A comparative study of the stability and efficiency of the seat’s isolator with QZS’s different models

To evaluate in detail the vibration characteristics and isolation efficiency of the driver’s seat using the different structures of the quasi-zero dynamic stiffness (QZS), four different models of QZS, including the QZS using X-shaped structure (QZS-X), QZS using the scissor-like structures (QZS-SS), QZS combined with KDamper (QZS-KD), and QZS using pneumatic springs (QZS-PS), are proposed and established. The effect of the design parameters on their efficiency and stability is then analyzed. The design parameters are then optimized to compare the isolation efficiency between QZS-X, QZS-SS, QZS-KD, and QZS-PS based on the index of the seat’s acceleration. The study results indicate that the dynamic parameters and ratios of the geometric dimensions and stiffness greatly affect the dynamic stiffness and comfort of the driver; even a small change in these parameters also greatly affects their isolation efficiency. Accordingly, these parameters and ratios need to be accurately calculated to ensure the efficiency and stability of the models. These parameters and ratios need to be accurately estimated in the design to provide the best efficiency and stability of the models. Besides, the isolation efficiency and stability of different models are different. The models that use the negative force generated by the QZS directly acting on the driver’s seat to balance the positive force generated by the seat isolator have better isolation efficiency and stability than the models that use the QZS indirectly acting on the driver’s seat. Accordingly, the design method of the seat isolator using the QZS directly acting on the driver’s seat should be adopted.