CONTROL SYSTEM, AGRICULTURAL UTILITY VEHICLE AND METHOD FOR CONTROLLING AN AGRICULTURAL UTILITY VEHICLE

Abstract

The invention refers to a control system for an agricultural utility vehicle (1) comprising a distributor linkage (4) for applying material, such as fertiliser, plant protection agents or seed, said distributor linkage extending transversely to the direction of travel and having a centre part (2) and two lateral extension arms (3), which are connected to the centre part (2) by joints and having a plurality of linkage sections which can be folded in towards one another in the transport position and folded out in the working position. The centre part (2) is arranged so that it can be moved along a vertical axis to adjust the height of the distributor linkage. At least one hydraulic device is associated with each extension arm (3), whereby the respective extension arm (3) is pivotable about a horizontal axis. Furthermore, at least three sensors (5) for determining the distance between the centre part (2) and the respective extension arm (3) to the ground are assigned to the distributor linkage (4), and the system comprises a data processing unit which is configured in such a way that the signals from the sensors (5) are processed as actual values and on the basis of which an actuating signal for the hydraulic device is generated for adaptation to a target distance. Thus, the target distance for pivoting the extension arms (3) is formed using the current actual value of the centre part (2). The invention also refers to an agricultural utility vehicle (1) and a method for controlling an agricultural utility vehicle (1).

Claims

1. A control system for an agricultural utility vehicle, comprising: a distributor linkage for applying material, the distributor linkage extending transversely to a direction of travel, and comprising a center part and two lateral extension arms which are connected to the center part by joints and having a plurality of linkage sections connected by additional joints, which are configured to be folded in relative to one another in a transport position and folded out in a working position, wherein the center part is arranged movably along a vertical axis for height adjustability of the distributor linkage, wherein at least one hydraulic device is assigned to each of the extension arms, whereby a respective one of the extension arms is configured to be pivoted about a horizontal axis, and wherein at least three sensors for determining a distance between the center part and the respective extension arm to a ground are arranged on the distributor linkage, wherein the control system comprises a data processing unit which is configured in such that measurement signals of the sensors are processed as actual values so as to generate an actuating signal for the hydraulic device adapted to a target distance, and wherein the target distance for pivoting the extension arms is formed by a current actual value of the center part.

2. The control system according to claim 1, wherein the target distance for pivoting the extension arms is configured to be adapted dynamically to the current actual value of the center part of the data processing unit.

3. The control system according to claim 1, wherein at least one of the current actual value of the center part and a current actual value of the extension arm is formed by a distance from the ground measured by the sensors.

4. The control system according to claim 1, wherein the sensors are at least one of ultrasonic sensors, optical sensors, and radar sensors.

5. The control system according to claim 1, wherein the current actual value of the center part is detectable via the sensors arranged on the center part.

6. The control system according to claim 5, wherein the current actual value of the center part is detected by the plurality of sensors on the center part by averaging in the data processing unit.

7. The control system according to claim 1, wherein the actual values determined by the sensors of the extension arms are configured to be adapted by the data processing unit via averaging to the current actual value of the center part.

8. The control system according to claim 1, wherein the sensors are assigned to the respective extension arm, and the current actual value of the respective extension arm is formed by a smallest distance to the ground measured by the sensors.

9. The control system according to claim 1, wherein, based on the measurement signals of the sensors, at least one of a height adjustment of the distributor linkage and pivoting of the extension arms is set by the data processing unit via the hydraulic device.

10. The control system according to claim 1, wherein the hydraulic device comprises a double-acting hydraulic cylinder, a hydraulic line which is connected to the hydraulic cylinder for supplying hydraulic fluid, and at least one hydraulic valve unit for adapting a cylinder position, the valve unit being adjustable via an actuating signal of the data processing unit.

11. The control system according to claim 10, wherein the hydraulic valve unit is formed by a proportional valve.

12. The control system according to claim 1, wherein the data processing unit forms a single unit with the sensors and the hydraulic device.

13. An agricultural utility vehicle for applying at least one of fertilizer, plant protection products, and seed, comprising: the control system according to claim 1.

14. A method for controlling an agricultural utility vehicle comprising: applying material, by a distributor linkage, the distributor linkage extending transversely to a direction of travel, and comprising a center part and two lateral extension arms which are connected to the center part by joints and having a plurality of linkage sections connected by additional joints which are configured to be folded in relative to one another in a transport position and folded out in a working position, wherein the center part is arranged movably along a vertical axis for height adjustability of the distributor linkage, wherein at least one hydraulic device is assigned to each of the extension arms, whereby a respective one of the extension arms is configured to be pivoted about a horizontal axis, wherein at least three sensors for determining a distance between the center part and the respective extension arm to a ground are arranged on the distributor linkage, and wherein the control system comprises a data processing unit which is configured such that measurement signals of the sensors are processed as actual values so as to generate an actuating signal for the hydraulic device adapted to a target distance, and wherein pivoting of the extension arms is based on the target distance which is formed by the current actual value of the center part.

15. The method according to claim 14, wherein the target distance for pivoting the extension arms is dynamically adapted to the current actual value of the center part by the data processing unit.

16. The method according to claim 14, wherein the current actual value of the center part is detected via the sensors arranged on the center part.

17. The method according to claim 14, wherein the current actual value of the center part is detected by the plurality of sensors on the center part by averaging in the data processing unit.

18. The method according to claim 14, wherein the actual values determined by the sensors of the extension arms are adapted by the data processing unit via averaging to a desired distance of the center part, which is formed by the current actual value of the center part, by the data processing unit.

19. The method according to claim 14, wherein, based on the measurement signals of the sensors, at least one of a height adjustment of the distributor linkage and the pivoting of the extension arms is set by the data processing unit via the hydraulic device.

20. The control system according to claim 1, wherein the material applied by the distributor linkage is at least one of fertilizer, plant protection agent, and seed.

21. The method according to claim 14, wherein the material applied by the distributor linkage is at least one of fertilizer, plant protection agent, and seed.

Description

[0033] The invention is explained in more detail below with reference to the attached schematic drawings. The embodiments shown are only examples of how the control system according to the invention can be designed and do not represent a conclusive limitation.

[0034] FIG. 1 shows a schematic view of a control system according to the invention for the angular position of the extension arms with a distributor linkage according to a first embodiment;

[0035] FIG. 2 shows a schematic view of a control system according to the invention for the position of the centre part with a distributor linkage according to the first embodiment;

[0036] FIG. 3 shows a schematic view of a control system according to the invention for the distributor linkage inclination with a distributor linkage according to the first embodiment;

[0037] FIG. 4 shows a schematic view of a control system according to the invention with a distributor linkage according to a further embodiment.

[0038] FIG. 1 shows a schematic view of a control system for an agricultural utility vehicle 1 according to a first embodiment. The control system comprises a distributor linkage 4 for applying material such as fertiliser, plant protection agents or seed, which extends transversely to the direction of travel. The distributor linkage 4 has a centre part 2 and two lateral extension arms 3 connected to the centre part 2 by joints. The lateral extension arms, which are connected by joints 3 comprise several linkage sections which can be folded to each other in transport position and folded out in working position. The centre part 2 is arranged so that it can be moved along a vertical axis in order to adjust the height of the distributor linkage 4. Each of the two lateral extension arms 3 is associated with at least one hydraulic device, which is not shown, whereby the respective extension arm 3 can be pivoted about a horizontal axis. Three sensors 5 are assigned to distributor linkage 4. One sensor 5 is arranged on the centre part, and the other two sensors 5 are assigned to the respective outer end of the right-hand and left-hand extension arm 3. The sensors 5 are attached to the lower edge of the respective extension arm 3 and the middle part 2. The sensors 5 can measure the current distance of the respective extension arm and the centre part to the ground. The sensors 5 are designed for instance as ultrasonic sensors or radar sensors for this purpose.

[0039] The measured distance to the ground is defined for the left hand extension arm 3 by the height h.sub.l, and equivalent for the right hand extension arm 3 by the height h.sub.r. The measured distance to the bottom of the centre part 2 is equally defined by the height h.sub.m.

[0040] Furthermore, the control system has a data processing unit, which is not shown, which is configured such that the signals of the sensors 5 are processed as actual values and on the basis of which a control signal for the hydraulic devices, which is not shown, can be generated for adaptation to a target distance. For this purpose, the data processing unit may have a control and/or evaluation program and generally be formed as a computer-aided system. The measurement signals of the sensors 5 can be transmitted to the data processing unit via cable connections or wirelessly.

[0041] The control of the distributor linkage configuration, i.e. the height of the centre part 2, the angle of attack of the extension arms 3 as well as the inclination of the entire distributor linkage is carried out by means of three control processes, which are shown in FIGS. 1 to 3. These processes preferably run simultaneously, but can also be carried out one after the other.

[0042] The data processing unit is configured in such a way that from the measured distances to the bottom of the two extension arms 3, i.e. the measured values h.sub.l and h.sub.r, the actual values are processed in a first control process. A mean value is formed from the measured values h.sub.l and h.sub.r. This mean value is compared with the current actual value of the centre part 2. The current actual value of the centre part 2 is formed by the measured distance h.sub.m. If the mean value of the two extension arms 3 deviates from the current actual value of the centre part 2, in other words if there is a control difference, the data processing unit can generate a control signal for the hydraulic devices for pivoting the extension arms 3. The target distance for pivoting the extension arms 3 is therefore formed by the current actual value of the centre part 2.

[0043] The hydraulic device, which is not shown, associated with each extension arm 3, may advantageously comprise a hydraulic cylinder, in particular a double-acting hydraulic cylinder, a hydraulic line connected to the hydraulic cylinder for supplying hydraulic fluid, and at least one hydraulic valve unit for adjusting a cylinder position. The hydraulic valve unit can be adjusted via a control signal from the data processing unit. If there is a positive control difference between the current actual value of the centre part 2 and the mean value of the two measured distances to the bottom of the extension arm 3, the data processing unit can generate a control signal for the hydraulic devices of the extension arm 3, whereby the two hydraulic cylinders of the extension arm 3 are bent. In case of a negative control deviation, both hydraulic cylinders of the two extension arms 3 can be angled. Therefore, based on the control signal of the data processing unit, a pivoting of the two extension arms 3 is effected.

[0044] As an example, when the agricultural utility vehicle 1 is driven over uneven ground, the measured distance to the ground of the right-hand and left-hand extension arms 3 and 2 can be 100 cm everywhere. The target distance of the distributor linkage 4 to the ground can therefore also be 100 cm. If the agricultural utility vehicle 1 runs over an unevenness in the ground, both the centre part 2 and the two extension arms 3 may lower. For example, the measured distance to the ground of the centre part 2 may lower from a height h.sub.m=100 cm to a height h.sub.m=80 cm. In the same way, the height of the two extension arms 3 can for instance be reduced from h.sub.l=h.sub.r=100 cm to h.sub.l=h.sub.r=80 cm.

[0045] Due to the deflection of the distributor linkage 4 from its initial position, the data processing unit can generate a control signal for a hydraulic device for the height adjustability of the distributor linkage 4, whereby the entire distributor linkage 4 is raised again to the target distance specification h.sub.m=100 cm. The centre part can be moved along a vertical axis for height adjustment.

[0046] The target distance for pivoting the extension arms 3 is formed by the current actual value of the centre part 2. This means that initially the target distance for the pivoting of the extension arms 3 is formed by the value h.sub.m=80 cm of the deflection of the centre part 2 which occurred. Contrary to the state of the art, the extension arms are not bent and/or angled, since the target distance of the extension arms 3 is formed by the actual distance of the centre part according to the invention, and thus the target distance of the extension arms is reduced from 100 cm to 80 cm corresponding to the actual distance of the centre part. Due to the target value specification of the centre part 2 of 100 cm, the target distance for pivoting the extension arms 3 is therefore dynamically adapted to the current actual value of the centre part 2. This means that the pivoting of the extension arms 3 is adapted to the height control of the centre part 2. In other words, the pivoting of the extension arms 3 is dependent on the change in the current actual value of the centre part 2. This has the advantage that the pivoting of the extension arms 3 requires a lower force or time than if the pivoting of the extension arms should reach a set target value of 100 cm. Therefore, lower forces are preferably applied to the entire distributor linkage 4 when driving over uneven ground. Furthermore, an additional bending/angling of the extension arms 3 can be efficiently avoided, which can result from inertial forces of the entire distributor linkage 4. Therefore, the extension arms 3 are not bent first and then angled after the centre part has reached its target value again, as is the case with a fixed absolute target value for extension arms 3. This means that optimized control of the pivoting of the two extension arms 3 can be achieved. In other words, the lifting gear of the centre part for height adjustment always influences the value of h.sub.m, h.sub.l, and h.sub.r identically. If they all deviate by the same value, it is therefore advantageous to move the lifting gear and leave the hydraulic cylinders to rest in order to bend/angle the extension arms 3. Otherwise the extension arms 3 and the centre part 2 may move in opposite directions.

[0047] FIG. 2 shows a schematic view of a control system for the height control of the centre part of an agricultural utility vehicle 1 according to the first embodiment for the execution of the second control procedure. The control system has a distributor linkage 4 for applying material, such as fertiliser, plant protection agents or seed, which extends transversely to the direction of travel. The distributor linkage 4 also comprises a centre part 2 and two lateral extension arms 3 connected to the centre part 2 by joints. The centre part 2 is arranged so that it can be moved along a vertical axis to adjust the height of the distributor linkage 4. Each of the two lateral extension arms 3 is associated with at least one hydraulic device, which is not shown, whereby the respective extension arm 3 can be pivoted about a horizontal axis. Three sensors 5 are assigned to the distributor linkage, whereby the distance of the centre part 2 and the respective extension arm 3 to the ground can be determined. For this purpose the sensors 5 are each arranged at the lower edge of the centre part 2 and at the lower edge of the right-sided and left-sided extension arm 3. The sensors 5 can be designed for distance measurement as ultrasonic sensors or as radar sensors.

[0048] If the agricultural utility vehicle 1 should drive over an unevenness in the ground, and the distributor linkage 4 should therefore be raised or lowered, the currently determined actual value of the centre part 2, which is determined by the actual distance to the ground h.sub.m, changes. The actual values currently determined by the sensors 5 for the actual distance of the extension arms 3 and the centre part 2 from the ground are transmitted to a data processing unit, which is not shown, which is configured in such a way that the measured signals of the sensors 5 are processed as actual values and on the basis of which a control signal for the respective hydraulic device of the extension arms 3 is generated for adaptation to a target distance.

[0049] The data processing unit can carry out a target value/actual value comparison if the current actual value of the centre part deviates by 2 h.sub.m from a target distance specified by a user. In other words, the difference between the target distance of the distributor linkage 4 and the currently measured actual value of the centre part 2 h.sub.m is calculated and the distributor linkage 4 is raised or lowered due to this control difference. This corresponds to a height adjustment of the entire distributor linkage 4, in particular of the extension arms 3, based on the specified target distance.

[0050] FIG. 3 shows a third control procedure for adjusting the inclination of the distributor linkage. Here a difference formation of the distance values determined by the sensors 5 is carried out. The distance of both extension arms to the ground should be as identical as possible and correspond to the actual distance h.sub.m of the centre part. In the ideal case, the result of the difference formation is therefore 0. The result of the difference formation therefore serves to control the rotation about an axis lying in the direction of travel. For this purpose an actually known actuator, which is not shown, is provided, and which rotates the extension arm as a whole around the axis clockwise or counterclockwise, depending on the sign of the result of the difference formation, until the measuring signals h.sub.l and h.sub.r of the sensors 5 on the extension arms are identical.

[0051] In summary, the adjustment of the position of the distributor linkage is carried out in three steps: [0052] 1. The extension arm is bent an angled in such a way that the distance between the extension arm sides and the ground corresponds on average to the distance between the centre part and the ground. [0053] 2. The height of the distributor linkage is adjusted by measuring the distance between the centre part and the ground and adjusting it to a target distance. [0054] 3. The inclination of the distributor linkage is adjusted by rotating the entire distributor linkage about an axis in the direction of travel until the distances h.sub.l and h.sub.r are identical.

[0055] In this way the three parameters angle of attack of the extension arms, height and inclination of the distributor extension arm can be set independently. The advantage of this control over conventional height control of each individual section of the distributor linkage is that the various control processes, in particular the control of the angle of attack and the height, cannot work against each other.

[0056] FIG. 4 shows a schematic view of a control system according to the invention according to another embodiment. The control system for an agricultural utility vehicle 1 comprises a distributor linkage 4 for applying material such as fertiliser, plant protection agents or seed, which extends transversely to the direction of travel and has a centre part 2 and two lateral extension arms 3 connected to the centre part. The centre part 2 is arranged to be movable along a vertical axis for height adjustment of the distributor linkage 4 and each extension arm 3 is assigned at least one hydraulic device, which is not shown. This allows the respective extension arm 3 to be pivoted about a horizontal axis.

[0057] Six sensors 5 are assigned to the distributor linkage. The sensors 5 can, for example, be designed as ultrasonic sensors or radar sensors. It is also conceivable that the sensors 5 are designed as optical sensors. The sensors 5 detect a current distance between the distributor linkage 4 and the ground. Two sensors 5 are assigned to the centre part 2 on the right and left side, and two sensors 5 are assigned to each of the right and left side extension arms 3. Accordingly, the distance between the centre part 2 and the right-hand and left-hand extension arm to the ground to be worked can be determined using a plurality of sensors. As an example, the current distance to the bottom of the centre part 2, i.e. the current actual value of the centre part 2, can be measured via the two sensors 5 which are assigned to the centre part 2. These two sensors 5 each detect a distance to the ground h.sub.m1 and h.sub.m2 on the right and left side of the centre part 2.

[0058] The control system further comprises a data processing unit, which is not shown, which is configured such that the signals of the sensors 5 are processed as actual values and on the basis of which a control signal can be generated for the hydraulic devices of the extension arms 3 for adaptation to a target distance. The data processing unit can therefore determine a mean value for the current actual value of the centre part from the two measured distances to the ground h.sub.m1 and h.sub.m2.

[0059] In the same way a mean value of the measured distances to the ground of the two sensors, h.sub.l1 and h.sub.l2, as well as h.sub.r1 and h.sub.r2, assigned to the respective extension arm 3, can be determined for the right-hand and left-hand extension arm 3. Alternatively, the smallest measured distance of the respective sensors 5 can be used for the measurement of h.sub.l1 and h.sub.l2, as well as h.sub.r1 and h.sub.r2 from the data processing unit for the two extension arms 3. For the respective pivoting of the extension arms 3, the actual value of the respective extension arms 3 currently determined can thus be compared with the actual value of the centre part 2, and a control signal can be generated by the data processing unit based on this.

[0060] The averaging of the plurality of sensors 5 on the respective extension arm 3 and the centre part 2 has the advantage that a precise value for the current actual value of the extension arm 3 and the centre part 2 can be detected. Likewise, in the event of incorrect measurements of a single sensor 5, an exact value for the current actual value can still be detected. This means that the pivoting of the extension arm 3 can be efficiently controlled even if a single sensor 5 fails.

REFERENCE NUMERAL LIST

[0061] 1 agricultural utility vehicle [0062] 2 centre part [0063] 3 extension arms [0064] 4 distributor linkage [0065] 5 sensor