Title :
A study of two onramp metering schemes for congested freeways
Author :
Gomes, Gabriel ; Horowitz, Roberto
Author_Institution :
Dept. of Mech. Eng., California Univ., Berkeley, CA, USA
Abstract :
We investigate the stability of a nonlinear (piecewise linear and possibly discontinuous) model of a freeway onramp, controlled by two popular onramp metering schemes: alinea and percent-occupancy. The freeway model is based on Daganzo´s cell-transmission model and can be understood as a hybrid system switching among several discrete-time linear dynamics equations. It is shown, under conditions placed on the upstream mainline demand and on the controller parameters, that both of these controllers are capable of rejecting congestion near the onramp. In addition, we illustrate how the use of downstream measurements allows alinea to robustly drive the freeway to a predetermined uncongested desired state.
Keywords :
metering; road traffic; traffic control; Alinea; cell-transmission model; congested freeway; discrete-time linear dynamic equation; hybrid system switching; nonlinear model stability; onramp metering; percent occupancy; Delay effects; Equations; Gain measurement; Mathematical model; Mechanical engineering; Observability; Piecewise linear techniques; Robust control; Stability; Traffic control;
Conference_Titel :
American Control Conference, 2003. Proceedings of the 2003
Print_ISBN :
0-7803-7896-2
DOI :
10.1109/ACC.2003.1240419
