Researchers from the University of Tokyo, the University of Taipei, and others have developed a novel 2D tracking system that relies on magnets and smartphones. Information is everywhere — gas stations, school bulletin boards, billboards, grocery stores, and more. These are often printed on paper and boards on a flat surface. LCD panels and displays have become relatively cheap in recent years, meaning more information can be conveyed using digital signage. A lot of those are interactive with touch capabilities that allow users to garner more information. The same goes for projectors that have touch capabilities, all of which rely on touch interaction.
Those interactive systems require 2D input on a singular plane; however those systems tend to be expensive and require a power source, making them challenging to deploy. That said, the team devised a solution that enables 2D tracking without being expensive and retains its tracing efficiency. Known as FieldSweep, the system uses a series of permanent magnets calibrated with an ambient magnetic background. That ambient magnetic field information is subtracted from the measured field strength during tracking.
The neodymium magnets are the key, with the system measuring the magnetic fields using a three-axis magnetic sensor on the smartphone, in this case, a Huawei P30 Lite. The FieldSweep system works by placing the smartphone on the sensing surface and uses a program to measure the magnetic field vector. The data is then compared to the magnetic field direction vector, prepared in advance, to pinpoint the smartphone's position. The researchers state that the FieldSweep system could be used to display images from a camera on the other side of walls and doors as if they were see-through. Of course, it can also be used for interactions in multiplayer games.