Trajectory tracking control of a nonholonomic mobile robot with differential drive

Abstract

This paper presents the development and trajectory tracking control of a nonholonomic mobile robot with differential drive. The used control system is composed of two loops cascaded, with internal PID controlling the speed of the two wheels and an external loop controlling the robot position and orientation. The second one is a feedfoward kinematics controller which is tuned according to desired closed-loop characteristics specified by the user. The control strategies were embedded in a digital module based in a 32-bit ARM microcontroller. In order to evaluate the performance of the developed robot, trajectory tracking tests were carried out for different trajectories and initial conditions. Preliminary experimental results are presented for reference trajectories without obstacles.