Method and system for changing control parameters in accordance with state of process in process control.

摘要

A determination and control section (7) of a process control system samples a set value, a difference value, a manipulated variable, and a controlled variable to determine a state of a process (3). When it is determined that the process (3) is in an unstable state, an adaptive unit (5) estimates a dynamic characteristic of the process (3), and calculates PID control parameters using a partial model matching method in a frequency region. When it is determined that the process (3) is in an insufficient response state, the PID control parameter is regulated without operating the adaptive unit (5) to decrease the gain of the process control system.