A straight forward way to design nonlinear controllers for nonlinear processes by means of process discretization

摘要

Nonlinear controllers which include many adjustable parameters are more flexible in application and demonstrate better performance than do linear controllers if the appropriate parameters in the nonlinear controller can be found. We describe how to determine the appropriate parameters in a nonlinear controller for a nonlinear process in a simple and straightforward manner by formulating a parameter optimization problem in which the controller parameters sought are those that cause the controlled processes to exhibit responses close to those given by the design specifications. The nonlinear process model is discretized, so that one can determine the controller parameters by solving a set of algebraic equations instead of iteratively solving a set of ordinary differential equations representing the process, as is frequently required in standard parameter optimization procedures. An example of a nonlinear controller design for a nonlinear chemical reactor illustrates the validity and simplicity of the design procedure.