CN116823930A - Method for realizing vehicle body positioning in automobile production line - Google Patents
Method for realizing vehicle body positioning in automobile production line Download PDFInfo
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T7/00—Image analysis
- G06T7/70—Determining position or orientation of objects or cameras
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- G06Q—INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES; SYSTEMS OR METHODS SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES, NOT OTHERWISE PROVIDED FOR
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- G—PHYSICS
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- G06Q—INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES; SYSTEMS OR METHODS SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES, NOT OTHERWISE PROVIDED FOR
- G06Q50/00—Systems or methods specially adapted for specific business sectors, e.g. utilities or tourism
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- G—PHYSICS
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- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T7/00—Image analysis
- G06T7/80—Analysis of captured images to determine intrinsic or extrinsic camera parameters, i.e. camera calibration
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T2207/00—Indexing scheme for image analysis or image enhancement
- G06T2207/30—Subject of image; Context of image processing
- G06T2207/30244—Camera pose
Abstract
The invention discloses a method for realizing vehicle body positioning in an automobile production line, which comprises the following steps: calibrating the 4 cameras into the same coordinate system through an external instrument; acquiring images of 4 parts of a vehicle body at 4 angles of a camera, and searching two-dimensional image coordinates of inherent feature marking points capable of carrying out visual positioning on the vehicle body from the images; and fitting a plurality of mark points in the 4 images through software modeling according to the azimuth relation and the mark points between the cameras, calculating the spatial mathematical relation with the reference mark points, determining the optimal vehicle body azimuth, calculating the correction vector between the current azimuth and the theoretical azimuth, transmitting the correction vector to the mechanical arm, correcting the path of the mechanical arm taught before by the mechanical arm, and performing operations such as gluing, welding, spraying and the like. The invention realizes the non-contact three-dimensional azimuth positioning to find the offset of the workpiece; the full automation of production control can receive external signal trigger; the positioning accuracy is high, and the stability is good.
Description
Technical Field
The invention relates to the technical field of automobile automatic production lines, in particular to a method for realizing automobile body positioning in an automobile production line.
Background
With the development of society, various production lines have been realized with extremely high automation, particularly automobile production lines. In an automobile production line, an automobile body is usually transported to a designated position by a conveyor, and after the conveyor is stopped, the automobile body is subjected to operations such as coating, welding, painting, and the like by a robot.
Due to factors such as inherent reasons of the conveying apparatus, machine variation, and mounting errors of the conveying apparatus, working of the vehicle body only by the position to which the conveying apparatus is stopped, results in that the stop position/posture of the conveyed workpiece is not always constant, and that parallel rotation in position of the vehicle body workpiece may occur. If the robot performs operations such as gluing, sealing, coating, welding and the like at the moment, the robot program taught in the prior art can be greatly deviated. In order to improve the in-place accuracy, a high requirement for the conveying device is required, resulting in an increase in cost. Meanwhile, the conveying device is worn, and as the frequency of use increases, the conveying precision is reduced, and the quality is affected.
Disclosure of Invention
The invention aims to provide a system and a method for realizing vehicle body positioning in an automobile production line, so as to solve the technical problems in the prior art.
In order to achieve the above object, an embodiment of the present invention provides a system for achieving positioning of a vehicle body in an automobile production line, including: at least 4 cameras, a visual analysis device for calibrating the 4 cameras and at least 4 mechanical arms,
the method comprises the steps of shooting images of 4 parts of a vehicle body from 4 angles by using 4 calibrated cameras, wherein shooting focuses of the images correspond to at least one preset feature hole of the vehicle body, coordinates of the preset feature hole are coordinate points under a vehicle body coordinate system, and according to absolute position relations of the coordinate points of the feature hole under the vehicle body coordinate system, fixed conversion values (X, Y, Z, rx, ry, RZ) of a current vehicle body coordinate system and a zero vehicle coordinate system are calculated, wherein the zero vehicle is defined as a position where a vehicle without offset is located, and the zero vehicle coordinate system is calculated through an external instrument; the camera shoots the preset feature holes, the shot round image center points are used as feature mark points, the camera searches the feature mark points and obtains two-dimensional image coordinates of the feature mark points, meanwhile, according to the azimuth relation among the cameras and the coordinates under the vehicle body coordinate system of the feature mark points, a correction vector is solved through mathematical operation by utilizing a specific relation existing in space, and therefore the vehicle body is positioned through the 4 cameras; the specific relation existing in the space refers to original fixed coordinate points of the characteristic mark points of the 4 cameras under a vehicle body coordinate system;
the visual analysis device is used for calibrating the 4 cameras, adopts a laser calibration instrument, calibrates the 4 cameras, the 4 mechanical arms and the vehicle body under one coordinate system through the laser calibration instrument, calculates the fixed conversion value of each coordinate system relative to a world coordinate system, and realizes the conversion of any two coordinate systems;
after the vehicle body is positioned, positioning information of the vehicle body is sent to the mechanical arm, and the mechanical arm compensates the path of the mechanical arm taught before according to the positioning information, so that automatic operation is carried out on the vehicle body.
Further, the robot arm carries out process track programming by using the vehicle body coordinate system, and the 4 cameras shoot the vehicle body and then calculate the deviation value of the current vehicle body and the reference vehicle body; the mechanical arm is corrected by the deviation value to ensure that the motion track of the mechanical arm is consistent with the process track of the vehicle body, so that visual compensation is realized.
The invention also provides a vehicle body positioning method adopting the system for realizing vehicle body positioning in the automobile production line, which comprises the following steps:
step 1, calibrating 4 cameras into the same coordinate system through an external instrument;
step 2, 4 images of 4 parts of the vehicle body are collected from 4 angles, and two-dimensional image coordinates of feature mark points on the vehicle body to be visually positioned are searched in the 4 images;
step 3, fitting a plurality of characteristic marking points in the 4 images through software modeling according to the azimuth relation among the cameras and the characteristic marking points, and calculating the spatial mathematical relation between the plurality of marking points and the reference marking points;
and 4, after the optimal vehicle body azimuth is mathematically determined, calculating correction vectors (X, Y, Z, RX, RY and RZ) between the current azimuth and the theoretical azimuth, and sending the correction vectors to the mechanical arm, wherein the mechanical arm corrects a mechanical arm path taught before, and automatic operation is carried out.
Furthermore, in the step 1, a fixed tool or a laser calibration instrument is specifically adopted to calibrate the 4 cameras, and the absolute position relationship of the 4 cameras under the world coordinate system is determined through calibration.
Further, the step 2 specifically includes selecting 4 specific positions on the vehicle body as feature mark points, where the specific positions have clear and definite image information or have clear boundaries.
Further, the step 3 is to generate a vehicle body model through software modeling, and the position and the posture of the whole vehicle body under a space coordinate system are determined according to 4 characteristic mark points on the vehicle body model.
Further, the specific mathematical implementation method of the step 4 is as follows: the world coordinate system Fw and the vehicle body coordinate system F0 are set, and the coordinate systems F1, F2, F3, and F4 of the 4 cameras and the 4 target areas A, B, C, D are set to calculate the position (R, T) of F0 at Fw.
Further, the mathematical implementation method further includes: when each camera can only see one point in the target area, a, b, c, d points are respectively seen in the 4 target areas A, B, C, D, and if the measured coordinates of the point a in the camera 1 are (u, v), the point a is necessarily on a straight line, and a point a straight line equation is obtained; expressing a linear equation in a world coordinate system Fw, and solving an equation of the point a in FW; and the equations of points b and c in FW are solved by the same principle, and 9 unknowns and 6 equations are obtained.
Further, the mathematical implementation method further includes: the coordinate values (R, T) are obtained by adopting a three-point method (ICPψ method), the fourth point is redundant, and the least square method is obtained; according to the steps, three points are selected at will from a, b, c, d points, namely, the position and the gesture of the vehicle body are obtained by adopting three cameras, the rest fourth point is used as a redundant point, and mathematical optimization is carried out through a least square method.
Further, the step 4 is configured to identify a feature mark point on the vehicle body to determine a current deviation of the vehicle body, that is, coordinate transformation of 6 degrees of freedom, and transmit the deviation to the mechanical arm, so that the mechanical arm accurately corrects its motion track, and ensures that the track of the mechanical arm is consistent with a gap of the vehicle body in a spatial position.
The method of the invention has the following advantages:
(1) Locating the offset of the workpiece in a non-contact three-dimensional azimuth;
(2) The full automation of production control can receive external signal trigger;
(3) The positioning precision is high, the stability is good, the precision is controlled within 1mm, and the recognition time is within 2 s.
Drawings
Fig. 1 shows the implementation of a body positioning system configuration using 4 cameras in an automotive production line.
FIG. 2 shows a flow chart of a method for achieving vehicle body positioning using 4 cameras in an automotive production line;
figure 3 shows the coordinate system of the four cameras and the position of F0 in Fw in the target area A, B, C, D,
in the figure, 1: a camera; 2: a mechanical arm; 3: a vehicle body.
Detailed Description
The technical solution of the present invention will be clearly and completely described in conjunction with the specific embodiments, but it should be understood by those skilled in the art that the embodiments described below are only for illustrating the present invention and should not be construed as limiting the scope of the present invention. All other embodiments, which can be made by one of ordinary skill in the art without undue burden on the person of ordinary skill in the art based on the embodiments of the present invention, are within the scope of the present invention.
Due to errors in the transfer system, the vehicle body cannot be stopped in exactly the same orientation each time, i.e. there may be one deviation in the vehicle body coordinate system, at which time the control system will automatically trigger the vision system to determine the current orientation deviation of the vehicle body, i.e. the 6 degrees of freedom coordinate transformations (X, Y, Z, RX, RY, RZ), by identifying some inherent feature marks on the vehicle body and to transfer this orientation correction loss to the robot via the PLC, so that the robot can accurately "find" the vehicle body and perform the corresponding glue application.
According to the invention, when the automobile on the production line reaches a designated position through the conveying line by adopting four cameras, the automobile body is positioned when the automobile body is not positioned accurately, and after the automobile body is positioned, a new position is sent to a robot or other executing mechanisms to perform automatic operations, such as gluing, welding, coating, assembling and the like.
One embodiment of the present invention provides a system for achieving vehicle body positioning in an automotive production line, as shown in fig. 1, the system comprising: at least 4 cameras 1, a visual analysis device, at least 4 mechanical arms 2 and a vehicle body 3;
the method comprises the steps of shooting images of 4 parts of a vehicle body from 4 angles by using 4 calibrated cameras, wherein shooting focuses of the images correspond to at least one preset feature hole of the vehicle body, coordinates of the preset feature hole are coordinate points under a vehicle body coordinate system, and according to absolute position relations of the coordinate points of the preset feature hole under the vehicle body coordinate system, a fixed conversion value (X, Y, Z, rx, ry, RZ) of a current vehicle body coordinate system and a zero vehicle coordinate system, namely a position offset, is calculated by an external instrument, namely the position offset (X, Y, Z, rx, ry, RZ) of the current vehicle body and the zero vehicle coordinate system is obtained, wherein the zero vehicle is defined as the position where the vehicle without offset is located. The cameras search for inherent feature mark points and acquire two-dimensional image coordinates of the inherent feature mark points, and meanwhile, according to the azimuth relation among the cameras and coordinates of the inherent feature mark points under a vehicle body coordinate system, a specific relation existing in space, namely original fixed coordinate points of four feature mark points under the vehicle body coordinate system, is utilized, and a correction vector is solved through mathematical operation, so that the vehicle body is positioned through the 4 cameras;
the visual analysis device is used for calibrating 4 cameras, the visual analysis device generally adopts a laser calibration instrument similar to that of the American FARO company, the 4 cameras, the mechanical arm and the vehicle body are calibrated under one coordinate system through the laser calibration instrument, the fixed conversion value of each coordinate system is calculated, the conversion of any two coordinate systems is realized, the vehicle body coordinates are used as standard in practical application, the mechanical arm programs the process track according to the vehicle body coordinate system, and the deviation value of the current vehicle body and the reference vehicle body is calculated after the 4 cameras shoot. After the mechanical arm is corrected by using the deviation value, the motion track of the mechanical arm can be ensured to be consistent with the process track required by the vehicle body, and the visual compensation effect is realized; and
the mechanical arm replaces manual operation, after the automobile body is positioned, positioning information of the automobile body is sent to the mechanical arm, and the mechanical arm compensates a path which is taught well before according to the positioning information, so that automatic operations such as gluing, welding and spraying are performed on the automobile body. The robot arm 2 is thus a final work actuator for performing automated operations such as body gluing, body painting, etc.
Another embodiment of the present invention provides a method for achieving vehicle body positioning in an automotive production line, as shown in fig. 2, the method comprising:
step 1, calibrating 4 cameras into the same coordinate system through an external instrument;
the fixed tool or the laser calibration instrument is generally adopted to calibrate the 4 cameras, and the absolute position relationship of the 4 cameras under the coordinate system is determined through calibration.
Step 2, acquiring images of 4 parts of the vehicle body from 4 angles, and searching two-dimensional image coordinates of inherent feature mark points on the vehicle body in the images;
generally, 4 specific positions on the vehicle body are selected, wherein the specific positions have clear and definite image information, such as characteristic information of round holes on some vehicle bodies, and the round holes have clear boundary positions and serve as inherent characteristic marking points;
step 3, according to the azimuth relation among all cameras and the inherent characteristic mark points, the body model modeled by software is theoretically consistent with the actual appearance of the vehicle, and each camera coordinate, each robot coordinate and the body coordinate are unified under one coordinate system through an external instrument, so that the conversion relation (x, y, z, rx, ry, rz) of each coordinate system can be obtained, namely a mathematical model, a plurality of mark points in 4 images are fitted, and the spatial mathematical relation with the reference mark points is calculated;
the model of the vehicle body is known, and the position and the posture of the whole vehicle body under a space coordinate system are determined according to four characteristic points;
and 4, mathematically determining the optimal vehicle body azimuth, calculating correction vectors (X, Y, Z, RX, RY and RZ) between the current azimuth and the theoretical azimuth, transmitting the correction vectors to the mechanical arm, and carrying out automatic operations such as gluing, welding, spraying and the like on the mechanical arm path taught before the mechanical arm correction.
The specific mathematical implementation method comprises the following steps:
as shown in fig. 3, the world coordinate system Fw, the vehicle body coordinate system F0, the coordinate systems F1, F2, F3, and F4 of the four cameras, and 4 target areas A, B, C, D, the position of F0 at Fw (R,
if each camera can only see one point within the area, a, b, c, d points are seen in the 4 target areas A, B, C, D:
1. let the measured coordinates of point a in camera 1 be (u, v), then point a must lie on a straight line, the straight line equation is expressed as:
wherein, the liquid crystal display device comprises a liquid crystal display device,c 1 =1, wherein fx, fy, cx, cy is a camera internal parameter, (x 1 ,y 1 ,z 1 ) Is the coordinate of point a in the camera 1 coordinate system.
2. The straight line equation is expressed in the world coordinate system Fw due to
( 1 Tw is known to
In (x) 1w ,y 1w ,z 1w ) X is the coordinate of point a in the world coordinate system 1w ＝[x 1w ,y 1w ,z 1w ,1]' substituting, the straight line is expressed as:
( 1 ti is 1 Tw ith row
There are three unknowns, 2 linear equations in equation (1).
The value range of each parameter is provided with a plurality of values, 1 tw is known, the values meet the homogeneous transformation matrix specification, a 1 、b 1 、c 1 Also known as real numbers.
3. The same applies the equation of the straight line where the points b and c are located in FW, and the equation is 9 unknowns and 6 equations
There are three unknowns in equation (2), 2 linear equations. 2 Tw is known, the values meet the homogeneous transformation matrix specification, a 1 、b 1 、c 1 Also known as real numbers.
There are three unknowns, 2 linear equations in equation (3). 3 Tw is known, the values meet the homogeneous transformation matrix specification, a 1 、b 1 、c 1 Also known as real numbers.
The three-point relative relationship of a, b and c is known, three equations are supplemented,
(x 1w -x 2w ) 2 +(y 1w -y 2w ) 2 +(z 1w -z 2w ) 2 ＝d 2 AB
(x 2w -x 3w ) 2 +(y 2w -y 3w ) 2 +(z 2w -z 3w ) 2 ＝d 2 BC
(x 1w -x 3w ) 2 +(y 1w -y 3w ) 2 +(z 1w -z 3w ) 2 ＝d 2 AC (4)
a positive number d AB ，d BC ，d AC The lengths of the straight lines AB, BC and AC are respectively 9 unknowns, 6 primary linear equations and 3 secondary linear equations, and the coordinates of the three points a, b and c in FW can be obtained.
The above discussion intuitively understands that finding three points on three known out-of-plane straight lines satisfies the relative distance constraint by using x from the first 6 linear equations 1w ,y 1w ,z 1w Expression of (2) represents x 2w ,y 2w ,z 2w ，x 3w ,y 3w ,z 3w Then substituting the three-dimensional quadratic equation into the last 3 quadratic equations to solve the three-dimensional quadratic equation, wherein the three-dimensional quadratic equation can be realized by codes or by calling matlab functions.
The values that are solved may have two sets of solutions, where the body of one set of solutions is flipped upside down, and it may be excluded that only the other set of solutions that meets the conditions remains.
5. Coordinate values (R, T) can be obtained by the "three-point method" (ICP ψ method):
2.t * ＝μ q -Rμ p
6. the fourth point is redundant and the least squares method can be found.
According to the first three points a, b and c, namely three cameras, the pose information of the vehicle body can be obtained, and the fourth point d is used as a redundant point to carry out mathematical optimization through a least square method.
And meanwhile, when one camera fails, the pose information of the vehicle body can be determined.
For example, in a painting shop PVC robot gluing project, a vision system formed by four cameras determines the three-dimensional orientation of a vehicle body: the automatic conveying of the vehicle body on the production line is realized by the vehicle body through a skid or a lifting appliance; when the car body reaches the PVC gluing station, the robot automatically glues the PVC glue. Because of errors of the conveying system, the vehicle body cannot be stopped at the same azimuth at each time, namely, the coordinate system of the vehicle body can have a deviation, at the moment, the control system automatically triggers the vision system, the current azimuth deviation of the vehicle body, namely, the coordinate conversion of 6 degrees of freedom, is determined by identifying some inherent characteristic mark points on the vehicle body, and the deviation loss is transmitted to the mechanical arm of the robot, so that the robot can accurately correct the motion trail of the robot, the space position consistency between the trail of the mechanical arm of the robot and a gap of the vehicle body is ensured, and the production process requirement is met.
While the invention has been described in detail in the foregoing general description and specific examples, it will be apparent to those skilled in the art that modifications and improvements can be made thereto. Accordingly, such modifications or improvements may be made without departing from the spirit of the invention and are intended to be within the scope of the invention as claimed.
Claims (10)
1. A system for achieving vehicle body positioning in an automotive production line, comprising: the system comprises at least 4 cameras, a visual analysis device for calibrating the 4 cameras and at least 4 mechanical arms;
the method comprises the steps of shooting images of 4 parts of a vehicle body from 4 angles by using 4 calibrated cameras, wherein shooting focuses of the images correspond to at least one preset feature hole of the vehicle body, coordinates of the preset feature hole are coordinate points under a vehicle body coordinate system, and according to absolute position relations of the coordinate points of the preset feature hole under the vehicle body coordinate system, fixed conversion values (X, Y, Z, rx, ry, RZ) of a current vehicle body coordinate system and a zero vehicle coordinate system are calculated, wherein the zero vehicle is defined as a position where a vehicle without offset is located, and the coordinate system of the zero vehicle is obtained through external instrument measurement; the camera shoots the preset feature holes, the shot round image center points are used as feature mark points, the camera searches the feature mark points and obtains two-dimensional image coordinates of the feature mark points, meanwhile, according to the azimuth relation among the cameras and the coordinates under the vehicle body coordinate system of the feature mark points, a correction vector is solved through mathematical operation by utilizing a specific relation existing in space, and therefore the vehicle body is positioned through the 4 cameras; the specific relation existing in the space refers to original fixed coordinate points of the characteristic mark points of the 4 cameras under a vehicle body coordinate system;
the visual analysis device is used for calibrating the 4 cameras, adopts a laser calibration instrument, calibrates the 4 cameras, the 4 mechanical arms and the vehicle body under one coordinate system through the laser calibration instrument, calculates the fixed conversion value of each coordinate system relative to a world coordinate system, and realizes the conversion of any two coordinate systems;
after the vehicle body is positioned, positioning information of the vehicle body is sent to the mechanical arm, and the mechanical arm compensates the path of the mechanical arm taught before according to the positioning information, so that automatic operation is carried out on the vehicle body.
2. The system for realizing vehicle body positioning in an automobile production line according to claim 1, wherein the robot arm performs process track programming by using the vehicle body coordinate system, and the 4 cameras calculate the deviation value of the current vehicle body and a reference vehicle body after photographing the vehicle body; the mechanical arm is corrected by the deviation value to ensure that the motion track of the mechanical arm is consistent with the process track of the vehicle body, so that visual compensation is realized.
3. A vehicle body positioning method employing the system for achieving vehicle body positioning in an automobile production line according to any one of claims 1 or 2, comprising:
step 1, calibrating 4 cameras into the same coordinate system through an external instrument;
step 2, 4 images of 4 parts of the vehicle body are collected from 4 angles, and two-dimensional image coordinates of feature mark points on the vehicle body to be visually positioned are searched in the 4 images;
step 3, fitting a plurality of characteristic marking points in the 4 images through software modeling according to the azimuth relation among the cameras and the characteristic marking points, and calculating the spatial mathematical relation between the plurality of marking points and the reference marking points;
and 4, after the optimal vehicle body azimuth is mathematically determined, calculating correction vectors (X, Y, Z, RX, RY and RZ) between the current azimuth and the theoretical azimuth, and sending the correction vectors to the mechanical arm, wherein the mechanical arm corrects a mechanical arm path taught before, and automatic operation is carried out.
4. The vehicle body positioning method according to claim 3, wherein the step 1 specifically comprises calibrating the 4 cameras by using a fixed tool or a laser calibration instrument, and determining the absolute positional relationship of the 4 cameras in a world coordinate system through calibration.
5. A vehicle body positioning method according to claim 3, wherein the step 2 is specifically to select 4 specific positions on the vehicle body as feature mark points, and the specific positions have clear and definite image information or clear boundaries.
6. A vehicle body positioning method according to claim 3, wherein the step 3 generates a vehicle body model through software modeling, and determines the position and the posture of the whole vehicle body under a space coordinate system according to 4 feature mark points on the vehicle body model.
7. The vehicle body positioning method according to claim 3, wherein the specific mathematical implementation method of step 4 is as follows: the world coordinate system Fw and the vehicle body coordinate system F0 are set, and the coordinate systems F1, F2, F3, and F4 of the 4 cameras and the 4 target areas A, B, C, D are set to calculate the position (R, T) of F0 at Fw.
8. The vehicle body positioning method according to claim 7, characterized in that the mathematical implementation method further comprises: when each camera can only see one point in the target area, a, b, c, d points are respectively seen in the 4 target areas A, B, C, D, and if the measured coordinates of the point a in the camera 1 are (u, v), the point a is necessarily on a straight line, and a point a straight line equation is obtained; expressing a linear equation in a world coordinate system Fw, and solving an equation of the point a in FW; and the equations of points b and c in FW are solved by the same principle, and 9 unknowns and 6 equations are obtained.
9. The vehicle body positioning method according to claim 8, characterized in that the mathematical implementation method further comprises: the coordinate values (R, T) are obtained by adopting a three-point method (ICPψ method), the fourth point is redundant, and the least square method is obtained; according to the steps, three points are selected at will from a, b, c, d points, namely, the position and the gesture of the vehicle body are obtained by adopting three cameras, the rest fourth point is used as a redundant point, and mathematical optimization is carried out through a least square method.
10. The vehicle body positioning method according to claim 3, wherein the step 4 is configured to identify a feature mark point on a vehicle body to determine a current azimuth deviation amount of the vehicle body, that is, coordinate conversion of 6 degrees of freedom, and transmit the deviation amount to the mechanical arm, so that the mechanical arm accurately corrects its motion track, and ensures that the track of the mechanical arm is consistent with a gap of the vehicle body in spatial position.
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