Engine Actuator Fault Accommodation Using Synthesized Position Feedback

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Solution Overview

Problem

Conventional engine control systems for aircraft vehicles lack effective methods to detect and accommodate faults in actuators and sensors in real-time, leading to potential system failures and reduced efficiency.

Innovation Solution

An engine control system that utilizes an electronic hardware engine controller with an EPOS model to synthesize actuator positions, detect faults, and adjust actuator positions based on synthesized values, thereby compensating for faulty actuators and sensors, ensuring continued operation and preventing further damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional engine control systems are used without fault detection and accommodation mechanisms, then the device complexity is reduced, but the reliability deteriorates due to inability to detect and accommodate faults in real-time

Engineering Contradiction:
Improvefault detection and accommodation capabilityVSAvoidcontrol system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system performs preliminary fault detection by continuously monitoring actuator positions and comparing commanded versus actual positions before faults can propagate. The fault detection mechanism is built into the control loop, allowing early identification of discrepancies between commanded and actual actuator states, enabling preventive accommodation actions.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system implements feedback mechanisms where the actual actuator position is continuously measured and compared with the commanded position. This feedback loop enables real-time detection of faults by identifying deviations beyond threshold values, and triggers accommodation strategies that adjust control commands to compensate for detected faults, maintaining system reliability.

Inventive Principle:
Principle #23Feedback

2Reliability

If fault accommodation mechanisms are implemented, then the reliability is improved, but the device complexity increases due to additional sensors and control logic

Engineering Contradiction:
Improvesystem operation continuityVSAvoidsensor and control logic complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The control system performs self-diagnosis by monitoring its own actuator responses and detecting faults autonomously. The system uses built-in sensors to measure actual actuator positions and compares these with commanded positions, automatically identifying faults without requiring external diagnostic equipment. This self-service capability maintains reliability while minimizing additional hardware complexity.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system creates a virtual model or copy of the expected actuator behavior through simulation or mathematical modeling. This virtual copy is continuously compared with actual sensor measurements to detect deviations indicating faults. By using a computational copy rather than additional physical sensors, the system achieves fault detection capability without proportionally increasing hardware complexity.

Inventive Principle:
Principle #26Copying

3Reliability

If real-time fault detection is implemented, then the reliability is improved, but the loss of time in processing and responding to faults increases

Engineering Contradiction:
Improvefault response accuracyVSAvoidfault detection and response time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The fault detection mechanism operates continuously as part of the normal control loop, rather than as a separate periodic check. The system continuously compares commanded and actual actuator positions with every control cycle, ensuring that faults are detected immediately upon occurrence. This continuous monitoring eliminates detection delays while maintaining accurate and timely fault response.

Inventive Principle:
Principle #20Continuity of useful action

Data Source

PatentEP3527803B1On-board estimator actuator system fault accommodation in engine control
Publication Date: 2021.10.13 RTX CORP
  • EP3527803B1 patent drawingFigure 1
  • EP3527803B1 patent drawingFigure 2A
  • EP3527803B1 patent drawingFigure 2B

AI summary

An engine control system includes an electronic hardware engine controller (150) and an actuator (124) that operates at different positions to control operation of an engine (130). An actuator sensor (125a, 125b) measures an actuator position, and the engine controller (150) generates a synthesized actuator position. In response to detecting a faulty actuator (124), a faulty actuator sensor (125a, 125b), or both, the engine controller (150) adjusts the position of the actuator (124) based on the synthesized actuator position.