Aircraft pitch-axis stability and command augmentation system

US5979835A · kind A · utility

Assignee

• The Boeing Company · US

Inventors

• Kioumars Najmabadi · Bellevue, US
• Monte R. Evans · Federal Way, US
• Robert J. Bleeg · Mercer Island, US
• Richard S. Breuhaus · Issaquah, US

Key dates

• Filing date: Nov 4, 1997
• Grant date: Nov 9, 1999
• Expiry date: Nov 4, 2017

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02T50/40
• WIPO field: Control
• WIPO sector: Instruments

Abstract

Disclosed is a pitch-axis stability and command augmentation system (19) in which a pilot column input (.delta..sub.C) is provided to a pitch command processor (26), the output of which is a C*U feedforward command (C*U.sub.FFC) that is supplied as an additive input to a combining unit (20). The combining unit (20) receives a second additive input of an augmented feedback command signal (AFB.sub.COM). The resulting output is filtered and generates an elevator command signal (.delta..sub.e,FILT). The command processor (26) additionally supplies a corrected column position signal (.delta..sub.C,COR) to a pitch command C*U processor (26) that converts the corrected column position signal (.delta..sub.C,COR) into a C*U pitch command (C*U.sub.PilotCmd), representative of the pilot's requested elevator pitch which is generated by movement of the control column. A computed C*U processor (32) forms a computed C*U signal (C*U.sub.Computed) that is based on the current state of the aircraft. The C*U processor (32) includes a speed stability processor (150) that computes the difference between a reference speed (V.sub.REF) and calibrated airspeed (V.sub.CAS). The speed stability processor (15…