1. A robot program user coordinate system automatic compensation method is characterized by comprising the following steps:

(1) determining the position of the vehicle body coordinate system after the deviation in a theoretical vehicle body coordinate system;

(2) and converting the body coordinate system after the deviation into the position of the robot coordinate system according to the relative position of the known theoretical body coordinate system in the robot coordinate system.

2. The automatic compensation method according to claim 1, wherein the step (1) is specifically: the offset body coordinate system sequentially undergoes four movements, namely rotation angles w, p, and R (sequentially to intermediate positions W, P and R) about the x, y, and z axes of the offset body coordinate system, and then translates to a final position.

3. The automatic compensation method according to claim 1, wherein the step (1) comprises the sub-steps of:

(11) rotating the offset vehicle body coordinate system around the self x axis by a rotation angle W to reach an intermediate position W; i.e. the coordinate system Y_WOZ_WShowing the vehicle body coordinate system after the deviation, setting the point M in the coordinate system Y_WOZ_WHas the coordinate of (x)_W,y_W,z_W) The coordinate of which in the theoretical body coordinate system is (x)₀,y₀,z₀) Thus, there are:

(12) in thatRotating the body coordinate system after the deviation of the middle position W around the y axis of the body coordinate system by a rotation angle P to reach the middle position P; i.e. the coordinate system Z_POX_PShowing the vehicle body coordinate system after the deviation, setting the point M in the coordinate system Z_POX_PHas the coordinate of (x)_P,y_P,z_P) In a coordinate system Z_WOX_WHas the coordinate of (x)_W,y_W,z_W) Thus, there are:

(13) rotating the body coordinate system after the deviation of the middle position P around the z axis of the body coordinate system to reach the middle position R; i.e. the coordinate system X_ROY_RShowing the vehicle body coordinate system after the deviation, setting the point M in the coordinate system X_ROY_RHas the coordinate of (x)_R,y_R,z_R) In a coordinate system X_POY_PHas the coordinate of (x)_P,y_P,z_P) Thus, there are:

(14) from the equations (1), (2), and (3), it is not difficult to obtain a rotation transformation matrix Q from the vehicle body coordinate system after the deviation from the neutral position R to the theoretical vehicle body coordinate system:

(15) the body coordinate system after the shift of the intermediate position R is translated to a position in the theoretical body coordinate systemAnd reaching the final position of the vehicle body coordinate system after the deviation, thereby obtaining the transformation from the vehicle body coordinate system after the deviation to a theoretical vehicle body coordinate system:

(16) to be provided withRepresenting the theoretical position of the measuring point X1 in the body coordinate system after the offset,the corresponding measured values at measuring point X1, which are obtained from the position sensor, are represented, and the meaning of the symbols for the remaining measuring points is analogized, so that six equations are obtained for determining the position of the offset body coordinate system relative to the theoretical body coordinate system:

(17) the positions of the vehicle body coordinate system after the deviation relative to the theoretical vehicle body coordinate system can be obtained by simultaneously solving the nonlinear equations (7) - (12)And three rotation angles w, p and r.

4. The automatic compensation method according to claim 1, wherein the step (2) comprises the sub-steps of:

(21) the position of the origin of the theoretical body coordinate system in the robot coordinate system is set asThe origin is coincident, and the three rotation angles of the theoretical body coordinate system relative to the robot coordinate system areAndthe transformation of the theoretical body coordinate system into the robot coordinate system is then:

(22) and (3) leading the theoretical body coordinate into a coordinate transformation formula (6) from the body coordinate system after the deviation to the theoretical body coordinate system, and obtaining:

on the other hand, the transformation from the body coordinate system after the shift to the robot coordinate system is as follows:

(23) comparing the formulas (15) and (16), and obtaining the position of the origin of the body coordinate system after the deviation in the robot coordinate system

(24) And a rotation transformation matrix U of the vehicle body coordinate system and the robot coordinate system after the offset is TQ, wherein the form of U is as follows:

whereinDetermining the rotation angle of the vehicle body coordinate system to the robot coordinate system after the deviation

5. The method of claim 4Method for dynamic compensation, characterized in that in step (24), ifIs determined as followsAnd

in the step (24), ifThen because ofEquation (18) cannot be used directly. At this point, the system of nonlinear equations is solved:

6. an automobile online binding system, comprising:

a white automobile body conveying line preparation station;

the automobile body-in-white rear wheel cover robot online trimming station is connected with the automobile body-in-white conveying line preparation station and comprises a lower tool, so that the body-in-white is positioned through a positioning and clamping device of the lower tool;

the device comprises an automobile body-in-white right rear wheel cover movable trimming tire film and position correction data measurement output device, a digital sensor and a data processing device, wherein the automobile body-in-white right rear wheel cover movable trimming tire film and position correction data measurement output device is arranged at an online trimming station of an automobile body-in-white rear wheel cover robot, and a digital sensor of the device is used for outputting a digital variable quantity of a reference value;

the device comprises an automobile body-in-white left rear wheel cover movable trimming tire membrane and position correction data measurement output device, a digital sensor and a data processing device, wherein the automobile body-in-white left rear wheel cover movable trimming tire membrane and position correction data measurement output device is arranged at an online trimming station of an automobile body-in-white rear wheel cover robot so as to output digital variation of a reference value through the digital sensor of the device;

the robot for the movable binding tire film of the right rear wheel cover of the white automobile body and the position correction data measurement output device comprises a robot body and a special robot floating binding head, so that the robot binding of the parts of the movable binding tire film of the right rear wheel cover of the white automobile body and the position correction data measurement output device is realized;

the robot comprises a robot body and a special robot floating trimming head, so that robot trimming is carried out on the parts of the automobile body-in-white left rear wheel cover movable trimming tire film and the position correction data measurement output device;

the line PLC control cabinet body is respectively in line connection with the automobile body-in-white left rear wheel cover trimming robot, the automobile body-in-white right rear wheel cover trimming robot, the automobile body-in-white left rear wheel cover movable trimming tire film and position correction data measurement output device, the automobile body-in-white right rear wheel cover movable trimming tire film and position correction data measurement output device, and is responsible for collecting information sent back by various components such as the automobile body-in-white left rear wheel cover trimming robot, the automobile body-in-white right rear wheel cover trimming robot, the automobile body-in-white left rear wheel cover movable trimming tire film and position correction data measurement output device, the automobile body-in-white right rear wheel cover movable trimming tire film and position correction data measurement output device and sending the information to an execution component for execution after the information is subjected to command processing;

a special industrial personal computer which is connected with the linear PLC control cabinet body, and utilizes the robot program user coordinate system automatic compensation method of any one of claims 1 to 5 to carry out optimization calculation on the displacement quantities collected by the automobile white body right rear wheel cover movable border tire film and position correction data measurement output device and the automobile white body left rear wheel cover movable border tire film and position correction data measurement output device, so as to respectively obtain the space change positions of the white body in the robot coordinate system after the automobile white body right rear wheel cover movable border tire film and position correction data measurement output device and the automobile white body left rear wheel cover movable border tire film and position correction data measurement output device are in place.

7. The automotive on-line hemming system of claim 6 wherein the automotive body-in-white left rear wheel house hemming robot comprises a first robot and a second robot, the first robot comprising a first grasping mechanism and a first locking mechanism, the first grasping mechanism and the first locking mechanism being integrated together; the first robot is arranged on the first base, and a first floating edge rolling head is arranged on the wrist part of the first robot; the second robot comprises a second grabbing mechanism and a second locking mechanism, and the second grabbing mechanism and the second locking mechanism are integrated together; the second robot is installed on the second base, and a second floating edge rolling head is installed on the wrist of the second robot.

8. The automobile on-line trimming system of claim 7, wherein the first robot is slidably disposed through a first sliding table and a first sliding rail, the first sliding table is configured with a first clamping mechanism for locking the first sliding table, and the first robot is configured with a first in-place detection mechanism for detecting whether the first robot slides in place; the second robot passes through second slip table and the slidable setting of second slide rail, the second slip table disposes the second clamping mechanism who is used for locking the second slip table, the second robot disposes the second that is used for detecting whether the second robot slides and targets in place detection mechanism.

9. The on-line automotive hemming system according to claim 7 wherein the automotive body-in-white left rear wheel house movable hemming tire mold and position correction data measurement output device comprises a first Y-direction floating mechanism, a second Y-direction floating mechanism and a first Z-direction floating mechanism, wherein the first Y-direction floating mechanism, the second Y-direction floating mechanism and the first Z-direction floating mechanism are all provided with displacement sensors; the automobile body-in-white right rear wheel cover movable border tire mold and position correction data measurement output device comprises a third Y-direction floating mechanism, a first X-direction floating mechanism and a second Z-direction floating mechanism, wherein displacement sensors are arranged on the third Y-direction floating mechanism, the first X-direction floating mechanism and the second Z-direction floating mechanism; and the first Y-direction floating mechanism, the second Y-direction floating mechanism, the first Z-direction floating mechanism, the third Y-direction floating mechanism, the first X-direction floating mechanism and the second Z-direction floating mechanism are all provided with displacement sensors.

10. An automobile online binding method is characterized by comprising the following steps:

1) the body-in-white of the automobile arrives at a preparation station;

2) the white automobile body of the automobile is transmitted in place through a conveying mechanism;

3) a positioning and clamping device of the lower tool is used for positioning the body in white;

4) the first robot drives the first sliding table to reach a theoretical positioning position through the first sliding rail, the first in-place detection mechanism has a signal, and meanwhile, the first clamping mechanism locks the first sliding table;

5) the second robot drives the second sliding table to reach a theoretical positioning position through the second sliding rail, the second in-place detection mechanism has a signal, and meanwhile, the second clamping mechanism locks the second sliding table;

6) respectively attaching a first Y-direction floating mechanism, a second Y-direction floating mechanism and a third Y-direction floating mechanism to the surface of the vehicle type, and locking;

7) respectively attaching the first Z-direction floating mechanism and the second Z-direction floating mechanism to the surface of the vehicle type, and locking;

8) the first X-direction floating mechanism is tightly attached to the surface of the vehicle type and locked;

9) outputting displacement amount by 6 displacement sensors;

10) the PLC control cabinet body and the line are used for collecting information sent back by the output displacement of the 6 displacement sensors, and the information is sent to the execution component for execution after being subjected to command processing;

11) the method for automatically compensating the user coordinate system of the robot program according to any one of claims 1 to 5 is used for carrying out optimization calculation on displacement amounts collected by the automobile body-in-white right rear wheel cover movable border tire membrane and position correction data measurement output device and the automobile body-in-white left rear wheel cover movable border tire membrane and position correction data measurement output device through a special industrial personal computer, and spatial change positions of the automobile body-in-white in the robot coordinate system after the automobile body-in-white right rear wheel cover movable border tire membrane and position correction data measurement output device and the automobile body-in-white left rear wheel cover movable border tire membrane and position correction data measurement output device are in place are obtained respectively.

Background

The sources of error in robot programs fall into two categories: external errors caused by jig manufacturing and installation and internal errors caused by robot body manufacturing. The errors of the offline procedure are mainly caused by external errors [4 ]. The elimination of errors in the relative positions of the robot and the installation of professional equipment has been the focus of research in the industry, and many professionals in the robot industry have made efforts in this direction, ranging from principles to mechanisms and methods. In the calibration method for off-line programming of the robot, a tool coordinate system fitting calibration method is researched by Caijiang and the like, 3 points for establishing a tool coordinate system are collected on site, and values of the 3 points in the robot coordinate system and a vehicle body coordinate system are respectively measured and are coincided, so that the relative positions of the robot and a clamp are calibrated. The WcsCal software of the laser optics technology limited company adopts three-coordinate professional measuring equipment to collect 15 sets of data of a robot coordinate system and a vehicle body coordinate system 2, and can directly calculate a corrected robot tool coordinate system. These calculation methods are all off-line to modify the robot tool coordinate system. The robot binding program has a lot of points needing debugging, and in order to improve efficiency and quality, the existing method mostly uses digital factory simulation software to perform refined simulation to be used as an off-line program, and the usability of the robot program can be improved after the calculated tool coordinates are used for calibrating the robot off-line program. This measuring method works well for fixing a workpiece to a tire membrane using a special jig.

In the design and planning process of the automobile body-in-white welding production line, the design structure of part of automobile types is planned to be a side wall inner general splicing structure and a side wall outer general splicing structure, and a wrapping process is needed in the A-level area of the side wall rear wheel cover appearance. Due to the accumulated error of the manufacturing process, generally, after a white body is subjected to a welding process, actual body data and theoretical body data of the body are not matched due to various reasons, and products are damaged and scrapped in the edge covering process of the robot after the offset is too large. After the relative positions of the binding tire membrane, the binding workpiece and the robot are fixed, and after the off-line program adjustment of the robot is completed, the high repetition precision and flexibility of the robot are utilized, so that the binding planning of various vehicle types can be realized. The process is completed by utilizing a robot hemming technology to complete the hemming process of the outer plate and the inner plate of the side-wall rear wheel cover on the production line of the white automobile body of the automobile, and at present, two modes are basically provided: in the first mode, a robot is adopted to replace a tire membrane on a clamp, a tire membrane positioning device is designed on the clamp to clamp the tire membrane, and after the edge rolling action of the robot is finished, a body in white is conveyed to the next station; and in the second mode, the white automobile body of the automobile is adopted for self-positioning, and a driving mechanism is arranged on the binding tire membrane. Both of these ways are to fit the membrane to the body well.

After the white automobile body of the existing automobile is conveyed to a working position through a roller bed conveying system, the working target of the robot generates some system deviations due to factors such as equipment precision, system tolerance of different automobile bodies and the like, and the deviation values exceed the working requirement due to the working precision requirement of the robot; therefore, it is urgently needed to design an algorithm for performing online calibration on the relative relationship between the working targets and the robot, performing spatial coordinate transformation on the deviation value of each working target through the algorithm, and compensating the system error after the relative relationship between the robot and the working targets is calibrated, and the process needs to be online and real-time.

Disclosure of Invention

The invention aims to provide a robot user coordinate system compensation method, an automobile online border system and an automobile online border method, which can perform online calibration on the relative relationship between a working target and a robot, perform spatial coordinate transformation on the deviation value of each working target through an algorithm, and compensate system errors after the relative relationship between the robot and the working target is calibrated. The position and direction of the body coordinate system after the offset relative to the robot coordinate system, i.e. the position of the origin of the body coordinate system after the offset in the robot coordinate system, and the three rotation angles of the body coordinate system after the offset relative to the robot coordinate system, are determined.

In order to achieve the purpose, the invention adopts the following technical scheme:

a robot program user coordinate system automatic compensation method comprises the following steps:

(1) determining the position of the vehicle body coordinate system after the deviation in a theoretical vehicle body coordinate system;

(2) and converting the body coordinate system after the deviation into the position of the robot coordinate system according to the relative position of the known theoretical body coordinate system in the robot coordinate system.

As a further description of the above technical solution: the step (1) is specifically as follows: the offset body coordinate system sequentially undergoes four movements, namely rotation angles w, p, and R (sequentially to intermediate positions W, P and R) about the x, y, and z axes of the offset body coordinate system, and then translates to a final position.

As a further description of the above technical solution: the step (1) comprises the following substeps:

(11) rotating the offset vehicle body coordinate system around the self x axis by a rotation angle W to reach an intermediate position W; i.e. the coordinate system Y_WOZ_WShowing the vehicle body coordinate system after the deviation, setting the point M in the coordinate system Y_WOZ_WHas the coordinate of (x)_W,y_W,z_W) The coordinate of which in the theoretical body coordinate system is (x)₀,y₀,z₀) Thus, there are:

(12) rotating the body coordinate system after the deviation of the middle position W around the y axis of the body coordinate system by a rotation angle P to reach the middle position P; i.e. the coordinate system Z_POX_PShowing the vehicle body coordinate system after the deviation, setting the point M in the coordinate system Z_POX_PHas the coordinate of (x)_P,y_P,z_P) In a coordinate system Z_WOX_WHas the coordinate of (x)_W,y_W,z_W) Thus, there are:

(13) rotating the body coordinate system after the deviation of the middle position P around the z axis of the body coordinate system to reach the middle position R; i.e. the coordinate system X_ROY_RShowing the vehicle body coordinate system after the deviation, setting the point M in the coordinate system X_ROY_RHas the coordinate of (x)_R,y_R,z_R) In a coordinate system X_POY_PHas the coordinate of (x)_P,y_P,z_P) Thus, there are:

as a further description of the above technical solution: the step (1) further comprises the following substeps:

(14) from the equations (1), (2), and (3), it is not difficult to obtain a rotation transformation matrix Q from the vehicle body coordinate system after the deviation from the neutral position R to the theoretical vehicle body coordinate system:

(15) the body coordinate system after the shift of the intermediate position R is translated to a position in the theoretical body coordinate systemAnd reaching the final position of the vehicle body coordinate system after the deviation, thereby obtaining the transformation from the vehicle body coordinate system after the deviation to a theoretical vehicle body coordinate system:

(16) to be provided withRepresenting the theoretical position of the measuring point X1 in the body coordinate system after the offset,the corresponding measured values at measuring point X1, which are obtained from the position sensor, are represented, and the meaning of the symbols for the remaining measuring points is analogized, so that six equations are obtained for determining the position of the offset body coordinate system relative to the theoretical body coordinate system:

(17) solving the nonlinear equations (7) - (12) simultaneously to obtain the vehicle body coordinate system after deviation relative to the theoryPosition of the coordinate system of the vehicle bodyAnd three rotation angles w, p and r.

As a further description of the above technical solution: in the step (17), the initial values of the six solutions can be set to zero when solving, because the vehicle body coordinate system after being offset is only slightly offset relative to the theoretical vehicle body coordinate system.

As a further description of the above technical solution: the step (2) comprises the following substeps:

(21) the position of the origin of the theoretical body coordinate system in the robot coordinate system is set asThe origin is coincident, and the three rotation angles of the theoretical body coordinate system relative to the robot coordinate system areAndthe transformation of the theoretical body coordinate system into the robot coordinate system is then:

(22) and (3) leading the theoretical body coordinate into a coordinate transformation formula (6) from the body coordinate system after the deviation to the theoretical body coordinate system, and obtaining:

on the other hand, the transformation from the body coordinate system after the shift to the robot coordinate system is as follows:

(23) comparing the formulas (15) and (16), and obtaining the position of the origin of the body coordinate system after the deviation in the robot coordinate system

(24) And a rotation transformation matrix U of the vehicle body coordinate system and the robot coordinate system after the offset is TQ, wherein the form of U is as follows:

whereinDetermining the rotation angle of the vehicle body coordinate system to the robot coordinate system after the deviation

As a further description of the above technical solution: in the step (24), ifIs determined as followsAnd

as a further description of the above technical solution: in the step (24), ifThen because ofEquation (18) cannot be used directly. At this point, the system of nonlinear equations is solved:

an automotive on-line hemming system comprising:

a white automobile body conveying line preparation station;

the automobile body-in-white rear wheel cover robot online trimming station is connected with the automobile body-in-white conveying line preparation station and comprises a lower tool, so that the body-in-white is positioned through a positioning and clamping device of the lower tool;

the device comprises an automobile body-in-white right rear wheel cover movable trimming tire film and position correction data measurement output device, a digital sensor and a data processing device, wherein the automobile body-in-white right rear wheel cover movable trimming tire film and position correction data measurement output device is arranged at an online trimming station of an automobile body-in-white rear wheel cover robot, and a digital sensor of the device is used for outputting a digital variable quantity of a reference value;

the device comprises an automobile body-in-white left rear wheel cover movable trimming tire membrane and position correction data measurement output device, a digital sensor and a data processing device, wherein the automobile body-in-white left rear wheel cover movable trimming tire membrane and position correction data measurement output device is arranged at an online trimming station of an automobile body-in-white rear wheel cover robot so as to output digital variation of a reference value through the digital sensor of the device;

the robot for the movable binding tire film of the right rear wheel cover of the white automobile body and the position correction data measurement output device comprises a robot body and a special robot floating binding head, so that the robot binding of the parts of the movable binding tire film of the right rear wheel cover of the white automobile body and the position correction data measurement output device is realized;

the robot comprises a robot body and a special robot floating trimming head, so that robot trimming is carried out on the parts of the automobile body-in-white left rear wheel cover movable trimming tire film and the position correction data measurement output device;

the line PLC control cabinet body is respectively in line connection with the automobile body-in-white left rear wheel cover trimming robot, the automobile body-in-white right rear wheel cover trimming robot, the automobile body-in-white left rear wheel cover movable trimming tire film and position correction data measurement output device, the automobile body-in-white right rear wheel cover movable trimming tire film and position correction data measurement output device, and is responsible for collecting information sent back by various components such as the automobile body-in-white left rear wheel cover trimming robot, the automobile body-in-white right rear wheel cover trimming robot, the automobile body-in-white left rear wheel cover movable trimming tire film and position correction data measurement output device, the automobile body-in-white right rear wheel cover movable trimming tire film and position correction data measurement output device and sending the information to an execution component for execution after the information is subjected to command processing;

and the special industrial personal computer is connected with the linear PLC control cabinet body, and is used for optimizing and calculating displacement collected by the automobile white body right rear wheel cover movable border tire film and position correction data measurement and output device and the automobile white body left rear wheel cover movable border tire film and position correction data measurement and output device by utilizing the robot program user coordinate system automatic compensation method to respectively obtain the spatial change positions of the white body in the robot coordinate system after the automobile white body right rear wheel cover movable border tire film and position correction data measurement and output device and the automobile white body left rear wheel cover movable border tire film and position correction data measurement and output device are in place.

As a further description of the above technical solution:

the automotive body-in-white left rear wheel cover trimming robot comprises a first robot and a second robot, wherein the first robot comprises a first grabbing mechanism and a first locking mechanism, and the first grabbing mechanism and the first locking mechanism are integrated together; the first robot is arranged on the first base, and a first floating edge rolling head is arranged on the wrist part of the first robot; the second robot comprises a second grabbing mechanism and a second locking mechanism, and the second grabbing mechanism and the second locking mechanism are integrated together; the second robot is installed on the second base, and a second floating edge rolling head is installed on the wrist of the second robot.

As a further description of the above technical solution:

the first robot is arranged in a sliding mode through the first sliding table and the first sliding rail, the first sliding table is provided with a first clamping mechanism used for locking the first sliding table, and the first robot is provided with a first in-place detection mechanism used for detecting whether the first robot slides in place or not.

As a further description of the above technical solution:

the second robot passes through second slip table and the slidable setting of second slide rail, the second slip table disposes the second clamping mechanism who is used for locking the second slip table, the second robot disposes the second that is used for detecting whether the second robot slides and targets in place detection mechanism.

As a further description of the above technical solution:

the automotive body-in-white left rear wheel cover movable border tire mold and position correction data measurement output device comprises a first Y-direction floating mechanism, a second Y-direction floating mechanism and a first Z-direction floating mechanism, wherein the first Y-direction floating mechanism, the second Y-direction floating mechanism and the first Z-direction floating mechanism are respectively provided with a displacement sensor; the automobile body-in-white right rear wheel cover movable border tire mold and position correction data measurement output device comprises a third Y-direction floating mechanism, a first X-direction floating mechanism and a second Z-direction floating mechanism, wherein displacement sensors are arranged on the third Y-direction floating mechanism, the first X-direction floating mechanism and the second Z-direction floating mechanism.

As a further description of the above technical solution:

and the first Y-direction floating mechanism, the second Y-direction floating mechanism, the first Z-direction floating mechanism, the third Y-direction floating mechanism, the first X-direction floating mechanism and the second Z-direction floating mechanism are all provided with displacement sensors.

An automobile online binding method comprises the following steps:

1) the body-in-white of the automobile arrives at a preparation station;

2) the white automobile body of the automobile is transmitted in place through a conveying mechanism;

3) a positioning and clamping device of the lower tool is used for positioning the body in white;

4) the first robot drives the first sliding table to reach a theoretical positioning position through the first sliding rail, the first in-place detection mechanism has a signal, and meanwhile, the first clamping mechanism locks the first sliding table;

5) the second robot drives the second sliding table to reach a theoretical positioning position through the second sliding rail, the second in-place detection mechanism has a signal, and meanwhile, the second clamping mechanism locks the second sliding table;

6) respectively attaching a first Y-direction floating mechanism, a second Y-direction floating mechanism and a third Y-direction floating mechanism to the surface of the vehicle type, and locking;

7) respectively attaching the first Z-direction floating mechanism and the second Z-direction floating mechanism to the surface of the vehicle type, and locking;

8) the first X-direction floating mechanism is tightly attached to the surface of the vehicle type and locked;

9) outputting displacement amount by 6 displacement sensors;

10) the PLC control cabinet body and the line are used for collecting information sent back by the output displacement of the 6 displacement sensors, and the information is sent to the execution component for execution after being subjected to command processing;

11) the special industrial control computer is used for optimizing and calculating the displacement collected by the movable binding tire film and the position correction data measurement output device of the automobile white body right rear wheel cover and the movable binding tire film and the position correction data measurement output device of the automobile white body left rear wheel cover by utilizing the robot program user coordinate system automatic compensation method, and the space change positions of the white automobile body in the robot coordinate system after the movable binding tire film and the position correction data measurement output device of the automobile white body right rear wheel cover and the movable binding tire film and the position correction data measurement output device of the automobile white body left rear wheel cover are in place are respectively obtained.

The invention has the following beneficial effects:

the invention carries out online calibration on the relative relationship between the working target and the robot, carries out space coordinate transformation on the deviation value of each working target through an algorithm, and can compensate the system error after calibrating the relative relationship between the robot and the working target, and the process needs to be online and real-time. The position and orientation of the body coordinate system after the offset relative to the robot coordinate system, i.e. the position of the origin of the body coordinate system after the offset in the robot coordinate system, and the three rotation angles of the body coordinate system after the offset relative to the robot coordinate system are determined.

The method solves the problem that the robot edge rolling procedure generates waste products due to the fact that the coordinate system of the white body to be rolled changes and entangles and deviates at any time by adopting the research of the automatic compensation floating algorithm, can be popularized to other similar robots and working scenes that the work object changes at any time, can change the data acquisition mode into laser or camera, and can expand the application scene of the robot as long as the change of the work object can be accurately obtained.

Drawings

In order to more clearly illustrate the embodiments or technical solutions in the prior art of the present invention, the drawings used in the description of the embodiments or prior art will be briefly described below, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic diagram of the transformation of an intermediate position W to a coordinate system 0;

FIG. 2 is a schematic diagram of the transition from the neutral position P to the neutral position W;

FIG. 3 is a schematic diagram of the transition from the intermediate position R to the intermediate position P;

FIG. 4 is a schematic connection diagram of an online vehicle trimming system according to the present invention;

FIG. 5 is a tabular diagram of raw data and simulation test data for simulation software;

FIG. 6 is a table chart of the comparative deviation of the algorithm results from the theoretical values;

FIG. 7 is a table diagram of simulation theory OBJ of robot simulation software and calculation software algorithm results;

FIG. 8 is a table diagram of the comparison result between the theoretical value and the operation value;

FIG. 9 is a schematic structural diagram of an online vehicle trimming system according to the present invention;

FIG. 10 is a partial schematic view of a robotic floating border system;

FIG. 11 is a schematic structural view of the slip measurement of the binding workstation of the left robot;

fig. 12 is a schematic structural diagram of the slippage measurement of the right-side robot binding workstation.

Reference numerals: 0-vehicle body-in-white conveying line preparation station; 1-a conveying mechanism; 2-lower part tooling; 3-a movable binding tire mold and a position correction data measurement output device of a left rear wheel cover of the white automobile body; 4-a movable binding tire mold and a position correction data measurement output device of a white automobile body right rear wheel cover of the automobile; 5-a first robot; 6-a first base; 8-a second robot; 9-a second base; 11-a line PLC control cabinet body; 12-special industrial personal computer; 13-a first floating hemming head; 14-a second floating hemming head; 15-a first gripping mechanism; 16-a second grasping mechanism; 17-a first ramp; 18-a second slide table; 19-a first locking mechanism; 20-a second locking mechanism; 21-a first slide rail; 22-a second slide rail; 23-a first clamping mechanism; 24-a second clamping mechanism; 25-a first in-position detection mechanism; 26-a second in-position detection mechanism; 27-a first Y-direction floating mechanism; 28-a second Y-direction floating mechanism; 29-a third Y-direction floating mechanism; 30-a first Z-direction float mechanism; 31-a second Z-direction floating mechanism; 32-first X-direction float mechanism.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention provides components of 6 coordinate points, x and y respectively, through special equipment₁，y₂，y₃，z₁，z₂The values of the variables are transmitted to an industrial personal computer system controlled by a PLC system through a sensor, the calculated values of the variables are transmitted to a corresponding robot control system through the PLC system according to requirements through a special system algorithm, and the robot system replaces the variables in the process of calling a working program.

A robot program user coordinate system automatic compensation method comprises the following steps:

(1) determining the position of the vehicle body coordinate system after the deviation in a theoretical vehicle body coordinate system;

(2) and converting the body coordinate system after the deviation into the position of the robot coordinate system according to the relative position of the known theoretical body coordinate system in the robot coordinate system.

The following terms are agreed:

coordinate system 0: namely a theoretical body coordinate system;

coordinate system 1: a vehicle body coordinate system after the offset;

coordinate system 2: robot coordinate system.

In theory, coordinate system 1 should coincide with coordinate system 0, but due to various factors, coordinate system 1 is offset from coordinate system 0. This shifting process can be understood as four movements of the coordinate system 1 that occur sequentially, i.e. in turn rotating by angles w, p and R about the x, y and z axes of the coordinate system 1 (in turn reaching intermediate positions W, P and R) and then translating to the final position.

In this embodiment, the step (1) specifically includes: the coordinate system 1 sequentially takes four movements, i.e., sequentially rotates about the x, y, z axes of the coordinate system 1 by angles w, p, and R (sequentially to intermediate positions W, P and R), and then translates to a final position.

In this embodiment, the step (1) includes the following sub-steps:

(11) rotating the coordinate system 1 around the x axis to reach the middle position W; as shown in FIG. 1, i.e. coordinate system Y_WOZ_WThe coordinate system 1 at this time is shown, and the set point M is in the coordinate system Y_WOZ_WHas the coordinate of (x)_W,y_W,z_W) The coordinate in the coordinate system 0 is (x)₀,y₀,z₀) Thus, there are:

wherein (x)₀,y₀,z₀) Is a coordinate in coordinate system 0; (x)_W,y_W,z_W) Point M in coordinate system Y_WOZ_WThe coordinate value of (1);

(12) rotating the angle P around the y axis of the coordinate system 1 at the middle position W to reach the middle position P; as shown in fig. 2, i.e. coordinate system Z_POX_PThe coordinate system 1 at this time is shown, and the set point M is in the coordinate system Z_POX_PHas the coordinate of (x)_P,y_P,z_P) In a coordinate system Z_WOX_WHas the coordinate of (x)_W,y_W,z_W) Thus, there are:

wherein (x)_W,y_W,z_W) For point M in the coordinate system Y_WOZ_WThe coordinate value of (1); (x)_P,y_P,z_P) Is M in the coordinate system Z_POX_PThe coordinate value of (1);

(13) rotating the angle R around the z axis of the coordinate system 1 at the middle position P to reach the middle position R; as shown in fig. 3, i.e. coordinate system X_ROY_RThe coordinate system 1 at this time is shown, and the set point M is in the coordinate system X_ROY_RHas the coordinate of (x)_R,y_R,z_R) In a coordinate system X_POY_PHas the coordinate of (x)_P,y_P,z_P) Thus, there are:

wherein (x)_R,y_R,z_R) Is M in the coordinate system X_ROY_RThe coordinate value of (1); (x)_P,y_P,z_P) Is M in the coordinate system Z_POX_PThe coordinate value of (1);

(14) from equations (1), (2), and (3), it is not difficult to derive a rotation transformation matrix Q from the coordinate system 1 at the intermediate position R to the coordinate system 0:

wherein Q is a rotation transformation matrix between a coordinate system 1 and a coordinate system 0;

(15) the coordinate system 1 at the intermediate position R is translated to a position in the coordinate system 0The final position of coordinate system 1 is reached, thus resulting in a transformation of coordinate system 1 to coordinate system 0:

wherein Q is a rotation transformation matrix between a coordinate system 1 and a coordinate system 0; (x)₀,y₀,z₀) Is a theoretical coordinate value in coordinate system 0;

(16) to be provided withRepresenting the measuring point X1 in the coordinate system 1The theoretical position of the device,the corresponding measured value at measurement point X1 from the position sensor is represented, and the meaning of the symbols for the remaining measurement points is analogized to the others, thus yielding six equations that determine the position of coordinate system 1 relative to coordinate system 0:

(17) the positions of the coordinate system 1 relative to the coordinate system 0 can be obtained by simultaneously solving the nonlinear equations (7) - (12)And three rotation angles w, p and r.

In this embodiment, in the step (17), the initial values of the six solutions may be set to zero when solving, because the coordinate system 1 is slightly offset from the coordinate system 0.

In this embodiment, the step (2) includes the following sub-steps:

(21) let the position of the origin of coordinate system 0 in coordinate system 2 beThe origin points coincide and the three rotation angles of the coordinate system 0 relative to the coordinate system 2 areAndthe transformation of coordinate system 0 to coordinate system 2 is:

wherein (x)₂,y₂,z₂) The theoretical coordinate value of the M point coordinate in the coordinate system 2; (x)₀,y₀,z₀) The theoretical coordinate value of the M point coordinate in a coordinate system 0; t is a transformation matrix from a coordinate system 0 to a coordinate system 2;

(22) and substituting the theoretical body coordinate system into a coordinate transformation formula (6) from a coordinate system 1 to a coordinate system 0 to obtain:

wherein T is a transformation matrix from a coordinate system 0 to a coordinate system 2; q is a rotation transformation matrix between a coordinate system 1 and a coordinate system 0;

on the other hand, the transformation directly from coordinate system 1 to coordinate system 2 is:

wherein, U is a rotation transformation matrix between a coordinate system 1 and a coordinate system 2;

(23) comparing the formulas (15) and (16), the position of the origin of the coordinate system 1 in the coordinate system 2 is obtained

(24) The rotation transformation matrix U of coordinate system 1 and coordinate system 2 is TQ, and U has the following form:

whereinIs the rotation angle of the coordinate system 1 to the coordinate system 2, and determines

Wherein the content of the first and second substances,is the x-rotation angle of coordinate system 1 to coordinate system 2;is the y-rotation angle of coordinate system 1 to coordinate system 2;is the z-rotation angle of coordinate system 1 to coordinate system 2;

in this embodiment, in the step (24), ifIs determined as followsAnd

in this embodiment, in the step (24), ifThen because ofEquation (18) cannot be used directly. At this point, the system of nonlinear equations is solved:

as shown in fig. 5, 9, 10, 11 and 12, an automobile online binding system includes:

a white automobile body conveying line preparation station;

the automobile body-in-white rear wheel cover robot online trimming station is connected with the automobile body-in-white conveying line preparation station and comprises a lower tool, so that the body-in-white is positioned through a positioning and clamping device of the lower tool;

the device comprises an automobile body-in-white right rear wheel cover movable trimming tire film and position correction data measurement output device, a digital sensor and a data processing device, wherein the automobile body-in-white right rear wheel cover movable trimming tire film and position correction data measurement output device is arranged at an online trimming station of an automobile body-in-white rear wheel cover robot, and a digital sensor of the device is used for outputting a digital variable quantity of a reference value;

the device comprises an automobile body-in-white left rear wheel cover movable trimming tire membrane and position correction data measurement output device, a digital sensor and a data processing device, wherein the automobile body-in-white left rear wheel cover movable trimming tire membrane and position correction data measurement output device is arranged at an online trimming station of an automobile body-in-white rear wheel cover robot so as to output digital variation of a reference value through the digital sensor of the device;

the robot for the movable binding tire film of the right rear wheel cover of the white automobile body and the position correction data measurement output device comprises a robot body and a special robot floating binding head, so that the robot binding of the parts of the movable binding tire film of the right rear wheel cover of the white automobile body and the position correction data measurement output device is realized;

the robot comprises a robot body and a special robot floating trimming head, so that robot trimming is carried out on the parts of the automobile body-in-white left rear wheel cover movable trimming tire film and the position correction data measurement output device;

the line PLC control cabinet body is respectively in line connection with the automobile body-in-white left rear wheel cover trimming robot, the automobile body-in-white right rear wheel cover trimming robot, the automobile body-in-white left rear wheel cover movable trimming tire film and position correction data measurement output device, the automobile body-in-white right rear wheel cover movable trimming tire film and position correction data measurement output device, and is responsible for collecting information sent back by various components such as the automobile body-in-white left rear wheel cover trimming robot, the automobile body-in-white right rear wheel cover trimming robot, the automobile body-in-white left rear wheel cover movable trimming tire film and position correction data measurement output device, the automobile body-in-white right rear wheel cover movable trimming tire film and position correction data measurement output device and sending the information to an execution component for execution after the information is subjected to command processing;

and the special industrial personal computer is connected with the linear PLC control cabinet body, and is used for optimizing and calculating displacement collected by the automobile white body right rear wheel cover movable border tire film and position correction data measurement and output device and the automobile white body left rear wheel cover movable border tire film and position correction data measurement and output device by utilizing the robot program user coordinate system automatic compensation method to respectively obtain the spatial change positions of the white body in the robot coordinate system after the automobile white body right rear wheel cover movable border tire film and position correction data measurement and output device and the automobile white body left rear wheel cover movable border tire film and position correction data measurement and output device are in place.

In the embodiment, the automotive body-in-white left rear wheel cover hemming robot comprises a first robot and a second robot, wherein the first robot comprises a first grabbing mechanism and a first locking mechanism, and the first grabbing mechanism and the first locking mechanism are integrated together; the first robot is arranged on the first base, and a first floating edge rolling head is arranged on the wrist part of the first robot; the second robot comprises a second grabbing mechanism and a second locking mechanism, and the second grabbing mechanism and the second locking mechanism are integrated together; the second robot is installed on the second base, and a second floating edge rolling head is installed on the wrist of the second robot.

In this embodiment, the first robot is slidably disposed through a first sliding table and a first sliding rail, the first sliding table is configured with a first clamping mechanism for locking the first sliding table, and the first robot is configured with a first in-place detection mechanism for detecting whether the first robot slides in place; the second robot passes through second slip table and the slidable setting of second slide rail, the second slip table disposes the second clamping mechanism who is used for locking the second slip table, the second robot disposes the second that is used for detecting whether the second robot slides and targets in place detection mechanism.

In this embodiment, the automotive body-in-white left rear wheel cover movable border tire mold and position correction data measurement output device comprises a first Y-direction floating mechanism, a second Y-direction floating mechanism and a first Z-direction floating mechanism, wherein the first Y-direction floating mechanism, the second Y-direction floating mechanism and the first Z-direction floating mechanism are all provided with displacement sensors; the automobile body-in-white right rear wheel cover movable border tire mold and position correction data measurement output device comprises a third Y-direction floating mechanism, a first X-direction floating mechanism and a second Z-direction floating mechanism, wherein displacement sensors are arranged on the third Y-direction floating mechanism, the first X-direction floating mechanism and the second Z-direction floating mechanism; and the first Y-direction floating mechanism, the second Y-direction floating mechanism, the first Z-direction floating mechanism, the third Y-direction floating mechanism, the first X-direction floating mechanism and the second Z-direction floating mechanism are all provided with displacement sensors.

As shown in fig. 9 to 12, an online automobile trimming method includes the following steps:

1) the body-in-white of the automobile arrives at a preparation station;

2) the white automobile body of the automobile is transmitted in place through a conveying mechanism;

3) a positioning and clamping device of the lower tool is used for positioning the body in white;

4) the first robot drives the first sliding table to reach a theoretical positioning position through the first sliding rail, the first in-place detection mechanism has a signal, and meanwhile, the first clamping mechanism locks the first sliding table;

5) the second robot drives the second sliding table to reach a theoretical positioning position through the second sliding rail, the second in-place detection mechanism has a signal, and meanwhile, the second clamping mechanism locks the second sliding table;

6) respectively attaching a first Y-direction floating mechanism, a second Y-direction floating mechanism and a third Y-direction floating mechanism to the surface of the vehicle type, and locking;

7) respectively attaching the first Z-direction floating mechanism and the second Z-direction floating mechanism to the surface of the vehicle type, and locking;

8) the first X-direction floating mechanism is tightly attached to the surface of the vehicle type and locked;

9) outputting displacement amount by 6 displacement sensors;

10) the PLC control cabinet body and the line are used for collecting information sent back by the output displacement of the 6 displacement sensors, and the information is sent to the execution component for execution after being subjected to command processing;

11) the special industrial control computer is used for optimizing and calculating the displacement collected by the movable binding tire film and the position correction data measurement output device of the automobile white body right rear wheel cover and the movable binding tire film and the position correction data measurement output device of the automobile white body left rear wheel cover by utilizing the robot program user coordinate system automatic compensation method, and the space change positions of the white automobile body in the robot coordinate system after the movable binding tire film and the position correction data measurement output device of the automobile white body right rear wheel cover and the movable binding tire film and the position correction data measurement output device of the automobile white body left rear wheel cover are in place are respectively obtained.

The following are the actual measurement cases given according to the simulation software and the algorithm:

as shown in fig. 5-8, we need further verification for the calculation result obtained by the optimization algorithm to be used in the actual project. And (3) establishing a working environment by using Siemens PDPS software, and taking a part of discrete data in a working range to perform corresponding checking and comparison: and selecting 35 groups of offset values to respectively obtain a change result in the simulation software and a result obtained by using an optimization algorithm to compare, wherein the error values of X, Y and Z are less than 0.1, and the error values of three angles are less than 0.003.

Through the verification, the theoretical algorithm can meet the actual engineering requirements of people. In actual projects, the automobile body-in-white rear wheel cover robot rolls a station on line, the automobile body-in-white rear wheel cover movable roll edge tire mold and a position correction data measurement output device are used for outputting digital variation of a reference value through a displacement sensor, 6 displacement sensors output displacement amounts to be read through a PLC system, collected displacement amounts are optimized and calculated through an industrial personal computer, space variation positions of the in-place automobile body in a robot coordinate system are obtained respectively, the computer result is transmitted to a roll edge robot through the PLC, the roll edge robot replaces a user coordinate system in a program with the digital values, and the robot roll edge program can carry out roll edge normally.

Through the research of the automatic compensation floating algorithm, the problem that waste products are generated in the process of the robot edge rolling due to the fact that the coordinate system of a white vehicle body subjected to edge rolling changes and is wound and deviated at any time is solved, the algorithm can be popularized to other similar robots and working scenes that working objects change at any time, the data acquisition mode can be changed into laser or a camera, the change of the working objects can be accurately obtained, and the application scene of the robot is expanded.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments or portions thereof without departing from the spirit and scope of the invention.