Fault diagnosis device, fault diagnosis method and machine to which fault diagnosis device is applied

Patent metadata

Field	Value
Publication number	US-11892828-B2
Application number	US-201917041358-A
Country	US
Kind code	B2
Filing date	Jan 30, 2019
Priority date	Apr 24, 2018
Publication date	Feb 6, 2024
Grant date	Feb 6, 2024

Abstract

Personal dependency related to fault tree construction is reduced, and the reliability of an operating machine is improved by improving the accuracy of a fault diagnosis. The present invention provides a fault diagnosis device for a machine in operation, the device comprising: an abnormality degree analysis unit that calculates the abnormality degree of each component configuring the machine by comparing input/output data of the machine with a threshold value; a fault tree automatic generation unit that holds a fault tree of each component in which the fault of each component and the fault of a sensor in each component are associated with each other and generates the fault tree of the entire machine by coupling the fault trees of the components on the basis of a correlation between the input/output data of each component; a fault analysis unit that analyzes the fault of the machine on the basis of the abnormality degree and information of the fault tree of the entire machine; and a display unit that displays information analyzed by the fault analysis unit and issues an alarm.

First claim

The invention claimed is:

1. A fault diagnosis device for a machine in operation, the device comprising:
an abnormality degree analysis unit that calculates the abnormality degree of each component configuring the machine by comparing output data of the machine with a threshold value;
a fault tree automatic generation unit that holds a fault tree of each component in which the fault of each component and the fault of a sensor in each component are associated with each other and generates the fault tree of the entire machine by coupling the fault trees of the components on the basis of a correlation between the output data of each component;
a fault analysis unit that analyzes the fault of the machine on the basis of the abnormality degree and information of the fault tree of the entire machine;
a display unit that displays information analyzed by the fault analysis unit and issues an alarm; and
wherein in the fault tree of the component, the fault of the sensor is described using a phenomenon that is caused by the fault, and for a fault mode that is high in the abnormality degree analyzed by the abnormality degree analysis unit, the fault analysis unit counts the number of phenomena with the same description in the fault tree of the entire machine and calculates the fault degree on the basis of the number.

2. The fault diagnosis device according to claim 1 ,
wherein the information analyzed by the fault analysis unit is input into the machine to control an operation of the machine.

3. The fault diagnosis device according to claim 1 ,
wherein for a fault mode that is high in the abnormality degree analyzed by the abnormality degree analysis unit, the fault analysis unit calculates the position of a hierarchy where the fault mode is written in the fault tree of the entire machine, and calculates the fault degree on the basis of the position.

4. The fault diagnosis device according to claim 1 ,
wherein the fault of the machine analyzed by the fault analysis unit includes any one of a fault part, a fault mode, and a fault degree.

5. A machine to which the fault diagnosis device according to claim 1 is applied.

Assignees

• Hitachi Ltd

Inventors

• Tanno Yohei
• Shimizu Yuuki

Classifications

• G05B23/0248 Primary

  Causal models, e.g. fault tree; digraphs; qualitative physics · CPC title

• G05B23/027

  Alarm generation, e.g. communication protocol; Forms of alarm · CPC title

• G05B23/0278 Primary

  Qualitative, e.g. if-then rules; Fuzzy logic; Lookup tables; Symptomatic search; FMEA · CPC title

• G05B19/418

  Total factory control, i.e. centrally controlling a plurality of machines, e.g. direct or distributed numerical control [DNC], flexible manufacturing systems [FMS], integrated manufacturing systems [IMS] or computer integrated manufacturing [CIM] · CPC title

• G05B23/0251

  Abstraction hierarchy, e.g. "complex systems", i.e. system is divided in subsystems, subsystems are monitored and results are combined to decide on status of whole system · CPC title