CN114942449B - Laser radar receiving system, laser radar and ranging intensity improvement method - Google Patents
Laser radar receiving system, laser radar and ranging intensity improvement method Download PDFInfo
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- CN114942449B CN114942449B CN202210486864.3A CN202210486864A CN114942449B CN 114942449 B CN114942449 B CN 114942449B CN 202210486864 A CN202210486864 A CN 202210486864A CN 114942449 B CN114942449 B CN 114942449B
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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
- G01S17/02—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
- 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
- G01S7/4802—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00 using analysis of echo signal for target characterisation; Target signature; Target cross-section
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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
- G01S7/481—Constructional features, e.g. arrangements of optical elements
- G01S7/4811—Constructional features, e.g. arrangements of optical elements common to transmitter and receiver
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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
- G01S7/481—Constructional features, e.g. arrangements of optical elements
- G01S7/4816—Constructional features, e.g. arrangements of optical elements of receivers alone
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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
- G01S7/4861—Circuits for detection, sampling, integration or read-out
- G01S7/4863—Detector arrays, e.g. charge-transfer gates
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A90/00—Technologies having an indirect contribution to adaptation to climate change
- Y02A90/10—Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation
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- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Computer Networks & Wireless Communication (AREA)
- General Physics & Mathematics (AREA)
- Radar, Positioning & Navigation (AREA)
- Remote Sensing (AREA)
- Electromagnetism (AREA)
- Optical Radar Systems And Details Thereof (AREA)
Abstract
本发明提供了一种激光雷达接收系统、激光雷达及测距强度提升方法，涉及激光雷达技术领域，为解决现有激光雷达会使得接收到的信号的信噪比劣化的问题而设计。该激光雷达接收系统包括沿光路返回方向依次设置的接收镜头和光电探测器，沿远离接收镜头的方向，光电探测器偏离接收镜头的焦平面。本发明使得大角度的入射光线无法照射至光电探测器，保证光电探测器能够最大限度地接收中心反射信号光，同时，接收镜头在汇聚近端光线时，汇聚光会在焦平面之前，而光电探测器设置在焦平面的后端，因此更容易避开杂散信号，从而有效提升接收到的信号的信噪比。
The present invention provides a laser radar receiving system, a laser radar, and a method for improving ranging intensity, which relate to the field of laser radar technology and are designed to solve the problem that the existing laser radar will deteriorate the signal-to-noise ratio of the received signal. The laser radar receiving system includes a receiving lens and a photodetector arranged in sequence along the return direction of the optical path, and the photodetector deviates from the focal plane of the receiving lens in the direction away from the receiving lens. The present invention prevents incident light at a large angle from irradiating the photodetector, ensuring that the photodetector can receive the center reflected signal light to the maximum extent. At the same time, when the receiving lens converges the proximal light, the converged light will be in front of the focal plane, and the photodetector is arranged at the rear end of the focal plane, so it is easier to avoid stray signals, thereby effectively improving the signal-to-noise ratio of the received signal.
Description
Technical Field
The invention relates to the technical field of laser radars, in particular to a laser radar receiving system, a laser radar and a ranging intensity improving method.
Background
The principle of the laser scanning detection technology is that based on the measurement of the flight time of a laser beam, laser pulses are sent out according to defined time intervals, and the time intervals between the sent pulses and the received pulses are calculated through a timer to obtain the distance between the laser pulses and a detected target. The pulsed laser beam is scanned by a scanning assembly inside the ranging sensor, and the profile curve of the detected target is determined by a series of pulses received.
Currently, the optical path of a laser scanning sensor is one using a transmit-receive separation optical path, and the optical path is one using a coaxial optical path. Specifically, the coaxial optical path is that emitted light is emitted in the center of a receiving lens, reflected after irradiating a detection object, and then receives a signal. Because the window cover installed by the laser radar emits echoes and the problem that rain, snow and fog interfere with the reflection of a stronger signal at the near end exists, the phenomenon that the received echoes irradiate the window cover or the rain, the snow and the fog at the near end can generate trigger distance, and meanwhile, the influence of signal delay of the receiving detector is caused, so that short-distance ranging cannot be completed when detection devices such as SiPM (Silicon photomultiplier, a silicon photomultiplier), APD (AVALANCHE PHOTO DIODE, an avalanche diode) and the like are used, and the breakthrough cannot be realized due to the ranging capability of the coaxial two-dimensional scanning laser radar. In addition, the scheme of using the remote ranging to send and receive the abnormal axis still has the interference problem of near-end rain, snow, fog, simultaneously, the rotation of sending and receiving the abnormal axis needs to use the magnetic ring transmission to influence the life of complete machine, perhaps uses large area array detector to lead to the cost to be high. Therefore, solving or improving the above problems and drawbacks is extremely important for optical, mechanical, electrical, computational design and optimization of laser ranging devices.
The traditional range finding blind area reducing scheme includes the steps of 1, using amplifiers with different amplification factors to amplify gradually, then extracting signals in the middle, setting different thresholds to ensure near-end distance testing, 2, changing the sensitivity of the detector by applying different voltages to the detector to ensure near-end distance testing, 3, dividing light in a receiving light path, partially giving the light to a PIN (Positive-Intrinsic-Negative, P-type semiconductor-impurity-N-type semiconductor) detector, mainly dividing light to SiPM, 4, adopting a mode of strong-weak multiple emission, 5, using two threshold comparators to receive the light path, one high-low to reduce the near-end blind area, 6, adding a diaphragm in the receiving lens, and realizing stray signal reduction by utilizing the limitation of the diaphragm to the light beam. Although the range blind area of the laser radar can be reduced by the schemes, the signal to noise ratio of the received signal is low.
Disclosure of Invention
A first objective of the present invention is to provide a lidar receiving system, so as to solve the technical problem that the signal-to-noise ratio of the received signal will be degraded by the existing lidar.
The laser radar receiving system provided by the invention comprises a receiving lens and a photoelectric detector which are sequentially arranged along the return direction of a light path, wherein the photoelectric detector deviates from the focal plane of the receiving lens along the direction away from the receiving lens.
Further, the distance of the photoelectric detector away from the focal plane is L, l= (1/5-1/2) x f, wherein f is the focal length of the receiving lens.
Further, the receiving lens includes a positive lens group configured to focus the signal light returned by the detection target and a negative lens group configured to emit the light focused by the positive lens group toward the photodetector, which are sequentially arranged in the optical path returning direction.
Further, the negative lens group includes a plano-concave lens and a biconcave lens that are sequentially arranged in the optical path returning direction, the concave surface of the plano-concave lens faces the positive lens group, and/or the positive lens group includes a plano-convex lens, and the plane of the plano-convex lens faces the negative lens group.
Further, the photoelectric detector is an array detector, the array detector comprises a plurality of pixels, the pixels are arranged in M rows and N columns, each row and each column can be independently controlled to be turned on and off, M and N are integers, and M is greater than 1, and N is greater than 1.
Further, the type of the photodetector is any one of MPPC (Multi-Pixel Photon Counter ), siPM, SPAD (Single Photon Avalanche Diode, single photon avalanche diode) and APD.
The laser radar receiving system has the beneficial effects that:
When the laser radar receiving system works, on one hand, after the incident light rays with large angles are received by the receiving lens, the incident light rays with large angles are scattered outside the receiving surface of the deviated photoelectric detector due to defocusing, so that the incident light rays with large angles cannot irradiate the photoelectric detector, meanwhile, due to defocusing of the photoelectric detector, the light rays received by the central view field are focused firstly, pass through the focus and then scatter, and the scattered light rays coincide with the outline of the photoelectric detector, so that the photoelectric detector can receive central reflected signal light to the greatest extent, on the other hand, the rain, snow and fog reflected noise signals collected by the near end are stronger than those of the target signal at the far end, and meanwhile, when the receiving lens collects the near-end light rays, the collected light rays are arranged in front of the focal plane, and the photoelectric detector is arranged at the rear end of the focal plane, so that stray signals are avoided more easily.
Through the arrangement, the laser radar receiving system can effectively improve the signal-to-noise ratio of the received signal, and the arrangement only changes the position of the photoelectric detector without arranging other components, so that the volume of the laser radar receiving system is greatly reduced. Furthermore, the diaphragm is not required to be arranged, so that the suppression of the diaphragm to the effective optical signal is avoided, and the weakening of the intensity of the target signal is prevented. In addition, the laser radar receiving system can receive stray signals and target signals at the same time, components such as a beam splitter and a threshold comparator are not required to be arranged, multiple times of emission are not required, and the working efficiency of the laser radar receiving system is improved while the cost of the laser radar receiving system is reduced.
A second objective of the present invention is to provide a lidar to solve the technical problem that the prior lidar may deteriorate the signal-to-noise ratio of the received signal.
The laser radar provided by the invention comprises an MEMS (Micro-Electro-MECHANICAL SYSTEM, micro-electromechanical system) galvanometer, a transmitting unit, a main control unit and the laser radar receiving system, wherein the MEMS galvanometer, the transmitting unit and the laser radar receiving system are electrically connected with the main control unit.
Further, the lidar also includes a power supply unit configured to provide electrical energy to electrical components of the lidar.
The laser radar has the beneficial effects that:
When the laser radar works, the transmitting unit transmits optical signals to the MEMS galvanometer, the MEMS galvanometer scans and transmits, part of light passing through the window sheet returns along the optical path, the main light source irradiates the detection target through the window sheet, the signals are received by the laser radar receiving system after returning, echo signals are sent to the main control unit, the main control unit counts the detection signals to obtain detection distances, and the detection distances of a plurality of angles are arrayed and summarized to form point clouds.
By arranging the laser radar receiving system in the laser radar, the laser radar has all advantages of the laser radar receiving system, and therefore, the description is omitted herein.
The third objective of the present invention is to provide a ranging intensity improving method, so as to solve the technical problem that the signal-to-noise ratio of the received signal is degraded by the existing lidar, so that the ranging intensity is lower.
The range finding intensity improving method comprises the steps of enabling the distance between a window sheet and a detection target to be larger than a set distance, collecting received signals by using the photoelectric detector, wherein the received signals comprise front-end signals and rear-end signals, the front-end signals comprise window sheet reflected signals and reflected signals in the laser radar receiving system, the rear-end signals are target signals, controlling on and off of rows and columns of the photoelectric detector, detecting changes of the front-end signals and the rear-end signals respectively, turning off the rows and columns with strong front-end signals to enable the front-end signals to be weakened, turning on the rows and columns with strong rear-end signals to enable the rear-end signals to be strengthened, and finally leaving the rows and columns with weakest front-end signals and strongest rear-end signals.
Further, in the step of controlling the on and off of the rows and columns of photodetectors, the off control is performed from the edge rows and columns of photodetectors to the inside thereof.
The distance measurement strength improving method has the beneficial effects that:
The ranging intensity improving method achieves the aim of improving the ranging intensity by enabling a laser radar receiving system to avoid stray light, and specifically comprises the steps of installing a window sheet after the installation of a photoelectric detector is completed, enabling the distance between the window sheet and a detection target to be larger than a set distance, collecting and receiving stray signals at the front end and target signals at the rear end by the photoelectric detector, respectively detecting changes of the front end signals and the rear end signals by controlling the on and off of a row and a column of the photoelectric detector, finding out the row and column with the strongest reflection signals of the window sheet, turning off, observing the increase and decrease of the target signals, finding out the optimal turn-off row by switching, turning off the row with the strong front end signals, enabling the row with the strong rear end signals to be turned on, enabling the rear end signals to be enhanced, finally leaving the row with the weakest front end signals and the strongest rear end signals, guaranteeing that the signal to reach the optimal ratio, and achieving the aim of improving the ranging intensity. The mode of selectively switching off the rows and columns of the photoelectric detectors can furthest reduce row and column pixels receiving stray light, and simultaneously can switch on row and column pixels receiving effective signals, so that the signal to noise ratio is furthest improved, and the aim of improving the ranging strength is fulfilled.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only embodiments of the present invention, and that other drawings can be obtained according to the provided drawings without inventive effort for a person skilled in the art.
Fig. 1 is a schematic diagram of a lidar according to an embodiment of the present invention;
fig. 2 is a schematic structural diagram of a lidar receiving system according to an embodiment of the present invention;
fig. 3 is a schematic diagram of an optical path of a lidar receiving system according to an embodiment of the present invention when receiving light at a normal angle;
fig. 4 is a schematic diagram of an optical path of a lidar receiving system according to an embodiment of the present invention when receiving light with a large angle;
Fig. 5 is a schematic structural diagram of a photodetector of a lidar receiving system according to an embodiment of the present invention;
Fig. 6 is a schematic diagram of a received signal collected by a photodetector of a lidar receiving system according to an embodiment of the present invention;
Fig. 7 is a flowchart illustrating a ranging strength improvement method according to an embodiment of the present invention.
Reference numerals illustrate:
010-laser radar receiving system, 020-MEMS galvanometer, 030-transmitting unit, 040-main control unit;
100-receiving lens, 200-photoelectric detector, 300-focal plane;
110-plano-convex lens, 120-plano-concave lens, 130-biconcave lens;
210-picture element.
Detailed Description
In order that the above objects, features and advantages of the invention will be readily understood, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.
Fig. 1 is a schematic diagram of a lidar according to the present embodiment. As shown in fig. 1, the present embodiment provides a laser radar, which includes a MEMS galvanometer 020, a transmitting unit 030, a main control unit 040, and a laser radar receiving system 010, wherein the MEMS galvanometer 020, the transmitting unit 030, and the laser radar receiving system 010 are all electrically connected with the main control unit 040.
When the laser radar works, the transmitting unit 030 transmits optical signals to the MEMS galvanometer 020, the MEMS galvanometer 020 scans and transmits, part of light passes through the window sheet and returns along the optical path, the main light source irradiates the detection target through the window sheet, the signal returns and is received by the laser radar receiving system 010, echo signals are sent to the main control unit 040, the main control unit 040 clocks the detection signals to obtain detection distances, and the detection distances of a plurality of angles are arrayed and summarized to form point clouds.
In this embodiment, the lidar further comprises a power supply unit, wherein the power supply unit is configured to provide electrical energy to the electrical components of the lidar.
Through setting up the power supply unit in the laser radar, can realize the power supply to the power consumption part in the laser radar to the use of laser radar of being convenient for.
It should be noted that, the working principle of the lidar is available to those skilled in the art, and the present embodiment is not modified in this way, so that the description will not be repeated.
In the following text, a specific structure and an operation principle of the lidar receiving system 010 will be described.
Fig. 2 is a schematic structural diagram of a lidar receiving system 010 according to the present embodiment. As shown in fig. 2, the lidar receiving system 010 provided in the present embodiment includes a receiving lens 100 and a photodetector 200 sequentially arranged in the return direction of the optical path, wherein the photodetector 200 is deviated from the focal plane 300 of the receiving lens 100 in the direction away from the receiving lens 100.
Fig. 3 is a schematic diagram of an optical path of the laser radar receiving system 010 according to the present embodiment when receiving light beams at a normal angle, and fig. 4 is a schematic diagram of an optical path of the laser radar receiving system 010 according to the present embodiment when receiving light beams at a large angle. As shown in fig. 3 and fig. 4, when the lidar receiving system 010 is operated, by making the photodetector 200 deviate from the focal plane 300 of the receiving lens 100 by a distance along the direction away from the receiving lens 100, on one hand, after the incident light beam with a large angle is received by the receiving lens 100, the incident light beam with a large angle is scattered out of the receiving plane deviating from the photodetector 200 due to defocusing, particularly please refer to fig. 4, so that the incident light beam with a large angle cannot irradiate the photodetector 200, meanwhile, due to defocusing arrangement of the photodetector 200, the light beam received by the central field of view is focused, and then scattered after passing through the focus, and the scattered light beam coincides with the outer contour of the photodetector 200, so that the photodetector 200 can receive the central reflected signal light to the maximum extent, and on the other hand, since the rain, snow and fog reflected noise signal collected at the near end is stronger than the target signal at the far end, and meanwhile, when the receiving lens 100 collects the near-end light beam, particularly please refer to fig. 4, the collected light beam is prevented from being arranged at the rear end of the focal plane, so that the stray signal is easier.
Through the arrangement, the laser radar receiving system 010 can effectively improve the signal-to-noise ratio of the received signal, and the arrangement only changes the position of the photoelectric detector 200 without arranging other components, so that the volume of the laser radar receiving system 010 is greatly reduced. Furthermore, the diaphragm is not required to be arranged, so that the suppression of the diaphragm to the effective optical signal is avoided, and the weakening of the intensity of the target signal is prevented. In addition, the laser radar receiving system 010 can receive stray signals and target signals at the same time, components such as a beam splitter and a threshold comparator are not required to be arranged, multiple times of emission are not required, and the working efficiency of the laser radar receiving system 010 is improved while the cost of the laser radar receiving system 010 is reduced.
In this embodiment, as shown in fig. 3, the focal plane 300 refers to a plane passing through the focal point F and perpendicular to the return direction of the optical path, and the left end is the front end of the focal plane 300, i.e., the front end of the focal point F, and the right end is the rear end of the focal plane 300, i.e., the rear end of the focal point F, in the view angles of fig. 3 and 4.
With continued reference to fig. 3, in the present embodiment, the distance of the photodetector 200 from the focal plane 300 is L, l= (1/5-1/2) ×f, where f is the focal length of the receiving lens 100.
By setting the distance of the photodetector 200 from the focal plane 300 to L as described above, the stray light received by the photodetector 200 can be reduced, and the effective light received by the photodetector 200 can be increased, thereby ensuring that the lidar receiving system 010 of the present embodiment is in a preferable working condition.
It should be noted that, in the present embodiment, f in the drawing is merely illustrative of the focal length of the receiving lens 100, and in practical situations, the focal length is obtained through corresponding calculation, which is related to the lens parameters in the receiving lens 100. How to calculate the focal length is well known to those skilled in the art, and will not be described.
With continued reference to fig. 3 and 4, in the present embodiment, the receiving lens 100 includes a positive lens group and a negative lens group sequentially disposed along the return direction of the optical path, wherein the positive lens group is configured to focus the signal light returned by the detection target, and the negative lens group is configured to direct the light focused by the positive lens group to the photodetector 200.
In the receiving lens 100, the positive lens group and the negative lens group are combined to form a positive focal length lens, and smooth receiving of light can be realized by using the receiving lens 100.
With continued reference to fig. 3 and 4, in the present embodiment, the negative lens group includes a plano-concave lens 120 and a biconcave lens 130 sequentially arranged along the optical path returning direction, wherein the concave surface of the plano-concave lens 120 faces the positive lens group.
The negative lens group is arranged in a mode of effectively focusing light, and is simple in structure and low in cost.
With continued reference to fig. 3 and 4, in the present embodiment, the positive lens group includes a plano-convex lens 110, and the plane of the plano-convex lens 110 faces the negative lens group.
Fig. 5 is a schematic structural diagram of a photodetector 200 of the lidar receiving system 010 according to the present embodiment. As shown in fig. 5, in this embodiment, the photodetector 200 is an array detector, specifically, the array detector includes a plurality of pixels 210, and the plurality of pixels 210 are arranged in M rows and N columns, where M and N are integers, and M >1, N >1, and each of the rows and the columns can be independently controlled to be turned on and off.
By setting the photodetectors 200 as array detectors, each row and each column of the photodetectors 200 can be independently turned on and off, so that the lidar receiving system 010 can pass the actual light path test in use, and the turn-off of the rows and the columns is regulated, so that the photodetectors 200 can not receive stray signals as much as possible.
In addition, the photodetector 200 is in the form of an array detector, and the receiving intensity of the photodetector 200 can be controlled by controlling the switch of the array detector row and column, so that the laser radar receiving system 010 of the embodiment can increase the dynamic range of the photodetector 200 by adjusting the intensity of the detection signal.
In order to suppress stray light, a conventional receiving optical path generally employs a method of adding a diaphragm to suppress stray light, but this arrangement may simultaneously reduce the intensity of the effective signal. In the present application, the intensity of the signal-to-noise ratio can be quantitatively tested by using the array detector, thereby selectively turning on and off the picture elements 210.
With continued reference to fig. 5, in this embodiment, m=28, n=28, and each of the 28 rows and 28 columns of the photodetector 200 has a separate control unit, so that the photodetector 200 is prevented from being subjected to spurious signals as much as possible by controlling 56 rows and columns. In other embodiments, M and N may take other values.
As a specific example, the photodetector 200 has a side length of 1mm, the pixel 210 has a size of 25 μm and a gap of 10 μm, the focal length f of the receiving lens 100 is 25mm, and the photodetector 200 is disposed at a position of 5mm at the rear end of the focal point, that is, l=5 mm.
In this embodiment, the specific type of photodetector 200 may be any one of MPPC, siPM, SPAD and APD.
The embodiment also provides a ranging strength improving method, which comprises the steps of enabling the distance between a window sheet and a detection target to be larger than a set distance by using the laser radar receiving system 010 when the photoelectric detector 200 is an array detector to avoid stray light, collecting received signals by using the photoelectric detector 200, wherein the received signals comprise front-end signals and rear-end signals, the front-end signals comprise window sheet reflected signals and reflected signals in the laser radar receiving system 010, the rear-end signals are target signals, controlling the on and off of rows and columns of the photoelectric detector 200, detecting the change of the front-end signals and the rear-end signals respectively, turning off the rows and columns with strong front-end signals to enable the front-end signals to be weakened, turning on the rows and columns with strong rear-end signals to enable the rear-end signals to be enhanced, and finally leaving the rows and columns with weakest front-end signals and strongest rear-end signals.
The mode of selectively turning off the rows and columns of the photoelectric detector 200 can furthest reduce row and column pixels 210 receiving stray light, and simultaneously can turn on row and column pixels 210 receiving effective signals, so that the signal to noise ratio is furthest improved, and the aim of improving the ranging strength is fulfilled.
Fig. 6 is a schematic diagram of a received signal collected by the photodetector 200 of the lidar receiving system 010 according to the present embodiment. As shown in fig. 6, the front-end signal is a spurious signal, the back-end signal is a target signal, and the abscissa is time. Through the arrangement, most of the received signals are target signals at the rear end, so that the signal-to-noise ratio is maximized, and the aim of improving the ranging strength is fulfilled.
In the present embodiment, in the step of controlling the turning on and off of the rows and columns of the photodetectors 200, the turning off control is performed from the edge rows and columns of the photodetectors 200 to the inside thereof. So set up, when promoting range finding intensity, can also improve light path efficiency of software testing.
Fig. 7 is a flowchart of a ranging strength improvement method according to the present embodiment. As shown in FIG. 7, one embodiment of the method for improving the ranging intensity comprises the following steps of S100, completing the installation of a detector, installing a window film, irradiating the detector with a specified distance, wherein the distance between the detector and the window film is more than 5 meters, S200, collecting the intensity of received signals, wherein the front signals are the window film and an internal reflection signal, which are stray signals, and the rear signals are detected target signals, which are target signals, S300, controlling the array detector, performing turn-off control inwards from an edge row and a column with the strongest reflection signal, finding the row with the strongest window film, S400, turning off the row with the strong reflection signal, and turning on the row with the strong target signal, so as to finally leave the row with the weakest front signals and the strongest rear signals.
In summary, the laser radar receiving system, the laser radar and the ranging intensity improving method provided by the application can be used for better reducing stray light by changing the distance between the photoelectric sensor and the receiving lens 100 based on the laser radar of the MEMS vibrating mirror 020, wherein the stray light comprises 1, interference generated by internal reflection of the laser radar receiving system 010, 2, interference of sunlight noise light sources with a large angle and 3, generated by near-end rain, snow and fog, and on the other hand, the receiving intensity can be controlled based on the laser radar using the array detector, the row pixel 210 receiving the stray light can be furthest reduced by selectively switching off the row pixel 210 receiving an effective signal, and meanwhile, the signal to noise ratio can be furthest improved, thereby improving the ranging intensity.
Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications may be made by one skilled in the art without departing from the spirit and scope of the invention, and the scope of the invention should be assessed accordingly to that of the appended claims.
Finally, it is further noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises an element.
In the above embodiments, descriptions of orientations such as "left", "right", and the like are shown based on the drawings.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114200426A (en) * | 2020-09-02 | 2022-03-18 | 宁波舜宇车载光学技术有限公司 | Light receiving module, light receiving method, laser radar system and vehicle |
| CN217954744U (en) * | 2022-05-06 | 2022-12-02 | 洛伦兹(宁波)科技有限公司 | Laser radar receiving system and laser radar with same |
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| CN106154248A (en) * | 2016-09-13 | 2016-11-23 | 深圳市佶达德科技有限公司 | A kind of laser radar optical receiver assembly and laser radar range method |
| JP7170401B2 (en) * | 2018-02-14 | 2022-11-14 | キヤノン電子株式会社 | Light source angle measurement device, light source position detection device, and artificial satellite |
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| CN113748358B (en) * | 2020-03-10 | 2024-04-26 | 深圳市速腾聚创科技有限公司 | Laser receiving device, laser receiving method and laser radar |
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