Analysis Of Landing And Handling Characteristic Of Aircraft With Four Wheels

The landing process and ground maneuver characteristics of aircraft are directly related to the safety of flight missions, which is an important part in the design of modern aircraft. The object of this paper is Unmanned Aerial Vehicle with four wheels. Based on the principle of multi body dynamics, the relative coordinate systems are established according to the characteristics of the ground maneuver, and the conversion relationships of the coordinate systems are deduced. Then, the dynamic equations of aircraft ground movement are established. The accurately mathematical model of tire is established by studying the dynamic characteristics of tire detailedly. 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 influences 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 analyzed. 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 relationship between nose wheel steering angle and aircraft speed is obtained to ensure the safety of steering operations. According to the principle of braking, braking system is acceded to the dynamical model of aircraft ground movement. During differential braking operations, some important results are analyzed in different braking torques and aircraft speeds, such as the dynamic response of the aircraft and the lateral friction force of tire. In this paper, the research methods and some valuable conclusions have important significance for the further study of landing and ground handling characteristic of aircraft with four wheels.