WO2024131868A1

WO2024131868A1 - Lidars, ambient light detection methods and devices therefor, and storage media

Info

Publication number: WO2024131868A1
Application number: PCT/CN2023/140427
Authority: WO
Inventors: Angli LIU; Peijun Wang; Shaoqing Xiang
Original assignee: Hesai Technology Co., Ltd.
Priority date: 2022-12-20
Filing date: 2023-12-20
Publication date: 2024-06-27
Also published as: CN118258489A

Abstract

LiDARs, ambient light detection methods, devices for ambient light detection, and storage media are provided. The ambient light detection methods include: receiving an ambient light detection value generated in response to reception of an ambient light signal by a light receiving device (101); receiving a calibration value, where the calibration value is configured as a detection value outputted by an ambient light detection circuit (102) when the light receiving device(101) is controlled to stop outputting an electric signal to the ambient light detection circuit (102); and correcting the ambient light detection value using the calibration value.

Description

LIDARS, AMBIENT LIGHT DETECTION METHODS AND DEVICES THEREFOR, AND STORAGE MEDIA

CROSS-REFERENCE TO RELATED APPLICATION (S)

This application claims priority to Chinese Patent Application No. 202211641729.8, filed on December 20, 2022, the content of which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

This disclosure relates to the field of LiDARs and, in particular, to LiDARs, ambient light detection methods and devices therefor, and storage media.

BACKGROUND

A light detection and ranging ( “LiDAR” ) is an important sensor for autonomous driving, and a common LiDAR includes components such as a light emitting device and a light receiving device. The light receiving device is typically a single-photon detector. A single-photon detector can be a silicon photomultiplier ( “SiPM” ) , a single-photon avalanche diode ( “SPAD” ) array, or the like. The single-photon detectors can detect single photons with high sensitivity. However, ambient light can exist around the LiDAR and can form a noise signal in a signal generated by the single-photon detector, resulting in inaccuracy of the acquired distance from and reflectivity of an object. Therefore, determining the accurate ambient light information can be important, so that an appropriate object echo detection threshold can be set to reduce or avoid the influence of the ambient light on the object echo detection, thereby improving the accuracy of the acquired distance from and reflectivity of the object.

However, existing ambient light detection systems is unable to measure ambient light accurately due to errors existing in the existing ambient light detection system, such as a manufacturing error of an electronic component, a mismatch error between electronic components, or the like.

SUMMARY

This disclosure provides LiDARs, ambient light detection methods and devices therefor, and storage media. This disclosure can improve the accuracy of ambient light detection.

In the first aspect, the embodiments of this disclosure provide method of ambient light detection for a LiDAR. The method includes receiving an ambient light detection value generated in response to reception of an ambient light signal by a light receiving device of the LiDAR, wherein the light receiving device is configured to receive the ambient light signal and convert the ambient light signal into an electrical signal; receiving a calibration value, wherein the calibration value is a detection value outputted by an ambient light detection circuit of the LiDAR when the light receiving device is controlled to stop outputting the electrical signal to an ambient light detection circuit of the LiDAR, wherein the light receiving device is selectively in communication with the ambient light detection circuit for outputting the electrical signal to the ambient light detection circuit, and the ambient light detection circuit is configured to output the ambient light detection value based on the electrical signal; and correcting the ambient light detection value using the calibration value.

Optionally, the correcting the ambient light detection value using the calibration value includes: determining a difference value between the ambient light detection value and the calibration value.

Optionally, the method further includes: determining a calibration coefficient; and correcting the difference value by using the calibration coefficient to determine a calibrated ambient light detection value, wherein the calibrated ambient light detection value is an ambient light detection value outputted by the ambient light detection circuit within an integral gain interval.

Optionally, the determining the calibration coefficient includes: receiving a test value outputted by the ambient light detection circuit when a predetermined electrical signal is inputted and a test calibration value outputted by the ambient light detection circuit when the predetermined electrical signal is stopped from being inputted; receiving a reference value of the ambient light detection circuit within the particular integral gain interval when the predetermined electrical signal is inputted; and determining the calibration coefficient as a ratio of a difference value between the test value and the test calibration value to the reference value.

Optionally, the receiving the test value outputted by the ambient light detection circuit when the predetermined electrical signal is inputted and the test calibration value outputted by the ambient light detection circuit when the predetermined electrical signal is stopped from being inputted includes: controlling the predetermined electrical signal to be inputted to the ambient light detection circuit; receiving the test value outputted by the ambient light detection circuit; controlling the predetermined electrical signal to be stopped from being inputted to the ambient light detection circuit; and receiving the test calibration value outputted by the ambient light detection circuit.

Optionally, the determining the calibration coefficient includes reading the calibration coefficient from a memory of the LiDAR, wherein the calibration coefficient is stored in the memory.

Optionally, the LiDAR comprises a plurality of light receiver groups, and each of the plurality of light receiver groups comprises a light receiving device. The receiving the ambient light detection value generated in response to reception of the ambient light signal by the light receiving device includes: within an ambient light detection period for detecting ambient light, controlling the light receiving device to output an electrical signal generated from the ambient light signal to the ambient light detection circuit in a time division manner; and receiving the ambient light detection value outputted by the ambient light detection circuit.

Optionally, the correcting the ambient light detection value using the calibration value includes: correcting the ambient light detection value using the calibration value within the ambient light detection period, wherein the calibration value is a detection value outputted by the ambient light detection circuit within the ambient light detection period when the light receiving device is controlled to stop outputting the electrical signal to the ambient light detection circuit; or correcting the ambient light detection value using the calibration value within a predetermined period, wherein the predetermined period is an integer multiple of the ambient light detection period, and the calibration value is a detection value outputted by the ambient light detection circuit based on the predetermined period when the light receiving device is controlled to stop outputting the electrical signal to the ambient light detection circuit; or correcting the ambient light detection value using the calibration value before the ambient light detection period, wherein the calibration value is a detection value outputted by the ambient light detection circuit before the ambient light detection period when the light receiving device is controlled to stop outputting the electrical signal to the ambient light detection circuit.

Optionally, the LiDAR comprises N light receiver groups and N control gating modules. Each of the N control gating module is configured to selectively supply a drive voltage to a light receiving device in a same light receiver group, and N is a positive integer. The receiving the calibration value includes: receiving N calibration values, wherein each calibration value is configured as a detection value outputted by the ambient light detection circuit when each control gating module supplies a drive voltage and when a light receiving device in a same light receiver group driven by the control gating module is controlled to stop outputting the electrical signal to the ambient light detection circuit.

Optionally, the correcting the ambient light detection value using the calibration value includes: correcting, using a calibration value corresponding to the control gating module driving the light receiving device, the ambient light detection value generated in response to the reception of the ambient light signal by the light receiving device.

Optionally, the LiDAR further includes an echo signal detection circuit for detecting an object echo, and the ambient light detection value is corrected using the calibration value within a calibration period for calibrating an echo signal outputted by the echo signal detection circuit.

In the second aspect, embodiments of this disclosure provide device of ambient light detection for a LiDAR. The device includes an acquisition module, configured to receive an ambient light detection value generated in response to reception of an ambient light signal by a light receiving device of the LiDAR, wherein the light receiving device is configured to receive the ambient light signal and convert the ambient light signal into an electrical signal; a calibration value acquisition module, configured to receive a calibration value, wherein the calibration value is a detection value outputted by an ambient light detection circuit of the LiDAR when the light receiving device is controlled to stop outputting the electrical signal to the ambient light detection circuit, wherein the light receiving device is selectively in communication with the ambient light detection circuit for outputting the electrical signal to the ambient light detection circuit, and the ambient light detection circuit is configured to output the ambient light detection value; and a correction module, configured to correct the ambient light detection value using the calibration value.

In the third aspect, embodiments of this disclosure provide a non-transitory computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a computer, performs the method of ambient light detection for a LiDAR.

In the fourth aspect, embodiments of this disclosure provide a LiDAR. The LiDAR includes: a light receiving device, configured to receive an ambient light signal and convert the ambient light signal into an electrical signal; an ambient light detection circuit, configured to receive the electrical signal and output an ambient light detection value based on the electrical signal; a memory and a processor, wherein the memory comprises a computer program executable on the processor stored thereon, and wherein the processor, when executing the computer program, performs the method of ambient light detection for a LiDAR.

In the fifth aspect, embodiments of this disclosure provide a terminal device including a processor and a memory, and the memory has a computer program executable by the processor stored thereon, the processor, when executing the computer program, executes steps of the method of ambient light detection for a LiDAR.

Compared with the existing art, the technical solutions of the embodiments of this disclosure have the following beneficial effects.

In the technical solutions of this disclosure, after an ambient light detection value generated in response to the reception of an ambient light signal by a light receiving device is received, the ambient light detection value can be corrected using a calibration value. Because the calibration value is a detection value outputted by an ambient light detection circuit when the light receiving device is controlled to stop outputting an electrical signal to the ambient light detection circuit, the calibration value can be able to reflect the ambient light detection value error caused by the mismatch error between the electronic components in the LiDAR. Therefore, the ambient light detection value error caused by the mismatch error between the electronic components in the ambient light detection circuit can be eliminated by correcting the ambient light detection value using the calibration value, thereby obtaining a more accurate ambient light detection value, improving the accuracy of ambient light detection, and improving the accuracy of determining the distance from and the reflectivity of an object based on the ambient light detection value.

Further, in the technical solutions of this disclosure, a calibration coefficient can also be determined, and the ambient light detection value corrected by the calibration value can be corrected using the calibration coefficient to obtain the calibrated ambient light detection value. Because the calibration coefficient can be used for correcting an error (e.g., an integral gain error) caused by the manufacturing error of the electronic component (e.g., an integrator) in the ambient light detection circuit, the error in the ambient light detection value caused by the above-mentioned integral gain error can be eliminated through the calibration coefficient, so that the calibrated ambient light detection value is more accurate, thereby further improving the accuracy of the ambient light detection.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a structure schematic diagram of an example ambient light detection system, consistent with some embodiments of this disclosure.

FIG. 2 shows a flowchart of an example ambient light detection method, consistent with some embodiments of this disclosure.

FIG. 3 shows a structure schematic diagram of an example ambient light detection system, consistent with some embodiments of this disclosure.

FIG. 4 shows a structure schematic diagram of another example ambient light detection system, consistent with some embodiments of this disclosure.

FIG. 5 shows a schematic diagram of an example time sequence of a light detection period, consistent with some embodiments of this disclosure.

FIG. 6 shows a schematic diagram of an example time sequence of another light detection period, consistent with some embodiments of this disclosure.

FIG. 7 shows a schematic diagram of an example time sequence of yet another light detection period, consistent with some embodiments of this disclosure.

FIG. 8 shows a structure schematic diagram of an example LiDAR, consistent with some embodiments of this disclosure.

FIG. 9 shows a schematic diagram of an example control time sequence, consistent with some embodiments of this disclosure.

FIG. 10 shows a structure schematic diagram of another example LiDAR, consistent with some embodiments of this disclosure.

FIG. 11 shows a schematic diagram of another example control time sequence, consistent with some embodiments of this disclosure.

FIG. 12 shows a structure schematic diagram of yet another example LiDAR, consistent with some embodiments of this disclosure.

FIG. 13 shows a structure schematic diagram of an example ambient light detection device, consistent with some embodiments of this disclosure.

FIG. 14 shows a structure schematic diagram of an example LiDAR, consistent with some embodiments of this disclosure.

DETAILED DESCRIPTION

There are various symmetrical structures formed by pairs of electronic components in an ambient light detection system of a LiDAR. However, in reality, these symmetrical structures are not completely symmetrical, which is referred to as a mismatch error. Due to the mismatch error between the electronic components in the ambient light detection system (e.g., the mismatch error between a pair of resistors, or the mismatch error between a pair of transistors) or due to a manufacturing error of an electronic component, the existing ambient light detection system is unable to accurately measure the ambient light. The manufacturing error of the electronic component refers to the deviation between an actual value and a design designated value when the electronic component is produced.

Consistent with embodiments of this disclosure, after receiving an ambient light detection value generated in response to reception of an ambient light signal by a light receiving device, the ambient light detection value can be corrected using a calibration value. The calibration value can be a detection value outputted by an ambient light detection circuit when the light receiving device is controlled to stop outputting an electrical signal to the ambient light detection circuit. In such a case, the calibration value can be able to reflect an error caused by the mismatch error between the electronic components in the LiDAR. Therefore, the ambient light detection value error caused by the mismatch error between the electronic components in the ambient light detection circuit can be reduced or eliminated by correcting the ambient light detection value using the calibration value. By doing so, a more accurate ambient light detection value can be determined, and accuracy of ambient light detection and accuracy of determining the distance from and the reflectivity of an object based on the ambient light detection value can both be improved.

To make the objects, features, and advantages of this disclosure more comprehensible, some embodiments of this disclosure can be described in detail below in conjunction with the drawings.

For example, referring to FIG. 1, FIG. 1 shows the structure of an example ambient light detection system for a light receiving device of a LiDAR, consistent with some embodiments of this disclosure. The ambient light detection system can be used for detecting ambient light, such as sunlight around the LiDAR. As shown in FIG. 1, the ambient light detection system includes a light receiving device 101 and an ambient light detection circuit 102. The number of the light receiving device 101 can be one or more. For example, the light receiving device can be a SiPM or a SPAD. A plurality of light receiving devices can also be arranged in a one-dimensionally arranged array (e.g., arranged in a column or a row) or a two-dimensionally arranged array (e.g., arranged in an planar array or a two-dimensional array) . For example, the light receiving devices can be arranged in a matrix or arranged in multiple interleaving columns or rows.

In some embodiments, the light receiving device 101 can be used for receiving an ambient light signal and converting the ambient light signal into an electrical signal. The light receiving device 101 can be selectively in communication with the ambient light detection circuit 102. When the light receiving device 101 is in communication with the ambient light detection circuit 102, the light receiving device 101 outputs the electrical signal to the ambient light detection circuit 102, and the ambient light detection circuit 102 can output an ambient light detection value based on the electrical signal. When the light receiving device 101 is not in communication with the ambient light detection circuit 102, the light receiving device 101 can stop outputting the electrical signal to the ambient light detection circuit 102. At this point, the ambient light detection circuit 102 can output a calibration value (e.g., an error signal caused by the mismatch error between the electronic components) .

In some embodiments, the number of light receiving devices 101 can be more than one. Each light receiving device 101 can output the electrical signal to the ambient light detection circuit 102. For example, each light receiving device can transmit an electrical signal to the ambient light detection circuit 102 based on a predetermined time sequence in a time division manner. The ambient light detection circuit 102 can output an ambient light detection value corresponding to each light receiving device 101. In some embodiments, an ambient light signal received by each light receiving device 101 can be outputted as an ambient light detection value by the ambient light detection circuit 102.

In some embodiments, due to the mismatch error between the electronic components in the ambient light detection circuit 102, the ambient light detection value outputted by the ambient light detection circuit 102 can be inaccurate. For example, the electronic components in the ambient light detection circuit 102 that generate the mismatch error can be a pair of electronic components. For example, referring to FIG. 4, a resistor Rhv0 and a resistor Rhv1 can have a mismatch error between them. As another example, a MOS transistor HVM0 and a MOS transistor HVM1 can also have a mismatch error between them.

FIG. 2 is a flowchart of an example ambient light detection method, consistent with some embodiments of this disclosure. As shown in FIG. 2, the ambient light detection method can include the following steps.

In step 201, an ambient light detection value generated in response to the reception of an ambient light signal by a light receiving device can be received.

In some embodiments, in step 201, the ambient light detection value corresponding to the light receiving device 101 can be received in real time. In some embodiments, the ambient light detection value corresponding to the light receiving device 101 can be received periodically. When the ambient light detection value is received periodically, the ambient light detection value corresponding to the light receiving device 101 can be received from a memory that can store the generated ambient light detection value. The ambient light detection value can be directly outputted by the ambient light detection circuit 102 and may include an ambient light detection value error caused by the mismatch error between the electronic components in the ambient light detection circuit. The ambient light detection value can be corrected.

In step 202, a calibration value can be received. The calibration value can be a detection value outputted by an ambient light detection circuit when the light receiving device is controlled to stop outputting an electrical signal to the ambient light detection circuit.

In some embodiments, in step 202, the calibration value can be received in real time. In some embodiments, the calibration value can also be pre-received. When the ambient light detection value is to be corrected, the calibration value can be read directly from the memory that pre-store the calibration value. When the light receiving device 101 is controlled to stop outputting the electrical signal to the ambient light detection circuit 102, the detection value (e.g., the calibration value) outputted by the ambient light detection circuit 102 can reflect the mismatch error between the electronic components in the ambient light detection circuit 102.

In step 203, the ambient light detection value can be corrected using the calibration value.

In some embodiments, in step 203, the ambient light detection value can be corrected using the calibration value to reduce or eliminate the ambient light detection value error caused by the mismatch error between the electronic components in the ambient light detection value. By doing so, a more accurate ambient light detection value can be determined.

In some embodiments, a difference value between the ambient light detection value and the calibration value can be determined to determine the calibrated ambient light detection value.

In some embodiments, in a case where the number of light receiving devices 101 is more than one, the steps 201-203 can be executed separately on the ambient light detection value corresponding to each light receiving device 101.

For example, the LiDAR can include a plurality of light receiver groups, and each light receiver group can include a light receiving device (e.g., one or more light receiving devices) . In the process of receiving the ambient light detection value, each light receiving device in each light receiver group can be controlled to output an electrical signal to the ambient light detection circuit 102 in a time division manner, and an ambient light detection value outputted by the ambient light detection circuit 102 can be received. An ambient light detection value corresponding to each light receiving device 101 can be corrected using a calibration value.

For example, a calibration value can be received by any of the light receiving devices in a same light receiver group. Ambient light detection values generated in response to the reception of ambient light signals by the light receiving devices (e.g., part of all of the light receiving devices) in the light receiver group can be corrected using the calibration value. In another example, calibration values can be received by some or all of the light receiving devices in the same light receiver group. An average value or a median value of the calibration values received by some or all of the light receiving devices in the same light receiver group can be calculated. Ambient light detection values generated in response to the reception of the ambient light signals by all the light receiving devices in the light receiver group can be corrected using the average value or the median value.

The detailed description is given below in conjunction with the example circuit structure of the ambient light detection circuit 102.

For example, referring to FIG. 3, the LiDAR includes an ambient light detection system. The ambient light detection system includes a light receiving device 101, an ambient light detection circuit 102, and a control gating module 103. The control gating module 103 can be used for controlling the light receiving device 101 to be selectively in communication with the ambient light detection circuit 102. For example, the control gating module 103 can supply a high-voltage signal to drive the light receiving device 101 to achieve the communication of the light receiving device 101 with the ambient light detection circuit 102.

For example, the LiDAR can include a plurality of light receiver groups. Each light receiver group can include a plurality of light receiving devices 101. The plurality of light receiving devices 101 can be selectively in communication with the ambient light detection circuit 102 through the control gating module 103. The control gating module 103 can select a light receiving device 101 from the plurality of light receiving devices 101 and supply power to drive the selected light receiving device 101. For example, the selected light receiving device 101 can output an electrical signal to the ambient light detection circuit 102. The ambient light detection circuit 102 can output an ambient light detection value based on the electrical signal.

In some embodiments, with reference to FIG. 4, the control gating module 103 can output a high-voltage signal HVREF. The output terminal of the light receiving device 101 (e.g., the cathode of a SiPM) can output a voltage HVSIG. The voltage difference HVREF-HVSIG (e.g., the voltage across the resistor Rhvres) between the output terminal of the control gating module 103 and the output terminal of the light receiving device 101 can be an electrical signal converted from the ambient light signal received by the light receiving device 101.

With reference to FIG. 4, the voltages HVREF and HVSIG can pass through a level shifter 1021 and a voltage buffer module 1022 to output voltages Vref and Vsig, respectively. The voltages Vref and Vsig can be integrated by an integrator 1023 to output a voltage Valc_out. An analog-digital converter 1024 (e.g., an ADC) can perform analog-digital conversion on the voltage Valc_out to output an ambient light detection value ALC_out. The level shifter 1021 can be used for reducing the inputted voltages HVREF and HVSIG to working voltages that can be used by subsequent devices for signal processing. The voltage buffer module 1022 can be used for supplying a certain drive capability.

For example, still referring together to FIG. 4, the input of the ambient light detection system can be a current I_al generated by the light receiving device 101 (e.g., a SiPM) when receiving an ambient light signal, and the output can be the ambient light detection value ALC_out outputted by the analog-digital converter 1024. The resistor Rhvres can be used for converting the current I_al into a voltage difference between the voltages HVREF and HVSIG, and the voltages HVREF and HVSIG can pass through the MOS transistors HVM0 and HVM1 of the level shifter 1021 as well as the voltage buffer module 1022 to output the voltages Vref and Vsig, respectively. The integrator 1023 can integrate the differential signal between the voltages Vref and Vsig at a certain integral gain within an integration time Tint to output a voltage Valc_out, and can further input the voltage Valc_out to the positive phase input terminal of the analog-digital converter 1024. A reference voltage generation module REFGEN can be used for inputting a reference voltage Vadc_n to the negative phase input terminal of the analog-digital converter 1024. In some embodiments, the analog-digital converter 1024 can be an ADC to perform analog-digital conversion on the voltage Valc_out to output the ambient light detection value ALC_out.

In some embodiments, the input voltage of the control gating module 103 can be amplified by the control gating module 103. The amplified voltage can pass through the ambient light detection circuit 102 that includes pairs of electronic components and can be collected by the analog-digital converter 1024. By doing so, the ambient light detection value outputted by the analog-digital converter 1024 can include an error caused by the mismatch error between the electronic components.

For example, the mismatch error can be generated due to the mismatch between a pair of electronic components on the signal transmission link, such as a mismatch error between the resistor Rhv0 and the resistor Rhv1, a mismatch error between the MOS transistor HVM0 and the MOS transistor HVM1, or a mismatch error across an amplifier RCint.

In some embodiments, within an ambient light detection period, the light receiving device 101 can be controlled to output an electrical signal to the ambient light detection circuit 102. The ambient light detection circuit 102 can output an ambient light detection value. The light receiving device 101 can be controlled to stop outputting an electrical signal to the ambient light detection circuit 102. The ambient light detection circuit 102 can output a calibration value. The ambient light detection value can be corrected using the calibration value.

In some embodiments, the LiDAR can detect ambient light within an ambient light detection period. To achieve the correction of the ambient light detection value, in some embodiments, the ambient light detection period can be divided into a detection period and a calibration period. The ambient light detection value can be outputted within the detection period, and the calibration value can be outputted within the calibration period.

For example, still referring together to FIG. 4, within the detection period, the control gating module 103 can drive the light receiving device 101 so that the light receiving device 101 can work and receive the ambient light signal to generate a current I_al. The current I_al can be converted into a voltage difference between the voltages HVREF and HVSIG through a resistor Rhvres. The voltages HVREF and HVSIG can pass through the level shifter 1021 and the voltage buffer module 1022 to output the voltages Vref and Vsig, respectively. The output voltage of the integrator 1023 can be reset to an initial voltage Vcm_m. The integrator 1023 can integrate the differential signal between the voltages Vref and Vsig at a gain G within an integration time Tint to output the voltage Valc_out, where the gain G can be a process value during the production of the integrator. The ambient light detection value code_m outputted by the analog-digital converter 1024 when collecting the voltage Valc_out can be measured.

Within the calibration period, the current path can be switched off. For example, the control gating module 103 can stop driving the light receiving device 101. By doing so, the light receiving device 101 can be switched off and can stop receiving the ambient light signal, and the voltages HVSIG and HVREF on both ends of the resistor Rhvres can be the same. The output voltage of the integrator 1023 can be reset to an initial voltage Vcm_c. The integrator 1023 can perform integration at the gain G within an integration time Tint. The calibration value code_c outputted by the analog-digital converter 1024 can be measured. Further, the difference value between the ambient light detection value code_m and the calibration value code_c can be calibrated ambient light detection value acquired.

It is to be noted that the initial voltage Vcm_m (to which the integrator can be reset within the detection period) can be different from the initial voltage Vcm_c (to which the integrator can be reset within the calibration period) . The calibration value can be measured using the maximum gain of the integrator without causing output saturation of the analog-digital converter 1024. Based on the measured calibration value, an appropriate initial voltage as well as an integral gain can be selected to perform ambient light detection within the detection period. By doing so, the dynamic range of the analog-digital converter 1024 can be utilized through the selected initial voltage and integral gain.

In some embodiments, the ambient light detection value error included in the ambient light detection value can be outputted by the analog-digital converter 1024 after the integrator 1023 and can be divided into multiple parts (e.g., two parts) . A first part of the ambient light detection value error can be a mismatch error between electronic components due to the mismatch of a pair of electronic components, which can affect the ambient light detection value. A second part of the ambient light detection value error can be the integral gain error caused by the manufacturing error of the integrator 1023, which can also affect the ambient light detection value.

Consistent with embodiments of this disclosure, the ambient light detection value error caused by the mismatch error between the electronic components can be eliminated by subtracting the calibration value code_c from the ambient light detection value code_m, because the ambient light detection value error can be generated due to the mismatch error between a pair of electronic components within both the detection period and the calibration period, and the ambient light detection value error within the detection period can be substantially the same as the ambient light detection value error within the calibration period. Because the calibration value code_c can reflect the ambient light detection value error generated by the mismatch error between the electronic components, the ambient light detection value error caused by the mismatch error between the electronic components can be reduced or eliminated by subtracting the calibration value code_c from the ambient light detection value code_m.

In some embodiments, the LiDAR can include a plurality of light receiver groups A-H. Each light receiver group can include a plurality of light receiving devices (e.g., 16 light receiving devices) . The plurality of light receiver groups A-H can perform the same control time sequence. For example, referring to FIG. 5, the detection period can be time windows shown by a time sequence seq0 to a time sequence 15, and the calibration period can be a time window shown by a time sequence seq16. For the light receiver groups A-H, 16 light receiving devices in each of the light receiver groups A-H can be controlled to receive ambient light signals in a time division manner based on the same time sequences. The first light receiving devices in the light receiver groups A-H can be activated simultaneously to receive ambient light signals at the time t0 within the time window of the time sequence seq0. The 16th light receiving devices in the light receiver groups A-H can be activated simultaneously to receive ambient light within the time window of the time sequence seq15. Within the time window of the time sequence seq16, a calibration value can be received in the above-described manner. The ambient light detection period includes the above-mentioned time sequences seq0 to seq16.

Further, a calibration value can be received by any one of the light receiving devices in the same light receiver group within the time window of the time sequence seq16. Ambient light detection values generated in response to the reception of the ambient light signals by the light receiving devices (e.g., part of or all of the light receiving devices) in the light receiver group can be corrected using the calibration value. In some embodiments, calibration values can be received by some or all of the light receiving devices in the same light receiver group within the time window of the time sequence seq16. An average value or a median value of the calibration values received by some or all of the light receiving devices in the same light receiver group can be calculated, and ambient light detection values generated in response to the reception of the ambient light signals by all the light receiving devices in the light receiver group can be corrected using the average value or the median value.

It is to be noted that the time window of the time sequence seq16 can be a time window for receiving the calibration value, and the time length of the time window can be set accordingly in different acquisition methods, which is not limited in this disclosure.

As the working time of the LiDAR increases, the temperature of the electronic components in the LiDAR can also continue to rise, and accordingly, the detection value (e.g., the calibration value) measured by the ambient light detection circuit 102 within the calibration period can changes greatly over time. Therefore, in some embodiments, the calibration value can be received once in each ambient light detection period, and the ambient light detection value can be corrected to reduce or avoid the difference in the calibration value due to the temperature change, thereby improving the accuracy of the ambient light detection.

If the detection value (e.g., the calibration value) measured by the ambient light detection circuit 102 within the calibration period changes little over time, the calibration value can be received only once during the entire working process of the LiDAR.

In some embodiments, the calibration period can be executed before the ambient light detection period (e.g., the detection period) , the light receiving device 101 can be controlled to stop outputting an electrical signal to the ambient light detection circuit 102, and the ambient light detection circuit 102 can output a calibration value. Within the ambient light detection period, the light receiving device 101 can output the electrical signal to the ambient light detection circuit 102. The ambient light detection circuit 102 can output an ambient light detection value. The ambient light detection value obtained within the ambient light detection period can be corrected using the calibration value.

For example, the calibration value acquisition process can be executed once before the ambient light detection period. The ambient light detection values received within ambient light detection periods (e.g., all ambient light detection periods) can be corrected using the calibration value.

For example, referring to FIG. 6, the ambient light detection period can include time windows of the time sequences seq0 to seq15. The time window of a time sequence seqM can be added before some or all the ambient light detection periods (e.g., the detection periods) . The calibration value acquisition process can be executed once within the time window of the time sequence seqM. By doing so, the light emission time resources of the LiDAR can be saved.

In some embodiments, the calibration value can be pre-stored in a memory. The calibration value can be read from the memory when the ambient light detection value is to be corrected.

In some embodiments, in consideration of the change in the detection value (e.g., the calibration value) that is measured by the ambient light detection circuit 102 within the calibration period in response to the temperature change, the calibration value can also be received periodically. The period for receiving the calibration value can be greater than the ambient light detection period. For example, the period for receiving the calibration value can be a predetermined period. The predetermined period can be an integer multiple of the ambient light detection period.

In some embodiments, within each ambient light detection period in the predetermined period, the light receiving device 101 can be controlled to output an electrical signal to the ambient light detection circuit 102. The ambient light detection circuit 102 can output an ambient light detection value. The light receiving device 101 can be controlled to stop outputting the electrical signal to the ambient light detection circuit 102 within the predetermined period. The ambient light detection circuit 102 can output a calibration value. The ambient light detection value can be corrected using the calibration value.

For example, a calibration period can be added after every 8, 12, or 16 ambient light detection periods (e.g., the detection periods) . Calibrated ambient light detection values can be determined by subtracting the received calibration value from ambient light detection values determined in each of the preceding ambient light detection periods within the calibration period, respectively.

For example, referring to FIG. 7, a time window of the time sequence seqM (e.g., the calibration period) can be added after every 8, 12 or 16 ambient light detection periods. The ambient light detection period can be the time windows shown by the time sequence seq0 to the time sequence 15 in FIG. 6, and the calibration value acquisition process can be executed once within the time window of the time sequence seqM.

In some embodiments, the calibration value can be stored in a memory, and the calibration value can be read from the memory when the ambient light detection value is to be corrected.

Although the ambient light detection value error caused by the mismatch error can be eliminated from the ambient light detection value in some embodiments, there can be a certain error between the actual integral gain and the design integral gain of the integrator 1023. The ambient light detection value can be corrected to eliminate the ambient light detection value error caused by the integral gain error.

In some embodiments, for example, referring back to FIG. 4, the integral gain of the integrator 1023 can be related to the impedance of a resistor R0 and the capacitance of a capacitor C0. Due to a manufacturing error of the electronic component, the impedance design value of the resistor R0 can be inconsistent with its actual impedance, and the capacitance design value of the capacitor C0 can be inconsistent with its actual capacitance. For example, the impedance and capacitance design values can be 10k ohms and 10 picofarads (pF) , respectively. However, the actual impedance and capacitance can be 9k ohms and 11 pF, respectively. Such inconsistency can result in a certain error between the actual integral gain and the design integral gain (e.g., a particular integral gain interval) of the integrator 1023.

In some embodiments, the ambient light detection value error in the ambient light detection value caused by the integral gain error can be eliminated through a calibration coefficient. The calibration coefficient can be obtained during the chip test stage of a receiving chip, and the receiving chip can include the ambient light detection circuit 102.

For example, the calibration coefficient can be pre-stored in a memory, and the calibration coefficient can be read from the memory when the ambient light detection value needs to be corrected.

In some embodiments, a test value that is outputted by the ambient light detection circuit 102 when a predetermined electrical signal is inputted and a test calibration value that is outputted by the ambient light detection circuit 102 when the predetermined electrical signal is stopped from being inputted can be acquired. A reference value of the ambient light detection circuit 102 within the particular integral gain interval when the predetermined electrical signal is inputted can be determined. A ratio of a difference value between the test value and the test calibration value to the reference value can be calculated and taken as the calibration coefficient.

In some embodiments, during the acquisition of the test value, the predetermined electrical signal can be controlled to be inputted to the ambient light detection circuit 102. The test value outputted by the ambient light detection circuit 102 can be acquired. During the acquisition of the test calibration value, the predetermined electrical signal can be controlled to be stopped from being inputted to the ambient light detection circuit 102. The test calibration value outputted by the ambient light detection circuit 102 can be acquired.

It is to be noted that the test value outputted by the ambient light detection circuit 102 when the predetermined electrical signal is inputted can be at a particular gain (e.g., the design integral gain of the integrator 1023) . At this time, it can be unnecessary to obtain the calibration coefficient. Typically, in a case that the test value is not at a particular gain, the calibration coefficient can be determined. The particular gain can be a particular integral gain interval formed due to a certain redundancy in the design integral gain.

For example, still referring to FIG. 4, the predetermined electrical signal can be a predetermined current. Within the detection period of the ambient light detection period, the light receiving device 101 can be controlled to stop inputting the electrical signal to the ambient light detection circuit 102. The current flowing through the resistor Rhrves can be controlled to be a predetermined current I_al0. The ambient light detection circuit 102 can output a test value code_m1_pre. Within the calibration period of the ambient light detection period, the predetermined current I_al0 can be stopped from being inputted. By doing so, the voltages HVSIG and HVREF on both ends of the resistor Rhvres can be the same. The ambient light detection circuit 102 can output a test calibration value code_c1_pre.

The calibration coefficient can be expressed by the following formula: k_corr=code_m1_pre-code_c1_pre/code_I_al 0, where code_I_al 0 represents the reference value of the ambient light detection circuit 102 within the particular integral gain interval when the predetermined electrical signal is inputted.

In some embodiments, the ambient light detection value can be corrected by both the calibration value and the calibration coefficient. For example, referring back to FIG. 2, in some embodiments of step 203, the difference value between the ambient light detection value and the calibration value can be received. The calibration coefficient can be determined. The difference value can be corrected using the calibration coefficient to obtain the calibrated ambient light detection value. The calibrated ambient light detection value can be the ambient light detection value outputted by the ambient light detection circuit within the particular integral gain interval.

In some embodiments, the ambient light detection value can be corrected through the calibration coefficient. By doing so, the ambient light detection value error can be reduced or eliminated in the ambient light detection value caused by the integral gain error. Each ambient light detection value can be corrected to be within the particular integral gain interval.

For example, the particular integral gain interval can be a typical process value interval (e.g., a set gain interval range) for the production of the integrator 1023.

In some embodiments, the correction of the difference value using the calibration coefficient can be the calculation of the quotient of the difference value and the calibration coefficient. For example, if the ambient light detection value is 10, the calibration value can be 2, and the calibration coefficient can be 0.5. The calibrated ambient light detection value can be (10-2) /0.5=16.

In some embodiments, in a case where the number of light receiving devices 101 is more than one, the calibration process can be executed separately on the ambient light detection value corresponding to each light receiving device 101 using the calibration value and the calibration coefficient. The time point of correcting the ambient light detection value using the calibration value and the calibration coefficient can be consistent with the time point of correcting the ambient light detection value in some embodiments corresponding to FIGS. 5-FIGS. 7, which is not repeated hereinafter.

FIG. 8 shows the structure of an example LiDAR, consistent with some embodiments of this disclosure. For example, FIG. 8 shows a structure of a receiving chip in a LiDAR.

The LiDAR can include a plurality of light receiver groups: a light receiver group A, a light receiver group B, ..., or the like. Each light receiver group can include eight light receiving devices (e.g., photoelectric conversion devices) . The eight light receiving devices can share the same control gating module.

In the test stage of the receiving chip, a switch sw_fcal can be adjusted to select an external current source. The external current source can supply a predetermined electrical signal. The calibration coefficient k_corr can be obtained based on the calibration coefficient acquisition process and written in a memory (e.g., adisposable programmable chip) .

In the use stage of the receiving chip, the switch sw_fcal can be switched. In such a case, the light receiving devices can receive the ambient light signals, and the normal working mode of the receiving chip can start. For example, referring to FIG. 9, the process of detecting ambient light by the light receiver group 0 can be described in conjunction with the time sequences of control signals.

For example, referring to FIG. 12, for the light receiver group A, a high-voltage control signal en_hvres0 can be applied to the control gating module 0. The control gating module 0 can supply power to the eight light receiving devices in the light receiver group 0. For example, the control gating module 0 can drive the eight light receiving devices in the light receiver group 0 in a time division manner. In such a case, an echo signal detection circuit 201 for detecting an object echo and the ambient light detection circuit 102 in the LiDAR can receive an object echo and an ambient light signal, respectively, and then store them. For the ambient light detection circuit, the detection period can be executed. The eight light receiving devices in the light receiver group A can be driven in a time division manner. The integrator 0 can be controlled to integrate a signal outputted by an activated light receiving device through a control signal en_alc_int0 and generate an integrated signal. The analog-digital converter 0 can be controlled to perform analog-digital conversion on the integrated signal through a control signal adc_clk0. The ambient light detection circuit can output the ambient light detection values generated in response to the reception of the ambient light signals by the eight light receiving devices in the light receiver group A, respectively. The calibration period can be executed. The switch sw_bcal0 can be disconnected. For example, the control gating module 0 can be disconnected to any of the light receiving devices in the light receiver group A. The calibration operation can be executed. The ambient light detection circuit can output the calibration value. Then, the calibration value can be subtracted from the ambient light detection values (e.g., that are generated in response to the reception of the ambient light signals by the eight light receiving devices in the light receiver group A, respectively) to determine difference values between the ambient light detection values and the calibration value. The difference values between the ambient light detection values and the calibration value can be divided by the calibration coefficient, respectively, to determine the calibrated ambient light detection values.

By analogy, the ambient light detection process of the light receiver group B can be similar, which is not repeated hereinafter.

The above-described operations can be repeated in one or more light detection periods (e.g., every light detection peiord) . The ambient light detection value error caused by the mismatch error and the integral gain error in the ambient light detection circuit can be compensated in real time with the change of time, working condition, or working state. In some embodiments, in one or more ambient light detection periods (e.g., every ambient light detection period) , periodical correction can be performed using the calibration value and the calibration coefficient stored in the memory. By doing so, more accurate ambient light can be outputted.

For example, referring to FIG. 10, FIG. 10 shows a structure diagram of another example LiDAR, consistent with some embodiments of this disclosure. In some embodiments, the eight light receiving devices can be driven by at least two control gating modules.

For example, referring to FIG. 10, two control gating modules can supply drive voltages to the eight light receiving devices. For the light receiver group A, the control gating module 0a can supply a drive voltage to the light receiving devices 0-3. For the light receiver group B, the control gating module 0b can supply a drive voltage to the light receiving devices 4-7. In some embodiments, for the light receiver group c, the control gating module 1a can supply a drive voltage to the light receiving devices 0-3. For the light receiver group D, the control gating module 1b can supply a drive voltage to the light receiving devices 4-7.

In the test stage of the receiving chip, a switch sw_fcal can be adjusted to select an external current source. The external current source can supply a predetermined electrical signal. The calibration coefficient k_corr can be determined based on the calibration coefficient acquisition process and written in a memory.

In the use stage of the receiving chip, the switch sw_fcal can be switched. By doing so, the light receiving devices can receive the ambient light signals, and the normal working mode of the receiving chip can start. For example, referring to FIG. 11, the process of detecting ambient light by the light receiver group A and the light receiver group B can be described in conjunction with the time sequences of control signals.

In some embodiments, because the two control gating modules can switch back and forth and each control gating module can have a different mismatch error, the ambient light detection value can be corrected for different mismatch errors. For example, the ambient light detection value can be corrected twice within the ambient light detection period to determine two calibration values. The correction can be performed by subtracting the two calibration values from the corresponding ambient light detection values.

For example, the detection period can be executed. For the light receiver group A and the light receiver group B, the high-voltage control signals en_hvres0a and en_hvres0b can be sequentially applied to the control gating module 0 to cause the control gating module 0a to supply power to the four light receiving devices (e.g., light receiving devices 0-3) in the light receiver group A, and cause the control gating module 0b to supply power to the four light receiving devices (e.g., light receiving devices 4-7) in the light receiver group B. For example, the high-voltage control signal en_hvres0a can be applied to the control gating module 0a while the high-voltage control signal en_hvres0b is not applied to the control gating module 0b. By doing so, the control gating module 0a can supply power to the light receiving device 0 in the light receiver group A. In some embodiments, when the control gating module 0a supplies power, the control gating module 0a can be connected to the integrator 0 through the switch sel_path0. The integrator 0 can be controlled to integrate a signal outputted by the activated light receiving device 0 through a control signal en_alc_int0 and generate an integrated signal. The analog-digital converter 0 can be controlled to perform analog-digital conversion on the integrated signal through a control signal adc_clk0. The ambient light detection circuit can output an ambient light detection value generated in response to the reception of an ambient light signal by the light receiving device 0 in the light receiver group A.

The high-voltage control signal en_hvres0b can be applied to the control gating module 0b while the high-voltage control signal en_hvres0a is not applied to the control gating module 0a. By doing so, the control gating module 0b can supply power to the light receiving device 4 in the light receiver group B. In some embodiments, when the control gating module 0b supplies power, the control gating module 0b can be connected to the integrator 0 through the switch sel_path0. The integrator 0 can be controlled to integrate a signal outputted by the activated light receiving device 4 through a control signal en_alc_int0 and to generate an integrated signal. The analog-digital converter 0 can be controlled to perform analog-digital conversion on the integrated signal through a control signal adc_clk0. The ambient light detection circuit can output an ambient light detection value generated in response to the reception of an ambient light signal by the light receiving device 4 in the light receiver group B. In some embodiments, the ambient light detection circuit can in turn output the ambient light detection values generated in response to the reception of ambient light signals by other light receiving devices in the light receiver group A and the light receiver group B.

Then, the calibration period can be executed. The switch sw_bcal0 can be disconnected, to control the control gating module 0a not to be connected to any of the light receiving devices in the light receiver group A, and the control gating module 0b not to be connected to any of the light receiving devices in the light receiver group B. The calibration operation can be executed. The high-voltage control signal en_hvres0a can be applied to the control gating module 0a while the high-voltage control signal en_hvres0b can be not applied to the control gating module 0b. The control gating module 0a can be connected to the integrator 0 through the switch sel_path0. The ambient light detection circuit can output a calibration value a. Then, the high-voltage control signal en_hvres0b can be applied to the control gating module 0b while the high-voltage control signal en_hvres0a is not applied to the control gating module 0a. The control gating module 0b can be connected to the integrator 0 through the switch sel_path0. The ambient light detection circuit can output a calibration value b. Also, the calibration value a can be subtracted from each of the ambient light detection values corresponding to the light receiving devices 0-3. The calibration value b can be subtracted from each of the ambient light detection values corresponding to the light receiving devices 4-7. Each of the results can be divided by the calibration coefficient to determine the calibrated ambient light detection values.

The ambient light detection process of the light receiver group C and the light receiver group D can be similar, which is not repeated herein.

It is to be noted that in some embodiments, eight light receiving devices can be divided into one or two light receiver groups and one or two control gating modules supply the drive voltages, which can be illustrative. In practical applications, the number of light receiver groups can be N. Each light receiver group can include P light receiving devices. The number of control gating modules can be M, where N, M, and P can be positive integers, and P/M can be a positive integer. The values of N, M, or P are not limited in this disclosure.

It is understood that in practical applications, the LiDAR can be set on a printed circuit board ( “PCB” ) using discrete devices instead of the chip structure described above, which is not limited in this disclosure.

Consistent with embodiments of this disclosure, the above-described ambient light detection method can be executed by a LiDAR. For example, the respective steps of the above-described method can be executed using a processor inside the LiDAR. The respective steps of the above-described method can be executed by a terminal device connected to the LiDAR.

It is to be noted that the sequence numbers of the respective steps in this disclosure do not limit the order in which the respective steps are executed. It is to be understood that in some embodiments, the ambient light detection method can be implemented by a software program that runs in a processor (e.g., being integrated into a chip or a chip module) . The method can also be implemented by software combined with hardware, and this disclosure does not make any limitation in this regard.

For example, referring to FIG. 12, the LiDAR further includes an echo signal detection circuit 201 for detecting an object echo. Within a detection period of the object detection period, the echo signal detection circuit 201 can be controlled to detect an echo signal of the object echo. Within a calibration period of the object detection period, the echo signal detection circuit 201 can be calibrated.

In some embodiments, the ambient light detection period can also include a detection period for detecting ambient light and a calibration period for calibrating ambient light. The detection period of the ambient light detection period and the detection period of the object detection period can be synchronously executed in parallel. The detection period of the ambient light detection period can be executed before the detection period of the object detection period. The detection period of the object detection period can be executed before the detection period of the ambient light detection period.

Similarly, the calibration period of the ambient light detection period and the calibration period of the object detection period can be executed concurrently to save time resources.

In some embodiments, the calibration period of the ambient light detection period can be executed before the calibration period of the object detection period, to reduce or avoid interference of the ambient light signal on the object detection. By doing so, the accuracy of the object detection can be improved or ensured.

In some embodiments, the calibration period of the object detection period can be executed before the calibration period of the ambient light detection period. By doing so, the ambient light calibration can be executed after the light signal of the object echo can be weakened, thereby improving the accuracy of the ambient light calibration.

In some embodiments, the detection period of the ambient light detection period can be first executed, then the detection period of the object detection period can be executed. Then, the calibration period of the object detection period and the calibration period of the ambient light detection period can be synchronously executed in parallel. For example, the object echo signal correction and the ambient light correction can be executed within the calibration period.

For example, the ambient light detection value and the object feature value (e.g., a time of flight) outputted within the detection period of the ambient light detection period and the detection period of the object detection period, respectively, can be stored in a register. Within the calibration period, the ambient light detection value and the calibration value can be received, and the ambient light detection value can be corrected using the calibration value. Meanwhile, the object echo signal and the correction value can be acquired, and the object echo signal can be corrected using the correction value.

In some embodiments, the correction of the ambient light can be achieved through the calibration period of the echo signal detection circuit 201. By doing so, the power consumption of the LiDAR can be reduced, and the accuracy of ambient light detection can be improved.

For example, referring to FIG. 13, in some embodiments, an ambient light detection device 120 is provided. The ambient light detection device 120 can include an acquisition module 1201, a calibration value acquisition module 1202, and a correction module 1203.

The acquisition module 1201 can acquire an ambient light detection value generated in response to the reception of an ambient light signal by a light receiving device. The calibration value acquisition module 1202 can acquire a calibration value. The correction module 1203 can correct the ambient light detection value using the calibration value.

It is to be noted that the ambient light detection device 120 can be provided in the receiving chip shown in FIG. 8 or FIG. 10, or can be provided outside of the receiving chip, which is not limited in this disclosure.

In some embodiments, the correction module 1203 can determine a difference value between the ambient light detection value and the calibration value. In some embodiments, the correction module 1203 can determine the difference value between the ambient light detection value and the calibration value. The correction module 1203 can also determine a calibration coefficient. The correction module 1203 can further correct the difference value using the calibration coefficient.

In some embodiments, the correction module 1203 can correct the ambient light detection value using a calibration value within the ambient light detection period. The calibration value can be a detection value outputted by the ambient light detection circuit within the ambient light detection period when the light receiving device is controlled to stop outputting an electrical signal to the ambient light detection circuit.

In some embodiments, the correction module 1203 can correct the ambient light detection value using a calibration value within a predetermined period. The predetermined period can be an integer multiple of the ambient light detection period, and the calibration value can be a detection value outputted by the ambient light detection circuit based on the predetermined period when the light receiving device is controlled to stop outputting the electrical signal to the ambient light detection circuit.

In some embodiments, the correction module 1203 can correct the ambient light detection value using a calibration value before the ambient light detection period. The calibration value can be a detection value outputted by the ambient light detection circuit before the ambient light detection period when the light receiving device is controlled to stop outputting the electrical signal to the ambient light detection circuit.

For more details on the working principle and working mode of the ambient light detection device 120, reference can be made to the relevant descriptions in FIGS. 1 to 11 and corresponding embodiments, and the details are not repeated hereinafter.

In some embodiments, the ambient light detection device can correspond to a chip having an ambient light detection function in a LiDAR or a terminal device, such as a system-on-a-chip ( “SOC” ) , a baseband chip, or the like. The ambient light detection device can also correspond to a chip module having an ambient light detection function in a LiDAR or a terminal device. The ambient light detection device can also correspond to a chip module having a data processing function chip or correspond to a LiDAR or a terminal device.

Some embodiments of this disclosure also disclose a LiDAR. For example, referring to FIG. 14, the LiDAR includes a light emitting device 1301 and a light receiving device 1302. The LiDAR can emit a detection signal (e.g., a pulse signal) through the light emitting device 1301. The light receiving device 1302 can receive an echo of the detection signal reflected by an object 1303. The light receiving device 1302 can also be used for receiving an ambient light signal.

Further, the light receiving device 1302 can be provided corresponding to the light emitting device 1301.

The respective modules or units included in the respective devices and products described in the preceding embodiments can be software modules or units, hardware modules or units, or partly software modules or units and partly hardware modules or units. For example, for the respective devices and products applied to or integrated into a chip, the respective modules or units contained therein can be implemented by means of hardware (e.g., circuits) . In some embodiments, at least some of the modules or units can be implemented by a software program running on a processor integrated into the chip, and the remaining modules or units can be implemented by means of hardware such as circuits; for the respective devices and products applied to or integrated into a chip module, the respective modules or units contained therein can be implemented by hardware (e.g., circuits) , where different modules or units can be located in the same component (e.g., a chip or a circuit module) or different components of the chip module. In some embodiments, at least some of the modules or units can be implemented by a software program running on a processor integrated into the chip module, and the remaining modules or units can be implemented by hardware (e.g., circuits) . For the respective devices and products applied to or integrated into a terminal, the respective modules or units contained therein can be implemented by hardware (e.g., circuits) , where different modules or units can be located in the same component (e.g., a chip or a circuit module) or different components of the terminal, or at least some of the modules or units can be implemented by a software program running on a processor integrated into the terminal and the remaining (if any) modules or units can be implemented by hardware such as circuits.

Some embodiments of this disclosure further disclose a storage medium. The storage medium can be a computer-readable storage medium having a computer program stored thereon, where the computer program, when run, can execute steps of the method described above. The storage medium can include a read-only memory ( “ROM” ) , a random-access memory ( “RAM” ) , a magnetic disk, an optical disk, or the like. The storage medium can also include a non-volatile memory or a non-transitory memory.

Some embodiments of this disclosure further disclose a terminal device. The terminal device can include a processor and a memory, and the memory has a computer program, executable by the processor, stored thereon. The processor can execute the steps of the method described above when running the computer program. Alternatively, the terminal device includes the obstruction detection device described above and a LiDAR.

The terms "or" and "and/or" of this disclosure describe an association relationship between associated objects, and represent a non-exclusive inclusion. For example, each of "A and/or B" and "A or B" can include: only "A" exists, only "B" exists, and "A" and "B" both exist, where "A" and "B" can be singular or plural. For another example, each of "A, B, and/or C" and "A, B, or C " can include: only "A" exists, only "B" exists, only "C" exists, "A" and "B" both exist, "A" and "C" both exist, "B" and "C" both exist, and "A" , "B" , and "C" all exist, where "A, " "B, " and "C" can be singular or plural. In addition, the symbol "/" herein indicates that the associated objects before and after the character are in an "or" relationship. In this disclosure, the term “at least one of A or B” has a meaning equivalent to “A or B” as described above. The term “at least one of A, B, or C” has a meaning equivalent to “A, B, or C” as described above.

In this disclosure, the terms “a, ” “an, ” and “the” are intended to represent singular or plural forms, unless expressly stated otherwise in the context. For example, without expressly stated otherwise in the context, “the method for driving a laser” can refer to the method for driving a plurality of lasers.

[0118] The term “a plurality of” in this disclosure refers to two or more. The term “multiple” in this disclosure refers to a number of two or more. For example, multiple objects can include two objects, or more than two objects. The term “at least one” in this disclosure refers to a number of one or more. For example, at least one object can include one object, or two objects, or ten objects, or the like.

The descriptions of first, second, and so on in the embodiments of this disclosure are only for the purpose of illustrating and distinguishing between the objects described, do not represent any particular order, do not represent any special limitation on the number of devices in the embodiments of this disclosure, and thus cannot form any limitation on the embodiments of this disclosure.

The "connection" in the embodiments of this disclosure refers to various connection methods such as direct connection or indirect connection to achieve communication between devices, and the embodiments of this disclosure do not make any limitation in this regard.

It is to be understood that in the embodiments of this disclosure, the processor can be a central processing unit ( “CPU” ) , and the processor can also be a general-purpose processor, a digital signal processor ( “DSP” ) , an application-specific integrated circuit ( “ASIC” ) , a field-programmable gate array ( “FPGA” ) or another programmable logic device, a discrete gate or a transistor logic device, or a discrete hardware component. The general-purpose processor can be a microprocessor or any conventional processor.

It is to be understood that the memory in the embodiments of this disclosure can be a volatile memory or a non-volatile memory, or can include both a volatile memory and a non-volatile memory. The non-volatile memory can be a read-only memory ( “ROM” ) , a programmable ROM ( “PROM” ) , an erasable PROM ( “EPROM” ) , an electrically EPROM ( “EEPROM” ) or a flash memory. The volatile memory can be a random access memory ( “RAM” ) , which can be used as an external cache. By way of illustrative but not limiting description, various forms of RAMs can be available, such as a static RAM ( “SRAM” ) , a dynamic RAM ( “DRAM” ) , a synchronous DRAM ( “SDRAM” ) , a double data rate SDRAM ( “DDR SDRAM” ) , an enhanced SDRAM ( “ESDRAM” ) , a synchlink DRAM ( “SLDRAM” ) , and a direct rambus RAM ( “DR RAM” ) .

The embodiments described above can be implemented, in whole or in part, in software, hardware, firmware, or any combination thereof. If implemented in software, the embodiments described above can be implemented, in whole or in part, in the form of a computer program product. The computer program product includes one or more computer instructions or computer programs. The computer instructions or computer programs, when loaded or executed on a computer, produce, in whole or in part, processes or functions in accordance with the embodiments of this disclosure. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions can be transmitted, by wired or wireless means, from one web site, computer, server or data center to another web site, computer, server or data center. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server, data center, or the like, containing one or more collections of available media. It is to be understood that in various embodiments of this disclosure, the serial numbers of the preceding processes do not mean an execution sequence and the execution sequence of the preceding processes should be determined based on their functions and internal logics, which should not limit an implementation process of the embodiments of this disclosure in any improper manner.

In the various embodiments provided in this disclosure, it should be understood that the methods, devices, and systems disclosed herein can be implemented in other ways. For example, the device embodiments described above are merely illustrative; for example, the division of the units is merely a division of logical functions which can be divided by other ways in the actual implementation; for example, various units or components can be combined or integrated in another system or certain features can be omitted, or not implemented. Additionally, other items shown or discussed as coupled or directly coupled or communicating with each other can be indirectly coupled or communicating through some interface, device, or unit whether electrically, mechanically, or otherwise.

The units shown as separated components can or cannot be physically separated, and the components shown as units can or cannot be physical units. For exmaple, they can be located in one place or can be distributed over a plurality of network units. Some or all of these units can be selected based on practical requirements to achieve the objects of the solutions in the embodiments.

Additionally, various functional units in respective embodiments of this disclosure can be integrated into one processing unit, each unit can be physically presented separately, or two or more units can be integrated into one unit. The above integrated units can be implemented in the form of hardware or in the form of hardware plus software functional units.

The above integrated units implemented in the form of software function units can be stored in a computer-readable storage medium. The above software functional units are stored in a storage medium and contain a number of instructions to enable a computer device (which can be a personal computer, a server or a network device) to perform some of the steps of the method described in various embodiments of this disclosure.

Although this disclosure is disclosed as above, this disclosure cannot be limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of this disclosure, and therefore the scope of protection of this disclosure shall be as limited by the claims.

Claims

A method of ambient light detection for a LiDAR, the method comprising:

receiving an ambient light detection value generated in response to reception of an ambient light signal by a light receiving device of the LiDAR, wherein the light receiving device is configured to receive the ambient light signal and convert the ambient light signal into an electrical signal;

receiving a calibration value, wherein the calibration value is a detection value outputted by an ambient light detection circuit of the LiDAR when the light receiving device is controlled to stop outputting the electrical signal to an ambient light detection circuit of the LiDAR, wherein the light receiving device is selectively in communication with the ambient light detection circuit for outputting the electrical signal to the ambient light detection circuit, and the ambient light detection circuit is configured to output the ambient light detection value based on the electrical signal; and

correcting the ambient light detection value using the calibration value.
The method of claim 1, wherein correcting the ambient light detection value using the calibration value comprises:

determining a difference value between the ambient light detection value and the calibration value.
The method of claim 2, further comprising:

determining a calibration coefficient; and

correcting the difference value by using the calibration coefficient to determine a calibrated ambient light detection value, wherein the calibrated ambient light detection value is an ambient light detection value outputted by the ambient light detection circuit within an integral gain interval.
The method of claim 3, wherein determining the calibration coefficient comprises:

receiving a test value outputted by the ambient light detection circuit when a predetermined electrical signal is inputted and a test calibration value outputted by the ambient light detection circuit when the predetermined electrical signal is stopped from being inputted;

receiving a reference value of the ambient light detection circuit within the particular integral gain interval when the predetermined electrical signal is inputted; and

determining the calibration coefficient as a ratio of a difference value between the test value and the test calibration value to the reference value.
The method of claim 4, wherein receiving the test value outputted by the ambient light detection circuit when the predetermined electrical signal is inputted and the test calibration value outputted by the ambient light detection circuit when the predetermined electrical signal is stopped from being inputted comprises:

controlling the predetermined electrical signal to be inputted to the ambient light detection circuit;

receiving the test value outputted by the ambient light detection circuit;

controlling the predetermined electrical signal to be stopped from being inputted to the ambient light detection circuit; and

receiving the test calibration value outputted by the ambient light detection circuit.
The method of claim 3, wherein determining the calibration coefficient comprises:

reading the calibration coefficient from a memory of the LiDAR, wherein the calibration coefficient is stored in the memory.
The method of claim 1, wherein the LiDAR comprises a plurality of light receiver groups, each of the plurality of light receiver groups comprises a light receiving device, and receiving the ambient light detection value generated in response to reception of the ambient light signal by the light receiving device comprises:

within an ambient light detection period for detecting ambient light, controlling the light receiving device to output an electrical signal generated from the ambient light signal to the ambient light detection circuit in a time division manner; and

receiving the ambient light detection value outputted by the ambient light detection circuit.
The method of claim 7, wherein correcting the ambient light detection value using the calibration value comprises:

correcting the ambient light detection value using the calibration value within the ambient light detection period, wherein the calibration value is a detection value outputted by the ambient light detection circuit within the ambient light detection period when the light receiving device is controlled to stop outputting the electrical signal to the ambient light detection circuit; or

correcting the ambient light detection value using the calibration value within a predetermined period, wherein the predetermined period is an integer multiple of the ambient light detection period, and the calibration value is a detection value outputted by the ambient light detection circuit based on the predetermined period when the light receiving device is controlled to stop outputting the electrical signal to the ambient light detection circuit; or

correcting the ambient light detection value using the calibration value before the ambient light detection period, wherein the calibration value is a detection value outputted by the ambient light detection circuit before the ambient light detection period when the light receiving device is controlled to stop outputting the electrical signal to the ambient light detection circuit.
The method of claim 1, wherein the LiDAR comprises N light receiver groups and N control gating modules, each of the N control gating module is configured to selectively supply a drive voltage to a light receiving device in a same light receiver group, and N is a positive integer, and wherein receiving the calibration value comprises:

receiving N calibration values, wherein each calibration value is configured as a detection value outputted by the ambient light detection circuit when each control gating module supplies a drive voltage and when a light receiving device in a same light receiver group driven by the control gating module is controlled to stop outputting the electrical signal to the ambient light detection circuit.
The method of claim 9, wherein correcting the ambient light detection value using the calibration value comprises:

correcting, using a calibration value corresponding to the control gating module driving the light receiving device, the ambient light detection value generated in response to the reception of the ambient light signal by the light receiving device.
The method of any of claims 1 to 10, wherein the LiDAR further comprises an echo signal detection circuit for detecting an object echo, and the ambient light detection value is corrected using the calibration value within a calibration period for calibrating an echo signal outputted by the echo signal detection circuit.
A device of ambient light detection for a LiDAR, the device comprising:

an acquisition module, configured to receive an ambient light detection value generated in response to reception of an ambient light signal by a light receiving device of the LiDAR, wherein the light receiving device is configured to receive the ambient light signal and convert the ambient light signal into an electrical signal;

a calibration value acquisition module, configured to receive a calibration value, wherein the calibration value is a detection value outputted by an ambient light detection circuit of the LiDAR when the light receiving device is controlled to stop outputting the electrical signal to the ambient light detection circuit, wherein the light receiving device is selectively in communication with the ambient light detection circuit for outputting the electrical signal to the ambient light detection circuit, and the ambient light detection circuit is configured to output the ambient light detection value; and

a correction module, configured to correct the ambient light detection value using the calibration value.
A non-transitory computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a computer, performs the method of any of claims 1 to 11.
A LiDAR, comprising:

a light receiving device, configured to receive an ambient light signal and convert the ambient light signal into an electrical signal;

an ambient light detection circuit, configured to receive the electrical signal and output an ambient light detection value based on the electrical signal;

a memory and a processor, wherein the memory comprises a computer program executable on the processor stored thereon, and wherein the processor, when executing the computer program, performs the method of any of claims 1 to 11.