Personal Warning Device Localization via GNSS Pseudolite Fusion

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Solution Overview

Problem

Existing personal warning systems for track workers lack sufficient accuracy in locating warning devices, which can lead to unreliable warnings and potential safety hazards due to the limitations of GPS and WLAN technologies in achieving precise localization.

Innovation Solution

The system repeatedly locates warning devices using a central unit with a first location system, generating initial location information as a reference position, and combines GNSS signals from satellites and a pseudolite central unit to enhance accuracy, allowing for more precise monitoring and warning of workers in real-time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If GPS and WLAN are combined for device location, then the coverage area is expanded, but the localization accuracy remains insufficient (5 m or less)

Engineering Contradiction:
Improvecoverage areaVSAvoidlocalization accuracy
Core Design Contradiction:
Area of stationary objectVSMeasurement precision

Solution Approach 1:

The patent combines multiple location systems (GNSS, WLAN, Bluetooth, and active location system) into a unified location solution. The central unit integrates signals from different sources and uses algorithms to fuse location data, achieving both wide coverage and high accuracy (sub-meter level) by leveraging the complementary strengths of each system.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces a pseudolite as an intermediary device that emulates satellite signals. This pseudolite transmits location signals to the warning device, enabling the active location system to function in environments where GNSS signals are unavailable or insufficient, thereby maintaining high localization accuracy across diverse areas.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If Bluetooth is used for device location, then localization accuracy improves (2 m or less), but the range of action is insufficient (up to 6 m)

Engineering Contradiction:
Improvelocalization accuracyVSAvoidrange of action
Core Design Contradiction:
Measurement precisionVSArea of stationary object

Solution Approach 1:

The patent merges Bluetooth-based active location system with GNSS and pseudolite systems. The central unit processes location data from multiple sources simultaneously, using Bluetooth for indoor precision and GNSS/pseudolite for outdoor or long-range positioning, thereby achieving both high accuracy and extended range of action.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of operation

If personal devices are used in gang warning systems, then individual warning capability is provided, but the risk of inaccurate location increases safety hazards

Engineering Contradiction:
Improveindividual warning capabilityVSAvoidwarning reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent implements continuous feedback mechanisms where the central unit repeatedly locates the warning device and compares location data over time. The system provides feedback on location accuracy and monitors for inconsistencies, allowing real-time adjustment and ensuring reliable warnings by validating location information before triggering safety alerts.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent performs preliminary location verification and reference position establishment before actual warning operations. The system pre-establishes reference positions and validates location accuracy in advance, ensuring that when warnings are triggered, the location data is already verified and reliable, thereby preventing safety hazards from inaccurate positioning.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4112421A1Warning system and method for operating the warning system with at least one personal warning device
Publication Date: 2023.01.04 SIEMENS MOBILITY GMBH
  • EP4112421A1 patent drawingFigure 1
  • EP4112421A1 patent drawingFigure 2
  • EP4112421A1 patent drawingFigure 3

AI summary

The invention relates to a method for operating a warning system with at least one warning device (PD1 ... PD4) for personal use by a worker, in particular track workers (GLA), wherein, upon activation of the warning device, a communication link (K4) is established between the warning device (PD1 ... PD4) and at least one central unit (BZT) of the warning system. After the communication link (K4) has been established, the warning device (PD1 ... PD4) is repeatedly located by the central unit (BZT) using a first location system. From an initial location, initial location information for the warning device (PD1 ... PD4) is generated. The initial location information is stored as the reference position of the warning device (PD1 ... PD4). Furthermore, the invention comprises a warning system, a warning device (PD1 ...PD4) for a warning system, a central unit for a warning system, a computer program product and a delivery device for the computer program product.