1.Overall project overview and system architecture
1.1 Application background
The development of expressway construction in China has been grown rapidly in recent years.Since the completion of the first expressway in 1988,the mileage of expressways in China has approached 45,000 kilometers by the end of 2007.According to “National Highway Network Plan”,we will spend 30 years in building a “seven shots,nine verticals and eighteen horizontals”highway network,the total mileage will reach to 85,000 kilometers,forming the “Capital connecting provincial capitals and provincial capitals to each other and connecting city's highway network” covering important counties and cities will connect all major transportation hub cities, including 67 railway hubs,50 waterway hubs and over 140 highway hubs. It will cover more than 1 billion people and provide direct service to the region.With the GDP accounting for more than 85% of the national total, the development of expressways has had an increasingly important impact on the national economy.
However,changes in weather conditions, especially extreme weather conditions have brought enormous risks to highway vehicles, not only seriously affecting transportation, but also causing serious losses of property and people’s lives.In July 2005, Meteorological Administration and Ministry of Communications signed a memorandum for joint development of meteorological weather forecasting for traffic at Beijing.Two parties will cooperate to establish a scientific and efficient forecasting release mechanism for meteorological information on highway traffic to provide accurate information to the public.Comprehensive road meteorological information will avoid delays in road traffic and reduce traffic accidents induced by bad weather.As a meteorological sensor research enterprise, Xi'an Zhongming Electrical Co., Ltd. has developed a set of real-time monitoring systems suitable for meteorological environmental monitoring of highways.
2.Function and Structure of Highway Meteorological Monitor&Warning System
2.1 Functions
Highway meteorological monitoring and early warning system,(hereinafter referred to as :HMWS) is a set of solutions especially designed for traffic and weather monitoring services, which makes the full use of modern science and technology.It measures visibility,surface conditions (pavement temperature,fluid depth,ice,etc.) and the relevant basic meteorological parameters (temperature,humidity,precipitation,wind direction,wind speed,pressure,etc.) It mainly used in timely detect various abnormal traffic environment factors and meteorological conditions at each road section and key points,then transmit data to highway meteorological disaster warning stations to provide real-time decision-making scientific basis for meteorological monitoring services and traffic control departments.Real-time meteorological conditions and weather warning information are sent to the road surface information display screen to provide real-time meteorological information and services for drivers on the expressway.Practice has proved that applying this system in highway road monitoring work, meteorological monitoring department will not only becoming more professional of monitoring data, but also improving the traffic management department's response to sudden weather conditions (such as heavy snow & fog,storm).The accuracy of the decision and the data basis for the pre-implementation of the traffic diversion scheme are the strong guarantees for the meteorological monitoring service and the traffic control department, which is conducive to the further improvement of the road traffic safety.
2.2 Compositions of Highway meteorological monitoring and warning system
Xi'an Zhongming Electric Co., Ltd.developed a pre-warning system for meteorological and environmental disasters monitoring department based on the urgent needs of the expressway in China.Including: Highway Meteorology and Environment Monitoring System(HMS),Highway Meteorological Disaster Warning and Dissemination System (HMD) and Highway Meteorology,Environment and Disaster Pre-warning Center(HMC),HMS mainly includes various meteorological type element monitoring automatic stations, an external weather station data network along the expressway, and weather forecast information input.HMD mainly includes road electronic warning signs and the public media distribution channels;HMC is control center of the data receiving and distribution for the entire system.
3.Highway Meteorological Information Monitoring Station
3.1 Introduction of highway meteorological information monitoring station
The highway meteorological information monitoring station will not only monitor road environmental conditions accurately and timely,but also combine with other monitoring subsystems to acchieve an intelligent traffic protection network system.The system can automatically monitor the visibility,road conditions, wind direction, wind speed, temperature, humidity, rainfall and other elements.
3.2 Features of Freeway Meteorological Information Monitoring Station
1.automatic data acquisition, transmission and monitoring, long-term unattended.
2. Long-term and stable operation in all kinds of harsh environments.
3. All items can be real-time monitored, such as fog, ice, and snow.
4. The acquisition and processing core unit adopts the real-time multi-task embedded system with international advanced level, which can acchieve various functions and can be customized according to the requirements.
5. The system has high accuracy, good reliability, and high intelligence & flexibility.
3.3 Application options:
Observation elements: Visibility, road surface and other environmental parameters can be arbitrarily increased or decreased. Meteorological parameters such as temperature, humidity, wind, and rain can be selected as needed.
Connecting method: Analog signal, digital signal, serial port and other access methods.
Power supply matching: Provide AC, DC and other power supply methods
Communication options: It can be equipped with various current types of communication access devices, providing a good interface for wired, wireless, and other communication means, and supporting protocols such as TCP/IP.
