Non-contact Sensor for Agricultural Vehicle Load Detection

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Solution Overview

Problem

Current tire pressure control systems for agricultural vehicles, particularly tractors, face challenges in accurately measuring mechanical loads on components due to the rigidity of axle components and exposure to environmental factors, leading to inaccurate and complex strain sensor measurements, especially for unsprung axles.

Innovation Solution

A modular sensor arrangement using non-contact distance measurement sensors, which measure relative deformation between components and their housing, allowing for accurate detection of mechanical loads without direct contact and reduced sensitivity to disturbances, and can be easily integrated and retrofitted, with optional magnetostrictive sensors for torque measurement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If strain sensors are used to measure mechanical loads on axle components, then measurement capability is provided, but measurement precision deteriorates due to the rigidity of axle housing and environmental exposure

Engineering Contradiction:
Improvemeasurement precisionVSAvoidreliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent replaces mechanical strain sensors with optical sensors (laser distance sensors) that measure deformation optically. The laser sensor measures the distance to a reflective surface on the axle component, and changes in this distance indicate deformation. This substitution eliminates the need for mechanical contact, avoiding the problems of strain gauge rigidity requirements and environmental exposure, thereby improving both measurement precision and reliability.

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

Solution Approach 2:

The patent introduces a reflective surface (mirror or retroreflector) as an intermediary between the laser sensor and the axle component being measured. This intermediary allows the optical measurement system to indirectly detect mechanical deformation without direct contact, isolating the measurement system from environmental factors like dirt, temperature, and mechanical impact, thus improving reliability while maintaining precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If strain sensors are mounted on axle components, then mechanical load detection is enabled, but device complexity increases due to installation requirements

Engineering Contradiction:
Improveease of installationVSAvoiddevice complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical strain sensor installation (requiring valley-shaped recesses to be machined into the axle housing) with a simple optical setup. The laser distance sensor can be mounted externally on the vehicle body, pointing at a reflective surface on the axle component. This eliminates the need for complex machining and installation procedures, significantly reducing device complexity while improving ease of installation and maintenance.

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

3Object-affected harmful factors

If lowest permissible tire pressure is used for field work, then soil compaction is minimized, but tire load-bearing capacity is reduced

Engineering Contradiction:
Improvesoil compactionVSAvoidtire load-bearing capacity
Core Design Contradiction:
Object-affected harmful factorsVSStrength

Solution Approach 1:

The patent implements a feedback system where laser sensors continuously monitor the actual mechanical load on the tires during field work. This load information is fed back to the control system, which can dynamically adjust tire pressure in real-time. When the measured load approaches the tire's load-bearing capacity limit, the system increases pressure to prevent overload; when load is low, pressure is reduced to minimize soil compaction. This closed-loop feedback enables optimal tire pressure management that adapts to actual working conditions.

Inventive Principle:
Principle #23Feedback

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

This solution provides a simplified and accurate method for measuring wheel forces and torques, reducing the complexity of sensor installation and maintenance, while compensating for temperature and eccentricity influences, enhancing the reliability of mechanical load detection in agricultural vehicles.

Implementation Method 1

the sensor arrangement comprises at least one sensor, based on the principle of non-contact distance measurement, for detecting a physical quantity characteristic of a mechanical load

Methodology Applied
Scientific EffectNon-contact distance measurement:

Implementation Method 2

EP 2 851 667 A2 discloses a sensor arrangement based on the principle of inverse magnetostriction for detecting mechanical stress in a component of an agricultural vehicle

Methodology Applied
Scientific EffectInverse magnetostriction: Magnetostriction

Data Source

PatentEP3298871B1Agricultural vehicle, process for detecting a mechanical load on components of an agricultural vehicle
Publication Date: 2019.08.07 CLAAS TRACTOR
  • EP3298871B1 patent drawingFigure 1
  • EP3298871B1 patent drawingFigure 2
  • EP3298871B1 patent drawingFigure 3

AI summary

The present invention relates to an agricultural vehicle (1) comprising components (5, 14) subjected to mechanical stress by forces and/or moments, a control device (6) and a measuring device for detecting the mechanical stress on at least one of the components (14), wherein the agricultural vehicle (1) has a sensor arrangement (20), in particular a modular one, for arrangement on at least one component (5, 14) of the vehicle (1), wherein the sensor arrangement (20) has at least one sensor (10, 11) based on the principle of non-contact distance measurement for detecting a physical quantity characteristic of a mechanical stress.