Lawn-mower Anomaly Detection via Wheel Speed Comparison

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing grass-cutting apparatuses, such as robotic lawn-mowers, are inefficient in detecting and addressing operating anomalies like sliding, stoppage, and lifting, which can lead to unsafe and inefficient operation.

Innovation Solution

A method and apparatus that continuously monitor the speed of drive and driven wheels using a magnetic induction-type encoder and contactless sensor to detect anomalies, identifying irregular conditions and restoring safe operation by adjusting the lawn-mower's movement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a strain gauge is used to detect the position of the lawn-mower, then the position can be monitored, but the system cannot detect all possible irregular conditions and operating anomalies

Engineering Contradiction:
Improveanomaly detection capabilityVSAvoiddetection coverage of irregular conditions
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The anomaly detection system is segmented into multiple independent sensing channels: drive wheel speed sensing, driven wheel speed sensing, and comparison logic. Each segment detects specific aspects of operation, and together they provide comprehensive anomaly detection coverage including sliding, stoppage, lifting, and other irregular conditions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The speed comparison system serves multiple functions simultaneously: it detects sliding anomalies, identifies stoppage conditions, recognizes lifting events, and monitors overall operational regularity. This multi-functional approach allows a single detection mechanism to handle diverse anomaly types that a strain gauge alone could not detect.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Productivity

If the lawn-mower operates under anomalous conditions, then cutting function may continue, but safety is compromised and energy consumption increases

Engineering Contradiction:
Improvecutting operation continuityVSAvoidoperational safety
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system continuously compares actual wheel speeds with expected speeds and provides real-time feedback on operational status. When anomalies such as sliding, stoppage, or lifting are detected through speed discrepancies, the system can immediately respond by adjusting operation or halting, ensuring safety while maintaining productivity during normal conditions.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The speed monitoring and comparison system operates continuously before anomalies cause safety issues or excessive energy consumption. By detecting irregularities in advance through wheel speed analysis, the system can take preliminary corrective actions to prevent unsafe operation and energy waste while maintaining cutting productivity.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If the lawn-mower operates under anomalous conditions, then cutting function may continue, but energy consumption increases

Engineering Contradiction:
Improvecutting operation continuityVSAvoidenergy consumption during anomalies
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The continuous speed comparison provides real-time feedback on operational efficiency. When anomalies like sliding or lifting are detected through speed discrepancies, the system can immediately adjust operation to minimize energy consumption while maintaining cutting productivity during normal operation.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The monitoring system detects energy-wasting anomalies in advance by analyzing wheel speed patterns before significant energy consumption occurs. By identifying sliding, stoppage, or lifting conditions early through speed comparison, the system can take preliminary corrective actions to minimize energy waste while maintaining cutting operation continuity.

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

Enables accurate detection of anomalies, ensuring safety and minimizing energy consumption by identifying and addressing irregular conditions in real-time.

Implementation Method 1

a magnetic induction-type encoder configured to detect magnetic field variations as a function of a movement of permanent magnets in the at least one driven wheel

Methodology Applied
Scientific EffectMagnetic induction: Electromagnetic Induction

Data Source

PatentEP2883437B1Method and apparatus for cutting grass
Publication Date: 2018.03.28 BERNINI FAB
  • EP2883437B1 patent drawingFigure 1a~1b
  • EP2883437B1 patent drawingFigure 2
  • EP2883437B1 patent drawingFigure 3

AI summary

The invention describes a method of identifying an anomalous position of an apparatus (100) for cutting grass, in which the apparatus comprises a lawn-mower (1) provided with one or more blades for cutting grass and a movement means (20) comprising at least one drive wheel (20m) and at least one driven wheel (20c), a control unit (200) configured to continuously control the movement of the lawn-mower (1) and configured to identify an anomalous operating status (AW) of the lawn-mower and identify a corresponding type of operating anomaly (Ta1, Ta2, Ta3). The invention further describes an apparatus adapted to implement the method of identifying an anomalous position.