Research And Implementation Of Tram Priority Control Based On Road Microscopic Traffic Simulation System

Vigorous development of urban public transportation has become an important measure to solve the problem of traffic congestion.In order to ensure the efficient operation of high-traffic trams,priority is given to them,which is of great significance for the operational efficiency and driving safety of trams and for improving urban traffic congestion.At present,there are real-time priority,passive priority and active priority control methods among domestic and foreign research on the priority rights of trams,but they are mostly based on the theoretical research.This thesis studies the practical technology,and the priority control algorithms is programmed and embedded into the simulation signal software.And the control effect of the priority of the tram is verified by accessing the road micro-simulation system.The subject analyzes three control methods.The real-time priority control relies on the control center adaptive system to participate in the control,which is difficult to implement.Passive priority will disturb the phase sequences and cause potential safety hazards to social vehicles.Therefore,this thesis takes the active priority control strategy as a practical application object for signal priority control.The control scheme of the signal consists of the specific contents of phase sequences,cycle length,split and phase difference.Based on the principle of signal control,the subject researched the influence of several key parameters related to priority control on the control process.According to the distribution of the time on the time axis of the signal cycle operation when the tram arrives at the stop line,the Waiting for the green time is statistically calculated for determining the optimal position(distance)of the detector.The subject analyses the relationship about influence of the length and running speed of the tram on the yellow light time,inter green time and control means of the Tram traffic phase.This thesis has programmed the priority control algorithm of the research results,and realized the priority control of the tram through the external sensing control program interface provided by the simulation signal machine.In the test,the random arrival of the trams is made by setting the tram departure parameters and detector setting parameters of the road micro-simulation platform.The simulation signal machine obtains the arrival information of the tram through the shared memory,and acquires the signal operating status through the interface function.When receiving the tram approaching information of the detector,it can calculate the state and time of the signal when the tram arrives at the intersection stop line.If the state and time are within the maximum green light extension time after the green light of the same phase of the train ends,the green light extension scheme will be adopted,otherwise the red light shortening scheme will be adopted.The modification of the predetermined time of the green light and the control of the signal state transition are implemented by using the interface function of the simulation signal machine.In the program test,the correctness of the tram priority control algorithm is verified by observing the moment when the intersection signal light changes in the micro simulation screen and the dynamic process of the tram priority passing through the intersection.