Motion planning with dynamic constraints for manipulators in the presence of moving obstacles

This paper deals with acceleration (or torque) constraints in motion planning of a manipulator among moving obstacles. It is known that motion planning with dynamic constraints in dynamic environments can be formulated in a state-time space. This paper shows that acceleration constraints of a manipulator can be represented as parabolas in a local small motion so that admissible velocities are efficiently computed. An algorithm is also presented for planning the optimal trajectory for a manipulator on a given path. To improve computation efficiency, this algorithm does not construct or search the total 3D state-time space but only a subspace corresponding to admissible regions in the 2D time-configuration and state spaces. Its usefulness is shown by a simulation for a 6 DOF manipulator