This paper presents the application of pulse input techniques in order to study tire dynamics in the frequency domain. Many tire researchers analyze tire dynamics by means of studying the frequency response of tire output responses to sinusoidal frequency inputs, for example, the frequency response of tire lateral force to sinusoidal slip angle input. Pulse techniques are applied in order to obtain frequency responses. The aim is to replace expensive and time-consuming sinusoidal frequency tests. A series of slip angle pulse input tests in various conditions (several normal forces, speeds, and magnitudes of slip angle inputs) are executed on a pneumatic tire. The tire output responses to the slip angle pulse to the slip angle pulse inputs are transformed into the frequency domain using discrete Fourier transform. Several rules of Fourier transform related to the study of tire dynamics are detailed. The frequency responses obtained by pulse techniques are validated by comparison with the results from sinusoidal frequency tests. (A)
Abstract