Consideration of Restoration in Yaw Resonance

Yaw resonances cause the rear-end of the vehicle to swing, which is related to the feeling of handling. As a basis for improving this motion, this paper considers the restoration of yaw resonance. The equilibrium position of the yaw resonance is the extension of the velocity vector at the “heading point,” where the vehicle median line is perpendicular to the turning radius in a steady state turn. Toward this position, the center of percussion at the rear-end of the vehicle travels. This travel is the restoration of yaw. Observing the vehicle behavior from the earth-fixed coordinate system at the moment when the heading point changes direction of travel, the heading point and the center of percussion travel in their respective directions. Each motion continues for a distance from the rear wheel to the heading point to reach the equilibrium position. This continues time equals “yaw lead time constant.” Therefore, when the yaw lead time constant is small, the vehicle is restored in a short time.