Non-linear Scale Graduations for Conformal Aircraft Displays
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In aircraft display units, the three-dimensional terrain representation using OpenGL leads to stretching and distortion of terrain features at different distances from the aircraft, causing a mismatch between symbolic attitude information and the terrain image, which can compromise flight safety.
Innovation Solution
A system and method for generating non-linearly spaced graduations for symbolic linear scales that are conformal to the three-dimensional perspective of a scene outside the aircraft, using navigation reference data and a symbology generator to produce symbology data that is merged with pixel image data, ensuring accurate representation on the display unit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a linear scale with equally-spaced graduations is used for symbolic attitude information, then the scale is simple and easy to manufacture, but it creates a non-conformality and mismatch with the perspective-distorted terrain image
Solution Approach 1:
The patent transforms the graduation spacing from a linear parameter to a non-linear parameter that varies according to the perspective projection. The spacing between graduations is adjusted based on the distance from the center of the image, creating a conformal scale that matches the distorted terrain representation while maintaining mathematical precision through a defined transformation function.
2Measurement precision
If perspective projection is used to render three-dimensional terrain on a two-dimensional screen, then the terrain depth and perspective are accurately represented, but stretching and distortion of terrain features occur at different distances from the aircraft
Solution Approach 1:
Instead of trying to correct the distorted terrain image back to a non-distorted view, the patent inverts the approach by distorting the symbolic attitude scale to match the terrain distortion. The graduations are spaced non-linearly to correspond to the perspective projection, so that the scale itself conforms to the distorted background rather than attempting to restore the original geometry.
3Measurement precision
If identical objects are projected onto the near plane from different positions within the frustum, then the three-dimensional perspective is captured, but the objects appear stretched and distorted on the near plane
Solution Approach 1:
The patent applies different spacing characteristics to different regions of the scale. graduations near the center of the image are spaced differently from those near the periphery, with the spacing adjusted locally to account for the perspective distortion at each position. This creates a piecewise conformal transformation that preserves accuracy across the entire field of view.
Data Source
AI summary
Present novel and non-trivial system, module, and method for generating non-linearly spaced graduations for a symbolic linear scale are disclosed. Symbology data representative of a scale having non-linear graduations is generated as a function of a graduation reference assigned to each graduation, navigation reference data provided from an appropriate source, and a constant. Navigation reference data comprises pitch attitude data and/or aircraft heading data, from which a symbolic pitch attitude scale and/or heading scale is generated. Current attitude and/or heading may be used as a central reference from which spacing is measured, and the value of the constant is dependent on the size of the scale occupied on the screen of a display unit. Each symbolic linear scale may be merged with data representative of the scene outside the aircraft and presented on the screen along with a flight path predictor mapped to the non-linear scale.