Aircraft Brake Control System for Landing Gear Load Alleviation
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Solution Overview
Problem
Aircraft landing gear experiences high dynamic loads during braking due to sudden application of braking forces, leading to heavy and bulky designs, as existing hydraulic-based systems do not effectively alleviate loads based on current operating conditions like aircraft speed or brake pedal deflection.
Innovation Solution
An electric brake system that varies the onset timing of brake torque in accordance with aircraft speed and brake pedal deflection data, smoothing the braking force application to reduce dynamic loading on the landing gear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If sudden brake application is used to achieve rapid deceleration, then braking efficiency is improved, but dynamic loading on landing gear increases
Solution Approach 1:
The brake control system dynamically adjusts the brake torque application rate based on real-time operating conditions including aircraft speed, brake pedal deflection, and rate of pedal deflection. This dynamic control allows the system to optimize braking efficiency while preventing excessive dynamic loads on the landing gear by modulating the brake torque smoothly rather than applying it abruptly.
Solution Approach 2:
The system changes the parameter of brake torque application rate based on multiple input parameters including aircraft speed, brake pedal deflection amount, and rate of pedal deflection. By varying these parameters continuously, the system achieves both rapid deceleration and load alleviation, resolving the contradiction between braking efficiency and landing gear loading.
2Reliability
If landing gear is designed to withstand high braking loads, then reliability is improved, but weight increases
Solution Approach 1:
The patent replaces the traditional mechanical approach of designing landing gear to withstand maximum possible braking loads with an electronic control system that actively manages brake torque application. This substitution allows the landing gear to be designed for lower static load capacity while the electronic control prevents excessive dynamic loads, thereby reducing landing gear weight while maintaining reliability.
Solution Approach 2:
The brake control system uses feedback from sensors monitoring aircraft speed, brake pedal deflection, and rate of pedal deflection to continuously adjust brake torque application. This feedback mechanism ensures that braking forces remain within safe limits for the landing gear structure, allowing the landing gear to be optimized for weight while maintaining sufficient load capacity through active control.
3Force
If hydraulic-based load alleviation schemes are used, then dynamic loading is reduced, but adaptability to current operating conditions deteriorates
Solution Approach 1:
The system incorporates multiple feedback signals including aircraft speed, brake pedal deflection amount, and rate of pedal deflection to continuously adapt the brake torque application rate. This multi-parameter feedback enables the system to respond appropriately to different operating conditions, resolving the contradiction between load alleviation and adaptability.
Solution Approach 2:
The brake control system is fully dynamic, continuously adjusting the brake torque application rate based on real-time operating conditions. Unlike fixed hydraulic schemes, this electronic control system can adapt to any operating condition, providing both load alleviation and high adaptability to current aircraft state and pilot input.
Data Source
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AI summary
An electric brake system for an aircraft employs a brake control process to alleviate high dynamic structural loading of the aircraft landing gear caused by braking maneuvers. The system obtains and processes real-time data - which may include the current aircraft speed, the current brake pedal deflection position, and the current brake pedal deflection rate - to determine how best to control the onset of the brakes. The braking control scheme delays the onset of the desired braking condition to reduce high dynamic loading and lurching of the aircraft.