Rotorcraft Lateral Shuffle Filter for Tail Section Vibration
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Solution Overview
Problem
Rotorcraft experience significant mechanical vibrations due to airflow interactions, particularly in the tail section, which affect flight stability and comfort, and existing solutions require additional structural modifications that increase weight and drag.
Innovation Solution
A fly-by-wire flight control system employs a bandpass or notch filter to attenuate lateral vibrations by processing sensor feedback signals from inertial sensors, using a discrete-time filter with specific transfer function coefficients to suppress vibrations without adding extra stability structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If additional structural modifications are added to reduce vibrations, then vibration reduction is improved, but weight and drag increase
Solution Approach 1:
The patent replaces mechanical vibration reduction structures with an electronic control system. A sensor detects lateral vibrations, and a controller processes this signal through filtering (bandpass or notch filter) to generate corrective commands that actuate control surfaces, actively counteracting vibrations without adding physical vibration-damping structures.
Solution Approach 2:
The patent introduces an electronic control system as an intermediary between the vibration source and the structural components. The controller receives sensor data, processes it through signal filtering, and generates actuator commands that indirectly counteract vibrations, avoiding direct mechanical intervention.
2Object-affected harmful factors
If additional structural modifications are added to reduce vibrations, then vibration reduction is improved, but aerodynamic drag increases
Solution Approach 1:
The patent substitutes mechanical vibration-reduction structures with an electronic control system that uses sensors, signal processing, and actuator commands to counteract vibrations, eliminating the need for additional aerodynamic surfaces or structural modifications that would increase drag.
Solution Approach 2:
The patent implements a feedback control loop where sensors continuously monitor lateral vibrations, the controller processes this information through filtering algorithms, and actuators apply corrective actions in real-time, creating a closed-loop system that actively suppresses vibrations without physical structural additions.
3Object-affected harmful factors
If complex filtering is applied to sensor signals, then vibration attenuation is improved, but system complexity increases
Solution Approach 1:
The patent applies targeted filtering (bandpass or notch filter) that addresses only the specific frequency ranges associated with lateral vibrations, rather than implementing comprehensive complex filtering across all frequencies. This partial action approach effectively attenuates problematic vibrations while keeping the filtering system relatively simple.
Solution Approach 2:
The patent applies frequency-specific filtering tailored to the particular vibration characteristics of the rotorcraft. The bandpass or notch filter is configured to target specific frequency bands where lateral vibrations occur, providing localized correction rather than broad-spectrum complex filtering.
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 receiving a measured yaw rate from a yaw rate sensor or a measured lateral acceleration from a lateral acceleration sensor of the rotorcraft (101), filtering the measured yaw rate or the measured lateral acceleration using a filter to form a filtered measured yaw rate or a filtered measured lateral acceleration , and regulating a yaw rate or a lateral acceleration of the rotorcraft based on the measured yaw rate or the measured lateral acceleration. The filter includes a bandpass characteristic or a notch characteristic, and the filtering is configured to reduce lateral vibrations caused by airflow in a tail section (123) of the rotorcraft (101).