University: University of Texas at Dallas
Team Member(s):Ben Delay, Chris Baronne, Peter Dimberio, Matthew Krenik
Faculty Advisors: Dr. Marco Tacca
Country: United States
Real-time position tracking has classically required compromises between cost and accuracy. The flagship positioning technology, the Global Positioning System (GPS), uses electromagnetic signals to calculate a receiver’s position. However, GPS becomes prohibitively expensive at high levels of accuracy. Radio frequency signals travel so quickly that accuracies of one millimeter require clock time resolutions in the picosecond range. The expense of these clocks has prevented the adoption of positioning systems in many localized applications. Fortunately, ultrasound positioning offers a compelling alternative to RF positioning systems. Because sound propagates similarly, but more slowly than electromagnetic waves, these systems have lower polling frequencies while still working on principles similar to established GPS techniques. Our design project would seek to integrate low frequency ultrasound transducers into a GPS inspired positioning system to achieve high spatial resolution, real-time position tracking at a relatively low cost.
Our project makes use of many LabVIEW products, including both hardware and software. Design Project Support from National Instruments would greatly assist our endeavors over the next two semesters.
Initially, we plan to perform basic distance and encoding testing in LabView using an external arbitrary waveform generator and oscilloscope. This would require a more in-depth use of LabVIEW than covered in conventional undergraduate courses and the engineering mentor and technical support from National Instruments would be invaluable.
After we have properly modeled aspects of the positioning system using LabVIEW, we then plan to transfer the appropriate code over to the NI sbRIO-9636 embedded system to further the development of a portable, standalone unit. This unit will generate encoded signals (on multiple, fixed ultrasound transducers), receive these signals (from a separate, moveable transducer), correlate the received signals, and then calculate the position of the separate transducer.
Almost all of the components necessary for this project are available from National Instruments. Design Project Support from NI would greatly assist the completion of our design project. Additionally, through this experience we would become familiar with NI products and acquainted with NI personnel.
Our project goal is to design and construct a positioning device that achieves a distance resolution of 1 mm for a transducer unit that can move up to 1 m/s in a 1m2 area. Some complications that we expect to face are: the high attenuation of ultrasound signals in air, the Doppler shift caused by the relative movement of the transducer unit to be tracked, and the inconsistent velocity of mechanical wave propagation. Additionally, commercially available resonant transducers have a narrow bandwidth that limits the signal processing techniques that can be employed.
Despite these concerns, a review of literature has shown that the basic principles of our project are certainly viable. Once we have created a baseline positioning system as a proof of concept, we will try to outfit this technology to an application where our receiver unit performs a function based on location. This may include robotic vision, remote surgery, or home use applications. We believe that positioning and spatial technology is at the forefront of technology today. Our project will encourage our development of critical engineering skills and potentially produce a useful, innovative product. Although there are many challenges, we believe that they can be overcome and we look forward to that experience.