COMBINE HARVESTER WITH A SENSOR SYSTEM

Description

[0001] The invention relates to a combine harvester with a sieve-like element and a sensor system.

[0002] From EP3222133A1, a method for detecting the number of grains in a harvested crop stream is known. In this method, grains impacting a sensor's impact surface are detected by means of a measurement signal. The sensor is not able to identify what type of elements are impacting the sensor's impact surface.

[0003] From EP3301407A1, a method for determining a mass flow rate is known. In this method, the force exerted by a mass flow on a sensor is measured. The sensor is unable to identify which elements exert the force. Further known combine harvesters with a sieve-like element and sensor systems are disclosed in DE19934881A1, US6121782A and US6700392B2.

[0004] The object of the invention is to provide a sensor that delivers more information about the detected elements.

[0005] The problem is solved by a sensor system for detecting elements of a crop flow, particularly in an agricultural machine, wherein the sensor system comprises a resonant circuit and a measuring device, wherein the resonant circuit consists of at least one capacitive element with a capacitance and an inductive element with an inductance, wherein the resonant circuit has a resonant frequency, the resonant frequency depending on the capacitance and the inductance, wherein the measuring device is provided and configured to determine the resonant frequency of the resonant circuit, wherein the capacitive element is arranged in the area of ​​the crop flow, and wherein the capacitive element is configured such that the capacitance is influenced by individual elements of the crop flow.the sensor system is designed and configured to infer at least one property of the respective element of the crop flow from the resonant frequency of the resonant circuit.

[0006] The sensor system measures the effect of each element of the crop flow on the capacitance of the capacitive component. Changes in capacitance alter the resonant frequency of the resonant circuit. These changes in resonant frequency, and thus capacitance, can be measured, allowing the crop flow element to be detected. The detected crop flow elements can then be counted.

[0007] The inductive component can be integrated into the measuring device, for example, in the form of an integrated circuit. If the inductance is known, the capacitance can be directly determined from the resonant frequency. Therefore, instead of measuring the change in resonant frequency, the change in capacitance can also be determined.

[0008] The magnitude of the change in capacitance and resonant frequency depends on the permittivity of the element in the crop flow. By determining the resonant frequency, the sensor system can deduce the element's permittivity. Permittivity is also called the permittivity or dielectric constant.

[0009] The sensor system is preferably designed and configured to distinguish between grain elements and non-grain elements, particularly straw elements. Grain elements have a significantly higher permittivity than straw elements. A grain element therefore changes the resonance frequency more than a straw element. The distinguishing property of the elements in the harvested crop stream in this case is whether the respective element is a grain element or a straw element.

[0010] The measuring device preferably determines the resonance frequency using a predetermined measurement frequency. The regular determination of the resonance frequency allows the sensor system to determine the temporal profile of the measurement of elements within the crop flow.

[0011] The resonant frequency is preferably greater than 1 kHz. The higher the resonant frequency, the faster it can be measured accurately.

[0012] The measurement frequency is preferably less than one-tenth of the resonance frequency. This relatively small measurement frequency allows for at least ten periods of the resonant circuit's oscillations to be measured in each measurement, thus determining the resonance frequency. This results in a more accurate determination of the resonance frequency than if only a few periods were measured.

[0013] The measurement frequency multiplied by the length of the capacitive element in the direction of movement of the crop flow is preferably greater than 2 m / s, particularly preferably greater than 30 m / s, and most preferably greater than 40 m / s. The measurement frequency multiplied by the length of the capacitive element in the direction of movement of the crop flow indicates the velocity of the elements of the crop flow that are still reliably detected by the sensor system. At a velocity of 2 m / s, grains that are separated from the husk and accelerated only by gravity can be reliably detected. This is the case, for example, in a combine harvester at the straw walker or the cleaning sieve. At a velocity of 10 m / s, grains that have been accelerated by the threshing drum or a rotor in the combine harvester can be reliably detected.At a movement speed of 25m / s, grains that have been accelerated for ejection in a forage harvester can be reliably captured.

[0014] The sampling frequency should be distinguished from the measurement frequency. The sampling frequency indicates how often a voltage and / or current is measured in the resonant circuit. The sampling frequency is at least twice the resonant frequency expected by the resonant circuit. Preferably, the sampling frequency is ten times the resonant frequency expected by the resonant circuit.

[0015] The capacitive component is designed as a planar capacitor. The capacitance of a planar capacitor is influenced by elements in the immediate vicinity of its surface. A planar capacitor can be mounted at the edge of the crop flow and detects the elements of the crop flow passing by it. A planar capacitor disturbs the crop flow less than a parallel-plate capacitor with two plates.

[0016] The capacitive component is designed as an interdigital capacitor. An interdigital capacitor exhibits a uniform sensitivity across its surface to elements from the crop flow. Therefore, each element influences the resonant frequency to the same extent, regardless of its position.

[0017] The sensor system is installed in a combine harvester. The invention relates to a combine harvester with a sieve-like element and a sensor system, wherein the sensor system comprises a resonant circuit and a measuring device, wherein the resonant circuit comprises at least one capacitive component with a capacitance and an inductive component, wherein the capacitive component is located in the immediate vicinity of the sieve-like element, wherein elements of a crop flow passing through the sieve-like element pass through the capacitive component and at least temporarily change the capacitance of the capacitive component, wherein the measuring device is provided and configured to determine the resonant frequency of the resonant circuit, and wherein the sensor system is provided and configured to infer at least one property of the respective element of the crop flow from the resonant frequency of the resonant circuit.

[0018] In this case, the sensor system counts elements of the harvested crop flowing through the combine harvester.

[0019] The capacitive element is positioned downstream of the sieve-like element in the direction of the crop flow. The sensor system therefore only counts the elements of the crop flow that pass through the sieve-like element. Elements of the crop flow that flow past the sieve-like element are not counted.

[0020] The sieve-like element is preferably a threshing concave, a flap matrix under a rotor, a shaker, or a cleaning sieve. A sieve-like element is characterized by a grid structure. The size of the openings is variable and can differ from element to element and may be adjustable. For example, the openings of a cleaning sieve are adjustable in size and are usually set to a size that is barely larger than the grains to be harvested. The openings of a threshing concave, on the other hand, are typically of a fixed size and significantly larger than the grains.

[0021] The surface normal of the planar capacitor is preferably oriented essentially perpendicular to the direction of flow of the harvested material. The elements of the harvested material flow thus move essentially along the surface of the capacitor. This arrangement combines minimal disturbance of the harvested material flow with accurate counting of the elements within the harvested material flow.

[0022] The capacitive component is preferably mounted on a surface of the sieve-like element. When mounted directly on the surface of the sieve-like element, the disruption of the crop flow is minimal.

[0023] The invention is explained in more detail below with reference to an exemplary embodiment. The figures show in Fig. 1: a combine harvester with straw walkers, Fig. 2: a combine harvester with a separating rotor, Fig. 3: a rotor of an axial separator, Fig. 4: a schematic of a sensor system for detecting elements of a crop flow, Fig. 5: an interdigital capacitor. Fig. 6 Figure 1 shows a sieve plane of the combine harvester. Figure 7 shows a detail of the sieve plane.

[0024] Figure 1 Figure 1 schematically shows a self-propelled agricultural machine 2 designed as a combine harvester 1. The combine harvester 1 has a multitude of working elements 3 for conveying and / or processing the harvested crop (not shown).

[0025] The crop is picked up by means of a header 4 and conveyed in a supplied crop stream 50 to the threshing unit 7 by means of an inclined conveyor 6. The threshing unit 7 comprises a concave 8, an acceleration drum 9, a threshing drum 10, and a deflection drum 11. At the concave 8, a first separation of freely moving grains (not shown) takes place in the form of a first crop stream 51.

[0026] After passing through the threshing unit 7, a second crop stream 52, containing straw fragments and unthreshed grains, is fed to a separation unit 13 designed as a straw walker 12. The free-moving grains still contained in the second crop stream 52 are separated by the straw walker 12 into a third crop stream 53, which is then directed onto a return floor 14 and a preparation floor 15. The remaining fourth crop stream 54, consisting primarily of straw fragments, is conveyed out of the harvester 2. The fourth crop stream 54 passes over a first grain loss counter 42. The grain loss counter 42 is a sensor system 26, as described in Figure 4The diagram shows a capacitor, preferably a planar interdigital capacitor, mounted on a flat surface over which the fourth crop stream flows. The sensor system detects the elements of the crop stream and distinguishes between grain and non-grain elements.

[0027] The invention does not only relate to combine harvesters 1 with a separation unit 13 designed as a straw walker 12. Rather, it is within the scope of the invention that it can also be a combine harvester 1 with separation rotors or other separation units 13.

[0028] Both the first and third crop streams 51, 53, which emerge from the threshing concave 8 and the straw walker 12 and contain primarily grain, are combined via the return floor 14 and the preparation floor 15 to form a fifth crop stream 55 and fed to a cleaning unit 19 consisting of several sieve levels 16, 17 and a blower 18. Here, the grains of the fifth crop stream 55 are cleaned, and non-grain components, such as chaff and straw, are separated in the form of a sixth crop stream 56 and conveyed out of the harvester 2. The sixth crop stream 56 passes over a second grain loss counter 43. The grain loss counter 43 is a sensor system 26, as described in Figure 4 The operating principle is identical to the first loss grain counter 42.

[0029] The illustrated combine harvester 1 also has a return auger 20, via which a seventh, incompletely threshed crop stream 57 can be fed back to the threshing unit 7. On its way to the return auger 20, the seventh crop stream 57 passes a return grain counter 44. The return grain counter 44 is a sensor system 26, as described in Figure 4 The operating principle is identical to the first loss grain counter 42.

[0030] A cleaned eighth crop stream 58, consisting of grain, is fed into a grain tank 21. The crop streams 50-58 shown are not exhaustive and depend on the technical configuration of the harvesting machine 2.

[0031] The illustrated combine harvester 1 has a multitude of sensor systems on its sieve-like elements, namely the threshing concave 8, the straw walker 12, and the sieve levels 16, 17. The sensor systems count the elements of the crop flow passing through the sieve-like elements 8, 12, 16, 17. The sensor systems distinguish between grain and straw.

[0032] A variety of sensor systems can distinguish how many grains are separated at each sieve-like element 8, 12, 16, 17 and how much straw passes through these elements. From this, conclusions can be drawn about the efficiency of the respective working elements 9, 10, 11, 12, 16, 17.

[0033] Each sieve-like element has a multitude of sensor systems distributed across its surface. This allows, for example, the detection of how many grain and straw elements pass into the third crop stream 53 at shaker 12. Based on this information, it can be determined whether the shaker is properly adjusted and the settings can be modified if necessary.

[0034] The readings from the sensor systems are collected in a control unit 31. The control unit 31 displays the readings to the operator, who can then adjust the settings of the working elements 3. Alternatively, the control unit 31 can make the adjustments automatically.

[0035] Figure 2 shows an alternative version of a combine harvester 1 with a separating rotor 22. The following only highlights the differences to Figure 1The rotor 22 serves as an alternative to the straw walker 12 and receives the second crop flow 52. The outer surface of the rotor 22 has a grid structure 23 and is thus a sieve-like element. The elements of the third crop flow 53 exit the separating rotor through the grid structure 23. Sensors on the grid structure 23 count the elements of the third crop flow 53. The sensors distinguish between grain elements and straw elements.

[0036] Figure 3 shows a separating rotor 22 of the combine harvester 1 from Figure 2 A separator rotor 22 is an axial separator. In Figure 3The separating rotor 22 is shown from below. The outer surface of the separating rotor 22 has a grid structure 23. The openings of the grid structure 23 can be partially closed by flaps 24. Planar capacitors 25 are attached directly to the grid structure 23. The surface of the capacitors 25 extends perpendicular to the outer surface of the cylindrical separating rotor 22. The elements of the crop flow in the separating rotor 22 typically exit the separating rotor 22 perpendicular to the outer surface of the separating rotor 22. The surface normal of the capacitor 25 is thus oriented essentially perpendicular to the direction of movement of the crop flow. The planar capacitors 25 can also be attached to the surface of the flaps 24. When the flaps 24 are open, the surface normal of the capacitor 25 is oriented essentially perpendicular to the direction of movement of the crop flow.Depending on the design of the sensor system, the entire sensor system can also be attached directly to the grid structure 23 or to the flaps 24.

[0037] Figure 4 Figure 26 shows a schematic diagram of a sensor system 26 for detecting elements of a crop flow. The sensor system 25 comprises a capacitor 25, an inductive component 27, such as a coil, and a measuring device 28. The measuring device 28 excites the resonant circuit consisting of the capacitor and coil via a voltage source 29 and measures a first voltage 30 across the capacitor 25, a second voltage 31 across the coil 27, and / or the current 32 through the resonant circuit. It is understood that the resonant circuit can be configured as either a series or a parallel connection.

[0038] Figure 5Figure 1 shows a schematic of an interdigital capacitor 25. The interdigital capacitor 25 has two electrodes 33, 34. The electrodes 33, 34 each have a multitude of finger-like structures, which are interlocked. An element 35 from the crop stream influences the capacitance of the interdigital capacitor 25 independently of its position on the surface of the interdigital capacitor 25. The element 35 of the crop stream can therefore be detected over the entire length 36 of the interdigital capacitor 25 in the direction of motion 37 of the crop stream.

[0039] Figure 6Figure 1 shows a sieve level 16 of the combine harvester 1. The fifth crop stream 55 falls from above onto the front end 38 of the sieve level 16. The crop is conveyed to the rear end 39 of the sieve level 16 by cyclical movements of the sieve level through throwing motions. During this process, elements of the crop stream fall through the grid-like structure of the sieve element.

[0040] Figure 7Figure 1 shows a detail of the sieve plane 16 in cross-section. The sieve plane 16 has movable elements. An upper part 40 of the movable element can be tilted from a position in the plane of the sieve plane 16 to a position perpendicular to the plane of the sieve plane. Depending on the angle of inclination of the movable element, the openings of the grid-like structure are larger or smaller. The angle of inclination therefore determines the size of the elements of the harvested material that can pass through the grid-like structure. A lower part 41 of the movable element is connected to the upper part of the movable element at a fixed angle. A capacitor 25 is attached to the lower part 41 of the movable element. Elements 35 of the harvested material flow passing through the openings influence the capacitance of the capacitor 25. The direction of movement 37 of the elements is essentially perpendicular to the sieve plane 16. The capacitor 25 is part of a Figure 4The sensor system 26 shown measures the change in capacitance of the capacitor. The permittivity of the respective element 35 can be determined from the magnitude of the change in capacitance of the capacitor 25. The permittivity can be used, for example, to distinguish grains from straw elements.

[0041] It is understood that each sensor system 26 can comprise a large number of capacitors 25. Smaller capacitors 25 allow for better detection of the elements within the respective crop flow, as fewer elements are measured simultaneously during a single measurement. Ideally, only one element is within the measuring range for each count. If multiple elements are present during a measurement, their influence on the capacitor's capacitance is additive, and the number and type of elements must be calculated accordingly. To ensure that as many elements as possible within the respective crop flow are detected, it is advantageous to select a higher measurement frequency when using smaller capacitor surfaces. Similarly, a higher measurement frequency is advantageous when the crop flow's velocity is higher.At excessively low measurement frequencies, elements of the crop flow can move across the capacitor between measurements without being detected by the sensor system. The manufacturer of the agricultural harvesting machine knows the capacitor sizes and the speeds of the crop flows, allowing them to predetermine appropriate measurement frequencies. Reference symbol list

[0042] 1Combine harvester 2Agricultural machine 3Working tool 4Attachment 50Input crop flow 51First crop flow 52Second crop flow 53Third crop flow 54Fourth crop flow 55Fifth crop flow 56Sixth crop flow 57Seventh crop flow 58Eighth crop flow 6Incline conveyor 7Threshing unit 8Threshing concave 9Acceleration drum 10Threshing drum 11Redirecting drum 12Horse shaker 13Separating unit 14Return floor 15Preparation floor 16Screening level 17Screening level 18Blower 19Cleaning unit 20Reverse auger 21Grain tank 22Rotor 23Grid structure 24Flap 25Condenser 26Sensor system 27 Coil 28 Measuring device 29 Voltage source 30 First voltage 31 Second voltage 32 Current 33 Electrode 34 Electrode 35 Element of a crop current 36 Length 37 Direction of movement 38 Front end of the screen plane 39 Rear end of the screen plane 40 Upper part of the moving element 41 Lower part of the moving element 42 First loss grain counter 43 Second loss grain counter 44 Reverse grain counter

Claims

1. Combine harvester (1) with a sieve-like element (8, 12, 16, 17) and a sensor system (26), wherein the sensor system (26) comprises an oscillating circuit and a measuring device (28), wherein the oscillating circuit consists of at least a capacitive component (25) with a capacitance and an inductive component (27), wherein the capacitive component (25) is attached in the immediate vicinity of the sieve-like element (8, 12, 16, 17), wherein elements (35) of a crop flow (50, 51, 52, 53, 54, 55, 56, 57, 58) that pass through the sieve-like element (8, 12, 16, 17) pass the capacitive component (25) and at least temporarily change the capacitance of the capacitive component (25), wherein the measuring device (28) determines the resonant frequency of the oscillating circuit, wherein the capacitive element (25) is arranged downstream of the sieve-like element (8, 12, 16, 17) in the direction of movement (37) of the crop flow (50, 51, 52, 53, 54, 55, 56, 57, 58), wherein the capacitive component (25) is formed as a planar capacitor (25), namely is designed as an interdigital capacitor (25).

2. Combine harvester according to Claim 1, characterized in that the sieve-like element (8, 12, 16, 17) is a threshing concave (8), a rotor, a walker (12) or a cleaning sieve (16, 17).

3. Combine harvester according to either of Claims 1 and 2, characterized in that the surface normal of the capacitor (25) is oriented substantially perpendicularly to the direction of movement (37) of the crop flow (50, 51, 52, 53, 54, 55, 56, 57, 58).

4. Combine harvester according to any of the preceding claims, characterized in that the capacitive component (25) is attached to a surface of the sieve-like element (8, 12, 16, 17).

5. Combine harvester according to any of the preceding claims, characterized in that the measuring device (28) determines the resonant frequency with a predetermined measurement frequency.

6. Combine harvester according to Claim 5, characterized in that the resonant frequency is greater than ten times the measurement frequency.

7. Combine harvester according to Claim 5, characterized in that the measurement frequency multiplied by the length (36) of the capacitive component (25) in the direction of movement (36) of the crop flow (50, 51, 52, 53, 54, 55, 56, 57, 58) is greater than 2 m / s, preferably greater than 10 m / s, particularly preferably 25 m / s.