AUTOMATIC ADJUSTMENT CONTROL METHOD

摘要

PURPOSE:To attain an optimum process control by performing an automatic control of parameters for proportional, integral and derivative control actions and performing the process control based on the prescribed parameters. CONSTITUTION:A process 10 is controlled by a control signal received from a PID controller 21 with a modified parameter of its derivative control action. Here an arithmetic part 22 compares a response area Ss for one cycle of a process response waveform with the previous response area S1 and the derivative action time of a parameter adjuster 23 is changed by a unit time in the decreasing direction of the response area. Then the process 10 is controlled by the control signal received from the controller 21 whose parameter of the derivative action is set at Td+DELTA2Td. Here a response area S3 for one cycle of the response waveform of the process 10 is determined. Then the derivative action time is increased again by a unit time DELTATd if S3<S2 holds and a response area S4 is obtained. The control of the process 10 is repeated until the response area Sn of the present time is larger than the previous response area Sn-1. Then the previous derivative action time Td+(n+1)DELTATd and the response area Sn-1 are stored when Sn>Sn-1 is satisfied.