A hybrid automaton for multi-class ramp metering in freeway systems

In this paper a hybrid automaton is proposed for regulating traffic in freeway systems in which the adopted control measure is ramp metering. The lower level of the control scheme is given by a set of discrete-time systems and regulators whereas at the higher level a supervisor chooses the control law to be applied to the system and it evolves according to a discrete-event dynamics. The main novelty of this work regards adopting a multi-class prediction model in the Model Predictive Control scheme in order to explicitly consider two vehicle classes, i.e. cars and trucks. In this way, it is possible to obtain different control actions for the two classes and to assign them different priorities. In the paper, the 2-class prediction model and the regulator is described in detail, as well as the discrete-time discrete-event automaton adopted for representing the proposed hybrid control scheme.