APPLICATION OF CONTINUATION AND BIFURCATION METHODS TO THE DESIGN OF CONTROL-SYSTEMS

The use of nonlinear dynamics theory for the analysis of aircraft moti on and the assessment of aircraft control systems is well known. In th is paper the continuation and bifurcation methods are applied to aircr aft nonlinear control design problems. The search for the recovery con trol from spin regimes is based on the minimization of an energy-like scalar function constrained by the aircraft's equilibria conditions. T he design of a global stability augmentation system for severe wing-ro ck motion is performed by using bifurcation diagrams for equilibrium a nd periodical modes. The nonlinear control law, which totally suppress es wing-rock motion, is derived, taking into account both local stabil ity characteristics of aircraft equilibrium states and domains of attr action, along with the requirement that all other attractors be elimin ated.