薄膜感測器之感測電路與無線通訊設計

Design of Sensing Circuitry for Thin-film Sensor and Wireless Communication System

陳俊豪(Jun-Hao Chen)

指導教授 ： 丁鏞

中原大學/工學院/機械工程研究所/碩士(2020年)

https://doi.org/10.6840/cycu202000492

摘要

本研究之主要目標為設計製作壓電薄膜式感測器之感測電路以及無線通訊傳輸資料。此感測電路包含緩衝電路、差動電路、放大電路、峰值取樣電路、微處理器及無線通訊晶片。為解決壓電薄膜感測器易受環境雜訊60Hz 影響，本研究所設計之差動電路係利用共模特性將感測電壓訊號中的雜訊成份去除，另一特點是利用差模特性來放大感測訊號。因感測器所產生的訊號為脈衝訊號，響應時間極為短暫僅約數百奈秒，使得微處理器可能無法順利擷取訊號。因此考慮加入峰值取樣電路，透過電容之充放電效果將響應時間增長。而充放電時間則需由微處理器依據實測情況調整控制。在峰值取樣電路後端使用RC 濾波方法，將信號中低頻訊號還原其波形。無線通訊是利用藍芽5.0 來鏈結網狀拓撲網，其資料傳輸快速適用於即時資料顯示。最後，經實際測試扳手以及銑切削應用範例之結果，可驗證所設計之感測電路能有效量測的最小解析度範圍0.8mv，且無線通訊可傳輸大量資料且不遺漏封包。

關鍵字

差動式感測電路；信號擷取與分析；無線通訊

並列摘要

In this thesis, design of the sensing circuitry for thin-film sensor and transmission of measured data via wireless communication is investigated. The sensing circuitry mainly includes a buffer circuit, a differential circuit, an amplifying circuit, an insertion sampling circuit, a peak detector circuit, a microcontroller and a wireless communication chip. To overcome the problem of piezoelectric PVDF sensor susceptible to environmental noise at 60Hz, the differential circuit is designed to use the common mode to remove the noise components in the sensed voltage signal and amplify the sensed signal. Thereby,the actual signals can be effectively identified for interpretation. Because the signal generated by the sensor is an impulse signal with extremely short-time period of several hundred nanoseconds, a microcontroller is very difficult to
collect the signal effectively. Thus, using the charge and discharge effect of capacitor of a peak detector circuit is designed, which will increase the response time. The wireless communication uses the Bluetooth 5.0 features, which can link the mesh topology network and transmit the data very fast to achieve the
purpose of real-time data display. Finally, practical testing on the wrench and milling process is carried out. From the experimental results, the designed sensing circuit can effectively measure the signal in a minimum resolution range 0.8mv, and the wireless communication can transmit a large amount of data without missing packets.

並列關鍵字

sensing circuitry；wireless communication；wrench torque measurement；milling process force measurement.

參考文獻

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