Aircraft Thrust Reverser Control via Analog Voltage Thresholds
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Solution Overview
Problem
Existing thrust reversal systems for aircraft, such as those in the A380 and C919, rely on complex components due to the ARINC 429 standard, which requires encoding and decoding 32-bit words as analog voltage signals, making the local control module intricate and costly.
Innovation Solution
A simplified thrust reversal system where the local control module identifies predefined value ranges for analog signals, allowing for the use of simpler components, and optionally includes analog-to-digital converters or analog circuits to process these signals, reducing complexity and cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the ARINC 429 standard is used for digital bus communication, then reliable command transmission is achieved, but the local control module becomes complex and costly
Solution Approach 1:
The patent extracts the complex encoding/decoding functionality from the local control module by implementing command encoding directly in the EEC module and command detection through simple voltage threshold comparison in the ETRAS module. This removes the need for complex ARINC 429 protocol handling in the local control module while maintaining reliable command transmission.
Solution Approach 2:
The patent replaces the electrical/digital ARINC 429 bus system with a simpler electrical voltage-based command transmission system. Instead of using digital encoding with twisted pair wires and sequential bit transmission, the invention uses direct voltage level comparison (e.g., comparing voltage to a reference threshold) to detect commands, substituting complex digital electronics with simpler electrical comparison circuitry.
2Reliability
If the ARINC 429 standard is used for digital bus communication, then reliable command transmission is achieved, but the system cost increases
Solution Approach 1:
The patent extracts the complex and costly ARINC 429 protocol implementation from the system by moving encoding functionality to the EEC module and using simple voltage threshold detection in the ETRAS module. This extraction eliminates the need for expensive digital bus infrastructure while maintaining reliable command transmission.
Solution Approach 2:
The patent employs simpler, less expensive electrical components (voltage dividers, reference voltage sources, and threshold comparators) to replace the expensive ARINC 429 digital bus infrastructure. These simpler components achieve the same functional goal of reliable command transmission at a lower manufacturing cost.
3Device complexity
If simple components are used in the local control module, then cost and complexity are reduced, but command detection capability may be compromised
Solution Approach 1:
The patent introduces a reference voltage (Vref) as an intermediary element that mediates between the command signal and the detection logic. By comparing the command voltage to this reference voltage, the system can reliably detect different command types (e.g., deploy, stow, release) using simple threshold comparison circuitry, maintaining detection capability while using simple components.
Solution Approach 2:
The patent uses parameter changes in voltage levels to encode different commands. By assigning specific voltage ranges to different commands (e.g., different voltage levels for deploy vs. stow commands), the simple threshold comparison circuitry can reliably detect and distinguish between different command types based on voltage parameter values, maintaining detection capability with simple components.
Data Source
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AI summary
This system (101) includes: - a thrust-reversal cowling (112) designed to be selectively moved between a retracted position for leaving unchanged the thrust of a turbine engine (102) of the aircraft (100), and a deployed position for reversing the thrust of the turbine engine (102); - an electrical actuator (114) of the cowling (112); - a local control module (120) designed to receive commands from a global control module (104) in order to control the electrical actuator (114) in such a way as to move the cowling (112), these commands including a retraction command and a deployment command; and - a connection (122) between the global control module (104) and the local control module (120) for conveying at least one analogue signal. The local control module (120) is designed to: - identify one among a plurality of predefined ranges of values, in which each analogue signal is located at a given instant, each command being associated with one or more value ranges; and - determining the received command as being that associated with the identified range or ranges of values.