Tool coordinate system calibration method and device for three-axis mechanical arm

Abstract

The invention provides a tool coordinate system calibration method and device for a three-axis mechanical arm. The calibration method comprises the following steps of enabling a mechanical arm to carry out the nth photographing actions according to a plurality of different postures based on the same circular marker, and carrying out the photographing in a first posture, photographing in a second posture when the end part of a calibration jig reaches the circle center position in the ith photographing action, correspondingly recording coordinates OEi and OEj corresponding to the tail end of themechanical arm in the jth photographing action when the end part of the calibration jig reaches the circle center position, and establishing an equation for solving, finally, obtaining the horizontaldistance W between the tail end of the mechanical arm and the end of the calibration jig and the included angle theta between a connecting line of the tail end of the mechanical arm and the tool center point and the X-axis direction of a coordinate system at the tail end of the mechanical arm. According to the calibration method, the calibration process is greatly simplified, and the calibrationprecision is guaranteed through visual use.

Description

technical field [0001] The invention relates to the field of tool coordinate system calibration, in particular to a tool coordinate system calibration method and a calibration device of a three-axis mechanical arm. Background technique [0002] In industrial production lines, special parts are usually fixed at the end of the mechanical arm of the industrial robot as tools, such as fixtures, welding torches and other devices. A coordinate system is usually established at a fixed position on these tools, the so-called tool coordinate system. The trajectory planning of the robot is usually planned for a certain point of the tool after the above-mentioned tools are added, and this point is usually called the Tool Center Point (TCP: Tool Center Point). Under normal circumstances, the origin of the tool coordinate system is the TCP. After the tool is installed on the end of the robot's mechanical arm, unless its installation position is artificially changed, the tool coordinate sy...

AI Technical Summary

Problems solved by technology

Using the conventional method to calibrate the tool coordinate system is done manually by the operator, and the accuracy is difficult to guarantee. It often needs to go through multiple calibrations to obtain the calculation result with the smallest error, which consumes a lot of time a...

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