Semi-Active Vibration Dynamics Control of Multi-Cart Systems Using a Magnetorheological Damper Master’s Thesis in the International Master’s programme Applied Mechanics

Application of Magneto-Rheological (MR) dampers in semi-active vibration dynamics control of a multi-cart system is studied. The dynamics and vibration behaviour of a two cart system is investigated mathematically and an experimental test-rig is employed to verify the model, experimentally. The Bouc-Wen model is utilized to represent the mathematical behaviour of MR damper. Different types of semi-active control strategies as well as passive vibration control technique are implemented in MATLAB and LabView Compaq-RIO. In the passive case, the damping coefficient remains constant during the operation. While in semi-active control strategy, the main idea is to change (in real time) the passive components characteristics to improve the damping performance. Semi-active control technique can be used for vibration control and energy dissipation purposes in different dynamical systems to adjust the damping components and improve the performance while consume a small amount of energy. In this regard, different semi-active control techniques including Skyhook, Groundhook and so on are explored and compared mathematically and experimentally. In each particular case, the root mean square (RMS) values of the first and second cart displacement, velocity and acceleration levels are determined and compared. Finally, the results have shown significant improvement in semi-active control strategies, up to 20%, in comparison with the corresponding optimized passive case.