Tugger Train Trailer Yaw Detection Using Optical Markers

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Solution Overview

Problem

The challenge is to reduce the number of sensors in a tugger train system while ensuring compatibility with various trailer types and maintaining safety and efficiency, particularly in automated guided vehicle (AGV) systems.

Innovation Solution

An angle determination method for tugger train components using a smaller number of sensors, involving optical markers attached to trailers, detected by a camera, and calculating yaw angles based on rotation vectors and position determinations relative to the towing vehicle, without requiring additional sensors on the trailers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the number of sensors is reduced to lower operating costs, then operating costs decrease, but the safety and reliability of the tugger train system deteriorates

Engineering Contradiction:
Improveoperating costsVSAvoidsafety
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The patent replaces physical sensors with optical markers and camera-based detection. Instead of using multiple sensors to detect trailer positions and angles, the system uses optical markers attached to trailers that are detected by cameras mounted on the towing vehicle. This substitution reduces the number of physical sensors needed while maintaining the ability to monitor system state for safety purposes.

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

Solution Approach 2:

The patent uses optical markers as visual copies or representations of the trailers' physical state. These markers encode position and orientation information that can be read by cameras, creating an information copy of the trailer configuration without requiring direct physical sensing of each component.

Inventive Principle:
Principle #26Copying

2Device complexity

If the number of sensors is reduced, then the device complexity decreases, but the measurement precision of trailer positions and angles deteriorates

Engineering Contradiction:
Improvesensor countVSAvoidangle determination accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent transitions from one-dimensional sensor measurements to two-dimensional optical marker detection. By using camera images that capture marker position, orientation, and shape in two dimensions, the system extracts multiple pieces of information (x-position, y-position, angle, distance) from a single optical detection event, maintaining measurement precision while reducing sensor count.

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

Solution Approach 2:

The patent changes the measurement parameters from direct physical sensing to optical pattern recognition. By detecting the position, orientation, and distortion of optical markers in camera images, the system calculates trailer angles and positions through mathematical relationships, achieving precise measurement with fewer physical components.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If optical markers and camera-based detection are used instead of multiple sensors, then compatibility with different trailer types improves, but the difficulty of detecting and measuring angles deteriorates

Engineering Contradiction:
ImprovecompatibilityVSAvoidangle detection complexity
Core Design Contradiction:
Adaptability or versatilityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent implements a universal detection system where optical markers serve multiple functions across different trailer types. The same marker design and detection algorithm work for various trailer configurations, making the system adaptable to different models without requiring type-specific sensors or calibration. The camera-based system universally captures marker information regardless of trailer variety.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent introduces optical markers as intermediary elements between the trailers and the detection system. These markers act as mediators that translate physical trailer states into detectable optical patterns, simplifying the detection process. The camera detects marker patterns rather than directly measuring trailer geometry, reducing the complexity of angle and position measurement.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Enables efficient and safe operation of tugger trains with different trailer types by reducing sensor count, enhancing compatibility and flexibility, and providing early collision detection and emergency stops, thus improving system safety and reducing operational costs.

Implementation Method 1

detecting at least one optical marker on at least one trailer using a camera

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP4703838A1Method and device for determining the angle of individual components of a route
Publication Date: 2026.03.04 SIEMENS AG
  • EP4703838A1 patent drawingFigure 1
  • EP4703838A1 patent drawingFigure 2
  • EP4703838A1 patent drawingFigure 3

AI summary

A method for determining the angle of individual components of a tugger train is proposed, wherein the components comprise at least one trailer and a towing vehicle, wherein - a calculation of a yaw angle of at least one of the trailers is performed as a function of a spatial orientation with respect to the towing vehicle, characterized by the following steps: - attaching at least one optical marker to at least one trailer; - detecting at least one optical marker on at least one trailer using a camera; - calculating a rotation vector for at least one detected optical marker per trailer; - wherein the calculation of the yaw angle for at least one trailer of the tugger train is performed as a function of the rotation vector;and - a first position determination for a first trailer directly coupled to the towing vehicle, which is provided relative to the position of the camera, wherein the first position determination depends on a first yaw angle of the first trailer and a length of the first trailer, and a position of the first trailer is provided as a result. The invention further relates to a device.