WO2023133965A1

WO2023133965A1 - Laser radar system and ambient light sensing method therefor

Info

Publication number: WO2023133965A1
Application number: PCT/CN2022/076492
Authority: WO
Inventors: 常健忠; 寿翔
Original assignee: 杭州宏景智驾科技有限公司
Priority date: 2022-01-13
Filing date: 2022-02-16
Publication date: 2023-07-20
Also published as: CN114594493B; CN114594493A

Abstract

An ambient light sensing method for a laser radar system. The method comprises: emitting a laser pulse to a detection region (3) (S101); detecting, within a predetermined time period for emitting the laser pulse, the number of light excitation signals generated by each pixel unit of a photoelectric detector (4) (S102); and determining the ambient light intensity of each pixel unit (42) according to the detected number of light excitation signals (S103).

Description

LiDAR system and its ambient light perception method

This application claims the priority of the Chinese patent application No. 202210034743.5 submitted on January 13, 2022, and the content disclosed in the above Chinese patent application is cited in its entirety as a part of this application.

technical field

The present disclosure relates to the field of advanced driver assistance systems (ADAS) and automatic driving systems, and in particular to the laser radar technology applied in the advanced driver assistance systems and automatic driving systems.

Background technique

In advanced driver assistance systems and automatic driving systems, lidar is widely used for spatial distance measurement and three-dimensional environment reconstruction of the surrounding environment of the vehicle, which is an important prerequisite for realizing high-precision automatic driving control. Lidar is susceptible to interference from ambient light during use. In particular, in different scenarios, such as sunny, cloudy, rainy, night, tunnel, smog, etc., ambient light will have different effects on the lidar detection capability. For this reason, lidar needs to adjust its own parameter performance according to different ambient light intensities in different scenes, so as to overcome the influence of ambient light on lidar performance.

State-of-the-art lidars usually use a single preset threshold to detect the light intensity of the external environment. However, the external scene is unpredictable and the range of change is difficult to determine. Even in the same scene, the ambient light intensity corresponding to different detection angles and test distances is different. Therefore, it is difficult to accurately interpret the light intensity of the external environment using a single threshold, which greatly affects the performance of the lidar.

Contents of the invention

In view of the defects in the prior art, the present disclosure further improves the laser radar system, so as to improve the good performance of the laser radar in various ambient light scenarios.

In one aspect, a method of ambient light perception for a lidar system is provided, the method comprising:

emit laser pulses to the detection area;

Detecting the number of optical excitation signals generated by each pixel unit of the photodetector during the predetermined period of emitting the laser pulse;

The ambient light intensity of each pixel unit is determined according to the number of detected light excitation signals.

Advantageously, the pixel unit is a single pixel on the photodetector.

Advantageously, the pixel unit comprises two or more pixels of a photodetector.

In another aspect, another ambient light sensing method for a lidar system is provided, the method comprising:

Obtaining the total amount of optical excitation signals generated by the predetermined pixel unit of the photodetector within a preset period of time during which the laser emits laser pulses to the detection area; and

Comparing the total amount of light excitation signals with the light intensity threshold table to determine the ambient light intensity level, wherein the light intensity threshold table includes a plurality of light intensity thresholds, each light intensity threshold has a preset number of light excitation signals and represents a corresponding ambient light intensity level.

Advantageously, the acquisition of the total amount of optical excitation signals of the predetermined pixel unit includes:

Setting the preset time period to consist of multiple time series, each time series including multiple time units; and

The photoexcitation signal output of the predetermined pixel unit of the photodetector is recorded in each time unit, and the photoexcitation signals of all the time units of the time series are accumulated to obtain the total amount of the photoexcitation signal.

Beneficially, there is a serial time interval between two consecutive time series.

Advantageously, the predetermined pixel unit is a single pixel unit of the photodetector.

Advantageously, the predetermined pixel unit is two or more pixel units of the photodetector.

Advantageously, the photodetector is a single photon avalanche diode chip.

In yet another aspect, yet another ambient light perception method for a lidar system is provided, the method comprising:

Obtaining the total amount of optical excitation signals generated by each pixel unit of the photodetector within a preset period of time during which the laser emits laser pulses to the detection area; and

comparing the total amount of the light excitation signal with the light intensity threshold table to determine the ambient light intensity level of each pixel unit, wherein the light intensity threshold table includes a plurality of light intensity thresholds, and each light intensity threshold has a preset light excitation Signal quantity and characterize the corresponding ambient light intensity level.

In yet another aspect, a lidar system is provided, comprising:

a laser configured to emit laser pulses into the detection area;

a photodetector configured to generate a photoexcitation signal upon receipt of a photon signal;

a collector, which is configured to count the total amount of light excitation signals generated by each pixel unit of the photodetector within a preset period of time; and

a comparator configured to receive the total amount of the light excitation signal and compare it with a light intensity threshold table to determine the ambient light intensity level, wherein the light intensity threshold table includes a plurality of thresholds, each threshold has a preset light intensity Excitation signal quantities and characterize corresponding ambient light intensity levels.

Advantageously, the collector is further configured as:

recording the preset period of time, wherein the preset period of time consists of a plurality of time series, each time series comprising a plurality of time units; and

The optical excitation signal output of each pixel unit in each time unit is recorded and the total amount of optical excitation signal is obtained by statistics.

Advantageously, the pixel unit of the photodetector is a single pixel of the photodetector.

Advantageously, the pixel unit of the photodetector is two or more pixels of the photodetector.

In yet another aspect, an electronic device is provided, comprising: at least one processor and a memory communicatively connected to the at least one processor, the memory stores instructions executable by the at least one processor, and the instructions are executed by The at least one processor executes to perform the methods described in this disclosure.

Description of drawings

Other details and advantages of the present disclosure will be further described in detail below in conjunction with the accompanying drawings, wherein:

Fig. 1 shows a structural block diagram of a lidar system according to one or more embodiments;

Fig. 2 shows a flowchart of an ambient light sensing method for a lidar system according to one or more embodiments;

Fig. 3 shows a pixel schematic diagram of a single photon avalanche diode (Single-Photon Avalanche Diode, hereinafter referred to as SPAD) sensor applied according to one or more embodiments;

FIG. 4 shows another ambient light perception method for a lidar system according to one or more embodiments;

Fig. 5 shows a schematic diagram of the steps of acquiring the number of optical excitation signals of a predetermined pixel unit applied according to one or more embodiments;

Fig. 6 shows yet another ambient light sensing method for a lidar system according to one or more embodiments.

Detailed ways

Fig. 1 shows a structural block diagram of a lidar system according to one or more embodiments of the present disclosure, in which only some components, electronic devices or functional modules of the lidar system are shown. Those skilled in the art may think that after understanding the principle of the present disclosure, in order to realize the present disclosure, other related units, devices or modules need or may be added to the system in the figure.

The laser radar system includes a laser 1 and a controller 2, wherein the laser 1 emits a laser pulse to the detection area 3 under the control of the controller 2, and the laser pulse forms a diffuse reflection echo on the surface of the detection area in the form of a laser beam and is detected by the laser. Radar system detection for functions such as distance measurement of the detection area.

The laser 1 may be any form of laser known in the art, such as a semiconductor laser such as a distributed feedback laser or a vertical cavity surface emitting laser. In one or more embodiments, the controller sends a pulse signal to the laser according to a preset time sequence, and the laser emits a laser pulse to the detection area after receiving the pulse signal.

The controller 2 is used to send working instructions to the laser, such as pulse signals, so as to realize functions such as turning on and off the laser and adjusting laser pulse width, repetition frequency, and energy parameters. The controller can be a dedicated electronic control device, or the control function can be realized through a central processing unit.

The lidar system also includes a photodetector 4, which is configured to generate a light excitation signal when receiving an external light wave. The photodetector 4 is, for example, a CCD light sensor, a CMOS sensor, a PD photodiode, an APD avalanche diode, a SPAD single photon avalanche diode, and the like. In one or more embodiments, a SPAD chip (Single Photon Avalanche Diode) is used as the photodetection sensor. The SPAD chip is a digital chip with a pixel array composed of multiple pixels. Each pixel is in an avalanche state under an external high voltage difference (in some special scenarios, its magnification is not the maximum state, and it can also be in a linear magnification state. Geiger pattern). In the avalanche state, when the pixel unit receives the photon signal of laser diffuse reflection echo or external ambient light, it is excited and discharged by the photon signal, and the output value is "1". If it does not receive the laser diffuse reflection echo or external ambient light It is not excited, does not output any value or the output value is "0".

The lidar system further includes a collector 5 configured to collect emission time information of the laser and count the total amount of optical excitation signals generated by the pixel units of the photodetector within a preset period of time. In one or more embodiments, the collector 5 includes a TDC circuit (Time-Distance Convert, time-distance conversion), which is connected with the SPAD chip to determine that the laser is emitted and that the SPAD photodetector detects the diffuse reflection echo of the laser To calculate the distance from the detection area to the lidar, the calculation formula is: S = speed of light × time difference/2. The TDC circuit directly calculates the time difference of the laser pulse from emitting the laser to receiving the diffuse echo as the distance between the lidar system and the detection area, eliminating the need for optical signals-analog signals-digital signals when using other photosensitive elements The signal change process has higher execution efficiency.

The laser radar system also includes a comparator 6, which receives the total amount of the optical excitation signal generated by the predetermined pixel unit of the photodetector, and compares the total amount of the optical excitation signal with a preset light intensity threshold table to determine Ambient light intensity level. The light intensity threshold table includes a plurality of thresholds, each threshold has a preset number of light excitation signals and represents a corresponding ambient light intensity level.

The setting method of the light intensity threshold value table: place the laser radar in different scenes completely, such as at night, cloudy, rainy, cloudy, sunny, etc., test against the distance, and obtain the total number of single pixels in the light detector The excitation amount is used as a standard to set the light intensity threshold.

Another setting method of the beam intensity threshold table is to set different illuminances in the laboratory, collect the total excitation amount of a single pixel, and set the corresponding light intensity threshold.

The lidar system further includes a memory 7, which is, for example, a non-volatile computer-readable storage medium for storing non-volatile software programs, non-volatile computer-executable programs, modules, and the like. The non-volatile software programs, instructions and modules stored in the memory are run by the controller or other processors to execute various functional applications and data processing of the system. The memory may include a program storage area and a data storage area, wherein the program storage area may store, for example, an operating system, an application program required by at least one function, etc.; the data storage area may store, for example, an option list, a light intensity threshold table, and the like. In some embodiments, the memory may include memory that is remotely located relative to the processor, and these remote memories may be connected to external devices through a network. Examples of the network include but are not limited to the Internet, intranets, local area networks, mobile communication networks, and its combination.

Fig. 2 shows an ambient light perception method for a lidar system according to one or more embodiments, the method includes:

S101: Transmit laser pulses to the detection area.

As the detection signal source, the laser pulse can be a laser pulse emitted separately for detecting ambient light, or it can be a laser pulse emitted by the lidar in actual detection work. In one or more embodiments, the laser of the lidar system emits a laser pulse to the detection area under the control of the controller, and the laser pulse forms a diffuse reflection echo on the surface of the detection area in the form of a laser beam and is received by the photodetector A light excitation signal occurs. For example, according to the work instructions issued by the controller of the laser radar system, the laser starts to work at a predetermined time, and emits a laser beam with parameters such as predetermined pulse width, repetition frequency, and energy.

S102: Detect the number of optical excitation signals generated by each pixel unit of the photodetector within a predetermined period of emitting laser pulses.

A photodetector is generally provided with a plurality of pixel units. In one example, the pixel unit is arranged as a single pixel on a photodetector, for example. In another example, the pixel unit is configured as two or more pixels on a photodetector, for example. In the method in FIG. 2 , for example, the collector acquires the photoexcitation signal of each pixel of the photodetector, and counts the number of photoexcitation signals generated by the plurality of pixels constituting the pixel unit within a predetermined period of time.

Fig. 3 shows a pixel schematic diagram of a specific photodetector applied according to one or more embodiments, the photodetector is, for example, a SPAD sensor, and the sensor is provided with a pixel array (20×10), including 20 pixels Unit 42, each pixel unit includes 10 pixels 41, when each pixel receives the photon signal of laser diffuse reflection echo or external ambient light, it is excited and discharged by the photon signal, and the output value is "1", if there is no is excited, no value is output or the output value is "0". As shown in the figure, within a predetermined period of time, 10 pixels in the pixel unit are lasered by an optical signal, and the collector collects the amount of laser light of each pixel in each time unit. Other pixel units are also detected in the same way to determine the total number of light excitation signals of a single pixel within a predetermined period of time.

S103: Determine the ambient light intensity of each pixel unit according to the number of detected light excitation signals.

In one or more embodiments, the comparator of the lidar system receives the total amount of optical excitation signal of each pixel unit and compares it with a preset light intensity threshold table to determine the detection area position corresponding to each pixel unit ambient light intensity level. The light intensity threshold table is preset with a plurality of thresholds, and each threshold has a preset number of light excitation signals to represent the corresponding ambient light intensity level.

For example, the light intensity threshold table presets N thresholds, and the preset photo-excitation numbers of each threshold are K1, K2, ..., Kn respectively, and the preset photo-excitation numbers may be specific values or ranges of values. By comparing the number of optical excitation signals of each pixel unit with the light intensity threshold table, determine the specific threshold it falls into, thereby determining the level of light intensity received by the pixel unit, where K1 is the weakest light intensity, and Kn is the lowest Strong light.

First, put the lidar in different scenarios, such as night, rainy day, cloudy day, cloudy day, sunny day, etc., and test it against the distance. The total excitation amount within the preset time will be measured and averaged to obtain a set of data. For example, the excitation amount measured at night is 1000, rainy days are 2000, cloudy days are 3000, cloudy days are 5000, and sunny days are 8000 , take this as the default value, set K1 to 2000, K2 to 3000, K3 to 5000, and K4 to 8000, and record them into the memory. In the actual test of the lidar, by comparing the The number of optical excitation signals is compared with the preset K value to interpret the environment measured by each pixel.

There is also a preset value method, which is set according to the illuminance of the environment. In the illuminance standard laboratory, different illuminance is set, and the illuminance is set to 500Lux, 10000Lux, 20000Lux, 100000Lux, respectively, for each pixel of the pixel unit of the laser radar. According to the actual demand, different intervals of illumination and different numbers of illumination levels can be set, so as to set the environmental threshold and threshold number of different intervals.

Fig. 4 shows another ambient light perception method for a lidar system according to one or more embodiments, the method comprising:

S201: Obtain the total amount of optical excitation signals generated by predetermined pixel units of the photodetector within a preset period of time when the laser emits laser pulses to the detection area.

The predetermined pixel unit is, for example, set as a single pixel on the photodetector, or includes two or more pixels on the photodetector.

The preset time period is composed of multiple time series, and each time series includes multiple time units. The total amount of the light excitation signal is obtained by recording and counting the output of the light excitation signal of the predetermined pixel unit of the photodetector in each time unit. In one example, there is a serial time interval between two consecutive time series.

In this step, after the laser is activated by the controller to emit laser pulses to the detection area, the laser pulses form diffuse reflection echoes on the surface of the detection area in the form of laser beams, and the echoes and other ambient light are received by the photodetector to generate light fire signal. At the same time, for example, a collector is used to monitor the light excitation signal of a predetermined pixel unit of the photodetector, and the number of light excitation signals of the predetermined pixel unit within a preset period of time is counted.

Fig. 5 illustrates a specific method for counting the number of optical excitation signals of a predetermined pixel unit within a preset period according to one or more embodiments:

First, the controller sends a pulse signal to the laser, the laser emits the first laser pulse to the test area, the TDC circuit starts timing, every other time unit T _unit , the light excitation signal of the predetermined pixel unit of the photodetector in the time unit The output situation is recorded, a total of M time units, a total of T _sum time is required, and the output results of the optical excitation signal of the M time units are stored in a register, for example.

After the connection, the laser emits the second laser pulse to the detection area, and the TDC circuit starts timing again. Every time unit T _unit , record the output of the light excitation signal of the predetermined pixel unit of the photodetector in the time unit, and the total For M time units, T _sum time is required in total, and the output results of the optical excitation signals of the M time units are stored in a register, for example.

Then, after the laser emits laser pulses N times, the number of optical excitation signals of each pixel of the predetermined pixel unit within a predetermined period of time N*M*T _unit is accumulated, which is recorded as the total amount of optical excitation signals K.

More specifically, the controller sends a pulse signal to the laser, the laser emits the first laser pulse to the test area, the TDC circuit starts timing, and the main frequency of the TDC circuit is 500MHz, that is, every other time unit 2ns The photoexcitation signal output of the predetermined pixel unit is recorded for a total of 1000 time units, which takes 2 μs in total, and the photoexcitation signal output results of 1000 time units are stored in a register, for example.

After connection, the laser emits the second laser pulse to the detection area, and the TDC circuit starts timing again, and records the output of the optical excitation signal of the predetermined pixel unit of the photodetector in the time unit every 2ns, a total of 1000 time unit, a total of 2 μs is required, and the output results of the optical excitation signal for 1000 time units are stored in a register, for example.

Repeat the previous steps until the laser emits 150 laser pulses, then accumulate the number of optical excitation signals of each pixel of the predetermined pixel unit within a predetermined period of 0.3 ms, and record it as the total amount of optical excitation signals K.

S202: Compare the total amount of light excitation signals with a light intensity threshold table to determine an ambient light intensity level.

The light intensity threshold table is preset with a plurality of thresholds, and each threshold has a preset number of light excitation signals to represent the corresponding ambient light intensity level. For example, the light intensity threshold table presets N thresholds, and the preset photo-excitation numbers of each threshold are K1, K2, ..., Kn respectively, and the preset photo-excitation numbers can be specific values or ranges of values . By comparing the total amount K of the optical excitation signal of the predetermined pixel unit within the predetermined period N*M*T _unit with the light intensity threshold table, determine the specific threshold it falls into, thereby determining the level of light intensity received by the predetermined pixel , where K1 is the weakest light intensity, and Kn is the strongest light intensity.

For example, the comparator of the lidar system receives the total amount of optical excitation signals of the predetermined pixel unit and compares it with a preset light intensity threshold table to determine the ambient light intensity level.

Fig. 6 shows yet another ambient light perception method for a lidar system according to one or more embodiments, the method comprising:

S301: Obtain the total amount of optical excitation signals generated by each pixel unit of the photodetector within a preset period of time during which the laser emits laser pulses to the detection area.

The photodetector of the laser system is provided with a plurality of pixel units, and the pixel unit can be provided as a single pixel, or as two or more pixels on the photodetector.

The preset time period is composed of multiple time series, and each time series includes multiple time units. The total amount of the light excitation signal is obtained by recording and counting the light excitation signal output of the photodetector pixel unit in each time unit. In one example, there is a serial time interval between two consecutive time series.

According to one or more embodiments, within a preset period of time when the laser emits laser pulses to the detection area, the laser pulses form diffuse reflection echoes on the surface of the detection area in the form of laser beams, and the echoes are detected by the photodetector along with other ambient light. A photoexcitation signal is generated upon receipt. The collector is used to monitor the light excitation signal of each pixel unit of the photodetector, and the number of light excitation signals of each pixel unit in the preset unit is counted to obtain the total amount of light excitation signal.

S302: Compare the total amount of the light excitation signal with the light intensity threshold table, and determine the ambient light intensity level of each pixel unit.

In one or more embodiments, the comparator of the lidar system receives the total amount of the light excitation signal of each pixel unit of the photodetector and compares it with a preset light intensity threshold table to determine the light intensity of each pixel unit. Ambient light intensity level. The light intensity threshold table is preset with a plurality of thresholds, and each threshold has a preset number of light excitation signals to represent the corresponding ambient light intensity level. For example, the light intensity threshold table presets N thresholds, and the preset photo-excitation numbers of each threshold are K1, K2, ..., Kn respectively, and the photo-excitation preset numbers can be specific values or ranges of values. By comparing the total amount of optical excitation signal of each pixel unit with the light intensity threshold table, determine the specific threshold that it falls into, so as to determine the level of light intensity received by the pixel, where K1 is the weakest light intensity, and Kn is the lowest Strong light.

In one or more embodiments, the total output value is determined by recording, storing, reading, and counting the output of the optical excitation signal of each pixel unit of the photodetection unit within a predetermined period of time, and each pixel unit The ambient light intensity is judged separately, which more accurately reflects the actual ambient light intensity of the monitoring area, and avoids determining the intensity of the entire ambient light by one pixel. Furthermore, the light intensity measured by each pixel will be adjusted in real time as the external ambient light intensity changes, which improves the timeliness and accuracy of the lidar's perception of ambient light. In addition, by setting different ambient light intensity levels, it can better meet the ambient light intensity in different scenes. In addition, the laser radar in the present invention collects ambient light data in the same method and data as the laser radar detection distance, and is the same set of data, without additional data collection work, which increases the laser radar test efficiency.

Those skilled in the art can understand that all or part of the steps in the method of the above-mentioned embodiments can be executed by instructing the relevant hardware through a program. etc.) or a processor to execute all or part of the steps of the methods described in the various embodiments of the present application. The storage medium includes: various media capable of storing program codes such as U disk, mobile hard disk, read-only memory, random access memory, magnetic disk or optical disk.

Claims

An ambient light perception method for a lidar system, the method comprising:

emit laser pulses to the detection area;

Detecting the number of optical excitation signals generated by each pixel unit of the photodetector during the predetermined period of emitting the laser pulse;

The ambient light intensity of each pixel unit is determined according to the number of detected light excitation signals.
The ambient light sensing method according to claim 1, wherein the pixel unit is a single pixel on the photodetector.
The ambient light sensing method according to claim 1, wherein the pixel unit comprises two or more pixels of a photodetector.
An ambient light perception method for a lidar system, the method comprising:

Obtaining the total amount of optical excitation signals generated by the predetermined pixel unit of the photodetector within a preset period of time during which the laser emits laser pulses to the detection area; and

Comparing the total amount of light excitation signals with the light intensity threshold table to determine the ambient light intensity level, wherein the light intensity threshold table includes a plurality of light intensity thresholds, each light intensity threshold has a preset number of light excitation signals and represents a corresponding ambient light intensity level.
The ambient light sensing method according to claim 4, wherein the acquisition of the total amount of optical excitation signals of the predetermined pixel unit comprises:

The preset time period is set to be composed of multiple time series, and each time series includes multiple time units;

The photoexcitation signal output of the predetermined pixel unit of the photodetector is recorded in each time unit, and the photoexcitation signals of all the time units of the time series are accumulated to obtain the total amount of the photoexcitation signal.
The ambient light perception method according to claim 5, characterized in that there is a sequence time interval between two consecutive time sequences.
The ambient light sensing method according to claim 5, wherein the predetermined pixel unit is a single pixel unit of a photodetector.
The ambient light sensing method according to claim 5, wherein the predetermined pixel unit is two or more pixel units of a photodetector.
The ambient light sensing method according to claim 4, wherein the photodetector is a single photon avalanche diode chip.
An ambient light perception method for a lidar system, the method comprising:

Obtaining the total amount of optical excitation signals generated by each pixel unit of the photodetector within a preset period of time during which the laser emits laser pulses to the detection area; and

comparing the total amount of the light excitation signal with the light intensity threshold table to determine the ambient light intensity level of each pixel unit, wherein the light intensity threshold table includes a plurality of light intensity thresholds, and each light intensity threshold has a preset light excitation Signal quantity and characterize the corresponding ambient light intensity level.
The ambient light sensing method according to claim 10, wherein the acquisition of the total amount of optical excitation signals of each pixel unit comprises:

The preset time period is set to be composed of multiple time series, and each time series includes multiple time units;

The optical excitation signal output of each pixel unit in each time unit is recorded and counted to obtain the total amount of optical excitation signal.
The ambient light perception method according to claim 11, characterized in that there is a sequence time interval between two consecutive time sequences.
The ambient light sensing method according to claim 10, wherein the photodetector is a single photon avalanche diode chip.
The ambient light sensing method according to claim 10, wherein the pixel unit is a single pixel of the photodetector.
The ambient light sensing method according to claim 10, wherein the pixel unit is two or more pixels of the photodetector.
A lidar system comprising:

a laser configured to emit laser pulses into the detection area;

a photodetector configured to generate a photoexcitation signal upon receipt of a photon signal;

a collector, which is configured to count the total amount of light excitation signals generated by each pixel unit of the photodetector within a preset period of time;

a comparator configured to receive the total amount of the light excitation signal and compare it with a light intensity threshold table to determine the ambient light intensity level, wherein the light intensity threshold table includes a plurality of thresholds, each threshold has a preset light intensity Excitation signal quantities and characterize corresponding ambient light intensity levels.
The laser radar system according to claim 16, wherein the collector is further configured as:

Recording the preset period of time, wherein the preset period of time is composed of multiple time series, and each time series includes multiple time units;

The optical excitation signal output of each pixel unit in each time unit is recorded and the total amount of optical excitation signal is obtained by statistics.
The lidar system according to claim 16, wherein the pixel unit of the photodetector is a single pixel of the photodetector.
The lidar system according to claim 16, wherein the pixel unit of the photodetector is two or more pixels of the photodetector.
An electronic device, comprising: at least one processor and a memory communicatively connected to the at least one processor, the memory stores instructions executable by the at least one processor, wherein the instructions are executed by the At least one processor is executed to perform the method of any one of claims 1-15.