Aircraft Yaw Damping Using Roll Control Surfaces
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing yaw damping systems for aircraft are susceptible to failure when yaw control surfaces are jammed or inoperable, and they do not provide effective independent damping of the dutch roll mode without reducing the stability of other damping mechanisms.
Innovation Solution
A method using roll control surfaces, such as ailerons or spoilers, to measure and actuate damping signals proportional to aircraft motion parameters like lateral acceleration, sideslip angle, and yaw rate, with the application of proportional, integral, and derivative gains, and washout filters to remove long-term effects, allowing independent damping of the dutch roll mode without interfering with classical yaw dampers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a classical yaw damper is used to dampen the dutch roll mode, then the dutch roll mode is effectively dampened, but the system becomes susceptible to failure when yaw control surfaces are jammed or inoperable
Solution Approach 1:
The yaw damping function is segmented into two independent systems: the classical yaw damper using yaw control surfaces and the alternative yaw damper using roll control surfaces. This segmentation ensures that failure of one system does not prevent yaw damping functionality, as the alternative system can operate independently when the classical system fails.
Solution Approach 2:
The invention changes the control parameter from yaw rate feedback to roll rate feedback. By measuring roll rate instead of yaw rate and applying feedback through roll control surfaces, the system achieves yaw damping without depending on yaw control surface operability, thus resolving the reliability issue.
2Reliability
If an alternative yaw damper using roll control surfaces is implemented, then redundancy is provided, but it may interfere with the stability of classical yaw dampers
Solution Approach 1:
The alternative yaw damper implements feedback control by measuring roll rate and applying corrective feedback through roll control surfaces. The feedback signal is processed through proportional, integral, and derivative gains to generate appropriate control commands that dampen dutch roll oscillations while maintaining stability.
Solution Approach 2:
The system applies periodic damping actions synchronized with the dutch roll oscillation frequency. By detecting the oscillatory nature of dutch roll and applying counteracting control inputs at the appropriate phase, the system effectively dampens the oscillations without causing instability or interference with classical yaw damper operation.
3Reliability
If proportional, integral, and derivative gains are applied to damping signals, then effective damping of dutch roll mode is achieved, but the system complexity increases
Solution Approach 1:
The invention replaces complex mechanical yaw damping mechanisms with an electrically-operated system using roll control surfaces. By substituting mechanical yaw surface actuation with electrical control of roll surfaces, the system achieves comparable damping effectiveness while reducing mechanical complexity and improving reliability.
Solution Approach 2:
The system changes the control approach by applying proportional, integral, and derivative gains to roll rate signals rather than yaw rate signals. This parameter transformation allows the use of existing roll control surfaces for yaw damping purposes, achieving effective dutch roll damping through signal processing rather than complex mechanical modifications.
Data Source
AI summary
An alternative system for damping the dutch roll mode in an aircraft is provided using roll control surfaces. Classical yaw dampers for the dutch roll mode utilize the yaw control surfaces such as a rudder to dampen the dutch roll mode oscillations. An alternative damper is described that utilizes roll control surfaces such as spoilers or ailerons to dampen the dutch roll mode.