A Hierarchy Control Algorithm and its application in Urban Arterial Control Problem

The purpose of this paper is to investigate the application of a hierarchy control algorithm in solving the traffic signal timing control problem for an oversaturated traffic arterial. In the local control layer, the concept of feeding delay and non-feeding delay is introduced , and the cell transmission model is used to calculate the feeding delay and the non-feeding delay, then the control problem is formulated as an conflicted multi-objective control problem, and an IPNSGA-II based compatible controller installed at adjacent junctions is used to design signal timing plan for each junctions. Then in the coordination layer, based on the state of density on each link, three rules are proposed to define the range of the junctions required to be coordinated. Finally, the IPNSGA-II is used to design the traffic signal timing plan for the junction group. Simulation results show that the proposed algorithm is capable of dealing with real-time oversaturated traffic arterial control problem. The algorithm is tested in a simulation environment consisting of a core area of 7 junctions. It can be concluded that the proposed method is much more effective in relieving oversaturation in a network than the isolated intersection control strategy.