Autonomous Lawn Mower Navigation Using Signal Loops and Docking Orientation

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Solution Overview

Problem

Existing autonomous lawn mowers face challenges in navigating diverse and complex garden landscapes, leading to inadequate performance and reliance on manual control due to unpredictability of terrain and varying landscape profiles.

Innovation Solution

An autonomous lawn mower equipped with a navigation system, signal detecting and generating modules, and sensors to detect navigational markers, allowing the mower to determine its position and operate within predefined areas, and a detachable docking module for battery charging and orientation, enabling efficient navigation and edge trimming.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If traditional push mowers are used to maintain lawns, then manual control allows overcoming terrain problems, but significant physical effort is required

Engineering Contradiction:
Improvemanual control capabilityVSAvoidphysical effort
Core Design Contradiction:
Ease of operationVSForce

Solution Approach 1:

The patent replaces the mechanical push-pull operation with an autonomous electromagnetic system. The mower body incorporates motors that drive wheels to propel the mower automatically, eliminating the need for manual physical effort while maintaining control capabilities through electronic navigation systems and signal detection modules.

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

Solution Approach 2:

The autonomous mower performs self-navigation and self-control functions. The navigation system and signal detecting module enable the mower to autonomously determine its position, detect boundaries and obstacles, and adjust its path without human intervention, allowing it to service the lawn independently.

Inventive Principle:
Principle #25Self-service

2Extent of automation

If autonomous lawn mowers are manufactured to replace push mowers, then automation is achieved, but inadequate performance occurs due to landscape unpredictability

Engineering Contradiction:
Improveautonomous operationVSAvoidnavigation performance
Core Design Contradiction:
Extent of automationVSReliability

Solution Approach 1:

The patent introduces signal loops as intermediary markers placed along garden boundaries and obstacles. These physical intermediaries provide reliable reference points that the signal detecting module can consistently identify, enabling the navigation system to accurately determine the mower's position and navigate complex landscapes without failing due to unpredictability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The navigation system continuously receives feedback from the signal detecting module about the mower's position relative to signal loops. This real-time feedback allows the controller to adjust the mower's trajectory dynamically, maintaining reliable navigation performance even in unpredictable landscape conditions by constantly correcting based on detected signal positions.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If navigation systems are added to autonomous mowers, then position determination is enabled, but device complexity increases

Engineering Contradiction:
Improveposition determination accuracyVSAvoidnavigation system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

Instead of using complex active sensors or cameras to detect environmental features, the patent uses a simple signal detecting module that detects passive signal loops. The signal loops are simple wire configurations that create electromagnetic fields, which are much simpler to detect than visual or complex electromagnetic features, thereby achieving position determination with lower device complexity.

Inventive Principle:
Principle #26Copying

4Measurement precision

If signal loops are used for navigation markers, then boundary detection is improved, but manufacturing cost increases

Engineering Contradiction:
Improveboundary detection accuracyVSAvoidmanufacturing cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The signal loops are implemented using simple, inexpensive wire or cable that can be easily laid along garden boundaries. These are disposable or easily replaceable components that cost far less than permanent installation systems, GPS infrastructure, or complex sensor arrays, making the boundary detection system economically viable despite improved precision.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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

The autonomous lawn mower effectively navigates and maintains lawn areas with varying terrain by using signal loops and sensors to detect boundaries and obstacles, ensuring efficient operation and edge trimming, while the docking module facilitates battery charging and orientation, enhancing its autonomy and performance.

Implementation Method 1

a signal detecting module arranged to detect a signal representative of a navigational marker

Methodology Applied
Scientific EffectElectromagnetic signal detection: Electromagnetic Induction

Implementation Method 2

the signal detecting module includes a sensor arranged to detect the magnitude of the signal loop

Methodology Applied
Scientific EffectSignal magnitude detection: Electromagnetic Induction

Data Source

PatentEP3844585B1An autonomous lawn mower and a system for navigating thereof
Publication Date: 2023.07.26 TECHTRONIC CORDLESS GP
  • EP3844585B1 patent drawingFigure 1
  • EP3844585B1 patent drawingFigure 2
  • EP3844585B1 patent drawingFigure 3

AI summary

A system and method for an autonomous lawn mower(100) comprising a mower body(102) having at least one motor(212) arranged to drive a cutting blade(212b) and to propel the mower body(102) on an operating surface via a wheel arrangement, wherein the mower body(102) includes a navigation system(204) arranged to assist a controller(202) to control the operation of the mower body within a predefined operating area(414), wherein the mower body(102) further includes a signal detecting module(222) arranged to detect a signal representative of a navigational marker.