Aircraft Tyre Pressure Estimation Using Dual Internal Temperature Sensors
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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 aircraft downtime, which increases the risk of measurement errors and reduces operational efficiency.
Innovation Solution
A method and system using two temperature sensors positioned 160-200 degrees apart in the tire to determine a 'retained' temperature, allowing for the calculation of cold tire pressure based on hot measurements, incorporating altitude and brake temperature considerations, and accounting for thermal dynamics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If the tire is allowed to cool for 3 hours before measurement, then the measurement can be performed, but the measurement uncertainty increases due to temperature inhomogeneity and the aircraft downtime increases
Solution Approach 1:
The patent applies preliminary action by performing temperature and pressure measurements immediately after the aircraft stops (when the tire is still hot), rather than waiting for the tire to cool. The cold pressure is then calculated using a transfer function that accounts for the thermal state, eliminating the need to wait 3-5 hours for cooling while maintaining measurement accuracy.
Solution Approach 2:
The patent replaces the mechanical/waiting-based cooling process with a computational approach. Instead of physically waiting for the tire to cool down over several hours, the system uses temperature sensors and a transfer function to calculate the cold pressure from hot state measurements, substituting a computational model for the physical cooling process.
2Productivity
If the pressure is measured when the tire is hot, then the aircraft downtime is reduced, but the measurement accuracy deteriorates due to temperature variations within the tire
Solution Approach 1:
The patent performs measurements in advance (immediately after stopping) rather than waiting, capturing the hot state temperature and pressure data. The cold pressure is then derived computationally, allowing the aircraft to be turned around quickly without sacrificing measurement accuracy through the use of the transfer function.
Solution Approach 2:
The patent changes the measurement parameters from waiting for thermal equilibrium (cold state) to measuring in the non-equilibrium hot state and using a transfer function that incorporates temperature as a key parameter. This allows the system to account for temperature variations and calculate accurate cold pressure values from hot state measurements.
3Device complexity
If a single temperature sensor is used, then the device complexity is reduced, but the measurement reliability decreases due to sensor position uncertainty affecting the transfer function
Solution Approach 1:
The patent segments the temperature measurement by using multiple sensors positioned at different locations within the tire (specifically 160-200 degrees apart). This segmentation allows the system to capture temperature variations at different positions and determine a retained temperature that is less sensitive to individual sensor positioning errors, thereby improving reliability.
Solution Approach 2:
The patent uses asymmetric positioning of temperature sensors at specific angular distances (160-200 degrees) rather than symmetric positioning. This asymmetric arrangement, combined with selecting or averaging temperatures from these specific positions, optimizes the determination of retained temperature and reduces the impact of positioning uncertainty on the overall measurement reliability.
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 using hot measurements, enhancing operational efficiency and safety.
Implementation Method 1
a first internal gas temperature is measured at a first position in the tire with a first sensor installed in the tire, a step during which a second internal gas temperature is measured at a second position in the tire
Implementation Method 2
an internal air pressure of the tire is determined, a step during which a cold pressure of the tire is determined as a function of the retained temperature, as a function of the pressure and as a function of a predetermined transfer function
Data Source
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AI summary
The invention relates to a method and a system for determining the temperature in a mounted aircraft tyre. The system is characterized in that it comprises two temperature sensors installed inside the tyre.