2 p.m. - 3 p.m. Location: ECSS 3.503
University of California – San Diego
Traffic Flow Control: Calming “Stop-and-Go” in Congested Traffic
“Stop-and-go” traffic oscillations are akin to thermoacoustic instabilities in combustion and laser chambers, as well as to slugging flows in oil production risers. The models of all these problems are quite similar - coupled nonlinear hyperbolic PDEs for density and velocity. The key difference is that the Aw-Rascle-Zhang model of traffic includes elements of human behavior (“forward-oriented" attention, collision avoidance, etc.). Actuation by ramp metering (the durations of red and green lights) propagates, through human action, upstream, i.e., against the direction of the cars’ motion. This makes it possible to calm stop-and-go at large distances from the ramp. I will show how PDE backstepping controllers, which have been implemented in oil drilling and production applications, can also stabilize stop-and-go, even in the absence of distributed measurements of vehicle speed and density, and when driver reaction times are unknown.
This is a joint Mathematics Distinguished Colloquium and CCST seminar.