四十年代以前,大多数工厂在化工生产中都由人工直接操作,生产中各关键参数靠工人观察,操作条件的改变靠工人执行。五十年代出现了应用反馈原理的自动控制系统,这时期自动化的目的在于自动控制生产过程,使生产过程中某些关键工艺参数稳定不变或按工艺要求主动改变,使产量和质量都保持在一个稳定的水平上。随着工业的发展,六十年代中期以 Before the forties, most of the factories operated by hand in chemical production. The key parameters of production were observed by the workers. The change of operating conditions was carried out by the workers. In the 1950s, an automatic control system based on feedback principle emerged. The purpose of automation in this period was to control the production process automatically. Some of the key process parameters in the production process were kept stable or changed according to the process requirements. The output and quality were maintained at A stable level. With the development of industry, the mid-1960s