In order to improve the operational accuracy of microsurgical instruments and increase the success rate of surgery, a six-degree-of-freedom microsurgical instrument is designed and analyzed based on a rigid-flexible coupling multi-body system. First, an improved kinematic modeling method is proposed based on the pseudo-rigid body theory. Second, a rigid-flexible coupling simulation system is built to analyze the error sources in terms of the remote center of motion, preload, and side load. Then, the function of motion scaling, the accuracy of kinematic modeling, and the validity of the workspace are demonstrated by analyzing the workspace. In addition, the maximum stress is analyzed to ensure the safety and reliability of the application. The analysis results show that the improved kinematic modeling method improves the positioning accuracy by more than two times, and the root mean square error at the tool tip of the microsurgical instrument does not exceed 1 μm under a side load of 0.1 N. Finally, the experimental results show that the improved kinematic modeling method has higher pointing accuracy, and the maximum error does not exceed 10 μm. The designed microsurgical instrument can meet the requirements of surgical operations.
Journal of Mechanisms and Robotics Open Issues