一种集成SPC与EPC的过程控制方法

在多品种、小批量生产模式下,不合格品经常发生在由一种水平过渡到另一种水平的暂态阶段.采用由一阶动态过程和稳态干扰ARMA(1,1)组成的系统模拟制造过程,针对当输入发生阶跃变化时过程出现的暂态阶段,设计了集成统计过程控制(SPC)与工业过程控制(EPC)的过程控制方法.以往,SPC与EPC是减少过程波动的两种截然不同的方法,而集成控制方法是应用ARMA控制图对制造过程进行监视,同时PI控制器对过程进行调整.模拟结果表明:集成控制方法不但能减少过程输出波动,提升系统性能;并且在调整涉及成本因素时,集成控制方法更具有潜在的成本优势.

Study on a Process Control Approach Integrating SPC with EPC

Subquality products often occur in a transient phase during which the level of technological process transfers from one to another if the production is multi-product with small scale.To solve the problem that the transient phase is occurring with the step change in input procedure,a process control approach is designed integration SPC(statistical process control)with EPC(engineering process control)by introducing the system simulation for the manufacturing process comprising the 1st-order dynamic process and the steady-state disturbance ARMA(1,1).Conventionally SPC and EPC as the means to reduce process fluctuation are quite distinct from each other,while the approach designed integrating SPC and EPC applies ARMA control chart to monitoring the whole manufacturing process with PI controller used to readjust the process.The simulation results showed that the approach is not only able to reduce the fluctuation of process output so as to upgrade the system performance but also potentially advantageous to the cost involved in readjusting it when necessary.