AGRICULTURAL DISTRIBUTION MACHINE HAVING A DISTRIBUTION LINKAGE, AND METHOD FOR CONTROLLING THE DISTRIBUTION LINKAGE

Abstract

The invention relates to an agricultural distribution machinehaving a distribution linkage for applying agricultural material with two lateral booms, each having a plurality of application elements for applying the material, and a method of operation thereof. The distribution machine includes a controllable actuating device for altering a position of the distribution linkage relative to a target agricultural area to be worked, a sensor device configured to sense in anticipation changing vertical distances between the distribution linkage and the target area and/or upcoming changes in contour of the target area, and a control device that, for the purpose of controlling the position, preferably controlling the height, of the distribution linkage, is configured to generate actuating signals for the actuating means based upon the changing vertical distances sensed in anticipation and/or changes in contour, in order to at least partially reduce a response time in the position control device.

Claims

1. A mobile agricultural distribution machine having a first direction of travel and a travel speed, the machine comprising: a) a distribution linkage for applying agricultural material, the distribution linkage comprising two lateral booms, each having a plurality of application elements for applying the material; b) a controllable actuating device for altering a position of the distribution linkage relative to a target agricultural area to be worked; c) a sensor device configured to sense in anticipation a change in vertical distance between the distribution linkage and the target area and/or upcoming changes in contour of the target area; and d) a control device for the purpose of controlling the position of the distribution linkage, the control device being configured to generate actuating signals for the actuating device based upon at least one of the change in vertical distance sensed in anticipation and/or the changes in contour, in order to at least partially reduce a response time in the position control device.

2. The agricultural distribution machine according to claim 1, the sensor device being further configured to sense the vertical distance between the distribution linkage and the target area at a plurality of measurement locations that are spaced apart from each other in the direction of travel.

3. The agricultural distribution machine according to claim 1, wherein the sensor device is further configured to: a) sense the vertical distance between the distribution linkage and the target area at a first measurement location and at a second measurement location; and/or b) scan a contour of the target area at a first measurement location and at a second measurement location, the second measurement location being located at least partially ahead of the first measurement location when viewed in the direction of travel.

4. The agricultural distribution machine according to claim 3, the control device being further configured to determine a time point for the generation of an actuating signal in the position control based upon the travel speed and/or a variable derived therefrom, such that a travel time between the first measurement location and the second measurement location substantially corresponds to the response time of the actuating device in the position control.

5. The agricultural distribution machine according to claim 3, wherein: a) the first measurement location corresponds to an area beneath or diagonally down ahead of the distribution linkage, and is between zero metres and one metre from the distribution linkage; and b) the second measurement location is equidistant or further from the distribution linkage compared to the first measurement location, the second measurement location being between one metre and 50 metres from the distribution linkage.

6. The agricultural distribution machine according to claim 3, the control device being further configured to: a) determine, based upon the measurement values sensed at the second measurement location, a change in vertical distance or a variable derived therefrom that indicates whether the vertical distance between the distribution linkage and the target area remains the same, decreases or increases in comparison with the current vertical distance; and b) generate an actuating signal for the actuating device for the purpose of adapting the position of the distribution linkage to the change in vertical distance, before the distribution linkage reaches the second measurement location, based upon the determined change in vertical distance or the variable derived therefrom.

7. The agricultural distribution machine according to claim 1, the control device being further configured to determine a direction of a gradient of the vertical distance between the distribution linkage and the target area based upon the changing vertical distances sensed in anticipation and/or changes in contour.

8. The agricultural distribution machine according to claim 1, the control device being further configured to: a) to determine a value for the actuating signal in proportion to a value of the changing vertical distance sensed in anticipation and/or of the change in contour; or b) to generate, based upon the changing vertical distance sensed in anticipation and/or on the change in contour, an actuating signal that causes the position of the distribution linkage to be altered by an offset value relative to the agricultural target area to be worked.

9. The agricultural distribution machine according to claim 3, the control device being further configured to determine a vertical distance between the distribution linkage and the target area based upon the measurement values sensed at the first measurement location, and to use this determined distance to adjust the vertical distance between the distribution linkage and the target area to a predetermined setpoint vertical distance.

10. The agricultural distribution machine according to claim 3, the control device being further configured to: a) determine, based upon the measurement values sensed by the sensor device, whether a switchover condition is fulfilled; and b) if the switchover condition is fulfilled, to change from a first operating mode, in which the vertical distance of the distribution linkage is adjusted to a setpoint vertical distance based upon the measurement values sensed at the first measurement location, to a second operating mode, and in the second operating mode to generate, based upon the changing vertical distances sensed at the second measurement location, actuating signals for alteration of the position of the distribution linkage, which cause a current position of the distribution linkage to be altered in response to a change in vertical distance before the second measurement location is reached.

11. The agricultural distribution machine according to claim 10, wherein the switchover condition is fulfilled if a change in vertical distance between the distribution linkage and the target area, or a variable derived therefrom, based upon the measurement values sensed at the second measurement location, exceeds a predetermined threshold value.

12. The agricultural distribution machine according to claim 1, the control device being further configured to identify and filter out oscillations of the distribution linkage such that vertical oscillations and/or horizontal oscillations of the distribution linkage do not affect the determination of a vertical distance of the distribution linkage.

13. The agricultural distribution machine according to claim 1, the control device being further configured to form an average value based upon vertical distances determined at the first and second measurement locations, which is used to generate the actuating signals and/or to control the position of the distribution linkage.

14. The agricultural distribution machine according to claim 1, wherein the response time and/or a system speed in the controlling of the position of the distribution linkage is stored in the control device, and/or the control device being configured to determine the response time and/or the system speed on the basis of a time measurement.

15. A method for controlling the position of a distribution linkage of a mobile agricultural distribution machine having a distribution linkage for applying agricultural material, the distribution linkage having two lateral booms, each having a plurality of application elements for applying the material, the method comprising the steps of: a) anticipatory sensing, by a sensor device, of a change in the vertical distance from the distribution linkage to a target area to be worked between a first measurement location and a second measurement location; and b) based upon the change in vertical distances sensed in anticipation, generating actuating signals for an actuating device for the purpose altering a position of the distribution linkage relative to the target area; wherein a response time in the position control of the distribution linkage is least partially reduced such that the actuating signals are generated before the distribution linkage reaches the second measurement location.

16. The agricultural distribution machine according to claim 5, wherein the second measurement location is between one metre and six metres from the distribution linkage.

17. The agricultural distribution machine according to claim 5, wherein the second measurement location is between six metres and 20 metres from the distribution linkage.

18. The agricultural distribution machine according to claim 5, wherein the second measurement location is between 20 metres and 50 metres from the distribution linkage.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0099] The preferred embodiments and features of the invention described above can be combined with one another in any manner. Further details and advantages of the invention are described below with reference to the accompanying drawings. In the drawings:

[0100] FIG. 1A shows a schematic perspective view of a distribution machine, according to an embodiment of the invention;

[0101] FIG. 1B shows a schematic rear view of the distribution machine from FIG. 1A;

[0102] FIG. 2 shows an illustration of sensing of changing vertical distances by means of a close-range and a far-range sensor, according to an embodiment of the invention;

[0103] FIGS. 3A, 3B and 4 show schematic block diagrams to illustrate controlling of the position of the distribution linkage, according to embodiments of the invention;

[0104] FIGS. 5 and 6 each show an illustration of sensing of changing vertical distances by means of a close-range and a far-range sensor, according to an embodiment of the invention;

[0105] FIG. 7A shows a schematic perspective view of a distribution machine, according to an embodiment of the invention;

[0106] FIG. 7B shows a schematic rear view of the distribution machine from FIG. 7A;

[0107] FIG. 8A shows a schematic side view of a distribution machine, according to an embodiment of the invention;

[0108] FIG. 8B shows a schematic detail view from behind the distribution machine from FIG. 8A;

[0109] FIG. 9A shows a schematic rear view of the distribution machine, according to an embodiment of the invention; and

[0110] FIG. 9B shows a schematic detail view of two adjacent segments of a boom that can be pivoted relative to one another, according to an embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0111] In the figures, elements that are the same or functionally equivalent are in some cases denoted by the same references, and in some cases not described separately.

[0112] The distribution machine 1 is in the form, for example, of a trailed field sprayer, i.e. as an agricultural field sprayer that can be coupled, or trailed, by means of a towing vehicle. The direction of travel is indicated by the arrow V. The direction of longitudinal extent of the distribution linkage is indicated by the arrow L.

[0113] The distribution machine 1 has a distribution linkage 2 mounted, directly or indirectly on a carrier vehicle 5, for applying material such as fertiliser, plant protectant or seed. In the case of a field sprayer, the material to be applied is a spray liquid. The distribution linkage 2 comprises two lateral booms 3, which are fastened in a pivotable manner at their inner end to a central part 4 and have an outer free end. The distribution linkage 2 in this case may have, for example, a working width of more than 20 metres. The distribution linkage 2, or the booms 3, may be formed, at least in sections, by a truss-like linkage structure, or by a truss construction. Furthermore, the linkage structure, or the truss construction, is of a greater height than depth.

[0114] The two lateral booms 3 and the central part 4 each have a plurality of application elements for applying the material, e.g. spray nozzles arranged at intervals in the direction of longitudinal extent of the distribution linkage.

[0115] For the purpose of setting its vertical distance relative to an agricultural target area Z to be worked, the central part 4 is mounted on the carrier vehicle 5 so as to be adjustable in height by means of an actuating device 32 for adjusting the height of the central part 4. For this purpose, the actuating device 32 for adjusting the height of the central part 4 comprises a height-adjustable lifting frame 33 on which the central part 4 is mounted. The lifting frame 33 is mounted on the carrier vehicle 5 in a height-adjustable manner by means of a parallelogram linkage 34, in a manner known per se. The actuating device 32 for adjusting the height of the central part 4 also comprises two fluidically actuated actuating cylinders 35, which are supported at one end on the carrier vehicle 5 and at the other end on the lifting frame 33. The actuating device 32 can thus be used to raise and lower the entire distribution linkage for the purpose of height control. The actuating device 32 is also represented more clearly in FIG. 8A.

[0116] For the purpose of controlling the position of the distribution linkage 2, the distribution linkage, the booms 3 and, optionally, also individual segments of the booms 3 can be pivoted about horizontal axes extending in the direction of travel V, which is known per se from the prior art and will be explained in more detail below in connection with FIGS. 7A to 9B.

[0117] As represented in FIG. 1B and FIG. 2, the distribution machine 1 has a sensor device 10. The sensor device is is configured to sense in anticipation changing vertical distances between the distribution linkage 2 and the target area Z. For this purpose, the sensor device 10 comprises respectively one close-range sensor 11 and one far-range sensor 12 on two of three segments of each boom 3. Alternatively, there may also be only one pair, of a close-range sensor 11 and a far-range sensor 12, arranged for the entire distribution linkage 2 or for each boom 3, or there may be a pair, of a close-range sensor and a far-range sensor 12, arranged on each segment of the boom 3.

[0118] Shown in detail in FIG. 2 is an illustration of sensing of changing vertical distances h by means of a close-range and a far-range sensor, according to an embodiment of the invention. For greater clarity, only the distribution linkage 2 is represented in a side view in FIG. 2, but neither the actuating device by which the position of the distribution linkage can be altered nor the carrier vehicle 5 are shown. As can be seen in FIG. 2, the upcoming vertical distance h of the distribution linkage may change along the direction of travel V if the distribution linkage were to maintain its current vertical position.

[0119] The vertical distance h here corresponds to a distance between the underside of the distribution linkage 2 and a target area Z, in this case a crop P. The vertical distance changes here, for example starting from h1 to h2, h3 etc., because the contour K of the target area changes in the direction of travel.

[0120] During application, the distance between the distribution linkage and the ground or the crop during travel should remain as constant as possible in the direction of travel.

[0121] The sensor device 10 comprises a close-range sensor 11, which is configured to sense actual values h1 for the vertical distance between the distribution linkage and the target area at a first measurement region (measurement region) M1, and/or to sense an actual contour of the target area.

[0122] The sensor device 10, which is configured to sense in anticipation changing vertical distances h between the distribution linkage 2 and the target area Z, further comprises for this purpose a far-range sensor 11, which is configured to sense upcoming values h2 for the vertical distance at a second measurement location (measurement region) M2, and/or to scan an upcoming contour of the target area, the second measurement location M2 - as viewed in the direction of travel V -being located several metres ahead of the first measurement region M1.

[0123] The close-range sensor 11 and the far-range sensor 12 are each in the form of ultrasonic sensors. Compared to the close-range sensor 11, however, the far-range sensor 12 has a direction of view that is oriented further forward onto the target area.

[0124] The close-range sensor 11 has a downwardly oriented direction of view 15 that forms with a vertical Z an angle α1 that is in the range of from 0° to 15°. The far-range sensor 12, on the other hand, has an obliquely forward-oriented direction of view 15 that, compared to the direction of view of the close-range sensor, is directed further forward. The direction of view of the far-range sensor 12 may form with a vertical an angle α2 that is in a range of from 5° and 90° or in a range of 15° to 70° with respect to the vertical Z. The angle α1 to the vertical Z is thus smaller than α2. In the example shown in FIG. 2, the angle α2 has the value 45°, merely as an example.

[0125] Thus, the first measurement location M1 corresponds to a close range beneath or obliquely in front of the distribution linkage 2. The first measurement location M1 may include measurement points of a range that - as viewed in the direction of travel V - is at a distance in the range of from zero metres to one metre from the distribution linkage 2. The second measurement location M2, on the other hand, corresponds to a far range that - as viewed in the direction of travel V - is located ahead of the close range. The second measurement location M2 may include measurement points of a range that - as viewed in the direction of travel (V) -is at a distance in a range of from one to 50 metres, preferably in a range of from one to 10 metres, from the distribution linkage 2.

[0126] The actual vertical distance h1 can be sensed relatively accurately by means of the close-range sensor 11. However, if this sensor 11 detects a changed vertical distance, to which a response required so that the desired vertical distance between the distribution linkage and the target area Z can be maintained, this adaptation of the vertical distance may not be effected in time.

[0127] The reason is the technical response time T.sub.R that is needed to set the new linkage position. The response time T.sub.R is specific to each distribution machine and is influenced, for example, by the comparatively high mass inertia of the linkage, the response time of the hydraulics and the time taken to process the sensor data. At a travel speed v.sub.0, the linkage covers the distance s= v.sub.0* T.sub.R in this time T.sub.R.

[0128] With the present sensor device 10, changing vertical distances h between the distribution linkage 2 and the target area Z may be sensed in anticipation, or predicted, by device of the far-range sensor 12. The anticipatory sensing of changing vertical distances allows actuating signals to be generated for adaptation to these changing vertical distances before the distribution linkage 2 reaches a changed vertical distance. Accordingly, the response time for this adaptation can be at least partially compensated.

[0129] An example of such a position control is explained in FIGS. 3A and 3B, which illustrate a position control of the distribution linkage, according to one embodiment of the invention.

[0130] The distribution machine 1 comprises a control device 20, which is configured to generate actuating signals 31 for the actuating device 30 based upon the changing vertical distances sensed in anticipation for the purpose of controlling the position, preferably controlling the height, of the distribution linkage 2 in order to at least partially compensate a response time in the position control. For this purpose, the control device 10 receives, on the input side, measurement data 14 from the second measurement location M2 and the far-range sensor 12, and measurement data 13 from the first measurement location M1 and the close-range sensor 11, i.e. measurement data 13 relating to the actual vertical distance h1 and measurement data 14 relating to the upcoming vertical distance h2.

[0131] The actuating device 30 may be, for example, an actuating device 32 for adjusting the height of the central part 4. This is the case if the control of the position of the distribution linkage 2 corresponds to a control of the height of the distribution linkage 2 by means of an adjustment of the height of the central part 4.

[0132] This embodiment makes use of the fact that at the first measurement location M1 vertical distance data are sensed accurately, but too late to compensate the response time, whereas at the second measurement location M height distance data can be sensed less accurately but with anticipation, such that it is possible to respond at an early stage to changing vertical distance data. The use of vertical distance data from both measurement locations M1, M2 in combination allows rapid and particularly accurate position control of the distribution linkage in response to changing vertical distances between the distribution linkage 2 and the target area Z.

[0133] Although the measurement of vertical distance by means of the far-range sensor 12 is less accurate due to the oblique direction of view 15, in practice, however, it is nevertheless sufficient to detect whether the vertical distance remains the same, decreases or increases in comparison with the current vertical distance, such that a correction of the vertical position can be initiated even at an early stage. For this purpose, the control device 20 may comprise a vertical-position pre-control module 22 providing this functionality.

[0134] A precise adjustment may then subsequently be effected on the basis of measurement values of the close-range sensor 11. For this purpose, the control device 2 may comprise a vertical-position closed-loop control module 21 providing this functionality.

[0135] As illustrated in FIG. 3B, the control device 20, in particular the vertical-position pre-control module 22, is configured to determine in anticipation, based upon the measurement values 14 sensed by the far-range sensor 12, a change in vertical distance, or a variable derived therefrom, that indicates whether the vertical distance between the distribution linkage 2 and the target area Z remains the same, decreases or increases in comparison with the current vertical distance. Based upon this, a new setpoint vertical position 25 is determined. If no upcoming change in height is detected on the basis of the far-range sensor data, or at least none that is greater than a threshold value, the value for the setpoint vertical position remains unchanged. The setpoint vertical position 25 is transmitted to the vertical-position closed-loop control module 21.

[0136] The control device 20, preferably the closed-loop control module 21, is configured to determine a deviation of the actual vertical distance h1, between the distribution linkage and the target area Z, from the setpoint vertical distance 25 based upon the measurement values 13 sensed by the close-range sensor 11, and in dependence thereon to generate actuating signals 31 for the actuating device 30 for the purpose of adjusting the actual vertical distance to the setpoint vertical distance.

[0137] Thus, if no change in the vertical distance is predicted by means of the far-range sensor 12, the setpoint vertical distance remains the same and is continuously monitored and adjusted by the height closed-loop control module 21. This corresponds to a first operating mode 26, in which the vertical distance of the distribution linkage 2 is adjusted to a setpoint vertical distance based upon the measurement values 13 sensed at the first measurement location.

[0138] However, as soon as a (minimum) change in the vertical distance is predicted on the basis of the measurement data 14 of the far-range sensor 12, a change is made to a second operating mode 27, in which actuating signals for the anticipatory alteration of the position of the distribution linkage 2 are generated based upon the changing vertical distances sensed in anticipation at the second measurement location M2, which actuating signals cause a current position of the distribution linkage 2 to be adapted to the changing vertical distances, before the second measurement location M2 is reached.

[0139] The control device 20 may further be configured to check and calibrate measurement data 14 of the less accurate far-range sensor 12 at a time point t on the basis of measurement data 13 of the more accurate close-range sensor 11, where t+x corresponds to the time at which the first measurement location M1 reaches the location of the second measurement location M2 in the current travel operation. If, for example, the check reveals a deviation of a vertical distance determined by means of the measurement data of the far-range sensor at time point t from a vertical distance determined by means of the measurement data of the close-range sensor 11 at the time point t+x, this deviation is used as an offset or correction value for the measurement data of the far-range sensor 12. The offset or correction value may be adapted continuously. This functionality may be provided by an optional calibration module 23.

[0140] Furthermore, the control device 21 may optionally be configured to factor out in the height control a deviation of the distribution linkage from a setpoint position, caused by an oscillation of the distribution linkage 2, preferably in such a manner that vertical oscillations S and/or horizontal oscillations of the distribution linkage do not affect the determination of the vertical distance of the distribution linkage and/or the height control.

[0141] Due to the wide working width of distribution linkages, it is known that disturbing vertical oscillations and/or horizontal oscillations of the distribution linkage may occur, in which the free ends of the booms swing back and forth. Such oscillations may be sensed by sensors, e.g. acceleration sensors arranged on the distribution linkage, and/or by the close-range sensor 11. The oscillations sensed in this way constitute a disturbing influence upon the measurement of the vertical distance. Vertical oscillations result in upward or downward deviations from the average vertical position of the distribution linkage. Horizontal oscillations result in forward or rearward deviations from the average position in the direction of travel of the distribution linkage. The control device may be configured to factor out these effects computationally on the basis of the oscillations sensed by the sensors. Accordingly, more accurate sensing of vertical distances and improved position control can be achieved. Examples of such vertical oscillations are illustrated by the double arrows s in FIG. 7B.

[0142] FIG. 4 shows a schematic block diagrams to illustrate controlling of the position of the distribution linkage, according to a further embodiment variant. This functionality may be implemented, for example, in the vertical-position pre-control module 22.

[0143] For example, the control device 20, e.g. of the vertical position pre-control module 22, may be configured to determine in anticipation, based upon the measurement values sensed at the second measurement location (M2), a change in contour of the target area, i.e. a change in vertical distance or a variable derived therefrom (cf. module 22a), that indicates only whether the vertical distance between the distribution linkage and the target area remains the same, decreases or increases in comparison with the current vertical distance. Even if the measurement by means of the far-range sensor 12 is less accurate than with the close-range sensor 11, it can still be reliably established whether the vertical distance between the distribution linkage and the target area at the second measurement location M2 will remain the same, decrease or increase in comparison with the current vertical distance. This means that it can be predicted whether the vertical distance will change and if so, in which direction. For example, the change in vertical distance or the variable derived therefrom may be determined as a gradient of the vertical distance between the distribution linkage 2 and the target area Z, with optionally only a direction of the gradient and not a magnitude of the gradient being determined.

[0144] Before the distribution linkage 2 reaches the second measurement location M2, an actuating signal 31 is generated for the actuating device 30 based upon the determined change in vertical distance, or the variable derived therefrom, for the purpose of adapting the position of the distribution linkage 2 to the change in vertical distance. For an advantageous implementation, the vertical position pre-control module 22 may be configured to adapt the setpoint vertical position by an offset value 24 based upon the determined change in vertical distance, or the variable derived therefrom, such that there is generated in response thereto an actuating signal 31 that causes the position of the distribution linkage 2 to be altered, by the offset value 24 (cf. module 22b), relative to the agricultural target area Z to be worked. If, for example, the current setpoint vertical position is set to 50 cm, an offset value of, for example, 5 or 10 cm may be selected. If in this case an increase in the vertical distance is detected in anticipation, the current setpoint vertical distance is briefly reduced by 5 or 10 cm in anticipation. The setpoint vertical position can then be reset to 50 cm, e.g. after the second measurement location M2 has been reach, such that the closed-loop control module 21 can perform a more precise adjustment based on the close-range sensor 11.

[0145] It is also optionally possible to store a plurality of offset values 24 in advance, in order to select one of the stored offset values based upon the sensed change in vertical distance. The offset values can thus be used to realize a discrete pre-control in order to adapt the position of the distribution linkage to predicted changes in height. The anticipatory adaptation by means of an offset value is therefore not directly proportional to the sensed upcoming change in vertical distance, but it is nevertheless rapid and robust.

[0146] In a further variant, the control device 20 is configured to determine a time point for the generation of an actuating signal 31 for at least partial compensation of the response time in the position control based upon the travel speed 7 and/or a linkage speed in the direction of travel. The time point is approximately determined in such a way that a travel time remaining after the time point until the second measurement location M2 is reached substantially corresponds to the response time. For this purpose, the response time 28 may be stored in the control device 20, e.g. in a data store. This functionality may be realized by an optional timing module 22c. The travel speed 7 may be provided by an ordinary travel-speed sensor 6.

[0147] With the present sensor device 10, however, changing vertical distances h1, h2, h3 between the distribution linkage 2 and the target area Z can be sensed in anticipation, or predicted, by use of the far-range sensor 12. The time point for the generation of an actuating signal 31 is in this case preferably selected in such a way that it anticipates to such an extent that the travel time T.sub.F at the current travel speed v0 up to the point at which the adaptation of the linkage position is completed substantially corresponds to the response time T.sub.R, i.e. T.sub.R ≈ T.sub.F= s/v.sub.0 (cf. FIG. 2). The time point for the generation of an actuating signal 31 may be effected approximately by determination of the time point at which the vertical-position pre-control module adapts the setpoint vertical position 25 to the vertical distance sensed in anticipation. At slow travel speeds, the time point may thus be delayed so that the height adjustment is not effected too early.

[0148] FIG. 5 illustrates a further exemplary embodiment of sensing of changing vertical distances by means of a close-range and a far-range sensor.

[0149] The special feature of this exemplary embodiment is that a direction of view of the far-range sensor 16, which is again in the form of an ultrasonic sensor, can be altered for the purpose of altering the position of the second measurement location M2. For the purpose of altering the direction of view, the far-range sensor 16 is arranged in a pivotable manner on the distribution linkage 2. The far-range sensor 16 may be such that it can be driven by the control device 20 for the purpose of altering its pivot position, and thus its direction of view 17. The pivoting may be effected by an actuator that can be driven accordingly by the control device 20, e.g. one that can be actuated electrically (not represented).

[0150] FIG. 5 shows the far-range sensor in a first pivot position in which the direction of view 17 is directed towards the measurement location M2. A dashed line in FIG. 5 shows a further possible pivot position in which the far-range sensor has a direction of view 17 that is directed further forward, in this case onto the measurement location M3. In the second pivot position, the angle α2 of the direction of view 17 to the vertical Z is greater than in the first pivot position.

[0151] The control device 20 may be configured to alter the direction of view of the far-range sensor 16 based upon the travel speed or a variable derived therefrom, in such a manner that, as the travel speed increases, the direction of view 17 is altered to be further forwards. Particularly advantageous is an embodiment in which the direction of view 17 of the far-range sensor 16 is dynamically directed onto an upcoming measurement location at such a distance ahead of the distribution linkage that a travel time required, on the basis of the current travel speed, until the distribution linkage reaches this measurement location substantially corresponds to the response time or to a variable derived therefrom. If, for example, the response time is 0.5 s, then, as it were, a travel time of 0.5 s is viewed ahead. Thus, as it were, a real-time measurement of the vertical position / vertical distance is made possible at the point at which control of the vertical position is effected.

[0152] In other words, the second measurement location M2 and/or the direction of view 17 of the far-range sensor 12 are/is preferably selected in such a way that they/it anticipate/s to such an extent that the travel time T.sub.F at the current travel speed v0 up to the point at which the adaptation of the linkage position is completed substantially corresponds to the response time T.sub.R, i.e. T.sub.R ≈ T.sub.F= s/v.sub.0.

[0153] Alternatively or additionally, the pivot position 16, and thus the direction of view 17, may also be manually adjustable, e.g. by an operation in which the sensor is adapted in advance to the anticipated travel speed. The further aspects concerning the embodiment variant of FIG. 5 may correspond to those described in FIGS. 2 to 3B, so that reference is made thereto.

[0154] FIG. 6 illustrates a further exemplary embodiment of sensing of changing vertical distances by means of a close-range and a far-range sensor.

[0155] The special feature of this exemplary embodiment is that the far-range sensor is now realized as a radar sensor 18. The radar sensor is configured to simultaneously measure the vertical distance between the distribution linkage 2 and the target area Z at a plurality of measurement locations M2, M3, M4, M5, which are spaced apart from each other in the direction of travel. For example, the control device 20 may be configured to select one measurement location from the plurality of measurement locations M2, M3, M4, M5 based upon the travel speed or a variable derived therefrom. At slow travel speeds, for example, the measurement location M2 may be used as the closest measurement location ahead in the direction of travel. The closer the measurement location, the more accurately can the height profile be determined. With increasing travel speed, the response time for adaptation of the linkage position is no longer sufficient, such that measurement location M3, M4 or M5 that is further ahead is expediently selected.

[0156] Here, the radar sensor 18 is arranged on the carrier vehicle. However, the radar sensor may also be arranged on the distribution linkage, e.g. at a location above the close-range sensor 11. The further aspects of this embodiment variant may correspond to those described in FIGS. 2 to 3B.

[0157] In a further embodiment variant, the radar sensor 18 may additionally be used as a close-range sensor if one of its measurement locations is directed onto the region M1 beneath the distribution linkage 2, this being represented by the dashed line 15 in FIG. 6. In this case, there may optionally not be any separate close-range sensor 11. In this case, it is also particularly advantageous to arrange the radar sensor directly on the distribution linkage 2, e.g. on an upper region of the distribution linkage.

[0158] Further application examples and embodiment variants are described below with reference to FIGS. 7A to 9B.

[0159] The present technique for anticipatory sensing of changing vertical distances of the distribution linkage may be used for different position controls of the distribution linkage if the control of the position of the linkage depends on a measurement of distance between it and the target area, e.g. the crop.

[0160] An example of this is the height adjustment of the entire distribution linkage, preferably by means of a height adjustment of a central part of the distribution linkage. The actuating device 30 in this case is the actuating device 32 as described in FIG. 1. Another example is the pivoting of the distribution linkage or parts thereof about pivot axes extending in the direction of travel.

[0161] FIG. 7A shows a schematic perspective view of a distribution machine according to an embodiment of the invention, to illustrate the possible pivot axes.

[0162] The present technique for anticipatory sensing of changing vertical distances of the distribution linkage may be applied for controlling the pivot position of the distribution linkage 2, preferably the central part, about a pivot axis D extending in the direction of travel, as illustrated in FIG. 7A. Another example is the pivoting, e.g. angling, of the booms 3 relative to each other about the boom axis A, which likewise extends in the direction of travel. Another example is the angling of adjacent segments 3a of the booms 3 about segment axes B extending in the direction of travel.

[0163] According to the embodiment shown in FIG. 7A, the distribution linkage 2 is arranged, either directly or indirectly, on a carrier vehicle 5 of the distribution machine 2 so as to be movable about a pivot axis D extending in the direction of travel. The pivoting of the distribution linkage 2 about the pivot axis D is effected by means of a pivoting of the central part 4 about the pivot axis D extending in the direction of travel. A further actuating device is provided for this purpose, by means of which an actuating force can be generated in order to move the distribution linkage 2 about the pivot axis D. Such pivoting means for pivoting the central part 4 about the axis D are known per se from the prior art. The pivoting device may be configured, for example, as described in the published patent applications DE 20 2007 011 631 U1, EP 2 591 657 A1, or WO 2015/040133 A1 and for this purpose comprise, for example, one double-acting or two single-acting actuating cylinders that can be actuated fluidically.

[0164] A possible example is represented in FIG. 8B. FIG. 8B shows a detail view of a central portion 4 of the distribution linkage 2 according to a possible embodiment. The distribution linkage 2 is mounted on a support frame of the distribution machine via a pivot frame. The support structure may be, for example, a height-adjustable lifting frame 33 for altering the vertical position of the distribution linkage (see FIG. 8A).

[0165] The pivot frame comprises a horizontal beam, as well as a ball joint mount that is fastened to the horizontal beam and mounted on the support structure via a ball joint (not represented) in the region of the pivot axis D. The ball joint mount 37 is only exemplarily designed in the form of two symmetrical wing-shaped retaining plates. In the present case, the ball-joint mount 37, merely by way of example, is in the form of two symmetrical wing-shaped retaining plates. The ball joint enables the distribution linkage 20 to be pivoted about a pivot axis D extending in the direction of travel, as well as about a vertical axis, such that the distribution linkage 20 can also be pivoted in the horizontal direction. The horizontal beam is at the same time part of a parallelogram suspension by means of which the central portion of the distribution linkage is held on the pivot frame.

[0166] The pivot frame can be pivoted about the axis D by means of the actuating device 38. A pivoting movement of the pivot frame results in a pivoting movement of the entire distribution linkage 20 about the axis D. The actuating device 38 comprises two hydraulically operating actuating elements (actuating cylinders). For the purpose of coupling the pivot frame with the actuating cylinders 38, the pivot frame also has a downwardly projecting V-shaped holder (concealed in FIG. 8B). The actuating cylinders 38 are arranged symmetrically on opposite sides - as viewed in the direction of travel V - of the holder and the pivot axis D, and are each fastened, at an end portion, to the downwardly projecting holder. For support, the actuating cylinders 38 are fastened via their other end portion to the support structure 33. Extending of one of the actuating cylinders 38 and simultaneously retracting of the other actuating cylinder 38 results in a pivoting movement of the pivot frame, relative to the carrier vehicle, about the pivot axis D extending in the direction of travel F. This results in a corresponding pivoting movement of the entire distribution linkage 20 in a plane perpendicular to the direction of travel.

[0167] For example, for a process of applying material, the control device 20 is configured to constantly controll a distance between an upper edge of the crop and the applicationelements device to a defined distance, by controlling, by closed-loop control, the pivot position of the distribution linkage 20 about the pivot axis D, and for this purpose accordingly generate control signals 31 for driving, or controlling by closed-loop control, the actuating cylinders 38. By means of the sensor device 10, which is configured to sense in anticipation changing vertical distances h between the distribution linkage 2 and the target area Z, actuating signals 31 for controlling the pivot position about the pivot axis D can advantageously be generated at an early stage by the control device 20.

[0168] It has already been mentioned above that, in order to control the position of the distribution linkage 2, the distribution linkage 2, the booms 3 and optionally also individual segments 3a of the booms 3 can be pivoted about horizontal axes (boom axes A, segment axes B) extending in the direction of travel V, which is known per se from the prior art and will be explained in more detail below in connection with FIGS. 9A to 9B.

[0169] FIG. 9A shows a distribution linkage 2, comprising two lateral booms 3 and a central part 4, the lateral booms 3 each being mounted on the central part 4 of the distribution linkage 2 so as to be pivotable about an axis A extending in the direction of travel (cf. also FIG. 7A). The booms 3 may thus be angled relative to each other, as illustrated in FIG. 9A, which shows a slightly angled position. Both booms 3 are pivoted slightly upwards at the central part 4.

[0170] Furthermore, the booms 3 are each composed of three segments 3a, again arranged so as to be pivotable relative to each other about axes B extending in the direction of travel (cf. also FIG. 7A). Thus, adjacent segments 3a can also be angled relative to each other. This means that the booms, as viewed in the direction of longitudinal extent L of the booms, are each composed of a plurality of segments 3a connected by joints 3b.

[0171] This is shown in the detail view of FIG. 9B. Two adjacent segments (linkage portions) 3a connected by joints 3b comprise an inner and outer segment 3a (linkage section) in relation to the central part. According to this embodiment, the actuating device 30 additionally comprises actuating elements 36, by means of which the segments can be pivoted about the axes (segment axes) B running in the direction of travel. The actuating elements 36 are designed as hydraulic actuating cylinders. In other words, such an additional actuating element 36 which can be controlled by the control device 20 is assigned in each case to two adjacent segments 3a and/or to the joint 3b which forms the segment axis B. Accordingly, adjacent segments 3a may be angled relative to each other in order to set a separate vertical position for the individual segments 3a.

[0172] This is particularly advantageous for the individual adaptation of a vertical distance of each boom 3 and/or of individual segments 3a to an - as viewed in the direction of longitudinal extent L of the distribution linkage - uneven target area.

[0173] The present technology for anticipatory sensing of changing vertical distances of the distribution linkage may thus furthermore also be used advantageously for such a position control of the booms 3 and/or of the segments 3a, i.e. a position control, in particular a height control, that comprises an angling of the booms relative to each other and/or the angling of adjacent segments relative to each other based upon the changing vertical distances sensed in anticipation.

[0174] The sensor device 10, which configured to sense in anticipation changing vertical distances h between the distribution linkage 2 and the target area Z, can be used, advantageously, to generate actuating signals 31 at an early stage to control the pivot position about the pivot axis A.

[0175] For this purpose, the sensor device 10 comprises, per boom 3 or on at least two segments 3a per boom 3, respectively at least one close-range sensor 11, which is arranged on the respective boom or segment and is configured to sense actual relating to the vertical distance between the distribution linkage and the target area, and/or to scan an upcoming contour of the target area, and furthermore at least one far-range sensor 12 arranged on the respective boom or segment, which sensor is configured to sense upcoming relating to the vertical distance, and/or to scan an upcoming contour of the target area. In the example of FIG. 9A, both a close-range sensor 11 and a far-range sensor 12 are arranged, respectively, on the outermost segment 3a and the innermost segment 3a of each boom 3.

[0176] This offers the advantage that both an actual vertical distance (by means of the close-range sensor) and an upcoming change in height may be sensed in anticipation in a boom-specific manner or also for individual segments 3a of each boom. Accordingly, rapid but also precise position control with regard to vertical distances is made possible. System-related response times may be advantageously compensated, at least in part. According to these embodiments, there are thus a plurality of pairs of respectively one close-range sensor 11 and one far-range sensor 12, which are arranged at a distance from each other as viewed in the direction of longitudinal extent of the distribution linkage. The far-range sensors 12 and close-range sensors 11 may be realized as already described above. In this respect, reference is made to the explanations given above.

[0177] The invention is not limited to the preferred exemplary embodiments described above. Rather, a multiplicity of variants and modifications that also make use of the inventive concept, and therefore fall within the scope of protection, are possible. In particular, the invention also claims protection for the subject-matter and the features of the dependent claims, independently of the claims referred to.

TABLE-US-00001 List of references 1 agricultural distribution machine 2 distribution linkage 3 boom 3a boom segment 3b joint 4 central part 5 carrier vehicle 6 speed sensor, e.g. for travel speed, linkage speed 7 travel speed 8 folding cylinder 9 angular position transducer 10 sensor device 11 close-range sensor 12 far-range sensor 13 measurement data relating to the actual vertical distance, from close-range sensor, first measurement location) 14 measurement data relating to the upcoming vertical distance (from far-range sensor, second measurement location) 15 direction of view 16 pivotable sensor 17 direction of view 18 radar sensor 20 control device 21 vertical-position closed-loop control module 22 vertical-position pre-control module 22a module for determining change in contour 22b module for determining change in setpoint vertical position 22c time control module 23 calibration module 24 offset 25 setpoint vertical position 26 first operating mode 27 second operating mode 28 elapsed response times 30 actuating device 31 actuating signal 32 actuating device of height adjustment of central part 33 lifting frame 34 parallelogram linkage 35 actuating cylinder 36 actuating element, actuating cylinder 37 ball joint mount 38 actuating element, actuating cylinder h vertical position, vertical distance h1 actual vertical distance h2, h3, h4, h5 upcoming vertical distance A boom axis B segment axis D pivot axis, central part P crop Z target area K contour of the target area L direction of longitudinal extent of the distribution linkage V direction of travel Z vertical M1, M2, M3, M4, M5 measurement location S linkage oscillation α1 angle of inclination of the direction of view to the vertical α2 angle of inclination of the direction of view to the vertical