Simulation Results Using Shock Absorbers with Primary Intelligence–VZN

Abstract

This paper presents the new concept of a self-adjustable shock absorber called VZN, some simulation results at some specific excitation regimes, and a theoretical roll study. The acronym VZN stands for “VARIABLE ZETA necessary for well NAVIGATION”, where ZETA represents the relative damping, which is changed stepwise automatically, according to the piston position. Both on rebound and compression, the damping coefficients have low values at the beginning of the stroke, becoming medium at the middle of the stroke, and high and very high at its end. Thus a better wheel/road holding, comfort, and protection at the end of the stroke are assured, compared to standard shock absorbers.

The VZN shock absorber, having primary intelligence, is much better than standard ones because this self-adjustable shock absorber confers the possibility of stepwise adjustment of the damping force as a function of the instantaneous piston position, correlated with the load and road conditions.

The simulation tests, using Matlab/Simulink software, conducted on a quarter car model excited by harmonic and multi-harmonic inputs, show better body stability, skyhook behaviour, lower body acceleration, and increased protection of car axles and body, as compared with those provided by conventional shock absorbers.

The theoretical study denotes progressive anti-roll torque, having an anti-gyration effect and favouring the redressing movement.

With other advantages like decreasing lift/squat at acceleration, decreasing dive/lift at braking, and decreasing pick/roll, the automotive self-adjustable shock absorber confers high performances, almost like semi-active suspensions, at low costs, comparable to those of standard shock absorbers.