Motion Planning and Trajectory for Wheeled Mobile Robot

In general, the problems of robots can be divided into two sub-problems of motion planning and motion control. A motion planning problem is solved where a geometrical model is given. Furthermore, motion planning problems can be fundamentally divided into path, trajectory and task planning problems. These planning have many constraints concerning kinematics and dynamics of the robot as well its environment. This paper introduces path, trajectory and task planning methods for wheeled mobile robots. Wheeled mobile robots are becoming increasingly important in industry as a means of transport, inspection, and operation because of their efficiency and flexibility. The motion of a wheeled mobile robot, in general, be subject to non-holonomic constraints due to the rolling constraints of the wheels, which render a motion perpendicular to the wheels impossible. These non-holonomic constraints give rise to highly nonlinear mathematical models of the mobile robots, and the control problem is not trivial although the full state is measured. Feedback control of non-holonomic mobile robots is, therefore, a challenging problem which combines nonlinear control theory and differential geometry. Path planning in mobile robots must ensure optimality of the path. The optimality achieved may be in path, time, energy consumed etc. Path planning in robots also depends on the environment in which it operates like, static or dynamic, known or unknown etc. Global path planning using A* algorithm and genetic algorithm is investigated in this paper. A known dynamic environment, in which a control station will compute the shortest path and communicate to the mobile robot and the mobile robot will traverse through this path to reach the goal.