Aircraft Brake Junction Box Layout for Reduced Wiring Mass
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Solution Overview
Problem
The centralized architecture of aircraft electric braking systems results in bulky, heavy, and costly harnesses due to numerous electrical wires, increasing the mass and complexity of the braking system.
Innovation Solution
Implementing a junction box to pool control signals and reduce the number of cables between the aircraft fuselage and brakes, integrating digital processing means to manage control signals and power distribution, thereby reducing the number of components and harnesses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a centralized architecture is used with multiple electromechanical actuators connected to a single computer, then control functionality is consolidated, but the number of electrical wires and harnesses increases significantly
Solution Approach 1:
The system divides the braking control into independent modular units, each brake assembly having its own control electronics and power conversion components. This segmentation allows each module to be self-contained, reducing the need for extensive wiring between central computer and individual actuators.
Solution Approach 2:
Each brake assembly is designed as a universal module that integrates multiple functions: electromechanical actuation, control signal processing, power conversion, and diagnostic capabilities. This multi-functionality reduces the need for separate dedicated components and wiring for each function.
2Reliability
If numerous electrical wires are used to connect actuators to the computer, then control signals and power can be transmitted, but the mass and volume of the braking system increase
Solution Approach 1:
The control electronics and power conversion components are merged into integrated units located at each brake assembly. This combining of functions eliminates the need for separate wiring harnesses for control signals and power transmission, reducing overall system mass.
Solution Approach 2:
Local control electronics serve as intermediaries between the flight control system and the electromechanical actuators. These intermediaries process control signals locally and manage power distribution, reducing the need for direct high-power wiring connections to the central computer.
3Object-affected harmful factors
If common mode current filtering circuits are integrated into computers, then electromagnetic interference is reduced, but the mass, complexity and cost of the computer increase
Solution Approach 1:
The filtering and electromagnetic interference protection functions are extracted from the central computer and placed at the brake assembly level. This extraction reduces the complexity and mass requirements of the central computer while maintaining EMI protection capabilities.
Solution Approach 2:
Each brake assembly is equipped with its own filtering and protection circuits that serve the local module independently. This self-service approach allows each module to protect itself from electromagnetic interference without requiring complex centralized filtering systems.
4Power
If bulky harnesses with long power supply wires are used, then sufficient power can be delivered to actuators, but the system mass and complexity increase
Solution Approach 1:
Power conversion and regulation are performed locally at each brake assembly before power is delivered to the actuator. This preliminary action of converting and regulating power at the point of use eliminates the need for long high-power wiring runs from the aircraft fuselage to each brake.
Solution Approach 2:
The system changes the electrical parameters (voltage, current) locally at each brake assembly using integrated power conversion electronics. This allows flexible power delivery to actuators without requiring heavy-gauge wires capable of handling high currents over long distances.
Data Source
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AI summary
Aircraft braking system architecture, comprising: - a brake (300) including friction elements and electromechanical actuators (303) to exert a braking torque on the wheel; - a computer (301) located in the aircraft fuselage and arranged to produce first piloting signals; - a junction box (302) located on the landing gear, the junction box being connected to the computer and the electromechanical actuators, the junction box being arranged to receive the first piloting signals, the junction box including electrical processing means arranged to produce, from the first piloting signals, second piloting signals for the electromechanical actuators to control the electromechanical actuators.