iWhere: Applied research on received signal strength algorithms for indoor location of PPE and objects

The quality, safety, environmental, and R&D&I policies of industrial companies give priority to people's safety, health, and well-being, encouraging work under safe conditions. In this context, iWhere investigated indoor location algorithms based on received signal strength (RSSI), in order to overcome the limitations of the solutions available on the market, which are geared only toward outdoor geolocation or toward fixed-point algorithms that do not allow continuous indoor location.

Unlike known deployments of this type of technology in hospitals, academic campuses, or airports, which focus on locating people, iWhere proposed locating resources (PPE and equipment or tools) in an industrial environment with large amounts of metal, where interference or loss of signal quality can occur.

Objectives:

• To investigate received signal strength (RSSI) algorithms to determine the position of a mobile node from fixed nodes at known positions.
• To investigate algorithms that make it possible to determine the movement flow (tracking) of mobile nodes.
• To validate the technical feasibility of the solution through a proof of concept, reaching a technology readiness level of TRL3.

The most efficient algorithm for indoor location turned out to be iterative multilateration, with a root mean square error of 1.72 meters, validated through experimental tests at 15 different positions on a test bench that simulated real industrial conditions.

CTIC carried out iWhere with funding from the Asturias Program, co-funded by the European Regional Development Fund (ERDF) of the European Union and the Principality of Asturias through the Plan de Ciencia, Tecnología e Innovación 2013-2017.