Indoor location could mitigate COVID-19

To prevent the further spread of COVID-19, the world is shifting to a “new normal” in which social distancing is practiced and contact between people is avoided. Due to early evidence suggesting the spread of COVID-19 is much more aggressive indoors than outdoors, many companies have begun efforts to monitor workers’ movements and trace contacts to keep offices and factories from becoming new epicenters of infection.

The Need to Monitor

Keeping a safe distance from others and avoiding contact is essential to prevent getting infected with COVID-19. However, there are many situations where avoiding contact with others at indoor locations such as offices and factories is difficult. Hence, there is a growing need for technologies that monitor contact between workers and their movement histories in real time.

Indoor location information can be obtained using various wireless communication technologies including Wi-Fi, Bluetooth and ultra-wideband (UWB). For example, Bluetooth beacons have been deployed at commercial facilities to enable services that provide location-relevant information to customers with smartphones. The positioning accuracy of Bluetooth, however, is only around 3 to 10 meters and is dependent on infrastructure installation.

To be useful for contact tracing of infectious diseases, the number of beacons must be increased to achieve an adequate level of accuracy. UWB technology features high positioning accuracy, but deployment in a wide area would require installation of a large number of radio transceivers and repeaters, putting it at a cost disadvantage.

Solution Based on Geomagnetism

Given this background, a solution using geomagnetism is attracting attention. TDK has developed VENUE, which displays the real-time locations of people by utilizing geomagnetic sensors found in today’s smartphones. Each indoor location has a geomagnetic signature that can be used to ascertain the position of the phone.

There are several approaches to indoor positioning, but geomagnetism, tightly coupled with inertial navigation, optimally balances accuracy, reliability and cost of deployment and maintenance.

“The beauty of geomagnetic positioning is that it works in all large venues whose structures interfere with Earth’s magnetic field, making this an infrastructure-free approach to indoor positioning that is accurate to better than 2 meters,” said Chris Goodall, founder and managing director of Trusted Positioning Inc., a TDK Group Company based in Calgary, Alberta, Canada.

VENUE provides a position display with even higher accuracy by combining geomagnetic information with information from accelerometers and gyroscopic sensors inside smartphones.

VENUE requires only the creation of a geomagnetic map that combines an indoor layout map with the geomagnetic data of that particular location acquired through a survey, with no need to install new devices and terminals. This leads to low installation cost. The accuracy of positioning using geomagnetism is better than two meters (6 feet) — sufficient for tracing contact with infected persons. In addition, VENUE provides a position display with even higher accuracy by combining geomagnetic information with information from accelerometers and gyroscopic sensors inside smartphones.

“People may hold their smartphones while walking or put them in their pockets or bags,” Goodall said. “Since the orientation to the user changes constantly, the movements and pedestrian use cases need to be corrected using inertial sensors. Solving these issues was the greatest challenge for practical applications such as tracking, and took our team many years to create, perfect and protect.”

Comparison of indoor location information technologies. (Chart: Trusted Positioning)

Real-World Trial Under Way

Beginning in August, a contact tracing trial among workers is being conducted at TDK’s headquarters in Nihonbashi, Tokyo, using VENUE. Employees carry smartphones with a special app installed, and their positions and movement histories on the floor are combined with anonymous identification information. If an employee is found to be infected, the data will be analyzed to identify people who had contact with that employee within the preceding two weeks, and measures such as stay-at-home instruction will be taken.

This solution not only can identify those who were in close contact with the infected person as primary contacts, but also trace those who stayed in areas where the infected person had been shortly before as potential “area contacts.” Analysis that combines location and elapsed time enables more effective contact tracing by improving primary contact tracing indoors and enabling area-based contact tracing over time.

Ongoing Trial at TDK Headquarters: VENUE displays an individual worker’s tracking data on the dashboard. (Conceptual illustration: Trusted Positioning)

Ongoing Trial at TDK Headquarters: A worker’s durations of stay and positions can be visualized in the form of a heat map. (Conceptual illustration: Trusted Positioning)

New Possibilities Opened

Because VENUE can display the positions and histories of people and objects using not only workers’ smartphones but special tags containing geomagnetic and inertial sensors (under development), it can be deployed for a wide range of applications beyond contact-tracing of infectious diseases. Possible uses include monitoring the flow of employees to improve operational efficiency or tracking positions of equipment to manage their operational statuses. TDK is working with a number of companies on solutions to improve business efficiencies using location information.

Many offices have introduced open seating, so maintaining a “real-time seating chart” using VENUE is a real advantage so staff can more easily find one another in large office settings, encouraging more collaboration between staff and departments.
Companies have been using Bluetooth low-energy (BLE) beacons to manage the movement of workers, materials and equipment indoors in warehouses, factories and construction sites. VENUE can reduce the installation and maintenance costs of such systems, especially in large-scale facilities.

VENUE is also useful for other contact-tracing applications that do not focus on viral transmission, such as human-to-machine, human-to-vehicle and human-to-robot contacts. The future work environment will undoubtedly change with more automation, and the interaction of humans and machines poses safety concerns. VENUE’s designers hope it can improve safety in many types of contact-tracing applications.

Similar to the expansion of GPS for outdoor positioning applications, indoor positioning technologies will likely grow in our everyday lives. VENUE is one indoor location information solution that enables highly accurate location information to be obtained while keeping infrastructure costs down.