Rotorcraft Speed Control Stabilization During High Acceleration
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Solution Overview
Problem
Fly-by-wire systems for rotorcraft face challenges in maintaining control during sudden changes in acceleration caused by wind gusts or pilot control settings, leading to instability or speed errors due to high or low loop gains in the speed control loop.
Innovation Solution
A method and system that temporarily disables the speed control mode upon detecting high longitudinal acceleration, stabilizes the rotorcraft, and reenables the speed control mode when the acceleration falls below a specified threshold, using a flight control system with flight control computers and sensors to adjust pitch attitude and power output.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the speed control loop uses high loop gains to maintain accurate speed control, then speed control precision is improved, but the system becomes unstable during sudden acceleration changes
Solution Approach 1:
The control system dynamically adjusts the loop gain based on flight conditions. During sudden acceleration changes, the system reduces the loop gain to maintain stability, while under normal conditions it uses higher loop gains for precise speed control. This dynamic adaptation resolves the contradiction between precision and stability.
Solution Approach 2:
The system changes the control parameter (loop gain) based on the acceleration condition. When high acceleration is detected, the loop gain is reduced; when acceleration is normal, the loop gain is increased. This parameter change allows the system to optimize both precision and stability under different operating conditions.
2Stability of the object's composition
If the speed control loop uses low loop gains to maintain stability during acceleration changes, then system stability is improved, but speed control errors increase
Solution Approach 1:
The system dynamically adjusts the loop gain based on flight conditions. During sudden acceleration changes, the system reduces the loop gain to maintain stability, while under normal conditions it uses higher loop gains for precise speed control. This dynamic adaptation resolves the contradiction between precision and stability.
Solution Approach 2:
The system changes the control parameter (loop gain) based on the acceleration condition. When high acceleration is detected, the loop gain is reduced; when acceleration is normal, the loop gain is increased. This parameter change allows the system to optimize both precision and stability under different operating conditions.
3Ease of operation
If fly-by-wire systems are implemented in rotorcraft to provide automated stabilization and control, then pilot workload is reduced and safety is improved, but the complexity of controlling and stabilizing the rotorcraft increases
Solution Approach 1:
The system extracts and handles the complex stabilization and control tasks automatically through the fly-by-wire system, freeing the pilot from manual stabilization efforts. The complex control algorithms are embedded in the flight control computer, reducing pilot workload while managing the inherent system complexity through automation.
Data Source
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AI summary
In accordance with an embodiment of the present invention, a method of operating a rotorcraft (101) includes operating the rotorcraft (101) in a speed control mode, where a speed of the rotorcraft (101) is proportional to a pilot control command; detecting a high longitudinal acceleration condition; upon detection of the high longitudinal acceleration condition, temporarily disabling the speed control mode and stabilizing the rotorcraft (101) while the speed control mode is disabled; and reestablishing the speed control mode when a measured longitudinal acceleration of the rotorcraft (101) falls below a first threshold.