A novel multi-point trajectory generator for robotic manipulators based on piecewise motion profile and series-parallel analytical strategy

A novel time-optimal multi-point trajectory generator (TMTG) based on piecewise motion profile and series-parallel analytical strategy is proposed for robotic manipulators to improve the motion accuracy and efficiency. The multi-point trajectory is composed of various subtrajectories to eliminate overshoot and undershoot according to the constrained velocity direction at the desired points. The piecewise motion profile is acted as a fundamental subtrajectory model for a jerk-continuous subtrajectory. A series-parallel analytical strategy provides a closed-form solution for the time-optimal multi-point trajectories. The series analytical strategy for a single-joint trajectory generates the time-optimal trajectory and the upper velocities of the desired points. The parallel analytical strategy for multi-joint subtrajectories synchronizes the joint movements to enhance the multi-joint motion accuracy. The simulations and experiments conducted on a manipulator validate that TMTG outperforms state-of-the-art approaches in terms of accuracy and efficiency for a multi-joint manipulator. The absolute position errors of all joint by TMTG at the end of motion are within 0.007°. Therefore, TMTG is a functional solution for manipulators to construct time-optimal multi-point trajectories.