JPH0128404B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a transplant machine equipped with an automatic steering device. 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. To this end, various automatic steering devices have been proposed that steer the aircraft so that it travels straight.

Therefore, even in transplanted aircraft equipped with an automatic steering system, a steering wheel is naturally installed to compensate for deficiencies in automatic steering control, to deal with emergencies, and even when driving on the road. The structure allows for manual steering by rotating the .

The present invention enables automatic switching between an automatic mode in which an automatic steering device performs automatic steering, and a manual mode in which priority is given to manual steering by a steering wheel over automatic steering control by an automatic steering device, Our goal is to provide transplanters with improved operability and safety.

The transplanting machine according to the present invention includes an automatic steering device,
In addition, in a transplant machine that allows manual steering using a steering wheel, there is a means for detecting the presence or absence of a rotational operation of the steering wheel, and when the means detects a rotational operation, the manual operation using the rotational operation is immediately performed. means for causing the steering wheel to rotate; a means for timing the time during which the steering wheel is not rotated; and when the time measured by the means exceeds a predetermined time, automatic steering is performed by the automatic steering device. The invention is characterized by comprising means for

Although the present invention can be applied to various types of transplanters equipped with various types of automatic steering devices, the present invention will be applied to a riding type rice transplanter using a photointerrupter as a sensor for obtaining control input for automatic steering. An explanation will be given based on the drawings showing an embodiment.

FIG. 1 is a left side view of the rice transplanter according to the present invention, where 1 is the front wheel attached to the front body 2, 3 is the rear wheel attached to the rear body 4, and 5 is the front wheel attached to the front body 2. 6 shows a seedling planting device attached to the front fuselage 2 so as to be located in front of the front wheels 1.

The power unit 7 is mounted on the rear fuselage 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, allowing the aircraft to travel by four-wheel drive. The seedling planting device 6 operates in synchronization with the speed of this traveling to plant multiple rows of seedlings in the paddy field.

The front body 2 and the rear body 4 are connected to each other using pins 8 and 9 at their respective rear and front ends so as to be horizontally rotatable.
When the steering wheel 5a is rotated to the left or right, the pitman arm 10 rotates forward or backward, and the rod 15, whose one end is connected to the pitman arm 10 and the other end is connected to the rear fuselage 4, rotates forward or backward. The rear fuselage 4 is horizontally rotated so as to bend relative to the front fuselage 2, and the bending direction and bending angle are determined according to the rotation direction and rotation angle of the steering wheel 5a, that is, the steering angle. According to the bending direction and bending angle, manual steering is performed so that the traveling direction of the aircraft body is changed to either the left or right by an angle corresponding to the bending angle.

In addition, the transmission shaft 1 is adjusted so that the transmission is not damaged due to the bending of the front fuselage 2 and the rear fuselage 4.
Bar field type universal joints 13 and 14 are provided halfway between 1 and 12.

Next, the sensor 20 connects the front body 2 and the seedling planting device 6.
One piece is attached to each of the pair of left and right lower links 16 that connect the two. This sensor 20, as shown in FIG.
It consists of two sets of photo interrupters 21 and 22, each consisting of a light receiver 21b and a light receiver 21b and 22b. The mounting height positions of the projectors 21a, 22a and the 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.
The height is such that the light beams P ₁ and P ₂ emitted substantially horizontally from each of the seedlings q 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 beams P ₁ and
P ₂ are arranged to intersect at approximately the center of each passage route. In other words, in the figure, the white arrow indicates the direction of movement of the aircraft, with the emitter 21a at the front left, the emitter 22a at the rear left, and the receiver 21b at the rear right.
The light receiver 22b is disposed at the front right, with the light emitter 21a and the light receiver 21b facing each other, and the light emitter 22a and the light receiver 22b facing each other.

Note that the photo interrupters 21 and 22 do not necessarily need to be arranged so that the light beams P ₁ and P ₂ intersect within the same plane, and may have slightly different levels, in other words, the light beams
It is sufficient that P ₁ and P ₂ intersect in plan view.

Furthermore, this sensor 20 is located at the center of the outermost (unplanted) seedling row Q formed by the seedlings q that have already been planted in the previous step (at the intersection of the light beams P ₁ and P ₂ ). It is attached to the outside of the fuselage so that it can be positioned.

The light receiver 21b or 22b receives the light beam _P1 or
There is no change in the output signal when P ₂ is being received, but if the light beam P ₁ or P ₂ is blocked by each seedling q that makes up the seedling row Q, the output signal will change as shown in Figure 2. The detection signal R ₁ or R ₂ is output in the form of a rectangular wave pulse. Such a detection signal is transmitted from the sensor 20 located on the side where the seedlings have been planted out of the left and right sensors 20 to the control circuit 31 provided at an appropriate part of the front body 2.
The information is sequentially input as the aircraft progresses.

This control circuit 31 is composed of a microcomputer or the like, and is based on two detection signals R ₁ and R ₂ to determine the relative positional relationship between the machine and the planted seedlings that the sensor 20 faces, that is, the intersection of the light beams P ₁ and P ₂ ; It performs functions such as detecting the amount of deviation of each seedling or row of seedlings in the left-right direction of the machine body, and instructing the motor drive circuit 32 to set a steering angle according to the detected value.

In the steering device 5, a driven gear 35 for automatic steering is fitted to a steering shaft 5b that rotates integrally with the steering wheel 5a and transmits the rotation to the pitman arm 10, and is arranged close to the steering device 5. A drive gear 34 is fitted onto the rotating shaft of the pulse motor 33, and both gears 34 and 35 are in mesh with each other. and,
Based on the input data from the control circuit 31, the motor drive circuit 32 generates a pulse signal to rotate the pulse motor 33 in required steps. Steering is now taking place.

A cutting angle sensor 36 formed of a rotary potentiometer is connected to the drive gear 34, and its voltage signal is input to the control circuit 31. The control circuit 31 recognizes the steering position from the voltage value.

Next, automatic steering control by the control circuit 31 will be explained.

This control circuit 31 monitors the difference in the timing of generation of the detection signals R ₁ and R ₂ , that is, the time difference t ₁ between the rise points of the two and the generation period t ₂ .

(1) First, as shown in FIG. 3A, the detection signals R ₁ ,
The timing of occurrence of R ₂ matches (t ₁ = 0)
or if there is a very slight deviation (t ₁ ≒ 0), the seedlings q of the already planted seedling row Q will pass one after another at the intersection of the light beams P ₁ and P ₂ as shown in Figure 4A. In other words, the aircraft is moving straight, and in this case, the motor drive circuit 3
2, or do not issue any signal.

(2) Next, as shown in FIG. 3B, if R 2 starts to lag behind R ₁ even though the timings of generation of the detection signals R _{1 and R 2 have} coincided, the fourth As shown in Figure B, the intersection of the light beams P ₁ and P ₂ has shifted to the right of the already planted seedling row Q, which means that the aircraft has started to veer to the right. To the circuit 32, the body of the seedling row Q, specifically the intersection of the light beams P ₁ and P ₂ , or the sensor 20
The steering angle is commanded according to the amount of deviation from the center of the steering wheel.

That is, since the time difference t ₁ between the rise points of the detection signals R ₁ and R ₂ is a value that changes in length depending on the magnitude of the deviation amount, the control circuit 31 calculates the deviation amount based on this time difference. When performing calculations to calculate the amount of deviation, it is necessary not only to simply multiply the time difference _t1 by a predetermined conversion coefficient to convert it into a dimension of the amount of deviation (dimension), but also to convert it into a dimension of the amount of deviation (dimension). Multiply by the appropriate correction coefficient. In other words, even if the amount of deviation is the same, the traveling speed is high,
This is because the time difference t ₁ changes from short to long depending on the temperature.

Information regarding the traveling speed of the aircraft is detected, for example, by successively reading the generation period t ₂ of the detection signal R ₁ and finding the average value thereof. This is because the planting interval of the seedlings q in the seedling row Q is approximately constant regardless of the traveling speed of the aircraft. and,
Using this average value as an index, the correction coefficient is read out from the memory and the amount of deviation is calculated.

The control circuit 31 calculates the amount of deviation as described above, and outputs a signal to the motor drive circuit 32 to instruct the steering angle based on the amount of deviation. Based on the input signal from the control circuit 31, the motor drive circuit 32 generates a pulse to rotate the pulse motor 33 by a required angle in a required direction, thereby causing the pulse motor 33 to rotate. As a result, the aircraft corrects its traveling direction to the left so that it returns to the straight-ahead state, that is, the center of the sensor 20 returns to the state where it travels along the seedling row Q.

(3) Furthermore, as shown in Fig. 3C, even though the generation timings of the detection signals R ₁ and R ₂ have coincided up to that point, if R ₂ starts to advance beyond R ₁ , as shown in Fig. 4 As shown in C, the intersection of the light beams P ₁ and P ₂ has shifted to the left of the seedling row Q, which means that the aircraft has begun to veer to the left. A similar control is performed so that the pulse motor 33 rotates in the opposite direction to that described, thereby correcting the traveling direction of the aircraft to the right and returning to the straight-ahead state.

In this way, the transplanter according to the present invention has the sensor 20
Automatic steering based on detection signals R ₁ and R ₂ and manual steering by rotating the steering wheel 5a are performed.If an automatic selection switch (not shown) is not turned on, only manual steering is possible. On the other hand, when this is turned on, automatic steering and manual steering are automatically switched as explained below.

FIG. 5 shows a control circuit 31 related to this automatic switching.
3 is a flowchart showing the operation sequence of FIG.

The control circuit 31 recognizes the steering position (rotation position) of the steering wheel 5a by reading the voltage signal from the turning angle sensor 36, which is constantly inputted, in a short predetermined cycle. (). Then, a plurality of pieces of read data are stored in a random access memory within the control circuit 31 (). The stored data is updated one by one each time new data is input. Next, whether it is automatic or manual is determined based on the on/off state of the automatic selection switch or the internal state of the control circuit 31. In the case of automatic steering, the presence or absence of a turning operation of the steering wheel is then determined by comparing the latest data in the random access memory with past data ().
When there is a rotation operation, manual steering is given priority by ().
If there is none, let automatic steering continue ().

On the other hand, if manual steering is selected in the step, when new data is input, this latest data θ ₀ is compared with the data θ ₁ read immediately before the data θ ₀ , and θ ₀ Determine if has changed from θ ₁ ().

If there is a change (YES), perform manual steering ().

This is done by stopping the automatic steering operation by stopping the operation of the motor drive circuit 32 or ignoring the detection signal from the sensor 20, so that only the steering by the steering wheel 5a becomes effective.

On the other hand, if θ ₀ does not change from θ ₁ (NO), then
In other words, if the steering position remains unchanged, a predetermined number of data θ ₂ , θ ₃ ... θ _o and θ ₀ read before θ ₁
Find the number of unchanged data.
Since the steering position is read from the turning angle sensor 36 in a predetermined cycle, the counted value of the number of data for which the steering position remains unchanged is equivalent to the time period during which the steering position remains unchanged. The time obtained in this way is compared with a predetermined constant time (6'). If there is no change for a certain period of time (YES), it is assumed that the automatic steering is being performed normally and the automatic steering is continued.
Or, assuming that the manual steering has already been completed, the manual steering is switched to the automatic steering ().

If the time period during which the count value or the steering position remains unchanged is shorter than the constant time period to be compared (NO), manual steering is performed ().

In addition, in the transplanted machine according to the present invention as described above, the switching between automatic steering and manual steering is performed automatically, so it is difficult to determine in which mode the steering is being performed. It is appropriate to provide a display means to notify the driver. Furthermore, it goes without saying that the automatic selection switch described above does not need to be provided.

Furthermore, in order to prevent the above-mentioned switching from being performed carelessly, the control circuit 31 includes information such as the rotational speed of the power unit 7, the position of the gear shift lever, the vertical position of the seedling planting device 6, the engagement and disengagement of the clutch, and the left and right sensors 20. It is desirable that the selected state of the selection status, etc. be recognized, and that automatic switching is performed only when seedlings are being planted in a normal manner.

As described above, in the case of the present invention, the driver does not have to switch between automatic steering and manual steering depending on the situation, which was conventionally required, and has excellent operability, and in an emergency, the driver can simply turn the steering wheel. Just by operating it, manual control is given priority immediately, making it possible to provide a transplanter with excellent safety.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a left side view of a riding rice transplanter according to the present invention, FIG. 2 is a schematic diagram of an automatic steering device together with a steering device, etc., and FIG. Figures A, B, and C are the detection signals R ₁ ,
Timing chart showing the occurrence state of R ₂ , 4th
Figures A, B, and C are schematic plan views showing the positional relationship between the light beam and the seedling row, and Figure 5 is a flowchart showing the operation of the control circuit. 5... Steering device, 5a... Rudder wheel, 20
...Sensor, 31...Control circuit, 32...Motor drive circuit, 33...Pulse motor, 36...Turn angle sensor.

Claims (1)

[Claims] 1. In a transplanted machine equipped with an automatic steering device and capable of manual steering using the steering wheel, there is a means for detecting whether or not the steering wheel is rotated, and when the means detects a rotation operation. means for immediately performing manual steering by the rotational operation; means for timing the time during which the steering wheel is not rotated; and when the time measured by the means exceeds a predetermined time, the automatic steering 1. A transplanting machine characterized by comprising means for automatic steering by a steering device.