Optimal Control of a Class of Discrete Multivariable Nonlinear Systems: Application to a Fermentation Process

The optimal control of a class of discrete multivariable nonlinear systems given by: xk+1=a(xk)+B(xk)uk, yk=C xk, is analysed. A closed-loop structure is obtained with the proposed performance index. The addition of numerical integrators to the output error and the design of an optimal control law for the resultant augmented system lead to a very robust control structure. The performance of this control law is evaluated by applying it to a simulated continuous culture fermentation process.