Single-Region Robust Perimeter Traffic Flow Control

In this paper, we propose a two-stage robust perimeter flowcontrol policy to prevent congestion in single- regiontransport networks. We describe the single-region trafficdynamics by utilising the so-called Macroscopic or NetworkFundamental Diagram (MFD or NFD), a nonlinear relation be-tween network-wide mean flow and accumulation of vehicles.By using MFD relaxation conditions and structuringuncertainties, we reformulate the nonlinear flow dynamicsto set of uncertain Linear Parametrically Varying (LPV)ones. In controller design stage one, we apply the conceptof a two degree of freedom, induced L2 norm minimising LPVcontroller. Within the generalised performance output, weinclude tracking performance to follow a pre-definedcritical accumulation in uncertain model environment.Output feedback LPV controller ensures generaliseddisturbance attenuation conditions with appropriate gatedinput flow at the perimeter. Second, an optimal quadraticcontrol allocation algorithm is employed to distribute theordered flow to entrance link green stages (flow equivalentgreen time) in a number of candidate junctions at theperimeter of the network. The constrained allocationtechniques complement the robust controller enablingreal-time applicability of the proposed methodology.Finally, the suggested robust control scheme is tested inmacroscopic simulation environment. Results shows the via-bility of the method in rapid and accurate trackingbehaviour under highly uncertain parameters of the MFD