飞机起落架缓冲器的主动控制技术的分析与研究

【作者】 王铁勇；

【导师】 侯明善；

【作者基本信息】 西北工业大学 ， 电力电子与电力传动， 2003， 硕士

【摘要】 在飞机起飞和着陆过程中，由着陆冲击和跑道不平引起的冲击载荷和振动，会造成飞机机体疲劳损伤、乘客不适及地面驾驶操纵能力的降低。因此，在设计飞机起落架缓冲器时，必须限制起落架传递给飞机的冲击载荷。传统的起落架缓冲器是一种被动控制系统，其参数一经选定，在飞机起降过程中就无法进行改变，因而缓冲效果不理想。本文主要研究了主动控制技术在起落架缓冲器控制系统中的应用，针对缓冲器系统变参数的特点，运用不同的方法来对主动控制器进行了设计，达到了改善系统性能的目的。 本文的主要工作有以下几个方面： (1)建立了飞机起落架缓冲器主动控制系统的数学模型。本文首先给出了起落架缓冲器物理模型(包括质量-弹簧-阻尼器力学模型)，通过对力学模型的分析得出了系统的动力学方程。随后，通过公式推导，建立了整个系统的数学模型和传递函数表达式。 (2)分析了参数的变化对系统性能的影响。在飞机起降过程中，系统的一些参数(如飞机机体的质量、起落架缓冲器的阻尼系数与刚度系数，地面输入等)都会发生变化。本文分析了这些参数的变化对系统性能的影响，并给出了这些参数的变化范围。 (3)进行了主动控制器的设计。在确定控制系统的结构后，本文采用由简到繁的设计方法，依次使用PID控制、前馈控制、模糊控制、自适应控制进行了主动控制器的设计。 (4)比较了被动控制系统与主动控制系统的性能。本文对被动控制系统和加入不同控制器后的主动控制系统分别进行了仿真，并对仿真结果进行了分析比较。结果表明，添加主动控制器后，主动控制系统的性能与被动控制系统相比得到了明显的改善。更多还原

【Abstract】 During aircraft take-off and landing phases, the dynamic loads and vibrations caused by landing impact and the unevenness of runway will result in airframe fatigue , discomfort of passenger and the reduction of the pilot’s ability to control the aircraft. Therefore, the dynamic loads should be considered and limited in designing landing gear. The traditional landing gear is a passive system and the parameters changes may produce an unsatisfactory performance. This paper mainly researches the application of the active control technology to the landing gear system. The aim is using different control methods to design the active controller to improve the performance of the system, according to the characteristic of the parameters’ variations. The main work of this thesis:1 . The mathematical model describing the landing gear active control system is established. An available mechanical model with two degree of freedom that consists of a mass, a spring and two dampers is given. By the use of this model, motion equation and formulas are deduced. Then the mathematical model and the transport functions are established.2. The influence of the parameters on the system performance is studied. Severalparameters will change during aircraft take-off and landing phases. This papergives the fields of the parameters’ variations and analysis the influence ofparameters’ variations on the system performance.3. Active controller, such as PID type , feed-forward type , fuzzy type and adaptivetype are designed and used in the system.4. Simulations are formed for the passive control system and active control system with different controller. Then the performance of the active and passive control system is compared. The results show that active control system has superior performance over the passive control system.更多还原