T-CPS Based Multi-vehicle Cooperative Driving Strategy In The Vicinity Of Traffic Signals Under V2X

As a link between the common road section and signal control area in the road system,the vicinity of traffic signals has important significance and influence on the traffic system.In this area,the continuous traffic flow is subject to the control of the constantly changing signal lights,presenting periodic stopping phenomenon,which can easily lead to traffic accidents,delay and fuel wastage.These problems are mainly caused by the lack of communication and coordination between vehicles,and it is difficult to make correct driving decisions from the overall situation.Therefore,it is important to study the driving law of vehicles in the vicinity of traffic signals and design the corresponding multi-vehicle cooperative driving strategy in V2 X environment,which is helpful to improve driving safety,to enhance traffic efficiency and to reduce energy consumption.The deep integration of cyber systems and physical systems is the main advantage of the Cyber-Physics System(CPS).Multi-vehicle cooperative driving based on CPS is expected to be an effective way to solve the traffic problem in the vicinity of traffic signals under V2 X environment.Therefore,based on the Transportation Cyber Physical System and the multi-vehicle cooperative driving around the vicinity of traffic signals,a decision tree-based cooperative car-following model and a cooperative lane change strategy based on lane change immediacy are proposed,respectively.In order to verify and analyze the performance of multi-vehicle cooperative model under non-ideal V2 X communication environment,we analyzed the characteristics of three mainstream V2 X communication technologies and verified the performance of the model under typical communication delay and interruption effects.As an extension of the multi-vehicle cooperative driving model in the vicinity of traffic signals,the problem of cooperative control of unsignalized intersections is studied.The main contents are as follows:(1)As to the specific situation faced by vehicles in the vicinity of traffic signals,the cooperative car-following model based on decision tree is studied.The scenarios considered by the existing studies are relatively simple,and most of them take signal vehicle as the optimal objective,and it is difficult to achieve an overall efficiency improvement.Based on this,the situation of the vehicle in the vicinity of traffic signals,including the state of traffic lights,the distance between the vehicle and the traffic lights,and the position of the vehicle in the traffic flow are analyzed.The cooperative driving strategy is given and a multi-vehicle cooperative driving model based on decision tree is proposed.The simulation experiments are used to verify the advantages of the proposed model in improving the overall traffic efficiency and reducing the parking time in the vicinity of traffic signals.(2)For the particularity of the lane changing scenario in the vicinity of traffic signals,the cooperative lane changing strategy on the basis of the immediacy of the lane change is studied.By analyzing the characteristics of lane change behavior in the vicinity of traffic signals,the safety conditions of vehicle lane change are proposed.Under the condition that whether the safety condition is met,the conventional lane change strategy and the conditional cooperative lane change strategy are proposed.Through the simulation experiments,the improvement of safety performance and the efficiency of lane change are verified.(3)Based on the characteristics of mainstream V2 X technology,the performance of multi-vehicle cooperative driving system under typical communication delay and communication interruption effect is explored.The cooperative driving model proposed by the existing studies often works in an ideal communication environment,which is inconsistent with the communication delay and interruption of the V2 X technology in practical applications.Based on this,the article summarizes the development route and application status of V2 X technology,and analyzes the advantages and disadvantages of three V2 X communication technologies,including DSRC,LTE-V2 X and 5G-V2 X.Through simulation experiments,it explores and analyzes the performance of the multi-vehicle cooperative driving system proposed earlier under the condition of typical communication delay and communication interruption conditions.(4)As an extension of the multi-vehicle cooperative driving model in the vicinity of traffic signals,the problem of cooperative control of unsignalized intersections is studied.By mapping the driving state information of the vehicles existing in different lanes in physical space to a same virtual lane of the cyber space,the virtual car-following technology and dynamic scheduling algorithm are proposed.Based on this,the efficient allocation of time and space resources and the collision avoidance mechanism are implemented,so as to improve the traffic efficiency of the whole intersection and its adjacent area.