Design of nonlinear flight control law based on bifurcation tailoring

The global and continuous flight control law was designed via the bifurcation tailoring and eigenstructure assignment methods. Based on the equilibrium branches of aircraft flight dynamics, the feedforward control law was designed by utilizing the continuous method, by which the shape of the equilibrium branches was modified to make the output variables trace the input commands. The uncoupled gain-scheduled feedback control law was designed via the eigenstructure assignment technique to meet the requirement of flying qualities, and the equilibrium branches of the uncommand motion were tailored. Control bifurcation was analyzed for the feedforward open-loop control system and the feedback closed-loop control system. The control law design and computer simulation for a static unstable aircraft were presented to demonstrate that the unexpected bifurcation behaviors were restrained and the stable flight envelope was extended.