Research Of Optimization Method For Information Interaction Performance In Intelligent Vehicle Infrastructure Cooperative System

Intelligent Vehicle Infrastructure Cooperative System (I-VICS) is the safe, efficient and environmentally friendly transportation system with information processing technology, navigation, positioning technology, computer control technology, communication technology, sensor technology and artificial intelligence technology. Information interaction is the embodiment of I-VICS and its performance directly affects the driving strategy formulation and driving safety. On the basis of the study and summarizes the research status of information interaction in I-VICS, the principle of information interaction performance optimization methods and the application in traffic environment were analyzed. In this paper, from the aspects of channel access protocol and multi-modes of communication integration, optimization methods which combine the traffic system characteristics for information interaction’s performance in I-VICS were studied. Modeling and simulation technology of I-VICS provides a platform for the realization and validation of the information interaction optimization method and it also provide technical support for the actual technology research and development of I-VICS.Firstly, MAC layer channel access protocol determines the fair and efficient utilization of network resources in I-VICS. Through the analysis of the MAC layer of different handshake mechanism and typical back off algorithm, then combining with the characteristics of I-VICS and the characteristics of the IEEE802.11p, paper puts forward the adaptive channel access protocol-ATEDCA. ATEDCA merges vehicle density and the number of transmission times into the optimization of the handshake mechanism and adaptive back off algorithm, and then it reduces the possibility of channel collision among nodes to improve the network performance.Secondly, multi-modes of communication integration mechanism based on adaptive neural network is designed which includes WAVE, WLAN and3G mode. By studying the optimal communication mode samples of various traffic situations, vehicle density, average speed and transmission data volume regard as input parameters, and after learning by the LMS algorithm, the proposed integration mechanism can accurately predict the most reasonable communication mode of traffic scenarios.At the same time, information interaction simulation platform of I-VICS based on High Level Architecture (HLA) is designed, and it has an adaptive time synchronization mechanism to control the real-time performance of the simulation modules based on feedback mechanism. Communication model in the simulation platform is mainly built and completed in OPNET Modeler, and the information interaction simulation software is designed at the same time which is used in the communication process of feedback control and the collection of communication result.The testing and verification of information interaction optimization method in I-VICS was completed on the basis of information interaction simulation platform in which typical traffic application scenario including the car-following warning and intersection warning were simulated and verified. The simulation results indicated the proposed optimization method can improve the communication performance. This paper provides simulation support for the real information interaction process in I-VICS, and it has certain value for engineering application of research and development of the wireless network.