Single-Region Robust Perimeter Traffic Flow Control
Paper in proceedings, 2015
In this paper, we propose a two-stage robust perimeter flow
control policy to prevent congestion in single- region
transport networks. We describe the single-region traffic
dynamics by utilising the so-called Macroscopic or Network
Fundamental Diagram (MFD or NFD), a nonlinear relation be-
tween network-wide mean flow and accumulation of vehicles.
By using MFD relaxation conditions and structuring
uncertainties, we reformulate the nonlinear flow dynamics
to set of uncertain Linear Parametrically Varying (LPV)
ones. In controller design stage one, we apply the concept
of a two degree of freedom, induced L2 norm minimising LPV
controller. Within the generalised performance output, we
include tracking performance to follow a pre-defined
critical accumulation in uncertain model environment.
Output feedback LPV controller ensures generalised
disturbance attenuation conditions with appropriate gated
input flow at the perimeter. Second, an optimal quadratic
control allocation algorithm is employed to distribute the
ordered flow to entrance link green stages (flow equivalent
green time) in a number of candidate junctions at the
perimeter of the network. The constrained allocation
techniques complement the robust controller enabling
real-time applicability of the proposed methodology.
Finally, the suggested robust control scheme is tested in
macroscopic simulation environment. Results shows the via-
bility of the method in rapid and accurate tracking
behaviour under highly uncertain parameters of the MFD.