Intelligent transportation system, also known as intelligent transportation system, is to effectively and comprehensively apply advanced science and technology (information technology, computer technology, data communication technology, sensor technology, electronic control technology, automatic control theory, operations research, artificial intelligence, etc.) to transportation. Transportation, service control and vehicle manufacturing strengthen the connection between vehicles, roads, and users, thereby forming an integrated transportation system that ensures safety, improves efficiency, improves the environment, and saves energy.
1. Concept of intelligent transportation system
The predecessor of the intelligent transportation system is the intelligent vehicle road system. The intelligent transportation system effectively and comprehensively applies advanced information technology, data communication technology, sensor technology, electronic control technology and computer technology to the entire transportation management system, thereby establishing a large-scale, all-round function, real-time , Accurate and efficient integrated transportation and management system.
Intelligent Transportation System (ITS), as a large-scale, all-round coverage transportation and management system, relies on the rapid development of the Internet of Things in recent years, and combines advanced control, sensing, communication, information technology and computer technology efficiently. Applied to the entire traffic management system. Because it greatly relieves traffic congestion, effectively reduces the occurrence of traffic accidents, improves the safety of traffic systems, and reduces environmental pollution, it has become the most representative application in the field of Internet of Things. Intelligent transportation system includes many branch systems, mainly including traveler information system, traffic management system, public transportation system, vehicle control and safety system, non-stop charging system, emergency management system, and commercial vehicle operation system. Each system performs its own duties and complements each other to effectively improve traffic conditions.
2. Application Scope of intelligent transportation system
Including airport, station passenger flow evacuation system, urban traffic intelligent dispatching system, expressway intelligent dispatching system, operating vehicle dispatching management system, motor vehicle automatic control system, etc.
3. The role of intelligent transportation systems
Through the harmony and close cooperation of people, vehicles and roads, the intelligent transportation system improves the efficiency of transportation, relieves traffic congestion, improves the passing capacity of the road network, reduces traffic accidents, reduces energy consumption, and reduces environmental pollution.
According to the application of intelligent transportation system in a certain area, the predicted benefits in 2015 are: reduce traffic congestion by 10% to 50%; save energy by 5% to 15%; reduce air pollution by more than 25%; reduce operating costs of enterprises by 5% to 25%; reduce accidents 30 %～60%.
4. Components of intelligent transportation system
4.1 Traffic information collection system, manual input, GPS vehicle navigation instrument, GPS navigation mobile phone, vehicle traffic electronic information card, CCTV camera, infrared radar detector, coil detector, optical detector;
4.2 Information processing and analysis system
Information server, expert system, GIS application system, manual decision-making;
4.3 Information release system
Internet, mobile phone, vehicle terminal, broadcasting, roadside broadcasting, electronic information board, telephone service desk;
5. Status of ITS application in intelligent transportation system
The most widely used area of intelligent transportation system in the world is Japan. For example, Japan's ITS system is quite complete and mature, followed by the United States, Europe and other regions are also widely used. China's intelligent transportation system is developing rapidly, and advanced intelligent transportation systems have been built in large cities such as Beijing, Shanghai, and Guangzhou; among them, Beijing has established 4 Large ITS system; Guangzhou has established three major ITS systems including the main traffic information sharing platform, the logistics information platform and the static traffic management system. With the development of intelligent transportation system technology, intelligent transportation system will be more and more widely used in the transportation industry.
5.2 Framework of China's Intelligent Transportation System
The basic situation of the current China ITS system framework (Second Edition) is as follows: user services include 9 service areas, 47 services, and 179 sub-services; the logical framework includes 10 functional areas, 57 functions, 101 sub-functions, 406 processes and 161 data flow diagrams; the physical frame includes 10 systems, 38 subsystems, 150 system modules, and 51 physical frame flow diagrams; the application system includes 58 application systems.
6. Subsystems of intelligent transportation system
6.1 Vehicle Control System
Refers to a system that assists the driver in driving the car or replaces the driver to drive the car autonomously. The system can accurately judge the distance between the car and the obstacle through the radar or infrared detectors installed on the front and side of the car. In case of emergency, the on-board computer can issue an alarm in time or automatically brake to avoid, and according to the road conditions Adjusting the driving speed is called "intelligent car". More than 3,000 companies in the United States have been engaged in the research and development of high-intelligence vehicles, and have launched high-tech products such as automatic constant speed controllers and infrared intelligent navigators.
6.2 Traffic Monitoring System
Similar to an airport's aviation controller, the system will establish rapid communication links between the road, vehicles and drivers. Where the traffic accident happened. Where there is heavy traffic, which road is the most free, the system will provide drivers and traffic managers with the fastest speed.
6.3 Operating Vehicle Height Management System
The system realizes the two-way communication between the driver and the dispatching management center through the car's on-board computer, the altitude management center computer and the GPS satellite network to provide the operational efficiency of commercial vehicles, buses and taxis. The system has strong communication capabilities and can control vehicles across the country and even a wider range. Twenty buses on the streets of Paris, France, and about 2,500 taxis in London, England, are already under the command of satellites.
6.4 Travel Information System
It is a system designed to provide timely various traffic information for outbound travelers. The system provides information in a variety of media, such as computers, televisions, telephones, road signs, radios, in-vehicle displays, etc. Any one of them can be used. Whether you are in the office, on the street, at home, or in the car, as long as you use any of these methods, you can get the information you need from the information system. With this system, outgoing travelers can see six roads and listen to all directions.
7. System composition of intelligent transportation system
The intelligent transportation system is a complex and comprehensive system. From the perspective of system composition, it can be divided into the following subsystems:
7.1 Advanced Traffic Information Service System (ATIS)
ATIS is based on a sound information network. Traffic participants provide real-time traffic information to the traffic information center through sensors and transmission equipment installed on roads, cars, transfer stations, parking lots, and weather centers; Provide road traffic information, public transportation information, transfer information, traffic weather information, parking lot information and other information related to travel to traffic participants; travelers determine their travel methods and choose routes based on this information. Further, when the car is equipped with an automatic positioning and navigation system, the system can help the driver to automatically choose the driving route.
7.2 Advanced Traffic Management System (ATMS)
Part of ATMS shares information collection, processing and transmission systems with ATIS, but ATMS is mainly used by traffic managers to detect, control and manage road traffic, and to provide communication links between roads, vehicles and drivers. It will conduct real-time monitoring of traffic conditions, traffic accidents, meteorological conditions and traffic environment in the road system, relying on advanced vehicle detection technology and computer information processing technology to obtain information about traffic conditions, and based on the collected information. Control, such as signal lights, release guidance information, road control, accident handling and rescue, etc.
7.3 Advanced Public Transport System (APTS)
The main purpose of APTS is to use various intelligent technologies to promote the development of the public transportation industry, so that the public transportation system can achieve the goals of safety, convenience, economy and large capacity. For example, through personal computers, closed-circuit television, etc., to provide consultation to the public on travel modes and events, routes and train selection, etc., and to provide real-time running information of vehicles to waiters through displays at bus stops. In the bus vehicle management center, according to the real-time status of the vehicle, plans such as departure and collection can be reasonably arranged to improve work efficiency and service quality.
7.4 Advanced Vehicle Control System (AVCS)
The purpose of AVCS is to develop various technologies that help the driver to exercise control of the vehicle so that the vehicle can be driven safely and efficiently. AVCS includes warning and assistance to the driver, obstacle avoidance and other autonomous driving technologies.
7.5 Freight Management System
This refers to an intelligent logistics management system based on expressway network and information management system and using logistics theory for management. Comprehensive use of satellite positioning, geographic information system, logistics information and network technology to effectively organize cargo transportation and improve freight efficiency.
7.6 Electronic Toll Collection (ETC)
ETC is the most advanced road and bridge toll collection method in the world. Through the microwave dedicated short-range communication between the vehicle-mounted device installed on the windshield of the vehicle and the microwave antenna on the ETC lane of the toll station, the computer networking technology is used to carry out background settlement processing with the bank, so that the vehicle can pass the road and bridge toll station without parking. And the purpose of paying road and bridge tolls, and the fees paid are cleared and distributed to the relevant income owners after background processing. Installing an electronic non-stop toll collection system on the existing lanes can increase the traffic capacity of the lanes by 3 to 5 times.
7.7 Emergency Rescue System (EMS)
EMS is a special system, which is based on ATIS, ATMS and related rescue agencies and facilities. Through ATIS and ATMS, the traffic monitoring center and professional rescue agencies are integrated into an organic whole to provide road users with emergency vehicle failure on-site. Services such as disposal, towing, on-site ambulance, and accident removal.
8. Background of intelligent transportation system
8.1 Infrastructure shortages coexist with inefficiencies in their utilization;
8.2 The speed of infrastructure construction lags behind the growth rate of vehicles. As of 2013, the national car ownership was 137 million, with an average annual increase of more than 11 million cars in the past ten years, an increase of 5.7 times the number of cars in 2003, while urban roads only increased by 3-5% per year;
8.3 Traffic congestion has become a common phenomenon in large and medium-sized urban traffic;
8.4 The traffic safety situation is severe and the losses are huge. In 1999, a total of 412,800 traffic accidents occurred nationwide, of which 83,529 were killed and 286,808 were injured. The direct losses caused by traffic accidents amounted to RMB 2.1 billion;
8.5 Motor vehicle exhaust emissions have become the main source of urban air pollution. The pollutants emitted by motor vehicles in some big cities have contributed more than 60% to many air pollution indicators, which are seriously endangering people's health;
8.6 Transport efficiency is low and energy consumption is rising. A sample survey shows that the actual load rate of freight vehicles in the country is less than 70%. However, with the continuous improvement of vehicle technology today, the fuel consumption of transport vehicles has increased from 6.9 liters per 100 kilometers in 1992 to 7.4 liters in 1998.
9. New technologies for intelligent transportation system
New security technologies for intelligent transportation systems are constantly emerging and applied, and the emergence of new technologies has strong pertinence in the field of expressways. For example, 3G wireless transmission is a unique method used for the harsh climate and geographical environment of the highway. Highway mobile wireless monitoring is generally used in a certain section of the highway. The patrol car can transmit the video situation during the patrol back to the highway management center in real time, which enhances the real-time management of the intelligent transportation system. In addition, the application of other new technologies to a greater extent also provides further support for the efficiency of system management.
Mobile bayonet system: an overspeed capture system using technologies such as computer vision simulation, radar speed measurement, intelligent image analysis and database management. It can accurately measure the speed of the vehicle. Once the speed is exceeded, the system will automatically capture the picture, clearly capture the whole picture of the vehicle, license plate number, vehicle type, body color and other elements, save the picture in the database, and superimpose the date, time, Information such as the road section, the actual driving speed of the vehicle at the time of the violation, and the limited driving speed of the road section, etc., the database can be classified and queried according to the date, license plate number and other conditions, and the photo of the illegal vehicle can be output in real time through the printer, with automatic license plate recognition, on-site alarm, mobile With functions such as storage and comprehensive management, and its online version of the product architecture, the system integrates on-site law enforcement, 3G remote transmission, and command center network dispatch management, providing a reliable basis for scientific law enforcement by high-speed management departments, and fully complies with the need for science and technology to strengthen police. strategy;
GPS positioning: GPS positioning of police vehicles is convenient for dispatching, so as to quickly deal with traffic accidents.
Vehicle inspection and release system: The bayonet captures the speeding of the vehicle and compares the black license plate. After the alarm is found, the illegal vehicle information is displayed in real time at the toll booth or on the front-end LED screen, and intercepted at the toll booth.
In addition, GIS thoroughly understands the status quo and changes of the situation along the expressway in space and time, lays the digital foundation required for expressway management, and completes the analysis of static traffic information (toll booths, service areas, tunnels, wireless video and other basic equipment) The reorganization of dynamic traffic information (weather changes, road maintenance closures, sudden traffic accidents and other road conditions) provides intuitive, systematic and scientific management tools for expressway management; Exchange of departmental data to improve and perfect expressway management. According to the requirements of each subsystem, the required information is transmitted to the subsystem in a prescribed format, such as wireless communication terminal applications (such as mobile phone SMS, PDA, etc.) according to service requests and query permissions to provide customer data, graphics or images and other information.