Bifurcation theory: a tool for nonlinear flight dynamics

This paper presents a survey of some applications of bifurcation theory in flight dynamics at ONERA. After describing basic nonlinear phenomena due to aerodynamics and gyroscopic torque, the theory is applied to a real combat aircraft, and its validation in flight tests is shown. Then, nonlinear problems connected with the introduction of control laws to stabilize unstable dynamic systems and transient motions are addressed. To extend the scope of applications, ongoing research devoted to the analysis of complex dynamic systems, including both continuous and discrete time parts, is mentioned. In conclusion, as a result of work undertaken at ONERA, it is stated that this theory is a useful tool for the study and control of high-dimensional dynamic systems.