With the continuous development and improvement of GPS technology, truck gps vehicle terminals have been widely used in vehicle management systems such as taxis, logistics vehicles, long-distance buses, etc., to achieve vehicle positioning, tracking, dispatching and other functions, and have achieved good economic benefits. However, for the special requirements of some vehicles, such as real-time image monitoring of long-distance buses, anti-robbery of taxis, etc., the existing truck gps tracker management system has not been fully satisfied. In view of the above, a solution is proposed: based on the existing truck gps tracker management system, the USBHOST interface is extended on the truck gps tracker vehicle terminal, and a USB digital camera is connected to realize real-time image monitoring of the vehicle.
USB digital video camera is mainly composed of three parts. The DSP part adopts the image processing chip ZC0301P of Konggong Technology, and the 300,000 pixel CMOSSENSORPB0330 is used as the image sensor. In order to obtain better image effects in low light conditions such as night, the night vision compensation infrared LED matrix controlled by photoresistors is added At night or under low light conditions, the infrared LED is automatically turned on for compensation. ZC0301P chip adopts advanced image control technology such as automatic gain enhancement technology of image light source, automatic brightness, white balance control technology, color saturation, contrast, edge enhancement and gamma correction, etc. With CMOSSENSOR, all technical indicators are compatible with CCD Comparable. Support USB1.1 interface; compatible with TWAIN standard; supports VGA resolution (640 × 480). Up to 15 frames / second rate in VGA mode, 30 frames / second rate in CIF (52 × 288) and SIF (320 × 240) mode; and provides 640X480 format high-definition still image capture mode, supports standard JPEG Compression mode.
gps tracking device for trucks terminal uses USBHUB chip to expand multiple USBHOST interfaces, and each USBHOST interface can be connected to a USB camera, which can basically meet the requirements for vehicle image monitoring. In general, a dome-type USB camera can be installed on the roof of the co-pilot in front of the co-driver to monitor the situation in the entire car. For large buses, a USB camera can be installed in the front and middle of the car.
The USB camera installed on the vehicle captures the status of the cabin in real time, and transmits the compressed image data or video stream to the truck gps tracker vehicle terminal through the USB interface. The truck gps tracker vehicle terminal uses the wireless public communication network platform GPRS or CDMA network to transmit data to the monitoring center According to the needs, relevant staff can obtain the on-site dynamic images of the vehicle through the Internet to understand the real-time running status of the vehicle.
At present, the data communication between the best buy truck gps tracker vehicle terminal and the monitoring center is transmitted through the 2.5G GPRS or CDMA wireless network platform. The 2.5G GPRS / CDMA bandwidth cannot meet the requirements for transmitting a complete and smooth video stream. Therefore, in actual applications, the transmission of image data is still the main method. There are three working modes, which are.
1) Timely transmission, such as uploading an image every 10 seconds.
2) Command mode, obtain the monitoring image through the command issued by the monitoring center.
3) Event triggering, such as triggering uploading of monitoring images by opening and closing the door and other events.
In some cases, the video data of the USB camera can also be stored in a USB flash drive via a best truck gps tracker vehicle terminal and played back on a computer afterwards. It is expected that 3G will be launched in the future, and the truck gps tracker vehicle terminal communication module can also be upgraded to 3G, which can fully realize the wireless real-time video monitoring of vehicle.