Vehicle Camera Lens Foreign Matter Detection

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Solution Overview

Problem

Existing three-dimensional object detection systems for vehicles often misidentify foreign matter on the camera lens as other vehicles, leading to errant detection and reduced precision in identifying vehicles in adjacent lanes.

Innovation Solution

The system detects foreign matter on the camera lens by analyzing changes in luminance values and differential waveform information over time, and adjusts processing to prevent misidentification of foreign matter as vehicles, thereby enhancing the accuracy of vehicle detection in adjacent lanes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the system detects objects in adjacent lanes using image capturing, then vehicle detection capability is improved, but foreign matter on the lens is errantly detected as vehicles

Engineering Contradiction:
Improvevehicle detection precisionVSAvoiddetection reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The system performs preliminary detection of foreign matter on the lens before conducting vehicle detection. By analyzing luminance value changes and differential waveforms in advance, the system identifies foreign matter presence and prevents it from causing errant vehicle detections, thus resolving the contradiction between detection capability and reliability

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system introduces an intermediary evaluation mechanism that analyzes luminance changes and differential waveforms as a mediator between the image capturing system and the vehicle detection system. This intermediary layer filters out false detections caused by foreign matter while preserving genuine vehicle detection capabilities

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the system suppresses assessment of detected three-dimensional objects as vehicles when foreign matter is detected, then errant detection is prevented, but detection of actual vehicles may be reduced

Engineering Contradiction:
Improvedetection reliabilityVSAvoidvehicle detection efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system applies local quality control by suppressing vehicle assessment only in specific regions where foreign matter is detected, rather than globally suppressing all detections. This localized approach maintains detection reliability in affected areas while preserving vehicle detection efficiency in unaffected areas

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system implements partial suppression of vehicle assessment when foreign matter is detected, rather than complete suppression. This partial action approach prevents errant detections caused by foreign matter while maintaining detection of actual vehicles, balancing reliability and productivity

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP2879382B1Three-dimensional object detection device and foreign object detection device
Publication Date: 2021.10.13 NISSAN MOTOR CO LTD
  • EP2879382B1 patent drawingFigure 1
  • EP2879382B1 patent drawingFigure 2
  • EP2879382B1 patent drawingFigure 3

AI summary

The present invention is provided with a camera (10) for capturing images rearward of a vehicle, three-dimensional object detection units (33, 37) for detecting three-dimensional objects based on image information, a three-dimensional object assessment unit (34) for assessing whether or not a detected three-dimensional object is another vehicle (VX), a foreign matter detection unit (38) for detecting whether or not foreign matter has adhered to a lens based on the change over time in luminance values for each predetermined pixel of the image capturing element and the change over time in the difference between an evaluation value and a reference value, and a controller (39) for outputting control commands to the other means to suppress the assessment of foreign matter as another vehicle (VX) when foreign matter has been detected.