The efficiency and real-time of production and operation management directly affect the production efficiency and cost control of enterprises. At present, the construction and management of the factory is developing in the direction of information and intelligence. By installing a whole set of network video monitoring system on the local area network inside the enterprise, the safety production personnel can monitor the operation status of each equipment in real time, the security personnel can monitor the personnel flow in important places such as entrances and exits, roads and key buildings in real time, and the leaders of relevant departments of the enterprise can also monitor the operation status of the whole enterprise at any time in the office.
1、 Construction objectives and tasks
The main purpose of installing the security monitoring system in the production workshop of the plant is to realize the safety production in the production workshop area. The main installation area is 5 production workshops, 1 finished product warehouse and 1 warehouse aisle. Among them, No.1, No.2 and No.3 production workshops, warehouse aisle and finished product warehouse are on the first floor, No.4 production workshop is on the second floor, and No.5 production workshop is on the third floor. 1. There are four production lines in No. 2, No. 3 and No. 4 workshops. The production line is double row with dense personnel. No. 5 workshop has three production lines. The semi-finished product warehouse mainly stores raw materials for canning. Warehouse aisle is the area connecting workshop and warehouse. The relatively important areas are filling room and semi-finished product warehouse. The packaging room and warehouse aisle of the workshop are the secondary important areas. In order to ensure the safe production of the workshop, it is necessary to monitor the important area (i.e. the production line of the filling room) in an all-round way without dead angle, and cruise the other public areas. Cruise scanning is carried out for sub important areas.
2、 Demand analysis
The preliminary design of the factory video monitoring system should meet the performance requirements of the existing resources and network; The construction of the front-end monitoring subsystem and the video management system of the monitoring center meet the performance requirements of “opinions on the construction of urban alarm and monitoring technology system” issued by the Ministry of public security, and strive for stable operation of the system, reliable data storage, and regular filing of video data. According to the requirements of the government departments and the relevant requirements of the enterprise internal safety production management, and according to the relevant national standards, combined with the factory video monitoring requirements, the network video monitoring system functions are developed to achieve the following goals:
1) Information collection function. The front-end monitoring system collects the video, compresses and encodes it according to the transmission requirements, and converts it into the information format that can be transmitted on the digital exchange network through the access gateway.
2) Information transmission function. The compressed and encoded video information is transmitted in the factory private network according to the workflow. According to the security management authority, all levels of transmission network system are formed. At the same time, it can meet the management needs of the monitoring system, transmit to the superior system and store information.
3) Information processing function. The system at all levels processes the received video information according to its meaning and belonging, and processes the called stored information.
4) Information storage and backup function. The server of monitoring center should store the video information and system log; The stored and backed up historical data information can be played back in the network system according to the authority.
5) System control function. According to the authorization, the control commands sent by the network users are transmitted to the front-end system to realize the call and control of any monitoring image by the monitoring center and authorized users.
3、 Design ideas
The construction of the network video monitoring system will ensure that the personnel of each functional department in the plant area can timely and accurately understand and master the video information within the scope of their responsibilities, realize the systematic, scientific and modern unified management of the monitoring system, and effectively meet the management and business requirements of the public security industry for the image system. Relying on the network, the system has built a network video monitoring system covering the whole plant area. According to the preliminary statistics, XX monitoring points have been set up in the production line and warehouse. The design plan takes full account of the possible construction requirements such as the expansion of the later stage and management changes, and follows the principles of advanced technology, reasonable structure, unified technical standards, economy, practicality, standardization, maintainability, manageability, safety and openness.
The design idea is as follows:
1. The server cluster structure is adopted to achieve the goal of “large capacity, multi picture processing, real-time video recording and playback, network remote monitoring”.
2. It is convenient for users to install, operate and maintain in the future.
3. Considering all kinds of compatibility and expansion requirements: including the access of existing digital equipment, the later expansion of control and monitoring points, the expansion of system scale, the remote monitoring of temporary authorized users and other possible expansion modes, the compatibility and convenience of the existing network are considered. The designed system can meet the requirements of compatibility and smooth expansion.
4. The system design has good adaptability to network transmission routing, and can run in LAN, Wan, man, wireless network and other modes. According to the situation of network resources, the coding format can be set flexibly in different network bandwidth to obtain different image quality.
5. The design of the system is standard and open, and the system software adopts the general mainstream standard; For example, the system adopts standard TCP / IP protocol and interface standard; It is suitable for the integration of each standard subsystem of the security system in the production plant.
6. The system considers the operation redundancy, data security, remote authentication and other technical means to ensure the safe operation of the system and free from external intrusion, and has perfect identity authentication ability to ensure the stable operation of the system.
7. The scheme adopts the practical principle, does not pursue the stacking of high-end equipment, but in line with the practical principle of scientific configuration suggestions, in order to achieve the maximum technical cost performance.
4、 Network video monitoring architecture
The key equipment of digital network integrated monitoring system is network camera and platform monitoring system software. This project uses the network camera of axis company of Sweden and csvision network video management platform software of Yihua Zhongsheng to build the system. According to the requirements of the network video monitoring system in the production plant, combined with the actual situation, all video transmission and switching are mainly completed by wide dynamic high-speed network ball machine, high-definition network camera and csvision network video monitoring management platform software. The system structure is shown in Figure 1
Figure 1: structure diagram of network video monitoring system
1. Configuration of monitoring center
PC, network storage disk array and other equipment installed with client and server software of csvision video management platform are placed in the monitoring center of the production plant. The server is responsible for storing and forwarding the video stream sent by the front-end network camera. A single video management server supports 75 channels of D1 (calculated according to the 2MB code stream) image quality image storage and forwarding 400 channels of video stream at the same time. The server system can cascade multiple servers into a whole monitoring system by cascading, which is convenient for users.
The client software is responsible for decoding and displaying the real-time video or video data forwarded by the server. If a user needs to view the monitoring image, he only needs to install the client software of csvision monitoring platform. With the authorization of the central administrator, he can log on to the server through the client to realize the monitoring of the whole monitoring system. The client can be added according to the specific situation, as long as the PC is connected with the network, the center does not need to add any equipment. If there is a problem at the monitoring point, the person on duty shall inform the person on duty at the place of the accident in time or deal with it in person.
2. Network demand analysis
Front end monitoring point network bandwidth calculation: front end link construction is actually the problem of front-end network camera and monitoring center networking. Axis HD network camera and wide dynamic network high speed ball machine need 2MB bandwidth. Based on the maximum peak bandwidth of the monitoring center: the monitoring center is also the data processing center of the system, digital video monitoring will produce a lot of data, and the data flow and equipment exchange pressure will be brought in the transmission process. In order to achieve the high-speed stability of data transmission, Gigabit exchange machine is used as the core exchange equipment of the center.
3. Storage space calculation
The video storage adopts the centralized storage mode of the monitoring center, and the calculation method of the required disk array capacity: the bandwidth occupied by the network camera is about 2m / BPs, and the code rate of each channel (KB) / 8 = a (Note: dividing by 8 is the conversion from bit to byte, the unit of the device code rate is kbit, and the minimum unit of the disk capacity is byte); A × 3600 seconds × 24 hours = B (Note: B is the required storage space every day); B × Number of webcams × Video storage days = C (Note: C is the total storage space of all network cameras); The final “C” is the size of the video space needed, in kilobytes. According to 1000KB = 1MB, 1000mb = 1GB, 1000gb = 1TB, the total storage space required can be calculated.
According to the above calculation formula, single channel video storage needs about 880MB disk space per hour, and 24-hour video recording needs about 21GB disk space per day.
4. Security system
The security system considered in the design of the network monitoring system mainly includes physical security, user rights security, monitoring equipment management security, network congestion and so on.
1) Physical security. Physical security is mainly divided into device security and network security.
2) User authority security: for the user security of the whole system, it is recommended to use the identity secret authentication system to authenticate the users of the whole system. Users of each level of organization only need to open accounts and assign permissions in their own monitoring center. In this way, user rights can be set up (which can be subdivided into image browsing, control, voice and other rights).
3) Monitoring device management security: all the front-end monitoring information and permissions are managed by the device management server, and the permissions of the device management server are managed by the directory server, forming a unified management mechanism. All devices must be authenticated before they can log in.
4) Network congestion: the design scheme of video monitoring system in the production plant adopts the design concept of distributed multi server group, and uses streaming media technology to complete the storage and forwarding of video signals, so as to avoid the client directly accessing the front-end network camera, reduce the network traffic, and avoid the problem of network congestion caused by large traffic data, So that the whole system will not be paralyzed and can still operate normally when some subsystems fail. In the limited bandwidth, the following technologies are mainly used to avoid network congestion: rate control based on the originator, frame extraction strategy, packaging strategy and access strategy.
5. Main functions of monitoring platform
The system is a network video monitoring system based on Distributed Multi-level architecture, which supports the access of axis full series network cameras. The single server system supports 75 channel D1 (or 150 channel CIF) video real-time storage, no less than 400 channel image forwarding and 2000 monitoring points management. The system supports the cascade expansion of multiple servers, and can realize the unlimited expansion of browsing, video recording and management channels, which can meet the requirements of all-round monitoring of customers. The main functions include: image browsing and control, multi-level electronic map, audio and video storage and access, time bar playback, snapshot search based on video files, bookmark, two-way voice function, defense area linkage alarm, access control integration, user management, log management, etc.
6. Network monitoring platform architecture
Csvision network video monitoring system is a set of digital graphics monitoring system using modern computer network technology and multimedia information compression and decompression technology. The video, audio, alarm and control signals monitored by the system can be transmitted to each node in the network. Users can monitor and control one or some remote places in different places at the same time by using the computer network. At the same time, it has the functions of dynamic perception, video storage, alarm management and so on.
Figure 5: framework of network monitoring platform
As a general video monitoring platform, csvision system is composed of device control module, media control module, connection management module, client management module, server management module and system diagnosis module (as shown in Figure 5).
Editor in charge: GT