Feedback controller design and algorithm of freeway system

In order to improve the using efficiency of freeway system, a feedback controller was designed and its iterative algorithm was proposed, the controller could track vehicles' real-time densities and compare them with the anticipant density, then it sent the errors to the vehicles, and guaranteed the convergence of the real vehicle density to the anticipant density under appropriate speed command followed by vehicles.Simulation result indicates that the maximum relative error of vehicles' densities and travel speeds is 0.32%, and the average time consumption is 0.32 s after the fourth iteration of the algorithm, so the controller guarantees the smooth and stable traffic flow, reduces the vehicle's delay and increases the efficiency of the system.