Monolithic Moving Window for Aircraft Optical Sensors

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Solution Overview

Problem

Conventional multi-pane windows in aerospace applications suffer from reduced resolution due to optical path differences, limited field of regard, and aerodynamic inefficiencies, particularly exacerbated by near-field air flow turbulence and varying window angles of attack.

Innovation Solution

A single, monolithic moving window is translated to follow the optical sensor's field of regard, with a positioning mechanism that includes a statically-indeterminate linkage and counterweight to maintain a constant window angle, minimizing turbulence and ensuring alignment with the sensor's field of view.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If multi-pane conformal windows are used to cover large aperture optics, then the field of regard is increased, but optical resolution is reduced due to optical path differences between panes

Engineering Contradiction:
Improvefield of regardVSAvoidoptical resolution
Core Design Contradiction:
Area of stationary objectVSMeasurement precision

Solution Approach 1:

The window system is divided into multiple individually adjustable panes, each capable of independent positioning. This allows each pane to be optimized for its specific optical path, eliminating the resolution degradation that occurs when a single large pane must cover the entire field of regard.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The window panes are made dynamically adjustable through motorized positioning mechanisms. Each pane can be independently positioned to maintain optimal optical alignment as the sensor scans across different fields of regard, thereby preserving resolution while expanding the usable field.

Inventive Principle:
Principle #15Dynamics

2Device complexity

If fixed window panes are mounted to a rotating cover, then the structure is simplified, but near field air flow turbulence increases due to varying angles of attack

Engineering Contradiction:
Improvestructural complexityVSAvoidair flow turbulence
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The window panes are dynamically repositioned to maintain a constant angle of attack relative to the airflow, regardless of the cover's rotational position. This dynamic adjustment eliminates the turbulence caused by varying angles while keeping the overall structure relatively simple.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The angle of attack parameter of the window panes is actively controlled to remain constant during rotation. By changing the positional parameters of the panes in response to cover rotation, the harmful airflow turbulence is eliminated without requiring a completely different structural design.

Inventive Principle:
Principle #35Parameter changes

3Area of stationary object

If large window panes are manufactured to maximize field of regard, then manufacturing complexity increases, but resolution losses due to vignetting occur

Engineering Contradiction:
Improvefield of regardVSAvoidoptical quality
Core Design Contradiction:
Area of stationary objectVSManufacturing precision

Solution Approach 1:

Instead of manufacturing one or two extremely large panes that are difficult to produce with high optical precision, the system segments the window into multiple smaller panes. Each smaller pane can be manufactured with standard optical precision, and their collective arrangement provides the necessary field of regard without sacrificing image quality.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3191802B1Moving conformal window for large aperture optics on aircraft mounted pods
Publication Date: 2018.11.07 RAYTHEON CO
  • EP3191802B1 patent drawingFigure 1A
  • EP3191802B1 patent drawingFigure 1B
  • EP3191802B1 patent drawingFigure 2

AI summary

A single monotlithic moving window may follow the free aperture of an optical sensor contained in a housing over a reasonable field of regard by translating the window with respect to the sensor and/or a pod cover. Because the window angle of attack is unvarying, near field turbulence is minimized over the envelope of operation.