Laser radar device and ranging adjustment method thereof

Abstract

The application provides a laser radar device and a ranging adjustment method thereof. The ranging adjustment method first acquires histogram data of ambient light, adjusts the detection efficiency of a laser receiving module according to the histogram data, realizes dynamic adjustment, then acquires light signals containing ambient light and echo signals and corresponding histogram data, compares the light signals, determines the histogram data of the current echo signals and distance information of a to-be-measured object, adjusts the detection efficiency of the laser receiving module, reduces the influence of ambient light in the laser ranging process, and improves ranging accuracy.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of laser radar, and particularly relates to a laser radar device and a ranging adjustment method thereof. BACKGROUND

[0002] With the development of artificial intelligence and unmanned driving, the requirements for the detection precision and detection distance of laser radars are also increasing.

[0003] The detection precision and detection distance of a laser radar device are not only affected by the properties of the object to be detected, but also easily affected by the ambient light.

[0004] For example, when there is strong sunlight, the laser receiving device of the laser receiving module, such as a photodetector avalanche diode, is prone to saturation. When a return signal is received in this environment, the return signal of the target object cannot be received due to the saturation and dead time of the photoreceiver device itself, the actual distance information cannot be accurately calculated, and the ranging accuracy of the laser radar is reduced. SUMMARY

[0005] The present application aims to provide a ranging adjustment method for a laser radar device, which aims to solve the problem that the traditional laser radar device is easily affected by ambient light, resulting in reduced ranging accuracy.

[0006] The first aspect of the embodiment of the present application provides a ranging adjustment method for a laser radar device, the laser radar device comprising a laser emitting module and a laser receiving module, the ranging adjustment method for the laser radar device comprising the following steps:

[0007] Turning off the laser emitting module and turning on the laser receiving module to obtain histogram data of ambient light;

[0008] Adjusting the detection efficiency of the laser receiving module according to the histogram data of the ambient light;

[0009] Turning on the laser emitting module and the laser receiving module to obtain histogram data of the current light signal;

[0010] Comparing the histogram data of the current light signal with the histogram data of the ambient light, and determining the histogram data of the return signal and the distance information of the object to be detected according to the ratio or the difference.

[0011] Optionally, the ranging adjustment method for the laser radar device further comprises:

[0012] Adjusting the detection efficiency of the laser receiving module according to the histogram data of the ambient light, and correspondingly adjusting the emission power and / or the number of laser emissions of the laser emitting module in a frame of scanning image; or

[0013] After the distance information of the object to be measured is determined, the histogram data of the echo signal is used to adjust the emission power and / or the number of laser emissions of the laser emission module in a frame of scanning image.

[0014] Optionally, the step of obtaining the histogram data of the ambient light specifically comprises:

[0015] The laser emission module is turned off and the laser receiving module is turned on to receive the current ambient light.

[0016] The ambient light received multiple times is converted into a plurality of pulse signals corresponding to the ambient light, and the histogram data of the ambient light is formed by superimposing the plurality of pulse signals.

[0017] Optionally, the step of converting the ambient light received multiple times into a plurality of pulse signals corresponding to the ambient light, and forming the histogram data of the ambient light by superimposing the plurality of pulse signals specifically comprises:

[0018] The plurality of pulse signals converted from the ambient light received multiple times are subjected to mean value processing, a plurality of pulse signals with equal amplitudes are generated, and the histogram data of the ambient light is formed by superimposing the plurality of pulse signals.

[0019] Optionally, the step of adjusting the detection efficiency of the laser receiving module according to the histogram data of the ambient light, and adjusting the emission power and / or the number of laser emissions of the laser emission module in a frame of scanning image specifically comprises:

[0020] When the histogram data of the ambient light is greater than a first preset threshold of histogram data, the detection efficiency of the laser receiving module is reduced, and the emission power and / or the number of laser emissions of the laser emission module in a frame of scanning image is increased.

[0021] When the histogram data of the ambient light is less than a first preset threshold of histogram data, the detection efficiency of the laser receiving module is increased, and the emission power and / or the number of laser emissions of the laser emission module in a frame of scanning image is reduced.

[0022] When the histogram data of the ambient light is within a first preset range of histogram data, the detection efficiency of the laser receiving module is adjusted to a constant preset detection efficiency, and the emission power of the laser emission module in a frame of scanning image is adjusted to a constant power and / or the number of laser emissions is adjusted to a constant number of emissions.

[0023] Optionally, the step of adjusting the emission power and / or the number of laser emissions of the laser emission module in a frame of scanning image according to the histogram data of the echo signal after the distance information of the object to be measured is determined specifically comprises:

[0024] decrease the emission power and / or the number of laser emissions of the laser emission module in a frame of scanning image when the histogram data of the echo signal is greater than a second preset threshold of histogram data;

[0025] increase the emission power and / or the number of laser emissions of the laser emission module in a frame of scanning image when the histogram data of the echo signal is less than a second preset threshold of histogram data;

[0026] adjust the emission power of the laser emission module in a frame of scanning image to be a constant power and / or the number of laser emissions to be a constant number of emissions when the histogram data of the echo signal is within a second preset range of histogram data.

[0027] A second aspect of the embodiment of the present application provides a laser radar device, comprising a laser emission module, a laser receiving module and a control circuit connected with the laser emission module and the laser receiving module respectively, the control circuit comprising a memory, a processor and a computer program stored in the memory and executable on the processor, the processor implementing the steps of the ranging adjustment method of the laser radar device as described above when executing the computer program.

[0028] Optionally, the laser emission module comprises:

[0029] a laser emission assembly;

[0030] a laser driving circuit connected with the control circuit and the laser emission assembly respectively, the laser driving circuit being correspondingly turned on or off and correspondingly adjusting the emission power and / or the number of laser emissions of the laser emission assembly in a frame of scanning image according to the control signal output by the control circuit;

[0031] the laser emission assembly comprising a plurality of lasers.

[0032] Optionally, the laser receiving module comprises:

[0033] a laser receiving assembly for converting a corresponding optical signal into an electric current signal;

[0034] a power supply circuit connected with the control circuit and the laser receiving assembly respectively, the power supply circuit being triggered to output a voltage signal of a corresponding size to the laser receiving assembly by the control signal of the control circuit to adjust the detection efficiency of the laser receiving assembly;

[0035] a signal processing circuit connected with the laser receiving assembly and the control circuit respectively, the signal processing circuit being used for converting the electric signal converted and output by the laser receiving assembly into corresponding histogram data and outputting the corresponding histogram data to the control circuit;

[0036] The laser receiving component includes a photoelectric converter.

[0037] Optionally, the photoelectric converter includes a photodetector avalanche diode.

[0038] The beneficial effects of the embodiments of the present invention compared with the prior art are as follows: The ranging adjustment method of the above-mentioned lidar device first acquires the histogram data of ambient light, and adjusts the detection efficiency of the laser receiving module according to the histogram data to achieve dynamic adjustment. Then, it acquires the light signal containing ambient light and echo signal and the corresponding histogram data, compares them, and determines the histogram data of the current echo signal and the distance information of the object to be measured. By adjusting the detection efficiency of the laser receiving module, the influence of ambient light during laser ranging is reduced, and the ranging accuracy is improved. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of a first structure of a lidar device provided in an embodiment of the present invention;

[0040] Figure 2 This is a schematic diagram of the first process of the ranging adjustment method for a lidar device provided in an embodiment of the present invention;

[0041] Figure 3 A histogram diagram of the ranging adjustment method of the lidar device provided in the embodiment of the present invention;

[0042] Figure 4 This is a schematic diagram of a second process for adjusting the ranging of a lidar device according to an embodiment of the present invention;

[0043] Figure 5 This is a schematic diagram of the third process of the ranging adjustment method of the lidar device provided in the embodiment of the present invention;

[0044] Figure 6 for Figure 2 The flowchart shows the specific steps of the ranging adjustment method of the lidar device shown in step S10.

[0045] Figure 7 for Figure 4 The flowchart shows the specific steps of the ranging adjustment method of the lidar device shown in step S50.

[0046] Figure 8 for Figure 6 The flowchart of step S60 of the ranging adjustment method of the lidar device shown is detailed.

[0047] Figure 9 A timing diagram illustrating the ranging adjustment method of a lidar device provided in an embodiment of the present invention;

[0048] Figure 10 A second structural schematic diagram of a laser radar device provided for an embodiment of the present application is shown in the figure;

[0049] Figure 11 A third structural schematic diagram of a laser radar device provided for an embodiment of the present application is shown in the figure;

[0050] Figure 12 A fourth structural schematic diagram of a laser radar device provided for an embodiment of the present application is shown in the figure. DETAILED DESCRIPTION

[0051] In order to make the technical problems to be solved by the present application, technical solutions and beneficial effects more clearly, the present application will be further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not used to limit the present application.

[0052] In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0053] A first aspect of an embodiment of the present application proposes a ranging adjustment method of a laser radar device 1, wherein, as shown in the figure, Figure 1 The laser radar device 1 includes a laser emission module 10 and a laser receiving module 20, the laser emission module 10 includes a laser emission assembly 11 and a corresponding driving circuit, the driving circuit is controlled to drive the laser emission assembly 11 to emit a laser signal, the laser receiving module 20 includes a corresponding laser receiving assembly 21 and a corresponding signal processing circuit 23, the laser receiving assembly 21 is used to receive an ambient light Light1 and / or a reflected echo signal Light2 of a to-be-measured object 2, and convert the ambient light Light1 and / or the reflected echo signal Light2 into a current signal to the signal processing circuit 23, and the signal processing circuit 23 converts the current signal into a corresponding pulse signal.

[0054] The ambient light Light1 includes sunlight, irradiation light emitted by a luminous object, etc., wherein, in order to ensure sufficient sensitivity, the laser radar device 1 adaptively changes the gain of the laser receiving assembly 21 in the laser receiving module 20 following the intensity of the light, which is easy to cause saturation or too small gain, resulting in too small converted electric signal, for example, when the detector is in a strong ambient light Light1 environment, the adaptive change is high gain, the detector is saturated, the echo signal Light2 of the target object cannot be received, the actual distance information cannot be accurately calculated, and the laser radar ranging accuracy is reduced.

[0055] To solve this problem, a ranging adjustment method of a laser radar device 1 is proposed, as shown in Figure 2 includes the following steps:

[0056] Step S10, turn off the laser emission module 10 and turn on the laser receiving module 20, obtain the histogram data of the ambient light Light1, the laser receiving module 20 works alone and receives the current ambient light Light1, and performs photoelectric conversion and signal processing, and converts and outputs the corresponding pulse signal, wherein the histogram data refers to the histogram formed by the pulse signals converted and output multiple times in time sequence, as shown in Figure 3 The pulse signals formed by multiple measurements form a histogram data of time sequence and amplitude variation, wherein the histogram data of the ambient light Light1 is a random noise waveform.

[0057] To obtain the histogram data of the ambient light Light1 while improving the detection accuracy, optionally, as shown in Figure 6 The step of obtaining the histogram data of the ambient light Light1 specifically includes:

[0058] Step S11, turn off the laser emission module 10 and turn on the laser receiving module 20, receive the current ambient light Light1;

[0059] Step S12, according to the histogram acquisition method, convert the ambient light Light1 received multiple times into corresponding multiple pulse signals, and superimpose to form the histogram data of the ambient light Light1.

[0060] At the same time, in order to improve the detection accuracy and avoid the error of the histogram data caused by the problem of missing reception and misreception, optionally, the step of converting the ambient light Light1 received multiple times into corresponding multiple pulse signals and superimposing to form the histogram data of the ambient light Light1 specifically includes:

[0061] The multiple pulse signals converted from the ambient light Light1 received multiple times are subjected to mean value processing, and multiple pulse signals with equal amplitudes are generated, and the histogram data of the ambient light Light1 is superimposed, the histogram data includes multiple pulse signals with equal amplitudes and according to the preset phase sequence change, multiple mean value processing is realized, and the accuracy of the histogram data of the ambient light Light1 is improved.

[0062] Step S20, adjust the detection efficiency of the laser receiving module 20 according to the histogram data of the ambient light Light1.

[0063] The photon detection efficiency refers to a ratio of a number of photons detected by the laser receiving assembly 21 (such as a silicon photomultiplier, a photodetector avalanche diode 211, etc.) to a number of incident photons, that is, an efficiency of the laser receiving assembly 21 in converting the optical signal into the electrical signal. The higher the photon detection efficiency, the stronger the sensitivity of the laser receiving module 20 to the photons; the lower the photon detection efficiency, the weaker the sensitivity of the laser receiving module 20 to the photons.

[0064] When the histogram data of the ambient light Light1 is acquired, the intensity of the current ambient light Light1 can be determined. In order to avoid excessive saturation caused by excessively large gain of the laser receiving assembly 21 or excessively small gain, the laser receiving assembly 21 converts the output electrical signal into a small value, the detection efficiency of the laser emitting module 10 is adjusted according to the intensity of the ambient light Light1, that is, when strong ambient light Light1 is detected, the detection efficiency of the laser receiving assembly 21 is reduced, the sensitivity of the laser receiving assembly 21 is reduced, and excessive saturation caused by excessively large gain of the laser receiving assembly 21 is avoided. At the same time, when weak ambient light Light1 is detected, the detection efficiency of the laser receiving assembly 21 is increased, the sensitivity and gain of the laser receiving assembly 21 are increased, and thus the laser receiving assembly 21 can reliably receive the current ambient light Light1 and the echo signal Light2.

[0065] The detection efficiency of the laser receiving assembly 21 is related to the working voltage thereof, and thus the working voltage of the laser receiving assembly 21 is adjusted to adjust the detection efficiency thereof.

[0066] In step S30, the laser emitting module 10 and the laser receiving module 20 are turned on, and the histogram data of the current optical signal is acquired.

[0067] In step S40, the histogram data of the current optical signal is compared with the histogram data of the ambient light Light1, and the histogram data of the echo signal Light2 and the distance information of the object 2 are determined according to the ratio or the difference.

[0068] When the detection efficiency of the laser receiving module 20 is adjusted to the corresponding value, the lidar device 1 starts the ranging function and simultaneously turns on the laser emitting module 10 and the laser receiving module 20. It acquires ambient light Light1 and the reflected echo signal Light2, and obtains the histogram data of the total optical signal through multiple measurements. At the same time, in order to obtain the histogram data of the echo signal Light2, the histogram data of the current optical signal is further compared with the initially acquired histogram data of ambient light Light1, for example, by division or subtraction. The histogram data of the echo signal Light2 is determined according to the ratio obtained by comparison, i.e., the signal-to-noise ratio, or the histogram data of the echo signal Light2 is determined directly according to the difference. Thus, the amplitude and reception time of the echo signal Light2 are obtained, and the distance information of the object under test 2 is determined according to the amplitude and reception time of the echo signal Light2.

[0069] Among them, since the ranging performance of lidar device 1 changes when the detection efficiency changes, in order to simultaneously consider ranging capability, such as Figure 4 and Figure 5 As shown, the ranging adjustment method of lidar device 1 further includes:

[0070] The detection efficiency of the laser receiving module 20 is adjusted according to the histogram data of ambient light, and the emission power and / or number of laser emissions of the laser emitting module 10 in a frame of scanned image are adjusted accordingly.

[0071] Alternatively, after determining the distance information of the object to be measured, the emission power and / or number of laser emissions of the laser emission module 10 in a frame of scanned image can be adjusted according to the histogram data of the echo signal Light2.

[0072] In this embodiment, once the detection efficiency to be adjusted is determined, the emission power and / or the number of laser emissions of the laser emission module 10 in a frame of scanned image can be adjusted accordingly, or ranging can be performed with the adjusted detection efficiency. Then, based on the ranging information, the emission power and / or the number of laser emissions of the laser emission module 10 in the next frame can be adjusted to improve the ranging capability of the current frame of scanned image or the next frame of scanned image. Specifically, by increasing the number of laser emissions in a frame of scanned image, i.e., increasing the number of superpositions of histogram data, the signal-to-noise ratio of the signal can be improved, thereby enhancing the ranging capability. By increasing the emission power, the intensity of the echo signal Light2 can be increased, thereby enhancing the ranging capability. One of the two methods can be selected or adjusted according to the timing sequence.

[0073] Optionally, such as Figure 7 As shown, when adjusting the detection efficiency, the emission power of the laser emission module 10, and / or the number of laser emissions in a single frame of a scanned image, the specific steps include:

[0074] Step S51, when the histogram data of the ambient light is greater than the first preset threshold of the histogram data, the detection efficiency of the laser receiving module 20 is reduced, and the emission power and / or the laser emission times of the laser emission module 10 in a frame of scanning image are increased;

[0075] Step S52, when the histogram data of the ambient light is less than the first preset threshold of the histogram data, the detection efficiency of the laser receiving module 20 is increased, and the emission power and / or the laser emission times of the laser emission module 10 in a frame of scanning image are reduced;

[0076] Step S53, when the histogram data of the ambient light is within the first preset range of the histogram data, the detection efficiency of the laser receiving module 20 is adjusted to a constant preset detection efficiency, and the emission power of the laser emission module 10 in a frame of scanning image is adjusted to a constant power and / or the laser emission times is adjusted to a constant emission times.

[0077] The set value of the emission power and the set value of the laser emission times can be data simulated in advance according to design requirements, or data calibrated according to design requirements, which is not limited in the application.

[0078] In the embodiment, the first preset threshold of the histogram data corresponds to the preset detection efficiency of the laser receiving assembly 21. When the histogram data of the ambient light Light1 exceeds the first preset threshold of the histogram data, it indicates that the current ambient light Light1 is too strong, which is easy to cause the laser receiving assembly 21 to be saturated. At this time, the detection efficiency of the laser receiving assembly 21 of the laser receiving module 20 is reduced, and at the same time, in order to avoid the decrease of the ranging ability caused by the decrease of the detection efficiency, the emission power and / or the laser emission times of the laser emission module 10 in a frame of scanning image is increased to improve the ranging ability.

[0079] When the histogram data of the ambient light Light1 is less than the first preset threshold of the histogram data, it indicates that the current ambient light Light1 is weak, which is easy to cause the gain of the laser receiving assembly 21 to be too small. At this time, the detection efficiency of the laser receiving assembly 21 of the laser receiving module 20 is increased, and at the same time, in order to match the change of the detection efficiency, avoid the decrease of the ranging ability caused by the too large power or the too high laser emission times in a frame of scanning image, the emission power and / or the laser emission times of the laser emission module 10 in a frame of scanning image is reduced to improve the ranging ability.

[0080] Meanwhile, when the histogram data of the ambient light Light1 is detected to be within a first preset range of the histogram data, it indicates that the current is normal ambient light Light1, at this time, the detection efficiency of the laser receiving assembly 21 of the laser receiving module 20 is controlled to be a constant preset detection efficiency, and in order to match the change of the detection efficiency, avoid the power being too large or too small or the number of laser emissions in a frame of scanning image being too high or too low, which leads to the decrease of the ranging capability, the emission power and / or the number of laser emissions of the laser emission module 10 in a frame of scanning image is adjusted to a constant preset value, thereby improving the ranging capability.

[0081] Or as Figure 8 indicated, after determining the distance information of the object to be measured, the step of adjusting the emission power and / or the number of laser emissions of the laser emission module 10 in a frame of scanning image according to the histogram data of the echo signal Light2 specifically includes:

[0082] Step S61, when the histogram data of the echo signal Light2 is greater than a second preset threshold of the histogram data, the emission power and / or the number of laser emissions of the laser emission module 10 in a frame of scanning image is reduced;

[0083] Step S62, when the histogram data of the echo signal Light2 is less than the second preset threshold of the histogram data, the emission power and / or the number of laser emissions of the laser emission module 10 in a frame of scanning image is increased;

[0084] Step S63, when the histogram data of the echo signal Light2 is within a second preset range of the histogram data, the emission power of the laser emission module 10 is adjusted to be a constant power and / or the number of laser emissions in a frame of scanning image is adjusted to be a constant emission number.

[0085] In the embodiment, when the histogram data of the echo signal Light2 obtained in the last frame is detected to be greater than the second preset threshold of the histogram data, it indicates that in the last frame of scanning image, the detection efficiency of the adjusted laser receiving module 20 is too high, which finally leads to the increase of the determined histogram data of the echo signal Light2 and the decrease of the accuracy of the ranging information, at this time, in order to obtain accurate histogram data of the echo signal Light2 and improve the ranging capability of the next frame of scanning image, the number of laser emissions and / or the emission power in the next frame of scanning image is reduced, so that the amplitude of the echo signal Light2 in the next frame of scanning image is within a preset range.

[0086] Similarly, when it is detected that the histogram data of the echo signal Light2 obtained in the last frame is less than the second preset threshold of the histogram data, it indicates that the detection efficiency of the adjusted laser receiving module 20 in the last frame of scanning image is too low, which finally leads to the decrease of the determined histogram data of the echo signal Light2 and the decrease of the accuracy of the ranging information. At this time, in order to obtain accurate histogram data of the echo signal Light2 and improve the ranging capability of the next frame of scanning image, the laser emission times and / or emission power in the next frame of scanning image are increased, so that the amplitude of the echo signal Light2 in the next frame of scanning image is within the preset range.

[0087] When it is detected that the histogram data of the echo signal Light2 obtained in the last frame is within the second preset range of the histogram data, it indicates that the detection efficiency of the adjusted laser receiving module 20 in the last frame of scanning image is within a reasonable range. At this time, the laser emission times and / or emission power in the next frame of scanning image are maintained at a constant power or a constant emission times, so as to improve the ranging capability.

[0088] The first preset threshold and the second preset threshold of the histogram data can be set according to the ambient light and the corresponding histogram data of the echo signal Light2, and are obtained through self-learning or multiple detections. The specific size is not limited.

[0089] The beneficial effects of the embodiment of the present application compared with the prior art are as follows: The ranging adjustment method of the laser radar device 1 first obtains the histogram data of the ambient light Light1, adjusts the detection efficiency of the laser receiving module 20 according to the histogram data, realizes dynamic adjustment, then obtains the light signal containing the ambient light Light1 and the echo signal Light2 and the corresponding histogram data, and compares them to determine the histogram data of the current echo signal Light2 and the distance information of the object 2 to be measured. By adjusting the detection efficiency of the laser receiving module 20, the influence of the ambient light Light1 in the laser ranging process is reduced, and the ranging accuracy is improved.

[0090] Optionally, the ranging adjustment method of the laser radar device 1 further comprises:

[0091] The above steps of the ranging adjustment method of the laser radar device 1 are repeated at a preset time interval, as shown in FIG. 6, that is, the histogram acquisition of the ambient light Light1, the adjustment of the detection efficiency of the laser receiving module 20, the adjustment of the emission power and / or laser emission times of the laser emission module 10 in a frame of scanning image, and the determination of the amplitude of the echo signal Light2, the receiving time and the distance information of the object 2 to be measured in each time period according to the current light signal are performed at a preset frequency. Figure 9

[0092] ​The preset time interval can be set according to requirements, for example, when the ambient light Light1 is sunlight, the time interval can be set according to weather, season, morning or evening time, etc.

[0093] Alternatively, an adaptive adjustment method is adopted, according to the change of the ambient light Light1, the acquisition of the histogram of the ambient light Light1, the adjustment of the detection efficiency of the laser receiving module 20, the adjustment of the emission power and / or the laser emission times of the laser emission module 10 in a frame of scanning image, and the determination of the amplitude of the echo signal Light2, the receiving time, and the frequency of the distance information of the object 2 in each time period according to the current light signal are automatically changed, that is, when the ratio or the difference is detected to be out of the preset value interval, the above steps of the ranging adjustment method of the laser radar device 1 are repeated.

[0094] For example, when the laser radar device 1 is installed on a car, when the car enters a tunnel from a tunnel entrance, the normal ambient light Light1 or the strong ambient light Light1 changes to the weak ambient light Light1, at this time, the histogram data of the ambient light Light1 in the total light signal becomes small, causing the histogram data of the total light signal to become small, at this time, the ratio or the difference becomes small, the histogram data of the obtained echo signal Light2 becomes small, resulting in a decrease in ranging accuracy, or when the car exits the tunnel from the tunnel entrance, the weak ambient light Light1 changes to the normal ambient light Light1 or the strong ambient light Light1, at this time, the histogram data of the ambient light Light1 in the total light signal becomes large, causing the histogram data of the total light signal to become large, at this time, the ratio or the difference becomes large, the histogram data of the obtained echo signal Light2 becomes large, resulting in ranging error, therefore, when the ratio or the difference is detected to change to the outside of the preset value interval, the next ranging adjustment is actively performed, and the ranging accuracy is improved.

[0095] It should be understood that the size of the serial number of each step in the above embodiment does not mean the order of execution, the execution order of each process should be determined according to its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present application.

[0096] The second aspect of the embodiment of the present application proposes a laser radar device 1, as shown in the figure, the laser radar device 1 comprises a laser emission module 10, a laser receiving module 20, and a control circuit 30 connected with the laser emission module 10 and the laser receiving module 20 respectively, the control circuit 30 comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the steps of the ranging adjustment method of the laser radar device 1 as above when executing the computer program. Figure 10

[0097] ​In this embodiment, the control circuit 30 adjusts the ranging according to the preset time interval or the calculated ratio or difference. Each time the ranging is adjusted, the laser emitting module 10 is first turned off and the laser receiving module 20 is turned on, and the pulse signals converted multiple times are obtained through the laser receiving module 20, and the multiple pulse signals are converted into the histogram data of the ambient light Light1 according to the time sequence and amplitude, and the detection efficiency of the laser receiving module 20 is adjusted according to the histogram data of the ambient light Light1, and the emission power and / or the number of laser emissions of the laser emitting module 10 in a frame of scanning image are adjusted, or the emission power and / or the number of laser emissions of the laser emitting module 10 in the next frame of scanning image are adjusted according to the determined histogram data of the echo signal Light2 after the ranging of the last frame ends.

[0098] When the histogram data of the ambient light Light1 is obtained, the intensity of the current ambient light Light1 can be determined. In order to prevent the laser receiving assembly 21 from being excessively saturated due to excessive gain or the converted output electrical signal being too small due to insufficient gain, the control circuit 30 adjusts the detection efficiency of the laser emitting module 10 according to the intensity of the ambient light Light1, that is, when a strong ambient light Light1 is detected, the detection efficiency of the laser receiving assembly 21 is reduced, the sensitivity of the laser receiving assembly 21 is reduced, and the gain of the laser receiving assembly 21 is prevented from being excessively large to cause excessive saturation. At the same time, when a weak ambient light Light1 is detected, the detection efficiency of the laser receiving assembly 21 is increased, the sensitivity and gain of the laser receiving assembly 21 are increased, so that the laser receiving assembly 21 can reliably receive the current ambient light Light1 and the echo signal Light2.

[0099] At the same time, when the detection efficiency changes, the ranging performance of the laser radar device 1 changes. In order to take into account the ranging ability, the control circuit 30 adjusts the emission power and / or the number of laser emissions of the laser emitting module 10 in a frame of scanning image, increases the number of laser emissions in a frame of scanning image, that is, increases the number of superimpositions of the histogram data, so as to improve the signal-to-noise ratio of the signal, improve the ranging ability, and increase the emission power to improve the intensity of the echo signal Light2, so as to improve the ranging ability. One of the two methods or the two methods are adjusted according to the time sequence.

[0100] Or after determining the distance information of the object 2, the emission power and / or the laser emission times of the laser emission module 10 in a frame of scanning image are adjusted according to the histogram data of the echo signal Light2, the signal-to-noise ratio of the signal is improved by increasing the laser emission times in a frame of scanning image, that is, the superposition times of the histogram data, and the ranging capability is improved, the emission power is increased to improve the intensity of the echo signal Light2, and the ranging capability is improved. One of the two methods or the corresponding adjustment according to the time sequence is selected.

[0101] As shown in Figure 11 Optionally, the laser emission module 10 comprises:

[0102] a laser emission assembly 11;

[0103] a laser drive circuit 12 connected with the control circuit 30 and the laser emission assembly 11, the laser drive circuit 12 is opened or closed according to the control signal output by the control circuit 30, and the emission power and / or the laser emission times of the laser emission assembly 11 in a frame of scanning image are adjusted;

[0104] The laser emission assembly 11 comprises a plurality of lasers.

[0105] In this embodiment, when the control circuit 30 obtains the histogram data of the ambient light Light1, the laser drive circuit 12 is controlled to be closed, and then the detection efficiency of the laser receiving module 20 is adjusted, the emission power and / or the laser emission times of the laser drive circuit 12 in a frame of scanning image are adjusted, and after the emission power and / or the laser emission times in a frame of scanning image are adjusted, the control circuit 30 controls the laser drive circuit 12 to be opened and works, and drives the laser to work according to the adjusted emission power and / or the laser emission times.

[0106] Or after adjusting the detection efficiency of the laser receiving module 20, the control circuit 30 controls the laser drive circuit 12 to be opened and works, and drives the laser receiving module 20 to work according to the adjusted detection efficiency, and then adjusts the emission power and / or the laser emission times of the laser in the next frame of scanning image according to the determined histogram data of the echo signal Light2.

[0107] Please continue to refer to Figure 11 Optionally, the laser receiving module 20 comprises:

[0108] a laser receiving assembly 21, the laser receiving assembly 21 is used for converting the corresponding optical signal into a current signal;

[0109] A power supply circuit 22 connected with the control circuit 30 and the laser receiving assembly 21 respectively, the power supply circuit 22 is triggered to output a voltage signal of corresponding size to the laser receiving assembly 21 by the control signal of the control circuit 30, so as to adjust the detection efficiency of the laser receiving assembly 21;

[0110] A signal processing circuit 23 connected with the laser receiving assembly 21 and the control circuit 30 respectively, the signal processing circuit 23 is used for converting the electrical signal converted and output by the laser receiving assembly 21 into corresponding histogram data, and outputting the corresponding histogram data to the control circuit 30;

[0111] The laser receiving assembly 21 comprises a photoelectric converter.

[0112] When the control circuit 30 performs histogram data acquisition of the ambient light Light1, the control circuit 30 controls the laser receiving assembly 21, the processing circuit and the power supply circuit 22 to be turned on, the laser receiving assembly 21 realizes conversion of the optical signal into the current signal, the signal processing circuit 23 performs conversion of the current signal into the voltage signal, and outputs a plurality of pulse signals to the control circuit 30, the control circuit 30 determines the histogram data of the current ambient light Light1, adjusts the output voltage of the power supply circuit 22, and further adjusts the detection efficiency of the photoelectric converter, wherein the detection efficiency is in a positive proportional relationship with the output voltage, that is, the higher the output voltage, the higher the detection efficiency, and the lower the output voltage, the lower the detection efficiency.

[0113] Meanwhile, when receiving the total optical signal, the photoelectric converter and the signal processing circuit 23 sequentially perform conversion of the optical signal into the current signal and conversion of the current signal into the voltage signal, and output a plurality of pulse signals to the control circuit 30, the control circuit 30 determines the histogram data of the total optical signal and determines the histogram data, amplitude and receiving time of the echo signal Light2, and further realizes the ranging purpose of the measured object 2.

[0114] The photoelectric converter can be a silicon photomultiplier, a photoelectric avalanche diode 211 or the like, and optionally, as shown in Figure 12 The photoelectric converter comprises a photoelectric avalanche diode 211, the photoelectric avalanche diode 211 follows the adaptive gain change of the intensity of the light, the control circuit 30 adjusts the working voltage of the photoelectric avalanche diode 211 according to the acquired histogram data of the ambient light Light1, and further adjusts the detection efficiency of the photoelectric avalanche diode 211, and improves the anti-strong light capability and anti-interference capability of the laser radar device 1.

[0115] Optionally, as shown in Figure 12 The signal processing circuit 23 comprises:

[0116] A transconductance amplifier 231 is configured to convert the current signal into an analog echo signal Light2 of the voltage type;

[0117] A TDC detection circuit 232 is configured to collect the analog echo signal Light2 and output a plurality of pulse signals to the control circuit 30.

[0118] The transconductance sensor is connected to the photodetection avalanche diode 211 and converts the current signal output by the photodetection avalanche diode 211 into a voltage signal. The voltage signal is collected by the TDC detection circuit 232 and converted into a plurality of pulse signals output to the control circuit 30. The control circuit 30 obtains corresponding histogram data from the plurality of pulse signals, and further determines the histogram data, amplitude, and reception time of the echo signal Light2, thereby achieving the purpose of measuring the distance of the object 2.

[0119] The above-described embodiments are only used to illustrate the technical solutions of the present application, and not to limit them. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can modify the technical solutions described in the foregoing embodiments, or make equivalent replacements to some technical features. These modifications or replacements do not change the essence of the corresponding technical solutions, and are within the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A method of range adjustment of a laser radar device, the laser radar device comprising a laser emission module and a laser reception module, the laser reception module comprising corresponding laser reception components and corresponding signal processing circuitry, characterized in that, The ranging adjustment method of the laser radar device comprises the following steps: The laser emission module is closed and the laser receiving module is opened to obtain histogram data of ambient light; The detection efficiency of the laser receiving module is adjusted according to the histogram data of ambient light, wherein the detection efficiency of the laser receiving assembly is related to the working voltage thereof, the detection efficiency of the laser receiving assembly is adjusted by adjusting the working voltage thereof, and the size of the detection efficiency is negatively correlated with the size of the histogram data of ambient light; The laser emission module and the laser receiving module are opened to obtain histogram data of current light signals; The histogram data of current light signals is compared with the histogram data of ambient light, and the histogram data of echo signals and distance information of the object to be measured are determined according to the ratio or difference; The step of obtaining histogram data of ambient light comprises the following steps: The laser emission module is closed and the laser receiving module is opened to receive current ambient light; The ambient light received multiple times is converted into corresponding multiple pulse signals, and the histogram data of ambient light is formed by superposition; The ranging adjustment method of the laser radar device further comprises: After the distance information of the object to be measured is determined, the emission power and / or the number of laser emissions of the laser emission module in the next frame of scanning image are adjusted according to the histogram data of echo signals.

2. The method of range adjustment of a lidar device according to claim 1, wherein, The ranging adjustment method of the laser radar device further comprises: The detection efficiency of the laser receiving module is adjusted according to the histogram data of ambient light, and the emission power and / or the number of laser emissions of the laser emission module in a frame of scanning image are adjusted correspondingly.

3. The method of range adjustment of a lidar device according to claim 1, wherein, The step of converting the ambient light received multiple times into corresponding multiple pulse signals and superimposing to form the histogram data of ambient light comprises the following steps: The multiple pulse signals converted from the ambient light received multiple times are subjected to mean value processing, multiple pulse signals with equal amplitudes are generated, and the histogram data of ambient light is formed by superposition.

4. The method of range adjustment of a lidar device according to claim 2, wherein, The step of adjusting the detection efficiency of the laser receiving module according to the histogram data of ambient light and adjusting the emission power and / or the number of laser emissions of the laser emission module in a frame of scanning image comprises the following steps: When the histogram data of ambient light is greater than a first preset threshold of histogram data, the detection efficiency of the laser receiving module is reduced, and the emission power and / or the number of laser emissions of the laser emission module in a frame of scanning image is increased; When the histogram data of ambient light is less than a first preset threshold of histogram data, the detection efficiency of the laser receiving module is increased, and the emission power and / or the number of laser emissions of the laser emission module in a frame of scanning image is reduced; When the histogram data of ambient light is within a first preset range of histogram data, the detection efficiency of the laser receiving module is adjusted to a constant preset detection efficiency, and the emission power of the laser emission module in a frame of scanning image is adjusted to a constant power and / or the number of laser emissions is adjusted to a constant number of emissions.

5. The method of range adjustment of a lidar device according to claim 2, wherein, The step of adjusting the emission power and / or the number of laser emissions of the laser emission module in a frame of scanning image according to the histogram data of the echo signal after determining the distance information of the object specifically comprises: When the histogram data of the echo signal is greater than the second preset threshold of the histogram data, the emission power and / or the number of laser emissions of the laser emission module in a frame of scanning image is reduced; When the histogram data of the echo signal is less than the second preset threshold of the histogram data, the emission power and / or the number of laser emissions of the laser emission module in a frame of scanning image is increased; When the histogram data of the echo signal is within the second preset range of the histogram data, the emission power of the laser emission module in a frame of scanning image is adjusted to a constant power and / or the number of laser emissions is adjusted to a constant number of emissions.

6. A lidar device, comprising: The laser radar device comprises a laser emission module, a laser receiving module, and a control circuit connected with the laser emission module and the laser receiving module respectively, the control circuit comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the steps of the ranging adjustment method of the laser radar device according to any one of claims 1 to 5 when executing the computer program.

7. The lidar device of claim 6, wherein, The laser emission module comprises: a laser emission assembly; a laser driving circuit connected with the control circuit and the laser emission assembly respectively, the laser driving circuit is opened or closed according to the control signal output by the control circuit, and the emission power and / or the number of laser emissions of the laser emission assembly in a frame of scanning image is adjusted correspondingly; The laser emission assembly comprises a plurality of lasers.

8. The lidar device of claim 6, wherein, The laser receiving module comprises: a laser receiving assembly for converting the corresponding optical signal into an electric current signal; a power supply circuit connected with the control circuit and the laser receiving assembly respectively, the power supply circuit is triggered to output a voltage signal of a corresponding size to the laser receiving assembly according to the control signal of the control circuit, so as to adjust the detection efficiency of the laser receiving assembly; a signal processing circuit connected with the laser receiving assembly and the control circuit respectively, the signal processing circuit is used for converting the electric signal converted and output by the laser receiving assembly into corresponding histogram data, and outputting the corresponding histogram data to the control circuit; The photoelectric converter comprises a photoelectric detection avalanche diode.

9. The lidar device of claim 8, wherein, The photoelectric converter comprises a photoelectric detection avalanche diode.

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