A three-dimensional extension control for the dynamic boundary entrance of congested road networks

The dynamics and randomness of traffic demand require changes in the scope and boundary flow of congested traffic areas in a timely manner. Because of this, existing control methods have difficulty accurately detecting the boundary flow and executing an effective control strategy. Combined with the characteristics of extension theory, this paper transforms the boundary flow of congested traffic regions into a fuzzy variable and proposes a variable structure three-dimensional extension control method. Variable structure control consists of two parts. The first part is based on the matter-element model, and the correlation function of extension theory, boundary selection and entrance metering (BSEM) is proposed to evaluate the link density data in the periphery of the congested area and determine its dynamic boundary. According to the results of boundary selection, a proportion integration (PI) controller is designed to regulate the input flow of the congested area. Then, considering the measurement error of road network outflow, an extension lifting feedback (ELF) control is proposed. ELF takes the difference between the actual outflow rate of the road network and the expected outflow rate of the macroscopic fundamental diagram (MFD) curve of the congested region as the characteristic variable, divides the road network data, and adopts different control strategies to improve the input flow adjustment accuracy in the congested area. Finally, a case analysis is performed, and the results show that compared with Bang-Bang control, PI control and BSEM for congested regions without considering outflow fluctuation control, the proposed BSEM-ELF cooperative control can effectively reduce the total delay and average fuel consumption of the road network.