Looking at future development forces from monitoring common problems

Video surveillance is an important part of the security system, including front-end cameras, transmission cables, and video surveillance platforms. The cameras can be divided into network digital cameras and analog cameras, which can be used as front-end video image signal acquisition. It is a comprehensive system with strong prevention capabilities. With the development, more and more public places use video surveillance systems, followed by frequent system failures.

Analysis of Video Surveillance FAQs 1. Improper power supply caused by equipment failures Incorrect power supply, such as incorrect power supply, may be as follows: The power supply line or power supply voltage is incorrect, and the power is not enough (or the line diameter of a certain power supply line is not enough; Large, etc.), transmission lines of the power supply system appear short circuit, open circuit, instantaneous overvoltage and so on. In particular, the device may be damaged due to power supply errors or instantaneous overvoltage.

2, the quality of the equipment or components itself In general, after careful selection of commercially available equipment or components, there should be no quality problems. Even if something goes wrong, it often happens after the system has been delivered and run for a long time. In addition to the quality of the product mentioned above, the most common problem is due to improper adjustment of the equipment. For example, the adjustment of the intercept after the camera is a very precise and precise job. Without careful adjustment, problems such as poor focusing or defocusing in various operations of the three-variable lenses may occur. In addition, whether the positions of some switches and adjustment knobs on the camera are correct, whether they meet the technical requirements of the system, the correctness of the encoder coding switch or other adjustable position settings directly affect the normal use of the device itself or affect the normal performance of the entire system.

3. Problems caused by incorrect connection between equipment (or components) and equipment (or components) 1) Impedance mismatch. If the video is connected to a monitor with a high impedance, the image will be bright and the characters will appear. There is sometimes no jitter or character appearance.

2) The communication interface or communication method is incorrect. This situation often occurs between a control host and a device such as a decoder or control keyboard that has a communication control relationship. This is mostly due to the fact that the selected control host and decoder or control keyboard are not products of one manufacturer. In general, different manufacturers use different communication methods or transmission control codes. Therefore, the same manufacturer's products should be used for the host, the decoder, and the control keyboard.

3) The drive capacity is insufficient or exceeds the specified number of device connections. For example, the number of main control keyboards and sub-control keys corresponding to the control host is regulated. Exceeding the prescribed amount will cause the system to work abnormally. Decoder pan/tilt working power power is lower than the actual pan-tilt, it can not drive the PTZ.

4, the failure of the PTZ. A pan/tilt does not work or cannot rotate at a short time after use. This is a common failure of the pan/tilt. In addition to the factors of product quality, it is mainly caused by the following reasons; only the camera is allowed to be installed (ie The head of the camera sitting in the upper part of the turntable of the PTZ is used for hoisting (ie the camera is mounted under the turntable of the PTZ). In this case, the hoisting method leads to an increase in the operating load of the pan/tilt. Therefore, the use of the hoisting method will soon lead to damage to the drive mechanism of the pan/tilt, or even burn the motor.

The total weight of the camera and its protective cover exceeds the weight of the PTZ. Especially for PTZs that are used outdoors, the weight of the protective cover is often too large, and there is often the problem that the PTZ will not move (especially the vertical direction). The outdoor pan/tilt head is faulty or even damaged due to poor ambient temperature, low temperature, waterproof, and frost protection measures.

5. When the distance is too far, the keyboard cannot be controlled by the decoder on the camera (including the lens) and the gimbal. This is mainly because the control signal is greatly attenuated when the distance is too far, and the control signal received by the decoder is too weak. . At this time, a relay box should be installed at a certain distance to amplify the shaping control signal.

6. The image contrast of the monitor is too small. If the phenomenon of light image is not the problem of controlling the host computer and the monitor itself, the transmission distance is too long or the attenuation of the video transmission line is too large. In this case, the line amplification and compensation device should be added.

7, the image clarity is not high, the details of the loss, serious color signal loss or color saturation is too small This is because the high-frequency end of the image signal loss is too large, resulting in more than 3MHz frequency of the signal is basically lost. In this case, either the transmission distance is too long and there is no amplification compensation device in the middle; or the distribution capacitance of the video transmission cable is too large; or the equivalent capacitance is concentrated in the transmission link between the core wire and the shielded wire. Caused.

Video Surveillance Assessing People constantly explore the path of reform and innovation, find problems and solve problems in the process of continuous improvement and continuous improvement, and they can continuously improve. Due to the huge investment and complicated technology of urban network video surveillance systems, it is very important to make an objective overall assessment of the system before construction. The basic characteristics of urban video surveillance systems are the overall investment, technical requirements, users involved, and many links (involving image acquisition, transmission, storage, management, sharing, etc.). In general, whether the urban video surveillance system can meet the actual needs of the application; whether the system can be managed and maintained; whether the system has the ability to expand and upgrade; whether it can provide conditions for the upgrade of intelligent functions; whether the system has the capacity for sustainable development. It is important that these points are inextricably linked with whether the industry has corresponding development power.

1. Practicality. The system should take into account factors such as local environmental conditions, monitoring targets, monitoring methods, maintenance, and investment scales to meet the needs of the normal operation of urban video surveillance systems and social public safety management.

2. Reliability and stability. The system should use mature technologies and reliable equipment, and have backup or redundancy measures for key equipment. The system software has maintenance support capabilities and strong fault tolerance and system recovery capabilities to ensure that the system is running as long as possible, and that in the event of a system failure, timely and effective repairs can be performed.

3. Extensibility. Should adopt the distributed system and the modular structure design, in order to meet the system scale expansion, the function expansion, the matching software upgrade demand. Users can expand or tailor the system as needed to provide sufficient flexibility.

4. Advanced and inherited. The construction of an urban video surveillance system cannot simply abandon the original simulation-based system. The proper approach is to include the original simulation system as far as possible on the premise of planning a fully digital system. The most ideal system is to be able to seamlessly connect between the two to form a complete city video image network monitoring.

5. Performance and price ratio. The designer should reasonably set the system function, correctly configure the system and select the equipment. Under the premise of good grades of key equipment, the overall price of the system is guaranteed to be low, so that the system has a higher cost performance. The camera selection at the front end of the system and the level of the back-end software should be the focus of attention. If the number of lines of the front camera is lower than 460 lines, no matter how good the follow-up system is, it is impossible to ensure that the system has clear image effects. In some applications, advanced features such as wide dynamic range are also needed.

6. System management functions and ease of operation. Considering the scale and complexity of the networked system, the management software platform should have a good system architecture. The system core management and business management must be clearly separated to ensure that they meet different application requirements. Due to the large number of various management servers, storage and forwarding servers in the system, the network management functions of the system must be powerful. Otherwise, routine maintenance cannot be performed. The management and user interface provided by the system should be clear, concise and friendly, and the operation should be simple and convenient. Flexible, easy to learn and use, easy to manage and maintain.

7. The degree of security of the system. System security includes many aspects, among which the main purpose is to prevent the access of illegal users and devices. Therefore, in addition to different levels of authentication methods for different users (including administrators and users), it is also necessary to ensure that illegal devices cannot be accessed. Go to the system. Networked monitoring systems are most vulnerable to hackers and effective security protection measures should be taken to prevent the system from being illegally accessed, illegally attacked and infected by viruses. In addition, it is also necessary to prevent unsafe factors such as lightning, overload, power failure, electromagnetic interference, and man-made damage to provide comprehensive and effective security measures.