應用dsPIC微處理器於表面聲波元件之無線扭力量測系統之研究

Study on Wireless Torque Measurement using SAW Devices Based on dsPIC Microprocessor

劉國興(Guo-Xing Liu)

指導教授 ： 林志哲

國立臺北科技大學/機電學院/自動化科技研究所/碩士(2011年)

https://doi.org/10.6841/NTUT.2011.00203

摘要

本論文為描述了開發出了一種無線式聲表面波感測詢答系統用於測量扭力。扭力測量一直是一個重要的挑戰，許多工業應用中如航空和汽車業。特別是車用的電子輔助轉向系統(EPAS)。本研究的目的是為了設計與製做出一個利用射頻無線式的表面聲波扭力感測系統。本論文之研究，主要在於裝設於旋轉軸上之SAW諧振型式扭力感測器的無線聲波量測，利用dsPIC33微處理器系統晶片控制市售之德州儀器公司RF晶片CC1101作為發射端與接收端，並針對SAW的特性設計中心頻率搜尋程式，目的是要在旋轉軸受扭力變化時可即時量測出其變化程度，以即時監測的方式應用於車輛電子領域或是需要即時監控的精密加工環境之中，可在被測物受扭力時傳送出所受扭力大小之訊號並與其他系統溝通，系統主要使用RSSI強度來判斷SAW當時的中心頻率值，並與未受力狀態計算出頻率漂移程度。無線部份以短距離式天線裝設於軸上，不會受旋轉影響訊號的傳遞。頻率漂移結果傳至UART以及CANBUS上，可及即時將扭力的的變化傳送至電腦端LabView作觀測。

關鍵字

Surface Acoustic Wave ； Torque Sensors ； dsPIC33 ； RF ； RSSI

並列摘要

This thesis describes the development of a Wirelessly interrogated passive SAW sensors for measurements in a Torque. Measurement of torque has always been an important challenge in numerous industries like aerospace and automobile. In particular, there is increasing interest in electric power-assisted steering (EPAS) systems among vehicle manufacturers and component suppliers. To measure the torque via wireless sensing, the purpose of this study is to investigate a measurement system with the SAW sensors via wireless RF electromagnetic waves. In this study, the SAW sensors are attached on a rotational axis and a dsPIC33F microprocessor is used to control the Wireless RF chips CC1101 to do the transmitting and receiving task. Measuring the shift of the center frequency of the SAW sensors can be used to obtain the applied torque of the rotation axis. The measuring system mainly uses the RSSI signal with respect to the frequency to investigate center frequency value of the SAW, and then the value of frequency shift can be transferred to the torque value. Besides, to achieve the wireless transmission, a coupling-type antenna is applied on the axis. Finally, the torque signal is passed through UART and CANBUS to integrate with the other vehicles electron systems.

並列關鍵字

Surface Acoustic Wave ； Torque Sensors ； dsPIC33 ； RF ； RSSI

參考文獻

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B.Jakoby,“Wirelessly interrogable acoustic sensor,” IEEE INTERNATIONAL

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