Investigation on a two-stage platform of large stroke for broadband vertical vibration isolation

2018 ◽  
Vol 25 (6) ◽  
pp. 1233-1245 ◽  
Author(s):  
Xiling Xie ◽  
Mingke Ren ◽  
Hongbo Zheng ◽  
Zhiyi Zhang
Keyword(s):  
Vibration Isolation ◽  
Vertical Vibration ◽  
Optical Switches ◽  
Static Properties ◽  
Two Stage ◽  
Maximum Displacement ◽  
Primary Stage ◽  
Low Frequencies ◽  
Attenuation Rate ◽  
Secondary Stage

For the purpose of preventing vibration-sensitive optical switches from malfunction caused by broadband vertical vibration, a novel two-stage vibration isolation platform is proposed. The primary stage is a bellows-type isolator of large stroke and low isolation frequency, and the secondary stage is a small-stroke hybrid isolator composed of bellows and voice-coil actuators. In the primary stage, two pre-compressed horizontal bellows and one vertical bellows are used to counter the weight of the switch and to reduce the total height of the isolator. The static properties of the primary stage are analyzed, and the vibration isolation of the platform is investigated. Numerical results indicate that the two-stage platform is effective in isolating vertical vibration. Experiments are also conducted to verify the performance of the platform. It is exhibited that the transmissibility is less than 0 dB over 2 Hz, and the attenuation rate reaches −35 dB/dec at high frequencies. The frequency range of test is 2–200 Hz, and the maximum displacement is 10 mm at 2 Hz. In the secondary stage, the actuators can substantially suppress the resonance peak, and promote isolation performance at low frequencies.

scholarly journals Shock response of a two-stage vibration isolation system

2020 ◽  
Vol 21 (2) ◽  
pp. 1-11
Author(s):  
Diego Francisco Ledezma Ramirez ◽  
Pablo Ernesto Tapia Gonzalez ◽  
Martín Castillo Morales ◽  
Tania Paloma Berber Solano ◽  
Adriana Salas Zamarripa
Keyword(s):  
Vibration Isolation ◽  
Two Stage ◽  
Isolation System ◽  
Short Pulses ◽  
Vibration Isolation System ◽  
Secondary Stage ◽  
Shock Response ◽  
Vibration Isolation Performance ◽  
Two Degree Of Freedom ◽  
Isolation Performance

Abstract. Two-degree of freedom system, or two-stage mount are used to improve the high frequency vibration isolation performance with the disadvantage of increasing the mass of the system and adding a second resonance. The vibration isolation property is a well-understood topic for harmonic vibration considering linear and nonlinear elements, but not its shock response. The absolute and relative response of a two-stage mount under shock excitation is investigated in this paper. Analysing the effect of the mass ratio between the two-stage, and its respective viscous damping. The potential advantages and issues behind this system are discussed and compared with the single mount. Experimental validation was performed using two commercial isolator and different masses. Findings suggested that a large secondary mass could reduce the shock response in terms of absolute motion. This effect is only significant for the case of short pulses and when the added mass is at least five times greater than the main mass. Being useful to have light damping only on the secondary stage.

scholarly journals Tilt Active Vibration Isolation Using Vertical Pendulum and Piezoelectric Transducer with Parallel Controller

2021 ◽  
Vol 11 (10) ◽  
pp. 4526
Author(s):  
Lihua Wu ◽  
Yu Huang ◽  
Dequan Li
Keyword(s):  
Piezoelectric Transducer ◽  
Vibration Isolation ◽  
Vertical Vibration ◽  
Open Loop ◽  
Negative Effects ◽  
Voltage Controller ◽  
Hysteresis Nonlinearity ◽  
Passive Vibration Isolation ◽  
Active Vibration ◽  
Active Vibration Isolation

Tilt vibrations inevitably have negative effects on some precise engineering even after applying horizontal and vertical vibration isolations. It is difficult to adopt a traditional passive vibration isolation (PVI) scheme to realize tilt vibration isolation. In this paper, we present and develop a tilt active vibration isolation (AVI) device using a vertical pendulum (VP) tiltmeter and a piezoelectric transducer (PZT). The potential resolution of the VP is dependent on the mechanical thermal noise in the frequency bandwidth of about 0.0265 nrad, which need not be considered because it is far below the ground tilt of the laboratory. The tilt sensitivity of the device in an open-loop mode, investigated experimentally using a voltage controller, is found to be (1.63±0.11)×105 V/rad. To compensate for the hysteresis nonlinearity of the PZT, we experimentally established the multi-loop mathematical model of hysteresis, and designed a parallel controller consisting of both a hysteresis inverse model predictor and a digital proportional–integral–differential (PID) adjuster. Finally, the response of the device working in close-loop mode to the tilt vibration was tested experimentally, and the tilt AVI device showed a good vibration isolation performance, which can remarkably reduce the tilt vibration, for example, from 6.0131 μrad to below 0.0103 μrad.

Force transmissibility of a two-stage vibration isolation system with quasi-zero stiffness

2016 ◽  
Vol 87 (1) ◽  
pp. 633-646 ◽  
Author(s):  
Xinlong Wang ◽  
Jiaxi Zhou ◽  
Daolin Xu ◽  
Huajiang Ouyang ◽  
Yong Duan
Keyword(s):  
Vibration Isolation ◽  
Two Stage ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Force Transmissibility

Adaptive control of a two‐stage vibration isolation mount

1990 ◽  
Vol 88 (2) ◽  
pp. 938-944 ◽  
Author(s):  
Scott D. Sommerfeldt ◽  
Jiri Tichy
Keyword(s):  
Adaptive Control ◽  
Vibration Isolation ◽  
Two Stage

scholarly journals Vibration Frequency Characteristic Study of Two-stage Excitation Valve Used in Vibration Experiment System

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Yongping WU ◽  
Chengwei XIONG ◽  
Yi LIU ◽  
Jiafei ZHENG ◽  
Mingxuan ZOU
Keyword(s):  
High Frequency ◽  
Rotary Valve ◽  
Two Stage ◽  
Maximum Displacement ◽  
Experiment System ◽  
Oil Supply ◽  
Supply Pressure ◽  
Vibration Experiment ◽  
Working Principle ◽  
Large Flow

To satisfy the demands of higher frequency and amplitude in hydraulic vibration experiment system, the two-stage excitation valve is presented, and a mathematical model of two-stage excitation valve is established after analyzing the working principle of two-stage excitation valve, then the influence of relevant parameters on the displacement of main spool of two-stage excitation valve is studied by using Matlab/Simulink to calculate and analyze. The results show that the displacement of main spool will be smaller with bigger diameter and more secondary valve ports. When the reversing frequency is higher and the oil supply pressure is lower as well as the axial guide width of valve ports is smaller, the maximum displacement of main spool is smaller. The new two-stage excitation valve is easy to adjust reversing frequency and flow. The high frequency can be achieved by improving the rotation speed of servo motor and adding the number of secondary valve ports; the large flow can be realized by increasing the axial guide width of secondary valve ports and oil supply pressure. The result of this study is of guiding significance for designing the rotary valve for the achievement of higher reversing frequency and larger flow.

Multi-objective optimization of composite two-stage vibration isolation system for sensitive equipment

2016 ◽  
Vol 14 (2) ◽  
pp. 343-361
Author(s):  
Wei Huang ◽  
Jian Xu ◽  
Dayong Zhu ◽  
Cheng Liu ◽  
Jianwei Lu ◽  
...  
Keyword(s):  
Thin Plate ◽  
Vibration Isolation ◽  
Composite System ◽  
Optimization Technique ◽  
Two Stage ◽  
Isolation System ◽  
Vibration Isolation System ◽  
Content Type ◽  
Multi Objective ◽  
Precision Equipment

Purpose The purpose of this paper is to propose a novel strategy of optimal parameters configuration and placement for sensitive equipment. Design/methodology/approach In this study, clamped thin plate is considered as the foundation form, and a novel composite system is proposed based on the two-stage isolation system. By means of the theory of mechanical four-pole connection, the displacement amplitude transmissibility from the thin plate to precision equipment is derived. For the purpose of performing optimal design of the composite system, a novel multi-objective idea is presented. Multi-objective particle swarm optimization (MOPSO) algorithm is adopted as an optimization technique, which can achieve a global optimal solution (gbest), and selecting the desired solution from an equivalent Pareto set can be avoided. Maximum and variance of the four transmitted peak displacements are considered as the fitness functions simultaneously; the purpose is aimed at reducing the amplitude of the multi-peak isolation system, meanwhile pursuing a uniform vibration as far as possible. The optimization is mainly organized as a combination of parameter configuration and placement design, and the traversal search of discrete plate is performed in each iteration for the purpose of achieving the global optimum. Findings An important transmissibility based on the mechanical four-pole connection is derived, and a composite vibration isolation system is proposed, and a novel optimization problem is also defined here. This study reports a novel optimization strategy combined with artificial intelligence for parameters and placement design of precision equipment, which can promote the traditional view of two-stage vibration isolation. Originality/value Two-stage vibration isolation systems are widely applied to the vibration attenuation of precision equipment, but in these traditional designs, vibration participation of foundation is often ignored. In this paper, participation of foundation of equipment is considered, and a coherent new strategy for equipment isolation and foundation vibration is presented. This study shows a new vision of interdisciplinary including civil engineering, mechanical dynamics and computational science.

Sign in / Sign up

Export Citation Format

Share Document