Papers by Keyword: Semi-Passive

Abstract: This paper describes the implementation of semi-passive switching shunt control for electro-magneto-mechanically coupled flexible structures. This simple system consists of a permanent magnet attached to an aluminum beam and a coil placed below the magnet with a switching circuit connected to the end of the coil. The MATLAB Simulink program and dSPACE hardware were employed for realizing the switching mechanism. Switching is done between open-circuit and short-circuits states. When the structure moves away from equilibrium, the circuit is short circuited, thereby dissipating energy, subsequently the system returns back to open circuit state. This novel self-sensing electromagnetic switching damper was compared with the traditional laser-sensing method for vibration control of the structure. The results show that the proposed semi-passive switching shunt damper can be successfully applied to minimize the magnitude of vibrating flexible structures.

Abstract: When a proper shunt circuit is connected with a curved piezoelectric membrane, its bended stiffness can be intensified. The system can be used for sound isolation. This mechatronic system， a typically multi-physics problem, was analyzed with FEM in detail. Frequency response characteristics were obtained when shunted with negative-capacitance in parallel. Transmission Loss was presented from 100Hz to 1000Hz. A wonderful sound isolation performance is obtained when shunted with proper values of negative capacitance. Negative capacitance and the loss of piezoelectric material are the main factors of the system. At some frequencies, the sound isolation performance can be increased when a compensated resistance paralleled with negative capacitance. This compensation is dependent on the frequencies. Due to its ordinary electrical parameters, the sound isolation system is realizable in practice. This sound isolation technology can be used in some fields such as windows of room and car.