一种改进的非定常气动力模糊逻辑建模方法
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摘要
针对飞机过失速机动时气动力和气动力矩出现严重的非线性、耦合性和迟滞性等现象,提出了一种改进的模糊逻辑非定常气动力建模方法。该方法基于大幅振荡风洞实验数据分析结果,充分考虑了影响飞机气动力和气动力矩的不同因素,通过二次型隶属度函数将迎角、迎角导数、迎角二阶导数、侧滑角和缩减频率等转化为模糊输入,将模糊规则计算出的气动力和气动力矩作为模糊输出。与其他方法相比,该方法能够对模糊逻辑模型的结构和参数统一辨识,通用性强,模型精度满足给定的多层相关系数要求。最后,根据奇异摄动理论,设计了时标分离的动态逆控制律,采用了串接链方法实现过驱动系统的舵面偏转分配。通过对比常规气动力和非定常气动力下典型的"眼镜蛇"机动仿真结果,说明了过失速机动时建立精确非定常气动力模型的必要性,也验证了动态逆方法对于非线性系统有良好的控制效果。
We aim at the severe nonlinearity, coupling and hysteresis of the aerodynamic forces and moments whenan airplane has post-stall maneuver. The modeling method is based on large-amplitude oscillatory wind tunnel testdata analysis results and considers various factors that influence the aerodynamic forces and moments. Then we usethe quadratic membership function to transform the angle of attack and its first and second-order derivatives, yawangle and reduced frequency into fuzzy inputs. The aerodynamic forces and moments calculated with fuzzy rules areused as outputs. Compared with other modeling methods, our modeling method can identify the structure and fuzzylogic model in a unitary way and is versatile. The precision of the model satisfies the requirements for given correla-tion coefficients. We design the time-scale dynamic and inverse control law according to the singular perturbationtheory. We also use the Daisy-chain method to allocate the actuator′s deflection in an over-actuated system. Thecomparison of simulation results on the "Cobra" typical maneuver under normal and unsteady aerodynamic forcesshows the necessity of establishing a precise unsteady aerodynamic model when an airplane has post-stall maneuverand verifies the good control effect of the dynamic inversion method on a nonlinear system.
We aim at the severe nonlinearity, coupling and hysteresis of the aerodynamic forces and moments whenan airplane has post-stall maneuver. The modeling method is based on large-amplitude oscillatory wind tunnel testdata analysis results and considers various factors that influence the aerodynamic forces and moments. Then we usethe quadratic membership function to transform the angle of attack and its first and second-order derivatives, yawangle and reduced frequency into fuzzy inputs. The aerodynamic forces and moments calculated with fuzzy rules areused as outputs. Compared with other modeling methods, our modeling method can identify the structure and fuzzylogic model in a unitary way and is versatile. The precision of the model satisfies the requirements for given correla-tion coefficients. We design the time-scale dynamic and inverse control law according to the singular perturbationtheory. We also use the Daisy-chain method to allocate the actuator′s deflection in an over-actuated system. Thecomparison of simulation results on the "Cobra" typical maneuver under normal and unsteady aerodynamic forcesshows the necessity of establishing a precise unsteady aerodynamic model when an airplane has post-stall maneuverand verifies the good control effect of the dynamic inversion method on a nonlinear system.
引文
[1]孙海生,张海酉,刘志涛.大迎角非定常气动力建模方法研究[J].空气动力学学报,2012,29(6):733-737Sun Haisheng,Zhang Haiyou,Liu Zhitao.Comparative Evaluation of Unsteady Aerodynamics Modeling Approaches at High An-gle of Attack[J].Journal of Aerodynamics,2012,29(6):733-737(in Chinese)
[2]Wang Z,Lan C E,Brandon J M.Fuzzy Logic Modeling of Nonlinear Unsteady Aerodynamics[R].AIAA-1998-4351
[3]尹江辉,刘昶.非定常气动力辨识的模糊逻辑方法[J].南京航空航天大学学报,2000,32(5):545-550Yin Jianghui,Liu Chang.Fuzzy Logic Technique of Unsteady Aerodynamic Identification[J].Journal of Nanjing University ofAeronautics&Astronnautics,2000,32(5):545-550(in Chinese)
[4]孔轶男,王立新,何开锋,等.过失速机动的模糊逻辑建模仿真[J].北京航空航天大学学报,2007,33(10):1174-1177Kong Yinan,Wang Lixin,He Kaifeng,et al.Fuzzy Logic Models for Unsteady Post Stall Maneuver[J].Journal of Beijing Uni-versity of Aeronautics and Astronautics,2007,33(10):1174-1177(in Chinese)
[5]Snell S A,Nns D F,Arrard W L.Nonlinear Inversion Flight Control for a Supermaneuverable Aircraft[J].Journal of Guidance,Control,and Dynamics,1992,15(4):976-984
[6]张力,王立新.推力矢量飞机控制律设计及过失速机动仿真研究[J].飞行力学,2008,26(4):1-3Zhang Li,Wang Lixin.Research on Flight Control Law Design of Fighter with Vectoring Thrust and Post-Stall Maneuver Simula-tion[J].Flight Dynamics,2008,26(4):1-3(in Chinese)
[7]谢蓉,王新民,李俨.超机动飞机动态逆-PID控制器设计[J].飞行力学,2009,27(2):67-71Xie Rong,Wang Xinmin,Li Yan.Dynamic Inversion-PID Controller of a Supermaneuverable Aircraft[J].Flight Dynamics,2009,27(2):67-71(in Chinese)
[8]史静平,章卫国.基于AMS结构分析的串接链可达集求解与优化设计[J].西北工业大学学报,2012,30(4):582-588Shi Jingping,Zhang Weiguo.An Efficient Optimization Method of Daisy Chain Control Allocation Based on Genetic Algorithm[J].Journal of Northwestern Polytechnical University,2012,30(4):582-588(in Chinese)
[2]Wang Z,Lan C E,Brandon J M.Fuzzy Logic Modeling of Nonlinear Unsteady Aerodynamics[R].AIAA-1998-4351
[3]尹江辉,刘昶.非定常气动力辨识的模糊逻辑方法[J].南京航空航天大学学报,2000,32(5):545-550Yin Jianghui,Liu Chang.Fuzzy Logic Technique of Unsteady Aerodynamic Identification[J].Journal of Nanjing University ofAeronautics&Astronnautics,2000,32(5):545-550(in Chinese)
[4]孔轶男,王立新,何开锋,等.过失速机动的模糊逻辑建模仿真[J].北京航空航天大学学报,2007,33(10):1174-1177Kong Yinan,Wang Lixin,He Kaifeng,et al.Fuzzy Logic Models for Unsteady Post Stall Maneuver[J].Journal of Beijing Uni-versity of Aeronautics and Astronautics,2007,33(10):1174-1177(in Chinese)
[5]Snell S A,Nns D F,Arrard W L.Nonlinear Inversion Flight Control for a Supermaneuverable Aircraft[J].Journal of Guidance,Control,and Dynamics,1992,15(4):976-984
[6]张力,王立新.推力矢量飞机控制律设计及过失速机动仿真研究[J].飞行力学,2008,26(4):1-3Zhang Li,Wang Lixin.Research on Flight Control Law Design of Fighter with Vectoring Thrust and Post-Stall Maneuver Simula-tion[J].Flight Dynamics,2008,26(4):1-3(in Chinese)
[7]谢蓉,王新民,李俨.超机动飞机动态逆-PID控制器设计[J].飞行力学,2009,27(2):67-71Xie Rong,Wang Xinmin,Li Yan.Dynamic Inversion-PID Controller of a Supermaneuverable Aircraft[J].Flight Dynamics,2009,27(2):67-71(in Chinese)
[8]史静平,章卫国.基于AMS结构分析的串接链可达集求解与优化设计[J].西北工业大学学报,2012,30(4):582-588Shi Jingping,Zhang Weiguo.An Efficient Optimization Method of Daisy Chain Control Allocation Based on Genetic Algorithm[J].Journal of Northwestern Polytechnical University,2012,30(4):582-588(in Chinese)