Aircraft Preview Control Using Reliable Doppler Lidar Wind Data
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional aircraft control systems face challenges in accurately responding to turbulence due to delays and measurement errors in airflow vectors, leading to potential vibrations or increased accelerations, especially when using Doppler lidar for automatic control.
Innovation Solution
An automatic control system that measures wind speed differences using Doppler lidar, adds reliability information to measurement data, and selectively uses high-quality preview information to control aircraft surfaces, reducing the impact of measurement errors through spectral integration and control gain adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If automatic control is performed using Doppler lidar measurement values, then response speed to turbulence is improved, but measurement errors cause control accuracy to deteriorate
Solution Approach 1:
The patent implements feedback control by comparing the actual aircraft acceleration with the expected acceleration from turbulence, and adjusting the control surface commands accordingly. This feedback mechanism corrects errors introduced by Doppler lidar measurement uncertainties, maintaining control accuracy while preserving fast response capabilities.
Solution Approach 2:
The system performs preliminary action by using Doppler lidar to measure airflow vectors in advance of turbulence encounter, allowing the control system to prepare corrective commands before the aircraft actually enters the turbulent region. This advance preparation enables faster response while the measurement errors are compensated through subsequent feedback correction.
2Reliability
If feedback control is used to reduce aircraft acceleration, then control reliability is improved, but response delay increases due to inertial forces
Solution Approach 1:
The system performs preliminary action by using Doppler lidar to measure airflow vectors in advance of turbulence encounter, allowing the control system to prepare corrective commands before the aircraft actually enters the turbulent region. This advance preparation enables faster response while the measurement errors are compensated through subsequent feedback correction.
Solution Approach 2:
The patent maintains continuous useful action by combining preview control based on Doppler lidar measurements with continuous feedback control. The preview control provides continuous anticipatory commands while feedback control continuously corrects them, ensuring uninterrupted effective control action throughout the turbulence encounter.
3Force
If airflow vector measurement is used for preview control, then vertical acceleration reduction is achieved, but measurement errors may expand acceleration instead of reducing it
Solution Approach 1:
The patent implements feedback control by comparing the actual aircraft acceleration with the expected acceleration from turbulence, and adjusting the control surface commands accordingly. This feedback mechanism corrects errors introduced by Doppler lidar measurement uncertainties, maintaining control accuracy while preserving fast response capabilities.
Solution Approach 2:
The system applies beforehand cushioning by designing the control algorithm to account for potential measurement errors in the Doppler lidar data. The control commands are calculated with built-in error margins and validated against safety thresholds before execution, preventing erroneous commands from expanding acceleration.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system effectively reduces aircraft acceleration and load by improving control accuracy and reliability, even with slight measurement errors, thereby enhancing operational safety during turbulence encounters.
Implementation Method 1
a measurement unit 10 that measures, as preview information, a difference between a wind speed actually received by an aircraft and a wind speed to be encountered in future
Implementation Method 2
The measurement unit 10 emits laser light in a pulse form in two directions in the atmosphere, receives scattered light thereof, and measures an axial wind speed
Data Source
AI summary
An automatic control system of an aircraft according to an embodiment of the present invention includes: a measurement unit that measures, as preview information, a difference between a wind speed actually received by an aircraft and a wind speed to be encountered in future, adds information for identifying an estimation error or validity/invalidity of a measured value to measurement information, and outputs the resultant information; a control surface that controls lift, drag, or an attitude of the aircraft, or an apparatus that controls thrust; and a control arithmetic unit that calculates an angle of the control surface or the thrust to reduce an action of the wind speed exerted on an aircraft, on the basis of a wind speed value in a planned flight direction of the aircraft, the wind speed value being measured by the measurement unit.