An amendatory dynamic model with slip for four-wheeled omni-directional mobile robot

Compared with the common differential driving ones, omni-directional mobile robots (OMRs) have more agilely locomotion performance, which therefore have been applied in many fields. One kind of four-wheeled OMR used in RoboCup Middle Size League competition is presented in this paper. Its kinematics and dynamic model is introduced. And considering the independent drive of four wheels which creates inevitable slipping in motion, the amendatory dynamics model that includes slipping between the wheels and the motion surface is presented. Based on the above slipping model, the velocity feedback PID controller implemented by DSP as the kernel is also given here. Experiments results demonstrate the feasibility of the dynamic model and controller.