Study On Nonlinear Characteristics Of Traffic Flow And Four-way Pedestrian Traffic

The urban transportation system has become an indispensable component of economic activity.With the influx of a large number of vehicles and population into cities,the problem of traffic congestion has become increasingly prominent.Various nonlinear phenomena in traffic flow,such as bifurcations,solitary waves,shocks,and chaos,are closely related to the formation of traffic congestion.Research on the nonlinear behavior in traffic flow is a primary method for revealing the internal mechanism of the transition from smooth traffic flow to congestion.Therefore,studying the nonlinear characteristics of traffic flow is of great significance for solving traffic congestion.The main research work of this paper is as follows:The main research work of this paper is as follows:1、This paper proposes a car-following model that considers jerk behavior and delayed feedback control to address sudden acceleration or deceleration behavior of drivers on the road.To investigate the dynamic behavior of the model,the stability conditions and equilibrium points of the model were obtained through stability analysis and nonlinear Hopf bifurcation analysis.The Definite Integral Stability(DIS)method was employed to calculate the number of unstable characteristic roots of the characteristic equation in the right-half plane,and the stable delay interval was determined.Based on this,a delayed feedback controller was designed to make the traffic system stable.The results showed that the feedback controller suppressed the impact of jerk behavior on the traffic system,and improved the stability of vehicle traffic.The numerical simulation results were consistent with the theoretical analysis results,providing a theoretical basis for traffic control to alleviate road congestion.2 、 In the context of a mixed traffic flow consisting of human-driven vehicles(HDVs)and adaptive cruise control vehicles(ACCs)in intelligent transportation systems,it is necessary to investigate the nonlinear characteristics of this mixed traffic flow,which differs from those of a single flow.Therefore,a macroscopic traffic model considering the mixed traffic of HDVs and ACCs is proposed in this paper.Under large disturbances,the global stability conditions of the uniform flow under the initial equilibrium state are obtained by using the wavefront expansion technique.Nonlinear bifurcation analysis is used to demonstrate the existence of subcritical and supercritical bifurcations in the system under different ACC vehicle penetration rates.The dynamical behavior of the system near the bifurcation point is analyzed by using phase space diagrams and spatiotemporal density evolution diagrams,which explains the alternating transformation of stop-and-go waves and traffic congestion to smooth flow in the traffic system.3、A four-way pedestrian traffic lattice hydrodynamic model considering turning capacity was proposed.Stability conditions were obtained through stability analysis,and the m Kd V equation was derived using the method of nonlinear analysis and perturbation reduction,and the corresponding density wave solutions were obtained.Numerical simulations of the spatiotemporal patterns of pedestrian flow density evolution and density distribution at different times were carried out under different initial conditions,and the simulation results were consistent with the theoretical analysis.The research results showed that the equilibrium distribution of pedestrians along horizontal and vertical channels can promote the stability of pedestrian traffic,while pedestrians can stimulate traffic congestion at intersections when turning.