The problem considered in this paper is motivated by the fact that the existing feedback control approaches to freeway congestion prevention may result in an unfair capacity allocation whereby one ramp may capture most of the highway capacity, depending on its relative location in the network. To avoid this problem, a new control architecture is proposed.
This paper addresses a control algorithm to congestion control in freeway networks where sources adjust their admission rate in response to feedback information from the network nodes and in response to input rates from the on-ramps.
Specifically, a controller structure and system architecture are introduced and the analysis of the resulting closed loop system is presented. Conditions for asymptotic stability are derived. It is shown that:(1) the steady states of the system satisfy the proposed fairness property; (2) there exists controller gains that ensure asymptotic stability of these steady states. Finally, results of numerical investigation, which support the conclusions of the analytical study, are reported.
