Vehicle-mounted all-round camera calibration grid automatic alignment device

Abstract

The invention discloses a vehicle-mounted all-around camera calibration grid automatic alignment device which comprises a calibration grid adjusting device fixedly arranged over a ground parking marking line, the calibration grid adjusting device comprises a second fixing frame, and a grid light ray projection lamp is installed on the second fixing frame. The grid light ray projection lamp is used for forming calibration grid light rays on the ground around the ground parking marking line; the second fixing frame has a degree of freedom of rotating around the Z axis, and the second fixing frame is rotated according to the deflection angle of the to-be-measured vehicle, so that the light of the calibration grid is parallel to the to-be-measured vehicle. According to the invention, a traditional vehicle moving scheme is adjusted to actively align with the to-be-detected vehicle by using the calibration grid light, and the method has advantages in the aspects of cost, power consumption and the like.

Description

Technical Field

[0001] The present invention relates to the calibration of intelligent driving assistance equipment, and in particular to an automatic alignment device for a calibration grid of a vehicle-mounted surround-view camera. Background Art

[0002] The panoramic surround view system of an intelligent vehicle stitches the captured images based on pre-calibrated camera parameters to synthesize a 360° surround view image around the vehicle. During camera calibration, the vehicle to be tested needs to be driven to the calibration area so that the vehicle to be tested remains parallel to the calibration grid. However, due to factors such as the vehicle's driving path and the driver's operating level, it is difficult for the vehicle to remain parallel to the calibration grid. CN111272082B discloses an automatic alignment device for an on-board surround view camera of an intelligent vehicle. The device lowers a motion platform to the ground, lays a grid calibration blanket around the motion platform, and adjusts the vehicle to align according to the deflection angle of the vehicle to be tested. The existing technical problems are: the vehicle to be tested is heavy, and a heavy-duty motion platform needs to be configured, which requires large equipment investment and high power consumption; the ground needs to be excavated, and the construction is complicated. Summary of the Invention

[0003] Purpose of the invention: The purpose of the present invention is to provide a low-cost, low-power vehicle-mounted surround view camera calibration grid automatic alignment device.

[0004] Technical solution: The present invention provides an automatic alignment device for a vehicle-mounted surround-view camera calibration grid, comprising a calibration grid adjustment device fixedly arranged directly above a ground parking mark, the calibration grid adjustment device comprising a second fixing frame, on which a grid light projection lamp is mounted, the grid light projection lamp being used to form a calibration grid light on the ground around the ground parking mark; the second fixing frame has the freedom to rotate about the Z axis, and the second fixing frame is rotated according to the deflection angle of the vehicle to be tested so that the calibration grid light is parallel to the vehicle to be tested.

[0005] Furthermore, the second fixing frame also has the freedom to move horizontally along the X-axis and the Y-axis.

[0006] Furthermore, the calibration grid adjustment device also includes a first fixed frame, a lateral displacement drive mechanism, a longitudinal displacement drive mechanism and an angle deflection drive mechanism. The first fixed frame is fixedly arranged, the angle deflection drive mechanism is installed below the first fixed frame, and the lateral displacement drive mechanism is installed at the rotation output end of the angle deflection drive mechanism to drive the longitudinal displacement drive mechanism to move along the Y axis; the longitudinal displacement drive mechanism is used to drive the second fixed frame to move along the X axis.

[0007] Furthermore, the displacement drive mechanism adopts a linear module, the longitudinal displacement drive mechanism is fixed to the screw nut of the transverse displacement drive mechanism, and the second fixing frame is fixed to the screw nut of the longitudinal displacement drive mechanism.

[0008] Furthermore, the first fixing frame is fixed on the top of the factory building, or fixed through a supporting frame.

[0009] Furthermore, the second fixing frame is cross-shaped, and grid light projection lamps are installed on its four ends through angle adjustment seats. The projection angle of each grid light projection lamp satisfies the requirement of connecting the calibrated grid light into one.

[0010] Furthermore, when the height of the calibration grid adjustment device is more than twice the height of the vehicle to be tested, a grid light projection lamp is installed at the middle position of the bottom of the second fixing frame, and the calibration grid light projected by the grid light projection lamp can cover the periphery of the ground parking marking line.

[0011] Furthermore, the automatic alignment device for the vehicle-mounted surround-view camera calibration grid also includes an offset measuring device, which includes an L-shaped bracket fixed to the top of the vehicle to be tested, the long rod of the L-shaped bracket is parallel to the vehicle width direction, and the first laser displacement sensor and the second laser displacement sensor are horizontally installed on the long rod of the L-shaped bracket; a first reference reflector is installed under the second fixed bracket, and the first reference reflector is arranged along the Y-axis; the laser projection directions of the first and second laser displacement sensors match the first reference reflector; the difference in distance between the first and second laser displacement sensors and the first reference reflector is calculated, and the inverse tangent value of the difference and the ratio of the distance between the first and second laser displacement sensors is the deflection angle of the vehicle to be tested.

[0012] Furthermore, a second reference reflector is installed under the second fixed frame, and the second reference reflector is arranged along the X-axis; a third laser displacement sensor is horizontally installed on the short rod of the L-shaped bracket, and the laser projection direction of the third laser displacement sensor matches the second reference reflector; after the angle correction is completed, the longitudinal displacement drive mechanism performs X-direction motion correction according to the measured distance between the first laser displacement sensor and the first reference reflector and the first set reference value; the lateral displacement drive mechanism performs Y-direction motion correction according to the measured distance between the third laser displacement sensor and the second reference reflector and the second set reference value.

[0013] Furthermore, the reference reflector is fixed below the second fixing frame via a support rod, and the L-shaped bracket is fixed to the top of the vehicle to be tested via a suction cup.

[0014] In addition to being able to perform angle correction of the calibration grid light, the present invention can also perform longitudinal and lateral correction, so that the position of the adjusted calibration grid light has high precision and good consistency.

[0015] Beneficial Effects: Compared to existing technologies, this invention offers the following significant advantages: It utilizes projection lamps to create a calibration grid of light, which is automatically aligned with an inaccurately parked vehicle under test. This eliminates the need for expensive, heavy-duty motion platforms to move the vehicle under test, and eliminates the need for excavation to install such platforms. This invention offers the advantages of easy alignment, low power consumption, and minimal investment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 1 is a schematic structural diagram of an automatic alignment device for calibrating a grid for a vehicle-mounted surround view camera provided by an embodiment of the present invention;

[0017] Figure 2 is a structural diagram of a calibration grid adjustment device according to an embodiment of the present invention;

[0018] Figure 3 2 is a schematic structural diagram of an offset measurement device in an embodiment of the present invention. DETAILED DESCRIPTION

[0019] The present invention will be further described below with reference to the accompanying drawings.

[0020] Attachment Figures 1 to 3 The reference numerals in the figures are as follows:

[0021] 1. Ground parking markings;

[0022] 2. Vehicle to be tested;

[0023] 3. Calibration grid adjustment device; 31. First fixed frame; 32. Transverse displacement drive mechanism; 321. First reduction drive motor; 322. First screw; 323. First screw nut; 33. Longitudinal displacement drive mechanism; 331. Second reduction drive motor; 332. Second screw; 333. Second screw nut; 34. Angle deflection drive mechanism; 35. Second fixed frame; 36. Grid light projection lamp; 37. First reference reflector; 38. Second reference reflector;

[0024] 4, offset measuring device; 41, L-shaped bracket; 42, suction cup; 43, first laser displacement sensor; 44, second laser displacement sensor; 45, third laser displacement sensor; 46, data transmitting device;

[0025] 5. Calibrate the grid light.

[0026] like Figure 1 As shown, an embodiment of the present invention provides a device for automatically aligning a calibration grid of a vehicle-mounted surround view camera, comprising a calibration grid adjustment device 3, an offset measurement device 4 and a control system.

[0027] The calibration grid adjustment device 3 is located just above the ground parking marking line 1. Figure 2 The calibration grid adjustment device 3 includes a first fixed frame 31, a lateral displacement drive mechanism 32, a longitudinal displacement drive mechanism 33, an angle deflection drive mechanism 34 and a second fixed frame 35, wherein the lateral displacement drive mechanism 32 and the longitudinal displacement drive mechanism 33 adopt linear modules, the lateral displacement drive mechanism 32 includes a first frame, a first reduction drive motor 321, a first screw rod 322 and a first screw rod nut 323, and the longitudinal displacement drive mechanism 33 includes a second frame, a second reduction drive motor 331, a second screw rod 332 and a second screw rod nut 333.

[0028] The first fixed frame 31 is fixed to the top of the factory building or fixed by a support frame. The angle deflection drive mechanism 34 is installed below the first fixed frame 31. The angle deflection drive mechanism 34 can adopt a hub motor, a pan-tilt head, etc. The lateral displacement drive mechanism 32 is arranged horizontally, and its frame is installed at the rotation output end of the angle deflection drive mechanism 34. The longitudinal displacement drive mechanism 33 is arranged horizontally, and its frame is fixed to the first screw nut 323. The second fixed frame 35 is cross-shaped and arranged horizontally. The long rod of the second fixed frame 35 is parallel to the longitudinal displacement drive mechanism 33, and the short rod of the second fixed frame 35 is parallel to the lateral displacement drive mechanism 32. The center position of the second fixed frame 35 is fixed to the second screw nut 333. Therefore, the angle deflection drive mechanism 34 can drive the second fixed frame 35 to rotate around the Z axis, the longitudinal displacement drive mechanism 33 can drive the second fixed frame 35 to move along the X axis, and the lateral displacement drive mechanism 32 can drive the second fixed frame 35 to move along the Y axis.

[0029] The four ends of the second fixing frame 35 are equipped with grid light projection lamps 36 through angle adjustment seats. The calibration grid light 5 projected by the four grid light projection lamps 36 is located on the ground around the parking mark 1. The projection angle of each grid light projection lamp 36 is adjusted so that the calibration grid light 5 is connected into one.

[0030] When the factory building height allows and the height of the calibration grid adjustment device 3 is more than twice the height of the vehicle 2 to be tested, a grid light projection lamp 36 can be used. The grid light projection lamp 36 is installed in the middle position at the bottom of the second fixed frame 35. The calibration grid light 5 projected by the grid light projection lamp 36 can cover the periphery of the ground parking marking line 1.

[0031] A first reference reflector 37 and a second reference reflector 38 are fixed below the second fixing frame 35 via support rods. The first reference reflector 37 is located below and parallel to the short rod of the second fixing frame 35. The second reference reflector 38 is located below and parallel to the long rod of the second fixing frame 35.

[0032] like Figure 3 As shown, the offset measurement device 4 includes an L-shaped bracket 41 secured to the top of the vehicle 2 to be measured via a suction cup 42. The long rod of the L-shaped bracket 41 is parallel to the vehicle width. A first laser displacement sensor 43 and a second laser displacement sensor 44 are mounted horizontally on the long rod of the L-shaped bracket 41. The laser projection directions of the first and second laser displacement sensors align with the first reference reflector 37. A third laser displacement sensor 45 is mounted horizontally on the short rod of the L-shaped bracket 41. The laser projection direction of the third laser displacement sensor 45 aligns with the second reference reflector 38.

[0033] The angle deflection drive mechanism 34 is always positioned directly above the center of the parking marking 1. In the initial state, the short rod of the second mounting bracket 35 is parallel to the width of the parking marking 1, and the long rod of the second mounting bracket 35 is parallel to the length of the parking marking 1. Each grid light projection lamp 36 projects a calibration grid light around the perimeter of the parking marking 1, parallel or perpendicular to the parking marking 1.

[0034] The vehicle 2 to be tested is driven into the range indicated by the parking markings 1 on the ground. Due to factors such as driving skills, it is generally difficult for the vehicle to be tested to park accurately, and angle deviation and horizontal and vertical displacement deviation are allowed.

[0035] Fix the offset measuring device 4 on the top of the vehicle 2 to be tested by the suction cup 42. The long rod of the L-shaped bracket 41 is parallel to the vehicle width direction. Find the top reference edge of the vehicle 2 to ensure the consistency of position each time it is placed.

[0036] Automatic alignment:

[0037] The distances between the first and second laser displacement sensors and the first reference reflector 37 are measured. The measured data is transmitted to a control system (not shown) via a data transmitter 46. The difference between the two distance measurements is calculated. The inverse tangent of the difference and the ratio of the distances between the first and second laser displacement sensors is then calculated to provide the deflection angle of the vehicle 2 under test. Based on this deflection angle, the control system controls the rotation of the angle deflection drive mechanism 34, causing the second mounting bracket 35 to rotate, thereby aligning the calibration grid light 5 with the vehicle 2 under test.

[0038] After the angle correction is complete, the distance measured between the first laser displacement sensor 43 and the first reference reflector 37 is compared with the first set reference value, and the longitudinal displacement drive mechanism 33 is controlled to perform X-direction motion correction. Simultaneously, the distance measured between the third laser displacement sensor 45 and the second reference reflector 38 is compared with the second set reference value, and the lateral displacement drive mechanism 32 is controlled to perform Y-direction motion correction.

[0039] After the angle correction, lateral correction and longitudinal correction are completed, the calibration grid light projected by the grid light projection lamp 36 is evenly distributed around the vehicle to be tested 2, maintaining a relatively vertical or parallel relationship with the vehicle to be tested 2, for vehicle-mounted surround view camera calibration.

[0040] After the calibration is completed, the vehicle is driven out of the parking mark 1 area on the ground, and the automatic alignment device of the on-board surround view camera calibration grid is restored to the initial state.

Claims

1. A vehicle-mounted surround view camera calibration grid automatic alignment device, characterized in that: The invention comprises a calibration grid adjustment device (3) fixedly arranged just above a ground parking mark (1), the calibration grid adjustment device (3) comprising a second fixing frame (35), a grid light projection lamp (36) being mounted on the second fixing frame (35), the grid light projection lamp (36) being used to form calibration grid light (5) on the ground around the ground parking mark (1); the second fixing frame (35) having a degree of freedom of rotation about a Z axis, and the second fixing frame (35) being rotated according to a deflection angle of a vehicle to be tested (2), so that the calibration grid light (5) is parallel to the vehicle to be tested (2).

2. The automatic alignment device for calibrating a grid for a vehicle-mounted surround view camera according to claim 1, characterized in that: The second fixing frame (35) also has the freedom to move horizontally along the X-axis and the Y-axis.

3. The automatic alignment device for calibrating a grid for a vehicle-mounted surround view camera according to claim 2, characterized in that: The calibration grid adjustment device (3) further comprises a first fixed frame (31), a lateral displacement driving mechanism (32), a longitudinal displacement driving mechanism (33) and an angular deflection driving mechanism (34); the first fixed frame (31) is fixedly arranged; the angular deflection driving mechanism (34) is installed below the first fixed frame (31); the lateral displacement driving mechanism (32) is installed at the rotation output end of the angular deflection driving mechanism (34) and is used to drive the longitudinal displacement driving mechanism (33) to move along the Y axis; and the longitudinal displacement driving mechanism (33) is used to drive the second fixed frame (35) to move along the X axis.

4. The automatic alignment device for calibrating a grid for a vehicle-mounted surround view camera according to claim 3, characterized in that: The displacement drive mechanism adopts a linear module, the longitudinal displacement drive mechanism (33) is fixed to the screw nut of the transverse displacement drive mechanism (32), and the second fixing frame (35) is fixed to the screw nut of the longitudinal displacement drive mechanism (33).

5. The automatic alignment device for calibrating a grid for a vehicle-mounted surround view camera according to claim 3, characterized in that: The first fixing frame (31) is fixed on the top of the factory building, or fixed through a supporting frame.

6. The automatic alignment device for calibrating a grid for a vehicle-mounted surround view camera according to claim 1, characterized in that: The second fixing frame (35) is cross-shaped, and grid light projection lamps (36) are installed at its four ends through angle adjustment seats. The projection angle of each grid light projection lamp (36) satisfies the requirement of connecting the calibration grid light (5) into one body.

7. The automatic alignment device for calibrating a grid for a vehicle-mounted surround view camera according to claim 1, characterized in that: When the height of the calibration grid adjustment device (3) is more than twice the height of the vehicle to be tested (2), a grid light projection lamp (36) is installed at the middle position of the bottom of the second fixing frame (35), and the calibration grid light (5) projected by the grid light projection lamp (36) can cover the periphery of the ground parking marking line (1).

8. The automatic alignment device for calibrating a grid for a vehicle-mounted surround view camera according to claim 3, characterized in that: The invention also includes an offset measuring device (4), which includes an L-shaped bracket (41) fixed on the top of the vehicle (2) to be tested, a long rod of the L-shaped bracket (41) being parallel to the vehicle width direction, and a first laser displacement sensor (43) and a second laser displacement sensor (44) being horizontally mounted on the long rod of the L-shaped bracket (41); a first reference reflection plate (37) being mounted below the second fixing bracket (35), and the first reference reflection plate (37) being arranged along the Y axis; the laser projection directions of the first and second laser displacement sensors being matched with the first reference reflection plate (37); and the difference in distance between the first and second laser displacement sensors and the first reference reflection plate (37) being calculated, and the inverse tangent value of the difference and the ratio of the distance between the first and second laser displacement sensors is the deflection angle of the vehicle (2) to be tested.

9. The automatic alignment device for calibrating a grid for a vehicle-mounted surround view camera according to claim 8, characterized in that: A second reference reflector (38) is also installed below the second fixing frame (35), and the second reference reflector (38) is arranged along the X axis; a third laser displacement sensor (45) is horizontally installed on the short rod of the L-shaped bracket (41), and the laser projection direction of the third laser displacement sensor (45) matches and corresponds to the second reference reflector (38); after the angle correction is completed, the longitudinal displacement driving mechanism (33) performs X-direction motion correction based on the measured distance between the first laser displacement sensor (43) and the first reference reflector (37) and the first set reference value; and the lateral displacement driving mechanism (32) performs Y-direction motion correction based on the measured distance between the third laser displacement sensor (45) and the second reference reflector (38) and the second set reference value.

10. The automatic alignment device for calibrating a grid for a vehicle-mounted surround view camera according to claim 9, characterized in that: The reference reflector plate is fixed below the second fixing frame (35) via a support rod, and the L-shaped bracket (41) is fixed on the top of the vehicle to be tested (2) via a suction cup (42).

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