Vehicle Stereocamera Correction With Telescope-Generated Virtual Images

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Solution Overview

Problem

Existing stereocamera systems face challenges in accurately correcting for optical distortions and positional shifts due to vehicle-mounted installations, which cause measurement errors, and existing solutions are costly, bulky, or require high installation accuracy.

Innovation Solution

A method using a first optical device with a first chart and a mirror surface to generate a virtual image, employing a reflecting or catadioptric telescope to correct stereocamera parameters, allowing for high-accuracy correction at low cost and reduced installation requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a collimator with large diameter is used to generate optical path equivalent to infinity position, then measurement precision is improved, but device complexity and cost increase

Engineering Contradiction:
Improvestereocamera correction accuracyVSAvoidoptical device complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent uses a reflecting telescope or catadioptric telescope to create an optical path that copies the effect of having a chart at infinity position. The telescope generates a virtual image of the chart placed at a finite distance, making it optically equivalent to a chart at infinity, thereby achieving high measurement precision without requiring a large-diameter collimator

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent replaces the mechanical collimator system with an optical telescope system. Instead of using a large-diameter collimator to create parallel light rays, the invention uses a reflecting or catadioptric telescope to generate the same optical effect with a more compact and cost-effective design

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

2Manufacturing precision

If multiple charts at different distances are used for correction, then manufacturing precision requirements are relaxed, but device complexity and space requirements increase

Engineering Contradiction:
Improvechart installation accuracyVSAvoidcorrection device space
Core Design Contradiction:
Manufacturing precisionVSVolume of moving object

Solution Approach 1:

The patent uses a single chart placed at a finite distance, and the telescope creates a virtual image of this chart that appears to be at infinity. This single physical chart serves the dual purpose of both close-range and far-range calibration targets, eliminating the need for multiple charts at different distances while maintaining relaxed manufacturing precision requirements

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent transforms the spatial arrangement from multiple charts at different distances (one-dimensional arrangement) to a single chart with its virtual image created by the telescope (adding the optical dimension). This allows the system to achieve the calibration effect of multiple charts using only one physical chart

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Adaptability or versatility

If test camera is mounted on vehicle for in-situ correction, then adaptability is improved, but installation accuracy becomes difficult to achieve

Engineering Contradiction:
Improvein-situ correction capabilityVSAvoidinstallation accuracy
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent creates a virtual image of the chart through the telescope that appears at infinity position, allowing the stereocamera to be calibrated in its actual vehicle-mounted position without requiring precise installation. The virtual image provides the necessary optical reference that compensates for installation inaccuracies

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The system performs self-calibration in the actual vehicle-mounted environment using the telescope and single chart. The correction is done in-situ without requiring external calibration equipment or precise installation, allowing the system to correct its own parameters in the actual operating condition

Inventive Principle:
Principle #25Self-service

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

The method provides accurate stereocamera correction in a space-saving manner, relaxing installation accuracy and reducing costs while maintaining high precision.

Implementation Method 1

a first optical device that has a first chart having a predetermined pattern and a mirror surface having a diameter equal to or greater than a baseline length of the stereocamera generates a virtual image of the first chart

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

either a reflecting telescope or a catadioptric telescope

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP4012495B1Method for correcting stereocamera and device for correcting stereocamera
Publication Date: 2025.07.30 ASTEMO LTD
  • EP4012495B1 patent drawingFigure 1~3
  • EP4012495B1 patent drawingFigure 4~6
  • EP4012495B1 patent drawingFigure 7~9

AI summary

Provided is a method for correcting a stereocamera mounted in a vehicle. A first optical device that includes a first chart having a predetermined pattern and a mirror surface with a diameter that is larger than or equal to the baseline length of the stereocamera creates the virtual image of the first chart. The stereocamera uses images obtained by capturing the virtual image with a plurality of cameras to correct a parameter corresponding to the relative position of the images obtained by the cameras.