High order sliding mode control for real-time ramp metering

We propose the application of the High Order Sliding Mode Control (HOSMC) and the concept of differentially flat systems in order to solve the ramp metering problem. The main characteristic of differential flatness is that, the whole system behavior is described by the trajectory of a so called “flat output” and a number of its successive time-derivatives. This leads to a simple design of trajectories without integration of any differential equation. On the other hand, HOSMC is known to be a robust control method appropriate for uncertain systems. The effectiveness of the proposed approach is demonstrated via some simulation results from a case study and enable to foresee several very promising further developments for ramp metering and integrated traffic flow control.