Vibration control of a precision fabrication platform under multiple frequency excitations

Recently, with the development of precision machining and precision measurement technology, how to reduce the micro-vibration in precision fabrication platforms has attracted more attention. The existing micro-vibration control methods mainly are the passive and active vibration isolation methods. However, the mentioned two methods have their own limitations. As the structure and parameters are fixed, the traditional passive vibration isolator has a poor adaptability for various kinds of vibrations. The active one with high power consumption is unstable for high frequency vibration isolation. As a typical semi-active control technology, magnetorheological elastomer (MRE) with the advantages of low power consumption and good stability has become a hotspot in vibration control fields, whose parameters such as stiffness and damping in real time can be adjusted according to the external excitation. In the paper, a MRE isolator combined with a fuzzy controller (FC) was used to suppress the vibration of the platform under multi-frequency excitations and to deal with the nonlinearity of the isolation system. The model of MRE isolation was established, and the semi-active control conditions applicable to the MRE vibration isolation system were derived. Considering the high nonlinearity of the MRE isolator and the multiple frequency excitation, a frequency-division FC was designed. The effectiveness of the designed controller was verified by control experiments. The designed controller is independent of the system's precise model and can maintain the vibration attenuation performance at a satisfactory level. © 2019, Editorial Office of Journal of Vibration and Shock. All right reserved.