Aircraft Controller Safe Mode for Repetitive Power Failure Protection

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Solution Overview

Problem

Aircraft control systems experience unpredictable behavior and downstream effects due to intermittent power cycling, leading to repetitive power failures and flight diversions, highlighting a need for improved circuit failure protection.

Innovation Solution

A software safe module in the aircraft electrical system controller determines sudden power failures by checking a data flag, operating in software safe mode if a failure is detected, and requiring manual intervention to exit, thereby preventing repetitive power failures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the controller automatically recovers from power failures by resetting, then system availability is improved, but repetitive power cycling occurs causing unpredictable behavior and downstream effects

Engineering Contradiction:

Improvesystem availabilityVSAvoidsystem behavior stability

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The system performs preliminary detection of power failure conditions and sets a data flag in memory before attempting recovery. This preliminary action prevents automatic reset by establishing a recorded state that blocks the normal recovery path, thereby avoiding repetitive power cycling while maintaining system availability through controlled intervention only.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If manual intervention is required to exit software safe mode, then repetitive power failures are prevented, but system recovery time increases

Engineering Contradiction:

Improvepower failure preventionVSAvoidrecovery time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The data flag in memory acts as an intermediary mechanism that records power failure events and mediates between the power failure condition and the recovery process. This intermediary prevents direct automatic recovery by presenting a recorded state that requires manual acknowledgment, thereby preventing repetitive failures while providing a clear recovery pathway without excessive delay.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If the controller operates in software safe mode after power failure, then system protection is improved, but operational capability is reduced

Engineering Contradiction:

Improvecircuit failure protectionVSAvoidcontroller operational capability

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The software safe mode serves as a beforehand cushioning mechanism that protects the system from the harmful effects of repetitive power cycling. By entering this protected state after detecting a power failure through the data flag, the system cushions against further instability while maintaining essential protection, with full operational capability restored upon manual intervention that clears the protective barrier.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentEP4148513A1Systems and methods for circuit failure protection

Publication Date: 2023.03.15 HAMILTON SUNDSTRAND CORP

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AI summary

In accordance with at least one aspect of this disclosure, a controller (102) for an aircraft electrical system includes, a software safe module (110). During the controller initialisation, the software safe module (110) is configured to determine whether there was a power failure during the previous shutdown and if this was the case, cause operation of the controller (102) in a software safe mode, such that manual intervention is required to leave the software safe mode to prevent repetitive power failure of the controller.