JPS6348486B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention enables mobile agricultural machines such as combines and tractors to perform harvesting, ridge raising, etc. by following a tracking target line consisting of the side edges and ridges of an uncut grain field in a field. The purpose is to accurately control automatic steering based on highly accurate detection of the target line to be followed using a non-contact distance sensor, and to proceed with work smoothly and efficiently. .

Conventionally, mobile agricultural machinery has been automatically steered and controlled based on detecting a tracking target line using a contact-type limit switch. However, the detection rod of the limit switch has a relatively large number of erroneous contacts, which reduces the accuracy of steering control. Moreover, since only the vicinity of the moving mobile agricultural machine can be detected, the steering control must be performed rapidly, resulting in the mobile agricultural machine being steered left and right in a zigzag pattern. Therefore, the mobile agricultural machine tends to meander frequently, which not only reduces work accuracy and work efficiency, but also reduces the durability of the agricultural machine.

In order to eliminate the above-mentioned drawbacks, the present inventors have conducted research and development on automatic steering control of mobile agricultural machinery based on detecting a tracking target line with a non-contact type sensor.

However, unlike machine tools, mobile agricultural machinery has a long target line to follow, which has large variations, and there are many variables, making detection extremely difficult.Moreover, precise steering control cannot be performed due to slippage of the traveling device. , it became more difficult to detect the target line to follow, and the device for detecting the target line to follow became complicated and large, making it difficult to put it into practical use.

Through further research and development and solving the previous problems, the present invention detects the tracking target line with high precision using a simple device consisting of a non-contact distance sensor, and accurately detects the target line based on this detection signal. Automatic steering control is provided.

That is, the tracking sensor detects a detection area of approximately a predetermined distance and a predetermined opening angle in front of the mobile agricultural machine, and the boundary point between the detection point on the left side of the tracking target line and the detection point on the right side is the tracking reference point. This is to perform tangential control in the direction of getting closer.

Embodiments of the present invention will be described below based on the drawings.

Figure 1 shows a combine harvester C as a mobile agricultural machine.
The control platform 2 is on the front right side, the preprocessing device 3 is on the left side,
A threshing device 4 is arranged at the rear. Each part is driven by an engine (not shown), and the machine body 1 moves forward with a pair of left and right crawlers 5R and 5L, and the grain culms 18 to be planted in the rice field are separated by the weeder 6 of the pretreatment device 3. The grain is raised by a raising device 7, harvested by a reaping device 8, conveyed rearward by conveying devices 9, 10, 11, and 12 to a horizontal position, and threshed by a threshing device 4.

2 to 5 show the structure and function of the automatic steering device D of the combine harvester C. That is, the tracking sensor 19 detects the tracking target line L, which is the side edge of the cut area A on the uncut area B side of the grain culm 18 to be planted in the rice field, and based on this detection signal, the tracking control device M It is configured to operate and control the steering device D to cause the aircraft 1 to travel along the tracking target line L, thereby harvesting grains.

The tracking control device M consists of a microcomputer (hereinafter abbreviated as microcomputer), inputs the detection signal of the tracking sensor 19 to an input interface 20, transmits it to the central processing unit 21, and stores the information stored in the storage device 22. Therefore, it is configured to process and output from the output interface 23 to switch the steering oil passage switching valve 17 of the steering device D.

In the steering device D, when the switching valve 17 is switched from the neutral position to the right or left, the right or left hydraulic cylinders 14R, 14L extend, and the transmission case 13 is extended via the right or left clutch levers 15R, 15L.
Disconnect the right or left clutch 16R, 16L inside, stop the right or left crawler 5R, 5L,
It is configured to steer the aircraft 1 to the right or left.

The tracking sensor 19 is configured of an ultrasonic projection/reception type distance measuring device among non-contact type distance sensors.

This distance measuring device is attached to the right-end pulling device 7 at a predetermined height above the ground so as to face obliquely forward and downward.

The detection area 25 is set as a sector-shaped area having a predetermined opening angle β in the left-right direction, and a follow-up reference point 24 is set as a fixed point on the combine C in the middle of this opening angle.

The tracking sensor 19 is configured to scan the detection area 25 at a constant speed for each detection.
detection signals, that is, a total of i detection signals, are input to the input interface 20 of the tracking control device M. As shown in Fig. 4, ultrasonic waves are emitted from the detection sensor toward a point r in front at an angle of depression α, but when the grain culm 18 is detected, the measurement distance l ₁ is short, and when the grain culm 18 is not detected, the measurement distance is distance
l ₂ will be detected for a long time.

Therefore, a critical distance l ₀ is set in the control device M, and it is detected whether the measured distances l ₁ and l ₂ to each detection point detected by the distance sensor 19 are larger or smaller than the critical distance l ₀ . By doing so, it is configured to determine whether each detection point is located on the left or right side of the tracking target line L.

In this way, a boundary point between a detection point that detects the left side of the tracking target line L and a detection point that detects the right side of the tracking target line L can be obtained at a position approximately in the front direction by a radius r within the detection area 25.

Here, as shown in FIG. 6, the distance sensor 19 rotates the shaft 29 at a predetermined rotational angular velocity by rotating a pinion 28 via a worm gear 27 with a small electric motor 26 (switchable between forward and reverse rotation). It is formed so that it can swing from side to side. and,
For each detection, the distance sensor 19 is in the detection area 2.
It scans from the right side of 5 to the left side and returns to its original position on the right side after detection.

The tracking control device M is configured to store the boundary point obtained as described above in the control device M, and to control the steering of the combine harvester C in a direction in which this boundary point approaches the tracking reference point 24.

The stored information regarding the boundary point is updated by the above detection every time the combine C advances a predetermined distance or every time a predetermined time elapses.

Here, in FIG. 5, if there is a grain culm uncut land detection point 30 in a part of the grain culm uncut land detection point area A on the detection area 25 of the distance sensor 19,
Since grain culm uncut land detection points 30 are detected on both sides of a plurality of grain culm uncut land detection points, it can be determined by the control device M, and in this case, this grain culm uncut land detection point 30 It is desirable to configure the combine C to be steered and controlled while ignoring the above.

Furthermore, when detecting the area between the grain culms 18 and 18, despite the grain culm uncut area detection point area B, the grain culm 1
8 may not be detected, but there is a tendency that grain culm 18 is detected at the detection point next to it.
It is assumed that the following control device M makes the determination.

In this way, the boundary point between the detection points on the right side and the left side of the tracking target line L can be reliably detected.

The above embodiment can be modified as follows.

(a) In the above embodiment, an ultrasonic projection/reception distance measuring device is used as the distance sensor, but a light wave receiving distance measuring device may be used to measure the distance. In short, the distance sensor may be a non-contact type distance sensor.

(b) A dedicated electronic control circuit combined with a logic circuit, etc. may be used as the tracking control device.

(c) The automatic steering device of the present invention can be applied to binders, seedling planting machines, tractors, etc. in addition to combine harvesters. The binder can be applied immediately as it is, and when applied to a seedling planting machine, the uncut land in the combine can be considered as the area where the seedlings will be planted, and the already cut area can be considered as the area where the seedlings have already been planted.

Furthermore, even in the ridge-building and trenching work using a tractor, ridges and grooves can be formed parallel to the already completed ridges and grooves.

(d) Unlike the previous embodiment, the distance sensor does not have a structure in which it moves back and forth to the left and right to detect each detection point, but instead has a structure in which the distance sensor simultaneously detects each detection point within the detection area.

Since the present invention is configured as described above, it has the following effects.

(1) Since the tracking target line is detected by a non-contact sensor, there are fewer detection errors and detection errors, which not only improves the accuracy of steering control of mobile agricultural machinery, but also reduces the incidence of detection errors and failures. It has excellent durability and can maintain high-precision steering control over a long period of time.

(2) By detecting with a tracking sensor across a detection area extending left and right at a predetermined opening angle in front of the mobile agricultural machine, and determining whether each detection point is located on the left or right side of the tracking target line. , the position of the boundary point at a position approximately a predetermined distance in front of the mobile agricultural machine (approximately equal to the position of the tracking target line) is determined, and the steering control is performed so that the tracking reference point approaches this, so that the position is always a predetermined distance in front of the mobile agricultural machine. The steering will be controlled according to the situation at the location. Therefore, steering control can be performed appropriately from a long-term perspective, regardless of the immediate situation of the mobile agricultural machine.

(3) Since only a non-contact distance sensor as a means for detecting the tracking target line, a steering device with a simple structure, and a tracking control device are attached, implementation is simple and inexpensive.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is an overall perspective view of a combine harvester, FIG. 2 is a schematic configuration diagram of an automatic steering device, FIG. 3 is a block diagram of a steering device, and FIG.
5 is a schematic side view and a schematic plan view showing the reaping state, and FIG. 6 is a schematic plan view of the distance sensor drive mechanism. C... Mobile agricultural machine (combine harvester), D... Steering device, M... Tracking control device, L... Tracking target line,
l ₀ ...Critical distance, _l1 , _l2 ...Measurement distance of each detection point, A...Grain culm already mown detection point area, 19...Following sensor (distance sensor), 24...Following reference point ,
25...detection area, 30...grain culm uncut land detection point.

Claims (1)

[Scope of Claims] 1. A steering device of a mobile agricultural machine is configured to be able to be steered by a tracking control device based on a detection signal from a tracking sensor, and the tracking sensor detects a tracking target line formed in a field. Based on this, the tracking control device is activated to control the steering device to cause the mobile agricultural machine to travel while following the tracking target line, and the tracking sensor is configured with a non-contact type distance sensor. , this distance sensor is mounted on a mobile agricultural machine diagonally forward and downward at a predetermined ground height, and the detection area of the distance sensor is set to have a predetermined opening angle that extends in the left and right directions, and a tracking reference point is set in the middle of the opening angle. The critical distance for detecting whether each detection point on the detection area of the distance sensor is shifted to the left or right of the tracking target line is set to a certain dimension, and each measurement of each detection point of the distance sensor is performed. By detecting whether the distance is larger or smaller than a critical distance, it is configured to determine which side of the tracking target line, left or right, each detection point is detecting, and the left side of the tracking target line is determined as the detection point. An automatic steering device for a mobile agricultural machine, characterized in that a tracking control device is configured to control the steering device in a direction such that a boundary point with a detection point for detecting the right side approaches a tracking reference point. 2. The automatic steering system as set forth in claim 1, wherein the mobile agricultural machine is a combine harvester. 3. The automatic steering system according to claim 1, wherein the mobile agricultural machine is a binder. 4. In the automatic steering system set forth in claim 1, the mobile agricultural machine is a seedling planting machine. 5. The automatic steering system according to claim 1, wherein the mobile agricultural machine is a tractor. 6. The automatic steering device according to any one of claims 1 to 5, wherein the distance sensor is an ultrasonic projection/reception type distance measuring device. 7. The automatic steering system according to any one of claims 1 to 5, wherein the distance sensor is a light wave receiving distance measuring device. 8. In the automatic steering device according to any one of claims 1 to 7, the distance sensor has a structure in which the distance sensor sequentially detects each detection point within the detection area by reciprocating from side to side. What you have. 9. The automatic steering system according to any one of claims 1 to 7, in which the distance sensor simultaneously detects each detection point within the detection area. 10. The automatic steering system according to any one of claims 1 to 9, in which the tracking control device comprises a microcomputer. 11. The automatic steering system according to any one of claims 1 to 9, in which the tracking control device comprises a dedicated electronic control circuit. 12. In the automatic steering device according to claim 2, claim 3, or any one of claims 6 to 11, a grain culm mowed land detection point on the detection area of the distance sensor A follow-up control device is configured so that when a slight uncut grain culm detection point is detected in a part of the area, the control is performed while ignoring this grain culm uncut detection point. 13. In the automatic steering device according to any one of claims 1 to 12,
A tracking control device configured to input a detection signal from a distance sensor to the tracking control device each time the mobile agricultural machine advances a predetermined distance.