Integrated Internal Boundary Control and Ramp Metering in Lane-Free Highway Systems: A Combined Feedback Linearization and MPC Approach

The concept of Internal Boundary Control (IBC) has been recently incorporated into Lane-free automated vehicle movement with the aim of maximizing the utilization of cross-road infrastructure in both directions. Although IBC is generally successful in alleviating congestion, there are scenarios where it may not be able to fully dissolve it. Employing Ramp Metering (RM) can be an effective strategy for managing the flow of traffic from the on-ramp to the mainstream in this situation. This paper proposes an online scheme optimization approach for integrated IBC and RM in lane-free traffic. For controller design, a dynamic traffic flow model based on a first-order macroscopic model with the driver's anticipation term is considered. The nonlinear and multivariable characteristics of this macroscopic highway model make it unlikely to be practical to create an online optimization mechanism for it, primarily due to the expected high computational expenses. So, a feedback linearization approach is employed to tackle the complexities of the macroscopic model. Following that, a linear Model Predictive Control (MPC) is designed based on the feedback linearized model to obtain an efficient and real-time solution. The suggested approach undergoes examination through a series of simulation tests to evaluate its performance. The simulation results verify the efficacy of the proposed approach in enabling real-time and efficient traffic management in future lane-free highway systems.