Bluetooth low energy (BLE) real-time location system (RTLS) having simple transmitting tags, beacons and bridges, that use a combination of motion detection and RSSI measurements to determine room-location of the tags

摘要

A real-time location system (RTLS) uses Bluetooth Low Energy (BLE) transmitting tags, bridges, and beacons. The fixed beacons broadcast BLE advertisements containing motion-status information about recent history of perceived motion in a room as determined from a motion sensor in the beacon. The bridges forward the beacon's received advertisements to a location engine, which records timestamps of motion events seen by each beacon in each room. One or more simple transmitting tags then report their own motion status based on a tag-based accelerometer. The system utilizes a series of location-engine steps, to estimate the room-location of the tags based on a specific combination of RSSI analysis, and a comparison of tag-motion history to the perceived and recorded motion-status in a room. This analysis of tag-motion history and motion-in-room status produces a better estimate of room-level location of the tag than can be estimated by simple proximity or multi-lateration using radio signal strengths.