Modeling and Control of Omnidirectional Mobile Robots with Active Casters

Abstract

This paper presents modeling and control of omnidirectional mobile robots propelled by active-casters (poweredcasters) . This type of mobile robot is redundantly actuated since it is controlled by more than four motors while its configuration is represented by three DOF on the ground. The modeling method is generalized down to n-wheeled mobile robots and a unified modeling procedure is presented for flexible designs with variety of wheel layout. The kinematic model derived by proposed method enables continuous linear full state feedback control with no consideration for singular configurations of robots. Performances of three- and fourwheeled robots with full state feedback controllers and proposed kinematic models are tested by computer simulations. Furthermore, a three-wheeled robot prototype is design, built and tested for the verification of the proposed modeling and control method for omnidirectional mobile robots in the real world.