It is understood that the intelligent analysis currently used in the expressway is mainly the license plate recognition technology, which is used in the highway toll collection system, and can automatically register, verify, monitor and alarm the passing vehicles. Event detection, if the recognition rate is high, there are many false positives, and the effect is even more limited when the light is poor. In addition, the equipment is required to have good anti-sun and wind resistance, and the severity is not inferior to other industries. From the lunar calendar, it has entered the twelfth lunar month, and the Spring Festival with unique Chinese characteristics is about to begin. In the face of the upcoming traffic problems, how can high-speed traffic monitoring work?

Intelligent analysis focuses on "vehicle" behavior

It is urgent to improve the efficiency of highway operation and management, to ease congestion, and to better serve the public. The highway has put forward higher requirements in traffic flow monitoring and traffic incident detection systems, forming a video surveillance system with unique system structure and monitoring requirements. Li Ning, chief engineer of Shanghai Jiaotong Development Co., Ltd. pointed out: "The analysis required for expressway is different from general security. It does not focus on people, but focuses on the behavior analysis of vehicles, and there is no perimeter security requirement for general security." The intelligent analysis for highway video surveillance includes license plate recognition, traffic incident detection and analysis, and video traffic status detection. Since the scene does not have more interference with the vehicle, the high-speed industry can expand its functions to realize intelligent analysis functions such as illegal detection, dynamic forensics, no lane driving, and large car occupancy lanes.

Despite the obvious demand characteristics in intelligent analysis, the intelligent analysis and development application of expressway is not satisfactory. “The highway is working around the clock, and it is difficult to realize video analysis under the light of nighttime. It is even more difficult to have a tunnel without daylight throughout the day.” Zhu Yue, chief engineer of China Tektronix Traffic Engineering Co., Ltd. pointed out that in his view, the expressway Intelligent analysis should conduct in-depth analysis and research for specific applications, and customize the corresponding products according to the operating environment and light source of the expressway.

Segmented "HD" dominates

In general, the application of intelligent analysis technology depends largely on the clarity of the image quality. The general HD camera can take detailed shots of the passing vehicle license plate number and local features of the road network. The clearer the video surveillance image, the more complete the picture details, the more clear the target information can be provided for video analysis and processing operations, and the intelligent analysis function The accuracy is also higher. However, at present, the highway monitoring system is still in the high-definition upgrade, but the front-end architecture is mainly mixed with high-definition standard definition, and the standard definition still accounts for the majority.

The progress of HD is slow, except that the application technology of HD products is still immature and needs to be further improved. There are also reasons for the limited transmission resources of the previous highways, and some sections cannot support the large bandwidth required for HD video transmission. In addition, in the view of the monitoring requirements of the highway operators from the management level, the SD image is sufficient. Even in HD, the definition of 720P is sufficient. Based on the current status of highway monitoring, the highway monitoring system usually stratifies the whole monitoring points according to the monitoring level. The high monitoring level uses HD monitoring, and vice versa. Chongqing Keke Research and Design Institute Zhou Keqin takes the Chongqing Expressway as an example: “Chongqing will divide the road sections into three categories, Class A uses 1080P, Class B uses 720P, and Class C uses general standard definition. According to location classification, such as toll stations, service areas, The entrance and exit is Class A."

“The charging system requires the picture quality of the license plate number. The toll station generally uses high-definition cameras. Individual provinces require the expressway operators to cooperate with the public security and traffic police to jointly manage the cameras. Some cameras along the line also use high-definition cameras.” Zhongti Tek Zhu Yue further Analysis, "But it involves transmission, storage, and there is not much demand along the highway. In addition, high-definition technology is mainly applied to images, such as license plate numbers and path settings, and continuous monitoring with high-definition video streams is relatively rare."

Unified coding to create a national network foundation

In fact, whether the highway video surveillance is in the process of high-definition or intelligent, the inconsistency between the operation and the public security is one of the obstacles. Quan Hongbo, vice president of Beijing Bailian Zhida Technology Development Co., Ltd., took an example of a highway intelligent construction project that his company participated in: “At that time, the project first established a model for the joint construction of public security traffic police and highway management companies. Realize the sharing of resources between the two parties. The main construction contents are the detection of traffic flow data, the automatic discovery of traffic events, the real-time release of traffic information and the visual management of command and dispatch services. The implementation of the whole project has played a significant role in traffic management of the road. The effect of timely handling of traffic accidents can ensure the smooth flow of traffic during public travel, and also effectively guarantee the charges of highway operation and management enterprises, and truly achieve the goal of “win-win”, and how to coordinate the needs of both operations and public security is high-speed. A major problem in the road safety is inevitable.

There is no doubt that once a traffic accident occurs in the expressway, the traffic hazard is more prominent, and the traffic control and plan setting requirements are stronger than the urban road. Therefore, a faster and more convenient early warning system platform is needed. With the continuous laying and expansion of the expressway network, the smooth networking of the various sections to achieve a more powerful integrated management system platform, the demand is more urgent.

The highway network monitoring system can generally be composed of three levels of network: provincial monitoring center (provincial level), regional monitoring center (road level), and road section/tunnel monitoring station (station level). Due to factors such as segmentation investment and segmentation construction, the early highway monitoring system is basically designed with a single road segment as an independent monitoring network. The built-up area monitoring system is basically concentrated at the road level, and the optical matrix video matrix is ​​generally monitored. Mode, the monitoring centers of each area are relatively independent, lacking unified planning and technical coordination between each other, and can not achieve interoperability and information sharing of provincial monitoring.

Provincial-level network monitoring needs to realize huge subsystem integration, docking and networking of all levels of road network systems, and the project can be described as complicated and huge. Fundamentally solve the compatibility problem of video surveillance products, and ensure the smooth connection of the system is the basis for advancement. On December 30, 2011, the national standard GBT28059-2011 "Technical Specification for Road Network Image Information Management System Platform Interconnection" was released, and was implemented on July 1, 2012, specifying H.264 coding technology for highway video coding. standard.

"Recently, high-speed construction video surveillance construction is generally based on H.264, and does not need to be greatly modified. But for the earlier monitoring system, it must be modified." Zhong Tek Tai Ke Zhu Yue pointed out. In the process of integrated monitoring of networked monitoring, equipment that cannot meet the requirements is facing a phase of elimination.

According to Zhou Keqin of Chongqing Transportation Research and Design Institute, Chongqing used the MPEG-2 encoding format to facilitate the inter-provincial networking in the future. Now the H.264 encoding format is basically unified, and the intercommunication in the road can also use the original encoding format. However, data exchange with the outside world must be transformed.

Although the national standard has specified the video encoding format, the standard is not exhaustive, such as the format of the transmission package is not specified. At the same time, each manufacturer has a small private agreement for the development of H.264. To achieve interconnection, it is generally necessary for the owner to specify the province's H.264 networking standard, and then each manufacturer will change according to the needs. “All localities follow the unified standards and basically meet the requirements from the national level. The images can be collected in the road control center and the provincial center.” Zhong Tek Taike Zhu Yue said.

At present, each province conducts networked monitoring tests based on the H.264 encoding format, and hopes to solve the two problems of system architecture and standardization that have been plagued by the province for a long time, realize integration with other systems, and distribute and deploy various monitoring resources, and realize Unified management, breaking the previous island-based monitoring, laying the foundation for the province's highway monitoring IP large-scale networking. In addition, according to the wide range of highway radiation, climate and geographical characteristics, patrol cars using 3G wireless transmission technology have been used in some sections of the expressway. The camera is installed on the patrol car, and the road condition is monitored while walking, and the road condition is sent to the central area by using the 3G network. Thereby further strengthening the real-time nature of highway system management and the ability of global monitoring.