无人机前轮转弯操纵性能仿真分析

Analysis of Aircraft Landing Gear with Four Wheels Nose Wheel Steering Control

飞机地面操纵特性直接关系到飞行任务的安全,四点式起落架由于双前轮的独特设计,其地面操纵系统设计无现成经验可借鉴。以四点起落架无人机为研究对象,基于Matlab/Simulink建立包含气动力、发动机推力、四组起落架缓冲器支柱力及轮胎力的飞机地面运动动力学模型,对飞机不同姿态着陆滑跑过程的动态响应及起落架载荷变化进行仿真分析。分析四点起落架飞机地面转弯原理,得到转弯半径与前轮操纵角、侧偏角的关系。分析不同滑跑速度、不同操纵角度下的三种前轮操纵方式转弯过程中的转弯效果,结果表明,双前轮主动操纵转弯半径最小。重点研究了轮胎侧向力的变化规律以及随动前轮的跟随性能,得到确保飞机转弯操纵安全的前轮操纵角与滑行速度的关系。

Aircraft ground maneuver characteristics are directly related to the safety of flight missions, Four point landing gear due to the unique design of double front wheels, the ground control system design has no ready-made ex- perience can learn .from. The object of this paper is Unmanned Aerial Vehicle with four wheels. The dynamical model of aircraft ground movement contained aerodynamic force, engine thrust, four groups of strut force and tire deflection is established in Matlab/Simulink. The dynamic response of aircraft and landing gear loads are simulated during the process of different attitude landing. By analyzing the ground maneuver principle of aircraft with four wheels, the influ- ences of two important parameters, such as the nose wheel steering angel and the slip angel, on the turning radius are discussed. Turning effects of three types of nose wheel steering mode in different speeds and steering angles are ana- lyzed. Results indicate that the turning radius of double nose wheels steering mode is minimum. The variation law of the lateral friction force of the tire and the following performance of the nose wheel are studied primarily. The relation- ship between nose wheel steering angle and aircraft speed is obtained to ensure the safety of steering operations.