Abstract: To address the constrained vibration absorption bandwidth of passive shock absorbers, a novel solution is proposed in the form of a triple-auxiliary-chambers air spring vibration absorber. This design leverages the variable volume-variable stiffness properties of the air spring and employs the semi-active control strategy known as the "composite frequency response curve" method. Additionally, a nonlinear model is developed for the passive three-additional air chamber air spring, followed by the establishment of the system transfer function through linearization. Finally, an analytical expression for the natural frequency of the air spring is derived.The open-loop and closed-loop pneumatic servo models of active air springs are established using the nonlinear air spring model. Through simulation, the variable volume-stiffness characteristics are observed. In the conducted experiment, the estimated excitation frequency is acquired through the utilization of the fast Fourier transform (FFT) algorithm. Additionally, the infinite impulse response (IIR) filter compensation network is devised employing the zero-pole matching technique to rectify the bandwidth of the velocity sensor. Finally, the vibration absorption characteristics of the active three-additional air chamber air spring are verified. The experimental results show that in the active environment, the natural frequency of the air spring can be incrementally adjusted by dynamically altering the quantity of supplementary air chambers. Moreover, the operational frequency range is broadened in conjunction with the excitation frequency, effectively mitigating resonance of the controlled object within the 1-10 Hz range.

Key words: air spring vibration absorber, additional air chamber, semi active control, composite frequency response curve method, zero pole matching method