Laser radar system and laser radar control method

Abstract

The invention discloses a laser radar system and a laser radar control method. The method comprises the steps that a microcontroller carries out register configuration on a register in an SPAD module; the SPAD module generates a laser light-emitting signal according to the register configuration information and a time sequence, and sends the laser light-emitting signal to the laser; the laser controls the target light-emitting channel to emit light according to the laser light-emitting signal, and sends a light-emitting feedback signal to the SPAD module; and the SPAD module controls the SPAD unit to be activated according to the light-emitting feedback signal so as to receive the echo signal and obtain SPAD scanning data. According to the invention, a traditional FPGA main control platform is abandoned, but the highly integrated SPAD module is used as a core control unit, the channel light emitting time sequence of the laser is directly controlled, and the simplification of control logic and the optimization of hardware resources are realized. The overall size of the laser radar system is remarkably reduced, and meanwhile the complexity and the manufacturing cost of the system are greatly reduced.

Description

Technical Field

[0001] The present application relates to the field of laser radar control technology, and in particular to a laser radar system and a laser radar control method. Background Art

[0002] With the rapid development of autonomous driving, robot navigation, drone obstacle avoidance and 3D reconstruction, LiDAR, as a key sensor for obtaining environmental depth information, has become a key factor restricting the popularization and application of technology due to its performance and cost-effectiveness. Traditional LiDAR systems mostly use complex multi-component architectures, among which solid-state LiDAR has gradually become a research hotspot due to its compact structure, fast scanning speed and high reliability.

[0003] In solid-state LiDAR, SPAD (Single Photon Avalanche Diode) is widely used to achieve long-distance, high-precision ranging due to its high sensitivity, low noise and fast response characteristics. The current mainstream SPAD solid-state LiDAR architecture usually relies on a field-programmable gate array (FPGA) as the main control unit, which is responsible for accurately controlling the exposure timing of the SPAD to match the light-emitting timing of the laser to ensure the accuracy and stability of ranging. At the same time, the FPGA also needs to undertake tasks such as laser channel switching, data processing, algorithm implementation, and data interaction with external devices. Although this design is powerful, it also leads to a large LiDAR architecture, high power consumption and high cost. Summary of the invention

[0004] In view of this, the present application provides a laser radar system and a laser radar control method, which abandons the traditional FPGA main control platform and adopts a highly integrated SPAD module as the core control unit to directly control the channel light emission timing of the laser, thereby simplifying the control logic and optimizing the hardware resources. While significantly reducing the overall volume of the laser radar system, it also greatly reduces the system complexity and manufacturing cost.

[0005] According to one aspect of the present application, a laser radar system is provided, including a microcontroller, a SPAD module and a laser, wherein:

[0006] The microcontroller is connected to the SPAD module and is used to configure registers of the SPAD module;

[0007] The SPAD module is connected to a laser and is used to generate a laser light emission signal to control the target light emission channel.

[0008] According to another aspect of the present application, a laser radar control method is provided, comprising:

[0009] The microcontroller configures registers within the SPAD module;

[0010] The SPAD module generates a laser light emission signal in a time sequence according to the register configuration information, and sends the generated laser light emission signal to the laser;

[0011] The laser controls the target light-emitting channel to emit light according to the laser light-emitting signal, and sends a light-emitting feedback signal to the SPAD module;

[0012] The SPAD module controls the activation of the SPAD unit corresponding to the target light-emitting channel according to the light-emitting feedback signal, so as to receive the echo signal corresponding to the target light-emitting channel and obtain SPAD scanning data.

[0013] By means of the above technical solution, the present application provides a laser radar system and a laser radar control method, which abandons the traditional FPGA master control platform and adopts a highly integrated SPAD module as the core control unit to directly control the light emission timing of the laser channel, thereby simplifying the control logic and optimizing the hardware resources. While significantly reducing the overall volume of the laser radar system, it also greatly reduces the system complexity and manufacturing cost.

[0014] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0016] Figure 1 A schematic diagram of a flow chart of a laser radar control method provided in an embodiment of the present application is shown;

[0017] Figure 2 A schematic structural diagram of a laser radar system provided in an embodiment of the present application is shown;

[0018] Figure 3 A schematic diagram of the structure of another laser radar system provided in an embodiment of the present application is shown;

[0019] Figure 4A schematic diagram of the interaction between a microcontroller, a SPAD module, and a host computer provided in an embodiment of the present application is shown;

[0020] Figure 5 A schematic diagram of dividing a sub-field of view and a macro pixel set provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0021] The present application will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other without conflict.

[0022] Traditional solid-state LiDAR usually relies on FPGA as the main control unit, which is responsible for accurately controlling the timing of transmission and reception to ensure the accuracy and stability of ranging. At the same time, FPGA also needs to undertake tasks such as transmission and reception channel switching, point cloud data processing, algorithm implementation, and data interaction with external devices. Although this design is powerful, due to the large size and high cost of FPGA itself, the LiDAR architecture is large, power-hungry, and expensive.

[0023] The present application embodiment first provides a laser radar architecture, such as Figure 3 As shown, the laser radar includes two PCB boards, one is a traditional TP board, which integrates the laser, laser driver, SPAD receiving module, and peripheral power supply circuits of several modules. The other is a microcontroller board, which integrates the microcontroller and peripheral power supply and data conversion circuits. Among them, the microcontroller is connected to the SPAD module to configure the registers of the SPAD module; the SPAD module is connected to the laser, and the SPAD module generates a laser light-emitting signal and sends it to the laser driver, so that the laser driver controls the target light-emitting channel of the laser to emit light. Due to the single function of the microcontroller, the point cloud processing algorithm cannot be integrated, and the point cloud data collected by the SPAD module cannot be processed on the microcontroller. Therefore, this part of the work is handed over to the main control module separated from the radar. The data conversion circuit is responsible for converting the format of the point cloud data generated by the SPAD into the format required by the main control module, and sending the converted data to the main control module. Among them, when the radar is installed on the vehicle, the main control can be the vehicle-mounted main controller; when the radar is installed on the robot, the main control can be the core control unit of the robot. That is to say, in this architecture, the process of applying point cloud processing algorithms to process point cloud data is separated from the radar product, and the point cloud data processing function is implemented by reusing the control module of the smart device on which the radar is installed, while other transceiver controls can be implemented using a microcontroller + SPAD chip.

[0024] Compared with the traditional lidar architecture, the lidar architecture proposed in this application does not include the traditional FPGA platform, but uses a microcontroller with limited functions to replace part of the functions of the original FPGA platform, and then entrusts the control functions of the SPAD and laser modules to the SPAD module, and entrusts the radar point cloud processing function to the intelligent device controller separated from the radar. The microcontroller is only responsible for configuring the registers of the SPAD. Since the microcontroller is relatively simple and small in size, it does not affect the aesthetics when integrated into smart devices such as vehicles. Since the FPGA platform and the peripheral circuits that power the FPGA are removed at the same time, the entire radar can be miniaturized, and the microcontroller can be implemented using the simplest control chip on the market, such as stm32, which can reduce the cost by a hundred times compared to the FPGA platform. Therefore, the lidar architecture proposed in this application can also greatly reduce the development cost of the lidar.

[0025] In view of the above laser radar architecture, this embodiment provides a laser radar control method, such as Figure 1 As shown, the method includes:

[0026] Step 101, the microcontroller configures registers in the SPAD module;

[0027] Step 102, the SPAD module generates a laser light emission signal in a time sequence according to the register configuration information, and sends the generated laser light emission signal to the laser;

[0028] Step 103, the laser controls the target light-emitting channel to emit light according to the laser light-emitting signal, and sends a light-emitting feedback signal to the SPAD module;

[0029] Step 104: the SPAD module controls the activation of the SPAD unit corresponding to the target light-emitting channel according to the light-emitting feedback signal, so as to receive the echo signal corresponding to the target light-emitting channel and obtain SPAD scanning data.

[0030] In the embodiment of the present application, the microcontroller (MCU, full spelling: Microcontroller Unit) is the control center of the entire laser radar system, responsible for executing predefined programs or instructions to realize the configuration of the internal registers of the SPAD module. These configurations determine how the SPAD module works. The register parameter configuration process of the SPAD is similar to the existing process, except that the parameter types that need to be configured are different from the prior art. The parameters that need to be configured in this application include not only how the SPAD itself works, but also how the SPAD module controls the laser to work. The SPAD module is a key component in the laser radar system, responsible for generating the transceiver timing control signal according to the register configuration information configured by the microcontroller, controlling the laser to emit light, and controlling itself to receive the echo signal. The laser is the transmitting end of the laser radar system, responsible for emitting light pulses or light beams, which will be reflected back after hitting the target object and received by the SPAD unit, thereby obtaining SPAD scanning data. Among them, the SPAD module is a receiving chip, on which a plurality of SPAD minimum detection units (hereinafter referred to as "SPAD units") distributed in an array are integrated.

[0031] In this embodiment, first, the microcontroller writes configuration information to the register of the SPAD module to configure the working parameters of the SPAD itself and the working parameters of the SPAD module to control the laser light emission, such as the pulse width, repetition frequency, delay time, etc. of the light emission signal. Specifically, the SPAD module accurately generates the laser light emission signal in time sequence according to the configured timing information, and sends the generated laser light emission signal to the laser, specifically the laser driver, and then the laser driver controls the channel that currently needs to emit light (target light emission channel) to emit light at the right time. These laser light emission signals can be pulsed signals for triggering laser light emission. Here, the target light emission channel can be a light emission channel corresponding to the laser light emission signal. It should be noted that since each target light emission channel emits light multiple times in succession, for each target light emission channel, the SPAD module can generate multiple laser light emission signals in time sequence according to the register configuration information.

[0032] Due to the lack of an FPGA master control platform, there is a lack of an upper control module between the transceiver modules for establishing a unified transceiver mechanism, but it relies on the information interaction of the transceiver modules themselves. Therefore, the opening or closing of the receiving channel requires the establishment of a signal feedback mechanism between the transceiver modules to ensure the matching effect. That is, after the target light-emitting channel emits light, the laser can generate a light-emitting feedback signal, which is an important sign to confirm that the target light-emitting channel has been successfully activated and emits a light signal. The specific form of the light-emitting feedback signal may include electrical pulses, voltage changes, etc., depending on the design and implementation of the system. Subsequently, the SPAD module receives the light-emitting feedback signal from the laser, and triggers the activation of the SPAD unit corresponding to the target light-emitting channel according to the received light-emitting feedback signal. Here, there can be multiple SPAD units corresponding to the target light-emitting channel. After the SPAD unit is activated, the echo signal corresponding to the target light-emitting channel is received to obtain SPAD scanning data, that is, radar point cloud data.

[0033] By applying the technical solution of this embodiment, the embodiment of the present application abandons the traditional FPGA master control platform and instead adopts a highly integrated SPAD module as the core control unit to directly control the light emission timing of the laser channel, thereby simplifying the control logic and optimizing the hardware resources. While significantly reducing the overall volume of the laser radar system, it also greatly reduces the system complexity and manufacturing cost.

[0034] In an embodiment of the present application, optionally, the microcontroller is also used to: receive the SPAD scanning data and perform format conversion, and send the converted SPAD scanning data to a host computer.

[0035] In this embodiment, the SPAD module can also send the collected SPAD scan data to the microcontroller, which performs format conversion so that the converted SPAD scan data can be recognized by the host computer. The microcontroller can then send the SPAD scan data after format conversion to the host computer, which performs subsequent processing and analysis. Among them, the data conversion function can be implemented using a microcontroller with a data conversion function, or using an existing data conversion circuit.

[0036] Here, the host computer can be a vehicle-mounted controller, etc., which is not limited here. In the embodiment of the present application, the FPGA is cancelled and the laser is controlled by the SPAD module to switch channels and emit light. However, the control capability of the SPAD module itself is weak and does not have the ability to process point cloud data. It is impossible to achieve algorithm optimization on the LiDAR side. Therefore, the algorithm is partially transplanted to the host computer, and the SPAD scanning data such as the original point cloud data is subsequently uploaded to the host computer, and the host computer performs subsequent analysis and processing on the SPAD scanning data. The LiDAR system can provide an algorithm optimization SDK package for the host computer to call, so that the SPAD module can be in charge and reduce the size and cost of the LiDAR system.

[0037] In the method described in the embodiment of the present application, optionally, it also includes:

[0038] The SPAD module determines whether the echo intensity needs to be adjusted according to the SPAD scanning data and the echo intensity threshold;

[0039] If so, the microcontroller reconfigures the registers in the SPAD module.

[0040] The control parameters of traditional LiDAR are not static, but have the ability to adaptively adjust according to the point cloud effects detected during the detection process. For example, if there is overexposure in the point cloud image of the previous frame, the emission power of the laser will be appropriately reduced during the next frame control. The adaptive adjustment function is generally implemented through the FPGA master control. However, in this application, because the FPGA master control is cancelled and the function of the microcontroller is relatively single, it is impossible to realize the adaptive function through algorithm analysis of the point cloud image. Based on this, the present application proposes another embodiment, so that some adaptive adjustment functions can be performed in the radar architecture without FPGA master control.

[0041] In this embodiment, during the initialization process, the microcontroller configures the registers of the SPAD unit, and the configuration content includes the initial light-emitting strategy for controlling the light emission. The initial light-emitting strategy may include parameters such as the light-emitting time, light-emitting times, light-emitting cycle, light-emitting intensity, and switching timing of the target light-emitting channel. Then, according to the initial light-emitting strategy, the SPAD module generates a laser light-emitting signal in a timing sequence, and waits for the laser to return a light-emitting feedback signal to confirm that the light emission is successful. When the SPAD module receives the light-emitting feedback signal, the SPAD unit can be activated to receive the echo signal corresponding to the target light-emitting channel, and the SPAD scanning data can be determined based on the received echo signal.

[0042] After obtaining the SPAD scanning data, the SPAD module can also determine the received echo intensity based on the SPAD scanning data, and determine whether the currently received echo intensity is too large or too small, that is, whether it is overexposed or underexposed, by comparing the magnitude relationship between the echo intensity and the echo intensity threshold. The echo intensity threshold includes an echo intensity upper limit or an echo intensity lower limit.

[0043] Specifically, the SPAD module stores the histogram signal generated after each SPAD unit collects the echo signal. In the histogram signal, the ambient light level, signal strength and signal location can be reflected. Among them, the highest peak position of the signal in the histogram corresponds to the location of the point cloud point that the SPAD unit will eventually output, and the height of the peak corresponding to the signal peak is the signal strength. When the signal strength is too large and greater than the preset echo strength upper limit, it is considered that there is a greater possibility of overexposure. On the contrary, if it is less than the preset echo strength lower limit, it is considered that the exposure is insufficient. Both situations require adjustment of the laser's luminous power. Due to the lack of FPGA master control in this architecture, the luminous power of the laser cannot be directly adjusted through the FPGA master control. Therefore, it is still necessary to reconfigure the register information of the SPAD through the microcontroller, and then the SPAD sends a drive signal to the laser driver according to the updated register configuration information, and the laser driver drives the laser to work at a higher or lower luminous power, that is, indirectly adjust the luminous strategy. The above process can be repeated afterwards, and the judgment and adjustment are made again according to the echo intensity corresponding to the new SPAD scanning data.

[0044] In addition to the above-mentioned adjustment of the laser's luminous power, adjusting the SPAD voltage is also a way of adaptive adjustment. For example, when the SPAD voltage decreases, the sensitivity of the SPAD will decrease, causing the peak value of the received signal to decrease, thereby reducing overexposure. Conversely, when the voltage increases, the sensitivity increases, the signal peak increases, and thus the exposure increases. Of course, adjusting the SPAD voltage also requires configuring the SPAD registers through the microcontroller. In short, all working modes and working parameters of the SPAD need to be configured through registers.

[0045] In the embodiment of the present application, the SPAD module dynamically adjusts the light emission strategy so that during the laser light emission process, the SPAD module adjusts the laser light emission times, voltage and other parameters in real time according to the echo intensity, and can more accurately control the laser light emission, thereby adapting to different environmental conditions and improving the scanning performance of the laser radar. At the same time, by reducing unnecessary light emission times and optimizing the light emission cycle, the laser radar system can use resources more effectively and improve scanning efficiency.

[0046] In the previous embodiment of the present application, the adaptive adjustment is performed in units of macro-pixels, and each macro-pixel includes multiple SPAD units. However, due to the large number of macro-pixels and the weaker function of the SPAD module compared to the FPGA master control, it is impossible to take into account more complex computing tasks at the same time. This processing method will increase the time consumption and cause excessive pressure on the system. Based on this, the present application proposes another embodiment, in which the laser radar control method also includes:

[0047] determining a target macropixel echo intensity of a target macropixel corresponding to the sub-field of view;

[0048] Calculating the sub-field of view echo intensity corresponding to the sub-field of view according to the target macro-pixel echo intensity;

[0049] Comparing the sub-field of view echo intensity with a sub-field of view echo intensity threshold, and determining whether to reconfigure the register of the target macro-pixel through the microcontroller;

[0050] The sub-field of view is a part of the radar field of view area.

[0051] Reference Figure 5 , the entire field of view of the laser radar is divided into multiple sub-fields of view, each sub-field of view is a square field of view, assuming that a total of 3×3 sub-fields of view are divided, each sub-field of view corresponds to multiple macro pixel sets on the SPAD module. Figure 5 , the 3×3 sub-fields of view correspond to the macro-pixel sets of P1 to P9 respectively. Each macro-pixel set includes multiple macro-pixels - the macro-pixel set P1 corresponds to the sub-field of view 1, and P1 includes multiple macro-pixels. Each macro-pixel is composed of multiple SPAD units, that is, assuming that each macro-pixel includes 4×4 SPAD units, then during the back-end processing, the current and voltage signals detected by the 4×4 SPAD units will be combined and processed as the macro-pixel signal. Therefore, the echo intensity generated by each SPAD minimum detection unit in the macro-pixel is accumulated to obtain the echo intensity corresponding to the macro-pixel.

[0052] Then, for sub-field of view 1, each macropixel in the macropixel set P1 corresponding to sub-field of view 1 is called target macropixel S1-S9, and the echo intensity of each macropixel in the target macropixels S1-S9 can be obtained according to the echo intensity of each SPAD unit included in the target macropixel (for example, the macropixel echo intensity X1 of the target macropixel S1 is obtained by adding the echo intensity of each SPAD unit included in S1). The same operation is performed on the target macropixels S1-S9 to obtain the target macropixel echo intensity (X1, X2.....X9) of the target macropixels S1-S9. Then add (X1, X2....X9) and calculate the average value, or take the median, to obtain the echo intensity of sub-field of view 1. Subsequently, compare the echo intensity of sub-field of view 1 with the sub-field of view echo intensity threshold, specifically, the upper limit of the sub-field of view echo intensity and / or the lower limit of the sub-field of view echo intensity. When the echo intensity of sub-field of view 1 is greater than the upper limit of the sub-field of view echo intensity, it is considered to be overexposed, and the microcontroller is used to reconfigure the register of the SPAD module so that the SPAD sends a signal to the driver of the laser, and when the sub-field of view 1 is scanned next time, the laser light power is reduced and / or the voltage of the target macro pixel is reduced; when the echo intensity of sub-field of view 1 is less than the lower limit of the sub-field of view echo intensity, it is underexposed, and the microcontroller is used to reconfigure the register of the SPAD module so that the SPAD sends a signal to the driver of the laser, and when the sub-field of view 1 is scanned next time, the laser light power is increased and / or the voltage of the target macro pixel is increased; and the adaptive adjustment of sub-field of view 1 is completed.

[0053] In this embodiment, the register configuration information is dynamically adjusted through the echo intensity of the new SPAD scanning data to adjust the laser's light emission strategy, which can optimize the scanning effect. This dynamic adjustment strategy allows the lidar system to respond to different scanning environments and scanning requirements more flexibly, improving the accuracy and efficiency of scanning. In addition, the radar field of view is divided into multiple sub-fields of view and the corresponding target macro-pixels in the sub-field of view are uniformly processed, which not only reduces the computing pressure of the SPAD module itself, but also ensures the uniformity and consistency of the point cloud effect in the sub-field of view.

[0054] In the embodiment of the present application, optionally, the calculating the sub-field of view echo intensity corresponding to the sub-field of view according to the target macro-pixel echo intensity further includes:

[0055] Determining the weight of each target macro-pixel corresponding to the sub-field of view;

[0056] The weights of the target macro-pixels corresponding to the sub-field of view and the target macro-pixel echo intensity are weighted summed to obtain the sub-field of view echo intensity corresponding to the sub-field of view.

[0057] LiDAR generally has ROI function, which means that it pays more attention to the imaging effect of a part of the full field of view. For example, for vehicle-mounted radar, the sub-field of view in the central area of ​​the entire field of view of the radar is more important than the edge area. Even for each sub-field of view, the central area of ​​the sub-field of view is more important. Based on this, in this solution, when the entire field of view of the radar is divided into multiple sub-fields of view, the target macro-pixels of the sub-field of view can be distinguished by weights to calculate the sub-field of view echo intensity. That is:

[0058] Z=X 1 α 1 +X 2 α 2 +.......+X n α n

[0059] Among them, Z is the sub-field echo intensity, X 1 ~X N is the target macro-pixel echo intensity of each target macro-pixel corresponding to the sub-field of view, α 1 ~α n is the weight corresponding to each target macro pixel, α 1 ~α n The sum is equal to 1.

[0060] The first way to set the weight is to set it in a way that the weight gradually decreases from the center to the edge in each sub-field of view. Figure 5 For example, the target macro pixel set P1 corresponds to sub-field 1, and the target macro pixel set P5 corresponds to sub-field P5. The central macro pixel S5 of P1 has the highest weight, and the weights of the remaining macro pixels of P1 are set according to the distance from S5. The greater the distance, the smaller the weight setting. Finally, normalization is performed to ensure that the sum of the weights of all target macro pixels in P1 is 1. Similarly, the central macro pixel S14 of P5 has the highest weight, and the weights of the remaining macro pixels of P5 are set according to the distance from S14. The greater the distance, the smaller the weight setting. Finally, normalization is performed to ensure that the sum of the weights of all target macro pixels in P5 is 1.

[0061] The second way to set the weights is to consider the characteristics of the radar's full field of view and set the weights in a way that gradually decreases from the center to the edge of the full field of view. Figure 5 Assuming that the macro pixel at the center of the radar full field of view is S14, the weights of other macro pixels in the radar full field of view, no matter in which sub-field of view they are located, are set according to the distance from S14. The greater the distance, the smaller the weight setting. Finally, normalization is performed in each sub-field of view to ensure that the sum of the weights of all macro pixels in each sub-field of view is 1.

[0062] Of course, the setting of weights can also be defined manually and is not limited to the above method.

[0063] In the above embodiment, the weight corresponding to each target macropixel can be preset. Therefore, for the target macropixel corresponding to each sub-field of view, after determining the target macropixel echo intensity corresponding to each target macropixel, a product result can be obtained by multiplying the target echo intensity and the corresponding weight, and then the echo intensities of each target macropixel are added together, and the sum is used as the sub-field of view echo intensity. The embodiment of the present application assigns different weights to different target macropixels, which can make the target echo intensity of important macropixels account for a higher proportion in the sub-field of view echo intensity, so that the sub-field of view echo intensity finally calculated is closer to the actual situation.

[0064] In an embodiment of the present application, optionally, the SPAD scanning data corresponding to the sub-field of view includes row data, column data or area data.

[0065] Among them, row data, column data and area data refer to the division method of sub-field of view. Assuming that the radar scans in a row scanning mode, the sub-field of view can be divided according to each row, if the radar scans in a column scanning mode, the sub-field of view can be divided according to each column, if the radar scans in an area scanning mode, then the sub-field of view can be divided according to the area. Figure 5 The sub-field division method shown is an example of division according to regions.

[0066] In other embodiments, if the sub-field of view is divided according to rows or columns, the SPAD scanning data corresponding to the sub-field of view is the histogram data detected by a row or column of macro pixels. The sub-field of view is applied to a one-dimensional scanning method in the manner of dividing the sub-field of view in rows or columns. For row data, it is obtained by receiving the echo signal after controlling the pixels of a row to light up each time, and then lighting the pixels row by row, and finally obtaining the SPAD scanning data corresponding to the entire sub-field of view; for column data, it is obtained by receiving the echo signal after controlling the pixels of a column to light up each time, and then lighting the pixels column by column, and finally obtaining the SPAD scanning data corresponding to the entire sub-field of view. For row data or column data, the echo intensity threshold of a row or column of target macro pixels can also be judged, such as taking the average value and median of the echo intensity of a row or column of target macro pixels as the sub-field of view echo intensity, and then comparing the sub-field of view echo intensity with the sub-field of view echo intensity threshold. If adjustment is required, the specific adjustment method can refer to the above embodiment.

[0067] Of course, different weights may also be assigned to target macro pixels at different positions in a row or a column. For example, the weights of macro pixels near the center of a row or a column may be set larger than those near the edge, and then normalized to ensure that the sum of the weights in a row or a column of target macro pixels is 1.

[0068] In the embodiment of the present application, optionally, applied to the microcontroller, the method further includes:

[0069] Performing an initialization operation on the SPAD module and recording the initialization operation time;

[0070] Monitor the SPAD module, record the first time when the SPAD module sends the first frame signal, and determine the second time when the host computer sends the handshake signal;

[0071] Calculating a time difference between the first time and the initialization operation time;

[0072] The initialization operation time is updated according to the time difference and the second time, so that the second time is equal to the first time when the SPAD module sends the first frame signal again.

[0073] In this embodiment, since the laser light emission is completely controlled by the SPAD module, the laser radar system and the host computer cannot directly and actively perform frame synchronization. In order to solve this problem, the present application uses the frame signal emitted by the SPAD module for passive frame synchronization, and ensures effective communication and data synchronization between the SPAD module and the host computer through precise time control. First, the microcontroller initializes the SPAD module and records the initialization operation time. This time point is used as a reference point for subsequent time calculation, which helps to accurately control the time of subsequent operations. Next, the microcontroller monitors the SPAD module. After the SPAD module is initialized, it can start to send frame signals normally. The microcontroller records the time of the first frame signal sent by the SPAD module after the initialization operation, which is recorded as the first time. In addition, the microcontroller can also determine the time when the host computer is about to send a handshake signal, which is recorded as the second time. The host computer sends a handshake signal to indicate that it is ready to receive data, so frame synchronization can be performed according to the handshake signal sent by the host computer and the frame signal sent by the SPAD module. Then, the microcontroller calculates the time difference between the first time and the initialization operation time. This time difference reflects the time taken by the SPAD module from the completion of initialization to the sending of the first frame signal, which helps to understand the response speed of the SPAD module. This time difference and the second time are used to update the initialization operation time, that is, to determine the time to configure the registers in the SPAD module. After updating the initialization operation time, the SPAD module can be initialized again. After the reinitialization operation, the first time when the SPAD module sends the first frame signal again is consistent with the second time when the host computer sends the handshake signal, which ensures effective synchronization and efficient data transmission between the SPAD module and the host computer.

[0074] In this embodiment, the time of radar initialization can be controlled manually, but after the initialization configuration is completed, the time (first time) when the SPAD module sends the first frame is fixed and cannot be manually adjusted. However, in order to ensure the systematization with the host computer, the first time must be consistent with the time when the host computer sends the handshake signal. Therefore, in this application, it is necessary to adjust the initialization time in combination with the timing of the host computer sending the handshake signal, and indirectly adjust the first time to be consistent with the handshake signal time. For example, assuming that the initialization operation time is T1, the first time is T1+2ms, and the second time is T2, then the time difference between the first time and the initialization operation time is 2ms. According to the time difference of 2ms, after the SPAD module is initialized, the SPAD module can respond after 2ms, so the SPAD module can be initialized again at the first 2ms of the T2 time, that is, T2-2ms, that is, the microcontroller can complete the register configuration of the SPAD module at this time, so that 2ms later, that is, T2, the SPAD module can send a frame signal again, which is also the time when the host computer sends a handshake signal, thereby realizing the frame synchronization between the SPAD module and the host computer.

[0075] After the above initialization configuration is completed, the SPAD module and the laser module can work according to the established timing. This timing generally does not need to be changed. However, if the system executes the above adaptive function, the register configuration is changed. Whether resynchronization is required at this time depends on the content of the change. If the changed configuration is related to the timing, resynchronization is generally required, such as changing the number of laser transmission and reception times; conversely, if the changed configuration is not related to the timing, such as changing the SPAD voltage, the laser light emission voltage, etc., resynchronization is generally not required.

[0076] In the embodiment of the present application, considering the lack of necessary communication mechanism between the radar and the external host computer, a frame synchronization mechanism is proposed to ensure effective data transmission and control between the radar and the host computer.

[0077] Further, as Figure 1 The specific implementation of the laser radar control method, the embodiment of the present application provides a laser radar system, such as Figure 2 As shown, the system includes a microcontroller, a SPAD module and a laser, wherein:

[0078] The microcontroller is connected to the SPAD module and is used to configure registers of the SPAD module;

[0079] The SPAD module is connected to a laser and is used to generate a laser light emission signal to control the target light emission channel.

[0080] Optionally, the laser is used to control the target light-emitting channel to emit light according to the laser light-emitting signal, and send a light-emitting feedback signal to the SPAD module;

[0081] The SPAD module is also used to control the activation of the SPAD unit corresponding to the target light-emitting channel according to the light-emitting feedback signal, so as to receive the echo signal corresponding to the target light-emitting channel and obtain SPAD scanning data.

[0082] Optionally, the microcontroller is further used for:

[0083] The SPAD scan data is received and format converted, and the converted SPAD scan data is sent to a host computer.

[0084] Optionally, the SPAD module is further used to determine whether the echo intensity needs to be adjusted according to the SPAD scanning data and the echo intensity threshold;

[0085] If so, the microcontroller is further used to reconfigure the registers in the SPAD module.

[0086] Optionally, the SPAD module is further used for:

[0087] determining a target macropixel echo intensity of a target macropixel corresponding to the sub-field of view;

[0088] Calculating the sub-field of view echo intensity corresponding to the sub-field of view according to the target macro-pixel echo intensity;

[0089] Comparing the sub-field of view echo intensity with a sub-field of view echo intensity threshold, and determining whether to reconfigure the register of the target macro-pixel through the microcontroller;

[0090] The sub-field of view is a part of the radar field of view area.

[0091] Optionally, the SPAD module is further used for:

[0092] Determining the weight of each target macro-pixel corresponding to the sub-field of view;

[0093] The weights of the target macro-pixels corresponding to the sub-field of view and the target macro-pixel echo intensity are weighted summed to obtain the sub-field of view echo intensity corresponding to the sub-field of view.

[0094] Optionally, the SPAD scanning data corresponding to the sub-field of view includes row data, column data or area data.

[0095] Optionally, the microcontroller is further used for:

[0096] Performing an initialization operation on the SPAD module and recording the initialization operation time;

[0097] Monitor the SPAD module, record the first time when the SPAD module sends the first frame signal, and determine the second time when the host computer sends the handshake signal;

[0098] Calculating a time difference between the first time and the initialization operation time;

[0099] The initialization operation time is updated according to the time difference and the second time, so that the second time is equal to the first time when the SPAD module sends the first frame signal again.

[0100] It should be noted that for other corresponding descriptions of the functional units involved in a laser radar system provided in an embodiment of the present application, reference can be made to Figure 1 The corresponding description in the laser radar control method will not be repeated here.

[0101] Further, as a refinement and extension of the specific implementation of the above embodiment, in order to fully illustrate the specific implementation process of this embodiment, another laser radar system is provided, such as Figure 3 and Figure 4 As shown, the whole hardware of the system has two PCB (Printed Circuit Board) boards, namely the power plus data conversion board and the TP board. A microcontroller is arranged on the power plus data conversion board, which is mainly responsible for powering the laser radar system, controlling the startup process of the SPAD module and related register control, receiving the SPAD scan data and sending it to the host computer. Specifically, the microcontroller can convert the received SPAD scan data into a format that can be recognized by the host computer, such as the USB3.0 format, and then send it to the host computer. In a specific embodiment, the microcontroller only needs a USB3.0 connection line to communicate with the host computer and power the laser radar system. In addition, when the microcontroller performs the initialization process configuration and register configuration of the SPAD module, it can be realized through IIC (Inter-Integrated Circuit, a synchronous, multi-master, multi-slave, packet switching, single-ended, serial computer bus). The whole machine receives and transmits optical modules and shares the same set of modules, and the image plane size and number of points of the laser and SPAD module correspond one to one. In another embodiment, the SPAD module may also send a channel switching signal to the laser driver, and the laser driver controls the laser to switch channels according to the channel switching signal. After that, the SPAD module sends a laser light emission signal to control the laser to emit light.

[0102] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties.

[0103] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0104] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A laser radar system, characterized in that: It includes a microcontroller, a SPAD module and a laser, among which: The microcontroller is connected to the SPAD module and is used to configure registers of the SPAD module; The SPAD module is connected to a laser and is used to generate a laser light emission signal to control the target light emission channel.

2. A laser radar control method, characterized in that: include: The microcontroller configures registers within the SPAD module; The SPAD module generates a laser light emission signal in a time sequence according to the register configuration information, and sends the generated laser light emission signal to the laser; The laser controls the target light-emitting channel to emit light according to the laser light-emitting signal, and sends a light-emitting feedback signal to the SPAD module; The SPAD module controls the activation of the SPAD unit corresponding to the target light-emitting channel according to the light-emitting feedback signal, so as to receive the echo signal corresponding to the target light-emitting channel and obtain SPAD scanning data.

3. The method according to claim 2, characterized in that The microcontroller is also used to: The SPAD scan data is received and format converted, and the converted SPAD scan data is sent to a host computer.

4. The method according to claim 2, characterized in that: Also includes, The SPAD module determines whether the echo intensity needs to be adjusted according to the SPAD scanning data and the echo intensity threshold; If so, the microcontroller reconfigures the registers in the SPAD module.

5. The method according to claim 4, characterized in that Also includes, determining a target macropixel echo intensity of a target macropixel corresponding to the sub-field of view; Calculating the sub-field of view echo intensity corresponding to the sub-field of view according to the target macro-pixel echo intensity; Comparing the sub-field of view echo intensity with a sub-field of view echo intensity threshold, and determining whether to reconfigure the register of the target macro-pixel through the microcontroller; The sub-field of view is a part of the radar field of view area.

6. The method according to claim 5, characterized in that The step of calculating the sub-field of view echo intensity corresponding to the sub-field of view according to the target macro-pixel echo intensity further includes: Determining the weight of each target macro-pixel corresponding to the sub-field of view; The weights of the target macro-pixels corresponding to the sub-field of view and the target macro-pixel echo intensity are weighted and summed to obtain the sub-field of view echo intensity corresponding to the sub-field of view.

7. The method according to claim 4, characterized in that: The SPAD scanning data corresponding to the sub-field of view includes row data, column data or area data.

8. The method according to claim 2, characterized in that: Applied to the microcontroller, the method further comprises: Performing an initialization operation on the SPAD module and recording the initialization operation time; Monitor the SPAD module, record the first time when the SPAD module sends the first frame signal, and determine the second time when the host computer sends the handshake signal; Calculating a time difference between the first time and the initialization operation time; The initialization operation time is updated according to the time difference and the second time, so that the second time is equal to the first time when the SPAD module sends the first frame signal again.

Images