A method, device, equipment and medium for evaluating rotation accuracy of a robot around a point

Abstract

The application belongs to the technical field of robots, and discloses a robot point rotation precision evaluation method, device, equipment and medium. The method obtains a plurality of real-time position data of a robot end effector, the real-time position data being position data of a robot joint arm rotating to a plurality of collection positions along a single coordinate axis of a preset tool coordinate system; center position data of robot joint arm rotation is calculated based on all real-time position data; based on the real-time position data and the center position data, the position change amount between the real-time position data and the center position data of each collection position is calculated; and the point rotation precision of the robot is evaluated based on the position change amount of each collection position. The point precision of the robot system is accurately evaluated.

Description

Technical Field

[0001] This application relates to the field of robotics technology, and in particular to a method, apparatus, equipment and medium for evaluating the accuracy of a robot's rotation around a point. Background Technology

[0002] In automated manufacturing, multi-axis robots are increasingly widely used, and their positioning accuracy and repeatability during machining are crucial to machining quality. Especially in the manufacturing of parts with complex shapes, robots not only need to perform precise linear movement, but also need to be able to perform precise rotation around a point to adapt to complex machining tasks.

[0003] However, current measurements of the positioning accuracy of robot end effectors mainly focus on the linear movement accuracy of the robot, while relatively little attention is paid to the evaluation methods of rotational accuracy around a point. This situation leads to unsatisfactory positioning accuracy of robot systems when applied to complex machining tasks, resulting in deviations and low precision. Summary of the Invention

[0004] Therefore, embodiments of this application provide a method, apparatus, device, and medium for evaluating the rotational accuracy of a robot around a point, enabling accurate evaluation of the rotational accuracy of a robot system.

[0005] Firstly, this application provides a method for evaluating the accuracy of a robot's rotation around a point.

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

[0007] A method for evaluating the rotational accuracy of a robot around a point, the method comprising:

[0008] Acquire several real-time position data of the robot end effector, wherein the real-time position data is the position data of the robot articulated arm rotating to several acquisition positions according to a single coordinate axis of a preset tool coordinate system;

[0009] Calculate the center position data of the robot's articulated arm rotation based on all real-time position data;

[0010] Based on real-time location data and central location data, calculate the position change between the real-time location data and the central location data at each collection location;

[0011] The accuracy of the robot's rotation around the point is evaluated based on the position change at each acquisition location.

[0012] In a preferred example of this application, the system may be further configured to acquire several real-time position data points of the robot's end effector, including:

[0013] Acquire the initial position data of the robot end effector when the robot articulated arm is not rotating;

[0014] The robot's articulated arm is controlled to rotate around a single coordinate axis of a preset tool coordinate system by a fixed angle θ each time, until the i-th acquisition position is reached. The position data of the robot's end effector is acquired using a laser tracker until n real-time position data are acquired.

[0015] Where n satisfies 10≤n≤15, and θ satisfies 10°≤θ≤20°.

[0016] In a preferred embodiment of this application, the single coordinate axis of the preset tool coordinate system can be further configured as follows:

[0017] The Z-axis of the preset tool coordinate system;

[0018] Or the Y-axis of the preset tool coordinate system;

[0019] Or the X-axis of a preset tool coordinate system.

[0020] In a preferred example of this application, the calculation of the center position data of the robot articulated arm rotation based on all real-time position data can be further configured to satisfy the following relationship:

[0021]

[0022] Where, x i Let x be the x-axis coordinate of the i-th acquisition position, and y be the y-axis coordinate of the i-th acquisition position. i Let z be the y-coordinate of the i-th acquisition position, z i Let P be the z-axis coordinate of the i-th acquisition position. center The central location data for all real-time location data.

[0023] In a preferred embodiment of this application, the step of calculating the positional change of each acquisition location relative to the center point based on the center position data can be further configured to satisfy the following relationship:

[0024] ΔP=|P i -P center |,

[0025]

[0026] Among them, P i For the location data of the i-th collection location, P center Here, ΔP represents the positional change between the positional data of the i-th acquisition location and the positional data of the center point. This represents the average change across all data collection locations.

[0027] In a preferred example of this application, the robot's rotation accuracy around a point can be further evaluated based on the position change at each acquisition location, including:

[0028] Calculate the standard deviation of the position coordinates of all acquired locations based on the position change:

[0029]

[0030] The accuracy of robot rotation around a point is evaluated based on standard deviation, where σ represents the standard deviation and P... i For the location data of the i-th collection location, P center Let ΔP be the position data of the center point, and let ΔP represent the positional change between the position data of the i-th acquisition location and the position data of the center point.

[0031] In a preferred example of this application, the method may be further configured to acquire several real-time position data points of the robot's end effector, and may also include:

[0032] Acquire several first real-time position data of the first robot end effector and several second real-time position data of the second robot end effector.

[0033] Secondly, this application provides an evaluation device for the rotational accuracy of a robot around a point.

[0034] This application is achieved through the following technical solution:

[0035] An evaluation device for assessing the rotational accuracy of a robot around a point, for performing the method described in the first aspect above, the evaluation device comprising:

[0036] The data acquisition module is used to acquire several real-time position data of the robot end effector. The real-time position data is the position data of the robot articulated arm rotating to several acquisition positions according to a single coordinate axis of a preset tool coordinate system.

[0037] The accuracy assessment module is used to calculate the center position data of the robot's articulated arm rotation based on all real-time position data; calculate the position change between the real-time position data and the center position data at each acquisition position based on the real-time position data and the center position data; and evaluate the robot's rotation accuracy around the point based on the position change at each acquisition position.

[0038] Thirdly, this application achieves its goal through the following technical solutions:

[0039] A computer device includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of any of the above-described methods for evaluating the accuracy of robot rotation around a point.

[0040] Fourthly, this application provides a computer-readable storage medium.

[0041] This application is achieved through the following technical solution:

[0042] A computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of any of the above-described methods for evaluating the accuracy of robot rotation around a point.

[0043] In summary, compared with the prior art, the beneficial effects of the technical solution provided in this application include at least the following:

[0044] This application acquires several real-time position data points of a robot's end effector. These real-time position data are the position data of the robot's articulated arm rotating to several acquisition positions along a single coordinate axis of a preset tool coordinate system. Based on all the real-time position data, the center position data of the robot's articulated arm rotation is calculated. Based on the real-time position data and the center position data, the position change between the real-time position data and the center position data at each acquisition position is calculated. Based on the position change at each acquisition position, the rotational accuracy of the robot around a point is evaluated. By controlling the robot to rotate around one coordinate axis of the tool coordinate system, and measuring and recording the position change of the end effector during rotation, the rotational accuracy of the robot is evaluated based on the position change during rotation. This provides a method for quantitatively evaluating the rotational accuracy of a robot around a point. This allows for adjustments to the robot's control parameters to improve rotational accuracy when the evaluation results show that the robot's rotational accuracy does not meet requirements. Ultimately, this enables the robot system to play a greater role in complex machining tasks. Attached Figure Description

[0045] Figure 1 A flowchart illustrating a method for evaluating the rotational accuracy of a robot around a point, provided in an embodiment of this application;

[0046] Figure 2 A schematic diagram of the structure of a robot rotation accuracy evaluation device provided in an embodiment of this application;

[0047] Explanation of reference numerals in the attached figures:

[0048] Data acquisition module-101, accuracy evaluation module-201. Detailed Implementation

[0049] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

[0050] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0051] Furthermore, the term "and / or" in this application is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this application, unless otherwise specified, generally indicates that the preceding and following related objects have an "or" relationship.

[0052] In this application, the terms "first," "second," etc., are used to distinguish identical or similar items with essentially the same function. It should be understood that there is no logical or temporal dependency between "first," "second," and "nth," nor are there any restrictions on quantity or execution order.

[0053] The embodiments of this application will now be described in further detail with reference to the accompanying drawings.

[0054] like Figure 1 As shown, this application proposes a method for evaluating the rotation accuracy of a robot around a point. This method specifically includes the following steps:

[0055] S10: Acquire several real-time position data of the robot end effector. The real-time position data is the position data of the robot articulated arm rotating to several acquisition positions according to a single coordinate axis of the preset tool coordinate system.

[0056] This application employs a high-precision laser tracker for real-time monitoring of the robot's end effector position. The end effector is either a laser tracker target ball or another tool with accurate coordinate information. Tools with accurate coordinate information include calibration target balls, calibration probes, standard calibration blocks, dedicated calibration tools, or robot calibration rods. The laser tracker target ball or tool is securely mounted on the end-effector of the robot arm to prevent displacement during data acquisition. After mounting, the accurate position and orientation of the target ball or tool are input into the robot controller, and a tool coordinate system (TCP, Tool Center Point) is set. This TCP coordinate system defines the position of the end effector.

[0057] Specifically, firstly, a laser tracker is used to acquire the position data of the robot's end effector at its initial position A1 before rotation around the target point; this initial position A1 is the first acquisition position. Then, the robot control system controls the robot's articulated arm to rotate around one of the coordinate axes of a preset tool coordinate system, rotating to different acquisition positions A2 to A1. n n is a positive integer greater than 2. At each acquisition position, a laser tracker is used to acquire the position data of the robot's end effector at that position. Each position data includes at least the coordinate information (x, y, y) of that acquisition position. i ,y i ,z i ).

[0058] S20: Calculate the center position data of the robot arm's rotation based on all real-time position data. The center position data refers to the position data of the center point of all collected locations.

[0059] Specifically, a center point (or center location point) is obtained by calculating the average of the real-time position data from all collected locations. This center point can be regarded as a fixed point around which the robot's TCP rotates.

[0060] S30: Based on real-time location data and center location data, calculate the position change between the real-time location data and the center location data for each acquisition location.

[0061] Specifically, the position change is the distance difference between the position data of each collected location and the position data of the center location.

[0062] S40: Evaluate the robot's rotation accuracy around the point based on the position change at each acquisition location.

[0063] Specifically, the average change in position data across all acquisition points is calculated based on the position change at each acquisition point. Further, based on the average change, the standard deviation and root mean square error of the position change between the real-time position data at each acquisition point and the center position data are calculated for the robot arm during its rotation around a point. The standard deviation and root mean square error are then used to comprehensively evaluate the robot's rotation accuracy around the point.

[0064] This application provides a method for quantitatively evaluating the rotational accuracy of a robot around a tool coordinate system by controlling the robot to rotate around one axis and measuring and recording the positional changes of the end effector during rotation. The rotational accuracy is then assessed based on these positional changes. This allows for adjustments to the robot's control parameters to improve rotational accuracy when the evaluation results indicate that the robot's rotational accuracy is unsatisfactory. Ultimately, this enables the robot system to play a greater role in complex machining tasks.

[0065] It should be noted that, to ensure the measurement data accurately reflects the robot's performance and improves the accuracy and reliability of the evaluation results, the robot itself must be precisely calibrated before implementing the above evaluation method. This ensures that key parameters such as the zero position of the robot encoder and the reduction ratio of the reducer are set correctly.

[0066] In a preferred embodiment, acquiring several real-time position data of the robot end effector includes: acquiring the initial position data of the robot end effector when the robot joint arm is not rotating;

[0067] The robot's articulated arm is controlled to rotate around a single coordinate axis of a preset tool coordinate system by a fixed angle θ each time, until the i-th acquisition position is reached. The position data of the robot's end effector is acquired using a laser tracker until n real-time position data are acquired. Here, n satisfies 10≤n≤15, and θ satisfies 10°≤θ≤20°. For example, the initial position of the robot's end effector is marked as the first acquisition position A1, and the position data P1 = (x1, y1, z1) is captured using a laser tracker. The robot control system controls the robot's articulated arm to rotate 10° around the Z-axis of the tool coordinate system, marked as the second acquisition position A2, and the position data P1 = (x1, y1, z1) is captured using a laser tracker. The robot control system controls the robot's articulated arm to rotate 20° around the Z-axis of the tool coordinate system, marked as the third acquisition position A3, and the position data P3 = (x3, y3, z3) is captured using a laser tracker. This rotation is repeated until the articulated arm rotates 30° around the Z-axis of the tool coordinate system, marked as the fourth acquisition position, and the position data P4 = (x4, y4, z3) is captured using a laser tracker. 4) Rotate to 40°, mark as the fifth acquisition position, and use a laser tracker to capture position data P5 = (x5, y5, z5); rotate to 50°, mark as the sixth acquisition position, and use a laser tracker to capture position data P6 = (x6, y6, z6); rotate to 60°, mark as the seventh acquisition position, and use a laser tracker to capture position data P7 = (x7, y7, z7); rotate to 70°, mark as the eighth acquisition position, and use a laser tracker to capture position data P8 = (x8, y8, z8); rotate to 80°, mark as the ninth acquisition position, and use a laser tracker to capture position data P9 = (x9, y9, z9); rotate to 90°, mark as the tenth acquisition position, and use a laser tracker to capture position data P... 10 =(x 10 y 10 , z 10 ).

[0068] In some optional implementations, the single coordinate axis of the preset tool coordinate system is: the Z-axis of the preset tool coordinate system; or the Y-axis of the preset tool coordinate system; or the X-axis of the preset tool coordinate system. Specifically, when the robot arm rotates around a point along the Z-axis of the preset tool coordinate system, all acquisition positions are kept within the same XY plane; when the robot arm rotates around a point along the Y-axis of the preset tool coordinate system, all acquisition positions are kept within the same XZ plane; and when the robot arm rotates around a point along the X-axis of the preset tool coordinate system, all acquisition positions are kept within the YZ plane.

[0069] In some preferred embodiments, the center position data of the robot articulated arm rotation is calculated based on real-time position data from all acquisition locations, satisfying the following relationship:

[0070]

[0071] Where, x i Let x be the x-axis coordinate of the i-th acquisition position, and y be the y-axis coordinate of the i-th acquisition position. i Let z be the y-coordinate of the i-th acquisition position. i Let P be the z-axis coordinate of the i-th acquisition position. center This provides the location data of the center point for all collected locations.

[0072] In a preferred embodiment, the position change at each acquisition location is calculated based on the center position coordinates, satisfying the following relationship:

[0073] ΔP=|P i -P center |,

[0074]

[0075] Among them, P i For the location data of the i-th collection location, P center Let ΔP be the position data of the center point, and let ΔP represent the positional change between the position data of the i-th acquisition location and the position data of the center point. This represents the average change across all data collection locations.

[0076] In a preferred embodiment, the robot's rotation accuracy around a point is evaluated based on the position change at each acquisition location, including:

[0077] Calculate the standard deviation of the position coordinates of all acquired locations based on the position change:

[0078]

[0079] The accuracy of robot rotation around a point is evaluated based on standard deviation.

[0080] Root mean square error (RMSE) is used as the overall accuracy metric:

[0081]

[0082] In a preferred embodiment, obtaining several rotational position coordinates of the robot end effector further includes:

[0083] Several first rotational position coordinates of the first robot's end effector and several second rotational position coordinates of the second robot's end effector are acquired. Then, based on the first rotational position coordinates, a first center position data is calculated, and the first position change at each acquisition position is calculated based on the first center position data. Similarly, based on the second rotational position coordinates, a second center position data is calculated, and the second position change at each acquisition position is calculated based on the second center position data. Finally, the first and second position changes are combined to determine the robot's rotational accuracy around a point. In actual implementation, a fixture with two target balls is installed at the robot's end effector, symmetrically distributed. This improves the accuracy of the measurement data and enhances the system's robustness.

[0084] Another embodiment of this application also provides a device for evaluating the accuracy of robot rotation around a point, used to perform the above-described method, such as... Figure 2 As shown, the device includes:

[0085] The data acquisition module 101 is used to acquire several real-time position data of the robot end effector. The real-time position data is the position data of the robot articulated arm rotating to several acquisition positions according to a single coordinate axis of the preset tool coordinate system.

[0086] The accuracy evaluation module 201 is used to calculate the center position data of the robot's articulated arm rotation based on all real-time position data; calculate the position change between the real-time position data and the center position data at each acquisition position based on the real-time position data and the center position data; and evaluate the robot's rotation accuracy around the point based on the position change at each acquisition position.

[0087] The specific limitations of the robot rotation accuracy evaluation device provided in this embodiment can be found in the embodiments of the robot rotation accuracy evaluation method described above, and will not be repeated here. Each module in the above-described robot rotation accuracy evaluation device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device in hardware form, or stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each module.

[0088] This application provides a computer device that may include a processor, memory, network interface, and database connected via a system bus. The processor provides computational and control capabilities. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system, computer programs, and a database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The network interface communicates with external terminals via a network connection. When the computer program is executed by the processor, it causes the processor to perform the steps of the robot rotation accuracy evaluation method as described in any of the above embodiments.

[0089] The working process, working details, and technical effects of the computer equipment provided in this embodiment can be found in the embodiment of the robot rotation accuracy evaluation method described above, and will not be repeated here.

[0090] This application provides a computer-readable storage medium storing a computer program thereon. When executed by a processor, the computer program implements the steps of the robot rotation accuracy evaluation method as described in any of the above embodiments. The computer-readable storage medium refers to a data storage medium, which may include, but is not limited to, floppy disks, optical disks, hard disks, flash memory, USB flash drives, and / or memory sticks. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices.

[0091] The working process, working details, and technical effects of the computer-readable storage medium provided in this embodiment can be found in the embodiment of the robot rotation accuracy evaluation method described above, and will not be repeated here.

[0092] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0093] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0094] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is used as an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the system described in this application can be divided into different functional units or modules to complete all or part of the functions described above.

Claims

1. A method for evaluating the rotational accuracy of a robot around a point, characterized in that, The method includes: Acquire several real-time position data of the robot end effector, wherein the real-time position data is the position data of the robot articulated arm rotating to several acquisition positions according to a single coordinate axis of a preset tool coordinate system; Calculate the center position data of the robot's articulated arm rotation based on all real-time position data; Based on real-time location data and central location data, calculate the position change between the real-time location data and the central location data at each collection location; The robot's rotation accuracy around a point is evaluated based on the position change at each acquisition location, including: Calculate the standard deviation of the position coordinates of all acquired locations based on the position change: ; Evaluate the robot's rotational accuracy around a point based on standard deviation; in, Indicates standard deviation, This represents the real-time location data for the i-th data collection location. For the center location data, This represents the change in position between the real-time position data of the i-th acquisition location and the center position data. This represents the average position change across all data collection locations.

2. The method for evaluating the accuracy of robot rotation around a point according to claim 1, characterized in that, Acquire several real-time position data points from the robot's end effector, including: Acquire the initial position data of the robot end effector when the robot articulated arm is not rotating; Control the robot's articulated arm to rotate at a fixed angle around a single coordinate axis of a preset tool coordinate system for each rotation. Rotate to the i-th acquisition position and use a laser tracker to collect real-time position data of the robot's end effector until n real-time position data are collected. in, satisfy , satisfy .

3. The method for evaluating the accuracy of robot rotation around a point according to claim 2, characterized in that, The single coordinate axis of the preset tool coordinate system is: The Z-axis of the preset tool coordinate system; Or the Y-axis of the preset tool coordinate system; Or the X-axis of a preset tool coordinate system.

4. The method for evaluating the accuracy of robot rotation around a point according to claim 2, characterized in that, The calculation of the center position data of the robot articulated arm rotation based on all real-time position data satisfies the following relationship: ， in, Let x be the x-coordinate of the i-th acquisition position. Let be the y-coordinate of the i-th acquisition position. Let be the z-axis coordinate of the i-th acquisition position. The central location data for all real-time location data.

5. The method for evaluating the accuracy of robot rotation around a point according to claim 4, characterized in that, Based on real-time location data and center location data, the change in position between the real-time location data and the center location data at each collection location is calculated, satisfying the following relationship: ， ； in, This represents the real-time location data for the i-th data collection location. For the center location data, This represents the change in position between the real-time position data at the i-th acquisition location and the center position data. This represents the average position change across all data collection locations.

6. The method for evaluating the accuracy of robot rotation around a point according to any one of claims 1 to 5, characterized in that, Acquiring several real-time position data of the robot's end effector also includes: Acquire several first real-time position data of the first robot end effector and several second real-time position data of the second robot end effector.

7. An evaluation device for the rotational accuracy of a robot around a point, characterized in that, The apparatus for performing the method as described in any one of claims 1 to 6 comprises: The data acquisition module is used to acquire several real-time position data of the robot end effector. The real-time position data is the position data of the robot articulated arm rotating to several acquisition positions according to a single coordinate axis of a preset tool coordinate system. The accuracy assessment module is used to calculate the center position data of the robot's articulated arm rotation based on all real-time position data; calculate the position change between the real-time position data and the center position data at each acquisition position based on the real-time position data and the center position data; and evaluate the robot's rotation accuracy around the point based on the position change at each acquisition position.

8. A computer device, characterized in that, The method includes a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the method according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the method according to any one of claims 1 to 6.

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