Ability of energy harvesting MR damper to act as a velocity sensor in vibration control systems

The study investigates the self-sensing ability in an energy harvesting magnetorheological damper (EHMRD). The device consists of a conventional linear MR damper and an electromagnetic harvester. The objective of the work is to demonstrate that the EHMRD with specific self-powered feature can also serve as a velocity sensor. Main components of the device and design structure are summarized and its operation principle is highlighted. The diagram of the experimental set-up incorporating the measurement and processing unit is provided, the experimental procedure is outlined and data processing is discussed. The self-sensing function is proposed whereby the relative velocity of the EHMRD can be reconstructed from the electromotive force (emf) induced in the harvester coil. To demonstrate the adequacy of the self-sensing action (i.e., the induced emf should agree well with the relative velocity), the proposed self-sensing function is implemented and tested in the embedded system that will be a target control platform. Finally, the test results of the system utilizing a switching control algorithm are provided to demonstrate the potentials of the EHMRD acting as a velocity sensor and to confirm its applicability in semi-active vibration control systems.