Elliptical Contour Target Detection for Space Rendezvous

Solution Overview

Problem

Existing target detection and tracking algorithms for air or space rendezvous require complex three-dimensional models, leading to high calculation times and limited adaptability to different types of targets, making real-time detection and tracking challenging, especially in space rendezvous scenarios.

Innovation Solution

A method that calculates intensity gradients for pixels within an area of interest around an elliptical contour, selects tangent lines, and uses a least squares algorithm to estimate the elliptical contour parameters, allowing for real-time detection and tracking without relying on complex three-dimensional models, and is adaptable to various targets with quadratic surfaces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If three-dimensional model-based algorithms are used for target detection and tracking, then measurement precision is improved, but calculation time increases significantly

Engineering Contradiction:

Improvetarget pose estimation accuracyVSAvoidcalculation time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent extracts only the essential elliptical contour information from the target image, separating the detection task from the complex three-dimensional model processing. By focusing solely on the elliptical parameters (center, axes, orientation) extracted from image data, the system achieves accurate target pose estimation without the computational burden of loading and manipulating complete three-dimensional models, thus resolving the contradiction between precision and calculation time.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent creates a simplified two-dimensional elliptical representation of the target from image data, serving as a computational copy that captures the essential geometric information. This elliptical contour model replaces the complex three-dimensional model in the calculation process, maintaining measurement precision for pose estimation while dramatically reducing calculation time through simpler mathematical operations.

Inventive Principle:

Principle #26Copying

2Measurement precision

If three-dimensional model-based algorithms are used for target detection and tracking, then measurement precision is improved, but device complexity increases

Engineering Contradiction:

Improvetarget pose estimation accuracyVSAvoidalgorithm complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts only the essential elliptical contour information from the target image, separating the detection task from the complex three-dimensional model processing. By focusing solely on the elliptical parameters (center, axes, orientation) extracted from image data, the system achieves accurate target pose estimation without the computational burden of loading and manipulating complete three-dimensional models, thus resolving the contradiction between precision and calculation time.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent creates a simplified two-dimensional elliptical representation of the target from image data, serving as a computational copy that captures the essential geometric information. This elliptical contour model replaces the complex three-dimensional model in the calculation process, maintaining measurement precision for pose estimation while dramatically reducing calculation time through simpler mathematical operations.

Inventive Principle:

Principle #26Copying

3Measurement precision

If three-dimensional model-based algorithms are used for target detection and tracking, then measurement precision is improved, but adaptability to different target types decreases

Engineering Contradiction:

Improvetarget pose estimation accuracyVSAvoidadaptability to different target types

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent develops a universal detection algorithm based on the common elliptical contour feature shared by multiple target types (satellites, space stations, cylindrical objects). By extracting elliptical parameters from images and using these to estimate pose, the same algorithm can accurately track different target types without requiring separate three-dimensional models for each, thus achieving both precision and broad adaptability simultaneously.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentEP3776471B1Method for locating a target from an elliptical contour

Publication Date: 2024.08.21 AIRBUS DEFENCE & SPACE SAS

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AI summary

The invention proposes a method for locating a target (C) with respect to a vehicle (V), the target comprising at least one three-dimensional external component (Cs) having a quadratic surface, the method being implemented by a computer (21, 31) and comprising: - acquiring an image of the target comprising a zone of interest in which the external component of the target is visible in the form of an elliptical contour, - for each of a plurality of pixels of the zone of interest of the image, calculating an intensity gradient of the image around the pixel, and determining, from the intensity gradient, parameters of a straight line having a direction normal to the gradient of the pixel, - selecting, among the set of determined straight lines, a set of straight lines tangential to the elliptical contour, and - estimating the parameters of the elliptical contour in the image from the parameters of the tangents to the elliptical contour.