Agricultural implement and method of controlling agricultural implement

Abstract

An agricultural implement (1) comprises a first frame section (10, 16a, 16b, 16c, 16d, 16e, 16f, 16r), and a second frame section, which is pivotably connected to the first frame section (10, 16a, 16b, 16c, 16d, 16e, 16f, 16r) about a pivot joint, which presents a substantially horizontal pivot axis (A1b, A1c, A2a, A2b, A3a, A3b), wherein the second frame section carries a plurality of soil-working tools (17), wherein an actuator (18a, 18b) is operable between the first frame section (10, 16a, 16b, 16c, 16d, 16e, 16f, 16r) and the second frame section (10, 16a, 16b, 16c, 16d, 16e, 16f, 16r) to control a pivot angle about said pivot joint, characterized by at least one first height sensor (21, 21a, 21b, 21d, 21e) arranged on the second frame section (10, 16a, 16b, 16c, 16d, 16e, 16f, 16r) and configured to provide a first height signal for the second frame section (10, 16a, 16b, 16c, 16d, 16e, 16f, 16r), indicating a height over ground (0) of the second frame section (10, 16a, 16b, 16c, 16d, 16e, 16f, 16r), and a controller (20), configured to receive the first height signal and to control the actuator (18a, 18b) based on the first height signal, wherein the second frame section (10, 16a, 16b, 16c, 16d, 16e, 16f, 16r) is supported towards the ground (0) only by the soil working tools (17).

Description

[0001] AGRICULTURAL IMPLEMENT AND METHOD OF CONTROLLING AGRICULTURAL IMPLEMENT

[0002] Technical field

[0003] The present disclosure relates to an agricultural implement, and in particular to an agricultural implement having folding side frame sections, which do not have any dedicated ground support, such as support wheels, or the like.

[0004] The disclosure further relates to a method of controlling the position of folding side frame sections.

[0005] Background

[0006] Agricultural implements are known and widely used, having various toolcarrying frame sections that are foldable between e.g. a working state and a transport state.

[0007] Each such frame section is provided with one or more dedicated ground supports, such as support wheels or rollers, which provide a reference height for the implement frame, whereby the working depth of the various tools fitted to the agricultural implement can be controlled in relation to the implement frame.

[0008] However, such support wheels present a problem in connection with folding of the agricultural implement, in that they take up space and need to be taken into account when designing the agricultural implement to be foldable, in particular into the transport state. Moreover, the support wheels add weight and cost to the agricultural implement.

[0009] However, if the dedicated ground support was to be removed, then it would become difficult to control the working depth of the various tools.

[0010] Hence, there is a need for an agricultural implement, which provides for accurate control of the tools' working depth, while facilitating folding, in particular into the transport state.

[0011] Summary

[0012] It is an objective of the present disclosure to provide an improved agricultural implement and an improved method of controlling an agricultural implement, which eliminate, or at least alleviate, the above mentioned disadvantages.

[0013] The invention is defined by the appended independent claims.

[0014] According to a first aspect, there is provided an agricultural implement, comprising a first frame section, and a second frame section, which is pivotably connected to the first frame section about a pivot joint, which presents a substantially horizontal pivot axis. The second frame section carries a plurality of soil-working tools. An actuator is operable between the first frame section and the second frame section to control a pivot angle about said pivot joint. At least one first height sensor is arranged on the second frame section and configured to provide a first height signal for the second frame section, indicating a height over ground of the second frame section. A controller is configured to receive the first height signal and to control the actuator based on the first height signal. The second frame section is supported towards the ground only by the soil working tools.

[0015] A frame section may be made up of a single beam, or of a 2D arrangement of beams, as the case may be.

[0016] The term "supported towards the ground only by the soil working tools" implies that there is no dedicated ground support, such as wheels or rollers, which would otherwise provide a fixed ground height reference for the frame section, arranged on the frame section. In particular, the side frame section would not be provided with any support wheel.

[0017] The agricultural implement may optionally comprise soil working tools which provide some ground support, but which are not dedicated for supporting the frame relative to the ground. Examples of such non-dedicated ground supporting soil working tools include reconsolidation rollers, disc tools, gauge wheels, closing wheels, or the like, which have a primary function in working the soil and which may provide some ground support as a secondary function.

[0018] The substantially horizontal pivot axis may extend in a horizontal plane + / - about 15 degs, preferably + / - about 10 degs, + / - about 5 degs, + / - about 1 degs, or horizontal.

[0019] Thus, by measuring the height over ground of the second frame section, it is possible to control the actuator to maintain the second frame section at a desired ground height, such that the working depth of the tools supported by the second frame section can be controlled relative to the second frame section without the need for any dedicated supporting wheel or roller.

[0020] The agricultural implement may comprise at least one second height sensor, arranged on the first frame section and configured to provide a second height signal for the first frame section. The controller may be configured to receive the second height signal and to control the actuator also based on the second height signal.

[0021] The agricultural implement may comprise at least one third height sensor arranged on the second frame section, spaced from the first height sensor in a direction perpendicular to the pivot axis, and configured to provide a third height signal for the second frame section, said third height signal indicating a second height over ground for the second frame section.

[0022] The one or more third height sensors may be positioned at different distances from the pivot axis, such that two or more height signals are provided for the second frame section.

[0023] The controller may be configured to control the actuator based also on the third height signal.

[0024] For example, the controller may control the actuator based on an average of the height signals. Alternatively, the height signals may be weighted, e.g. in response to them indicating a curvature of the ground, such that a desired frame orientation is achieved.

[0025] At least one of the first, second and third height sensors may be selected from a group consisting of a radar sensor, an ultrasound sensor, and an angle sensor connected to at least one of the soil-working tools.

[0026] The height sensors may be of the same type, or of different types.

[0027] The soil working tools may be selected from a group consisting of tillage tools, weeding tools, product dispensing tools and scraping tools.

[0028] Hence, the soil working tools may comprise, or consist of, any type of tool which works the soil without providing any dedicated ground supporting function, hence excluding e.g. rollers. A product dispensing tool may be any type of tool or output unit for dispensing a product, such as seeds, fertilizer or pesticide to the ground. In particular, the tools may be output units for seeding or row units planting, which may comprise a furrow opening device, a product dispensing device, and a furrow closing device. Optionally, the output unit or row unit may also comprise a compacting or pressing device for pressing the product into the ground.

[0029] The first frame section may be a main frame section. The second frame section may be a side frame section. The horizontal pivot axis may be parallel with a working direction of the agricultural implement.

[0030] A main frame section may be a frame section that is fixedly connected to a towing or carrying arrangement, such as a towbar or a hitch, as the case may be. The main frame section may, but need not, carry soil working tools.

[0031] The first frame section may be a first side frame section. The second frame section may be a second side frame section, which may be arranged laterally outside the first side frame section. The horizontal pivot axis may be parallel with a working direction of the agricultural implement.

[0032] The first frame section may be a main frame section. The second frame section may be a front frame section, which is arranged longitudinally in front of the first frame section. The horizontal pivot axis may be perpendicular to a working direction of the agricultural implement.

[0033] It is understood that the main frame section in this case may be a fixed frame section, or a foldable frame section, i.e. a side frame section.

[0034] The first frame section may be a main frame section. The second frame section may be a rear frame section, which may be arranged longitudinally behind the first frame section. The horizontal pivot axis may be perpendicular to a working direction of the agricultural implement.

[0035] It is understood that the main frame section in this case may be a fixed frame section, or a foldable frame section, i.e. a side frame section.

[0036] According to a second aspect, there is provided a method of controlling an agricultural implement, which comprises a first frame section, and a second frame section, which is pivotably connected to the first frame section about a pivot joint, which presents a horizontal pivot axis. The second frame section carries a plurality of soil-working tools. An actuator is operable between the first frame section and the second frame section to control a pivot angle about said pivot joint. The method comprises receiving a first height signal for the second frame section, indicating a distance between a portion of the second frame section and ground, and controlling the actuator based on the first height signal. The second frame section is supported towards the ground only by the soil working tools.

[0037] Figs la-lc are perspective views schematically illustrating an agricultural implement in the form of a seeder.

[0038] Fig. 2 schematically illustrates the seeder as seen from behind.

[0039] Figs 3-8 schematically illustrate various frame configurations to which the present concept can be applied.

[0040] Detailed description

[0041] The present inventive concept finds use on various types of soil working agricultural implements, including tillage implements, such as harrows or cultivators, but also on seeders, planters or other implements configured to distribute a product to ground over which the agricultural implement travels.

[0042] The implement may be configured to be towed and / or carried by a traction vehicle, such as a tractor. Alternatively, the implement may be configured to be towed and / or carried by a gantry type traction vehicle.

[0043] In the following description, the inventive concept will be described with reference to an agricultural implement 1 in the form of a seeder, comprising a main frame section 10, a rear frame section 11, which is pivotably connected to the main frame section 10, such that the rear frame section 11 is pivotable about a first horizontal axis Al that is perpendicular to the working direction Dw. A first actuator 12 may be provided for controlling the relative position of the rear frame and the main frames.

[0044] The main frame section 10 comprises a tow bar 13 and supports, inter alia, a product container 14. The main frame section 10 is further supported by a pair of ground supports 15 in the form of wheels.

[0045] A pair of side frame sections 16a, 16b are pivotably connected to the rear frame section 11, such that the side frame sections 16a, 16b are pivotable relative to the rear frame section 11 about respective second pivot axes A2a, A2b that, when the agricultural implement 1 is in the working state, are horizontal and parallel with the working direction Dw, as illustrated in fig. la. Each of the side frame sections 16a, 16b comprises laterally extending beams 161, 162, which support a plurality of tools 17, which in this embodiment are exemplified by output units.

[0046] Each output unit may be configured for dispensing a product to the ground 0 over which the agricultural implement travels.

[0047] Second actuators 18a, 18b are operable between each of the side frame sections 16a, 16b and the rear frame section 11, such that a relative angular position of the respective side frame section 16a, 16b and the rear frame section 11 is controlled by the second actuators 18a, 18b.

[0048] Figs la-lc illustrate a folding sequence of the agricultural implement 1.

[0049] In fig. la, the agricultural implement 1 is illustrated in its working state, with the rear frame section 11 folded down relative to the main frame section 10 and with the side frame sections 16a, 16b folded down relative to the rear frame section 11, such that the tools 17 can engage the ground 0.

[0050] In fig. lb, the agricultural implement 1 is illustrated in an intermediate state of the folding sequence, where the rear frame section 11 has been lifted to its transport position by pivoting about the first horizontal axis Al.

[0051] In fig. lc, the agricultural implement 1 has been folded to its transport state, where the side frame sections 16a, 16b have been pivoted about the second pivot axes A2a', A2b', which are vertical when the rear frames section 11 is in the transport state, such that the side frame sections 16a, 16b extend forwardly.

[0052] As can be noted from figs la-lc, the side frame sections 16a, 16b support only the tools 17. Hence, the side frame sections 16a, 16b do not have any ground supports, such as wheels or rollers.

[0053] Fig. 2 schematically illustrates the agricultural implement 1 as seen from behind, with the rear frame section 11, the side frame sections 16a, 16b, the tools 17 supported by the side frame sections 16a, 16b and the actuators 18a, 18b which are operable between the rear frame section 11 and the respective side frame sections 16a, 16b.

[0054] In fig. 2, sensors are only illustrated on one of the side frame sections 16a, 16b, but it is understood that similar or identical sensor arrangements may be provided on both side frame sections 16a, 16b. Fig. 2 further illustrates height sensors 21, 22, 23, which are mounted to the frame sections 11, 16a, 16b, and which are configured for measuring a distance between the associated frame section 11, 16a, 16b and the ground 0.

[0055] Such ground sensors 21, 22, 23 may be contactless, such as to utilize techniques like radar, ultrasound or light (e.g. laser) for sensing the distance. Alternatively, a ground sensor may be provided in the form of an angle sensor or a proximity sensor fitted to a tool that has a portion which contacts, but does not penetrate, the ground surface. Examples of such tools include output units, such as row units, which may comprise a gauge wheel, a stop wheel, or the like, which may be configured to roll on the ground surface, rather than to penetrate it.

[0056] For example, an angle sensor may be fitted to an arm or to a parallel linkage that connects the output unit to the associated frame section.

[0057] In its most simple configuration, the agricultural implement 1 may be configured such that the main frame section 10 and / or the rear frame section 11 provides a predetermined height, e.g. due to its ground support 15.

[0058] In such case, a single first height sensor 21 may be provided on each side frame section 16a, 16b, spaced from the respective second pivot axis A2a, A2b, and connected to a controller 20.

[0059] The controller 20 is further connected to the associated actuators 18a, 18b, such that the actuator 18a, 18b can be controlled, and in particular continuously controlled by the controller 20 based on a height signal from the first height sensor 21. The connection between the controller 20 and the actuators 18a, 18b may comprise an electrically controllable hydraulic system (not shown), such that the actuators 12, 18a, 18b may be hydraulic actuators.

[0060] In an alternative configuration, also the rear frame section 11, and / or the main frame section 10 may be provided with a second height sensor 22, which may also be connected to the controller 20, such that the controller 20 may receive a height signal from the second height sensor 22. For example, the height signal from the second height sensor 22 may be used as a reference height signal, whereby the actuators 18a, 18b are controlled such that the first height sensor 21 provides a height signal that follows as closely as possible the height signal from the second height sensor 22. In yet an alternative configuration, which may be based on the first or second configuration, one or more third height sensors 23 may be provided on one or more of the side frame sections 16a, 16b, such that two or more height signals may be provided for each side frame section 16a, 16b. The third height sensors 23 may be spaced from the first height sensor 21 as seen in a direction perpendicular to the second pivot axis A2a, A2b.

[0061] In this configuration, the controller 20 may use two or more height signals for determining the actual height of the side frame section 16a, 16b, with an algorithm being used to determine how to control the actuator 18a, 18b to achieve the optimum height of the associated side frame section 16a, 16b.

[0062] Fig. 3 schematically illustrates a first alternative agricultural implement configuration, as seen from above, with the main frame section 10, and first and second side frame sections 16a, 16b. The side frame sections 16a, 16b may carry a plurality of soil-working tools. No ground support may be arranged to the side frame sections 16a, 16b, such that the side frame sections 16a, 16b may be supported towards the ground only by the tools. Hence, the only ground support may be provided on the main frame section 10.

[0063] The side frame sections 16a, 16b may be pivotably connected to the main frame section 10 about respective horizontal pivot axes A2a, A2b, parallel with the working direction Dw. Actuators (not shown) may be operative between the main frame section 10 and respective side frame section 16a, 16b, as illustrated in fig. 2.

[0064] Sensors 21a, 21b may be arranged on the first and second side frame sections 16a, 16b. Optionally, at least one sensor 22 may be arranged to the main frame section 10. Yet optionally, further sensors 23 may be arranged on the first and second side frame sections 16a, 16b, as illustrated in fig. 2.

[0065] The controller (not shown), analogous with disclosure in fig. 2, may be configured to maintain the side frame sections 16a, 16b at a predetermined height above ground, which may be the same as that of the main frame section 10.

[0066] Fig. 4 schematically illustrates a second alternative agricultural implement configuration, as seen from above, with the main frame section 10, a central frame section 16c, and the first and second side frame sections 16a, 16b.

[0067] The central frame section 16c may carry a plurality of soil-working tools. No ground support may be arranged on the central frame section 16c. The central frame section 16c may be fixedly connected to the main frame section 10. Hence, the only ground support may be provided on the main frame section 10.

[0068] Alternatively, the central frame section 16c may be connected to the main frame section 10 such that a height of the central frame section 16c may be adjusted.

[0069] The first and second side frame sections 16a, 16b may be pivotably connected to the central frame section 16c about respective horizontal pivot axes A2a, A2b, parallel with working direction Dw. The side frame sections 16a, 16b may carry a plurality of soil-working tools.

[0070] Actuators (not shown) may be operative between the main frame section 10 or central frame section 16c and the respective side frame sections 16a, 16b, as illustrated in fig. 2.

[0071] Sensors 21a, 21b may be arranged on the side frame sections 16a, 16b. Optionally, sensors 22 may be arranged on the main frame section 10 and / or on the central frame section 16c. Yet optionally, further sensors 23 may be arranged on the first and second side frame sections 16a, 16b, as illustrated in fig. 2.

[0072] The controller (not shown), analogous with disclosure in fig. 2, may be configured to maintain the side frame sections 16a, 16b at a predetermined height above ground, which may be the same as that of the central frame section 16c and / or the main frame section 10.

[0073] Fig. 5 schematically illustrates a third alternative agricultural implement configuration, as seen from above, with the main frame section 10, the first and second frame section 16a, 16b, and a first and second outer side frame section 16d, 16e.

[0074] The first and second side frame sections 16a, 16b may carry a plurality of soilworking tools. The first and second side frame sections 16a, 16b may be pivotably connected to the main frame section 10 about respective horizontal pivot axes A2a, A2b, parallel with the working direction Dw.

[0075] Actuators (not shown) may be operative between the main frame section 10 and respective side frame section 16a, 16b, as illustrated in fig. 2.

[0076] The first and second outer side frame sections 16d, 16e may carry a plurality of soil-working tools. The outer side frame sections 16d, 16e may be pivotably connected to the side frame sections 16a, 16b about respective horizontal third pivot axes A3a, A3b, parallel with the working direction Dw.

[0077] At least one of the side frame sections 16a, 16b and the outer side frame sections 16d, 16e may not have any ground support, such as support wheels or rollers. Hence, the only ground support may be provided on the main frame section 10.

[0078] Hence, in some embodiments, none of the side frame sections 16a, 16b or the outer side frame sections 16d, 16e, have any ground support.

[0079] Alternatively, in some embodiments, e.g. the side frame sections 16a, 16b may have no ground support while the outer side frame sections 16d, 16e do have one or more ground supports.

[0080] Alternatively, in other embodiments, e.g. the side frame sections 16a, 16b may have one or more ground supports, while the outer side frame sections 16d, 16e have no ground support.

[0081] Further actuators (not shown) may be operative between the side frame section 16a, 16b and respective outer side frame section 16d, 16e, similar to what was illustrated in fig. 2.

[0082] Sensors 21a, 21b, 21d, 21e may be arranged on the side frame sections 16a, 16b, 16d, 16e. Sensors 22 may be arranged on the main frame section 10. Yet optionally, further sensors 23 may be arranged on any of the frame sections 16a, 16b, 16d, 16e, as illustrated in fig. 2.

[0083] The controller (not shown), analogous with disclosure in fig. 2, may be configured to maintain the side frame sections 16a, 16b and / or the outer side frame sections 16d, 16e at a predetermined height above ground, which may be the same as that of the main frame section 10.

[0084] Fig. 6 schematically illustrates a fourth alternative agricultural implement configuration, as seen from above, with a main frame section 10, a central frame section 16c, first and second side frame sections 16a, 16b, and first and second outer side frame sections 16d, 16e.

[0085] The central frame section 16c may carry a plurality of soil-working tools. The first and second side frame sections 16a, 16b may carry a plurality of soil-working tools. No ground support may be arranged to the first and second side frame sections 16a, 16b, such that the first and second side frame sections are only supported towards the ground by the soil-working tools. The first and second side frame sections 16a, 16b may be pivotably connected to the central frame section 16c about respective horizontal pivot axes A2a, A2b, parallel with the working direction Dw.

[0086] Actuators (not shown) may be operative between the main frame section 10 or central frame section 16c and respective side frame section 16a, 16b, similar to what was illustrated in fig. 2.

[0087] The first and second outer side frame sections 16d, 16e may carry a plurality of soil-working tools. No ground support may be arranged to the first and second outer side frame sections 16d, 16e, such that the outer side frame sections 16d, 16e are supported towards the ground only by the soil-working tools. Hence, the only ground support may be provided on the main frame section 10.

[0088] The first and second outer side frame sections 16d, 16e may be pivotably connected to the side frame sections 16a, 16b about respective horizontal third pivot axes A3a, A3b, parallel with the working direction Dw.

[0089] Analogous with the embodiment illustrated in fig. 5, ground supports may be provided on either only side frame sections 16a, 16b or only outer side frame sections 16d, 16e.

[0090] Further actuators (not shown) may be operative between the side frame section 16a, 16b and respective outer side frame section 16d, 16e.

[0091] Sensors 21a, 21b, 21d, 21e may be arranged on the frame sections 16a, 16b, 16d, 16e. Optionally, sensors 22 may be arranged on the central frame section 16c and / or on the main frame section 10. Yet optionally, further sensors 23 may be arranged on any of the frame sections 16a, 16b, 16d, 16e, as illustrated in fig. 2.

[0092] The controller (not shown), analogous with disclosure in fig. 2, may be configured to maintain the side frame sections 16a, 16b and / or the outer side frame sections 16d, 16e at a predetermined height above ground, which may be the same as that of the central frame section 16c and / or the main frame section 10.

[0093] Fig. 7 schematically illustrates a fifth alternative agricultural implement configuration, as seen from above, with the main frame section 10, the central frame section 16c, and a front frame section 16f. The central frame section 16c may carry a plurality of soil-working tools. The front frame section 16f may carry a plurality of soil-working tools.

[0094] Typically, the soil-working tools carried by the front frame section 16f would be different from those carried by the main frame section 16c. In particular, a front frame section could carry a straw harrow and / or levelling tools. No ground support may be arranged to the front frame section 16f, such that the front frame section 16f is supported towards the ground only by the soil-working tools. The front frame section 16f may be pivotable relative to the central frame section 16c and / or the main frame section 10 about a fourth pivot axis Alb, which is horizontal and perpendicular to the working direction Dw.

[0095] An actuator (not shown) may be operative between the main frame section 10 and / or the central frame section 16c and the front frame section 16f, similar to what was illustrated in fig. 2.

[0096] A sensor 21 may be arranged on the front frame section 16f. A sensor 22 may optionally be arranged on the central frame section 16c and / or on the main frame section 10.

[0097] The controller (not shown), analogous with disclosure in fig. 2, may be configured to maintain the front frame section 16f at a predetermined height above ground which may be the same as that of the central frame section 16c and / or of the main frame section 10.

[0098] Fig. 8 schematically illustrates a sixth alternative agricultural implement configuration, as seen from above, with the main frame section 10, the central frame section 16c, and a rear frame section 16r.

[0099] The central frame section 16c may carry a plurality of soil-working tools.

[0100] The rear frame section 16r may carry a plurality of soil-working tools.

[0101] Typically, the soil-working tools carried by the rear frame section 16r would be different from those carried by the main frame section 16c. In particular, a rear frame section could carry a straw harrow and / or levelling tools. No ground support may be arranged to the rear frame section 16r, such that the rear frame section 16r is supported towards the ground only by the soil-working tools. The rear frame section 16r may be pivotable relative to the central frame section 16c and / or the main frame section 10 about a fifth pivot axis Ale, which is horizontal and perpendicular to the working direction Dw. An actuator (not shown) may be operative between the main frame section 10 and / or the central frame section 16c and rear frame section 16r, similar to what was illustrated in fig. 2.

[0102] A sensor 21 may be arranged on the rear frame section 16r. Optionally, a sensor 22 may be arranged on the central frame section 16c and / or on the main frame section 10.

[0103] The controller (not shown), analogous with disclosure in fig. 2, may be configured to maintain a predetermined height above ground of the rear frame section 16r, which may be the same as a height of the central frame section 16c and / or of the main frame section 10.

[0104] In each of the configurations illustrated in figs 3-8, each frame section may support a plurality of tools in the form of be output units, such as row units in a seeder or planter. Alternatively, or additionally, a frame section may support a plurality of tools in the form of harrow tines, cultivator tines, straw harrow tines, scraper tools, levelling tools, disc tools, or other tools which penetrate the ground over which the agricultural implement travels.

[0105] In each of the configurations illustrated in figs 3-8, sensors 21, 21a, 21b, 21d, 21e, 22, 23 may be positioned analogously with what was described with reference to fig. 2.

[0106] It is contemplated that an implement having one or more side frame sections 16a, 16b and optionally outer side frame sections 16d, 16e, may have front frame sections 16r and / or rear frame sections 16r connected to the respective side frame section 16a, 16b and outer side frame section 16d, 16e, as well as to the central frame section 16c, with some or all of the frame sections provided with one or more height sensors connected to the controller for controlling the ground height of the respective frame section.

[0107] Each of the pivot axes Ala, Alb, Ale, A2b, A3a, A3b may be implemented by respective pivot joints, which may include conventional bearing arrangements, such as slide bearings and / or roller bearings.

Claims

CLAIMS1. Agricultural implement (1), comprising: a first frame section (10, 16a, 16b, 16c, 16d, 16e, 16f, 16r), and a second frame section (10, 16a, 16b, 16c, 16d, 16e, 16f, 16r), which is pivotably connected to the first frame section (10, 16a, 16b, 16c, 16d, 16e, 16f, 16r) about a pivot joint, which presents a substantially horizontal pivot axis (Alb, Ale, A2a, A2b, A3a, A3b), wherein the second frame section (10, 16a, 16b, 16c, 16d, 16e, 16f, 16r) carries a plurality of soil-working tools (17), wherein an actuator (18a, 18b) is operable between the first frame section (10, 16a, 16b, 16c, 16d, 16e, 16f, 16r) and the second frame section (10, 16a, 16b, 16c, 16d, 16e, 16f, 16r) to control a pivot angle about said pivot joint, characterized by at least one first height sensor (21, 21a, 21b, 21d, 21e) arranged on the second frame section (10, 16a, 16b, 16c, 16d, 16e, 16f, 16r) and configured to provide a first height signal for the second frame section (10, 16a, 16b, 16c, 16d, 16e, 16f, 16r), indicating a height over ground (0) of the second frame section, and a controller (20), configured to receive the first height signal and to control the actuator (18a, 18b) based on the first height signal, wherein the second frame section (10, 16a, 16b, 16c, 16d, 16e, 16f, 16r) is supported towards the ground (0) only by the soil working tools (17).

2. The agricultural implement (1) as claimed in claim 1, further comprising at least one second height sensor (22), arranged on the first frame section (10, 16a, 16b, 16c, 16d, 16e, 16f, 16r) and configured to provide a second height signal for the first frame section (10, 16a, 16b, 16c, 16d, 16e, 16f, 16r), wherein the controller (20) is configured to receive the second height signal and to control the actuator (18a, 18b) also based on the second height signal.

3. The agricultural implement as claimed in claim 1 or 2, further comprising at least one third height sensor (23) arranged on the second frame section (10, 16a, 16b, 16c, 16d, 16e, 16f, 16r), spaced from the first height sensor(21, 21a, 21b, 21d, 21e) in a direction perpendicular to the pivot axis (Alb, Ale, A2a, A2b, A3a, A3b), and configured to provide a third height signal for the second frame section, said third height signal indicating a second height over ground (0) for the second frame section.

4. The agricultural implement (1) as claimed in claim 3, wherein the controller (20) is configured to control the actuator (18a, 18b) based also on the third height signal.

5. The agricultural implement (1) as claimed in any one of the preceding claims, wherein at least one of the first, second and third height sensors (21, 21a, 21b, 21d, 21e, 22, 23) is selected from a group consisting of a radar sensor, an ultrasound sensor, and an angle sensor connected to at least one of the soil-working tools (17).

6. The agricultural implement (1) as claimed in any one of the preceding claims, wherein the soil working tools (17) are selected from a group consisting of tillage tools, weeding tools, product dispensing tools and scraping tools.

7. The agricultural implement (1) as claimed in any one of the preceding claims, wherein the first frame section is a main frame section (10) and wherein the second frame section is a side frame section (16a, 16b, 16d, 16e), wherein the horizontal pivot axis (Alb, Ale, A2a, A2b, A3a, A3b) is parallel with a working direction (Dw) of the agricultural implement (1).

8. The agricultural implement (1) as claimed in any one of claims 1-4, wherein the first frame section is a first side frame section (16a, 16b, 16d, 16e) and wherein the second frame section is a second side frame section (16a, 16b, 16d, 16e), which is arranged laterally outside the first side frame section (16a, 16b, 16d, 16e), and wherein the horizontal pivot axis (Alb, Ale, A2a, A2b, A3a, A3b) is parallel with a working direction (Dw) of the agricultural implement (1).

9. The agricultural implement (1) as claimed in any one of claims 1-4, wherein the first frame section is a main frame section (10) and wherein the second frame section is a front frame section (16f), which is arranged longitudinally in front of the first frame section (10, 16a, 16b, 16c, 16d, 16e, 16f, 16r), and wherein the horizontal pivot axis (Alb, Ale, A2a, A2b, A3a, A3b) is perpendicular to a working direction (Dw) of the agricultural implement (1).

10. The agricultural implement (1) as claimed in any one of claims 1-4, wherein the first frame section (10, 16a, 16b, 16c, 16d, 16e, 16f, 16r) is a main frame section (10) and wherein the second frame section is a rear frame section (16r), which is arranged longitudinally behind the first frame section (10, 16a, 16b, 16c, 16d, 16e, 16f, 16r), and wherein the horizontal pivot axis (Alb, Ale, A2a, A2b, A3a, A3b) is perpendicular to a working direction (Dw) of the agricultural implement (1).

11. A method of controlling an agricultural implement (1), which comprises: a first frame section (10, 16a, 16b, 16c, 16d, 16e, 16f, 16r), and a second frame section (10, 16a, 16b, 16c, 16d, 16e, 16f, 16r), which is pivotably connected to the first frame section about a pivot joint, which presents a horizontal pivot axis (Alb, Ale, A2a, A2b, A3a, A3b), wherein the second frame section (10, 16a, 16b, 16c, 16d, 16e, 16f, 16r) carries a plurality of soil-working tools (17), wherein an actuator (18a, 18b) is operable between the first frame section (10, 16a, 16b, 16c, 16d, 16e, 16f, 16r) and the second frame section (10, 16a, 16b, 16c, 16d, 16e, 16f, 16r) to control a pivot angle about said pivot joint, the method comprising: receiving a first height signal for the second frame section (10, 16a, 16b, 16c, 16d, 16e, 16f, 16r), indicating a distance between a portion of the second frame section (10, 16a, 16b, 16c, 16d, 16e, 16f, 16r) and ground (0), and controlling the actuator (18a, 18b) based on the first height signal, wherein the second frame section (10, 16a, 16b, 16c, 16d, 16e, 16f, 16r) is supported towards the ground (0) only by the soil working tools (17).

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