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Center for Nonlinear Studies |
This talk describes how the mobile internet is changing the face of traffic monitoring at a rapid pace. In the last five years, cellular phone technology has bypassed several attempts to construct dedicated infrastructure systems to monitor traffic. Today, GPS equipped smartphones are progressively morphing into an ubiquitous traffic monitoring system, with the potential to provide information almost everywhere in the transportation network. Traffic information systems of this type are one of the first instantiations of participatory sensing for large scale cyberphysical infrastructure systems. However, while mobile device technology is very promising, fundamental challenges remain to be solved to use it to its full extent, in particular in the fields of modeling and data assimilation. The talk will present a new system, called Mobile Millennium, launched recently by UC Berkeley, Nokia and Navteq, in which the driving public in Northern California can freely download software into their GPS equiped smartphones, enabling them to view traffic in real time and become probe vehicles themselves. The smartphone data is collected in a privacy-by-design environment, using spatially aware sampling. Using data assimilation, the probe data is fused with existing sensor data, to provide real time estimates of traffic. The data assimilation scheme relies on the appropriate use of Ensemble Kalman Filtering on networked hyperbolic first order partial differential equations, and the construction of lower-semicontinuous viability solutions to Moskowitz Hamilton-Jacobi equations. Results from experimental deployments in California and New York will be presented, as well as preliminary results from a pilot field operational test in California, with already more than 5,000 downloads. Additional applications will be discussed, in particular how to use smartphones interfaced with sensors to monitor chemical agents which might be transported by air, social networks user generated content (such as twitter from the phone) for emergency response (for example earthquakes or attacks).
Host: Misha Chertkov