WO2023280668A1

WO2023280668A1 - Selective raising of ground engaging tools

Info

Publication number: WO2023280668A1
Application number: PCT/EP2022/068017
Authority: WO
Inventors: Jakob LINDBERG; Johan SÖDERBERG; Oskar GUNNARSSON
Original assignee: Väderstad Holding Ab
Priority date: 2021-07-05
Filing date: 2022-06-30
Publication date: 2023-01-12
Also published as: SE2150873A1

Abstract

An agricultural implement (100) is provided, comprising ground engaging tools (120), connected to an attachment frame (110) via a linkage arrangement (130), a plurality of linear actuators (140), and a fluid control system. The fluid control system is arranged to enable selective raising of a ground engaging tool using the linkage arrangement and the linear actuator by controlling the relation between a rod chamber control pressure supplied to a rod chamber (520) of the linear actuator and a cap chamber control pressure supplied to a cap chamber (530) of the linear actuator to create a net force on a piston (540) to move towards the rod end, and thus push a piston rod (550) out of a barrel (510) of the linear actuator, thereby causing the ground engaging tool to be raised from the ground. A method for selective raising of one or more ground engaging tools is also provided.

Description

SELECTIVE RAISING OF GROUND ENGAGING TOOLS

TECHNICAL FIELD

The present disclosure relates generally to selective raising of ground engaging tools, such as e.g. row units, in an agricultural implement, such as e.g. an agricultural planter.

BACKGROUND

Agricultural implements are often arranged with ground engaging tools that work the ground. For example, an agricultural planter normally comprises a number of row units or seeding units that put seed into the ground as the machine moves over a field. Each row unit comprises a furrow opener that cuts a furrow in the ground into which seed is deposited before being covered.

The row units must have sufficient weight to force the furrow opener fully into the soil to the desired depth. More weight is needed for firmer soils. Since row units often do not have sufficient weight to fully penetrate the furrow opener into the soil, agricultural planters are typically provided with a supplemental down force system. Such a supplemental down force system may simply be a mechanical spring, but it may also comprise hydraulic or pneumatic linear actuators that provide the supplemental down force. The amount of supplemental down force is typically controlled by regulating the relation between the rod chamber control pressure and the cap chamber control pressure supplied to the linear actuators.

It is sometimes desired to selectively raise row units from the ground. Selective raising of row units may e.g. be used for sowing crops having wider distances between the rows. For example, some farmers would like to use a planter with 16 rows as an 8 row planter, having double distance between the rows, and this can be done by raising every other row unit. Some farmers would like to sow different crops at different occasions with different row units, e.g. sowing every other row at each occasion, and this can also be done by raising every other row unit.

EP1752031 describes an agricultural planter where each group of row units is arranged with a spring that raises the group of row units from the ground unless a single acting hydraulic cylinder is actuated to counteract the spring force.

US9888624 describes an individual row lift system for agricultural planters, where each row unit is operable to be raised and lowered by a single acting hydraulic lift cylinder, in order to respond to specific usage requirements, such as when the plantable ground is smaller than the width of the agricultural planter. PROBLEMS WITH THE PRIOR ART

The selective raising of ground engaging tools that is described in EP1752031 and US9888624 is expensive, since a special hydraulic or pneumatic arrangement is required for selectively raising the ground engaging tools.

There is thus a need for an improved method for selective raising of ground engaging tools in an agricultural implement.

SUMMARY

The above described problem is addressed by the claimed agricultural implement. The agricultural implement may comprise: an attachment frame; a plurality of ground engaging tools, each connected to the attachment frame via a linkage arrangement; a plurality of linear actuators, each comprising a barrel, divided into a rod chamber and a cap chamber by a piston with a connected piston rod extending into the rod chamber, the piston having a rod chamber piston area and a cap chamber piston area, where each linear actuator is arranged to control the pivoting of one of the linkage arrangements, so that there for each ground engaging tool is a linear actuator arranged to provide a supplemental down force to the ground engaging tool via the linkage arrangement; and a fluid control system. The fluid control system may be arranged to: control the size of the supplemental down force provided by each of the plurality of linear actuators by regulating the relation between a rod chamber control pressure supplied to the rod chamber and a cap chamber control pressure supplied to the cap chamber, creating a net force on the piston; and enable selective raising of one or more ground engaging tools from the ground by, for each engaging tool to be raised, using the linkage arrangement and the linear actuator, by controlling the relation between the rod chamber control pressure supplied to the rod chamber and the cap chamber control pressure supplied to the cap chamber, to create a net force on the piston that causes the ground engaging tool to be raised from the ground.

The above described problem is further addressed by the claimed method for selective raising of ground engaging tools in an agricultural implement. The method may comprise: connecting a plurality of ground engaging tools to the attachment frame of an agricultural implement via a linkage arrangement for each ground engaging tool; for each ground engaging tool, arranging a linear actuator to control the pivoting of the linkage arrangement, so that there for each ground engaging tool is a linear actuator arranged to provide a supplemental down force to the ground engaging tool via the linkage arrangement, where each linear actuator comprises a barrel, divided into a rod chamber and a cap chamber by a piston with a connected piston rod extending into the rod chamber, the piston having a rod chamber piston area and a cap chamber piston area; arranging a fluid control system to control the size of the supplemental down force in each of the plurality of linear actuators by regulating the relation between a rod chamber control pressure supplied to the rod chamber and a cap chamber control pressure supplied to the cap chamber, creating a net force on the piston; and arranging the fluid control system to enable selective raising of one or more ground engaging tools from the ground by, for each engaging tool to be raised, using the linkage arrangement and the linear actuator, by controlling the relation between the rod chamber control pressure supplied to the rod chamber and the cap chamber control pressure supplied to the cap chamber, to create a net force on the piston that causes the ground engaging tool to be raised from the ground.

This enables selective raising of ground engaging tools, using the arrangement that controls the down force on the ground engaging tools. Thus, no specific arrangement is needed for enabling the selective raising of ground engaging tools.

In embodiments, the fluid control system comprises a number of fluid control sub-systems that are arranged to control the rod chamber control pressure supplied to the rod chamber and the cap chamber control pressure supplied to the cap chamber, using e.g. valve arrangements.

In embodiments, the fluid control system is arranged to be able to supply a different relation between the rod chamber control pressure supplied to the rod chamber and the cap chamber control pressure supplied to the cap chamber, creating a different net force on the piston, to each linear actuator, thereby enabling the selective raising of each individual ground engaging tool.

In embodiments, the fluid control system is arranged to be able to supply the same relation between the rod chamber control pressure supplied to the rod chamber and the cap chamber control pressure supplied to the cap chamber, creating the same net force on the piston, to a group of linear actuators, thereby enabling the selective raising of a group of ground engaging tools. This enables the use of a simpler control system, that does not need to provide individual control pressures to each linear actuator.

The selective raising of the ground engaging tools may be used for creating a tramline pattern on a field. In embodiments, a control system determines, based on a desired tramline pattern, which ground engaging tools should be raised for each pass of the agricultural implement across a field, and controls the selective raising of the plurality of ground engaging tools in accordance with this determination for each pass of the agricultural implement across the field, to thereby create the desired tramline pattern.

In embodiments, the agricultural implement is an agricultural planter, and the ground engaging tools are row units.

In this application, the term "fluid” comprises both gas and liquids. In this application, the term "agricultural implement” means any type of implement that may be used for agriculture. It may be a vehicle comprising its own driving means, or it may be an implement intended to be towed or carried by a vehicle such as e.g. a tractor.

The scope of the invention is defined by the claims, which are incorporated into this section by reference. A more complete understanding of embodiments of the invention will be afforded to those skilled in the art, as well as a realization of additional advantages thereof, by a consideration of the following detailed description of one or more embodiments. Reference will be made to the appended sheets of drawings that will first be described briefly.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 schematically illustrates the creation of a tramline using an agricultural implement comprising an attachment frame and a plurality of ground engaging tools, in accordance with one or more embodiments described herein.

Fig. 2 schematically illustrates the creation of a tramline pattern using an agricultural implement comprising an attachment frame and a plurality of ground engaging tools, in accordance with one or more embodiments described herein.

Fig. 3 schematically illustrates an agricultural implement comprising an attachment frame and a plurality of ground engaging tools, in accordance with one or more embodiments described herein.

Fig. 4 illustrates an example of a ground engaging tool and a linkage arrangement, in accordance with one or more embodiments described herein.

Fig. 5 schematically illustrates a linear actuator, in accordance with one or more embodiments described herein.

Figs. 6 and 7 schematically illustrate different embodiments of a fluid control system in accordance with one or more embodiments described herein.

Fig. 8 schematically illustrates a method for selective raising of ground engaging tools in an agricultural implement, in accordance with one or more embodiments described herein.

Embodiments of the present disclosure and their advantages are best understood by referring to the detailed description that follows. It should be appreciated that like reference numerals are used to identify like elements illustrated in one or more of the figures. DETAILED DESCRIPTION

It is sometimes desired to selectively raise row units from the ground. Selective raising of row units may e.g. be used for sowing different crops at different occasions with different row units, e.g. sowing every other row at each occasion. Prior art systems for enabling selective raising of ground engaging tools in an agricultural implement are expensive, since they require a special hydraulic or pneumatic arrangement for selectively raising the ground engaging tools.

The claimed invention enables selective raising of ground engaging tools in an agricultural implement, using the same arrangement that controls the down force on the ground engaging tools. Embodiments of the disclosed solution are presented in more detail in connection with the figures.

In order to avoid driving over rows where seeds have been planted, it is known to create tramlines for the wheels of an agricultural vehicle by disabling certain seeding units during seeding. US9043951 describes the creation of tramlines by disabling different seeding units on different passes through the field. However, tramlines created by just disabling certain seeding units during seeding will not be visible until the crops have grown enough to be seen above the ground. In order to create tramlines that are immediately visible, selective raising of row units may instead be used.

Fig. 1 schematically illustrates the creation of a tramline using an agricultural implement 100 comprising an attachment frame 110 and a plurality of ground engaging tools 120. In Fig. 1, two of the ground engaging tools 120 have been raised from the ground to create tramlines for the wheels 250 of the agricultural vehicle 200, so that it can drive on a sown field without damaging any crops. Since the soil is not engaged when a ground engaging tool 120 is raised, a tramline can be immediately seen where a ground engaging tool 120 has been raised. There will be visible strips that are not affected by any ground engaging tools 120.

If it is always the same agricultural vehicle 200 towing an agricultural implement 100 of the same width that will drive on the field, it is enough to raise the ground engaging tools 120 behind the wheels 250 of the agricultural vehicle 200 to create the tramlines. However, if it is planned that agricultural implements of different widths will be towed in the field, and/or that a vehicle 200 with another distance between the wheels 250 will drive on the field, a more complex raising pattern of the ground engaging tools 120 may be needed.

Fig. 2 illustrates how different ground engaging tools 120 may be raised in different passes across the field to create a desired tramline pattern for an agricultural aftertreatment implement having a different width. Agricultural aftertreatment implements are generally much wider than agricultural planters, since the force required for aftertreatment such as spreading fertilizer or pesticide is much lower than the force required for seeding. If the agricultural implement 100 comprises a control system (which may be arranged in the agricultural implement 100 or in an agricultural vehicle 200 towing the agricultural implement 100), the control system may be provided with information about the width of an agricultural aftertreatment implement intended to be used on the field. The control system may then be arranged to determine, based on the desired tramline pattern, which ground engaging tools should be raised for each pass of the agricultural implement across the field, and control the selective raising of the plurality of ground engaging tools in accordance with this determination for each pass of the agricultural implement across the field, to thereby create the desired tramline pattern. This enables the creation of an immediately visible tramline pattern as an agricultural implement having a plurality of ground engaging tools moves across a field in successive passes.

Fig. 3 schematically illustrates an agricultural implement 100 comprising an attachment frame 110 and a plurality of ground engaging tools 120, and Fig. 4 illustrates an example of a ground engaging tool 120 and a linkage arrangement 130. Preferably, each ground engaging tool 120 in Fig. 3 is connected to the attachment frame 110 via a linkage arrangement 130 such as e.g. the one illustrated in Fig. 4. For each linkage arrangement 130, there is preferably a linear actuator 140 arranged to control the pivoting of the linkage arrangement 130. Thus, for each ground engaging tool 120, there is preferably a linear actuator 140 arranged to provide a supplemental down force to the ground engaging tool 120 via the linkage arrangement 130. The agricultural implement 100 is arranged to be towed by a vehicle such as e.g. a tractor 200.

A typical linear actuator 140 comprises a barrel 510 in which two chambers, a rod chamber 520 and a cap chamber 530, are separated by a piston 540 having a connected piston rod 550 extending into the rod chamber 520, as illustrated in Fig 5. The movement of the piston 540 in the barrel 510 is controlled by the relation between the control pressures that are supplied to the rod chamber 520 and the cap chamber 530, creating a net force on the piston 540. If the same control pressure is supplied to both the rod chamber 520 and the cap chamber 530, there will be a resulting force on the piston 540 to move towards the rod end, since the cap chamber piston area is always larger than the rod chamber piston area (caused by there being a piston rod 550 in only the rod chamber 520). The size of this force will depend on the ratio between the rod chamber piston area and the cap chamber piston area. If a force on the piston 540 to move towards the cap end is desired, a higher control pressure must be supplied to the rod chamber 520 than to the cap chamber 530. Thus, the movement of the piston 540 can be controlled by controlling the relation between the rod chamber control pressure and the cap chamber control pressure.

The agricultural implement 100 preferably comprises a fluid control system that is arranged to control the supplemental down force by regulating the relation between the rod chamber control pressure and the cap chamber control pressure, and thus the net force on the piston 540, for the plurality of linear actuators 140. The same fluid control system may be used also for selective raising of one or more ground engaging tools 120 by, for each engaging tool 120 to be raised, controlling the relation between the rod chamber control pressure supplied to the rod chamber 520 and the cap chamber control pressure supplied to the cap chamber 530, to create a net force on the piston 540 that causes the ground engaging tool 120 to be raised from the ground.

If the linear actuators 140 are mounted as illustrated in Fig. 4, a raising of a ground engaging tool 120 is caused by regulating the relation between the rod chamber control pressure and the cap chamber control pressure so that there is a net force on the piston 540 to move towards the rod end, and thus push the piston rod 550 out of the barrel 510. However, the linear actuators may instead be mounted so that a raising of a ground engaging tool 120 is caused by regulating the relation between the rod chamber control pressure and the cap chamber control pressure so that there is a net force on the piston 540 to move towards the cap end, and thus pull the piston rod 550 into the barrel 510.

The ground engaging tools 120 may be controlled to be raised individually or in groups. Raising them in groups enables the use of a simpler control system, that does not need to provide individual control pressures to each linear actuator 140. For example, if the wheels 250 of the agricultural vehicle 200 are wide enough to always require the raising of two ground engaging tools 120 to create a tramline, the ground engaging tools 120 may be connected in pairs that are always supplied with the same control signals.

The fluid control system preferably comprises a number of fluid control sub-systems that are arranged to supply a different relation between the rod chamber control pressure supplied to the rod chamber 520 and the cap chamber control pressure supplied to the cap chamber 530 of the linear actuators 540 from fluid distributed by a pair of main fluid lines containing differentiated pressures. The fluid control sub-systems may control the rod chamber control pressure supplied to the rod chamber 520 and the cap chamber control pressure supplied to the cap chamber 530 using e.g. valve arrangements.

Fig. 6 schematically illustrates an embodiment of fluid control system comprising a number of fluid control sub-systems 600, each supplied with fluid from the two main fluid lines. In Fig. 6, there is a fluid control sub system 600 for each linear actuator 140. This means that the fluid control system is able to supply a different relation between the rod chamber control pressure supplied to the rod chamber 520 and the cap chamber control pressure supplied to the cap chamber 530, creating a different net force on the piston 540, to each linear actuator 140, thereby enabling the selective raising of each individual ground engaging tool 120.

Fig. 7 schematically illustrates another embodiment of a fluid control system comprising a number of fluid control sub-systems 700, each supplied with fluid from the two main fluid lines. In Fig. 7, each fluid control sub-system 700 is common to a group of linear actuators 140, so that there is a fluid control sub-system 700 for each group of linear actuators 140. This means that the fluid control system supplies the same relation between the rod chamber control pressure supplied to the rod chamber 520 and the cap chamber control pressure supplied to the cap chamber 530, creating the same net force on the piston 540, to a group of linear actuators 140, thereby enabling the selective raising of a group of ground engaging tools 120.

The fluid control system shown in Fig. 7 is simpler and cheaper than the fluid control system shown in Fig. 6, since fewer fluid control sub-systems 600, 700 are needed.

Fig. 8 schematically illustrates a method 800 for enabling selective raising of a ground engaging tool 120 in an agricultural implement 100. The method 800 may comprise:

Step 830: connecting a plurality of ground engaging tools 120 to an attachment frame 110 of an agricultural implement 100 via a linkage arrangement 130 for each ground engaging tool 120.

Step 840: for each ground engaging tool 120, arranging a linear actuator 140 to control the pivoting of the linkage arrangement 130, so that there for each ground engaging tool 120 is a linear actuator 140 arranged to provide a supplemental down force to the ground engaging tool 120 via the linkage arrangement 130, where each linear actuator 140 comprises a barrel 510, divided into a rod chamber 520 and a cap chamber 530 by a piston 540 with a connected piston rod 550 extending into the rod chamber 520, the piston 540 having a rod chamber piston area and a cap chamber piston area.

Step 850: arranging a fluid control system to control the size of the supplemental down force in each of the plurality of linear actuators 140 by regulating the relation between a rod chamber control pressure supplied to the rod chamber 520 and a cap chamber control pressure supplied to the cap chamber 530, creating a net force on the piston 540.

Step 860: arranging the fluid control system to enable selective raising of one or more ground engaging tools 120 by, for each engaging tool 120 to be raised, using the linkage arrangement 130 and the linear actuator 140, by controlling the relation between the rod chamber control pressure supplied to the rod chamber 520 and the cap chamber control pressure supplied to the cap chamber 530, to create a net force on the piston 540 that causes the ground engaging tool 120 to be raised from the ground.

This enables selective raising of ground engaging tools, using the same arrangement that controls the down force on the ground engaging tools.

In embodiments, the agricultural implement 100 is an agricultural planter, and the ground engaging tools 120 are row units.

In embodiments, the method 800 further comprises at least one of the following: Step 810: determining, based on a desired tramline pattern, which ground engaging tools 120 should be raised for each pass of the agricultural implement 100 across a field.

Step 820: controlling the selective raising of the plurality of ground engaging tools 120 in accordance with this determination for each pass of the agricultural implement 100 across the field to thereby create the desired tramline pattern. This enables the creation of an immediately visible tramline pattern as an agricultural implement having a plurality of ground engaging tools moves across a field in successive passes.

Step 870: arranging the fluid control system to comprise a number of fluid control sub-systems 600, 700 that control the rod chamber control pressure supplied to the rod chamber 520 and the cap chamber control pressure supplied to the cap chamber 530, using e.g. valve arrangements.

Step 880: arranging the fluid control system to be able to supply a different relation between the rod chamber control pressure supplied to the rod chamber 520 and the cap chamber control pressure supplied to the cap chamber 530, creating a different net force on the piston 540, to each linear actuator 140, thereby enabling the selective raising of each individual ground engaging tool 120.

Step 890: arranging the fluid control system to be able to supply the same relation between the rod chamber control pressure supplied to the rod chamber 520 and the cap chamber control pressure supplied to the cap chamber 530, creating the same net force on the piston 540, to a group of linear actuators 140, thereby enabling the selective raising of a group of ground engaging tools 120. This enables the use of a simpler control system, that does not need to provide individual control pressures to each linear actuator 140.

The fluid control system may be controlled by a control system in the vehicle 200 towing the agricultural implement 100. The fluid control system may even be connected to a fluid supply in the towing vehicle 200. The control system may e.g. be a general control system in the vehicle 200 pulling the agricultural implement 100, that the farmer may use to control all aspects of operation of the agricultural implement 100. There may e.g. be a control pad arranged in front of the driver's seat, and commands may be input into the control system using this control pad.

The control system in the vehicle may comprise information on the desired location of the tramlines for the wheels 250 of the agricultural vehicle 200 based on the width of the agricultural implement 100 that will be used for the next treatment of the field. The control system may, based on this information, automatically determine which ground engaging tools 120 should be raised for each drive across the field. The raising of the selected ground engaging tools 120 may then take place automatically by the system. However, the farmer may also manually enter the information about which ground engaging tools 120 to raise on each drive across the field. The foregoing disclosure is not intended to limit the present invention to the precise forms or particular fields of use disclosed. It is contemplated that various alternate embodiments and/or modifications to the present invention, whether explicitly described or implied herein, are possible in light of the disclosure. For example, the raising of ground engaging tools 120 has in this disclosure been described mainly in connection with the creation of tramlines, but it may be desirable to raise ground engaging tools 120 also for many other purposes, as when the plantable ground is smaller than the width of the agricultural planter, when the agricultural planter needs to partly overlap a previously sown area, or for sowing crops having wider distances between the rows. Further, not all of the steps of the claims have to be carried out in the listed order. All technically meaningful orders of the steps are covered by the claims. Accordingly, the scope of the invention is defined only by the claims.

Claims

1. Agricultural implement (100) comprising: an attachment frame (110); a plurality of ground engaging tools (120), each connected to the attachment frame (110) via a linkage arrangement (130); a plurality of linear actuators (140), each comprising a barrel (510), divided into a rod chamber (520) and a cap chamber (530) by a piston (540) with a connected piston rod (550) extending into the rod chamber (520), the piston (540) having a rod chamber piston area and a cap chamber piston area, where each linear actuator (140) is arranged to control the pivoting of one of the linkage arrangements (130), so that there for each ground engaging tool (120) is a linear actuator (140) arranged to provide a supplemental down force to the ground engaging tool (120) via the linkage arrangement (130); and a fluid control system, arranged to: control the size of the supplemental down force provided by each of the plurality of linear actuators (140) by regulating the relation between a rod chamber control pressure supplied to the rod chamber (520) and a cap chamber control pressure supplied to the cap chamber (530), creating a net force on the piston (540); and enable selective raising of one or more ground engaging tools (120) by, for each engaging tool (120) to be raised, using the linkage arrangement (130) and the linear actuator (140), by controlling the relation between the rod chamber control pressure supplied to the rod chamber (520) and the cap chamber control pressure supplied to the cap chamber (530), to create a net force on the piston (540) that causes the ground engaging tool (120) to be raised from the ground.

2. Agricultural implement (100) according to claim 1, wherein the fluid control system comprises a number of fluid control sub-systems (600, 700) that are arranged to control the rod chamber control pressure supplied to the rod chamber (520) and the cap chamber control pressure supplied to the cap chamber (530), using e.g. valve arrangements.

3. Agricultural implement (100) according to claim 1 or 2, wherein the fluid control system is arranged to be able to supply a different relation between the rod chamber control pressure supplied to the rod chamber (520) and the cap chamber control pressure supplied to the cap chamber (530), creating a different net force on the piston (540), to each linear actuator (140), thereby enabling the selective raising of each individual ground engaging tool (120).

4. Agricultural implement (100) according to claim 1 or 2, wherein the fluid control system is arranged to be able to supply the same relation between the rod chamber control pressure supplied to the rod chamber (520) and the cap chamber control pressure supplied to the cap chamber (530), creating the same net force on the piston (540), to a group of linear actuators (140), thereby enabling the selective raising of a group of ground engaging tools (120).

5. Agricultural implement (100) according to any one of claims 1-4, further comprising a control system arranged to determine, based on a desired tramline pattern, which ground engaging tools (120) should be raised for each pass of the agricultural implement (100) across a field, and control the selective raising of the plurality of ground engaging tools (120) in accordance with this determination for each pass of the agricultural implement (100) across the field, to thereby create the desired tramline pattern.

6. Agricultural implement (100) according to any one of claims 1-5, wherein the agricultural implement (100) is an agricultural planter, and the ground engaging tools (120) are row units.

7. Method (800) for enabling selective raising of a ground engaging tool (120) in an agricultural implement (100), the method (800) comprising: connecting (830) a plurality of ground engaging tools (120) to the attachment frame (110) of an agricultural implement (100) via a linkage arrangement (130) for each ground engaging tool (120); for each ground engaging tool (120), arranging (840) a linear actuator (140) to control the pivoting of the linkage arrangement (130), so that there for each ground engaging tool (120) is a linear actuator (140) arranged to provide a supplemental down force to the ground engaging tool (120) via the linkage arrangement (130), where each linear actuator (140) comprises a barrel (510), divided into a rod chamber (520) and a cap chamber (530) by a piston (540) with a connected piston rod (550) extending into the rod chamber (520), the piston (540) having a rod chamber piston area and a cap chamber piston area; arranging (850) a fluid control system to control the size of the supplemental down force in each of the plurality of linear actuators (140) by regulating the relation between a rod chamber control pressure supplied to the rod chamber (520) and a cap chamber control pressure supplied to the cap chamber (530), creating a net force on the piston (540); and arranging (860) the fluid control system to enable selective raising of one or more ground engaging tools (120) by, for each engaging tool (120) to be raised, using the linkage arrangement (130) and the linear actuator (140), by controlling the relation between the rod chamber control pressure supplied to the rod chamber (520) and the cap chamber control pressure supplied to the cap chamber (530), to create a net force on the piston (540) that causes the ground engaging tool (120) to be raised from the ground.

8. Method (800) according to claim 7, further comprising arranging (870) the fluid control system to comprise a number of fluid control sub-systems (600, 700) that control the rod chamber control pressure supplied to the rod chamber (520) and the cap chamber control pressure supplied to the cap chamber (530), using e.g. valve arrangements.

9. Method (800) according to claim 7 or 8, further comprising arranging (880) the fluid control system to be able to supply a different relation between the rod chamber control pressure supplied to the rod chamber (520) and the cap chamber control pressure supplied to the cap chamber (530), creating a different net force on the piston (540), to each linear actuator (140), thereby enabling the selective raising of each individual ground engaging tool (120).

10. Method (800) according to claim 7 or 8, further comprising arranging (890) the fluid control system to be able to supply the same relation between the rod chamber control pressure supplied to the rod chamber (520) and the cap chamber control pressure supplied to the cap chamber (530), creating the same net force on the piston (540), to a group of linear actuators (140), thereby enabling the selective raising of a group of ground engaging tools (120).

11. Method (800) according to any one of claims 7-10, further comprising determining (810), based on a desired tramline pattern, which ground engaging tools (120) should be raised for each pass of the agricultural implement (100) across a field, and controlling (820) the selective raising of the plurality of ground engaging tools (120) in accordance with this determination for each pass of the agricultural implement (100) across the field, to thereby create the desired tramline pattern.

12. Method (800) according to any one of claims 7-11, wherein the agricultural implement (100) is an agricultural planter, and the ground engaging tools (120) are row units.