Filtering Device for Parallax Validation in Environment Recognition

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Solution Overview

Problem

Existing collision avoidance and cruise control systems face challenges in accurately determining valid parallax values due to similar patterns in images, leading to erroneous derivations and failure to effectively exclude invalid parallax values under varying environmental conditions.

Innovation Solution

A filtering device and environment recognition system that evaluates correlations between image blocks using an evaluation value deriving module, sets an evaluation range based on the highest correlation value, and determines the validity of parallax values using a difference value determining module, which considers the ratio or area of evaluation values within this range to exclude invalid parallax values.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If pattern matching is used to calculate parallax by comparing image blocks, then relative distance information can be acquired, but erroneous parallaxes are derived when similar patterns continue horizontally in the images

Engineering Contradiction:
Improveparallax calculation accuracyVSAvoidvalidity of derived parallax
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent applies preliminary action by evaluating multiple candidate parallaxes in advance before final selection. The system calculates correlation values for multiple candidate blocks, evaluates their validity using predetermined conditions, and selects the most reliable parallax from valid candidates, thereby preventing erroneous parallaxes from being used in distance calculations.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback by using correlation values to evaluate the validity of candidate parallaxes. The system calculates correlation between reference blocks and comparison blocks, uses these correlation values to determine whether candidate parallaxes are valid based on predetermined conditions, and iteratively selects the best parallax candidate, ensuring reliable parallax derivation even in challenging imaging conditions.

Inventive Principle:
Principle #23Feedback

2Adaptability or versatility

If fixed threshold values are used to evaluate parallax validity, then the evaluation process is simple, but the system cannot adapt to varying environmental conditions such as fogging or brightness changes

Engineering Contradiction:
Improveenvironmental condition adaptationVSAvoidevaluation process complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies dynamics by making the evaluation process adaptive to varying environmental conditions. Instead of using fixed threshold values, the system dynamically evaluates candidate parallaxes based on correlation values calculated from actual image data, allowing the validity criteria to adjust automatically to different imaging conditions such as fog, brightness variations, or pattern similarities.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by using correlation values as dynamic evaluation parameters rather than fixed thresholds. The system calculates correlation values between image blocks and uses these parameter values to determine parallax validity, allowing the evaluation criteria to change based on actual image characteristics and environmental conditions, thereby improving adaptability.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If average value difference matching is used to reduce noise effects, then low-frequency noise is suppressed, but evaluation values still greatly vary under different imaging conditions

Engineering Contradiction:
Improvenoise resistanceVSAvoidevaluation value consistency
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent applies preliminary action by performing multiple evaluation steps before final parallax determination. The system first calculates correlation values, then evaluates candidate parallaxes against predetermined conditions, and finally selects valid candidates. This multi-stage preliminary evaluation ensures that noise-resistant matching is combined with adaptive validity checking, improving both reliability and measurement precision.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback by using correlation values to continuously evaluate parallax validity. The system calculates correlation between image blocks, uses these values to determine whether candidate parallaxes are valid, and adjusts selection based on this feedback. This feedback mechanism maintains noise resistance while improving evaluation value consistency across different imaging conditions.

Inventive Principle:
Principle #23Feedback

Data Source

PatentUS9524645B2Filtering device and environment recognition system
Publication Date: 2016.12.20 SUBARU CORP
  • US9524645B2 patent drawing
  • US9524645B2 patent drawing
  • US9524645B2 patent drawing

AI summary

A filtering device includes an evaluation value deriving module that derives, for a pair of images having mutual relevance, multiple evaluation values indicative of correlations between any one of blocks (reference block) that is extracted from one of the images (reference image) and multiple blocks (comparison blocks) extracted from the other image (comparison image), an evaluation range setting module that sets an evaluation range of the evaluation values, the evaluation range having one of boundaries at the evaluation value with the highest correlation among the multiple evaluation values, and a difference value determining module that determines whether the evaluation value with the highest correlation is valid as a difference value based on the multiple evaluation values and the evaluation range.