Modelling and robust control of traffic signal systems

This paper first proposes a model of traffic signal control systems for avoiding traffic congestion in urban road networks. The model is constructed so that it is controllable, and disturbances of traffic flow and changes of traffic situations can be taken into account. As a result, the proposed model is described as a linear system with polytopic uncertainties. Next, a robust control method is applied to the proposed model so as to achieve robust stability and performance under the uncertainties. The proposed control method gives a control law for real-time and network-wide traffic signal systems. A numerical example is given to show the effectiveness of the proposed method.