Trajectory tracking of Wheeled Mobile Robots: A kinematical approach

Abstract

This paper presents a novel control approach for trajectory tracking control of nonholonomic Wheeled Mobile Robots (WMRs) which is named “Lyapunov-based Guidance Control (LGC)”. To date, various methodologies have been suggested for solving this problem. However, the proposed kinematical method of this investigation has some advantages in terms of its mathematical simplicity, and good tracking performance due to the developed “Guidance” scheme. The controller is designed to guide the robot to its proper orientation at each instant. In this paper, a heading angle scheduler is first proposed which provides an appropriate heading angle of the mobile robot at each instant. Then, to adjust the linear and angular velocities of the robot, a set of control laws is proposed based on the appropriate heading angle. It is also proved that the closed-loop control system is stable. The achieved results of the proposed scheme are compared with those of Model Predictive Control (MPC), Linear State Tracking Control (LSTC) and Nonlinear State Tracking Control (NSTC) methods. The experimental implementation results obtained through a WMR test-bed show the effectiveness of the proposed kinematical controller.