Microprocessor Control of Low Speed VSTOL Flight.
Abstract
This paper considers the design of an improved three-axis stability augmentation system (SAS) for the AV-8B Advanced Harrier VSTOL aircraft using microprocessor-based digital control. It focuses on improving the handling qualities of the airplane through SAS redesign in the low speed flight regime. Particular attention is paid to the so-called 'weather-cocking' instability encountered in transition (hover to/from conventional) flight. There was a dearth of information about the Harrier's flight characteristics until the development of MCAIR's X22A AV-8B mathematical model, which yielded a set of linearized stability derivatives for the aircraft. The first step toward improvement of the AV-8B SAS requires the use of these coefficients in the developemnt of an analog/hybrid model of both the aircraft itself and of the unmodified SAS. The controller design uses digital state feedback control to relocate the system closed loop poles. It is concludedthat this method of control represents a valid approach to the final solution of the Harrier's stability and control problems and that this controller design concept might be applied to future aerospace vehicles.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 08, 1979
- Accession Number
- ADA077661
Entities
People
- Robert V. Walters
Organizations
- United States Naval Academy