Road monitoring

Overview The urban road monitoring system plays an important role in the prevention and control of public security. Further optimizing the monitoring system and expanding its various functions can not only reduce its construction and maintenance costs, but also provide for the detection of various types of traffic and public security cases. Technical support greatly improves the level and efficiency of public security agencies' law enforcement cases.

The urban road is the basic skeleton of the city. In a sense, the urban road monitoring network is the skeleton of the urban public security monitoring system. As the main force of road traffic management, the traffic police has undertaken urban road traffic television monitoring, motor vehicle traffic monitoring and snapping, smart bayonet and other system construction. The monitoring scope of these three systems are motor vehicle lanes. The monitoring targets are motor vehicles. The important part of the urban road monitoring network system has a very important role in the construction of the urban public security prevention and control network system.

In order to improve the traffic congestion situation, cities are gradually promoting the implementation of real-time traffic situation image monitoring system plans for major traffic crossings, ie installing an intelligent road monitoring system at each important traffic crossing in the city, and realizing road traffic conditions through image transmission channels. Uploaded to the road monitoring command center, the center staff on duty can understand the road conditions in each area in order to adjust the flow of vehicles at each intersection to ensure smooth traffic. To monitor the violation of road vehicles, they can find and arrange road traffic in a timely manner. Whether it is a red light or a reverse driving, as long as the motor vehicle violates the “People’s Republic of China Road Traffic Safety Law” when passing through the main intersection in the city, it will be recorded by the electronic police and camera monitoring equipment. The illegal vehicle information is in the public security traffic command and control center. Was printed in time. The use of high technology to manage traffic has increased work efficiency and has facilitated the driver.

Characteristics The road traffic television monitoring is mainly based on fastball monitoring. The monitoring points are distributed in the intersections of roads and roads where traffic flow and concentration of people are relatively concentrated. These monitoring points are the main nodes of the urban road network and street surface, and it is necessary to realize the entire city. Or, for traffic safety surveillance in a certain area, it is necessary to control these nodes first. Whether it is from the needs of traffic management or the need to consider the prevention and control of urban public security, the layout of these monitoring points must be scientific and rational. The general idea is: relying on the road network structure, gradually built three points of monitoring, line, surface. Point control is to achieve point-by-point monitoring of all road intersections and key road sections. The line control is to gradually realize the convergence between points and points on the basis of point control, and to achieve full monitoring and seamless coverage as far as possible. Surface control is to realize the control of a certain area on the basis of point control and line control. From the central area to the periphery, one, two, three, four, five... multi-level monitoring ring networks are formed in turn.

The intelligent bayonet monitoring system is used in highways, urban expressways, transit highways, interprovincial entrances and exits, city groups, and urban-rural junctions, which is more conducive to realizing all-weather automatic recording, intelligent identification and deployment of all passing motor vehicles. This is not what fast ball monitoring can do. Looking at the actual situation of domestic road traffic management, many cities' highways and bayonet monitoring network distribution points are full of loopholes. The system equipment is old and has not been able to meet the needs and is in urgent need of reform and improvement. The author believes that we must gradually establish a three-level “electronic fence” for the prevention and control of urban traffic safety. First-grade fence: near the junction of highways, national highways, provincial highways, and expressways connected to neighboring provinces and cities. The key target of monitoring is the vehicles entering the city (simultaneous monitoring of out-of-town vehicles). HD imaging and number plate recognition should be used. Technology, and access to provincial and municipal two-level monitoring and control of large network networking. Secondary fences: Armed along the urban-rural junctions to monitor the roads that connect urban and rural areas and can pass motor vehicles. The focus of surveillance is on out-of-town vehicles (simultaneous monitoring of vehicles entering the city). Visual monitoring conditions and different monitoring methods are required. . Three-level fences: Located on the connecting road between city groups or neighborhoods (including townships and townships), monitoring of traffic between groups, neighborhoods, and townships and towns, urban areas can generally use illegal traffic monitoring and video capture systems at intersections. Functional extensions are implemented so that construction and maintenance costs can be greatly reduced.

At present, many cities are equipped with electronic traffic police surveillance video capture system, the expansion of video resources has great potential for application. The author proposes to increase the video recording function in all intersection electronic police systems, and may even consider adding a bayonet capture function to realize video or number plate recognition for all motor vehicles passing through intersections. It can be monitored remotely through the Internet and can be effective. Make up for the shortcomings of fastball surveillance at intersections, improve the coverage of video surveillance, and perform remote or local playback queries when necessary to achieve comprehensive utilization of video resources. This can effectively implement grid-intensive monitoring of all city groups and neighborhoods. It is beneficial to investigate road junction traffic accidents and public security criminal cases.

At present, the construction and application level of video surveillance systems in many domestic cities is still at a very elementary level. In particular, different video surveillance systems have not yet been integrated and video resources have not yet been integrated and utilized. The development direction of video surveillance technology is distributed collection centralized management, high-quality image compression processing, open standard unified interface, unified authentication to ensure safety, humanization of operation, function integration, structural modularization, and transmission diversity. The road traffic monitoring system is not only part of the city monitoring network, but also has its own uniqueness and self-contained system. Therefore, while actively participating in the construction of a large-scale monitoring platform for urban security, we must also do a good job in the construction of an intelligent transportation system integrated control platform, and build an application platform with traffic management characteristics, such as video surveillance, smart card slots, intersections and other electronic police. The monitoring system is integrated to realize resource integration and associated use of various road monitoring.

In a large number of video resources, searching for a specific video object in an artificial way is like a needle in a haystack, which takes time and effort. Therefore, it is necessary to research and develop vehicle trajectory inspection systems based on the integration and integration of various video surveillance resources, and analyze various typical traffic monitoring video streams such as road television monitoring, smart bayonet, and intersection electronic police, according to vehicle types, colors, and Size and other characteristic information, search for designated vehicles in various traffic surveillance video information in the city, extract video clips containing specific targets, so as to grasp or find out the specific vehicle's infestation time and running trajectory, and provide for the investigation and handling of traffic accident escape and criminal cases of public security Technical Support.

Summarized the main role of urban road monitoring system has the following two points:

1. Real-time monitoring of road conditions: cameras at each intersection will timely transmit the real-time images of the monitored area to the traffic command center so that the traffic commanders can grasp the traffic conditions of each intersection and road section in real time. For example, whether the traffic flow and signal light of the road section are working properly. , whether there is illegal behavior and traffic accidents. This information can help the traffic management department to take appropriate measures in a timely manner.

2. Real-time recording: The image of the video surveillance will be saved to the video server of the traffic command center as evidence for the handling of traffic accidents, irregularities, and even crimes such as public security crimes.

Technical parameters The most widely used in traffic surveillance cameras is fixed-lens cameras. These types of cameras should focus on the following major technical parameters and functions in their selection and application:

1, camera resolution, image resolution is greater than 500 lines, and then configure the high-definition monitor, there will be a better monitoring effect. Cameras with a horizontal resolution greater than 500 lines have a sharper, sharper image than cameras with 480 lines. Therefore, the higher the resolution, the better the camera's performance.

2, the camera's signal to noise ratio. When the light is very good, the camera's signal-to-noise ratio is very good, the noise point can not be seen in the image, but when the light is dark, the camera image with good signal-to-noise ratio index is still clear and the noise point is small. In cameras with poor signal-to-noise ratio, noise points can overwhelm the entire image.

3, camera light suppression, road surveillance cameras require clear shooting vehicle license at night, which requires strong light suppression indicators better. The camera with this technology can effectively suppress the strong light (vehicle headlights) of the oncoming vehicles, so that the license plate can be captured more clearly and the picture is true and complete. Many road surveillance cameras use "solar eclipse" technology, which is very good for shooting license plates at night, but it often occurs during the day, which affects the overall appearance and integrity of the image.

4, camera backlight compensation function, the camera shooting license plates at night, backlight compensation technology is good or bad, is directly related to whether you can clearly see the license plate, whether to make the rear-end video detection and analysis system to give correct judgment results. Good camera for the backlight compensation area can be flexibly set and area selection.

5, the camera's color reproduction performance, the camera does not have a specific color index, can only use the color adjustment and white balance adjustment to make the color true reduction. Different types of cameras have different color reproduction performances. This indicator only compares with debugging and actual color in the scene. You can select cameras with many white balance adjustment methods, such as white balance manual adjustment mode, white balance automatic tracking adjustment mode, indoor mode, and outdoor mode.

6, camera digital noise reduction technology, in the dark environment, due to illumination problems, camera noise will inevitably increase, you can use the current unique digital noise reduction technology. Make the images under low light conditions clearer and more pleasing.

Digital noise reduction technology is the use of professional video signal processing technology, DSP chip by detecting and analyzing the image information in the frame memory, automatically reduce the relative amplitude of the still picture, greatly eliminating the signal interference noise wave, which effectively improve Picture clarity and cleanliness.

7, the convenience of camera debugging, the camera in addition to reliable quality, but also easy to install and debug. Road surveillance cameras are mostly installed on posts that are 9-15 meters high. They require special tool carts for installation and removal. They are dangerous high-altitude operations. If the quality is unreliable or debugging is inconvenient, it will inevitably cause great costs for construction and engineering. And affect the normal use.

8, can use the camera's RS-485 port to set and debug the camera. Through this port, you can remotely control the camera, modify the parameters inside the camera, and do not need to go to the scene to adjust the camera; through this quick and convenient port, it greatly saves manpower and debugging time. At present, many cameras have this interface function.

The requirements for selecting a road video surveillance camera and the choice of road monitoring are all-weather surveillance. Therefore, the requirements for the front-end camera are relatively high. The camera is required to clearly monitor the vehicle license plate, vehicle type, and color on the road.

If the video system in road monitoring is likened to the human visual system, then the video camera in the video system is like the eyes of human beings. Its importance is self-evident, so the choice of cameras in traffic surveillance is very demanding.

Traffic road surveillance camera selection must first consider the following two requirements:

1, performance: camera performance is directly related to the ability to take a clear picture under a variety of conditions, can see the license plate at night, the color of the picture taken is true;

2. Reliability: The camera should be able to work stably for a long time in various harsh environments to ensure that the image quality does not deteriorate and the failure rate is low. If the "eyes" of a traffic monitoring system are not good or go wrong, even if the rest of the system is perfect, the defects of the entire system are clear.