【摘要】 飞机在地面低速滑行阶段转弯时前轮和主轮不应发生侧滑^[1]。在实际应用中,为满足上述条件,前轮偏转角速度多取为许用角速度下限进行匀速转弯,但该方式大幅降低了飞机的地面操纵性能。同时,由于复杂布局小车式起落架系统的自由度较高,往往难以求出前轮许用偏转角速度的通解。为解决上述问题,对复杂布局小车式起落架系统建立一套动力学分析模型;并基于模糊控制理论,设计一套前轮转弯角速度控制律。经仿真运算证明:飞机前轮转弯许用角速度主要受飞机速度、前轮偏转角度以及飞机航向载荷等因素影响;在不改变飞机构型、不影响飞机性能及安全性的前提下,可通过降低飞机速度及发动机推力等方式提高起落架系统许用前轮转弯角速度;模糊控制理论可应用于飞机前轮转弯角速度控制律设计;基于模糊控制理论的飞机前轮转弯角速度控制律可充分发掘起落架系统地面运动能力,并显著提升起落架系统地面操纵性能。更多还原

【Abstract】 It is required that,during low-velocity taxi phase,neither nose gears nor main gears shall slide side when aircrafts are swerving[1]. In practical application,the nose wheel turns at a constant rate,equal to the lower limit of the nose wheel allowable steering rate to meet above requirements. However,in this control method,aircraft ground maneuver control performance reduces significantly. Meanwhile, due to the degree of freedom of a multiple-bogie undercarriage system is high,it is too complicated to find the general solution of a nose wheel allowable steering rate. To solve above problems,a kinetic analysis model of a multiple-bogie undercarriage system was built and a control law was designed based on the fuzzy control theory. The calculations and simulations demonstrate that allowable nose wheel steering rate can be affected by aircraft velocity,nose wheel steering angle,and engine thrust; allowable nose wheel steering rate can be improved by reducing aircraft velocity and engine thrust on condition that aircraft configuration is identical and aircraft safety and performance not reduce. Fuzzy control theory can be implemented on nose wheel steering rate control design. Nose wheel steering rate control law based on the fuzzy control theory can fully make use of aircraft ground maneuver control capability and improve aircraft ground maneuver control performance.更多还原