Agricultural Mower Cutting Height Control via Dual Tilt Sensors

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Solution Overview

Problem

Setting a defined cutting height for mowing elements of a mower attached to an agricultural tractor is complex and error-prone, especially when the tractor is operating on an incline, as the driver must manually measure and adjust the cutting height, which is difficult to estimate from the cab.

Innovation Solution

A control system using two inclination sensors, one on the mower and one on the tractor, determines the actual cutting height based on the angle difference between them, allowing for easy and reliable adjustment, even when the tractor is on a slope, and includes a control device to automatically adjust the mower position to maintain a target cutting height.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the driver manually measures and adjusts the cutting height after each top link length adjustment, then the cutting height can be set, but the process becomes complex and error-prone requiring the driver to dismount and measure

Engineering Contradiction:
Improvecutting height precisionVSAvoidadjustment complexity
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The patent replaces manual mechanical measurement with electronic inclination sensors that automatically detect the cutting height. The control unit processes sensor signals to determine the actual cutting height, eliminating the need for manual measurement and top link length adjustments.

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

Solution Approach 2:

The system enables self-adjustment of cutting height through automatic control. The control unit compares the actual cutting height with the desired cutting height and automatically adjusts the mower deck position without driver intervention, allowing the system to serve itself.

Inventive Principle:
Principle #25Self-service

2Measurement precision

If the cutting height is adjusted manually from the ground, then the cutting height can be measured accurately, but the driver must dismount and the process becomes time-consuming

Engineering Contradiction:
Improvecutting height measurement accuracyVSAvoidadjustment time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent replaces ground-based manual measurement with electronic inclination sensors mounted on the mower that continuously and automatically measure the cutting height from the machine itself, eliminating the need for the driver to dismount and measure from the ground.

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

Solution Approach 2:

The inclination sensors continuously measure the cutting height throughout operation, allowing for real-time monitoring and adjustment without interrupting work. The measurement process becomes continuous rather than discrete, saving time by eliminating repeated mounting and dismounting.

Inventive Principle:
Principle #20Continuity of useful action

3Adaptability or versatility

If the top link length is adjusted to change cutting height, then the cutting height can be modified, but the adjustment is difficult to estimate from the driver's cab especially on inclines

Engineering Contradiction:
Improvecutting height adjustabilityVSAvoidcutting height estimation difficulty
Core Design Contradiction:
Adaptability or versatilityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent replaces visual estimation from the driver's cab with electronic inclination sensors that directly measure the actual cutting height. The control unit processes sensor data to provide accurate cutting height information, eliminating the difficulty of visual estimation especially on inclines where perspective is distorted.

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

Solution Approach 2:

The system implements feedback by continuously measuring the actual cutting height with inclination sensors and comparing it with the desired cutting height. The control unit uses this feedback to automatically adjust the mower deck position, ensuring the actual cutting height matches the target value even on inclines.

Inventive Principle:
Principle #23Feedback

4Extent of automation

If inclination sensors are permanently mounted on the tractor, then the cutting height can be automatically controlled, but the system becomes more complex and expensive

Engineering Contradiction:
Improvecutting height automatic controlVSAvoidsensor installation complexity
Core Design Contradiction:
Extent of automationVSDevice complexity

Solution Approach 1:

The patent extracts the inclination sensors from permanent tractor mounting and relocates them to the mower deck. This allows automatic cutting height control to be achieved with simpler, more flexible installation that does not require permanent modifications to the tractor, reducing system complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The mower deck serves as an intermediary mounting platform for the inclination sensors. By mounting sensors on the mower rather than the tractor, the system achieves automatic control with simpler installation and easier sensor replacement, using the mower as a mediator between the control system and the cutting elements.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 precise and automatic adjustment of the cutting height of the mower, ensuring consistent mowing quality regardless of the tractor's inclination, without the need for permanent sensors on the tractor or complex plug connections.

Implementation Method 1

a first inclination sensor which can be mounted on the mower and detects a first inclination angle

Methodology Applied
Scientific EffectInclination sensing: Accelerometer

Implementation Method 2

a second inclination sensor which can be mounted on the towing vehicle and detects a second inclination angle

Methodology Applied
Scientific EffectInclination sensing: Accelerometer

Data Source

PatentEP3944751B1Control system for an agricultural vehicle set comprising a tractor and a mower, mower and vehicle set
Publication Date: 2024.06.26 CLAAS SAULGAU GMBH
  • EP3944751B1 patent drawingFigure 1
  • EP3944751B1 patent drawingFigure 2
  • EP3944751B1 patent drawingFigure 3

AI summary

Control system for an agricultural tractor unit (10) consisting of a tractor (11) and a mower (12), with a first tilt sensor (23) that can be mounted on the mower (12) and detects a first tilt angle, with a second tilt sensor (24) that can be mounted on the tractor (11) and detects a second tilt angle, with a control unit (26) that receives the first tilt angle from the first tilt sensor (23) and the second tilt angle from the second tilt sensor (24) and determines an actual cutting height of the mower (12) depending on an actual angle difference between the first tilt angle and the second tilt angle.