臺灣博碩士論文加值系統

利用接收訊號強度指標（Received Signal Strength Indication，RSSI）進行距離估算的研究，通常只有考慮到環境影響的因素，往往忽略了天線角度或節點感測器偏移對接收訊號強度的影響。另外，大部分研究的量測距離大多只有幾十公尺，對於無線傳感器網路的實用性並不大。因此，為了改善上述缺點與增加量測距離的準確度，本研究將量測距離增加到了500公尺，並將天線角度對接收訊號強度的影響進行校正，以提高RSSI測距的準確度。本研究利用曲線擬合（Curve Fitting）創建出角度補償校正公式和RSSI測距模型，以改善一般RSSI測距準確度不高的缺點。本研究設計出具角度補償功能的RSSI測距節點來接收訊號強度，利用收到的訊號強度以及九軸姿態感測模組的資料，進行距離和角度補償的計算。此節點由微處理器、LoRa傳輸模組、九軸姿態感測模組再加上偶極天線所組成。微處理器選用STM32F411CEU6作為核心，並利用Keil uVision5及CubeMX軟體進行程式開發及撰寫，此微處理器功能齊全、資料完整、周邊設備完善，因此本次研究的系統採用此晶片作為開發晶片。傳輸模組選用LoRa調變的模組，利用LoRa傳輸距離長、低功耗的特性，可以有效地將測試距離拉長至500公尺。本研究創建RSSI測距模型比一般RSSI測距使用的對數陰影模型（Log Normal Shadowing Model）有更好的準確度。另外，有角度補償功能與無角度補償相比，約減少了兩倍的均方根誤差。

In the past, the environmental factors are mostly used to measure the distance by using the received signal strength indication (RSSI), but the influence of antenna angle and sensor node offset factors on the RSSI is often ignored. Furthermore, the measurement of distance is mostly only a few ten meters, but it is not practical for wireless sensor networks. Therefore, the purpose of this research is to improve the shortcomings and increase the accuracy on the measurement of distance. In the research, the measurement of distance is increased from 10 to 500 meters, and the influence of the antenna angle on the RSSI is corrected. It is to increase the practicality of the ranging node, and the angle compensation correction formula and the RSSI ranging model are created by using curve fitting. The RSSI of ranging node with angle compensation function is designed, and the node is composed of a microcontroller, LoRa transmission module, nine-axis attitude sensing, and dipole antenna. STM32F411CEU6 is used as the core of the microprocessor, and Keil uVision5 and CubeMX software is used to develop the program. The transmission module selects the communication mode of LoRa modulation, and utilizes the characteristics of long transmission distance and low power consumption of LoRa, which can effectively extend the test distance to 500 meters. The results showed that the new RSSI ranging model is better than the Log Normal Shadowing model that is usually used in the general RSSI ranging on accuracy. Moreover, the angle compensation function is also better than no angle compensation function.

摘要.............i
Abstract.........ii
誌謝..............iii
目錄..............iv
表目錄............vi
圖目錄............vii
第一章 緒論.......1
1.1 前言.......1
1.2 研究動機 ...2
1.3 文獻探討....3
1.4 論文架構....11
第二章 背景知識....12
2.1 常見的測距技術類型................12
2.1.1 TOA（Time of Arrival）測距.......12
2.1.2 TDOA（Time Difference of Arrival）測距......13
2.1.3 AOA（Angle of Arrival）測距.................14
2.1.4 RSSI（Received signal Strength Indicator）測距.........14
2.2 LORA技術簡介 16
第三章 具角度補償RSSI測距節點設計..................19
3.1 系統架構..................................19
3.1.1 STM32F411微處理器.........................21
3.1.2 RF95M(W) LoRa傳輸模組.....................24
(1)展頻因子(Spreading Factor).....................27
(2)編碼率（Coding Rate）..........................27
(3)頻寬（Bandwidth）..............................28
3.1.3 CMPS12 九軸姿態感測模組....................32
3.1.4 偶極天線...................................35
3.2 開發環境 ..................................41
3.3 接收端系統設計.............................47
3.4 發射端系統設計.............................55
第四章 系統功能與測試.............................57
4.1 CMPS12功能測試.............................57
4.2 實驗步驟...................................58
4.3 RSSI測距實驗...............................59
4.3.1 空曠環境RSSI測距與測距模型創建...............60
4.3.2 角度補償測試................................60
4.3.3 不同環境測試................................71
4.3.4 測試結果統整................................75
第五章 結論與未來展望...............................77
5.1 結論.......................................77
5.2 未來展望....................................78
參考文獻..........................................79
Extended Abstract................................81

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