The hottest intelligent vehicle guided by machine

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Intelligent vehicle guided by machine vision and its application in the field of logistics

automatic guided vehicle (AGV for short) is an industrial vehicle that loads goods automatically or manually, automatically drives or pulls the truck to the designated place according to the set route, and then loads and unloads goods automatically or manually. According to the definition of jisd68oi in Japan: AGV is an industrial vehicle with automatic operation and driving with battery as the power source. Only according to the requirements of automation, flexibility and punctuality of material handling operations, the automatic guided vehicle system (agvs:automated guided vehicle system for short) can play a real role

with the continuous development of computer hardware technology, parallel and analytical processing technology, automatic control technology, sensor technology and software development environment, it provides the necessary technical material foundation for the research and application of AGV. The development of artificial intelligence technology, such as understanding and search, task and path planning, fuzzy and neural network control technology, makes AGV develop towards intelligence and autonomy. The research and development of AGV integrates artificial intelligence, information processing and image processing, involving many disciplines such as computer, automatic control, information communication, mechanical design and electronic technology, and has become one of the hotspots of logistics automation research

The research and application of AGV in China started late. In the late 1970s, Beijing lifting and Transportation Machinery Research Institute developed three wheeled AGV. In the late 1980s, Beijing Institute of automation of machinery industry developed AGV in three-dimensional warehouse for second automobile and Shenyang Institute of automation developed AGV for automobile engine assembly for Jinbei Automobile Company. In the 1990s, the national "industry 4.0" of Tsinghua University described the future prospects of manufacturing industry. CIMS Engineering Center successfully applied the AGV introduced from abroad to the experimental research of CIMS. The Department of computer technology application of Tsinghua University developed the AGV for the postal center. Kunming Shipbuilding Equipment Research Institute developed the laser guided AGV, and the intelligent vehicle research group of Jilin University developed the line vision guided AGV for the automobile assembly line

I. technical analysis of intelligent vehicles in the field of logistics

the guidance mode of AGV not only determines the flexibility of the logistics system composed of it, but also affects the systematic reliability and configuration cost. Until the 1980s, buried wire electromagnetic induction guidance technology was still only one of the optional guidance technologies. However, the development of electronic technology has diversified AGV guidance technology and guidance methods. Therefore, the performance of AGV is further improved and can adapt to more complex working environment, and its application is more extensive

according to the source of AGV guidance information, the guidance mode can be divided into external guidance and internal guidance. External guidance refers to the setting of guidance information media (such as wires with variable-frequency induction electromagnetic fields, magnetic tapes or color bands, etc.) on the vehicle's running path. The characteristics of guidance information (such as frequency, magnetic field intensity, light intensity, etc.) are detected by the sensor on the vehicle, and then this information is processed to control the vehicle to drive along the guidance route. Internally guided means that the running path coordinates are preset on the vehicle, the current position coordinates of the vehicle are detected in real time during vehicle operation and compared with the preset coordinates, and then the running direction of the vehicle is controlled, that is, the so-called coordinate positioning principle is adopted. In addition, according to the form of AGV guide line, the guide can be divided into wired and wireless. See Table 1 for specific guidance methods of the above two categories. Table 1 guidance method of AGV

ultrasonic guidance, laser guidance and optical guidance in the external guidance method can be called the range of beacon reflection method (beacon, namely stem). The internal derivation method can be called dead reckoning

among the above-mentioned guidance methods, the guidance technologies used mainly include electromagnetic induction technology, laser detection technology, ultrasonic detection technology, optical reflection detection technology, inertial navigation technology, image recognition technology and coordinate recognition technology

image recognition technology

there are two methods using image recognition technology. One is to use CCD system to dynamically capture the image information of the surrounding environment of the motion path, and compare it with the information of the image database of the surrounding environment of the proposed operation path, so as to determine the current position and make decisions on the continuous operation route. Micro markers that can be inspected through a microscope (magnified by 10 times) - colorless encoded small particles. This method does not require any physical path, so it has the best guiding flexibility in theory. However, there are still some problems in the practical application of this method, mainly the poor real-time performance and the difficulty in establishing the environmental information base around the running path. The second is the identification method of the marking line image, which is to draw a clearly marked guide line on the ground where the AGV runs, use the CCD system to dynamically capture the marking image and identify the poor solution and distance deviation of the fixture 1 of the AGV relative to the marking line, so as to control the vehicle to run along the set marking line, as shown in Figure 1

Figure 1 principle of marking identification guidance mode

II. Application of intelligent vehicles in the logistics field

according to the statistical results of the main guidance technologies used by more than a dozen foreign AGV companies in 27 series of products (see Table 2), we can clearly see the application of various guidance technologies. Among them, electromagnetic induction guidance technology accounts for the highest proportion of applications, which shows that this technology has been very mature and has the most applications. However, the application proportion of machine vision guidance technology is still small, so this technology still needs in-depth research and continuous improvement. In addition, autonomous navigation technology is still in the research stage, and there are still many technical problems to be solved. Table 2 proportion of main guiding technologies applied by AGV

III. conclusion

this paper briefly introduces the concept, research purpose, significance, application status of intelligent vehicles for logistics, as well as the current research direction and scope of intelligent vehicles for logistics in the world. On the whole, limited to the level of infrastructure and economic strength of our country, there is a certain distance between the research in this field in our country and the industrial developed countries. It is not realistic to develop and implement the application of intelligent vehicles for logistics on a large scale in a certain period of time. However, whether from the perspective of discipline development and theoretical research, or from the perspective of developing automobile industry and related industries, as well as market competition, advanced research is necessary. Therefore, although there is a large gap with the industrial developed countries, this does not mean that China will never do anything in this field, and has been following the developed countries to walk up and down several times without load. Combined with China's national conditions (economic conditions, industrial conditions, scientific research conditions, etc.), in-depth and detailed research in one or some aspects will provide strong theoretical and technical support for China and even the world in the field of intelligent vehicles, and lay a solid foundation for the development and practical application of intelligent vehicles in the future. Its significance is extremely far-reaching. (end)

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