Trajectory planning of transcranial magnetic stimulation manipulator based on time-safety collision optimization

Abstract

In this study, an optimal time-safety collision trajectory planning method of manipulator is proposed. It optimizes the coupling and contradictory performance indexes of manipulator joint motion time and safety collision coefficient. The trajectory of the manipulator can be transformed into the position and time series in the joint space by Inverse Kinematics (IK). Among the splines, quintic B-spline used commonly for interpolating robotic trajectories is preferred also in this study. Under the constraints of the manipulator, non-dominated sorting genetic algorithms-II (NSGA-II) is used to optimize the objective function. The total optimized running time is shortened by 33.07 s. The main joints damage before and after optimization of safety collision have been reduced more than 49.4%. After quintic B-spline interpolation, the time-safety collision of manipulator trajectory are effectively optimized. In general, the execution efficiency of the manipulator is improved, the collision damage to the human head is reduced, and the motion control performance of TMS manipulator is improved to be widely used in medical clinic.