Sliding Mode Robust Control for Two-wheeled Mobile Robot with Lower Center of Gravity

Two-wheeled mobile robots (2WMRs) with lower center of gravity exhibit more practicality and operability because their mass center locates on the bottom of the configuration center. By analyzing motion behaviors of the vehicle body, we present the underactuated property and give the dynamics equation of this kind of robot. The system matrices and nonholonomic constraint change drastically because of the unavoidable oscillation companying with underactuated vehicle body. Considering this fact, we propose a sliding mode robust controller based on the nominal models of the system matrices to realize the trajectory planning. The tracking performances can be achieved by adaptively regulating the coefficients of this control law. Simulation results verify the proposed controller is simple, practical and effective for the 2WMRs with lower gravity of center.