Collision-free control of an omni-directional vehicle

This study addresses the problem of controlling an omni-directional vehicle with both state and control dependent constraints. The task of the vehicle is to attain its desired final position given in the task space. The control constraints resulting from the physical abilities of actuators driving the vehicle wheels are also taken into account during the robot movement. The problem of collision avoidance is solved here based on an exterior penalty function approach which results in smooth vehicle velocities near obstacles. Provided that, a solution to the aforementioned vehicle task exists, the Lyapunov stability theory is used to derive the control scheme. The numerical simulation results carried out for the omni-directional vehicle operating in both a constraint-free task space and task space including obstacles, illustrate the performance of the proposed controllers. (C) 2009 Elsevier B.V. All rights reserved.