Centimeter-Level GPS Positioning

Todd Humphreys and his research group recently developed and tested a centimeter-accurate GPS system on the UT Austin campus. This work may soon be the answer to many driverless car issues, including blurred lane markings, bad weather, and blind spots.

Precise vehicle positioning is 100 times more accurate than your standard GPS. University of Texas professor Todd Humphreys has been working on the project for four years.

Currently, this type of precise GPS is used mostly by surveyors—at a high price tag. That’s where Humphreys and his students come into the picture. They are working on making this type of precise GPS for a cheaper price ($50 instead of $5,000, the current going rate for centimeter-accurate GPS receivers), therefore making it more affordable for the mass market. The research is being funded by Samsung who hopes to build precise positioning into cars and smartphones.

The UT researchers are also working on a more intuitive way to drive, by projecting routes onto the windshield itself. Meaning drivers would no longer have to take their eyes off the road to look at their cellphones

“If we can illuminate the windshield with a path that takes you home and the path changes as it determines that there are faster or slower routes to home. That just eases the burden on the driver. It’s the yellow brick road it’s already lit up for me,” explains Humphreys.

To acquire this accuracy, 20 solar powered reference stations were placed around Austin at the end of May 2016. You can think of this network of 20 reference stations as smart infrastructure that make it possible to use a $50 device, instead of a $500 or $5000 device, to locate a bicyclist, a bus, or a car within its lane of travel.

The materials cost of the receiver system in the car at just US $35 per car, running their software-defined system entirely on a $5 Raspberry Pi processor.

The software could piggyback, almost unnoticed, on the powerful robocar processors that are coming down the pike from companies like Nvidia and NXP.

Just as important as the receivers is the ground network of base stations, which the Texas team has shown must be spaced within 20 kilometers (12 miles) for full accuracy. And, because the students’ solar-powered, cellphone-network-connected base stations cost only about $1,000 to build, it wouldn’t be too hard to pepper an entire region with them.

Humphreys is still looking for the killer app to justify superaccurate GPS in handheld systems.

“We’re looking into outdoor virtual reality,” Humphreys says. “You could put on a visor and go on your favorite running trail, and it would represent it to you in a centimeter-accurate way, but artistically enhanced—maybe you’d always have a blue sky. You could craft the world to your own liking.” While staying on the path, of course.

SOURCES – University of Texas at Austin, Youtube, IEEE spectrum, KXAN