JPH023682Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an automatic steering device installed in a transplanting machine such as a rice transplanter. More specifically, the present invention relates to an automatic steering device that is installed in a transplanting machine such as a rice transplanter. This paper proposes an automatic steering system for transplanted aircraft that not only improves the accuracy of automatic steering by detecting the current situation, but also has excellent economic efficiency.

The present invention will be specifically described below based on drawings showing embodiments thereof. Fig. 1 is a left side view of a riding rice transplanter equipped with an automatic steering device according to the present invention (hereinafter referred to as the proposed device), and Fig. 2 is an electronic circuit diagram of its main parts. Part fuselage F and rear fuselage R
The steering wheel 101 has a bent-body structure that horizontally rotates the steering wheel 101 about its connecting axis, and the steering can be performed manually by rotating the steering wheel 101 or automatically by the device of the present invention. That is, as shown in FIG. 2, a part of the drag rod 102' interposed between the rear fuselage R and the pitman arm 102, which is rotated back and forth by the rotation of the steering wheel 101, is connected to a double-acting hydraulic cylinder 92. During manual steering, the supply and discharge of pressure oil is prohibited and the operation of the steering wheel 101 is controlled from the rear fuselage R.
and by energizing the solenoid 91l or 91r of the solenoid valve 91 during automatic steering.
The pressure oil flow path of the hydraulic circuit (not shown) is switched and the hydraulic cylinder 92 is operated to convert the rear fuselage R to the front fuselage F.
The steering wheel is configured to be rotated relative to the steering wheel to perform steering to the left or right.

Steering sensors 30l and 30r are attached to the left and right sides of the bumper 103' of the planting section 103, respectively. Left and right steering sensors 30l, 30r
have the same structure, one steering sensor 30l
Or 30r uses two light emitting diodes 35l or 35r, 36 or 36r and one photodiode 37l or 37r as the light emitting and light receiving elements, respectively, and the two light emitting diodes 35l or 35r, 3
6l or 36r are arranged on the upper left and right respectively, and both light emitting diodes 35l or 35r, 36l or 36
Photodiode 37l or 37 below the center of r
r, with each emitter and light receiving surface facing the front of the aircraft,
One converging lens is placed in front of both the light emitting diodes 35l or 35r, 36l or 36r, and one converging lens is placed in front of the photodiode 37l or 37r. The projected light emitted from each light emitting diode 35l or 35r, 36l or 36r is reflected by the seedlings Z constituting the row of already planted seedlings closest to the aircraft, and the reflected light is captured by the photodiode 37l or 37r. There is. Figure 3 shows each light emitting diode 35l or 35
FIG. 4 is a plan view showing the light-receiving area of the photodiode 37l or 37r, respectively. , 36l or 36r, and conversely, the light emitting area b of the right light emitting diode 36l or 36r is on the left. Also photodiode 37l or 3
The light receiving area c of 7r is the photodiode 37l.
Or they are evenly spaced on the left and right sides of the front of 37r.

The sensor box 301l or 301r of the steering sensor 30l or 30r is attached to a mounting rod 302l or 302 which is erected on the left or right side of the bumper 103'.
02r is installed with the light emitting/receiving surface tilted forward so as to reliably detect the reflected light after the projected light is reflected from the already planted seedlings Z located approximately 1.5 m in front of the bumper 103'. ing. Also, each mounting rod 302l on the left and right side of the bumper 103',
Slightly inside the fuselage from 302r, side markers 8l and 8r, which serve as steering targets during alignment, are provided to protrude forward.

Now, as shown in Fig. 2, a key switch 3 is connected to the positive terminal of the battery 31, one end of which is grounded to the body.
Pulse oscillators 33 and 34 are connected through 2, and the output of each pulse oscillator 33 and 34 is given to light emitting diodes 35l, 35r, 36l and 36r, respectively. Each light emitting diode 35l, 35r,
36l, 36r are photodiodes 37l, 3
Each light emitting diode (35l) is designed so that the 7r can be distinguished from sunlight or illumination light (120 or 100Hz).
Alternatively, it is modulated and driven with pulses of 9.8 kHz and 14 kHz, respectively, so that the light emitted by 35r, 36l, or 36r can be discriminated.

Light emitting diode 35l or 35r, 36l or 3
The light emitted from 6r is reflected by the already planted seedlings z,
The light is received by a photodiode 37l or 37r whose cathode is connected to a terminal 10 that outputs a reference potential of 6.4V of a comparator 20, which will be described later. From photodiode 37l or 37r,
An output current corresponding to the amount of incident light is obtained, and each output current is sent to the AC amplifier circuit 4 via a buffer amplifier 38.
1, is amplified by the AC amplifier circuit 41, and is output to bandpass filters 43 and 44.
Each bandpass filter 43, 44 passes only frequencies within a predetermined range centered around the frequencies of 9.8kHz and 14kHz of the modulated light emitted by each light emitting diode 35l or 35r, 36l or 36r, and each output has a peak value. each peak hold circuit 45, 46.
1/2 of the reference potential of the window comparator 20 at
That is, with the potential of 6.4/2V (=3.2V) as a reference, a potential corresponding to the amount of received light is obtained. The outputs of both peak hold circuits 46 and 47 are added together and input to a DC amplifier circuit 51. The DC amplifier circuit 51
Then, a potential difference V ₅₁ with respect to the reference potential of 3.2V is obtained and outputted to the input terminal 8 to which a voltage defining the midpoint of the window of the window comparator 20 to be described later is to be applied. Therefore, the terminal 8 of the window comparator 20 has the amount of reflected light from the planted seedlings captured by the photodiode 37l or 37r, and the amount of reflected light of 9.8 kHz emitted by the light emitting diode 35l or 35r whose projection area is on the left side. 14k emitted by a light emitting diode 36l or 36r whose projection area is on the right side
A signal having information related to the difference between the amount of reflected light and the amount of reflected light in Hz is input.

Furthermore, the outputs of the peak hold circuits 45 and 46 are the +inputs of the comparators 52 and 53, respectively, and one input terminal of each comparator 52 and 53 is connected between the terminal 10 of the window comparator 20 to be described later and the body ground. The connection point between the 4.3 kΩ resistor R ₁ and the 5.1 kΩ resistor R ₂ inserted in the 4.3 kΩ resistor R ₃ and the 5.1 kΩ resistor
_R4 , and each comparator 52,
It is one input of 53. Comparators 52, 53
outputs a high level signal when its + input becomes larger than its - input, and the respective high level outputs are given to switch circuits 54 and 55, respectively, to turn them on and turn on the side marker. 8l, 8
Lamps 56l, 57l, 56 provided in each r
Turn on r and 57r, respectively. Also, comparators 52, 5
The anodes of diodes 58 and 59 are connected to the output terminal of 3, respectively, and the connection point between the two cathodes is connected to the negative input terminal of the comparator 61. An electrolytic capacitor 62 connected to the positive line of the battery 31 is connected to the negative input terminal of the comparator 61, and is also grounded to the body through a series circuit of a resistor _R5 and a variable resistor _R6 for setting a time constant. Comparator 6
The + input terminal of No. 1 is connected to the connection point between the resistors R ₁ and R ₂ mentioned above, and is connected to the connection point of the resistors R 1 and R 2 described above.
1/2 of the reference potential output from terminal 10 of 0 (=
3.2V) is input.
The output terminal of the comparator 61 is connected via a resistor to the base of a transistor 63 whose emitter is grounded to the body, and the collector of this transistor is connected to the base of a transistor 73 whose emitter is grounded to the body, as will be described later. It is connected to diodes 71 and 72, which are connected to terminals 4 and 12 of the window comparator, respectively, and a limit switch 68. The collector of the transistor 73 is connected to the diodes 71 and 7 via the buzzer 64.
2 and limit switch 68.

The window comparator 20 is a semiconductor device that discriminates a changing input voltage by comparing it with two freely settable comparison reference voltages, and in this embodiment, TCA965 manufactured by Siemens is used.

In the figure, reference numeral 11 denotes a power supply terminal, which is connected to the positive terminal of a battery 31 via a switch 32 which is to be closed when automatic steering is selected. The terminal 10 of the window comparator 20 is connected to the ground terminal 1 when a predetermined voltage is applied to the power supply terminal 11.
This is a terminal that emits a constant voltage of 6.4V as the aforementioned reference potential, and in addition to being connected as described above, it is also connected to one end of the steering sensor 69. The steering sensor 69 is composed of a potentiometer connected to a rod of a hydraulic cylinder 92, and the other end is grounded via a resistor. The output voltage V ₆₉ of the steering sensor ₆₉ changes depending on the advance and retreat positions of the rod of the hydraulic cylinder 92, and becomes a signal representing the steering angle. , 7. The steering sensor 69 indicates that the steering angle is 0 degrees (the aircraft is moving straight).
It is set so that V ₆₉ =3.2V (=6.4/2V) when the voltage is . It is also connected to the rod of the hydraulic cylinder so that when the steering is steered to the left, the _V69 increases, and conversely, when the steering is steered to the right, the _V69 decreases.

As shown in FIG. 5, the terminal 8 of the window comparator 20 is an input terminal to which a voltage defining the midpoint of the window should be applied, and is connected to the output terminal of the DC amplifier circuit 51, so that the potential V ₅₁ is applied to the terminal. 8
given to.

The aforementioned terminal 10 is also connected to a fixed resistor R ₇ of 9.1 kΩ.
It is grounded through a series circuit with a variable resistor R ₈ of 1 kΩ, and the intermediate terminal potential of the variable resistor R ₈ is applied to the terminal 9 of the window comparator 20 . terminal 9
The input voltage V ₉ to defines the 1/2 width of the window as shown in FIG.

Terminals 4 and 12 are terminals that inhibit the output operation of the window comparator 20 when set to ground potential, and terminals 4 and 12 are connected to diodes 71 and 12, respectively.
It is connected to the connection point between the input terminal of the transistor 63 and the output terminal of the comparator 61 via the transistor 72, and to the collector of the transistor 63 and the buzzer 64 via the resistor as described above.

Terminals 2 and 14 are the output terminals of the window comparator 20, and are connected to drive circuits 19r and 19l each formed by connecting two transistors in Darlington connection, and when the respective outputs become low level, solenoids 91r and 91l are activated. It is designed to be each excited.

Between the positive electrode line that is opened and closed by the switch 32 and the body ground, there is connected in parallel a series circuit consisting of an automatic selection lamp 65, which indicates the closing of the switch 32 by its lighting, a normally open limit switch contact 66, and a straight ahead indicator lamp 67. It is connected. This limit switch is placed facing the rotation range of the pitman arm 102, and its normally open contact 66 closes in a narrow rotation angle range (about 1 degree) of the pitman arm when the aircraft is traveling approximately straight. However, the fact that the aircraft is traveling substantially straight is reported by lighting the straight ahead indicator lamp 67. Further, the positive electrode line is connected to a buzzer 64 via a limit switch 68. The limit switch 68 is disposed near the steering wheel 101, and is configured to close when the steering wheel 101 is moved forward as in the case of seedling succession.

Next, the operation of the window comparator 20 will be briefly explained based on FIG.

Figure 5 A and B are binary outputs of terminals 2 and 14, respectively.
V ₂ and V ₁₄ are shown with V ₆₉ taken on the horizontal axis.
V ₁₄ is low level when V ₆₉ < V ₅₁ − V ₉ , V ₆₉ > V ₅₁ −
High level at V ₉ , and V ₂ is V ₆₉ < V ₅₁ + V ₉
It becomes high level when V ₆₉ > V ₅₁ + V ₉ , and becomes low level when V 69 > V 51 + V 9. The range from V ₅₁ −V ₉ to V ₅₁ +V ₉ is called a window, with V ₅₁ defining the midpoint and V ₉ defining 1/2 of the width. In the proposed device, 1/2 width is specified.
_V9 is fixed at an appropriately set value by variable resistor _R8 , but _V51 changes depending on the relative position between the aircraft and the planted seedlings Z, and _V69 also changes depending on the steering state. In other words, depending on the relative positional relationship between the planted seedlings and the aircraft and the steering condition, V ₂ or V ₁₄ becomes low level and solenoid 91r or 91l is energized, resulting in steering to the right or left. Become. And if V ₆₉ is within the window, that is V ₅₁ −V ₉
~V ₅₁ +V ₉ , steering is not performed as a dead zone for steering control.

The window midpoint, ie, _V51 , has a meaning as information representing the relative position between the planted seedlings and the aircraft body, which will be explained below.

The light emitted from the light emitting diode 35l or 35r, 36l or 36r is reflected by the already planted seedlings Z and received by the photodiode 37l or 37r. 35l light emitting diode located
Or the light emitting area of 36l is both light emitting diodes 35
It is closer to the right (or left) of the center front of 1, 36l. Further, the light receiving area of the photodiode 38l is equally spaced left and right from the center of both the light emitting diodes 35l and 36l. When the currently planted seedling Z is located in front of the center of both the light emitting diodes 35l and 36l, the photodiode 37l receives equally the light emitted from each of the light emitting diodes 35l and 36l and reflected by the already planted seedling. At this time, each bandpass filter 43, 44 passes the light captured by the photodiode 37l to a light emitting diode 35, respectively.
Frequency of modulated light emitted by l, 36l: 9.8kHz, 14k
The peak hold circuits 46 and 47 divide the light into light in the vicinity of Hz, and output a potential corresponding to the amount of light that has passed through each bandpass filter 43 and 44 with 3.2V as a reference, so that the photodiode 37l is connected to each light emitting diode 35l, If it is emitted from 36l and receives the reflected light from the already planted seedlings equally,
The output potential V ₅₁ of the DC amplifier circuit 51 is 3.2V (=6.4/
2V). Regarding the left sensor 30l, the planted seedlings Z are deviated to the left (or right) side of the machine from the center front of both light emitting diodes 35l and 36l (i.e. the machine is deviated to the right (or left) from the row of already planted seedlings). When the photodiode 37l is located on the right (or left) side, the photodiode 37l is the light emitting diode 36l located on the right (or left) side.
Or, more of the light emitted by 35l and reflected by the already planted seedlings will be received, and the potential V ₅₁ will become higher (or lower) in proportion to the amount of deviation. The same applies to the right steering sensor 30r.

Therefore, V ₅₁ is in an ideal running situation at 3.2V,
If it is larger than this, the aircraft is moving away from the row of already planted seedlings, and the sensor on the left (or right) side is 30l or 30l.
Looking at r, the situation is that the seedlings have shifted to the right (or left) from the planted seedlings. (or right) side sensor 30
When looking at l or 30r, it is in a situation where it deviates to the left (or right) from the row of already planted seedlings, and the smaller the value, the greater the deviation.

In this way, V ₅₁ includes information indicating the position of the aircraft relative to the row of already planted seedlings, but there is a limit to the detection range of the steering sensor 30l or 30r. However, as described below, the aircraft was moving straight when switching to automatic steering.
Moreover, as long as the operation is performed under the condition that the seedling Z is detected by the sensor, the steering control will not become uncontrollable.

The device of the present invention having such a configuration is used and operates as follows. That is, automatic steering becomes possible after one or more rows of planting are completed and a row of already planted seedlings is formed. If the row of planted seedlings is currently on the left side of the aircraft, the steering wheel 10 is moved so that the steering sensor 30l on the left side follows the row of planted seedlings.
When the automatic steering selection switch 32 is closed while performing manual steering according to step 1, the automatic lamp 65 lights up.

When the photodiode 37l of the steering sensor 30l captures the light emitted from the light emitting diode 35l or 36l and reflected by the already planted seedlings, the output of the peak hold circuit 45 or 46 becomes a potential corresponding to the amount of light received, and this When the voltage becomes higher than the negative input of the comparator 52 or 53, a high level signal is output to the switch circuit 54 or 55 to turn it on, and the lamps 56 attached to the side markers 8l and 8r are turned on.
l or 57l, 56r or 57r lights up.

Therefore, when manually steering the aircraft to follow the row of planted seedlings, if the row of planted seedlings is on the left (or right) side of the aircraft, the driver should use the side marker 8l or 8r on the left (or right) side. All you have to do is to steer while looking at it, and when the steering sensor 30l or 30r detects a planted seedling, the side marker 8l or 8r will turn on the lamp 56.
Since light is emitted when either 1, 57l or 56, 57r is lit, the driver can easily know that it is now possible to shift to automatic steering.

Under these circumstances, when the aircraft is able to travel straight, the limit switch 66 is turned on and the straight travel indicator lamp 67 lights up. The driver now knows that it is now possible to switch to automatic steering, and more precisely, the aircraft is now in a state where it can safely switch to automatic steering without the aircraft traveling in an unexpected direction. I realized that I was getting older, and at this point the steering wheel was 10.
Move 1 forward. Then, the limit switch 68 is turned on, and if a row of already planted seedlings exists on the left side, automatic steering is performed by the steering sensor 30l.

Then, for some reason, the aircraft moves to the right (or left).
When the light emitting diode 3 on the left (or right) side
The amount of light received by the photodiode 37l of the reflected light emitted by 5l or 36l and reflected by the already planted seedlings is emitted by the right (or left) side light emitting diode 36l or 35l and reflected by the already planted seedlings. The amount of light received by the reflected light is greater than that captured by the photodiode 37l, and the DC amplifier circuit 5
1's output potential V ₅₁ becomes larger (or smaller) than 3.2 V, and the window moves to the high (or low) voltage side. Output potential of steering sensor 69 V ₆₉
Since the limit switch 66 was turned on and switched to automatic steering, it is 3.2V (straight ahead) or a value close to this, but by moving the window to the high voltage side (or low voltage side), it is V ₁₄ or V ₂ becomes low level and the solenoid 91l or 91r is energized, and as a result, the machine corrects its traveling direction to the left (or right), and the machine returns to the state of following the already planted seedling row. This operation is the same when the aircraft has deviated significantly to the right (or left), but in this case, the amount of movement of the window toward the high (or low) voltage side is large, so the temporary control Even if the output of the sensor 69 is slightly higher (or lower) than 3.2V, that is, even if the direction is being corrected to the left (or right), V ₁₄ or V ₂ will not be the same. When the level becomes low, the solenoid 91l or 91r is energized, and the hydraulic cylinder 92 is operated to increase the amount of leftward (or rightward) steering and quickly return to the straight traveling state.

Steering sensor 3 on the left (or right) side like this
While the steering control by 0l or 30r is being performed, the other steering sensor 30r or 30l is connected to the light-emitting diodes 35r, 36 of the right (or left) sensor 30r or 30l because there are no already planted seedlings.
The photodiode 37r located below captures the light emitted by r or 35l and 36l and reflected by the already planted seedlings.
Therefore, the light captured by the photodiode 37l or 37r of the left (or right) steering sensor 30l or 30r is passed through the bandpass filters 43 and 44 to the left (or right) sensor 30l. Alternatively, the light emitted by the light emitting diodes 35l, 36l or 35r, 36r of 30r is only the light reflected by the already planted seedlings, and there is no problem with automatic steering regardless of whether the left or right side is used as a reference.

Furthermore, in the present device, when the photodiode 37l or 37r cannot capture the reflected light from the already planted seedlings, for example, when the aircraft reaches a headland, the photodiode 37l or 37r
If the state in which the light emitted from 5l or 35r, 36l or 36r and reflected by the already planted seedlings cannot be detected continues for a predetermined period of time or more, an alarm is issued. That is, the + inputs of the comparators 52 and 53 become low potential, and the outputs of the comparators 52 and 53 become low level. Then, the capacitor 62 starts discharging, and when this low level time continues for a time determined by the capacitor 62, resistor _R5 , and variable resistor _R6 , the output of the comparator 61 becomes low level, and the transistor 63 is turned off. 7
3 is turned on and the buzzer 64 sounds. In addition, when the transistor 63 is turned off, the terminals 4 and 12 of the window comparator 20 become ground potential, and the window comparator 20 becomes prohibited from outputting, which may cause the aircraft to run onto a ridge or the like or travel in an unexpected direction. disappears.

In the present device, the relative position between the planted seedlings and the machine body can be detected in an analog manner, so it has a simple structure and is hardly affected by noise. Furthermore, since it uses modulated light to capture the reflected light from the already planted seedlings,
It is possible to detect already planted seedlings located far from the aircraft without being affected by external light, and by using the already planted seedlings as a guide for automatic steering, the planting can be done with almost no risk of hunting. The attached locus can be made substantially constant. It is also economical because it is only necessary to use one expensive photodiode as a light-receiving element, one each on the left and right sides of the fuselage. Since multiple light emitting elements are installed and their projection areas are different on the left and right, the monitoring area is wide, reducing the chance of losing sight of the already planted seedlings that are imitating the steering, and improving the stability and accuracy of steering control. Increase. Note that three or more light emitting diodes as light emitting elements may be provided on each of the left and right sides of the aircraft body. In this case, the light emitting area is expanded and more precise steering becomes possible.

As described in detail above, the present invention is an automatic steering system for a transplanter that detects the relative positional relationship between the already planted seedlings and the machine body and causes the machine to travel along the rows of already planted seedlings. The light emitting elements emit different modulated lights, and the projection areas are different on the left and right. A light receiving element receives the reflected light from the planted seedlings, and a light receiving element receives the reflected light from the planted seedlings. It is equipped with a means for detecting the difference in the amount of light received, and is configured to determine the relative positional relationship between the planted seedlings and the aircraft based on the detection results, so it not only improves the accuracy of automatic steering but also has excellent economic efficiency. It has a great effect.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention.
The figure is a left side view of a riding rice transplanter equipped with the proposed device, Figure 2 is its main electronic circuit diagram, Figure 3 is a plan view showing the light emitting area of the light emitting diode, and Figure 4 is the light receiving area of the photodiode. A plan view showing the area, and FIGS. 5A and 5B are explanatory diagrams of the operation of the window comparator. 20...Window comparator, 30l, 30
r... Steering sensor, 33, 34... Pulse oscillator, 35l, 35r, 36l, 36r... Light emitting diode, 37l, 37r... Photo diode, 41... AC amplifier circuit, 43, 44... Band pass filter , 45, 46... Peak hold circuit, 51... DC amplifier circuit, 52, 53, 61
... Comparator, 64 ... Buzzer, 69 ... Steering sensor, 91l, 91r ... Solenoid, 92 ... Hydraulic cylinder.

Claims (1)

[Scope of utility model registration request] The automatic steering device of the transplanter, which detects the relative positional relationship between the planted seedlings and the machine body and causes the machine to travel along the rows of already planted seedlings, emits different modulated lights and has multiple projection areas with different left and right projections. A light-emitting element, a light-receiving element that receives the reflected light from the planted seedlings of the light emitted by each light-emitting element, and a means for detecting the difference in the amount of received reflected light, and based on the detection result, the planted seedlings are detected. An automatic steering device for a transplanted aircraft, characterized in that it is configured to capture the relative positional relationship between the aircraft and the aircraft.