Mechanism Design and Optimization of a Haptic Master Manipulator for Laparoscopic Surgical Robots

Serve as the human-robot interface of laparoscopic surgical robot, the master device always plays a crucial role in terms of master-slave manipulation. Growing demands of robot-assisted surgery system also warrant more rational design and optimization for the master manipulator mechanism, which turn out to be important for improving the performance of surgical operations. In this paper, a novel 9 degrees of freedom (DOFs) haptic master manipulator applied to laparoscopic surgical robots is proposed. First of all, the mechanical configuration of the serial master manipulator is presented along with its corresponding kinematic analysis. The proposed strategy can decouple the posture and position completely and to a certain extent simplify the kinematics calculations. Then a mechanism optimization index which synthesizes the global kinematic performances, the global positioning accuracy and the structure length utilization of the manipulator mechanism is introduced. Finally, an improved particle swarm optimization algorithm is proposed to find the optimal mechanism design parameters. The optimization index and algorithm are verified by comparing the optimized parameters with the initial settings. Theoretical analysis and optimization results have demonstrated that the master manipulator can achieve better kinematic performances while maintaining 6 dimensions force feedback.