Optimal motion planning for a wheeled mobile robot

Abstract

Concerns the time optimal motion planning problem under kinematic and dynamic constraints for a 2-DOF wheeled mobile robot (WMR). The dynamic model of a WMR is derived using a Newton-Euler method and its constraints are analyzed. Kinematic constraints are imposed by its nonholonomy and structural limits while dynamic constraints are due to motor saturation. The motion planning problem is formulated as two stage planning. First, path planning under kinematic constraints is transformed into a pure geometric problem. The shortest path composed of circular arcs and straight lines is obtained. Then, combined with dynamic characteristics of the WMR, a time optimal velocity profile is generated under dynamic constraints. Since constraints of a WMR are fully exploited, the proposed method is simple and effective for motion planning. Simulation results illustrate the capability of the planning scheme.