Risk Assessment And Information Access Mechanism In Internet Of Vehicles At Intersection

In recent years,with the rapid development of wireless communication systems,the concept of advanced cooperative driving can be achieved.The cooperation through car communication ensures driving safety.Urban road intersections are one of the most dangerous areas in the road network.Because the different types of road users interact in the limited area of the intersection,the intersection is the most complicated.Therefore,in the urban intersection area,it is of great significance to establish an effective vehicle risk assessment method and ensure timely and accurate transmission of safety information.In this paper,we propose a collision probability prediction model at the intersection.Firstly,the driver’s intention is modeled by the BP neural network,of which the maximum probability is selected as the driver’s intention by probabilistic calculation.Then,the identified probability is taken as the control matrix of the Kalman filter and the vehicle trajectory is predicted by the Kalman filter.Finally,seting the trajectory at the intersection,we can define the collision probability model of the vehicles at the intersection.According to the probability of collision,we determine whether the driver’s intention should be adjusted and then implement the final driver’s intention to avoid the occurrence of collision risk.The simulation results show that the average relative error is about 0.6% and the prediction accuracy is higher than that of the TTC index.Compared with the TTC index,the collision probability predicted by our scheme has smaller variation range and the prediction accuracy is high.After accurate prediction of vehicle collision information,it’s necessary to ensure reliable and timely delivery of information.VANETs improve vehicle safety mainly through the car to car communication.The safety information mainly contains beacon and EMW information.Frequent exchange of beacon information causes a great network load to the communication channel,in high-density conditions,which can easily lead to information congestion,reducing throughput and increasing the delay.At the same time,when accident occurs,information transmission between beacon information and EMW information needs to be coordinated.In order to guarantee the reliable and timely transmission of safety information,this paper proposes a MAC-based safety information access protocol based on a large number of safety information transmission protocols.First,the vehicles and road is divided into several partitions,every which is centralized scheduling and the vehicle closest to the center of the partition is selected to be the scheduling vehicle.Then,the transmission time slot of beacon and EMW information is used to divide based on the TDMA access mechanism.In order to improve the utilization of the channel,we share time slot between partitions which don’t have interference.The simulation results show that our proposed scheme greatly improves the vehicle network throughput,reduces the system MAC delay,ensures the full utilization of the time slot,and realizes the reliable communication between the vehicle safety information.In summary,in order to ensure the driving safety and information demand of the vehicle in the urban intersection area,it is applicable to the safety-related application technology in the vehicle self-organizing network.It is of great value to propose the driver’s intention-foridentification and risk assessment method and the network access mechanism.