Design of Digital Image Monitoring System Based on MCU and Bus Technology

In the information society, the development of science and technology is changing with each passing day. With the continuous development of the national economy, many occasions such as electric power generation, hydrological survey, and TV relay broadcast have problems of remote monitoring with multiple devices and multiple parameters. The digital image remote centralized monitoring system is a digital image monitoring system construction plan that combines advanced computer network technology, multimedia technology, and communication technology to meet the diverse needs of users in telecommunications, power, banking, transportation, water conservancy, and public security industries.

Author: Fang Lu; Wang Gang

1 Introduction

In the information society, the development of science and technology is changing with each passing day. With the continuous development of the national economy, many occasions such as electric power generation, hydrological survey, and TV relay broadcast have problems of remote monitoring with multiple devices and multiple parameters. The digital image remote centralized monitoring system is a digital image monitoring system construction plan that combines advanced computer network technology, multimedia technology, and communication technology to meet the diverse needs of users in telecommunications, power, banking, transportation, water conservancy, and public security industries.

2. Networking method

The system can use a multi-point control system (MCU) as the tandem center, and connect to each monitoring point in the form of radiation. The image, voice, and data of each monitoring point are processed through the MCU to implement monitoring. The advantages of the entire system networking mode are simple network structure, convenient control, flexible connection, and rapid expansion. However, the monitoring system needs a network communication platform with good security, high reliability, strong stability, capable of transmitting multimedia information, strong scalability, and conforming to international standards. Therefore, there are three main requirements for the network.

The network is required to have a larger bandwidth and a higher source compression ratio.

The network delay is small, and the bit error rate is low.

In order to adapt to the development trend of the interactivity and flexibility of the network transmission system, multimedia monitoring is required and the network support system is required to be easy to expand and upgrade.

3. Working principle

The digital image remote monitoring system can be divided into a low-rate system and a high-rate system according to the different needs of users. The low-rate system can provide image monitoring within 6B, and can adopt PSIN dedicated line, ISDN, B-ISDN and DDN methods. The high-rate system can guarantee 6B~30B image monitoring, but it needs to use a bandwidth of 2M or more to transmit various signals. Transmission methods include: E1 transmission method based on physical transmission network, high-speed optical fiber, wireless microwave, UTP twisted pair cable and leased public network 2M line.

As shown in Figure 1, smoke detectors, ventilation and other detectors transmit the collected analog signals to the A/D converter, and the digital signals converted by the converter are transmitted to the image encoding transmitter by RS232 or RS485.

Design of Digital Image Monitoring System Based on MCU and Bus Technology

The monitoring center is connected to the decoder through DDN/ISDN/E1/MW and other transmission methods with respectable multipoint controllers in each sub-control center. The video signal output by the central codec enters the picture processor. After it is divided, it outputs multiple video signals to the TV wall or management station. Video switching means that the image processing equipment transmits the images collected by the camera of the terminal to the image encoding transmission equipment at a certain time interval. The device encodes and compresses the graphics according to a certain algorithm, and sends them to a multipoint controller (MCU) via DDN/ISDN/E1/MW lines. MCU is similar to a small switch, it can provide multiple ports for the various monitoring signals of each sub-monitoring unit to access, and according to a certain algorithm to process the audio stream, video stream, and data stream. The MCU sends these signals to the superior monitoring center, data acquisition processor, closed-circuit television or warp codec to the CRT through matrix switching.

LAN can use Ethernet or FDDI and other forms of networking. The data acquisition processor decodes the signal sent by the MCU and publishes it to the LAN. The monitoring center or sub-monitoring center can realize a friendly connection with the local MIS network or other networks. Local MIS users can access the video signals collected by the monitoring system through the video server through the authorization identification. The main function of the video server is video-on-demand (VOD), and at the same time realizes online user video access management and video access deployment management. The video server in this system is responsible for the intelligent information processing of the entire network, and realizes the collaborative work of multiple processors through a modular design. Users can order video programs on the video server through the network. Under normal circumstances, you can choose a video server suitable for a small or medium-scale network, and the number of users is between 0-50 or 50-1000. The video server responds to the user’s demand, and transmits the video program to the computer of each workstation in the form of video stream. In this way, each workstation can browse and send commands (such as: turn the camera 50 degrees to the left and drop 2 cm vertically) and so on. This command is compiled by the software, uploaded on the LAN and sent to the decoder for decoding, and then sent to the image encoding and transmission equipment through the MCU switching, optical fiber and other transmission lines. The device interprets the command as a control signal and sends it to the pan-tilt to direct the camera to work, thus realizing remote monitoring.

4. Conclusion

The digital image remote centralized monitoring system is a brand-new monitoring system, which breaks the limitations of the traditional closed-circuit television monitoring system, can coordinate the needs of different devices, ensure seamless communication, and solve the problem of video, audio, digital and other signals on the network. transmission. This emerging interactive multimedia monitoring system will gradually penetrate into all aspects of production and life. With the development and maturity of network technology, communication technology and video-on-demand technology, it will be widely used.

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