Trailer End Position Tracking From Successive Camera Images

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Solution Overview

Problem

Existing camera-based systems for monitoring rear traffic in vehicles with swiveling trailers struggle to accurately detect the trailer end edge, especially at low speeds and during reversing maneuvers, due to limitations in sensor reliability at low speeds.

Innovation Solution

A camera-based system processes reduced image data sets from a camera sensor, determining feature points based on image parameters and gradients. These feature points are used to select pawns along a predetermined direction, creating a path that describes the trailer's course, and determining the trailer end edge position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If wheel sensors are used to track the trailer end edge, then tracking is reliable at higher speeds, but tracking accuracy is insufficient at low speeds and during reversing maneuvers

Engineering Contradiction:
Improvesensor reliabilityVSAvoidtrailer end edge detection accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent replaces the mechanical wheel sensor system with a camera-based optical detection system. The camera captures images of the trailer end edge, and image processing algorithms determine the position and orientation of the trailer end by analyzing edge pixels and fitting geometric models (lines or conics) to the detected features. This substitution enables accurate tracking at all speeds including reversing, where wheel sensors fail.

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

2Ease of operation

If the trailer corners are used as reference points for tracking, then the trailer end edge can be displayed centrally in the monitor image, but the rear part of the trailer near the rear axle is lost and traffic behind is obscured when cornering

Engineering Contradiction:
Improvetrailer end edge display positioningVSAvoidrear traffic visibility
Core Design Contradiction:
Ease of operationVSLoss of information

Solution Approach 1:

The system continuously tracks the trailer end edge position in the camera image and provides feedback to dynamically adjust the monitor display. By calculating the trailer's orientation and position from detected edge features, the system adjusts the displayed image section to keep the trailer end edge centrally positioned while maintaining visibility of relevant rear traffic areas, resolving the conflict between centered display and traffic visibility.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4553770A1Camera-based system and method for determining the position of a trailer
Publication Date: 2025.05.14 MEKRA LANG GMBH & CO KG
  • EP4553770A1 patent drawingFigure 1~2b
  • EP4553770A1 patent drawingFigure 3
  • EP4553770A1 patent drawingFigure 4

AI summary

A method and a camera-based system for determining the position of a trailer end of a swiveling trailer (5) extending rearward from a towing unit (4) of a vehicle by processing temporally successive camera images (6), wherein the method executable by the camera-based system comprises the following steps: capturing the temporally successive camera images (6) by an image sensor of at least one image acquisition device (2) of the camera-based system; determining a plurality of feature points (8) in each of the camera images (6) based on at least one image parameter, wherein a feature point (8) corresponds to at least one pixel in the camera image (6);Selecting prominent feature points from the plurality of feature points (8) along a preferred direction determined by the density and location of the feature points (8) as path elements (10) based on a positional displacement (dx, dy) between the plurality of feature points (8) in a camera image (6) and a corresponding plurality of feature points (8) in a temporally subsequent camera image (6); generating at least one path (11) describing the trailer (5) along the preferred direction based on the path elements (10); and determining a position on the path (11) as the trailer end.