# Design, Experiment, and Improvement of a Quasi-Zero-Stiffness Vibration Isolation System
## 4 Experimental Setup and Results  
### Experimental Apparatus  
An experimental prototype of the proposed QZS isolator shown in Figure 9a was developed to validate the vibration isolation performance. The entire experimental system consisted of an experimental prototype, an acceleration analyzer, a power amplifier, a shaking table, and a data acquisition analyzer. The experimental prototype contained an isolator and a mass. An acceleration sensor was mounted onto each of the shaking table and the mass, and the acceleration signals were transmitted to the data acquisition analyzer. The shaking table provided excitation movement for the prototype of the QZS isolator. Figure 9b depicts the scheme of the experimental system.  
Figure 8: The force transmissibility of the QZS system: (**a**) the transmissibility when \(\zeta\) increased and (**b**) the transmissibility when \(\overline{F}_{0}\) increased.  
There were three main parts of the QZS experiment system. The first part was the excitation chain, which included the computer, the power amplifier, and the shaking table. The power amplifier received the signal about the frequency sweep range from the computer and transmitted the signal to the shaking table for movement. The second part was the QZS vibration isolation system, which included the isolation platform and the mass, as shown in Figure 1. The platform at the bottom of the isolator was rigidly connected to the shaking table using bolts. There were two linear motion bearings to ensure that the platform and the mass could have movement in the vertical direction. The third part was the signal acquisition system, which included two acceleration sensors (the acceleration type was EY2010, input range: \(\pm\)10 g, full-scale accuracy: \(\pm\)5%, work frequency: DC-2 kHz; YEC, Inc. Yangzhou, China ), data acquisition analyzer (the data acquisition analyzer type was Elite, input channels: 4, input voltage: 0-10 V, input frequency: 0-10 kHz, CMI, Inc. Beijing, China), and the analysis software was Elite **II** (Version 1.3). An acceleration sensor was put on each of the mass and the shaking table. The data acquisition analyzer could receive the acceleration signals and transfer them to Elite **II** to get the result of the experiment after analysis. The entire block diagram of the experiment can be seen in Figure 10.  
Figure 10: The block diagram of the experiment.  
Figure 9: Experimental prototype and scheme for the QZS isolator system: (**a**) experimental prototype and (**b**) scheme of the experiment system.  
This study conducted two different kinds of experiment: the experiment for the QZS isolation system, and the experiment for the corresponding linear vibration isolation system. A comparison was made between the results of the two different experiments. The corresponding linear vibration isolation platform was that of the QZS vibration isolation platform without the magnetic rings. The geometric parameters of the magnetic rings are shown in Table 1.  
To verify the effectiveness of the QZS system, the dynamic test experiments were conducted for both the QZS system and the linear system. Then, the experiment used to detect the jump range of the QZS system was carried out.