emitting unit 111 transmits a plurality of detection pulses L in one detection process, the detecting device 120 comprises at least one detecting unit 121, and each detecting unit 121 comprises a pixel array, and the detection method 10 comprises the following steps of:
In step S11, a first set of detection pulses is first transmitted, wherein the first set of detection pulses comprises one or more detection pulses;
In step S12, a first set of detection data is generated in response to echoes of the first set of detection pulses reflected on the obstacle OB by the pixel array of the detection unit 121, and
In step S13, a subsequent transmission strategy is determined from the first set of probe data.
According to a preferred embodiment of the present invention, the step S13 includes:
performing a first convolution process on the first set of detection data to obtain a first recombined pixel array, and
Determining a subsequent emission strategy of the emission device according to the first recombined pixel array.
According to a preferred embodiment of the present invention, the step S13 includes:
counting the data of the reorganized pixels in the first reorganized pixel array, and
Based on the statistics, a subsequent transmission strategy of the transmitting device 110 is determined.
According to a preferred embodiment of the present invention, the step of counting the data of the rebinned pixels in the first rebinned pixel array comprises:
Counting whether threshold crossing pulses exist in the data of the recombined pixels in the first recombined pixel array and obtaining a pulse counting result, wherein the threshold crossing pulses are pulses exceeding a first intensity threshold;
and determining a subsequent transmission strategy of the transmitting device according to the pulse statistical result.
According to a preferred embodiment of the present invention, when the threshold crossing pulse is present in the data of the rebinned pixels in the first rebinned pixel array, the step of counting the data of the rebinned pixels in the first rebinned pixel array further comprises:
further counting one or more of the intensity of each of said threshold crossing pulses, the distance of the obstacle to which each of said threshold crossing pulses corresponds, the number of rebinned pixels in which said threshold crossing pulse is present, and the ratio of rebinned pixels in which said threshold crossing pulse is present to all rebinned pixels in said first array of rebinned pixels;
Based on the results of the further statistics, a subsequent transmission strategy of the transmitting means 110 is determined.
According to a preferred embodiment of the invention, said step S13 comprises ambient light compensation of at least part of the recombined pixel data in said first recombined pixel array.
According to a preferred embodiment of the invention, wherein said transmission strategy comprises one of the following:
continuing to transmit a second set of detection pulses, wherein the second set of detection pulses comprises one or more detection pulses, and
And stopping transmitting the detection pulse, and ending the detection.
According to a preferred embodiment of the invention, the step of continuing to transmit the second set of probe pulses comprises:
continuing to transmit the second set of detection pulses at a reduced transmission intensity, or
The second set of detection pulses continues to be transmitted at a constant transmission intensity.
According to a preferred embodiment of the present invention, the step S13 includes:
And stopping transmitting the detection pulse when the obstacle is detected based on a preset standard through the first group of detection data, and otherwise, continuing transmitting the second group of detection pulse.
According to a preferred embodiment of the present invention, the detection method 10 further comprises:
feeding back the transmission strategy to the transmitting means 110, and
The transmitting means 110 is controlled to perform the fed back transmission strategy.
According to a preferred embodiment of the present invention, during a detection process, when the second set of detection pulses continues to be transmitted, the detection method 10 further comprises:
Acquiring a second set of detection data generated by the pixel array in response to echoes of the second set of detection pulses reflected on the obstacle OB, and
The subsequent transmission strategy is determined from the second set of probe data.
According to a preferred embodiment of the present invention, when it is determined that the emission strategy is to stop emitting detection pulses, the detection method 10 further includes performing a second convolution process on detection data generated according to at least one set of detection pulses emitted by the emitting device, obtaining a second recombinant pixel array, and generating a laser radar point cloud according to the second recombinant pixel array, wherein the detection data generated by the at least one set of detection pulses includes the first set of detection data.
According to a preferred embodiment of the present invention, the step of performing the second convolution processing on the detection data includes performing the convolution processing on the detection data by using a plurality of convolution kernels with different sizes, so as to obtain a plurality of second recombinant pixel arrays, and generating a laser radar point cloud according to the plurality of second recombinant pixel arrays.
According to a preferred embodiment of the present invention, the detection method 10 further comprises ambient light compensation of at least part of the reconstructed pixel data in the second reconstructed pixel array.
According to a preferred embodiment of the present invention, the detection method 10 further comprises determining a final rebinned pixel array from the state of rebinned pixel data in the plurality of second rebinned pixel arrays, and generating a lidar point cloud from the final rebinned pixel array.
According to a preferred embodiment of the invention, the step of determining the final recombined pixel array from the state of the recombined pixel data in the plurality of second recombined pixel arrays comprises determining the final recombined pixel array from pulse threshold crossing states of neighboring recombined pixels in at least two of the second recombined pixel arrays.
According to a preferred embodiment of the present invention, the step of determining the final rebinned pixel array based on the state of rebinned pixel data in the plurality of second rebinned pixel arrays further comprises determining a manner of calculating the intermediate rebinned pixel data based on the threshold state of pulses of at least two neighboring rebinned pixel data in the second rebinned pixel array.
According to a preferred embodiment of the present invention, wherein the step of determining the final rebinned pixel array based on the states of the rebinned pixel data in the plurality of second rebinned pixel arrays further comprises determining the manner of calculation of the intermediate rebinned pixel data based on the pulse threshold states of the at least two rebinned pixel data and the distance and/or reflectivity of their corresponding obstacles.
According to a preferred embodiment of the present invention, the calculation mode of the intermediate rebinned pixel data includes one of interpolation of the intermediate pixels, single-point calculation of the intermediate pixels, and convolution calculation of the intermediate pixels.
The present invention also provides a computer readable storage medium comprising computer executable instructions stored thereon which, when executed by a processor, implement the detection method 10 of lidar 100 as described above.
In some preferred embodiments, the computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. The computer-readable storage medium may employ any combination of one or more computer-readable media. The computer readable storage medium may be, for example, but is not limited to, an electronic, magnetic, optical, or semiconductor form or device, more specific examples (a non-exhaustive list) including an electrical connection having one or more wires, a portable computer hard disk, a hard disk, random Access Memory (RAM), non-volatile random access memory (NVRAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.
The present invention further provides a computer device (not shown) comprising a memory configured to store computer executable instructions which, when executed by the processor, implement the detection method 10 as described above.
In some preferred embodiments, the Processor/data processing device 130/feedback processing module 131/output processing module 132 may include a central processing unit (Central Processing Unit, CPU), and may include other general purpose processors, digital signal processors (DIGITAL SIGNAL processors, DSPs), application Specific Integrated Circuits (ASICs), off-the-shelf Programmable gate arrays (Field-Programmable GATE ARRAY, FPGA) or other Programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc., as the present invention is not limited in this regard.
In summary, the scheme of the invention is described in detail, the laser radar of the invention works based on a feedback mechanism, and in a detection process, the transmitting device firstly transmits a first group of detection pulses, and the feedback processing module determines a subsequent transmission strategy of the transmitting device according to the first group of detection data. The subsequent emission strategy may be to stop the emission of light, or to continue to emit probe pulses at a reduced emission intensity, or to continue to emit probe pulses at a constant emission intensity. Therefore, the integral scanning times can be reduced, and the system power consumption of the laser radar is greatly saved. Meanwhile, each light-emitting unit in the plurality of light-emitting units can decide the corresponding total scanning times of the light-emitting units according to the real-time detection result, so that the self-adaptive adjustment of the quantity of emitted detection pulses is realized, and the system power consumption is reduced while the higher detection accuracy in the whole view field range is ensured.
Further, the feedback processing module performs the first convolution processing by adopting a larger step size and a smaller convolution check on the first group of detection data, so that the calculated amount of the first convolution processing is lower, the calculation speed is higher, and the system power consumption of the laser radar can be reduced.
Further, in the second convolution processing process, compared with the convolution step length in the first convolution processing, the output processing module preferentially adopts smaller convolution step length to carry out the second convolution processing, and through a mode of firstly thickening and then thinning, the calculation amount can be reduced, the system power consumption of the laser radar is reduced, and meanwhile, the fine calculation result can be finally obtained.
Further, the feedback processing module/output processing module can reduce interference of ambient light by performing ambient light compensation on the data of at least part of the recombined pixels in the first/second recombined pixel arrays, so that the result is more accurate.
In addition, the total luminous times can be adjusted through a feedback mechanism according to different detection targets, fewer luminous times are adopted for a near-distance high-reflectivity (strong echo signal) area, and more luminous times are adopted for a far-distance low-reflectivity (weak echo signal) area, so that the luminous times can be adjusted in a self-adaptive mode according to real-time echo signals, and the system power consumption of the whole laser radar is reduced.
In addition, the laser radar can realize the adjustment of spatial resolution and signal-to-noise ratio, can realize high spatial resolution for the targets with short distance and high reflectivity, can keep high signal-to-noise ratio for the targets with long distance and weak reflectivity, can realize farther detection capability, can also relieve the problem of expansion of the objects with high reflectivity and the problem of false targets, is beneficial to improving the accuracy of detection results, and enables the laser radar to dynamically keep better detection performance in the whole field of view.
It should be noted that although several modules or sub-modules of lidar 100 are mentioned in the detailed description above, this division is not mandatory only. Indeed, the features and functions of two or more modules described above may be implemented in a single module in accordance with an embodiment of the invention. Conversely, the features and functions of one module described above may be further divided into a plurality of modules to be embodied.
It is noted that the present specification provides method operational steps as described in the examples or schematics, but may include more or fewer operational steps based on conventional or non-inventive labor. The order of steps recited in the embodiments is merely one way of performing the order of steps and does not represent a unique order of execution. When a system or apparatus product in practice is executed, it may be executed sequentially or in parallel according to the method shown in the embodiment or the flowchart.
It should be noted that the above-mentioned embodiments are merely preferred embodiments of the present invention, and the present invention is not limited thereto, but may be modified or substituted for some of the technical features thereof by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (38)
1. A lidar, comprising:
a transmitting device including at least one light emitting unit configured to transmit a plurality of detection pulses for detecting an obstacle in one detection process;
A detection device comprising at least one detection unit, wherein each detection unit comprises an array of pixels, wherein the array of pixels is responsive to echoes of the detection pulses reflected on an obstacle and generates detection data, and
A data processing device coupled to the detection device and configured to acquire the detection data;
the data processing device comprises a feedback processing module, and the feedback processing module is coupled with the transmitting device;
Wherein during a detection process, the transmitting means first transmits a first set of detection pulses, wherein the first set of detection pulses comprises one or more detection pulses;
the data processing device acquires a first group of detection data, wherein the first group of detection data is generated after the pixel array responds to an echo reflected by the first group of detection pulses on an obstacle;
The feedback processing module is configured to determine a subsequent transmission strategy of the transmitting device based on the first set of probe data.
2. The lidar of claim 1, wherein the feedback processing module is configured to:
performing a first convolution process on the first set of detection data to obtain a first recombined pixel array, and
Determining a subsequent emission strategy of the emission device according to the first recombined pixel array.
3. The lidar of claim 2, wherein the feedback processing module is configured to:
counting the data of the reorganized pixels in the first reorganized pixel array, and
And determining the subsequent transmission strategy of the transmitting device according to the statistical result.
4. The lidar of claim 3, wherein the feedback processing module is configured to:
Counting whether threshold crossing pulses exist in the data of the recombined pixels in the first recombined pixel array and obtaining a pulse counting result, wherein the threshold crossing pulses are pulses exceeding a first intensity threshold;
and determining a subsequent transmission strategy of the transmitting device according to the pulse statistical result.
5. The lidar of claim 4, wherein the feedback processing module is configured to:
when the threshold crossing pulse exists in the data of the recombined pixels in the first recombined pixel array, one or more of the following parameters, namely the intensity of each threshold crossing pulse, the obstacle distance corresponding to each threshold crossing pulse, the number of the recombined pixels with the threshold crossing pulse and the proportion of the recombined pixels with the threshold crossing pulse to all the recombined pixels in the first recombined pixel array are further counted;
and determining a subsequent transmission strategy of the transmitting device according to the result of the further statistics.
6. The lidar of claim 2, wherein the feedback processing module is configured to ambient light compensate for data of at least a portion of the rebinned pixels in the first rebinned pixel array.
7. The lidar according to any of claims 1-6, wherein the transmission strategy comprises one of the following:
continuing to transmit a second set of detection pulses, wherein the second set of detection pulses comprises one or more detection pulses, and
And stopping transmitting the detection pulse, and ending the detection.
8. The lidar of claim 7, wherein the continuing to transmit the second set of detection pulses comprises continuing to transmit the second set of detection pulses at a reduced transmit intensity, or
The second set of detection pulses continues to be transmitted at a constant transmission intensity.
9. The lidar of claim 7, wherein the feedback processing module is configured to:
And stopping transmitting the detection pulse when the obstacle is detected based on a preset standard through the first group of detection data, and otherwise, continuing transmitting the second group of detection pulse.
10. The lidar of claim 7, wherein the feedback processing module is configured to feedback the transmission strategy to the transmitting device, the transmitting device being configured to execute the transmission strategy.
11. The lidar of claim 10, wherein during a detection, when the transmitting device continues to transmit a second set of detection pulses, the data processing device is configured to obtain a second set of detection data, the second set of detection data being detection data generated by the pixel array in response to echoes of the second set of detection pulses reflected on an obstacle, and the feedback processing module is configured to determine a subsequent transmission strategy of the transmitting device based on the second set of detection data.
12. The lidar of claim 7, wherein the data processing device further comprises an output processing module coupled to the feedback processing module, the output processing module configured to perform a second convolution process on probe data generated from at least one set of probe pulses transmitted by the transmitting device to obtain a second array of recombinant pixels from which a lidar point cloud is generated, wherein the probe data generated from at least one set of probe pulses comprises the first set of probe data, when the feedback processing module determines that the transmission strategy is to stop transmitting probe pulses.
13. The lidar of claim 12, wherein the second convolution process comprises convolving the detection data with a plurality of different sized convolution kernels, respectively, to obtain a plurality of second reconstructed pixel arrays, and generating a lidar point cloud from the plurality of second reconstructed pixel arrays.
14. The lidar of claim 12, wherein the output processing module is configured to ambient light compensate for at least a portion of the reconstructed pixel data in the second reconstructed pixel array.
15. The lidar of claim 13, wherein the output processing module is configured to determine a final rebinned pixel array from a state of rebinned pixel data in the plurality of second rebinned pixel arrays, and to generate a lidar point cloud from the final rebinned pixel array.
16. The lidar of claim 15, wherein the output processing module is configured to determine the final array of rebinned pixels based on pulse threshold crossing states of neighboring rebinned pixels in at least two of the second arrays of rebinned pixels.
17. The lidar of claim 16, wherein the output processing module is configured to determine a manner of calculating the intermediate rebinned pixel data based on a threshold state of pulse crossing of at least two neighboring rebinned pixel data in the second rebinned pixel array.
18. The lidar of claim 17, wherein the output processing module is configured to determine a manner of computation of the intermediate rebinned pixel data based on a pulse-through threshold state of the at least two neighboring rebinned pixel data and a distance and/or reflectivity of its corresponding obstacle.
19. The lidar of claim 17, wherein the manner of computing the intermediate rebinned pixel data comprises one of interpolating the intermediate rebinned pixel, single-point computing the intermediate rebinned pixel, and convolving the intermediate pixel.
20. A detection method of a laser radar comprises a transmitting device and a detecting device, wherein the transmitting device comprises at least one light emitting unit, the light emitting unit can transmit a plurality of detection pulses in one detection process, the detecting device comprises at least one detecting unit, each detecting unit comprises a pixel array, and the detecting method comprises the following steps of,
S11, firstly, transmitting a first group of detection pulses, wherein the first group of detection pulses comprises one or more detection pulses;
s12, responding to the echoes reflected by the obstacle by the first group of detection pulses by the pixel array of the detection unit and generating a first group of detection data, and
And S13, determining a subsequent transmission strategy according to the first group of detection data.
21. The probing method of claim 20, wherein the step S13 includes:
performing a first convolution process on the first set of detection data to obtain a first recombined pixel array, and
Determining a subsequent emission strategy of the emission device according to the first recombined pixel array.
22. The probing method of claim 21, wherein the step S13 includes:
counting the data of the reorganized pixels in the first reorganized pixel array, and
And determining the subsequent transmission strategy of the transmitting device according to the statistical result.
23. The detection method of claim 22, wherein the step of counting the data of the rebinned pixels in the first rebinned pixel array comprises:
Counting whether threshold crossing pulses exist in the data of the recombined pixels in the first recombined pixel array and obtaining a pulse counting result, wherein the threshold crossing pulses are pulses exceeding a first intensity threshold;
and determining a subsequent transmission strategy of the transmitting device according to the pulse statistical result.
24. The detection method of claim 23, wherein the step of counting the data of the rebinned pixels in the first rebinned pixel array further comprises:
further counting one or more of the intensity of each of said threshold crossing pulses, the distance of the obstacle to which each of said threshold crossing pulses corresponds, the number of rebinned pixels in which said threshold crossing pulse is present, and the ratio of rebinned pixels in which said threshold crossing pulse is present to all rebinned pixels in said first array of rebinned pixels;
and determining a subsequent transmission strategy of the transmitting device according to the result of the further statistics.
25. The detection method according to claim 21, wherein said step S13 comprises ambient light compensation of at least part of the rebinned pixel data in said first rebinned pixel array.
26. The detection method according to any of claims 20-25, wherein the transmission strategy comprises one of:
continuing to transmit a second set of detection pulses, wherein the second set of detection pulses comprises one or more detection pulses, and
And stopping transmitting the detection pulse, and ending the detection.
27. The detection method of claim 26, wherein the step of continuing to transmit a second set of detection pulses comprises:
continuing to transmit the second set of detection pulses at a reduced transmission intensity, or
The second set of detection pulses continues to be transmitted at a constant transmission intensity.
28. The probing method of claim 26, wherein the step S13 includes:
And stopping transmitting the detection pulse when the obstacle is detected based on a preset standard through the first group of detection data, and otherwise, continuing transmitting the second group of detection pulse.
29. The detection method of claim 26, further comprising:
Feeding back the transmission strategy to the transmitting device, and
And controlling the transmitting device to execute the fed-back transmitting strategy.
30. The detection method of claim 29, further comprising, during a detection, when continuing to transmit the second set of detection pulses:
Acquiring a second set of detection data generated by the pixel array in response to echoes of the second set of detection pulses reflected on the obstacle, and
The subsequent transmission strategy is determined from the second set of probe data.
31. The detection method of claim 26, further comprising performing a second convolution process on detection data generated from at least one set of detection pulses transmitted by the transmitting device when the transmission strategy is determined to cease transmitting detection pulses, obtaining a second array of recombinant pixels from which a lidar point cloud is generated, wherein the detection data generated from the at least one set of detection pulses includes the first set of detection data.
32. The method of claim 31, wherein the step of performing a second convolution process on the probe data generated from the at least one set of probe pulses transmitted by the transmitting device includes performing a convolution process on the probe data using a plurality of convolution kernels of different sizes, respectively, to obtain a plurality of second reconstructed pixel arrays, and generating a lidar point cloud from the plurality of second reconstructed pixel arrays.
33. The method of detecting according to claim 31, further comprising ambient light compensating at least a portion of the rebinned pixel data in the second rebinned pixel array.
34. The detection method of claim 32, further comprising determining a final rebinned pixel array based on a state of rebinned pixel data in the plurality of second rebinned pixel arrays, and generating a lidar point cloud based on the final rebinned pixel array.
35. The detection method of claim 34, wherein determining a final rebinned pixel array based on the status of rebinned pixel data in the plurality of second rebinned pixel arrays comprises determining the final rebinned pixel array based on the pulse threshold crossing status of adjacent rebinned pixels in at least two of the second rebinned pixel arrays.
36. The detection method of claim 35, wherein determining the final rebinned pixel array based on the state of rebinned pixel data in the plurality of second rebinned pixel arrays further comprises determining a manner of computation of intermediate rebinned pixel data based on the threshold state of pulse crossing of at least two neighboring rebinned pixel data in the second rebinned pixel array.
37. The detection method of claim 36, wherein determining a final one of the plurality of second one of the plurality of pixel arrays based on the state of the pixel data further comprises determining a manner of calculating the intermediate one of the plurality of pixel data based on the pulse threshold state of the at least two pixel data and the distance and/or reflectivity of its corresponding obstacle.
38. The detection method of claim 36, wherein the calculation of the intermediate rebinned pixel data comprises one of interpolating the intermediate pixel, single point calculating the intermediate pixel, and convolving the intermediate pixel.
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