Effective suppression of pneumatic vibration isolators by using input–output linearization and time delay control

• Published in: Journal of sound and vibration Vol. 329; no. 10; pp. 1636 - 1652
• Main Authors: Chang, Pyung-hun, Ki Han, Dong, Shin, Yun-ho, Kim, Kwang-joon
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.05.2010; Elsevier
• Subjects: Disturbances; Earthquake design; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Physics; Pneumatics; Seismic engineering; Seismic phenomena; Solid mechanics; Structural and continuum mechanics; Time delay; Vibration; Vibration isolators; Vibration, mechanical wave, dynamic stability (aeroelasticity, vibration control...); Closed loop; Vibration; Error estimation; State space; State space method; Pneumatic damper; Experimental study; Low frequency; Vibration isolation; Modeling; Robust control; Engineering design; Added mass; Uncertain system; Earthquakes; Resonance frequency; Accelerometer; Fluidic control; Vibration control; Delay time; Reliability; Linearization
• ISSN: 0022-460X; 1095-8568
• DOI: 10.1016/j.jsv.2009.12.003

This paper presents a new state space representation of pneumatic vibration isolators (PVIs) and a design of a robust control, Time Delay Control (TDC), based on it. The new state space model, derived by using the input–output linearization method, is of the phase variable form with the air mass-flow as the control input. This model offers a framework that enables simultaneous suppression of both seismic vibration and direct disturbance (or payload disturbance) with an accelerometer only. Based on this model, TDC is designed and verified with experiments on a single chamber PVI with an accelerometer only. In the experiment, the PVI with TDC successfully suppresses seismic vibration and direct disturbance, both individually and simultaneously. Faced with seismic vibration, the transmissibility of the PVI with TDC has virtually no resonance peak at low frequency; under direct disturbance, the former achieves a 68 percent reduction in settling time of the latter. The final analysis of experimental result shows that TDC effectively estimates the modeling error along with other uncertainties and cancels them, while achieving desired closed-loop dynamics.