Abstract
In classical control systems, integral-type controllers are widely used to cope with process parameter variations and other perturbations or disturbances. In this paper a method based on the regulator theory to synthesize an optimal multivariable servo-system incorporating the integral-type controllers is described. The principle of this method is similar to the previous one1), but is different in that the integrated values of the tracking errors are introduced as the new process state variables. The advantages of this method are as follows:
(1) Optimal control is easily obtainable.
(2) The resulting control system has feedback and feedforward pass and has optimal tracking properties. Even if process parameters vary from their nominal values, steady state errors do not arise.
In an actual process, state variables are often inaccessible. For such a process the control system can be constructed by utilizing an observer. It is shown in the example that the input-output characteristics of a control system using the observer are less influenced by the process parameter variations than are those of a state feedback system.
