The study of the indoor positioning based on smart wearable technologies

We design a low energy Bluetooth (BLE) device including reference-tag-based indoor position algorithm to solve different situations including location determining, route guideline and tracking in this study. It can not only help the visitor or patient to understand the position but also provide a system for medical staff to monitor the safety of patients and new born babies in hospital. This device is tiny enough to be embedded into visitor's wristband, baby's foot band and patient's clothes. It is composed of signal control unit, signal sensing unit and wireless connection unit. The signal control unit is responsible to control and memorize the status of the device by an ultra-low power MCU and an EEPROM memory chip. The signal sensing unit is a motion tracking sensor module to capture the accelerometer signal. The wireless connection unit combined of beacon and Bluetooth module to send data package as a BLE sender. The indoor location-based services (LBS) system is combined with smart beacon and Wi-Fi gateway. Beacon plays the role of client and Wi-Fi gateway is server. The RSSI (Received Signal Strength Indicator) of BLE signal to determine whether the beacon owner is in a particular area. However, there may be two or more Wi-Fi gateways to receive the same beacon signal in the same time, we add a reference beacon to each Wi-Fi gateway to reduce the error rate of determining beacon's location. The result of experiment shows that there is only 5% error rate for determining the position of devices.