双通道飞机刹车系统控制方法研究

【作者】 陈金花；

【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】 飞机防滑刹车系统是飞机上相对独立的子系统,在飞机的起飞、着陆及滑行过程中起着重要作用,控制律的设计是刹车系统中最为关键的技术。 针对目前刹车系统建模与控制方法都基于单通道模式所存在的不足,本文通过对飞机机体及轮胎等模型的双通道建模,给出了双通道刹车系统控制律的设计方法。采用模糊控制和BP神经网络的思想来设计控制律,并以双通道平衡调节方法来协调左右主轮的防滑控制。 该模糊控制方法以基准速度与机轮速度之差及其变化率为输入变量,防滑控制电流为输出变量,借助专家的实践经验总结出控制规则,设计出了基于该输入输出变量和控制规则的二维模糊控制器。同时针对飞机滑跑过程中存在低速段深度打滑现象,采用BP神经网络改善了飞机刹车过程中的低速性能。BP神经网络选取速度差和防滑电流作为网络训练的输入-输出数据对,以平均误差和最大误差作为评价标准,经过离线训练得到理想网络结构并将其应用于刹车系统。 在Matlab6.5/simulink平台下,对建立的双通道刹车系统模型及改进后的控制方法进行了全系统的数字仿真。仿真结果表明:基于双通道模式所建立的数学模型基本能反映飞机真实刹车过程;所设计的控制律能使飞机左右主轮速度基本保持一致,防止了飞机左右主轮载荷不平衡情况下的侧滑,避免了飞机滑跑过程中易出现的低速打滑现象,改善了刹车系统性能。更多还原

【Abstract】 Aircraft anti-skid braking system is a relatively separate subsystem in aircraft, which plays a very important role in taking off, landing and skidding, and the design of control law is regarded as the most important technique in the whole system.For the shortage that system model and control are both based on single channel, the bilateral wheels models are separately established and the double channels system control law is put forward in this paper. The fuzzy control and BP neural network are used to design control law in this paper, and bilateral wheels is coordinated to control by balance algorithm of double channels.The difference between the reference velocity and wheel velocity and its differential are used as input variables. Anti-skidding current is used as output variable. And control rules are summarized according to the experience of professionals. The 2-dimention fuzzy controller is designed consequently. For the shortage that airplane is easy to skid at low speed, BP neural network is used to improve system performance. The difference between the reference velocity and wheel velocity and anti-skidding current are used as input-output datum in BP neural network, and the most great error and average error are applied to evaluate controller. The perfect controller used in system is given by training.The double channels model and improved control used in the system are simulated in the Matlab6.5/simulink. The result shows: The model based on double channels accords with the fact. The control law ensures that airplane bilateral wheels velocity is consistent, prevents sideslip and severe slip, improves system performance.更多还原