Electronic Rudder Bias System for Twin-Engine Aircraft
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Solution Overview
Problem
Mechanical rudder bias systems in twin engine aircraft are always active, leading to undesired rudder deflection and weight addition, and require pilot input force measurement for proportional boost, making them difficult to accurately operate and inefficient.
Innovation Solution
An electronic rudder bias system that calculates thrust estimates based on primary and secondary signals, generates an engage command based on thrust differential, and provides torque assistance independent of pilot input, ensuring system robustness and accuracy without pilot force measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a mechanical rudder bias system is implemented to counteract engine failure, then the system provides rudder bias during engine failure, but the system is always active and adds undesired weight to the aircraft
Solution Approach 1:
The patent replaces the mechanical pneumatic rudder bias system with an electronic system that uses sensors, processors, and actuators to detect engine failure conditions and apply rudder bias electronically, eliminating the need for continuous mechanical pneumatic pressure systems and reducing aircraft weight
Solution Approach 2:
The electronic system automatically detects engine failure conditions through sensor inputs and autonomously applies rudder bias without requiring pilot activation, while remaining inactive during normal operation to avoid adding weight and complexity
2Reliability
If a mechanical rudder bias system is implemented, then the system provides rudder bias during engine failure, but the system is difficult to operate accurately and requires pilot input force measurement
Solution Approach 1:
The electronic system incorporates sensors that continuously monitor engine parameters and provide feedback to a processor, which automatically adjusts the rudder bias actuator to provide accurate and consistent bias force during engine failure without requiring pilot input force measurement
Solution Approach 2:
The patent replaces the mechanical system requiring pilot input force measurement with an electronic sensing and control system that automatically detects engine failure conditions and applies precise electronic control to achieve accurate rudder bias
3Ease of operation
If a rudder boost system measures pilot input force to provide proportional boost, then the system provides proportional assistance, but the system requires complex measurement and control mechanisms
Solution Approach 1:
The patent extracts the force measurement requirement from the system by using electronic sensors to directly detect engine failure conditions and calculate the required rudder bias mathematically, eliminating the need for mechanical pilot input force measurement devices and complex control mechanisms
Data Source
AI summary
A rudder bias system for an aircraft with a right engine and a left engine includes a component determining a left and right primary and secondary thrust estimates. The system includes a left engine thrust estimate selector determining a left selected estimate based on the left thrust estimates and a right engine thrust estimate selector determining a right selected estimate based on the right thrust estimates. The system includes an enable and mode component determining one or more corresponding validities for the thrust estimates. The system includes a control component generating an engage command based on a thrust differential between the right engine and the left engine, calculated from the left selected estimate and the right selected estimate and a torque command based on an equivalent pedal force assistance calculated as a difference between the thrust differential and an activation threshold.