CONTROL AND / OR REGULATION SYSTEM FOR AGRICULTURAL EQUIPMENT

Description

[0001] The invention relates to a control and / or regulation system for agricultural equipment. Furthermore, the invention relates to agricultural equipment and a method for controlling and / or regulating agricultural equipment.

[0002] These types of equipment are used in agriculture for applying materials such as fertilizers, pesticides, or seeds, for example, in field sprayers. To apply the material efficiently and over a large area of ​​the field, these agricultural implements have a spreader boom with several application elements, such as spray nozzles. The spreader boom extends perpendicular to the direction of travel and can have working widths of up to 40 meters. The distance between the spreader boom and the ground should remain as constant as possible across the entire working width of the boom. This means that the spreader boom should be kept as parallel as possible to the soil being worked.

[0003] As is well known, the distributor boom has a central section, for example a centrally located frame, and two lateral arms connected to the central section. These arms contain several boom sections that fold inwards for transport and unfold outwards for working. The individual boom sections can be pivoted about vertical axes via their respective joints and are rotatably mounted around these axes. By means of the unfoldable boom sections, the distributor boom can thus be moved from a space-saving transport position to a working position. The transport position describes the folded state of the distributor boom, in which the lateral arms are completely folded towards the central section. In contrast, the working position describes the state of the distributor boom in which all boom sections are unfolded.In other words, the distributor linkage has its entire working width in the working position.

[0004] When operating an agricultural implement with such a large working width, vibrations of the spreader boom can occur in or against the direction of travel, for example, due to driving over uneven ground, acceleration, or braking of the implement or a vehicle towing or carrying the implement. Such vibrations can generate very high forces on the spreader boom, and homogeneous material application can no longer be guaranteed. It is therefore known, for example, from EP 2 829 177 B1, to arrange adjusting and / or damping devices between the central section and the booms, or between the boom sections, such that the spreader boom can be moved from a transport position to a working position and vice versa, and that vibrations occurring in the spreader boom in the direction of travel can be dampened.The actuating and / or damping devices can, for example, be designed as hydraulically operated cylinders. Vibrations of the distributor linkage create pressure differences in the hydraulic cylinders.

[0005] To control vibration damping, the actuators and / or dampers can be controlled by a data processing unit. For this purpose, the data processing unit evaluates the signals from several sensors arranged on the distributor linkage to generate a control signal for the hydraulic cylinders. These sensors monitor the position and speed of the agricultural implement. Using sensors such as radar sensors or pulse generators, the current movement of the agricultural vehicle is determined—that is, whether the vehicle is moving at a constant speed or whether it is accelerating or decelerating. The position of the distributor linkage can be monitored using an angle sensor.

[0006] It is also known from DE 10 2017 104 814 A1 to take into account a pressure offset on a hydraulic cylinder when controlling the damping system.

[0007] Pressure offset refers to the pressure difference that exists between the pressure chambers of a hydraulic cylinder when the distributor linkage is in its intended position. The pressure offset takes into account external forces acting on the distributor linkage in this position. Such forces can occur, for example, if the linkage is not mounted perfectly symmetrically. They can also occur when driving on inclines or curves. The pressure offset can vary individually for each hydraulic cylinder of every hydraulic component in the system. The pressure offset is intended to reflect the forces actually acting on the distributor linkage during normal operation, i.e., without fluctuations.

[0008] This ensures that the hydraulic system only corrects the vibrations described above and works to keep the system in the desired position.

[0009] Such a pressure offset is specified as a fixed value in a known manner. For example, it can be calculated based on map data of the terrain to be worked, or specified by the manufacturer of the agricultural equipment. This fixed value can be transmitted to the control unit by a user, either directly or via an external device such as a computer or smartphone. However, this can be disadvantageous if the specified value deviates from the actual value, i.e., if the pressure differential at the target position differs from the specified pressure offset. The system will then attempt to regulate to the "wrong" value. In extreme cases, this can lead to the system continuously regulating in one direction to reach the "wrong" value, without ever actually achieving it.

[0010] For example, if there is actually a pressure difference of 35 bar at the target position of the hydraulic cylinder, and a pressure offset of 30 bar is specified, the system will constantly try to reach the value of 30 bar. However, since this is not possible due to the external forces, the system will move the hydraulic cylinder in one direction to its maximum.

[0011] The invention is therefore based on the objective of providing a reliable control system for agricultural equipment, capable of precisely damping vibrations occurring in or against the direction of travel. Such vibrations are hereinafter also referred to as horizontal vibrations. In principle, this control system can also be used for vertical vibrations, i.e., vibrations around a horizontal axis.

[0012] This problem is solved by a control and / or regulation system according to claim 1. Preferred embodiments are described in the dependent claims.

[0013] According to the invention, by determining the pressure offset with the control system based on processed signals from the sensor device, the pressure offset is prevented from accurately reflecting the actual conditions during operation of the agricultural implement. In particular, the sensor device signals can be used to monitor the pressure profile of the hydraulic system during operation. This pressure profile will generally have a "quasi-static" component and a "dynamic" component. The quasi-static component is a value that changes only slowly, if at all. The dynamic component, on the other hand, consists of fluctuations around the value of the static component, for example, due to the vibrations described above.The fluctuations of the dynamic component occur on a short timescale compared to changes in the quasi-static component. For example, a typical timescale for a change in the quasi-static component is several tens of seconds, while changes in the dynamic component occur on a timescale of 1 second or less.

[0014] In other words, the quasi-static component represents the pressure offset in the target position. The control system according to the invention thus determines the actual pressure offset during operation of the agricultural implement. This ensures that the system always controls the hydraulic system taking into account the forces actually occurring on the implement due to vibrations.

[0015] The sensor device can comprise one or more sensors. The sensors can be designed as pressure sensors for direct pressure measurement, in particular as pressure transmitters. Such a design as a pressure sensor has the advantage that both relative and absolute pressure can be determined. Furthermore, the sensors can preferably be designed as differential pressure transmitters for determining a differential pressure, or a pressure difference. Advantageously, the pressure transmitters can detect the pressure to be measured via a measuring diaphragm, which is mechanically deformed depending on the respective pressure. This mechanical change is measured electronically, output as an analog or digital signal, and transmitted to the data processing unit. The sensor device can also comprise a combination of sensors of different types.

[0016] In the target position, the distributor linkage can be in the operating position described above. In particular, the target position of the distributor linkage is characterized by the absence, or at least minimal, relative movement between the central section and the distributor linkage itself, especially in the direction of travel. Specifically, in the target position, no, or at least minimal, relative movements due to vibrations of the distributor linkage occur, particularly in the direction of travel. It should be noted that the target position is an idealized position that cannot be achieved continuously, or only briefly, during operation with active damping.

[0017] The signals from the sensor device can be processed to determine the pressure offset by filtering them using a low-pass filter. This is a simple way to extract the quasi-static component from the signals. The low-pass filter can be implemented as a first-order lag element (PT1 element). The time constant of the low-pass filter can be between 10 and 60 seconds, preferably between 20 and 40 seconds.

[0018] The sensor system can comprise a first sensor and a second sensor. In this case, the first sensor can be configured to detect a first pressure corresponding to a pressure on the side of an annular surface of the hydraulic cylinder, and the second sensor can be configured to detect a second pressure corresponding to a pressure on the side of a piston surface of the hydraulic cylinder. This has the advantage of allowing precise determination of the differential pressure, in particular the pressure offset, present at the hydraulic cylinder. The first and second sensors can be configured as described above.

[0019] The data processing unit can be configured to process the signals from the first and second sensors, taking into account the ratio of the annular area to the piston area of ​​the hydraulic cylinder, in order to generate the control signal for the respective hydraulic device. Since the forces acting on the hydraulic cylinder are determined by the respective pressures and areas on the piston and annular sides of the hydraulic cylinder, considering the area ratio normalizes the respective pressures relative to each other, thus simplifying further processing of the values.

[0020] The data processing unit can be further configured to determine a multitude of differential pressure values ​​based on the signals from the first and second sensors, taking into account the ratio of the annular area to the piston area of ​​the hydraulic cylinder. The data processing unit can be configured to determine differential pressure values ​​at time intervals of 5 ms to 1 s, preferably at intervals of 5 ms to 100 ms. It can also be configured to apply a filter, in particular a low-pass filter, to the multitude of differential pressure values ​​and to determine the pressure offset based on the filtered differential pressure values. In this way, the pressure offset can be precisely determined during the operation of the agricultural equipment.

[0021] The respective hydraulic device may further comprise a hydraulic line which is connected to the hydraulic cylinder for the supply and removal of hydraulic fluid, as well as at least one hydraulic valve unit for regulating the hydraulic pressure, wherein the valve unit can be controlled via a control signal from the data processing unit.

[0022] The hydraulic system can generally be designed as an actuator to convert the electrical control signals from the data processing unit into a mechanical movement. This allows the distributor linkage to be moved from a transport position to a working position and also dampens vibrations occurring in the direction of travel. The hydraulic valve unit advantageously provides reliable and rapid overload protection for the hydraulic cylinder. Overall, the hydraulic pressure at the hydraulic cylinder can be adjusted using the hydraulic valve unit, which can be controlled by the data processing unit via a control signal.

[0023] The hydraulic line connected to each hydraulic cylinder can be linked to at least one hydraulic accumulator. It is conceivable that the control system includes a central hydraulic accumulator, or alternatively, that a hydraulic accumulator is assigned to each of the right-hand or left-hand arms of the distributor linkage. Advantageously, the hydraulic accumulator generates the hydraulic pressure acting in the hydraulic cylinder.

[0024] It is possible for the hydraulic systems assigned to each boom to form a closed hydraulic circuit, with the hydraulic cylinders of the systems connected by a common hydraulic line. Ideally, this eliminates the need for separate hydraulic lines. Furthermore, in this case, a sensor for detecting pressure changes in the hydraulic systems can also be installed on the common hydraulic line.

[0025] At least one hydraulic valve unit can be formed by a proportional valve. In particular, it can be a 4-way valve. It can also be a 2-way valve. The hydraulic valve unit can also be formed, for example, by a pressure regulating valve or other circuits for changing the applied hydraulic pressure in the hydraulic system.

[0026] Furthermore, the hydraulic valve unit can be electronically controlled and adjustable based on a known characteristic curve. This characteristic curve generally reflects the functional relationship between the output signal and the input signal. Ideally, the output signal changes linearly with the input pressure. The ideal characteristic curve would therefore be a straight line. However, the measured, or in other words, the actual characteristic curve of the hydraulic valve unit cannot be exactly linear; even at the beginning and end of the pressure range, the output signals can deviate from the respective ideal values. Therefore, for precise adjustment of the damping of vibrations occurring on the distributor linkage, it is advantageous to adjust the hydraulic valve unit based on its characteristic curve and thus adapt it to and counteract the pressure changes.For example, the pressure sensors can be used to determine, based on the characteristic curve of the valve unit, how much control current is required to be switched to the valve unit in order to counteract the pressure change that occurs.

[0027] Furthermore, the first sensor can be configured to detect a pressure that corresponds to a common pressure on the annular surfaces of all hydraulic cylinders in the system. For example, the first sensor can be configured to detect the pressure in a hydraulic line of the system that supplies the annular chambers of all hydraulic cylinders with hydraulic fluid. Such an arrangement simplifies the system because it reduces the total number of sensors required. Therefore, such a system is also more cost-effective.

[0028] The control system can further include additional sensors on the distributor linkage configured to determine rotation around a folding axis and / or the position of a linkage section and / or boom. The data processing unit is configured to generate the control signal based on the determined rotation and / or position. These sensors can, for example, be designed as potentiometers. The potentiometer determines whether a single linkage section or the entire boom is deflected from its target position and how its position changes. The deflection can occur, for example, due to vibration. It can also occur due to the vibration damping described above. The folding axis around which the linkage is folded is preferably vertically oriented but has at least one vertical component.The data processing unit can perform a target / actual value comparison for the folding axis and, based on the control deviation and in combination with the pressure offset and the measurement of the pressure change occurring at the hydraulic system, adjust the hydraulic valve unit. The combination of various measured values ​​in the data processing unit enables very precise adjustment of the hydraulic valve unit. Any measurement inaccuracies that may occur can also be compensated for.

[0029] The data processing unit can form a single unit with the sensor device and the respective hydraulic components. This implies a direct connection, for example via cables or wirelessly, between the sensor unit, the data processing unit, and the hydraulic components. Therefore, the measurement signal acquired by the sensor device can be efficiently and rapidly transmitted to the hydraulic components for vibration damping via a control signal from the data processing unit.

[0030] Overall, the data processing unit can control or adjust the associated hydraulic valve unit of the hydraulic system for damping vibrations occurring in the distributor linkage, based on the measurement signal from the sensor device and / or the current position of the linkage section or boom. It is generally conceivable to use the measured signals from the sensor device in a control system as an actual value and for adjusting a setpoint. The data processing unit can be configured, or in other words, have a control and / or evaluation program, such that, based on the measured signal from the sensor device as input for the control system, a corresponding setpoint for the respective hydraulic system is determined, and the hydraulic system is then controlled or adjusted to this setpoint.

[0031] Furthermore, at least one hydraulic valve unit of the respective hydraulic system of one boom can be independently controlled and / or adjusted by the control system from the hydraulic valve unit of the respective hydraulic system of the other boom. This means that the hydraulic valve unit of the associated hydraulic system of the respective boom can be controlled independently via an electronic signal from the data processing unit. Therefore, the control system is efficiently usable for both symmetrical and asymmetrical distributor linkages.

[0032] The invention further provides an agricultural implement for applying materials such as fertilizers, pesticides, or seeds, comprising a control and / or regulation system. The control and / or regulation system may have one or more of the features described above. The agricultural implement may, in particular, be a field sprayer. The field sprayer may be self-propelled. It may also be a trailed or hand-held field sprayer.

[0033] The invention further provides a method for controlling and / or regulating an agricultural implement. The agricultural implement has a distribution boom for applying material, such as fertilizer, pesticides, or seeds, which extends transversely to the direction of travel and comprises a central section and two lateral arms connected to the central section, each with several linkage sections that fold inwards in the transport position and unfold outwards in the working position and are connected by joints. Each arm is assigned at least one hydraulic device. The respective hydraulic device can be controlled to dampen vibrations occurring in the horizontal and / or vertical direction on the distribution boom, and the respective hydraulic device comprises a hydraulic cylinder, in particular a double-acting hydraulic cylinder. The method comprises the following steps: Detecting pressure changes at the respective hydraulic device caused by vibrations of the distributor linkage in the horizontal and / or vertical direction using a sensor device. Generating a control signal for the respective hydraulic device based on the detected pressure change, wherein the control signal is generated taking into account a pressure offset that corresponds to a pressure difference between an annular area and a piston area of ​​the hydraulic cylinder in a target position of the distributor linkage, wherein the pressure offset is determined based on processed signals from the sensor device.

[0034] In this process, the signals from the sensor device can be processed by filtering them using a low-pass filter.

[0035] The process may further include the following steps: Acquisition of a first pressure corresponding to a pressure on the annular surface of the hydraulic cylinder. Acquisition of a second pressure corresponding to a pressure on the piston surface of the hydraulic cylinder. Processing of the first and second pressures, taking into account the ratio of the annular area to the piston area of ​​the hydraulic cylinder. Generation of the control signal for the respective hydraulic device based on the processed pressure values.

[0036] Additionally, the procedure may include the following steps: Determine a multitude of pressure differential values ​​based on the first and second pressures, taking into account the ratio of the annular area to the piston area of ​​the hydraulic cylinder. Apply a filter, in particular a low-pass filter, to the multitude of pressure differential values. Determine the pressure offset based on the filtered multitude of pressure differential values.

[0037] In this process, the first pressure can be assigned to a common pressure on the side of the annular surfaces of all hydraulic cylinders in the system.

[0038] The process may further include the following steps: Determining a rotation around a folding axis and / or a position of a linkage section and / or boom. Generating the control signal based on the determined rotation and / or position.

[0039] The control system can have one or more of the characteristics described above.

[0040] Further features and advantages of the invention are explained below with reference to the exemplary figures. These show: Fig. 1 schematically shows a distributor linkage with a control and / or regulating system and with a central section and two lateral arms connected to the central section in a top view; Fig. 2 schematically shows a detailed view of a distributor linkage with a control and / or regulating system and with a central section and two lateral arms connected to the central section; Fig. 3 schematically shows a control circuit diagram for a control and / or regulating system; Fig. 4 schematically shows a method for determining a pressure offset; Fig. 5 schematically shows a control circuit diagram for a control and / or regulating system; Fig. 6 schematically shows a hydraulic circuit diagram for a control and / or regulating system according to one embodiment; Fig. 7 schematically shows a hydraulic circuit diagram for a control and / or regulating system according to a further embodiment; and Fig. 8 schematically shows a hydraulic circuit diagram for a control and / or regulating system according to a further embodiment.

[0041] Fig. 1 Figure 12 schematically shows a distribution boom 12 for use with a control and / or regulation system according to the invention for an agricultural implement in a top view. The agricultural implement is designed here as a field sprayer. The distribution boom 12 serves to apply material, such as fertilizer, pesticides, or seeds, and extends transversely to the direction of travel. The distribution boom 12 has a central section 2 and two lateral extensions 3 connected to the central section 2, each with several boom sections 4 that can be folded inwards in the transport position and unfolded in the working position and are connected by joints.

[0042] Fig. 2 schematically shows a detailed view of the in Fig. 1 The distributor linkage 12 shown. It can be seen that a hydraulic cylinder 10 a, b is assigned to each of the right and left booms 3, which is connected to the central section 2 and the respective boom 3. By means of the respective hydraulic cylinder 10 a, b, the respective boom 3, and thus the distributor linkage 12, can be moved from a transport position to a working position. In doing so, the hydraulic cylinders 10 a, b fold the distributor linkage 12 into the working and transport positions via vertical axes. To move the boom completely from the transport to the working position, further devices may be present, which are shown in Fig. 1 and Fig. 2 not shown. For example, each linkage section 4 can be assigned another hydraulic cylinder that can fold the respective linkage section 4 in and / or out.

[0043] In the area of ​​hydraulic cylinders 10 a, b, sensors (not shown) can be installed to detect the working position of the distributor linkage. These sensors can be designed as potentiometers, for example. This allows the position or working position of the hydraulic cylinder's piston rod to be determined. A corresponding measurement or position signal can be transmitted via a data line to a data processing unit (not shown), which controls the folding process of the linkage sections based on the measurement signal. The data processing unit is configured to process the sensor signals and generate a control signal for the hydraulic cylinders. Thus, the potentiometers can be used to detect the position and control the folding process of the distributor linkage.

[0044] When the distributor linkage is in its working position, or in other words, fully extended, vibrations occurring in the distributor linkage can be dampened by the control system via the hydraulic cylinders 10 a, b, and the distributor linkage 12 can be held as close as possible to its target position. As described above, the target position of the distributor linkage 12 is characterized by the absence of any relative movement between the vehicle supporting the distributor linkage and the distributor linkage itself, particularly in the direction of travel. Since this is an idealized position that applies to the entire distributor linkage, it is possible that individual sections of the distributor linkage may move more with active vibration damping than they would without it. For example, vibrations may occur at one outer end of the distributor linkage due to the elasticity of the booms.These vibrations can be eliminated or reduced by means of the control system. However, this can be associated with movement of the distributor linkage near the central section due to the actuation of the hydraulic cylinders. In other words, active vibration damping can result in slightly larger deviations from the target position in the center of the distributor linkage, but in return for significantly lower vibration amplitudes at the end of a boom.

[0045] The control system comprises sensors (not shown) designed to detect pressure changes at the hydraulic cylinders 10a, 10b caused by vibrations of the distributor linkage 12. Specifically, the sensors 15a, 15b, preferably designed as pressure sensors, can measure the pressure difference at each hydraulic cylinder 10a, 10b. Based on the pressure sensor signals, the data processing unit can control a hydraulic valve unit (not shown) assigned to each hydraulic cylinder 10a, 10b, thereby equalizing the pressure and damping the vibrations.

[0046] Fig. 3 shows a block diagram of a possible implementation of a control and evaluation program of a data processing unit according to Fig. 1 . This involves measurement signals from several sensors, which are attached to the distributor linkage 12 according to Fig. 1 These parameters can be arranged in various configurations and transmitted as input variables to the control and evaluation program. For example, a potentiometer can be used to determine the actual value of the rotation around the folding axis of the associated linkage section 4 and / or boom 3, or in other words, its deflection from the rest position, or the current position, and compare it to a setpoint. The difference or control deviation between the actual value and the setpoint of the rotation around the folding axis of linkage section 4 and / or boom 3 can be adjusted using a PID controller (proportional-integral-derivative controller).

[0047] Furthermore, pressure sensors 15 a, b can be used to determine the pressure on the annular surface and the piston surface of a hydraulic cylinder 10 a, b for moving the distributor linkage 12 from a transport to a working position and for damping vibrations occurring on the distributor linkage 12. In other words, the pressure sensors 15 can detect any pressure changes occurring on the hydraulic cylinders 10 a, b. When measuring the pressure on the annular surface, a pressure offset—that is, a pressure difference that can arise due to an external force in the target position of the distributor linkage 12—can be compensated for by using this measurement as an input for the control and evaluation program. This pressure offset can result, for example, from a pitching tendency of the agricultural implement in or against the direction of travel.Such a pitching tendency of the device can be taken into account, for example, by means of appropriately positioned sensors on the device or by means of map data of the field to be traversed. Advantageously, the pressure offset can be determined dynamically during operation of the agricultural implement. An exemplary method for such a determination of the pressure offset is described below in conjunction with [reference to relevant section]. Fig. 4 described.

[0048] Advantageously, the ratio K between the ring and piston areas of the hydraulic cylinder 10 a, b must be taken into account to compensate for the difference in area between the two cylinder chambers of the hydraulic cylinder 10 a, b. For example, a pressure of 90 bar can be measured on the ring area of ​​the hydraulic cylinder 10 a, b. The piston area is typically larger than the ring area by a factor K, for example by a factor of 2. Accordingly, a lower pressure would prevail on the piston area than on the ring area, for example 45 bar. If the difference between the two measured values, corrected by the ratio of ring and piston areas and taking the pressure offset into account, should be zero, the control and evaluation program will not output a signal for adjusting the hydraulic cylinder 10 a, b.The adjustment of the hydraulic cylinder 10 a, b then occurs solely based on the control of the position of the linkage section 4 and / or boom 3. Should the difference of the corrected pressures deviate from zero, an external force acts on the distributor linkage 12 and the control and evaluation program can output a control signal for the hydraulic cylinder 10 a, b by means of a PID controller.

[0049] To generate the control signal for the hydraulic cylinder 10 a, b, the signals from the potentiometer can be combined with the signals from the pressure sensors 15 a, b. Depending on the control deviation, an output signal for the valve opening can be generated based on the characteristic curve of a hydraulic valve unit assigned to the hydraulic cylinder 10 a, b. This allows for the calculation of the required valve flow for folding and unfolding, or for extending and retracting, the cylinder. Thus, based on the sensor signals, a precise control signal for the hydraulic cylinder 10 a, b can be generated to dampen vibrations occurring on the distributor linkage 12.

[0050] Fig. 4 This illustrates a method by which a print offset can be determined or adjusted during the operation of the agricultural equipment. In particular, this can be used for the in Fig. 3 The pressure offset is designated as follows. As described above, a pressure difference between the pressure sensors 15 a, b can be determined. Preferably, this is done by including the piston and ring areas of the hydraulic cylinders 10 a, b, as described above. Preferably, a plurality of successive pressure difference values ​​are processed by the data processing unit in such a way that a "quasi-static" pressure difference component can be determined, i.e., a component that changes only slowly, if at all. Since, in the target position, as explained above, no relative movement occurs between the commercial vehicle carrying the distributor linkage and the distributor linkage itself, particularly in the direction of travel, i.e., a static situation exists, the quasi-static pressure component then corresponds to the desired pressure offset. In the Fig. 3 In the illustrated method, the quasi-static pressure component is determined by filtering the pressure difference values ​​using a low-pass filter. Here, the low-pass filter is implemented as a first-order lag element (PT1 element). The PT1 element has, for example, a time constant of 30 seconds. However, the time constant can be larger or smaller depending on the application.

[0051] The filter's output value can then be used directly as a pressure offset. It is also possible to average multiple output values ​​and use the averaged value as the pressure offset. The pressure offset can then be used in the control and / or regulation system, as is the case, for example, in... Fig. 3 illustrated, incorporated. Fig. 4 It is further indicated that the pressure offset value can be limited. For example, the value can be limited based on the sensors that detect the angular position of the distributor linkage. This may be necessary because the measured pressure difference in a position of the distributor linkage that does not correspond to the operating position may deviate from the desired pressure offset. For example, the previously mentioned setpoint for the rotation about the folding axis of linkage section 4 and / or boom 3 between a boom and the direction of travel may be 90°. If the actual value deviates from this value, the system will adjust the difference between the actual value and the setpoint using a PID controller (proportional-integral-derivative controller), as described above.Since additional pressure can occur at the hydraulic cylinder during this process, it is possible that an incorrect pressure offset will be determined, which would cause the hydraulic system to actively counteract the adjustment of the rotation. This can be prevented by the described limitation of the pressure offset.

[0052] Fig. 5 This shows a possible implementation of a control and evaluation program. Compared to the one in Fig. 3 The illustrated version here refers to Fig. 4 The described determination of the pressure offset is directly implemented.

[0053] The Fig. 6 bis 8 These are schematic representations of a hydraulic circuit diagram for a control and / or regulation system. Various hydraulic circuit diagrams are shown as examples. It should be noted that further components may be present, but are not shown in the figures for the sake of simplicity.

[0054] Fig. 6 presents a hydraulic circuit diagram for a hydraulic device according to an embodiment of the invention for pressurizing the right and left hydraulic cylinders 10 a, b according to Fig. 1 The system is designed to move the distributor linkage from a transport position to a working position and to adjust the damping of vibrations occurring on the distributor linkage in the direction of travel. The right and left hydraulic cylinders 10 a, b are designed as double-acting hydraulic cylinders. The hydraulic cylinders 10 a, b are connected to the distributor linkage according to... Fig. 1 The hydraulic cylinders 10 a, b are connected as described above. The hydraulic line 17 connects them to a hydraulic reservoir (not shown). The hydraulic reservoir contains hydraulic fluid, which can be supplied to the respective hydraulic cylinders 10 a, b via the hydraulic line 17. The hydraulic line 17 consists of a pressure line, designated by reference numeral P in the figures, and a hydraulic reservoir line, designated by reference numeral T.

[0055] Two pressure sensors 15 a, b are assigned to each of the right and left hydraulic cylinders 10 a, b. These pressure sensors are positioned such that pressure can be measured both on a piston surface and on an annular surface of the hydraulic cylinder 10 a, b. The hydraulic cylinder 10 a, b has two differently sized effective surfaces on the two sides of the piston 11. The effective surface of the hydraulic cylinder facing the piston rod is smaller than the effective surface facing away from the piston rod. Therefore, pressure sensor 15a measures a different, and in particular a higher, pressure on the annular surface than pressure sensor 15b measures on the piston surface.

[0056] The pressure sensors 15a, b are connected to a supply line 17a and a discharge line 17b of the respective hydraulic cylinders 10a, b for measuring the pressure at the annular and piston surfaces of the hydraulic cylinders 10a, b. Within the scope of the application, the supply line 17a of the hydraulic line 17 describes that section of the hydraulic line 17 which connects the hydraulic reservoir (not shown) to the annular surface of the hydraulic cylinders 10a, b. In contrast, within the scope of the application, the discharge line 17b of the hydraulic line 17 describes that section of the hydraulic line 17 which connects the hydraulic reservoir to the piston surface of the hydraulic cylinders 10a, b.

[0057] The pressure sensors 15 a, b are designed here as pressure transmitters. A pressure transmitter is generally an electrical transmitter for measuring the pressure present in the hydraulic cylinder 10 a, b. Thus, a pressure change caused by vibrations of the distributor linkage can be determined using the pressure sensor. For example, a pressure difference at the hydraulic cylinder 10 a, b, and therefore at the hydraulic system, can be measured using the pressure transmitters 15 a, b.

[0058] Furthermore, each hydraulic cylinder 10 a, b is assigned a hydraulic valve unit for regulating the hydraulic pressure. The hydraulic valve unit is arranged in the hydraulic line 17 and is designed, for example, as a proportional valve 16, or in other words, as a multi-way valve. The pressure sensors 15 a, b assigned to the respective hydraulic cylinder 10 a, b are arranged on the supply line 17a and discharge line 17b between the hydraulic cylinder 10 a, b and the associated proportional valve 16. The proportional valve 16 is specifically designed as a 4 / 3-way valve. The proportional valve 16 can be controlled and adjusted by a data processing unit (not shown). For this purpose, the proportional valve 16 is connected to the data processing unit, for example, via cables or wirelessly. The data processing unit is also connected to the pressure sensors 15 a, b.Based on the signals detected by the pressure sensors 15 a, b, the data processing unit can control the proportional valve 16. Specifically, the proportional valve 16, which is assigned to the respective hydraulic cylinder 10 a, b, can be controlled for pressure equalization based on the values ​​detected by the pressure sensors 15 a, b. In the rest position of the proportional valve 16, the valve is preferably closed, or in other words, in a centered position. The data processing unit can deflect the valve to the left or right. By deflecting the valve, the pressure at the annular surface, or the piston surface, of the hydraulic cylinder can be increased or decreased by means of the proportional valve, or in other words, the piston of the hydraulic cylinder 10 a, b can be extended or retracted.

[0059] The data processing unit, the pressure sensors 15 a, b, and the hydraulic valve unit 16 of the hydraulic system form a single unit. Thus, based on the signals determined by the pressure sensors 15 a, b, the data processing unit and the proportional valves for pressure equalization in the hydraulic cylinders 10 a, b can dampen vibrations occurring on the distributor linkage.

[0060] Fig. 7 Figure 1 shows a further schematic representation of a hydraulic circuit diagram for a control and / or regulation system according to the invention and a further embodiment. As with reference to Fig. 6 The right and left hydraulic cylinders 10 a, b for folding the right and left-hand booms 3 of the distributor linkage 12 are described according to Fig. 2 and, for damping vibrations occurring on the distributor linkage 12, are designed, for example, as double-acting hydraulic cylinders 10 a, b and connected to a hydraulic line 17. For measuring the hydraulic pressure at the ring and piston surfaces of the respective hydraulic cylinder 10 a, b, each hydraulic cylinder 10 a, b is equipped with two pressure sensors 15 a, b as described with reference to Fig. 6 described and assigned.

[0061] In the respective supply line 17a of the hydraulic line 17 to the respective hydraulic cylinders 10 a, b, a shut-off valve 19 can be arranged between the hydraulic reservoir (not shown) and the respective hydraulic cylinder 10 a, b. The shut-off valve 19 can be designed as a check valve and be spring-loaded. By means of the shut-off valve 19, the flow can be blocked in one direction and released in the opposite direction. Thus, hydraulic pressure can be continuously applied to the annular surface of the respective hydraulic cylinder 10 a, b.

[0062] A multi-way valve 18b is arranged in the respective discharge line 17b of the respective hydraulic cylinder 10 a, b. The hydraulic pressure is measured by the pressure sensor 15b between the hydraulic cylinder 10 a, b and the multi-way valve 18b. The multi-way valve 18b can be electronically controlled via the data processing unit for pressure equalization based on the measurement signals from the pressure sensor 15 a, b.

[0063] The supply line 17a and the discharge line 17b are connected by means of an additional intermediate line 17c. A further multi-way valve 18a is arranged in the intermediate line 17c. The multi-way valve 18a can be electronically controlled by the data processing unit. Furthermore, a shut-off valve 19 can be arranged on the side of the multi-way valve 18a facing the discharge line 17b.

[0064] The two multi-way valves 18a serve to connect the annular and piston surfaces of the respective hydraulic cylinders 10a, b. To extend the hydraulic cylinders 10a, b, the annular and piston surfaces are connected, or rather, the hydraulic cylinder extends over the proportionally larger area of ​​the piston surface. In other words, when the respective multi-way valve 18a is actuated by the data processing unit, the respective hydraulic cylinder 10a, b can extend.

[0065] The retraction of each hydraulic cylinder 10 a, b can be achieved by means of the multi-way valve 18 b assigned to the respective hydraulic cylinder 10 a, b. When the multi-way valve 18b is actuated by the data processing unit, hydraulic fluid can be released from the piston side of the hydraulic cylinder 10 a, b. Due to the continuous supply of hydraulic pressure to the annular surface of the hydraulic cylinder 10 a, b, the hydraulic cylinder 10 a, b can therefore retract.

[0066] To ensure that identical forces are generated when extending and retracting the hydraulic cylinder 10 a, b, the ratio between the ring and piston area should ideally be 1:2. Thus, based on the values ​​measured by the pressure sensors 15 a, b, which are evaluated and processed by the data processing unit, the extension and retraction of the hydraulic cylinder 10 a, b can be efficiently controlled via the electronically controlled opening and closing of the two multi-way valves 18 a, b.

[0067] Fig. 8 Figure 1 shows a further schematic representation of a hydraulic circuit diagram for a control and / or regulation system according to a third embodiment. The basic structure and the operation of the individual components of the hydraulic circuit diagram are as described with reference to Figure 2. Fig. 7 described. Unlike Fig. 6Only a single pressure sensor 15a is arranged in the hydraulic line 17 to measure the pressure on the annular surface of both hydraulic cylinders 10a, b. Accordingly, the single pressure sensor 15a is located in the hydraulic line 17 between the hydraulic reservoir (not shown) and the respective supply line 17a of each hydraulic cylinder 10a, b. In other words, the single pressure sensor 15a is connected to the pressure line of the hydraulic line 17, which is marked with the reference numeral P in the figures and includes the supply line 17a. Should the pressure on the annular side of the hydraulic cylinder 10a, b increase during operation, the hydraulic fluid within the supply line 17a is forced against the shut-off valve 19.In other words, the hydraulic fluid column is supported by the shut-off valve 19, and the actual pressure on the annular surface of the hydraulic cylinder 10 a, b is higher than the pressure measured by the pressure sensor 15 a. Consequently, the multi-way valve 18 a or the multi-way valve 18 b can be opened to equalize the pressure. This results in an equalization of the pressures in the pressure line and the annular surface of the hydraulic cylinder 10 a, b, since hydraulic fluid can flow in from the pressure line in both cases.

[0068] It is understood that the features mentioned in the previously described embodiments are not limited to these specific combinations and are also possible in any other combination. Furthermore, it is understood that the geometries shown in the figures are only examples and are also possible in any other configuration.

Claims

1. Open-loop and / or closed-loop control system for an agricultural apparatus having a distributor linkage (12) for spreading material, such as fertilizer, plant protection agent or seed, which linkage extends transversely to the direction of travel and has a central part (2) and two lateral arms (3) connected to the central part (2) with a plurality of linkage portions (4) which can be folded in toward one another in the transport position and folded out in the working position and are connected by joints, wherein each arm (3) is assigned at least one hydraulic device, wherein each hydraulic device can be controlled to dampen vibrations occurring on the distributor linkage (12) in the horizontal and / or vertical direction, and wherein each hydraulic device comprises a hydraulic cylinder (10 a,b), in particular a double-acting hydraulic cylinder, wherein the open-loop and / or closed-loop control system comprises: a sensor device configured to detect a pressure change occurring at the relevant hydraulic device caused by vibrations in the horizontal and / or vertical direction of the distributor linkage (12); and a data processing unit configured to process signals from the sensor device and to generate a control signal for the relevant hydraulic device on the basis of these signals, wherein the control signal is generated taking into account a pressure offset which corresponds to a pressure difference between the pressure chambers of the relevant hydraulic cylinder (10a,b) in a target position of the distributor linkage, and wherein the pressure offset is determined based on signals from the sensor device.

2. Open-loop and / or closed-loop control system according to claim 1, wherein the signals from the sensor device for determining the pressure offset are processed by being filtered by means of a low-pass filter.

3. Open-loop and / or closed-loop control system according to either of the preceding claims, wherein the sensor device comprises a first sensor (15a) and a second sensor (15b), wherein the first sensor (15a) is configured to detect a first pressure associated with a pressure on the side of an annular surface of the hydraulic cylinder (10 a,b) of a hydraulic device, and wherein the second sensor (15b) is configured to detect a second pressure associated with a pressure on the side of a piston surface of the hydraulic cylinder (10 a, b) of the relevant hydraulic device.

4. Open-loop and / or closed-loop control system according to claim 3, wherein the data processing unit is configured to process the signals from the first sensor (15a) and the second sensor (15b), in particular taking into account the ratio of the annular surface and the piston surface of the hydraulic cylinder (10 a,b), in order to generate the control signal for the relevant hydraulic device.

5. Open-loop and / or closed-loop control system according to claim 4, wherein the data processing unit is configured to determine a plurality of pressure difference values based on the signals from the first sensor (15a) and the second sensor (15b) taking into account the ratio of the annular surface and the piston surface of the hydraulic cylinder (10 a,b), to apply a filter, in particular a low-pass filter, to the plurality of pressure difference values, and to determine the pressure offset based on the filtered pressure difference values.

6. Open-loop and / or closed-loop control system according to any of the preceding claims, wherein each hydraulic device further comprises: a hydraulic line (17) which is connected to the hydraulic cylinder for supplying hydraulic fluid; and at least one hydraulic valve unit (16) for controlling the hydraulic pressure, wherein the valve unit (16) is controllable via a control signal from the data processing unit.

7. Open-loop and / or closed-loop control system according to claim 6, wherein the at least one hydraulic valve unit (16) is formed by a proportional valve.

8. Open-loop and / or closed-loop control system according to any of claims 3 to 7, wherein the first sensor (15a) is configured to detect a pressure associated with a common pressure on the side of the annular surfaces of all hydraulic cylinders (10 a,b) of the system.

9. Open-loop and / or closed-loop control system according to any of the preceding claims, further comprising further sensors on the distributor linkage (12) which are configured to determine a rotation about a folding axis and / or a position of a linkage portion (4) and / or arm (3), wherein the data processing unit is configured to generate the control signal based on the determined rotation and / or position.

10. Open-loop and / or closed-loop control system according to any of the preceding claims, wherein the hydraulic device can transfer the distributor linkage (12) from a transport position to a working position and vice versa.

11. Agricultural apparatus for spreading material, such as fertilizers, plant protection agents or seed, having an open-loop and / or closed-loop control system according to any of the preceding claims.

12. Method for open-loop and / or closed-loop control of an agricultural apparatus having a distributor linkage (12) for spreading material, such as fertilizer, plant protection agent or seed, which linkage extends transversely to the direction of travel and has a central part (2) and two lateral arms (3) connected to the central part (2) with a plurality of linkage portions (4) which can be folded in toward one another in the transport position and folded out in the working position and are connected by joints, wherein each arm (3) is assigned at least one hydraulic device, wherein each hydraulic device can be controlled to dampen vibrations occurring on the distributor linkage in the horizontal and / or vertical direction, and wherein each hydraulic device comprises a hydraulic cylinder (10 a,b), in particular a double-acting hydraulic cylinder, wherein the method comprises the following steps: detecting a pressure change occurring at the relevant hydraulic device caused by vibrations in the horizontal and / or vertical direction of the distributor linkage (12) by means of a sensor device; and generating, on the basis of the detected pressure change, a control signal for the relevant hydraulic device, wherein the control signal is generated taking into account a pressure offset which corresponds to a pressure difference between an annular surface and a piston surface of the hydraulic cylinder (10 a,b) in a target position of the distributor linkage, wherein the pressure offset is determined based on signals from the sensor device.

13. Method according to claim 12, wherein the signals from the sensor device are processed by being filtered by means of a low-pass filter.

14. Method according to claim 12 or 13, further comprising the steps of: detecting a first pressure associated with a pressure on the annular surface of the hydraulic cylinder (10 a,b); detecting a second pressure associated with a pressure on the piston surface of the hydraulic cylinder (10 a,b); processing the first pressure and the second pressure taking into account the ratio of the annular surface and the piston surface of the hydraulic cylinder (10 a,b); generating the control signal for the relevant hydraulic device based on the processed pressure values.

15. Method according to claim 14, further comprising the steps of: determining a plurality of pressure difference values based on the first pressure and the second pressure taking into account the ratio of the annular surface and the piston surface of the hydraulic cylinder (10 a,b); applying a filter, in particular a low-pass filter, to the plurality of pressure difference values; and determining the pressure offset based on the filtered plurality of pressure difference values.

16. Method according to one of claims 14 or 15, wherein the first pressure is associated with a common pressure on the annular surfaces of all hydraulic cylinders of the hydraulic cylinder (10 a,b) of the system.

17. Method according to any of claims 12 to 16, further comprising the steps of: determining a rotation about a folding axis and / or a position of a linkage portion and / or arm; generating the control signal based on the determined rotation and / or position.