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

Abstract

The invention provides a tool coordinate system calibration method and a calibration device of a three-axis mechanical arm. The calibration method includes the following steps: based on the same circular marker, the mechanical arm performs n times of shooting actions according to a plurality of different postures, and takes the first posture Shooting, the end of the calibration jig reaches the center of the circle during the i-th shooting action, and shoots in the second posture, and the end of the calibration jig reaches the center of the circle during the j-th shooting action, Record the coordinates O corresponding to the end of the mechanical arm during the shooting action E i with O E j , establish an equation solution, and finally obtain the horizontal distance W from the end of the mechanical arm to the end of the calibration jig, and the angle θ between the line connecting the end of the mechanical arm and the center point of the tool and the X-axis direction of the coordinate system at the end of the mechanical arm. The present invention greatly The calibration process is simplified, and the use of vision also ensures the calibration accuracy.

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 and energy. The calibration process also has certain technical threshold requirements for the operator. It is not conducive to field application, so a fast, accurate and automatic three-axis manipulator tool coordinate system calibration method will be urgently needed in practical applications

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