Study On Highway Weather Information Acquisition System

Highway is reputed as the bridge through which a country goes to modernization. Intelligent traffic system has become the core of the development of modern transportation. Weather information system for highway as the major component of the intelligent traffic system is at the start development phase at present, This article designs a highway weather information acquisition system with CAN field bus technology, GPRS technology and embedded Technology, and the research and development for the key technologies have been completed.The system is composed by the following five parts: intelligent node for weather information acquisition, CAN field bus, embedded data-gathering implement, GPRS radio communication, man-machine interface. The weather data of each highway is collected by intelligent node for weather information acquisition, then transferred to the embedded data-gathering implement to be dealt with by CAN field bus, and then transferred to remote highway administrative center by GPRS module. In the system, CAN field bus and GPRS radio communication make an easy and convenient construction of the system and flexible expansion, which is the key to ensure a real time and accurate data transmission.In view of the characteristics of the system technology, taking LPC2119 processor with rich hardware resources and ARM7-based kernel as the core chip, we make a hardware design for the minimum system in detail. Based on this work, we complete the circuit design of serial interface, CAN bus hardware interface and GPRS module, we work out the design schematic diagram, and have made a careful selection of type and access design for weather sensor module in the article.Considering the real-time requirement and the need to perform all kinds of tasks of the system, the system uses a software development mode of embedded real-time operating system-μC/OS-II. This task analyzes the transplanting points in detail, and get the transplanting source code, implement the transplant in the LPC2119 processor successfully, and then design the software structure of this system. In system task design, we have realized the program of temperature data acquisition based on the DS18B20; We design the CAN bus communication program in detail which is suitable for the system by analyzing the technology feature of the CAN bus. We define a ring data buffer area in the program, achieving a remarkable enhancement of the efficiency of data sending and receiving of CAN bus; The system adopts the GPRS module-GTM900, and we have completed the design of the GPRS communication program. The system is made an experiment test under the condition of ARM ADS 1.2, and meets the requirements of the design. The system design manifests the advantages of high performance, low power consumption and low cost of the embedded design, and achieves a real time collection and wireless, automation, networking and intelligent handling of highway weather information.