Agricultural machine with attachment and reversing camera for fault detection of the attachment

Description

[0001] The present invention relates to an agricultural machine with an attachment for cultivating agricultural land and an optical sensor for detecting the cultivated area. Such a sensor facilitates the detection of errors during cultivation, so that if an error occurs, corrective action can be taken quickly and effectively.

[0002] Agricultural machines of this type are known from EP 2 545 761 B1 and DE 10 2014 201203 A1. In particular, EP 2 545 761 B1 discloses a combine harvester that uses a camera mounted below the intake chute as an optical sensor. Such a camera enables the monitoring of parts of the agricultural area freshly harvested by the header, which are hidden from direct observation by the machine operator due to the intake chute. Those parts of the area that remain visible to the operator on both sides of the intake chute are difficult to see from the camera's low-lying position. DE 10 2014 201203 A1 proposes a drone for monitoring the stubble behind an agricultural harvesting machine. Such a drone can only relieve the operator if it flies fully autonomously, without requiring the operator's attention. Such drones are currently still expensive.At the same time, the evaluation of the images supplied by the drone is made more difficult by the fact that it is not a priori clear from which perspective they were taken.

[0003] EP 3 409 097 B1 discloses a forage harvester in which a camera mounted on the discharge spout is used during reverse travel to identify objects and avoid potential collisions. The same camera is used during harvesting to control the discharge flow from the forage harvester into a transport vehicle.

[0004] Further agricultural machinery is known from EP 3 145 290 A1 and EP 3 747 248 A1.

[0005] One object of the present invention is to create an agricultural machine with an attachment device in which the proper functioning of the attachment device can be verified or ensured with minimal effort.

[0006] The problem is solved with an agricultural machine according to claim 1.

[0007] Further preferred embodiments are defined by the dependent claims.

[0008] Reversing cameras are fitted to many self-propelled agricultural machines to enable safe reversing even when the operator has difficulty seeing the area behind the machine, either directly or via mirrors. For this purpose, they are mounted in a location on the machine that offers a good view of the area behind it. When the machine is moving forward during normal operation, the reversing camera is not needed for its original function and can therefore be used to monitor the work progress on the cultivated area without any loss of functionality and at minimal cost.

[0009] According to the invention, an image processing unit is connected to the reversing camera and configured to detect the presence of an error in the processing of the surface using images from the reversing camera and to output an error signal if an error is present.

[0010] Images that can be evaluated for processing errors are only generated when the agricultural machine is moving forward. An image processing unit, which otherwise serves to detect potential hazards during reversing using images from the reversing camera, has nothing to do when moving forward; therefore, the processing power of such an image processing unit can be used during forward movement to monitor the cultivated area and detect potential processing errors, which in turn helps to minimize the costs of implementing the invention.

[0011] According to the invention, the reversing camera is connected to a screen in the driver's cab via a control unit. If this screen, in a normal operating state where no error is detected in the processing of the area, displays images that the machine operator has a strong interest in monitoring, then it can be assumed that the screen is continuously monitored with due attention. Therefore, if the screen can be switched to an operating state in which it displays images of the processed area taken by the reversing camera, the operator will notice this immediately and, if necessary, take appropriate action.

[0012] The images displayed on this screen during normal operation may, for example, show the loading of a transport vehicle accompanying the agricultural machine with harvested crops. The source of these images could be a camera mounted on a pipe extension from the machine, which stretches across the loading platform of the transport vehicle during the loading process. This same camera could also serve as a reversing camera.

[0013] The image processing unit can also be configured to identify a location on the machined surface where a defect is present in the images from the reversing camera and to mark this location in the images transmitted to the screen. This makes it easier for the driver to check whether the image processing unit's assessment of the presence or absence of a defect is correct and, if necessary, to determine appropriate corrective measures.

[0014] According to the invention, the image processing unit is configured to assess the certainty with which a defect exists and to display the degree of certainty in the images transmitted to the screen, e.g., by marking the location where the defect is presumed to be located with different colors depending on the degree of certainty. Thus, after briefly examining the displayed image, the user can confidently ignore a defect suspected by the image processing unit with low certainty if they get the impression that the defect is not present, whereas a higher degree of certainty on the part of the image processing unit justifies a more detailed examination of the image and may require appropriate corrective measures.

[0015] A key indicator of a potential error is the length of the stubble left behind by the header on the cultivated area. If the stubble is too short, there is a high risk that the header will pick up soil along with the harvested crop, thus contaminating it. Conversely, excessively long stubble, especially in the case of corn, increases the risk of it serving as winter shelter for pests. Therefore, the image processing unit should be configured to assess stubble length based on images from the reversing camera.

[0016] Furthermore, a control unit for the attachment is preferably provided to correct the working height of the attachment based on the stubble length.

[0017] Alternatively or additionally, the image processing unit can be configured to detect drag marks from the header on the ground. These can also indicate that the header height is generally too low and can be eliminated by raising the header. However, drag marks can also occur if the header height itself is correct, but it hits an isolated bump in the ground and pushes it along. If soil accumulates on the header in this process, it can cause it to get stuck.

[0018] In such a case, a remedy can be achieved by configuring the control unit to temporarily increase the working height of the attachment when the image processing unit detects grinding marks. This allows the attachment to overcome the material accumulating in front of it and then resume operation at its original height.

[0019] Another fault that the image processing unit should be able to detect is flattened crop. This is usually caused by an obstacle blocking access to the knives at the front edge, causing the crop stalks to be knocked over by the obstacle instead of reaching the knives. In this case, it is generally necessary to stop the machine and remove the obstacle; therefore, the control unit is preferably configured to stop the machine when it detects flattened crop.

[0020] Further features and advantages of the invention will become apparent from the following description of exemplary embodiments with reference to the accompanying figures. These show: Fig. 1 shows an agricultural machine according to the invention in a side view; Fig. 2 shows the agricultural machine in a top view; Fig. 3 shows an image produced by a reversing camera of the machine; and Fig. 4 shows an image displayed on a screen of the machine.

[0021] Fig. 1 und 2 Figure 1 shows a side view and a top view of a forage harvester 1 as a preferred example of an agricultural machine to which the invention is applicable. The forage harvester has a rigid body 2 to which a header 3, typically a corn header, is mounted in a height-adjustable manner, and a discharge spout 4 is pivotably mounted about a vertical axis. A chopping unit 6 and a post-accelerator 7 are housed within the body 2, below a driver's cab 5. In a manner known per se, the former serves to chop the crop fed by the header 3, and the latter to accelerate the resulting chopped material to a speed required for it to pass through the discharge spout 4.

[0022] Fig. 1 The figure shows the discharge spout 4 in a rearward orientation, extending against the normal direction of travel. Fig. 2 The discharge spout 4 is swivelled 90° to the side to discharge the chopped material onto a loading platform 8 of an accompanying vehicle 9 driving alongside the forage harvester 1.

[0023] In a first embodiment, a reversing camera 10 for monitoring the area behind the forage harvester 1, which is poorly visible or not visible at all from the driver's cab 5, is mounted on the discharge spout 4. The reversing camera 10 is connected via a control unit 11 to a screen 12 in the driver's cab 5. The control unit 11 is configured to display images from the reversing camera 10 on the screen 12, at least when the forage harvester 1 is moving in reverse.

[0024] When the forage harvester is moving forward during harvesting, the discharge spout 4 must be in a sideways-swiveled position as shown in Fig. 2 so that the chopped material can be continuously transferred from the forage harvester 1 to the accompanying vehicle 9. In order for the reversing camera 10 to monitor a harvested area 13 behind the forage harvester 1 in this operating state, it can be mounted on the discharge spout 4 in a pivoting manner, so that it can rotate in the opposite direction to the discharge spout and maintain a rearward view regardless of its pivot position.

[0025] According to a first alternative, the reversing camera 10 has such a wide viewing angle that the area 13 behind the forage harvester 1 is still within its field of view even when it is mounted immovably on the discharge spout 4 and the discharge spout 4 is in the position shown in the diagram. Fig. 2 shown is swivelled to the side. In this case, the screen 12 only shows a section of the images taken by the reversing camera 10, whereby the section can be set by the control unit 11 so that essentially the same area 13 is visible behind the forage harvester 1 when reversing as well as when driving forward during harvesting operations.

[0026] If, in this first alternative, the discharge spout 4 is in the position of the Fig.2 Since the loading platform 8 is located, a significant portion of it is also within the field of view of the reversing camera 10, allowing it to be used to monitor the transfer to the escort vehicle 9. For this purpose, the control unit 11 supports two operating states of the screen 12: a first, in which the jet of chopped material ejected from the discharge spout 4 and its point of impact on the loading platform 8 are visible, and a second, in which the area 13 behind the forage harvester 1 is visible.

[0027] Since the control unit 11 receives the entire image from the reversing camera 10, an image processing unit 14 of the control unit 11 is always able to evaluate the part of the image in which the area 13 behind the forage harvester 1 is shown.

[0028] According to a second alternative, the reversing camera 10 is swivelling together with the discharge spout, so that when the discharge spout 4 is as in Fig. 2 When the discharge spout 4 is swivelled to the side, the field of view of the reversing camera 10 also swivels, and the loading platform 8 fills this field of view instead of the area behind the forage harvester 1. To still allow monitoring of the area behind the forage harvester 1, a mirror 15 is provided, which can be swivelled in front of the reversing camera 10 to redirect its view back to the area 13 behind the forage harvester 1. The mirror 15 can be temporarily positioned in front of the reversing camera 10 so that its images alternately show the stream of chopped material and the area 13 behind the forage harvester 1; it is also conceivable that, as long as the discharge spout 4 is swivelled to the side, the mirror is positioned so that the stream of chopped material is visible in one part of the field of view and the area behind the forage harvester 1 in the other.

[0029] According to a third alternative, a reversing camera 10 can also be mounted at the rear of the body 2. The function of the camera 10 on the discharge manifold 4 can then be limited to monitoring the flow of shredded material.

[0030] In each of these alternatives, images of the area behind the forage harvester 1 are available at all times during a harvesting process – if necessary, after appropriate positioning of the mirror. These images are examined in real time by the image processing unit 14 for possible defects.

[0031] Examples of possible errors include: The length of stubble left on the field is below a lower limit; the length of the stubble is above an upper limit; there is flattened crop material on the field; skid marks are visible on the field.

[0032] When the image processing unit 14 detects an error, it sends an error signal to the control unit 11, which then triggers a corrective action. The upper and lower limits, as well as the corrective action to be taken for a given error, can be defined by the user.

[0033] In the event of a limit value being undershot or exceeded, the remedial measure can consist of the control unit 11 correcting the height of the attachment device 3 above the ground by means of an actuator 16 until the limit values ​​are met again.

[0034] Such a correction can be made fully automatically, without driver intervention. Alternatively, the presence of the error signal can cause the images from the reversing camera to be displayed on the screen, possibly along with an indication of the direction of a height correction intended by control unit 11, and this correction is only carried out after approval by the driver.

[0035] Fig. 3 Figure 1 shows an image of the area behind the forage harvester 1, taken by the reversing camera 10 at the discharge spout 4, which projects laterally from the body. A portion of the body 2 is visible at the bottom of the image. A strip 17 of flattened corn plants extends between the body 2 and the edge of an unharvested stand 18. With a header 3 as shown in Figure 1, the following applies: Fig. 2 As depicted, with several rotors 20 each flanked by stem dividers 19, such a fault pattern can occur if a gap 21 between a stem divider 19 and an adjacent rotor 20 is blocked by foreign material and the intake of the stems fails there. In this case, it is necessary to stop the forage harvester 1 and remove the foreign material. The corrective action taken by the control unit 11 may initially be limited to indicating the presence of the fault to the operator.Alternatively, or if the driver ignores the displayed error, the control unit 11 may stop the forage harvester 1, possibly also reversing it slightly to make it easier for the driver to reach the affected section 21 between the front edge of the header 3 and the edge of the unharvested crop, and / or briefly reversing the rotors 20 to clear the section 21 of crop material and quickly make the foreign material accessible.

[0036] Fig. 4Figure 1 shows an image of the area behind the forage harvester 1, taken by the reversing camera 10' at the rear of the forage harvester 1 and displayed on the screen 12. Tire tracks 22 extend on both sides of the image center; these are unavoidable and do not indicate a defect; due to their regular pattern of lug marks, they are easily identified by the image processing unit 14 and can be dismissed as irrelevant. A skid mark 23 extends between the tire tracks 22; it is recognizable by the image processing unit 14 by its uniformly elongated structure. The skid mark could be caused by a single clod of earth that the header 3 has struck and which is subsequently smeared across the ground surface by the header 3.If such a skid mark 23 is detected, the control unit 11 can end it by briefly raising the attachment 3 with the help of the actuator 16 until the remains of the clod of earth are behind it, and then lowering it again.

[0037] It can be provided that the control unit 11 takes such a measure fully automatically upon detection of a skid mark, without driver intervention. In this case, it is not necessary to display the images from the reversing camera in which the skid mark is detected on the screen 12.

[0038] Alternatively, the detection of a skid mark can initially cause the screen 12 to switch from the aforementioned first to the second operating state, i.e., the images showing this skid mark are displayed on the screen 12. In the displayed images, the image processing unit 14 adds a marker 24 to each of the image areas interpreted as the skid mark. The marker 23 comprises two lines running on either side of the skid mark 23 at a distance from it so as not to obscure it, thus allowing the driver to interpret the image content.

[0039] The color of marker 24 on screen 12 can serve to signal to the driver the reliability of the assessment by the image processing unit 14. The more closely the marked area of ​​the image corresponds to the criteria for a skid mark specified by the image processing unit 14, the higher the reliability is set. If it exceeds an initial, lower threshold, which is required to generate the fault signal and switch screen 12 to the second operating state, but remains below a second, higher threshold, the marker appears, for example, in yellow, whereas it appears in red if the second threshold is exceeded. Other ways to signal the reliability of the assessment or the urgency of a corrective action include using different brightness levels or line widths for marker 24, or switching between continuous and flashing display.

[0040] Based on the images displayed on screen 12, the operator can assess the problem and decide whether and, if so, which corrective action is appropriate. If the operator fails to do so within a specified time, the control unit 11 is designed to automatically implement a corrective action. As described above, the corrective action may involve temporarily raising the header 3; however, if errors occur frequently, for example, because the skid mark is not caused by individual clods of earth but by a long, continuous undulation in the ground, the corrective action may also involve stopping the forage harvester 1 to allow the operator to investigate the problem and resolve it permanently. Reference sign

[0041] 1 Forage harvester 2 Body 3 Header 4 Discharge spout 5 Driver's cab 6 Chopper 7 Post-accelerator 8 Loading platform 9 Escort vehicle 10 Reversing camera 11 Control unit 12 Screen 13 Surface 14 Image processing unit 15 Mirror 16 Actuator 17 Strip 18 Crop 19 Stem divider 20 Rotor 21 Wedge 22 Tire track 23 Drag track 24 Marking

Claims

1. Agricultural machine (1) having a driver's cab (5), a screen (12) located in the driver's cab (5), and a control unit (11), an attachment (3) for processing an agricultural area, and an optical sensor in the form of a rear view camera (10, 10') for capturing the space behind the agricultural machine (1) which is difficult to see or not visible at all from the driver's cab (5), wherein the rear view camera (10) is connected via the control unit (11) to the screen (12) in the driver's cab (5) and the control unit (11) is furthermore designed, whenever the agricultural machine (1) is reversing, to present images from the rear view camera (10) on the screen (12), wherein the reversing camera (10, 10') is configured and designed, in harvesting mode, to capture the processed area (13) behind the machine (1) relative to the direction of travel thereof, wherein an image processing unit (14) which is connected to the rear view camera (10, 10') and is designed to identify that there is an error in the processing of the area (13) using images from the rear view camera (10, 10') and to output an error signal when there is an error, characterized in that the image processing unit (14) is designed to assess the certainty with which there is an error and to display the degree of certainty in the images transmitted to the screen (12).

2. Agricultural machine according to Claim 1, characterized in that a screen (12) of the machine (1) is connected to the rear view camera (10, 10') and can be transferred by way of the error signal into an operating state in which it displays images of the area (13) taken by the rear view camera (10, 10').

3. Agricultural machine according to Claim 2, characterized in that the image processing unit (14) is designed to determine a location where there is an error in images from the rear view camera (10, 10') and to indicate the location of the error in the images from the rear view camera transmitted to the screen by way of a marking (24).

4. Agricultural machine according to any one of Claims 1 to 3, characterized in that the image processing unit (14) is designed to assess the length of stubble left behind by the attachment (3) on the processed area (13).

5. Agricultural machine according to Claim 4, characterized by a control unit (11) designed to correct the working height of the attachment (3) based on the stubble length.

6. Agricultural machine according to any one of Claims 1 to 5, characterized in that the image processing unit (14) is designed to identify trails (23) from the attachment (3).

7. Agricultural machine according to Claim 6, characterized by a control unit (11) designed to temporarily increase the working height of the attachment (3) upon identification of trails (23) by way of the image processing unit (14).

8. Agricultural machine according to any one of Claims 1 to 7, characterized in that the image processing unit (14) is designed to identify harvest crops that have been pushed down.

9. Agricultural machine according to Claim 8, characterized by a control unit (11) designed to stop the machine (1) upon identification of harvest crops that have been pushed down.