JPS6247481B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a mobile agricultural machine, and more particularly, to a mobile agricultural machine capable of automatically steering.

(Prior art) Conventionally, when a mobile agricultural machine is automatically moved in a desired direction in a field to perform agricultural work as appropriate, guides are used that are formed in the form of vertical walls on the side of a ridge or approximately in the direction of tillage, or that are arranged at regular and even intervals. A detector is provided so as to be able to come into pressure contact with an object to be detected, such as a stump of a planted crop, and the contact pressure of the detector with respect to the object to be detected is detected to output the amount of deviation from the reference working direction. The steering device is controlled by this.

(Problems to be Solved by the Invention) When the device is configured as described above, there is a problem that the structure is complicated and expensive, and foreign objects may protrude from the object to be detected that presses the detector, or If a part of the part is missing, the detection by the detector is unstable and there is a problem that the detection cannot be performed constantly and reliably.

An object of the present invention is to accurately detect the boundary between unworked land and worked land, and to automatically and accurately perform agricultural work without manual operation, while having a simple structure. In particular, it is an object of the present invention to provide a mobile agricultural machine capable of automatically cultivating unworked land adjacent to already worked land.

(Means for Solving the Problems) The present invention was invented by focusing on the fact that the reflected waves of infrared rays reflected from the ground differ between unworked areas and already worked areas. Unworked area detection element 30 that detects reflected infrared waves
a first detector 32 having an existing work area detection element 3;
a boundary detecting device 192, which is equipped with a second detector 33 having a second detector 33 having an area of
The present invention is characterized in that it includes a controller 2 that controls the steering device based on the output signal from the detection device 192.

(Operation) The output value of the first detector 32 and the output value of the second detector 33 are compared, and if the deviation between these output values is constant or absent, it means that the vehicle is traveling correctly in the desired direction. Although the steering device is not controlled, if the deviation of the output value is positive or negative, it means that the traveling direction has deviated from the desired direction toward the unworked area or the already worked area. The steering device is controlled based on the output signal from the boundary detecting device 192 to correct the traveling direction, and this control allows the aircraft to travel correctly in the desired direction with a simple configuration. This allows work to be carried out reliably on unworked areas.

(Example) Examples of the present invention will be described in detail below based on the drawings.

In this embodiment, a tilling device is installed at the rear of the agricultural tractor so that the tiller can be operated, so in FIG. It is.

This steering device 1 changes the direction of the front wheels (not shown) and performs steering control, and consists of two hydraulic cylinders 3 and 4, a front wheel direction changer 5, etc. 3 and 4 each rod 6 and 7
are connected. Oil pipes 10, 11 are connected to the piston side chambers 8, 9 of each cylinder 3, 4, and a spring 14 is provided in the rod side chambers 12, 13 of each cylinder 3, 4, both of which are open to the atmosphere. There is. Then, when oil flows in from the pipe 10, the rod 6 resists the spring 14 and moves into the cylinder 3.
At the same time, the spring 14 causes the rod 7 to move back into the cylinder 4, and the direction changer 5 steers the front wheel to the left by a predetermined angle. 7 advances from cylinder 4, while rod 6
moves into and out of the cylinder 3, and the direction changer 5 steers the front wheels to the right by a predetermined angle. Sho 1
A steering wheel 5 is connected to the direction changer 5.

The controller 2 is composed of an electric control circuit 16, a 4-port 3-position solenoid valve 17, a pump 18, etc. When a negative signal is input to the electric control circuit 16, the first solenoid S1 of the solenoid valve 17 is activated. When a control signal is output only to switch the solenoid valve 17 to the left symbol position, and when a positive signal is input to the electric control circuit 16, the second solenoid S2 of the solenoid valve 17
A control signal is output only when the solenoid valve 17 is switched to the right symbol position, and when no signal is input to the electric control circuit 16, the solenoid valve 1
No control signal is output to either the first or second solenoids S1 and S2 of the solenoid valve 17, and the solenoid valve 17 is positioned at the neutral position shown in FIG.

In addition, as shown in FIG. 2, the output port A of the solenoid valve 17,
The pipes 10 and 11 are connected to the port B, the output side of the pump 18 is connected to the input port P, and the tank T is connected to the port R.

Then, by supplying a signal to only the solenoid S1 in the solenoid valve 17 and energizing it, the port P
and A, ports B and R are in communication with each other, and oil from input port P flows from output port A to cylinder 3.
While the rod 6 moves forward against the spring 14, the rod 7 moves back into the cylinder 4 due to the pressure of the spring 14, and the oil from the cylinder 4 is returned to the tank T from the port B. In this way, the front wheels can be steered to the left. or,
By supplying a signal to and energizing only solenoid S2, ports P and B and ports A and R are connected to each other, and rod 7 advances from cylinder 4, contrary to when only solenoid S1 is energized. 6 moves into and out of cylinder 3, allowing the front wheels to be steered to the right. Also, both solenoids S
1. When the signal supply to S2 is removed and both solenoids S1 and S2 are demagnetized, ports A, B, P, R
Both cylinders 3 and 4 are connected to the tank T, and both cylinders 3 and 4 are configured to maintain the front wheels in a neutral state based on the neutral position.

Therefore, in the cultivator constructed as described above, the present invention includes a boundary detecting device 192 that detects the reflected waves of infrared rays reflected from the ground to detect the boundary between uncultivated land and cultivated land. A device 192 is attached to the front of the aircraft (not shown), and this detection device 192
The steering device 1 is controlled via the controller 2 using an output signal from the controller 2.

As shown in FIG. 1, the boundary detection device 192 includes an unworked area detection element 3 for detecting the reflected wave.
0, and a second detector 33 having an existing work area detection element 31 that also detects the reflected wave, and compares the output values from these detectors 32 and 33. This is done to detect the boundary between unworked land and completed work land.

The first and second detectors 32 and 33 in this detection device 192 have the same configuration, and each detection element 30 in each of these detectors 32 and 33,
31 is connected in series with resistors 36 and 40, and this series circuit is made up of transistors 34 and 38 and resistors 37 and 4.
1 is connected in parallel with each series circuit of 1 and connected to a DC power supply, and an intermediate position between the unworked area detection element 30 and the resistor 36 is connected to the base side of the transistor 34, and an already worked area detection element Element 31 and resistor 4
0 is connected to the base side of the transistor 38, and each of these transistors 3
The output values corresponding to the reflected waves detected by the respective detection elements 30 and 31 are outputted to the emitter sides 35 and 39 of Nos. 4 and 38, and the output values are compared and unworked. It detects the boundary between the ground and the existing work area.

The detection elements 30 and 31 mainly have wavelengths
It is designed to operate in response to infrared rays of about 6500 to 6700 angstroms, and in order to utilize infrared reflected waves, for example, when the infrared rays are emitted, the temperature rises due to the amount of radiated heat, and this temperature rise causes the electrical resistance to increase. Radiant thermocouples whose characteristic values change, such as bolometers, Golay cells, and other devices that detect heat; photovoltaic cells, photoconductive cells, photodiodes, etc. made of lead sulfide, lead selenide, thallium sulfide, germanium, silicon, etc. A device that detects light, such as a phototransistor, is used. In Fig. 1, thermocouples are used as the detection elements 30 and 31, which increase the temperature and decrease the electrical resistance when exposed to infrared rays. When installing and operating, the unworked area M and the already worked area N are separated as shown in Figure 3.
They are placed above the boundary O between them.

The more water there is on the radiation surface, the greater the amount of infrared rays contained in the emitted sunlight will be absorbed by the radiation surface, and the more the amount of infrared radiation absorbed by the radiation surface will be the larger the amount reflected from the radiation surface. The so-called reflectance K of
Since the amount of water on the ground surface is smaller in the unworked area M than in the unworked area, this reflectance K is greatest when the detection elements 30 and 31 are located on the unworked area M, as shown in FIG. When moving from the ground M to the already worked place N across the boundary O between the two places M and N, this reflectance K gradually decreases, and becomes the smallest when located on the already worked place N.

That is, the output voltages E ₂ and E ₃ outputted from the emitter sides 35 and 39 of the transistors 34 and 38 to the comparator 21 are such that the more the amount of infrared radiation to the detection elements 30 and 31 is As the resistance becomes smaller, the DC voltage value divided to the resistors 36 and 40 connected in series with the detection elements 30 and 31 becomes larger, and the input voltage to the bases of the transistors 34 and 38 becomes larger. Therefore, the values of the output voltages E ₂ and E ₃ for moving the detection elements 30 and 31 from the unworked area M to the already worked area N change similar to the reflectance K as shown in FIG. .

Therefore, the resistors 36, 3 of the first detector 32
7 and the resistors 40 and 41 of the second detector 33, the first detection element 30 is correctly positioned on the unworked area M, and the second detection element 31 is correctly positioned on the already worked area N, so that the front wheel When E _{2 and} E ₃ maintain a neutral state without moving left or right in the direction of boundary O, the difference voltage (E ₂ - E ₃ ) between both voltages E 2 and E 3 becomes zero, and the output signal from comparator 21 becomes When the differential voltage (E ₃ − _{E 2} ) is positive, a positive output signal is output.
When the differential voltage (E ₃ −E ₂ ) is negative, a negative output signal is output.

However, in the tiller configured as above,
There is no deviation in the output value when the unworked land detection element 30 is located on the unworked land M, and the worked land detection element 31 is located on the already worked land N, and the tilling operation is performed. Therefore, there is no output from the comparator 21, and as a result, both solenoids S1 and S2 of the electromagnetic valve 17 are not energized, and the output ports A and B are opened to the tank T as shown in FIG. The tillage section maintained in the direction of O (not shown)
The unworked land M adjacent to the worked land N is tilled.

Then, when the detection element 31 for the already worked area moves from the boundary O to the unworked area M side, the amount of infrared rays to the detection element 31 increases, and the second detector 32
As the output voltage _E3 increases, a positive output signal is output from the comparator 21, which excites the solenoid S2 of the solenoid valve 17, so that the ports P and B and ports A and R of the solenoid valve 17 are connected to each other. , the direction of the front wheels is changed to the right by the direction changer 5, that is, the direction of the detection element 31 for the existing work area is changed back to the N side of the existing work area, and the signal is not output from the comparator 21 and the front wheels do not move left or right. The direction is controlled so that the state is the same.

When the unworked area detection element 30 moves from the boundary O to the already worked area N side, the amount of infrared radiation to the detection element 30 becomes smaller, and the output voltage E ₂ from the first detector 31 becomes smaller. A negative output signal is output from the comparator 21, and the solenoid S1 of the solenoid valve 17
, so the solenoid valve 17 is connected to ports P and A,
Ports B and R are connected to each other, the front wheel is changed to the left by the direction changer 5, that is, the direction of the unworked area detection element 30 is changed back to the unworked area M side, and no signal is output from the comparator 21. The direction is controlled so that the front wheels are in a straight-line state.

In the above explanation, the solenoid valve 17 is an on-off type so-called solenoid on-off valve, but the solenoid control valve is used to control the output ports A and B according to the magnitude of the signal input to the solenoids S1 and S2. The amount of direction change of the front wheels to the left or right may be controlled by changing the opening degree of the valve, and by doing so, the automatic tilling operation can be performed more reliably along the boundary O. It is.

In addition, although the solenoid valve 17 is used as the controller 2 to steer the front wheels,
The brakes on the rear wheels may be operated to enable steering of the front wheels and sharp turns.

In addition, even if the boundary O is formed in a straight line, rectangular with rounded corners, or curved such as a wave, the tilling operation can be performed automatically without providing any special structure. It is possible to do this.

(Effects of the Invention) As described above, the present invention has a first detector 32 having an unworked area detection element 30 that detects reflected waves of infrared rays reflected from the ground, and an existing work area detection element 31.
a second detector 33 having a
a boundary detecting device 192 that detects the boundary between the unworked area and the already worked area by comparing the output values of 2 and 33; and a controller 2 that controls the steering device based on the output signal from this detecting device 192. Because it is equipped with a simple structure that does not require any special objects to be detected in the field, it can be steered in the desired direction, automatically controlling the field at all times. Moreover, the boundary between the unworked land and the worked land is equipped with a first detector 32 having an unworked land detection element 30 that detects the reflected waves, and a first detector 32 that detects the reflected waves. Since the detection is performed by comparing each output value with the second detector 33 having the detection element 31 for the existing work area, in other words, the output value of one is used as the reference value and the output value of the other is compared. However, since the boundary is detected based on this comparison, there is no need to use a reference value setting device to set the reference value, and even if field conditions change, the reference value does not need to be changed each time. In both cases, it is possible to accurately detect boundaries with a simple configuration.

Therefore, the boundary can be detected accurately with a simple configuration, and automatic steering can be performed easily and reliably.

[Brief explanation of the drawing]

FIG. 1 is an electric circuit diagram showing an embodiment of the present invention, FIG. 2 is an explanatory diagram showing an embodiment of a steering device and a controller, and FIG. 3 is an explanatory diagram showing the relationship between a field and a detection element. FIG. 4 is a characteristic diagram showing the relationship between the output voltage of the detector and the position of the detection element. DESCRIPTION OF SYMBOLS 1... Steering device, 2... Controller, 30... Unworked area detection element, 31... Existing work area detection element, 32... First detector, 33... Second detector, 192... Border detection device, M...unworked land, N...worked land.

Claims (1)

[Claims] 1 A boundary detection device 191 that has a detector 20 that receives reflected infrared rays from the ground and emits a signal, and detects the boundary between uncultivated land and cultivated land, and this detection device 19
1. A mobile agricultural machine comprising: a controller 2 that controls a steering device according to an output signal from the controller 1.