Star Sensor Test Bench Using Collimated Sky Projection

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Solution Overview

Problem

Existing test benches for star trackers require disassembly and are complex and costly, with the introduction of optical units risking damage and contamination.

Innovation Solution

A test bench with a protective baffle, collimator, and a digital screen that projects a collimated image of the sky onto the star tracker's sensitive surface, allowing for non-invasive testing without disassembly, using a removable cover and reflective surface for illumination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If an optical unit with micro-display is introduced into the star tracker, then testing capability is improved, but device complexity and cost increase

Engineering Contradiction:

Improvetesting capabilityVSAvoiddevice complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The optical unit is extracted from the star tracker interior and placed externally. The test bench projects stellar images through the protective baffle opening without requiring internal components like micro-displays, thereby reducing device complexity while maintaining testing capability

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

A projection system serves as an intermediary between the test environment and the star tracker sensor. Instead of placing complex optical units inside the star tracker, the system projects test images externally through the protective baffle, achieving testing capability without increasing internal device complexity

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If an optical unit is introduced into the star tracker, then testing capability is improved, but risk of damage and contamination increases

Engineering Contradiction:

Improvetesting capabilityVSAvoidrisk of damage and contamination

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The optical testing unit is extracted from the star tracker interior and positioned externally. The protective baffle serves as the interface, allowing light transmission while physically isolating the sensor from external contaminants and handling risks

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The protective baffle acts as a pre-established barrier that cushions the sensor against potential damage and contamination. By projecting images through the baffle opening rather than introducing optical units into the sensor environment, the system maintains testing capability while protecting against harmful factors

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Ease of operation

If the star tracker is disassembled for testing, then testing accessibility is improved, but reliability and risk of damage increase

Engineering Contradiction:

Improvetesting accessibilityVSAvoidrisk of damage

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The testing operation is extracted from the disassembly process. The projection system tests the star tracker through the intact protective baffle, providing testing accessibility without requiring disassembly and thereby maintaining system reliability

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The protective baffle serves as an intermediary that enables testing accessibility while maintaining system integrity. The projection system interfaces with the sensor through the baffle opening, allowing tests to be performed on the assembled unit without disassembly

Inventive Principle:

Principle #24Intermediary (Mediator)

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

Enables cost-effective, less complex testing of star trackers in situ, reducing the risk of damage and contamination, and providing flexible, non-invasive adaptation.

Implementation Method 1

a collimator mounted on one end of the protective baffle, a screen capable of displaying a scrolling portion of the sky, the screen being arranged at a distance of focus from the collimator so as to project towards a sensitive surface from the stellar sensor a collimated image of the scrolling portion of the sky

Methodology Applied

Scientific EffectCollimation: Lens

Implementation Method 2

the surface of the screen is reflective, and the bench further comprises a light projector oriented towards the surface of the screen, allowing projection of an image towards the sensitive surface of the star tracker by reflection on the surface of the screen

Methodology Applied

Scientific EffectReflection: Reflection

Data Source

PatentEP2813434B1Test bench for star sensor, and test method

Publication Date: 2016.05.18 CENT NAT DETUD SPATIALES (CNES)

Figure 1~2
Figure 3

AI summary

The invention relates to a test bench (1) for a stellar sensor, characterized in that it comprises: - a stellar sensor (2) comprising a protective baffle (3), - a collimator (7) mounted on one end of the protective baffle (3), - a screen (5) capable of displaying a moving portion of the sky, the screen (5) being disposed at the focal distance of the collimator (7), so as to project a collimated image of the moving portion of the sky onto a sensitive surface (15) of the stellar sensor (2).