초록 ▼

PID control method and PID controller for determining, from a control response from a process, characteristic values representative of controllability and automatically deriving and setting PID constants from the determined characteristic values. The error between a set point and a controlled value

PID control method and PID controller for determining, from a control response from a process, characteristic values representative of controllability and automatically deriving and setting PID constants from the determined characteristic values. The error between a set point and a controlled value is decided as to whether to be due to a change in set point or due to a disturbance, and PID constants are set on the basis of results of decision.

대표청구항 ▼

An auto-tuning PID controller operable to determine, from a control response from a process, characteristic values representative of controllability for said process based on PID constants currently set and to automatically derive and set new PID constants from the determined characteristic values,

An auto-tuning PID controller operable to determine, from a control response from a process, characteristic values representative of controllability for said process based on PID constants currently set and to automatically derive and set new PID constants from the determined characteristic values, said controller comprising: means for extracting characteristic values representative of controllability from an error between a set point for said process and a controlled value therefrom; means for detecting a change in the set point in order to calculate a change width of the set point and to decide whether a control response from said process is due to a change in set point or due to a disturbance applied; and PID-constant determining means for deriving PID constants on the basis of said characteristic values, said determining means including a first determining unit for determining PID constants corresponding to the set point change, a second determining unit for determining PID constants corresponding to the applied disturbance, and means for selecting either one of the first and second determining units on the basis of results of the decision from said detecting means.