Dynamics and control of an omnidirectional unmanned ground vehicle

An unmanned ground vehicle with the ability to change directions without a significant loss in speed would haver superior mobility in confined spaces and tight corridors compared to Ackerman-steered or skid-steered vehicles. Omnidirectional vehicles, which can move in any planar direction regardless of their current kinematic pose, inherently have this capability. However, most omnidirectional vehicle designs are not practical for outdoor use because they are based on specialized wheels that can easily become clogged with dirt and debris. This paper presents a dynamic model of an omnidirectional UGV designed to operate in outdoor, real-world environments at sppeds high enough to excite the dynamics of the vehicle. The analysis includes derivation of vehicle's equations of motion and a control strategy using inverse dynamics. Simulation results are shown to validate the model.