Robotic Lawnmower Boundary Mapping With Corrected Satellite Positioning

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Solution Overview

Problem

Existing robotic lawnmower systems face precision issues in defining work area boundaries due to drifting positions sensed by mobile devices, leading to incomplete cutting or unnecessary processing of areas.

Innovation Solution

A method involving a mobile device that receives satellite positioning data and correction positioning data from a reference station, enhancing the precision of boundary definition by combining these data sources, and transmitting the refined positions to a robotic lawnmower.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If mobile device positioning relies on GPS, accelerometers and visual odometry, then the positioning system is simple and cost-effective, but the position data drifts increasingly in relation to the global coordinate system

Engineering Contradiction:
Improvepositioning precisionVSAvoidpositioning system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces a reference station as an intermediary element that provides known coordinate positions to the mobile device. This reference station acts as a mediator between the satellite positioning system and the mobile device, enabling the mobile device to correct its drifting position data by comparing with the known reference coordinates, thereby improving positioning precision without significantly increasing system complexity

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent implements a feedback mechanism where the mobile device receives correction data from the reference station and uses this feedback to adjust and correct its position calculations. The system continuously compares the measured position with the known reference position and applies corrections to eliminate drift accumulation, maintaining accurate positioning over time

Inventive Principle:
Principle #23Feedback

2Productivity

If virtual markers are placed based on drifted position data, then the boundary definition process is simple and fast, but the actual cutting precision deteriorates with drift accumulation

Engineering Contradiction:
Improveboundary definition speedVSAvoidboundary definition precision
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by establishing a reference station with known coordinates before the boundary definition process begins. This pre-established reference point provides a stable foundation for subsequent position corrections, ensuring that even if drift occurs during the boundary definition process, the positions can be corrected against the predetermined reference coordinates to maintain precision

Inventive Principle:
Principle #10Preliminary action

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

Improves the precision of work area boundary definition, ensuring accurate navigation and processing by the robotic lawnmower, reducing errors in cutting and processing areas.

Implementation Method 1

The separate, mobile device receives satellite positioning data from a plurality of satellites

Methodology Applied
Scientific EffectSatellite positioning:

Implementation Method 2

correction positioning data from at least one reference station

Methodology Applied
Scientific EffectPosition correction:

Data Source

PatentEP4575693A1Robotic lawnmower system
Publication Date: 2025.06.25 HUSQVARNA AB
  • EP4575693A1 patent drawingFigure 1~2
  • EP4575693A1 patent drawingFigure 3~4
  • EP4575693A1 patent drawingFigure 5~6

AI summary

The present disclosure relates to a method for defining a boundary of a work area (30) in a robotic lawnmower system, the system comprising a robotic lawnmower (1), configured to process the work area (30) and to determine its position (xr, yr, zr) in the work area, and a separate, mobile device (11) configured to determine its position (xm, ym, zm) in the work area (30) and having a camera (13) configured to capture images of the work area (30) and a display (15) which provides a user interface, enabling a user to define boundary segments (33, 37) of the work area boundary (31, 39) therein as a set of positions which are transferred to the robotic lawnmower (1). The separate, mobile device (11) receives satellite positioning data from a plurality of satellites and correction positioning data from a reference station (31), thereby increasing the precision of its position detection.