Apparatus and method for preventing runaway of the integral term of a proportional plus integral controller
US5270916A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 27, 1990 |
| Grant date | Dec 14, 1993 |
| Priority date | — |
| Expiry date | Feb 27, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05B5/01
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
An apparatus and method are provided for preventing the runaway of the integral term of a proportional integral differential controller which is usable in a feedback system. An error signal is supplied to the controller by the feedback system. The controller produces a control variable output signal from the error signal. In accordance with the invention, the controller imposes a slew rate limit on the control variable output signal. Also in accordance with the invention, whenever the controller attempts to drive the control variable output signal to exceed the slew rate limit, the integral term associated with the controller is adjusted to a value which forces the control variable output signal to its slew rate limited value. In this manner, runaway of the integral term associated with the controller is desirably avoided.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.