Research On Intersection Cooperative Control And Its Active Safety Method

The method of intersection collaborative control has become a research focus in the field of intelligent traffic control.Many scholars abroad have proposed lots of traffic light control algorithms that are based on the island intersection.These algorithms cannot meet the requirements of real-time traffic,cannot guarantee the fairness of each phase in every cycle,cannot ensure the traffic safety at intersections,and neglect the active safety issues among all traffic flows.Aiming at the problems of active safety,efficiency and fairness at intersections,this paper proposes a longitudinal safety collaboration control algorithm of a single intersection and multiple intersections,respectively.Moreover,we design a transverse active safety algorithm of the fleet,based on the existing inter-intersection cooperative control system.We used the simulation tools to validate the algorithms proposed in this paper,and contrast with other algorithms.Moreover,to validate the algorithms,we design a simulation platform that is composed of micro intelligent vehicles in the laboratory.The main contents of this paper are as follows:(1)A 3-Level Buffer(TLB)based Virtual Traffic Lights(VTL)scheme,named TLB-VTL,is proposed for intelligent collaborative island intersections.First,a three-level buffer is set up at the intersection,to control the traffic flows at the intersection,effectively and reasonably,and to reduce the complexity of the coordinated control system.Secondly,the size of the 3-level buffer is adjusted by the traffic flows of the recent history datum.And the method can adapt to the real-time traffic flow,effectively.Using the VTL algorithm can overcome shortcomings and limitations of the road traffic infrastructure,reduce the cost of transportation facilities at intersections,and ensure the vertical security among all traffic flows.The main role of the 3-level buffer is to rationally divide the traffic flow and limit the length of traffic lights.The main role of virtual traffic lights is to plan the phase sequence of traffic lights.Their effective combination can form a complete signal control command.In addition,combining the 3-level buffer with the virtual traffic lights can increase the throughput of intersections,ensure the fairness of all phases,and reduce the possibility of traffic jams at intersections.(2)This paper proposes a dynamic cooperative traffic control framework for multiple intersections based on virtual-grids,named VGC-COM.Dividing the road by the virtual grids,can facilitate the data fusion.In addition,the data includes two parts,one is the traffic flows near the intersection,and another is the traffic flows coming from the upstream traffic intersection into the local intersection.Moreover,it is convenient to simplify the cooperative control parameters of intersection.On the premise of ensuring that each phase of traffic flows gets the right of way fairly,the TLB-VTL algorithm optimizes both the phase sequence and phase time allocation by local real-time traffic flows and the traffic conditions of the surrounding intersections,and makes the throughput of intersection to maximize.Moreover,according to the saturation of the traffic flows that are in the virtual grids,the traffic flows can be scheduled reasonably.And the method not only reduces the probability of traffic congestion at intersection,effectively,but also improves the throughput of the road network and the utilization rate of the road.(3)We have established a fault detection and isolation system with a two-level fault diagnosis architecture about vehicular spacing of vehicle platoon.Traffic flow is an important control parameter in the intersection collaborative control.In addition,the transverse safety problem among traffic flows is a standard to measure the performance of an intersection coordinated control algorithm.We regard the traffic flow around the intersection as a macro-fleet.For the horizontal security of the fleet,a two-level fault diagnosis framework is proposed,which includes the system failure and the component element failure.For the component element failure,the structural analysis of the vehicle is strengthened.And the residual model of the vehicular sensor is designed by the vehicle mathematical model,which detects and isolates the sensor failure of the vehicle effectively.According to the spatial geometry theory,we have deduced the residual generator of vehicular spacing.Then,we design an adaptive threshold residual decision module to separate the fault,which reduces the external interference and false alarm rate,effectively.Finally,traffic scenarios of single-lane and multi-lane traffic are designed on the semi-physical traffic platform in the laboratory.Based on abundant experiments,the feasibility and reliability of both the two-level fault diagnosis model and the intersection coordination control algorithm proposed in this paper are verified.After further improvement,it not only can be directly transplanted to the intelligent transportation system(ITS),but also to provide solutions for collaborative control and active safety research about intelligent transportation intersections in smart cities.