Research on adaptive evaluation method of manipulator trajectory accuracy

Abstract

In the evaluation of manipulator trajectory accuracy, the selection of measured reference points and equipment installation effects the evaluation results. Therefore, a geometric model of ruled surface is proposed to describe the error motion of the manipulator. The directrix error and spherical image error are defined as parameters to describe the range of error motion. The above mathematical model is optimized to obtain the minimal directrix error vector and the minimal spherical image error vector on the moving coordinate system, and these vectors are selected as the evaluation indicators, it is unique to evaluate the accuracy of manipulator trajectory, which can eliminate the impact of measured reference points and equipment installation. This approach has been verified on the LR7-710 manipulator, the minimal directrix error of the manipulator trajectory is 0.2673mm, and the minimal spherical image error is $7.0048\times {10}^{-4}\mathrm{rad}$ . The feasibility of the method is verified by three contrast tests.