Reconfigurable robots with Heterogeneous Drive Mechanisms: The kinematics of the Heterogeneous Differential Drive

Statically and dynamically reconfigurable robot mechanisms have been extensively studied by a number of researchers. Control formulations have been proposed for specific mechanisms and some researchers have tried to build unified frameworks for general robot control. This paper reports an extension of the differential drive mechanism that we call the Heterogeneous Differential Drive. Bridging the gap between differential drive mechanisms and skid-steered mechanisms, the heterogeneous differential drive permits the modular combination of different types of actuators with different capabilities under one unified framework. It is a step toward a unified framework for actuators we call Heterogeneous Drive Mechanisms that permits reconfigurable mechanisms with homogeneous or heterogeneous components. The heterogeneous differential drive is a theoretical class of vehicles that lies in the gray area between pure differential drive vehicles and pure skid steered vehicles, yet represents either at the extremes. The heterogeneous differential drive also provides the basis for our preliminary development of the heterogeneous drive. This paper develops the kinematic model of the heterogeneous differential drive from the kinematic model of the differential drive formulation and describes an example mechanism.