The on-board image monitoring system is an important part of the construction of the urban subway operation system. The system monitors the interior of the running subway train with real-time video images and records these video images for the subway operating company and the subway public security branch to know the situation in the passenger compartment in time. Facilitating subway operation management and public security prevention is part of the construction of a safe China, which is conducive to social harmony and development.
The vehicle-mounted image monitoring system is mainly composed of vehicle-mounted camera, vehicle-mounted video encoder, industrial Ethernet ring network switch, vehicle-mounted network video recorder and power supply system. The vehicle-mounted local area network is equipped with a MIGE7008G Gigabit Industrial Ethernet switch in each carriage and the driver's cab at the end to form a Gigabit redundant self-healing ring network. MAIWE ring network industrial Ethernet switch supports self-healing ring network technology, which can automatically recover when the transmission medium breaks, ensuring that the self-healing time of each node is less than 5 milliseconds; the self-healing time of the ring network composed of 6 nodes does not exceed 30 milliseconds.
The vehicle adopts a 6-section marshalling, with 2 color fixed hemispheric fixed focus cameras in each compartment, and a color fixed hemispheric fixed focus camera with recording function in the front and rear cabs. There are a total of 14 cameras per train, of which 12 monitor the inside of the carriage, and 2 monitor the driving console and outside the car. The vehicle-mounted video encoder adopts H.264 video encoder, and each encoder is connected to the camera through a shielded cable in a one-to-one correspondence. Each encoder is connected to the 10/100/1000M Ethernet port on the vehicle industrial Ethernet switch MIGE7008G through its own independent 10/100M Ethernet port. The video encoder can send two video streams with different bit rate at the same time. One of the bit streams can be set as a constant bit stream for the on-board video recorder to record; the other one can be dynamically adjusted according to the bandwidth of the wireless system. Ensure the quality of vehicle video and real-time image quality on the ground.