Electromechanical Brake Actuator Load Cell Failure Compensation
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Solution Overview
Problem
Braking systems on aircraft face reduced performance and increased stopping distance due to load cell failures in electromechanical actuators, as disabling one actuator can degrade closed-loop control and reduce braking efficiency.
Innovation Solution
A brake system and method that estimate the force of a failed load cell using data from a second and third load cell, allowing the controller to select an input for the first electromechanical brake actuator (EBA) and maintain operation by switching to external load cell inputs, thereby preventing actuator disablement and maintaining braking performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a load cell fails in an electromechanical actuator, then the actuator can be protected from damage, but braking performance is reduced and stopping distance increases
Solution Approach 1:
The patent merges the force measurement capability across multiple load cells by combining data from operational load cells (second and third load cells) to compensate for the failed first load cell. This allows the system to maintain accurate force measurement and closed-loop control by integrating information from multiple sources rather than relying on a single load cell per actuator.
Solution Approach 2:
The patent implements multi-functionality by enabling load cells to serve multiple actuators. When the first load cell fails, the second and third load cells are repurposed to provide force measurement data for the first electromechanical actuator, allowing one load cell to serve multiple functions and multiple actuators simultaneously.
2Reliability
If a load cell fails, then system safety is maintained by disabling the actuator, but braking efficiency is reduced
Solution Approach 1:
The patent applies beforehand cushioning by implementing a fail-operational design where compensation mechanisms are pre-configured. Before the load cell failure impacts braking performance, the system is already designed to use alternative load cell data, ensuring continuous safe operation without interruption or performance degradation.
Solution Approach 2:
The patent uses feedback from multiple load cells to maintain accurate force measurement. By continuously monitoring force data from operational load cells and using this feedback to control the electromechanical actuator, the system maintains closed-loop control and braking efficiency even when one load cell fails.
3Productivity
If multiple load cells are used to compensate for failure, then braking performance is maintained, but system complexity increases
Solution Approach 1:
The patent segments the force measurement function across multiple independent load cells, allowing the system to tolerate individual failures. Each load cell operates independently, and the control system processes data from specific segments (load cells) based on their operational status, enabling graceful degradation rather than complete system failure.
Data Source
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AI summary
Systems and methods of controlling a brake system (100) are provided. The system may include the step of detecting, by a controller, a failure of a first load cell (108A) of a first electromechanical brake actuator (EBA). The method may further comprise estimating, by the controller, a force of the first EBA using a force output from a second load cell (108B), and commanding, by the controller, the first EBA in response to the estimated force of the first EBA.