Affordable Fly-By-Wire System Design and Handling Quality Considerations

摘要

Helicopter handling qualities have been well-addressed for conventional helicopter flightrncontrol designs in which a direct mechanical or electrical linkage, or both in the case of arnstability augmentation system, exists between the pilot inceptors and the actuators. Arnnew flight control design is being considered that takes a somewhat different approachrnthan conventional designs. The proposed design is a derivative of the current AH-64rnApache flight control system which is itself a unique flight control design. The Apacherncurrently makes use of a stability and command augmentation system with a uniquernhydraulic actuator. The actuator allows switching from partial-authority electrical controlrnto full-authority electrical control, and thus provides the aircraft with a full-authority,rnself-engaging, fly-by-wire backup control system.rnThe proposed design makes use of the existing unique hydraulic actuator and arnmechanical coupler that permits a new form of fly-by-wire (FBW) control while at thernsame time providing a mechanical backup. The approach allows the removal of much ofrnthe electrical redundancy that conventional FBW systems require while providing all thernbenefits of a full-authority fly-by-wire system. However, it is different from manyrnpresent-day FBW helicopter designs because the actuators define the inceptor’s referencernpoint in all axes. Further, in one of the proposed approaches, there may be some actuatorrnback drive on the inceptors. This paper describes the design, discusses the results ofrninitial desktop simulation work, and future piloted simulation work to assess the resultantrnimpacts on aircraft handling qualities.