Forage Harvester Knife Wear Monitoring for Sharpening Scope

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Solution Overview

Problem

Existing methods for determining the grinding requirements of chopping knives in a self-propelled forage harvester lack a suitable benchmark, making it difficult for operators to assess the specific scope of the grinding process needed, leading to subjective decision-making.

Innovation Solution

A method and system where a monitoring device allows operators to specify a target state for the chopping knives, continuously comparing it with the actual wear state, providing information on the deviation through familiar parameters like grinding cycles or visual comparisons, enabling informed decision-making on when to perform grinding operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the operator is informed when a critical wear condition is reached, then the operator can be alerted to perform sharpening, but the operator remains unclear about the specific scope of the grinding process to be carried out

Engineering Contradiction:
Improvewear condition monitoringVSAvoidgrinding scope information
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The monitoring device provides continuous feedback not only on the current wear state but also on the deviation from the target state. This feedback loop enables the operator to understand both when sharpening is needed and how much sharpening work is required, transforming a simple alert system into an informative guidance system that reduces uncertainty about the grinding scope.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent introduces an intermediary calculation and visualization layer between the raw wear measurement and the operator decision-making process. By calculating and displaying the deviation from target state, the system mediates the information gap, translating complex wear data into actionable insights about the required grinding scope without requiring the operator to perform subjective assessments.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If subjective assessment by the operator is required, then the system remains simple, but the decision-making process becomes less precise and more variable

Engineering Contradiction:
Improvesystem simplicityVSAvoidwear assessment accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The monitoring device performs self-assessment of the wear condition through automated sensing and calculation. Instead of relying on the operator to subjectively evaluate wear, the system autonomously measures the wear state, compares it to the target state, and calculates the deviation. This self-service approach eliminates human subjectivity while maintaining system accessibility, achieving both precision and operational simplicity.

Inventive Principle:
Principle #25Self-service

3Productivity

If continuous monitoring and information generation is implemented, then the operator is kept constantly informed, but the information may be overwhelming without proper benchmarking

Engineering Contradiction:
Improveinformation delivery frequencyVSAvoidinformation interpretability
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The patent transforms the monitoring information from raw wear measurements into a meaningful parameter: the deviation from target state. By changing the parameter representation from absolute wear values to relative deviation values, the system makes continuous monitoring information interpretable and actionable. This parameter transformation allows frequent updates without overwhelming the operator, as each update expresses information in a consistent, easily understood format that directly indicates required grinding work.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4091435B1Method for determining the need to sharpen chopping knives of a chopping device
Publication Date: 2026.01.21 CLAAS SELBSTFAHRENDE ERNTEMASCHINEN GMBH
  • EP4091435B1 patent drawingFigure 1
  • EP4091435B1 patent drawingFigure 2
  • EP4091435B1 patent drawingFigure 3

AI summary

The present invention relates to a method for determining the grinding requirement of chopping knives (8) of a chopping device (6) of a self-propelled forage harvester (1), wherein a wear state is cyclically determined by a monitoring device (29), wherein the monitoring device (29) comprises an input-output unit (19) by means of which a target state of the chopping knives (8) to be produced by a grinding device (17) is entered or selected as a target specification, and wherein the monitoring device (29) generates information, in particular continuously, depending on the target state and the determined wear state, and visualizes by the input-output unit (19) the extent to which the currently determined wear state deviates from the target state.