EXTENDED NONLINEAR FLIGHT CONTROLLER-DESIGN FOR AIRCRAFT

In this paper, we consider the problem of control of a high performanc e aircraft at large angle of attack using a new method of scheduling l ocal nonlinear control laws designed at different equilibrium points. This approach, referred to here as the extended nonlinear flight contr ol (ENFC), extends the well-known concept of gain scheduling and the m ethods of extended linearization and pseudo-linearization. First, loca l nonlinear feedback controls are designed at a number of operating po ints, using a nonlinear optimal control design method. Then these loca l nonlinear control laws are scheduled using the proposed ENFC approac h. The scheduled nonlinear control law is such that, at any equilibriu m operating point, the Taylor-series-expansion of the control law matc hes exactly that of the local nonlinear control law designed for that operating point. Simulation results are presented to show the effectiv eness of this design methodology. Copyright (C) 1996 Elsevier Science Ltd.