Laser radar equipment and distance measurement adjusting method thereof

Abstract

The invention provides a laser radar device and a ranging adjustment method thereof, and the method comprises the steps: firstly obtaining the histogram data of ambient light, adjusting the detection efficiency of a laser receiving module according to the histogram data, achieving the dynamic adjustment, then obtaining an optical signal containing the ambient light and an echo signal, and the corresponding histogram data, and adjusting the detection efficiency of the laser receiving module according to the histogram data. And the histogram data of the current echo signal and the distance information of the to-be-measured object are determined through comparison, and the influence of ambient light in the laser ranging process is reduced by adjusting the detection efficiency of the laser receiving module, so that the ranging accuracy is improved.

Description

[0001] This application is a divisional application. The original application has the application number 202210467360.7 and the filing date is April 29, 2022. The entire contents of the original application are incorporated herein by reference. Technical Field

[0002] This invention belongs to the field of lidar technology, and particularly relates to a lidar device and its ranging adjustment method. Background Technology

[0003] With the increasing development of artificial intelligence and autonomous driving, the requirements for the detection accuracy and detection range of lidar are also increasing.

[0004] The detection accuracy and detection range of lidar equipment are not only affected by the properties of the object being measured, but are also easily affected by the ambient light.

[0005] For example, when there is strong sunlight, the laser receiving device of the laser receiving module, such as the photodetector avalanche diode, is prone to saturation. When the echo signal is received in this environment, due to the saturation and dead time of the photodetector itself, it is unable to receive the echo signal of the target object, and cannot accurately calculate the actual distance information, resulting in a decrease in the ranging accuracy of the lidar. Summary of the Invention

[0006] The purpose of this invention is to provide a ranging adjustment method for lidar equipment, which aims to solve the problem that traditional lidar equipment is easily affected by ambient light, resulting in a decrease in ranging accuracy.

[0007] A first aspect of this invention provides a ranging adjustment method for a lidar device, the lidar device including a laser emitting module and a laser receiving module, the ranging adjustment method comprising the following steps: Turn off the laser emitting module and turn on the laser receiving module to obtain histogram data of ambient light; Adjust the detection efficiency of the laser receiving module based on the histogram data of ambient light; Turn on the laser emitting module and the laser receiving module to obtain the histogram data of the current optical signal; The histogram data of the current optical signal is compared with the histogram data of the ambient light, and the histogram data of the echo signal and the distance information of the object under test are determined according to the ratio or the difference.

[0008] Optionally, the ranging adjustment method of the lidar device further includes: Adjust the detection efficiency of the laser receiving module based on the histogram data of ambient light, and correspondingly adjust the emission power and / or number of laser emissions of the laser emitting module in one frame of scanned image; or After determining the distance information of the object to be measured, the emission power and / or the number of laser emissions in a frame of scanned image are adjusted according to the histogram data of the echo signal.

[0009] Optionally, the step of acquiring the histogram data of ambient light specifically includes: Turn off the laser emitting module and turn on the laser receiving module to receive the current ambient light; The received ambient light signals are converted into multiple corresponding pulse signals and superimposed to form histogram data of the ambient light.

[0010] Optionally, the step of converting multiple received ambient light signals into corresponding multiple pulse signals and superimposing them to form ambient light histogram data specifically includes: The multiple pulse signals from the received ambient light conversion are averaged to generate multiple pulse signals with equal amplitude, which are then superimposed to form histogram data of ambient light.

[0011] Optionally, the steps of adjusting the detection efficiency of the laser receiving module based on the histogram data of ambient light, and adjusting the emission power and / or the number of laser emissions of the laser emitting module in a frame of scanned image specifically include: When the histogram data of the ambient light is greater than a first preset threshold of the 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 emitting module in a frame of scanned image is increased. When the histogram data of the ambient light is less than a first preset threshold of the histogram data, the detection efficiency of the laser receiving module is improved, and the emission power and / or the number of laser emissions of the laser emitting module in a frame of scanned image is reduced. When the histogram data of the ambient light is within a first preset range of the 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 emitting module in a frame of scanned image is adjusted to a constant power and / or the number of laser emissions is adjusted to a constant number of emissions.

[0012] Optionally, the step of adjusting the emission power and / or the number of laser emissions of the laser emission module in a frame of scanned image according to the histogram data of the echo signal after determining the distance information of the object to be measured specifically includes: 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 scanned image are 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 scanned image are 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 scanned image is adjusted to a constant power and / or the number of laser emission times is adjusted to a constant number of emission times.

[0013] A second aspect of the present invention provides a lidar device, including a laser emitting module, a laser receiving module, and a control circuit connected to the laser emitting module and the laser receiving module respectively. The control circuit includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the ranging adjustment method of the lidar device as described above.

[0014] Optionally, the laser emitting module includes: Laser emitting components; A laser driving circuit is connected to the control circuit and the laser emitting component respectively. The laser driving circuit turns on or off according to the control signal output by the control circuit, and adjusts the emission power and / or the number of laser emissions of the laser emitting component in a frame of scanned image accordingly. The laser emitting assembly includes multiple lasers.

[0015] Optionally, the laser receiving module includes: A laser receiving component, wherein the laser receiving component is used to convert a corresponding optical signal into a current signal; A power supply circuit is connected to the control circuit and the laser receiving component respectively. The power supply circuit is triggered by the control signal of the control circuit to output a voltage signal of corresponding magnitude to the laser receiving component, so as to adjust the detection efficiency of the laser receiving component. A signal processing circuit is connected to the laser receiving component and the control circuit respectively. The signal processing circuit is used to convert the electrical signal output by the laser receiving component into corresponding histogram data and output the corresponding histogram data to the control circuit. The laser receiving component includes a photoelectric converter.

[0016] Optionally, the photoelectric converter includes a photodetector avalanche diode.

[0017] 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

[0018] Figure 1 This is a schematic diagram of a first structure of a lidar device provided in an embodiment of the present invention; 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; Figure 3 A histogram diagram of the ranging adjustment method of the lidar device provided in the embodiment of the present invention; 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; 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; Figure 6 for Figure 2 The flowchart shows the specific steps of the ranging adjustment method of the lidar device shown in step S10. Figure 7 for Figure 4 The flowchart shows the specific steps of the ranging adjustment method of the lidar device shown in step S50. Figure 8 for Figure 5 The flowchart of step S60 of the ranging adjustment method of the lidar device shown is detailed. Figure 9 A timing diagram illustrating the ranging adjustment method of a lidar device provided in an embodiment of the present invention; Figure 10 This is a schematic diagram of a second structure of a lidar device provided in an embodiment of the present invention; Figure 11 This is a schematic diagram of a third structure of a lidar device provided in an embodiment of the present invention; Figure 12 This is a schematic diagram of a fourth structure of a lidar device provided in an embodiment of the present invention. Detailed Implementation

[0019] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0020] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0021] A first aspect of this invention provides a ranging adjustment method for a lidar device 1, wherein, as... Figure 1 As shown, the lidar device 1 includes a laser emitting module 10 and a laser receiving module 20. The laser emitting module 10 includes a laser emitting component 11 and a corresponding driving circuit. The driving circuit controls the laser emitting component 11 to emit laser signals. The laser receiving module 20 includes a corresponding laser receiving component 21 and a corresponding signal processing circuit 23. The laser receiving component 21 is used to receive the echo signal Light2 reflected by the ambient light Light1 and / or the object under test 2, and convert it into a current signal to the signal processing circuit 23. The signal processing circuit 23 converts the current signal into a corresponding pulse signal.

[0022] Ambient light Light1 includes sunlight, illumination light emitted by luminous objects, etc. In order to ensure sufficient sensitivity, the laser receiving component 21 in the laser receiving module 20 adaptively changes its gain according to the intensity of the light. However, this can easily lead to saturation or insufficient gain, resulting in a small converted electrical signal. For example, when the detector is in a strong ambient light Light1 environment, it adaptively changes to high gain, causing the detector to saturate and fail to receive the echo signal Light2 of the target object. This makes it impossible to accurately calculate the actual distance information, resulting in a decrease in the ranging accuracy of the laser radar.

[0023] To address this issue, a ranging adjustment method for lidar device 1 is proposed, such as... Figure 2 As shown, it includes the following steps: Step S10: Turn off the laser emitting module 10 and turn on the laser receiving module 20 to acquire the histogram data of the ambient light Light1. The laser receiving module 20 works independently to receive the current ambient light Light1 and perform photoelectric conversion and signal processing to output the corresponding pulse signal. The histogram data refers to the histogram formed by the sequential superposition of multiple converted pulse signals, such as... Figure 3As shown, the pulse signal formed by multiple measurements generates histogram data of timing and amplitude changes. Among them, the histogram data of ambient light Light1 is a random noise waveform.

[0024] In order to improve detection accuracy while acquiring the histogram data of ambient light Light1, optionally, such as Figure 6 As shown, the specific steps for obtaining the histogram data of ambient light Light1 include: Step S11: Turn off the laser emitting module 10 and turn on the laser receiving module 20 to receive the current ambient light Light1; Step S12: According to the histogram acquisition method, the multiple received ambient light Light1 signals are converted into multiple corresponding pulse signals and superimposed to form the histogram data of ambient light Light1.

[0025] Meanwhile, to improve detection accuracy and avoid histogram data errors caused by missed or incorrect reception, optionally, the steps of converting multiple received ambient light Light1 signals into corresponding multiple pulse signals and superimposing them to form histogram data of ambient light Light1 specifically include: The multiple pulse signals received from the ambient light Light1 are averaged to generate multiple pulse signals with equal amplitudes, and these are superimposed to form the histogram data of the ambient light Light1. The histogram data includes multiple pulse signals with equal amplitudes that change according to a preset phase sequence. This multiple averaging process improves the accuracy of the histogram data of the ambient light Light1.

[0026] Step S20: Adjust the detection efficiency of the laser receiving module 20 according to the histogram data of ambient light Light1.

[0027] Photon detection efficiency refers to the ratio of the number of photons detected by the laser receiving component 21 (such as a silicon photomultiplier tube, a photodetector avalanche diode 211, etc.) to the number of incident photons; that is, the efficiency with which the laser receiving component 21 converts optical signals into electrical signals. A higher detection efficiency indicates a stronger sensitivity of the laser receiving module 20 to photons; a lower detection efficiency indicates a weaker sensitivity of the laser receiving module 20 to photons.

[0028] When the histogram data of ambient light Light1 is acquired, the intensity of the current ambient light Light1 can be determined. In order to prevent the laser receiving component 21 from becoming too large and causing oversaturation or too small and the output electrical signal from becoming too small, the detection efficiency of the laser emitting module 10 is adjusted according to the intensity of ambient light Light1. That is, when strong ambient light Light1 is detected, the detection efficiency of the laser receiving component 21 is reduced, the sensitivity of the laser receiving component 21 is reduced, and the oversaturation caused by excessive gain of the laser receiving component 21 is avoided. At the same time, when weak ambient light Light1 is detected, the detection efficiency of the laser receiving component 21 is increased, the sensitivity and gain of the laser receiving component 21 are increased, thereby ensuring that the laser receiving component 21 reliably receives the current ambient light Light1 and the echo signal Light2.

[0029] The detection efficiency of the laser receiving component 21 is related to its operating voltage. Therefore, the detection efficiency can be adjusted by adjusting the operating voltage of the laser receiving component 21.

[0030] Step S30: Turn on the laser emitting module 10 and the laser receiving module 20 to obtain the histogram data of the current optical signal; Step S40: Compare the histogram data of the current light signal with the histogram data of the ambient light Light1, and determine the histogram data of the echo signal Light2 and the distance information of the object under test 2 based on the ratio or the difference.

[0031] 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.

[0032] 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: 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. 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.

[0033] 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.

[0034] 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: Step S51: When the histogram data of ambient light is greater than the first preset threshold of histogram data, reduce the detection efficiency of laser receiving module 20 and increase the emission power and / or number of laser emission times of laser emitting module 10 in a frame of scanned image. Step S52: When the histogram data of ambient light is less than the first preset threshold of histogram data, increase the detection efficiency of laser receiving module 20 and reduce the emission power and / or number of laser emissions of laser emitting module 10 in a frame of scanned image. Step S53: When the ambient light histogram data is within the first preset range of the histogram data, adjust the detection efficiency of the laser receiving module 20 to a constant preset detection efficiency, and adjust the emission power of the laser emitting module 10 in one frame of scanned image to a constant power and / or the number of laser emission times to a constant number of emission times.

[0035] The set values ​​for the emission power and the number of laser emission can be data simulated in advance according to design requirements, or data actually calibrated according to design requirements. This application does not limit them.

[0036] In this embodiment, the first preset threshold of the histogram data corresponds to the preset detection efficiency of the laser receiving component 21. When the preset detection efficiency is exceeded, the gain of the laser receiving component 21 is too large or too small, resulting in saturation or the converted electrical signal is too small. Therefore, when the histogram data of the ambient light Light1 is detected to exceed the first preset threshold of the histogram data, it indicates that the current ambient light Light1 is too strong, which is likely to cause the laser receiving component 21 to saturate. At this time, the detection efficiency of the laser receiving component 21 of the laser receiving module 20 is reduced. At the same time, in order to avoid the reduction in ranging capability caused by the reduction in detection efficiency, the emission power and / or the number of laser emission in a frame of scanned image of the laser emitting module 10 are increased accordingly to improve the ranging capability.

[0037] And when the histogram data of the ambient light Light1 is detected to be less than the first preset threshold of the histogram data, it indicates that the current ambient light Light1 is weak, which is likely to cause the gain of the laser receiving component 21 to be too small. At this time, the detection efficiency of the laser receiving component 21 of the laser receiving module 20 is increased. At the same time, in order to match the change in detection efficiency and avoid excessive power or excessive number of laser emission in a frame of scanned image leading to a decrease in ranging capability, the emission power and / or number of laser emission in a frame of scanned image of the laser emitting module 10 is reduced accordingly to improve the ranging capability.

[0038] Meanwhile, when the histogram data of ambient light Light1 is detected to be within the first preset range of the histogram data, it indicates that the current ambient light Light1 is normal. At this time, the detection efficiency of the laser receiving component 21 of the laser receiving module 20 is controlled to be a constant preset detection efficiency. At the same time, in order to match the change of detection efficiency and avoid excessive or insufficient power or excessive or insufficient laser emission in a frame of scanned image, which would lead to a decrease in ranging capability, the emission power and / or the number of laser emission in a frame of scanned image of the laser emitting module 10 are adjusted to a constant preset value to improve the ranging capability.

[0039] Or such as Figure 8 As shown, after determining the distance information of the object to be measured, the steps of adjusting the emission power and / or the number of laser emissions in a frame of scanned image of the laser emission module 10 according to the histogram data of the echo signal Light2 specifically include: Step S61: When the histogram data of the echo signal Light2 is greater than the second preset threshold of the histogram data, reduce the emission power and / or the number of laser emissions of the laser emission module 10 in a frame of scanned image; Step S62: When the histogram data of the echo signal Light2 is less than the second preset threshold of the histogram data, increase the emission power and / or the number of laser emissions of the laser emission module 10 in a frame of scanned image; Step S63: When the histogram data of the echo signal Light2 is within the second preset range of the histogram data, adjust the emission power of the laser emission module 10 to a constant power and / or the number of laser emission times in a frame of scanned image to a constant number of emission times.

[0040] In this embodiment, when the histogram data of the echo signal Light2 acquired in the previous frame is detected to be greater than the second preset threshold of the histogram data, it indicates that the detection efficiency of the adjusted laser receiving module 20 in the previous frame scan image is too high, which ultimately leads to the increase of the determined histogram data of the echo signal Light2 and the reduction 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 scan image, the laser emission count and / or emission power in the next frame scan image are reduced accordingly, so that the amplitude of the echo signal Light2 in the next frame scan image is within the preset range.

[0041] Similarly, when the histogram data of the echo signal Light2 acquired in the previous frame is detected to be 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 previous frame scan image is too low, which ultimately leads to a smaller histogram data of the determined echo signal Light2 and a decrease in 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 scan image, the laser emission count and / or emission power in the next frame scan image are increased accordingly, so that the amplitude of the echo signal Light2 in the next frame scan image is within the preset range.

[0042] And when the histogram data of the echo signal Light2 acquired in the previous frame is detected to be within the second preset range of the histogram data, it indicates that the detection efficiency of the adjusted laser receiving module 20 in the previous frame scan image is within a reasonable range. At this time, the laser emission count and / or emission power in the next frame scan image are controlled to be maintained at a constant power or a constant emission count to improve the ranging capability.

[0043] The first and second preset thresholds of the histogram data can be set according to the histogram data corresponding to ambient light and echo signal Light2, and can be obtained through self-learning or multiple detections, with no limit on their specific size.

[0044] 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 1 first acquires the histogram data of ambient light Light1, and adjusts the detection efficiency of the laser receiving module 20 according to the histogram data to achieve dynamic adjustment. Then, it acquires the light signal containing ambient light Light1 and echo signal Light2 and the corresponding histogram data, compares them, determines the current histogram data of echo signal Light2 and the distance information of the object to be measured 2, and reduces the influence of ambient light Light1 during laser ranging by adjusting the detection efficiency of the laser receiving module 20, thereby improving the ranging accuracy.

[0045] Optionally, the ranging adjustment method of lidar device 1 further includes: The above steps of the ranging adjustment method of lidar device 1 are repeated according to the preset time interval, such as... Figure 9 As shown, the process involves acquiring the histogram of ambient light Light1 at a preset frequency, adjusting the detection efficiency of the laser receiving module 20, adjusting the emission power and / or number of laser emissions of the laser emitting module 10 in a frame of scanned image, determining the amplitude and reception time of the echo signal Light2 based on the current light signal, and finally determining the distance information of the object 2 under test in each time period.

[0046] The preset time interval can be set according to the requirements. For example, when the ambient light Light1 is sunlight, the time interval can be set according to the weather, season, time of day, etc.

[0047] Alternatively, an adaptive adjustment method can be adopted, which automatically changes the acquisition of the histogram of ambient light Light1, the adjustment of the detection efficiency of the laser receiving module 20, the adjustment of the emission power and / or the number of laser emissions of the laser emitting module 10 in a frame of scanned image, and determines the amplitude and reception time of the echo signal Light2 based on the current light signal, and determines the frequency of the distance information of the object 2 under test in each time period. That is, when the ratio or difference is detected to be outside the preset value range, the above steps of the ranging adjustment method of the lidar device 1 are repeated.

[0048] For example, when the LiDAR device 1 is installed on a car, as the car enters the tunnel from the tunnel entrance, the ambient light (Light1) changes from normal or strong ambient light to weak ambient light. At this time, the histogram data of the ambient light (Light1) in the total light signal decreases, resulting in a smaller histogram data of the total light signal. Consequently, the ratio or difference decreases, leading to a smaller histogram data of the echo signal (Light2), thus reducing ranging accuracy. Alternatively, when the car exits the tunnel, the ambient light (Light1) changes from weak to normal or strong ambient light, resulting in a larger histogram data of the total light signal. This also leads to a larger ratio or difference, resulting in a larger histogram data of the echo signal (Light2), causing ranging errors. Therefore, when a change in the ratio or difference is detected to be outside the preset range, the next ranging adjustment is actively performed to improve ranging accuracy.

[0049] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0050] A second aspect of the present invention provides a lidar device 1, such as... Figure 10 As shown, the lidar device 1 includes a laser emitting module 10, a laser receiving module 20, and a control circuit 30 connected to the laser emitting module 10 and the laser receiving module 20 respectively. The control circuit 30 includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the ranging adjustment method of the lidar device 1 as described above.

[0051] In this embodiment, the control circuit 30 starts ranging adjustment according to a preset time interval or according to the calculated ratio or difference. Each time ranging is adjusted, the laser emitting module 10 is turned off and the laser receiving module 20 is turned on. The laser receiving module 20 acquires the pulse signal obtained by multiple conversions and converts the multiple pulse signals into histogram data of ambient light Light1 by superimposing them according to the timing and amplitude. The detection efficiency of the laser receiving module 20 is adjusted according to the histogram data of ambient light Light1. The emission power and / or number of laser emission of the laser emitting module 10 in a frame of scanned image are also adjusted. Alternatively, after the ranging of the previous frame is completed, the emission power and / or number of laser emission of the laser emitting module 10 in the next frame of scanned image are adjusted according to the histogram data of the determined echo signal Light2.

[0052] When the histogram data of ambient light Light1 is acquired, the intensity of the current ambient light Light1 can be determined. In order to prevent the laser receiving component 21 from becoming too large and causing oversaturation or too small and causing the output electrical signal to be too small, the control circuit 30 adjusts the detection efficiency of the laser emitting module 10 according to the intensity of ambient light Light1. That is, when strong ambient light Light1 is detected, the detection efficiency of the laser receiving component 21 is reduced, the sensitivity of the laser receiving component 21 is reduced, and the oversaturation caused by excessive gain of the laser receiving component 21 is avoided. At the same time, when weak ambient light Light1 is detected, the detection efficiency of the laser receiving component 21 is increased, the sensitivity and gain of the laser receiving component 21 are increased, thereby ensuring that the laser receiving component 21 reliably receives the current ambient light Light1 and the echo signal Light2.

[0053] Meanwhile, when the detection efficiency changes, the ranging performance of the lidar device 1 changes. In order to take into account the ranging capability at the same time, the control circuit 30 adjusts the emission power and / or the number of laser emission in a frame of scanned image of the laser emission module 10. By increasing the number of laser emission in a frame of scanned image of the laser, that is, increasing the number of superpositions of histogram data, the signal-to-noise ratio of the signal is improved, thereby improving the ranging capability. By increasing the emission power, the intensity of the echo signal Light2 is increased, thereby improving the ranging capability. One of the two methods can be selected or adjusted separately according to the timing sequence.

[0054] Alternatively, after determining the distance information of the object to be measured 2, 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 according to the histogram data of the echo signal Light2. By increasing the number of laser emissions in a frame of scanned image, that is, increasing the number of times the histogram data is superimposed, 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.

[0055] like Figure 11 As shown, optionally, the laser emitting module 10 includes: Laser emitting component 11; The laser driving circuit 12 is connected to the control circuit 30 and the laser emitting component 11 respectively. The laser driving circuit 12 turns on or off according to the control signal output by the control circuit 30, and adjusts the emission power and / or the number of laser emissions of the laser emitting component 11 in a frame of scanned image. The laser emitting assembly 11 includes multiple lasers.

[0056] In this embodiment, when the control circuit 30 acquires the histogram data of the ambient light Light1, it controls the laser driving circuit 12 to turn off. Subsequently, when adjusting the detection efficiency of the laser receiving module 20, it adjusts the emission power and / or the number of laser emissions in a frame of scanned image by the laser driving circuit 12. After adjusting the emission power and / or the number of laser emissions in a frame of scanned image, the control circuit 30 controls the laser driving circuit 12 to turn on and drive the laser to work according to the adjusted emission power and / or the number of laser emissions.

[0057] Alternatively, after adjusting the detection efficiency of the laser receiving module 20, the control circuit 30 controls the laser driving circuit 12 to start working and drives the laser receiving module 20 to work according to the adjusted detection efficiency. Then, based on the determined histogram data of the echo signal Light2, the emission power of the laser and / or the number of laser emissions in the next frame of the scanned image are adjusted accordingly.

[0058] Please continue reading. Figure 11 Optionally, the laser receiving module 20 includes: Laser receiving component 21, which is used to convert the corresponding optical signal into a current signal; The power supply circuit 22 is connected to the control circuit 30 and the laser receiving component 21 respectively. The power supply circuit 22 is triggered by the control signal of the control circuit 30 to output a voltage signal of corresponding magnitude to the laser receiving component 21 in order to adjust the detection efficiency of the laser receiving component 21. The signal processing circuit 23 is connected to the laser receiving component 21 and the control circuit 30 respectively. The signal processing circuit 23 is used to convert the electrical signal output by the laser receiving component 21 into corresponding histogram data and output the corresponding histogram data to the control circuit 30. The laser receiving component 21 includes a photoelectric converter.

[0059] When acquiring histogram data of ambient light Light1, control circuit 30 controls the laser receiving component 21, processing circuit, and power supply circuit 22 to turn on. Laser receiving component 21 converts light signals into current signals, signal processing circuit 23 converts current signals into voltage signals, and outputs multiple pulse signals to control circuit 30. Control circuit 30 determines the current histogram data of ambient light Light1 and adjusts the output voltage of power supply circuit 22, thereby adjusting the detection efficiency of photoelectric converter. The detection efficiency is directly proportional to 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.

[0060] Simultaneously, upon receiving the total optical signal, the photoelectric converter and signal processing circuit 23 sequentially convert the optical signal to a current signal and the current signal to a voltage signal, and output multiple pulse signals to the control circuit 30. The control circuit 30 determines the histogram data of the total optical signal and the histogram data, amplitude, and reception time of the echo signal Light2, thereby achieving the distance measurement purpose of the object under test 2.

[0061] The photoelectric converter can be a silicon photomultiplier tube, a photodetector avalanche diode 211, or other photoelectric converters. Optionally, such as... Figure 12 As shown, the photoelectric converter includes a photoelectric avalanche diode 211. The photoelectric avalanche diode 211 adaptively changes its gain according to the intensity of light. The control circuit 30 adjusts the operating voltage of the photoelectric avalanche diode 211 based on the histogram data of the acquired ambient light Light1, thereby adjusting the detection efficiency of the photoelectric avalanche diode 211 and improving the anti-strong light and anti-interference capabilities of the lidar device 1.

[0062] Optionally, such as Figure 12 As shown, the signal processing circuit 23 includes: Transconductance amplifier 231 is used to convert a current signal into a voltage-type analog echo signal Light2; The TDC detector circuit 232 acquires data from the analog echo signal Light2 and outputs multiple pulse signals to the control circuit 30.

[0063] The transconductance sensor is connected to the photodetector avalanche diode 211 and converts the current signal output by the photodetector avalanche diode 211 into a voltage signal. At the same time, the voltage signal is detected and acquired by the TDC detection circuit 232 and converted into multiple pulse signals to the control circuit 30. The control circuit 30 obtains the corresponding histogram data based on the multiple pulse signals, and then determines the histogram data, amplitude, and reception time of the echo signal Light2, thereby achieving the distance measurement purpose of the object under test 2.

[0064] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A ranging adjustment method for a lidar device, the lidar device comprising a laser emitting module and a laser receiving module, the laser receiving module comprising a corresponding laser receiving component and a corresponding signal processing circuit, characterized in that, The ranging adjustment method of the lidar device includes the following steps: Turn off the laser emitting module and turn on the laser receiving module to obtain histogram data of ambient light; Adjust the detection efficiency of the laser receiving module based on the histogram data of ambient light; Turn on the laser emitting module and the laser receiving module to obtain the histogram data of the current optical signal; The histogram data of the current optical signal is compared with the histogram data of the ambient light, and the histogram data of the echo signal and the distance information of the object under test are determined according to the ratio or the difference. The ranging adjustment method of the lidar device also includes: 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 in the next frame of the scanned image are adjusted according to the histogram data of the echo signal.

2. The ranging adjustment method for a lidar device as described in claim 1, characterized in that, The ranging adjustment method of the lidar device also includes: The detection efficiency of the laser receiving module is adjusted based on the histogram data of the ambient light, and the emission power and / or number of laser emissions of the laser emitting module in a frame of scanned image are adjusted accordingly.

3. The ranging adjustment method for a lidar device as described in claim 1, characterized in that, The step of converting multiple received ambient light signals into corresponding multiple pulse signals and superimposing them to form ambient light histogram data specifically includes: The multiple pulse signals from the received ambient light conversion are averaged to generate multiple pulse signals with equal amplitude, which are then superimposed to form histogram data of ambient light.

4. The ranging adjustment method for a lidar device as described in claim 2, characterized in that, The steps of adjusting the detection efficiency of the laser receiving module based on the histogram data of ambient light, and adjusting the emission power and / or the number of laser emissions of the laser emitting module in a frame of scanned image, specifically include: When the histogram data of the ambient light is greater than a first preset threshold of the 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 emitting module in a frame of scanned image is increased. When the histogram data of the ambient light is less than a first preset threshold of the histogram data, the detection efficiency of the laser receiving module is improved, and the emission power and / or the number of laser emissions of the laser emitting module in a frame of scanned image is reduced. When the histogram data of the ambient light is within a first preset range of the 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 emitting module in a frame of scanned image is adjusted to a constant power and / or the number of laser emissions is adjusted to a constant number of emissions.

5. The ranging adjustment method for a lidar device as described in claim 2, characterized in that, The step of adjusting the emission power and / or the number of laser emissions in a frame of scanned image according to the histogram data of the echo signal after determining the distance information of the object to be measured specifically includes: 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 scanned image are 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 scanned image are 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 scanned image is adjusted to a constant power and / or the number of laser emission times is adjusted to a constant number of emission times.

6. A lidar device, characterized in that, The device includes a laser emitting module, a laser receiving module, and a control circuit connected to the laser emitting module and the laser receiving module respectively. The control circuit includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the ranging adjustment method of the lidar device as described in any one of claims 1 to 5.

7. The lidar device as described in claim 6, characterized in that, The laser emitting module includes: Laser emitting components; A laser driving circuit is connected to the control circuit and the laser emitting component respectively. The laser driving circuit turns on or off according to the control signal output by the control circuit, and adjusts the emission power and / or the number of laser emissions of the laser emitting component in a frame of scanned image accordingly. The laser emitting assembly includes multiple lasers.

8. The lidar device as described in claim 6, characterized in that, The laser receiving module includes: A laser receiving component, wherein the laser receiving component is used to convert a corresponding optical signal into a current signal; A power supply circuit is connected to the control circuit and the laser receiving component respectively. The power supply circuit is triggered by the control signal of the control circuit to output a voltage signal of corresponding magnitude to the laser receiving component, so as to adjust the detection efficiency of the laser receiving component. A signal processing circuit is connected to the laser receiving component and the control circuit respectively. The signal processing circuit is used to convert the electrical signal output by the laser receiving component into corresponding histogram data and output the corresponding histogram data to the control circuit. The laser receiving component includes a photoelectric converter.

9. The lidar device as described in claim 8, characterized in that, The photoelectric converter includes a photodetector avalanche diode.

10. The lidar device as described in claim 8, characterized in that, The signal processing circuit includes: A transconductance amplifier, wherein the transconductance amplifier is used to convert a current signal into a voltage-type analog echo signal; The TDC detector circuit acquires data from the analog echo signal and outputs multiple pulse signals to the control circuit.

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