JPS60743Y2 - Automatic steering control device in transplant machine - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an automatic steering control device for a transplanting machine such as a rice transplanter, which allows the machine to move straight and plant seedlings in a straight line.

In a transplanting machine such as a rice transplanter, it is extremely important to plant seedlings in an orderly straight line for uniform growth of seedlings, mechanization of harvesting work, etc.

Various devices have been proposed in the past to automatically steer the aircraft so that it travels straight, but the basic information for steering control is generally based on the relative positional relationship between the planted seedlings and the aircraft. We are trying to detect and use this.

Sensors for detecting the above-mentioned positional relationship are attached to the aircraft body so as to be located on the left and right sides of the seedling row, and when the aircraft body veers to the left or right, either sensor on the left or right comes into pressure contact with the seedlings in the seedling row. When activated, a control signal is generated to correct the aircraft's heading in a predetermined direction.

However, rice seedlings and other seedlings to be transplanted are small and soft, so even if the sensor comes into contact with them, the sensor is not securely pressed by the seedlings, resulting in mis-steering, making it impractical for practical use. The reality is that this has not yet been achieved.

The present invention was developed in view of the above circumstances, and is a transplanter that enables reliable steering by having a structure that detects the relative position between the machine and the row of seedlings in a non-contact manner. For the purpose of providing an automatic steering control device, an embodiment of a riding rice transplanter will be described below in detail based on drawings.

FIG. 1 is a left side view of a riding rice transplanter equipped with an automatic steering control device according to the present invention (hereinafter referred to as the device of the present invention).
is a front wheel attached to the front frame 2, 3 is a rear wheel attached to the rear frame 4, 5 is a steering device attached to the front frame 2, and 6 is a front frame located in front of the front wheel 1. The seedling planting device attached to the is shown in each figure.

The power unit 7 is mounted on the rear frame 4, and its rotation is transmitted to the left and right pairs of front wheels 1 and rear wheels 3 through a transmission device including a differential gear, and the aircraft travels by four-wheel drive. The seedling planting device 6 operates in synchronization with the traveling speed to plant multiple rows of seedlings in the paddy field.

The front frame 2 and the rear frame 4 are connected to each other using pins 8 and 9 at their rear and front ends so that they can rotate horizontally, and the steering wheel 5a of the steering device 5 can be rotated to the left or right. When the pitman arm 10 is rotated forward or backward, the rod 15 connected at one end to the pitman arm 10 and at the other end to the rear frame 4 is driven forward or backward, and the rear frame 4 is rotated forward or backward. It rotates horizontally so as to bend with respect to the frame 2, and the bending direction and bending angle are determined according to the rotation direction and rotation angle of the steering wheel 5a. According to this bending direction and bending angle, the aircraft moves in either the left or right direction. Then, the steering is performed so as to change the traveling direction by an angle corresponding to the bending angle.

In order to prevent damage to transmission due to bending of the frame 2 and rear frame 4, Barfield type universal joints 13 and 14 are provided in the middle of the transmission shafts 11 and 12.

Next, the sensor 20, which is the main part of the present invention, is attached to the left lower link 16 of the pair of left and right lower links connecting the front frame 2 and the seedling planting device 6, and protrudes to the left side of the machine body by an appropriate length. It is installed as follows.

As shown in FIG.
It consists of a set of photointerrupters 21 and 22.

The light projector 21a. 22a and the light receivers 21b, 22b are set so that they are slightly higher than the water surface when the aircraft is located in a paddy field as shown in FIG. light beam p3. P2 is set at a height that can be blocked by the base of the seedling q above the water surface.

The planar arrangement of the photointerrupters 21 and 22 is such that the light beam P1. P2 intersect at approximately the center of each passage route.

In other words, the white arrow mark in the figure indicates the aircraft's direction of travel,
The projector 21a is located at the front left, the projector 22a is located at the rear left, the receiver 21b is located at the rear right, and the receiver 21b is located at the front right.The projector 21a and the receiver 21b face each other, and the projector 22a
and the light receiver 22b are arranged to face each other.

Furthermore, this sensor 20 is located at the center position of the outermost (unplanted) seedling row Q formed by the seedlings planted in the previous step, that is, the light beam P1. It is attached so that the intersection point of P2 is located.

When the light receiver 21b or 22b is receiving the light beam P1 or P2, there is no change in the output signal, but the light beam P
1 or P2 is blocked by each seedling q constituting the seedling row Q, a rectangular pulse-shaped detection signal R is generated as shown in FIG.
□ or output R2.

This detection signal R1°R2 is transmitted to a generation timing comparison circuit 31 of a control circuit 30 provided at an appropriate portion of the frame 2.
It is now entered into

This generation timing comparison circuit 31 determines the time difference between the rising points of two pulse-like inputs, that is, the detection signals R and R2, and outputs information on the relationship between the rising points of the two and the time difference.

In the steering device 5, a driven gear 35 for automatic steering is attached to a steering shaft 5b that rotates integrally with the steering wheel 5a and transmits the rotation to the pitman arm 10.
A drive gear 34 is fitted to the rotating shaft of a pulse motor 33 disposed close to the steering device 5, and both gears 34 and 35 are in mesh with each other.

In the control circuit 30, the motor drive circuit 32 connected after the generation timing comparison circuit 31 is a circuit for controlling the rotation of the pulse motor 33, and receives the signal output from the generation timing comparison circuit 31. The pulse motor 33 is controlled as follows.

First, as shown in FIG. 3A, if the timing of the generation of the detection signals R1 and R2, that is, the rising time of both coincide, or the rising time of both is slightly different from each other, the timing for driving the pulse motor 33 is Does not output pulse signals.

Next, as shown in FIG. 3B, if the detection signal R1 is generated earlier than R2 by a predetermined time or more, the detection signal R1, A number corresponding to the time difference between the rising points of R2 is output.

Furthermore, as shown in FIG. 3C, if the detection signal R1 is generated later than R2 by a predetermined time or more, the pulse for rotationally driving the pulse motor 33 is set according to the time difference between the rise points in order to rotate the steering shaft 5b clockwise. Output only the number corresponding to .

A riding rice transplanter equipped with the present device configured as described above operates as follows.

That is, when the aircraft first moves straight along the outermost seedling row Q formed in the previous step, the light beam P1. Since the intersection point of P2 passes through the planting position of each seedling q or a position close to the planting position, the light beams P,, R2
The light blocking is performed simultaneously or substantially simultaneously, and the light receiving devices 21b and 2
The timing relationship of the detection signals R, , R2 issued by the sensor 2b is as shown in FIG. 3A.

Therefore, the pulse motor 33 is not driven and the machine continues to move straight, and along with this, the seedling rows are also formed in a straight line.

Next, if the front wheel 1 or the rear wheel 3 turns to the side in a soft paddy field, or if the steering wheel 5a is inadvertently rotated incorrectly, and the aircraft's direction of travel is biased to the right, the 4th As shown in Figure B, the aircraft moves away from the seedling row Q.

Then, as the aircraft moves, the light beam P1 is first blocked, and after a predetermined time, the light beam P2 is blocked, so the detection signals R, ,
The timing relationship of R2 is as shown in FIG. 3B.

Therefore, the pulse motor 33 rotates the steering wheel 5a by the required amount to rotate the steering wheel 5a to the left.The waist body corrects the traveling direction to the left.The waist body returns to the state of straight traveling along the seedling row Q, and accordingly, the seedling row is also aligned in a straight line. It comes to be formed into a shape.

Further, if the aircraft's traveling direction is biased to the left due to the same reason as before, the aircraft approaches the seedling row Q as shown in FIG. 4C.

Then, as the aircraft moves, the light beam P2 is first blocked, and after a predetermined time, the light beam P is blocked, so the detection signals R1 and R are emitted by the light receivers 21b and 22b, respectively.
The timing relationship of 2 is as shown in FIG. 3C.

Therefore, the pulse motor 33 rotates the steering wheel 5a by the required amount to rotate the steering wheel 5a to the right, and the machine body corrects its traveling direction to the right, and the waist machine body returns to the state of moving straight along the seedling row Q.

As described in detail above, according to the device of the present invention, the sensor 20 detects the relative positional relationship between the seedling and the machine body without contacting the seedling. Compared to the conventional method that detects the relationship, automatic steering to make the aircraft go straight can be performed more reliably, and the straightness of the planted seedling rows is improved, and there is no risk of steering errors. This is extremely rare, and there is no possibility that the aircraft will veer too far left or right and damage the seedlings due to the sensor or front and rear wheels.

Note that the photointerrupter 21.2 that constitutes the sensor 20
2 is not limited to the above-mentioned arrangement, and the projector 21a
, 22a can be placed on the left and right sides of the front, and the light receivers 22b and 21b can be placed on the left and right sides of the rear.

Also, the light beam P1. P2 does not necessarily need to intersect, but it appears as if they intersect when shown in a plan view as shown in FIG.
Both photo interrupters 21 and 22 are arranged so that they can pass through an upper or lower position in any part of the passage route.
Of course, it is also possible to attach it to the fuselage.

Furthermore, in the above-mentioned embodiment, the sensor 20 was attached to the outside of the machine body to detect the relative positional relationship between the machine body and the seedling row Q that had been planted in the previous process. By attaching it to the lower part of the frame 2 so that its center position is located behind one of the planting claws 6a, and detecting the relative positional relationship between the seedling row itself and the machine body, which is being formed by the machine running. It is also possible to configure the vehicle to perform steering control.

[Brief explanation of the drawing]

Figure 1 is a left side view of a riding rice transplanter equipped with the device of the present invention, Figure 2 is a schematic plan view for explaining the arrangement of the photointerrupter along with a block diagram of the control circuit, etc., and Figures 3A and B. , C is a timing chart showing the generation states of the detection signals R1 and R2, and FIG. 4 is a schematic plan view showing the positional relationship between the light beam and the row of seedlings. 1...Front wheel, 3...Rear wheel, 5...Curved steering device, 6...Seedling planting device, 20...
...Sensor, 21゜22...Photo interrupter, 21a, 22a...Floodlight, 21b, 2
2b... Light receiver, 30... Control circuit,
31... Occurrence timing comparison circuit, 32...
...Motor drive circuit.

Claims (1)

[Scope of utility model registration request] In an automatic steering control device for a transplanter that plants seedlings in rows as the machine moves, two sets of photointerrupters each consisting of a light emitter and a light receiver are arranged so that the seedling row is positioned between the respective light emitters and receivers. However, the light beam P emitted from the light projector of one photointerrupter intersects the light beam P2 emitted from the light projector of the other photointerrupter, or any part of the passage path of the light beam P2 The light beam P1. Automatic steering control characterized in that the aircraft is steered using the timing of generation of signals obtained from each light receiver due to the light blocking effect that occurs when a row of seedlings is located in the middle of the passage path of P2 as control information. Device.