【摘要】 针对无人机的飞行安全这一典型的系统工程问题,从目前国际惯用的非线性控制和辨识建模的角度出发,通过建立波动信息能量函数模型并结合模糊评价理论,量化分析了DFT变换对无人机系统建模和控制的不稳定性影响;通过对无人机非线性运动模型的分析,说明了该模型中各参数的不稳定关系和不稳定特征,提出了符合Shilnikov定理的三阶非线性模型;通过构造综合影响函数和进行参数配置,确定了无人机非线性运动模型的若干鞍焦点和异宿轨道,从而找到了该系统的若干混沌运动轨道.最后通过仿真证明了直升机非线性运动模型的混沌运动特征和运用DFT辨识模型进行控制的条件下出现无人机不稳定性现象,说明了无人机非线性运动模型混沌运动的存在性及DFT变换中的高阶能量损失和参数配置方式的共同作用模式可构成无人机系统不稳定性的条件.更多还原

【Abstract】 For a typical system engineering problem of unmanned airplane vehicle flight safety,the paper quantitatively analysised the instability effects between the DFT transform and modeling control of the UAV system through the establishment of fluctuation energy function and the combinations of fuzzy evaluation theory from the current international practices perspective of nonlinear controlling and modeling identification,gave out the instability relationship between the parameters and their instability characteristic of the nonlinear motion model of helicopter through the analysis of the modeling process,raised the three-order nonlinear model in line with Shilnikov theorem,showed the possibility of the existence of chaotic orbits.By constructing the comprehensive effect function and parameter configuration,a number of saddle-focus and heteroclinic orbits were discovered.Finally,the chaotic motion characteristics of the non-linear model were proven by stimulation,and the conditions and causes of the existence of the instability were listed by DFT identification model.Additionally,the existence of chaos in a UAV nonlinear motion model was proven.The common mode action of high-level energy loss in DFT transformation and the configuration of parameters constitute the conditions under which a UAV system is not stable.更多还原