Research On Low-Speed-Vehicles-based Congestion Characteristics And Congestion Control Methods In T-CPS

In actual traffic,low-speed vehicles can be caused by drivers' characteristics,driving behavior,and vehicles' attributes.Affected by low-speed vehicles,vehicles accelerate and decelerate frequently,and their speed dispersion increases.It can cause traffic flow to deviate from the stable and equilibrium state,reducing traffic efficiency and driving comfort,and increasing traffic accidents and fuel consumption.Also,low-speed vehicles can increase local density of road sections and form a mobile bottleneck effect.So traffic congestion caused by low-speed vehicles cannot be ignored.At the same time,with the development of information technology,the transportation system will no longer be segmented,and its impact on transportation problems has become more and more negligible.However,most of the existing traffic congestion analysis and suppression strategy research is based only on the traffic physical model,and the description of the information action mechanism is relatively simplified,making it difficult to support effective congestion suppression methods.Therefore,based on the perspective of cyber physics fusion,analyzing the characteristics of traffic congestion caused by low-speed vehicles,and then form a targeted congestion suppression strategy.It is important to theoretical and practical significance.In fact,the road traffic system is an organic whole,and the information feedback mechanism is crucial to the relationship between vehicles.Its interactive feedback and action mechanism have the typical characteristics of the cyber physical system(CPS).To this end,from the perspective of CPS,this paper takes the traffic congestion characteristics of low-speed vehicles as a breakthrough point,and studies the congestion suppression strategy based on the traffic flow model under the stimulation of low-speed vehicles affected of the information action mechanism.The congestion suppression method that considers the average effect of flow information of multiple lattices when there is no lane change and the congestion suppression method considering the two-way gap of delay effect when lane change is allowed are mainly studied.On the other hand,considering the impact of lane change stimulus on vehicles in the fast lane,a congestion suppression method considering the delay effect of lane change stimulus is studied.At the same time,combined with the specific scenario of the ramp under the highway,low-speed vehicles are likely to cause an increase in traffic density and it is difficult to efficiently change lanes.A congestion suppression strategy based on IDM cooperative lane change is studied.The main research work completed in this paper includes:(1)Analysis of traffic congestion characteristics affected by low-speed vehicles.The Jiang model is extended by considering the influence of low-speed vehicles,and the results show the influence and propagation of lane change behavior on the macroscopic traffic conditions under the influence of low-speed vehicles,and the traffic phase transition phenomena of macroscopic traffic conditions from free flow to synchronous flow and wide motion under the influence of low-speed vehicles,which reveal the characteristics that lane change behavior under the influence of low-speed vehicles tends to increase the discreteness of road speeds and decrease the orderliness of vehicles.(2)A congestion suppression method based on lane change stimulus is proposed from the micro level.Under the influence of low-speed vehicles and with lane change condition,through the perception of the speed and position information of adjacent vehicles in the T-CPS environment,a congestion suppression method based on LM-FVD model with delay is proposed.Through linear stability analysis,the linear stability condition is obtained.Through numerical simulation,it is found out that when the model delay is larger or the radical coefficient is higher,the model is more likely to evolve into traffic congestion,and the weighting coefficient of the suppression term can effectively eliminate the traffic congestion in the traffic flow.(3)A congestion suppression method based on IDM cooperative lane change is proposed from the micro level.In the T-CPS environment,when the increase in traffic density caused by low-speed vehicles is difficult to efficiently change lanes,a congestion suppression strategy based on IDM cooperative lane change is proposed.The low-speed vehicles are guided to complete the lane changethrough the cooperative lane change strategy,which reduces the waiting time.Through the simulation experiments of the on-ramp and other scenarios,it is verified that the new model can effectively reduce the lane-changing time and the average driving time,and can suppress traffic congestion.(4)A macroscopic level of congestion suppression method based on the average field effect is proposed.Under the influence of low-speed vehicles and without lane change condition,a traffic jam suppression method based on MF-LHM model is proposed by sensing the flow information of multiple lattices under T-CPS environment.Through theoretical analysis of the model,the linear stability criterion of the model and the m Kd V equation describing the nonlinear vehicle flow propagation characteristics of the model are obtained.Numerical simulation results show that the average effect of multi-lattices flow information plays a very important role in suppressing traffic congestion.(5)A congestion suppression method based on bilateral gap is proposed from the macro level.Under the influence of low-speed vehicles and having lane change condition,through the T-CPS environment to perceive the neighboring grid flow information,a congestion suppression method based on the BGL-LHM model with delay is proposed.Through theoretical analysis of the model,the linear stability criterion of the model and the m Kd V equation describing the nonlinear traffic flow propagation characteristics of the model are obtained.The simulation results show that when the delay is greater or the lane departure rate is lower,the model is more likely to evolve into traffic congestion,and the weighting coefficient of the suppression term can effectively eliminate traffic congestion in traffic flow.In summary,the paper studies the traffic congestion characteristics and suppression strategies affected by low-speed vehicles from the perspective of cyber physical fusion.Based on the information mechanism,with the consideration of speed,location,and flow,it proposes traffic congestion suppression strategies stimulated by low-speed vehicles from both micro and macro levels.Theoretical analysis and numerical simulation all verified the effectiveness of the above method.The results can more clearly describe the impact mechanism of low-speed vehicles on road capacity,and are also expected to provide guidance for the study of traffic congestion suppression caused by low-speed vehicles from the perspective of CPS,and lay the foundation for the improvement of road traffic efficiency.