Under the background of Industry 4.0,the availability of automatic production lines(APL)is hard to be evaluated, aiming at the difficulties for evaluating availability of APL,the computerized simulation method is adopted for modeling,testing and analyzing.Taking automotive automatic welding and assembling line as an object,two controlling modes named as synchronous movement(SM)and asynchronous movement(AM),and the seven time sequences within a single automated workstation job tick are analyzed respectively,and then the availability evaluation is defined.Through the design of examples,the specific data that needs to be collected for evaluation of the availability is given.Based on reliability theory and the fault superposition effect of parallel and serial jobs,multiple robots on a single workstation are regarded as one robot for modeling,and the acquisition method of reliability parameters are given.The WITNESS simulation platform is used to test the examples,and the method and process of simulation test and result analysis of availability evaluation are given.The quantitative influences of spreaders number between the production lines,equipment quality level,and on-site maintenance level on availability of synchronous and asynchronous movement production lines are obtained.The experiments' results verify that simulation can evaluate the availability of APL precisely,and it is a good analyzing tool to evaluate or improve the APL design scheme.%针对工业4.0背景下自动生产线开动率难以精确评估的问题,利用计算机仿真方法进行建模和试验分析.以汽车自动焊装线为对象,分析了产线的同步移动和异步移动两类控制模式以及单个自动工作站作业节拍内的七个时序,并对开动率评估问题进行了界定.通过算例设计,给出了开动率评估需要收集的具体数据.基于可靠性理论和并行与串行作业故障叠加效应,将单个工作站多台机器人视为一台机器人进行建模,并给出了可靠性参数获取方法.通过WITNESS仿真平台对算例进行试验,给出了开动率评估仿真试验与结果分析的方法和过程,获得了产线间吊具数量、设备质量水平和现场维修水平对同步移动和异步移动两类产线开动率的定量化影响规律.试验结果验证了该方法是自动生产线设计方案评估和改善的一种有效分析手段.
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