Flight Characteristic Calculation Correction for Vertical Wind
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for calculating airplane flight characteristics, particularly the drag coefficient, do not accurately account for vertical wind, leading to inaccurate results due to measurement biases and difficulties in obtaining precise vertical wind data during flight.
Innovation Solution
A method that corrects pitch angle and angle of attack measurements by introducing correction terms Δθ0 and Δα(Cz), ensuring the average vertical wind is zero, allowing for more accurate calculation of flight characteristics like the drag coefficient Cx by incorporating vertical wind into the aerodynamic model.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If in-flight measurements are used to calculate drag coefficient, then results closer to reality are obtained, but measurement biases and vertical wind inaccuracies reduce precision
Solution Approach 1:
The patent applies feedback by using the calculated vertical wind information to iteratively correct pitch angle and angle of attack measurements. The system continuously refines the measurements by incorporating vertical wind effects back into the calculation process, thereby improving the accuracy of drag coefficient determination while accounting for measurement biases.
Solution Approach 2:
The patent changes the parameters being measured by introducing correction terms for pitch angle (Δθ0) and angle of attack (Δα) that account for vertical wind effects. Instead of directly measuring vertical wind with imprecise instruments, the method transforms the problem by adjusting other measurable parameters (pitch angle and angle of attack) to compensate for vertical wind inaccuracies.
2Device complexity
If vertical wind is not taken into account, then calculation simplicity is maintained, but accuracy of flight characteristic results deteriorates
Solution Approach 1:
The patent introduces correction terms (Δθ0 for pitch angle and Δα for angle of attack) as intermediaries that indirectly account for vertical wind effects. Rather than directly incorporating complex vertical wind measurements into the drag coefficient calculation, these intermediary correction parameters simplify the implementation while maintaining accuracy by bridging the gap between simple measurements and accurate results.
3Measurement precision
If measurement correction terms are introduced, then accuracy of flight characteristics is improved, but complexity of calculation process increases
Solution Approach 1:
The patent applies preliminary action by calculating correction terms (Δθ0 and Δα) before performing the final drag coefficient calculation. By pre-computing these correction parameters based on available measurements and then applying them to adjust pitch angle and angle of attack, the method simplifies the overall process structure while maintaining high precision in the final results.
Data Source
AI summary
Disclosed is a method of correcting at least one result of calculating at least one flight characteristic of an airplane, based on in-flight measurements and on values calculated from the measurements, the in-flight measurements being taken in at least one determined flight condition defining a determined flight point, each flight condition being defined by particular flight parameter values, the measurements and values being in particular: θmeasure the measured pitch angle of the airplane and αmodel the angle of attack calculated by solving a lift equation and an aerodynamic model associating the angle of attack α of the airplane with at least one flight parameter, which is the lift coefficient Cz of the airplane. The pitch angle measurements θmeasure are corrected by a pitch angle correction term Δθ0 that is a particular constant for each flight, and the calculated angles of attack αmodel are corrected by an angle of attack correction term Δα(Cz . . . ).