Patent · US Expired

Field based process control system with auto-tuning

US5691896A · kind A · utility

39Cited by
25References
29Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 15, 1995
Grant dateNov 25, 1997
Priority date
Expiry dateAug 15, 2015

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG05B11/42
  • WIPO fieldControl
  • WIPO sectorInstruments

Abstract

A process control system controls a process through a control output signal based on a set point and a measured process variable. The process control system 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 on the control output as a function of the set point received on the set point input and the measured process variable received on the process variable input. An auto-tuning circuit excites the process, 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 and then tunes the control function to the process based on the process model. The auto-tuning circuit 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 such in field-mounted control units.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.