Robot Lawnmower Perimeter Teaching for Reliable Boundary Confinement

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Solution Overview

Problem

Existing autonomous lawn mowers rely on complex systems of sensors and barriers for navigation and confinement, which can be inefficient and prone to errors, especially when dealing with irregular lawn shapes and obstacles.

Innovation Solution

An autonomous lawn mower equipped with a sensor system including edge following sensors, grass sensors, and a navigation system that uses boundary markers and an operator feedback unit to learn and map the lawn perimeter, allowing for efficient and accurate navigation and confinement within defined areas.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If complex systems of sensors and barriers are used for navigation and confinement, then navigation accuracy and confinement reliability are improved, but device complexity and cost increase

Engineering Contradiction:
Improveconfinement reliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces boundary markers as intermediary objects placed in the environment to facilitate robot navigation and confinement. These markers serve as mediators between the robot's sensors and the physical boundaries, enabling reliable confinement through simple optical detection rather than complex sensor systems or physical barriers

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent extracts the confinement function from complex sensor systems and physical barriers, isolating it into simple boundary markers that define the operational area. This separation allows the robot to use basic sensors to detect markers rather than requiring complex integrated systems

Inventive Principle:
Principle #2Taking out (Extraction)

2Measurement precision

If complex systems of sensors and barriers are used for navigation and confinement, then navigation accuracy is improved, but device complexity increases

Engineering Contradiction:
Improvenavigation accuracyVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

Boundary markers act as intermediaries that enhance navigation accuracy by providing distinct, easily detectable reference points in the environment. The markers enable precise position detection using simple optical sensors rather than requiring complex sensor arrays or active beacon systems

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent uses passive optical markers that can be detected by the robot's vision system, creating a simplified representation of boundary information. This approach replaces complex active beacons or multiple sensor types with simple visual cues that provide sufficient navigation precision

Inventive Principle:
Principle #26Copying

3Ease of operation

If random motion confinement methods are used, then ease of operation is improved, but productivity and mowing efficiency deteriorate

Engineering Contradiction:
Improveease of operationVSAvoidmowing efficiency
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The patent implements preliminary localization and mapping actions before the mowing operation begins. The robot first localizes itself relative to boundary markers and creates a map of the mowing area, enabling subsequent efficient path planning rather than relying on random motion throughout the entire operation

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent transitions the robot from static random motion patterns to dynamic, adaptive path planning based on localized environmental information. The robot dynamically adjusts its trajectory using detected boundary markers and map data, optimizing mowing efficiency while maintaining ease of operation through autonomous adaptation

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3889717B1Autonomous mobile robot
Publication Date: 2024.07.17 IROBOT CORP
  • EP3889717B1 patent drawingFigure 1A
  • EP3889717B1 patent drawingFigure 1B
  • EP3889717B1 patent drawingFigure 1C

AI summary

A robot lawnmower (10) includes a robot body (100), a drive system (400), a localizing system (550), a teach monitor (600), and a controller (150) in communication with one another. The drive system is configured to maneuver the robot lawnmower over a lawn. The teach monitor determines whether the robot lawnmower is in a teachable state. The controller includes a data processing device (152a) and non-transitory memory (152b) in communication with the data processing device. The data processing device executes a teach routine (155) when the controller is in a teach mode for tracing a confinement perimeter (21) around the lawn (20) as a human operator pilots the robot lawnmower, when the robot lawnmower is in the teachable state, the teach routine stores global positions determined by the localizing system in the non-transitory memory, and when the robot lawnmower is in the unteachable state, the teach routine issues an indication of the unteachable state.