Point Stabilization And Trajectory Tracking Control On Nonholonomic Mobile Robot

This paper considers nonholonomic mobile robot as the control object and in view of both theory and application, studies the control problems focusing on point stabilization and trajectory tracking, which are one of the most important issues on nonholonomic mobile robot motion control. The final objective of this paper consists in constructing a nonholonomic mobile robot motion control system composed of point stabilization and trajectory tracking controllers, which are stable and effective in theory and are practical and feasible in application.Firstly, as for point stabilization control, this paper establishes posture error model denoted by Polar coordinates in global coordinates and makes use of the inherent discontinuousness of the closed-loop system model to propose a novel nonlinear state feedback control law, which causes closed-loop system state space equation to have isolated equilibrium state at origin. Through analysing the local uniform asymptotical stability at origin under the proposed point stabilization control law, the scale of control parameters is confirmed. By Lyapunov candidate function method, this paper concludes that the closed-loop system is globally uniformly asymptotically stable at origin.Then, as for trajectory tracking control, this paper establishes posture error model denoted by Cartesian coordinates in local coordinates and proposes a novel nonlinear state feedback control law, which causes closed-loop system state space equation to have isolated equilibrium state at origin. Through analysing the local uniform asymptotical stability at origin and the instability of isolated boundary equilibrium state at non-origin under the proposed trajectory tracking control law, the scale of control parameters is confirmed. By Lyapunov candidate function method, this paper concludes that the closed-loop system is globally uniformly asymptotically stable at origin.Finally, utilizing SmarR0B2 nonholonomic middle-size autonomous wheeled mobile robot and by means of software, this paper compiles program to implement nonholonomic mobile robot motion control system. Simulation and implementation results validate that the point stabilization and the trajectory tracking control laws proposed in this paper are effective.