Vibrations and cultural heritage preservation: a new approach to protect objects

Vibrations of cultural objects due to different sources (transport, exhibitions, local works) have recently been raising more and more interest from the heritage community. Consequently, the development of anti-vibration protection systems has become a major issue. However, most of the proposed solutions suffer from a lack of adaptability, practicality and effectiveness. To overcome these limits, this paper investigates the possibility to design a vibration control system based on the active control technique, whose purpose is to cancel out the disturbance vibration by creating an opposite vibration. This approach, which allows to control vibrations without contact to the object, is particularly suitable for heritage objects protected by cultural ethics rules. To test the feasibility of this approach, an experimental demonstration bench including a reproduction of a museum shelf and an active control device, composed of sensors and an electro-dynamic actuator, is developed. Vibration source signals similar to those previously measured in situ are applied to the shelf by a vibration exciter. A classic control algorithm, the Filtered Least Mean Square, is used to control the shelf vibrations. Results point out that the control device is able to reduce the amplitude of harmonic, respectively broadband, primary sources by 37.4 dB in 0.15 s and by 14.0 dB in 0.67 s. Furthermore, the system is robust to both amplitude and frequency content changes. Finally, a parametric study shows that the greatest vibration attenuation and the fastest control cannot be achieved simultaneously, so the algorithm parameters must result from a compromise.