Pusan National University team engineers adaptive smart vibration isolator

Conventional vibration isolators rely on a trade-off: soft springs are necessary for low-frequency isolation, but they struggle to support heavy loads. Quasi-zero stiffness (QZS) systems have attempted to decouple these requirements by pairing positive and negative stiffness elements. However, these systems traditionally fail when payloads change, as their performance depends on rigid parameter tuning. They also frequently suffer from residual resonant peaks, leading to high-amplitude oscillations.

A team led by Professor Seunghun Baek at Pusan National University addressed these flaws by developing a rhombus-shaped QZS isolator equipped with motor-driven actuators. Published in the journal Mechanical Systems and Signal Processing, the study details how the system uses two distinct control laws. The first shifts the equilibrium point to accommodate varying weights, while the second dynamically adjusts the system to dampen resonance. Experiments on a prototype confirmed the design's effectiveness, maintaining stability across payloads ranging from 1.01 kg to 1.21 kg. This development could prove vital for high-precision industries such as semiconductor manufacturing and robotics, where equipment must compensate for shifting weights in real time.