Robot Lawnmower Swath Edge Detection for Low-Complexity Navigation

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Solution Overview

Problem

Existing autonomous lawn mowers rely on complex systems of sensors and beacons for navigation, which can be cumbersome and require additional power sources, and lack efficient boundary detection and obstacle avoidance mechanisms.

Innovation Solution

An autonomous robot lawnmower with a detachable manual push/pull handle and foldable handle configuration, utilizing edge following sensors and boundary detectors to navigate and avoid obstacles, allowing for both autonomous and manual operation modes without the need for complex GPS or odometric systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If complex systems of sensors and beacons are used for navigation, then navigation capability is improved, but device complexity and power requirements increase

Engineering Contradiction:
Improvenavigation capabilityVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts and removes the complex GPS, odometric systems, and extensive beacon networks from the navigation architecture. Instead, it retains only the essential edge-following sensors and boundary detectors that are integral to the mower's body, eliminating unnecessary complexity while preserving core navigation functionality.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The navigation system serves itself by using the cutting edges and boundary detectors already present on the mower body. These components naturally follow lawn edges and property boundaries without requiring external infrastructure or complex computational systems, making the system self-sufficient and simpler.

Inventive Principle:
Principle #25Self-service

2Reliability

If complex systems of sensors and beacons are used for navigation, then navigation capability is improved, but power consumption increases

Engineering Contradiction:
Improvenavigation capabilityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent removes power-hungry components such as GPS receivers, odometric sensors, and active beacon systems. The remaining navigation components (edge-following sensors and boundary detectors) consume minimal power, extending operational duration between battery charges.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The navigation system uses passive detection methods that require minimal energy. The cutting edges and boundary detectors naturally sense their environment without requiring active transmission or complex processing, significantly reducing power consumption while maintaining navigation reliability.

Inventive Principle:
Principle #25Self-service

3Ease of operation

If a detachable manual push/pull handle is provided, then ease of operation is improved, but device complexity increases

Engineering Contradiction:
Improveoperational flexibilityVSAvoidhandle configuration
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The handle is segmented into a detachable manual push/pull component that can be separately attached or removed from the mower body. This allows users to switch between autonomous and manual operation modes as needed, providing operational flexibility without permanently increasing system complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The handle configuration is made dynamic through its foldable and detachable design. The handle can be folded against the body when not in use and detached when autonomous operation is required, adapting the system's operational state to match user needs while maintaining a compact form factor.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3404505B1Lawn care robot
Publication Date: 2023.12.06 IROBOT CORP
  • EP3404505B1 patent drawingFigure 1A
  • EP3404505B1 patent drawingFigure 1B
  • EP3404505B1 patent drawingFigure 2A~2B

AI summary

A robot lawnmower (10, 11, 12, 13, 14, 15, 16, 17, 18, 19) includes a drive system (400) carried by a body (100) and configured to maneuver the robot (10, 11, 12, 13, 14, 15, 16, 17, 18, 19) across a lawn (20, 1020). The robot (10, 11, 12, 13, 14, 15, 16, 17, 18, 19) includes a grass cutter (200, 200A, 200B, 2000A, 2050, 2100, 2200) carried by the body (100) and a swath edge detector (310A, 310B, 310C, 310D, 310E, 310F, 310G, 310H, 310I) carried by the body (100) and configured to detect a swath edge (26) between cut grass (24) and uncut grass (22) while the drive system (400) maneuvers the robot (10, 11, 12, 13, 14, 15, 16, 17, 18, 19) across the lawn (20, 1020) while following a detected swath edge (26). The swath edge detector (310, 310A, 310B, 310C, 310D, 310E, 310F, 310G, 310H, 310I) includes a calibrator (320, 320A, 320B) that monitors uncut grass (22) adjacent the swath edge (26) for calibration of the swath edge detector (310, 310A, 310B, 310C, 310D, 310E, 310F, 310G, 310H, 310I).