Urban rail transit is an important part of the urban public transportation system, which generally refers to the fast, large and medium-capacity public transportation running along specific tracks in the city. With the development of economy in recent years, my country's urbanization and motorization The pace has entered an accelerating stage, and rail transit has quickly become the first choice for many cities to solve traffic problems, and has formed a diversified development trend in my country, mainly by subway, urban express railway, and elevated light rail. The urban rail transit system has very high requirements for rail transit safety due to its airtightness and high crowd density. Building a comprehensive and powerful security system to ensure the safe operation of rail transit is an indispensable link in the construction of urban rail transit.

       I. Historical Opportunities Steady Development of Rail Transit

       Under the influence of various factors, my country's rail transit construction has ushered in a historic opportunity for large-scale development. As an important part of rail transit safety precautions, video surveillance in the rail transit industry has also gained unprecedented development space, and its market size can be seen from the above data.

      As a public place with very high mobility and a large number of people, rail transit especially needs to use video surveillance to achieve full and all-round security. In fact, from the situation of deployed applications around the world, rail transit video surveillance systems have indeed played a very important role.

       Driven by the rapid growth of urban population and economy as well as the strong promotion of public policy measures, China's urban rail transit is entering a new stage of rapid development, and urban rail transit will become a hot spot for future investment and a new growth point to drive the steady growth of urban economy.

       It is foreseeable that the population size of megacities and megacities will continue to grow, more and more cities will enter the ranks of megacities and megacities, and urban agglomerations (belts) and urban agglomerations will gradually increase. With the improvement of living standards, urban residents will have higher requirements for the quality of transportation (speed, flexibility, comfort and safety).

      Under the guidance of the national land, environment and energy conservation and emission reduction policies, urban land development and utilization will develop in the direction of high density and intensification. Many cities have also realized that a well-planned urban rail transit system can become the central link and engine of intensive land use development. Therefore, in megacities, large cities, and urban agglomerations, there will be more transportation corridors suitable for the construction of large-capacity rapid rail transit.

      2. Urban rail transit security application

       The video surveillance of the urban rail transit security system usually consists of two parts: dedicated video and public security video systems. The dedicated video surveillance system is to provide visual information about train operation, disaster prevention and environmental control, and passenger evacuation for line control center dispatchers and duty personnel in the comprehensive control rooms of various stations, so that they can observe train entry and exit, passenger flow dynamics and related issues in a timely manner. The operation of the equipment can achieve the purpose of effectively organizing and directing passenger transportation and emergency rescue; at the same time, in view of the continuous occurrence of terrorist incidents in subways around the world, the public security department should also add a public security video surveillance system in the subway for the public security department to maintain daily security and Handle emergencies. Now, with the development of video surveillance technology, the two parts are often unified into one integrated monitoring platform to reduce the repeated construction of monitoring points and equipment. With the demand of network operation, video surveillance system is an important means of network operation coordination and command and a necessary means to prevent terrorist incidents and deal with emergencies. Establishing a multi-level command management system is the first problem that the system needs to face. .

       (1) Subway video surveillance system

      According to the application requirements of the video system under network operation, the newly built subway video surveillance system should be developed into a multi-level network including station-level monitoring, line-level monitoring, network-level monitoring, and city-level monitoring.

      1. Station-level monitoring: including local monitoring of stations, vehicles, depots, etc. Currently, it is mainly station monitoring, generally composed of cameras, video matrix (switching equipment), display equipment, etc. After each image signal is collected, it is output after video processing. Two analog video signals, one video signal is sent to the remote line control center, and the other video signal is sent to the video switching matrix of the station for use by the station traffic commanders and public security personnel on duty.

      2. Line-level monitoring: Each station of each line transmits the image information to the line control center through the optical transmission equipment, and sends the image to the traffic dispatcher, power dispatcher, disaster prevention dispatcher, dispatching director and public security dispatcher on duty, etc. Provides image display and control. Generally, the line control center has the ability to display multi-channel video information, and the center has the right to choose and control the camera for each channel of image.

      3. Network-level monitoring: The video signal of each line is transmitted to the subway network monitoring center and the public security monitoring center for the use of network-level commanders and dispatchers, while providing remote image routing and image control functions. Since the subway line monitoring centers in major cities are basically set up relatively centrally or decentralized, in order to establish a network-operated monitoring center, a corresponding network platform needs to be established.

      4. City-level monitoring: According to the requirements of the municipal traffic linkage command, the monitoring images of the subway need to be transmitted to the relevant municipal-level emergency centers and other departments in real time.

      (2) Unified deployment of LCD splicing

      With the formulation of security industry standards, the integration of the overall security system has become a trend and has also been applied in some rail transit projects. Moreover, it is precisely because the integration of rail transit security systems involves many subsystems, so only in the case of coordination of each system, deep integration can meet the requirements of rail transit development for security systems.

      Previously, in the field of rail transit, the bidding for security systems was relatively scattered, video surveillance was usually placed in the communication system, the access control system was in the integrated video surveillance system, and the burglar alarm was included in the fire protection system. Therefore, the security systems were all separate systems. , independent operation, the integration of each system is weak, and the integration advantages cannot be effectively exerted. Rail transit security involves many subsystems. Only when each system is coordinated and deeply integrated, can intelligent alarms, intelligent emergency plans, and unified command and deployment of relevant departments be better realized.

      (3) Electronic fences are essential

      At present, the safety of railway operating lines is a matter of national concern. The high-speed rail is a link that carries more social responsibilities and economic development. Maintaining the safe operation of high-speed rail lines has been mentioned as the primary problem to be solved. On high-speed rail lines, a small detail, a movement, or a negligence may lead to a major traffic accident. Therefore, in the low-foundation road section, the position of the low bridge pier, the densely populated, and the traffic intersections, set up pulse electronic It is forbidden to climb over the fence, adding a barrier to the operation of the high-speed rail is a very important protective measure. The advantages of installing electronic fences on high-speed rail lines are highlighted:

      Electronic fences have a deterrent function: high-voltage power grids and warning signs give intruders a great psychological deterrent effect, preventing them from committing crimes;

      The active protection of the electronic fence is strong: when the criminals invade, they will be effectively electronically hit to stop their illegal behavior;

      The electronic fence can be tightly guarded and has no dead ends: the installation of the front-end fence is not affected by the length, size and terrain of the perimeter. It is easy to install and has no dead ends. At the same time, it can also be installed on the ground to provide comprehensive protection and eliminate blind spots;

      The false alarm rate of the electronic fence is low. It can work around the clock: the intelligent alarm delay function can greatly reduce the false alarm.

       The electronic fence can be networked with security and IT systems.

      The installation of electronic fences on high-speed railways can effectively prevent the damage of railway line subgrades. The installation of electronic fences on high-speed railways can timely alarm on the spot to prevent hidden dangers, intrusions, etc., and the on-site electronic fence host can immediately send an alarm signal to the duty room, and then notify the local police to deal with it.