Self-calibration methods for lidar, lidar, devices, equipment and media

Abstract

This application provides a self-calibration method for a lidar, a lidar, an apparatus, an electronic device, and a computer-readable storage medium, relating to the field of radar technology. The method includes: firstly, setting a first marker and a second marker with different positions and reflectivities on the inner wall of the periphery of the lidar window; firstly, controlling a laser transceiver to emit a laser beam; then, acquiring a first echo signal of the laser beam reflected by the first marker and a second echo signal of the laser beam reflected by the second marker; next, calculating the difference information between the first echo signal and the second echo signal; and then determining the operating parameters of the laser transceiver based on the difference information and preset difference information. This achieves self-calibration of the lidar's operating parameters. The calibration work does not require manual intervention, specific calibration equipment, or site limitations, which is beneficial to improving the efficiency of the calibration work.

Description

Technical Field

[0001] This application relates to the field of radar technology, and more specifically, to a self-calibration method for a lidar, a lidar, an apparatus, an electronic device, and a computer-readable storage medium in the field of radar technology. Background Technology

[0002] The application of lidar is becoming increasingly widespread with the expansion of high-tech industries, and its visual presentation effects are quite remarkable. However, the safe use of lidar remains a top priority for the industry. In actual use, as the usage time increases, the internal functional modules of the lidar gradually age, causing changes in its operating parameters (such as emission power), thus reducing its ranging capability. Therefore, calibrating the operating parameters of the lidar is one of the key steps in its use.

[0003] In existing related technologies, the calibration of the operating parameters of lidar generally requires specific equipment. For example, calibrating the emission power of lidar requires specific standard reflectivity plates, power meters, and point cloud acquisition equipment. The calibration process is complex and cumbersome, and it is difficult to achieve anytime and anywhere. Summary of the Invention

[0004] This application provides a self-calibration method for lidar, lidar, device, electronic equipment, and computer-readable storage medium. The method enables self-calibration of the lidar's operating parameters, simplifies the operating parameter calibration process, and helps improve measurement accuracy and calibration efficiency.

[0005] In a first aspect, a self-calibration method for a lidar is provided, applied to a lidar comprising a laser transceiver and a window plate. A first marker and a second marker are disposed on the inner wall of the periphery of the window plate. The positions of the first marker and the second marker are different, and the reflectivities of the first marker and the second marker are different. The self-calibration method comprises: controlling the laser transceiver to emit a laser beam; acquiring a first echo signal reflected from the laser beam by the first marker and a second echo signal reflected from the laser beam by the second marker; determining difference information between the first echo signal and the second echo signal; and determining operating parameters of the laser transceiver based on the difference information and preset difference information.

[0006] In conjunction with the first aspect, in some possible implementations, the operating parameters include the transmission power of the laser beam emitted by the laser transceiver; controlling the laser transceiver to emit the laser beam includes: controlling the laser transceiver to emit a laser beam with a first transmission power; determining the operating parameters of the laser transceiver based on the difference information and preset difference information includes: determining the difference between the difference information and the preset difference information; when the difference is greater than or equal to a preset value, controlling the laser transceiver to emit a laser beam with a second transmission power based on the difference; returning to the step of acquiring the first echo signal of the laser beam reflected by the first identifier and the second echo signal of the laser beam reflected by the second identifier, until the difference is less than the preset value.

[0007] In combination with the first aspect and the above implementation methods, in some possible implementation methods, controlling the laser transceiver to transmit a laser beam with a second transmission power based on the difference includes: obtaining the first transmission power charging time of the laser transceiver transmitting a laser beam with the first transmission power in the previous transmission cycle; determining the transmission power charging change time based on the difference; determining the second transmission power charging time required for the laser transceiver to transmit a laser beam with the second transmission power in the current transmission cycle based on the first transmission power charging time and the transmission power charging change time; and driving the laser transceiver using the second transmission power charging time to enable the laser transceiver to transmit a laser beam with the second transmission power.

[0008] In conjunction with the first aspect and the above implementation methods, in some possible implementation methods, determining the difference information between the first echo signal and the second echo signal includes: acquiring a first signal curve of the first echo signal; acquiring a second signal curve of the second echo signal; and determining the energy difference between the echo energy of the first echo signal and the echo energy of the second echo signal based on the first signal curve and the second signal curve, thereby obtaining the difference information.

[0009] In conjunction with the first aspect and the above implementation methods, in some possible implementation methods, obtaining the first echo signal of the laser beam reflected by the first identifier and the second echo signal of the laser beam reflected by the second identifier includes: determining whether the laser beam is directed towards the first identifier and / or the second identifier; if the laser beam is directed towards the first identifier and the second identifier, determining the first signal analysis area corresponding to the first identifier and the second signal analysis area corresponding to the second identifier; obtaining the reflected signal of the laser beam received by the laser transceiver in the first signal analysis area to obtain the first echo signal; obtaining the reflected signal of the laser beam received by the laser transceiver in the second signal analysis area to obtain the second echo signal.

[0010] In combination with the first aspect and the above implementation, in some possible implementations, determining whether the laser beam is directed toward the first sign and / or the second sign includes: determining the emission angle of the laser beam emitted by the laser transceiver; determining whether the emission angle matches a specific field of view corresponding to the first sign and the second sign; if so, determining that the laser beam is directed toward the first sign and / or the second sign.

[0011] In combination with the first aspect and the above implementation methods, in some possible implementation methods, the lidar further includes a scanning device; determining the emission angle of the laser beam emitted by the laser transceiver includes: acquiring the pitch angle and yaw angle of the scanning device; determining the vertical emission angle in the emission angle based on the pitch angle; and determining the horizontal emission angle in the emission angle based on the yaw angle.

[0012] Secondly, a lidar is provided, the lidar comprising:

[0013] A window panel, wherein a first mark and a second mark are provided on the inner wall of the periphery of the window panel, the positions of the first mark and the second mark are different, and the reflectivity of the first mark and the second mark are different;

[0014] A laser transceiver is used to emit a laser beam and acquire a first echo signal of the laser beam reflected by the first identifier and a second echo signal of the laser beam reflected by the second identifier.

[0015] The parameter correction module is used to determine the difference information between the first echo signal and the second echo signal, and to determine the operating parameters of the laser transceiver based on the difference information and preset difference information.

[0016] In conjunction with the second aspect, in some possible implementations, the laser transceiver includes multiple devices, and multiple identification combinations are provided on the inner wall. Each identification combination includes the first identification and the second identification, and each laser transceiver corresponds to one identification combination.

[0017] In combination with the second aspect and the above implementation, in some possible implementations, for each of the identification combinations, the first identification is disposed near the first edge of the inner wall of the periphery of the window piece, and the second identification is disposed near the second edge of the inner wall of the periphery of the window piece, with the first edge and the second edge opposite to each other.

[0018] In combination with the second aspect and the above implementation, in some possible implementations, for each of the identification combinations, the first identification and the second identification are both disposed near the single edge of the inner wall of the periphery of the window piece, the first identification and the second identification are spaced apart, and the first identification and the second identification are parallel to each other.

[0019] In combination with the second aspect and the above implementation, in some possible implementations, for each of the identification combinations, the first identification and the second identification are both located near the single edge of the inner wall of the periphery of the window piece, the first identification and the second identification are located on the same horizontal line, and the center line of the single edge is the line of symmetry between the first identification and the second identification.

[0020] Thirdly, a self-calibration device for a lidar is provided, which is configured in a lidar. The lidar includes a laser transceiver and a window. A first mark and a second mark are provided on the inner wall of the periphery of the window. The positions of the first mark and the second mark are different, and the reflectivities of the first mark and the second mark are different.

[0021] The self-calibration device of the lidar includes:

[0022] A laser emitting module is used to control the laser transceiver to emit a laser beam;

[0023] An echo acquisition module is used to acquire a first echo signal of the laser beam reflected by the first identifier, and a second echo signal of the laser beam reflected by the second identifier;

[0024] The difference calculation module is used to determine the difference information between the first echo signal and the second echo signal;

[0025] The parameter adjustment module is used to determine the operating parameters of the laser transceiver based on the difference information and the preset difference information.

[0026] In conjunction with the third aspect, in some possible implementations, the operating parameters include the transmission power of the laser beam emitted by the laser transceiver;

[0027] The laser emitting module is specifically used to control the laser transceiver to emit a laser beam with a first emission power.

[0028] The parameter adjustment module includes:

[0029] A difference calculation unit is used to determine the difference between the difference information and the preset difference information;

[0030] A first control unit is configured to control the laser transceiver to emit a laser beam with a second emission power based on the difference when the difference is greater than or equal to a preset value.

[0031] The second control unit is configured to return to the step of acquiring the first echo signal of the laser beam reflected by the first identifier and the second echo signal of the laser beam reflected by the second identifier, until the difference is less than a preset value.

[0032] In conjunction with the third aspect and the above implementation methods, in some possible implementations, the first control unit includes:

[0033] The time acquisition subunit is used to acquire the first transmission power charging time of the laser transceiver device transmitting the laser beam with the first transmission power in the previous transmission cycle.

[0034] The first calculation subunit is used to determine the transmission power charging change time based on the difference;

[0035] The second calculation subunit is used to determine the second transmission power charging time required for the laser transceiver to transmit the laser beam with the second transmission power in the current transmission cycle, based on the first transmission power charging time and the transmission power charging change time.

[0036] A driving subunit is used to drive the laser transceiver device with the second transmit power charging time, so that the laser transceiver device transmits a laser beam with the second transmit power.

[0037] In combination with the third aspect and the above implementation methods, in some possible implementations, the difference calculation module includes:

[0038] The curve acquisition unit is used to acquire a first signal curve of the first echo signal and a second signal curve of the second echo signal.

[0039] The difference calculation unit is used to determine the energy difference between the echo energy of the first echo signal and the echo energy of the second echo signal based on the first signal curve and the second signal curve, and obtain the difference information.

[0040] In combination with the third aspect and the above implementation methods, in some possible implementations, the echo acquisition module includes:

[0041] A region determination unit is used to determine whether the laser beam is directed toward the first marker and / or the second marker;

[0042] The time period acquisition unit is used to determine the first signal analysis area corresponding to the first identifier and the second signal analysis area corresponding to the second identifier when the laser beam is directed at the first identifier and the second identifier.

[0043] The first signal acquisition unit is used to acquire the reflected signal of the laser beam received by the laser transceiver in the first signal analysis area, and obtain the first echo signal.

[0044] The second signal acquisition unit is used to acquire the reflected signal of the laser beam received by the laser transceiver in the second signal analysis area, and obtain the second echo signal.

[0045] In combination with the third aspect and the above implementation methods, in some possible implementations, the region determination unit includes:

[0046] The emission angle acquisition subunit is used to determine the emission angle of the laser beam emitted by the laser transceiver.

[0047] The region determination subunit is used to determine whether the emission angle matches the specific field of view range corresponding to the first identifier and the second identifier. If so, it is determined that the laser beam is directed towards the first identifier and / or the second identifier.

[0048] In conjunction with the third aspect and the above implementation methods, in some possible implementation methods, the lidar further includes a scanning device, and the emission angle acquisition subunit is specifically used to acquire the pitch angle and yaw angle of the scanning device; determine the vertical emission angle in the emission angle based on the pitch angle; and determine the horizontal emission angle in the emission angle based on the yaw angle.

[0049] Fourthly, an electronic device is provided, comprising the aforementioned lidar, memory, and processor. The memory stores executable program code, and the processor retrieves and runs the executable program code from the memory, causing the electronic device to execute the lidar self-calibration method described in the first aspect or any possible implementation thereof.

[0050] Fifthly, a computer program product is provided, comprising: computer program code, which, when executed on a computer, causes the computer to perform the self-calibration method of the lidar in the first aspect or any possible implementation thereof.

[0051] In a sixth aspect, a computer-readable storage medium is provided, which stores computer program code that, when executed on a computer, causes the computer to perform the self-calibration method of the lidar in the first aspect or any possible implementation thereof.

[0052] The self-calibration method, lidar, device, electronic device, and computer-readable storage medium provided in the embodiments of this application have the following technical effects:

[0053] The self-calibration method for lidar provided in this application embodiment pre-sets a first marker and a second marker with different positions and reflectivities on the inner wall of the lidar window. By first controlling the laser transceiver to emit a laser beam, then acquiring the first echo signal of the laser beam reflected by the first marker and the second echo signal of the laser beam reflected by the second marker, and then calculating the difference information between the first and second echo signals, the operating parameters of the laser transceiver are determined based on the difference information and preset difference information. This technical solution achieves self-calibration of the lidar's operating parameters. The calibration work requires no manual intervention, no specific calibration equipment, and is not limited by location; it can be performed anytime and anywhere. This not only simplifies the calibration process of the lidar's operating parameters but also reduces the cost of calibration work and improves the efficiency of calibration. Attached Figure Description

[0054] Figure 1 A schematic flowchart of a self-calibration method for lidar provided in an embodiment of this application is shown;

[0055] Figure 2 A schematic diagram of the internal structure of the lidar provided in an embodiment of this application is shown;

[0056] Figure 3 A plan view of the window panel is shown;

[0057] Figure 4 This paper shows an internal structural block diagram of a lidar provided in an embodiment of the present application;

[0058] Figure 5 An exemplary schematic diagram showing the setting of a first identifier and a second identifier is shown;

[0059] Figure 6Another exemplary schematic diagram showing the setting of the first and second identifiers is shown;

[0060] Figure 7 Another exemplary schematic diagram showing the setting of the first identifier and the second identifier is shown;

[0061] Figure 8 A schematic diagram of the structure of a self-calibration device for a lidar provided in an embodiment of this application is shown;

[0062] Figure 9 A schematic diagram of the structure of an electronic device provided in an embodiment of this application is shown. Detailed Implementation

[0063] The technical solutions in this application will be clearly and thoroughly described below with reference to the accompanying drawings. In the description of the embodiments of this application, unless otherwise stated, " / " means "or," for example, A / B can mean A or B. "And / or" in the text is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Furthermore, in the description of the embodiments of this application, "multiple" refers to two or more than two.

[0064] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating 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.

[0065] The application of lidar is becoming increasingly widespread with the expansion of high-tech industries, and its visual presentation effects are quite remarkable. However, the safe use of lidar remains a top priority for the industry. During actual use, as the usage time increases, the internal functional modules of the lidar gradually age, causing changes in its operating parameters (such as transmit power and receive conversion efficiency), thus reducing its ranging capability. Therefore, calibrating the operating parameters of the lidar is one of the key steps in its use.

[0066] In existing technologies, lidar operating parameters need to be calibrated at the factory. This calibration is done manually in a specific calibration environment. After manual calibration, the values ​​are written into memory for data processing. However, once the lidar is in use, its internal components gradually age, causing the actual operating parameters to deviate from the calibrated values. This leads to decreased measurement accuracy, and returning the lidar for calibration is time-consuming and labor-intensive. For example, a lidar's operating parameter is its transmit power, also known as the output power of the laser beam. Correcting this transmit power typically requires specific equipment, such as a standard reflectivity plate, power meter, and point cloud acquisition equipment. This calibration process is complex and cumbersome, making it difficult to perform anytime, anywhere. In addition, in actual use, ambient temperature will also affect the transmission power of lidar, resulting in unstable radar performance. Currently, compensation is mainly achieved by introducing temperature calibration and reserving margins, which increases production costs and the compensation effect is not good. Therefore, there is a need for a lidar that can perform self-calibration after leaving the production line.

[0067] The calibration values ​​obtained from the calibration of operating parameters during the manufacturing process of a lidar are used for data calculation. Therefore, calibration of operating parameters before the lidar leaves the production line is a necessary process, and only one calibration is required. Since the calibration of lidar operating parameters occurs before the lidar leaves the production line, i.e., before the lidar is put into use, there is no issue of device aging. This means that for lidar operating parameter calibration, there is no need to find a method to achieve self-calibration of lidar operating parameters to solve the problem of inaccurate measurements due to device aging. This application mainly addresses the problem of inaccurate measurements caused by device aging during the operation of a lidar after the operating parameters have been calibrated and the lidar has been put into actual use. Specifically, after a certain period of operation, the lidar devices age, the transmitter power decreases, or the photoelectric conversion capability of the receiver decreases, resulting in a smaller amplitude of the reflected signal. Sampling and calculating the reduced reflected signal using the sampling threshold and reflectivity value calibrated at the factory based on the ideal reflected signal amplitude will lead to inaccurate detection results; a decrease in transmitter power will also reduce ranging capability. Therefore, based on the problem of inaccurate measurement caused by device aging during operation of lidar, this application proposes a self-calibration method, lidar, device, electronic device, and computer-readable storage medium for lidar, which can realize the self-calibration of the operating parameters of lidar, simplify the operating parameter calibration process, improve measurement accuracy and calibration efficiency, and reduce production costs.

[0068] The following is an embodiment of a self-calibration method for lidar provided in this application.

[0069] Figure 1 This illustration shows a schematic flowchart of a self-calibration method for lidar provided in an embodiment of this application. Figure 2 A schematic diagram of the internal structure of the lidar provided in an embodiment of this application is shown. Figure 1 and Figure 2 As shown in the embodiment of this application, the self-calibration method of the lidar is applied to the lidar, which includes a laser transceiver, a scanning device 4, and a window 7. The laser transceiver includes a laser receiver 1, a laser emitter 2, an optical device 3, and a folding mirror 6. The laser emitter 2 includes a laser and a laser driving module. A first mark 5 and a second mark 8 are provided on the inner wall of the periphery of the window 7. The positions of the first mark 5 and the second mark 8 are different, and the reflectivity of the first mark 5 and the second mark 8 are different. The first mark 5 and the second mark 8 reflect the laser beam generated by the laser transceiver.

[0070] The self-calibration methods for the aforementioned lidar include the following schemes:

[0071] S110: Control the laser transceiver to emit a laser beam;

[0072] S120: Obtain the first echo signal of the laser beam reflected by the first identifier, and the second echo signal of the laser beam reflected by the second identifier;

[0073] S130: Determine the difference information between the first echo signal and the second echo signal;

[0074] S140: Determine the operating parameters of the laser transceiver based on the difference information and the preset difference information.

[0075] In one exemplary embodiment, the lidar has a self-calibration function. During actual use, the lidar calibrates the operating parameters of the laser transceiver once at regular intervals to ensure the reliability of the lidar and improve the accuracy of detection and ranging capability. The calibration of the operating parameters of the laser transceiver can also be understood as recalibrating the operating parameters of the laser transceiver.

[0076] After the self-calibration function of the lidar is triggered, the laser transceiver is controlled to emit a laser beam. That is, the laser driver module drives the laser to emit a laser beam. The laser beam is output to the reflector through the optical device. The laser beam is reflected by the reflector to the scanning device. After passing through the scanning device, the laser beam will reach the window. Most of the laser beam that reaches the window will be projected into the external environment through the window. The laser beam at the edge of the field of view will be reflected by the first and second markers, so that the first echo signal of the laser beam reflected by the first marker and the second echo signal of the laser beam reflected by the second marker can be obtained.

[0077] After acquiring the first and second echo signals, the difference between them is calculated. This difference is then compared to a preset difference, which serves as the basis for determining whether to adjust the operating parameters of the laser transceiver. Since the laser transceiver is a key active device in the front-end of a lidar system, its operating parameters can also be understood as the operating parameters of the lidar system.

[0078] Based on the comparison results, if the difference between the obtained and preset difference information is small, it indicates that the detection accuracy and ranging capability of the lidar are normal, and no adjustment of the operating parameters of the laser transceiver is needed. Conversely, if the difference between the obtained and preset difference information is large, it indicates that the detection accuracy and ranging capability of the lidar have decreased. In this case, the operating parameters of the laser transceiver are adjusted to restore the lidar's detection accuracy and ranging capability to their initial state. This ensures that the detection accuracy and ranging capability of the lidar in use are consistent with its factory settings, avoiding inconsistent detection results in the same scene due to fluctuations. This achieves self-calibration of the operating parameters of the laser transceiver, eliminating the need for manual intervention or specific calibration equipment, simplifying the calibration process and improving efficiency. The adjusted operating parameters can be either transmission or reception parameters. Adjusting these parameters corrects the transmission power and reception conversion efficiency, thus restoring the amplitude of the echo signal to its initial state. In addition, the bias voltage of the laser transceiver can also be adjusted. However, adjusting the bias voltage will affect other quantities in the receiving link, such as the amplitude of the preamble signal, and affect subsequent signal sampling. Therefore, this application prefers to correct the transmission power of the laser transceiver.

[0079] The self-calibration method for lidar provided in this application embodiment pre-sets a first marker and a second marker with different positions and reflectivities on the inner wall of the lidar window. By first controlling the laser transceiver to emit a laser beam, then acquiring the first echo signal of the laser beam reflected by the first marker and the second echo signal of the laser beam reflected by the second marker, and then calculating the difference information between the first and second echo signals, the operating parameters of the laser transceiver are determined based on the difference information and preset difference information. This technical solution achieves self-calibration of the lidar's operating parameters. The calibration work requires no manual intervention, no specific calibration equipment, and is not limited by location; it can be performed anytime and anywhere. This not only simplifies the calibration process of the lidar's operating parameters but also reduces the cost of calibration work and improves the efficiency of calibration.

[0080] The following are Figure 1 The specific implementation methods of each step in the illustrated embodiment will be explained below:

[0081] In one possible implementation, the operating parameters of the laser transceiver include the transmission power of the laser beam emitted by the laser transceiver. In S110 above, controlling the laser beam emitted by the laser transceiver includes the following schemes:

[0082] The laser transceiver is controlled to emit a laser beam with a first emission power.

[0083] It should be understood that before the operating parameters of the laser transceiver are adjusted, the laser transceiver emits a first laser beam according to a preset timing sequence. The power of the first laser beam is the first transmission power. The first transmission power can be determined by the calibration results at the time of manufacture of the lidar, or it can be determined after the last self-calibration. During the first transmission cycle after the lidar's self-calibration function is triggered, the laser transceiver continues to emit a laser beam with the first transmission power. The triggering of the lidar's self-calibration function can be customized according to actual needs, such as triggering the self-calibration function at specific time intervals, such as the lidar performing self-calibration every 30 days of operation; or performing self-calibration every time the lidar is powered on.

[0084] In one possible implementation, the above-mentioned S140, determining the operating parameters of the laser transceiver based on the difference information and preset difference information, includes the following schemes:

[0085] Determine the difference between the discrepancy information and the preset discrepancy information;

[0086] When the difference is greater than or equal to the preset value, the laser transceiver is controlled to emit a laser beam with a second transmission power according to the difference.

[0087] Return to step S120, which involves acquiring the first echo signal of the first identified reflected laser beam and the second echo signal of the second identified reflected laser beam, until the difference is less than a preset value.

[0088] After controlling the laser transceiver to emit a laser beam with a first emission power, the system acquires the first echo signal of the laser beam reflected by a first identifier and the second echo signal of the laser beam reflected by a second identifier. Then, it calculates the difference between the first and second echo signals and compares this difference with a preset difference value. If the difference is large, it indicates a significant decrease in the detection accuracy and ranging capability of the laser radar. In this case, the system adjusts the emission power of the laser transceiver to adjust its operating parameters. Specifically, the system determines the difference between the initial difference and the preset difference value and compares them. If the difference is less than the preset value, the difference is close to the preset value; if the difference is greater than or equal to the preset value, the difference is large.

[0089] The transmission power of the laser transceiver is determined based on the difference information and preset difference information. If the difference is less than the preset value, the first transmission power remains unchanged; if the difference is greater than or equal to the preset value, the first transmission power is adjusted to the second transmission power. The second transmission power is not the same as the first transmission power; it may be greater than or less than the first transmission power.

[0090] When the difference is greater than or equal to a preset value, the laser transceiver is controlled to emit a laser beam with a second emission power, and then the process returns to execute S120. That is, after controlling the laser transceiver to emit a laser beam with a first emission power, the first echo signal corresponding to the first identifier and the second echo signal corresponding to the second identifier are acquired, and the difference information between the two echo signals is compared with the preset difference information using the same method described above. After adjusting the emission power of the laser beam emitted by the laser transceiver, if the difference is less than the preset value, it indicates that the detection accuracy and ranging capability of the lidar have been restored to the initial state. Therefore, the emission power of the laser transceiver is no longer adjusted, the adaptive adjustment process is exited, and the adjusted emission power continues to operate.

[0091] If the difference is still large, for example, greater than or equal to the preset value, then continue to control the laser transceiver to emit a laser beam with the second transmission power according to the difference information and the preset difference information, and return to execute S120 to obtain the first echo signal corresponding to the first identifier and the second echo signal corresponding to the second identifier, compare the difference information with the preset difference information, until the difference is less than the preset value.

[0092] Through the above iterative process, the transmission power of the laser transceiver is continuously adjusted until the transmission power of the adjusted laser beam can compensate for the deviation caused by the performance degradation of the laser transceiver. The difference between the difference information of the two echo signals and the preset difference information meets the preset value, thereby restoring the detection accuracy and ranging capability of the lidar to the initial state.

[0093] When the difference is less than the preset value, it means that the detection accuracy and ranging capability of the lidar remain in the initial state, and there is no need to adjust the transmission power of the laser beam emitted by the laser transceiver. Then, the laser transceiver continues to be controlled to emit a laser beam with the first transmission power, and exits the adaptive adjustment process.

[0094] In one possible implementation, the method of controlling the laser transceiver to emit a laser beam with a second transmission power based on the difference when the difference is greater than or equal to a preset value includes the following schemes:

[0095] The first transmission power charging time of the laser beam with the first transmission power emitted by the laser transceiver in the previous transmission cycle is obtained.

[0096] The charging time of the transmission power change is determined based on the difference;

[0097] Based on the first transmit power charging time and the transmit power charging change time, determine the second transmit power charging time required for the laser transceiver to transmit a laser beam with the second transmit power in the current transmit cycle.

[0098] The laser transceiver is driven by the charging time of the second transmission power so that it can transmit a laser beam with the second transmission power.

[0099] The laser transceiver drives the laser through a charging-conversion-enabling process to precisely control its transmission power. Adjusting the transmission power of the laser transceiver is achieved by controlling the charging time, as follows:

[0100] The process involves obtaining the first transmit power charging time S_last of the laser beam emitted by the laser transceiver in the previous transmission cycle, determining the charging time adjustment based on the difference, and calculating the transmit power charging change time ΔS. The second transmit power is adjusted based on the detection results of the laser beam with the first transmit power. Using S_last and ΔS, the second transmit power charging time S_put required for the laser transceiver to emit the laser beam in the current transmission cycle is calculated as S_put = S_last + ΔS. The transmit power control module controls the laser beam emission of the laser transceiver, adjusting the transmit power by controlling the charging time. The transmit power control module primarily uses a PID controller. The PID controller's set proportional parameter KP = a (e.g., a = 1), integral parameter KI = b (e.g., b = 0.05), and derivative coefficient KD = c (e.g., c = 0). The formula for calculating ΔS is: ΔS = (J*KP + J*KI + J*KD)*EC, where EC is the energy-to-charge conversion coefficient, and J is the difference between the difference information and the preset difference information.

[0101] After obtaining S_put, the laser transceiver is driven by the second transmit power charging time S_put, and the laser transceiver emits a laser beam with the second transmit power, thus achieving laser beam transmit power adjustment. The process of driving the laser transceiver to emit a laser beam with the second transmit power using the second transmit power charging time S_put includes: the transmit power control module controls the charging module to continuously charge the charging module for the second transmit power charging time S_put, accumulating energy on the charging capacitor. The longer the second transmit power charging time S_put, the more energy accumulates on the charging capacitor. Charging is completed after the second transmit power charging time S_put ends; then, all the energy accumulated on the charging capacitor is transferred to the conversion capacitor of the conversion module; upon receiving the enable signal, the energy on the conversion capacitor is released all at once, and the laser emits a laser beam with the second transmit power. Based on the driving characteristics of the laser transceiver, ΔS is calculated based on the difference between the previous cycle's transmission charging time S_last and the calculated charging time of the current cycle. Then, based on the calculated charging time of the current cycle, S_put is further calculated to determine the laser beam required by the laser transceiver to transmit in the current transmission cycle. Using S_last to drive the laser transceiver enables the laser driver module to respond quickly and achieve rapid adjustment of the transmission power.

[0102] In one possible implementation, the above-mentioned S130, determining the difference information between the first echo signal and the second echo signal, includes the following schemes:

[0103] Obtain the first signal curve of the first echo signal;

[0104] Obtain the second signal curve of the second echo signal;

[0105] Based on the first signal curve and the second signal curve, the energy difference between the echo energy of the first echo signal and the echo energy of the second echo signal is determined, and the difference information is obtained.

[0106] After being reflected by the first marker, the laser beam returns to its first reflected beam. This first reflected beam is received by the laser receiving device and, after photoelectric conversion, is converted into a first echo signal. The first echo signal curve is a curve showing the voltage changing over time, which can be represented by a function. The horizontal axis of the first echo signal curve represents time, and the vertical axis represents voltage. Similarly, after being reflected by the second marker, the laser beam returns to its second reflected beam. This second reflected beam is received by the laser receiving device and, after photoelectric conversion, is converted into a second echo signal. The second echo signal curve is also a curve showing the voltage changing over time, which can be represented by a function.

[0107] Since the emitted laser beam is pulsed, the received reflected beam is also pulsed, but with a wider pulse width than the emitted laser beam. The echo energy of the first echo signal is obtained by integrating the function corresponding to the first echo signal, which is equivalent to calculating the area enclosed by the first signal curve and the horizontal axis. Similarly, the echo energy of the second echo signal is obtained by integrating the function corresponding to the first echo signal, which is the area enclosed by the second signal curve and the horizontal axis.

[0108] The energy difference between the echo energy of the first echo signal and the echo energy of the second echo signal is calculated by subtracting their respective energy values. This energy difference represents the difference information between the first and second echo signals. Calculating this energy difference as difference information can eliminate background noise in the echo signal, reduce the impact of ambient light changes on the echo energy, and thus avoid affecting the self-calibration judgment and adjustment.

[0109] In addition, by establishing the first signal curve, the change in echo energy of the first echo signal can be visualized. By establishing the second signal curve, the change in echo energy of the second echo signal can be visualized. Combining the first signal curve and the second signal curve, the difference between the first echo signal and the second echo signal can be seen intuitively.

[0110] In one possible implementation, the above-described S120, which involves acquiring the first echo signal of the laser beam reflected by the first identifier and the second echo signal of the laser beam reflected by the second identifier, includes the following scheme:

[0111] Determine whether the laser beam is directed at the first and / or second marker;

[0112] When the laser beam is directed at the first and second markers, the first signal analysis area corresponding to the first marker and the second signal analysis area corresponding to the second marker are determined.

[0113] The reflected signal of the laser beam received by the laser transceiver in the first signal analysis area is obtained to obtain the first echo signal;

[0114] The reflected signal of the laser beam received by the laser transceiver in the second signal analysis area is obtained to obtain the second echo signal.

[0115] The lidar system contains a clock module, and the laser beams are emitted sequentially, each with a corresponding timestamp. Taking a laser beam L1 as an example during the operation of the laser transceiver, laser beam L1 has a corresponding analysis zone. The start time of the analysis zone is the emission time of laser beam L1, and the duration of the analysis zone is greater than or equal to the maximum flight time of laser beam L1. The reception time of the reflected beam R1 corresponding to laser beam L1 falls within the analysis zone.

[0116] The positions of the first and second identifiers within the field of view are known. Based on this known position information, the corresponding sub-regions and the emission timestamps of the laser beams are determined, thereby identifying the corresponding analysis areas. Specifically, the first identifier corresponds to sub-region i (e.g., the m-th row and n-th column, where m and n are both positive integers) within the field of view. The i-th laser beam emitted during the detection cycle scans this sub-region i, and the emission time and duration of the i-th laser beam are obtained, thus determining the first signal analysis area corresponding to the first identifier. Here, 1 ≤ i ≤ k, i is an integer, and k is the number of laser beams emitted within one detection cycle. The method for determining the second signal analysis area corresponding to the second identifier is similar and will not be repeated here.

[0117] The laser transceiver emits laser beams sequentially within the detection period, while simultaneously receiving reflected beams. Because the distances to the objects in the field of view vary, resulting in different photon flight times, the reflected beams are not received sequentially within the detection period. Therefore, based on the first signal analysis area corresponding to the first identifier and the second signal analysis area corresponding to the second identifier, the first and second echo signals can be accurately acquired within the corresponding time periods.

[0118] In one possible implementation, the determination of whether the laser beam is directed at the first and / or second identifier includes the following schemes:

[0119] Determine the exit angle of the laser beam emitted by the laser transceiver;

[0120] Determine whether the emission angle matches the specific field of view corresponding to the first and second marks. If so, determine that the laser beam is directed towards the first mark and / or the second mark.

[0121] Within a detection cycle, the laser transceiver sequentially emits laser beams to scan the field of view, with each laser beam corresponding to a sub-region within the scanned field of view. The detection cycle comprises multiple emission cycles, with at least one laser beam emitted in each cycle. For lidar with a scanning device, the laser beam emitted by the transceiver is directed towards the target area via the scanning device to achieve scanning. Within a detection cycle, the sequentially emitted laser beams are deflected by the scanning device and emitted outwards at a corresponding field of view angle, targeting a sub-region within the field of view.

[0122] The positions of the first and second markers within the field of view are known. Based on this known position information, a specific field of view range corresponding to the first and second markers is determined. The field of view of the laser beam emitted by the laser transceiver is then compared with this specific field of view range. If the field of view is within the specific field of view range, the laser beam is determined to be directed towards the first and / or second marker. Typically, a laser beam is directed towards only one marker. However, when the first and second markers are adjacent, it is possible for a laser beam to be directed precisely at the point where the two markers meet. Specifically, the field of view of the laser transceiver covers a horizontal angle of -12° to 12° and a vertical angle of -11° to 11°. The specific field of view range corresponding to the first marker is -12° to -11° horizontally and 10° to 11° vertically. The exit angle of laser beam L1 after deflection by the scanning device is -12° horizontally and -11° vertically. Since the exit angle of laser beam L1 is within the specific field of view range, it is determined that laser beam L1 is directed towards the first marker. Similarly, the method for determining whether to shoot at the second marker is similar and will not be repeated here.

[0123] By establishing the correspondence between the emission angle and the field of view, it is possible to directly determine whether the currently emitted laser beam is directed towards the first and / or second marker. If so, the first or second signal analysis area can be further determined based on the timestamp of the currently emitted laser beam, and the first and second echo signals can be accurately acquired.

[0124] As mentioned above, the laser beam is projected outwards into the field of view through the window, and the size of the window is generally matched to the size of the field of view. In order to make full use of the light-transmitting area of ​​the window, the field of view formed by the laser beam emitted by the laser transceiver after being deflected by the scanning device will be slightly larger than the light-transmitting area of ​​the window. That is, a small part of the laser beam falls on the edge area of ​​the window, or even on the inner wall of the outer shell surrounding the window. This is also the reason why the first and second marks are set on the inner wall of the window in this application, so as to combine the physical structure with the software method to realize the self-calibration of the lidar.

[0125] In one possible implementation, the determination of the emission angle of the laser beam emitted by the laser transceiver includes the following schemes:

[0126] Acquire the pitch and yaw angles of the scanning device;

[0127] Determine the vertical exit angle from the exit angle based on the pitch angle;

[0128] The horizontal exit angle is determined based on the yaw angle.

[0129] Because the laser beam is emitted outward through a window after passing through a scanning device, in a lidar system using a galvanometer as the scanning device, the laser beam emitted by the laser transceiver is deflected by the galvanometer and emitted outward at a certain emission angle, including a vertical emission angle and a horizontal emission angle. The principle by which the galvanometer reflects the laser beam and changes its field of view is as follows: when the galvanometer vibrates, it corresponds to an elevation angle and a yaw angle, which change periodically. The elevation angle determines the vertical scanning angle of the laser beam, i.e., the vertical emission angle, and the yaw angle determines the horizontal scanning angle of the laser beam, i.e., the horizontal emission angle. The elevation angle of the galvanometer corresponds to the vertical emission angle, and the yaw angle corresponds to the horizontal emission angle. Based on the feedback signal of the galvanometer, the elevation angle and yaw angle of the galvanometer can be obtained, thereby yielding the corresponding vertical and horizontal emission angles of the laser beam.

[0130] The embodiments of this application achieve the following specific effects through the self-calibration method of the aforementioned lidar:

[0131] 1. As the usage time of lidar increases, the lifespan of the laser transceiver gradually decreases, and the energy of the laser beam emitted by the laser in the laser transceiver will experience a certain energy attenuation, resulting in a decrease in the ranging capability of the laser beam at the same transmission power. This application embeds a real-time automatic calibration device for the transmission power of the lidar into the lidar, enabling a self-calibration method. The lidar will recalibrate or adjust the transmission power of the laser beam emitted by the laser transceiver at certain usage cycles to meet the ranging requirements.

[0132] 2. This application integrates the above-mentioned self-calibration method of lidar into the lidar system in the form of software, eliminating the step of setting up a special laser beam emission power calibration station, requiring no specific calibration equipment and not being limited by the site, and eliminating the need for return to the factory for processing.

[0133] 3. In existing technologies, when a lidar is in the testing phase, the emission power calibration process is inevitably repeated, and the data needs to be reprocessed after each calibration. This application, however, is applicable to the testing phase of lidar, can adapt to lidar emission power calibration in different environments, and stores and compares the data, facilitating self-checking when error warnings are generated.

[0134] 4. This application adopts a new method for real-time automatic calibration of transmission power and designs a control system model to standardize and systematize the parameter adjustment of transmission power. Compared with the traditional method of power meter measurement combined with reflectivity data acquisition, the technical solution of this application has a stable data source, and at the same time, by adjusting dynamic parameters and plotting curves, the variables can be visualized.

[0135] The following is an embodiment of a lidar provided in this application.

[0136] like Figure 2 As shown in the figure, an embodiment of this application provides a lidar including a laser transceiver, a scanning device 4, a window 7, and a parameter correction module. Wherein:

[0137] like Figure 3 As shown, Figure 3 A plan view of the window plate is shown. A first identifier 5 and a second identifier 8 are disposed on the inner wall of the periphery of the window plate 7. The positions of the first identifier 5 and the second identifier 8 are different, and the reflectivity of the first identifier 5 and the second identifier 8 are different. The first identifier 5 and the second identifier 8 reflect the laser beam emitted by the laser transceiver. The window plate 7 has a viewing area and a non-viewing area surrounding the viewing area. The viewing area allows the laser beam and reflected beam to pass through for detection of the field of view. The non-viewing area is typically the area where the window plate 7 meets the radar housing and is opaque. The first identifier 5 and the second identifier 8 are usually disposed in the non-viewing area, i.e., on the inner wall of the periphery of the window plate 7.

[0138] The laser transceiver includes a laser receiver 1, a laser transmitter 2, an optical device 3, and a folding mirror 6; the laser transmitter 2 includes a laser and a laser driver module. The laser transceiver is used to transmit a laser beam and acquire the first echo signal of the laser beam reflected by the first identifier 5 and the second echo signal of the laser beam reflected by the second identifier 8.

[0139] The parameter correction module is used to determine the difference information between the first echo signal and the second echo signal, and to determine the operating parameters of the laser transceiver based on the difference information and the preset difference information.

[0140] The working principle of adjusting the operating parameters of the laser transceiver device in a lidar system is as follows:

[0141] LiDAR has a self-calibration function. During actual use, the operating parameters of the laser transceiver are calibrated at regular intervals to ensure the reliability of the lidar and improve detection accuracy and ranging capability. This calibration of the laser transceiver's operating parameters can also be understood as standardizing its operation.

[0142] After the self-calibration function of the lidar is triggered, the laser transceiver emits a laser beam, that is, the laser driver module drives the laser to emit a laser beam. The laser beam is output to the folding mirror 6 through the optical device 3. The laser beam is reflected by the folding mirror 6 to the scanning device 4. After passing through the scanning device 4, the laser beam will reach the window plate 7. Most of the laser beam that reaches the window plate 7 will be emitted into the external environment through the window plate 7. The laser beam at the edge of the field of view will be reflected by the first marker 5 and the second marker 8. The laser receiving device can obtain the first echo signal of the laser beam reflected by the first marker 5 and the second echo signal of the laser beam reflected by the second marker 8.

[0143] After the laser receiving device acquires the first and second echo signals, the parameter correction module calculates the difference information between them. This difference information is then compared with preset difference information, which serves as the basis for determining whether to adjust the operating parameters of the laser transceiver. Since the laser transceiver is a key active device in the front end of a lidar system used for detection, its operating parameters can also be understood as the operating parameters of the lidar system.

[0144] Based on the comparison results, the parameter correction module determines the following: if the difference between the obtained and preset difference information is small, it indicates that the detection accuracy and ranging capability of the lidar are normal, and no adjustment of the operating parameters of the laser transceiver is needed. Conversely, if the difference between the obtained and preset difference information is large, it indicates that the detection accuracy and ranging capability of the lidar have decreased, and the operating parameters of the laser transceiver are adjusted to restore the lidar's detection accuracy and ranging capability to their initial state. This ensures that the detection accuracy and ranging capability of the lidar in use are consistent with its factory settings, avoiding inconsistent detection results in the same scene due to fluctuations. This achieves self-calibration of the operating parameters of the laser transceiver, eliminating the need for manual intervention or specific calibration equipment, simplifying the calibration process and improving efficiency. The adjusted operating parameters can be either transmission or reception parameters. Adjusting these parameters corrects the transmission power and reception conversion efficiency, thus restoring the amplitude of the echo signal to its initial state. In addition, the bias voltage of the laser transceiver can also be adjusted, but after the bias voltage is adjusted, it will affect other quantities on the receiving link, such as the preamble signal. Therefore, this application prefers to correct the transmission power of the laser transceiver.

[0145] Figure 4The diagram shows the internal structure of the lidar provided in an embodiment of this application, as follows: Figure 4 As shown, the parameter correction module includes: an angle acquisition module, a signal extraction module, an energy difference calculation module, an energy difference setting module, and a transmit power control module. The specific process of adjusting the operating parameters of the laser transceiver is as follows:

[0146] The operating parameters of the laser transceiver include the transmission power of the laser beam emitted by the laser transceiver. The laser transceiver emits a laser beam with the first transmission power according to a preset timing sequence. After the laser beam with the first transmission power passes through the scanning device 4 (galvanometer), the galvanometer reflects the laser beam, and the scanning device 4 outputs the laser beam to the window plate 7. When the galvanometer reflects the laser beam, the angle acquisition module can identify the pitch and yaw angles of the galvanometer during reflection. Since the pitch angle and vertical exit angle of the galvanometer correspond, and the yaw angle and horizontal exit angle of the galvanometer correspond, the angle acquisition module can identify the pitch and yaw angles of the galvanometer and obtain the corresponding vertical and horizontal exit angles of the laser beam based on the correspondence. That is, it obtains the exit angle of the laser beam. Then, based on the exit angle of the laser beam, it determines whether the laser beam is directed towards the first marker 5 and / or the second marker 8. In other words, it determines whether the exit angle of the laser beam matches the specific field of view corresponding to the first marker 5 and the second marker 8. If so, it is determined that the laser beam is directed towards the first marker 5 and / or the second marker 8. Then, the angle acquisition module sends the determination result of the laser beam being directed towards the first marker 5 and the second marker 8 to the signal extraction module.

[0147] After receiving the judgment result from the angle acquisition module, the signal extraction module determines the first signal analysis area corresponding to the first identifier 5 and the second signal analysis area corresponding to the second identifier 8. Then, it acquires the reflected signal of the laser beam received by the laser transceiver in the first signal analysis area to obtain the first echo signal, and acquires the reflected signal of the laser beam received by the laser transceiver in the second signal analysis area to obtain the second echo signal. Thus, it acquires the first echo signal of the laser beam reflected by the first identifier 5 and the second echo signal of the laser beam reflected by the second identifier 8. After acquiring the first and second echo signals, the signal extraction module obtains a first signal curve and a second signal curve. Both the first and second signal curves are voltage-time curves, which can be represented by functions. The area enclosed by the first signal curve and the horizontal axis is calculated to obtain the echo energy of the first echo signal, and the area enclosed by the second signal curve and the horizontal axis is calculated to obtain the echo energy of the second echo signal. Then, the echo energy of the first and second echo signals are sent to the energy difference calculation module.

[0148] After receiving the echo energy of the first echo signal and the echo energy of the second echo signal sent by the signal extraction module, the energy difference calculation module calculates the energy difference between them. It then compares this energy difference with a preset energy difference sent by the energy difference setting module and determines whether the difference is greater than or equal to a preset value. If the difference is greater than or equal to the preset value, the module sends the result (the difference value) and the preset energy difference to the transmit power control module. The energy difference setting module stores a preset energy difference, pre-set according to scenario requirements. It transmits the required laser beam power to the first and second markers (5 and 8) with known reflectivities, obtaining the theoretical energy difference between the echo signals of the laser beams reflected by the first and second markers (5 and 8). This theoretical energy difference is then used as the preset energy difference.

[0149] After receiving the judgment result and difference value sent by the energy difference calculation module, the transmit power control module obtains S_last, the laser beam with the first transmit power emitted by the laser transceiver in the previous transmission cycle. It then calculates ΔS using the formula ΔS = (J*KP + J*KI + J*KD)*EC. After obtaining ΔS, it calculates S_put, the laser beam with the second transmit power required for the laser transceiver to emit in the current transmission cycle, based on S_last and ΔS: S_put = S_last + ΔS.

[0150] After the transmit power control module calculates S_put, it uses S_put to drive the laser drive module. The laser drive module drives the laser to emit a laser beam with the second transmit power, thereby quickly adjusting the first transmit power of the laser beam emitted by the laser transceiver to the second transmit power.

[0151] After the laser transceiver emits a laser beam with the second emission power, the process of the laser transceiver emitting a laser beam with the first emission power is repeated until the energy difference calculation module calculates and determines whether the difference between the energy difference and the preset energy difference is greater than or equal to the preset value. If the difference is less than the preset value, it means that the detection accuracy and ranging capability of the lidar have been restored to the initial state. In this case, the emission power will no longer be adjusted, the adaptive adjustment process will be exited, and the adjusted emission power will continue to work.

[0152] If the difference is still large, for example, greater than or equal to the preset value, continue the above repeated process until the difference is less than the preset value.

[0153] Through the above iterative process, the transmission power of the laser transceiver is continuously adjusted until the transmission power of the adjusted laser beam can compensate for the deviation caused by the performance degradation of the laser transceiver. The difference between the difference information of the two echo signals and the preset difference information meets the preset value, thereby restoring the detection accuracy and ranging capability of the lidar to the initial state.

[0154] If the difference is less than the preset value, it means that the detection accuracy and ranging capability of the lidar remain in the initial state, and there is no need to adjust the transmission power of the laser beam emitted by the laser transceiver. Then, the laser transceiver continues to be controlled to emit a laser beam with the first transmission power, and exits the adaptive adjustment process.

[0155] This application provides a lidar that can self-calibrate its operating parameters, keeping the lidar's detection accuracy and ranging capability in their initial state. The calibration work does not require manual intervention or specific calibration equipment, simplifying the calibration process and improving the efficiency of the calibration work.

[0156] In one possible implementation, the first marker 5 is coated with a reflective material, the reflectivity of which differs from that of the inner wall surrounding the window 7. The second marker 8 has the same reflectivity as the inner wall surrounding the window 7. For example, a specific location on the inner wall surrounding the window 7 can be selected as the second marker 8. This means that after the first marker 5 is coated with the reflective material, its reflectivity differs from that of the second marker 8, allowing both markers to reflect the laser beam and distinguish the echo signals of the reflected laser beam. Alternatively, the first marker 5 is coated with a first reflective material, and the second marker 8 is coated with a second reflective material. The reflectivity of the first reflective material differs from that of the second reflective material, resulting in a difference in reflectivity between the first marker 5 and the second marker 8. This also allows both markers to reflect the laser beam and distinguish the echo signals of the reflected laser beam.

[0157] One possible implementation is, such as Figure 2As shown, the laser transceiver includes multiple units. Multiple identification combinations are arranged on the inner wall of the window 7, each combination including a first identification 5 and a second identification 8. Each laser transceiver corresponds to one identification combination. By setting multiple laser transceivers, each positioned at a different location, the emission angle of the laser beam emitted by the lidar can be increased, thereby expanding the lidar's detection range. Each laser transceiver corresponds to one identification combination; that is, the laser beam emitted by each laser transceiver is directed towards its corresponding identification. The adjustment method for the operating parameters of each laser transceiver is similar. Specifically, after emitting a laser beam, each laser transceiver acquires the first echo signal reflected from the first identification 5 and the second echo signal reflected from the second identification 8. The parameter correction module determines the difference between the first and second echo signals and, based on this difference and a preset difference, determines the operating parameters of the laser transceiver. Since the devices in each channel operate independently and their aging states differ, each channel uses the aforementioned adjustment method to correct its operating parameters.

[0158] In one possible implementation, for each combination of identifiers, the first identifier 5 is positioned near the first edge of the inner wall surrounding the window panel 7, and the second identifier 8 is positioned near the second edge of the inner wall surrounding the window panel 7, with the first and second edges opposite each other. For example... Figure 5 As shown, Figure 5 An exemplary schematic diagram showing the setting of a first identifier and a second identifier is shown. Figure 5 The left image shows how the first identifier 5 and the second identifier 8 are set in a single identifier combination. Figure 5 The right figure shows the arrangement of the first identifier 5 and the second identifier 8 in a combination of multiple identifiers. The first identifier 5 and the second identifier 8 belong to the double-edge arrangement of the inner wall around the window 7. For a lidar with multiple channels arranged horizontally, the sub-field of view covered by each channel is also arranged horizontally. In this arrangement, the sub-field of view of each channel can cover the corresponding first identifier 5 and second identifier 8, and the arrangement method is simple.

[0159] In one possible implementation, for each combination of identifiers, the first identifier 5 and the second identifier 8 are both positioned near one edge of the inner wall of the window panel 7, with a gap between them, and the first identifier 5 and the second identifier 8 are parallel to each other. Figure 6 As shown, Figure 6 Another exemplary schematic diagram showing the setting of the first and second identifiers is shown. Figure 6 The left image shows how the first identifier 5 and the second identifier 8 are set in a single identifier combination. Figure 6The right figure shows the arrangement of the first identifier 5 and the second identifier 8 in a combination of multiple identifiers. The first identifier 5 and the second identifier 8 are arranged on a single edge of the inner wall around the window piece 7. As mentioned above, this arrangement can cover the corresponding first identifier 5 and second identifier 8 in the sub-field of view of each channel, and the arrangement method is simple.

[0160] In one possible implementation, for each combination of identifiers, the first identifier 5 and the second identifier 8 are both positioned near the single edge of the inner wall of the window panel 7, with the first identifier 5 and the second identifier 8 located on the same horizontal line and symmetrical to each other. For example... Figure 7 As shown, Figure 7 Another exemplary schematic diagram showing the setting of the first and second identifiers is shown. Figure 7 The left image shows how the first identifier 5 and the second identifier 8 are set in a single identifier combination. Figure 7 The right image shows the arrangement of the first identifier 5 and the second identifier 8 in a combination of multiple identifiers. The first identifier 5 and the second identifier 8 represent another arrangement of the single edge of the inner wall surrounding the window piece 7. For Figure 7 The method of setting the identifier combination shown in the right image is still applicable to the aforementioned LiDAR with multiple channels arranged horizontally, where each channel corresponds to one identifier combination. For Figure 7 The left-hand diagram shows that the channels of the first and second identifiers 5 and 8 in the sub-field of view coverage identifier combination can be self-corrected, for example, the channel located in the middle position.

[0161] like Figures 5-7 As shown, each combination of identifiers has a different setting method. That is, each combination of identifiers can be flexibly set on the inner wall of the window plate 7. No matter how it is set, as long as the reflectivity of the first identifier 5 and the second identifier 8 is different, the laser beam can be reflected by the first identifier 5 and the second identifier 8, thereby realizing the calibration of the working parameters of the laser transceiver. It can flexibly calibrate the working parameters of the laser transceiver and improve the feasibility of automatic calibration.

[0162] The following are embodiments of the apparatus described in this application, which can be used to execute the embodiments of the method described in this application. For details not disclosed in the apparatus embodiments of this application, please refer to the embodiments of the method described in this application.

[0163] Figure 8 A schematic diagram of a self-calibration device for a lidar according to an embodiment of this application is shown. For example,... Figure 8As shown, this application embodiment provides a self-calibration device for a lidar, configured on a lidar, the lidar including a laser transceiver and a window, the inner wall of the periphery of the window being provided with a first mark and a second mark, the positions of the first mark and the second mark being different, the reflectivities of the first mark and the second mark being different, the self-calibration device 800 of the lidar including:

[0164] The laser emitting module 810 is used to control the laser transceiver to emit a laser beam.

[0165] The echo acquisition module 820 is used to acquire the first echo signal of the laser beam reflected by the first identifier and the second echo signal of the laser beam reflected by the second identifier;

[0166] The difference calculation module 830 is used to determine the difference information between the first echo signal and the second echo signal;

[0167] The parameter adjustment module 880 is used to determine the operating parameters of the laser transceiver based on the difference information and the preset difference information.

[0168] In one possible implementation, the operating parameters include the transmission power of the laser beam emitted by the laser transceiver.

[0169] The laser emitting module 810 is specifically used to control the laser transceiver to emit a laser beam with a first emission power.

[0170] The parameter adjustment module 880 includes:

[0171] A difference calculation unit is used to determine the difference between the difference information and the preset difference information;

[0172] A first control unit is configured to control the laser transceiver to emit a laser beam with a second emission power based on the difference when the difference is greater than or equal to a preset value.

[0173] The second control unit is configured to return to the step of acquiring the first echo signal of the laser beam reflected by the first identifier and the second echo signal of the laser beam reflected by the second identifier, until the difference is less than a preset value.

[0174] In one possible implementation, the first control unit includes:

[0175] The time acquisition subunit is used to acquire the first transmission power charging time of the laser transceiver device transmitting the laser beam with the first transmission power in the previous transmission cycle.

[0176] The first calculation subunit is used to determine the transmission power charging change time based on the difference;

[0177] The second calculation subunit is used to determine the second transmission power charging time required for the laser transceiver to transmit the laser beam with the second transmission power in the current transmission cycle, based on the first transmission power charging time and the transmission power charging change time.

[0178] A driving subunit is used to drive the laser transceiver device with the second transmit power charging time, so that the laser transceiver device transmits a laser beam with the second transmit power.

[0179] In one possible implementation, the difference calculation module 830 includes:

[0180] The curve acquisition unit is used to acquire a first signal curve of the first echo signal and a second signal curve of the second echo signal.

[0181] The difference calculation unit is used to determine the energy difference between the echo energy of the first echo signal and the echo energy of the second echo signal based on the first signal curve and the second signal curve, and obtain the difference information.

[0182] In one possible implementation, the echo acquisition module 820 includes:

[0183] A region determination unit is used to determine whether the laser beam is directed toward the first marker and / or the second marker;

[0184] The time period acquisition unit is used to determine the first signal analysis area corresponding to the first identifier and the second signal analysis area corresponding to the second identifier when the laser beam is directed at the first identifier and the second identifier.

[0185] The first signal acquisition unit is used to acquire the reflected signal of the laser beam received by the laser transceiver in the first signal analysis area, and obtain the first echo signal.

[0186] The second signal acquisition unit is used to acquire the reflected signal of the laser beam received by the laser transceiver in the second signal analysis area, and obtain the second echo signal.

[0187] In one possible implementation, the region determination unit includes:

[0188] The emission angle acquisition subunit is used to determine the emission angle of the laser beam emitted by the laser transceiver.

[0189] The region determination subunit is used to determine whether the emission angle matches the specific field of view range corresponding to the first identifier and the second identifier. If so, it is determined that the laser beam is directed towards the first identifier and / or the second identifier.

[0190] In one possible implementation, the lidar further includes a scanning device, and the emission angle acquisition subunit is specifically used to acquire the pitch angle and yaw angle of the scanning device; determine the vertical emission angle in the emission angle based on the pitch angle; and determine the horizontal emission angle in the emission angle based on the yaw angle.

[0191] It should be noted that the self-calibration device for lidar provided in the above embodiments is only illustrated by the division of the functional modules described above when executing the self-calibration method for lidar. In practical applications, the functions described above can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. In addition, the self-calibration device for lidar and the self-calibration method embodiments for lidar provided in the above embodiments belong to the same concept. Therefore, for details not disclosed in the device embodiments of this application, please refer to the embodiments of the self-calibration method for lidar described above in this application, which will not be repeated here.

[0192] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0193] Figure 9 A schematic diagram of the structure of an electronic device provided in an embodiment of this application is shown.

[0194] For example, such as Figure 9 As shown, the electronic device 900 includes a memory 901, a processor 902, and a lidar 903. The memory 901 stores executable program code 9011, and the processor 902 is used to call and execute the executable program code 9011 to perform a lidar self-calibration method.

[0195] This embodiment can divide the electronic device into functional modules according to the above method example. For example, each module can correspond to a separate functional module, or two or more functions can be integrated into one processing module. The integrated module can be implemented in hardware. It should be noted that the module division in this embodiment is illustrative and only represents one logical functional division. In actual implementation, there may be other division methods.

[0196] When each functional module is divided according to its corresponding function, the electronic device may include: a laser emission module, an echo acquisition module, a difference calculation module, a parameter adjustment module, etc. It should be noted that all relevant content of each step involved in the above method embodiments can be referenced from the functional description of the corresponding functional module, and will not be repeated here.

[0197] The electronic device provided in this embodiment is used to execute the self-calibration method of a lidar described above, and thus can achieve the same effect as the above implementation method.

[0198] When using integrated units, the electronic device may include a processing module and a storage module. The processing module is used to control and manage the operation of the electronic device. The storage module is used to support the execution of program code and data by the electronic device.

[0199] The processing module may be a processor or a controller, which can implement or execute various exemplary logic blocks, modules, and circuits as disclosed in this application. The processor may also be a combination of computing functions, such as a combination of one or more microprocessors, a combination of digital signal processing (DSP) and a microprocessor, etc., and the storage module may be a memory.

[0200] This embodiment also provides a computer-readable storage medium storing computer program code. When the computer program code is run on a computer, the computer executes the above-described related method steps to implement a self-calibration method for lidar in the above embodiment.

[0201] This embodiment also provides a computer program product that, when run on a computer, causes the computer to perform the aforementioned related steps to implement a self-calibration method for a lidar as described in the above embodiment.

[0202] In addition, the electronic device provided in the embodiments of this application may specifically be a chip, component or module. The electronic device may include a connected processor and a memory. The memory is used to store instructions. When the electronic device is running, the processor may call and execute the instructions to make the chip execute a self-calibration method of a lidar in the above embodiments.

[0203] In this embodiment, the electronic device, computer-readable storage medium, computer program product or chip are all used to execute the corresponding methods provided above. Therefore, the beneficial effects that can be achieved can be referred to the beneficial effects of the corresponding methods provided above, and will not be repeated here.

[0204] Through the above description of the embodiments, those skilled in the art will understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0205] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another device, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0206] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A self-calibration method for a lidar, characterized in that, The invention is applied to lidar, which includes a laser transceiver and a window. A first mark and a second mark are provided on the inner wall of the periphery of the window. The positions of the first mark and the second mark are different, and the reflectivities of the first mark and the second mark are different. The self-calibration method includes: The laser transceiver is controlled to emit a laser beam with a first emission power. Acquire the first echo signal of the laser beam reflected by the first identifier, and the second echo signal of the laser beam reflected by the second identifier; Determine the difference information between the first echo signal and the second echo signal; Determine the difference between the difference information and the preset difference information; When the difference is greater than or equal to a preset value, the first transmission power charging time of the laser transceiver that transmitted the first transmission power laser beam in the previous transmission cycle is obtained. The transmission power charging change time is determined based on the difference. Based on the first transmit power charging time and the transmit power charging change time, the second transmit power charging time required for the laser transceiver to transmit a laser beam with a second transmit power in the current transmit cycle is determined. The laser transceiver is driven by the charging time of the second transmission power, so that the laser transceiver emits a laser beam of the second transmission power; Return to the steps of obtaining the first echo signal of the laser beam reflected by the first identifier and the second echo signal of the laser beam reflected by the second identifier, until the difference is less than a preset value, and continue to operate based on the second transmission power when the difference is less than the preset value.

2. The self-calibration method according to claim 1, characterized in that, Determining the difference information between the first echo signal and the second echo signal includes: Obtain the first signal curve of the first echo signal; Obtain the second signal curve of the second echo signal; Based on the first signal curve and the second signal curve, the energy difference between the echo energy of the first echo signal and the echo energy of the second echo signal is determined, and the difference information is obtained.

3. The self-calibration method according to claim 1 or 2, characterized in that, The step of acquiring the first echo signal of the laser beam reflected by the first identifier and the second echo signal of the laser beam reflected by the second identifier includes: Determine whether the laser beam is directed at the first identifier and / or the second identifier; When the laser beam is directed at the first identifier and the second identifier, a first signal analysis area corresponding to the first identifier and a second signal analysis area corresponding to the second identifier are determined. The first echo signal is obtained by acquiring the reflected signal of the laser beam received by the laser transceiver in the first signal analysis area. The reflection signal of the laser beam received by the laser transceiver in the second signal analysis area is obtained to obtain the second echo signal.

4. The self-calibration method according to claim 3, characterized in that, The step of determining whether the laser beam is directed at the first identifier and / or the second identifier includes: Determine the emission angle of the laser beam emitted by the laser transceiver; Determine whether the emission angle matches the specific field of view range corresponding to the first and second identifiers. If so, determine that the laser beam is directed toward the first identifier and / or the second identifier.

5. The self-calibration method according to claim 4, characterized in that, The lidar also includes a scanning device; Determining the emission angle of the laser beam emitted by the laser transceiver includes: Obtain the pitch and yaw angles of the scanning device; The vertical exit angle in the exit angle is determined based on the pitch angle; The horizontal exit angle in the exit angle is determined based on the yaw angle.

6. A lidar, characterized in that, For implementing the self-calibration method according to any one of claims 1 to 5, the lidar comprises: A window panel, wherein a first mark and a second mark are provided on the inner wall of the periphery of the window panel, the positions of the first mark and the second mark are different, and the reflectivity of the first mark and the second mark are different; A laser transceiver is used to emit a laser beam and acquire a first echo signal of the laser beam reflected by the first identifier and a second echo signal of the laser beam reflected by the second identifier. The parameter correction module is used to determine the difference information between the first echo signal and the second echo signal, and to determine the operating parameters of the laser transceiver based on the difference information and preset difference information.

7. The lidar according to claim 6, characterized in that, The first mark is coated with a reflective material, the reflectivity of which is different from that of the inner wall of the window. Alternatively, the first mark may be coated with a first reflective material, and the second mark may be coated with a second reflective material, wherein the reflectivity of the first reflective material is different from that of the second reflective material.

8. The lidar according to claim 6 or 7, characterized in that, The laser transceiver includes multiple devices, and multiple identification combinations are provided on the inner wall. Each identification combination includes a first identification and a second identification, and each laser transceiver corresponds to one identification combination.

9. The lidar according to claim 8, characterized in that, For each of the aforementioned identifier combinations, the first identifier is disposed near the first edge of the inner wall of the periphery of the window panel, and the second identifier is disposed near the second edge of the inner wall of the periphery of the window panel, with the first edge and the second edge being opposite to each other.

10. The lidar according to claim 8, characterized in that, For each of the aforementioned identifier combinations, the first identifier and the second identifier are both located near one edge of the inner wall of the window panel, with a gap between them, and the first identifier and the second identifier are parallel to each other.

11. The lidar according to claim 8, characterized in that, For each of the aforementioned identifier combinations, the first identifier and the second identifier are both located near the single edge of the inner wall of the window panel, the first identifier and the second identifier are located on the same horizontal line, and the first identifier and the second identifier are symmetrical.

12. A self-calibration device for a lidar, characterized in that, The device is configured in a lidar, which includes a laser transceiver and a window. A first mark and a second mark are provided on the inner wall of the periphery of the window. The positions of the first mark and the second mark are different, and the reflectivities of the first mark and the second mark are different. The self-calibration device of the lidar includes: A laser transmitting module is used to control the laser transceiver to transmit a laser beam with a first transmitting power; An echo acquisition module is used to acquire a first echo signal of the laser beam reflected by the first identifier, and a second echo signal of the laser beam reflected by the second identifier; The difference calculation module is used to determine the difference information between the first echo signal and the second echo signal; The parameter adjustment module is used to determine the difference between the difference information and the preset difference information. When the difference is greater than or equal to the preset value, it obtains the first transmission power charging time of the laser transceiver device transmitting the first transmission power laser beam in the previous transmission cycle, determines the transmission power charging change time based on the difference, and determines the second transmission power charging time required for the laser transceiver device to transmit the second transmission power laser beam in the current transmission cycle based on the first transmission power charging time and the transmission power charging change time. It then drives the laser transceiver device using the second transmission power charging time to transmit the second transmission power laser beam, and returns to the step of obtaining the first echo signal of the laser beam reflected by the first identifier and the second echo signal of the laser beam reflected by the second identifier until the difference is less than the preset value, and continues to operate based on the second transmission power when the difference is less than the preset value.

13. An electronic device, characterized in that, The electronic device includes: The lidar as described in any one of claims 6 to 11; Memory, used to store executable program code; A processor for calling and running the executable program code from the memory, causing the electronic device to perform the method as described in any one of claims 1 to 5.

14. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed, implements the method as described in any one of claims 1 to 5.

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