Multi-channel laser radar reflectivity calibration device

Abstract

The utility model relates to a multi-channel laser radar reflectivity calibration device. The calibration device comprises an external frame, wherein a guide rail is arranged in the external frame; one end of the external frame is provided with a visual identification camera used for collecting the position of a laser spot of a radar to be measured; the two or more radar mounting platforms can rotate in the horizontal direction and the pitching direction; a moving platform is movably arranged on the guide rails; the mobile platform is provided with a multi-reflectivity target which comprises a plurality of plates with different reflectivity and can rotate along the axis; and the upper computer is used for reading image data of the visual identification camera. Compared with the prior art, the radar reflectivity calibration device can operate to a specified calibration position according to different radar requirements and flexibly switch the reflectivity of the target, reflectivity calibration of multiple radars can be completed, and the production speed of a production line is greatly increased.

Description

Technical Field

[0001] This utility model relates to the field of lidar calibration and testing technology, and in particular to a multi-channel lidar reflectivity calibration device. Background Technology

[0002] With the rapid development of smart devices in recent years, the demand for LiDAR, as a simple and cost-effective sensor solution, has increased rapidly. For LiDAR manufacturers, these increasing shipment demands are constantly testing their production line capabilities.

[0003] In lidar production lines, ranging calibration using targets with different reflectivities is a crucial step, directly impacting the lidar's ranging accuracy for objects with varying reflectivities during operation. Traditional lidar calibration and testing lines often place targets in fixed locations, allowing only one lidar to be calibrated and tested at a time. These limitations hinder the rapid improvement of production line capacity. Utility Model Content

[0004] The purpose of this invention is to overcome the defects of the existing technology and provide a multi-channel lidar reflectivity calibration device.

[0005] The objective of this utility model can be achieved through the following technical solutions:

[0006] As a first aspect of this utility model, a multi-channel lidar reflectivity calibration device is provided, the calibration device including an external frame with an internal guide rail;

[0007] One end of the external frame is equipped with: a visual recognition camera for acquiring the position of the radar laser spot to be measured; and two or more radar mounting platforms for fixing the radar to be measured, which can rotate in the horizontal and pitch directions.

[0008] A movable platform is movably mounted on the guide rail and moves along the guide rail; the movable platform is equipped with a multi-reflectivity target, which includes multiple plates with different reflectivities and can rotate movably along the axis, for measuring objects with different reflectivities by the lidar.

[0009] The host computer is connected to the visual recognition camera, each radar mounting platform, target, and mobile platform. It is used to read the image data from the visual recognition camera and control the horizontal and pitch rotation of the radar mounting platform, the rotation of the multi-reflectivity target, and the movement of the mobile platform to complete the multi-channel lidar reflectivity calibration at multiple distances.

[0010] As a preferred technical solution, the radar mounting platform includes a radar fixing fixture, a pitch rotation mechanism, and a horizontal rotation mechanism.

[0011] The pitch rotation mechanism is rotatably connected to the external frame by a horizontally set pitch rotation motor, and the pitch orientation of the radar to be measured is adjusted by the pitch rotation motor.

[0012] The horizontal rotation mechanism includes a horizontal rotation motor vertically mounted on the pitch rotation mechanism. The output end of the horizontal rotation motor is connected to the radar fixing fixture, and the horizontal orientation of the radar to be measured is adjusted by the horizontal rotation motor.

[0013] As a preferred technical solution, the radar fixing fixture is provided with radar mounting holes and a quick-release mechanism that cooperates with the radar mounting holes for fixing and installing the radar to be measured.

[0014] As a preferred technical solution, a rack and a guide rail are installed in parallel within the external frame; the guide rail is used for guiding the movement of the mobile platform; the rack is used to provide driving feedback force; the mobile platform is mounted above the guide rail and moves along it.

[0015] As a preferred technical solution, two sets of servo motors are installed below the mobile platform:

[0016] A rotary servo motor is used to control the rotation of a multi-reflectivity target along its axis, so that the different reflectivity plates set on the multi-reflectivity target face the radar to be measured.

[0017] The mobile servo motor meshes with the rack and pinion to achieve the reciprocating motion of the mobile platform.

[0018] As a preferred technical solution, the rotary servo motor is equipped with a first encoder to obtain the angle information of the multi-reflectivity target.

[0019] As a preferred technical solution, the mobile servo motor is equipped with a second encoder to obtain the position information of the multi-reflectivity target.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] This invention proposes a multi-channel lidar reflectivity calibration device. It uses a rack and pinion guide and a servo motor to move targets at different distances while ensuring distance accuracy. Multiple targets with different reflectivities are mounted on the moving platform, and a single servo motor enables rapid switching between them. The radar mounting platform has expandable mounting holes, allowing for calibration switching between multiple radars. Each radar mounting platform is equipped with horizontal and vertical rotation motors, and a visual recognition camera ensures that the calibration spot of a single radar is aligned with the target. This invention not only allows for flexible and convenient switching of target reflectivity but also enables the device to move to a designated calibration position according to different radar requirements. Furthermore, a single calibration process can complete the calibration of multiple radars, significantly accelerating production line speed. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the multi-channel lidar reflectivity calibration device of this utility model;

[0023] Figure 2 This is a schematic diagram of the radar mounting platform structure of this utility model.

[0024] Figure 3 This is a schematic diagram of the multi-channel lidar reflectivity calibration and device of this utility model;

[0025] Figure 4 This is a flowchart illustrating the working process of the multi-channel lidar reflectivity calibration device of this utility model.

[0026] The numbers in the diagram indicate: 1. Visual recognition camera, 2. Radar mounting platform, 3. Multi-reflectivity target, 4. Moving platform, 5. Servo motor, 6. Guide rail, 7. Rack, 8. Horizontal rotary motor, 9. Pitch rotary motor, 10. Quick release mechanism, 11. Radar fixing fixture. Detailed Implementation

[0027] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. This embodiment is based on the technical solution of the present invention and provides detailed implementation methods and specific operating procedures; however, the scope of protection of the present invention is not limited to the following embodiments.

[0028] Example 1

[0029] This invention provides a multi-channel lidar reflectivity calibration device for calibrating objects with different reflectivities and testing ranging accuracy during lidar production. Figure 1As shown, the entire device of this utility model is divided into a fixed part and a moving part. The fixed part consists of a host computer, a visual recognition camera 1, a radar mounting platform 2, a guide rail 6, a rack 7, and an external aluminum profile frame. The moving part consists of a moving platform 4, two sets of servo motors 5 and an encoder, and a multi-reflectivity target 3.

[0030] Radar mounting platform 2 is installed at one end of the entire testing device to fix the radar to be measured. The number of radar mounting platforms can be increased or decreased as needed to achieve target measurement by multi-channel radar. Figure 2 As shown, a single radar mounting platform consists of a horizontal rotary motor 8, a pitch rotary motor 9, a radar fixing fixture 11, a quick-release mechanism 10, and related structural components. The entire radar mounting platform is mounted on the profile frame via the pitch rotary motor, and the radar fixing fixture is fixed to the base below via the horizontal rotary motor. This method allows for the pitch and horizontal adjustment of the radar fixing fixture. The radar fixing fixture has radar mounting holes on top, which, together with the quick-release mechanism 10, enable the rapid installation or replacement of the radar.

[0031] The radar mounting platform 2 uses a quick-release mechanism 10 to install the radar to be measured, and the number of radar mounting platforms 2 can be adjusted according to needs. The visual recognition camera 1 is placed above the radar mounting platform to collect the position of the radar laser spot falling on the target. It works with the pitch and horizontal rotation motors 8 and 9 on the radar mounting platform 2 to perform visual position correction, ensuring that the single point spot of the radar to be measured falls on the target. Targets 3 with different reflectivities are installed on the moving platform 4 and rotated along the axis by a rotary servo motor to realize the measurement of objects with different reflectivities by the laser radar. The moving platform 4 moves along the guide rail 6 under the drive of the moving servo motor and the rack 7 to complete the calibration and testing requirements at different distances. The figure shows 4 types of reflectivity plates, and the number of reflectivity plates can be adjusted according to needs.

[0032] The rack 7 is installed parallel to the guide rail 6 and attached to the external frame of the entire device. The guide rail 6 is used for guiding the movement of the moving platform 4, and the rack 7 is used to provide drive feedback force for the moving servo motor. The moving platform 4 is installed above the guide rail 6 and moves along it. Two sets of servo motors 5 are installed below the moving platform 4 and are equipped with encoders to obtain position information. One set of moving servo motors is used to mesh with the rack 7 to realize the reciprocating motion of the moving platform 4, and the other set of rotary servo motors is used to control the rotation of the multi-reflectivity target 3 along its axis, so that the different reflectivity plates installed around it face the lidar to be measured. The multi-reflectivity target 3 shown in the figure has four sides around its perimeter, which can accommodate four different reflectivity plates, and is driven to rotate by the servo motors 5. The number of reflective plates on the target 3 can be increased or decreased by modifying its shape to meet actual use requirements.

[0033] like Figure 3As shown, the host computer is connected to the visual recognition camera 1, each radar mounting platform 2, the target 3, and the moving platform 4. It is used to read image data from the visual recognition camera 1; control the horizontal and pitch rotation of the radar mounting platform 2 and acquire the radar data to be measured; control the rotation of the multi-reflectivity target 3 and the movement of the moving platform 4; and obtain the actual angle of the multi-reflectivity target 3 and the actual distance between the multi-reflectivity target 3 and the radar to be measured from the encoder. The control device completes the multi-channel lidar reflectivity calibration at multiple distances.

[0034] like Figure 4 As shown, the working process of this calibration device is as follows:

[0035] First, the mobile platform 4 is moved to the farthest calibration point under control, and the multi-reflectivity target 3 is rotated to complete the self-test of the entire moving part and ensure that the movement of the entire device is unrestricted; at the same time, the horizontal rotation motors 8 of all radar mounting platforms 2 rotate 180° so that the radar fixing fixture faces the rear, preventing other radars from affecting it when the radar is calibrating the light spot or collecting data.

[0036] The radar to be measured is installed on the radar mounting platform 2 on the radar fixing fixture 11. The moving platform 4 is moved to the farthest position to be measured. The spot position is calibrated in sequence: the host computer controls the radar to be calibrated to emit laser and controls the radar mounting platform 2 to rotate horizontally by 180° so that the laser is emitted in the direction of the multi-reflectivity target 3. The visual recognition camera 1 collects the spot on the multi-reflectivity target 3. The host computer controls the pitch and horizontal rotation motors on the radar mounting platform 2 to move the spot of the radar to be measured to the center position of the reflectivity target 3, so as to prevent the spot from not falling accurately on the target due to the radar zero-degree angle or pitch angle problem. After the spot position is calibrated and the calibration position is recorded, the radar mounting platform is rotated backward and the spot calibration of the next radar is performed.

[0037] After calibrating the positions of all radar spots to be measured, the formal calibration procedure begins. The mobile platform 4 moves to the set distance and then rotates the radar mounting platform according to the recorded spot positions, completing data acquisition for each radar. After acquiring data for a single radar, it rotates backward. After acquiring data for a group of radars, the multi-reflectivity target 3 is rotated to switch to a different reflectivity to continue acquisition. Once all reflectivity acquisitions are complete, the mobile platform 4 is moved to the next set distance to continue the above steps.

[0038] Once all locations and reflectivity data have been collected, the process is complete.

[0039] The preferred embodiments of this utility model have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of this utility model without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of this utility model through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A multi-channel lidar reflectivity calibration device, characterized in that, The calibration device includes a host computer and an external frame with a guide rail (6) inside; One end of the external frame is provided with: a visual recognition camera (1); two or more radar mounting platforms (2), the radar mounting platforms (2) are used to fix the radar to be measured and can rotate in the horizontal and pitch directions; A movable platform (4) is movably disposed on the guide rail (6) and moves along the guide rail (6); the movable platform (4) is provided with a multi-reflectivity target (3), the multi-reflectivity target (3) includes multiple plates with different reflectivity and can rotate movably along the axis; The host computer is connected to the visual recognition camera (1), each radar mounting platform (2), target (3) and mobile platform (4) respectively.

2. The multi-channel lidar reflectivity calibration device according to claim 1, characterized in that, The radar mounting platform (2) includes a radar fixing fixture (10), a pitch rotation mechanism, and a horizontal rotation mechanism; The pitch and rotation mechanism is rotatably connected to the external frame by a horizontally mounted pitch and rotation motor (9); The horizontal rotation mechanism includes a horizontal rotation motor (12) vertically mounted on the pitch rotation mechanism, and the output end of the horizontal rotation motor (12) is connected to the radar fixing fixture (10).

3. The multi-channel lidar reflectivity calibration device according to claim 2, characterized in that, The radar mounting fixture (10) is provided with radar mounting holes and a quick-release mechanism (11) that cooperates with the radar mounting holes for fixing and installing the radar to be measured.

4. The multi-channel lidar reflectivity calibration device according to claim 1, characterized in that, A rack (7) and a guide rail (6) are installed in parallel within the external frame; the moving platform (4) is installed above the guide rail (6) and moves along it.

5. The multi-channel lidar reflectivity calibration device according to claim 4, characterized in that, The mobile platform (4) is equipped with two sets of servo motors (5): a rotary servo motor whose output end is connected to the axis of the multi-reflectivity target (3); and a moving servo motor whose output end meshes with a rack (7).

6. The multi-channel lidar reflectivity calibration device according to claim 5, characterized in that, The rotary servo motor is equipped with a first encoder.

7. The multi-channel lidar reflectivity calibration device according to claim 5, characterized in that, The mobile servo motor is equipped with a second encoder.

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