The Semi-Active Control Of Machine Tool Vibration Based On Magneto-rheological Dampers

At present, semi-active control systems have received a great deal of attention in academe and industrial circles to improve machining accuracy. The damper with dynamically variable damping properties is one of the key elements for semi-active suspension systems.MR dampers use MR fluids with a change in Theological behavior when a magnetic field is applied to produce controllable damping. In the dissertation, a state-of-the-art semi-active control system in which the MR dampers are used to replace the passive dampers as the semi-active control actuators has been proposed and developed based on the analytical and experimental investigations of the MR fluid and the MR damper. The theoretically analytical.mulation and experimental investigations are conducted to characterize the dynamical performance and to develop the semi-active control technology of the MR damping semi-active suspension system.The experiment setup of the semi-active system with MR dampers in the lab has been designed and developed. The effectiveness of the proposed the semi-active suspension system with MR dampers is successfully verified by evaluating the dynamical characteristics of different semi-active control algorithms for the semi-active system with MR dampers in time and frequency domains through the numerical simulation investigations and the lab tests under various road excitations. Each proposed semi-active algorithm resulted in improvements in performance of ride comfort and road holding and handling stability in some way. The test results show specially that both of fuzzy logic algorithms possess the flexibility to allow the control designer to adjust the control rules to much more effectively improve the control objectives and only one sensor is needed to measure the control signal for reducing cost. The experimental results of the dynamical characteristics of the semi-active system with MR dampers in time and frequency domains are consistent with the results of the theoretically analytical and simulation investigations. Magneto-Theological (MR) fluid dampers have recently emerged as enabling technology for implementing semi-active control in a variety of application because of their mechanical simplicity, low operating power requirements, environmental robustness, and demonstrated potential for developing forces sufficient for applications. Machine tool with MR dampers can improve machining accuracy...