JP7670285B2 - Harvesting Machine - Google Patents

Description

The present invention relates to a harvester.

For example, in the harvester disclosed in Patent Document 1, the current height above ground of the harvesting section (referred to as the "cutting section" in the document) that harvests crops in a field (referred to as the "planted culms" in the document) is detected. The current height above ground of the harvesting section is detected by a plate-shaped contact section provided at the bottom of the harvesting section.

JP 2021-23119 A

However, the ground contact part provided on the harvester disclosed in Patent Document 1 only detects the ground height relative to the field surface directly below the ground contact part, and cannot detect the ground height relative to the field surface located in front of the harvesting part. This means that there is a tendency for delays in detecting situations where the front end of the harvesting part is too high or too low relative to the field surface.

The object of the present invention is to provide a harvester that can effectively detect the current height of the harvesting section relative to the ground surface in front of the harvesting section.

The harvesting machine according to the present invention is characterized in that it comprises a harvesting unit that is supported on a body so as to be able to rise and fall vertically and harvests crops in the field; an imaging device that is provided on the harvesting unit and that captures images of the field scene located in front of the harvesting unit during work travel; a position calculation unit that calculates position information of the image capture target depicted in an image capture by the imaging device based on the image capture; a plane identification unit that identifies a planar portion of the image capture target based on changes over time in the position information of the image capture target in each of the multiple image captures; a distance calculation unit that calculates the distance between the planar portion and the imaging device based on changes over time in the position information of the image capture target in each of the multiple image captures; and a height calculation unit that calculates the current ground height of the harvesting unit relative to the field scene based on the distance.

According to the present invention, an imaging device is provided in the harvesting section, and the imaging device captures an image of a field scene located in front of the harvesting section as an imaging target. Then, position information of the imaging target is calculated based on the captured image, and the current ground height of the harvesting section is calculated based on the distance between the imaging device and a flat portion of the imaging target. In other words, the present invention makes it possible to calculate the current ground height with respect to the field scene located in front of the harvesting section. Therefore, compared to the method disclosed in Patent Document 1, a situation in which the front end of the harvesting section is too high or too low with respect to the field scene is detected earlier. This realizes a harvester that can suitably detect the current ground height of the harvesting section with respect to the field scene in front of the harvesting section.
In addition, in flat areas of the field scene, it is easier to calculate the current ground height of the harvesting part relative to the field scene with high accuracy compared to uneven areas of the field scene. Flat areas are identified based on the position information of the imaging target, but with this configuration, the position information of the imaging target is obtained from multiple captured images, so the current ground height of the harvesting part relative to the field scene can be calculated with even higher accuracy.

In the present invention, it is preferable that the position information is coordinates with the imaging device as a reference point.

With this configuration, the object captured in the image captured by the imaging device is managed as coordinates, making it easy to calculate the distance between the imaging device and the object.

In the present invention, it is preferable to provide a harvest height control unit that controls the elevation of the harvesting unit so that the ground height of the harvesting unit approaches the target ground height based on the current ground height and a preset target ground height of the harvesting unit.

This configuration allows the height of the harvesting unit above the ground to be appropriately adjusted depending on the field conditions in front of the harvesting unit.

In the present invention, it is preferable that the imaging device is provided below the harvesting section.

When the vehicle is traveling to work, crops are planted in the field in front of the harvesting unit. With this configuration, it is easier for the imaging device to capture images of the field scene compared to a configuration in which the imaging device is provided above the harvesting unit.

FIG. 2 is an overall side view of the harvester. FIG. FIG. 2 is a block diagram of a control system. 11A and 11B are diagrams illustrating how a flat portion is identified based on a captured image. FIG. 13 is a diagram showing an example of harvest height control.

[Basic configuration of the harvester]
Figures 1 and 2 show a head-feeding combine as an example of a harvester. As shown in Figures 1 and 2, this combine is equipped with a traveling body 1. The traveling body 1 is equipped with a crawler traveling device 2 and a body frame 3 supported by the crawler traveling device 2. A harvesting unit 4 is provided in front of the traveling body 1. The harvesting unit 4 is supported by the traveling body 1 around a swing axis X so as to be able to move up and down, and harvests crops (planted culms S, see Figure 4) in the field.
The combine harvester moves forward on the crawler travel device 2, while harvesting crops in front of the machine body one after another with the harvesting section 4. A driver's cabin 5 is provided at the front of the travel body 1, and the driver's cabin 5 is located behind the harvesting section 4.

An engine (not shown) is provided below the driver's cabin 5. A grain storage tank 6 is provided behind the driver's cabin 5, and stores grains after threshing. A threshing device 7 is provided to the left of the grain storage tank 6, and threshes the stalks harvested from the harvesting section 4. This allows the combine to travel while working. A grain discharge device 8 is connected to the grain storage tank 6, and discharges the grains in the grain storage tank 6.

The harvesting section 4 is configured for multiple cutting (six-row cutting in this embodiment). The harvesting section 4 is equipped with multiple (seven in this embodiment) weed-dividing tools 9, a raising section 10, a cutting blade device 11, and a conveying section 12. The weed-dividing tool 9 divides the planted culms S (see FIG. 4, the same below). The raising section 10 raises the planted culms S divided by the weed-dividing tool 9. The cutting blade device 11 cuts the base of the planted culms S raised by the raising section 10. The conveying section 12 conveys the harvested culms cut by the cutting blade device 11 toward the rear of the machine body. Of the multiple weed-dividing tools 9, the imaging device 13 is provided on the weed-dividing tool 9 two tools away (the third from the right end of the machine body) from the weed-dividing tool 9 on the right end of the machine body. In other words, the imaging device 13 is provided at the bottom of the harvesting section 4. The imaging device 13 is a so-called monocular camera, and is configured to capture images of the field scene in front of the harvesting unit 4 on a color screen.

In the example shown in FIG. 2, uncut planted culms S are indicated by circles, and cut residual culms are indicated by crosses. When the combine moves forward with the uncut planted culms S located between the two weed splitters 9, the harvesting section 4 harvests the planted culms S in front. The imaging device 13 is mounted on the third weed splitter 9 from the right end of the machine. Therefore, the images captured by the imaging device 13 are as shown in images P1 to P3 in FIG. 4. In images P1 to P3 in FIG. 4, uncut planted culms S are captured on the left and right, and a field scene is captured between the planted culms S on the left and right.

[Control system configuration]
3 shows a control system of the harvester according to the present invention. The control system of the combine harvester is composed of a control unit 20 and various input/output devices that perform signal communication (data communication) with the control unit 20 through a wiring network such as an on-board LAN. The control unit 20 is composed of a large number of electronic control units called ECUs. The control unit 20 is configured to input captured image data from the imaging device 13. The control unit 20 also outputs a signal for controlling the elevation of the harvesting section 4. The control unit 20 is equipped with a position calculation section 21, a plane identification section 22, a distance calculation section 23, a height calculation section 24, a harvest height control section 25, and a target harvest height setting section 26.

As described above, the imaging device 13 is provided on the weed splitter 9, and the imaging device 13 captures images in front of the harvesting unit 4. Therefore, when the harvesting unit 4 harvests the planted culms S in the field, the imaging device 13 captures images of the planted culms S and the ground between the two rows of the planted culms S, as shown in FIG. 4. In other words, the imaging device 13 captures images of the field scene located in front of the harvesting unit 4 over time while the combine is traveling. The images captured by the imaging device 13 are sent to the position calculation unit 21 over time.

Images P1 to P3 are shown in FIG. 4 as examples of images captured by the imaging device 13. Images P1 to P3 were captured while the combine was working. Image P2 was captured at a later time than image P1, and image P3 was captured at a later time than image P2. Each of images P1 to P3 shows object A (which may not be a specific object, but may be part of a field scene) as an example of an imaged subject. The position calculation unit 21 calculates the position information of object A captured in the captured image based on the image captured by the imaging device 13.

Images P1 to P3 each have different position information of object A on the screen. The position calculation unit 21 detects object A by performing a known matching process, such as ORB (Oriented FAST and Rotated BRIEF), on each of images P1 to P3, and calculates the three-dimensional coordinates of object A with the imaging device 13 as the reference point based on the change in the position information of object A on the screen. In other words, the position calculation unit 21 calculates the three-dimensional coordinates of object A with the imaging device 13 as the reference point based on multiple captured images as the position information of object A.

The position of the imaging device 13 in the field is different at the time when each of images P1 to P3 is captured. The change in the position of the imaging device 13 can be detected, for example, using a global navigation satellite system (GNSS), an inertial measurement sensor (IMU), a vehicle speed sensor, etc. The position calculation unit 21 may calculate the three-dimensional coordinates of object A with the imaging device 13 as the reference point based on the change in the position information on the screen of object A and the change in the position of the imaging device 13.

In addition to object A, images P1 to P3 contain many other captured objects in the field scene and planted stalks S, and these many captured objects are input to the position calculation unit 21 as point cloud data. The position calculation unit 21 calculates three-dimensional coordinates for each of these point cloud data. These point cloud data are sent from the position calculation unit 21 to the plane identification unit 22.

Based on the multiple point cloud data sent from the position calculation unit 21, the plane identification unit 22 identifies the plane portion F in the imaged object, i.e., the field scene, using a known technique called RANSAC (random sample consensus). In the example shown in FIG. 3, the plane portion F between the rows of the planted culm S as shown in image PF is identified based on images P1 to P3. In other words, multiple point cloud data including object A are acquired from multiple imaged objects, and among these point cloud data, the point cloud data of the portion shown in the plane portion F is identified as inlier point cloud data. In this way, the plane identification unit 22 identifies the plane portion F based on the position information obtained from the multiple captured images. The identification result of the plane identification unit 22 is sent to the distance calculation unit 23.

The distance calculation unit 23 calculates the distance D between the planar portion F and the imaging device 13 based on the three-dimensional coordinates included in the point cloud data of the portion shown on the planar portion F. The calculation result of the distance calculation unit 23 is sent to the height calculation unit 24. The height calculation unit 24 then calculates the current ground height H of the harvesting part relative to the field scene based on the distance D.

The target ground height HT is set by the target harvest height setting unit 26. The target harvest height setting unit 26 may be configured to set a value stored in advance in a storage device (not shown) built into the control unit 20 as the target ground height HT, for example, or may be configured to set a value set by manual operation as the target ground height HT.

The harvest height control unit 25 performs lifting control based on the current ground height H and the target ground height HT so that the ground height of the harvesting unit 4 approaches the target ground height HT. Here, lifting control means controlling the drive of the lifting actuator (not shown) of the harvesting unit 4. The harvest height control unit 25 automatically performs lifting control. Note that the harvest height control unit 25 does not have to perform lifting control automatically, and may, for example, assist manual lifting control. In other words, the harvest height control unit 25 only needs to perform lifting control of the harvesting unit 4 based on the current ground height H and the preset target ground height HT of the harvesting unit 4 so that the ground height of the harvesting unit 4 approaches the target ground height HT.

For example, Figure 5 shows a farm field with a flat portion F and a raised portion G. The raised portion G is located in front of the flat portion F in the direction of travel of the combine. The flat portion F is indicated by a thick line in Figure 5. The combine harvests the planted stalks S on the flat portion F after climbing over the raised portion G. When the combine harvester climbs over the raised portion G, the entire body of the combine is tilted upward at the front, and the current height H of the harvesting section 4 above the ground relative to the flat portion F becomes higher by the height of the raised portion G. For this reason, the stalk height becomes higher in the area of the flat portion F adjacent to the raised portion G. Considering subsequent tillage, it is desirable for the stalk height in the field to be as low as possible.

In the example shown in FIG. 5, when the combine harvester climbs over the raised portion G, the distance calculation unit 23 calculates the distance D between the flat portion F and the imaging device 13. The height calculation unit 24 then calculates the current ground height H based on the distance D. The current ground height H shown in FIG. 5 is higher than the target ground height HT. Therefore, the harvest height control unit 25 controls the lowering of the harvesting unit 4 so as to lower the ground height of the harvesting unit 4 relative to the flat portion F. Therefore, the harvesting unit 4 descends from the state shown by the dashed line in FIG. 5 to the state shown by the solid line in FIG. 5.

In FIG. 5, the distance calculation unit 23 calculates the distance d between the flat portion F and the imaging device 13 after the harvesting unit 4 has descended. The distance d is shorter than the distance D calculated before the harvesting unit 4 descends. The height calculation unit 24 then calculates the current ground height h after the harvesting unit 4 has descended based on the distance d. In FIG. 5, the target ground height HT is shown by a dashed line. The current ground height h is lower than the current ground height H shown in FIG. 5, and is closer to the target ground height HT than the current ground height H shown in FIG. 5.

In addition, immediately after the combine harvester passes over the raised portion G, the entire body of the combine harvester may tilt downward toward the front, causing the current ground height H of the harvesting section 4 relative to the flat portion F to be lower than the target ground height HT. In this case, the harvesting height control unit 25 controls the harvesting section 4 to rise so as to increase the ground height of the harvesting section 4 relative to the flat portion F. This reduces the risk of the tip of the harvesting section 4 piercing the field surface.

[Another embodiment]
The present invention is not limited to the configurations exemplified in the above-described embodiments, and other representative embodiments of the present invention will be described below.

(1) The imaging device 13 shown in the above embodiment is a so-called monocular camera, but the imaging device 13 may be a stereo camera. Even in this configuration, the plane surface identification unit 22 can identify the plane portion F based on position information obtained from multiple captured images.

(2) In the above embodiment, the position information of the imaging target calculated by the position calculation unit 21 is coordinates with the imaging device 13 as the reference point. This is not limited to the embodiment, and the position information of the imaging target may be, for example, coordinates with an arbitrary position of the harvesting unit 4 (such as the bottom of the harvesting unit 4) as the reference point.

(3) In the above embodiment, the imaging device 13 is provided on the weed dividing tool 9 two tools away (the third from the right end of the machine body) from the weed dividing tool 9 on the right end of the machine body. This embodiment is not limited to this, and the imaging device 13 may be provided on any weed dividing tool 9. For example, if there is no problem with capturing images of the remaining stalks that have already been cut, as shown in FIG. 2, the imaging device 13 may be provided on the weed dividing tool 9 on the right end of the machine body. The imaging device 13 may also be provided, for example, in front of the raising unit 10.

(4) In the above embodiment, the imaging device 13 captures the field scene in front of the harvesting unit 4 using a color screen, but it may also be configured to capture the field scene using a grayscale image having grayscale values.

The configurations disclosed in the above-mentioned embodiments (including other embodiments, the same applies below) can be applied in combination with configurations disclosed in other embodiments, so long as no contradiction occurs. Furthermore, the embodiments disclosed in this specification are merely examples, and the present invention is not limited to these embodiments, and can be modified as appropriate within the scope of the purpose of the present invention.

In addition to head-feeding combines, the present invention can also be applied to whole-culm-feeding combines, corn harvesters, forage harvesters, etc.

1: Traveling machine body 4: Harvesting unit 13: Imaging device 21: Position calculation unit 22: Plane identification unit 23: Distance calculation unit 24: Height calculation unit 25: Harvesting height control unit D: Distance between plane portion and imaging device F: Plane portion HT: Target ground height Hd: Current ground height

Claims (4)

A harvesting unit that is supported on the machine body so as to be capable of ascending and descending and harvests crops in a field;
An imaging device provided in the harvesting unit that captures an image of a field scene located in front of the harvesting unit during work travel;
a position calculation unit that calculates position information of the imaging target shown in the captured image based on the captured image captured by the imaging device;
a plane identifying unit that identifies a plane portion of the imaging target based on a change over time in the position information of the imaging target in each of the plurality of captured images;
a distance calculation unit that calculates a distance between the planar portion and the imaging device based on a change over time in the position information of the imaging target in each of the plurality of captured images ;
A harvester is provided with a height calculation unit that calculates the current ground height of the harvesting unit relative to a field scene based on the distance. The harvester according to claim 1, wherein the position information is coordinates with the imaging device as a reference point. A harvester as described in claim 1 or 2, which is provided with a harvest height control unit that controls the lifting and lowering of the harvesting unit so that the ground height of the harvesting unit approaches the target ground height based on the current ground height and a predetermined target ground height of the harvesting unit. The harvester according to claim 1 , wherein the imaging device is provided under the harvesting section.

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