Modeling and H∞ control for small-scale unmanned helicopter

In this paper, the problem of attitude stability control of small-scale unmanned helicopter under the environment of wind disturbance have been investigated. Firstly, we developed the nonlinear mathematical model for the unmanned helicopter using the integral algorithm in the framework of blade element theory. Then, for the sake of using H_∞ control theory, we derived the linear model based on the small disturbance theory at the hovering point, and described the upper bound function induced by various uncertainties and disturbance as a second order system. Finally, the H_∞ controller has been designed in the setup of H_∞ control theory, the control system simulation results demonstrate the proposed controller has the H_∞ wind disturbance attenuation performance.