Longitudinal flying qualities and controller design for nonlinear aircraft

Shiyang Ryu, Purdue University

Abstract

This thesis presents an analysis tool which predicts longitudinal flying qualities of aircraft subject to elevator rate limiting and nonlinear stick gradient. Our method is based on pilot-in-the-loop analysis and provides an explicit mathematical pilot model for nonlinear aircraft. Using pilot-in-the-loop simulation, flying qualities metrics can be computed for evaluation of the level of flying qualities. The proposed method is validated using real flight data. An aircraft compensator design methodology (CAWCOM) is also presented that improves the flying qualities despite the aircraft nonlinearities. As a result, the control system obtained by the CAWCOM methodology achieved the design goal of improving flying qualities both in terms of reducing the pilot's workload and enhancing the tracking performance. Pilot modeling to represent human pilot's nonlinear behavior and controller design that augments the pilot-vehicle closed-loop system for flying qualities enhancement are the key subjects of this research.

Degree

Ph.D.

Advisors

Andrisani, Purdue University.

Subject Area

Aerospace engineering

COinS