Sub-Optimal Motion Planner of Wheeled Mobile Manipulators With Under-Actuated Platform

Abstract

We propose a stochastic optimization scheme for point‐to‐point trajectory planning of nonholonomic wheeled mobile manipulators with under‐actuated platform. The problem is known to be complex, particularly if dynamic constraints are considered. The proposed method consists of extending to under‐actuated systems the random‐profile approach recently applied to wheeled mobile robots. This versatile method handles constraints on: geometry (obstacle avoidance, bounds on joint positions and path curvature), kinematics (bounded velocities and accelerations), dynamics (bounded torques, stability issues). It may be applied using a cost function involving travel time, efforts and power. A solution is presented for a planar wheeled manipulator with under‐actuated platform undertaking a point‐to‐point generalized task.