Automatic Judgement on Form-Position Precision Grade of Features

Based on GB/T1184-1996, four form-position tolerance tables are listed on the appendix B. The regularity of distribution for form-position tolerances is deliberately analyzed. This paper describes a formulated method for identifying the precision grade, deduces the functional relation formulae between the tolerance and its precision grade, and further confirms the automatic judgement method presented by a practical program on PC computed

分程控制方案在海上平台的应用及改进

介绍了分程控制的实现方法、类型及作用过程,分析了原设计分程控制方案的不足,结合XJ23-1油田自身控制需求的特点,在PKS-3000系统控制模块的基础上对原方案进行了改进,采用"软分程"组态方法,使分程控制回路分程点精确,修改简单,建立了±5%的"死区",氮气补给阀动作频率降低,节约了氮气。该方案提高了控制精度,使"自动"模式下压力控制平稳,"手动"模式下不仅实现了对调节阀的单独控制,而且使中控输入阀位信号与现场显示的阀位信号一致,方便了操作,确保了油田投产的顺利进行,效果良好。