Semi-active optimal control of parallel Multi-DOF vibration reduction system for instrument carried by vehicle

To instrument carried by vehicle, there exits Multi-DOF (multiple degree of freedom) vibration when vehicle is running, because of rough road, starting and braking, turning off and other reasons, which could induce breakage or short life of the instrument. In this paper, a 3-DOF vibration reduction system is designed by using 3-PRRP(4r) parallel mechanism as the main body and using MRFD(magneto-rheological fluid damper) as the absorber. According to the structure and the mathematics model of the system with MR dampers, a feasible LQR controller is proposed to control 3-DOF vibration produced by vehicle. In the experiment section, an experimental prototype including MR dampers is designed and manufactured. Experiment results are analyzed to validate the effectiveness of vibration reduction system. It shows the semi-active system with proposed control law is very effective to control 3-DOF vibration, and it also illuminates the system can be used as a vibration reduction platform for instrument carried by vehicle.