One, application background
Most of the traditional communication command vehicle monitoring system can only reach 4 cif (704 * 576) or D1 (720 x 480) resolution, existing image resolution is low, the visual range of small, video image low utilization rate of the disadvantage of the current video monitoring system, the comprehensive application of the characteristics and development trend, summarizes many years of communication command vehicle system design experience, puts forward the full hd communication command vehicle platform solutions. With the improved scheme of the full hd telephoto video monitoring technology, the breakthrough at present mark clear car video monitoring image acquisition, transmission, exchange, display and record the bottleneck, and can achieve multiple real-time (25 frames per second) telephoto (320 mm) 1080 p (1920 x 1080) resolution full hd monitor ability.
Two, the overall design idea
System USES full hd framework, including optical path, collection, compression and transmission, exchange, display, processing and record complete link all meet the full hd video requirements. The system performance for the current mainstream of hd system size including 1920 x 1080 or 1600 x 1200 2 million pixel specifications.
The main equipment reference cPCI/PXIe/ATCA standard telecommunication level platform design, function module using insertion type chip form, integration and reliability to meet the requirements; Hd video streaming scale to more than double the number four to cover around the vehicle.
High-speed backplane design hd digital flow and network flow double exchange bus to meet quality, exchange and transmission requirements.
System design high-speed calculation module provide hd video real-time processing capability, throw frame recovery and content detection.
Based on hd telephoto acquisition light path to camouflage light path for special design, the system can be in the car configuration 300 mm above the hd telephoto lens. Acquisition coding dual channel output using forward error correction coding technology (FEC) resistance body complex environmental interference.
Display unit design compatible HDMI and IP two channel system display.
Storage unit design based on the mainstream hd NVR mode, can according to need to RAID configuration mode.
Control bus and protocol to meet with flight telephoto control requirements, the control software can scout collaborative operation.
Three, the technical design
The whole system consists of communication command vehicle platform unit, hd telephoto camera, display unit, storage unit, control unit and parts, through the car gigabit network bus (1000 base - T), and high definition digital transmission line (HDMI) connection, the front end bus have network power supply (PoE) function, as shown in figure.
(1) communication command vehicle platform unit
Communication command vehicle platform unit is the whole communication command vehicle comprehensive processing equipment, reference cPCI \ PXIe \ ATCA standard design, support analog and digital video, mark clear and hd video matrix switching function, support video concentrated decoding, centralized switching functions. Platform unit chassis height 4 u, standard frame type design, have double power supply redundancy switching and intelligent fan automatic temperature. Platform contains multiple PICMG standard function module board slots, two control panel slots have lagging switching circuit to support the deputy control module of double machine hot backup. Platform unit also leave expansion slots convenient integrated hd wireless transmission module. The user can according to the function requirement agile configuration, meet the needs of future function expansion upgrade. Pin design support function board of hot plug, that can be in the normal work of the platform, the function board for insertion operation, so as to improve the car platform for full mobility and scalability, fault timely recovery ability. Platform unit including master control module board, hd video input and output module board, no block double current exchange lagging and calculation module board.
1, master control module board
Master control module based on ARM embedded Linux OS operation and application, manage various peripheral interface, responsible for data communication. In order to achieve high reliability operation, the system can be equipped with two pieces of the same master control module board is configured to double machine hot backup operation mode. When a piece of master control module fault occurs, the system automatically switch to another piece of master control module, and a seamless and operation.
2, hd video input and output module board
Hd video input and output module board platform unit of video interface, according to the actual system scale requirements can adjust the number of board. Input module embedded h.264 compression algorithm, can through the optical fiber interface connection front hd digital acquisition module, receiving a compression hd video signal direct input, support multiple 4 cif/HD1080P format image coding. Output module and at the same time support network to compress the data flow decoding output and original data flow direct output. Support multiple 4 cif/HD1080P image decoding and HDMI output.
3, no block double current exchange lagging
Platform without blocking lagging design a digital video high-speed switching bus and gigabit Ethernet switching bus. Digital video high-speed switching bus used for the transmission of the compressed video data, ensure the video low delay and high quality performance, Ethernet bus used for the transmission of coded video data, realize the video data storage, preview, playback applications.
4, calculation module and video real-time processing module
The calculation module board equipped with high performance SOC (DSP + ARM) and FPGA resources, has highly efficient video decoding and real-time processing capability. Can be embedded and system front-end hd collection module matching decoding algorithm hd LPR lost frame Recovery (Loss Packet Recovery), also can be configured to all kinds of real-time video content analysis processing module extension intelligent video analysis business, the implementation of intelligent video analysis function, such as cross line detection, flow statistics, into the area, items placed take, etc.
(2) hd telephoto camera system
Hd telephoto camera system USES a host with lens group way. Lens group including replaceable telephoto hd lens and hd collection coding module. Equipment image forensics ability mainly depends on the lens assembly equipment, the equipment can be the lens component including 10-320 mm telephoto hd lens assembly, 7.8 63 mm standard high-definition camera module and 8 - mm light lens component, hd lens group has 1080 p full frame rate image shooting ability, obtain image size can be up to 1920 x 1080 or 1600 x 1200 2 million pixels. Hd image acquisition coding module based on h.264 scalable video coding (SVC), module is integrated with forward error correction (FEC) technology of double channel more code flow output interface to implement in the complicated environment large capacity hd video data reliable transmission. Lens module designed to according to the need to quickly remove the replacement, in order to meet the needs of all image forensics.
(3) display unit design
System display points HDMI and IP two channels. The main display based on HDMI digital channel. HDMI channel to overcome the analog video image quality is low, the disadvantages of slopes league signal failure, to realize the image quality qualitative leap; Also overcome the IP video image large time delay, time delay between the analog video and network video between, can satisfy the practical application of telephoto image tracking control needs. And network channel display is based on the network hd decoding, image quality somewhat loss, delay is longer, but the deployment of agile and convenient.
(4) storage unit design
Storage unit using video monitoring system mainstream NVR storage mode. In order to use the bad environment condition and reliable data, can according to need to adopt various RAID mechanism. Storage unit compatible 2 million pixel hd, 1.3 million pixel hd, 4 cif mark clear image coding.
(5) control design
Due to the platform equipment module variety, quantity and can be extended, platform control system based on the control bus and Ethernet networks. Control bus support MODBUS protocol, and meet the equipment more than 800 mm telephoto lens with high definition of real-time control requirements. The etheric network support TCP/IP protocol cluster, support TCP, UDP, RTP, DHCP, DNS and agreement. The control software based on terminal design, can be deployed in the etheric network in more than one computer, facilitate multi-user collaborative operation. The control software can also run on touch with the tablet PC.
Four, the deployment of application
According to the design and development of the hd communication command vehicle, for the first time in China will be full hd telephoto camera system applied to the platform, greatly improving the communication command vehicle car image acquisition ability.
