Secondary Mirror Positioning Mechanism for Active Six-DOF Adjustment

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Solution Overview

Problem

Existing telescope systems, particularly those in orbit, face challenges with manual adjustment of secondary mirrors due to time-consuming trial and error methods, risk of damage from handling, and misalignment from vibrations and temperature changes, necessitating a system for active adjustment in six degrees of freedom that can sustain launch loads without additional constraints.

Innovation Solution

An apparatus featuring a linear motion actuator, lever arm, and flexure mechanism that allows for unconstrained motion of struts, enabling active adjustment of secondary mirrors in six degrees of freedom, with a U joint flexure and optional launch lock to manage load during launch, and incorporating a position sensor like an LVDT for precise displacement measurement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If manual adjustment of secondary mirror is used, then the system structure is simple, but the adjustment process is time-consuming and requires repeated trial and error

Engineering Contradiction:
Improvesystem structureVSAvoidadjustment process time
Core Design Contradiction:
Device complexityVSLoss of time

Solution Approach 1:

The patent replaces manual mechanical adjustment with an automated motorized positioning system. The secondary mirror is mounted on a motorized platform that can be remotely controlled to adjust the mirror's position, eliminating the need for manual trial-and-error adjustment and significantly reducing adjustment time while maintaining relatively simple system structure.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Ease of operation

If manual adjustment is performed with accessible housing, then adjustment is possible, but the optical system is exposed to contamination from fingerprints and dropped objects

Engineering Contradiction:
Improveadjustment accessibilityVSAvoidoptical contamination
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a remote control mechanism as an intermediary between the operator and the secondary mirror adjustment system. The motorized platform allows adjustment to be commanded from outside the telescope tube, so the housing can remain closed during adjustment, preventing fingerprints and contaminants from reaching the optical system while still enabling full adjustment capability.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Object-affected harmful factors

If the telescope system is closed during adjustment, then optical protection is improved, but manual adjustment becomes impossible requiring system opening

Engineering Contradiction:
Improveoptical protectionVSAvoidadjustment capability
Core Design Contradiction:
Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The patent replaces manual mechanical adjustment (which requires opening the housing) with an automated motorized positioning system that can operate remotely. This allows the telescope housing to remain closed during adjustment, protecting the optical system while maintaining full adjustment capability through electronic control of the motorized platform.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Ease of operation

If secondary mirror is adjusted manually before launch, then initial positioning is possible, but vibrations and temperature changes during launch cause misalignment

Engineering Contradiction:
Improvepre-launch positioningVSAvoidalignment stability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent implements a dynamic adjustment system with motors and sensors that can actively adjust the secondary mirror position in response to changing conditions. Rather than relying on static pre-launch positioning, the system can compensate for vibrations and temperature changes during launch and operation, maintaining alignment stability throughout the mission lifecycle.

Inventive Principle:
Principle #15Dynamics

5Manufacturing precision

If active adjustment system is implemented for secondary mirror, then alignment precision is improved, but device complexity increases

Engineering Contradiction:
Improvealignment precisionVSAvoidadjustment system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent employs a motorized platform that was originally designed for positioning primary mirrors in photometers. By adapting this existing multi-functional positioning mechanism for secondary mirror adjustment, the system achieves high alignment precision without proportionally increasing complexity, as the same type of motorized control can serve multiple mirror adjustment functions.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 precise, remote, and automated adjustment of secondary mirrors in orbit, reducing the risk of damage and misalignment, while sustaining loads during launch and allowing for ground-based setup and testing.

Implementation Method 1

a linear motion actuator located substantially parallel to the strut

Methodology Applied
Scientific EffectLinear motion actuator: Linear Motor

Implementation Method 2

a flexure operatively attached to the lever arm component at an edge of the lever arm component closest to the strut; the flexure being parallel to the strut and extending from the edge of the lever arm component closest to the strut to a base component

Methodology Applied
Scientific EffectFlexure: Elasticity

Implementation Method 3

incorporating a position sensor like an LVDT for precise displacement measurement

Methodology Applied
Scientific EffectLVDT (Linear Variable Differential Transformer): Electromagnetic Induction

Data Source

PatentEP3221733B1Secondary mirror positioning mechanism
Publication Date: 2018.10.24 RAYTHEON CO
  • EP3221733B1 patent drawingFigure 1
  • EP3221733B1 patent drawingFigure 2
  • EP3221733B1 patent drawingFigure 3a~3b

AI summary

Systems that provide an active adjustment of mirrors and specifically of secondary mirrors, and that provide active adjustment of secondary mirrors in six degrees of freedom, and that can carry the additional load during launch.