Based on Freescale i.mx27 robot video surveillance system

Robots are the highest-end products of mechatronics, and they are also a combination of high-tech products. They are widely used. The characteristics of robot development can be summarized as follows: horizontally, the application surface is wider and wider, extending from 95% of industrial applications to non-industrial applications in more fields, such as surgery, fruit picking, pruning, roadway excavation, detection, Demining and so on; in the vertical direction, there are more and more kinds of robots, like the micro-robot entering the human body, has become a new direction, can be as small as a rice grain.

In some industrial applications, such as exploration, disaster relief, alien detection, nuclear industry control, surgical robots, etc., in these occasions where recording and transmission of video is required, a video surveillance system must be provided to the robot. The video surveillance system consists of a real-time control system, a monitoring system, and a management information system. The real-time control system completes the real-time data acquisition, processing, storage, and upload functions; the monitoring system completes the all-weather monitoring of each monitoring point, and can simultaneously monitor and view images transmitted from multiple monitoring points; the management information system completes the storage of various required information. , processing and querying.

The robot video surveillance system based on Freescale I.MX27 is officially based on an intelligent high-tech product launched by the market for the urgent needs of robot video surveillance systems. It is composed of a server and a terminal device to form a video surveillance system. The terminal is responsible for collecting images, and the images are connected to the Ethernet through the network cable or transmitted to the server through 3G. The server performs image display, storage and processing functions. Some algorithms can be integrated on the server side, such as portrait recognition, fingerprint recognition, medical image analysis, etc. The captured images can be intelligently identified by different intelligent recognition algorithms.

The block diagram of the system is shown as follows:

The camera is installed where it needs to be monitored, connected to the Ethernet or transmitted to the monitoring center via 3G.

The main functions of the video surveillance system:

Video image acquisition

The video image is captured by the camera and the video image is compression encoded. If you use a high-definition camera, the image can reach D1 (720 * 576) resolution, video compression encoding can have many formats, such as MPEG2, MPEG4, H.264, etc., commonly used is H.264 format, because of high compression ratio , can reduce the file size and increase the transfer rate. The I.MX27 platform we use is a CPU with hardware H.264 codec. The H.264 codec does not occupy CPU resources, which greatly improves the CPU efficiency and reduces the system power consumption.

2. Video image local storage and upload

The images captured by the camera can be selected for local storage and upload, or you can choose to upload directly. Which method is selected depends on the user's needs and system configuration. The locally stored media can be an SD card or a SATA hard disk, which can be supported by both media systems.

The upload can be a wired network, connected to the network cable through RJ45, and supports 10/100M Ethernet. It can also be a wireless network, generally 3G. When 3G is selected as the transmission medium, the bandwidth is subject to certain restrictions. The transmission speed that our system can achieve is D1@30fps, which is subject to network bandwidth when selecting 3G network transmission.

3. Video image processing and recognition

We are a robot video surveillance system. The so-called robot is to replace some people with machines to complete some tasks, so as to reduce manpower input, improve production efficiency and reduce production costs.

Then how can the machine replace people? That is to say, after the video image is transmitted to the monitoring center, how can the monitoring center use the images to automatically complete some work? If these images are used with a certain pattern recognition algorithm, after the computer runs a certain algorithm, it can automatically make some judgments by using the features on the image, and then automatically complete some control actions, which greatly reduces the manpower input.

For example, the automatic identification of license plates is very important in the transportation industry, and it is widely used at present; as is the automatic capture of faces, automatic capture of faces in important places such as banks, it is also very meaningful for safety; For example, fingerprint recognition is currently widely used in attendance and access control systems, which is to establish the fingerprint library to use the uniqueness of the fingerprint as a recognition code for the person. And so on, in our daily work and life, has become more and more popular, technology is constantly improving, and there will be more fields to introduce and adopt these advanced technologies in the future.

Above we briefly introduced the working mode and function of the video surveillance system. The controller I.MX27 CPU is a high performance CPU with ARM926 400M frequency. Based on the system platform built by this high performance CPU, Many advantages: the scalability of local storage can be used as a hard disk recorder. When the network fails, the monitoring screen can be saved locally to ensure the reliability of monitoring; the high-speed and powerful CPU can run the mainstream real-time embedded operating system; The low-power CPU is suitable for different environments. Low power consumption can save resources. In some places where real-time monitoring is not required, low-power mode can be enabled. High-definition and continuous video stream is suitable. The need for most algorithmic applications facilitates the functionality of the robot.

Based on the i.mx27 robot video surveillance system may be a small star in many robot video surveillance systems, but we believe that in the digital and network development environment, this little star will be able to shine and enjoy it. Excellent features.