Simulation Study On Behavior Of CACC Vehicles Using VISSIM

With the development and application of wireless communication and intelligent information technology,fully Cooperative Adaptive Cruise Control(CACC)vehicle driving becomes a major trend in transportation field.Based on the domestic traffic road facilities and environment,it is not feasible to conduct field and real-time research and test on the mixed traffic flow of manual vehicles and CACC vehicles.Traffic simulation technology is a research process of using modern computer technology to establish a computer model that can replace the actual traffic system.It has the characteristics of controllability,real-time performance,low cost and easy access to traffic data.This technology provides the feasibility for analyzing the driving behavior research of manual driving vehicle and CACC vehicle hybrid flow.In this paper,software design and coding are implemented based on VISSIM simulation framework,so as to study the driving behavior between artificially driven vehicles and CACC vehicles.Research contents mainly include:(1)Design and implementation of traffic simulation software based on VISSIM simulation framework.Microscopic traffic simulation software VISSIM,can provide accurate traffic simulation environment,can microscopically simulate the running of the real road network traffic,can provide precise evaluation calculation method,however,vehicle model of VISSIM only provide two kinds of models,widesman74 and widesman99,which can’t meet the required vehicle control model.Therefore,the simulation software based on VISSIM simulation framework was developed through the API interface of VISSIM software,so that it has the characteristics of microscopic simulation and unbiased evaluation of VISSIM.Meanwhile,the simulation evaluation module of VISSIM software can be used to simulate and evaluate the detected traffic data.(2)Research on longitudinal control theory.Firstly,the longitudinal control system architecture of the standard cruise control system was studied and analyzed.On this basis,the theories of adaptive cruise control and coordinated cruise control are studied respectively.Secondly,in order to study the vehicle spacing strategy of longitudinal control,a workshop spacing control strategy based on the headway was proposed as the workshop spacing control strategy in this paper.Finally,the architecture of the control algorithm of the coordinated cruise control system for formation of vehicle queue was proposed to realize formation of vehicle queue and cruise control.(3)Establishing a highway network.For manual driving vehicles and CACC vehicles in the expressway network,data collection points were set at different locations in the roadnetwork to collect data.Through the analysis of the collected data,compared with the pure manual driving traffic flow of the vehicle input on the road,as the proportion of CACC vehicles in the road vehicle input increases,the road capacity also increases;compared with the three-lane Number of passing vehicles,when the proportion of CACC vehicles was the same in the input of vehicles on the road,the increase in lane parameters can enhance the capacity of the road;lane conversion has a certain impact on the capacity of the road,and the impact of CACC vehicles on the number of passing vehicles was more obvious in the lower proportion of road vehicle input.(4)Establishing the intersection network.For manual driving vehicles and CACC vehicles pass through intersections,establish four-phase signal controllers and collect nodes at intersections,and collect traffic data at four entrances from east,west,south,and north.Through the analysis of the collected data,the different proportions of CACC vehicles in the input volume of road vehicles have a certain impact on the capacity at the intersection;as the proportion of CACC vehicles in the input volume of road vehicles increases,the vehicle queue length increases first and then decreases trend.