Research Of AGV Visual Navigation System Based On RFID

In the recent years, Automated Guided Vehicles have been becoming the most important technology of the automation in industrial logistics. Compared with the traditional navigation methods, visual navigation has the advantages of informative, high-level intelligent, and the good flexibility. So it becomes the main study focus of AGV.The research work of this paper relies on the new type of visual navigation vehicle platform, which is developed independently by the Institute of Automated Instrumentation Engineering in Zhejiang University. In this paper, we mainly focus on the hardware and software architecture, image process system, radio frequency identification system, control strategies of paths following, AGVs wireless scheduling system, and other related issues.(1).Mechanical design of vehicle. It includes the configuration and hardware selection of drive system, navigation system and control system of AGV. Design the specific steering structure, which makes proper adjustment of the steering wheels, to achieve the goal of driving smoothly and avoiding deviation. And design the angle sensor of steering wheels independently, to realize the real-time collection of the dynamic information.(2). Image processing. To improve the adaptability to the road environment, this paper attempts to use a variety of image-processing techniques. The main methods discussed in this paper include: the threshold determination of road image binarization, image de-noising by horizontal scanning method and small connective component dismantling method, Hough transformation to fit straight lines, the road images' distortion rectification based on Cross ratio theorem and so on.(3). Path tracking control. The preview kinematics model of AGV is established to forecast the driving trends of vehicle by means of analyzing input variables such as angle of steering wheel, and road information. Taking the human driving experiences as a reference, the control algorithms based on expert system are established. At the same time, intelligent control algorithms such as the initial steering wheel adjustment, automatic path lost searching, and branch path control, are also introduced to help AGV to complete the handling of emergency situations in all kinds of complicated environment.(4). Localization by Radio Frequency Identification. By using the RF antenna, installed under the bottom of AGV, to detect the feedback of signals from the tags which are lay on the white guided line, and transmit information of tags to the RF reader, which connects the onboard computer with USB interface. With the usage of RFID, it could effectively achieve the goal of real-time communication between AGV and center computer.Above all, a set of visual navigation system has been completed to fulfill the requirements such as path following, locating by radio frequency identification, automatic control of AGV. And it also offers certain technology reserve to develop the intelligent transfer technology of production logistics system.