Abstract:

The robust stability analysis of three degrees of freedom helicopter singular systems is complex and difficult to design. Based on state-space theory, the linear dynamics model of three degrees of freedom helicopter was constructed. The conclusions that three degrees of freedom helicopter system is no feasible solution and nonrobust stability are obtained. The conditions for robust asymptotic stability of singular system was derived and proved using LMI(Linear Matrix Inequalities). The ruboust stability of state feedback control rate is found.The three degrees of freedom helicopter system state response curves, indicate that designed controller has better stability and robustness than the LQR(Linear Quadratic Regulator) controller.

Key words: three degrees of freedom helicopter system, linear dynamics model, linear matrix inequality(LMI), robust asymptotic stability, stability and robustness