Dimensional Optimization for Minimally Invasive Surgery Robot Based on Double Space and Kinematic Accuracy Reliability Index

Abstract

To improve the kinematic performance of the remote center mechanism for surgical robot, a double space index and kinematic accuracy reliability index are proposed to optimize the dimensional sizes of mechanism. First, the influence of the angular error on the position error and the operability of the remote center in the workspace are analyzed. The position error space and operability space index are weighted to establish the double space index. Second, a kinematic accuracy reliability index is established based on the influence of joint clearance on output position accuracy. Finally, the dimensional sizes of remote center adjustment mechanism and double parallelogram mechanism are optimized based on proposed optimization indices. Multipopulation genetic algorithm is used to obtain the optimal size parameters under the corresponding index. The optimized double space index is 56.7%, which is 56.5% higher than before optimization. The optimized kinematic accuracy reliability is 0.91, which is 22.9% higher than before optimization. The kinematic performance of remote center mechanism has been significantly improved after optimization.