Design of adaptive sliding mode control for spherical robot based on MR fluid actuator

Inner suspension platform of a spherical robot undergoes dynamic oscillation process when the robot is rolling ahead, which significantly reduces stability and precision of the motion. To suppress these vibrations, this study considers an adaptive sliding mode control method for a spherical robot based on application of magnetorheological (MR) fluid actuator. After analyzing the mechanical structure of the spherical robot, a dynamic model describing its rolling motion is derived. Considering the uncertainty of the disturbances introduced by modeling error and outside perturbation, an adaptive scheme is proposed to estimate the dynamic disturbances. Sliding mode technology is applied to construct system controller characterized by robustness and parameter insensibility. Simulations are performed in order to verify the effectiveness of the proposed control methods