Bifurcation Analysis and Control of Aircraft Flight Dynamics in Constrained Trims

Nandan Kumar Sinha, Research Scholar, Department of Aerospace Engineering, Indian Institute of Technology, Bombay

A standard bifurcation analysis (SBA) procedure, which requires one of the control parameters of a dynamical system to vary in a continuation and other control parameters to be kept fixed, has been extensively used in the past to investigate nonlinear behavior of dynamical systems. However, it is found that the SBA methodology is not adequate for bifurcation analysis of constrained motions of dynamical systems, which essentially requires manipulation of more than one control parameter at a time. As most of the dynamical systems are often required to perform under some constrained conditions while being free to manipulate all the controls available, it becomes justifiable to look for a bifurcation analysis methodology that would allow investigation of such constrained conditions. An extended bifurcation analysis (EBA) methodology is developed for this purpose, and illustrated with application to investigate constrained flights of aircraft. The analysis carried out by using the EBA technique closely resembles the actual physical conditions. Further, application of the EBA methodology in bifurcation control is explored, and illustrated with design of flight control laws; both, control interconnect and feedback laws. It is found that the EBA technique provides an efficient and economical way to design controllers that are based on intuitive ideas.