WO2025176665A1 - A spraying vehicle and a method of determining the progress in a stepwise folding and unfolding of an agricultural spray boom with a plurality of boom sections - Google Patents

Abstract

The disclosure relates to a spraying vehicle (1) comprising: - a spray tank (2); - fluid connections for fluidly connecting the tank (2) and spray nozzles via a pump for applying a spraying pressure and a spray boom (3) carrying said spray nozzles; - a hydraulic system comprising one or more hydraulic actuators (10) configured for levelling the spray boom (3) when extended in spraying position and a number of hydraulic actuators (4) in a hydraulic system configured for folding boom sections (5, 6, 7, 8) in relation to each other; - said boom sections (5, 6, 7, 8) being configured to be stored in a folded transport position and an at least partly unfolded spraying position, each boom section (5, 6, 7, 8) at least in one end is connected to a pivot axle (9); - at least one control valve (20) configured for controlling or operating the hydraulic actuators (4, 10); - a controller (21) controlling the operation of the hydraulic system, where the controller (21) determines position of boom sections (5, 6, 7, 8) based on readings/feedback from one or more pressure sensors (22) giving readings on a folding pressure P_Fold (32) in such a way that a first peak (33) in pressure indicates that a first folding actuator (4) is in its extreme position allowing a second folding actuator (4) to fold out a next section (6, 7, 8) of the spray boom (3) repeating such sequence until a last boom section is folded out or in, said readings/feedback is compared in the controller (21) to an already stored pressure profile (30) for the sprayer (1). The disclosure further relates to a method of determining the progress in a stepwise folding and unfolding of an agricultural spray boom (3) with a plurality of boom sections (5).

Description

A spraying vehicle and a method of determining the progress in a stepwise folding and unfolding of an agricultural spray boom with a plurality of boom sections

Technical field

The present disclosure relates to a spraying vehicle and a method of determining the progress in a stepwise folding and unfolding of an agricultural spray boom with a plurality of boom sections. More specifically, the disclosure relates to a spraying vehicle and a method of determining the progress in a stepwise folding and unfolding of an agricultural spray boom with a plurality of boom sections as defined in the introductory parts of the independent claims.

Background art

When folding or unfolding a spray boom having several boom sections the common technique is that a user manually operates a valve controlling the hydraulic system.

To be able to determine where in the folding process each boom section is, the spray boom can be provided with position sensors. A typical solution can be to mount angle sensors between each boom element or -part, or having stroke sensors in hydraulic boom folding actuators determining a position of pistons and thereby position of a piston rod. Implementing these sensors is difficult, and expensive.

US 2021/0329905 Al (Deere) discloses the use of sensors interacting with hydraulic actuators to sense a discrete folding or unfolding of the booms or the respective boom sections relative to each other.

EP 1 201 123 A2 (Deere) discloses distributor linkage, the motors which fold and unfold the individual linkage sections in relation to one another are provided with sensor elements which each generate an end position signal. This makes it possible to ensure that the individual linkage sections of the distributor linkage are folded in and out one afterthe other in an orderly fashion.

EP 2 510 784 Al (Amazonen Werke) discloses a distributor linkage, where the aim is to enable the individual linkage sections of the distributor linkage to be folded in and out quickly and yet gently where sensor elements detect a plurality of position signals between the respective end position signals and transmit them to a control device.

These solutions involve angular sensors or position sensors to be able to determine the position of the individual elements of the spray boom. Such sensors are expensive and can easily be damaged during use.

Sensors could also be built into hydraulic actuators to determine the position of the piston rod in relation to the actuator and thereby the extension of the clevis (attachment point) of the piston rod, resulting in a more expensive hydraulic actuator.

A problem with the solutions of the prior art is that components for the solutions, such as angular sensors or position sensors, are expensive components and retrofitting existing sprayers with these features are extensive. Further, if just one of the sensors is damaged, operation of the whole system can be unreliable. There is thus a need for improved methods and equipment within this area.

It is an object of the present disclosure to mitigate, alleviate or eliminate one or more of the above-identified deficiencies and disadvantages in the prior art and solve at least the above mentioned problem. More precisely It is an aim of the present disclosure to be able to determine the position of the individual linkages of the spray boom in a simpler way.

It is also an aim to be able to mount such systems on older sprayers already put in use, which do not have such features already.

According to a first aspect, there is provided a spraying vehicle comprising: a spray tank, fluid connections for fluidly connecting the tank and spray nozzles via a pump for applying a spraying pressure and a spray boom carrying the spray nozzles, a hydraulic system comprising one or more hydraulic actuators configured for levelling the spray boom when extended in spraying position and a number of hydraulic actuators in a hydraulic system configured for folding boom sections in relation to each other, the boom sections being configured to be stored in a folded transport position and an at least partly unfolded spraying position, each boom section at least in one end is connected to a pivot axle, at least one control valve configured for controlling or operating the hydraulic actuators, and a controller controlling the operation of the hydraulic system, where the controller determines position of boom sections based on readings/feedback from one or more pressure sensors giving readings on a folding pressure PFOICI in such a way that a first peak in pressure indicates that a first folding actuator is in its extreme position allowing a second folding actuator to fold out a next section of the spray boom repeating such sequence until a last boom section is folded out or in, the readings/feedback is compared in the controller to an already stored pressure profile of the folding pressure for the sprayer. Hereby it is possible, by measuring of the hydraulic pressure in the hydraulic folding circuit, to provide a low-cost solution to the problem as well as providing for a convenient retrofitting on sprayers already in service.

In an aspect, the controller comprises a memory in which memory values of pressure and time is stored during an initial unfolding and folding of the spray boom, said values being compared with actual values of pressure and time during following unfolding and folding sequences, to determine for each boom section if it is folded in or out.

Hereby is achieved a simple way to determine whether a boom section is fully folded out or in, and whether folding, out or in, of a next boom section can be started, and where the boom sections are positioned in the folding sequence, be it during folding out or folding in.

According to some embodiments, the controller compares pressure readings Pyiit from the hydraulic system configured for levelling the spray boom with the pressure profile of the folding pressure to verify if a boom section is folding in or out.

Hereby is achieved a simple way to verify whether a boom section is folding in or out.

According to some embodiments, the boom section closest to the spraying vehicle is connected pivotable to the spraying vehicle by a substantially horizontal pivot axle.

Hereby it is possible to bring the spray boom from a substantially upright transport position into a substantially horizontal working position by pivoting the inner boom section along a substantially vertical plane around the substantially horizontal pivot axle.

According to some embodiments, the boom section closest to the spraying vehicle is connected pivotable to the spraying vehicle by a substantially vertical pivot axle.

Hereby it is possible to bring the spray boom from a substantially horizontal transport position where the folded spray boom is placed substantially parallel with a driving direction and into a substantially horizontal working position being perpendicular to the driving direction, by pivoting the boom section along a substantially horizontal plane around the substantially vertical pivot axle. This is an advantage in case the spraying vehicle is a trailer sprayer or a self- propelled sprayer.

According to some embodiments, the boom sections connected to the boom section closest to the spraying vehicle are connected pivotable by a substantially vertical pivot axle. Hereby it is achieved that the rest of the boom sections fold out or in, in a substantially horizontal plane.

According to some embodiments, a peak in folding pressure PFOICI in the pressure profile is defined as a value being at least 30% higher than the value of the pressure measured 0,5 seconds before.

Hereby is achieved a way for the controller to distinguish a peak in the pressure profile of the folding pressure PFoid from other changes in pressure.

According to some embodiments, the folding pressure PFoid is measured in a supply line before the line enters a valve block.

In an alternative embodiment, the folding pressure PFoid is measured in a line between a valve and a hydraulic actuator.

Hereby it is achieved that the pressure is measured in an appropriate place in the hydraulic system for folding the spray boom, thereby minimizing the possibility of incorrect pressure measurements.

According to some embodiments, pressure P-nit is also measured in or on the hydraulic actuator configured for controlling levelling of the spray boom when extended in spraying position.

Hereby it is achieved that the pressure is measured in an appropriate place in the hydraulic system for leveling of the spray boom, thereby minimizing the possibility of incorrect pressure measurements. The pressure P-nit can be measured during the folding sequence from start to end.

According to a second aspect there is provided a method of determining the progress in a stepwise folding and unfolding of an agricultural spray boom with a plurality of boom sections, comprising the step of continuously measuring hydraulic pressure in a hydraulic line delivering hydraulic liquid to a plurality of hydraulic actuators coupled to two adjacent boom sections, and selecting each completed folding or unfolding to be represented by a sudden variation of the measured hydraulic pressure of at least 30%.

Hereby is achieved a reliable method of determining whether or not a spray boom or a boom section is folded out or in.

According to some embodiments, pressure readings, P-nit from a hydraulic system configured for levelling the spray boom is compared in the controller with a pressure profile of hydraulic pressure in the hydraulic line delivering hydraulic liquid the hydraulic actuators to verify if a boom section is folded in or out.

According to some embodiments, a stored pressure profile is compared with time elapsed since the folding of a boom section, in or out, has started.

Hereby is achieved a method of determining not only if a boom section is folded out or in, but also where in the folding sequence the boom sections are.

Effects and features of the second aspect are to a large extent analogous to those described above in connection with the first aspect. Embodiments mentioned in relation to the first aspect are largely compatible with the second aspect.

The present disclosure will become apparent from the detailed description given below. The detailed description and specific examples disclose preferred embodiments of the disclosure by way of illustration only. Those skilled in the art understand from guidance in the detailed description that changes and modifications may be made within the scope of the disclosure.

Hence, it is to be understood that the herein disclosed disclosure is not limited to the particular component parts of the device described or steps of the methods described since such device and method mayvary. It is also to be understood that the terminology used herein is for purpose of describing particular embodiments only, and is not intended to be limiting. It should be noted that, as used in the specification and the appended claim, the articles "a", "an", "the", and "said" are intended to mean that there are one or more of the elements unless the context explicitly dictates otherwise. Thus, for example, reference to "a unit" or "the unit" may include several devices, and the like. Furthermore, the words "comprising", "including", "containing" and similar wordings does not exclude other elements or steps.

Terminology -- The term "A sudden variation of the measured hydraulic pressure of at least 30%" is to be interpreted as a variation of measured hydraulic pressure (increase) of at least 30% within 1 second, preferably 0,8 seconds and more preferably 0,5 seconds.

Brief descriptions of the drawings

The above objects, as well as additional objects, features and advantages of the present disclosure, will be more fully appreciated by reference to the following illustrative and non- limiting detailed description of example embodiments of the present disclosure, when taken in conjunction with the accompanying drawings.

Figure 1 shows schematically a top view of a spray boom of a spraying vehicle with the spray boom in transport position;

Figure 2 shows schematically a top view of the spray boom in a position with a first section folded out/down;

Figure 3 shows schematically a top view of the spray boom in a position with a second section being folded out;

Figure 4 shows schematically a top view of the spray boom in a position with the second section folded out where the first section is reduced in length in the figure to reduce the size of the figure;

Figure 5 shows schematically a top view of one side of the spray boom in a position with a third section being folded out;

Figure 6 shows schematically a top view of one side of the spray boom in a position with the third section folded out;

Figure 7 shows schematically a top view of one side of the spray boom in a position with a fourth section being folded out;

Figure 8 shows schematically a top view of one side of the spray boom in a position with the fourth section folded out where the first section is reduced in length in the figure to reduce the size of the figure;

Figure 9 shows an example of a top view of one side of a spray boom with the first section folded out/down and the second section being folded out;

Figure 10 shows an example of a pressure profile for folding out the spray boom with time on the horizontal axis and pressure on the vertical axis;

Figure 11 shows an example of a pressure profile for folding in the spray boom with time on the horizontal axis and pressure on the vertical axis;

Figure 12 A shows an example of a possible hydraulic diagram for a spraying vehicle; and

Figure 12 B shows an example of an alternative hydraulic diagram for a spraying vehicle. Detailed description

The present disclosure will now be described with reference to the accompanying drawings, in which preferred example embodiments of the disclosure are shown. The disclosure may, however, be embodied in other forms and should not be construed as limited to the herein disclosed embodiments. The disclosed embodiments are provided to fully convey the scope of the disclosure to the skilled person.

The brief description of the drawings mentions the spray boom being folded out in Figure 1 to 9. It is clear that the same figures can show the spray boom being folded in if taken in reverse order. Further Figures 1 to 9 indicates a folding sequence in or out of both sides of the spray boom. It is clear that the folding in or out can be carried out for both sides simultaneously or by folding one side at a time, in or out. Figure 1 shows a sprayer with the spray boom in a transport position and Figures 2 to 8 shows stepwise sequences of the boom folding out one section at a time.

The first aspect of this disclosure shows a spraying vehicle 1 comprising: - a spray tank 2; - fluid connections for fluidly connecting the tank 2 and spray nozzles via a pump for applying a spraying pressure and a spray boom 3 carrying the spray nozzles; - a hydraulic system comprising one or more hydraulic actuators 10 configured for levelling the spray boom 3 when extended in spraying position and a number of hydraulic actuators 4 in a hydraulic system configured for folding boom sections 5, 6, 7, 8 in relation to each other; - the boom sections 5, 6, 7, 8 being configured to be stored in a folded transport position and an at least partly unfolded spraying position, each boom section 5, 6, 7, 8 at least in one end is connected to a pivot axle 9; - at least one control valve 20 configured for controlling or operating the hydraulic actuators 4, 10; - a controller 21 controlling the operation of the hydraulic system, where the controller 21 determines position of boom sections 5, 6, 7, 8 based on readings/feedback from one or more pressure sensors 22 giving readings on a folding pressure PFoid 32 in such a way that a first peak 33 in pressure indicates that a first folding actuator 4 is in its extreme position allowing a second folding actuator 4 to fold out a next section 6, 7, 8 of the spray boom 3 repeating such sequence until a last boom section is folded out or in, the readings/feedback is compared in the controller 21 to an already stored pressure profile 30 for the sprayer 1. In an embodiment, the controller 21 compares pressure readings, Pyiit 31 from the hydraulic system configured for levelling the spray boom 3 with the pressure profile 30 to verify if a boom section 5, 6, 7, 8 is folding in or out.

In an embodiment, the boom section 5, 6, 7, 8 closest to the spraying vehicle 1 is connected pivotable to the spraying vehicle 1 by a substantially horizontal pivot axle 9.

In an embodiment, the boom section 5, 6, 7, 8 closest to the spraying vehicle 1 is connected pivotable to the spraying vehicle 1 by a substantially vertical pivot axle 9.

In an embodiment, the boom sections 6, 7, 8 connected to the boom section 5 closest to the spraying vehicle is connected pivotable by a substantially vertical pivot axle 9.

In an embodiment, a peak 33 in folding pressure PFOICI 32 in the pressure profile 30 is defined as a value being at least 30% higher than the value of the pressure measured 0,5 seconds before.

In an embodiment, the folding pressure PFoid 32 is measured in a supply line 23 before the line enters a valve block 24.

In an alternative embodiment, the folding pressure PFoid 32 is measured in a line between a valve 20 and a hydraulic actuator 4.

In an embodiment, pressure Pyiit 31 is also measured in or on the hydraulic actuator 10 configured for controlling levelling of the spray boom 3 when extended in spraying position.

The second aspect of this disclosure shows a method of determining the progress in a stepwise folding and unfolding of an agricultural spray boom 3 with a plurality of boom sections 5, 6, 7, 8, comprising the step of continuously measuring hydraulic pressure 32 in a hydraulic line 23 delivering hydraulic liquid to a plurality of hydraulic actuators 4 coupled to two adjacent boom sections 5, 6, 7, 8, and selecting each completed folding or unfolding to be represented by a sudden variation 33 of the measured hydraulic pressure PFoid 32 of at least 30%.

Examples of pressure profiles 30 can be seen in Figures 10 and 11, showing examples of pressure peaks 33 in pressure curves for PFoid, 32 and pressure curves for Piiit, 31-

In an embodiment, pressure readings, Pyiit from a hydraulic system configured for levelling the spray boom is compared in the controller with a pressure profile 30 of hydraulic pressure in the hydraulic line 23 delivering hydraulic liquid the hydraulic actuators 4 to verify if a boom section 5, 6, 7, 8 is folding in or out. In an embodiment, a stored pressure profile 30 is compared with time elapsed since the folding of a boom section 5, 6, 7, 8, in or out, has started.

In yet an aspect, the method of determining position of boom sections 5, 6, 7, 8 of a spray boom 3 for a field sprayer 1 can comprise:

- a spray tank 2;

- fluid connections for fluidly connecting the tank 2 and spray nozzles (not shown) via a pump (not shown) for applying a spraying pressure and a spray boom 3 carrying said spray nozzles;

- a hydraulic system comprising one or more hydraulic actuators 10 configured for levelling the spray boom 3 when extended in spraying position and a number of hydraulic actuators 4 in a hydraulic system configured for folding boom sections 5, 6, 7, 8 in relation to each other;

- said boom sections 5, 6, 7, 8 are configured to be stored in a folded transport position and an at least partly unfolded spraying position, each boom section 5, 6, 7, 8 at least in one end is connected to a pivot axle 9;

- at least one control valve 20 configured for controlling or operating the hydraulic actuators 4, 10;

- a controller 21 controlling the operation of the hydraulic system, wherein a peak 33 in a pressure reading from one or more pressure sensors 22 in the hydraulic system configured for folding boom sections is compared with a pressure profile 30 for said field sprayer already stored in the controller 21, said peak indicates a section of the spray boom 5, 6, 7, 8 is folded out or in.

An example of a possible hydraulic diagram is shown in Figure 12.

The person skilled in the art realizes that the present disclosure is not limited to the preferred embodiments described above. The person skilled in the art further realizes that modifications and variations are possible within the scope of the appended claims. For example, an alternative solution to measuring pressure could be to measure flow. AThird aspect of this disclosure shows a spraying vehicle 1 comprising: - a spray tank 2; - fluid connections for fluidly connecting the tank 2 and spray nozzles via a pump for applying a spraying pressure and a spray boom 3 carrying the spray nozzles; - a hydraulic system comprising one or more hydraulic actuators 10 configured for levelling the spray boom 3 when extended in spraying position and a number of hydraulic actuators 4 in a hydraulic system configured for folding boom sections 5, 6, 7, 8 in relation to each other; - the boom sections 5, 6, 7, 8 being configured to be stored in a folded transport position and an at least partly unfolded spraying position, each boom section 5, 6, 7, 8 at least in one end is connected to a pivot axle 9; - at least one control valve 20 configured for controlling or operating the hydraulic actuators 4, 10; - a controller 21 controlling the operation of the hydraulic system, where the controller 21 determines position of boom sections 5, 6, 7, 8 based on readings/feedback from one or more flow sensors (not shown) giving readings on a folding flow in the hydraulic system in such a way that a first drop in flowrate indicates that a first folding actuator 4 is in its extreme position allowing a second folding actuator 4 to fold out a next section 6, 7, 8 of the spray boom 3 repeating such sequence until a last boom section is folded out or in, the readings/feedback is compared in the controller 21 to an already stored flow profile for the sprayer 1.

It is also possible to determine the end positions of each folding actuator 4 by storing in the controller, a characteristic oil volume associated with each folding actuator. Hereby it is possible to determine if a piston rod of a folding actuator is fully extended, fully retracted or even determine the range of extension of the piston rod.

In an embodiment, the controller 21 compares pressure readings, Pyiit 31 from the hydraulic system configured for levelling the spray boom 3 with the pressure profile 30 to verify if a boom section 5, 6, 7, 8 is folded in or out.

In an embodiment, the boom section 5, 6, 7, 8 closest to the spraying vehicle 1 is connected pivotable to the spraying vehicle 1 by a substantially horizontal pivot axle 9.

In an embodiment, the boom section 5, 6, 7, 8 closest to the spraying vehicle 1 is connected pivotable to the spraying vehicle 1 by a substantially vertical pivot axle 9.

In an embodiment, the boom sections 6, 7, 8 connected to the boom section 5 closest to the spraying vehicle is connected pivotable by a substantially vertical pivot axle 9.

In an embodiment, a drop in flowrate is defined as a value being at least 30% lower than the value of the flowrate measured 0,5 seconds before.

In an embodiment, the flow is measured in a supply line 23 before the line enters a valve block

24. In an embodiment, pressure Pyiit 31 is also measured in or on the hydraulic actuator 10 configured for controlling levelling of the spray boom 3 when extended in spraying position.

A fourth aspect of this disclosure shows a method of determining the progress in a stepwise folding and unfolding of an agricultural spray boom 3 with a plurality of boom sections 5, 6, 7, 8, comprising the step of continuously measuring hydraulic flow in a hydraulic line 23 delivering hydraulic liquid to a plurality of hydraulic actuators 4 coupled to two adjacent boom sections 5, 6, 7, 8, and selecting each completed folding or unfolding to be represented by a sudden variation of the measured hydraulic flow of at least 30%.

In an embodiment, pressure readings, P-nit from a hydraulic system configured for levelling the spray boom is compared in the controller with a flow profile hydraulic flow in the hydraulic line 23 delivering hydraulic liquid the hydraulic actuators 4 to verify if a boom section 5, 6, 7, 8 is folded in or out.

In an embodiment, a stored flow profile is compared with time elapsed since the folding of a boom section 5, 6, 7, 8, in or out, has started.

In yet an aspect, the method of determining position of boom sections 5, 6, 7, 8 of a spray boom 3 for a field sprayer 1 can comprise:

- a spray tank 2;

- fluid connections for fluidly connecting the tank 2 and spray nozzles (not shown) via a pump (not shown) for applying a spraying pressure and a spray boom 3 carrying said spray nozzles;

- a hydraulic system comprising one or more hydraulic actuators 10 configured for levelling the spray boom 3 when extended in spraying position and a number of hydraulic actuators 4 in a hydraulic system configured for folding boom sections 5, 6, 7, 8 in relation to each other;

- said boom sections 5, 6, 7, 8 are configured to be stored in a folded transport position and an at least partly unfolded spraying position, each boom section 5, 6, 7, 8 at least in one end is connected to a pivot axle 9;

- at least one control valve 20 configured for controlling or operating the hydraulic actuators 4, 10; - a controller 21 controlling the operation of the hydraulic system, wherein a drop in a flow reading from one or more flow sensors (not shown) in the hydraulic system configured for folding boom sections is compared with a flow profile for said field sprayer already stored in the controller 21, said drop in flowrate indicates a section of the spray boom 5, 6, 7, 8 is folded out or in.

Additionally, variations to the disclosed embodiments can be understood and effected by the skilled person in practicing the claimed disclosure, from a study of the drawings, the disclosure, and the appended claims.

Claims

1. A spraying vehicle (1) comprising:

- a spray tank (2);

- fluid connections for fluidly connecting the tank (2) and spray nozzles via a pump for applying a spraying pressure and a spray boom (3) carrying said spray nozzles;

- a hydraulic system comprising one or more hydraulic actuators (10) configured for levelling the spray boom (3) when extended in spraying position and a number of hydraulic actuators (4) in a hydraulic system configured for folding boom sections (5, 6,7,8) in relation to each other;

- said boom sections (5, 6, 7, 8) being configured to be stored in a folded transport position and an at least partly unfolded spraying position, each boom section (5, 6,7,8) at least in one end is connected to a pivot axle (9);

- at least one control valve (20) configured for controlling or operating the hydraulic actuators (4,10);

- a controller (21) controlling the operation of the hydraulic system,

- one or more pressure sensors (22) measuring the pressure in the hydraulic system, characterized in that the controller (21) is configured to determine the position of the boom sections (5, 6, 7, 8) based on readings/feedback from the one or more pressure sensors (22) giving readings on a folding pressure PFoid (32), which is the hydraulic pressure in a supply line (23) and/or the line between the control valve (20) and its associated folding actuator (4), in such a way that a first peak (33) in pressure indicates that a first folding actuator (4) is in its extreme position allowing a second folding actuator (4) to fold out a next section (6,7,8) of the spray boom (3) repeating such sequence until a last boom section is folded out or in, the controller (21) is furthermore configured to compare said readings/feedback) to an already stored pressure profile (30) for the sprayer (1).

2. The spraying vehicle (1) according to claim 1, wherein the controller (21) is configured to compare pressure readings, Pyiit (31) from the hydraulic system configured for levelling the spray boom (3) with the pressure profile (30) to verify if a boom section (5, 6, 7, 8) is folding in or out.

3. The spraying vehicle (1) according to any one or more of the claims 1 or 2, wherein the boom section (5, 6, 7, 8) closest to the spraying vehicle (1) is connected pivotable to the spraying vehicle (1) by a substantially horizontal pivot axle (9).

4. The spraying vehicle (1) according to any one or more of the claims 1 or 2, wherein the boom section (5, 6, 7, 8) closest to the spraying vehicle (1) is connected pivotable to the spraying vehicle (1) by a substantially vertical pivot axle (9).

5. The spraying vehicle (1) according to claim 3 or 4, wherein the boom sections (6,7,8) connected to the boom section (5) closest to the spraying vehicle is connected pivotable by a substantially vertical pivot axle (9).

6. The spraying vehicle according to claim 1, wherein a peak (33) in folding pressure PFoid (32) in the pressure profile (30) is defined as a value being at least 30% higher than the value of the pressure measured 0,5 seconds before.

7. The spraying vehicle (1) according to any one or more of the claims 1 to 6, wherein the folding pressure PFoid (32) is measured in a supply line (23) before the line enters a valve block (24).

8. The spraying vehicle (1) according to any one or more of the claims 1 to 6, wherein the folding pressure PFoid (32) is measured in a line between a valve (20) and a hydraulic actuator (4).

9. The spraying vehicle (1) according to any one or more of the claims 7 or 8, wherein pressure Pyiit is also measured in or on the hydraulic actuator (10) configured for controlling levelling of the spray boom (3) when extended in spraying position.

10. A method of determining the progress in a stepwise folding and unfolding of an agricultural spray boom (3) with a plurality of boom sections (5, 6, 7, 8), comprising the step of continuously measuring hydraulic pressure in a hydraulic line (23) delivering hydraulic liquid to a plurality of hydraulic actuators (4) coupled to two adjacent boom sections (5, 6, 7, 8), and selecting each completed folding or unfolding to be represented by a sudden variation of the measured hydraulic pressure PFoid of at least 30%.

11. The method according to claim 10, wherein pressure readings, Pyiit (31) from a hydraulic system configured for levelling the spray boom is compared in the controller with a pressure profile (30) of hydraulic pressure in the hydraulic line (23) delivering hydraulic liquid the hydraulic actuators (4) to verify if a boom section (5, 6, 7, 8) is folded in or out.

12. The method according to any one or more of the claims 10 or 11, wherein a stored pressure profile (30) is compared with time elapsed since the folding of a boom section (5, 6, 7, 8), in or out, has started.