藍牙定位追蹤基於 RSSI (接收訊號強度指示) 定位系統. 根據不同位置終端, Bluetooth location can be divided into network location and terminal location.
1. 什麼是藍牙低功耗技術
An intelligent, low-power Bluetooth wireless technology is called Bluetooth Low Power. The technique reduces smart gadgets’ size, 成本, and complexity, making them increasingly smarter.
藍牙 4.0 core standard first included Bluetooth Low Power, sometimes referred to as Bluetooth Smart. It was a short-range wireless communication technology created by Nokia before being accepted by the Bluetooth Technology Alliance. It was especially targeted for low bandwidth, 低成本, low complexity and low power with the initial objective of providing the lowest power wireless solution. 核心規範使這些設計目標變得清晰: 藍牙低功耗的目標是發展成為半導體生產商的低功耗標準和低成本, 有價值的應用. 如今，小電池可以讓低功耗藍牙裝置運作很長一段時間.
2. Can location be tracked using Bluetooth?
網路側 定位系統 包括終端藍牙網關, 藍牙信標節點, 後端資料伺服器和無線區域網. 具體定位流程如下:
- 首先放置一個信標和一個藍牙網關.
- 信標和終端設備（例如具有SDK軟體包的手機）組成了終端定位系統. 當終端到達信標訊號覆蓋區域時, 它可以偵測信標廣播訊號並使用藍牙網關計算信標下的 RSSI 值, 無線網路, 以及伺服器內建的定位演算法來確定終端的精確位置. 以下是具體的擺放原則:
- 藍牙信標必須先放置在附近.
- 信標在整個區域持續傳輸訊號和資料包.
- 當終端設備到達信標訊號範圍時, 測量多個基地台的RSSI值，然後利用手機內建的定位演算法來確定精確位置. 使用者終端定位在終端側通常用於 室內導航定位, 定位行銷, 以及其他使用者節點. 而且, 使用者終端在網路側的定位通常用於人員追蹤, 資產定位, 及客流分析. The ease of Bluetooth locating is a benefit because positioning accuracy is directly correlated with the Bluetooth beacon’s laying density and transmitting power. And incredibly power-efficient, achieving the goal of power-saving via deep sleep, no connectivity, and a simple protocol.
3. Definition of a Bluetooth gateway
Bluetooth Gateway is a scanning administration device for iBeacon devices. Bluetooth Gateway is a combined Bluetooth and Wi-Fi gateway device that is primarily used for iBeacon device remote cloud administration.
The Bluetooth gateway, which combines Bluetooth and Wi-Fi, scans the device and collects data via the Bluetooth module. The Wi-Fi module contains the scanning data before transferring it to the server across the network. 藍牙模組精確掃描其訊號覆蓋範圍內的iBeacon設備，並收集掃描到的設備的數據. 然後將監控到的裝置透過藍牙、Wi-Fi串列透過網路上傳到伺服器端, 伺服器端對這些掃描到的設備進行展示和維護.
4. What is a Bluetooth beacon, and how to locate a Bluetooth beacon
藍牙信標是一種使用電池供電並使用低功耗藍牙廣播協定的無線電子設備. 它通常固定在某個位置, 常向鄰居廣播, 然後與終端設備進行交互，交換訊息. 藍牙信標可以“標記”位置並“發送訊息”。
正如常識一樣, 藍牙定位通常基於 RSSI (接收訊號強度指示) 價值, which is then used to calculate the positioning of a positioning technology using the corresponding data to determine the distance between the signal point and the receiving point. The Bluetooth beacon’s RF performance, which serves as the Bluetooth positioning signal point, is intimately connected to the positioning outcome. The positioning impact is improved by greater RF performance. 所以, the location impact will be greatly enhanced by selecting a high-performance Bluetooth beacon.
Bluetooth Beacon An iBeacon-compatible Bluetooth beacon that uses a low-power broadcasting mechanism. It can’t connect to any low-power Bluetooth hosts and is often positioned at a permanent point in the room to broadcast constantly throughout. Every bit of broadcast data is organized in a precise way. Bluetooth beacons with H2 locations are commonly utilized right now.
優點:
- BLE offers a high standby duration and low power consumption.
- Uninterrupted broadcast status: A beacon may send information automatically, cover a user’s region, locate the user, and then transmit the appropriate information depending on the position.
- It can work in tandem with the shopping mall’s internal positioning and navigation system to perform indoor positioning tasks like shopping mall navigation and reverse automobile locating.
Disadvantages:
The BLE Bluetooth transmission distance limits the coverage range of a Bluetooth beacon, and information will only be pushed when the user is relatively near to the position of the Bluetooth beacon for a specific distance. The same mobile phone will repeatedly get push notifications if it frequently approaches the Bluetooth beacon’s vicinity.
5. Accuracy of Bluetooth positioning and tracking technology
Bluetooth AOA positioning theory, centimeter-level accuracy
The measurement of the electromagnetic wave’s arrival direction underlies AOA (angle-of-arrival), which enables the launch target’s location to be confirmed. Various positioning techniques are used following various antenna array types and algorithms. Both the linear array and the plane array are capable of measuring the incidence angle in stereo space.
Regardless of signal strength, the AOA method only measures signal to wave direction, unaffected by signal intensity, battery level, or antenna direction. It only determines position by angle, using multiple angles to obtain a more precise absolute position, and operates under conditions that fall within the Bluetooth standard specification for new positioning technology.
Bluetooth AOA indoor positioning
- High precision: positioning accuracy reaches sub-meter levels; maximum high precision positioning is 0.3-0.5m, which is on par with UWB in terms of precision;
- Low power use, long battery life: button batteries may last for months to years when employing low power Bluetooth technology;
- Various forms and tiny sizes: Bluetooth tags come in a variety of shapes, may be worn or affixed to things, and their smallest size is smaller than a one yuan coin;
- 低成本: concentrating on limited area scenes, the system cost is much less than the cost of the UWB tag;
- High throughput: Forward AOA single area single base station 1000 tags at 1Hz, Forward AOA multi-area unlimited overall capacity, Reverse AOD channel unlimited overall capacity, Wireless overall capacity;
- 藍牙 5.1 has good compatibility; it can be used with Bluetooth 5.0 和 4.2, which are compatible with billions of different Bluetooth terminals yearly, to provide exact location service for mobile phones.
6. Bluetooth location tracking application examples
It is very compatible with Bluetooth AOA indoor positioning technology. It may be employed in most interior locations and gather personnel positioning data more thoroughly and easily with the aid of hardware devices such base stations and labels with Bluetooth AOA positioning feature.
Personnel management
Bluetooth AOA indoor positioning for staff placement, daily attendance, time statistics, managing the on-duty/off-duty status, 行為分析, and other features. 另外, 它可以在特定位置執行某些獨特的任務, 如倉庫作業時提醒人員不要接近危險作業區域、在評標現場監控工作人員的活動軌跡等.
安全管理
Bluetooth AOA indoor positioning for staff placement, daily attendance, time statistics, managing the on-duty/off-duty status, 行為分析, and other features. 另外, 它可以在特定位置執行某些獨特的任務, 如倉庫作業時提醒人員不要接近危險作業區域、在評標現場監控工作人員的活動軌跡等.
