Water remote monitoring solution
With the development of modern communication technology and test and measurement technology, the era of "digital water conservancy" has arrived. The network image monitoring system adopting advanced communication technologies such as microwave communication technology, digital video processing technology, IP communication technology and fiber optic communication technology can observe various changes in rivers and reservoirs and the operation of culverts in real time, providing an intuitive guide for decision-making. Image information can also improve the working environment of observation and measurement staff, reduce staff, and achieve unattended and fewer on duty.
According to the characteristics of our past water conservancy projects and water conservancy industry, monitoring projects for important facilities such as rivers and reservoirs often involve a wide geographical scope, a large number of monitoring points, and the users who need to be monitored are relatively dispersed. Moreover, for large-scale monitoring, The project has very high requirements for system stability, and it is necessary to minimize future equipment maintenance work.
Based on the above characteristics, we designed the Xunfei Water Conservancy Video Monitoring System for the water conservancy industry. According to the networking method, it can be divided into four parts: front-end video collection, network communication, branch center, and total center.
The remote video surveillance system for water conservancy is planned to use a multi-level star topology with one center connected to N sub-centers, and each sub-center connected to several monitoring points. The center and each sub-center use broadband direct links. Depending on the actual geographical environment, the original network structure, etc., different transmission methods are used, which can be telecommunications broadband, wired network, microwave, WLAN, satellite, etc. Under this network topology, the monitoring points of various reservoirs, sluices, and hydrological stations in the front end will collect multiple analog video signals, MPEG-4 compression, local storage, and send the compressed data stream to the monitoring server of the jurisdictional center through the network. ; The sub-center server is responsible for providing data forwarding services to users in the jurisdiction; at the same time, the sub-center server can forward data to the central server according to requirements, and the central server provides data forwarding services to users outside this sub-center in the entire network; each sub-center Set up the sub-control station to manage and control all the devices in the jurisdiction, and set up the main control station to control and control all the devices in the center.
Third, the front-end video capture
The camera device is a device that collects the light signal of the subject and converts it into a TV signal. It is the forefront part of the entire system, including lenses, cameras, protective covers and supporting equipment. The specific configuration of the imaging device varies depending on the subject and the imaging location. At the same time, to meet the requirements of night monitoring, we can install high-power searchlights near the gate, and the system can remotely control the light power switch to ensure that remote personnel can clearly monitor the opening and closing status of the gate.
Video codec XF600x / acquisition workstation XF100x is an important device for network and digital processing. It has powerful data processing and system integration capabilities. It can achieve digital acquisition, image compression, and data storage of analog video surveillance signals on one platform. , Monitoring data processing, alarm signal collection, network data transmission, remote control and other functions. This reduces the cost of the system, improves the efficiency of monitoring and maintenance, and reduces the difficulty of use.
The built-in image compression card of XF100x series acquisition workstation (Xtream Producer) can efficiently compress and process the connected images, and real-time dynamic monitoring of all images can be realized through a computer monitor. At the same time, the system can call the historical data stored in the hard disk. This system uses the industry's top compression technology MPEG-4 algorithm, the compression ratio is as high as 1: 500, each channel only needs 60 ~ 180M hard disk space (including video and audio), and the bandwidth required for network transmission is adjustable from 10K ~ 1M. In addition, the automatic disk space dynamic detection function is realized, and the image is recorded when it is moving, and it is not recorded or slow recorded when it is not moved. In addition, the system can also flexibly set the linkage relationship between the alarm signal and the image. When an alarm occurs in the system, the corresponding camera recording and alarm output functions can be started by setting in advance. At the same time, the monitoring center can also get alarm signals at the same time, and can perform real-time monitoring and observation through remote control.
XF600x series video encoders (Network Video Encoder) are the latest generation of embedded network video encoders based on the most advanced MPEG-4 video compression technology, using communication, computer, Internet technologies and standards. It mainly completes the digitization of analog video and audio signals. The digitized video and audio signals are compressed and encoded using the MPEG4 video compression algorithm and the G.729 audio compression algorithm, and then the encoded audio and video data is transmitted to the IP packet through the IP network. The monitoring server or remote user can realize the network transmission of video and audio signals, network monitoring and network storage, and can support remote PTZ control and remote alarm management. XF600x network video encoder uses high-speed embedded processor and embedded real-time operating system, which makes the system have better stability, reliability and easy maintenance than other products, and can effectively prevent viruses.
Fourth, network communication
The Xunfei remote video monitoring system uses the standard TCP / IP protocol, which can not only transmit real-time images on the local LAN, but also ISDN, PSTN, xDSL router, LAN, WAN, INTERNET, microwave, WLAN, satellite, etc., where the network bandwidth is limited It is convenient to realize the synchronous transmission of video and audio on the network. For water conservancy applications, where some monitoring points are located in remote and scattered places outdoors, and it is not easy to lay wired lines, wireless spread spectrum technology or satellite communication can be used to solve the problem of long-distance communication. Through our tests on different network conditions, Xunfei remote video surveillance system can run stably on optical fiber networks, wireless spread spectrum networks and satellite channels.
V. Sub-centers / Headquarters
Set up master / sub-control workstations and monitoring servers in the sub-center and the main center respectively.
The main control / sub-control workstation uses Xunfei's Xtream Controller series XF2016, which can monitor any multi-channel video and audio on the 16-channel monitoring front-end with the same screen, and can control the front-end PTZ and lens through authorization; it can group front-end monitoring points Patrol monitoring; alarms generated by the monitoring station will be transmitted to the corresponding master control station in real time, and the master control station will notify the management staff by means of sound, light and text messages; the master control station can also perform audio and video interaction with multiple front-end interaction points, Leaders can give orders to front-end staff.
The monitoring server provides hierarchical management of front-end monitoring workstations and hierarchical rights management of users; users can store front-end audio and video data on the central server in real time through the network as required; the server database records all video material information (video files can be It is distributed in various monitoring workstations or servers), alarm information, monitoring point information, and other data information. General users log in to the server through the WEB and can query any authorized information on the unified interface; for the front-end and center, multiple support is not supported. Broadcast network environment, the server provides unicast to multicast data forwarding, so that multiple personnel in the center view the front-end real-time stream to save a lot of bandwidth.