System comprising an agricultural vehicle and method for controlling an agricultural vehicle

Abstract

In the context of an agricultural vehicle which has an activatable processing member for processing a crop or feed or for soil cultivation, and which is configured to travel autonomously in an operating area, measures are provided for increasing the operating safety of the agricultural vehicle. The agricultural vehicle is equipped with an optical detection mechanism and, in addition, there is at least one marking element in the operating area which is detectable by the optical detection mechanism of the agricultural vehicle. This makes it possible to perform a safety-check routine during which a check is performed to determine whether an observation of a marking element takes place at an expected position, and also whether an observation takes place at a position at which an observation of a marking element can be expected. If a deviation is found, it is possible to intervene in the movement of the agricultural vehicle and / or the operation of the processing member.

Description

[0001] System comprising an agricultural vehicle and method for controlling an agricultural vehicle

[0002] The invention relates to a system comprising: an agricultural vehicle with an activatable processing member for processing a crop or feed or for soil cultivation, which is configured to travel autonomously in an operating area, and an operating system which is configured to control the agricultural vehicle.

[0003] The invention also relates to a method for controlling an agricultural vehicle with an activatable processing member for processing a crop or feed or for soil cultivation, which is configured to travel autonomously in an operating area.

[0004] An agricultural vehicle with an activatable processing member for processing a crop or feed or for soil cultivation, which is configured to travel autonomously in an operating area, is known per se. WO-2021 / 125942-A1 discloses a driverless, autonomously movable device for automatically harvesting, conveying and dosing feed. The device is controlled and operated by means of an operating unit, such as a combination of a computer which comprises a processor, and navigation means. As a result thereof, the device is able to determine a demand for feed, to automatically harvest feed in a field where crops grow, and then to convey the feed to a dispensing location and subsequently dose it out at the dispensing location. After the feed has been dispensed, the device can return to the field for a subsequent harvest.

[0005] With agricultural vehicles which can travel autonomously, safety is an important point of attention. It is an object of the invention to provide a way of controlling such agricultural vehicles which ensures a high degree of safety. The object is achieved by providing a system comprising: an agricultural vehicle with an activatable processing member for processing a crop or feed or for soil cultivation, which is configured to travel autonomously in an operating area, and which is equipped with an optical detection mechanism to observe the close surroundings of the agricultural vehicle on the basis of optical techniques, an operating system which is configured to control the agricultural vehicle, and a marking element which is situated in the operating area and which is detectable by the optical detection mechanism of the agricultural vehicle, wherein reference position data which are representative of a position of the marking element in the operating area are stored in the operating system, wherein the operating system is configured to perform a safety-check routine on the basis of a first criterion, being an observation of the marking element by the optical detection mechanism of the agricultural vehicle, and also on the basis of a second criterion, being the agricultural vehicle reaching a position in the operating area which the operating system has determined to be a position for observing a portion of the operating area by the optical detection mechanism of the agricultural vehicle using position data which correspond to the reference position data, and wherein the operating system is furthermore configured to initiate, once the first criterion has been met, a first safety action which comprises an analysing step of comparing position data of the observation of the marking element with the reference position data, and an operating step which involves reducing the speed of or stopping the agricultural vehicle and / or deactivating the processing member if a difference between the respective position data is found which is greater than a permissible difference, and to initiate, once the second criterion has been met, a second safety action which comprises an analysing step of determining whether the marking element has been observed, and an operating step which involves reducing the speed of or stopping the agricultural vehicle and / or deactivating the processing member if the marking element is not, or not sufficiently, observed.

[0006] The invention also provides a method for controlling an agricultural vehicle with an activatable processing member for processing a crop or feed or for soil cultivation, which is configured to travel autonomously in an operating area, and which is equipped with an optical detection mechanism to observe the close surroundings of the agricultural vehicle on the basis of optical techniques, wherein a marking element is situated in the operating area which is detectable by the optical detection mechanism of the agricultural vehicle, wherein a safety-check routine is performed on the basis of a first criterion, being an observation of the marking element by the optical detection mechanism of the agricultural vehicle, and also on the basis of a second criterion, being the agricultural vehicle reaching a position in the operating area which during the control of the agricultural vehicle is determined to be a position for observing a portion of the operating area by the optical detection mechanism of the agricultural vehicle using position data which correspond to reference position data which are representative of a position of the marking element in the operating area, and wherein, when the first criterion has been met, a first safety action is initiated which comprises an analysing step of comparing position data of the observation of the marking element with the reference position data, and an operating step which involves reducing the speed of or stopping the agricultural vehicle and / or deactivating the processing member if a difference between the respective position data is found which is greater than a permissible difference, and to initiate, once the second criterion has been met, a second safety action which comprises an analysing step of determining whether the marking element has been observed, and an operating step which involves reducing the speed of or stopping the agricultural vehicle and / or deactivating the processing member if the marking element has not, or not sufficiently, been observed.

[0007] A first aspect of the invention is equipping the agricultural vehicle with an optical detection mechanism to observe the close surroundings of the agricultural vehicle on the basis of optical techniques. Information which is obtained by the optical detection mechanism during operation of the agricultural vehicle is useful in determining whether, viewed in a(n intended) direction of travel, the close surroundings of the agricultural vehicle are clear or whether an obstacle is present in the close surroundings of the agricultural vehicle, wherein, in the present context, the term obstacle is not only intended to mean an object, but certainly also a person or animal. The operating system may be configured to continuously receive input from the optical detection mechanism during operation of the agricultural vehicle and to interpret this input in real time, so that immediate action can be taken if an obstacle is detected, in particular by stopping the movement of the agricultural vehicle. The optical detection mechanism may be designed in any suitable way and may comprise, for example, a stereo camera.

[0008] A second aspect of the invention is the use of a marking element in the operating area in which the agricultural vehicle moves. According to the invention, a safety-check routine is performed on the basis of two criteria which are directly linked to the presence of the marking element in the operating area. A first criterion is an observation of the marking element by the optical detection mechanism of the agricultural vehicle. If this criterion has been met, a first safety action is initiated which comprises an analysing step of comparing position data of the observation of the marking element with the reference position data, and an operating step which involves reducing the speed of or stopping the agricultural vehicle and / or deactivating the processing member if a difference between the respective position data is found which is greater than a permissible difference. In other words, if it is found that the position data of the observation of the marking element deviate too much from the reference position data, action is taken with regard to the movement of the agricultural vehicle and / or the operation of the processing member, because this is an indication that an excessive deviation occurred in the course which was followed by the agricultural vehicle. A second criterion is the agricultural vehicle reaching a position in the operating area which during control of the agricultural vehicle is determined to be a position for observing a portion of the operating area by the optical detection mechanism of the agricultural vehicle using position data which correspond to reference position data which are representative of a position of the marking element in the operating area. If this criterion has been met, a second safety action is initiated which comprises an analysing step of determining whether the marking element has been observed, and an operating step which involves reducing the speed of or stopping the agricultural vehicle and / or deactivating the processing member if the marking element is not, or not sufficiently, observed. In other words, if it is found that the marking element has not, or has not sufficiently, been observed at a position in which complete observation of the marking element can be expected, action is taken with regard to the movement of the agricultural vehicle and / or the operation of the processing member, because this is an indication that an excessive deviation occurred in the course which was followed by the agricultural vehicle and / or that the operation of the optical detection mechanism of the agricultural vehicle is impeded, for example due to a failure or defect in the optical detection mechanism or due to, in the case of outdoor use, weather conditions hampering the optical detection mechanism.

[0009] According to an insight of the invention, the use of the optical detection mechanism as such improves the safety during use of the agricultural vehicle, but safety is significantly increased if an inspection of the observation by the optical detection mechanism and an inspection of a controlled movement of the agricultural vehicle could be performed from time to time. According to the invention, the only requirements to reach the increased safety level are fitting one or more marking elements in the operating area and performing a safety-check routine on the basis of two simple criteria. This prevents, inter alia, the optical detection mechanism from having to be tested extensively in order to determine its limitations, and a separate system having to be used to determine current weather conditions.

[0010] In the case that the operating step of at least one of the first safety action and the second safety action involves reducing the speed of the agricultural vehicle, safety is increased further if the agricultural vehicle is controlled to continue to travel at an adjusted reduced speed until another safety-check routine is performed. At that point in time, it is determined whether the reduced speed of the agricultural vehicle is still appropriate, or whether there is a good correspondence between sensed data and data to be expected, and the speed of the agricultural vehicle can therefore be returned to a normal level.

[0011] A surprising possibility of applying the invention emerges if the operating area comprises two zones with different safety rules and the marking element is situated at a boundary position between the zones. In such a case, it is advantageous if the first safety action comprises a decision step which means that the operating step is linked to data about a direction of travel of the agricultural vehicle in such a way that the operating step is only performed if the direction of travel of the agricultural vehicle is an inwardbound direction into a zone in which higher safety rules apply. In this way, it is possible to make a difference between the two zones and to only check if intervention on the movement of the agricultural vehicle and / or the operation of the processing member is required if the agricultural vehicle leaves a zone in which lower safety rules apply and enters a zone in which higher safety rules apply. In this way, unnecessary intervention on the movement of the agricultural vehicle and / or the operation of the processing member in the zone in which lower safety rules apply is prevented.

[0012] In the context of the two zones in which different safety rules apply, it may also be advantageous if the first safety action furthermore comprises a reset step of increasing the speed of the agricultural vehicle if the agricultural vehicle is travelling at a reduced speed, wherein the decision step of the first safety action furthermore means that the reset step is linked to data about a direction of travel of the agricultural vehicle in such a way that the reset step is only performed if the operating system has determined that the direction of travel of the agricultural vehicle is an inward-bound direction into a zone in which lower safety rules apply. The result thereof is that when the agricultural vehicle drives into the zone where lower safety rules apply, the speed is always at the normal level.

[0013] A practical example of the processing member of the agricultural vehicle is a reaping unit. It goes without saying that an active reaping unit should be prevented from coming into contact with a person or an animal at all times. In this case, deactivating the processing member might mean that the reaping unit has to be lifted up or stopped. Other practical examples of the processing member are a driven soil tillage member, such as a rotary cultivator, a non-driven soil tillage member, such as a plough, and a mixing or dosing member for feed.

[0014] There are several options available with regard to the marking element in the context of the invention. The marking element may be anchored, for example, in a terrain over which the agricultural vehicle travels during operation. It is therefore also possible for the marking element to be configured in such a way that the agricultural vehicle can drive over it without the agricultural vehicle being touched. In many practical cases, the number of marking elements in an operating area will be more than one. In connection with the agricultural vehicle travelling in the operating area, it is practical if a navigation system is used. Such a system may be configured to use a known navigation technique, such as GPS, LiDAR or UWB triangulation.

[0015] The invention will be explained below in more detail with reference to the figures which are generally diagrammatic and relate to a non-limiting exemplary embodiment of an agricultural vehicle with an activatable processing member and components which have a function in safely controlling the agricultural vehicle, in which identical reference numerals denote identical or similar components, and in which: Figure 1 diagrammatically shows a partial longitudinal section of an agricultural vehicle which is configured to travel autonomously in an operating area and to automatically harvest, convey and dispense feed;

[0016] Figure 2 diagrammatically shows the operating area, marking elements present therein and the agricultural vehicle.

[0017] Figure 1 diagrammatically shows a partial longitudinal section of an agricultural vehicle 1. It should be noted that the illustrated agricultural vehicle 1 is an example of an agricultural vehicle which is possible in the context of the invention, and which the invention in no way limits to this specific agricultural vehicle. With reference to Figure 2, it should furthermore be noted that the agricultural vehicle 1 is configured to travel autonomously in an operating area 100. Aspects hereof will be described later. First, the configuration of the agricultural vehicle 1 will be explained.

[0018] The agricultural vehicle 1 comprises a container device 2 which defines an internal storage space 3 on a frame 4 with wheels 5. Means for driving and steering the wheels 5 are not shown. At the front, the agricultural vehicle 1 is provided with an automatic reaping unit 6 for harvesting a feed crop 20, such as grass. In addition, the front of the agricultural vehicle 1 comprises an automatic loading mechanism 7, such as an ascending conveying belt with drive means 8 for transferring harvested feed crop 20 to the storage space 3 in the container device 2. A height sensor 9 is situated near an outlet of the loading mechanism 7.

[0019] The container device 2 has an internal conveying device 10, such as a plane conveying belt or a movable loading floor, and also has drive means 11 for conveying feed crop 20 to the back into in the container device 2, as is indicated by means of an arrow A in Figure 1. When loading harvested feed crop 20, a procedure is followed in which the feed crop 20 is shaped into a pile 21 until the height sensor 9 indicates that the pile has reached a maximum height. At that point in time, the pile 21 is displaced to the rear by means of the internal conveying device 10, and a new pile 21 may be formed. In this way, the entire internal storage space 3 may eventually be filled with a number of piles 21 of feed crop 20.

[0020] On the rear side, the agricultural vehicle 1 is provided with a mechanism 12 for automatically dispensing feed crop 20 at a dispensing location. In the illustrated example, the dispensing mechanism 12 comprises a number of rotatable discharge elements in the form of toothed dosing rollers 13 and drive means therefor (not shown). In addition, the agricultural vehicle 1 comprises a dosing conveying belt 14 which is configured to dispense feed crop 20 in a dosed way on a suitable side of the agricultural vehicle 1.

[0021] An operating system 30 is provided to control the agricultural vehicle 1 and comprises, for example, a computer and a navigation system. The operating system 30 may comprise components which are installed in the agricultural vehicle 1 and also components which are situated outside the agricultural vehicle 1 , wherein (wireless) communication between the various components is possible in any suitable way. Controlling the agricultural vehicle 1 is intended to achieve suitable displacement of the agricultural vehicle 1 in the operating area 100 and also to make the various components of the agricultural vehicle 1 which have a function in harvesting, loading, conveying and dispensing of the feed crop 20 work correctly.

[0022] Figure 2 shows a combination of an animal shed 101 , a field 102 where feed crop 20 grows, and an intermediate yard 103 as an example of an operating area 100. In the animal shed 101 , there is for example a central aisle 104 on which the agricultural vehicle 1 can drive, and feed fences 105, 106 are present on either side of the central aisle 104. Incidentally, Figure 2 only serves for illustrative purposes and is not to scale, meaning the size proportions of that which is shown in the figure are not realistic. Distances which the agricultural vehicle 1 travels may be significant and may be in the order of magnitude of several hundreds of metres to kilometres.

[0023] Since the agricultural vehicle 1 travels autonomously during operation, it is important to take measures which serve to increase the operating safety of the agricultural vehicle 1. A first measure in this context is to equip the agricultural vehicle 1 with an optical detection mechanism 40 which is configured to observe the close surroundings of the agricultural vehicle 1 on the basis of optical techniques. The optical detection mechanism 40 comprises, for example, one or more stereo cameras or suitable sensors in one or more strategic locations on the agricultural vehicle 1 , in particular on the front side. The optical detection mechanism 40 has a data connection with the operating system 30, so that the operating system 30 can intervene in the movement of the agricultural vehicle 1 and / or the operation of the various movable components of the agricultural vehicle 1 which are freely accessible from the outside of the agricultural vehicle 1.

[0024] A second measure which is intended to increase the operating safety of the agricultural vehicle 1 involves the use of marking elements 50 in the operating area 100. These marking elements 50 are designed to be detectable by the optical detection mechanism 40 of the agricultural vehicle 1. In the illustrated example, a total of six marking elements 50 are positioned in the operating area 100, namely two marking elements 50 at the location of a boundary between the animal shed 101 and the yard 103, two marking elements 50 at the location of a boundary between the field 102 and the yard 103, and two marking elements 50 in the centre of the animal shed 101. Reference position data which are representative of the respective positions of the marking elements 50 in the operating area 100 are stored in the operating system 30, and the operating system 30 is configured to perform a safety-check routine on the basis of a first criterion, being an observation of a marking element 50 by the optical detection mechanism 40 of the agricultural vehicle 1 , and also on the basis of a second criterion, being the agricultural vehicle 1 reaching a position in the operating area 100 which the operating system 30 has determined to be a position for observing a portion of the operating area 100 by the optical detection mechanism 40 of the agricultural vehicle 1 using position data which correspond to the reference position data. The operating system 30 is furthermore configured to initiate, once the first criterion has been met, a first safety action which comprises an analysing step of comparing position data of the observation of the marking element 50 with the reference position data, and an operating step which involves reducing the speed of or stopping the agricultural vehicle 1 and at least shutting down the reaping unit 6 if a difference between the respective position data is found which is greater than a permissible difference, and to initiate, once the second criterion has been met, a second safety action which comprises an analysing step of determining whether the marking element 50 has been observed, and an operating step which involves reducing the speed of or stopping the agricultural vehicle 1 and at least shutting down the reaping unit 6 if the marking element has not, or not sufficiently, been observed.

[0025] In effect, the operating system 30 is configured to verify the operation of the optical detection mechanism 40 of the agricultural vehicle 1 and the operation of the navigation system by means of the marking elements 50. As soon as there is any indication that the optical detection mechanism 40 of the agricultural vehicle 1 and / or the navigation system does not function as expected, action is taken so that unsafe situations are prevented in that case, in which case the agricultural vehicle 1 is stopped or slowed down and a deactivated state of movable components of the agricultural vehicle 1 is ensured. Incidentally, sub-optimal performance of the optical detection mechanism 40 of the agricultural vehicle 1 may be connected to factors which are outside the optical detection mechanism 40, for example environmental factors, such as foggy conditions on the field 102 and the yard 103.

[0026] In practice, it is readily possible to determine how many marking elements 50 are required for every operating area 100 to achieve safe use of the agricultural vehicle 1 , and what the suitable positions for those marking elements 50 are in the operating area 100. It is for example possible to maintain a certain maximum distance between two successive marking elements 50 in a possible direction of travel of the agricultural vehicle 1. After marking elements have been placed in an operating area 100, data of the positions of the marking elements 50 may be stored in the operating system 30 which will be used to control the agricultural vehicle 1 , before an agricultural vehicle 1 in the operating area 100 is started up.

[0027] It may be the case, for example, that higher safety rules apply for the animal shed 101 and the yard 103 than for the field 102. It may then be advantageous to determine, on the basis of information about the location where the agricultural vehicle 1 is situated and where the agricultural vehicle 1 is travelling towards, whether, in case of an indication that the optical detection mechanism 40 of the agricultural vehicle 1 and / or the navigation system does not function as expected, it is necessary or not to perform the operating step which involves reducing the speed of or stopping the agricultural vehicle 1 and at least shutting down the reaping unit 6. Thus, unnecessary interventions in the normal functioning of the agricultural vehicle 1 and the various components thereof are prevented. When controlling the agricultural vehicle 1 , an additional condition can therefore be stipulated that said operating step is only performed if the operating system 30 has determined that the agricultural vehicle 1 is situated at a boundary between two zones and that the direction of travel of the agricultural vehicle 1 is an inward-bound direction into a zone in which higher safety rules apply. In the example described, this is only the case if the agricultural vehicle 1 leaves the field 102 and drives onto the yard 103, leaves the yard 103 and enters the animal shed 101 , and leaves the animal shed 101 and drives onto the yard 103.

[0028] The marking elements 50 can be of a simple design and can be made, for example, from metal or plastic. The marking elements 50 may be secured directly onto the floor of the animal shed 101 and to the ground of the field 102 and the yard 103, in which case it is possible, for example, for the agricultural vehicle 1 to be able to drive over the marking elements 50. The marking elements 50 may have a specific colour which contributes to the detectability thereof by the optical detection mechanism 40 of the agricultural vehicle 1. The marking elements 50 may also have a shape which makes it possible to determine at which angle and in which direction the agricultural vehicle 1 approaches the marking elements 50.

[0029] The invention may be summarized as follows. In the context of an agricultural vehicle 1 which has an activatable processing member 6 for processing a crop 20 or feed or for soil cultivation, and which is configured to travel autonomously in an operating area 100, measures are provided for increasing the operating safety of the agricultural vehicle 1. The agricultural vehicle 1 is equipped with an optical detection mechanism 40 and, in addition, at least one marking element 50 which is detectable by the optical detection mechanism 40 of the agricultural vehicle 1 is situated in the operating area 100. This makes it possible to perform a safety-check routine during which a check is performed to determine whether an observation of a marking element 50 takes place at the expected position, and also whether an observation takes place at a position at which an observation of a marking element 50 can be expected. If a deviation is found, it is possible to intervene in the movement of the agricultural vehicle 1 and / or the operation of the processing member 6.

Claims

CLAIMS1. System comprising: an agricultural vehicle (1) with an activatable processing member (6) for processing a crop (20) or feed or for soil cultivation, which is configured to travel autonomously in an operating area (100), and which is equipped with an optical detection mechanism (40) to observe the close surroundings of the agricultural vehicle (1) on the basis of optical techniques, an operating system (30) which is configured to control the agricultural vehicle (1), and a marking element (50) which is situated in the operating area (100) and which is detectable by the optical detection mechanism (40) of the agricultural vehicle (1), wherein reference position data which are representative of a position of the marking element (50) in the operating area (100) are stored in the operating system (30), wherein the operating system (30) is configured to perform a safety-check routine on the basis of a first criterion, being an observation of the marking element (50) by the optical detection mechanism (40) of the agricultural vehicle (1), and also on the basis of a second criterion, being the agricultural vehicle (1) reaching a position in the operating area (100) which the operating system (30) has determined to be a position for observing a portion of the operating area (100) by the optical detection mechanism (40) of the agricultural vehicle (1) using position data which correspond to the reference position data, and wherein the operating system (30) is furthermore configured to initiate, once the first criterion has been met, a first safety action which comprises an analysing step of comparing position data of the observation of the marking element (50) with the reference position data, and an operating step which involves reducing the speed of or stopping the agricultural vehicle (1) and / or deactivating the processing member (6) if a difference between the respective position data is found which is greater than a permissible difference, and to initiate, once the second criterion has been met, a second safety action which comprises an analysing step of determining whether the marking element (50) has been observed, and an operating step which involves reducing the speed of or stopping the agricultural vehicle (1) and / or deactivating the processing member (6) if the marking element (50) is not, or not sufficiently, observed.

2. System according to Claim 1 , wherein, in the case that the operating step of at least one of the first safety action and the second safety action involves reducing the speed of the agricultural vehicle (1), the operating system (30) is configured to control the agricultural vehicle (1) to continue to travel at an adjusted reduced speed until anothersafety-check routine is performed.

3. System according to Claim 1 or 2, wherein the operating area (100) comprises two zones (101 , 103; 102) with different safety rules, wherein the marking element (50) is situated at a boundary position between the zones (101 , 103; 102), wherein the first safety action comprises a decision step which means that the operating step is linked to data about a direction of travel of the agricultural vehicle (1) in such a way that the operating step is only performed if the operating system (30) has determined that the direction of travel of the agricultural vehicle (1) is an inward-bound direction into a zone in which higher safety rules (101 , 103) apply.

4. System according to Claim 3, wherein the first safety action furthermore comprises a reset step of increasing the speed of the agricultural vehicle (1) if the agricultural vehicle (1) is moving at a reduced speed, and wherein the decision step of the first safety action furthermore means that the reset step is linked to data about a direction of travel of the agricultural vehicle (1) in such a way that the reset step is only performed if the operating system (30) has determined that the direction of travel of the agricultural vehicle (1) is an inward-bound direction into a zone (102) in which lower safety rules apply.

5. System according to any of Claims 1-4, wherein the processing member is a reaping unit (6), and wherein deactivating the processing member involves lifting up or stopping the reaping unit (6).

6. System according to any of Claims 1-5, wherein the marking element (50) is anchored in a terrain over which the agricultural vehicle (1) travels during operation, and wherein the marking element (50) is configured in such a way that the agricultural vehicle (1) can drive over it without the agricultural vehicle (1) being touched.

7. System according to an of Claims 1-6, comprising at least two marking elements (50).

8. System according to any of Claims 1-7, wherein the optical detection mechanism (40) of the agricultural vehicle (1) comprises a stereo camera.

9. System according to any of Claims 1-8, wherein the operating system (30) comprises a navigation system for navigating the agricultural vehicle (1) through the operating area (100).

10. System according to Claim 9, wherein the navigation system is configured to use one of GPS, LiDAR and UWB triangulation.

11. Method for controlling an agricultural vehicle (1) with an activatable processing member (6) for processing a crop (20) or feed or for soil cultivation, which isconfigured to travel autonomously in an operating area (100), and which is equipped with an optical detection mechanism (40) to observe the close surroundings of the agricultural vehicle (1) on the basis of optical techniques, wherein a marking element (50) is situated in the operating area (100) which is detectable by the optical detection mechanism (40) of the agricultural vehicle (1), wherein a safety-check routine is performed on the basis of a first criterion, being an observation of the marking element (50) by the optical detection mechanism (40) of the agricultural vehicle (1), and also on the basis of a second criterion, being the agricultural vehicle (1) reaching a position in the operating area (100) which during the control of the agricultural vehicle (1) is determined to be a position for observing a portion of the operating area (100) by the optical detection mechanism (40) of the agricultural vehicle (1) using position data which correspond to reference position data which are representative of a position of the marking element (50) in the operating area (100), and wherein, when the first criterion has been met, a first safety action is initiated which comprises an analysing step of comparing position data of the observation of the marking element (50) with the reference position data, and an operating step which involves reducing the speed of or stopping the agricultural vehicle (1) and / or deactivating the processing member (6) if a difference between the respective position data is found which is greater than a permissible difference, and to initiate, once the second criterion has been met, a second safety action which comprises an analysing step of determining whether the marking element (50) has been observed, and an operating step which involves reducing the speed of or stopping the agricultural vehicle (1) and / or deactivating the processing member (6) if the marking element (50) has not, or not sufficiently, been observed.

12. Method according to Claim 11 , wherein, in the case that the operating step of at least one of the first safety action and the second safety action involves reducing the speed of the agricultural vehicle (1), the agricultural vehicle (1) is controlled to continue to travel at an adjusted reduced speed until another safety-check routine is performed.

13. Method according to Claim 11 or 12, wherein the operating area comprises two zones (101 , 103; 102) with different safety rules, wherein the marking element (50) is situated at a boundary position between the zones (101 , 103; 102), wherein the first safety action comprises a decision step which means that the operating step is linked to data about a direction of travel of the agricultural vehicle (1) in such a way that the operating step is only performed if the direction of travel of the agricultural vehicle (1) is an inward-bound direction into a zone (101 , 103) in which higher safety rules (101 , 103)apply.

14. Method according to Claim 13, wherein the first safety action furthermore comprises a reset step of increasing the speed of the agricultural vehicle (1) if the agricultural vehicle (1) is travelling at a reduced speed, and wherein the decision step of the first safety action furthermore means that the reset step is linked to data about a direction of travel of the agricultural vehicle (1) in such a way that the reset step is only performed if the direction of travel of the agricultural vehicle (1) is an inward-bound direction into a zone (102) in which lower safety rules apply.

15. Method according to any of Claims 11-14, wherein the processing member is a reaping unit (6) is, and wherein deactivating the processing member involves lifting up or stopping the reaping unit (6).

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