Taxi to install cctv camera and mobile dvr has become mandatory, before Guangzhou, Chongqing, Wuhan, Nanjing, the Hangzhou, Chengdu, Tianjin, Hefei, Jiaxing, Wenzhou and many other city have issued the relevant regulations, proposed by the network monitoring system to realize the traffic control department of centralized management and control of the city tens of millions of taxi, taxi to enhance the overall quality of service at the same time. And for the safety of drivers and passengers, the installation of surveillance systems will also provide an extra layer of security.
Wireless vehicle monitoring technology is rising with the development of video surveillance technology. Before the network, the vehicle monitoring products mainly rely on the simulation standard. In recent years, with the rapid development of security IP, network HD has become the mainstream of the market. The richness of camera function and license plate recognition technology have been further developed, and the development of vehicle monitoring technology has shown a trend of diversification and iterative acceleration.
Application of 3G/4G and wireless vehicle monitoring technology
Due to the characteristics of vehicles moving continuously, wireless communication network technology becomes the only choice for data transmission and management operation of vehicle borne video surveillance. At present, with the breakthrough of communication technology in the field of 3G/4G, 3G/4G wireless mobile dvr has become the mainstream wireless communication technology in the current domestic market. As a part of mobile vehicle monitoring and surveillance, through the 3G/4G network to realize remote video browsing, remote control, geographic location, voice intercom and other functions, meet customers remote video viewing, remote emergency demand, wireless video monitoring service provided to customers whenever and wherever possible application, widely used in public security and armed police patrol, mobile command financial vehicles, transport vehicles. At the same time, the wireless portable monitoring system can meet the needs of users in some special industries.
In the mainstream of employment, the general vehicle monitoring system consists of three parts: vehicle terminal, 3G/4G network and monitoring center. Vehicle terminal is the front-end equipment of wireless vehicle monitoring system, generally installed in a variety of vehicles secretly, vehicle terminal equipment is mainly composed of wireless vehicle terminal, tablet PC, HD car PTZ camera, vehicle mounted support and equipment box and other equipment. When the system is turned on, it can browse the image in real time through the tablet PC, control the rotation of the vehicle pan tilt camera, and carry out two-way voice intercom with the back end monitoring center.
In specific case application, we can refer to the application case of vehicle monitoring system deployed by Hubei Forest Public Security bureau. The whole scheme is based on the application requirements of Forestry Department of forest law enforcement, relying on the telecom operators 3G/4G wireless communication network, building a wireless audio and video transmission system covering the entire area of Forest Public Security jurisdiction. A patrol car in 100 forest police car special roof mounted camera, capable of real-time dynamic information monitoring field of law enforcement, but also understand the road traffic conditions, convenient command forest public security patrol vehicle to choose the best route to realize remote supervision and management of Forest Public Security Law enforcement. In the event of sudden major events, the live broadcast or replay of video files can be carried out through the 3G/4G network, and the voice intercom between the command center and the field personnel can also be carried out by wireless transmission equipment, which is convenient for emergency command and remote visual command.
Reference technology of wireless vehicle monitoring
In the face of the customer, although the businesses in the main products of different technical characteristics, but a lot of security and non security requirements is similar, and the function and technology of many characteristic, in a period of time the market soon appeared with technology functions type products. While differentiating the advantages and disadvantages of wireless vehicle monitoring products and their functions, it is necessary to make judgments from the following key reference technical indicators.
H.265 encoding and decoding technology
The newly upgraded H.265 encoding technology, compared with H.264 in the same image quality, the size of video encoded by H.265 will be greatly reduced, further enhance the experience of wireless map transmission.
1080P real time video surveillance
The front end can access 1080P HD PTZ camera for real-time video surveillance, wireless vehicle terminal support real-time video remote browsing, remote real-time monitoring of high-definition vehicle video in the monitoring center.
Video storage playback
Wireless vehicle terminal in vehicle hard disk, support up to 1080P HD storage, convenient front-end storage, saving cyber source video, you can choose whether to take the audio video, car video remote query, download, video file download speed can be configured to support disk to automatically repair abnormality, abnormal alarm reporting disk support.
When the monitoring point is abnormal, the vehicle alarm linkage is mainly external alarm device, that is, the driver can alarm to the monitoring center in case of emergency in the process of driving, and can carry out two-way voice communication.
The built-in GPS module can report the location information of vehicle GPS, and realize the tracking of vehicle trajectory, which can fully understand the vehicle movement. Historical video playback can also show the trajectory of the vehicle, and also expand the Beidou positioning.
It can capture the scene image in front, and then save it on the car hard disk, which is convenient to trace back. The snapshot can be captured by three ways, such as alarm linkage shot, mobile detection, switch alarm, etc..
can provide 1 way two-way audio codec input and output, and the back-end Monitoring Center for two-way voice intercom.
Automatic sleep and remote wake up
The device can set automatic sleep function, when there is no video stream transmission, the device default in five minutes without the transmission of code, then disconnect the 3G/4G network, in order to save the tariff. If you wake up the device on the line, you can use the phone, SMS wake up front dormancy device online. Support the device by dialing and sending text messages to the device SIM card trigger the device on the line, only to be added to the phone and SMS white list of the phone number to have the right to activate the 3G/4G network connection. Phone and SMS lists support 5 phone numbers at most.
Switch volume activates on line
Support switch activation on the line, parallel port alarm, 3G/4G line, parallel port alarm recovery, 3G/4G offline, you can save money.
Shock absorption design
Because the vehicle will bump and vibration in the operation of the road surface and the equipment to a certain extent, for the normal and stable operation to ensure the equipment, audio and video input and output interface and power interface devices are using the aviation plug design, to ensure that the interface is firm, not loose, built-in wire rope absorber, the hard disk in the shock absorber and can effectively resist the lateral and longitudinal bumpy bumpy, to ensure reliable operation of the hard disk, video data integrity.
Bit stream bandwidth adaptive technique
Due to the characteristics of 3G/4G network signal transmission factor, bandwidth, easy interference, instability, will lead to the wireless bandwidth fluctuation, the Kodak launched a KWTP wireless transmission protocol independent research and development, the reliability of the bit stream transmission security, can be automatically adjusted according to the current network conditions, improve the video and audio transmission the stability and efficiency of.
HD portable PTZ camera
HD portable infrared PTZ network camera, as the mobile video capture device of wireless portable graph transmission device, supports 1080P resolution maximum. A replaceable battery module is used to realize the independent power supply, and the WiFi module is used to transfer the collected and encoded images to the portable host. With 5 powerful magnets at the bottom, it can be adsorbed on any surface of the magnet, and the installation method is more diverse.
Large capacity battery powered
The wireless portable picture transmission device is equipped with 16AH large capacity rechargeable battery, which can work independently for more than 12 hours for the portable host. At the same time, &ldquo can also be provided under the emergency condition of external equipment feeding; UPS&rdquo can supply power to the portable PTZ camera and tablet computer.
The modular design of on-board host is that each key module can be pluggable and replaced, such as wireless module is pluggable, hard disk is also pluggable.
And if not modular, such as in the 3G wireless communication protocol, bought a DVR, but suddenly mobile 4G appeared, then to replace the original device, it is necessary to replace the whole, not only to replace a module is so simple.
Anti shake and fog passing technology need to be improved
The application environment of on-board camera face is not fixed, so when the environment is complex and changeable, city roads, rural roads, mountain mud etc. are possible, resulting in the process of moving the camera, inevitably to take into account the impact of jitter caused by the vehicle bumps, and in haze weather under the condition of image clarity.
At present, the camera anti shake technology in the industry has not been a very good solution, mainly rely on the algorithm to achieve the stability of anti shake, other manufacturers on the lens are trying to do, but the effect remains to be further tested. There is no difference between the fog monitoring technology and the ground monitoring fog technology. The more advanced fog technology is &ldquo, optical + algorithm fog &rdquo, as the mainstream technology, for this third generation fog technology, each manufacturer has different understanding. In addition, in addition to the camera's own hardware configuration, mainly look at the advantages and disadvantages of fog penetration algorithm between each brand manufacturer and the fog effect in the actual application case.
Digital fog can retain the original color of the image, and the image restoration ability is slightly worse than the optical fog. Because of the use of infrared imaging, optical fog can restore the image better. After adding the fog third generation fog technology, we can get better fog effect, and still make clear imaging in dense fog.