Higher harmonic control system for X-Wing aircraft
US4953098A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 13, 1988 |
| Grant date | Aug 28, 1990 |
| Priority date | — |
| Expiry date | Oct 13, 2008 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB64C27/325
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
In an X-Wing aircraft a dynamic higher harmonic control (HHC) system addresses the vibration which typifies a very rigid rotor and is implemented in two ways--a scheduled HHC and an active HHC. A scheduled HHC is located within the quadruple redundant portion of the flight control computers (FCC). This includes look-up maps for the second through fifth harmonic coefficients of the control equation as a function of airspeed and lift for rotary wing (RW) operation, and as a function of rotor speed for conversion (CV) operation. These are added to the collective and cyclic terms of the control equation and implemented through the pneumatic control valve (PCV) actuators. This flight critical portion of the HHC maintains vibration loads within structural limits. An active HHC, implemented in a dual redundant configuration, is added primarily to enhance vibration control during maneuver conditions and during conversions. It monitors vibrations at selected locations and in selected axes of the vehicle and generates corrective factors, which are added to the scheduled coefficients. The active HHC, representing a significant computational burden, is implemented in a separate dual processor …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.