Frequency domain, pseudo-sliding mode control system for a flexible aircraft

Abstract

A control system synthesis technique referred to as pseudo-sliding mode design is applied to the synthesis of a longitudinal flight control system for a flexible aircraft model. The design is interpreted in the frequency domain. As reported in the literature, previous applications of the technique to aircraft flight control have indicated that significant robustness properties in the presence of modelled vehicle damage can be obtained while eliminating the need for control reconfiguration. Although control activity has been shown to be the price to be paid for this robustness, the current application indicates that the pseudo-sliding mode approach is applicable to flexible vehicles. A computer simulation of the flight control system including a mathematical model of the human pilot indicates stable operation in the presence of modelling errors, time delays, sensor noise, turbulence, and modelled vehicle damage.