Method for measuring positioning error of robot

Abstract

The invention discloses a method for measuring the positioning error of a robot. The method comprises the following steps of: providing measurement equipment and setting a measured reference point P; measuring the actual position of the measured reference point P in the coordinate system of the measurement equipment; converting the position of the measured reference point P in the flange coordinate system of the robot into a calculated position in the coordinate system of the measurement equipment by means of coordinate conversion, and calculating the difference between the actual position and the calculated position to obtain the positioning error.

Description

technical field [0001] The invention relates to a method for measuring robot positioning errors. Background technique [0002] The repetitive positioning accuracy of industrial robots is very high, but the absolute positioning accuracy is very poor. In order to improve the performance of the robot and expand the application range of industrial robots, it is necessary to calibrate the parameters of the robot kinematics model to reduce its absolute positioning error. Robot calibration is generally carried out in four steps: modeling, measurement, identification and compensation. The measurement of the absolute positioning error corresponding to the sampling point in the robot workspace is the premise of the calibration of the robot's structural parameters, and the validity of the measurement data determines whether the calibration of the robot parameters can be correctly realized. The process of robot absolute positioning error measurement generally includes the design and s...

AI Technical Summary

Problems solved by technology

The accuracy of the "measurement tool" determines the measurement accuracy of the positioning error; the "coordinate unification of the measurement data" is based on the position of the center of the measurement target at the end of the robot (tool coordinate system) and the relationship between the robot base coordinate system and the coordinate system of the measuring equipment The transformation matrix (base coordinate system) is calibrated, and the measurement data of the end flange center directly obtained from the robot and the data of the target center measured by the measuring equipment are unified into one coordinate system, so as to obtain the positioning error of the sampling point; " The effectiveness of the selection of "measurement data samples" largely determines the efficiency and accuracy of robot structural parameter calibration. The more sufficient data collected according to the needs, the more conducive to the calibration process. However, assuming that each of the robot's 6 joints takes 5 joints Angle combination measurement requires 15625 measurements, which is impossible in the actual data collection process

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