Research And Implementation Of Traffic Signal Wireless Transmission System Based On Cooperative Vehicle Infrastructure System

With the development of economy, the urban population and vehicles ownership increase year by year, bringing about the increase of traffic accidents. According to related statistics, the urban traffic accidents mostly happens at intersections and adjacent sections. One of the reasons for that is the drivers couldn’t perceive the traffic signal accurately owing to the road, environment and drivers. The existing research mostly adopt image identification, however, it has higher error and is easily influenced by the environment. Therefore, studying and designing a wireless transmission system which is little affected by the environment and provides more accurate data and is built more simple for car’s reception to remind drivers has great significance on the improvement of road network safety.The thesis adopts ARM Linux platform for designing an embedded wireless signal transmission system. It acquires the traffic information stem from traffic signal controller at intersections, processes data and sends them using Wi-Fi module for car’s reception and use. The main work of system designing and study are as follows:Through the analysis of system function, we determine the system’s overall framework and development process. The system is divided into two parts, the system hardware and system software design. In hardware design, we identify the required function modules according to system function, drawing function module circuit diagram, make the hardware platform of system requirements. System software development is divided into two parts:the first part includes the establishment of cross-compiler environment, transplant Bootloader, transplant system kernel and root file system to establish. The aim is to build a system for the embedded Linux software platform. The second part includes transplant drivers and the design of network communication program. When used the specific hardware, first, Linux kernel to support the hardware. System design, we mainly analyze and transplant the DM9000 network card and USB Wi-Fi module driver. Then, get the traffic signal data and wireless communications to send data over the network. The system uses a socket designed to transmit and receive information communication program. After the completion of system hardware and software, and performed functional tests to ensure that the system is designed to achieve final settlement of travelers unable to accurately obtain traffic signal problems.Test results show that the vehicles in urban road driving under the speed limit through a traffic signal wireless transmission system of Wi-Fi coverage are able to receive valid data.