| Automated Guided Vehicle(AGV),as a typical material transportation equipment,has been rapidly developed with the construction of smart factory in recent years,and has become an important equipment for flexible production line,flexible assembly line and logistics automation.This project is originated from the university-enterprise cooperation project "multi-AGV cooperative control system for automobile assembly line",which aims to design and implement the AGV control system for the flexible manufacturing production workshop as the automobile cab transfer,the AGV has the functions of automatic navigation operation,safe obstacle avoidance,station identification,data communication and so on.In this paper,based on the review of a large number of AGV-related literature,we analyze and summarize the current situation of AGV development at home and abroad,and discuss and analyze the current situation of its key technology development.According to the analysis of the specific functional requirements of AGVs,combined with the flexible manufacturing production workshop environment,magnetic navigation is determined as the AGV guidance method,and the body structure adopts the two-wheel differential drive method,and the important components are selected and designed according to their performance indexes.For AGV trajectory tracking problem,based on the analysis of its motion state,a kinematic model is established and a path tracking algorithm with improved fuzzy PID algorithm is designed.Firstly,the fuzzy control principle is introduced,and it is combined with traditional PID to achieve dynamic adjustment of parameters and improve the accuracy of AGV path tracking.On MATLAB platform,the simulation model of AGV fuzzy PID and traditional PID controller is built,and the simulation analysis is compared under two states of straight-line operation and circle operation.The simulation results show that the control response of the algorithm designed in this paper is faster,the overshoot is smaller,the error recovery time is shorter,and the system stability is stronger.Usually AGVs do not need the manned function,but for AGVs in special application areas such as automotive assembly lines,assembly workers are required to stand on top of the AGV to perform the assembly work of parts.To address the problem of variable speed control of manned AGVs during acceleration and deceleration and braking,we first analyze the human body’s adaptation to acceleration and compare typical acceleration and deceleration algorithms,and then propose an S-curve based AGV variable speed control method for human body adaptation,and simulate and test the variable speed control method for typical working conditions.The simulation results show that this variable speed control method can effectively control the acceleration and deceleration process of AGV,which meets the human adaptation conditions and AGV operation requirements.Finally,the software and hardware design of the AGV vehicle control system is carried out,and the STM32-based vehicle controller is designed independently in the hardware aspect.In terms of software,the system is designed to realize the functions of environment perception,navigation and positioning,human-machine interaction,motion control,wireless communication and autonomous obstacle avoidance.The AGV vehicle control system was verified on an automobile production and assembly line.40 AGVs were used in batch,and the operation time was over one year. |
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