System and method for determining threshing losses in a threshing system

Abstract

The present disclosure relates to a system and method for determining threshing loss in a threshing system. A method and system (100) for determining threshing loss in a threshing system (24) is provided. The method comprises illuminating a crop sample (500) downstream of at least a portion of the threshing system (24) with electromagnetic waves having a frequency in the range of 0.1-10 THz, measuring the reflection and / or transmission of the electromagnetic waves by the crop sample (500), establishing at least a two-dimensional terahertz image of the crop sample (500) based on the measured reflection and / or transmission, identifying at least one ear in the terahertz image, identifying at least one grain in the identified ear, and determining the threshing loss based on the identified grain.

Description

Technical Field

[0001] This invention relates to systems and methods for measuring threshing losses. It also relates to agricultural harvesters incorporating such systems. Background Technology

[0002] A combine harvester is a complex agricultural machine that travels through fields to harvest cereal crops while separating the ears of grain from the stalks and the grains from the ears. A header is mounted at the front of the combine harvester; the header is configured to cut the crop, remove it from the field, and feed it to a crop processing system that separates the grains from the rest of the harvested plant.

[0003] In the first stage of a crop processing system, grains are separated from the ears of grain. During this threshing stage, the crop is typically ground between threshing elements on a rotating threshing drum and a threshing cage partially surrounding the drum. In modern combine harvesters, the orientation of the threshing elements or the gap between the threshing drum and the threshing cage can be used to adjust the intensity of the threshing process. Intense threshing requires more energy and therefore results in higher fuel consumption. Additionally, intense threshing can cause grain breakage and increase wear on threshing system components. When threshing is not intense enough, grains remain in the ears of grain and are processed along with straw and other crop residues. These unprocessed grains that do not enter the grain bin are also known as threshing losses. Optimal threshing settings achieve a balance between minimal threshing losses and low fuel consumption.

[0004] Typically, threshing losses are estimated by the combine harvester operator, who periodically stops the harvester, goes out, and inspects some threshing residue by picking off ears of grain, rubbing them with his hand, and checking for any remaining grain. If so, the operator can increase the intensity of threshing. This manual assessment is labor-intensive and time-consuming, requiring considerable skill from the operator to accurately assess the situation.

[0005] European patent application EP 3797575 A1 discloses an arrangement for measuring threshing loss. A separating rotor, located downstream of the main threshing section, for separating already separated grains from other plant material, includes a small, periodically activated supplementary threshing section. A grain sensor detects grains from this supplementary threshing section. While the grains thus detected can be used as a measure of threshing loss in the main threshing section, this supplementary threshing section does have some drawbacks. The additional energy required for the extra threshing stage leads to higher fuel consumption, even when threshing loss is low and the additional threshing does not result in higher yields. Furthermore, the grain sensor used to determine threshing loss detects not only grains released from the ear by the supplementary threshing section but also grains separated from crop residue by the separator, thus reducing the accuracy of threshing loss measurements.

[0006] The purpose of this invention is to address one or more drawbacks associated with the prior art. Summary of the Invention

[0007] According to one aspect of the invention, a novel method for determining threshing loss in a threshing system is provided. The method includes irradiating at least a portion of a crop sample downstream of the threshing system with electromagnetic waves in the frequency range of 0.1-10 THz, measuring the reflection and / or transmission of the electromagnetic waves by the crop sample, constructing at least a two-dimensional terahertz image of the crop sample based on the measured reflection and / or transmission, identifying at least one ear of grain in the terahertz image, identifying at least one grain from the identified ear of grain, and determining the threshing loss based on the identified grain.

[0008] Terahertz waves are known to be used, for example, in medical imaging and security screening, and are very useful because they can penetrate lightweight fabrics and record density changes. Agricultural applications of terahertz radiation are less common, but are known for, for example, seed sorting in laboratory settings. By using terahertz radiation to analyze ears of harvested crops, the inventors have been able to distinguish between fully threshed ears containing no grains and unclamped (partially) empty ears containing grains that absorb most of the terahertz radiation. However, within or behind the threshing system, the grains in unclamped ears are not the only denser particles. The use of terahertz radiation offers the added advantage of performing well in dusty environments and not consuming much power. In a preferred embodiment, the electromagnetic waves have frequencies in the range of 0.1-6 THz, 0.1-3 THz, 0.5-3 THz, or 1-3 THz.

[0009] Standard terahertz imaging will similarly detect some high-density portions of lost grains along with straw and other crop residues. To ensure that only unclamped grains are considered when establishing threshing loss, the method according to the invention includes the step of first identifying ears of grain in a two-dimensional terahertz image. Therefore, the threshing loss determined using the method according to the invention is based solely on grains detected in unclamped ears of grain. Thus, the method according to the invention for determining threshing loss is more accurate than the alternative methods available to date.

[0010] Preferably, the method for determining threshing loss is not limited to detecting unclamped ears of grain, but also includes determining the number of grains in the identified ears based on measured reflectance and / or transmission. In addition to fully threshed and unclamped ears of grain, crop samples may also include partially threshed ears of grain still containing one or more grains. By calculating the number of grains remaining in the identified ears of grain, the effectiveness of the threshing system can be determined more accurately, and the operating settings of the threshing system can be better adjusted to optimize, for example, threshing intensity.

[0011] In one embodiment, the step of creating a terahertz image includes scanning point sensors in two directions. Alternatively, a two-dimensional terahertz image can be created by scanning an array of sensors in one direction, or a two-dimensional terahertz image sensor can be used.

[0012] Identifying ears of grain within a moving and thick layer of crop can be a challenging task. More accurate measurements of threshing loss can be achieved by separating the crop sample from the crop stream by diverting a portion of the crop stream through the threshing system or downstream of it to a bypass section prior to the irradiation step. In the bypass section, thinner and / or slower-moving or stationary crop samples can be analyzed.

[0013] Embodiments of the method according to the invention may further include the step of acquiring a second image of the sample using an image sensor for detecting radiation with a frequency greater than 10 THZ, and wherein the step of identifying at least one ear of grain includes identifying at least one ear of grain in the second image, aligning the terahertz image with the second image, and identifying at least one ear of grain in the terahertz image. When using a second image sensor to acquire a second image of the same sample, the use of different portions of the electromagnetic spectrum can improve the detection of ears of grain in the crop sample. While terahertz radiation is well-suited for detecting grains within unthreshed (or partially unthreshed) ears of grain, visible and / or infrared light may, for example, be better suited for detecting ears of grain in the crop sample. Further improvements can be achieved by combining image data from multiple different sensors to identify locations in the images where ears of grain can be found. When aligning images acquired by different sensors, the search for unthreshed grains in the terahertz image can be limited to those locations where ears of grain are detected in the second image. This allows for more efficient grain detection algorithms and better differentiation between grains within unthreshed ears and missing grains (or groups of missing grains) elsewhere in the crop sample.

[0014] To identify ears of grain and / or grains in different images obtained for performing the method according to the invention, trained neural networks and / or other artificial intelligence (AI) algorithms can be used.

[0015] According to another aspect of the invention, a system for determining threshing losses in a threshing system is provided. The system includes at least one terahertz transmitter for emitting electromagnetic waves in the frequency range of 0.1-10 THz, at least one terahertz sensor for measuring the reflection and / or transmission of the electromagnetic waves, and a controller operatively coupled to the terahertz transmitter and the terahertz sensor and configured to perform the method described above. This system can be provided as a standalone system for use with various threshing systems, or it can be part of an agricultural harvester having a threshing system.

[0016] In agricultural harvesters, the threshing system may include axially aligned threshing and / or separating rotors, and at least one terahertz sensor may be provided adjacent to the upper half of the threshing and / or separating rotor. Due to the gravity and mechanics of the crop being processed within the threshing system, the layer of crop passing through is typically thinner in the upper half of the threshing and / or separating rotor than in the lower half. Using the method and system according to the invention, the thinner crop layer helps improve the accuracy of threshing loss measurements. If the agricultural harvester includes a straw mixer located downstream of the threshing system, then at least one terahertz sensor may be provided adjacent to the lower half of the straw mixer.

[0017] Preferably, the controller in the agricultural harvester is configured to automatically adjust at least one operating setting of the threshing system based on the determined threshing loss. This allows for the establishment of a control loop, for example, minimizing threshing severity while ensuring low threshing loss. Attached Figure Description

[0018] Embodiments of the invention will now be described by way of example with reference to the accompanying drawings.

[0019] Figure 1 A combine harvester is shown, in which the method and system according to the invention can be advantageously used.

[0020] Figure 2 It shows Figure 1 A close-up of a portion of the combine harvester shown indicates some preferred locations of the threshing loss sensor according to the invention.

[0021] Figure 3 The diagram schematically illustrates a system used in combine harvesters to measure threshing loss. Detailed Implementation

[0022] Figure 1 An agricultural harvester in the form of a combine harvester 10 is shown, which generally includes front and rear circular joint wheels 14 and 16, a header 18, a feeder 20, an operator's cab 22, a threshing and separating system 24, a cleaning system 26, a grain tank 28, and an unloading pipe 30. It should be understood that although the agricultural harvester is shown as a combine harvester 10, the agricultural harvester according to the invention can be implemented as any construction that allows the harvesting of crop material, such as a conventional combine harvester (without a rotor), a rotary combine harvester, a hybrid combine harvester, a shredder harvester, etc.

[0023] The header 18 is mounted at the front of the combine harvester 10 and includes a cutter bar 34 for cutting the crop from the field during the combine harvester's forward movement. A rotatable reel 36 feeds the crop into the header 18, and a twin-helix conveyor 38 feeds the cut crop laterally from each side into the feeder 20. The feeder 20 conveys the cut crop to the threshing and separating system 24.

[0024] The threshing and separating system 24 is axial-flow type and includes a threshing rotor 40, which is at least partially located within and rotatable in the threshing recess 42. The threshing recess may be in the form of a perforated recess. Under the action of the threshing rotor 40 within the threshing recess 42, the grain from the chopped crop is threshed and separated from the MOG. Larger elements of the MOG (such as stems and leaves) do not pass through the perforations in the threshing recess 42 and are discharged from the rear of the combine harvester 10. The grain of the MOG and smaller elements (hereinafter referred to as small MOGs), such as chaff, dust, and straw, are small enough to pass through the perforations in the threshing recess 42 and are then discharged from the threshing and separating system 24.

[0025] The grain and small MOGs that have successfully passed through the threshing and separating system 24 fall onto the preparation tray 44 and are conveyed to the cleaning system 26. The cleaning system includes a series of sieves and a cleaning fan 52. This series of sieves includes a pre-cleaning sieve 46, an upper sieve (also referred to as a chaff sieve) 48, and a lower sieve (also referred to as a shoe sieve) 50. The cleaning fan 52 generates an airflow through the sieves 46, 48, and 50, which impacts the grain and small MOGs on them. Small MOGs are generally lighter than grains, so they separate from the grains while they are in the air. The small MOGs are then discharged from the combine harvester 10 based on the straw cover 54.

[0026] The preparation tray 44 and the pre-cleaning sieve 46 oscillate back and forth, conveying grains and small MOGs to the upper surface of the upper sieve 48. The upper sieve 48 is vertically arranged above the lower sieve 50 and also oscillates back and forth, so that the grains and small MOGs are scattered on the two sieves 48 and 50, while also allowing the cleaned grains to pass through the openings in the sieves 48 and 50 under the action of gravity.

[0027] Clean grain falls into a clean grain screw conveyor 56, which is positioned below and in front of the lower screen 50 and spans the width of the combine harvester 10. The clean grain screw conveyor 56 laterally conveys the clean grain to a vertical grain lift 60, which is arranged to deliver the clean grain to a grain tank 28. Once inside the grain tank 28, a grain tank screw conveyor 68 at the bottom of the grain tank laterally conveys the clean grain within the grain tank 28 to an unloading pipe 30 for discharge from the combine harvester 10.

[0028] Figure 2 It shows Figure 1 A close-up of a portion of the combine harvester 10 shown indicates some preferred locations of the threshing loss sensors 121, 122, and 123 according to the invention. Figure 1The threshing rotor 40 used in the exemplary combine harvester 10 is typically surrounded by a threshing recess 42 around its lower half and a rotor cover 43 around its upper half. The rotor cover 43 may include rotor blades (not shown) for guiding the crop along a helical trajectory surrounding the threshing rotor 40 and toward its rear end. The front portion of the threshing rotor 40 typically includes threshing elements that cooperate with the threshing recess 42 to separate the grains from the ears of harvested crop. The rear portion of the rotor 40 includes less aggressive separator elements configured to loosen the crop material so that falling grains can pass through the recess 42, while crop residue is moved to the rear of the combine harvester 10, where it can be shredded and discarded. Just behind the rear portion of the threshing rotor 40, a straw mixer 58 picks up the straw from the rear of the rotor 40 and pushes it toward an optional shredder and straw cover, from which the straw is scattered or falls onto the field.

[0029] According to the present invention, one or more threshing loss sensors 121, 122, 123 can be used to monitor threshing loss inside and after the threshing and separating sections of the combine harvester 10. Reference will be made below. Figure 3 The threshing loss sensors 121, 122, and 123, described in more detail, are used to detect whether any grains have not been properly threshed and are therefore remaining inside the ear of grain. One of the technical challenges that needs to be overcome when measuring these threshing losses is that the ear of grain only forms part of a dense and mobile layer of the other parts of the harvested plant. To mitigate this challenge, the threshing loss sensors 121, 122, and 123 are preferably placed in locations where the crop material layer is relatively thin and / or loose. Figure 2 The text indicates three suitable locations.

[0030] For example, multiple threshing loss sensors 121 can be arranged adjacent to the upper half of the threshing section of the rotor 40. Arranging the threshing loss sensors 121 along the entire length of the threshing section allows for monitoring of the threshing results. At the first threshing sensor 121 in the threshing section, many ears of grain still contain one or more kernels. At the last threshing sensor 121 in the threshing section, threshing loss should be minimal or nonexistent. Ideally, only the last threshing sensor 121 should not detect any unclamped ears of grain during threshing. Threshing may be too agitated when the threshing process has already been completed upstream. Therefore, some threshing settings can be adjusted to reduce threshing agitation. For example, the recessed gap between the threshing rotor 40 and the threshing recess 42 can be increased, movable threshing elements on the rotor 40 or the recess 42 can be moved, or the rotor speed can be adjusted. Threshing agitation can be increased when the last threshing sensor 121 in the threshing section still detects unclamped ears of grain.

[0031] Alternatively or additionally, one or more threshing loss sensors 122 may be positioned adjacent to the upper half of the separation section of rotor 40. Compared to the threshing section of rotor 40, the separation section may have a slightly looser crop layer with fewer loose grains, which can improve the accuracy of threshing loss measurements. Other threshing loss sensors 123 may be positioned adjacent to, for example, the straw mixer 58. It should be noted that the possible locations of these threshing loss sensors 121, 122, and 123 are not limited to... Figure 2 Examples are provided. The same or similar sensors could be equally useful for detecting unthreshed ears of grain in other parts of combine harvester 10, other agricultural machinery, or laboratory environments.

[0032] Figure 3 A system 100 for measuring threshing loss, used in a combine harvester 10, is schematically illustrated. System 100 includes one or more threshing loss sensors 121, 122, 123 and a controller 110 coupled to the threshing loss sensors. The controller 110 may be a dedicated controller used with system 100 solely for measuring threshing loss, or its functionality may be partially or fully provided by a general-purpose electronic controller of the combine harvester 10. Furthermore, multiple threshing sensors 121, 122, 123 may be coupled to and controlled by a central common controller 110, or each individual sensor 121, 122, 123 may include its own controller for controlling the sensor hardware and processing measurement results. Optionally, the controller 110 may be coupled to a monitor 130 or other type of output device for transmitting threshing loss measurement results to a user. For example, threshing loss may be presented to the user in numerical or percentage form. Alternatively, threshing loss may be visualized, for example by showing one or more ears of grain with a certain number of grains remaining, the number depending on the measured threshing loss. For example, empty ears of grain can indicate no threshing loss detected, and partially or fully filled ears of grain can indicate low and high threshing losses, respectively. Recorded threshing losses can be presented as figures showing the current threshing loss, graphs showing how threshing loss evolves over time, or maps showing how threshing loss changes across the entire field.

[0033] Each threshing loss sensor 121, 122, 123 includes at least one terahertz transmitter 210 for emitting electromagnetic waves in the frequency range of 0.1-10 THz, and at least one terahertz sensor 220 for measuring the transmission of the electromagnetic waves. In other embodiments, the terahertz sensor 220 may be configured to measure the reflection of electromagnetic waves at the crop sample 500 under study. A possible advantage of measuring reflection rather than transmission is that the measurement is less affected by the crop layer thickness, and the sensors 121, 122, 123 can be more compact. Threshing loss measurements may also be based on a combination of transmission and reflection.

[0034] The terahertz transmitter 210 may include, for example, a solid-state transmitter or a angular antenna, and may be adapted to a specific frequency in the range of 0.1-10 THz. In a preferred embodiment, the electromagnetic waves have frequencies in the range of 0.1-6 THz, 0.1-3 THz, 0.5-3 THz, or 1-3 THz. Combinations of two or more different frequencies in the 0.1-10 THz range can be used to improve the accuracy or sensitivity of the threshing loss sensors 121, 122, 123. Other antenna types that can be used are, for example, dipole antennas, photoconductive antennas, and on-chip antennas.

[0035] Figure 3 The threshing sensors 121, 122, and 123 shown also include an optional image sensor or camera 230 for creating images of the crop sample 500 based on visible and / or infrared light. The terahertz emitter 210, terahertz sensor 220, and image sensor or camera 203 can be housed in a single unit or as two or more separate units. Throughout the system 100, an external camera 230 can be used in conjunction with two or more separate threshing loss sensors 121, 122, and 123. Similarly, multiple terahertz sensors 220 can be used to detect electromagnetic waves emitted by a single terahertz emitter 210.

[0036] Based on the measured reflection and / or transmission of terahertz electromagnetic waves by the crop harvested within the combine harvester 10, at least a two-dimensional terahertz image of the crop sample 500 is constructed. The two-dimensional image can be obtained by scanning point sensors in two directions. Alternatively, the two-dimensional terahertz image can be constructed by scanning an array sensor in one direction or by using a two-dimensional terahertz image sensor. When processing the terahertz image, an image recognition algorithm is used to identify ears of grain in the imaged crop sample 500 and the grains remaining in the identified ears. Based on the identified unthreshed grains, threshing loss can be determined.

[0037] The step of identifying ears of grain in terahertz images is important for distinguishing individual, separated grains from those still held by the unthreshed ear. Ears of grain can be identified in the terahertz image itself, for example, by utilizing the characteristic that unthreshed grains are well aligned within the ear. This can be achieved using image sensors designed to detect radiation with frequencies greater than 10 THZ (such as...). Figure 3 The camera 230 shown acquires a second image of sample 500 to improve the detection of ears of grain in the two-dimensional image. When the terahertz image is aligned with the second image, the combination of available information from the two images can be used to identify the location of any ears of grain in crop sample 500 with increased accuracy. While terahertz radiation is well-suited for detecting grains within unthreshed (or partially unthreshed) ears of grain, visible and / or infrared light may be more suitable, for example, for detecting ears of grain in crop sample 500.

[0038] Further improvements can be achieved by combining image data from multiple different sensors to identify the locations where ears of grain can be found in the images. When aligning images obtained from different sensors, the search for uncropped grains in the terahertz image can be limited to those locations where ears of grain are detected in the second image. This allows for more efficient grain detection algorithms and better differentiation of grains within uncropped ears from missing grains (or groups of missing grains) elsewhere in the crop sample 500. To identify ears of grain and / or grains in different images obtained for performing the method according to the invention, trained neural networks and / or other artificial intelligence (AI) algorithms can be used.

[0039] Before attempting to detect any unthreshed ears of grain, diverting a portion of the crop stream, either through the threshing system or downstream of it, to a bypass section can further improve the accuracy of threshing loss measurements. Thinner and / or slower-moving or even stationary crop samples 500 can be analyzed when separating them from the main crop stream. Therefore, while this bypass section introduces some additional mechanical complexity, it can significantly improve the accuracy of threshing loss measurements. As an example only, a bypass section could be provided at the straw mixer 58, where some of the crop residue could be laterally diverted to the sensor used to measure threshing loss.

[0040] Preferably, the method for determining threshing loss is not limited to detecting unclamped ears of grain, but also includes determining the number of grains in the identified ears of grain based on measured reflectance and / or transmission. In addition to fully threshed and unclamped ears of grain, crop sample 500 may also include partially threshed ears of grain still containing one or more grains. By counting the number of grains remaining in the identified ears of grain, the effectiveness of the threshing system can be determined more accurately, and the operating settings of the threshing system can be better adjusted to optimize, for example, threshing intensity.

Claims

1. A method for determining threshing loss in a threshing system (24), the method comprising: At least a portion of the crop samples (500) downstream of the threshing system (24) are irradiated with electromagnetic waves in the frequency range of 0.1-10 THz. Measure the reflection and / or transmission of electromagnetic waves by crop samples (500). At least two-dimensional terahertz images of crop samples (500) are constructed based on the measured reflection and / or transmission. Identify at least one ear of grain in a terahertz image. Identify at least one grain from the identified ears of grain, and Threshing loss is determined based on the identified grains.

2. The method for determining threshing loss in the threshing system (24) as described in claim 1, further comprising determining the number of grains in the identified ear of grain based on measured reflection and / or transmission.

3. The method for determining threshing loss in a threshing system (24) as described in claim 1 or 2, wherein the step of establishing a terahertz image includes scanning point sensors in two directions.

4. The method for determining threshing loss in a threshing system (24) as described in claim 1 or 2, wherein the step of establishing a terahertz image includes scanning an array of sensors in one direction.

5. The method for determining threshing loss in a threshing system (24) as described in claim 1 or 2, further comprising transferring a portion of the crop stream passing through or downstream of the threshing system (24) to a bypass section prior to the step of irradiating the crop sample (500), thereby separating the crop sample (500) from the crop stream.

6. The method for determining threshing loss in a threshing system (24) as described in claim 1 or 2, further comprising the step of obtaining a second image of the sample using an image sensor (230) for detecting radiation with a frequency greater than 10 THZ, wherein the step of identifying at least one ear of grain comprises: Identify the at least one ear of grain in the second image. Align the terahertz image with the second image, and Identify at least one ear of grain in a terahertz image.

7. The method for determining threshing loss in a threshing system (24) as described in claim 6, wherein the image sensor (230) is an infrared sensor or a visible spectrum sensor.

8. The method for determining threshing loss in a threshing system (24) as claimed in claim 6, wherein the step of identifying the at least one ear of grain includes using a trained neural network and / or other artificial intelligence (AI) algorithms.

9. A computer program product comprising computer-executable instructions that, when executed by a computer, cause the computer to perform the method as described in any one of claims 1 to 8.

10. A system (100) for determining threshing loss in a threshing system (24), the system (100) comprising: At least one terahertz transmitter (210) is used to transmit electromagnetic waves in the frequency range of 0.1-10 THz. At least one terahertz sensor (220) is used to measure the reflection and / or transmission of electromagnetic waves, and The controller (110) is operatively coupled to the terahertz transmitter (210) and the terahertz sensor (220) and is configured to perform the method as described in any one of claims 1 to 8.

11. An agricultural harvester (10) comprising a threshing system (24) and a system (100) for determining threshing losses in the threshing system (24) as claimed in claim 10.

12. The agricultural harvester (10) of claim 11, wherein the threshing system (24) includes axially aligned threshing and / or separating rotors (40), and wherein the at least one terahertz sensor (220) is disposed adjacent to the upper half of the threshing and / or separating rotor (40).

13. The agricultural harvester (10) as claimed in claim 11 or 12 further includes a straw mixer (58) disposed downstream of the threshing system, wherein the at least one terahertz sensor (220) is disposed adjacent to the lower half of the straw mixer (58).

14. The agricultural harvester (10) as claimed in claim 11 or 12, wherein the controller (110) is further configured to automatically adjust at least one operating setting of the threshing system (24) according to the determined threshing loss.

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