A robot-related coordinate system calibration method and related product

Abstract

The present application relates to the field of robots, and in particular to a robot-related coordinate system calibration method and related products, comprising: controlling the rotation of the first joint axis of the robot to obtain a first trajectory point set; controlling the rotation of the second joint axis of the robot to obtain a second trajectory point set; calibrating the robot base coordinate system based on the first trajectory point set and the second trajectory point set; and calibrating the robot tool coordinate system based on the calibrated robot base coordinate system and in combination with robot pose data. The present application simplifies the data collection process, reduces the amount of data required, improves the overall efficiency of calibration, and uses the robot joint axis to construct the base coordinate system, ensuring high precision and high reliability of the calibration results. After completing the calibration of the base coordinate system, the tool coordinate system is directly calibrated by solving, improving the calibration efficiency.

Description

Technical Field

[0001] This invention relates to the field of robotics, including serial industrial robots, parallel robots, and hybrid robots. Specifically, it relates to a method for calibrating robot-related coordinate systems and related products, particularly to the calibration of robot base coordinate systems and tool coordinate systems. Background Technology

[0002] Robots are essential production equipment in industrial manufacturing sectors such as aviation, aerospace, defense, and automotive. In intelligent manufacturing units or production lines, due to the integration of a large number of complex robot systems, multi-robot collaborative work scenarios are very common. In such scenarios, robots need to exchange a large amount of pose data in real time. Therefore, the calibration of the robot's base coordinate system, and the calibration of the spatial pose relationships between the base coordinate systems of multiple robot systems, are not only key factors in ensuring the accuracy of multi-robot collaborative manufacturing, but also an indispensable part of the debugging process of intelligent manufacturing production lines.

[0003] In the manufacturing processes of large and complex contour products, such as machining, grinding, and welding, the robot's working path and trajectory are generated through offline simulation software combined with the machining process. The points and trajectory paths in the offline program are all referenced to the base coordinate system fixed to the robot's base. Therefore, the calibration accuracy of the robot's base coordinate system and the tool coordinate system is crucial for the robot to function correctly with the offline program. Similarly, in the field of robot pose accuracy measurement, whether the robot tool's center point can be accurately calibrated to the target sphere's center, and whether the laser tracker's measurement coordinate system can accurately coincide with the robot's base coordinate system, significantly impacts the measurement results of the robot's spatial pose and trajectory accuracy. Differences in the calibration accuracy of these two systems can cause deviations of several times or even tens of times in the final measurement results. In conclusion, the calibration accuracy of the robot's base coordinate system is of paramount importance for both the integrated application and accuracy measurement of robots.

[0004] Traditional methods for calibrating a robot's base coordinate system typically involve defining several spatial points within the robot's motion space, calibrating the robot's tool center point to the target sphere's center, controlling the robot to move to each spatial point, and then using a laser tracker to collect the spatial coordinates of the target sphere at the robot's end effector. Based on the robot's theoretical spatial point coordinates and the laser tracker's measured coordinates, the robot's base coordinate system and the laser tracking measurement coordinate system are then optimally fitted and calibrated. This method requires the participation of all robot joints and is susceptible to a series of error factors, including absolute positioning errors (geometric errors), non-geometric errors, and tool calibration errors, resulting in low calibration accuracy and failing to meet the requirements of high-precision robot applications and measurement fields. Against this backdrop, this paper proposes a new method for calibrating a robot's related coordinate system and related products, achieving high-precision and high-efficiency calibration. Summary of the Invention

[0005] The technical problem to be solved by this invention is how to simplify the calibration process, improve calibration efficiency, and at the same time ensure high accuracy of calibration results. The purpose is to provide a calibration method and related products for robot-related coordinate systems, which achieves high-precision calibration and high-efficiency calibration.

[0006] This invention is achieved through the following technical solution:

[0007] A method for calibrating a robot's relevant coordinate system, comprising:

[0008] The robot's first joint axis is controlled to rotate, and multiple spatial position points of the robot's end target point during the rotation process are collected using external measuring equipment to obtain a first trajectory point set;

[0009] The second joint axis of the robot is controlled to rotate, and the external measuring device is used to collect multiple spatial position points of the robot's end target point during the rotation process to obtain a second trajectory point set;

[0010] Based on the first and second trajectory point sets, the robot's base coordinate system is calibrated;

[0011] Based on the calibrated robot base coordinate system and combined with the robot pose data, the robot tool coordinate system is calibrated.

[0012] Optionally, the steps for calibrating the robot's base coordinate system include:

[0013] The first trajectory point set is fitted to obtain a first spatial circle and a first normal vector axis perpendicular to the plane of the first spatial circle; the first normal vector axis characterizes the direction of the first joint axis normal vector axis.

[0014] The second trajectory point set is fitted to obtain a second spatial circle and a second normal vector axis perpendicular to the plane of the second spatial circle; the second normal vector axis characterizes the direction of the second joint axis normal vector axis.

[0015] Determine whether the angle between the first normal vector axis and the second normal vector axis is within a preset range;

[0016] If so, then establish a measurement coordinate system based on the first normal vector axis and the second normal vector axis. Otherwise, re-collect the first and second trajectory point sets;

[0017] Wherein, the measurement coordinate system With robot base coordinate system Coincident, completing the alignment of the robot's base coordinate system The calibration.

[0018] Optionally, the measurement coordinate system The steps to establish it include:

[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, the preset range is 90°±0.03°.

[0026] Optionally, the steps for calibrating the robot tool coordinate system include:

[0027] Obtain the pose data of the robot flange end in its calibrated base coordinate system;

[0028] Based on the pose data, a coordinate transformation is performed on the base coordinate system to establish a measurement coordinate system that coincides with the robot flange coordinate system;

[0029] The position coordinates of the robot end target point are determined in the measurement coordinate system, and the position coordinates are determined as the position offset parameter of the tool coordinate system relative to the measurement coordinate system;

[0030] A temporary tool coordinate system is established with the measured target point of the robot end effector as the origin, and the attitude relationship between the measured coordinate system and the temporary tool coordinate system is calculated.

[0031] Based on the position offset parameters and attitude relationship, the tool coordinate system is calibrated.

[0032] Optionally, the methods for solving attitude relationships include:

[0033] Determine the homogeneous transformation matrix from the measurement coordinate system to the temporary tool coordinate system;

[0034] The attitude relationship between the measurement coordinate system and the temporary tool coordinate system is obtained by inverse calculation of the homogeneous transformation matrix.

[0035] Optionally, the step of obtaining the pose data includes: returning all joints of the robot to the zero position; and recording the pose data displayed on the robot teach pendant at the zero position.

[0036] Optionally, when collecting spatial location points, the robot's first joint axis and second joint axis are both rotated at preset fixed angle intervals;

[0037] The external measuring equipment is a three-dimensional measuring device such as a laser tracker.

[0038] A computer-readable storage medium storing a computer program that, when executed by a processor, implements a method for calibrating a robot-related coordinate system as described above.

[0039] A computer program product includes a computer program / instructions that, when executed by a processor, implement a calibration method for a robot-related coordinate system as described above.

[0040] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0041] This invention independently controls the rotation of the robot's first and second joint axes, collects the motion trajectory of the end-effector target point using external measuring equipment, fits the axial directions of the first and second joint axes, constructs an auxiliary plane using the normal axes of the two joints, and accurately calibrates the origin of the robot's base coordinate system based on the translation operation of the robot's DH link parameters. Then, by constraining the orthogonality between the fitted normal axes of the first and second joint axes under appropriate conditions, the high-precision calibration of the base coordinate system is finally completed. Finally, based on the calibrated high-precision base coordinate system, the tool coordinate system is calculated by combining the robot's own pose data, thus completing the calibration of the tool coordinate system.

[0042] This invention requires only a minimal number of joints to participate in the movement in order to calibrate the robot's base coordinate system and tool coordinate system, which can minimize the calibration error of the base coordinate system caused by the robot's geometric and non-geometric errors. It greatly simplifies the data acquisition process and reduces the amount of data to be processed. Therefore, this method can significantly improve the calibration accuracy and calibration efficiency of the robot. Attached Figure Description

[0043] 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.

[0044] Figure 1 This is a flowchart illustrating a method for calibrating a robot-related coordinate system according to the present invention.

[0045] Figure 2 This is a schematic diagram of the fitted space circle corresponding to the first joint axis and the second joint axis according to the present invention.

[0046] Figure 3 This is a schematic diagram of points, lines, surfaces, and coordinate systems constructed according to the present invention.

[0047] Figure 4 This is a schematic diagram of the distribution of the calibrated coordinate system according to the present invention. Detailed Implementation

[0048] 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.

[0049] It should also be noted that, for ease of description, only the parts relevant to the present invention are shown in the accompanying drawings.

[0050] 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 , 2 The present invention will be described in detail below with reference to embodiments 3 and 4.

[0051] To facilitate understanding, the correspondence between some general technical terms and specific devices or concepts commonly used in this field is clarified:

[0052] The robot base coordinate system is a global reference coordinate system that describes the robot's position. It is typically fixed to the robot's base and serves as the starting reference for all robot movements. Unless otherwise specified, the position data of all target points stored in the robot controller are defined relative to this coordinate system.

[0053] The tool coordinate system is a coordinate system fixed on the robot's end effector (such as a welding torch or gripper). The origin of this coordinate system is usually located at a critical operating point of the tool, such as the tip of the welding torch or the center of the gripper.

[0054] The flange coordinate system is a standard coordinate system on the output flange of the robot's last joint (usually the sixth joint).

[0055] External measuring devices are instruments that measure three-dimensional spatial coordinates independently of the robot system, such as laser trackers; they measure the three-dimensional coordinates of a target in space in real time by emitting a laser and tracking the target (a target ball).

[0056] An end-effector target point refers to a specific physical point installed or fixed at the end of a robot for tracking and measurement by external measuring equipment. Its spatial position is used to represent the actual pose of the robot's end-effector. Examples include a target ball and an optical reflective device with a spherical shape.

[0057] Trajectory point set: refers to a set of three-dimensional coordinate points obtained by continuous or discrete sampling of the end target point by external measuring equipment during the joint movement of a robot.

[0058] Spatial circle: refers to the optimally fitted three-dimensional spatial circle obtained by processing the set of trajectory points collected when a robot rotates a single joint through mathematical fitting algorithms (such as the least squares method).

[0059] Normal vector axis: refers to a straight line perpendicular to the plane containing the spatial circle. Since the spatial circle is generated by the rotation of a single joint of the robot, the direction of this normal vector axis represents the actual rotation axis direction of the corresponding robot joint.

[0060] Homogeneous transformation matrix: A mathematical tool in linear algebra used to describe rigid body transformations in three-dimensional space. A 4x4 homogeneous transformation matrix can simultaneously represent the rotation and translation relationship of one coordinate system relative to another, and is widely used in robotics and computer graphics.

[0061] Pose: A general term for position and orientation. It describes the state of an object in three-dimensional space and has six degrees of freedom (three translational components X, Y, Z and three rotational components A, B, C).

[0062] Example 1

[0063] like Figure 1 As shown, this embodiment provides a general framework method for robot coordinate system calibration. The first step is the calibration of the base coordinate system, followed by the calibration of the tool coordinate system. Specific steps include:

[0064] The robot's first joint axis is controlled to rotate, and multiple spatial position points of the robot's end target point during the rotation process are collected using external measuring equipment to obtain the first trajectory point set.

[0065] The robot is made to rotate only around the vertical axis of its base (i.e., the first joint axis). While rotating, an external measuring device (laser tracker) continuously captures and records the three-dimensional spatial coordinates of the target point (target ball) installed at the end of the robot. The recorded coordinate points together constitute the "first trajectory point set".

[0066] The second joint axis of the robot is controlled to rotate, and multiple spatial position points of the robot's end target point during the rotation process are collected using the external measuring device to obtain the second trajectory point set.

[0067] The robot rotates only around the pitch axis of its upper arm (i.e., the second joint axis). While rotating, an external measuring device (laser tracker) continuously captures and records the three-dimensional spatial coordinates of the target point (target ball) installed at the end of the robot. The recorded coordinate points together constitute the "second trajectory point set".

[0068] Based on the first and second trajectory point sets, the robot's base coordinate system is calibrated.

[0069] By mathematically fitting the first trajectory point set, the axial direction of the first joint axis is determined; similarly, by fitting the second trajectory point set, the axial direction of the second joint axis is determined. Through these two spatial axes, and combined with the robot's own mechanical structure parameters, the origin and direction of the coordinate axis of the robot base can be solved, thus completing the calibration of the base coordinate system.

[0070] Based on the calibrated robot base coordinate system and combined with the robot pose data, the robot tool coordinate system is calibrated.

[0071] The robot's perceived pose data is read from the robot controller, and the actual pose in the robot's flange coordinate system is reproduced using an external measuring device. Then, the position of the end-effector target point is measured again in the flange coordinate system, allowing the calculation of the transformation relationship between the tool coordinate system and the flange coordinate system, thus completing the tool coordinate system calibration.

[0072] Example 2

[0073] This embodiment details the specific steps for calibrating the robot's base coordinate system in Embodiment 1, including:

[0074] The first trajectory point set is fitted to obtain a first spatial circle and a first normal vector axis perpendicular to the plane of the first spatial circle; the first normal vector axis characterizes the direction of the first joint axis normal vector axis.

[0075] 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.

[0076] The second trajectory point set is fitted to obtain a second spatial circle and a second normal vector axis perpendicular to the plane of the second spatial circle; the second normal vector axis characterizes the direction of the second joint axis normal vector axis.

[0077] When collecting spatial location points, the robot's first and second joint axes rotate at preset fixed angle intervals; the external measuring device is a laser tracker.

[0078] 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 .

[0079] Determine whether the angle between the first normal vector axis and the second normal vector axis is within a preset range;

[0080] If so, then establish a measurement coordinate system based on the first normal vector axis and the second normal vector axis. Otherwise, re-collect the first and second trajectory point sets;

[0081] Wherein, the measurement coordinate system With robot base coordinate system Coincident, completing the alignment of the robot's base coordinate system The calibration.

[0082] Based on the first normal vector axis normal vector Second normal axis normal vector 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 data collection process.

[0083] The measurement coordinate system is further provided below. The steps to establish it include:

[0084] Based on the center of the second spatial circle, a second plane is constructed that passes through the center of the second spatial circle and is perpendicular to the first normal vector axis; the second plane is translated along the direction of the first normal vector axis 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 determined as the measurement coordinate system. The origin.

[0085] 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.

[0086] 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.

[0087] The direction of the second normal vector axis is defined 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;

[0088] The preset range is 90°±0.03°.

[0089] Example 3

[0090] This embodiment provides specific steps for calibrating the coordinate system of a robot tool, including:

[0091] The robot's pose data in its calibrated base coordinate system is obtained. The operator needs to read and record the pose data of the robot's current end flange relative to this base coordinate system from the robot controller (i.e., the teach pendant). It usually consists of six values ​​(X, Y, Z, A, B, C), which are theoretical values ​​calculated by the robot's internal encoder based on its own kinematic model.

[0092] To improve the accuracy, stability, and repeatability of the pose data, all joints of the robot are moved to their mechanical zero-point positions before data is read. The zero-point position is a reference state that is precisely calibrated for each robot at the factory. At the zero-point position, the pose data displayed on the robot's teach pendant is recorded.

[0093] Based on the pose data, a coordinate transformation is performed on the base coordinate system to establish a measurement coordinate system that coincides with the robot flange coordinate system. Using the six pose data points (X, Y, Z, A, B, C) read from the robot teach pendant in the previous step as transformation parameters, a rigid body transformation (i.e., translation and rotation) is performed on the already calibrated base coordinate system that exists in the measurement system. After this transformation, a new measurement coordinate system is generated in the measurement system. Since the transformation parameters are derived entirely from the robot's own description of its flange pose, the measurement coordinate system... The robot's position and orientation in space are theoretically completely aligned with the robot's actual flange coordinate system at the current moment.

[0094] In the measurement coordinate system The position coordinates of the target point at the robot's end effector are determined, and these position coordinates are defined as the tool coordinate system relative to the measurement coordinate system. Position offset parameters; the operator directly measures the spatial position of the robot's end effector target point (center of the target ball) using external measuring equipment (laser tracker). In the measurement coordinate system... The three-dimensional coordinates of the target point relative to the origin of the flange obtained by the measurement are as follows. This refers to the position offset parameter, which is one of the six parameters of the tool coordinate system (TCP).

[0095] A temporary tool coordinate system is established with the measured target point of the robot end effector as the origin, and the measurement coordinate system is then solved. The attitude relationship with the temporary tool coordinate system; in the software of the external measurement system, the end target point Establish a temporary tool coordinate system with the origin as the coordinate point and based on a preset or custom axis. Using the homogeneous transformation matrix, the three rotation angle parameters (A, B, C) representing the attitude relationship are calculated by performing inverse calculation on the matrix.

[0096] Based on the position offset parameters and attitude relationship, the tool coordinate system is calibrated. The position offset parameters are then... The calculated attitude relationship parameters (A, B, C) are integrated together to form a complete tool coordinate system definition. The six parameters are then input into the robot controller, thus completing the calibration of the tool coordinate system.

[0097] The method for calculating the attitude relationship includes: determining the homogeneous transformation matrix from the measurement coordinate system to the temporary tool coordinate system; and obtaining the attitude relationship between the measurement coordinate system and the temporary tool coordinate system by inverse calculation using the homogeneous transformation matrix.

[0098] Example 4

[0099] This embodiment provides a specific example.

[0100] 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 current 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 normal vector axis perpendicular to the circular plane Fit the circle and center of rotation about the second joint axis. and the normal vector axis perpendicular to the circular plane Construct the normal vectors of the circle and its plane that rotate around the normal vector axes of the first and second joint axes. , , ,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.

[0101] S2. Based on the normal axis of the fitted circle of rotation about the first joint axis Center of the circle of rotation 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.

[0102] 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 alignment; at this point, the calibration of the robot's base coordinate system is complete.

[0103] S4. Switch the robot tool coordinate system to the robot's default flange tool coordinate system. Return all robot joints to their zero positions and record the pose (X, Y, Z, A, B, C) displayed on the robot teach pendant. In the laser tracker measurement system, translate and rotate the coordinate system {B}, which coincides with the robot's base coordinate system, based on (X, Y, Z, A, B, C). Construct a new flange coordinate system from the translated and rotated coordinate system. coordinate system It precisely coincides with the flange coordinate system of the current robot;

[0104] S5. In the coordinate system of the laser tracker Below, measure the coordinates of the center of the target ball at the robot's end effector. At this moment, the coordinates of the target ball's center are... This refers to the offset of the target ball's center relative to the origin of the flange coordinate system, with the target ball's center as the reference point. Establish a robot tool coordinate system with user-defined coordinate axis directions at the origin. Define coordinate system X T Y T Z T The three unit vectors of the axes are projected onto the coordinate system. In this way, the coordinate system is obtained. With coordinate system Homogeneous matrix relations ,based on Reverse solveable coordinate system With coordinate system The attitude relationship, the target coordinate values The calculated posture relationship is then imported into the robot controller, thus completing the calibration of the robot's tool coordinate system.

[0105] In summary, by rotating the robot's first and second joint axes, fitting the spatial circles of rotation of the two joint axes using a laser tracker, and constructing the center and normal axis of the spatial circles around the first and second joint axes, a corresponding plane is constructed based on the normal axis and the center. By translating the plane based on the link length of the robot's A1 axis, the actual rotation center position of the robot's A1 axis can be quickly and accurately found. Based on this center position and the normal axis of the spatial circles around the first and second joint axes, the base coordinate system of the robot's base can be quickly established. Based on the pose data displayed by the robot's teach pendant, the base coordinate system can be rotated and offset to quickly obtain the robot's flange coordinate system or tool coordinate system.

[0106] Example 5

[0107] A computer-readable storage medium storing a computer program that, when executed by a processor, implements a method for calibrating a robot-related coordinate system as described above.

[0108] 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.

[0109] A computer program product includes a computer program / instructions that, when executed by a processor, implement a calibration method for a robot-related coordinate system as described above.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] 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 a robot's relevant coordinate system, characterized in that, include: The robot's first joint axis is controlled to rotate, and multiple spatial position points of the robot's end target point during the rotation process are collected using external measuring equipment to obtain a first trajectory point set; The second joint axis of the robot is controlled to rotate, and the external measuring device is used to collect multiple spatial position points of the robot's end target point during the rotation process to obtain a second trajectory point set; Based on the first and second trajectory point sets, the robot's base coordinate system is calibrated; Based on the calibrated robot base coordinate system and combined with the robot pose data, the robot tool coordinate system is calibrated.

2. The method for calibrating a robot-related coordinate system according to claim 1, characterized in that, The steps for calibrating the robot's base coordinate system include: The first trajectory point set is fitted to obtain a first spatial circle and a first normal vector axis perpendicular to the plane of the first spatial circle; the first normal vector axis characterizes the direction of the first joint axis normal vector axis. The second trajectory point set is fitted to obtain a second spatial circle and a second normal vector axis perpendicular to the plane of the second spatial circle; the second normal vector axis characterizes the direction of the second joint axis normal vector axis. Determine whether the angle between the first normal vector axis and the second normal vector axis is within a preset range; If so, then establish a measurement coordinate system based on the first normal vector axis and the second normal vector axis. Otherwise, re-collect the first and second trajectory point sets; Wherein, the measurement coordinate system With robot base coordinate system Coincident, completing the alignment of the robot's base coordinate system The calibration.

3. The method for calibrating a robot-related coordinate system according to claim 2, characterized in that, Measurement coordinate system The steps to establish it include: 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 method for calibrating a robot-related coordinate system according to claim 2, characterized in that, The preset range is 90°±0.03°.

5. The method for calibrating a robot-related coordinate system according to claim 1, characterized in that, The steps for calibrating the robot tool coordinate system include: Obtain the pose data of the robot flange end in its calibrated base coordinate system; Based on the pose data, a coordinate transformation is performed on the base coordinate system to establish a measurement coordinate system that coincides with the robot flange coordinate system; The position coordinates of the robot end target point are determined in the measurement coordinate system, and the position coordinates are determined as the position offset parameter of the tool coordinate system relative to the measurement coordinate system; A temporary tool coordinate system is established with the measured target point of the robot end effector as the origin, and the attitude relationship between the measured coordinate system and the temporary tool coordinate system is calculated. Based on the position offset parameters and attitude relationship, the tool coordinate system is calibrated.

6. The method for calibrating a robot-related coordinate system according to claim 5, characterized in that, Methods for solving attitude relationships include: Determine the homogeneous transformation matrix from the measurement coordinate system to the temporary tool coordinate system; The attitude relationship between the measurement coordinate system and the temporary tool coordinate system is obtained by inverse calculation of the homogeneous transformation matrix.

7. The method for calibrating a robot-related coordinate system according to claim 5, characterized in that, The steps for obtaining the pose data include: returning all joints of the robot to the zero position; and recording the pose data displayed on the robot teach pendant at the zero position.

8. The method for calibrating a robot-related coordinate system according to claim 1, characterized in that, When collecting spatial location points, the robot's first and second joint axes rotate at preset fixed angle intervals. The external measuring device is a three-dimensional measuring device.

9. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements a method for calibrating a robot-related coordinate system 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 a calibration method for a robot-related coordinate system as described in any one of claims 1-8.

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