飞机大迎角机动飞行控制律研究

CONTROL LAW STUDY OF AIRCRAFT MANEUVERS AT HIGH ATTACK ANGLE

本文以分歧突变理论为基础,采用非线性数学模型,建立了求解分歧面的理论方法。文中通过对分歧面的分析研究,得到了避免飞机出现急滚发散的舵面极限值;通过分析分歧面上平衡解的个数和稳定性的变化情况,设计了使飞机进入或退出失速尾旋的操纵规律。经时间历程验证,所得结论正确可靠。

Based on Bifurcation Analysis and catastrophe theory, a novel theoretical method to forecast jump bifurcation phenomena in the control space is established with nonlinear mathematical models. The jump bifurcation is a type of phenomenon which often occurs in the aircraft maneuvers, such as rapid-roll divergence departure, entry into stall and then into spin from steady, straight flight, or recovery into the state of low angle of attack from high angle of attack. Apparently prediction of these phenomena in the control space will be of much help in the design of control law. By means of studying singular lines in the bifurcation surfaces, we get the critical values of control surfaces avoiding rapid-roll divergence and provide the guide to extend rapid-toll maneuver scope. According to the change of numbers and stability of equilibrium solutions in the bifurcation surfaces, the thesis works out the control law of bringing planes entry into stall, spin, then returning to stable and controllable state at low angle of attack. The calculation of time history proves the conclusion.