Before testing or calibrating an industrial robot by a laser tracker

the calibration of the robot coordinate system is necessary. So a robot coordinate system calibration method based on nonlinear optimization is studied.Firstly

a target is fixed at the end of the robot

and the robot moves several poses

multi-pose constraint equation is established. while a laser tracker measures the target. Then

the base coordinate frame and the target coordinates are calibration synchronously by nonlinear optimization algorithm. This method does not require special mechanical tooling and can be applied to industrial robot systems with various actuators or no load at the end. The experimental results show that compared to the traditional closed-solution

the proposed method based on nonlinear optimization has good robustness and can effectively reduce the transformation error caused by the inaccuracy of the robot motion model.