Aircraft Antiskid Control Using Reference Wheel Data
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Solution Overview
Problem
Aircraft braking systems face challenges in controlling wheel braking when a wheel speed sensor fails, leading to degraded antiskid functionality and reduced braking efficiency, especially on surfaces with varying coefficients of friction.
Innovation Solution
A braking system with a controller that determines slip ratio, coefficient of friction, or braking pressure of a second wheel to adjust the braking pressure of a first wheel in real-time, using consistency values calculated from reference wheels, even if the first wheel's speed sensor is faulty, and adjusts the braking pressure proportionally based on the distance between wheels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If wheel speed sensor failure occurs, then the braking system loses wheel speed data for the affected wheel, but the system can still determine braking parameters using data from reference wheels
Solution Approach 1:
The patent uses reference wheels (wheels with functional speed sensors) as intermediaries to infer the braking state of the wheel with sensor failure. By measuring slip ratios, coefficients of friction, and braking pressures at reference wheels, the system indirectly determines the parameters for the affected wheel without direct measurement, thus maintaining control reliability despite information loss.
2Reliability
If the system uses reference wheels to determine braking parameters, then braking control can be maintained during sensor failure, but the system complexity increases due to consistency calculation and real-time adjustment mechanisms
Solution Approach 1:
The system continuously calculates consistency values between the inferred braking parameters and actual measurements from reference wheels, and uses this feedback to adjust braking pressure in real-time. This closed-loop feedback mechanism maintains antiskid functionality by dynamically adapting to changing conditions while compensating for the sensor failure.
Solution Approach 2:
The braking pressure adjustment is dynamic rather than static - the system continuously updates the braking pressure based on real-time consistency calculations and the specific distance between wheels. This dynamic approach allows the system to adapt to varying runway conditions and maintains reliability without requiring overly complex predetermined control strategies.
3Productivity
If braking pressure is adjusted based on consistency values and wheel distance, then braking performance is maintained on varied runway surfaces, but the calculation and control processes become more complex
Solution Approach 1:
The system applies different braking pressure adjustments to different wheels based on their specific characteristics - particularly the distance between the affected wheel and reference wheels. Each wheel receives customized braking control tailored to its local conditions (position on the aircraft, distance from reference wheels), which maintains braking efficiency across varied runway surfaces without requiring a universally complex control approach for all wheels.
Data Source
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AI summary
A braking system may include a controller (110), a first wheel (202, 204) and a second wheel (220, 222). The first wheel may be laterally displaced from the second wheel by a first distance. A first wheel speed sensor (208, 212) may be coupled to the first wheel and a second wheel sensor may be coupled to the second wheel. The controller may be configured to determine at least one of a slip ratio, a coefficient of friction, or a braking pressure of the second wheel in response to failure of the first wheel speed sensor. The controller may be configured to calculate a consistency value of the at least one of the slip ratio, the coefficient of friction, or the braking pressure. The controller may be configured to adjust a braking pressure of the first wheel speed sensor based upon the consistency value and the first distance.