Tugger Train Trailer Optical Positioning for Precise Load Transfer

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Solution Overview

Problem

Conventional positioning systems for autonomously operated tugger trains are inaccurate and costly, making precise load transfer between tugger train trailers and stationary transfer stations challenging.

Innovation Solution

A system comprising two light barriers on the tugger train trailer and a reflector at the stationary transfer station, which interact to control the tugger train's positioning with high accuracy and low cost, allowing precise alignment in the longitudinal direction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional positioning systems with laser scanners and reflectors are used, then positioning capability is provided, but accuracy is too low for autonomous tugger trains

Engineering Contradiction:
Improvepositioning accuracyVSAvoidpositioning reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent replaces conventional laser scanners with a light barrier system that uses optical fields instead of mechanical scanning components. The light barrier with transmitter and receiver creates an optical detection field that directly measures position without moving parts, achieving higher accuracy and reliability for autonomous positioning.

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

Solution Approach 2:

The patent uses a reflector to create an optical copy of the light barrier signal. The reflector positioned at the transfer station reflects the light barrier's optical field back to the receiver, creating a virtual detection point that enables precise positioning without requiring the receiver to be physically located at the transfer station.

Inventive Principle:
Principle #26Copying

2Measurement precision

If conventional positioning systems with magnetic strips on roadway are used, then positioning capability is provided, but installation complexity and costs are high

Engineering Contradiction:
Improvepositioning accuracyVSAvoidinstallation complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts the positioning function from the roadway infrastructure (magnetic strips) and relocates it to the tugger train itself through the light barrier system. This eliminates the need for complex roadway modifications while maintaining positioning accuracy, as the light barrier components are mounted on the vehicle rather than embedded in the infrastructure.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The light barrier system serves multiple functions: it provides positioning accuracy, works on existing roadway surfaces without modification, and can be used across different transfer station locations. The reflector at the transfer station serves as a universal reference point that works with any tugger train equipped with the light barrier system.

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

3Measurement precision

If manual positioning with laser pointer is used, then positioning capability is provided, but automation is not achieved

Engineering Contradiction:
Improvepositioning accuracyVSAvoidpositioning automation
Core Design Contradiction:
Measurement precisionVSExtent of automation

Solution Approach 1:

The patent implements self-service positioning where the tugger train's light barrier system automatically detects the reflector at the transfer station and determines its own position without human intervention. The system autonomously measures the distance and position based on optical field interactions, enabling fully automated positioning for driverless operation.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent creates a feedback loop where the light barrier continuously monitors the optical field reflection from the transfer station reflector. This real-time feedback provides continuous position information to the control system, enabling automated adjustment and maintenance of precise positioning without manual intervention.

Inventive Principle:
Principle #23Feedback

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 precise and cost-effective positioning of tugger train trailers at transfer stations, facilitating accurate load transfer even in the absence of a driver, with a simple and fail-safe design.

Implementation Method 1

a reflector (15) at the stationary transfer station (5a-5d), which interacts with the light barriers (12a, 12b)

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP4136014B1System comprising a tugger train and at least one stationary transfer station
Publication Date: 2025.09.03 LR INTRALOGISTIK GMBH
  • EP4136014B1 patent drawingFigure 1
  • EP4136014B1 patent drawingFigure 2a~2b
  • EP4136014B1 patent drawingFigure 2c~3a

AI summary

The invention relates to a system (1) comprising a tugger train (2), which has a towing vehicle (3) and at least one tugger train trailer (4a; 4b; 4c; 4d), and at least one stationary transfer station (5a; 5b; 5c; 5d) for transferring loads (L1; L2; L3; L4) between the tugger train trailer (4a; 4b; 4c; 4d) and the stationary transfer station (5a; 5b; 5c; 5d), wherein, in order to transfer loads, the tugger train trailer (4a; 4b; 4c; 4d) is located in a defined reloading position relative to the stationary transfer station (5a; 5b; 5c; 5d). The tugger train trailer (4a; 4b; 4c; 4d) has two light beams (LS1, LS2) which are spaced apart from each other in the longitudinal direction (F) of the tugger train trailer (4a; 4b; 4c; 4d) and which are arranged on the tugger train trailer (4a; 4b; 4c; 4d) in each case with a detection direction aligned in a transverse direction (Q) of the tugger train trailer (4a; 4b; 4c; 4d), and the stationary transfer station (5a; 5b; 5c; 5d) is provided with a reflector (RF) which cooperates with the light beams (LS1, LS2). The light beams (LS1, LS2) are operatively connected to a drive control (40) of the tugger train (2) and the drive control (40) is designed such that, by means of the light signals reflected by the light beams (LS1, LS2) on the reflector (RF), the tugger train trailer (4a; 4b; 4c; 4d) is stopped at the stationary transfer station (5a; 5b; 5c; 5d) in the defined reloading position.