Ship stabiliser automatic gain control system
US5452674A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 18, 1994 |
| Grant date | Sep 26, 1995 |
| Priority date | — |
| Expiry date | Jan 18, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05D1/0875
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
An improved fin stabilizer control system which has an automatic gain control (AGC) system which uses the difference between the control laws demand signals and the actual fin angles to calculate a gain factor to reduce the control laws demand until the non-linearities almost disappear. If more than one control law is used to generate a demand, the control laws can be prioritized and the available actuator power thus rationed. In particular, the automatic gain control (AGC) sub-system of the control law monitors the motions of the fins and detects when each fin is not following the control law demands. It adjusts the gain of the control law so as to reduce the slew rate limit and the fin angle limit effects. Although the automatic gain control (AGC) sub-system has the effect of reducing the control law loop gain, it reduces the ship motions below those achieved with a conventional control law because the phase lag between the demanded and actual fin angles is reduced and because generation of harmonics of the demanded fin angle is much reduced.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.