摘要
汽車胎壓偵測系統(TPMS)能在輪胎發生胎壓或胎溫異常時，主動並即時經由無線射頻(RF)系統警示輪胎發生異狀。由於現今的傳統式汽車胎壓偵測系統，大多數是以低於1GHz的Sub-GHz無線射頻頻段，來傳送數據與接收主機通訊，雖然在通訊的格式裡有循環冗餘檢查碼(CRC)的確認機制，也同時使用防止誤判的曼徹斯特編碼，但並沒有導入無線跳頻展頻技術(FHSS)與資料加密機制，有時會因為同頻段干擾而導致接收主機誤判。本論文基於抗無線射頻雜訊與裝置節能省電之功能訴求，研究以低功耗藍芽4.0版本(BLE4.0)，取代傳統式TPMS的無線射頻通訊。使用了128位元的進階加密標準機制(AES)，改善傳統式TPMS誤報的問題，運用低功耗藍芽4.0的省電特性，達到TPMS監測模組的低功耗需求。又基於未來物聯網(IoT)裝置的大量使用及電源節能概念，則能透過BLE4.0結合相關車載裝置與網際網路功能，提供智慧化車載識別與管理應用。
關鍵詞：汽車胎壓偵測系統、無線跳頻展頻技術、低功耗藍芽4.0版本
Abstract
Tire pressure monitoring system (TPMS) can immediately warn drivers of tire pressure or temperature problem. The driver can immediately know of a tire abnormality through a wireless radio frequency (RF) system. Most traditional TPMS systems use a Sub-GHz wireless spectrum under 1GHz radio frequency to transmit data. Although there are already cyclic redundancy checks (CRC) and Manchester Encoding configurations in communication formats, these systems do not include frequency-hopping spread spectrum (FHSS) or data encryption due to co-channel frequency interference. Using radio frequency noise reduction and power saving, we used a bluetooth low energy 4.0 system and BLE4.0 to replace traditional TPMS RF communication. We also adopted 128-bit advanced encryption standard (AES) mechanism to reduce problems with the TPMS system. The low-power features of BLE4.0 reduced power demand significantly. Using the Internet of things (IoT) and power saving ideas, this module can be integrated into vehicle devices through the Internet via BLE4.0 to provide intelligent vehicle identification and management applications in the future.
Keywords: Tire Pressure Monitoring System (TPMS), Cyclic Redundancy Check (CRC), Frequency-hopping Spread Spectrum (FHSS), Bluetooth Low Energy (BLE) 4.0, Advanced Encryption Standard (AES)