4G picture transmission vehicle monitoring technology and difficult analysis

Wireless vehicle monitoring technology is emerging with the development of video surveillance technology. Before the network, the vehicle monitoring products are mainly based on analog standard definition. In recent years, with the rapid development of security IP, network HD has become the mainstream of the market, the richness of camera functions and license plate recognition technology have been further developed, and the development of the entire vehicle monitoring technology has become diversified and iteratively accelerated.


3G/4G and wireless vehicle monitoring technology applications
 
Due to the characteristics of the vehicle's non-stop movement, wireless communication network technology has become the only choice for car video surveillance for data transmission and management operations. At present, with the breakthrough innovation of communication technology in the field of 3G/4G, 3G/4G wireless mobile technology has become the mainstream wireless communication technology in the domestic market. As a part of mobile monitoring, vehicle monitoring realizes remote video browsing, remote control, geographic location, voice intercom and other functions through 3G/4G network, meeting the needs of customers for remote video viewing and remote emergency command, and providing application customers with time. Wireless video surveillance services are widely used in public security police police patrols, mobile command vehicles, and financial escorts. At the same time, depending on the limitations of certain industry applications, wireless portable monitoring systems can also be used to meet user needs.
 
For mainstream manufacturers in employment, the general vehicle monitoring system consists of three parts: the vehicle terminal, the 3G/4G network and the monitoring center. The vehicle terminal is the front-end equipment of the wireless vehicle monitoring system, and is generally installed in various vehicles in secret. The vehicle terminal equipment is mainly composed of various devices such as a wireless vehicle terminal, a tablet computer, a high-definition vehicle cloud camera, a vehicle mounting bracket, and a equipment box. . When the system is turned on, the tablet can be used to view images in real time, control the car camera to rotate, and perform two-way voice intercom with the back-end monitoring center.
 
In the specific case application, refer to the application case of the vehicle monitoring system deployed by Hubei Forest Public Security. The whole plan is based on the application requirements of the forestry public security law enforcement of the Forestry Department, relying on the 3G/4G wireless communication network of the telecom operators to build a wireless audio and video transmission system covering the entire area under the jurisdiction of the forest public security. The car-mounted PTZ camera is installed on the roof of 100 forest public security patrol cars, which can monitor the dynamic information of the law enforcement site in real time, and also understand the traffic conditions of the road surface, and facilitate the command of the forest public security patrol vehicle to select the best route to realize the forest public security. Remote supervision and management of law enforcement activities. In the event of a major incident, live broadcast or video file playback can be performed through the 3G/4G network. The voice between the command center and the field personnel can also be voiced through the wireless transmission equipment for emergency command and remote visual command.

Reference technology for wireless vehicle monitoring
 
In the face of customers, although the main focus of the products in the main product technology features, but many security and non-security technical requirements are similar, and after many features and technologies appear, the market is very fast in a period of time There are products of the same technical function type. In distinguishing the advantages and disadvantages of wireless vehicle monitoring products and their functions, it is necessary to judge from the following key reference technical indicators.
 
H.265 codec technology
 
With the newly upgraded H.265 encoding technology, the video size encoded by H.265 will be greatly reduced compared to H.264 under the same image quality, further enhancing the wireless picture transmission experience.
 
1080P real-time video surveillance
 
The front end can access 1080P HD car PTZ camera for real-time video surveillance, and the wireless car terminal supports real-time video remote browsing, which can monitor HD vehicle video remotely in real time in the monitoring center.
 
Video storage playback
 
The wireless vehicle terminal has a car-mounted hard disk, supports up to 1080P HD storage, facilitates front-end storage, saves network resources, and can select whether to bring audio recording when recording, car video can be remotely queried and downloaded, video file download speed can be configured, and disk abnormality is supported. Automatically repaired when the disk is abnormal.
 
Alarm linkage
 
When an abnormality occurs in the monitoring point, the on-board alarm linkage is mainly an external alarm device, that is, the driver can alarm to the monitoring center in the event of an emergency during driving, and can perform a two-way voice call.
 
Location targeting
 
The built-in GPS module can report the GPS geographical location information of the vehicle, realize the tracking of the vehicle's movement trajectory, and fully understand the vehicle movement. Historical video playback can simultaneously display the trajectory of the vehicle running, and can also extend the Beidou positioning.
 
Image capture
 
It can capture the scene image in front and save it on the car hard disk for easy traceability. The capture can be captured by the alarm linkage capture, motion detection, and switch alarm.
 
Voice intercom: It can provide one-way two-way audio codec input and output, and can perform two-way voice intercom with the back-end monitoring center.
 
Auto sleep, remote wake
 
The device can set the automatic sleep function. When there is no video stream transmission, the device does not have code stream transmission within five minutes by default, then disconnects the 3G/4G network to save the tariff. If the wake-up device is online, the phone and SMS can be used to wake up the front-end sleep device. Supports the device to go online by making a call and sending a text message to the SIM card of the device. Only the phone number that has been added to the phone and SMS white list in advance has the right to activate the 3G/4G network connection. Both the phone and SMS whitelists support up to 5 phone numbers.
 
Switch quantity activates the upper and lower line
 
When the switch generates an alarm, the 3G/4G goes online and the 3G/4G goes offline. This saves the tariff.
 
Shock absorption design
 
Since the vehicle has bumps and vibrations on the road during operation and has certain influence on the equipment, in order to ensure the normal and stable operation of the equipment, the audio and video input and output interfaces and power interfaces of the equipment are designed with aviation plugs to ensure that the interface is firm and not It will be loose, built-in wire rope shock absorber, hard disk placed on the shock absorber, which can effectively resist lateral bumps and longitudinal bumps, ensure the reliable operation of the hard disk, and complete the video data.
 
Code stream bandwidth adaptive technique
 
Due to the characteristics of the signal transmission of the 3G/4G network itself, the narrow bandwidth, easy to interfere, unstable and other factors will cause the wireless bandwidth to fluctuate up and down. For this reason, Keda has launched the independently developed KWTP wireless transmission protocol, which is used for the transmission of the code stream. The reliability guarantee can be automatically adjusted according to the current network conditions, which improves the stability and efficiency of video and audio transmission.
 
HD portable PTZ camera
 
The high-definition portable infrared PTZ network camera is used as a mobile video capture source for wireless portable image transmission devices, and supports 1080P resolution at most. The battery module is replaceable for self-power supply, and the self-contained WiFi module can transmit the captured image to the portable host. With the bottom 5 powerful magnets, it can be attached to any magnet surface and the installation method is more diverse.
 
Large capacity battery powered
 
The wireless portable image transmission device has built-in 16AH large-capacity rechargeable battery, which can be used by the portable main unit for more than 12 hours. At the same time, in the emergency situation of external equipment feeding, it can also provide "UPS" function to power the portable PTZ camera and tablet. .
 
Modular design
 
The modular design of the car host is that each key module can be plugged and replaced. For example, the wireless module is pluggable and the hard disk is also pluggable.
 
And if it is not modular, such as the 3G wireless communication protocol, bought a DVR, but suddenly moved 4G appeared, then when you want to replace the original equipment, it must be replaced, not just a replacement module .
 
Anti-shake and fog-passing technology needs to be improved
 
Since the application environment faced by the car camera is not fixed, the environment encountered is also complex and changeable. Urban roads, country roads, mountain roads and the like are all possible, which causes the in-vehicle camera to move in the process. The ground should take into account the effects of bumpy vehicles and image clarity in severe weather conditions such as haze.
 
At present, the anti-shake technology of the camera has not been a very good solution in the industry, mainly relies on the algorithm to achieve the stability of anti-shake. Other manufacturers have tried on the lens, but the effect needs further testing. There is no difference between the fog-monitoring technology of on-board monitoring and the ground-monitoring and fog-passing technology. The current advanced fog-passing technology is based on “optical + algorithm-through fog” as the mainstream technology. For this third-generation fog-through technology, different manufacturers have different Understanding. On the whole, in addition to the hardware configuration of the camera itself, it mainly depends on the advantages and disadvantages of the fog-transparent algorithms among various brand manufacturers and the fog-through effect in practical application cases. The digital fog can retain the original color of the image, and the image reduction ability is slightly worse than the optical fog. Optical fogging is due to the use of infrared imaging, image reproduction ability is good, after adding the third generation of fog-through technology of the algorithm through fog, it can get better fog-transparent effect, and still clearly image under dense fog.
 

Custom Aspheric Lenses

Precision Aspheric Lenses are designed to focus light while eliminating spherical aberration from divergent light sources in applications including focusing the output of a laser diode. Aspheric lenses can increase the numerical aperture of a lens while minimizing system aberrations. Aspheric lenses may also reduce the number of elements needed in a multi-element system. Aspheric lenses can reduce overall system weight while providing advantages such as increasing throughput or simplifying assembly.

Convex Aspheric elements are used to reduce aberrations, apheric lens is ideal for light collection, projection, illumination, detection, and condensing applications.

VIS coating option provides less than 1.5% reflection from 425 – 675nm. NIR coating option provides less than 1.5% reflection from 600 – 1050nm. Contact us for volume pricing of the custom aspheric lenses.

aspheric surface

Specification of our Aspheric lenses:

Machining scope φ5-200mm+0/-0.2
Material All kinds of optical glass and infrared materials aspheric(silicon,germanium,crystals etc.)
The face accuracy P-V<0.3 muon m
Surface quality 20/10-40/20
Production capacity 2000 pieces per month

Custom Aspheric Lenses,Specialty Aspheric Lens,Aspheric Cylindrical Lens,Molded Aspheric Lenses

China Star Optics Technology Co.,Ltd. , https://www.realpoooptics.com