Jump phenomena in road-vehicle dynamics

Autor: Walter V. Wedig
Rok vydání: 2015
Předmět:
Zdroj: International Journal of Dynamics and Control. 4:213-220
ISSN: 2195-2698
2195-268X
DOI: 10.1007/s40435-015-0182-1
Popis: Provided that vehicles are riding with constant velocity, the mean value of the car driving force needed to compensate energy dissipation through the wheel damping, is calculated. For suitably strong harmonic road excitations, there are two stable and one unstable velocity near the critical speed of the car. This behavior is extended to the case of stochastic roads that shows corresponding effects when the calculated mean driving force is plotted versus the constant car velocity. More important is the inverse case that the driving force of the car is fixed by means of a suitable control meanwhile the car velocity is variable and fluctuates around a stationary mean value. For small car damping and narrow-banded road profile, a further acceleration of under-critical car velocities is no longer possible because of the blockade by the resonance characteristic. The car velocity finally jumps to much higher speeds when the driving force is strongly reinforced in order to pass over the resonance peak. This behavior is investigated for stochastic road profiles described by new second order filter equations under additive white noise applied to the across and along dynamics of quarter car models. To clarify main original contributions, this paper presents first investigations of the along dynamics of quarter car models applying a new nonlinear first order car equation which is strongly coupled through randomly fluctuating car velocities with the second order road and car equations of the vertical road and car displacements, respectively. The associated systematic behavior is numerically investigated by means of covariance equations showing jump phenomena of the mean car velocity that corresponds to the Sommerfeld effect, well-known in rotor dynamics.
Databáze: OpenAIRE
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