Nonlinear path control in automated vehicle guidance

The problem of path control of automatically guided vehicles along a desired trajectory is considered where both lateral and longitudinal dynamics have been incorporated in the vehicle model. It is shown that a nonlinear decoupling controller and pole-placement can be used to obtain a closed-loop behavior that is independent of the vehicle operation point. For the pole-placement, the entire state is necessary. Since the sideslip is not available from measurements, an observer is applied, estimating the sideslip. Due to the steady state errors imposed by the nonlinear controller, a predictive filter is used to calculate this steady state error. The effectiveness of this controller is then demonstrated by simulations.