Model Reference Cascade Control of Nonlinear Systems: Application to an Unstable CSTR

The design of a model reference cascade controller is analyzed for the control of a nonlinear system [xdot] = f(x) + g(x)u + d(t), y = cx which has a relative order two. Integral and derivative control actions are incorporated in the control law. Theoretical analysis on robustness of the proposed control scheme under process/model parameters uncertainty is provided. The controller design method is applied theoretically to the concentration control of a non-isothermal CSTR which has a severe nonlinearity and steady-state multiplicities.