Automatic Fault Tree Generation for Machine Fault Diagnosis

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The accuracy of fault diagnosis using Fault Tree Analysis (FTA) depends on the skill and experience of the creator, leading to potential omissions or inaccuracies in fault tree construction and probability estimation, resulting in variations in diagnosis accuracy due to personal dependency.

Innovation Solution

A fault diagnosis device that automatically generates a fault tree for a machine by associating component and sensor faults, using input/output data to couple component trees and calculate abnormality degrees, enabling real-time fault analysis and alarm issuance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a fault tree is manually created by an expert, then comprehensive fault analysis is achieved, but personal dependency and omission of phenomena occur

Engineering Contradiction:
Improvefault diagnosis accuracyVSAvoidfault tree construction complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system performs automatic fault tree generation by having the machine itself provide operational data that feeds into the fault tree construction process. The operational data automatically collected from sensors and system logs serves as input for generating the fault tree, eliminating the need for manual expert analysis while reducing personal dependency in fault tree creation.

Inventive Principle:
Principle #25Self-service

2Loss of information

If manual fault tree creation is performed, then fault modes can be identified, but time-consuming and experience-dependent process occurs

Engineering Contradiction:
Improvefault mode information completenessVSAvoidfault tree construction time
Core Design Contradiction:
Loss of informationVSLoss of time

Solution Approach 1:

The system performs preliminary data collection and processing by continuously gathering operational data from the machine before fault analysis is needed. This pre-collected data is then automatically used to generate the fault tree when needed, eliminating the time-consuming manual creation process while ensuring comprehensive fault mode information is captured.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If probability of occurrence is defined for each phenomenon, then fault probability estimation is achieved, but accurate definition is difficult due to enormous use conditions

Engineering Contradiction:
Improveprobability estimation accuracyVSAvoidprobability definition complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system uses feedback from actual machine operational data to dynamically adjust and refine probability estimates for fault phenomena. Instead of manually defining probabilities for numerous use conditions, the system continuously monitors actual occurrences and uses this feedback to update probability values, improving accuracy while reducing the complexity of probability definition.

Inventive Principle:
Principle #23Feedback

Data Source

PatentUS11892828B2Fault diagnosis device, fault diagnosis method and machine to which fault diagnosis device is applied
Publication Date: 2024.02.06 HITACHI LTD
  • US11892828B2 patent drawing
  • US11892828B2 patent drawing
  • US11892828B2 patent drawing

AI summary

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.