Changzhi Li’s research focuses on indoor mapping using radio frequencies.
Changzhi Li, an associate professor in the Department of Electrical & Computer Engineering in Texas Tech University's Edward E. Whitacre Jr. College of Engineering, received a three-year, $325,000 grant from the National Science Foundation (NSF) to further his work using radio frequencies.
Li's project, “Hybrid Wireless Localization With a New Radio Frequency Beamforming Scheme,” aims to help find people and/or objects within an indoor environment.
“We are trying to use a radio frequency signal to localize things and get a map of the environment,” Li said. “Our focus is indoor localization and indoor mapping. Think of it as Google Maps, but for inside a building. This could be pretty useful in a healthcare application taking care of senior people.”
So why not use a camera to track people inside instead of developing a radio frequency technology? There are a few reasons why radio frequency is a more practical application.
“A camera is definitely a very good technology,” Li said. “However, there also are limitations. For example, a camera is not the best way to protect your privacy. No one wants a camera in the bathroom. Also, for cameras, it's relatively difficult to get information of distance. Getting depth information, requires a lot of modification to a conventional, low-cost camera. Radio frequency can easily get depth information. It can precisely measure the distance from the device to any given target in space in front of the device.”
Another benefit of using radio frequencies is radio frequencies can travel farther and go through walls.
“Another advantage of radio frequency is that it penetrates through some obstacles,” Li said. “For example, sitting in a room, you can still use your cell phone because radio frequency signals go through the window, the walls and, eventually, hit a big station far away. There are fewer limitations with this technology than with cameras.”
Most of the grant money will go to recruiting and retaining student workers on the project, something of which Li is very proud.
“The majority of the grant is going to support student workers,” Li said. “Graduate student workers are very important in our group, but we also have undergraduate and high school students contributing to research. This summer, there are five visiting students coming to my lab. We have one undergraduate student from France who was recruited through the College of Engineering exchange program; we have one undergraduate from China and one undergraduate from Texas Tech. We also have a high school student, who is here from California through the Clark Scholars Program, and a high school student from Lubbock.”
After the initial three-year research is completed, Li anticipates pursuing either a startup company or other funding agencies to begin practical research applications.
“This technology, indoor localization and monitoring, also can be used to monitor people with concealed weapons,” he said. “If somebody has a concealed rifle underneath their jacket, their gait will be different. Our radio frequency signal can pick up those features and we can tell the difference of a person carrying a rifle versus a person who is carrying a gym bag. For this type of research, we may approach the Department of Homeland Security or other agencies for further funding.”
One thing Li knows for sure is the students help make this possible.
“I would like to thank my researchers, graduate students, undergraduate students, as well as the high school students in my lab,” he said. “They worked really hard to get preliminary data so we could get the funding.”