Mu control of aircraft in windshear

Abstract

Using H-Infinity/ mu control analysis and synthesis methods, a first-order controller is derived for aircraft flight through moderate to severe windshear. It satisfies robust performance as well as robust stability requirements for a constructed linearized uncertain system containing two repeated scalar uncertainties due to changes in dynamic pressure and angle of attack. Results of applying the derived mu controllers are given for the severe windshear models in W.J. Grantham (1990) and Y. Zhao and A.E. Bryson, Jr. (1990). The input to the controller is the tracking error between a commanded windshear-free nominal airspeed value and the actual windshear-free airspeed during flight through windshear. Controlling this error leads to robust performance against moderate to severe windshear. The results illustrate the significance of keeping the windshear-free airspeed near its nominal windshear-free value. Decreasing it before controlling the aircraft against windshear leads to unnecessary loss in altitude as flight progresses through windshear.<>