CUTTING UNIT WITH SENSORS FOR HEIGHT CONTROL

Description

[0001] The present invention relates to a cutting unit for attachment to the height-adjustable intake channel of a harvesting machine, comprising a frame, an attachment device connected to the frame for attaching the cutting unit to the harvesting machine, cutting elements, conveyor devices and drives, at least one distance sensor arranged on the cutting unit for determining the distance of the cutting unit from the ground, and an interface via which height-control-relevant signals can be transmitted to a control or regulating device arranged on the harvesting machine.

[0002] DE 44 06 892 A1 discloses a distance sensor located on the underside of the cutting unit that measures the cutting unit's clearance from the ground. The signal provided by the distance sensor is transmitted to a control device, which evaluates the signal and generates a control signal for an adjusting device. This control signal corrects the height of the cutting unit by an amount corresponding to the measured change in distance. In addition to the distance sensor, this document also discloses a pressure sensor that measures the hydraulic pressure in the hydraulic system for the hydraulic cylinders used to adjust the intake channel supporting the cutting unit. The height of the cutting unit is controlled alternatively using the sensor values ​​of the pressure sensor or the distance sensor.

[0003] EP 3 335 541 discloses a cutting unit comprising two sensor arrangements, each used separately in a specific operating mode with a rigid or flexibly switched cutting unit, but not in combined operation. While one sensor is a ground sensor whose movements are evaluated via a potentiometer, the other sensor is a rotary encoder that detects the movement of a support arm.

[0004] EP 3 363 276 A1 discloses a cutting unit in which the movements of two different moving machine elements for ground clearance measurement are measured by a common potentiometer and transmitted to a processor, which evaluates the transmitted sensor data to control the height of the cutting unit. Depending on the operating mode of the processor and the cutting unit—rigid or flexible—the movements of one or the other machine element are further processed by the processor via the potentiometer.

[0005] Finally, the generic document EP 2 695 511 A1 is also known from the prior art. This document discloses a height control system with a distance sensor, a weight sensor, an operating unit, and an electronic processing unit that determines a height value according to one of several algorithms depending on a height preselected by the operator. The sensor signals are each transmitted directly to the electronic processing unit. WO 2018 / 152266 A1 discloses only a distance sensor on a harvesting header. The distance sensor data is transmitted to the electronic control system via an interface located on the cutting unit.

[0006] When this description refers to a distance sensor, it can measure the distance from the lowest point of the cutting unit to the ground. However, the distance measured by the distance sensor can also be determined relative to another point on the cutting unit, for example, the distance of the cutter bar as the cutting element from the ground. For simplicity, the following only refers to the distance of the cutting unit to the ground, even if this distance value is determined relative to a specific component of the cutting unit that does not have the shortest distance of any cutting unit component to the ground.

[0007] Known sensor arrangements for height control serve the purpose of adapting the height control of the header to different harvesting conditions. For example, the ground sensors disclosed in DE 44 06 892 A1 are used to control the height control of the header in laid grain, while the pressure sensors and position sensors are used when the header is moved at a greater distance from the ground in standing crops. According to EP 3 335 541, the ground sensor is used to operate the header in a fixed operating mode at a greater distance from the ground, while the rotary encoder on the support arms is used in a flexible operating mode to raise or lower the header as needed.Also in the cutting unit disclosed in document EP 3 363 276, the movements of the ground sensor or the support arm are used in a rigid or flexible operating mode to control the height of the cutting unit.

[0008] The various sensor arrangements used in the cutting units known from the state of the art therefore only serve to provide the sensor values ​​they generate for a specific operating mode of the cutting unit's height control assigned to the respective sensor arrangement. To achieve this, it is necessary to switch the cutting unit's height control to a different operating mode. This switching can be done manually by the harvester operator, but automated switching is also possible, which occurs independently of operator inputs.

[0009] A disadvantage of the known solutions is that switching between the cutting units is only possible if the cutting unit on a harvester is adapted to the harvester's operating electronics. This is usually only possible within the electronic architecture of a particular harvester brand. Cutting units that are not part of the harvester's make are therefore excluded from switching.

[0010] A further disadvantage of existing systems is that the continuous switching requires the driver's concentration and supervision. This applies not only when the switchover has to be carried out manually, but also when automated switchovers are carried out, because these do not always occur in a timely and appropriate manner, or, viewed across the working width of a header, one operating mode would be desirable in one partial working width and another in another partial working width. The automatic switchover systems therefore distract the driver from other operating tasks and, if the driver is inattentive, can even cause damage to the header if its contact with the ground is too hard, or lead to crop losses if the header is raised too high.If the cutting unit is set close to the ground, which is actually the normal case, constant switching between the operating modes can occur, which unsettles the driver and causes him to set the cutting unit higher than is actually necessary and possible.

[0011] The object of the present invention is to improve the sensor-supported height control of cutting units.

[0012] The problem is solved for a generic cutting unit in that an evaluation device is arranged upstream of the interface, to which the sensor values ​​measured by the distance sensor are transmitted via a connecting line, the cutting unit has at least one additional load sensor which measures the load with which the cutting unit loads the intake channel, the sensor values ​​measured by the load sensor are also transmitted to the evaluation device via a connecting line, and the evaluation device has a program which, via suitable programming, calculates a height control-relevant signal from the transmitted sensor values ​​of the distance sensor and the load sensor, which signal is transmitted to the interface.

[0013] With the additional load sensor, the evaluation device can detect whether the cutting unit is supported solely by the intake channel or whether the load is partially or completely relieved due to the cutting unit making contact with the ground. However, the load on the intake channel is not determined by a pressure measurement in the hydraulic circuit of the hydraulic cylinders that support the intake channel, but rather directly in the cutting unit. Changes in the load on the intake channel are thus more quickly detectable because the load changes are not measured in a downstream hydraulic system after they have arrived there in the form of measurable pressure changes.

[0014] A further advantage is the direct, ongoing link between the sensor values ​​measured by the load sensor and the sensor values ​​measured by the distance sensor. The distance sensor only provides usable sensor values ​​for height control if the cutting unit is still at a certain distance from the ground. If the cutting unit is resting on the ground, the distance value is zero.

[0015] However, the distance sensor does not provide any information about whether or not part of the header's weight is still being supported by the feeder channel when it makes contact with the ground. However, it is precisely then that it is of particular interest for height control to know the weight of the header when it is resting on the ground. In contrast, a load sensor does not provide any useful sensor values ​​for header height control if the feeder channel bears the full weight of the header, because in this case 100% of the header's weight is always borne by the feeder channel. However, it is precisely then that it is of particular interest for height control to know whether the underside of the header is only 1 cm or 50 cm from the ground.

[0016] According to the state of the art, when ground contact is reached or terminated, the system switches to another operating mode in which other sensors with different sensor signals are used to control the height of the header. However, if the sensor signals from the distance sensor and the load sensor are continuously calculated in a common evaluation device to produce a height-control-relevant signal, the sensor values ​​generated by the distance sensor and the load sensor can be incorporated together into the continuously generated height-control-relevant signal without having to change the operating mode of the harvester and / or the header. Abrupt transitions between operating ranges, in which one or the other sensor type still delivers usable sensor values ​​or no longer delivers them, can be achieved smoothly by calculating the sensor values ​​to produce a height-control-relevant signal.

[0017] Switching back and forth between different operating modes is no longer necessary because the sensor values ​​from the various sensor types are continuously incorporated into the determination of the height control-relevant signal. The height control-relevant signal calculated from the various sensor types remains constant, especially when the header is frequently guided close to the ground during harvesting. This reduces the number of adjustments to the header height control and significantly relieves the driver of the resulting control tasks and manual control interventions. The risk of incorrect adjustments that could damage the header is reduced. At the same time, the harvester driver's confidence in the header height control increases, allowing them to set the header lower than with conventional technology.This can increase crop yields and also improve field hygiene because insects, fungi and other pests have less space to hide when the crop to be harvested is harvested more completely.

[0018] The distance sensor can be a mechanical probe or an optical, acoustic, or other sensor, such as a radar, ultrasonic, or laser sensor, with which the distance of the cutting unit from the ground can be measured. The sensor value of the distance sensor can be transmitted to the evaluation device via a wired connection line, electrically, by direct cabling or a bus network, via fiber optic cable, via an NFC chip, via radio / Wi-Fi, or in some other way. The distance sensor(s) are positioned on the cutting unit in such a way that they can continuously measure the distance of the cutting unit, preferably the cutting element, from the ground. The distance values ​​measured by the distance sensor can be corrected as a sensor value in relation to the pure measured value by an amount, for example by a height measurement by which the distance sensor is positioned higher or lower than the reference point on the cutting unit to which the sensor value refers.

[0019] The load sensor is a sensor that detects the load on the intake channel due to the weight of the cutting unit. The load sensor can be designed, for example, as a load cell, a strain gauge, a piezoelectric element, or the like. However, the load sensor can also provide relative or indirect sensor values ​​that allow inferences to be drawn about a degree of load, such as a pressure sensor that measures pressures in a medium loaded by the weight of the cutting unit, such as a liquid or gas, or a length or angle sensor that measures the deformation of a loaded component, such as a spring. The load sensor can be arranged on a component by which the cutting unit is held to the intake channel when attached.The sensor value of the distance sensor can also be transmitted to the evaluation device via a wired connection cable, electrically, by direct cabling or a bus network, via fiber optic cable, via an NFC chip, via radio / Wi-Fi or in any other way.

[0020] The interface provides the height control-relevant signal calculated by the evaluation unit so that it can be adopted as an input variable by a control or regulating device on the harvesting machine, which controls or regulates the pivot position of the intake channel and thus the distance of the cutting unit from the ground and the proportion of the weight of the cutting unit that the intake channel bears. The interface can be designed as a network node of a bus network connection, as a socket for the plug of a connecting cable between the harvesting machine and the cutting unit for electrical or optical signal transmission, as a radio interface that communicates the height control-relevant signal with the harvesting machine via a radio link, or in another suitable manner. The height control-relevant signal is provided in such a way that it can be processed by the control or regulating device of the harvesting machine.This also applies to compliance with any defined transmission protocol, reporting frequency, signal strength, and the like.

[0021] The control or regulation device on the harvester can further process the height control-relevant signal in a suitable operating mode. Harvesters such as combine harvesters typically have at least two operating modes in which the header height control can be operated. In In a first operating mode, the cutting unit is set to a normal position, which is then monitored and adjusted in an automatic mode via mechanical or other distance sensors. This type of height control is often selected when a cutting unit is to be operated at a certain distance from the ground. In In a second operating mode, the height is controlled via a measured contact pressure of the cutting unit on the ground. This operating mode is often selected in order to guide the cutting unit as close to the ground as possible. The inventive design of the cutting unit makes it possible to have the height control of the cutting unit on the harvester side run permanently via one of the two operating modes, without having to switch back and forth between these operating modes or have it switched back and forth via an automatic system. The cutting unit according to the invention can, for example, be operated in the first mode by setting it to a desired height at the start of harvesting and the height control thereafter only taking place depending on the size of the height control-relevant signal.Due to the different sensor types used in the header and the calculation of the sensor values ​​to a height control-relevant signal, ground guidance is more reliable, so that the header can be set closer to the ground in the preselected normal position in the first operating mode. The normal position is then similar or identical to the height of the header in the second operating mode. However, it is also possible to preselect a higher normal position of the header if desired. The header can also be lowered to ground contact in the second operating mode and then moved while evaluating the height control-relevant signal. Like a pressure sensor value, the height control-relevant signal also provides a value with which the header can be height-controlled like a ground pressure-controlled header.

[0022] To obtain the height control-relevant signal, the evaluation device calculates the sensor values ​​from the distance sensor and the load sensor. The calculation is performed by setting the sensor values ​​transmitted to the evaluation device in a ratio stored in the program. The resulting ratio results in a respective calculated value, which is transmitted as such or increased or reduced by a factor to the interface. From there, it can be accepted by the harvester and further calculated by the control or regulating device on the harvester to create a control command for the height control of the intake signal. The factor can be constant or variable. The evaluation device outputs the height control-relevant signal in a size that is suitable and processable for further processing by the control or regulating device of the harvester.In order to enable further processing of the height control-relevant signal from harvesting machines of different manufacturers, it can be adjusted by the evaluation device using a correction factor if necessary.

[0023] The invention is also achieved by a method for height control of a cutting unit mounted on the height-adjustable intake channel of a harvesting machine, wherein a distance sensor arranged on the cutting unit determines the distance of the cutting unit to the ground and generates a sensor value therefrom, which is transmitted to an evaluation device, a load sensor is arranged on the cutting unit, which measures the load with which the cutting unit loads the intake channel and generates a sensor value therefrom, which is transmitted to the evaluation device, the evaluation device has a program which, via suitable programming, calculates a height control-relevant signal from the transmitted sensor values ​​of the distance sensor and the load sensor, and the height control-relevant signal is transmitted to an interface via which it can be transmitted to a control or regulating device arranged on the harvesting machine.

[0024] The above statements apply accordingly to the procedure.

[0025] According to one embodiment of the invention, the cutting unit is connected to the intake channel of a harvesting machine via a spring system, and a device for measuring the spring deflection of the spring system serves as a load sensor. If part of the weight of the cutting unit is supported on the ground, the weight bearing on the springs is reduced. The springs thereby expand and lengthen. Conversely, the springs rebound when the portion of the cutting unit's weight supported on the ground decreases again. These movements can be easily recorded by a spring deflection measuring system, and the resulting measured values ​​can be transmitted to the evaluation device as sensor values.

[0026] According to one embodiment of the invention, the evaluation device averages the sensor values ​​transmitted within a time interval. For example, with two sensors, the sensor values ​​are added together and the sum is halved; with four sensors, the sensor values ​​are added together and the sum is quartered, and so on. By averaging the sensor values, the sensor values ​​of the distance sensor, when it signals no distance from the ground, and the sensor values ​​of the load sensor, when it signals full load on the intake channel, are included in the height control-relevant signal. However, by averaging the sensor values, these zero values ​​only have a dampening effect on the magnitude of the height control-relevant signal. Extreme control deflections of the height control are thus avoided.The damping also has a calming effect on the header height control, especially in the transition areas to the zero values ​​of the two sensor types, because there is no abrupt switching from one control mode to the other. Instead, the height control-relevant signal only changes slightly in magnitude, as the ground clearance or the proportion of the header weight borne by the intake channel changes. However, significant changes in the ground contour relative to the current header height setting are converted into a corresponding height control-relevant signal, which signals a raising or lowering of the header in the appropriate direction.

[0027] According to one embodiment of the invention, the evaluation device increases or decreases the sensor value of the distance sensor transmitted in a time interval by a correction factor if the sensor value of the load sensor signals a full load of the intake channel, and / or the evaluation device increases or decreases the sensor value of the load sensor transmitted in a time interval by a correction factor if the sensor value of the distance sensor signals no distance of the cutting unit from the ground. In order to increase or decrease the reaction speed of the control or regulating device on the harvesting machine, the evaluation device can increase or decrease the respective sensor value by offsetting it with a correction factor in order to reduce or increase the influence of the damping by averaging the sensor values. The correction factor can remain constant or be variable.

[0028] According to one embodiment of the invention, the sensor values ​​are transmitted to the evaluation device as percentage values ​​between the respective minimum and maximum values ​​of the distance and load sensors, or are converted by the evaluation device into percentage values ​​between the respective minimum and maximum values. Sensor values ​​transmitted as percentage values ​​or converted into percentage values ​​are easily further processed by a control or regulation device on the harvesting machine.

[0029] It is expressly pointed out that the above-described embodiments of the invention can be combined with the subject matter of the main claim, either individually or in any combination, provided that there are no technically compelling obstacles to this.

[0030] Further modifications and embodiments of the invention can be found in the following description and the drawings.

[0031] The invention will now be explained in more detail using exemplary embodiments. They show: Fig. 1: a side view of a harvesting machine with a cutting unit spaced from the ground, and Fig. 2: a side view of a harvesting machine with a cutting unit that has contact with the ground.

[0032] In Fig. 1 A harvesting machine 4 is shown, to which a cutting unit 2 is attached on the side facing in the direction of travel. The cutting unit 2 is held by its frame 8 on the height-adjustable intake channel 6. The frame 8 has an attachment device 10 with which the cutting unit 2 can be attached to the harvesting machine 4.

[0033] Cutting elements 12, such as a cutter bar, are located at the front edge of the cutting unit 2. Furthermore, the cutting unit features conveyor devices 14, such as augers and / or belt conveyors, which transport the cut crop toward the intake channel and discharge it there, or a reel, which can be seen in the side views. Furthermore, the cutting unit 2 features drives 16, which drive the cutting elements 12 and the conveyor devices 14. In the illustrated embodiment, the drives 16 are located behind the side flap, designated by reference number 16, on the side wall of the cutting unit 2.

[0034] As an example of a distance sensor 18, Fig. 1 a sensing skid is shown. However, any other sensor types can be used for the purposes of the invention, such as lasers, ultrasonic sensors or distance sensors that operate according to other physical principles. Fig. 1 In the working situation shown, the cutting unit 2 is held at such a large distance 20 from the ground that contact of the cutting unit 2 with the ground is excluded. However, the distance 20 is also small enough that the distance sensor 18 can measure the distance 20 from the ground.

[0035] The distance sensor 18 is connected to an evaluation device 24 via a connecting line 22.

[0036] A further sensor is a load sensor 26 in the cutting unit 2, which determines the load 28 exerted on the intake channel 6 of the harvesting machine 4 by the weight of the cutting unit. Since the cutting unit is in the Fig. 1 shown working position is held at a large distance 20 from the ground, the intake channel 6 carries the full weight of the cutting unit 2. The load sensor 26 transmits the sensor values ​​measured by it via a connecting line 22 to the evaluation device 24. In the exemplary embodiment, the load sensor 26 is a device for measuring the spring travel 44 of the spring system 42. Independently of this sensor type, other sensor types can also be used to determine the load on the intake channel 6 due to the weight of the cutting unit.

[0037] The evaluation device 24 has a program 30 which, through suitable programming, calculates a height control-relevant signal 32 from the sensor values ​​25 transmitted by the distance sensor 18 and load sensor 26. This signal is transmitted to the interface 34. The height control-relevant signal 32 is transferred from the header-side interface 34 to the harvester-side interface 36. The harvester-side interface 36 is connected to a control or regulating device 38 located on the harvester 4. Part of the control or regulating device 38 is an adjustment drive 40, by actuating which the height of the intake channel 6 of the harvester 4 can be adjusted. The adjustment drive 40 can, for example, consist of hydraulic cylinders (not shown in detail in the drawing), which lower or raise the intake channel 6 by extending and retracting, depending on the direction of movement.The hydraulic cylinders are actuated via a corresponding hydraulic system with corresponding valves.

[0038] In the Fig. 1 In the embodiment shown, for example, the distance sensor 18 reports a deflection of the sensing skid by 30% as sensor value 25 of the distance sensor 18. Since the full weight of the cutting unit 2 is borne by the intake channel 6, the load sensor 26 reports a load of 100% as sensor value 25. The following calculation results from these two numerical values: 30 % + 100 % = 130 % : 2 = 65 %

[0039] This value of 65% is transmitted by the evaluation device 24 as a height control-relevant signal 32 to the interface 34. This percentage value can be further processed by the control or regulating device 38 into a control signal to the adjustment drive 40 if this appears necessary after the evaluation of the height control-relevant signal 32 by the control or regulating device 38.

[0040] In the Fig. 2 In the embodiment shown, the contact shoe of the distance sensor 18 is completely folded in due to its contact with the ground. Accordingly, its deflection is 0%. Due to the contact of the cutting unit 2 with the ground, the intake channel 6 is partially relieved of its weight. Fig. 2 In the illustrated embodiment, the intake channel 6 still carries 20% of the weight of the cutting unit 2. The sensor value 25 of the load sensor 26 is therefore 20%. When the evaluation device calculates the two sensor values ​​25, the following calculation results: 0 % + 20 % = 20 % : 2 = 10 %

[0041] The height control-relevant signal 32 determined by the evaluation device 24 is therefore in the Fig. 2 shown second embodiment 10%.

[0042] Depending on the height setting of the cutting unit 2 on the intake channel 6, the sensor values ​​25 of the distance sensor 18 and the load sensor 26 described above can naturally vary. Depending on the magnitude of the sensor values ​​25, a correspondingly different height control-relevant signal 32 results.

[0043] By dividing the sum of the two sensor values ​​25 in half, they are weighted equally. Deviating from the exemplary embodiment, it is of course also possible to give the distance sensor 18 or the load sensor 26 a higher weighting than the other sensor. The respective weighting of the sensor values ​​25 can either be permanently programmed into the program 30, or the operator of the harvesting machine 4 has the option of changing the weighting as they see fit. In any case, by offsetting the sensor values, a break is avoided at the point at which the values ​​of one of the sensors no longer change, as with the distance sensor 18 when the distance to the ground is 0, and with the load sensor 26 when the intake channel 6 bears 100% of the weight of the cutting unit 4.

[0044] Likewise, in one embodiment, it can be provided that the evaluation device 24 averages the sensor values ​​25 transmitted in a time interval.

[0045] The invention also relates to a method which, according to the above-described pattern, determines a height control-relevant signal 32 and transmits this to a control or regulating device 38 arranged on the harvesting machine 4.

[0046] In the method, it is possible for the evaluation device 24 to increase or decrease the sensor value 25 of the distance sensor 18 transmitted in a time interval by a correction factor if the sensor value 25 of the load sensor 26 signals a full load 28 of the intake channel, and / or the evaluation device 24 to increase or decrease the sensor value 25 of the load sensor 26 transmitted in a time interval by a correction factor if the sensor value 25 of the distance sensor 18 signals no distance 20 of the cutting unit 2 to the ground.

[0047] According to a further embodiment, the sensor values ​​25 are transmitted to the evaluation device 24 as percentage values ​​between the respective minimum and maximum values ​​and / or are converted by the evaluation device 24 into percentage values ​​between the respective minimum and maximum values ​​in order to then transmit the result of this calculation to the interface 34 as a height control-relevant signal 32.

[0048] The invention is not limited to the above embodiments. Those skilled in the art will have no difficulty modifying the embodiments in a manner they deem appropriate to adapt them to a specific application. List of reference numbers

[0049] 2Header 4Harvester 6Feeder channel 8Frame 10Attachment 12Cutting element 14Conveyor device 16Drive 18Distance sensor 20Distance 22Connecting cable 24Evaluation device 25Sensor value 26Load sensor 28Load 30Program 32Height control-relevant signal 34Interface (header) 36Interface (harvester) 38Control or regulating device 40Adjustment drive (harvester) 42Spring system 44Device for spring travel measurement

Claims

1. Cutterbar (2) for attaching to the height-adjustable feeder housing (6) of a harvesting machine (4) with a frame (8), an attachment device (10) connected to the frame (8) for attaching the cutterbar (2) to the harvesting machine (4), cutting elements (12), conveyor devices (14) and drives (16), at least one distance sensor (18) arranged on the cutterbar (2) for determining the distance (20) of the cutterbar (2) from the ground, and an interface (34) via which signals (32) relevant to height control can be transmitted to a control or regulating device (38) arranged on the harvesting machine (4), wherein the cutterbar (2) has at least one additional load sensor (26) which measures the load (28) with which the cutterbar (2) loads the feeder housing (6), characterized in that the interface (34) is arranged upstream of an evaluation device (24) to which the sensor values (25) measured by the distance sensor (18) are transmitted via a connecting line (22), the sensor values (25) measured by the load sensor (26) are also transmitted to the evaluation device (24) via a connecting line (22), and the evaluation device (24) has a program (30) which uses suitable programming to calculate a signal (32) relevant to height control from the transmitted sensor values (25) of the distance sensor (18) and the load sensor (26), which signal is transmitted to the interface (34).

2. Cutterbar (2) according to claim 1, characterized in that the cutterbar (2) is connected to the feeder housing (6) of a harvesting machine (4) via a spring system (42) and a device for measuring the spring travel (44) of the spring system (42) is provided as a load sensor (26).

3. Method for height guidance of a cutterbar (2) attached to the height-adjustable feeder housing (6) of a harvesting machine (4), wherein a distance sensor (18) arranged on the cutterbar (2) determines the distance (20) of the cutterbar (2) from the ground and generates a sensor value (25) therefrom, which is transmitted to an evaluation device (24) of the cutterbar (2), a load sensor (26) is arranged on the cutterbar (2), which measures the load (28) with which the cutterbar (2) loads the feeder housing (6), and generates a sensor value (25) therefrom, which is transmitted to the evaluation device (24), the evaluation device (24) has a program (30) which calculates a height control-relevant signal (32) from the transmitted sensor values (25) of the distance sensor (18) and the load sensor (26) via suitable programming, and the height control-relevant signal (32) is transmitted to an interface (36) via which it can be transmitted to a control or regulating device (38) arranged on the harvesting machine (4).

4. Method according to claim 3, characterized in that the evaluation device (24) averages the sensor values (25) transmitted in a time interval.

5. Method according to claim 3 or 4, characterized in that the evaluation device (24) increases or decreases the sensor value (25) of the distance sensor (18) transmitted in a time interval by a correction factor if the sensor value (25) of the load sensor (26) signals a full load (28) of the feeder housing (6), and / or the evaluation device (24) increases or decreases the sensor value (25) of the load sensor (26) transmitted in a time interval by a correction factor if the sensor value (25) of the distance sensor (18) does not signal a distance (20) of the cutterbar (2) to the ground.

6. Method according to one of claims 3 to 5, characterized in that the sensor values (25) are transmitted as percentage values between the respective minimum and maximum values to the evaluation device (24) or are converted by the latter into percentage values between the respective minimum and maximum values.