Motion control is one of the most critical factors in the design of a robot. The purpose of this paper is to describe the research for applying motion control principles for a mobile robot systems design, which is on going at the University of Cincinnati Robotics Center. The mobile robot was constructed during the 1998-1999 academic year, and called BEARCAT II. Its design has inherited many features of its predecessor, BEARCAT II, such as vision guidance, sonar detection and digital control. In addition, BEARCAT II achieved many innovative motion control features as rotating sonar, zero turning radius, current control loop, and multi- level controller. This paper will focus on the motion control design, development and programming for the vehicle steering control and rotating sonar systems. The systems have been constructed and tested at the 1999 International Ground Robotics Competition with the BEARCAT II running an obstacle course for 153.5 feet and finishing fourth in the competition. The significance of this work is in the increased understanding of robot control and the potential application of autonomous guided vehicle technology for industry, defense and medicine.