IJCAS

In this paper, we propose a new sliding mode control for discrete time nonlinear uncertain systems. The uncertainties include both parametric uncertainties in the state model and external disturbances. To recover the lost invariance and robustness properties of discrete sliding mode control, we develop a disturbance estimation scheme to compensate the system uncertainties without affecting the control law. This control approach ensures the stability of the closed loop system as well as chattering reduction. The performance of the proposed controller is applied to control the motion of a cart-inverted pendulum used as a typical benchmark of nonlinear systems. The stabilization problem of the inverted pendulum system is to design a controller to keep the pendulum in its unstable equilibrium point in the presence of disturbances and parameters variation. The simulation result shows the effectiveness of the control design."

Keywords: Cart-inverted pendulum, discrete sliding mode control, nonlinear system, uncertainty, disturbance estimation.