PROCESS CONTROL METHODS AND APPARATUS

The present invention provides a method for controlling a process by inputting a deviation between setpoint and process variables to a controller to calculate a controlled/manipulated variable, and then inputting the controlled/manipulated variable to the process, wherein conditions for the process variable to settle within a finite length of time are determined from the final-value theorem, the transfer function of the controller is derived from the conditions, and the value of or change in the controlled/manipulated variable with which to control the process is calculated using the transfer function. With this control method and apparatus for the method, it is possible to allow even a process with a long dead time and a large time constant to settle within a short length of time.