Calibration of Kinematic Parameters of Industrial Robot Based on Binocular Vision and Distance Error Model

Kinematic parameter calibration of industrial robot is the necessary means to maintain and optimize the motion accuracy of manipulator end. The calibration method based on distance error model establishes the relationship between the motion distance errors and the kinematic parameters error. The transformation error of the coordinate system in the calibration process was avoided, and the calibration accuracy could be improved significantly. The vision measurement technology has the advantages of high precision, non-contact and real-time, et al. Compared with the traditional measuring method of manipulator motion errors, it has the advantages of low cost, easy operation. This paper will study a robot calibration method which combines the distance error model with the visual measurement technology, for improving the accuracy of industrial robot in specific workspace. The robot parameters are calibrated based on the proposed method, and the kinematic parameters are compensated using the calibration results. On the calibration trajectory, the average error of the absolute distance is reduced from 0.2852mm to 0.1012mm. And the distance error in the area around the calibration plane is also significantly reduced, which verifies the correctness and feasibility of the method.