Harvester Sensor Positioning for Grain Loss Detection

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Solution Overview

Problem

Existing self-propelled agricultural harvesting machines face issues with inaccurate grain loss measurement due to poorly positioned sensors, leading to contamination and undesirable distribution of grains on the field, resulting in incorrect sieve settings and increased cleaning losses.

Innovation Solution

The sensor is arranged at the end of the cleaning device to capture falling crop portions, which are then directed to a tailings device, preventing grains from landing on the field and ensuring only non-grain parts reach the chaff blower. The sensor is inclined away from the radial straw distributor and has a movable extension mat and step-shaped guide element to reduce interference from chaff and straw, and is connected to the chaff spreader feed base for precise measurement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the sensor is firmly screwed to the frame of the machine at a fixed installation position, then the sensor structure is simple and stable, but the sensor is strongly dependent on longitudinal inclination causing grain to fly over the sensor and not be detected

Engineering Contradiction:
Improvedetection reliabilityVSAvoidsensor mounting complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies the dynamics principle by making the sensor mounting position adjustable rather than fixed. The sensor can be moved along the cleaning device to find the optimal detection position that is independent of machine inclination, thereby improving detection reliability without requiring complex additional structures.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent segments the sensor mounting system into adjustable components, allowing the sensor to be positioned at different locations along the cleaning device. This segmentation enables the sensor to be optimally positioned for each specific operating condition, resolving the contradiction between simple mounting and reliable detection.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If the sensor is arranged at the rear end of the cleaning device, then cleaning losses can be detected, but grains fall onto the field floor after detection creating stalemate and green streaks

Engineering Contradiction:
Improvecleaning loss measurementVSAvoidfield contamination
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent extracts the harmful effect by separating the detection function from the discharge location. The sensor detects grains at the rear end of the cleaning device, but the grains are then diverted into the radial straw spreader system rather than falling to the field floor, eliminating stalemate and green streak formation while preserving measurement capability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces an intermediary mechanism - the radial straw spreader system - that receives the detected grains and redistributes them properly. This intermediary prevents direct contact between detected grains and the field floor, eliminating contamination while maintaining the ability to measure cleaning losses.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If sensors are integrated in the feed elements of the chaff spreader, then grain is detected and distributed, but pieces of good and non-good parts are thrown back at high speed triggering false signals and influencing measurements

Engineering Contradiction:
Improvegrain distribution efficiencyVSAvoidcleaning loss measurement accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent extracts the sensor from the high-speed chaff spreader feed elements where it would be exposed to false signals from thrown-back material. By positioning the sensor at the rear end of the cleaning device before the chaff spreader, the measurement function is separated from the high-speed distribution zone, eliminating false signals while grain distribution continues uninterrupted.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent segments the cleaning and distribution system into distinct zones: the cleaning device where grains are separated, the sensor detection zone at the rear end, and the chaff spreader distribution zone. This segmentation prevents interference between measurement and distribution functions, allowing both to operate optimally without mutual interference.

Inventive Principle:
Principle #1Segmentation

4Device complexity

If the sensor surface is parallel to the rake surface, then the sensor arrangement is simple, but the sensor is dependent on longitudinal inclination and cannot detect grain when the machine is inclined

Engineering Contradiction:
Improvesensor arrangement complexityVSAvoidgrain detection reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent applies asymmetry by orienting the sensor surface perpendicular to the rake surface rather than parallel to it. This asymmetric arrangement creates a detection geometry that is independent of machine inclination, allowing the sensor to reliably detect grains regardless of the longitudinal slope during harvesting operations.

Inventive Principle:
Principle #4Asymmetry

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 arrangement reduces incorrect measurements and contamination, allowing for targeted control of the cleaning process, with over 95% of cleaning losses detected, preventing grain from germinating on the field and maintaining accurate sieve settings.

Implementation Method 1

a sound pick-up, which detects the impact impulse

Methodology Applied
Scientific EffectImpact impulse: Impact Force

Implementation Method 2

the upper and lower sieves being designed as adjustable lamellar sieves and being traversed by the air flow generated by the blower

Methodology Applied
Scientific EffectAir flow: Fluid Spray

Implementation Method 3

The oscillating movement of the sieves and the air flow also cause the grain and non-grain fractions to be conveyed to the rear end of the upper sieve

Methodology Applied
Scientific EffectOscillating movement: Vibration

Data Source

PatentEP2005813B2Self-propelled agricultural harvester with loss measurement device
Publication Date: 2014.11.19 CLAAS SELBSTFAHRENDE ERNTEMASCHINEN GMBH
  • EP2005813B2 patent drawingFigure 1
  • EP2005813B2 patent drawingFigure 2
  • EP2005813B2 patent drawingFigure 3

AI summary

The machine (1) has a cleaning device (11) with sieves (12, 13), and a loss-measuring device (21). A sensor with a sensor surface is located at a back end of the cleaning device. The sensor is located at end of the cleaning device behind the sieves that detect a remaining crop material (3) in the harvesting machine and conveys the material to a tailings (27) device. A rake (20) abuts the sieves, and has a surface that is not parallel with the surface of the rake and tilted toward the cleaning device at certain angle. A sensor holder determines arrangement of the sensor.