Control of dynamics and sensor based motion planning for a differential drive robot

Extends results in sensor-based motion planning with dynamics for a point robot to a more realistic case of a dimensioned robot. We consider a disc-shaped mobile robot with a differential drive system operating in a planar environment with unknown arbitrarily shaped stationary obstacles. Given the constraints on the robot kinematics, dynamics, sensing, and control means, an algorithm is developed that generates collision-free trajectories with guaranteed convergence. To make the extension to a vehicle with finite dimensions possible, a suitable methodology for the choice of actuator controls is proposed. Under the proposed strategy, whenever a turn in the motion is required, the robot attempts to accomplish it in minimum time, while simultaneously moving in space. Even with a reasonably fast motion, its safety is guaranteed by maintaining at all times an emergency stopping path. Simulated examples demonstrate the algorithm's performance.