A step toward personalized, automated smart homes

The system that automatically identifies people moving around indoors could enable self-adjusting homes.


MIT analysts have manufactured a system that steps toward completely automated tech-savvy home by recognizing occupants, notwithstanding when they’re not carrying cell phones.

The system, called Duet, utilizes reflected remote signs to limit people. Be that as it may, it additionally incorporates algorithms that ping adjacent cell phones to anticipate the people’s personalities, in light of who last utilized the gadget and their anticipated development direction. It likewise utilizes logic to figure out who’s who, even in signal-denied areas.

The Duet originally is a wireless sensor installed on a wall that’s about a foot and a half squared. It incorporates a floor map with annotated areas, for example, the room, kitchen, bed, and living room sofa. It additionally gathers identification tags from the occupant’s phones.

Experiments were done in a two-bedroom apartment with four people and an office with nine people, over two weeks, showed the system can identify individuals with 96 percent and 94 percent accuracy, respectively, including when people weren’t carrying their smartphones or were in blocked areas.

Analysts noted that the Duet could potentially be used to recognize intruders or ensure visitors don’t enter private areas of your home. Moreover, it could capture behavioral-analytics insights for healthcare applications. Someone suffering from depression, for instance, may move around more or less, depending on how they’re feeling on any given day. Such information, collected over time, could be valuable for monitoring and treatment.

The specialists expect that their system would be utilized with express assent from any individual who might be recognized and followed with Duet. If necessary, they could likewise build up an application for clients to give or revoke Duet’s access to their area data at any time.

Scientists built this system upon a device-based localization system that tracks individuals within tens of centimeters, based on wireless signal reflections from their devices. It does so by using a central node to calculate the time it takes the signals to hit a person’s device and travel back. In experiments, the system was able to pinpoint where people were in a two-bedroom apartment and in a café.

Moreover, scientists combined their device-based localization with a device-free tracking system, called WiTrack that localizes people by measuring the reflections of wireless signals off their bodies.

Duet locates a smartphone and correlates its movement with individual movement captured by the device-free localization. If both are moving in tightly correlated trajectories, the system pairs the device with the individual and, therefore, knows the identity of the individual.

Deepak Vasisht, a PhD student in MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) said, “To ensure Duet knows someone’s identity when they’re away from their device, we designed the system to capture the power profile of the signal received from the phone when it’s used.”

“That profile changes, depending on the orientation of the signal, and that change is mapped to an individual’s trajectory to identify them. For example, when a phone is used and then put down, the system will capture the initial power profile. Then it will estimate how the power profile would look if it were still being carried along a path by a nearby moving individual. The closer the changing power profile correlates to the moving individual’s path, the more likely it is that individual owns the phone.”

Scientists also incorporated probabilistic algorithms to apply logical thinking to localization. To do as such, they outlined the system to perceive passage and leave limits of particular spaces in the home, for example, ways to each room, the bedside, and the side of a lounge chair. At any minute, the system will perceive the doubtless personality for every person. It at that point gathers who will be who by a procedure of elimination.

Vasisht said, “There are blind spots in homes where systems won’t work. But, because you have logical framework, you can make these inferences.”

Ranveer Chandra, a principal researcher at Microsoft, who was not involved in the work said, “Duet takes a smart approach of combining the location of different devices and associating it to humans, and leverages device-free localization techniques for localizing humans. Accurately determining the location of all residents in a home has the potential to significantly enhance the in-home experience of users. … The home assistant can personalize the responses based on who all are around it; the temperature can be automatically controlled based on personal preferences, thereby resulting in energy savings. Future robots in the home could be more intelligent if they knew who was where in the house. The potential is endless.”

Co-authors on the paper are: Dina Katabi, the Andrew and Erna Viterbi Professor of Electrical Engineering and Computer Science; former CSAIL researcher Anubhav Jain ’16; and CSAIL PhD students Chen-Yu Hsu and Zachary Kabelac.