Laser radar parameter calibration device and laser radar

Abstract

The present disclosure relates to a laser radar parameter calibration device and a laser radar, the device comprising: a laser radar to be calibrated, a displacement module, and a control module, the control module being used to: control the laser radar to measure distance before the first movement and after each movement, record the propagation time and pulse width time before the first movement and after each movement; determine each propagation time deviation between the propagation time after each movement and the propagation time before the first movement, and each pulse width time deviation between the pulse width time after each movement and the pulse width time before the first movement; determine the correlation between each propagation time deviation and each pulse width time deviation. The calibration process of the embodiment of the present disclosure is fully automated, does not require manual operation, has high efficiency and high speed, and determines the correlation between each propagation time deviation and each pulse width time deviation to perform parameter calibration of the laser radar to be calibrated, has high accuracy, and has low computational cost.

Description

Technical Field

[0001] The present disclosure relates to the field of measurement technology, and in particular to a laser radar parameter calibration device and a laser radar. Background Art

[0002] Currently, most products on the LiDAR market are based on the TOF (time of flight) ranging solution of pulsed laser. The ranging accuracy / repeatability of LiDAR is one of its most important indicators, and directly related to this indicator is the timing accuracy of the LiDAR system.

[0003] However, the timing accuracy in related technologies is usually low, which seriously restricts the ranging accuracy of lidar. Summary of the invention

[0004] According to one aspect of the present disclosure, a laser radar parameter calibration device is provided, the device comprising:

[0005] The laser radar to be calibrated comprises a transmitting unit, a receiving unit and a processing unit, wherein the transmitting unit is used to transmit a laser signal to a calibration target for ranging, the receiving unit is used to receive a reflected laser signal from the calibration target, and the processing unit is used to record a propagation time from when the transmitting unit transmits the laser signal to when the receiving unit receives the reflected laser signal, and a pulse width time of the reflected laser signal;

[0006] A displacement module is provided with an optical attenuation sheet, wherein the optical attenuation sheet includes a plurality of attenuation regions, each attenuation region has a different light transmittance, and the displacement module is used to control the movement of the optical attenuation sheet to change the light transmittance of the transmitting unit and / or the receiving unit;

[0007] A control module is connected to the laser radar to be calibrated and the displacement module, and is used to:

[0008] Control the displacement module to move the optical attenuation sheet M times, and control the laser radar to be calibrated to measure distance before the first movement and after each movement, and record the propagation time and pulse width time before the first movement and after each movement, where M is a positive integer;

[0009] Determine each propagation time deviation between the propagation time after each movement and the propagation time before the first movement, and each pulse width time deviation between the pulse width time after each movement and the pulse width time before the first movement;

[0010] The correlation between each propagation time deviation and each pulse width time deviation is determined to calibrate the parameters of the laser radar to be calibrated.

[0011] In a possible implementation manner, determining the correlation between each propagation time deviation and each pulse width time deviation to perform parameter calibration includes:

[0012] A cubic spline curve is fitted to each propagation time deviation and each pulse width time deviation to obtain the correlation relationship.

[0013] In a possible implementation manner, the laser radar to be calibrated is also used for:

[0014] During actual distance measurement, the target propagation time deviation is determined according to the difference between the actual pulse width time and the pulse width time before the first movement and the correlation, and the actual propagation time is corrected using the target propagation time deviation.

[0015] In a possible implementation manner, the control module is further used for:

[0016] Obtaining N standard pulse width time deviations from a minimum pulse width time deviation to a maximum pulse width time deviation according to the M pulse width time deviations at a target time step;

[0017] Obtaining N time deviation correction values ​​according to the N standard pulse width time deviations and the correlation;

[0018] The target time step is determined according to the number N of the maximum pulse width time deviation, the minimum pulse width time deviation and the standard pulse width time deviation.

[0019] In a possible implementation manner, before obtaining N standard pulse width time deviations from the minimum pulse width time deviation to the maximum pulse width time deviation according to the M pulse width time deviations at the target time step, the control module is further used to:

[0020] The M pulse width time deviations are sorted.

[0021] In a possible implementation manner, the control module is further used for:

[0022] Storing the N standard pulse width time deviations, the N time deviation correction values, and a mapping relationship between each standard pulse width time deviation and each time deviation correction value in the laser radar to be calibrated;

[0023] The pulse width time before the first movement is stored in the laser radar to be calibrated.

[0024] In a possible implementation manner, the laser radar to be calibrated is also used for:

[0025] During actual distance measurement, the actual pulse width time difference between the actual pulse width time and the pulse width time before the first movement is determined;

[0026] Determine the magnitude relationship between the actual pulse width time difference and the minimum pulse width time deviation and / or the maximum pulse width time deviation among the N standard pulse width time deviations;

[0027] Determine a target propagation time deviation according to the size relationship, the mapping relationship, the minimum pulse width time deviation or the maximum pulse width time deviation;

[0028] The actual propagation time is corrected using the target propagation time deviation.

[0029] In a possible implementation manner, determining the target propagation time deviation according to the size relationship, the mapping relationship, the minimum pulse width time deviation, or the maximum pulse width time deviation includes:

[0030] If the actual pulse width time difference is smaller than the minimum pulse width time deviation, the target propagation time deviation is determined according to the minimum pulse width time deviation and the mapping relationship.

[0031] In a possible implementation manner, determining the target propagation time deviation according to the size relationship, the mapping relationship, the minimum pulse width time deviation, or the maximum pulse width time deviation includes:

[0032] If the actual pulse width time difference is greater than the maximum pulse width time deviation, the target propagation time deviation is determined according to the maximum pulse width time deviation and the mapping relationship.

[0033] In a possible implementation manner, determining the target propagation time deviation according to the size relationship, the mapping relationship, the minimum pulse width time deviation, or the maximum pulse width time deviation includes:

[0034] If the actual pulse width time difference is between the minimum pulse width time deviation and the maximum pulse width time deviation, the target propagation time deviation is determined according to the value of the N standard pulse width time deviations closest to the actual pulse width time difference and the mapping relationship.

[0035] According to another aspect of the present disclosure, a laser radar is provided, wherein the laser radar stores a correlation between a propagation time deviation and a pulse width time deviation and a preset pulse width time, and the laser radar is used to:

[0036] Transmitting a laser signal to a target to be measured, and receiving a reflected laser signal from the target to be measured;

[0037] Acquire the actual propagation time from emitting the laser signal to receiving the reflected laser signal and the actual pulse width time of the reflected laser signal;

[0038] Determine a target propagation time deviation according to an actual pulse width time difference between the actual pulse width time and the preset pulse width time and the correlation, and use the target propagation time deviation to correct the actual propagation time;

[0039] The target distance is determined based on the corrected actual propagation time.

[0040] In a possible implementation manner, the laser radar also stores N standard pulse width time deviations, N time deviation correction values, and a mapping relationship between each standard pulse width time deviation and each time deviation correction value, and the laser radar is also used to: determine the size relationship between the actual pulse width time difference and the minimum standard pulse width time deviation and / or the maximum standard pulse width time deviation among the N standard pulse width time deviations;

[0041] Determine a target propagation time deviation according to the size relationship, the mapping relationship, the minimum pulse width time deviation or the maximum pulse width time deviation;

[0042] The actual propagation time is corrected using the target propagation time deviation.

[0043] In a possible implementation manner, determining the target propagation time deviation according to the size relationship, the mapping relationship, the minimum pulse width time deviation, or the maximum pulse width time deviation includes:

[0044] If the actual pulse width time difference is smaller than the minimum pulse width time deviation, the target propagation time deviation is determined according to the minimum pulse width time deviation and the mapping relationship.

[0045] In a possible implementation manner, determining the target propagation time deviation according to the size relationship, the mapping relationship, the minimum pulse width time deviation, or the maximum pulse width time deviation includes:

[0046] If the actual pulse width time difference is greater than the maximum pulse width time deviation, the target propagation time deviation is determined according to the maximum pulse width time deviation and the mapping relationship.

[0047] In a possible implementation manner, determining the target propagation time deviation according to the size relationship, the mapping relationship, the minimum pulse width time deviation, or the maximum pulse width time deviation includes:

[0048] If the actual pulse width time difference is between the minimum pulse width time deviation and the maximum pulse width time deviation, the target propagation time deviation is determined according to the value of the N standard pulse width time deviations closest to the actual pulse width time difference and the mapping relationship.

[0049] The disclosed embodiment proposes a laser radar parameter calibration device, including: a laser radar to be calibrated, a displacement module and a control module, the displacement module is controlled by the control module to make the optical attenuation plate move M times, and the laser radar to be calibrated is controlled to measure distance before the first movement and after each movement, and the propagation time and pulse width time before the first movement and after each movement are recorded; each propagation time deviation between the propagation time after each movement and the propagation time before the first movement, and each pulse width time deviation between the pulse width time after each movement and the pulse width time before the first movement are determined; the correlation between each propagation time deviation and each pulse width time deviation is determined to perform parameter calibration of the laser radar to be calibrated. The calibration process of the laser radar parameter calibration device of the disclosed embodiment is fully automated, does not require manual operation, has high efficiency and high speed, and determines the correlation between each propagation time deviation and each pulse width time deviation to perform parameter calibration of the laser radar to be calibrated, with high accuracy and low computing cost.

[0050] It should be understood that the above general description and the following detailed description are exemplary and explanatory only and do not limit the present disclosure. Other features and aspects of the present disclosure will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The drawings herein are incorporated into the specification and constitute a part of the specification. These drawings illustrate embodiments consistent with the present disclosure and are used to illustrate the technical solutions of the present disclosure together with the specification.

[0052] Figure 1 A schematic diagram of lidar timing error is shown.

[0053] Figure 2 A schematic diagram of a laser radar parameter calibration device according to an embodiment of the present disclosure is shown.

[0054] Figure 3 A workflow diagram of a laser radar parameter calibration device according to an embodiment of the present disclosure is shown.

[0055] Figure 4 A timing diagram of a distance measurement record according to an embodiment of the present disclosure is shown.

[0056] Figure 5 A block diagram of an electronic device according to an embodiment of the present disclosure is shown.

[0057] Figure 6 A block diagram of an electronic device according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0058] Various exemplary embodiments, features and aspects of the present disclosure will be described in detail below with reference to the accompanying drawings. The same reference numerals in the accompanying drawings represent elements with the same or similar functions. Although various aspects of the embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless otherwise specified.

[0059] In the description of the present disclosure, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present disclosure.

[0060] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present disclosure, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0061] In the present disclosure, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present disclosure can be understood according to specific circumstances.

[0062] The word “exemplary” is used exclusively herein to mean “serving as an example, example, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.

[0063] The term "and / or" herein is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the term "at least one" herein represents any combination of at least two of any one or more of a plurality of. For example, including at least one of A, B, and C can represent including any one or more elements selected from the set consisting of A, B, and C.

[0064] In addition, in order to better illustrate the present disclosure, numerous specific details are given in the following specific embodiments. It should be understood by those skilled in the art that the present disclosure can also be implemented without certain specific details. In some examples, methods, means, components and circuits well known to those skilled in the art are not described in detail in order to highlight the subject matter of the present disclosure.

[0065] For pulsed laser radar, the timing process is usually as follows: the transmitter sends out a ranging light pulse, which is used as a START signal to trigger the timing chip, which is recorded as t0; after the light pulse is diffusely reflected by the target, the echo pulse is detected and received by the receiver, and after photoelectric conversion, it is used as a STOP signal to trigger the timing chip, which is recorded as t1; in this way, a ranging (timing) is completed, where Δt = t1-t0 is the propagation time of the light pulse in this timing, and the final ranging result can be obtained by using the speed of light to perform "time-to-distance conversion", as shown in Formula 1:

[0066]

[0067] Among them, c represents the speed of light in the current medium, and l represents the distance.

[0068] It is not difficult to see that the key to the ranging accuracy of pulsed laser radar lies in the accurate recording of t0 and t1. In addition to relying on the hardware performance of the transmitter, receiver and timing chip, it is also necessary to conduct a specific analysis of the timing method of the timing chip. The timing chip commonly used in pulsed laser radars currently usually selects a fixed trigger threshold for the electrical signals sent by the transmitter and receiver, and performs timing at the moment when the signal amplitude exceeds the threshold. Since the START signal at the transmitter usually directly uses the same electrical trigger signal as the laser at the transmitter, its amplitude and waveform are relatively stable, that is, the timing error of t0 is usually very small, so the STOP signal after the photoelectric conversion at the receiver is mainly considered here.

[0069] Due to the uncertainty of parameters such as the distance, surface shape, and reflectivity of the target being measured, the waveform of the same measurement pulse will have a correspondingly large uncertainty after it is diffusely reflected and received by the receiving end. This usually refers to the pulse width and amplitude of the echo signal. Because the timing chip uses a fixed trigger threshold for timing, this uncertainty will have a very large impact on the timing accuracy. Even if the distances of multiple targets being measured are the same, due to differences in their surface shapes, reflectivities, etc., the difference in echo pulse widths will be very large, resulting in a large difference in the final timing result Δt (distance measurement result l), making the ranging error reach the cm (centimeter) or even dm (decimeter) level, and this level of ranging (timing) error is unacceptable for lidar.

[0070] Figure 1 A schematic diagram of lidar timing error is shown.

[0071] like Figure 1 As shown, for two echo pulses with the same center position (i.e., the actual distance to the target being measured is the same) and different pulse widths, if the same trigger threshold is used for timing, two timing results t1 and t`1 will be obtained that differ by several ns. Converted to distance values, there will be a difference of tens of centimeters.

[0072] Therefore, in order to improve the ranging accuracy of the laser radar, it is necessary to calibrate the echo pulse width of the laser radar (for example, pulse type) to ensure that the ranging accuracy meets the expected requirements (such as cm or even mm level). However, the calibration process of the related technical solution requires manual adjustment, which is inefficient, slow, and consumes a lot of manpower and material resources. At the same time, a certain kernel function (exponential function and linear function) is used to fit the relationship between distance and pulse width. This method has the problem of insufficient accuracy. In addition, the related technical solution requires complex function operations (such as exponential operations, etc.) for each compensation, which will bring a great burden to the data processing core of the laser radar (FPGA or single-chip microcomputer), the operation cost is high, and it cannot meet the power consumption and computing speed requirements.

[0073] The disclosed embodiment proposes a laser radar parameter calibration device, including: a laser radar to be calibrated, a displacement module and a control module, the displacement module is controlled by the control module to make the optical attenuation plate move M times, and the laser radar to be calibrated is controlled to measure distance before the first movement and after each movement, and the propagation time and pulse width time before the first movement and after each movement are recorded; each propagation time deviation between the propagation time after each movement and the propagation time before the first movement, and each pulse width time deviation between the pulse width time after each movement and the pulse width time before the first movement are determined; the correlation between each propagation time deviation and each pulse width time deviation is determined to perform parameter calibration of the laser radar to be calibrated. The calibration process of the laser radar parameter calibration device of the disclosed embodiment is fully automated, does not require manual operation, has high efficiency and high speed, and determines the correlation between each propagation time deviation and each pulse width time deviation to perform parameter calibration of the laser radar to be calibrated, with high accuracy and low computing cost.

[0074] Figure 2 A schematic diagram of a laser radar parameter calibration device according to an embodiment of the present disclosure is shown.

[0075] Figure 3 A workflow diagram of a laser radar parameter calibration device according to an embodiment of the present disclosure is shown.

[0076] like Figure 2 As shown, the device comprises:

[0077] The laser radar 10 to be calibrated includes a transmitting unit 110, a receiving unit 120 and a processing unit 130, wherein the transmitting unit 110 is used to transmit a laser signal to a calibration target 50 for ranging, the receiving unit 120 is used to receive a reflected laser signal from the calibration target 50, and the processing unit 130 is used to record a propagation time from when the transmitting unit 110 transmits the laser signal to when the receiving unit 120 receives the reflected laser signal, and a pulse width time of the reflected laser signal;

[0078] The displacement module 20 is provided with an optical attenuation sheet 40, wherein the optical attenuation sheet 40 includes a plurality of attenuation regions, each of which has a different light transmittance, and the displacement module 20 is used to control the movement of the optical attenuation sheet 40 to change the light transmittance of the transmitting unit 110 and / or the receiving unit 120;

[0079] The control module 30 is connected to the laser radar to be calibrated 10 and the displacement module 20. Figure 3 As shown, the control module 30 is used to:

[0080] Step S11, controlling the displacement module 20 to move the optical attenuation sheet 40 M times, and controlling the laser radar 10 to be calibrated to perform ranging before the first movement and after each movement, and recording the propagation time and pulse width time before the first movement and after each movement, wherein M is a positive integer;

[0081] Step S12, determining each propagation time deviation between the propagation time after each movement and the propagation time before the first movement, and each pulse width time deviation between the pulse width time after each movement and the pulse width time before the first movement;

[0082] Step S13, determining the correlation between each propagation time deviation and each pulse width time deviation to perform parameter calibration of the laser radar 10 to be calibrated.

[0083] The embodiments of the present disclosure do not limit the specific type, implementation method and specific implementation method of each unit of the laser radar 10 to be calibrated. Those skilled in the art may use pulse laser radars in related technologies to calibrate the parameters of the laser radars used. For example, the processing unit 130 may include a timing chip, the transmitting unit 110 may include a laser generating component and a transmitting component, and the receiving unit 120 may include a signal receiving circuit. It should be noted that the processing unit of the laser radar may also include other processing components (such as FPGA, etc.) for performing other operations and controls, such as a chip for performing distance operations. Of course, the processing component may also be separately set in the laser radar as a control unit, and the embodiments of the present disclosure do not limit this.

[0084] The embodiments of the present disclosure do not limit the specific implementation method of the displacement module 20. Exemplarily, the displacement module 20 may include a single-action displacement stage, the electric displacement stage includes a motor, a connection and a transmission mechanism (such as a screw), the optical attenuation sheet 40 may be set on the screw, and the control module 30 may control the stepping distance of the motor, and use the motor to control the movement of the transmission mechanism, so that the optical attenuation sheet 40 gradually blocks the transmitting unit 110 and / or the receiving unit 120 starting from 0 displacement (not blocking the transmitting unit 110 and the receiving unit 120. In this case, the transmittance of the transmitting unit 110 and the receiving unit 120 is 1).

[0085] The embodiments of the present disclosure do not limit possible implementations of the control module 30. In one example, the control module 30 may be implemented using a processing component, or an electronic device such as a terminal or server that includes a processing component.

[0086] In one example, the processing component includes but is not limited to a separate processor, or a discrete component, or a combination of a processor and a discrete component. The processor may include a controller having an execution instruction function in an electronic device, and the processor may be implemented in any appropriate manner, for example, by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic components. Inside the processor, the executable instructions may be executed by hardware circuits such as logic gates, switches, application-specific integrated circuits (ASICs), programmable logic controllers, and embedded microcontrollers.

[0087] In one example, the terminal is also called User Equipment (UE), Mobile Station (MS), Mobile Terminal (MT), etc., which is a device that provides voice and / or data connectivity to users, for example, a handheld device with wireless connection function, a vehicle-mounted device, etc. At present, some examples of terminals are: mobile phones, tablet computers, laptops, PDAs, mobile Internet devices (MID), wearable devices, virtual reality (VR) devices, augmented reality (AR) devices, wireless terminals in industrial control (Industrial Control), wireless terminals in self-driving, wireless terminals in remote medical surgery, wireless terminals in smart grid (Smart Grid), wireless terminals in transportation safety (Transportation Safety), wireless terminals in smart cities (Smart City), wireless terminals in smart homes (Smart Home), wireless terminals in Internet of Vehicles, etc.

[0088] See also Figure 4 , Figure 4 A timing diagram of a distance measurement record according to an embodiment of the present disclosure is shown.

[0089] As mentioned above, the echo pulse width of the pulsed laser radar will vary greatly under the influence of the reflectivity, surface shape and other parameters of the measured target, which will lead to unacceptable ranging errors when the timing chip uses a fixed threshold timing. The key to solving this problem lies in calibrating the echo pulse width. The following is an exemplary introduction to the process of echo pulse width calibration.

[0090] For example, Figure 4 As shown, when it is necessary to compensate the ranging value by the pulse width calibration method, the processing unit 130 (such as a timing chip) is required to record the emission time t0 of the laser signal emitted by the transmitting unit 110 and the reflected laser signal t1 received by the receiving unit 120. In addition, in addition to recording the two time values ​​t0 and t1, it is also necessary to record the falling edge time t2 of the echo. That is, in a ranging process, it is necessary to obtain the propagation time (t1-t0) and the echo pulse width time (t2-t1) by recording the above three time values, which are respectively recorded as T and W. Exemplarily, during the timing process, the processing unit 130 uses the same threshold to trigger the timing action. The embodiment of the present disclosure does not limit the specific size of the threshold, and those skilled in the art can set it as needed.

[0091] The following is an exemplary introduction to the parameter calibration process of the laser radar 10 to be calibrated.

[0092] In one example, if Figure 2 As shown, when calibrating multiple laser radars, except for the laser radar 10 to be calibrated, the other parts of the whole device can be kept fixed to reduce manual participation, reduce costs, and improve measurement efficiency. When a certain radar needs to be calibrated, it only needs to be placed on the corresponding tooling and fixed. When calibrating the next one, it can be removed and replaced with another one.

[0093] In one example, step S11 may be to perform ranging before the first movement, that is, to perform the first round of ranging on the laser radar without being affected by the attenuation sheet, and to record the propagation time T before the first movement. i,0 And pulse width time W i,0 For [T i,0 ,W i,0 ], where i represents the number of channels corresponding to the measurement value. If the laser radar 10 to be calibrated is a single-point laser radar, then i≡1. Of course, the laser radar can be a multi-channel radar. In this case, i>1 and is an integer.

[0094] In one example, step S11 can be to control the optical attenuation sheet 40 to gradually block the receiving end according to the set step distance (exemplarily, as the step distance increases, the transmittance of the optical attenuation sheet 40 gradually decreases or gradually increases) after completing the first distance measurement (the first distance measurement before movement), and control the laser radar 10 to be calibrated to perform a round of distance measurement at each step distance, and record the propagation time T of each channel. i,j and pulse width time W i,j For [T i,j ,W i,j ], where j represents the number of distance measuring rounds corresponding to the measurement value, and the number of distance measuring rounds corresponds to the number of steps of the displacement module 20. After completing the current round of measurement, the displacement module 20 controls the optical attenuation sheet 40 to move and performs the next measurement until all the predetermined rounds of measurement are completed.

[0095] In one example, step S12 determines the respective propagation time deviations Te between the propagation time after each movement and the propagation time before the first movement. i,j , and the pulse width time deviations We between the pulse width time after each movement and the pulse width time before the first movement i,j In step S12, the measured values ​​obtained in the calibration are processed, for example, the deviation data pair of each measurement is first calculated by the following formula 2:

[0096] [Te i,j ,Wei,j ]=[T i,j ,W i,j ]-[T i,0 ,W i,0 ] Formula 2

[0097] Among them, Te i,j =T i,j -T i,0 ,We i,j =W i,j -W i,0 .

[0098] In a possible implementation manner, step S13 determines the correlation between each propagation time deviation and each pulse width time deviation to perform parameter calibration, which may include:

[0099] A cubic spline curve is fitted to each propagation time deviation and each pulse width time deviation to obtain the correlation relationship, wherein the correlation relationship can be expressed by Formula 3:

[0100] T e =f i (We i,j ) Formula 3

[0101] The disclosed embodiment preferably utilizes cubic spline curve fitting to obtain the correlation relationship to improve the accuracy.

[0102] The embodiments of the present disclosure do not limit the specific implementation method of cubic spline curve fitting, and those skilled in the art can implement it using relevant technologies.

[0103] In a possible implementation manner, the laser radar 10 to be calibrated may also be used for:

[0104] During actual distance measurement, the target propagation time deviation is determined according to the difference between the actual pulse width time and the pulse width time before the first movement and the correlation, and the actual propagation time is corrected using the target propagation time deviation.

[0105] Exemplarily, when the correlation is obtained, the correlation and the pulse width time before the first movement can be stored in the memory of the laser radar and called by the control unit of the laser radar (such as the aforementioned processing component, i.e., FPGA, etc.) to correct the actual propagation time and improve the accuracy of the distance measurement. For example, during actual distance measurement, the laser radar 10 to be calibrated can obtain the actual propagation time and the actual pulse width time, and determine the difference between the actual pulse width time and the pulse width time before the first movement, and use the difference between the actual pulse width time and the pulse width time before the first movement and the correlation to determine the target propagation time deviation, and use the target propagation time deviation to correct the actual propagation time, and use the corrected actual propagation time to determine the distance.

[0106] Of course, the embodiment of the present disclosure may also discretize the correlation to reduce the computational cost of the lidar control unit (such as the aforementioned processing component including the FPGA), which is exemplarily introduced below.

[0107] In a possible implementation manner, the control module 30 may also be used for:

[0108] Obtaining N standard pulse width time deviations from a minimum pulse width time deviation to a maximum pulse width time deviation from the M pulse width time deviations at a target time step;

[0109] Obtaining N time deviation correction values ​​according to the N standard pulse width time deviations and the correlation;

[0110] The target time step is determined according to the number N of the maximum pulse width time deviation, the minimum pulse width time deviation and the standard pulse width time deviation.

[0111] In one example, the target time step can be obtained by the maximum pulse width time deviation We i,j MAX The minimum pulse width time deviation We i,j MIN The target time step Δt is determined by the ratio of the difference between the target time step Δt and the number N of the standard pulse width time deviations. For example, the target time step Δt can be obtained by formula 4:

[0112]

[0113] The embodiments of the present disclosure do not limit the specific value of N, and those skilled in the art can set it as needed.

[0114] The embodiments of the present disclosure can be implemented in a variety of ways to obtain N standard pulse width time deviations from the minimum pulse width time deviation to the maximum pulse width time deviation based on the M pulse width time deviations at the target time step. For example, N standard pulse width time deviations can be directly screened from the M pulse width time deviations from the minimum pulse width time deviation to the maximum pulse width time deviation at the target time step. It is also possible to obtain a continuously changing function based on the M pulse width time deviations and obtain N standard pulse width time deviations from the minimum pulse width time deviation to the maximum pulse width time deviation from the continuously changing function at the target time step. Of course, it can also be implemented using other models, which is not limited by the embodiments of the present disclosure.

[0115] In a possible implementation, before obtaining N standard pulse width time deviations from the minimum pulse width time deviation to the maximum pulse width time deviation according to the M pulse width time deviations at the target time step, the control module 30 may also be used to:

[0116] The M pulse width time deviations are sorted.

[0117] By sorting the M pulse width time deviations, the screening efficiency of the standard pulse width time deviation can be improved.

[0118] Exemplarily, M may be greater than N, and the embodiment of the present disclosure may directly screen out N standard pulse width time deviations from M pulse width time deviations.

[0119] Exemplarily, the embodiment of the present disclosure may start from the minimum pulse width time deviation, and gradually obtain the standard pulse width time deviation from M pulse width time deviations at a target time step, until N standard pulse width time deviations are obtained.

[0120] In one example, the present disclosure can establish a standard pulse width error table Sta_We i , store N standard pulse width time deviations into the standard pulse width error table Sta_We i In one example, M may also be less than N. In this case, the embodiment of the present disclosure may use a small number of M pulse width time deviations to determine the change trend function of the pulse width time deviation (a function of the pulse width time deviation and time t), for example, obtained by a pre-established and trained neural network model or other type of model, or by fitting. In this case, the embodiment of the present disclosure may use the change trend function to obtain N standard pulse width time deviations, for example, starting from the minimum pulse width time deviation, and gradually obtaining N standard pulse width time deviations including the minimum pulse width time deviation and the maximum pulse width time deviation from the change trend function with a target time step. The embodiment of the present disclosure does not limit the specific form of the change trend function, nor does it limit the model for obtaining the change trend function. Those skilled in the art may set it according to actual conditions and needs. The embodiment of the present disclosure may fit the relationship curve between the pulse width time deviation and the propagation time deviation through a pulse width time deviation of tens of orders of magnitude, through a cubic spline curve or the like. Since the curve already has an expression, it can be infinitely subdivided in theory to obtain any number (N) of standard pulse width time deviations. For example, the selection of the N value only needs to satisfy the accuracy of the compensation and the computing power of the radar control unit.

[0121] In one example, when N standard pulse width time deviations are obtained, the embodiment of the present disclosure can obtain N time deviation correction values ​​based on the N standard pulse width time deviations and the correlation. For example, the N standard pulse width time deviations are respectively substituted into the aforementioned correlation to obtain N time deviation correction values.

[0122] For example, the embodiment of the present disclosure may establish a time deviation correction table Sta_Te i And store each N time deviation correction value in the time deviation correction table Sta_Te i middle.

[0123] In a possible implementation manner, the control module 30 may also be used for:

[0124] Storing the N standard pulse width time deviations, the N time deviation correction values, and a mapping relationship between each standard pulse width time deviation and each time deviation correction value in the laser radar to be calibrated;

[0125] The pulse width time before the first movement is stored in the laser radar to be calibrated.

[0126] The disclosed embodiment can utilize the memory in the laser radar to be calibrated to store the N standard pulse width time deviations, the N time deviation correction values, and the mapping relationship between each standard pulse width time deviation and each time deviation correction value; and the pulse width time W before the first movement i,0 .

[0127] In one example, the memory may include a computer-readable storage medium, which may be a tangible device that can hold and store instructions used by an instruction execution device. The computer-readable storage medium may be, for example, but not limited to, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the above. More specific examples of computer-readable storage media (a non-exhaustive list) include: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a static random access memory (SRAM), a programmable read-only memory (PROM), a portable compact disk read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanical encoding device, such as a punch card or a raised structure in a groove on which instructions are stored, and any suitable combination of the above. The computer-readable storage medium used herein is not to be interpreted as a transient signal itself, such as a radio wave or other freely propagating electromagnetic wave, an electromagnetic wave propagating through a waveguide or other transmission medium (e.g., a light pulse through a fiber optic cable), or an electrical signal transmitted through a wire.

[0128] The above calibration process of the embodiments of the present disclosure can be automated. After the laser radar is fixed on the tooling and connected to the power supply and the host computer, the program on the host computer is started, and the calibration process of "measurement-motor stepping-...-measurement-host computer calculation, fitting, discretization-lookup table writing to the laser radar" can be continuously performed. In the actual production line, the tooling can be further modified to realize the automation of loading and unloading of the laser radar, thereby realizing the full automation of the entire mass production calibration process.

[0129] The above calibration process only involves a typical calibration system based on the solution of the present invention. In fact, some modules in the system can be adjusted according to actual needs:

[0130] The laser radar to be calibrated can be single-point detection, linear array detection, or area array detection;

[0131] The shielding object of the uniform optical attenuation sheet 40 can be the receiving end or the transmitting end, or even the receiving end and the transmitting end can be shielded at the same time, depending on the specific tooling and the architecture of the laser radar. The arrangement of the radar receiving end and the transmitting end and whether they share the same optical path will affect the final calibration system structure;

[0132] The calibration target 50 does not need to move during the entire calibration process, and there are no special requirements, but it is necessary to ensure that the distance is greater than the short-range blind area of ​​the laser radar 10 to be calibrated. At the same time, the distance should not be too large, the surface should not be too rough, and the reflectivity should not be too small. This is mainly to ensure that during the calibration process, [T i,0 ,W i,0 ] The corresponding waveform has reached saturation or even approximated a square wave, thus ensuring the stability and accuracy of the reference value;

[0133] The selection of the error table length N mainly considers the trade-off between the corrected accuracy level and the memory space. In theory, the larger the error table length, the higher the correction accuracy. However, after reaching the expected accuracy level, continuing to increase the error table length will occupy more storage space on the radar without bringing more benefits. Therefore, accurate evaluation and trade-off are required, and it should be set according to needs.

[0134] The following is an exemplary introduction to the real-time correction of the propagation time using the discrete correlation relationship. In a possible implementation, the laser radar 10 to be calibrated can also be used for:

[0135] During actual distance measurement, the actual pulse width time difference between the actual pulse width time and the pulse width time before the first movement is determined;

[0136] Determine the magnitude relationship between the actual pulse width time difference and the minimum pulse width time deviation and / or the maximum pulse width time deviation among the N standard pulse width time deviations;

[0137] Determine a target propagation time deviation according to the size relationship, the mapping relationship, the minimum pulse width time deviation or the maximum pulse width time deviation;

[0138] The actual propagation time is corrected using the target propagation time deviation.

[0139] The embodiment of the present disclosure can directly obtain the discretized correlation, that is, directly retrieve the N standard pulse width time deviations, the N time deviation correction values, and the mapping relationship between each standard pulse width time deviation and each time deviation correction value from the memory; and the pulse width time W before the first movement i,0 , determine the actual pulse width time difference between the actual pulse width time and the pulse width time before the first movement, determine the size relationship between the actual pulse width time difference and the minimum pulse width time deviation and / or the maximum pulse width time deviation among the N standard pulse width time deviations, and determine the target propagation time deviation according to the size relationship, the mapping relationship, the minimum pulse width time deviation or the maximum pulse width time deviation. Since no function calculation is required, the computing resource occupancy of the control unit of the laser radar is greatly reduced, computing resources are saved, and the computing speed is improved. The target propagation time deviation can be used to quickly and efficiently correct the actual propagation time, thereby improving the ranging accuracy.

[0140] In a possible implementation manner, determining the target propagation time deviation according to the size relationship, the mapping relationship, the minimum pulse width time deviation, or the maximum pulse width time deviation may include:

[0141] If the actual pulse width time difference is smaller than the minimum pulse width time deviation, the target propagation time deviation is determined according to the minimum pulse width time deviation and the mapping relationship.

[0142] For example, during the actual measurement process of the laser radar, the actual propagation time Tm of each channel is obtained in each round of measurement. i And the actual pulse width time Wm i , [Tm i ,Wm i ], where i also represents the channel number corresponding to the measured value. The actual pulse width time difference We corresponding to the measured value is calculated by the following formula 5 i :

[0143] We i =W i,0 -Wm i Formula 5

[0144] For example, if We i <We i,j MIN , then the target propagation time deviation Te i Select the minimum pulse width time deviation We i,j MIN In the mapping relationship (check the time deviation correction table Sta_Te i The corresponding propagation time deviation value is obtained, which is recorded as Tc i .

[0145] In a possible implementation manner, determining the target propagation time deviation according to the size relationship, the mapping relationship, the minimum pulse width time deviation, or the maximum pulse width time deviation may include:

[0146] If the actual pulse width time difference is greater than the maximum pulse width time deviation, the target propagation time deviation is determined according to the maximum pulse width time deviation and the mapping relationship.

[0147] For example, if We i >We i,j MAX , then the target propagation time deviation Te i Select the maximum pulse width time deviation We i,j MAX In the mapping relationship (check the time deviation correction table Sta_Te i The corresponding propagation time deviation value is obtained, which is recorded as Tc i .

[0148] In a possible implementation manner, determining the target propagation time deviation according to the size relationship, the mapping relationship, the minimum pulse width time deviation, or the maximum pulse width time deviation includes:

[0149] If the actual pulse width time difference is between the minimum pulse width time deviation and the maximum pulse width time deviation, the target propagation time deviation is determined according to the value of the N standard pulse width time deviations closest to the actual pulse width time difference and the mapping relationship.

[0150] For example, if We i,j MIN <We i <We i,j MAX , then according to We i Select the standard pulse width error table Sta_We i The value closest to the actual pulse width time difference is found, and Sta_Te corresponding to this value is found i The value in determines the target propagation time deviation Te i , denoted as Tc i .

[0151] The disclosed embodiment can quickly compare and look up the table to obtain the target propagation time deviation through the above method, so as to quickly and efficiently calibrate the propagation time and improve the accuracy of ranging.

[0152] In one example, the actual propagation time can be corrected by using the difference between the actual propagation time and the target propagation time deviation. For example, the actual propagation time measurement value can be corrected according to the following formula to obtain the final output propagation time value T i :

[0153] T i =Tmi -Tc i Formula 6

[0154] The calibration process and correction process of the disclosed embodiment are characterized by high efficiency and automation, which can meet the needs of the autonomic artery width calibration station of the mass production production line of the laser radar. At the same time, the calibration data obtained by this scheme can realize the low-power and high-efficiency real-time ranging value compensation function during the operation of the laser radar, which is of great significance for the optimization of the power consumption and performance indicators of the laser radar. The disclosed embodiment uses a lookup table written into the corresponding memory of the control module 30 to perform real-time ranging value compensation, which improves the efficiency of the calibration process and the real-time distance value compensation process, and can meet the needs of mass production of high-precision pulsed laser radars and high-efficiency and low-power ranging value compensation.

[0155] The disclosed embodiment also provides a laser radar parameter calibration method, which is applied to a control module of a laser radar parameter calibration device, such as Figure 2 As shown, the device includes: a laser radar 10 to be calibrated, including a transmitting unit 110, a receiving unit 120 and a processing unit 130, wherein the transmitting unit 110 is used to transmit a laser signal to a calibration target 50 for ranging, the receiving unit 120 is used to receive a reflected laser signal of the calibration target 50, and the processing unit 130 is used to record the propagation time from the transmitting unit 110 transmitting the laser signal to the receiving unit 120 receiving the reflected laser signal, and the pulse width time of the reflected laser signal; a displacement module 20, provided with an optical attenuation sheet 40, wherein the optical attenuation sheet 40 includes a plurality of attenuation regions, each of which has a different transmittance, and the displacement module 20 is used to control the movement of the optical attenuation sheet 40 to change the transmittance of the transmitting unit 110 and / or the receiving unit 120;

[0156] like Figure 3 As shown, the method includes:

[0157] Step S11, controlling the displacement module 20 to move the optical attenuation sheet 40 M times, and controlling the laser radar to be calibrated to perform ranging before the first movement and after each movement, and recording the propagation time and pulse width time before the first movement and after each movement, wherein M is a positive integer;

[0158] Step S12, determining each propagation time deviation between the propagation time after each movement and the propagation time before the first movement, and each pulse width time deviation between the pulse width time after each movement and the pulse width time before the first movement;

[0159] Step S13, determining the correlation between each propagation time deviation and each pulse width time deviation to perform parameter calibration of the laser radar 10 to be calibrated.

[0160] The disclosed embodiment controls the displacement module through the control module to move the optical attenuation plate M times, and controls the laser radar to be calibrated to measure distance before the first movement and after each movement, and records the propagation time and pulse width time before the first movement and after each movement; determines each propagation time deviation between the propagation time after each movement and the propagation time before the first movement, and each pulse width time deviation between the pulse width time after each movement and the pulse width time before the first movement; determines the correlation between each propagation time deviation and each pulse width time deviation to calibrate the parameters of the laser radar to be calibrated. The calibration process of the laser radar parameter calibration device of the disclosed embodiment is fully automated, does not require manual operation, has high efficiency and high speed, and determines the correlation between each propagation time deviation and each pulse width time deviation to calibrate the parameters of the laser radar to be calibrated, with high accuracy and low computing cost.

[0161] According to another aspect of the present disclosure, a laser radar is provided, wherein the laser radar stores a correlation between a propagation time deviation and a pulse width time deviation and a preset pulse width time, and the laser radar is used to:

[0162] Transmitting a laser signal to a target to be measured, and receiving a reflected laser signal from the target to be measured;

[0163] Acquire the actual propagation time from emitting the laser signal to receiving the reflected laser signal and the actual pulse width time of the reflected laser signal;

[0164] Determine a target propagation time deviation according to an actual pulse width time difference between the actual pulse width time and the preset pulse width time and the correlation, and use the target propagation time deviation to correct the actual propagation time;

[0165] The target distance is determined based on the corrected actual propagation time.

[0166] When measuring distance, the laser radar of the embodiment of the present disclosure can call the stored correlation and the pulse width time before the preset pulse width time (for example, the pulse width time before the first movement) to correct the actual propagation time and improve the accuracy of the distance measurement. For example, when actually measuring distance, the laser radar can obtain the actual propagation time, the actual pulse width time, and determine the difference between the actual pulse width time and the pulse width time before the first movement, and use the difference between the actual pulse width time and the pulse width time before the first movement and the correlation to determine the target propagation time deviation, and use the target propagation time deviation to correct the actual propagation time, and use the corrected actual propagation time to determine the distance, so as to improve the accuracy and precision of the distance measurement.

[0167] In a possible implementation manner, the laser radar also stores N standard pulse width time deviations, N time deviation correction values, and a mapping relationship between each standard pulse width time deviation and each time deviation correction value, and the laser radar is also used to: determine the size relationship between the actual pulse width time difference and the minimum standard pulse width time deviation and / or the maximum standard pulse width time deviation among the N standard pulse width time deviations;

[0168] Determine a target propagation time deviation according to the size relationship, the mapping relationship, the minimum pulse width time deviation or the maximum pulse width time deviation;

[0169] The actual propagation time is corrected using the target propagation time deviation.

[0170] The embodiment of the present disclosure can directly obtain the discretized correlation, that is, directly retrieve the N standard pulse width time deviations, the N time deviation correction values, and the mapping relationship between each standard pulse width time deviation and each time deviation correction value from the memory; and the pulse width time W before the first movement i,0 , determine the actual pulse width time difference between the actual pulse width time and the pulse width time before the first movement, determine the size relationship between the actual pulse width time difference and the minimum pulse width time deviation and / or the maximum pulse width time deviation among the N standard pulse width time deviations, and determine the target propagation time deviation according to the size relationship, the mapping relationship, the minimum pulse width time deviation or the maximum pulse width time deviation. Since no function calculation is required, the computing resource occupancy of the control unit (such as FPGA) in the laser radar is greatly reduced, computing resources are saved, and the computing speed is improved. The target propagation time deviation can be used to quickly and efficiently correct the actual propagation time, thereby improving the ranging accuracy.

[0171] In a possible implementation manner, determining the target propagation time deviation according to the size relationship, the mapping relationship, the minimum pulse width time deviation, or the maximum pulse width time deviation includes:

[0172] If the actual pulse width time difference is smaller than the minimum pulse width time deviation, the target propagation time deviation is determined according to the minimum pulse width time deviation and the mapping relationship.

[0173] In a possible implementation manner, determining the target propagation time deviation according to the size relationship, the mapping relationship, the minimum pulse width time deviation, or the maximum pulse width time deviation includes:

[0174] If the actual pulse width time difference is greater than the maximum pulse width time deviation, the target propagation time deviation is determined according to the maximum pulse width time deviation and the mapping relationship.

[0175] In a possible implementation manner, determining the target propagation time deviation according to the size relationship, the mapping relationship, the minimum pulse width time deviation, or the maximum pulse width time deviation includes:

[0176] If the actual pulse width time difference is between the minimum pulse width time deviation and the maximum pulse width time deviation, the target propagation time deviation is determined according to the value of the N standard pulse width time deviations closest to the actual pulse width time difference and the mapping relationship.

[0177] It can be understood that the above-mentioned various method embodiments mentioned in the present disclosure can be combined with each other to form a combined embodiment without violating the principle logic. Due to space limitations, the present disclosure will not repeat them. It can be understood by those skilled in the art that in the above-mentioned method of the specific implementation method, the specific execution order of each step should be determined according to its function and possible internal logic.

[0178] The embodiment of the present disclosure also provides a computer-readable storage medium, on which computer program instructions are stored, and when the computer program instructions are executed by a processor, the above method is implemented. The computer-readable storage medium may be a non-volatile computer-readable storage medium.

[0179] An embodiment of the present disclosure further proposes an electronic device, comprising: a processor; and a memory for storing instructions executable by the processor; wherein the processor is configured to call the instructions stored in the memory to execute the above method.

[0180] The embodiments of the present disclosure also provide a computer program product, including a computer-readable code, or a non-volatile computer-readable storage medium carrying the computer-readable code. When the computer-readable code runs in a processor of an electronic device, the processor in the electronic device executes the above method.

[0181] The control module of the embodiment of the present disclosure may be an electronic device, and the electronic device may be provided as a terminal, a server, or a device in other forms.

[0182] See also Figure 5 , Figure 5 A block diagram of an electronic device according to an embodiment of the present disclosure is shown.

[0183] For example, the electronic device 800 may be a mobile phone, a computer, a digital broadcast terminal, a messaging device, a game console, a tablet device, a medical device, a fitness device, a personal digital assistant, or the like.

[0184] Reference Figure 5, the electronic device 800 may include one or more of the following components: a processing component 802 , a memory 804 , a power component 806 , a multimedia component 808 , an audio component 810 , an input / output (I / O) interface 812 , a sensor component 814 , and a communication component 816 .

[0185] The processing component 802 generally controls the overall operation of the electronic device 800, such as operations associated with display, phone calls, data communications, camera operations, and recording operations. The processing component 802 may include one or more processors 820 to execute instructions to perform all or part of the steps of the above-mentioned method. In addition, the processing component 802 may include one or more modules to facilitate the interaction between the processing component 802 and other components. For example, the processing component 802 may include a multimedia module to facilitate the interaction between the multimedia component 808 and the processing component 802.

[0186] The memory 804 is configured to store various types of data to support operations on the electronic device 800. Examples of such data include instructions for any application or method operating on the electronic device 800, contact data, phone book data, messages, pictures, videos, etc. The memory 804 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disk.

[0187] The power supply component 806 provides power to the various components of the electronic device 800. The power supply component 806 may include a power management system, one or more power supplies, and other components associated with generating, managing, and distributing power to the electronic device 800.

[0188] The multimedia component 808 includes a screen that provides an output interface between the electronic device 800 and the user. In some embodiments, the screen may include a liquid crystal display (LCD) and a touch panel (TP). If the screen includes a touch panel, the screen may be implemented as a touch screen to receive input signals from the user. The touch panel includes one or more touch sensors to sense touch, slide, and gestures on the touch panel. The touch sensor may not only sense the boundaries of the touch or slide action, but also detect the duration and pressure associated with the touch or slide operation. In some embodiments, the multimedia component 808 includes a front camera and / or a rear camera. When the electronic device 800 is in an operating mode, such as a shooting mode or a video mode, the front camera and / or the rear camera may receive external multimedia data. Each front camera and rear camera may be a fixed optical lens system or have a focal length and optical zoom capability.

[0189] The audio component 810 is configured to output and / or input audio signals. For example, the audio component 810 includes a microphone (MIC), and when the electronic device 800 is in an operating mode, such as a call mode, a recording mode, and a voice recognition mode, the microphone is configured to receive an external audio signal. The received audio signal can be further stored in the memory 804 or sent via the communication component 816. In some embodiments, the audio component 810 also includes a speaker for outputting audio signals.

[0190] I / O interface 812 provides an interface between processing component 802 and peripheral interface modules, such as keyboards, click wheels, buttons, etc. These buttons may include but are not limited to: a home button, a volume button, a start button, and a lock button.

[0191] The sensor assembly 814 includes one or more sensors for providing various aspects of status assessment for the electronic device 800. For example, the sensor assembly 814 can detect the open / closed state of the electronic device 800, the relative positioning of the components, such as the display and keypad of the electronic device 800, and the sensor assembly 814 can also detect the position change of the electronic device 800 or a component of the electronic device 800, the presence or absence of contact between the user and the electronic device 800, the orientation or acceleration / deceleration of the electronic device 800, and the temperature change of the electronic device 800. The sensor assembly 814 may include a proximity sensor configured to detect the presence of a nearby object without any physical contact. The sensor assembly 814 may also include an optical sensor, such as a complementary metal oxide semiconductor (CMOS) or a charge coupled device (CCD) image sensor, for use in imaging applications. In some embodiments, the sensor assembly 814 may also include an acceleration sensor, a gyroscope sensor, a magnetic sensor, a pressure sensor, or a temperature sensor.

[0192] The communication component 816 is configured to facilitate wired or wireless communication between the electronic device 800 and other devices. The electronic device 800 can access a wireless network based on a communication standard, such as a wireless network (WiFi), a second generation mobile communication technology (2G) or a third generation mobile communication technology (3G), or a combination thereof. In an exemplary embodiment, the communication component 816 receives a broadcast signal or broadcast-related information from an external broadcast management system via a broadcast channel. In an exemplary embodiment, the communication component 816 also includes a near field communication (NFC) module to facilitate short-range communication. For example, the NFC module can be implemented based on radio frequency identification (RFID) technology, infrared data association (IrDA) technology, ultra-wideband (UWB) technology, Bluetooth (BT) technology and other technologies.

[0193] In an exemplary embodiment, the electronic device 800 may be implemented by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic components to perform the above methods.

[0194] In an exemplary embodiment, a non-volatile computer-readable storage medium is also provided, such as a memory 804 including computer program instructions, which can be executed by a processor 820 of an electronic device 800 to perform the above method.

[0195] See also Figure 6 , Figure 6 A block diagram of an electronic device according to an embodiment of the present disclosure is shown.

[0196] For example, the electronic device 1900 may be provided as a server. Figure 6 , the electronic device 1900 includes a processing component 1922, which further includes one or more processors, and a memory resource represented by a memory 1932 for storing instructions executable by the processing component 1922, such as an application. The application stored in the memory 1932 may include one or more modules, each corresponding to a set of instructions. In addition, the processing component 1922 is configured to execute instructions to perform the above method.

[0197] The electronic device 1900 may also include a power supply component 1926 configured to perform power management of the electronic device 1900, a wired or wireless network interface 1950 configured to connect the electronic device 1900 to a network, and an input / output (I / O) interface 1958. The electronic device 1900 may operate based on an operating system stored in the memory 1932, such as a Microsoft Server operating system (Windows Server 2003). TM ), a graphical user interface operating system launched by Apple (Mac OSX TM ), a multi-user, multi-process computer operating system (Unix TM ), a free and open source Unix-like operating system (Linux TM ), an open source Unix-like operating system (FreeBSD TM ) or similar.

[0198] In an exemplary embodiment, a non-volatile computer-readable storage medium is also provided, such as a memory 1932 including computer program instructions that can be executed by the processing component 1922 of the electronic device 1900 to perform the above method.

[0199] The present disclosure may be a system, a method and / or a computer program product. The computer program product may include a computer-readable storage medium carrying computer-readable program instructions for causing a processor to implement various aspects of the present disclosure.

[0200] Computer readable storage medium can be a tangible device that can hold and store instructions used by an instruction execution device. Computer readable storage medium can be, for example, (but not limited to) an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination thereof. More specific examples (non-exhaustive list) of computer readable storage medium include: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a static random access memory (SRAM), a portable compact disk read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanical encoding device, for example, a punch card or a convex structure in a groove on which instructions are stored, and any suitable combination thereof. The computer readable storage medium used here is not interpreted as a transient signal itself, such as a radio wave or other freely propagating electromagnetic wave, an electromagnetic wave propagated by a waveguide or other transmission medium (for example, a light pulse by an optical fiber cable), or an electrical signal transmitted by a wire.

[0201] The computer-readable program instructions described herein can be downloaded from a computer-readable storage medium to each computing / processing device, or downloaded to an external computer or external storage device via a network, such as the Internet, a local area network, a wide area network, and / or a wireless network. The network can include copper transmission cables, optical fiber transmissions, wireless transmissions, routers, firewalls, switches, gateway computers, and / or edge servers. The network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards the computer-readable program instructions for storage in the computer-readable storage medium in each computing / processing device.

[0202] The computer program instructions for performing the operation of the present disclosure may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-related instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages, such as Smalltalk, C++, etc., and conventional procedural programming languages, such as "C" language or similar programming languages. Computer-readable program instructions may be executed completely on a user's computer, partially on a user's computer, as an independent software package, partially on a user's computer, partially on a remote computer, or completely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., using an Internet service provider to connect via the Internet). In some embodiments, an electronic circuit, such as a programmable logic circuit, a field programmable gate array (FPGA), or a programmable logic array (PLA), may be customized by utilizing the state information of the computer-readable program instructions, and the electronic circuit may execute the computer-readable program instructions, thereby realizing various aspects of the present disclosure.

[0203] Various aspects of the present disclosure are described herein with reference to the flowcharts and / or block diagrams of the methods, devices (systems) and computer program products according to the embodiments of the present disclosure. It should be understood that each box in the flowchart and / or block diagram and the combination of each box in the flowchart and / or block diagram can be implemented by computer-readable program instructions.

[0204] These computer-readable program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, thereby producing a machine, so that when these instructions are executed by the processor of the computer or other programmable data processing device, a device that implements the functions / actions specified in one or more boxes in the flowchart and / or block diagram is generated. These computer-readable program instructions can also be stored in a computer-readable storage medium, and these instructions cause the computer, programmable data processing device, and / or other equipment to work in a specific manner, so that the computer-readable medium storing the instructions includes a manufactured product, which includes instructions for implementing various aspects of the functions / actions specified in one or more boxes in the flowchart and / or block diagram.

[0205] Computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device so that a series of operating steps are performed on the computer, other programmable data processing apparatus, or other device to produce a computer-implemented process, thereby causing the instructions executed on the computer, other programmable data processing apparatus, or other device to implement the functions / actions specified in one or more boxes in the flowchart and / or block diagram.

[0206] The flow chart and block diagram in the accompanying drawings show the possible architecture, function and operation of the system, method and computer program product according to multiple embodiments of the present disclosure. In this regard, each square box in the flow chart or block diagram can represent a part of a module, program segment or instruction, and a part of the module, program segment or instruction includes one or more executable instructions for realizing the specified logical function. In some alternative implementations, the function marked in the square box can also occur in a sequence different from that marked in the accompanying drawings. For example, two continuous square boxes can actually be executed substantially in parallel, and they can sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each square box in the block diagram and / or flow chart, and the combination of the square boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs the specified function or action, or can be implemented with a combination of special hardware and computer instructions.

[0207] The computer program product may be implemented in hardware, software or a combination thereof. In one optional embodiment, the computer program product is embodied as a computer storage medium, and in another optional embodiment, the computer program product is embodied as a software product, such as a software development kit (SDK) and the like.

[0208] The embodiments of the present disclosure have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A laser radar parameter calibration device, characterized in that: The device comprises: The laser radar to be calibrated comprises a transmitting unit, a receiving unit and a processing unit, wherein the transmitting unit is used to transmit a laser signal to a calibration target for ranging, the receiving unit is used to receive a reflected laser signal from the calibration target, and the processing unit is used to record a propagation time from when the transmitting unit transmits the laser signal to when the receiving unit receives the reflected laser signal, and a pulse width time of the reflected laser signal; A displacement module is provided with an optical attenuation sheet, wherein the optical attenuation sheet includes a plurality of attenuation regions, each attenuation region has a different light transmittance, and the displacement module is used to control the movement of the optical attenuation sheet to change the light transmittance of the transmitting unit and / or the receiving unit; A control module is connected to the laser radar to be calibrated and the displacement module, and is used to: Control the displacement module to move the optical attenuation sheet M times, and control the laser radar to be calibrated to measure distance before the first movement and after each movement, and record the propagation time and pulse width time before the first movement and after each movement, where M is a positive integer; Determine each propagation time deviation between the propagation time after each movement and the propagation time before the first movement, and each pulse width time deviation between the pulse width time after each movement and the pulse width time before the first movement; Determine the correlation between each propagation time deviation and each pulse width time deviation to calibrate the parameters of the laser radar to be calibrated. The laser radar to be calibrated is also used for: During actual distance measurement, the actual pulse width time difference between the actual pulse width time and the pulse width time before the first movement is determined; Determine the magnitude relationship between the actual pulse width time difference and the minimum pulse width time deviation and / or the maximum pulse width time deviation among N standard pulse width time deviations; Determine a target propagation time deviation according to the size relationship, the mapping relationship, the minimum pulse width time deviation or the maximum pulse width time deviation; The actual propagation time is corrected using the target propagation time deviation.

2. The device according to claim 1, characterized in that The determining of the correlation between each propagation time deviation and each pulse width time deviation to perform parameter calibration includes: A cubic spline curve is fitted to each propagation time deviation and each pulse width time deviation to obtain the correlation relationship.

3. The device according to claim 1 or 2, characterized in that: The laser radar to be calibrated is also used for: During actual distance measurement, the target propagation time deviation is determined according to the difference between the actual pulse width time and the pulse width time before the first movement and the correlation, and the actual propagation time is corrected using the target propagation time deviation.

4. The device according to claim 1, characterized in that The control module is also used for: Obtaining N standard pulse width time deviations from a minimum pulse width time deviation to a maximum pulse width time deviation according to the M pulse width time deviations at a target time step; Obtaining N time deviation correction values ​​according to the N standard pulse width time deviations and the correlation; The target time step is determined according to the number N of the maximum pulse width time deviation, the minimum pulse width time deviation and the standard pulse width time deviation.

5. The device according to claim 4, characterized in that Before obtaining N standard pulse width time deviations from the minimum pulse width time deviation to the maximum pulse width time deviation according to the M pulse width time deviations at the target time step, the control module is further used to: The M pulse width time deviations are sorted.

6. The device according to claim 4, characterized in that The control module is also used for: Storing the N standard pulse width time deviations, the N time deviation correction values, and a mapping relationship between each standard pulse width time deviation and each time deviation correction value in the laser radar to be calibrated; The pulse width time before the first movement is stored in the laser radar to be calibrated.

7. The device according to claim 1, characterized in that The determining of the target propagation time deviation according to the size relationship, the mapping relationship, the minimum pulse width time deviation or the maximum pulse width time deviation comprises: If the actual pulse width time difference is smaller than the minimum pulse width time deviation, the target propagation time deviation is determined according to the minimum pulse width time deviation and the mapping relationship.

8. The device according to claim 1, characterized in that The determining of the target propagation time deviation according to the size relationship, the mapping relationship, the minimum pulse width time deviation or the maximum pulse width time deviation comprises: If the actual pulse width time difference is greater than the maximum pulse width time deviation, the target propagation time deviation is determined according to the maximum pulse width time deviation and the mapping relationship.

9. The device according to claim 1, characterized in that The determining of the target propagation time deviation according to the size relationship, the mapping relationship, the minimum pulse width time deviation or the maximum pulse width time deviation comprises: If the actual pulse width time difference is between the minimum pulse width time deviation and the maximum pulse width time deviation, the target propagation time deviation is determined according to the value of the N standard pulse width time deviations closest to the actual pulse width time difference and the mapping relationship.

10. A laser radar, characterized in that: The laser radar stores the correlation between the propagation time deviation and the pulse width time deviation and the preset pulse width time, and the laser radar is used for: Transmitting a laser signal to a target to be measured, and receiving a reflected laser signal from the target to be measured; Acquire the actual propagation time from emitting the laser signal to receiving the reflected laser signal and the actual pulse width time of the reflected laser signal; Determine a target propagation time deviation according to an actual pulse width time difference between the actual pulse width time and the preset pulse width time and the correlation, and use the target propagation time deviation to correct the actual propagation time; Determine the target distance based on the corrected actual propagation time, The laser radar also stores N standard pulse width time deviations, N time deviation correction values, and a mapping relationship between each standard pulse width time deviation and each time deviation correction value. The laser radar is also used to: determine the size relationship between the actual pulse width time difference and the minimum standard pulse width time deviation and / or the maximum standard pulse width time deviation among the N standard pulse width time deviations; Determine a target propagation time deviation according to the size relationship, the mapping relationship, the minimum pulse width time deviation or the maximum pulse width time deviation; The actual propagation time is corrected using the target propagation time deviation.

11. The laser radar according to claim 10, characterized in that: The determining of the target propagation time deviation according to the size relationship, the mapping relationship, the minimum pulse width time deviation or the maximum pulse width time deviation comprises: If the actual pulse width time difference is smaller than the minimum pulse width time deviation, the target propagation time deviation is determined according to the minimum pulse width time deviation and the mapping relationship.

12. The laser radar according to claim 10, characterized in that: The determining of the target propagation time deviation according to the size relationship, the mapping relationship, the minimum pulse width time deviation or the maximum pulse width time deviation comprises: If the actual pulse width time difference is greater than the maximum pulse width time deviation, the target propagation time deviation is determined according to the maximum pulse width time deviation and the mapping relationship.

13. The laser radar according to claim 10, characterized in that: The determining of the target propagation time deviation according to the size relationship, the mapping relationship, the minimum pulse width time deviation or the maximum pulse width time deviation comprises: If the actual pulse width time difference is between the minimum pulse width time deviation and the maximum pulse width time deviation, the target propagation time deviation is determined according to the value of the N standard pulse width time deviations closest to the actual pulse width time difference and the mapping relationship.

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