Optical Marker Navigation for Low-Power Satellite Docking

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Solution Overview

Problem

Existing satellite navigation systems for docking in space are complex, power-intensive, and costly due to high power consumption and the need for advanced image processing, making them unsuitable for small satellites.

Innovation Solution

A navigation system that uses an optical marker attached to the target satellite, a lighting device emitting a specific wavelength band of light (300-400 nm) absorbed by the satellite's heat insulation film, and an image acquisition device with an optical filter to estimate the satellite's attitude, simplifying the system and reducing power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If laser light irradiation is used to estimate target satellite attitude, then attitude estimation capability is achieved, but power consumption increases significantly

Engineering Contradiction:
Improveattitude estimation capabilityVSAvoidpower consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent replaces the Flash Lidar system (which uses laser light and complex photodetector arrays) with a simpler optical imaging system using visible light illumination and standard image sensors. This substitution eliminates the need for high-power laser sources while maintaining attitude estimation capability through optical marker detection.

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

Solution Approach 2:

The patent uses inexpensive optical markers attached to the target satellite instead of complex active transponders or laser reflectors. These passive markers are simple, low-cost components that can be easily manufactured and deployed, significantly reducing the power requirements of the illumination system.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Measurement precision

If two-dimensional array photodetector is used to detect reflected light, then attitude estimation is achieved, but data volume increases and special processing systems are required

Engineering Contradiction:
Improveattitude estimation capabilityVSAvoidprocessing system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex photodetector arrays with standard image sensors (cameras) that capture two-dimensional images of optical markers. The image data from these sensors can be processed using conventional computer vision algorithms, eliminating the need for specialized FPGA processing systems while maintaining attitude estimation accuracy.

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

Solution Approach 2:

The patent uses optical markers that create visual copies or representations of the target satellite's orientation and position. By attaching patterned markers to the satellite surface, the system creates easily detectable visual features that can be captured by standard cameras and processed through image recognition algorithms to determine attitude.

Inventive Principle:
Principle #26Copying

3Measurement precision

If advanced image processing techniques are used to increase attitude estimation accuracy, then measurement precision improves, but system complexity and manufacturing effort increase

Engineering Contradiction:
Improveattitude estimation accuracyVSAvoidsystem design effort
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent pre-defines the geometric relationships and coordinate transformations between the optical markers attached to the satellite and the satellite's body frame. By establishing these transformation models in advance during the marker attachment phase, the system eliminates the need for complex real-time feature extraction and model building, allowing standard image processing algorithms to achieve high accuracy.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent employs optical markers with distinct visual patterns, colors, or reflectivity characteristics that make them easily distinguishable from the satellite background. These high-contrast markers can be detected and tracked using simple image processing techniques, achieving high attitude estimation accuracy without requiring complex algorithms for feature extraction in varying lighting conditions.

Inventive Principle:
Principle #32Color changes

4Measurement precision

If complex navigation systems are adopted for safe approach and docking, then navigation accuracy improves, but device size increases making it difficult to load on small satellites

Engineering Contradiction:
Improvenavigation accuracyVSAvoiddevice size
Core Design Contradiction:
Measurement precisionVSVolume of moving object

Solution Approach 1:

The patent replaces complex navigation systems (Flash Lidar with array photodetectors and FPGA processing) with a compact optical imaging system using standard cameras and conventional image processing. This substitution dramatically reduces the volume and mass of the navigation system while maintaining the capability to achieve safe approach and docking through accurate attitude estimation.

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

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

This configuration simplifies and downsizes the navigation system, reduces power consumption, and lowers development costs, enabling efficient attitude estimation and docking operations on small satellites.

Implementation Method 1

an optical marker 10 that is attached to the target object and reflects light

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

an optical lens provided with an optical filter which transmits the light of the predetermined wavelength band

Methodology Applied
Scientific EffectOptical filtering: Filter (optical)

Implementation Method 3

the light of the predetermined wavelength band is absorbed by a heat insulation film which forms a surface of the target object

Methodology Applied
Scientific EffectLight absorption: Absorption (EM radiation)

Data Source

PatentEP3404360B1Navigation system, aerospace vehicle and optical marker
Publication Date: 2022.04.27 ASTROSCALE JAPAN
  • EP3404360B1 patent drawingFigure 1
  • EP3404360B1 patent drawingFigure 2

AI summary

Simplify, downsize and reduce power of devices which comprise the satellite navigation system used in approach and docking in space. The navigation system 1 which estimates an attitude of a target object T in space comprises: an optical marker 10 that is attached to the target T and reflects light; a lighting device 20 that irradiates the target object T with light of a predetermined wavelength band; an image acquisition device 30 that acquires an image of the optical marker 10 which has reflected the light of the predetermined wavelength band; and an image processing device 40 that processes the image acquired by the image acquisition device 30 and thereby estimates the attitude of the target object T. The lighting device 20 and the image processing device 30 are loaded on an aerospace vehicle 2.