Continuous sliding-mode control for nonlinear systems with unmatched uncertainties

This paper proposes a virtual control technique based continuous SMC method for nonlinear systems with unmatched uncertainties. During the ideal sliding motion, the systems controlled using the proposed method behaves as a full-order system, not a reduced-order system. The continuous virtual control signals can be obtained to counteract the effect of unmatched uncertainties on the output, and the chattering is attenuated. A continuous and nonsingular control law can be obtained to force the system states to track the virtual control. The simulation results validate the proposed method.