公开(公告)号：CA2227545A1

公开(公告)日：1997-02-27

申请号：CA2227545

申请日：1996-08-09

Applicant: ROSEMOUNT INC

Inventor： HAYS COY L ,  WARRIOR JOGESH ,  HEDSTROM KALE P ,  ZOU HEHONG

IPC: G05B13/02 ,  G05B11/42 ,  G05B13/04 ,  G05B23/02

Abstract: A process control system (100) controls a process (110) through a control output signal (u(t)) based on a set point (YSET) and a measured process variable (y(t)). The process control system (100) includes a control circuit having a set point input, a process variable input and a control output. The control circuit generates the control output signal (u(t)) on the control output as a function of the set point (YSET) received on the set point input and the measured process variable (y(t)) received on the process variable input. An auto-tuning circuit (106) excites the process (110), estimates a process model based on a rising dead time, a rising rate-of-change, a falling dead time and a falling rate-of-change in the measured process variable (y(t)) and then tunes the control function to the process (110) based on the process model. The auto-tuning circuit (106) obtains robust results, but is computationally simple such that the circuit can be implemented with hardware or software in low-power and low-memory applications, such as in field-mounted control units.