A Control Approach of an Omnidirectional Mobile Robot with Differential Wheels

An omnidirectional mobile robot with the new generation of differential wheels-MY wheels (MY3) is developed. This robot is actuated with four MY3 wheels in longitudinal wheeled assemblies and controlled by real-time on-board computer-based control system. It can be used as an AGV on flexible automatic production line with high flexibility. Kinematic model of this robot is established and a hyperbolic filtering PD controller is proposed for the trajectory following. Simulation results illustrate that the trajectory following controller is valid. Due to the longitudinal wheel assemblies, the wheel speed curves are discontinuous and periodically jumped, which make it difficult for robot control. To solve this problem, a control strategy using sinusoidal method is proposed to simplify the control. Comparing the trajectory following errors with the general methods, the experimental results illustrated that by using the sinusoidal method tracking errors can reduce about 50%.