Propeller Blade Pitch Sensor Error Detection via Torque Feedback
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Solution Overview
Problem
Existing aircraft propulsion systems with variable-pitch propellers face challenges in accurately measuring propeller blade pitch, leading to potential detrimental handling characteristics due to erroneous measurements, which can result from sensor obstructions or calibration issues.
Innovation Solution
An assembly comprising a propeller, a blade position sensor, and a controller that measures propeller blade pitch and torque, using a detection zone defined by aircraft operating conditions to identify and correct erroneous pitch measurements, and generates warnings or substitute values as needed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If blade position sensor is used to measure propeller blade pitch, then pitch measurement capability is provided, but erroneous measurements may occur due to sensor obstructions or calibration issues
Solution Approach 1:
The system continuously monitors the relationship between pitch measurements and torque measurements, using feedback loops to detect when pitch measurements become erroneous. The controller compares actual torque with expected torque based on pitch position, and when discrepancies are detected, the system identifies the pitch measurement as erroneous and generates appropriate warnings or substitute values.
Solution Approach 2:
The system uses torque measurements as an intermediary parameter to verify the validity of pitch measurements. By introducing torque as a mediator, the system can indirectly validate whether pitch sensor readings are accurate without directly monitoring the sensor itself. The detection zone methodology uses torque-pitch relationships to identify erroneous measurements.
2Measurement precision
If detection zone methodology is used to identify erroneous measurements, then detection accuracy is improved, but system complexity increases due to additional processing requirements
Solution Approach 1:
The system changes the parameter space by considering both pitch and torque simultaneously rather than relying on pitch alone. The detection zone is defined in the two-dimensional parameter space of pitch versus torque, allowing the system to identify erroneous measurements by detecting points that fall outside the expected operational zone. This approach maintains relatively simple processing while improving detection accuracy.
Data Source
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AI summary
An assembly for an aircraft propulsion system (20) includes a propeller (62), a blade position sensor (92), and a controller (82). The propeller (62) is configured for rotation about a rotational axis (46) and includes a plurality of propeller blades (66), each configured for rotation about a respective lengthwise axis (74) to selectively vary the pitch. The blade position sensor (92) is configured to measure the pitch and to generate a pitch output signal representative of the measured pitch. The controller (82) is in signal communication with the blade position sensor (92) and includes a processor (100) in communication with a non-transitory memory (102) storing instructions, which instructions when executed by the processor (100), cause the processor (100) to detect a presence or an absence of an erroneous propeller blade pitch measurement using at least the pitch output signal.