Lidar calibration device

Abstract

The application discloses a kind of laser radar calibration devices, it is related to laser radar technical field, including: radar station, for installing the radar to be calibrated;Moving frame, located the rear of radar station, rotating device is provided on the moving frame;Calibration frame is connected to the rotating device, calibration mounting position is provided on the calibration frame, calibration mounting position is installed with calibration reflector, the radar can emit laser to the calibration reflector, the rotating device can drive the calibration frame rotation;Radar is installed on radar station and is calibrated, moving frame can drive calibration reflector to move, rotating device can drive calibration reflector to rotate, so that the automation of radar calibration work can be realized, full process does not need manual participation, and also improve the accuracy of radar calibration, ensure that the radar after calibration meets the product performance of factory standard.

Description

Technical Field

[0001] This invention relates to the field of lidar technology, and in particular to a lidar calibration device. Background Technology

[0002] LiDAR utilizes the high speed and linearity of laser light to emit laser beams and receive the returned information to describe the surface morphology of the measured object. For example, it can be applied in the field of intelligent driving.

[0003] As a core component of intelligent driving, LiDAR (Light Detection and Ranging) is susceptible to problems such as ranging deviation, point cloud distortion, and blind spot shift if not accurately calibrated, directly threatening the safety of autonomous driving and other functions. For example, before leaving the factory, LiDAR requires multiple calibration boards with high reflectivity to calibrate its reflectivity, distance, angle, and other parameters. However, in practice, it is difficult to ensure the consistency of the light output angle of each mirror surface during manual setup and adjustment when using multiple calibration boards to achieve high precision in mirror angles and assembly processes, thus affecting the accuracy of LiDAR calibration. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a lidar calibration device.

[0005] According to a first aspect of the present invention, a lidar calibration device includes: a lidar station for mounting a lidar to be calibrated; a movable frame located behind the lidar station, wherein a rotating device is provided on the movable frame; and a calibration frame connected to the rotating device, wherein a calibration mounting position is provided on the calibration frame, and a calibration reflector is mounted on the calibration mounting position, wherein the lidar is capable of emitting a laser towards the calibration reflector, and the rotating device is capable of driving the calibration frame to rotate.

[0006] According to some embodiments of the present invention, the calibration mounting position is a "U"-shaped frame structure, the calibration mounting position includes left and right vertical beams, an upper beam and a lower beam, the calibration reflector is connected to the left and right vertical beams, the upper beam and the lower beam; the upper beams of each calibration mounting position are connected by an upper support beam, the lower beams of each calibration mounting position are connected by a lower support beam, and an inner support beam connects the upper support beam and the lower support beam.

[0007] According to some embodiments of the present invention, a level is provided on the upper side of the calibration mounting position, and the level alignment part on the lower side of the level abuts against the middle position on the upper side of the calibration reflector.

[0008] According to some embodiments of the present invention, a slide rail is further included, on which a rack is provided; a slider is provided on the lower side of the movable frame, the slider slides on the slide rail, a drive motor is provided on the movable frame, the output shaft of the drive motor is connected to a drive gear, the drive gear meshes with the rack, and the drive motor can drive the movable frame to move along the slide rail.

[0009] According to some embodiments of the present invention, the movable frame is provided with a driven shaft, the driven shaft is connected to a driven gear, and the driven gear meshes with the rack.

[0010] According to some embodiments of the present invention, a plurality of slide rail support plates are provided on the side wall or the bottom side of the slide rail, and a support base plate is provided below the slide rail support plate. A height adjustment screw is connected between the slide rail support plate and the support base plate, and the slide rail support plate and the height adjustment screw are threadedly connected. The height of the slide rail support plate can be adjusted along the height adjustment screw.

[0011] According to some embodiments of the present invention, a rangefinder is provided on the radar station, a target plate is provided on the mobile frame, the target plate has crosshairs, and the rangefinder is capable of emitting light pulses toward the target plate.

[0012] According to some embodiments of the present invention, the radar station includes a fixed platform, and the radar to be calibrated can be detachably connected to the fixed platform.

[0013] According to some embodiments of the present invention, the calibration reflector is made of metal sheet and is coated with a reflective coating.

[0014] According to some embodiments of the present invention, the rotating device is an electric rotary table structure, which can drive the calibration frame to rotate around an axis extending vertically; the rotating device includes a rotary table fixing part, a rotary table rotating part, a stepper motor, a worm gear part, and a worm wheel. The rotary table fixing part is fixedly connected to the moving frame, the stepper motor is fixed on the rotary table fixing part, and the stepper motor can drive the worm gear structure of the worm gear part to rotate. The rotary table rotating part is fixed to the calibration frame, and the worm wheel is fixed to the lower side of the rotary table rotating part, and the worm wheel meshes with the worm gear structure of the worm gear part.

[0015] The lidar calibration device according to embodiments of the present invention has at least the following technical effects: 1. The radar is installed on the radar station for calibration. The moving frame can move the calibration reflector, and the rotating device can rotate the calibration reflector. This can automate the radar calibration process without human intervention, and also improve the accuracy of radar calibration, ensuring that the calibrated radar meets the product performance of the factory standard. 2. The slide rail is used to guide the movement path of the moving frame. The drive motor drives the drive gear to rotate. Through the meshing action between the drive gear and the rack, the entire moving frame is driven to move precisely and controllably along the direction of the slide rail to meet the high precision requirements of position adjustment during the calibration process. 3. The rangefinder can be used with a target plate to test and calibrate the distance between the reflector and the radar as the laser distance. By comparing the laser distance obtained by the rangefinder at the same specified position with the distance measured by the radar between the reflector and the calibrated reflector, the radar can be calibrated.

[0016] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0017] Additional aspects and advantages of the invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a perspective view of the lidar calibration device of the present invention; Figure 2 This is a perspective view of the calibration frame and rotation device of the present invention; Figure 3 This is an exploded view of the calibration frame of the present invention; Figure 4 yes Figure 3 Enlarged view of region A in the middle; Figure 5 This is a perspective view of the movable frame and slide rail of the present invention; Figure 6 yes Figure 5 Enlarged view of region B in the middle; Figure 7 This is a perspective view of the rotating device of the present invention.

[0018] Figure label: Radar station 100, fixed platform 110, electrical box 120; moving frame 200, slider 210, drive motor 220, drive gear 221, driven shaft 230, driven gear 231, target plate 240; calibration frame 300, calibration mounting position 310, upright beam 311, upper beam 312, lower beam 313, upper support beam 320, lower support beam 330, inner support beam 340, calibration reflector 350, level 360, level alignment part 361; rotating device 400, rotating table fixed part 410, rotating table rotating part 420, stepper motor 430, worm gear part 440, worm wheel 450; slide rail 500, rack 510, slide rail support plate 520, support base plate 530, height adjustment screw 531; rangefinder 600; radar 700. Detailed Implementation

[0019] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0020] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0021] In the description of this invention, "multiple" means two or more, and "greater than," "less than," "exceeding," etc., are understood to exclude the stated number. The use of "first" and "second" is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly specifying the number of indicated technical features or their sequential relationship.

[0022] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0023] The following is for reference. Figure 1 and Figure 2 A lidar calibration apparatus according to an embodiment of the present invention is described.

[0024] like Figure 1 and Figure 2 As shown, the lidar calibration device according to an embodiment of the present invention includes a lidar station 100, a moving frame 200, and a calibration frame 300.

[0025] Radar station 100 is used to install radar 700 to be calibrated; mobile frame 200 is located behind radar station 100, and a rotating device 400 is provided on mobile frame 200; calibration frame 300 is connected to rotating device 400, calibration mounting position 310 is provided on calibration frame 300, calibration reflector 350 is installed on calibration mounting position 310, radar 700 can emit laser to calibration reflector 350, and rotating device 400 can drive calibration frame 300 to rotate.

[0026] For example, such as Figure 1 and Figure 2As shown, the radar station 100 is fixed in place during operation. The radar station 100 is used to mount the radar 700 to be calibrated; once fixed in place, the radar 700 does not move. The movable frame 200 is located behind the radar station 100, meaning it can move within a certain range behind the radar station 100 to accommodate calibration testing. A rotating device 400 is provided on the movable frame 200, allowing it to move along with the movable frame 200. The calibration frame 300 is connected to the rotating device 400, meaning it can also move along with the movable frame 200. A calibration mounting position 310 is provided on the calibration frame 300, on which a calibration reflector 350 is mounted; the calibration reflector 350 can be fixedly mounted in the calibration mounting position 310. The calibration reflector 350 can be removed and replaced in the calibration mounting position 310. The radar 700 can emit a laser towards the calibration reflector 350. The rotating device 400 can drive the calibration frame 300 to rotate, thereby causing the calibration reflector 350 on the calibration frame 300 to rotate and move.

[0027] In actual operation, the radar 700 to be calibrated is first installed on the radar station 100. The radar 700 points towards the calibration reflector 350, meaning the radar 700 can emit laser light towards the calibration reflector 350. The moving frame 200 can move the calibration reflector 350, allowing it to be moved to a specific position for static calibration as needed, or to be dynamically calibrated while moving and testing. The rotating device 400 can rotate the calibration reflector 350, allowing it to be rotated to a specific angle for static calibration as needed, or to be dynamically calibrated while rotating and testing. Specifically, the calibration device of this invention can test the effect of the radar 700 on the same calibration reflector 350 at different angles, and can test the effect of the radar 700 on calibration reflectors 350 with different reflectivities.

[0028] Through the above design, the calibration device of this invention can automate the calibration of the Radar 700 without manual intervention, and also improves the accuracy of radar calibration, ensuring that the calibrated Radar 700 meets the product performance standards of the manufacturer. The calibration device of this invention can automatically control the switching of different reflectivity surfaces and set the calibration angle and calibration distance, eliminating the need for manual replacement and adjustment each time, thus achieving automated operation.

[0029] The calibration device of this invention is applicable to SPAD lidar, velocity measuring radar, dToF lidar, pure solid-state-Flash lidar, hybrid solid-state lidar, etc. Specifically, different calibration reflectors 350 can be replaced to calibrate the reflectivity to match the calibration and testing needs of different radars.

[0030] In some specific embodiments of the present invention, the calibration reflector 350 is a square plate, and the length and width of the calibration reflector 350 are each at least 1m. The calibration reflector 350 is fixed to the calibration mounting position 310 by screws.

[0031] In some embodiments of the present invention, reference is made to... Figure 2 , Figure 3 The calibration mounting position 310 has a "U"-shaped frame structure, including left and right upright beams 311, upper beam 312, and lower beam 313. The calibration reflector 350 is connected to the left and right upright beams 311, upper beam 312, and lower beam 313. The upper beams 312 of each calibration mounting position 310 are connected by upper support beams 320, and the lower beams 313 of each calibration mounting position 310 are connected by lower support beams 330. An inner support beam 340 connects the upper support beams 320 and the lower support beams 330.

[0032] The "U"-shaped frame structure of the calibration mounting position 310 consists of at least four interconnected beams, specifically including upright beams 311 on the left and right sides, an upper beam 312 at the top, and a lower beam 313 at the bottom. The upper ends of the upright beams 311 on the left and right sides connect to the left and right ends of the upper beam 312, and the lower ends of the upright beams 311 on the left and right sides connect to the left and right ends of the lower beam 313. These four parts together form a closed rectangular frame, corresponding to the four edges of the calibration reflector 350, thereby ensuring the positional stability of the calibration reflector 350 in the calibration mounting position 310 space and the accuracy of subsequent optical measurements. Furthermore, the frame structure of the calibration mounting position 310 can be reinforced; for example, an additional upright beam 311 can be installed between the middle of the upper beam 312 and the middle of the lower beam 313.

[0033] To enhance the overall rigidity and stability of the calibration frame 300, multiple calibration mounting positions 310 are interconnected via transverse support members. Specifically, the upper beams 312 of each calibration mounting position 310 are connected to each other by an upper support beam 320 running through the entire structure, while the lower beams 313 are correspondingly fixedly connected to each other by lower support beams 330. Furthermore, several inner support beams 340 are provided between the upper support beams 320 and the lower support beams 330. These inner support beams 340 connect the upper and lower support beams vertically or obliquely, which not only effectively improves the structural strength of the entire calibration frame 300, but also helps maintain the precise relative position of the calibration reflector 350 in three-dimensional space, thereby ensuring the reliability of subsequent calibration testing processes.

[0034] In some embodiments of the present invention, reference is made to... Figure 3 , Figure 4A level 360 is installed on the upper side of the calibration mounting position 310, and the alignment part 361 of the level 360 abuts against the middle of the upper side of the calibration reflector 350. The level 360 is responsible for calibrating whether the calibration reflector 350 is properly aligned on the calibration mounting position 310, and preventing the calibration reflector 350 from being installed incorrectly, which would affect the reliability of subsequent calibration and testing processes. For example, a double-line level can be used for the level 360.

[0035] In some embodiments of the present invention, reference is made to... Figure 5 , Figure 6 The calibration device of the present invention also includes a slide rail 500, on which a rack 510 is provided. A slider 210 is provided on the lower side of the movable frame 200, and the slider 210 slides on the slide rail 500. A drive motor 220 is provided on the movable frame 200, and the output shaft of the drive motor 220 is connected to a drive gear 221. The drive gear 221 meshes with the rack 510, and the drive motor 220 can drive the movable frame 200 to move along the slide rail 500.

[0036] The slide rail 500 is used to guide the movement path of the movable frame 200. The slide rail 500 is fixedly installed along its length, and at least one slide rail 500 is arranged, for example... Figure 1 The slide rails 500 are arranged in two sections on the left and right sides. Racks 510 are fixedly connected to the slide rails 500, and at least one rack 510 is also provided, extending along the slide rails 500. The lengths and trajectories of the slide rails 500 and racks 510 can be designed as needed, for example... Figure 5 The slide rail 500 and rack 510 extend in the front-to-back direction. The slider 210 of the movable frame 200 is required to be able to slide and fit precisely on the slide rail 500 to achieve low-friction linear sliding, thereby ensuring that the movable frame 200 can perform smooth and stable linear reciprocating motion on the slide rail 500.

[0037] A drive motor 220 is mounted at a suitable location (e.g., top or side) on the movable frame 200, serving as a driving device for moving the movable frame 200. The output axis of the drive motor 220 extends outward (e.g., Figure 6 The slide rail extends downwards as shown, and a drive gear 221 is fixedly connected to its end, enabling the drive motor 220 to control the rotation of the drive gear 221. The drive gear 221 meshes with the rack 510 provided on the slide rail 500.

[0038] When the drive motor 220 is powered on, its output shaft drives the drive gear 221 to rotate. Through the meshing action between the drive gear 221 and the rack 510, the rotational motion of the drive gear 221 is converted into the linear motion of the moving frame 200, thereby reliably driving the entire moving frame 200 to move precisely and controllably along the direction of the slide rail 500 to meet the high-precision requirements for position adjustment during the calibration process.

[0039] For example, when the output shaft of the drive motor 220 rotates forward one revolution, the drive gear 221 moves the rack 510 forward, causing the moving frame 200 and calibration frame 300 to move forward precisely by 1 mm; when the output shaft of the drive motor 220 rotates in reverse one revolution, the moving frame 200 moves backward by 1 mm. By precisely controlling the number of rotations of the output shaft of the drive motor 220, linear displacement of the calibration frame 300 micrometers in increments can be achieved.

[0040] In some specific embodiments of the present invention, the drive motor 220 adopts a servo motor + planetary reducer.

[0041] In some specific embodiments of the present invention, the slide rail 500 is made of high-strength quenched steel rail, and the surface is treated with hard anodizing or grinding to improve the support capacity of the slide rail 500.

[0042] In some embodiments of the present invention, a driven shaft 230 is provided on the movable frame 200, and a driven gear 231 is connected to the driven shaft 230. The driven gear 231 meshes with the rack 510. This means that during the movement of the movable frame 200, the driven gear 231, together with the aforementioned drive gear 221, meshes with the rack 510, improving the smoothness and accuracy of the movement of the movable frame 200. There is at least one driven gear 231, and its position on the movable frame 200 can be designed as needed.

[0043] In some embodiments of the present invention, a plurality of slide rail support plates 520 are provided on the side wall or the bottom side of the slide rail 500, and a support base plate 530 is provided below the slide rail support plate 520. A height adjustment screw 531 is connected between the slide rail support plate 520 and the support base plate 530. The slide rail support plate 520 and the height adjustment screw 531 are threadedly connected, and the height of the slide rail support plate 520 can be adjusted along the height adjustment screw 531.

[0044] The slide rail support plate 520 is located on the side wall or underside of the slide rail 500, and is used to provide stable and reliable support for the slide rail 500. Specifically, the slide rail support plate 520 and the slide rail 500 can be welded together or integrally formed.

[0045] Directly below the slide rail support plate 520, multiple support base plates 530 are arranged at equal intervals along the length of the guide rail, serving as the bottom load-bearing foundation for the entire slide rail 500; that is, the support base plates 530 support the ground or the optical platform in the laboratory. The slide rail support plate 520 and the support base plates 530 below are connected by at least one height adjustment screw 531, for example... Figure 5 The height adjustment screw 531 includes a thicker middle height adjustment screw 531 and two universal height adjustment screws 531 on both sides. The support base plate 530 can adopt an L-shaped support or an inverted T-shaped support structure.

[0046] One end of the height adjustment screw 531 is fixed or screwed onto the support base plate 530, while the other end passes through the slide rail support plate 520 and forms a threaded connection with it. For example, the support base plate 530 can be threaded by opening a threaded hole, setting a movable nut, welding a connecting nut, or installing an expansion bolt to achieve a threaded connection with the height adjustment screw 531.

[0047] Since the slide rail support plate 520 and the height adjustment screw 531 are connected by a thread, the slide rail support plate 520 can be driven to move up and down along the axial direction of the height adjustment screw 531 by rotating the height adjustment screw 531, thereby realizing the precise adjustment of the height of the slide rail support plate 520 and the slide rail 500 it supports, and meeting the height adaptation requirements of different installation or use scenarios.

[0048] In some embodiments of the present invention, reference is made to... Figure 1 A rangefinder 600 is installed on the radar station 100, and a target plate 240 with crosshairs is installed on the moving frame 200. The rangefinder 600 can emit light pulses towards the target plate 240. The light pulses from the rangefinder 600 are projected onto the target plate 240, forming a light spot that can be aligned with the crosshairs on the target plate 240. In this way, the rangefinder 600 can work with the target plate 240 to test and determine the distance between the calibration reflector 350 and the radar 700.

[0049] The laser distance measured by the rangefinder 600 refers to the one-way distance between the rangefinder 600 and the calibration reflector 350. The deviation between the laser distance and the actual distance is small. Therefore, by comparing the deviation between the laser distance at the same specified location and the distance measured by the radar 700 from the calibration reflector 350, the accuracy of the calibration can be improved. The specified location is determined before calibration. During the calibration test, the calculator can control the radar 700 and the rangefinder 600 to measure the distance between itself and the calibration reflector 350. After receiving the distance measured by the radar 700 from the calibration reflector 350 and the laser distance, the calculator feeds back to the radar 700 for calibration.

[0050] In some embodiments of the present invention, the radar station 100 includes a fixed platform 110, and the radar 700 to be calibrated can be detachably connected to the fixed platform 110, for example, by fixing it to the fixed platform 110 with screws, which makes it convenient to assemble different models of radar 700 as needed.

[0051] For example, the main structure of radar station 100 is fixed with an aluminum profile frame, and a metal panel is welded or installed on radar station 100 as a fixed platform 110. Radar station 100 can also house and store components such as computers. The rangefinder 600 is installed below radar station 100, coaxial with the fixed position center of radar 700. The fixed platform 110 has a threaded hole array composed of multiple screw holes, which can be adapted to different models of radar 700.

[0052] In some embodiments of the present invention, an electrical box 120 is provided on the radar station 100, which can supply power to the radar 700 to be calibrated. The electrical box 120 can also supply power to the rangefinder 600, computer, etc.

[0053] In some specific embodiments of the present invention, a laptop computer or other device with computing capabilities may be placed on the radar station 100 as a software running carrier (computing control device) for the control and interaction system, as well as other external devices such as DC power supply and multi-functional power conversion board.

[0054] In some embodiments of the present invention, reference is made to... Figure 5 , Figure 7 The rotating device 400 is an electric rotary table structure, which can drive the calibration frame 300 to rotate around an axis extending vertically. The rotating device 400 uses an electric rotary table, which can control the rotation of the calibration frame 300 with high precision and more stable operation.

[0055] During the calibration test, the rotating device 400 can be flexibly designed according to different radar calibration requirements and lidar reflectivity calibration system. During the test, it can either drive the calibration frame 300 to rotate continuously while performing dynamic testing, or drive the calibration frame 300 to rotate to a specific angle before performing static testing.

[0056] In a further embodiment of the present invention, the rotating device 400 includes a rotating table fixing part 410, a rotating table rotating part 420, a stepper motor 430, a worm gear part 440, and a worm wheel 450. The rotating table fixing part 410 is fixedly connected to the movable frame 200, and the stepper motor 430 is fixed to the rotating table fixing part 410, capable of driving the worm structure of the worm gear part 440 to rotate. The rotating table rotating part 420 is fixed to the calibration frame 300, and the worm wheel 450 is fixed to the lower side of the rotating table rotating part 420, meshing with the worm structure of the worm gear part 440. In this way, the stepper motor 430 can drive the rotating table rotating part 420 to rotate.

[0057] During the origin reset operation, the controller of the rotating device 400 drives the stepper motor 430 to rotate at low speed, and the rotating part 420 of the rotary table rotates synchronously. When the trigger structure on the side of the rotating part 420 of the rotary table aligns with the photoelectric origin switch, the encoder records the current position as the zero reference, completing the origin reset. Thereafter, all angle commands are executed based on this absolute coordinate system.

[0058] During bidirectional angle control, the motor shaft of stepper motor 430 is directly connected to the worm structure of worm gear section 440 via a coupling. The worm structure meshes with the worm wheel 450 at the bottom of rotary table rotating part 420. After the control module analyzes the input target angle, it outputs pulse commands to the driver—when the motor shaft of stepper motor 430 rotates one revolution clockwise, the worm structure rotates one revolution synchronously, driving worm wheel 450 and rotary table rotating part 420 to rotate counterclockwise by 0.1°; when the motor shaft of stepper motor 430 rotates one revolution counterclockwise, the rotary table rotating part 420 rotates 0.1° clockwise. By accurately calculating the number of pulses, precise positioning of the rotary table rotating part 420 at any angle can be achieved.

[0059] The rotating device 400 has a self-locking characteristic. Since the lead angle of the single-head worm gear is less than the friction angle, it forms a mechanical self-lock. In conjunction with the stepper motor 430 maintaining torque when the power is off, the rotating part 420 of the rotary table is doubly locked after it is in place, and there is no load reverse drive drift, which ensures that the angle reference is stable and reliable during the optical measurement process.

[0060] In some specific embodiments of the present invention, the calibration reflector 350 may include a single planar plate or may be composed of multiple planar plates joined together. For example Figure 2 The calibration reflector 350 on display is a single flat steel plate.

[0061] In some specific embodiments of the present invention, the calibration reflector 350 may be made of metal to reflect lasers and radar. The radar 700 is positioned directly opposite the calibration reflector 350 to avoid distance measurement errors caused by other positions, thereby improving the accuracy of calibration.

[0062] In some specific embodiments of the present invention, the calibration reflector 350 is made of metal sheet and is coated with a reflective coating to further ensure the reflectivity of the calibration reflector 350 and ensure the calibration effect. After the calibration reflector 350 is fixed to the calibration mounting position 310 by screws, the screws are also coated with a reflective coating.

[0063] In some embodiments of the present invention, the slide rail 500, the calibration reflector 350, and the radar station 100 are all housed within an electromagnetic shielding room (not shown in the figures). Absorbing materials can be arranged on the inner, upper, and lower sides of the electromagnetic shielding room to form an electromagnetic shielding layer, thus creating a microwave anechoic chamber. This provides an electromagnetic shielding environment, isolates scattered electromagnetic signals from interfering with the radar 700 test, and improves the accuracy of calibration.

[0064] The calibration apparatus according to a second aspect of the present invention includes the lidar calibration apparatus according to the first aspect of the present invention described above.

[0065] According to the calibration device of the present invention, by adopting the above-described lidar calibration device, the manual operation steps of the calibration device are reduced, which facilitates the automated and intelligent design of the calibration device, and can improve the accuracy of the calibration device and enhance the working effect of the radar product.

[0066] Other configurations and operations of the calibration apparatus according to embodiments of the present invention are known to those skilled in the art and will not be described in detail here.

[0067] The following is for reference. Figure 1 and Figure 2 A lidar calibration apparatus according to an embodiment of the present invention is described in detail with reference to a specific example. It is to be understood that the following description is merely illustrative and not intended to limit the invention in any specific way.

[0068] like Figure 1 and Figure 2 As shown, the lidar calibration device according to an embodiment of the present invention includes a lidar station 100, a moving frame 200, a calibration frame 300, a rotating device 400, a slide rail 500, and a rangefinder 600, which are responsible for the calibration and testing of the lidar 700.

[0069] The radar station 100 is equipped with a fixed platform 110 and an electrical box 120. The radar 700 and the rangefinder 600 are installed on the radar station 100. The radar 700 and the rangefinder 600 can be detached and connected on the fixed platform 110, so that the radar 700 and the rangefinder 600 can be replaced as needed.

[0070] The movable frame 200 moves on the slide rail 500. The movable frame 200 includes a slider 210, a drive motor 220, a drive gear 221, a driven shaft 230, a driven gear 231, and a target plate 240. The slide rail 500 includes a rack 510, a slide rail support plate 520, a support base plate 530, and a height adjustment screw 531. The slider 210 of the movable frame 200 is required to slide precisely onto the slide rail 500 to enable the movable frame 200 to slide. The drive gear 221 and driven gear 231 mesh with the rack 510. The target plate 240 can move with the movable frame 200. The slide rail support plate 520 is threadedly connected to the height adjustment screw 531, allowing the slide rail 500 to adjust its height along the height adjustment screw 531.

[0071] The movable frame 200 is equipped with a rotating device 400 and a calibration frame 300. The rotating device 400 includes a rotating table fixing part 410, a rotating table rotating part 420, a stepper motor 430, a worm gear part 440, and a worm wheel 450. The rotating table fixing part 410 is fixedly connected to the movable frame 200, and the stepper motor 430 is fixed to the rotating table fixing part 410. The stepper motor 430 can drive the worm structure of the worm gear part 440 to rotate. The worm wheel 450 meshes with the worm structure of the worm gear part 440. In this way, the stepper motor 430 can drive the calibration frame 300 to rotate. The calibration frame 300 includes a calibration mounting position 310, a vertical beam 311, an upper beam 312, a lower beam 313, an upper support beam 320, a lower support beam 330, an inner support beam 340, a calibration reflector 350, a level 360, and a level alignment part 361. The left and right side upright beams 311, the top beam 312, and the bottom beam 313 are connected together. The upper ends of the left and right side upright beams 311 are connected to the left and right ends of the top beam 312, and the lower ends of the left and right side upright beams 311 are connected to the left and right ends of the bottom beam 313. These four parts together form a closed rectangular frame, corresponding to the four edges of the calibration reflector 350. The level alignment part 361 on the lower side of the level 360 abuts against the middle of the upper side of the calibration reflector 350.

[0072] In actual work, the steps are as follows: 1. Install the radar 700 to be calibrated on radar station 100; 2. The calibration reflector 350 is installed on the calibration mounting position 310 of the calibration frame 300, and the angle is aligned using a level 360. 3. The drive motor 220 drives the moving frame 200 to move along the slide rail 500; 4. The light spot formed by the light pulse of the rangefinder 600 projected onto the target plate 240 can be aligned with the crosshairs on the target plate 240. The one-way distance between the rangefinder 600 and the calibration reflector 350 is used as the laser distance. The radar 700 is calibrated by the deviation between the laser distance at the same specified position and the distance between the radar 700 and the calibration reflector 350. 5. The drive motor 220 drives the calibration frame 300 to rotate, which can rotate the calibration reflector 350 on the calibration frame 300 to a certain angle for static calibration, or the calibration reflector 350 can be rotated while testing is performed for dynamic calibration.

[0073] According to the lidar calibration apparatus of the present invention, by the following configuration, at least the following effects can be achieved: the lidar 700 is mounted on the lidar station 100; the lidar 700 points towards the calibration reflector 350, that is, the lidar 700 can emit laser light towards the calibration reflector 350; the movable frame 200 can move the calibration reflector 350, allowing it to be moved to a certain position for static calibration as needed, or to perform dynamic calibration while moving and testing.

[0074] The rotating device 400 can drive the calibration reflector 350 to rotate. Besides rotating it to a certain angle for static calibration as needed, it can also perform dynamic calibration while rotating and testing simultaneously. Specifically, the calibration device of this invention can test the radar 700's performance on the same calibration reflector 350 at different angles, and can also test the radar 700's performance on calibration reflectors 350 with different reflectivities.

[0075] Through the above design, the calibration device of the present invention can automate the calibration of the radar 700 without human intervention, and also improves the accuracy of radar calibration, ensuring that the calibrated radar 700 meets the product performance of the factory standard.

[0076] In the description of this specification, references to terms such as "some embodiments" or "as one might imagine" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0077] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A lidar calibration device, characterized in that, Comprising: A radar station (100) for installing a radar (700) to be calibrated; A mobile rack (200), located behind the radar station (100), and a rotating device (400) is provided on the mobile rack (200); A calibration frame (300) is connected to the rotating device (400), a calibration mounting position (310) is provided on the calibration frame (300), a calibration reflector (350) is installed on the calibration mounting position (310), the radar (700) can emit laser towards the calibration reflector (350), and the rotating device (400) can drive the calibration frame (300) to rotate.

2. The lidar calibration device according to claim 1, characterized in that, The calibration mounting position (310) is in a "mouth" - shaped frame structure, the calibration mounting position (310) includes vertical beams (311) on the left and right sides, an upper beam (312) and a lower beam (313), and the calibration reflector (350) is connected to the vertical beams (311) on the left and right sides, the upper beam (312), and the lower beam (313); The upper beams (312) of each calibration mounting position (310) are connected by an upper support beam (320), the lower beams (313) of each calibration mounting position (310) are connected by a lower support beam (330), and an inner support beam (340) is connected between the upper support beam (320) and the lower support beam (330).

3. The lidar calibration device according to claim 1, characterized in that, A level (360) is provided on the upper side of the calibration mounting position (310), and a level alignment part (361) on the lower side of the level (360) abuts against the middle position on the upper side of the calibration reflector (350).

4. The lidar calibration device according to claim 1, characterized in that, It further includes a slide rail (500), and a rack (510) is provided on the slide rail (500); A slider (210) is provided on the lower side of the mobile rack (200), the slider (210) is slidably connected to the slide rail (500), a driving motor (220) is provided on the mobile rack (200), an output shaft of the driving motor (220) is connected to a driving gear (221), the driving gear (221) meshes with the rack (510), and the driving motor (220) can drive the mobile rack (200) to move along the slide rail (500).

5. The lidar calibration device according to claim 4, characterized in that, A driven shaft (230) is provided on the mobile rack (200), the driven shaft (230) is connected to a driven gear (231), and the driven gear (231) meshes with the rack (510).

6. The lidar calibration device according to claim 4, characterized in that, A plurality of slide rail support plates (520) are provided on the side wall or the lower side of the slide rail (500), a support bottom plate (530) is provided below the slide rail support plates (520), a height - adjusting screw rod (531) is connected between the slide rail support plates (520) and the support bottom plate (530), the slide rail support plates (520) are threadedly connected to the height - adjusting screw rod (531), and the slide rail support plates (520) can adjust their heights along the height - adjusting screw rod (531).

7. The lidar calibration device according to claim 1, characterized in that, The radar station (100) is equipped with a rangefinder (600), and the mobile frame (200) is equipped with a target plate (240). The target plate (240) has crosshairs, and the rangefinder (600) can emit light pulses to the target plate (240).

8. The lidar calibration device according to claim 1, characterized in that, The radar station (100) includes a fixed platform (110), and the radar (700) to be calibrated can be detached and connected to the fixed platform (110).

9. The lidar calibration device according to claim 1, characterized in that, The calibration reflector (350) is made of metal sheet and is coated with a reflective coating.

10. The lidar calibration device according to claim 1, characterized in that, The rotating device (400) is an electric rotary table structure, and the rotating device (400) can drive the calibration frame (300) to rotate around an axis extending vertically. The rotating device (400) includes a rotating table fixed part (410), a rotating table rotating part (420), a stepper motor (430), a worm part (440), and a worm wheel (450). The rotating table fixed part (410) is fixedly connected to the moving frame (200). The stepper motor (430) is fixed on the rotating table fixed part (410). The stepper motor (430) can drive the worm structure of the worm part (440) to rotate. The rotating table rotating part (420) is fixed to the calibration frame (300). The worm wheel (450) is fixed on the lower side of the rotating table rotating part (420). The worm wheel (450) meshes with the worm structure of the worm part (440).

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