Method, device and equipment for evaluating point-around rotation precision of robot and medium

Abstract

The invention belongs to the technical field of robots, and discloses a method, device and equipment for evaluating the point-around rotation precision of a robot and a medium. According to the method, a plurality of pieces of real-time position data of a robot end effector are obtained, wherein the real-time position data are position data of a robot joint arm rotating to a plurality of collection positions according to a single coordinate axis of a preset tool coordinate system; calculating center position data of rotation of the joint arm of the robot based on all the real-time position data; based on the real-time position data and the central position data, calculating the position variation between the real-time position data and the central position data of each acquisition position; and based on the position variable quantity of each collection position, the point-around rotation precision of the robot is evaluated. Accurate evaluation of the winding point precision of the robot system is realized.

Description

Technical Field

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

[0002] In the process of automated manufacturing, the application of multi-axis robots is becoming more and more widespread, and the positioning accuracy and repeatability of robots in the processing process are crucial to the processing quality. Especially in the manufacturing of parts with complex surfaces, 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 processing tasks.

[0003] However, the current measurement of the positioning accuracy of the robot's end-effector tools mainly focuses on the robot's linear movement accuracy, while relatively little attention is paid to the evaluation methods of the accuracy of rotation around a point. This situation results in the robot system's positioning accuracy often being unsatisfactory, prone to deviations, and having low accuracy when the robot system is used in complex processing tasks. Summary of the invention

[0004] To this end, the embodiments of the present application provide a method, device, equipment and medium for evaluating the rotation accuracy of a robot around a point, thereby achieving an accurate evaluation of the rotation accuracy of the robot system around a point.

[0005] In a first aspect, the present 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 solutions:

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

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

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

[0010] Based on the real-time position data and the central position data, calculating the position change between the real-time position data and the central position data of each collection position;

[0011] Based on the position change of each collected position, the robot's rotation accuracy around the point is evaluated.

[0012] In a preferred example of the present application, it can be further configured to obtain several real-time position data of the robot end effector, including:

[0013] When the robot joint arm does not rotate, the initial position data of the robot end effector is obtained;

[0014] Control the robot joint arm to rotate around a single coordinate axis of the preset tool coordinate system at a fixed angle θ each time to the i-th collection position, and use a laser tracker to collect the position data of the robot end effector until n real-time position data are collected;

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

[0016] In a preferred example of the present application, it can be further configured that the single coordinate axis of the preset tool coordinate system is:

[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 the preset tool coordinate system.

[0020] In a preferred example of the present application, it can be further configured that the center position data of the robot joint arm rotation is calculated based on all the real-time position data to satisfy the following relationship:

[0021]

[0022] Among them, x i is the x-axis coordinate of the ith acquisition position, y i is the y-axis coordinate of the i-th acquisition position, z i is the z-axis coordinate of the i-th acquisition position, P center The central location data for all real-time location data.

[0023] In a preferred example of the present application, it can be further configured that, based on the center position data, the position change amount between each acquisition position and the center point is calculated to satisfy the following relationship:

[0024] ΔP=|P i -P center |,

[0025]

[0026] Among them, P i is the position data of the i-th collection position, P center is the position data of the center point, ΔP represents the position change between the position data of the i-th acquisition position and the position data of the center point, Represents the average change of all sampling locations.

[0027] In a preferred example of the present application, it can be further configured that, based on the position change amount of each acquisition position, the rotation accuracy of the robot around a point is evaluated, including:

[0028] Calculate the standard deviation of the position coordinates of all collected positions based on the position change:

[0029]

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

[0031] In a preferred example of the present application, it can be further configured to obtain a number of real-time position data of the robot end effector, and further include:

[0032] A plurality of first real-time position data of the first robot end effector and a plurality of second real-time position data of the second robot end effector are obtained.

[0033] In a second aspect, the present application provides a device for evaluating the accuracy of a robot's rotation around a point.

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

[0035] A device for evaluating the accuracy of a robot's rotation around a point, used to execute the method described in the first aspect above, the device comprising:

[0036] A data acquisition module is used to acquire a plurality of real-time position data of the robot end effector, wherein the real-time position data is the position data of the robot joint arm rotating to a plurality of acquisition positions according to a single coordinate axis of a preset tool coordinate system;

[0037] The accuracy evaluation module is used to calculate the center position data of the robot's joint arm rotation based on all real-time position data; based on the real-time position data and the center position data, calculate the position change between the real-time position data and the center position data of each collected position; based on the position change of each collected position, evaluate the robot's rotation accuracy around a point.

[0038] On the third aspect, the present application is realized through the following technical solutions:

[0039] A computer device comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of any one of the above-mentioned methods for evaluating the accuracy of robot rotation around a point when executing the computer program.

[0040] In a fourth aspect, the present application provides a computer-readable storage medium.

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

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

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

[0044] The present application obtains several real-time position data of the robot end effector, and the real-time position data is the position data of the robot joint arm rotating to several acquisition positions according to a single coordinate axis of a preset tool coordinate system; the center position data of the robot joint arm rotation is calculated based on all the real-time position data; the position change between the real-time position data and the center position data of each acquisition position is calculated based on the real-time position data and the center position data; based on the position change of each acquisition position, the robot's rotation accuracy around a point is evaluated. By controlling the robot to rotate around a coordinate axis of the tool coordinate system, and measuring and recording the position change of the end effector during the rotation process; the robot's rotation accuracy is evaluated according to the position change during the rotation process, and a method for quantitatively evaluating the robot's rotation accuracy around a point is provided. So that when the evaluation results show that the robot's rotation accuracy does not meet the requirements, the robot's control parameters can be adjusted to improve the robot's rotation accuracy. Ultimately, the robot system plays a greater role in complex processing tasks. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 A schematic diagram of a flow chart of a method for evaluating the accuracy of a robot's rotation around a point provided in an embodiment of the present application;

[0046] Figure 2 A schematic diagram of the structure of a device for evaluating the accuracy of a robot's rotation around a point provided in one embodiment of the present application;

[0047] Description of reference numerals:

[0048] Data acquisition module-101, accuracy assessment module-201. DETAILED DESCRIPTION

[0049] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

[0050] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0051] In addition, the term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application, unless otherwise specified, generally indicates that the associated objects before and after are in an "or" relationship.

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

[0053] The embodiments of the present application are further described in detail below in conjunction with the accompanying drawings.

[0054] like Figure 1 As shown, the present application proposes a method for evaluating the accuracy of a robot's rotation around a point, and the method specifically comprises the following steps:

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

[0056] In this application, a high-precision laser tracker is used to monitor the position of the robot end effector in real time. Among them, the end effector is a laser tracker target ball or other tool with accurate coordinate information. Tools with accurate coordinate information include calibration target balls, calibration probes, standard calibration blocks, special calibration tools or robot calibration rods, etc. The above-mentioned laser tracker target ball or tool is installed on the mounting workpiece at the end of the robot joint arm to ensure that it is firmly installed to avoid displacement during data collection. After the installation is completed, the accurate position and direction of the target ball or tool are input into the robot controller to set the tool coordinate system (TCP, Tool Center Point), which is used to define the position of the end effector.

[0057] Specifically, a laser tracker is first used to collect the position data of the robot end effector at the initial position A1 before it rotates around the point. The initial position A1 is the first collection position. Then the robot control system controls the robot joint arm to rotate around one of the coordinate axes of the preset tool coordinate system to different collection positions A2~A n , n is a positive integer greater than 2. Every time the robot rotates to a collection position, a laser tracker is used to collect the position data of the robot end effector at that collection position. Each position data includes at least the coordinate information of each collection position (x i ,y i ,z i ).

[0058] S20: Calculate the center position data of the robot joint arm rotation based on all the real-time position data, wherein the center position data is the position data of the center point of all the collected positions.

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

[0060] S30: Based on the real-time position data and the central position data, calculate the position change between the real-time position data and the central position data of each collection position.

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

[0062] S40: Based on the position change of each collected position, the robot's rotation accuracy around the point is evaluated.

[0063] Specifically, the average change of the position data of all the collected positions is calculated based on the position change of each collected position. Furthermore, based on the average change, the standard deviation and root mean square error of the position change between the real-time position data of each collected position and the central position data during the rotation of the robot joint arm around the point are calculated; the robot's rotation accuracy around the point is comprehensively evaluated based on the standard deviation and root mean square error.

[0064] This application provides a method for quantitatively evaluating the robot's rotation accuracy around a point by controlling the robot to rotate around a coordinate axis of the tool coordinate system, measuring and recording the position change of the end effector during the rotation process, and evaluating the robot's rotation accuracy based on the position change during the rotation process. When the evaluation results show that the robot's rotation accuracy does not meet the requirements, the robot's control parameters can be adjusted to improve the robot's rotation accuracy. Ultimately, the robot system can play a greater role in complex processing tasks.

[0065] It should be noted that in order to ensure that the measurement data can truly reflect the performance of the robot and improve the accuracy and reliability of the evaluation results, the robot body must first be accurately calibrated before implementing the above evaluation method to ensure that key parameters such as the zero point position of the robot encoder and the reduction ratio of the reducer are set correctly.

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

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

[0068] In some optional embodiments, 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. When the robot joint arm rotates around the point according to the Z axis of the preset tool coordinate system, all the acquisition positions are kept in the same XY plane; when the robot joint arm rotates around the point according to the Y axis of the preset tool coordinate system, all the acquisition positions are kept in the same XZ plane; when the robot joint arm rotates around the point according to the X axis of the preset tool coordinate system, all the acquisition positions are kept in the YZ plane.

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

[0070]

[0071] Among them, x i is the x-axis coordinate of the ith acquisition position, y i is the y-axis coordinate of the i-th acquisition position, z i is the z-axis coordinate of the ith acquisition position, P center It is the location data of the center point of all collected locations.

[0072] In a preferred embodiment, based on the center position coordinates, the position change of each acquisition position is calculated to satisfy the following relationship:

[0073] ΔP=|P i -P center |,

[0074]

[0075] Among them, P i is the position data of the i-th collection position, P center is the position data of the center point, ΔP represents the position change between the position data of the i-th acquisition position and the position data of the center point, Represents the average change of all sampling locations.

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

[0077] Calculate the standard deviation of the position coordinates of all collected positions based on the position change:

[0078]

[0079] Evaluate the robot's rotation accuracy around a point based on standard deviation.

[0080] Use root mean square error (RMSE) as the comprehensive accuracy indicator:

[0081]

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

[0083] Obtain several first rotation position coordinates of the end effector of the first robot and several second rotation position coordinates of the end effector of the second robot. Then calculate a first center position data based on several first rotation position coordinates, and calculate the first position change of each acquisition position according to the first center position data; calculate a second center position data based on several second rotation position coordinates, and calculate the second position change of each acquisition position according to the second center position data; finally, combine the first position change and the second position change to determine the robot's rotation accuracy around the point. In the actual implementation process, two target ball tooling is installed at the end of the robot, and the two target balls are symmetrically distributed. Improve the accuracy of the measurement data and improve the robustness of the system.

[0084] Another embodiment of the present application also provides a device for evaluating the accuracy of a robot's rotation around a point, which is used to perform the above method, such as Figure 2 As shown, the device comprises:

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

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

[0087] The specific definition of the device for evaluating the accuracy of rotation of a robot around a point provided in this embodiment can be found in the embodiment of the method for evaluating the accuracy of rotation of a robot around a point described above, and will not be repeated here. Each module in the device for evaluating the accuracy of rotation of a robot around a point can be implemented in whole or in part by software, hardware, and a combination thereof. Each of the modules can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute operations corresponding to each of the modules above.

[0088] An embodiment of the present application provides a computer device, which may include a processor, a memory, a network interface, and a database connected via a system bus. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The network interface of the computer device is used to communicate with an external terminal via a network connection. When the computer program is executed by the processor, the processor executes the steps of the method for evaluating the accuracy of the robot's rotation around a point as in any of the above embodiments.

[0089] The working process, working details and technical effects of the computer device provided in this embodiment can be found in the embodiment of the method for evaluating the accuracy of robot rotation around a point described above, and will not be described in detail here.

[0090] The embodiment of the present application provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the method for evaluating the accuracy of the robot's rotation around a point as in any of the above embodiments are implemented. The computer-readable storage medium refers to a carrier for storing data, which may include but is not limited to a floppy disk, an optical disk, a hard disk, a flash memory, a USB flash drive, and / or a memory stick, etc. 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 method for evaluating the accuracy of robot rotation around a point described above, and will not be described in detail here.

[0092] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database 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. As an illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0093] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, 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 can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the system described in the present application is divided into different functional units or modules to complete all or part of the functions described above.

Claims

1. A method for evaluating the accuracy of a robot's rotation around a point, characterized in that: The method comprises: Acquire a plurality of real-time position data of the robot end effector, wherein the real-time position data is position data of the robot joint arm rotating to a plurality of acquisition positions according to a single coordinate axis of a preset tool coordinate system; Calculate the center position data of the robot joint arm rotation based on all real-time position data; Based on the real-time position data and the central position data, calculating the position change between the real-time position data and the central position data of each collection position; Based on the position change of each collected position, the robot's rotation accuracy around the point is evaluated.

2. The method for evaluating the accuracy of a robot's rotation around a point according to claim 1, characterized in that: Obtain several real-time position data of the robot's end effector, including: When the robot joint arm does not rotate, the initial position data of the robot end effector is obtained; Control the robot joint arm to rotate around a single coordinate axis of the preset tool coordinate system at a fixed angle θ each time to the i-th collection position, and use a laser tracker to collect the position data of the robot end effector until n real-time position data are collected; Among them, n satisfies 10≤n≤15, and θ satisfies 10°≤θ≤20°.

3. The method for evaluating the accuracy of a robot's 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 the preset tool coordinate system.

4. The method for evaluating the accuracy of a robot's rotation around a point according to claim 2, characterized in that: The center position data of the robot joint arm rotation is calculated based on all real-time position data, satisfying the following relationship: Among them, x i is the x-axis coordinate of the ith acquisition position, y i is the y-axis coordinate of the i-th acquisition position, z i is the z-axis coordinate of the i-th acquisition position, P center The central location data for all real-time location data.

5. The method for evaluating the accuracy of a robot's rotation around a point according to claim 4, characterized in that: Based on the center position data, the position change between each acquisition position and the center point is calculated to satisfy the following relationship: ΔP=|P i -P center |, Among them, P i is the position data of the i-th collection position, P center is the position data of the center point, ΔP represents the position change between the position data of the i-th acquisition position and the position data of the center point, Represents the average change of all sampling locations.

6. The method for evaluating the accuracy of a robot's rotation around a point according to claim 5, characterized in that: Based on the position change of each collected position, the robot's rotation accuracy is evaluated, including: Calculate the standard deviation of the position coordinates of all collected positions based on the position change: Evaluate the robot's rotation accuracy around a point based on standard deviation; Where σ represents the standard deviation, P i is the position data of the i-th collection position, P center is the position data of the center point, and ΔP represents the position change between the position data of the i-th acquisition position and the position data of the center point.

7. The method for evaluating the accuracy of a robot's rotation around a point according to any one of claims 1 to 6, characterized in that: Obtain several real-time position data of the robot's end effector, including: A plurality of first real-time position data of the first robot end effector and a plurality of second real-time position data of the second robot end effector are obtained.

8. A device for evaluating the accuracy of a robot's rotation around a point, characterized in that: For executing the method according to any one of claims 1 to 7, the device comprises: A data acquisition module is used to acquire a plurality of real-time position data of the robot end effector, wherein the real-time position data is the position data of the robot joint arm rotating to a plurality of acquisition positions according to a single coordinate axis of a preset tool coordinate system; The accuracy evaluation module is used to calculate the center position data of the robot's joint arm rotation based on all real-time position data; based on the real-time position data and the center position data, calculate the position change between the real-time position data and the center position data of each collected position; based on the position change of each collected position, evaluate the robot's rotation accuracy around a point.

9. A computer device, characterized in that: The method comprises 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 7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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