SCARA robot accurate positioning method based on granularity model

Abstract

The invention provides an SCARA robot accurate positioning method based on a granularity model combined with minimum distance error approximation principle. With the method, the spatial position distance relationship between an actual point and an expectation point that a robot end arrives for the first time is firstly analyzed; an initial granularity model of variable parameter is established; the distance error between four granularity points of the model and the expectation point is calculated; the granularity point with the minimum distance error within the model is established as the initial point of the variable parameter granularity model for the next step; and the regulation of the granularity model parameter is determined by a specific position of the granularity model on which the expectation point is located; only the simplified mathemetics structure model of a shaft 1 and a shaft 2 of the SCARA robot is needed to know; the SCARA robot accurate positioning method has the advantages of single parameter regulation, clear movement frequency, less movement frequency, strong industrial practicality and improved absolute positioning accuracy without changing SCARA robot repeating positioning accuracy; under the circumstance of big absolute positioning error, constriction is realized rapidly; and under the circumstance of small absolute positioning error, accurate positioning is realized.

Description

technical field [0001] The present invention relates to the field of absolute positioning accuracy of SCARA robots. Specifically, it refers to capturing the coordinate position of the desired point through a visual sensor and driving the end of the SCARA robot to move to this point for the first time. There is a deviation between the actual position point and the expected point, and an effective solution is proposed for reducing the deviation. The error compensation strategy improves the absolute positioning accuracy of the robot. Background technique [0002] The positioning of the SCARA robot on the plane depends on the joint action of axis 1 and axis 2. The performance indicators that determine the SCARA robot are: the repetitive positioning accuracy of the robot and the absolute positioning accuracy of the system. The repeated positioning accuracy of many industrial robots is about 20 μm, but the absolute positioning accuracy of the system is generally 1-3mm. [0003] ...

AI Technical Summary

Problems solved by technology

[0004] For the visual servo SCARA control system, the image coordinates of the desired point obtained from the image are transformed into the angle of the joint space of the robot through coordinate transformation, and the robot is driven to move according to the angle of the transformed joint space. However, due to the calibration (camera coordinates and the robot base The error caused by the coordinate relationship) will cause an irreversible deviation between the actual point and the expected point

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