Design and Research of Semiactive Quasi‐Zero Stiffness Vibration Isolation System for Vehicles

Abstract

The vehicle-mounted equipment is easy to be disturbed by external vibration excitations during transportation, which is harmful to the measurement accuracy and performance of the equipment. Aiming at the vibration isolation of the vehicle-mounted equipment, a semiactively controlled quasi-zero stiffness (QZS) vibration isolator with positive and negative stiffness is proposed. The vertical spring is paralleled with a magnetorheological (MR) damper, and the semiactive on-off control scheme is adopted to control the vibration. The analytical expression of the isolator’s displacement transmissibility is derived via the averaging method. Then, the vibration isolation performance under different road excitations and different driving speeds is simulated and compared with the uncontrolled passive QZS vibration isolator. In addition, the mechanical structure of the semiactive QZS isolator is designed and manufactured, and the test system is built by LabVIEW software and PXI embedded system. The isolation effect of the semiactive QZS isolator is verified through test data. It is found that the proposed semiactive QZS isolator shows excellent vibration isolation performance under various road excitations, while the passive QZS isolator is effective only under harmonic excitations. The vertical acceleration of vehicle-mounted device can be decreased over 70% after isolation, and the vibration isolation effect is remarkable. The design idea and research results of the semiactive QZS isolator may provide theoretical guidance and engineering reference for vibration isolation.

Performance analysis of the seat suspension using different models of the optimal negative-stiffness-structures

“…The ride comfort of the driver and the performance of the suspension system were mainly evaluated under the random excitation of the road surface based on the power spectrum density (PSD) G ( s 0 ) in ISO-8068 10 and white noise speed spectrum w ( t ). 21,25,26 To compare the isolation performance between the SS, RS, and AS on improving the driver’s ride comfort, the road surface roughness is also built based on the signal w ( t ) and the PSD of the road surface in the frequency region G ( f ) as follows 25,26 :…”

“…The study results of the SS 11,15,26 or the AS 12,17 in the NSS showed that the geometric dimension ratios of g 1 and g 2 ; and the stiffness ratios of b s,r and a 0 strongly influence the characteristic of the non-dimensional restoring force-deformation and the isolation performance of the driver's seat suspension system. To enhance the performance of the SS in the NSS, g 1 = 0.75, g 2 = 1.10, and b s = 0.505 were given in Ref.…”

“…The above results proved that the performance of the NSS is not only influenced by the geometrical dimension ratio and the stiffness ratio of the NSS provided in Refs. 11,12,15,17,26 but also influenced by the design parameters of the geometrical dimensions and dynamic stiffness in the NSS. Additionally, the analysis results also show that both the z wsb and z ·· ws with the AS are smaller than that of the SS and RS in the NSS.…”

Research on a Novel CRSM for a Type of QZS Vibration Isolator

“…A new parabolic cam-roller is designed and used in QZS isolator, and some important theoretical equations are given and the conditions for QZS characteristics are obtained [12]. In addition, CRSM also can be used as negative stiffness mechanism [13][14][15].…”

Vibration response analysis of a two-stage vibration isolation system for large airborne equipment

“…Liu et al . (2011, 2012), Li et al . (2012a, b) studied the influence of aircraft vibration on the vibration of the airborne optoelectronic pod, proposed a two-stage vibration reduction design scheme for the optoelectronic pod and designed two new types of metal rubber shock absorbers, which effectively suppressed the transmission of vibration and made the stability accuracy of airborne optoelectronic pod reach the target.…”