Handling Trolley Localization Using Inertial Zero-Motion Correction

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Solution Overview

Problem

Existing methods for locating industrial trucks are either expensive, prone to errors due to obstacles, or lack precision, especially when relying on GPS signals or telecommunications signal timing, and inertial units with low precision require frequent corrections.

Innovation Solution

A system comprising a communication terminal and an on-board electronic module with an inertial movement detection unit that includes linear and angular movement sensors, which detects zero angular movement and speed to correct errors and provide reliable positioning data, combined with a magnetic field alignment for improved accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If satellite positioning signal receivers (GPS) are used to locate trolleys, then positioning capability is provided, but the cost is expensive and obstacles may prevent signal reception

Engineering Contradiction:
Improvepositioning capabilityVSAvoidobstacles blocking signals
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces an intermediary solution by using telecommunication terminals as fixed reference points throughout the location. Instead of relying on external satellite signals that can be blocked, the system uses local telecommunication infrastructure to establish positioning references, thereby mediating between the trolley and the positioning system to overcome obstacle interference

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the satellite-based electromagnetic positioning system with a local telecommunication-based positioning system. By substituting GPS satellite signals with signals from local telecommunication terminals, the system eliminates dependence on external satellite coverage and overcomes blocking by physical obstacles in the environment

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

2Reliability

If telecommunications modules are used to transmit signals to fixed terminals for position determination, then positioning is achieved, but the precision is insufficient

Engineering Contradiction:
Improvepositioning availabilityVSAvoidlocation precision
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent implements feedback by having the on-board electronic module receive information about its own transmissions from the computer server. The system measures the time of flight of signals between the trolley and multiple telecommunication terminals, then uses this feedback information to calculate and determine the precise position of the trolley through triangulation or multilateration algorithms

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent transitions from one-dimensional or two-dimensional positioning to three-dimensional positioning by utilizing signals from multiple telecommunication terminals distributed in space. By measuring signal propagation times to multiple reference points in different spatial locations, the system achieves precise three-dimensional location determination

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

3Ease of manufacture

If low-cost MEMS inertial units are used for positioning, then cost is reduced, but accuracy is relatively low requiring periodic corrections

Engineering Contradiction:
ImprovecostVSAvoidpositioning accuracy
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent merges two different positioning approaches into a unified system: inertial positioning using low-cost MEMS units and telecommunication-based positioning using local terminal signals. The inertial unit provides continuous positioning data while the telecommunication system provides periodic correction references, combining the advantages of both methods to achieve both low cost and high accuracy

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The system enables self-service by allowing the inertial unit to autonomously provide continuous positioning data without requiring constant external corrections. The unit independently calculates position based on acceleration and angular velocity measurements, and only requires occasional corrections from telecommunication references to maintain accuracy, reducing dependency on external infrastructure

Inventive Principle:
Principle #25Self-service

4Reliability

If the on-board electronic module is mounted on a rotating element of the trolley, then movement detection reliability is improved, but the device complexity increases

Engineering Contradiction:
Improvemovement detection reliabilityVSAvoidmounting complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent makes the on-board electronic module universal by mounting it on a rotating element such that it serves multiple functions: it maintains reliable detection of linear and angular movements through its position on the rotating component, and simultaneously enables determination of the trolley's orientation and angular position. This multi-functional mounting approach achieves reliable movement detection without requiring separate dedicated sensors for each measurement type

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

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 localization of industrial trucks by correcting errors in linear movement detection and providing reliable positioning data, even at constant speeds, while avoiding vibrations and improving overall localization accuracy.

Implementation Method 1

an inertial motion detection unit which comprises a device for detecting linear motion along axes of a detection frame and a device for detecting angular motion around the axes of the detection frame and which is arranged to provide positioning data from linear motion measurement data and angular motion measurement data

Methodology Applied
Scientific EffectInertial motion detection: Accelerometer

Implementation Method 2

The unit further comprises an angular motion detection device comprising gyrometers arranged along the axes of the detection frame to measure the movements of the detection frame relative to a reference frame

Methodology Applied
Scientific EffectGyrometer: Gyroscope

Implementation Method 3

a magnetic device arranged to emit a magnetic field successively aligned on the first axis, on the second axis and on the third axis of the reference frame

Methodology Applied
Scientific EffectMagnetic field emission: Magnetic Field

Data Source

PatentEP3433579B1Method and system for finding handling trolleys
Publication Date: 2024.11.20 SAGEMCOM ENERGY & TELECOM SAS
  • EP3433579B1 patent drawingFigure 1~4

AI summary

System for finding at least one mobile trolley in a locale, the system comprising at least one communication beacon which has a range covering the locale and which is connected to a computer control unit, and at least one electronic module mounted on the trolley and comprising a transmission device arranged to transmit position data to the communication beacon, and an inertial motion detection hub that comprises a device for detecting linear motion along axes of a detection reference system and a device for detecting angular motion about the axes of the detection reference system and that is arranged to provide position data on the basis of linear motion measurement data and angular motion measurement data, the module being mounted on an element of the trolley such that any movement of the trolley within the locale causes angular movement of the element, the system being arranged to detect when the trolley is stopped when the angular motion measurement data correspond to zero angular motion at one measurement instant and being arranged to set to zero speeds calculated on the basis of the linear motion measurement data corresponding to the same measurement instant.