Robust speed control of a spherical robot using ARX uncertain modeling

Navigation of spherical robots with constant speed along a straight or curved path is investigated in this paper. A spherical robot driven by motors with constant speed will not necessarily move with constant linear speed. To overcome this problem, one must find a specific velocity function as the motors input which yields a constant linear speed for the robot. The nonlinearity which hides in the dynamics of the robot makes it behave differently at different motor (input) velocities. Therefore, a robust controller is needed to grant desirable performance at different speeds. Here, using ARX (Auto-Regressive Exogenous) modeling the uncertainties are modeled in order to design a robust controller. The models have been verified by experiments. Simulations performed on the controlled system support the proposed design.