Aircraft Taxi Brake Selection System Optimizing Carbon Wear

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Solution Overview

Problem

Carbon aircraft brakes experience excessive wear and oxidation due to the number of taxi braking events and temperature disparities, leading to reduced service lifetime and increased maintenance costs, as existing braking methods either overwork all brakes equally or cycle through them inefficiently, failing to account for individual brake temperatures and wear rates.

Innovation Solution

A taxi brake selection system that determines the estimated peak temperature of each brake assembly and activates only those within a specific temperature range, ensuring that the number of activated brakes matches the required number for braking events, thereby reducing wear and oxidation by optimizing brake usage based on temperature thresholds.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of stationary object

If all brakes are activated equally during taxi braking events, then brake life is extended for steel brakes, but carbon brake wear increases significantly due to the number of applications

Engineering Contradiction:
Improvebrake lifeVSAvoidcarbon brake wear
Core Design Contradiction:
Duration of action of stationary objectVSLoss of substance

Solution Approach 1:

The braking system divides the brake assemblies into multiple groups or subsets, where different brakes are selectively activated based on their individual temperature conditions. This segmentation allows the system to avoid uniform activation of all brakes, thereby reducing the number of applications for carbon brakes while maintaining adequate braking capability through coordinated use of subset brakes.

Inventive Principle:
Principle #1Segmentation

2Loss of substance

If brakes are cycled sequentially to reduce individual brake applications, then carbon brake wear from applications is reduced, but temperature disparities between brakes worsen leading to oxidation

Engineering Contradiction:
Improvecarbon brake wearVSAvoidbrake core temperature variance
Core Design Contradiction:
Loss of substanceVSTemperature

Solution Approach 1:

The braking control system incorporates temperature monitoring and feedback mechanisms that track the core temperature of individual brake assemblies. Based on this feedback, the controller dynamically adjusts which brakes are activated, avoiding activation of brakes that are already at high temperatures and preventing further temperature disparities and oxidation.

Inventive Principle:
Principle #23Feedback

3Reliability

If temperature monitoring is implemented to select brakes within optimal temperature range, then brake wear and oxidation are reduced, but system complexity increases

Engineering Contradiction:
Improvebrake service lifetimeVSAvoidbrake selection system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The braking system utilizes temperature as a key parameter to determine brake activation status. By monitoring temperature parameters and comparing them against predefined thresholds, the system selects appropriate brake subsets for activation. This parameter-based approach extends brake service lifetime by keeping brakes within optimal temperature ranges while managing system complexity through straightforward threshold comparisons.

Inventive Principle:
Principle #35Parameter changes

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 approach extends the life of carbon brake assemblies by reducing wear and oxidation, lowering maintenance and replacement costs by activating only the necessary brakes at optimal temperatures, thus improving the operational efficiency and longevity of aircraft brakes.

Implementation Method 1

The brake selection system includes a plurality of brake assembly temperature sensors, each sensor positioned proximate a respective one brake assembly

Methodology Applied
Scientific EffectTemperature sensing: Thermocouple

Implementation Method 2

Carbon reacts with oxygen at high temperatures to gradually form oxides, which may limit the service lifetime of the brakes

Methodology Applied
Scientific EffectOxidation: Oxidation

Implementation Method 3

carbon brakes primarily wear based on the number of applications... whereas steel brakes primarily wear based on the amount of heat energy generated

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3088266B1Brake selection system and methods
Publication Date: 2018.11.14 THE BOEING CO
  • EP3088266B1 patent drawingFigure 1
  • EP3088266B1 patent drawingFigure 2
  • EP3088266B1 patent drawingFigure 3

AI summary

Methods and apparatuses for selecting a plurality of brake assemblies (212) desired for activation during an aircraft taxi braking event from a total number of brake assemblies (212) are disclosed. One method includes determining an estimated peak temperature for each brake assembly (212) and determining a first subset of the brake assemblies (212) having an estimated peak temperature within a predetermined temperature range. The method also includes determining whether the number of first subset brake assemblies (212) is greater than or equal to the number of brake assemblies (212) desired for braking. At least a portion of the first subset brake assemblies (212) is then activated if the number of brake assemblies (212) in the first subset is determined to be greater than or equal to the number of desired brake assemblies (212), wherein the number of brake assemblies (212) in the activated portion of the first subset is greater than or equal to the number of desired brake assemblies (212).