Affine nonlinear mathematical model for helicopter flight dynamics

Preparing for further study of nonlinear system and nonlinear control law of helicopter, a math model of affine nonlinear system for helicopter flight dynamics is established. In the process of choosing sub-models and giving assumptions, a principle, for which all control variables in differential equations must be linearized and precision of model must be guaranteed simultaneously, should be abided. The model is used to calculate UH-60A helicopter in the conditions of trim in steady straight flight and dynamics responses to different control inputs. The results agree with flight test and have considerable precision comparing to Ames GENHEL model. So, the math model are validated, and the theories and methods that have been used in the math model are all proved.