Signal Optimization Control Method Of Single Intersection In The Mixed Traffic Environment

With the gradual maturity of automatic driving technology,autonomous vehicles will gradually appear on the road to replace human-driven vehicles,which will lead to the mixed traffic environment for a long time in the future.At the same time,the development of vehicle-road coordination technology and the promotion of automatic driving technology provide new possibilities for further tapping the traffic potential of intersections.Aiming at the difference of traffic efficiency between autonomous vehicles and human-driven vehicles caused by the difference of trajectory controllability and car following characteristics,this paper proposes vehicle scheduling strategy and signal control method at the entrance of intersection.It is expected to provide a reference for the optimal management of intersection space-time resources in the mixed traffic environment.Firstly,the principle of the existing signal control method of intelligent network intersection and the shortcomings of its application in the condition of the mixed traffic environment are discussed.In the framework of the system,the general idea of intersection signal optimization under the mixed traffic environment is elaborated.From the perspective of CAV penetration,the approach lane allocation model of intersection entrance is proposed to optimize the function and attribute of lane.The dynamic allocation mechanism of approach lane is established by using the effective utilization rate of green light and conversion index;In vehicle longitudinal control,the vehicle following strategy is proposed to induce vehicles to pass the intersection as soon as possible,and the bidirectional optimization process of signal timing parameters and vehicle trajectory is proposed based on vehicle-road two-way communication function in vehicle-road collaborative environment.Secondly,the method of defining the range of vehicles with trajectory optimization in each phase is proposed,and the trajectory optimization models of the CAVs in different motion states are established.In view of the change of vehicle parking times and delay after trajectory optimization,the PI evaluation model is established.With the minimum PI as the objective,the optimization model of signal control parameters is established,and determine the constraint conditions and give the solution algorithm.The solution algorithm is given to realize the optimal adjustment of intersection signal control scheme.The adaptability of the optimization model is analyzed,and it is concluded that intersection saturation,CAV permeability and maximum induction speed can have a significant impact on the signal optimization control effect.Finally,with the help of SUMO simulation platform,the fixed timing scheme of traditional transportation organization,the fixed timing scheme of only lane optimization configuration and the signal optimization control scheme proposed in this paper are compared and analyzed.The simulation results show that the PI value of the intersection can be significantly reduced by the optimal lane configuration under the condition of the mixed traffic environment,and the operation efficiency can be further improved by the collaborative optimization of signal and vehicle trajectory.The average PI of vehicles is reduced by 16.7%,which verifies that the signal optimization method proposed in this paper has good optimization effect.