Variable structure control of second order nonlinear system

The present paper is concerned with the variable structure control ofa second order nonlinear system. The system considered has an input map of saturation-type nonlinearity. The investigations are made on both kinds of saturation, viz. ideal and realistic ones, to which the feasibility of application of variable structure control has been sought. It is shown that in the case of a realistic saturation type input map even though its inverse is not possible, the switching control law using reaching conditions can still be designed. However, such a law thus designed may not be unique but the effect is shown to have no chattering. A two tank liquid-level system is considered as an example to support the result