Robot Magnetometer Mapping for Orientation Under Magnetic Interference

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Solution Overview

Problem

Autonomous mobile robots face challenges in determining their orientation within a previously mapped area, especially in residential environments with strong magnetic interference, which affects their navigation and self-localization capabilities.

Innovation Solution

The method involves measuring the direction and magnitude of physical vector fields, such as magnetic fields, at multiple poses to determine a preferred direction in the robot's application area, which is then used to improve navigation and self-localization by creating a magnetic field map and aligning map data for user-friendly display on a human-machine interface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If magnetic field measurements are used for robot navigation and orientation determination, then the robot's ability to self-localize and navigate is improved, but the reliability of measurements deteriorates in environments with strong magnetic interference

Engineering Contradiction:
Improveorientation determination accuracyVSAvoidmagnetic field measurement reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent segments the magnetic field measurement process into multiple discrete poses. The robot measures the magnetic field at several different positions and orientations within the operating area, then combines these segmented measurements to determine the preferred direction. This segmentation allows the system to distinguish between magnetic field variations caused by robot position changes versus those caused by interference sources.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary magnetic field measurements during a mapping phase before actual navigation tasks. The robot systematically measures the magnetic field at multiple poses while creating or updating the map, storing this preliminary data as reference information. During subsequent navigation, the robot compares current measurements against this pre-established baseline to determine orientation, avoiding the need to navigate in real-time magnetic interference conditions.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If multiple poses are measured to determine preferred direction of physical vector field, then navigation accuracy is improved, but the time required for mapping and setup increases

Engineering Contradiction:
Improvepreferred direction determination accuracyVSAvoidmapping setup time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent performs comprehensive magnetic field measurements at multiple poses during an initial mapping phase, storing this data for repeated use. This preliminary action eliminates the need to repeat time-consuming measurements during subsequent navigation tasks, as the robot can reuse the established preferred direction information from the stored map data.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent creates a simplified representation (copy) of the magnetic field characteristics by determining and storing the preferred direction as a single vector attribute in the map data. This copied information captures the essential orientation reference without requiring storage of complete multi-pose measurement datasets, reducing memory requirements and enabling fast retrieval during navigation.

Inventive Principle:
Principle #26Copying

3Ease of operation

If map data is aligned and transformed for user-friendly display on human-machine interface, then user interaction is improved, but computational complexity increases

Engineering Contradiction:
Improveuser interaction with map dataVSAvoidmap data processing complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent extracts and separates the preferred direction information as a distinct attribute from the overall map data structure. By isolating this specific piece of information, the system can apply coordinate transformations and alignments independently to the preferred direction vector without unnecessarily processing the entire map dataset, reducing computational overhead while maintaining user-friendly display capabilities.

Inventive Principle:
Principle #2Taking out (Extraction)

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

This approach enhances the robot's ability to navigate and self-localize by providing a consistent orientation reference, reducing ambiguity and improving user interaction with map data, even in environments with significant magnetic interference.

Implementation Method 1

a magnetic field generated by at least one magnet at the base station is measured, allowing the docking maneuver to be monitored based on the measured magnetic field

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Data Source

PatentEP3659001B1Magnetometer for robot navigation
Publication Date: 2023.04.19 ROBART GMBH
  • EP3659001B1 patent drawingFigure 1~2
  • EP3659001B1 patent drawingFigure 3(a)~3(c)
  • EP3659001B1 patent drawingFigure 4(a)~5

AI summary

Methods for an autonomous mobile robot are described. According to an exemplary embodiment, one method comprises the detection of information regarding the structure of the environment around the robot in the robot deployment area by means of a first sensor unit of the robot and the creation of a map based on the detected information. The method also comprises the measurement of a direction and/or a quantity of at least one physical vector field variable for one or more poses of the robot by means of a second sensor unit and the determination, based on the measurement(s) carried out for one or more poses of the robot, of a preferred direction of the at least one physical vector field variable for the robot deployment area (or a portion thereof). Furthermore, corresponding robots and robot systems are described.