A laser radar and camera time synchronization method and device, and a driving device

Abstract

The present application relates to the technical field of automatic driving, and particularly provides a laser radar and camera time synchronization method and device and driving equipment, aiming to solve the problems of low time synchronization accuracy and high demand for computing power of the existing laser radar and camera. To this end, the laser radar and camera time synchronization method of the present application comprises: acquiring a first time when the laser radar scans into a field angle region of a target camera, a scanning duration of the laser radar scanning the field angle region, and an exposure duration of the target camera in the field angle region; determining a trigger time of the target camera according to the first time, the scanning duration and the exposure duration; and controlling the target camera to perform exposure based on the trigger time, wherein when the target camera is controlled to perform exposure based on the trigger time, the middle time of the laser radar scanning the field angle region coincides with the middle time of the target camera exposure. This method can reduce the consumption of computing power and improve the accuracy of time synchronization.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automatic driving, and particularly provides a laser radar and camera time synchronization method and device and driving equipment. BACKGROUND

[0002] With the development of artificial intelligence technology, automatic driving technology is also increasingly mature. At present, automatic driving mainly relies on pure vision and multi-sensor fusion to obtain driving environment information, wherein laser radar and camera fusion is a widely used multi-sensor fusion method. Due to the differences in frequency, FOV (field of view) and installation position of each sensor, in the fusion process, in order to enable the laser radar and the camera to simultaneously perceive the environmental obstacle information, time synchronization of the multi-sensor is involved.

[0003] In the related art, time synchronization mainly includes two synchronization methods of post-processing and triggering:

[0004] Post-processing refers to that the laser radar and the camera scan according to their respective frequencies and record time stamps, then search for the data of the camera with relatively close time stamps based on the time of the laser radar with a lower frequency, and then fuse the data of the two. The scanning frequency of the radar is generally 10 Hz, and the frame rate of the camera is generally 30 fps. Since the frequencies and paces of the two sensors are inconsistent, time errors will inevitably be introduced during synchronization. In order to obtain smaller time errors, it is necessary to continuously improve the scanning frequency of the sensor, which puts higher requirements on the performance and price of the device.

[0005] Triggering refers to that the sensor starts scanning and exposure when receiving an external trigger signal. This method can ensure that the sensor achieves high-precision time synchronization. The laser radar generally scans by mechanical rotation or other methods, and has a large FOV. The camera adopts light exposure, and has a relatively small FOV. A common method is to trigger the camera to expose and record the time when the laser radar scans through the FOV center of the camera, and then fuse through post-processing. Since it is necessary to continuously calculate the angle of the laser radar scanning for alignment with the camera, a very high computing power is required, and the performance requirement of the main controller is very high. Meanwhile, this method does not consider the scanning time of the overlapping FOV of the laser radar and the camera and the exposure time of the camera, and there will still be a certain time error. SUMMARY

[0006] The present application aims to solve the above technical problems, i.e., to solve the problem of low time synchronization accuracy and high computing power requirement of the existing laser radar and camera.

[0007] In a first aspect, the present application provides a laser radar and camera time synchronization method, which comprises:

[0008] acquire a first time when a laser radar scan enters a field of view angle region of a target camera, a scanning time length of the laser radar scan in the field of view angle region, and an exposure time length of the target camera in the field of view angle region;

[0009] determine a trigger time of the target camera according to the first time, the scanning time length, and the exposure time length;

[0010] control the target camera to perform exposure based on the trigger time, wherein, when the target camera is controlled to perform exposure based on the trigger time, a middle time when the laser radar scans the field of view angle region coincides with a middle time when the target camera performs exposure.

[0011] In some embodiments, the trigger time of the target camera is determined by the following expression:

[0012] wherein T1 represents the first time, Δt1 represents the scanning time length, Δt2 represents the exposure time length, and T3 represents the trigger time of the target camera.

[0013] In some embodiments, the method further comprises establishing a correlation between a running time of the laser radar and a deflection angle according to a set parameter of the laser radar.

[0014] The acquiring of the first time when the laser radar scan enters the field of view angle region of the target camera comprises:

[0015] determining an entering deflection angle when the laser radar scan enters the field of view angle region of the target camera, and determining the first time according to the entering deflection angle and the correlation.

[0016] In some embodiments, the establishing of the correlation between the running time of the laser radar and the deflection angle according to the set parameter of the laser radar comprises:

[0017] establishing the correlation between the running time of the laser radar and the deflection angle according to an angular resolution and a trigger interval of the laser radar.

[0018] In some embodiments, the determining of the entering deflection angle when the laser radar scan enters the field of view angle region of the target camera comprises:

[0019] acquiring a set parameter of the target camera and position information of the target camera relative to the laser radar;

[0020] determining a scanning deflection angle of the laser radar from entering the field of view angle region to exiting the field of view angle region according to the set parameter of the target camera and the position information.

[0021] determine the entering deflection angle according to the scanning deflection angle and the position information.

[0022] In some embodiments, the method further comprises: acquiring a scanning duration of the laser radar scanning the field angle region, comprising:

[0023] determining an exiting deflection angle of the laser radar scanning out of the field angle region of the target camera; determining a second time according to the exiting deflection angle and the correlation; and determining the scanning duration according to the second time and the first time.

[0024] In some embodiments, the method further comprises: adjusting a scanning speed of the laser radar, and controlling the laser radar to be at a preset emission position at a preset operation time.

[0025] In a second aspect, the present application provides a laser radar and camera time synchronization device, comprising:

[0026] an acquisition module configured to acquire a first time at which the laser radar scans into a field angle region of a target camera, a scanning duration of the laser radar scanning the field angle region, and an exposure duration of the target camera in the field angle region;

[0027] a determination module configured to determine a trigger time of the target camera according to the first time, the scanning duration, and the exposure duration;

[0028] a control module configured to control the camera to perform exposure based on the target trigger time, wherein, when the camera is controlled to perform exposure based on the target trigger time, a middle time at which the laser radar scans the field angle region coincides with a middle time at which the target camera performs exposure.

[0029] In a third aspect, the present application provides a computer readable storage medium, wherein the computer readable storage medium stores a computer program, and the computer program is executed by a processor to implement the laser radar and camera time synchronization method according to any one of the above aspects.

[0030] In a fourth aspect, the present application provides a driving device, comprising a driving device body, a memory, and a processor, wherein the memory stores a computer program, and the computer program is executed by the processor to implement the laser radar and camera time synchronization method according to any one of the above aspects.

[0031] In the technical solution, the first time when the laser radar scans into the field angle region of the target camera, the scanning time length of the laser radar scanning field angle region, and the exposure time length of the target camera in the field angle region are obtained; the trigger time of the target camera is determined according to the first time, the scanning time length, and the exposure time length; and the target camera is controlled to perform exposure based on the trigger time, wherein, when the target camera is controlled to perform exposure based on the trigger time, the middle time of the laser radar scanning field angle region coincides with the middle time of the target camera exposure. The method converts to calculate the trigger time, avoids the problem that the scanning angle of the laser radar needs to be calculated in real time in the prior art, and can reduce the calculation power consumption. In addition, by considering the first time of the laser radar and the exposure time of the target camera, and by making the middle time of the laser radar scanning field angle region coincide with the middle time of the target camera exposure when the target camera is controlled to perform exposure based on the trigger time, the time error of the laser radar and the target camera can be effectively reduced, and the time synchronization accuracy can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0032] The preferred embodiments of the present application will be described below with reference to the accompanying drawings, in which:

[0033] Figure 1 is a laser radar and camera time synchronization method flowchart provided by an embodiment of the present application;

[0034] Figure 2 is a laser radar and camera time synchronization method flowchart provided by another embodiment of the present application;

[0035] Figure 3 is an overlapping field view top view of a laser radar and a target camera provided by the present application;

[0036] Figure 4 is a laser radar and camera time synchronization system structure schematic diagram provided by an embodiment of the present application;

[0037] Figure 5 is a structure schematic diagram of a laser radar and camera time synchronization device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0038] Some embodiments of the present application will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present application, and are not intended to limit the protection scope of the present application.

[0039] Referring to Figure 1 shown, Figure 1 is a laser radar and camera time synchronization method flowchart provided by an embodiment of the present application, which can include:

[0040] Step S11: obtaining a first time when the laser radar scanning enters a field of view angle region of the target camera, a scanning time length of the laser radar scanning field of view angle region, and an exposure time length of the target camera in the field of view angle region;

[0041] Step S12: determining a trigger time of the target camera according to the first time, the scanning time length, and the exposure time length;

[0042] Step S13: controlling the target camera to perform exposure based on the trigger time, wherein when the target camera is controlled to perform exposure based on the trigger time, a middle time of the laser radar scanning field of view angle region coincides with a middle time of the target camera exposure.

[0043] In some embodiments, step S12 can be specifically determined by the following expression to determine the trigger time of the target camera:

[0044] Wherein, T1 represents the first time, Δt1 represents the scanning time length, Δt2 represents the exposure time length, and T3 represents the trigger time of the target camera.

[0045] The trigger time determined based on the above expression controls the target camera to perform exposure, and the time error between the laser radar and the target camera is maximally Compared with the prior art, the time error between the laser radar and the target camera can be maximally reduced, and the precision of time synchronization is improved. For example, in the prior art, when the laser radar scanning passes through the FOV center of the camera, the camera is triggered to perform exposure and record the time, and the time error between the laser radar and the target camera is maximally which is greater than the corresponding time error when the exposure is controlled based on the trigger time in the embodiment of the application.

[0046] In some embodiments, the host can also time the laser radar, and when the laser radar runs to the trigger time in step S13, the target camera can be controlled to perform exposure.

[0047] In order to avoid real-time calculation of the scanning angle of the laser radar, in the embodiment of the application, the trigger time of the target camera is calculated, which can effectively reduce the demand for computing power.

[0048] In some embodiments, the association between the running time of the laser radar and the deflection angle can also be established in advance, and specific reference can be made to the following Figure 2 .

[0049] Figure 2 is a flowchart of a laser radar and camera time synchronization method provided by another embodiment of the application, which can include:

[0050] Step S20: According to the setting parameters of the laser radar, a correlation between the running time of the laser radar and the deflection angle is established.

[0051] Step S21: The first time when the laser radar scans into the field angle region of the target camera, the scanning duration of the laser radar scanning the field angle region, and the exposure duration of the target camera in the field angle region are obtained.

[0052] Step S22: The trigger time of the target camera is determined according to the first time, the scanning duration, and the exposure duration.

[0053] Step S23: The target camera is controlled to perform exposure based on the trigger time, wherein when the target camera is controlled to perform exposure based on the trigger time, the middle time of the laser radar scanning the field angle region coincides with the middle time of the target camera exposure.

[0054] Wherein, steps S22 and S23 can be realized in the same way as steps S12 and S13, and for the sake of brevity, the description is not repeated here, and the specific can be referred to the description in the above.

[0055] In some embodiments, the setting parameters of the laser radar can include the angular resolution and the trigger interval; and step S20 can be specifically establishing the correlation between the running time of the laser radar and the deflection angle according to the angular resolution and the trigger interval of the laser radar.

[0056] Wherein, the correlation between the running time of the laser radar and the deflection angle can be represented as:

[0057] T represents the running time of the laser radar, θ represents the deflection angle of the laser radar, α represents the angular resolution of the laser radar, and t represents the trigger interval of the laser radar.

[0058] In other embodiments, the setting parameters of the laser radar can include the scanning period and the trigger interval, and the horizontal field angle range of the laser radar can be 360°; and step S20 can be specifically calculating the angular resolution of the laser radar according to the scanning period and the trigger interval of the laser radar Wherein, t' represents the scanning period of the laser radar; and the correlation between the running time of the laser radar and the deflection angle is established according to the angular resolution and the trigger interval of the laser radar.

[0059] Referring to Figure 3 shown, Figure 3 is the overlapping field view top view of the laser radar and the target camera provided by the present application, wherein S1 represents the laser radar, S2 represents the target camera, S3 represents the overlapping field view region of the laser radar and the target camera, and S4 represents the field angle region of the target camera. Hereinafter, the correlation between the running time of the laser radar and the deflection angle will be described based on the laser radar and the target camera provided by the present application. Figure 3The time synchronization method provided by the application is described.

[0060] In some embodiments, the first time when the laser radar scanning enters the field angle region of the target camera in step S21 can be specifically:

[0061] determining the entering deflection angle of the laser radar scanning into the field angle region of the target camera;

[0062] determining the first time according to the entering deflection angle and the correlation.

[0063] In some embodiments, the entering deflection angle of the laser radar scanning into the field angle region of the target camera can be specifically:

[0064] obtaining the set parameters of the target camera and the position information of the target camera relative to the laser radar;

[0065] determining the scanning deflection angle of the laser radar from entering the field angle region to exiting the field angle region according to the set parameters of the target camera and the position information;

[0066] determining the entering deflection angle according to the scanning deflection angle and the position information.

[0067] The set parameters of the target camera can include the field angle and the effective range of the target camera, and the horizontal distance between the laser radar and the target camera and the deflection angle of the target camera relative to the horizontal initial emission position of the laser radar can be determined according to the position information, as shown in the following table: Figure 3 The horizontal initial emission position of the laser radar is set to 0°, and when the target camera is in the direction opposite to the initial emission position of the laser radar, the scanning deflection angle of the laser radar from entering the field angle region to exiting the field angle region can be determined by the following expression:

[0068]

[0069] Where θ1 represents the field angle of the target camera, θ2 represents the scanning deflection angle of the laser radar, S represents the effective range of the target camera, and d represents the horizontal distance between the laser radar and the target camera.

[0070] Correspondingly, determining the entering deflection angle according to the scanning deflection angle and the position information can be specifically calculating the difference between the deflection angle of the target camera relative to the horizontal initial emission position of the laser radar and to obtain the entering deflection angle of the laser radar. After obtaining the deflection angle, the first time can be determined according to the correlation constructed in step S20.

[0071] In some embodiments, the step S21 of acquiring the scan duration of the laser radar scanning the field angle region of the view field angle can include:

[0072] determining an exit deflection angle of the laser radar scanning out of the field angle region of the view field angle of the target camera;

[0073] determining a second time according to the exit deflection angle and the correlation, and determining the scan duration according to the second time and a first time.

[0074] In some embodiments, the exit deflection angle can be determined by the following steps:

[0075] acquiring the set parameters of the target camera and the position information of the target camera relative to the laser radar;

[0076] determining a scanning deflection angle of the laser radar from entering the field angle region to exiting the field angle region according to the set parameters of the target camera and the position information;

[0077] determining the exit deflection angle according to the scanning deflection angle and the position information.

[0078] The set parameters of the target camera can include the field angle and the effective range of the target camera, and the horizontal distance between the laser radar and the target camera and the deflection angle of the target camera relative to the horizontal initial emission position of the laser radar can be determined according to the position information, as shown in the following formula: Figure 3 The horizontal initial emission position of the laser radar is set to 0°, and when the target camera is in the opposite direction of the initial emission position of the laser radar, the scanning deflection angle of the laser radar from entering the field angle region to exiting the field angle region can be determined by the following expression:

[0079]

[0080] Wherein, θ1 represents the field angle of the target camera, θ2 represents the scanning deflection angle of the laser radar, S represents the effective range of the target camera, and d represents the horizontal distance between the laser radar and the target camera.

[0081] Correspondingly, the determination of the entry deflection angle according to the scanning deflection angle and the position information can specifically be the calculation of the sum of the deflection angle of the target camera relative to the horizontal initial emission position of the laser radar and θ22, to obtain the exit deflection angle of the laser radar.

[0082] In some embodiments, the scan duration can be obtained by calculating the difference between the second time and the first time. The first time corresponds to the time when the laser radar enters the field angle region, and the second time corresponds to the time when the laser radar exits the field angle region.

[0083] In other embodiments, obtaining the scanning time of the laser radar scanning field of view in step S21 can be specifically as follows:

[0084] Based on the target camera's settings and location information, determine the scanning deflection angle of the lidar from entering the field of view to exiting the field of view.

[0085] The scanning duration is determined based on the scanning deflection angle and correlation.

[0086] The target camera's settings can include its field of view and effective viewing distance. The horizontal distance between the lidar and the target camera, as well as the deflection angle of the target camera relative to the lidar's initial horizontal emission position, can be determined based on location information. Figure 3 As shown, with the initial horizontal emission position of the lidar set to 0°, when the target camera is in a direction opposite to the initial emission position of the lidar, the scanning deflection angle θ2 of the lidar from entering the field of view to exiting the field of view can be determined by the following expression:

[0087]

[0088] Where θ1 represents the field of view of the target camera, θ2 represents the scanning deflection angle of the lidar, S represents the effective line-of-sight of the target camera, and d represents the horizontal distance between the lidar and the target camera. Furthermore, the scanning time can be determined based on the scanning deflection angle and the correlation.

[0089] In some embodiments, the present invention may further include: adjusting the scanning speed of the lidar to control the lidar to be at a preset emission position at a preset operating time. For example, adjusting the scanning speed of the lidar ensures that the lidar returns to its initial emission position at the exact second it reaches in operation. Both the preset operating time and the preset emission position can be flexibly set according to requirements. This method allows for the calibration of the operating time and deflection angle, avoiding matching errors between the operating time and deflection angle caused by prolonged rotation or motor vibration.

[0090] Another aspect of the present invention provides a time synchronization system for lidar and camera, see [link to relevant documentation]. Figure 4 As shown, Figure 4 This is a schematic diagram of the time synchronization system structure of a lidar and camera provided in an embodiment of the present invention, which may include:

[0091] The system includes a lidar, a time synchronization unit, and multiple target cameras, which can be designated Camera1, Camera2, ..., CameraN. The lidar can be a mechanical rotating lidar supporting PTP (Precision Time Protocol) time synchronization. The time synchronization unit acts as the PTP master, and the lidar acts as the PTP slave, with the time synchronization unit providing time synchronization to the lidar. In some embodiments, the time synchronization unit can be an MPU (Microprocessor Unit) or a CPU (Central Processing Unit). The time synchronization unit can store the trigger times of the multiple target cameras. The trigger times of the multiple target cameras are obtained using the lidar and camera time synchronization method provided in any of the above embodiments. After obtaining the trigger times, they can be written as calibration values ​​into the time synchronization unit. The corresponding target camera is triggered once every scan cycle of the lidar. The time synchronization unit can trigger the target camera exposure through GPIO (General-purpose input / output) ports.

[0092] In another aspect, the present invention also provides a time synchronization device for a lidar and a camera, see [link to relevant documentation]. Figure 5 As shown, Figure 5 This diagram illustrates the structure of a lidar and camera time synchronization device provided in an embodiment of the present invention, which may include:

[0093] The acquisition module 51 is used to acquire the first moment when the lidar scans into the field of view of the target camera, the scanning time of the lidar scanning the field of view, and the exposure time of the target camera in the field of view.

[0094] The determination module 52 is used to determine the trigger time of the target camera based on the first moment, the scanning duration, and the exposure duration;

[0095] The control module 53 is used to control the camera to expose based on the target trigger time. When the camera is controlled to expose based on the target trigger time, the midpoint of the LiDAR scanning field of view coincides with the midpoint of the target camera exposure.

[0096] The laser radar and camera time synchronization device provided by the present application can be used to execute the laser radar and camera time synchronization method described above, and achieve the same beneficial effects as the laser radar and camera time synchronization method in the above embodiments. Further, it should be understood that, since the setting of each module is only for illustrating the functional units of the device of the present application, the physical device corresponding to the module can be the processor itself, or a part of software, a part of hardware, or a part of the combination of software and hardware in the processor. Therefore, Figure 5 The number of each module in the above embodiments is only illustrative. Those skilled in the art can understand that each module in the device can be adaptively split or combined. Such splitting or combining of specific modules does not cause the technical solution to deviate from the principles of the present application, and therefore, the technical solution after splitting or combining will fall within the protection scope of the present application.

[0097] Those skilled in the art can understand that all or part of the processes in the method of the above embodiments of the present application can also be completed by a computer program instructing related hardware. The computer program can be stored in a computer readable storage medium, and when the computer program is executed by a processor, the steps of each method embodiment described above can be implemented. The computer program includes computer program code, which can be in the form of source code, object code, executable files or some intermediate forms, etc. The computer readable storage medium can include any entity or device, medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory, random access memory, electrical carrier signal, telecommunication signal and software distribution medium, etc. that can carry the computer program code.

[0098] Another aspect of the present application also provides a computer readable storage medium, which stores a computer program. When the computer program is executed by a processor, the laser radar and camera time synchronization method in any of the above embodiments can be implemented. The computer readable storage medium can be a storage device formed by various electronic devices. Optionally, the computer readable storage medium in the embodiments of the present application is a non-transitory computer readable storage medium.

[0099] In another aspect of the present application, a driving device is also provided. The driving device can include a driving device body, a memory and a processor. The memory stores a computer program, and the computer program is executed by the processor to implement the laser radar and camera time synchronization method described above.

[0100] In some embodiments, the driving device can further include a laser radar and a target camera arranged on the driving device body.

[0101] The technical scheme of the present application has been described in combination with the preferred embodiments shown in the drawings, but it is easy for those skilled in the art to understand that the protection scope of the present application is obviously not limited to these specific embodiments. Those skilled in the art can make equivalent changes or replacements to the related technical features without departing from the principles of the present application, and the technical schemes after the changes or replacements will all fall within the protection scope of the present application.

Claims

1. A method for time synchronization of a laser radar and a camera, the method comprising: The method comprises: acquiring a first time when a laser radar scans into a field of view angle region of a target camera, a scanning duration of the laser radar scanning the field of view angle region, and an exposure duration of the target camera; The trigger time of the target camera is determined according to the first time, the scanning time length and the exposure time length by the following expression: Wherein, T1 represents the first time, Δt1 represents the scanning time length, Δt2 represents the exposure time length, and T3 represents the trigger time of the target camera. controlling the target camera to perform exposure based on the trigger time, wherein when the target camera is controlled to perform exposure based on the trigger time, a middle time when the laser radar scans the field of view angle region coincides with a middle time when the target camera performs exposure.

2. The method of claim 1, wherein, The method further comprises establishing a correlation between a running time of the laser radar and a deflection angle according to a set parameter of the laser radar; the establishing the correlation between the running time of the laser radar and the deflection angle according to the set parameter of the laser radar comprises: establishing the correlation between the running time of the laser radar and the deflection angle according to an angular resolution and a trigger interval of the laser radar. The acquiring the first time when the laser radar scans into the field of view angle region of the target camera comprises: determining an entering deflection angle at which the laser radar scans into the field of view angle region of the target camera; and determining the first time according to the entering deflection angle and the correlation.

3. The method of claim 2, wherein, The determining the entering deflection angle at which the laser radar scans into the field of view angle region of the target camera comprises: acquiring a set parameter of the target camera and position information of the target camera relative to the laser radar; determining a scanning deflection angle of the laser radar from entering the field of view angle region to exiting the field of view angle region according to the set parameter of the target camera and the position information; and determining the entering deflection angle according to the scanning deflection angle and the position information.

4. The method according to claim 2 or 3, characterized in that, The acquiring the scanning duration of the laser radar scanning the field of view angle region comprises: determining an exiting deflection angle at which the laser radar scans out of the field of view angle region of the target camera; determining a second time according to the exiting deflection angle and the correlation; and determining the scanning duration according to the second time and the first time.

5. The method of claim 1, wherein, The method further comprises adjusting a scanning speed of the laser radar to control the laser radar to be at a preset emission position at a preset running time.

6. A laser radar and camera time synchronization device, characterized by, The method comprises: an acquiring module configured to acquire a first time when a laser radar scans into a field of view angle region of a target camera, a scanning duration of the laser radar scanning the field of view angle region, and an exposure duration of the target camera in the field of view angle region; determining a trigger time of the target camera according to the first time, the scanning time length and the exposure time length by the following expression: wherein T1 represents the first time, Δt1 represents the scanning time length, Δt2 represents the exposure time length, and T3 represents the trigger time of the target camera. a control module configured to control the target camera to perform exposure based on the trigger time, wherein when the target camera is controlled to perform exposure based on the trigger time, a middle time when the laser radar scans the field of view angle region coincides with a middle time when the target camera performs exposure.

7. A computer readable storage medium characterized in that, The computer program stored in the computer readable storage medium is executed by the processor to implement the laser radar and camera time synchronization method in any one of claims 1 to 5.

8. A driving apparatus characterized by comprising: The driving device comprises a driving device body, a memory and a processor, the memory stores a computer program, and the computer program is executed by the processor to realize the method for time synchronization of the laser radar and the camera according to any one of claims 1 to 5.

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