Non-homogeneous disturbance observer-based second order sliding mode control

A robust second order sliding mode control scheme for first order dynamic systems is proposed in the present paper. The controller has finite time convergent property and contains two parts. A part is fast power reaching law which is used to stabilize sliding variable and its derivative to zero in finite time without disturbance. The other part is a non-homogeneous disturbance observer, which can provide for exact estimation of the sufficiently smooth disturbance in finite time. As a result, a continuous second order sliding mode is established in finite time. Computer simulation confirms the theoretical results.