CN-121973239-A - Mechanical arm positioning method, mechanical arm system and related device

CN121973239ACN 121973239 ACN121973239 ACN 121973239ACN-121973239-A

Abstract

The application discloses a mechanical arm positioning method, a mechanical arm system and a related device, which relate to the field of control and specifically comprise the steps of acquiring a theoretical pose of the tail end of a mechanical arm under a base coordinate when the tail end of the mechanical arm reaches a visual acquisition point and meets a compensation condition, acquiring a calibration plate image, calculating an actual pose of the tail end of the mechanical arm under the base coordinate system according to the theoretical pose, calculating a space error vector between the actual pose and the theoretical pose, correcting the theoretical pose according to the space error vector if the current space error is within a preset range, determining a reference coordinate of the tail end of the mechanical arm under the base coordinate based on the corrected theoretical pose, and realizing an online positioning compensation task based on visual feedback at the visual acquisition point; according to the relative position relation between the visual acquisition point and each operation point and the reference coordinates, coordinate values of each operation point are calculated and used as the basis for controlling the tail end of the mechanical arm to be positioned to each operation point, and the positioning compensation task from a single point to the whole operation point sequence is realized.

Inventors

WANG YUHONG
NIE JUANHONG
ZOU WEIHUA

Assignees

北京四方继保工程技术有限公司
北京四方继保自动化股份有限公司

Dates

Publication Date: 20260505
Application Date: 20260331

Claims (10)

1. The mechanical arm positioning method is characterized by comprising the following steps of: Under the condition that the tail end of the mechanical arm reaches a preset visual acquisition point and meets a preset compensation condition, acquiring a calibration plate image through a visual acquisition device and acquiring a theoretical pose of the tail end of the mechanical arm under a base coordinate; calculating the actual pose of the tail end of the mechanical arm under a base coordinate system according to the calibration plate image and a predetermined hand-eye conversion matrix; Calculating a space error vector between the actual pose and the theoretical pose; Correcting the theoretical pose according to the spatial error vector under the condition that the spatial error corresponding to the spatial error vector is in a preset range, and determining a reference coordinate of the tail end of the mechanical arm under a base coordinate based on the corrected theoretical pose; And calculating coordinate values of the operation points according to the relative position relation between the visual acquisition points and the operation points and the reference coordinates, and taking the coordinate values as a basis for controlling the tail end of the mechanical arm to be positioned to the operation points.
2. The method according to claim 1, wherein the compensation condition includes that the number of times of the positioning compensation does not exceed a preset maximum number of iterations, and/or that a modulus of a spatial error vector at the time of the last positioning compensation is not smaller than a preset positioning accuracy threshold.
3. The mechanical arm positioning method according to claim 2, wherein correcting the theoretical pose according to the spatial error vector includes: determining a compensation vector corresponding to the theoretical pose according to the space error vector and the historical compensation data; And correcting the theoretical pose according to the compensation vector corresponding to the theoretical pose.
4. The mechanical arm positioning method according to claim 3, wherein the history compensation data includes a history compensation vector corresponding to the theoretical pose at the last positioning compensation, wherein the history compensation vector at the initial time is a zero vector having the same dimension as the spatial error vector; According to the spatial error correction vector and the historical compensation data, determining a compensation vector corresponding to the theoretical pose comprises the following steps: and carrying out weighted summation calculation on the space error vector and the historical compensation vector according to the pre-configured weight to obtain a compensation vector corresponding to the theoretical pose, wherein the sum of the pre-configured weights of the space error vector and the historical compensation vector is 1.
5. The method for positioning a manipulator according to any one of claims 1-3, wherein the spatial error vector comprises a spatial error value in an X-direction, a spatial error value in a Y-direction, and a spatial error value in a Z-direction; The spatial error corresponding to the spatial error vector is within a preset range, wherein the absolute value of the spatial error value in the X direction is smaller than a first preset threshold, the absolute value of the spatial error value in the Y direction is smaller than a second preset threshold, and the absolute value of the spatial error value in the Z direction is smaller than a third preset threshold.
6. A robotic arm positioning device, comprising: The positioning compensation control unit is used for acquiring a calibration plate image through the vision acquisition device and acquiring the theoretical pose of the tail end of the mechanical arm under the basic coordinates under the condition that the tail end of the mechanical arm reaches a preset vision acquisition point and meets preset compensation conditions; The error calculation and compensation unit is used for calculating the actual pose of the tail end of the mechanical arm under a basic coordinate system according to the calibration plate image and a predetermined hand-eye conversion matrix, and calculating a space error vector between the actual pose and the theoretical pose; and the coordinate updating unit is used for determining a reference coordinate of the tail end of the mechanical arm under the base coordinate based on the corrected theoretical pose, and calculating the coordinate value of each operating point according to the relative position relation between the vision acquisition point and each operating point and the reference coordinate as a basis for controlling the tail end of the mechanical arm to be positioned to each operating point.
7. A robotic arm controller comprising at least one processor and a memory coupled to the processor, wherein: The memory is used for storing a computer program; the processor is configured to execute the computer program to enable the robot controller to implement the robot positioning method according to any one of claims 1 to 5.
8. The mechanical arm system is characterized by comprising a mechanical arm controller, a mechanical arm and a vision acquisition device, wherein the mechanical arm is in communication connection with the mechanical arm controller; The mechanical arm control equipment sends an image acquisition instruction to the visual acquisition device and acquires a theoretical pose of the tail end of the mechanical arm under a base coordinate under the condition that the tail end of the mechanical arm reaches a preset visual acquisition point and a preset compensation condition is met; the vision acquisition device acquires a calibration plate image and sends the calibration plate image to the mechanical arm control equipment; the mechanical arm control equipment calculates the actual pose of the tail end of the mechanical arm under a base coordinate system according to the calibration plate image and a predetermined hand-eye conversion matrix; the mechanical arm control equipment calculates a space error vector between the actual pose and the theoretical pose; the mechanical arm control device corrects the theoretical pose according to the spatial error vector under the condition that the spatial error corresponding to the spatial error vector is in a preset range, and determines a reference coordinate of the tail end of the mechanical arm under a base coordinate based on the corrected theoretical pose; The mechanical arm control equipment calculates coordinate values of all the operation points according to the relative position relation between the visual acquisition points and all the operation points and the reference coordinates, and the coordinate values are used as the basis for controlling the tail end of the mechanical arm to be positioned to all the operation points.
9. A computer program product comprising computer readable instructions which, when run on an electronic device, cause the electronic device to implement the robotic arm positioning method of any one of claims 1 to 5.
10. A computer storage medium carrying one or more computer programs which, when executed by an electronic device, enable the electronic device to implement the robot positioning method of any one of claims 1 to 5.

Description

Mechanical arm positioning method, mechanical arm system and related device Technical Field The present application relates to the field of control technologies, and in particular, to a mechanical arm positioning method, a mechanical arm system, and a related device. Background With the development of industrial automation, the mechanical arm is widely applied to the production flow of products by virtue of the advantages of high flexibility, strong stability, programmability and the like. In the application scene of the mechanical arm depending on the teaching path, the mechanical arm needs to be controlled to be accurately positioned to a plurality of discrete operation points taught in advance, and then actions such as key operation, precise assembly and the like are executed. The positioning accuracy of the mechanical arm is an important parameter for determining the operation efficiency of the mechanical arm, and has a decisive influence on the stability of the production process and the reliability of the product quality. At present, a fixed coordinate conversion relation between a camera and the mechanical arm is determined through a hand-eye calibration technology before the mechanical arm is put into use, and then the pose of a workpiece under the mechanical arm coordinate is determined according to the identification point and a predetermined conversion relation during actual use, so that the positioning task of the mechanical arm is realized. However, during the long-term operation of the system, mechanical wear, temperature change, load change and the like may occur, so that the predetermined conversion relationship is not applicable any more, and the positioning accuracy of the mechanical arm is reduced, which adversely affects the production process. Therefore, how to improve the positioning accuracy of the mechanical arm in the running process of the system becomes a technical problem to be solved by those skilled in the art. Disclosure of Invention In view of the above problems, the present application provides a mechanical arm positioning method, a mechanical arm system and related devices, so as to improve the positioning accuracy of the mechanical arm in the system operation process. The specific scheme is as follows: The first aspect of the application provides a mechanical arm positioning method, which comprises the following steps: Under the condition that the tail end of the mechanical arm reaches a preset visual acquisition point and meets a preset compensation condition, acquiring a calibration plate image through a visual acquisition device and acquiring a theoretical pose of the tail end of the mechanical arm under a base coordinate; calculating the actual pose of the tail end of the mechanical arm under a base coordinate system according to the calibration plate image and a predetermined hand-eye conversion matrix; Calculating a space error vector between the actual pose and the theoretical pose; Correcting the theoretical pose according to the spatial error vector under the condition that the spatial error corresponding to the spatial error vector is in a preset range, and determining a reference coordinate of the tail end of the mechanical arm under a base coordinate based on the corrected theoretical pose; And calculating coordinate values of the operation points according to the relative position relation between the visual acquisition points and the operation points and the reference coordinates, and taking the coordinate values as a basis for controlling the tail end of the mechanical arm to be positioned to the operation points. A second aspect of the present application provides a mechanical arm positioning device, including: The positioning compensation control unit is used for acquiring a calibration plate image through the vision acquisition device and acquiring the theoretical pose of the tail end of the mechanical arm under the basic coordinates under the condition that the tail end of the mechanical arm reaches a preset vision acquisition point and meets preset compensation conditions; The error calculation and compensation unit is used for calculating the actual pose of the tail end of the mechanical arm under a basic coordinate system according to the calibration plate image and a predetermined hand-eye conversion matrix, and calculating a space error vector between the actual pose and the theoretical pose; and the coordinate updating unit is used for determining a reference coordinate of the tail end of the mechanical arm under the base coordinate based on the corrected theoretical pose, and calculating the coordinate value of each operating point according to the relative position relation between the vision acquisition point and each operating point and the reference coordinate as a basis for controlling the tail end of the mechanical arm to be positioned to each operating point. A third aspect of the present application provides a robotic arm controller compri