Neural Networks and Fault Probability Evaluation for Diagnosis Issues

Table 1

Set of faults specified for Benchmark actuator.

Fault	Description	Time development
		S	M	B	Incipient
𝑓1	Valve clogging	*	*	*
𝑓2	Valve or valve seat sedimentation			*	*
𝑓3	Valve or valve seat erosion				*
𝑓4	Increasing of valve or bushing friction				*
𝑓5	External leakage				*
𝑓6	Internal leakage (valve tightness)				*
𝑓7	Medium cavity or critical flow	*	*	*
𝑓8	Twisted servomotor’s rod	*	*	*
𝑓9	Servomotor’s housing or terminals tightness				*
𝑓10	Servomotor’s diaphragm perforation	*	*	*
𝑓11	Servomotor’s spring fault			*	*
𝑓12	Electropneumatic transducer fault	*	*	*
𝑓13	Rod displacement sensor fault	*	*	*	*
𝑓14	Pressure sensor fault	*	*	*
𝑓15	Positioner spring fault			*
𝑓16	Positioner lever fault	*	*	*
𝑓17	Positioner supply pressure drop			*	*
𝑓18	Unexpected change of pressure difference	*	*	*	*
𝑓19	Fully or partly opened bypass valves	*	*	*