Robust switched linear controller for multimode helicopter models

This paper investigates the application of a robust hybrid control design for a small scale helicopter flying with multiple linearised mathematical models. A hybrid control architecture is proposed and will be developed to cope with the complexity of the non-linear system. A class of this control system is known as hybrid control systems which deal with dynamic changes and jump transition behaviour between the changes. The small scale helicopter is known to inherently have these features. In this paper, the behaviours of the small scale helicopter are represented into five linearized models at trim conditions. When a wider region of flight envelope is considered, this approach leads to a switching problem representing changes from one mode to another mode in a predifined order for a safe and successful flight. In this paper we specifically investigate the control of transition dynamics between many modes as a hybrid system. One approach of control for hybrid switch system is characterized by Linear Matrix Inequalities (LMIs) for performance analysis and control synthesis. State jumps of the controller responding to switched of plant dynamics are exploited to improve control performance.