In recent years, an authoritative survey shows that indoor positioning systems are always welcome as this is a rapidly evolving area .The following mainly introduces four mainstream indoor positioning technologies: WIFI positioning technology, Bluetooth positioning technology, ZigBee positioning technology and UWB positioning technology.
WIFI positioning technology
Each wireless AP (router) has a unique MAC address, and usually the wireless AP is basically not moved. After the device (such as a mobile phone) turns on the WiFi function, the surrounding wireless AP signals can be searched. Regardless of whether the wireless AP is encrypted or connected to the device, the MAC address of the wireless AP can be obtained. Then the device sends the obtained MAC address of the wireless AP to the location server. After the server receives the MAC address of the wireless AP, it can calculate or estimate the location of the device.
Application:
- Smart Nursing Home: You can locate the location of the elderly in real time and view the trajectory of their activities.
- Smart factory area: Visually view the location distribution of various types of personnel (employees of different types of work, visitors, etc.) and items, which facilitates work assignments and improves production efficiency; in the event of danger, quick rescue can be based on the location of personnel.
- Smart medical treatment: real-time viewing of patient location, positioning of medical equipment, infant anti-bug error, etc.
Advantages and disadvantages:
- Advantages: wide positioning range, automatic data update, fast positioning speed, etc.;
- Disadvantages: WIFI must be turned on on the mobile phone, connected to the Internet, long-term maintenance, etc.
Bluetooth positioning technology
Bluetooth positioning is divided into two types: network-side positioning and terminal-side positioning.
Network-side positioning: It is composed of Beacon, smart terminal, Bluetooth gateway, server (positioning engine, database), etc. When the smart terminal enters the coverage of the Beacon signal, the received RSSI value is uploaded to the server through the Bluetooth gateway, and the positioning engine processes it, and can be managed and viewed in the management background Terminal-side positioning: consists of Beacon, mobile terminal, server (positioning engine, database), etc. When the mobile terminal enters the coverage area of the base station, the received RSSI (signal strength) value is measured and the specific location is measured through the built-in positioning algorithm, and the map engine is used for display, navigation and other operations.
Application:
- Item location: Bluetooth's real-time location system (RTLS) can track important assets, such as identifying important equipment assets in warehouses and hospitals, and valuable items in museum exhibition halls. A battery-powered Bluetooth low energy transmitter (tag) is installed on the asset to send the asset's current location and received signal strength to the Bluetooth receiver at a fixed location for precise positioning.
- Location of tourists in scenic spots: The location of tourists can be checked through the location tag, which provides reliable protection for danger prevention and rescue.
Advantages and disadvantages:
- Advantages: Advantages: low power consumption, high efficiency, and low cost;
- Disadvantages: Disadvantages: small positioning range and large positioning error.
ZigBee Positioning Technology
ZigBee is a protocol and a standard that defines a series of communication protocols required for short-distance, low-data-rate wireless communication.
Application:
- Tunnel personnel positioning: positioning accuracy up to 3 meters. In the event of an emergency, the real-time location of the personnel is located in combination with the map, and timely and accurate rescue is implemented to ensure the safety of the personnel in the tunnel.
- Hospitals, nursing homes: real-time location positioning of patients and the elderly, providing timely and effective protection for personal safety.
Advantages and disadvantages:
- Advantages: low power consumption, low cost, high capacity;
- Disadvantages: Disadvantages:small positioning range, large positioning error, large multipath effect, poor anti-interference ability.
UWB positioning technology
UWB (Ultra Wideband) is an ultra-wideband, which does not use a carrier, but uses pulses with very short time intervals (less than 1 ns) for wireless communication. By transmitting extremely low-power signals over a wide frequency spectrum, UWB can achieve data transmission rates ranging from hundreds of Mbit/s to several Gbit/s within a range of about 10 meters.
Application:
- Industrial/Automotive Tracking: Track assets and inventory in real time, improve processes, improve search efficiency, and reduce waste of resources.
- Construction sites, warehouses, exhibition halls, etc.: precise positioning of personnel, goods, and transport machines to quickly find goods and improve management efficiency.
- Dangerous areas (mines, tunnels): personnel and resource positioning, emergency search for safe locations, to be safe and effective.
Advantages and disadvantages:
- Advantages: High transmission rate, low power consumption, high positioning accuracy、strong countermeasure ability.
- Disadvantages: It Requires laying equipment and relatively high cost.
Comparison： indoor positioning technology
