Indoor positioning systems are used to determine the location of a person, forklift, robot, drone, or device within a building or other indoor environment.
There are a number of reasons why indoor positioning may be necessary or useful:
Navigation: Indoor positioning can help people navigate within a building, whether they are looking for a specific room or just trying to find their way around a new environment.
Asset tracking: Indoor positioning can be used to track the location of assets within a facility, such as equipment or inventory. This can help with asset management and maintenance and can also improve efficiency by reducing the time spent searching for items.
Safety and security: Indoor positioning can help ensure people’s safety and security within a building. For example, it can be used to track the location of employees in case of an emergency or to prevent unauthorized access to certain areas.
Marketing and customer experience: Indoor positioning can be used to enhance the customer experience by providing location-based information and offers to people within a store or other retail environment.
Overall, indoor positioning systems can provide many benefits in a variety of different settings and can help improve efficiency, safety, and the overall user experience.
There are several types of indoor positioning systems (IPS) that can be used to determine the location of a person or device (robot, drone, forklift, crane, palette, etc.) within a building or other indoor environment. These include:
Wi-Fi-based IPS: Wi-Fi-based IPS uses the WiFi signals’ strength from Wi-Fi routers or access points to estimate the distance based on the signal strength (RSSI). Based on the distance estimate and using trilateration, the WiFi-based IPS determines the location of a device. This type of IPS is relatively inexpensive and easy to implement, but the accuracy can vary depending on the density of Wi-Fi access points and the presence of obstacles that can block or weaken the signals. It is a typical RSSI-based IPS system with all its advantages and disadvantages.
Bluetooth-based IPS: Bluetooth-based IPS uses the signals from Bluetooth low energy (BLE) beacons or other Bluetooth devices to determine the location of a device. The approach is the same – using the signal strength, which varies significantly due to multipath indoors. This type of IPS can be more accurate than Wi-Fi-based systems, but it requires the deployment of BLE beacons or other Bluetooth devices throughout the indoor environment. It is also an RSSI-based system, i.e., inherently inaccurate. BLE-based IPS flavors use an angle-of-arrival approach show better results than basic BLE by limiting directions from which the signal comes, thus somewhat combating the multipath and improving the accuracy. However, it comes at the expense of complexity and cost. The resulting accuracy is still ~1m or worse.
RFID-based IPS: Radio-frequency identification (RFID) technology can be used to determine the location of a device by detecting the signals from RFID tags or readers. RFID-based IPS can be accurate, but they require the use of RFID tags on the devices or people being tracked, which can add cost and complexity. RFID is not “real IPS”. It is a gate-based IPS. You can’t get the location of an RFID tag unless it is near an RFID reader.
Ultrasonic-based IPS: Ultrasonic-based IPS uses ultrasound waves to determine a device’s location. This type of IPS is about ten times more accurate than the UWB-based system, but it requires specialized ultrasonic sensors and may not work well in environments with high levels of ambient noise. The ultrasound-based IPS use the same time-of-flight approach as the UWB-based systems do, but instead of measuring the time of flight of radio in UWB, they use the time of flight of ultrasound. Since ultrasound travels much slower, ultrasound-based IPS is inherently more accurate than other types of IPS.