JPH0320204B2 - - 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 in a field is automatically moved in a desired direction to perform agricultural work as appropriate, guides formed in the form of vertical walls on the side of a ridge or in the general direction of cultivation, or guides arranged at regular intervals are used. 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 crop planted in The steering device is controlled by the output.

(Problems to be Solved by the Invention) If the device is configured as described above, there is a problem that the structure becomes complicated and expensive, and foreign matter may protrude from the detected object that presses the detector, or the detected portion When a part of the wafer is missing, there is a problem in that the detection by the detector is unstable and 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, while having a simple structure, and to be able to perform agricultural work automatically and accurately without manual operation. 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 reflected waves such as infrared rays reflected from the ground differ between unworked areas and already worked areas. Unworked detection element 4 that detects reflected waves such as infrared rays
5, a second detector 43 with a detecting element 46 for the already worked area, and a third detector 44 having a detecting element 47 for the boundary between the unworked area and the already worked area. The first and second detectors 42,
43 and the output value of the third detector 44 to detect a boundary between an unworked area and an already worked area; The present invention is characterized in that it is equipped with a controller 2 that controls the steering device based on the output signal of the controller 2.

(Operation) When the average value of the output values of the first and second detectors 42, 43 and the output value of the third detector 44 are compared, and the deviation value between these average values and the output value is equal, Because it is running correctly in the desired direction,
Although the steering device is not controlled, if the deviation value becomes positive or negative, it means that the traveling direction has deviated from the desired direction toward an unworked area or an already worked area, so the steering device is not controlled. the boundary detection device 1
The machine is controlled based on the output signal of 93 and corrects the traveling direction, and this control allows the machine to travel in the desired direction correctly for work on unworked areas, especially at the border with already worked areas. 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.

This embodiment is a tiller in which a tiller is installed at the rear of an agricultural tractor to enable tilling work.
In FIG. 2, reference numeral 1 denotes a steering device in an agricultural tractor, and 2 a controller for controlling the steering device 1. In FIG.

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
The piston side chambers 8, 9 of each cylinder 3, 4 are connected to oil pipes 10, 11, and the rod side chambers 12, 13 of each cylinder 3, 4 are provided with a spring 14, both of which are exposed to the atmosphere. It was opened in . 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. still,
A steering wheel 15 is connected to the direction changer 5.

The controller 2 also includes a solenoid valve 1 with 4 ports and 3 positions.
7. It consists of a pump 18, etc., and a solenoid valve 17.
When a control signal is output to the first solenoid S1,
When the solenoid valve 17 is switched to the left symbol position and a control signal is output to the second solenoid S2 of the solenoid valve 17, the solenoid valve 17 is switched to the right symbol position. When no signal is inputted, the solenoid valve 17 is 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.
The rod 6 moves forward against the spring 14 while the rod 7 moves back into the cylinder due to the pressure of the spring 14, and the oil from the cylinder 4 is returned from the port B to the tank T. 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 position based on the neutral position.

Further, the controller 2 controls the solenoid valve 1 as described above.
In addition to controlling the steering of the front wheels based on the control unit 7, the control units 57 and 58 for the rear wheels 51 and 52 may be controlled by hydraulic cylinders 59 and 60 as shown in FIG.

That is, in FIG. 3, rods 61 and 62 of the cylinders 59 and 60 are connected to the brakes 57 and 58 of the rear wheels 51 and 52, respectively.
Oil pipes 65, 6 from the rod side chambers 63, 64 of 60
6 is also an oil pipe 6 from the piston side chambers 68 and 67.
9 and 70 are connected to each other.

When oil flows in from the oil pipes 69 and 70, the rods 61 and 62 advance as shown in FIG. When oil flows in from 65 or 66, the rod 61 or 62 moves into or out of the cylinder 59 or 60, and the rear wheel 51 or 52 is braked by the brake 57 or 58. When the left rear wheel 51 is braked, the rear wheel 51 or 52 is braked. The aircraft is steered to the right, and when the right rear wheel 52 is braked, the aircraft is steered to the left.

In this case, the oil pipes 65, 66 and 69, 7
0 is connected to the pump 18 and tank T shown in FIG. 2 via a pair of solenoid valves 49, 50, and each solenoid S
3. When a signal is input to S4 and it is excited, each electromagnetic valve 49, 50 is operated, and one of the brakes 57, 58 is operated.

That is, the solenoid valves 49 and 50 use directional switching valves with 4 ports and 2 positions, and when a signal is supplied to each solenoid S3 and S4 of each of these solenoid valves 49 and 50, ports P and A, ports B and R communicate with each other, and oil from input port P flows from output port A to rod side chamber 6 of cylinders 59 and 60.
3 and 64, the rods 61 and 62 move into and out of the cylinders 59 and 60, and each solenoid S
3. When the signal supply to S4 is stopped, ports P and B and ports A and R are connected to each other, and oil from input port P flows from output port B to cylinder 5.
The rods 61 and 62 are introduced into the piston side chambers 67 and 68 of the pistons 9 and 60, and the rods 61 and 62 move forward.
That is, when a signal is supplied to the solenoid S3 of the solenoid valve 49, the left rear wheel 51 is braked and the aircraft can be controlled in the right direction, and when a signal is supplied to the solenoid S4 of the solenoid valve 50, the right rear wheel 52 is braked. This allows the aircraft to be controlled to the left. When no signal is supplied to both solenoids S3 and S4, both rear wheels 51 and 52 are not braked and the direction of the aircraft is not controlled.

In FIG. 3, reference numerals 83 and 84 are brake pedals connected to brakes 57 and 58, respectively.

Therefore, in the tiller constructed as described above, the present invention includes a boundary detecting device 193 that detects reflected waves such as mainly infrared rays reflected from the ground to detect the boundary between unworked land and worked land. This device 193 is attached to the front of the fuselage (not shown), and the steering device 1 is controlled by the output signal from the detection device 193 via the controller 2.

As shown in FIG. 1, the boundary detection device 193 includes an unworked area detection element 4 that detects the reflected wave.
5, and a second detector 42 having an existing work area detection element 46 that also detects the reflected wave.
It is equipped with a detector 43 and a third detector 44 having a detection element 47 for the boundary between an unworked area and an already worked area, and the average value of the output values output from the first and second detectors 42 and 43. The output value from the third detector 44 is compared to detect the boundary between the unworked area and the already worked area.

That is, what is shown in FIG.
2 and the output side of the second detector 43 are connected to the average output device 85, and the output side of the average output device 85 is connected to the comparator 21.
The output side of the third detector 44 is connected to the second input part 28 of the comparator 21, and the output side of the third detector 44 is connected to the first input part 27 of the comparator 21.
At the same time, the first output 53 of the detection device 193 is connected to the first input 54 of the controller 2, and the second output 55 of the detection device 193 is connected to the second input 56 of the controller 2. The steering device 1 is configured to be controlled by the output signal from the detection device 193.

Incidentally, each of the detectors 42, 43, 44 is as shown in FIG.
Each detection element 45, 46, 47 in 3, 44
are connected in series with resistors 73, 77, 81, and this series circuit is connected in parallel with a series circuit of transistors 71, 75, 79 and resistors 74, 78, 82 to connect to a DC power supply, and Each detection element 4
5, 46, 47 and resistors 73, 77, 81 are connected to the base sides of transistors 71, 75, 79 provided corresponding to each detection element, respectively. Each detection element 4 is placed on the emitter side 72, 76, 80.
Output values corresponding to the reflected waves detected at 5, 46, and 47 are output.

Further, the detection elements 44 to 47 are configured to operate in response to infrared rays having a wavelength of approximately 6500 to 6700 angstroms. Heat detection devices such as radiant thermocouples, bolometers, Golay cells, etc. whose temperature rises due to the amount of radiated heat and characteristic values such as electrical resistance change due to the temperature rise, or lead sulfide, lead selenide, thallium sulfide, etc. Photovoltaic cells, photoconductive cells, photodiodes, and phototransistors made of germanium, silicon, etc. are used for detecting light. In Fig. 1, the detection elements 44 to 47, when exposed to infrared rays, rise in temperature and increase their electrical resistance. It uses a thermocouple that reduces the

Further, each of the detectors 44 to 47 is installed at the front of the aircraft, and as shown in FIG.
The detector 44 is located above the unworked area M, and the second detector 4
6 is located above the worked land price N, and the third detector 47 is located above the boundary O between the unworked land M and the worked land N.

It should be noted that the more water there is on the radiation surface, the higher the ratio of the amount of infrared rays contained in the emitted solar rays absorbed by the radiation surface to the radiation amount, and the larger the ratio of the amount of infrared radiation contained in the radiation surface to the radiation 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 case of When the detection elements 45 to 47 are moved from the unworked area M to the completed work area N across the boundary O, this reflectance K gradually decreases, and becomes the smallest when located on the completed work area N. be.

That is, the output values output from the emitters 72, 76, 80 of the transistors 71, 75, 79 are:
The greater the amount of infrared radiation to the detection element, the smaller the electrical resistance of the detection element, the greater the DC voltage value divided to the resistor connected in series with the detection element, and the greater the input voltage to the base of the transistor. Therefore, the detection element is moved from the unworked area M over the boundary O to the already worked area N.
When moved upward, the output value changes similar to the reflectance K as shown in FIG.

However, these first to third detectors 42, 4
3, 44 resistors 73, 74, 77, 78, 8
1 and 82 are adjustable, and each detection element 45, 46, 4 can be adjusted by adjusting each of these resistances.
Each detector 42, 4 for the amount of infrared rays input to 7
The magnifications of the outputs E ₁ , E ₂ , and E ₃ of No. 3 and 44 are made equal.

The average value E 4 of the output value E ₁ of the first detector 42 and the output value E 2 of the second detector 43 is the average value E ₄ of the output value E ₁ of the first detector 42 and the output value E 2 of the second detector 43.
The output value E3 of the third detector 44 is inputted to the second input section 28 of the comparator 21, and the output value _E3 of the third detector 44 is inputted to the second input section 28 of the comparator 21.
1, and both input values E ₄ and E ₃
The pressure value E ₅ corresponding to the difference (E ₄ - E ₃ ) is determined by the discriminator 48.
Input it into .

Then, the discriminator 48 inputs the input value to the discriminator 48.
E ₅ is the first region whose absolute value is small (-e ₁ < E ₅ < e ₁
e ₁ ≧ 0), a second region with intermediate absolute values (e ₁ < e ₂ , −e ₂ < E ₈ <−e ₁ e ₂ ≧ 0), and a third region with large absolute values (E ₈ > e ₂ , E ₈ <-e ₂ ), it is determined in which region the value of the input voltage E ₈ exists, and the output signal corresponding to the region is divided into the first and second types.
It is output from the output sections 53 and 54.

That is, the discriminator 48 outputs positive first to third output signals corresponding to the input value E ₅ being positive and being in the first to third regions, and the input voltage E ₈ being negative, The negative first area corresponds to the first to third areas.
to output a third output signal.

The positive first output signal means that the first output section 53 outputs a positive output signal and the second output section 54 does not output an output signal, and the positive second output signal means that the first output section 53 outputs a positive output signal and the second output section 54 outputs no output signal. A positive output signal is output from the second output section 54 without outputting an output signal from the output section 54, and a positive third output signal means that a positive output signal is output from the first and second output sections 53 and 54. They refer to each. The negative first output signal means that the first output section 53 outputs a negative output signal and the second output section 54 outputs a negative output signal.
Also, a negative second output signal means that the first output section 53 does not output a negative output signal, but the second output section 54 outputs a negative output signal, and a negative third output signal means that the first and second output signals do not output from the second output section 54. This refers to outputting negative output signals from the output sections 53 and 54, respectively.

However, in the tiller configured as above,
An unworked area detection element 45 is located above the unworked area M, an already worked area detection element 46 is located above the already worked area N, and a detection element 47 for the boundary between the unworked area and the already worked area The front and rear wheels 51 and 5 are positioned above the boundary O and receive equal amounts of reflected waves from both the unworked area M and the already worked area N, respectively.
In the state where the tiller 2 is maintained in the neutral direction without shifting in the left-right direction and is performing tilling operation, that is, in the reference state shown in FIG. 4, both input voltages E ₄ and E ₃ to the comparator 21 are equal. Therefore, there is no output from the comparator 21, and therefore the first and second output sections 53,
Since there is no output from 55, each solenoid valve 17, 4
None of the solenoids S ₁ to S4 9 and 50 are energized, and the steering device 1 maintains the front wheels 51 and 52 in a neutral state, thereby maintaining the above-mentioned running reference state.

When the detection device 193 moves slightly to the left from the boundary O toward the unworked area M, the amount of reflected waves to the boundary detection element 47 increases, and the output voltage E from the third detector 44 increases. ₆ becomes larger, and the comparator 21 outputs a negative output signal _E5 .

However, when the value of this output signal _E5 is small and in the first region, a negative first output signal is output from the discriminator 48, the solenoid S2 of the solenoid valve 17 is energized, and the front wheels are directed to the right. As a result, the boundary detecting element 47 is located at an intermediate position on the boundary O, and a reference state is established in which the aircraft body is again held in a neutral direction without moving in the left-right direction. Further, when the value of the output signal _E5 is an intermediate value and is in the second region, a negative second output signal is output from the discriminator 48, the solenoid S3 of the solenoid valve 49 is energized, and the left rear wheel 51 is braked. As a result, the boundary detecting element 47 is located at an intermediate position on the boundary O, and the aircraft is controlled so as to return to the neutral direction and return to the reference state. Further, when the value of the output signal _E5 is large and in the third region, a negative third output signal is output from the discriminator 48, and both the solenoid S2 of the solenoid valve 17 and the solenoid S3 of the solenoid valve 49 are excited. The front wheels are controlled to the right, and the left rear wheel 51 is braked to control the direction of the aircraft to the right.
1 both control the direction of the aircraft to the right, the boundary detection element 47 is quickly returned to the intermediate position on the boundary O, and the aircraft returns to the center again.

Furthermore, when the detection device 193 moves to the right from above the boundary O toward the already worked area N, the amount of reflected waves to the boundary detection element 47 decreases, and the amount of reflected waves to the third detector 44 decreases.
The output voltage E ₃ from the comparator 21 becomes smaller and the positive output signal E ₅ from the comparator 21 is output.

And depending on the magnitude of this output signal E ₅ ,
That is, in response to this output signal E ₅ outputting positive values in the first to third regions, the discriminator 48 outputs positive first to third output signals, respectively, and the solenoid S1 of the solenoid valve 17 respectively outputs positive first to third output signals. Only the solenoid S4 of the solenoid valve 48 and the solenoids S1 and S4 of both the solenoid valves 17 and 48 are excited, respectively, to control the left direction of the front wheel, control the left direction of the aircraft by braking the right rear wheel 52, and control the front wheel and the right The leftward control of the aircraft body is performed by both the rear wheels 52, and the leftward control of the aircraft body can be performed in accordance with the magnitude of the output signal _E5 .

As described above, according to this embodiment, when the aircraft moves slightly left or right, steering control is performed only by changing the direction of the front wheels, and when the aircraft moves slightly left or right, one side is controlled. The aircraft is steered and braked by braking the rear wheels, and furthermore, when the aircraft swings significantly from side to side, automatic steering control is performed by braking the front wheels and one of the rear wheels, ensuring that the aircraft always moves in the desired direction. It can be operated reliably and stably.

Further, in addition to the case where the boundary O is formed in a straight line, even if the boundary O is formed in a circular shape, a rectangular shape with rounded corners, a curved shape such as a wavy shape, it can be cultivated automatically without providing any special structure. It is possible to drive.

(Effects of the Invention) As described above, the present invention provides an unworked area detection element 4 that detects reflected waves such as infrared rays reflected from the ground.
5, a second detector 43 with a detecting element 46 for the already worked area, and a third detector 44 having a detecting element 47 for the boundary between the unworked area and the already worked area. The first and second detectors 42,
A boundary detection device 193 that detects a boundary between an unworked area and a worked area by comparing the average value of the output values outputted from the third detector 43 with the output value of the third detector 44; Since the present invention is characterized in that it is equipped with a controller 2 that controls the steering device using the output signal of the The field can be cultivated automatically and reliably at all times in the same direction, and in addition, the boundary between the unworked land and the worked land is a first detection element with an unworked land detection element 45 that detects reflected waves. 42, the average value of the output values output from the second detector 43 having the detection element 46 for the existing work area, and the third detector 4 having the detection element 47 for the boundary.
Since this is done by comparing the output value of 4, the boundary can be detected accurately with a simple configuration, and thus automatic steering can be performed 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 an embodiment of a brake machine and a controller. FIG. 4 is an explanatory diagram showing the relationship between the field and the detection element, and FIG. 5 is a characteristic diagram showing the relationship between the output voltage of the detector and the position of the detection element. 1... Steering device, 2... Controller, 42... First
Detector, 43... Second detector, 44... Third detector, 45... Unworked area detection element, 46... Existing work area detection element, 47... Border detection element, 19
3... Boundary detection device, M... Unworked area, N... Already worked area.

Claims (1)

[Claims] 1 A first detector 42 having an unworked area detection element 45 that detects reflected waves such as infrared rays reflected from the ground, and a second detector 42 having an existing work area detection element 46.
It is equipped with a detector 43 and a third detector 44 having a detection element 47 for the boundary between the unworked area and the already worked area, and the average value of the output values output from the first and second detectors 42 and 43. and the output value of the third detector 44 to detect a boundary between an unworked area and an already worked area, and a steering device is controlled by the output signal from this detection device 193. A mobile agricultural machine characterized by comprising: a controller 2 for controlling a vehicle;