The sustAGE Outdoor and Indoor Positioning
The sustAGE project aims to develop and validate a person-centered smart solution to support the well-being scenario via informed recommendations for job role or task changes. The sustAGE system will function in real environments inside and outside of the workplace. For that reason, an open challenge is the person’s localization in the workplace due to the tasks of productivity & safety in high precision real-time manner. sustAGE utilizes two types of positioning services in order to meet the various positioning requirements in different working environments.
For the outdoor positioning the smartphone technology and Global Navigation Satellite Systems are combined. Smartphone technology is widespread both in the academic and in the commercial world. Almost every person has today a smartphone in their pocket, which is not only used to call other people but also to share their location on social networks or to plan activities.
A smartphone can compute person’s position using the device sensors, such as accelerometers, gyroscopes and magnetometers, proximity sensors, and GPS/GNSS chipset. GNSS positioning requires the GNSS tracking signals from the operational satellite constellations such as GPS, GLONASS, Galileo and BeiDou. GPS is the US satellite-based system that uses a constellation of 28 satellites orbiting the earth at approximately 20200 km every 12 hours to give a user an accurate position, GLONASS is the Russian global satellite navigation system, Galileo is the EU navigation system and BeiDou is the China’s satellite system.
In sustAGE scenario, each user carries its own smartphone (Xiaomi Mi-9) and with the support of satellite positioning and sustAGE application, can share its location to a specific server with specific accuracy. The initial estimated positional accuracy is at the level of few meters but in order to improve the positional accuracy, differential corrections are used and provided via Internet using the NTRIP protocol or by Satellite Based Augmentation Systems.
For estimating the user’s location for indoor areas, sustAGE project is developing a high precision indoor Real Time Location Tracking System using Ultra Wide Band Beacons and customized sophisticated positioning software algorithms. This approach aims to compensate for lack of precision to failure of GPS and other satellite technologies as in the case of e.g. inside multistory buildings, airports, manufacturing industries.
Indoor beacons use Ultra-Wide Band, which is a radio technology that can enable very accurate measure of the Time of Flight of the signals. In addition to this unique capability, Ultra-Wide Band can offer data communication while using extremely little energy – enabling coin cell operation for years without needing to be recharged or replaced.
The idea of this method is very similar to outdoor Global Navigation Satellite Systems. More specific, multiple reference points, called anchors, are deployed inside the workplace and are time synchronized. Users (mobile) devices will beacon, and when an anchor receives the beacon signal, it will be timestamped.
The timestamps from multiple anchors are then sent back to a central location engine which will run trilateration algorithms based on Time Difference of Arrival of the beacons signals to compute the X, Y, Z coordinates of the workers mobile devices on desired level of accuracy.