Harvester Crop Density Sensor Using Radar and Laser

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Solution Overview

Problem

Existing methods for determining crop throughput in harvesting machines are inadequate for real-time adjustment, leading to under- or overloading of processing devices and potential blockages due to inaccurate detection of plant density and moisture content.

Innovation Solution

A device using a combination of visible/infrared laser beams and radar waves to create spatially resolved distance images, allowing for precise determination of plant density and height, which is then used to calculate the quantity of plants and adjust harvesting machine speed for optimal utilization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If sensors are used to determine crop throughput in the harvesting machine, then the crop throughput can be measured, but the measurement only takes place after the crop has been picked up, so sudden changes in crop throughput cannot be compensated for in time, resulting in under- or overloading of crop processing devices or even blockages

Engineering Contradiction:
Improvecrop throughput measurementVSAvoidresponse time for adjustment
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The device performs preliminary measurement of crop throughput using optical sensors and radar before the crop is picked up by the harvesting machine. This allows the control system to anticipate changes in crop throughput and adjust processing parameters in advance, preventing under- or overloading of crop processing devices and avoiding blockages.

Inventive Principle:
Principle #10Preliminary action

2Length of stationary object

If radar beams are used to measure distance to the ground, then the propagation time can be recorded, but a large proportion of radar beams penetrate the canopy and are only reflected by the ground, making it difficult to accurately detect plant density and moisture content

Engineering Contradiction:
Improvedistance measurementVSAvoidplant density and moisture content detection
Core Design Contradiction:
Length of stationary objectVSMeasurement precision

Solution Approach 1:

The measurement system is segmented into multiple independent sensing channels: optical sensors (laser/visible light) for detecting plant canopy characteristics including density and moisture content, and radar sensors for measuring ground distance. Each sensor type targets specific properties, and the evaluation device integrates these segmented measurements to compute comprehensive crop throughput parameters.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The device employs multiple sensor types that serve different functions simultaneously: optical sensors for plant property detection, radar for ground reference measurement, and the evaluation device integrates both to provide comprehensive crop throughput determination. This multi-functional approach overcomes the limitations of any single sensor type.

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

3Measurement precision

If laser sensors are used to record plant profile, then the distance to the ground and grain surface can be measured, but in dense plant populations the waves do not penetrate to the ground, making it impossible to record the exact height of plants, which is particularly important in the case of uneven fields

Engineering Contradiction:
Improveplant height measurementVSAvoidmeasurement capability in dense stands
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

Radar waves serve as an intermediary measurement tool that can penetrate dense plant canopies where optical laser beams cannot. The radar measures the ground distance as a reference, and the evaluation device uses this ground reference combined with optical sensor data to calculate plant height, even in dense populations where direct optical penetration to ground is blocked.

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 accurate detection of plant quantity and density, preventing blockages and improving harvesting efficiency by allowing for anticipatory adjustments in machine speed and processing parameters, enhancing driving comfort and harvest results.

Implementation Method 1

a first transmitter (64) which, during operation, emits first electromagnetic waves in the visible or infrared range (in particular laser beams) onto a stand of plants (82), a first receiver (66) which is sensitive to first waves (64) reflected by the plants (82) or the ground (84)

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 2

a second transmitter (68) which emits second electromagnetic waves onto the crop during operation, a second receiver (70) which is sensitive to second waves (68) reflected from the ground (84)

Methodology Applied
Scientific EffectRadar: Radar

Implementation Method 3

The evaluation device determines the propagation time of the waves arriving from the transmitter to the receiver, which contains information about the distance of the reflection point from the transmitter and receiver due to the known, fixed speed of light

Methodology Applied
Scientific EffectTime of flight: Time of Flight

Data Source

PatentEP2517549B1Assembly and method for detecting the quantity of plants on a field
Publication Date: 2015.11.04 DEERE & CO
  • EP2517549B1 patent drawingFigure 1
  • EP2517549B1 patent drawingFigure 2

AI summary

The arrangement has a transmitter (64), which is operated to emit the electromagnetic waves within the visible or infrared wavelength range on a ground covering of a field (80). A receiver (66) is operated to receive waves reflected from the plants (82). An estimation unit (76) is operated to determine elapsed time of the reflected waves of the transmitter to the receiver at different points along a measuring direction. Another transmitter (68) is operated to emit other electromagnetic waves that are reflected from the earth (84) to the significant portion by penetrating the ground covering. An independent claim is included for a method for detecting the quantity of plants in a field.