Case-study based performance assessment of an event-triggered MPC scheme for freeway systems

The paper is aimed at the definition of an efficient control framework for freeway systems. To this end, a Model Predictive Control scheme based on the cell transmission model is adopted in which the considered control action refers to ramp metering. Two major aspects characterize the paper. First, the prediction model is formulated as a mixed logical dynamical system (i.e. it is described by linear dynamic equations and linear inequalities in which both real and integer variables are involved) in order to obtain a finite-horizon optimal control problem with the structure of a mixed-integer quadratic programming problem. In such a problem the objective function quadratically penalizes the deviation of the state variables from a specific equilibrium point. Secondly, an event-triggered scheme is used to further reduce the computational load of the control scheme making it more adequate for real applications. Numerical results based on data coming from a real case study relevant to Grenoble South Ring are also presented and discussed.