A robot working position error calibration and convergence method and related product

Abstract

The present application relates to the field of robot, specifically relates to a robot working pose error calibration and convergence method and related products, the method comprises establishing a measurement coordinate system;Obtain theoretical working pose data, and establish a theoretical working pose coordinate system under the measurement coordinate system based on the theoretical working pose data;The actual working pose of the robot end is measured, and the actual working pose coordinate system is established;Solving pose deviation;The tool coordinate system parameters of the robot are corrected, and iteratively converged to the pose deviation meets the preset requirement;The present application can match a most suitable tool bias parameter for the robot without manually adjusting the robot pose and modifying the automatic running program, so as to iteratively converge the actual working pose error of the robot and the theoretical working pose error.

Description

Technical Field

[0001] This invention relates to the field of robotics, including serial robots, parallel robots, and hybrid robots, and specifically to a method for calibrating and converging robot working posture errors and related products. Background Technology

[0002] Robots are indispensable basic production equipment in industries such as aviation, aerospace, shipbuilding, and automotive. In the processing, grinding, and welding of large and complex contour products, their working paths and trajectory programs are generated through offline simulation software in conjunction with specific processing techniques. Based on these application scenarios, robots need to have high end-effector positioning accuracy. However, due to factors such as machining and assembly errors in robot joints and joint deflection errors caused by loads, their end-effector spatial positioning errors are relatively large. Therefore, the accurate measurement and compensation of robot spatial positioning accuracy is a key factor determining whether robots can directly apply large-scale offline process programs.

[0003] Traditional methods for measuring robot spatial positioning accuracy typically employ laser trackers in conjunction with multi-target balls or 6D side-mounted heads as measurement hardware, following national or ISO standard measurement methods to measure the robot's spatial pose accuracy. This traditional method has significant limitations: the measurement hardware is expensive, the pre-measurement calibration process is cumbersome, and the robot's spatial pose error obtained through standard measurement methods cannot accurately represent its spatial pose error under actual working conditions.

[0004] Traditional robot spatial pose error compensation is usually achieved through DH parameter calibration. However, the DH parameters of most industrial robots are encapsulated inside the controller, and debugging personnel do not have the authority to modify them. Therefore, it is impossible to achieve robot spatial pose accuracy compensation through DH parameter calibration.

[0005] To address the aforementioned issues, this paper proposes a calibration and convergence scheme for the final working pose error of a robot after integration and debugging. Unlike traditional measurement methods, this scheme requires only a 3D measuring device and a single reflective device to complete the measurement, and eliminates the need for tool calibration of the robot's end effector reflective device, enabling precise measurement directly for specific robot working poses. Different from traditional pose error compensation approaches, this scheme obtains the deviation between the theoretical and actual working poses through multiple measurements and verifications, optimizes and matches the optimal tool parameters, and ultimately achieves the calibration and convergence of the robot's working pose error. Summary of the Invention

[0006] The technical problem to be solved by this invention is how to correct the error of the final working posture of a robot after integration and debugging. The purpose is to provide a robot working posture error calibration and convergence method and related products to solve the problem of posture error calibration and correction in actual work.

[0007] This invention is achieved through the following technical solution:

[0008] A method for calibrating and converging robot working pose error includes:

[0009] Establish robot base coordinate system Coincident measurement coordinate systems ;

[0010] Acquire the robot's theoretical working pose data in the base coordinate system, and then, based on the theoretical working pose data, in the measurement coordinate system... Establish a theoretical working pose coordinate system ;

[0011] The robot is controlled to move to the theoretical working pose, and the actual working pose of the robot's end effector is measured to establish the actual working pose coordinate system. ;

[0012] Based on the measurement coordinate system The theoretical working pose coordinate system is calculated. With the actual working pose coordinate system Positional deviation between them;

[0013] Based on the pose deviation, the robot's tool coordinate system parameters are corrected, and the process is iteratively converged until the pose deviation meets the preset requirements.

[0014] Optionally, a measurement coordinate system is established. The steps include:

[0015] The robot's first joint axis is controlled to rotate, and the spatial position points of the robot's end effector at multiple rotation angles are collected using external measuring equipment. A first spatial circle and a first normal axis perpendicular to the plane of the first spatial circle are then fitted using the spatial position points.

[0016] The robot's second joint axis is rotated, and the external measuring device is used to collect the spatial position points of the robot's end at multiple rotation angles. The second spatial circle and the second normal axis perpendicular to the plane of the second spatial circle are fitted by the spatial position points.

[0017] If the angle between the first normal vector axis and the second normal vector axis is within a preset range, then a measurement coordinate system is established based on the first normal vector axis and the second normal vector axis. Otherwise, refit the first normal vector axis and the second normal vector axis.

[0018] Optionally, the measurement coordinate system The specific structure includes:

[0019] The direction of the first normal vector axis is defined as the measurement coordinate system. The Z-axis direction;

[0020] The direction of the second normal vector axis is defined as the measurement coordinate system. The Y-axis direction;

[0021] Based on the center of the second spatial circle, construct a second plane that passes through the center of the second spatial circle and is perpendicular to the first normal vector axis;

[0022] Along the direction of the first normal vector axis, the second plane is translated according to the link length of the robot's first joint axis to obtain the translated first plane;

[0023] The intersection of the first plane and the first normal vector axis is defined as the measurement coordinate system. The origin;

[0024] According to the right-hand rule, the measurement coordinate system is determined by the Y-axis and Z-axis directions. The X-axis direction.

[0025] Optionally, establish an actual working pose coordinate system. The steps include:

[0026] Control the robot in its tool coordinate system Below, taking the current TCP point as the center, and circling the tool coordinate system respectively. axis, shaft and The axis performs attitude transformation;

[0027] During the attitude transformation process, multiple spatial coordinate points of the target ball installed at the robot's end effector are collected using external measuring equipment;

[0028] Based on all the collected spatial coordinate points, a spatial sphere and its center are obtained through fitting. and based on the surrounding axis, shaft and The spatial coordinates collected by the axis during attitude transformation are used to fit three rotation planes and their corresponding normal vectors.

[0029] Determine whether, among the three normal vectors, there exists any two normal vectors whose angle is within a preset perpendicularity range.

[0030] If it exists, then the center of the sphere is used. Using the origin as the reference point and selecting the two normal vectors whose included angle is closest to 90° as the reference axes, the actual working pose coordinate system is established according to the right-hand rule. ;

[0031] If not, repeat the above steps until the verticality range requirement is met.

[0032] Optionally, the preset range is 90°±0.03°; the preset verticality range is 90°±0.03°.

[0033] Optionally, the step of calculating the pose deviation includes:

[0034] In the measurement coordinate system The actual working pose coordinate system is then determined. The pose relationship is used as the actual working pose of the robot;

[0035] Obtain the theoretical working pose coordinate system With the actual working pose coordinate system Homogeneous matrix relationship between ;

[0036] The position and attitude deviations between the robot's actual working pose and its theoretical working pose are calculated.

[0037] Furthermore, the method also includes:

[0038] Determine whether both the positional deviation and the attitude deviation in the pose deviation meet the preset usage requirements;

[0039] If the positional or orientation deviations do not meet the usage requirements, then adjust the robot's tool coordinate system. The parameters are corrected and compensated, and the process is iteratively converged until the pose deviation meets the preset usage requirements.

[0040] If the positional deviation or attitude deviation both meet the usage requirements, the calibration is complete.

[0041] Optionally, the steps for correction and compensation include:

[0042] Based on the positional deviation, the robot's tool coordinate system Relative to the flange coordinate system Adjust the position offset parameters;

[0043] Based on the aforementioned attitude deviation, the robot's tool coordinate system Relative to the flange coordinate system Adjust the attitude parameters;

[0044] Update the adjusted position offset parameters and attitude parameters to the robot controller.

[0045] A computer-readable storage medium storing a computer program that, when executed by a processor, implements the robot work pose error calibration and convergence method as described above.

[0046] A computer program product includes a computer program / instructions that, when executed by a processor, implement the robot work pose error calibration and convergence method as described above.

[0047] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0048] This invention addresses a series of problems, such as the inability to directly measure and compensate for the final working posture error after robot integration and debugging, and proposes a technical solution for calibrating and converging robot working posture error.

[0049] This invention achieves high-precision calibration of the robot's base coordinate system by independently controlling the rotation of the first and second joint axes, constructing the normal vector axes of each joint, and using the two joint normal vector axes to construct an auxiliary plane. The origin of the robot's base coordinate system is precisely calibrated by constraining the orthogonality between the normal vector axes of the first and second joint axes. Based on the precisely calibrated base coordinate system, the theoretical working pose of the robot is constructed in the measurement system based on the robot's theoretical pose data. The actual working pose of the robot is then accurately constructed through end-effector posture adjustment. With both the theoretical and measured working poses available in the measurement system, the robot's working pose deviation can be calculated. Based on this deviation, the robot's tool parameters are corrected. Without manually adjusting the robot's pose or modifying the automatic operation program, an optimal tool offset parameter is matched to the robot to iteratively converge the error between the actual and theoretical working poses.

[0050] This invention not only solves the problem of error detection in the working posture of a robot after integration and debugging, but also completes the measurement and compensation convergence of the robot's spatial posture error with only one measuring reflection device and without the need for tool calibration of the reflection device. Attached Figure Description

[0051] The accompanying drawings illustrate exemplary embodiments of the present invention and, together with the description thereof, serve to explain the principles of the invention. These drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, but do not constitute a limitation on the embodiments of the present invention.

[0052] Figure 1 This is a schematic diagram of the state for calibrating the robot's working posture error according to the present invention.

[0053] Figure 2 This is a schematic diagram of the theoretical working pose coordinate system and the actual working pose coordinate system according to the present invention.

[0054] Figure 3 This is a flowchart illustrating a robot working posture error calibration and convergence method according to the present invention. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0056] It should also be noted that, for ease of description, only the parts relevant to the present invention are shown in the accompanying drawings.

[0057] Where there is no conflict, the embodiments and features described in the present invention can be combined with each other. Reference will be made below to the appendix. Figure 1 and Figure 2 The present invention will be described in detail with reference to the embodiments.

[0058] To facilitate understanding, the correspondence between some general technical terms and specific devices or concepts commonly used in this field is clarified:

[0059] External measuring equipment: refers to three-dimensional coordinate measuring equipment, such as laser trackers.

[0060] Measurement coordinate system : refers to the coordinate system established by the laser tracker software system, also known as the laser tracker measurement coordinate system.

[0061] The target point or target ball at the end of the robot: refers to the measurement reference object installed on the end flange or tool of the robot, which is used to be precisely locked by the laser tracker.

[0062] First joint axis and second joint axis: For a typical six-axis serial industrial robot, these refer to the robot's J1 axis (base rotation axis) and J2 axis (arm pitch axis), respectively.

[0063] Theoretical working pose coordinate system : refers to the virtual coordinate system established in the laser tracker measurement system based on the theoretical pose data read from the robot controller.

[0064] Actual working pose coordinate system : refers to the coordinate system established in the laser tracker measurement system after the robot's end-effector pose is actually measured by the laser tracker.

[0065] Example 1

[0066] like Figure 3 As shown, a method for calibrating and converging robot working pose error includes:

[0067] Before calibration begins, a benchmark unification needs to be established. This involves setting up a coordinate system with the robot's base coordinate system. Coincident measurement coordinate systems The measurement coordinate system ensures that the robot's theoretical pose and the actual measured pose are compared in the same coordinate system.

[0068] After the baseline is established, the error identification stage begins. The theoretical working pose data of the robot in the base coordinate system (i.e., the position and posture that the robot controller believes its end effector should reach) is acquired, and based on this theoretical working pose data in the measurement coordinate system... Establish a theoretical working pose coordinate system ;

[0069] The robot is controlled to move to the theoretical working pose, and a laser tracker is used to perform precise spatial measurements on the target ball at the robot's end effector to obtain the actual working pose of the robot's end effector, thus establishing a coordinate system for the actual working pose. ;

[0070] After identifying the error, the deviation calculation stage begins. This is based on the aforementioned measurement coordinate system. The theoretical working pose coordinate system is calculated. With the actual working pose coordinate system The pose deviation between them is reflected in the position deviation and attitude deviation in three-dimensional space.

[0071] Finally, the closed-loop correction stage begins. Based on the pose deviation, the robot's tool coordinate system (TCP) parameters are corrected. After each parameter correction, the aforementioned measurement and calculation process is repeated to determine whether the corrected pose deviation has been reduced to within the preset accuracy requirements. If not, a new round of correction and compensation is performed until the pose deviation meets the preset requirements.

[0072] Working principle: Using external measuring equipment, the precise deviation between the robot's theoretical command pose and the actual executed pose is quantified under a unified reference coordinate system. Based on this deviation, the robot's own tool coordinate system parameters are iteratively corrected and compensated, ultimately achieving convergence of compensation for pose error at a specific working point.

[0073] Example 2

[0074] This embodiment further explains and illustrates each step in Embodiment 1.

[0075] S1. Control the first joint axis of the robot to rotate, and use external measuring equipment to collect the spatial position points of the robot end at multiple rotation angles. Fit the first spatial circle and the first normal axis perpendicular to the plane of the first spatial circle through the spatial position points.

[0076] The robot's second joint axis is rotated, and the external measuring device is used to collect the spatial position points of the robot's end at multiple rotation angles. The second spatial circle and the second normal axis perpendicular to the plane of the second spatial circle are fitted by the spatial position points.

[0077] The robot's joints are returned to their zero positions, and the target ball is attached to the robot's end effector. The robot's first and second joint axes are rotated at fixed equal angles. After each fixed angle rotation, the laser tracker collects the position coordinates of the target ball at the robot's end effector and fits a first spatial circle around the first joint axis and its center. and the first normal axis perpendicular to the circular plane Fit the second spatial circle and its center that rotates about the second joint axis. and the second normal axis perpendicular to the circular plane ;

[0078] S2. If the angle between the first normal vector axis and the second normal vector axis is within a preset range, then a measurement coordinate system is established based on the first normal vector axis and the second normal vector axis. Otherwise, refit the first normal vector axis and the second normal vector axis.

[0079] Based on the first normal vector axis normal vector normal vector of the second normal axis Determine the included angle ,like If the included angle is within the range of 90°±0.03°, then stop the above operation procedure. If the included angles are not within the range of 90°±0.03°, repeat the operation process of step S1.

[0080] S3. Based on the center of the second spatial circle, construct a second plane that passes through the center of the second spatial circle and is perpendicular to the first normal vector axis;

[0081] Along the direction of the first normal vector axis, the second plane is translated according to the link length of the robot's first joint axis to obtain the translated first plane;

[0082] The intersection of the first plane and the first normal vector axis is defined as the measurement coordinate system. The origin;

[0083] Based on the first normal vector axis and the center Construct a circle through the center And with the straight line Vertical second plane Along the normal vector The direction is based on the length of the link of the robot's first joint axis. For the second plane Translate to construct the first plane Based on the first plane With a straight line Intersection constructs intersection point At this point This is the actual center point of the rotation of the robot's first joint axis.

[0084] The direction of the first normal vector axis is defined as the measurement coordinate system. The Z-axis direction; the direction of the second normal vector axis is determined as the measurement coordinate system. The Y-axis direction; according to the right-hand rule, the measurement coordinate system is determined by the Y-axis direction and the Z-axis direction. The X-axis direction. At this point, the coordinate system is based on the laser tracker. With robot base coordinate system Precise overlap;

[0085] S4. Switch the robot to its working pose P1; record the robot teach pendant's pose data in the base coordinate system. Based on P1 pose In a laser tracking measurement system, the coordinate system Perform translation and rotation operations, and define the coordinate system after the translation and rotation operations as follows: .

[0086] S5. Switch to the tool coordinate system of the robot's current tool in the robot control system. The robot's end effector is controlled by an automatic program to move to the working pose P1; the robot is controlled in its tool coordinate system. Below, taking the current TCP point as the center, and circling the tool coordinate system respectively. axis, shaft and The axis undergoes constant angle attitude transformation.

[0087] During the attitude change process, multiple spatial coordinate points of the target ball installed at the end of the robot are collected using external measuring equipment (laser tracker).

[0088] Based on all the collected spatial coordinate points, a spatial sphere and its center are obtained through fitting. and based on the surrounding axis, shaft and The spatial coordinates collected during the attitude transformation of the axis are used to fit three rotation planes and their corresponding normal vectors. , , .

[0089] Determine whether, among the three normal vectors, there exists any two normal vectors whose angle is within a preset perpendicularity range.

[0090] Find the angle between any two normal vectors. If any one of the included angles is within the range of 90°±0.03°, then stop the above operation process. If none of the three included angles are within the range of 90°±0.03°, then repeat the operation process of step S5.

[0091] S6. If it exists, then take the center of the sphere as... Using the origin as the reference point and selecting the two normal vectors whose included angle is closest to 90° as the reference axes, the actual working pose coordinate system is established according to the right-hand rule. At this point, the coordinate system is based on laser tracking. With robot tool coordinate system Precise overlap.

[0092] S7, in the measurement coordinate system The actual working pose coordinate system is then determined. pose relationship This serves as the actual working pose of the robot.

[0093] coordinate system in laser tracking measurement system With coordinate system Homogeneous matrix relationship between The coordinate system can be calculated. With coordinate system The pose relationship between them is the actual working pose of the robot measured by the laser tracker.

[0094] S8. Obtain the theoretical working pose coordinate system. } and the actual working pose coordinate system Homogeneous matrix relationship between ;

[0095] based on The positional deviation between the robot's actual working pose and its theoretical working pose is calculated. With attitude deviation .

[0096] S9. Determine whether the position deviation and attitude deviation in the pose deviation both meet the preset usage requirements;

[0097] If the positional or orientation deviations do not meet the usage requirements, then adjust the robot's tool coordinate system. The parameters are corrected and compensated, and the process is iterated until the pose deviation meets the preset usage requirements; if both the position deviation and the attitude deviation meet the usage requirements, the calibration is completed.

[0098] Position deviation based on actual working posture and theoretical working posture With attitude deviation The robot's working position error and working posture error are judged. If the position deviation is... With attitude deviation If all requirements are met, calibration and measurement are complete. If there is a positional deviation... Or attitude deviation If the requirements are not met, the robot's working position or posture will be corrected and compensated.

[0099] S10. Based on the position deviation, adjust the tool coordinate system of the robot. Relative to the flange coordinate system The position offset parameters are adjusted; based on the attitude deviation, the robot's tool coordinate system is adjusted. Relative to the flange coordinate system Adjust the attitude parameters;

[0100] Due to the robot's working posture The fitted coordinate system is measured when the robot is in its working pose. With robot tool coordinate system Overlap; based on positional deviation Robot tool coordinate system Origin relative to flange coordinate system Origin position offset Make adjustments Based on attitude deviation Robot tool coordinate system Relative flange coordinate system posture Make adjustments .

[0101] Adjust the position offset parameters and attitude parameters (tool pose data) Update to the robot controller.

[0102] S11. After adjusting the robot's tool coordinate system, run the automatic program to adjust the robot tool end effector to the working pose P1 again. Repeat steps S5-S10 to iteratively converge the robot's tool coordinate system based on the robot's working pose error until the robot's working pose meets the usage requirements.

[0103] Example 3

[0104] This embodiment provides a further detailed description of Embodiment 2.

[0105] S1. Return all robot joints to their zero positions, attach the target ball to the robot's end effector, and rotate the robot's first and second joint axes at fixed equal angles. For each fixed angle rotation, the laser tracker collects the position coordinates of the target ball at the robot's end effector, and fits the circle and its center around the first joint axis. and the first normal axis perpendicular to the circular plane Fit the circle and center of rotation about the second joint axis. and the second normal axis perpendicular to the circular plane .

[0106] Construct the normal vector of the circle of rotation about the first joint axis and the second joint axis. , , ,like If the included angle is within the range of 90°±0.03°, then stop the above operation procedure. If the included angles are not within the range of 90°±0.03°, repeat the operation process of step S1.

[0107] S2. Based on the normal axis of the fitted circle of rotation about the first joint axis The center of the circle rotating about the second joint axis Construct a circle through the center And with the straight line Vertical second plane Along the normal vector The direction is based on the length of the link of the robot's first joint axis. For plane Translate to construct the first plane Based on the first plane With a straight line Intersection constructs intersection point At this point This is the actual center point of the rotation of the robot's first joint axis.

[0108] S3. with , The two normal vectors represent the Z-axis and Y-axis of the coordinate system, and the actual center point of rotation about the robot's first joint axis. Establish a coordinate system using the right-hand rule with the origin as the coordinate origin. At this time, the coordinate system is based on the laser tracker. With robot base coordinate system Precise overlap;

[0109] S4. Switch the robot to its working pose P1; record the robot teach pendant's pose data in the base coordinate system. In a laser tracking measurement system, theoretical position data based on P1 pose... For coordinate system Perform translation based on theoretical pose data from pose P1. A rotation operation is performed on the coordinate system {B}, and the resulting coordinate system after translation and rotation is defined as follows: ;

[0110] S5. In the robot control system, switch to the tool coordinate system {T} to which the current tool of the machining robot belongs, and use the automatic program to control the robot end effector to move to the working pose P1; the robot revolves around the tool coordinate system using the TCP point of the current tool. axis, shaft and The robot undergoes constant-angle attitude transformations along the axis. The laser tracker acquires the spatial coordinates of the target ball at each robot's position within the tool coordinate system. axis, shaft and The space sphere and its center are obtained by measuring all spatial points by axis rotation and fitting the data. ,

[0111] The equations for the space sphere are as follows:

[0112] The equations are transformed as follows:

[0113] make

[0114] The above equation can be written in matrix form as follows:

[0115] The matrix is ​​transformed as follows:

[0116] Solving the equation above, we obtain A, B, C, and D. Substituting these values ​​into the equation... The coordinates of the sphere's center can then be obtained. And the radius R of the sphere.

[0117] And fit the surrounding A circle in rotation and its plane:

[0118] The spatial plane fitting equation can be expressed as:

[0119] The equation can be expressed in matrix form as follows:

[0120] After matrix transformation, the following equation can be obtained:

[0121] Solving for coefficients This yields the equation of the spatial plane. Combining this equation with the equation of the sphere obtained in the previous step, the coordinates of the center of the spatial circle can be determined. and radius r.

[0122] Build around The normal vector of the rotating circle and its plane , , Find the angle between any two normal vectors. If any of the included angles is within the range of 90°±0.03°, then stop the above operation process. If none of the three included angles are within the range of 90°±0.03°, then repeat the operation process of step S5.

[0123] S6. The robot returns to its working pose P1, with , , The two normal vectors that are closest to 90° between the three vectors are used as the reference axes, with the center of the fitted sphere as the reference axis. Establish a coordinate system with the origin using the right-hand rule. At this point, the coordinate system is based on laser tracking. With robot tool coordinate system Precise overlap.

[0124] S7. Coordinate system in laser tracking measurement system With coordinate system Homogeneous matrix relationship between The coordinate system can be calculated. With coordinate system The pose relationship between them is the actual working pose of the robot measured by the laser tracker;

[0125] S8. A coordinate system can be obtained in a laser tracking measurement system. With coordinate system Homogeneous matrix relations ,based on The positional deviation between the robot's actual working pose and its theoretical working pose can be calculated. With attitude deviation ;

[0126]

[0127] In the formula, for The origin is Location, for and Posture relationship.

[0128] Solving by rotating around a fixed coordinate axis Attitude angle, as shown in the following formula:

[0129]

[0130] Therefore, the solution is obtained. The expressions for each attitude angle are:

[0131] When ∆B≠90°,

[0132] When ∆B = 90°,

[0133] When ∆B = -90°,

[0134] Among them, based on homogeneous matrix relations The coordinate system obtained by the solution The origin of the coordinate system Location This refers to the positional deviation between the robot's actual working position and its theoretical working position. Based on homogeneous matrix relations The coordinate system obtained by the solution Relative to coordinate system posture relationship This refers to the attitude deviation between the robot's actual working position and its theoretical working position. ;

[0135] S9. Position deviation based on actual working pose and theoretical working pose With attitude deviation The robot's working position error and working posture error are judged. If the position deviation is... With attitude deviation If all requirements are met, calibration and measurement are complete. If there is a positional deviation... Or attitude deviation If the requirements are not met, the robot's working position or posture will be corrected and compensated.

[0136] S10. Due to the robot's working pose The fitted coordinate system is measured when the robot is in its working pose. With robot tool coordinate system Overlap; based on positional deviation Robot tool coordinate system Origin relative to flange coordinate system Origin position offset Make adjustments Based on attitude deviation Robot tool coordinate system Relative flange coordinate system posture Make adjustments Adjust the tool pose data Import into the robot controller;

[0137] S11. After adjusting the robot's tool coordinate system, run the automatic program to adjust the robot tool end effector to the working pose P1 again, and repeat steps S5-S10 to iteratively converge the robot's tool coordinate system based on the robot's working pose error until the robot's working pose meets the usage requirements.

[0138] In summary, by measuring and fitting the spatial circles and normal vector axes of each joint of the rotating robot, a laser tracker measurement coordinate system is established based on the normal vector axes. The coordinate system is precisely aligned with the robot's base coordinate system, and a corresponding theoretical working pose coordinate system is established in the laser tracking measurement system based on the robot's theoretical working pose data. The robot automatically positions itself to its theoretical working pose, and the laser tracker measures the coordinate system. Accurate measurements and fitting are used to obtain the robot's actual working pose. In a laser tracking measurement system, with both the theoretical and actual working poses of the robot, the deviation between them can be determined. Based on this deviation, the pose offset of the robot's tool coordinate system relative to the flange coordinate system is corrected. After correcting the tool coordinate system, the robot is automatically positioned back to its working pose, and the measurement is repeated. Based on the above measurement and correction process, an optimal tool parameter is matched to the robot, and the error between the robot's theoretical and actual working poses converges.

[0139] Example 4

[0140] A computer-readable storage medium storing a computer program that, when executed by a processor, implements the robot work pose error calibration and convergence method as described above.

[0141] Without loss of generality, computer-readable media can include computer storage media and communication media. Computer storage media includes volatile and non-volatile, removable and non-removable media implemented using any method or technology for storing information such as computer-readable instruction data structures, program modules, or other data. Computer storage media includes RAM, ROM, EPROM, EEPROM, flash memory or other solid-state storage technologies, CD-ROM, DVD or other optical storage, magnetic tape cassettes, magnetic tape, disk storage, or other magnetic storage devices. Of course, those skilled in the art will recognize that computer storage media are not limited to the above-mentioned types. The aforementioned system memories and mass storage devices can be collectively referred to as memory.

[0142] A computer program product includes a computer program / instructions that, when executed by a processor, implement the robot work pose error calibration and convergence method as described above.

[0143] Computer program products include computer programs or instruction sets used to perform specific tasks or achieve specific functions. These programs or instructions are designed to be executed by a processor to implement a series of predefined steps or operations. The program product may be stored in various forms of computer storage media, such as memory, hard disks, solid-state drives, optical discs, or other forms of digital storage devices. It may exist in the form of compiled binary code or in the form of scripts or bytecode that can be executed by an interpreter. Through carefully designed algorithms and logical instructions, the program product enables the processor to process data in a specific order and manner, performing various functions such as data analysis, user interaction, and device control.

[0144] In the description of this specification, the references to terms such as "one embodiment / mode," "some embodiments / modes," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment / mode or example is included in at least one embodiment / mode or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment / mode or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments / modes or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments / modes or examples described in this specification, as well as the features of different embodiments / modes or examples.

[0145] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0146] Those skilled in the art should understand that the above embodiments are merely for illustrating the present invention and are not intended to limit the scope of the invention. Those skilled in the art can make other changes or modifications based on the above invention, and these changes or modifications still fall within the scope of the present invention.

Claims

1. A method for calibrating and converging robot working pose error, characterized in that, include: Establish the robot's base coordinate system Coincident measurement coordinate systems ; Acquire the robot's theoretical working pose data in the base coordinate system, and then, based on the theoretical working pose data, in the measurement coordinate system... Establish a theoretical working pose coordinate system ; Control the robot to move to the theoretical working pose, measure the actual working pose of the robot's end effector, and establish the actual working pose coordinate system. ; Based on the measurement coordinate system The theoretical working pose coordinate system is calculated. With the actual working pose coordinate system Positional deviation between them; Based on the pose deviation, the robot's tool coordinate system parameters are corrected and converged until the pose deviation meets the preset requirements.

2. The robot working pose error calibration and convergence method according to claim 1, characterized in that, Establish a measurement coordinate system The steps include: The robot's first joint axis is controlled to rotate, and the spatial position points of the robot's end effector at multiple rotation angles are collected using external measuring equipment. A first spatial circle and a first normal axis perpendicular to the plane of the first spatial circle are then fitted using the spatial position points. The robot's second joint axis is rotated, and the external measuring device is used to collect the spatial position points of the robot's end at multiple rotation angles. The second spatial circle and the second normal axis perpendicular to the plane of the second spatial circle are fitted by the spatial position points. If the angle between the first normal vector axis and the second normal vector axis is within a preset range, then a measurement coordinate system is established based on the first normal vector axis and the second normal vector axis. Otherwise, refit the first normal vector axis and the second normal vector axis.

3. The robot working pose error calibration and convergence method according to claim 2, characterized in that, The measurement coordinate system The specific structure includes: The direction of the first normal vector axis is defined as the measurement coordinate system. The Z-axis direction; The direction of the second normal vector axis is defined as the measurement coordinate system. The Y-axis direction; Based on the center of the second spatial circle, construct a second plane that passes through the center of the second spatial circle and is perpendicular to the first normal vector axis; Along the direction of the first normal vector axis, the second plane is translated according to the link length of the robot's first joint axis to obtain the translated first plane; The intersection of the first plane and the first normal vector axis is defined as the measurement coordinate system. The origin; According to the right-hand rule, the measurement coordinate system is determined by the Y-axis and Z-axis directions. The X-axis direction.

4. The robot working pose error calibration and convergence method according to claim 2, characterized in that, Establish the actual working pose coordinate system The steps include: Control the robot in its tool coordinate system Below, taking the current TCP point as the center, and circling the tool coordinate system respectively. axis, shaft and The axis performs attitude transformation; During the attitude transformation process, multiple spatial coordinate points of the target ball installed at the robot's end effector are collected using external measuring equipment; Based on all the collected spatial coordinate points, a spatial sphere and its center are obtained through fitting. and based on the surrounding axis, shaft and The spatial coordinates collected by the axis during attitude transformation are used to fit three rotation planes and their corresponding normal vectors. Determine whether, among the three normal vectors, there exists any two normal vectors whose angle is within a preset perpendicularity range. If it exists, then the center of the sphere is used. Using the origin as the reference point and selecting the two normal vectors whose included angle is closest to 90° as the reference axes, the actual working pose coordinate system is established according to the right-hand rule. ; If not, repeat the above steps until the verticality range requirement is met.

5. The robot working pose error calibration and convergence method according to claim 4, characterized in that, The preset range is 90°±0.03°; the preset verticality range is 90°±0.03°.

6. The robot working pose error calibration and convergence method according to claim 1, characterized in that, The steps for calculating the pose deviation include: In the measurement coordinate system The actual working pose coordinate system is then determined. The pose relationship is used as the actual working pose of the robot. ; Obtain the theoretical working pose coordinate system With the actual working pose coordinate system Homogeneous matrix relationship between ; The position and attitude deviations between the robot's actual working pose and its theoretical working pose are calculated.

7. The robot working pose error calibration and convergence method according to claim 1, characterized in that, Also includes: Determine whether both the positional deviation and the attitude deviation in the pose deviation meet the preset usage requirements; If the positional or orientation deviations do not meet the usage requirements, then adjust the robot's tool coordinate system. The parameters are corrected and compensated, and the process is iteratively converged until the pose deviation meets the preset usage requirements. If the positional deviation or attitude deviation both meet the usage requirements, the calibration is complete.

8. The robot working pose error calibration and convergence method according to claim 7, characterized in that, The steps for correction and compensation include: Based on the positional deviation, the robot's tool coordinate system Relative to flange coordinate system Adjust the position offset parameters; Based on the aforementioned attitude deviation, the robot's tool coordinate system Relative to the flange coordinate system Adjust the attitude parameters; Update the adjusted position offset parameters and attitude parameters to the robot controller.

9. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the robot working posture error calibration and convergence method as described in any one of claims 1-8.

10. A computer program product comprising a computer program / instructions, characterized in that, When the computer program / instruction is executed by the processor, it implements the robot work pose error calibration and convergence method as described in any one of claims 1-8.

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