The Reconfigurable Omnidirectional Articulated Mobile Robot (ROAMeR)

Articulated Wheeled Robot (AWR) locomotion systems consist of a chassis connected to sets of wheels through articulated linkages. Such articulated ”legwheel systems” facilitate reconfigurability that has significant applications in many arenas, but also engender constraints that make the design, analysis and control difficult. In this paper we study this class of systems in the context of design, analysis and control of a novel planar reconfigurable omnidirectional wheeled mobile robot. This AWR distinguishes itself from existing wheeled mobile robots by having the capability to change the location of its wheels relative to the chassis. We first extend a twist-based modeling approach to systematically construct the symbolic kinematic model for a general class of AWR before specializing it to our planar AWR example. We then develop a kinematic redundancy resolution scheme to coordinate the motion of the articulated legs and wheels. Two generations of physical prototypes were developed, refined and tested using simulation/virtual prototyping and realtime/hardware in the loop methodologies. Representative results from both sets of approaches are presented to illustrate combined locomotion and reconfiguration.