Optimal integral control of trim in a reconfigurable flight control system

Abstract

Abstract In the event of control actuator or surface failures reconfigurable flight control is achieved by automatically constructing a new control law which uses, sometimes in a manner differing from custom, the remaining serviceable actuators and control surfaces. An early reconfiguration scheme is shown to be unsatisfactory as its use can lead to instability. Use of a weighted control distribution method produced satisfactory performance but did not restore the aircraft to its original trim state. This paper shows how the use of integral control can achieve reconfiguration, and the effectiveness of the technique in achieving acceptable flying qualities, even in the presence of several simultaneous control surface failures and atmospheric turbulence, without loss of the trim state is illustrated by means of simulation results.