초록 ▼

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). Th

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 computer section, complete with its own input/output signal processing.

대표청구항 ▼

A method of actively providing vibration alleviation by reducing vibratory air-loading in the rotor blades of the rotor in an X-Wing aircraft, which includes a series of pneumatic valve control actuators, comprising the following steps: (a) providing higher harmonic control (HHC) to the rotor and im

A method of actively providing vibration alleviation by reducing vibratory air-loading in the rotor blades of the rotor in an X-Wing aircraft, which includes a series of pneumatic valve control actuators, comprising the following steps: (a) providing higher harmonic control (HHC) to the rotor and implementing it in two forms, a scheduled HHC system and a closed loop active HHC; and (b) continuously processing vibration and HHC data from sensors monitoring vibrations at selected locations and in selected axes of the aircraft and updating the HHC based on the data a multiple number of times in each rotor revolution and generating corrective factors which are used in the HHC to further alleviate the vibration.