Abstract:

The model of aircraft’s ground motion is “operational”,where the airframe has six degrees of freedom. As long as the pilot’s command, the paddle’s displacement, for example, is given, the model can find out the motion of both the airframe and nose wheel, and the interaction between them. The non sliding model of tires is applied but no assumption of airframe’s motion is adopted. The turning angle of the nose wheel is not given in advance. The functions of tire force versus nose wheel’s turning angle are no longer needed while the tire rolling coefficients are employed. There are assumptions about aircraft’s ground motion; one of those widely used is “the center of simultaneous turning of the airframe is the same as the center of curvature of the mass center’s track”. The research in this paper reveals that this is true only when the aircraft is in a steady state turning.

Key words: aircraft, ground vehicles, mathematical models, dynamics, steering