| Since the "Made in China 2025" initiative was put forward,all industries have responded to the call of the state and taken the "Dark Factory" as the goal to improve equipment automation,process informatization and intelligent production.Among them,3C products are closely related to personal life,and most of them have relatively mature manufacturing process and high degree of automation of workshop equipment,so they have been playing an important role in the process of production and manufacturing reform.Production and transportation are two important parts of the workshop manufacturing process: production is the realization of manufacturing,transportation is the guarantee of production.Automated Guided Vehicle(AGV)is an important carrier of logistics and transportation for intelligent workshop of 3C products.In the intelligent workshop with batch arrival,single process and serial layout of tasks,the appropriate AGV scheduling algorithm can improve the logistics and transportation efficiency of the workshop,further optimize various performance indicators of the workshop and improve the production efficiency of the intelligent workshop.One-way track and two-way track are the only two alternative AGV track guidance methods,which have been applied in various production environments due to the actual demand of production.AGV in one-way track scenario has low path flexibility,relatively simple control strategy,low cost and small system fluctuation.AGVs in bidirectional trajectory scenarios have high path flexibility,complex control strategies,high cost and large random fluctuations.Different track guidance methods bring different challenges to the setting of AGV scheduling strategies: how to formulate appropriate AGV scheduling strategies for different track guidance environments to ensure orderly and efficient production.In view of this,the main research contents of this thesis are as follows:Firstly,it analyzes the research background and workshop business process,introduces the workshop path network of a single process intelligent workshop,describes the AGV guidance,task triggering,task response,AGV operation,material connection and CNC processing mechanism in the workshop,and makes reasonable assumptions and detailed analysis on the scheduling problems of AGV in the workshop.Secondly,a Simulation model based on EM-Plant Simulation discrete Simulation platform was built according to the working scene of 3C product intelligent workshop.Parameter of the Simulation model was configured,Simulation operation mechanism was established,and six kinds of AGV scheduling rules based on CNC center single attribute priority and eight kinds of workshop performance evaluation indexes were proposed.Then,the operation characteristics of the 3C product intelligent workshop with one-way AGV orbit are analyzed,and the experimental case is designed with the idea of segmentation experiment method.The effectiveness of the proposed AGV scheduling rules is verified by the comprehensive analysis of the performance indicators of the workshop.Finally,based on the analysis of the characteristics of 3C product intelligent workshop with bidirectional AGV track and the existing deadlock problems,the online real-time unlocking mechanism is proposed to solve the deadlock strategy of AGV operation,and the effective deadlock prevention strategy is formulated according to the layout of the workshop to ensure the smooth logistics and transportation of the workshop.Considering the random factors of two-way AGV tracks,a large number of experimental cases were simulated,and the improved AGV scheduling rules considering multiple attributes were proposed.According to the simulation results,the workshop performance indexes were counted,and the relative deviation index method was used to analyze the performance indexes.The performance indexes of the workshop with the AGV scheduling rules considering random factors were comprehensively analyzed. |
