Asymptotic Stabilization of Nonholonomic Four-Wheeled Vehicle with Steering Limitation based on Lyapunov Function Approach

In this paper, we propose a new control law for the asymptotic stabilization of a four-wheeled vehicle with a steering angle limitation. The control law is based on a locally semiconcave control Lyapunov function (LS-CLF) for the chained system proposed by Kimura et al. (2015) that is converted by coordinate and input transformations without singular points. We confirm that the LS-CLF is also effective for the four-wheeled vehicle case, i.e., such inputs exist in the input constraint that decrease the LS-CLF. We also design a control law by using the LS-CLF and steering angle constraint that achieves asymptotic stabilization of the origin of a four-wheeled system while avoiding pivot turns. We confirm the effectiveness of the proposed control law via a computer simulation and an experiment.