An LPV Control Law Design and Evaluation for the ADMIRE Model

Abstract

This chapter presents the design and evaluation of an LPV control law for the ADMIRE model over a specified wide flight envelope, including subsonic, transonic and supersonic regions. The design of the LPV control law is based on the parameter-dependent Lyapunov function approach with gridding of the parameter space. It is demonstrated that by using a linear piece-wise interpolation of the aircraft model the LPV approach allows the design of a controller for the whole flight envelope (including the transonic region) with satisfactory performance and robustness characteristics. The longitudinal LPV controller provides an automatic transition from the α-demand system at Mach numbers M < 0.58 to the nz-demand system at M < 0.62; in the intermediate region a mixed control principle is implemented. A thorough evaluation of the designed LPV controllers is performed using a number of methods, including time and frequency domain criteria, linear and nonlinear simulation tests, and also piloted simulation in real time on the HELIFLIGHT simulator at the University of Liverpool. The performed evaluation clearly demonstrates that the designed LPV control laws satisfy most of the design requirements. Ways of further improving the performance of the LPV controller are discussed at the end of the chapter.