本研究採用具力電轉換特性的壓電材料(PZT)作為振能回收之媒介，期能研發一自主調頻的壓電樑能量擷取系統(Piezoelectric vibration power harvesting systems)，以達成最大振能回收之功效。壓電樑能量擷取系統係由一具部份貼覆PZT之懸臂樑與一可經馬達驅動之中間支撐組合而成。吾人首先分析壓電懸臂樑獨立之機械特性，並加入力電耦合效應，以假設模態法求得系統的運動方程式。續應用接納法將壓電懸臂樑與中間支撐結合，導出整個能量擷取系統之固有頻率與中間支撐位置之函數關係。
研究中實際製作一自主調頻壓電樑能量擷取系統，當系統受到一外在頻率的激發，貼覆於樑上的PZT會產生一相對應的電壓，經由壓電材料產生之交流電壓，偵測出此電壓的頻率，系統經由已建立的資料庫，尋得支撐的最佳位置，計算所需脈波數並傳送至馬達，推動支撐至指定位置。由於壓電的磁滯效應及其它未定因素，當支撐移動至指定位置後未必是壓電材料輸出最大值，因此系統必須根據壓電材料產生的電壓大小進行微調，使得能量擷取系統的固有頻率能與外在頻率吻合共振，以獲得最大的振能回收效益。
此設計概念頗具創新性，理論模擬與實體量測的固有頻率誤差甚小，足可驗證理論的正確性，再者經由實體測試觀察出可調整的頻率範圍高53%以上，適可提供未來設計振能回收系統的工程人員一參考方向。

In this study, utilizing piezoelectric material(PZT) as a transformer between mechanical and electrical energy, an autonomous self-tuning power harvesting system has been developed for maximum power harvesting .The power harvesting system is composed of partially covered PZT patches on a cantilever beam and there is an adjustable intermediate support in between. Via adjusting the support location the beam vibrates at its resonant state so that maximizes the vibration power harvest.
In theoretical analysis, the electro-mechanical coupling effect of the PZT energy is included. Assumed mode method is then employed to yield the Lagrange’s equation of motion.The receptance method is applied to join the intermediate support and eventually yields the frequency equation.
An autonomous self-tuning PZT beam power harvesting system is set up for experimental work. When the system is stimulated with an external frequency, the PZT will generate a corresponding alternating voltage .By sensing the frequency of the voltage, the system references the established data base and then sends pulses to the motor to move support to an appropriate location.This system also has the ability of fine-tuning so that it yields the maximum power harvesting.
This concept of the research is quite innovative, and the theortical modeling and experimental results of the natural frequencies show precise agreement.The designed mechanism can adjust the frequency range up to 53% or more and it is believed to provide the engineers a valuable reference in power harvesting.

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