VFO control design for a mobile robot in the presence of time and input constraints

This paper presents a solution to the set-point control problem for nonholonomic mobile robots in the presence of time and control input constraints. We consider the kinematics of a unicycle mobile robot, in which the constraints on the control inputs are longitudinal and angular velocity limitations, while the time constraints impose an upper bound on a settling time for stabilization errors. We show a solution based on the Vector-Field-Orientation (VFO) methodology, which is characterized by non-oscillatory transient states and well-predictable time evolution of these states. Formally derived upper bounds of settling time for configuration errors are verified by results of numerical simulations and experimental results obtained in a fast prototyping system.