Video acquisition and storage technology and application of cameras in Internet of Vehicles

    According to the definition of the China Internet of Things School-Enterprise Alliance, the Internet of Vehicles is a huge interactive network consisting of information such as vehicle location, speed and route. Through GPS, RFID, sensors, camera image processing and other devices, vehicles can complete the collection of their own environment and status information; through Internet technology, all vehicles can transmit their various information to the central processor; through computer technology, the information of these large amounts of vehicles can be analyzed and processed, so as to calculate the best route for different vehicles, report road conditions in a timely manner and arrange traffic light cycles.

　　The Internet of Vehicles is a sub-application of the Internet of Things in the automotive field. It is the only way for the mobile Internet and the Internet of Things to develop towards business substance and depth. It is an integrated technology for the future development of information communication, environmental protection, energy conservation, and security.

　　The Internet of Vehicles uses radio frequency identification technology to digitally manage vehicles, including real-time tracking and monitoring of vehicle operating conditions. Like the Internet of Things, the foundation of the Internet of Vehicles is sensors. Strengthening sensor operations is essential, integrating information such as traffic signals, cameras, congested road reports, and weather conditions to form an "interconnection" between cars and roads. Through communication and cooperation between individual roads and technical management departments, the organic combination of cars, roads, and people is achieved, truly forming the Internet of Vehicles.

　　The Internet of Vehicles system refers to a network and application that uses advanced sensing technology, network technology, computing technology, control technology, and intelligent technology to fully perceive roads and traffic, realize large-scale, large-capacity data interaction between multiple systems, control the traffic of each car throughout the entire process, and control the traffic of each road in time and space, in order to provide traffic efficiency and safety-oriented networks.

　　
Figure 1. Architecture of Internet of Vehicles System

　　One of the basic technologies in the Internet of Vehicles is the video acquisition and storage of cameras (the perception layer). The most commonly used ones are vehicle-mounted DVRs and vehicle-mounted IP cameras.

　　Car DVR, commonly known as MDVR or car video recorder. It is based on digital video compression storage and 3G wireless transmission technology (Digital Video Record), combined with GPS positioning monitoring, car driving recorder, SD card large capacity storage, multi-channel data interface, voice call function. From the initial support for local recording to the current real-time transmission through 3G wireless, built-in GPS, car black box, CANbus, G-SENSOR and other technologies, the market potential of car DVR is getting bigger and bigger.

　　The four-channel video acquisition solution developed by Shanghai Chenhan Electronics based on the multimedia application development platform of i.MX27 a few years ago has been widely used in the field of in-vehicle video transmission. According to the new definition of the Internet of Vehicles, in response to the customer's customizability of products and differentiated market segments, this solution has burst into new vitality, with small development volume, stable and mature, flexible cutting, and accelerated mass production progress. It is the best choice for customers to develop and select systems in the field of in-vehicle video transmission. The chip has built-in H.264 hardware codec and eMMA to ensure fast and smooth video recording and playback; FEC (Fast Ethernet) ensures smooth transmission processing. The chip can also reach the vehicle temperature level, which truly meets the use in harsh environments. These are all things that other ARM9-level chips cannot handle.

　　In addition, this four-channel video solution supports a large number of peripheral interfaces: multiple UART interfaces, Wi-Fi & BlueTooth interfaces, GPS interface, USB interface, TV in (TV decode), TV out (TV encode), other interfaces: Hitachi 1.8” micro hard disk standard interface (ATA), SD/MMC card interface, 2-megapixel CMOS Sensor interface.

    Car IP Camera

　　Based on the development of digital signal processing technology (DSP) and network technology, video technology has developed from analog technology to mixed digital and analog DVR, and then to digital video such as IP video system. IP video system is different from traditional analog system and DVR in terms of distance, expansion capability and cost. In terms of distance, the network server in IP video system is directly connected to the network, without the limitation of cable length and signal attenuation, and without the concept of region; in terms of expansion capability, this system has no limit on the number of devices, and adding devices only means the expansion of IP addresses. In terms of cost, IP video system occupies less bandwidth and can use the existing network, saving the cost of wiring and network construction during installation.

　　The IP video system includes a network video server and an IP Camera, of which the IP Camera is the front-end processing part of the system. The CCD/CMOS image sensor converts the light signal of the scene into an electrical signal, which is then converted into a digital signal and transmitted to the DSP memory through a data interface. As the main processor chip for digital image processing and compression of the IP Camera and operation of the operating system, the DSP completes image compression and encoding while sending the data stream to a hard disk or other storage device for storage. As you can imagine, the front-end device has a great impact on the quality of the video image. Therefore, the choice of processor plays an important role in how developers can successfully meet the design requirements of digital video products for the Internet of Vehicles.

　　Freescale's i.mx53 chip is a chip that can integrate the performance of MCU and DSP, not only overcoming the defects of ARM core + DSP, but also retaining the advantages of both. Among them, i.MX536 is a processor that meets automotive-grade standards for the automotive industry, with many interfaces. Using it as the core processor of the intelligent terminal of the Internet of Vehicles meets the standards of the new generation of the Internet of Vehicles industry.

　　
Figure 1. Vehicle networking related platform functions, connections that can be established, and vehicle-mounted products

　　Shanghai Chenhan Electronics uses i.MX536 processor, and after more than one year of development, has completed a high-end vehicle-mounted front-mounted GPS video terminal solution that meets the new national standard, meeting the new system functions, personalization, and differentiation functions of a large number of customers. In addition to meeting the various index requirements of the front-end market, such as real-time vehicle conditions, driving records, high-definition multi-camera vehicle-mounted video monitoring, hard disk recorders, Beidou GPS intelligent navigation, voice recognition, vehicle-mounted interface detection, CAN, RS485, RS232, RFID modules, etc., it can also meet the requirements of the aftermarket entertainment market, such as 1080P decoding, multi-channel VGA, multi-screen anomalies, navigation, 3G, Bluetooth, and WIFI.