Aeroengine Variable Geometry Actuator Control Path Failure Detection
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Solution Overview
Problem
Existing aeroengine electric control systems for variable geometry actuators fail to detect electrical failures in passive control paths until they become active, leading to potential engine breakdowns, as these failures are not detected until it's too late for proper operation.
Innovation Solution
Implementing a self-testing method that delivers a predetermined test electric current through both control paths before the engine starter-generator is powered, evaluating the difference between the test current and the current transformed into hydraulic power, and detecting failures if the difference exceeds a predefined threshold, ensuring both paths are tested before they are used in operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the control system uses a passive control path that remains inactive until needed, then the system maintains operational simplicity and avoids unnecessary complexity, but electrical failures in the passive path remain undetected until they become active, leading to potential engine breakdowns
Solution Approach 1:
The patent applies preliminary action by performing self-tests on the passive control path before it is needed. The system delivers a predetermined test electric current through the passive path and evaluates the hydraulic power output before normal operation begins. This advance testing detects electrical failures in the passive path while it is still inactive, preventing undetected failures from causing engine breakdowns when the path is eventually activated.
2Reliability
If the system performs continuous monitoring of both control paths, then electrical failures are detected immediately, but the system complexity and power consumption increase significantly
Solution Approach 1:
The patent applies periodic action by performing self-tests at specific intervals rather than continuously monitoring. The system tests the passive control path periodically - specifically before engine start-up and at other predetermined moments - by delivering test currents and evaluating hydraulic power. This periodic testing approach detects electrical failures reliably while avoiding the excessive complexity and power consumption of continuous monitoring.
3Reliability
If the system tests the passive control path before activation, then electrical failures are detected early enabling timely maintenance, but additional testing time and power consumption are required
Solution Approach 1:
The patent performs self-tests on the passive control path during the engine start-up sequence, integrating the testing into the existing operational workflow. By delivering test currents and evaluating hydraulic power output before the engine begins normal operation, the system detects electrical failures early without requiring separate dedicated testing time, thus minimizing time loss while achieving early failure detection.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This proactive approach allows for the detection of dormant electrical failures, enabling timely maintenance and preventing engine failures by ensuring both control paths are verified before engine operation, thus guaranteeing reliable engine performance.
Implementation Method 1
an electrohydraulic member (e.g. a servo-valve or a solenoid) suitable for receiving an electric current from controlling electronics over a so-called 'active' control path and transforming it into hydraulic power
Data Source
AI summary
After the control system has been started, which system has two control paths that are used as alternatives for delivering a control electric current to an electrohydraulic member for transforming said current into hydraulic power that is delivered to the actuator, and before powering a starter-generator of the engine, the detection method comprises implementing the following steps for each of the control paths in succession:delivering a predetermined test electric current over said path;evaluating a difference between the test electric current and a measurement of the electric current as transformed into hydraulic power by the electrohydraulic member; andif said difference is greater than a predefined threshold, detecting an electrical failure on said path.