Research On Signal Priority Strategy And Method For Intelligent Connected Buses

Ensuring the bus priority at intersections and improving the level of bus service can effectively alleviate urban traffic congestion.Intelligent network bus has been gradually applied in Shanghai,Guangzhou,Nanjing,Hangzhou,Chongqing,Changsha and other cities.On the basis of conventional bus,the bus is reformed by loading the OBU,which can realize bidirectional information interaction with the signal controller,so as to realize signal priority and speed guidance.This paper mainly studies the priority control strategy and method of intelligent network bus at intersections.From three levels of single intersection,single line and section multi-line,the signal control strategy is designed and the optimization model is established.The main work includes:(1)Signal control model for multiple bus priority requests in single intersection.Most of the existing bus priority signal control methods are aimed at a small number of bus priority needs in a specific direction.In this paper,the queue length is predicted based on the traffic wave theory,and the bus delay prediction model is established.Taking the total delay of all buses arriving at the intersection as the goal,considering the constraint of signal control parameters,a mixed integer linear programming model is established,and the signal priority timing scheme is solved by MATLAB programming and rolling.(2)Single-line bus priority signal control model.Most of the existing signal control models do not consider the operation state information of the bus when carrying out bus priority control,which leads to the mismatch between bus priority and bus operation state.For example,the operation state information includes whether the bus arrives at the " early " or not,and whether there is a " bus string ".This paper establishes a bus priority signal control model based on bus headway equalization.Based on the bi-level programming model,the upper level takes the bus headway balance as the goal,and the lower level takes the minimum bus delay as the goal.The bus speed,dwell time and signal priority timing scheme are optimized to realize the coordinated optimization of bus priority and bus operation state.(3)Section multi-line bus priority signal control method and modeling.The existing bus priority signal control models are mostly for single intersection.Most of bus priority signal control models for multi-intersection only consider the coordinated control of bus green wave.It is difficult for non-coordinated buses to obtain priority services and ensure the effectiveness and fairness of bus priority.In this paper,the concept of section priority control is proposed for multi-intersections of the arterial line,which means bus priority is provided for specific bus lines at specific intersections.Firstly,for all bus lines within the scope of the study,according to the spatial relationship between intersections and bus lines,a section bus priority request allocation algorithm is designed to assign exclusive ’ priority intersection ’ for bus lines.Secondly,a bus priority signal control model based on section priority is established.The main goal is to minimize the delay of bus priority lines allocated at intersections,and optimize the signal timing scheme considering the delay of other bus lines.With the rapid development of artificial intelligence,mobile Internet,edge computing,cloud sharing and other technologies,China’s intelligent Internet bus has launched pilot projects in many places,and gradually popularized in major cities.This paper studies the intelligent network bus signal priority control strategy and method,has good practical application value.