Aircraft Tire Pressure Estimation Using Dual Internal Temperature Sensing
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Solution Overview
Problem
Existing methods for determining aircraft tire pressure require waiting for the tire to cool down to ambient temperature, leading to uncertainty and downtime due to non-uniform internal temperatures and prolonged measurement times, resulting in potential errors and reduced aircraft operational efficiency.
Innovation Solution
A method using two temperature sensors positioned 160-200 degrees apart in the tire to measure internal gas temperatures, determining a 'retained' temperature, and applying a transfer function to calculate cold tire pressure based on hot measurements, with optional inclusion of brake temperature and altitude considerations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the tire is allowed to cool for 3 hours before measurement, then the temperature becomes more uniform, but the measurement time and aircraft downtime increase significantly
Solution Approach 1:
The patent applies preliminary action by performing temperature measurements at multiple positions before the tire fully cools down. Instead of waiting for thermal equilibrium, the system proactively measures temperatures at various locations and uses computational methods to determine the cold pressure, thereby eliminating the need for prolonged cooling wait time while still achieving accurate results.
2Measurement precision
If the pressure is measured after 3 hours of cooling, then the tire temperature is closer to ambient, but temperature variations of up to 40°C remain and errors of up to 11 PSI occur
Solution Approach 1:
The system performs preliminary temperature measurements at multiple positions before complete cooling occurs. By measuring temperatures at various locations and using the transfer function approach, the system calculates the cold pressure without requiring the tire to reach full thermal equilibrium, thus reducing waiting time while maintaining measurement accuracy within acceptable limits.
Solution Approach 2:
The patent introduces a transfer function as an intermediary element that relates hot and cold pressure states. This transfer function, determined through calibration, allows the system to convert hot temperature and pressure measurements into accurate cold pressure values without requiring the tire to actually cool down completely, thereby eliminating the need for prolonged waiting while maintaining precision.
3Measurement precision
If temperature measurements are taken at different positions in the hot tire, then the temperature distribution can be characterized, but sensor positioning becomes critical to avoid distorted results
Solution Approach 1:
The system performs preliminary measurements at multiple predefined positions to characterize the temperature distribution pattern. By establishing the thermal profile early in the cooling process, the system captures the temperature gradient information needed for accurate cold pressure calculation without requiring precise sensor positioning during subsequent measurements.
Solution Approach 2:
The patent divides the tire into multiple measurement zones by placing temperature sensors at different positions (e.g., top, bottom, side walls). This segmentation allows the system to capture the three-dimensional temperature distribution and use the highest temperature reading to represent the overall tire temperature, thereby compensating for thermal gradients without requiring complex positioning systems.
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
Reduces measurement uncertainty and downtime by accurately determining cold tire pressure shortly after stopping, enhancing precision and operational efficiency.
Implementation Method 1
a first internal gas temperature is measured at a first position in the tyre, with a first sensor installed in the tyre; a second internal gas temperature is measured at a second position in the tyre
Implementation Method 2
when the vehicle is stopped, since the hot air present in the tyre tends to rise, the temperature at the bottom of the tyre will be lower than the temperature at the top of the tyre
Data Source
AI summary
A method and a system for determining the temperature in a mounted aircraft tyre is characterized in that it has two temperature sensors installed inside the tire.