Method for determining the air speed of a helicopter, system for carrying on this method and method for calibrating such air speed determining method and system
US4829441A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 18, 1987 |
| Grant date | May 9, 1989 |
| Priority date | — |
| Expiry date | Jun 18, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01P21/025
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The air speed is determined by solving the equation ##EQU1## in which P.sub.z is the pitch of the antitorque device, .gamma..sub.z, the vertical acceleration of the helicopter, k.sub.1 -k.sub.10, parameters depending on the type of helicopter, p.sub.x,y, the longitudinal or transverse cyclic pitch, p.sub.o the collective pitch of the main rotor, .theta..sub.x,y the angle of bank of the helicopter about the transverse or longitudinal axis of the helicopter. The system for determining the air speed may also include a conventional anemometer for hybridization with the computed speed. The parameters k.sub.1 -k.sub.10 are determined by self-calibration and by assuring that the variations of the ground speed and of the air speed are the same from one flight configuration to another one of a pair of flight configurations, among a series of pairs, for which the sensiting parameters of the helicopter are measured in the earth's reference by means of an airborne ground speed reference.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.