非对称载荷下飞机刹车系统控制与仿真技术

【作者】 姜伟；

【导师】 谢利理；

【作者基本信息】 西北工业大学 ， 电力电子与电力传动， 2006， 硕士

【摘要】 通过分析飞机刹车系统组成、工作原理、控制策略及其仿真平台的发展现状,基于国内飞机刹车系统研究的现实需求,考虑到仿真系统的实现条件和经济适应性,给出了刹车系统新型控制律设计和跑道模型参数辨识的方法,并构建了相应的仿真平台。 在控制律设计方面,针对飞机主起落架非对称载荷的影响,分析了目前刹车控制系统存在的问题,提出了基于自适应神经模糊推理的飞机防滑刹车系统控制律设计方案;该方案采用速度差加压力偏调的控制方式,通过神经网络的自学习特性制定模糊规则,完成模糊推理系统设计,它与压力偏调级和平衡调节级相结合,组成复合控制器,实现了飞机刹车系统的防滑控制与非对称载荷的平衡调节。 针对轮胎—跑道模型的不确定性,利用进化计算中的遗传规划算法,通过遗传程序对实际地面结合系数—滑移率样本库进行了遗传进化操作,得到各种跑道状况下的结合系数随滑移率变化特性,实现了跑道模型参数的辨识,并将辨识结果应用于模型的改进之中,取得良好的仿真效果。 设计了飞机刹车系统仿真平台方案,从仿真执行流程的角度出发,按照主、从子系统模块分离的方式完成了全系统模型的代码转换,并利用VC与MATLAB工具混合编程的方法,实现了飞机刹车仿真系统软件平台的构建。 针对本文提出的自适应神经模糊推理控制律设计方案以及跑道模型参数识别方法,以某型飞机为例,对飞机刹车系统进行了仿真研究,实验结果表明:飞机刹车系统控制律设计方案合理可行,控制方法有效、利用遗传规划的辨识方法得到的跑道模型能较真实地描述轮胎与跑道的变化特性,所构建的仿真平台也能较真实地反映飞机刹车系统环境。更多还原

【Abstract】 The structure and principle of aircraft braking system are analysed and the control strategy and simulation platform are reviewed. Considering the constraint of cost, new control law is designed. The runway model parameter identification method, which satisfy the requirement of development of aircraft braking system is also presented.On basis of analyzing problems caused by asymmetrical load of braking control system, an scheme is given to adjust anti-skid current with the method of PBM control that makes velocity dispersion as control variable and adopts the adaptive neuro-fuzzy inference system (ANFIS) to get fuzzy algorithm through neural network. Then, designation of anti-skid controller is completed through integration of ANFIS、 PBM module and balance adjusting module.For the purpose of overcoming the uncertainty of tyre-runway model, genetic programming(GP) based on evolution computation is used to get the relation of friction coefficent and slip ratio from the set of samples under different runway conditions, and the formulas from parameter identification are applid to improve system mathematic model.Moreover, the flow of generating programming code for the subsystems which are separated from the system model is presented and a method of mixed programming with VC and MATLAB tools is introduced in order to build software platform of the simulation system.The results of simulation under three different kind of runway conditions indicate that the control scheme is correct and feasible, the runway model improved via para--meter identification could describe the real frictional characteristics and the aircraft braking simulation system could reflect real environment and satisfy the requirement.更多还原