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

摘要

The present invention relates generally to a real-time location system (RTLS) and more particularly to a Bluetooth Low Energy (BLE) RTLS having tags, bridges, and beacons. To determine which room a tag is in, 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. Tags report received signal strength indications (RSSI) from nearby beacons, motion-in-room status sensed and reported by those beacons, plus their own motion status based on a tag-based accelerometer. A series of location-engine steps estimates the room-location of the tags based on a combination of RSSI analysis, and a comparison of tag-motion history to the perceived and recorded motion-status in a room. The analysis of tag-motion history and motion-in-room status produces a better estimate of room-level location of the tag than an RSSI estimate can produce alone.