Kinematics and open-loop control of an ilonator-based mobile platform

This paper describes the analysis and implementation of a motor drive control system for an intelligent wheelchair being developed at the Robotics Institute at Carnegie-Mellon University. The experimental mobile platform is mounted on four so-called Ilonators which permit motion in any direction without conventional steering of the wheel axes. The kinematics of the platform were determined analytically and a simulation program was developed to generate reference wheel velocity trajectories corresponding to several basic platform trajectories. These reference trajectories were used to drive the platform under open-loop control. The paper includes a description of the motor-drive hardware implementation, and experimental results. The results of this work provide the foundation for the implementation of feedback control of the wheels and higher-level supervisory control.