Enumeration and Motion Planning for Modular Mobile Robots

This report focuses on two different aspects of modular robots, the enumeration of distinct configurations of a modular robot and the generation of gaits for hybrid robots with wheels and legs. Given a particular set of modules from which the robot can be formed, a modular robot made up of these modules can attain a number of different configurations based on the relative attachment of the modules. The distinct configurations possible are enumerated for a locomotion system consisting of a base with multiple ports where wheel or leg modules can be attached. Given a particular configuration of the modular robot, we would like to generate a set of inputs that would drive the robot from an initial position to a desired position. The method used for this must be applicable to different kinds of modules that may be used for locomotion. The method presented here involves generating a set of constant inputs that will drive a drift-free system from an initial to a final desired position. Simulation results are generated for translation and rotation of the robot and motion along a Lie Bracket direction (sideways motion) for the hybrid mobile robot.