Method for reducing influence of robot joint structure errors on precision of robot

Abstract

The invention discloses a method for reducing an influence of robot joint structure errors on precision of a robot. The method comprises the following steps of, firstly, establishing a spinor theory expression mode and a robot forward kinematics model; secondly, analyzing geometrical errors of joints; thirdly, establishing a spinor expression of the geometrical errors; fourthly, bring the spinor expression of the geometric errors into the robot forward kinematics model, and obtaining an actual robot forward kinematics equation after the errors are considered. According to the method, based onthe spinor theory, by analyzing the position-space relationship of two axes of robot arm joint under different geometrical errors, the joint errors are expressed as the form of the spinor, combined with a POE formula, the forward kinematics formula of robot arm including joint errors is given, and the correctness of the formula is verified by Adams. The method reflects the intuitiveness and convenience of the spinor in robot motion analysis; and the method can be used not only for static and quasi-static error analysis, but also for dynamic error analysis if the size of the errors is considered to vary with the motion process of the robot.

Description

technical field [0001] The invention relates to the field of robot joint structures, and more particularly, relates to a method for reducing the influence of robot joint structure errors on its precision. Background technique [0002] The accuracy of industrial robots has always been an important indicator for evaluating the work requirements of industrial robots. Dimensional and geometric errors caused by the machining stage of robot parts and the gaps generated by joints during assembly will have a great impact on the pose of the end effector. [0003] There are many methods for analyzing robot pose errors. Yan Hua et al. summarized the robot pose error modeling methods into two categories: matrix method and vector method. The common models of matrix method are MD-H, S model, Wait. The vector method mainly includes the perturbation method. With the development of robots, more and more modern methods are applied to the analysis of robots, and screw is one of the importan...

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Problems solved by technology

[0005] The mathematical model established by the present invention for the screw theory in the prior art cannot directly reflect the specific error source of the joint. When the error screw is established, the positional relationship between the theoretical joint axis and the actual joint axis can only be attributed to three situations: intersection, parallel, and interlacing. There are certain deficiencies, and an analysis method based on screw theory for the influence of robot joint structure errors on its accuracy is provided

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