Vibration Control using an Adaptive Tuned Magneto-Rheological Fluid Vibration Absorber

An adaptive tuned vibration absorber (ATVA) can be used to suppress unwanted vibrations. If the excitation frequency is time harmonic but the frequency drifts with time it is desirable to retune the absorber so that the natural frequency of the absorber always coincides with the excitation frequency. One way of achieving this is to adjust the stiffness of the ATVA in real-time. This can be attained by integrating a control system with the ATVA so that its stiffness can be continuously adjusted. In this study, the ATVA was designed as a three-layer beam with Magneto-Rheological (MR) fluid in the middle layer. By altering the magnetic field applied to the fluid, the shear stiffness of the ATVA can be varied. A control algorithm is implemented. The control aims to drive the cosine of phase angle between the velocities of the host structure and the ATVA to zero. Computer simulation and experimental results demonstrate that this ATVA is able to retune itself and can maintain the tuned condition within a reasonably wide frequency range.