Modeling And Density Wave Analysis Of Macro Microscopic Traffic Flow Model

In this thesis,based on the microscopic car-following model and the macroscopic hydrodynamic model,considering the influence of some typical factors in the real traffic,several improved traffic flow models are proposed.The corresponding linear analysis and nonlinear analysis are performed.The critical phase transition and the evolution of the traffic density wave under small disturbance are explored.The validity of the model is verified by numerical simulation.The contents of thesis is arranged as follows:1.Car-following model based on cooperative driving with the consideration of jerkIn actual traffic,the driver's driving behavior will change by the environment change about the leading car,according to this phenomenon,based on the optimal velocity model proposed by Bando.and considering the influence of leading car and urgent push effect,we put forward a car-following model based on cooperative driving considering the effect of urgent push.Neutral stability curve and critical state are obtained by linear stability analysis and nonlinear stability analysis,also TDGL and mKdV equations are deduced by applying the method of reduced perturbation,and get the coexistence curve and metastable curve by thermodynamic potential,and numerical simulation validate the correctness of theoretical analysis,considering the urgent push effect can more effectively inhibit or ease traffic congestion.2.An improved car-following model considering the speed difference of current and historical moment based on the Intelligent Transportation System(ITS)In intelligent transportation system,due to the speed changes in different time of the leading car will affect the acceleration or deceleration of the current car,so for the condition of vehicle acceleration or deceleration too frequently,we put forward a car-following model which is based on ITS considering the speed difference influence of the current moment and the historical moment of the leading car.Stability condition and the critical state are obtained by linear and nonlinear stability analysis,and near the critical point,TDGL and mKdV equations are deduced by applying the method of reduced perturbation,then we studied the relationship between the two equations,The numerical results verify the correctness of the theoretical analysis.Compared with the existing research,the consideration of current moment and historical moment of the current speed difference from ITS is effective in avoiding the formation of traffic jam.3.An improved continuum model considering the effect of jerk based on full velocity difference modelIn actual traffic,the driver will often have an emergency brake or sudden acceleration behavior,aiming at the problem of the acceleration and deceleration is too intense,based on the full velocity difference car-following model which is put forward by Jiang,the full velocity difference microscopic car-following model has been established by considering the urgent push effect.Then through transformation between the microscopic and macroscopic traffic flow quantity,a full velocity difference macroscopic fluid mechanics model considering the urgent push effect that is proposed.The linear analysis for the model,we obtain the neutral stability conditions.The nonlinear analysis for the model,we get standard KdV-Burgers equation,and the analytical solution of the equation is presented.The numerical simulation has verified the correctness of theoretical analysis.The numerical analysis results show that considering urgent push effect is better than not to consider the factors contribute to the stability of traffic flow.4.An improved car-following model considering the optimal velocity effect of leading car of car-following modelIn daily traffic,according to the distance of the leading car,driver can select the corresponding acceleration or deceleration(i.e.,the change of optimizing velocity),for this situation,on the basis of full velocity difference model,considering the optimization speed impact of the leading car.the stability of curve and critical condition are obtained by linear stability analysis.Then through the nonlinear analysis,TDGL and mKdV equations are derived by using perturbation method in this paper,we also studied the relationship between the two equations and the solutions.Under the idea of energy conservation and emissions reduction,we studied the energy consumption problems of the model by the method of energy conversion,numerical simulation validate the correctness of theoretical analysis and numerical results show that considers the optimization speed is more conducive to smooth traffic flow.