3D dynamical analysis for a caster wheeled mobile robot moving on the frictional surface

In this paper, the equations of motion of the 3D dynamical model of the caster wheeled mobile robot moving on the horizontal flat surface are derived. During the process of deriving the equations of motion, the robot body and three wheels of the mobile robot system are viewed as four rigid bodies. The three wheels of the mobile robot are subject to sliding and skidding if the friction force at the contact point can not provide enough resistance to prevent the wheels from slipping. Therefore, the constraint arising from the non-slip condition between the wheels and the ground is released. The Lagrange equations of motion of the system with two inputs are obtained. These derived equations of motion can be expectantly used in many aspects, such as path tracking, adaptive control, and motion control of the mobile robot.