| Mobile manipulator systems hold promise in many industrial and service applications including assembly, inspection, and work in hazardous environments. The integration of a manipulator and a mobile robot base places special demands on the vehicle's drive system. For smooth accurate motion and coordination with an on-board manipulator, a holonomic vibration-free wheel system that can be dynamically controlled is needed. In this paper, we present the design and development of a powered caster vehicle (PCV), which is shown to possess the desired mechanical properties. To dynamically control the PCV, a new approach for modeling and controlling the dynamics of this parallel redundant system is proposed. The experimental results presented in the paper illustrate the performance of this platform and demonstrate the significance of dynamic control and its effectiveness in mobile manipulation tasks.