應用音圈馬達於負剛性系統之研發

Development of Negative Stiffness Systems Using Voice Coil Motors

林英帆(Ying-Fan Lin)

指導教授 ： 鄭志鈞

國立中正大學/工學院/機械工程學系/碩士(2012年)

摘要

本研究設計一藉由音圈馬達產生負剛性之隔振系統，其用以解決當被動式隔振器受低頻外力時隔振效果不彰之缺點。設計一負剛性系統，將其裝置於被動式隔振器上，使被動式隔振器在平衡位置保有原來之剛性，當受外力振動時，其負剛性系統可使隔振器的剛性降低，連帶降低自然頻率增加系統有效隔振範圍。研究中考量此負剛性系統啟動與關閉時機，設計一組電路，藉由位移訊號判別平台振動是否遠離平衡位置，藉此決定啟動負剛性系統之時機以達到隔振之目的。研究中藉由分析與實驗可知使用負剛性系統之等效剛性較未使用負剛性系統之等效剛性低，並由實驗結果可知此負剛性隔振系統僅約有2dB的減振效果；外來若能提高負剛性力量與控制力量大小則負剛性效果可更加顯著。

關鍵字

負剛性 ； 音圈馬達 ； 隔振系統

並列摘要

Negative stiffness produced by a voice coil motor to improve the performance of a vibration isolation system at low frequency is proposed. The passive isolator maintains its original stiffness while the system is statically in its equilibrium position. This isolator stiffness is reduced by the voice coil motor when the system vibrates away from its equilibrium position. The natural frequency of the system decreases due to negative stiffness produced by the voice coil motor, so its performance of vibration isolation can be improved. A circuit that determines the system is above or below its static equilibrium position is designed to timely actuate the voice coil motor. Results from both simulations and experiments show that the system stiffness is indeed reduced by the voice coil motor. Experimental results show that the performance in vibration isolation is improved for only2dB; however, it is believed that the isolation performance can be further improved if a more powerful actuator is adopted.

並列關鍵字

negative stiffness ； voice coil motor ； vibration isolation system

參考文獻

[1] Dijkstra, K., 1988, “Mechanical spring having negative spring stiffness useful in an electroacoustic transducer,” US patent number 4722517.

[2] Tanaka, S., 2003, “Bass reproduction speaker apparatus,” US patent number US 6574346 B1.

[6] S. T. Park and T. T. Luu, 2007, “Techniques for optimizing parameters of negative stiffness,” Proc. IMechE, Vol. 221, pp. 505-510.

[13] Mizuno, T., 2003, “Vibration isolation system using negative stiffness,” JSME, 46, No. 3, pp.807-812.

[3] Saiki, S., 2008, “Loudspeaker with internal negative stiffness mechanism,” US patent number US7454025 B2.