Flight control system design for an in-flight simulator

Abstract

This paper describes the theoretical development and nonlinear digital simulation results of the model-following flight control system for a new in-flight simulator. A detailed description of the manner in which the feedforward and feedback gains are obtained using an interactive computer-aided-design technique is given. Additional filters in the forward loop enable the feedforward gains to be made independent of the model aircraft parameters even when the actuator dynamics are modeled explicitly. The feedback gains are obtained by using a vector optimization technique. Several timeand frequency-domain measures are used to obtain the required performance. Modified robustness measures based on singular-value decomposition are used to constrain the feedback gains. The sensitivity of the model-following system to changes in flight condition is minimized using a multimodel formulation. Nonlinear simulation results are presented to show the quality of the model-following system and to substantiate the theory and design procedure.