Research On Dynamic Timing Of Traffic Signals In Vehicle-road Cooperative Environment

In urban road networks,the key to improving traffic efficiency is how to coordinate and reduce the time that vehicles pass through intersections.The balance of signal timing and the speed at which vehicles pass through intersections are constraints that affect the efficiency of traffic circulation.When traffic is congested,a small section of traffic flows can easily affect the rest of the traffic on the road section,and even affect the traffic at the upstream intersection.At present,the timing of signals at intersections in cities across the country still uses fixed-timing control,experience control,and other methods.At signalized intersections,vehicles passively accept the control of the remaining time of the green light,which easily causes vehicles to pass through the intersection a second time.It has long been unable to meet the needs of development trends such as real-time,high-efficiency,and integrity of urban traffic.In recent years,the research results of vehicle-road coordination technology have gradually come to fruition,and the timing of vehicles and road intersections has become possible.In this thesis,the method of dynamic timing of traffic signals in a coordinated environment of vehicles and roads is discussed.Firstly,the model of dynamic timing of traffic signals based on multi-objective optimization is studied.The single intersection is used as the research object,and a speed guidance scenario is designed.The average vehicle delay time and average time,the number of stops,average driving speed,and road capacity are taken as optimization targets.The cycle length,effective green light time of each phase,and the guidance vehicle speed at the intersection are used as control factors,and saturation is the constraint condition.Tracker software is used to process the vehicle running video.The GA program is written using MATLAB software to solve the problem.Secondly,the multi-intersection signal dynamic coordination research is conducted,and the multi-intersections on the arterial road are selected as the research objects.After selecting the key intersections,the multi-target dynamic timing model is used to calculate the cycle length,the effective green light time of each phase and the departure speed.It is used as the main line coordination speed,and then the digital solution is used to solve the phase difference at multiple intersections to dynamically coordinate the main line traffic.Finally,the traffic signal dynamic timing simulation is performed,and the internal VB environment of Visual Studio 2010 software is used to connect the VISSIM micro simulation software with COM interface,the single-intersection experimental object and the multi-intersection experimental object are selected for simulation on the spot.With the Webster method signal timing scheme,the simulation results show that the multi-target signal dynamic timing algorithm can effectively reduce the average vehicle delay,the average number of parking times,and improve the capacity and average speed of driving;when the average travel time,average delay,average number of parking times and the average queuing length is used as the evaluation index to simulate the multi-intersection dynamic coordinated control and timed control environments,the performance of the dynamic coordination control method to control the driving output of the vehicle is reduced.The method of dynamic timing of traffic signals under the environment of vehicle-road coordination studied in this paper improves the traffic capacity of intersections,and is suitable for the coordination of signals at multiple intersections.