Next-Generation Vehicle Positioning in Global Positioning System-Degraded Environments for Vehicle Safety and Automation Systems
The next generation of safety and vehicle automation will rely on precise positioning, yet GPS-based positioning is hampered by blockages of the global positioning system (GPS) signal—a broader approach is needed that does not rely exclusively on GPS. However, there is no one "silver bullet"; therefore, this proposed work seeks to achieve a major improvement in vehicle positioning performance by developing a multifaceted approach to achieving precise positioning, even in situations in which the GPS signal is inadequate due to a dense tree canopy, building shadowing, or other factors. The work builds on previous work done by the partners in other domains to apply these techniques to future safety and automation applications.
Three key technology areas hold promise individually, and the research intends to show that a combined, integrated system is even more powerful by exploiting the strengths of each technique. First, terrain-based localization (based on precise measurements of vehicle pitch and roll, combined with wheel odometry) can be readily used to find the vehicle's absolute longitudinal position within a premapped highway segment, compensating for drift, which occurs in dead-reckoning systems in long longitudinal stretches of road. Second, visual odometry keys upon visual landmarks at a detailed level to correlate position to a (visually) premapped road segment to find vehicle position along the roadway. Both of these preceding techniques rely on foreknowledge of road features; in essence, a feature-enhanced version of a digital map.
This becomes feasible in the "connected vehicle" fixture, in which tomorrow's vehicles have access to quantities of data orders of magnitude greater than today's cars, as well as the ability to share data at high data rates. The third technology approach relies on radio frequency ranging based on dedicated short range xommunications (DSRC) radio technology. In addition to pure radio frequency ranging with no GPS signals, information from radio frequency ranging can be combined with GPS-range measurements (which may be inadequate on their own) to generate a useful position.
- Exploratory Advanced Research
New algorithms and ways of handling global positioning system (GPS) data were discovered.