Automatic distribution system based on embedded system of ARM technology

The automated management operating system has become an indispensable part of modern enterprises. The video image transmission monitoring system has been widely used in important occasions such as transportation, hospitals, banks, homes and video conferencing. The early analog video monitoring system could not be connected to the Internet and could only communicate with the management center point-to-point. With the development of image and video processing technology, network technology and automatic control technology, the video image system has transitioned to digital network transmission. It takes the compression, transmission, storage and playback (playback) of digital video as the core, adopts advanced digital image compression encoding/decoding technology and transmission technology, and uses intelligent image processing and recognition technology for image display, adjustment and tracking. It tracks and identifies objects according to the on-site environment, and analyzes and processes images.
　　
1 Composition of the automated distribution system
　　
This system is based on the image acquisition subsystem of the USB camera, the ARM processor subsystem and the wireless network data transmission subsystem to form a video server system. The data interaction and transmission with the management center is realized through the GPRS module on the Samsung S3C2410 development board. The image data is received through the USB camera, the shelf position is located and identified, and then the identification information is sent to the distribution management center through the GPRS module device. The management center sends a control command to the delivery vehicle to place the goods on the delivery vehicle to the designated shelf position, or to take the goods from the designated shelf position and load them onto the delivery vehicle, as shown in Figure 1.

 
　　
2 Hardware implementation of the video server system
　　
The network video server in the above figure is mainly composed of a USB camera, a network video server, etc. Its workflow is shown in Figure 2.

 
　　
2.1 ARM embedded microprocessor
　　
The embedded microprocessor is the core of the hardware part, using Samsung's ARM microprocessor S3C42410. The microprocessor has a built-in 16/32-bit ARM9TDMI core, which can execute 32-bit ARM instructions or 16-bit Thumb instructions. The operating frequency is up to 203 MHz, providing 8 K bytes of cache and 2 full-duplex UART (Universal Asynchronous Receiver and Transmitter) channels, with the characteristics of low cost and high performance.
　　
2.2 Wireless communication system
　　
With the development of GPRS technology in the field of wireless communication, the use of GPRS modem in ARM system to achieve Internet access has also begun to be applied. GPRS can play the characteristics of always online, fast login, and traffic-based billing. This paper uses the AT command to dial in the embedded real-time operating system ARM CPU. After the response is fed back, a data transmission channel, namely the GPRS network, is established between the GPRS modem in this system and the Internet, thereby realizing the data interaction between the delivery vehicle and the monitoring management center, and realizing remote unattended automatic delivery.
　　
2.3 Design of video acquisition and compression module
　　
The video acquisition and compression module consists of two parts: video data acquisition and video data compression. The video data acquisition chip is responsible for collecting the analog video data sent by the USB camera and performing analog-to-digital conversion, compressing it in MPEG4 format, and then storing the data in the buffer memory through the data bus for processing by S3C2410. The compression chip uses VW2010, which is a commonly used real-time audio and video compression/decompression chip, compatible with MPEG-1, 2, 4, H. 263 standards, with high practicality and cost-effectiveness. It can capture and compress video signals in real time and dynamically at a sampling rate of 25 frames or 30 frames per second.
　　
3 Software structure and implementation of automated distribution system
　　
3.1 Software structure
　　
The embedded Linux operating system and application program are run on the video server. The server-side software development adopts C/S mode. The main function of the video server-side software is to collect, compress, store, and transmit the images captured by the camera. When the operating system is started, the real-time clock is started, the system loads serial port, USB and other driver modules, waits for the completion of video image acquisition, and then repeatedly collects and sends pictures.
　　
3.2 Client software
　　
The client refers to the management center, which can receive data transmitted from the video surveillance server. Its functions mainly include receiving images, data analysis, and file storage through the GPRS network. When the client (management center) receives the data, it first analyzes the intercepted data according to the protocol data specification, strips off the protocol header, analyzes the lower layer data, and performs layer by layer analysis until the final image data is obtained, and the information and traffic therein are counted, and then the two parts of information are stored or transmitted to the corresponding display module. In the automated distribution system, the monitoring center uses images to determine the location of the distribution vehicle and the size of the object to adjust the robotic arm and assemble the goods.
　　
4 Conclusion
　　
The automated distribution system based on the ARM embedded system has strong anti-interference ability and is suitable for long-distance transmission of the system. Based on the real-time operating system Linux, it has small size, low power consumption, strong reliability, easy installation, and strong real-time performance, enabling managers to realize real-time operation of the distribution vehicle from a distance, and uses wireless network GPRS technology to realize the transmission of video signals. The command and dispatch of the entire automated distribution system can be realized at any location in the network.