Stop-and-Go in Congested Traffic
Thursday, May 17, 2018 - 10:00am - 10:50am
Stop-and-go oscillations in congested traffic originate from the connectivity/networking of human driver behaviors, yet frustrate the drivers, and may be aggravated with the presence of autonomous vehicles, unless their control algorithms are designed to promote damping rather than merely safety and caution. State-of-the-art traffic models are coupled nonlinear hyperbolic PDEs for density and velocity, like for gases, but also include 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. I will show how PDE backstepping controllers stabilize stop-and-go, at large distances from the ramp, even in the absence of distributed measurements of vehicle speed and density, and when driver reaction times are unknown.