Abstract: The fault detection and diagnosis is very important for a security of control systems.By analyzing deeply on the relationship between changes associated with process variables and between the device failure,a diagnosis technique is presented for process fault based on the correlation coefficient in process variables.The process diagnosis function is defined for interrelated variables based on the correlation coefficient (correlation coefficient,multi-correlation coefficient,partial correlation coefficient) constraints,whether the involved devices and instruments are fault is estimated according to the correlation coefficient change variety.If a fault in device or system occurs,the correlation coefficient and the diagnosis function changes will be caused,the fault location and the failure equipments are determined by logic analysis for diagnosis function value.Finally,the validity of the method is verified with a distillation column practical engineering case.

Key words: process system, system safety, fault diagnosis, correlation coefficient, diagnosis function

摘要： 故障检测和故障诊断对提高控制系统的安全性具有重要意义。通过对过程变量之间的相关性变化与过程装置故障之间关系进行深入分析，提出了一种基于过程变量相关系数约束的过程故障诊断方法。对相关过程变量定义基于相关系数（含相关系数、多重相关系数、偏相关系数）约束的过程诊断函数，通过考察相关系数和诊断函数的变化，对与其所涉及变量相关的装置是否发生故障做出判断。如果装置或系统发生故障，则会引起相关系数和诊断函数值发生变化，可通过诊断函数值进行逻辑推断，最终确定故障位置和故障装置。最后通过一个精馏塔的实际工程案例，验证了该方法的有效性。

关键词: 过程系统, 系统安全, 故障诊断, 相关系数, 诊断函数