Research On Vehicle Lane Changing Area Setting Based On Route Selection Under Collaborative Control

The lane changing behavior of urban road vehicles is a common traffic phenomenon.Reasonable and orderly lane changing behavior can improve the traffic efficiency of the whole road section,while frequent and random lane changing behavior can reduce the traffic efficiency and increase the safety risks of traffic operation,especially in the bottleneck road section prone to traffic congestion.Aiming at the optimization problem of vehicle lane change in urban road,the paper puts forward the method of vehicle lane change organization and vehicle optimal control to reduce the total number of vehicle lane change,so as to reduce the overall delay of regional road network and optimize the traffic efficiency and safety of local road network.Specifically,four aspects are studied,including lane change area planning,coordinated lane change control strategy,vehicle control method and collaborative lane change simulation evaluation.(1)Planning and design of lane changing area.Vehicle local routing is the decisive factor to induce lane change.The frequency of lane change will not decrease with the increase of traffic flow.Through the division of functional areas of urban road sections,the organization scheme of vehicle collaborative lane change plans to set up fixed lane change areas and connecting road sections.The former is used for turning lane change of vehicles,reducing the number of random lane change,and the latter is used as the implementation area of variable speed limit of vehicles,for acceleration and deceleration of vehicles.Based on the planning and design of lane changing area,the vehicle control strategy and cooperative lane changing strategy are proposed.(2)Cooperative lane change control strategy.The cooperative lane change control strategy is used to guide the efficient operation of vehicles in the road section and the safe lane change of turning vehicles,including two parts: the control strategy of vehicle operation in the road section and the cooperative lane change strategy of turning vehicles.Among them,the vehicle operation control strategy includes variable speed limit strategy and static path planning,which is used to guide the vehicle speed and route selection on the road section;according to the relationship between the minimum safe distance of vehicle lane change and the available gap between vehicles,the coordinated lane change strategy is formulated for the turning vehicle to change lane at a constant speed or accelerate lane change strategy in the lane change area,which is also the basis of building the collaborative control vehicle operation model.(3)Vehicle cooperative control method.Based on the cooperative lane changing design,the car following model and lane changing model are established.According to the influencing factors of vehicle lane change,the minimum safety distance required for uniform and uniform acceleration lane change is analyzed based on relative speed,relative acceleration and relative distance.According to the different strategies of uniform and accelerated lane change,the uniform and accelerated lane change models are constructed respectively to control the running state and driving path of vehicles in the lane change area.(4)Simulation evaluation of cooperative lane change.Based on the scheme of vehicle coordinated lane change,combined with the operation model of collaborative control vehicle,with the help of VISSIM simulation software and python programming language,the simulation experiment of collaborative control vehicle lane change is designed.Based on the VISSIM simulation software to build the simulation scene,input the initial flow and steering ratio of each lane changing area,use MATLAB to fit the simulation data,and get the best setting length of lane changing area under different speed,flow and steering ratio conditions.The design of the comparative simulation experiment shows that: setting up the fixed lane changing area,making the path guidance strategy and cooperating to control the driving state of the vehicles in the lane changing area can effectively reduce the number of lane changing,avoid the invalid lane changing of vehicles,reduce the delay caused by lane changing of vehicles,improve the average travel speed of the vehicle section,and then improve the operation efficiency and safety of the traffic system.