JPH0750904A - Electromagnetic induction signal generator for automated vehicles - Google Patents

Abstract

(57) [Abstract] [Purpose] The length of the guide path for guiding a traveling vehicle by the AC magnetic field generated from the induction cable 27 can be increased without increasing the output value from the electromagnetic induction signal generator 150. To do. An electromagnetic induction signal generator 150 for supplying an alternating current to an induction cable 27 for generating a predetermined alternating magnetic field.
At the output side of the constant current output circuit 154, a capacitor 158 having a predetermined electric capacity is provided so as to be connected in series to the induction cable 27. As a result, the component of the capacitor 158 cancels out the decrease in the apparent electric resistance value due to the inductance (coil component) that is always generated when the induction cable 27 is laid along the zigzag work path. You can

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is for supplying a predetermined alternating current to an induction cable for guiding an automatic traveling vehicle such as an automatic traveling type chemical sprayer (speed sprayer) in an orchard. The present invention relates to an electromagnetic induction signal generator.

[0002]

2. Description of the Related Art Conventionally, in an automatic traveling type chemical spraying machine (speed sprayer) or the like in an orchard or the like, when an operator executes a chemical spraying work while riding on a traveling vehicle,
Considering that an operator may be exposed to a drug and may be harmful to health, the drug is sprayed while the traveling vehicle is unmanned. in this case,
As shown in FIG. 7A, an alternating current is applied to the induction cable 27 embedded in the groove CH provided along the work route (induction route) SK to change the intensity of the alternating magnetic field generated from the induction cable. Detected by magnetic sensors La and Lb such as a pair of left and right pickup coils mounted on the front part of the traveling vehicle 1, as shown in FIG.
The lateral deviation amount (deviation amount) and lateral deviation of the lateral deviation of the traveling vehicle by taking the difference between the output values (voltage values) e of the pair of left and right magnetic sensors La and Lb generated corresponding to the lateral deviation magnitude m of the traveling vehicle. The direction (right or left discrimination) is obtained, and the steering control is performed by changing the direction of the steered wheels of the traveling vehicle so that the traveling vehicle travels along the guide cable from these detection results, and the work of spraying the drug is performed. Is also performed (see Japanese Utility Model Laid-Open No. 2-84909).

[0003]

In this case, as shown in FIG. 8, the guide cables 27 are arranged in a meandering shape in plan view along the work route in the orchard site, and the guide cables 2
The electromagnetic induction signal generator 150 is connected to both ends of the electromagnetic wave generator 7, and a predetermined sine wave or other alternating current is supplied to the induction cable 27 to generate the above-mentioned alternating magnetic field.

However, when the induction cable 27 is arranged in parallel at a relatively short distance in plan view, a coil component (inductance) L is included in addition to a pure resistance component R due to the entire length of the induction cable 27. If this is regarded as an RL series circuit, the apparent resistance value increases. This is called impedance Z in AC electric theory, and Z = √ [R ² + (ωL) ² ].

Therefore, when the apparent resistance value is increased by the induction cable thus laid in the working path,
In the electromagnetic induction signal generator 150, it is necessary to supply an output (current) corresponding to it, but if the shape of the work path in plan view is changed, the apparent resistance value increases, which causes fluctuation. The electromagnetic induction signal generator 150 having a margin of output for one minute must be provided.

On the contrary, for the electromagnetic induction signal generator 150 having only a predetermined output value, there is a problem that it can be applied only to a work path (induction cable) having a length shorter than that of an induction cable having pure resistance. there were. An object of the present invention is to solve this problem and to provide an electromagnetic induction signal generator capable of lengthening the work path while maintaining a predetermined output.

[0007]

In order to achieve this object, an electromagnetic induction signal generator for an automatic vehicle according to the present invention comprises:
To automatically steer the vehicle automatically along the induction cable, the output of the output circuit of the electromagnetic induction signal generator that supplies an alternating current to the induction cable to generate a predetermined AC magnetic field has a predetermined capacitance. The capacitor is provided so as to be connected in series to the induction cable.

[0008]

EXAMPLE Next, an example in which the present invention is applied to an automatic traveling type chemical sprayer (speed sprayer) will be described. The speed sprayer has a driving operation unit 2 provided with a handle 3 on the front side of a traveling vehicle 1. The traveling vehicle 1 has a chemical liquid tank 4
And a spraying part 5 at the rear part.

The spray unit 5 is provided with a large number of spray nozzles 6 facing the outer peripheral surface of the traveling vehicle 1 except the lower surface thereof at an appropriate interval toward the radial outside, and a blower 7 for sending the air outward to the radius.
The spray nozzle 6 can be spray-controlled so as to perform spraying work in each of the three sections on the left and right and the upper surface of the traveling vehicle 1 or the two sections on the left and right. Reference numerals 8 and 8 are left and right front wheels,
Reference numerals 9 and 9 denote left and right rear wheels, and these four wheels are of a so-called four-wheel drive type in which power from the engine 10 is transmitted via the traveling speed change mechanism 11 to be driven.
The power from 0 drives the blower 7 via the PTO output speed change transmission mechanism 12 and drives the dynamic injection pump 13 for the spray nozzle 6.

The steering device 14 with the steering wheel 3 is a power steering mechanism 15 including a mechanical or hydraulic system as shown in FIG. 3. The power steering mechanism 15 is a double-acting hydraulic cylinder 17 in a hydraulic circuit 16. When actuated and the hydraulic cylinder 17 extends, the rear wheels 9, 9 are turned to the left through the bell crank 18 having a W-shape in plan view, and the connecting rod 19 and the bell crank 20 having a V-shape in plan view are used. The front wheels 8 and 8 are changed to the right (when the hydraulic cylinder 17 is contracted, the front wheels are changed to the left and the rear wheels are changed to the right). It is a wheel steering type.

The hydraulic circuit 16 is shown in FIG.
Is an electromagnetic solenoid type control valve for the hydraulic cylinder 17 for automatic steering. Reference numeral 29 is an electromagnetic solenoid type control valve for controlling the hydraulic cylinder 30 as an actuator for operating the traveling clutch and the brake.
Is a control valve used in the case of manual steering operation. The control valves 29 and 28 are connected to a hydraulic pipe 31 branched from an upstream side of the control valve 23 for manual steering when hydraulic oil is fed from the hydraulic pump 22, and further, control valves for running clutch and brake operation. 29 is connected in series so as to be located upstream of the control valve 28 for automatic steering.

Therefore, when the control valve 29 is operated to a position other than the neutral position in order to operate the traveling clutch and the brake, the hydraulic cylinder 30 is preferentially operated, and the operation of the hydraulic cylinder 17 for steering is secondary. To be the target.
During manual steering, the oil sent from the hydraulic pump 22 is sent to the hydraulic motor 21 via the control valve 23 so that the amount of oil sent from the hydraulic motor 21 is proportional to the turning angle of the handle 3. And sends this oil to a double-acting hydraulic cylinder 17 attached to the steering mechanism 15. During automatic steering control, hydraulic fluid is sent from the hydraulic pump 22 to the hydraulic cylinder 17 via the neutral position of the control valve 29 and the electromagnetic solenoid type control valve 28.

Reference numeral 25 is a steering angle sensor such as a potentiometer capable of detecting the steering angle of the front wheels 8. In this case, the average of the orientation angles of the left and right wheels may be obtained and detected. The front wheels and the rear wheels may be connected via separate hydraulic cylinder power steering mechanisms so that the front wheels and the rear wheels can be individually steered. On the lower surface of the traveling vehicle 1, a pair of left and right magnetic sensors 26a, 26
b is provided. The magnetic sensors 26a and 26b may be pickup coils in which conductors are wound in a coil shape, or may be Hall elements, Hall ICs, magnetoresistive elements, or magnetic transistors. By the sine wave alternating current of an appropriate frequency (1.5 kHz in the embodiment) supplied to the induction cable 27 at
The strength of the AC magnetic field generated around the induction cable 27 can be detected. Induction cable 27
Will be laid in the trench formed along the guide route, which is the working route of the orchard, or will be buried underground.

FIG. 5 shows an embodiment of the spray section 5, in which the liquid chemical from the chemical liquid tank 4 enters the dynamic injection pump 13 via the tank drain valve 32 and the filter 33, and passes through the main valve 34 and the pipe 35. Left and right and center (upper) from the chemical liquid distributor 36
To spray the spray nozzle 6 in each direction through the switching valves 37, 38, 39 of the switching valves 37, 38, 39.
The switching operation motors 37a, 38a, 39a are provided in, and it is possible to select spraying the chemical liquid only in a predetermined direction depending on the positional relationship between the traveling direction of the traveling vehicle and the object to be scattered (tree). Reference numeral 40 is a pressure regulating valve, and reference numeral 41.
Is a stop valve connected to the correction spray discharge pipe 42,
A hose (not shown) is connected to the tip of the pipe 42, and a tree that has not been sprayed with the chemical solution is manually sprayed.

When a key is inserted into a key switch (not shown) provided on the operation panel of the driving operation unit 2 at the time of starting and rotated by a predetermined angle, the control device 100 described later stands up (starts up) and prepares for execution. It becomes a state (standby state). Then, when further rotated by a predetermined angle, the starter motor is activated to operate the engine. As the automatic mode setting switch 46, an alternate push button switch is used as an example. Therefore, the pressed state (ON state) is held by the first pressing. When the automatic mode setting switch 46 is pressed again, the protruding state (OFF state) is restored. The display unit including a liquid crystal display element displays the current control status and instructions for the operator in characters or figures. Reference numeral 49 is a shift switch for the operator to separately confirm his / her intention, and the push button switch portion is covered with a transparent openable / closable cover body. Press. As will be described later, switching from the automatic mode to the manual mode, and conversely, switching from the manual mode to the automatic mode, in addition to the operation of the automatic mode setting switch 46, the shift switch based on a clear intention of the operator. 49
Or the detection signal of the switch that operates based on the operation performed under the clear intention of the operator (for example, the depression operation of the traveling clutch petal),
The purpose is to enable mode switching.

When the automatic mode is set,
The automatic mode lamp 47 is turned on, and when the manual mode is set, the automatic mode lamp 47 is turned off. FIG. 6 is a functional block diagram of the control device 100 when the control of the traveling vehicle is executed by the software of the microcomputer, and shows two microcomputer units (MPU) 101, 102.
The two MPUs 101, 102 are connected via a coupler with a detachable communication line 103, and mutually monitor whether or not the control on the other side is normally operating. Further, each MPU 101, 102 includes a central processing unit (CPU), a readable / writable memory (RAM), a read-only memory (ROM), an interface, and the like, which are not shown. In addition, these two MPUs 101, 1
02 is formed in the same form (same component) and is replaceable with each other, and in order to distinguish both MPUs, the determination port 104 of one MPU 101 is a low port,
The discrimination port 105 of the other MPU 102 is a high port.

An operation switch (manual operation switch) 10 for switching the operation section (left side, upper side, right side) of the spray nozzle 6 is provided at the input port of one MPU 101.
6, 107 and 108 terminals and the shift switch 4
9 terminals, a fan clutch operation switch 109 terminal for disconnecting power transmission to the blower 7, and a receiver for receiving command signals from a plurality of channels (six channels in the embodiment) from a transmitter 110 for remote operation. The output signal terminal of each channel of 111 and the output terminal of the reception monitor signal, the terminals of the pair of left and right obstacle detection sensors 112a and 112b mounted on the front part of the traveling vehicle 1, and the presence or absence of the chemical solution in the chemical solution tank The output terminal of the chemical liquid sensor 113 for detecting the size (full or empty) and the terminal of the automatic mode setting switch 46 are connected to each other to input a signal.

Further, the output ports of the MPU 101 are connected to the switching operation motors 37a, 38a, 39a of the switching valves 37, 38, 39 for supplying the chemical liquid for each of the operation sections (left side, upper side, right side) of the spray nozzle 6. Terminal, an electromagnetic solenoid terminal of an electromagnetic control valve 29 for the hydraulic cylinder 30 for automatic operation of the traveling clutch and brake, a terminal of an electric cylinder 114 for operating a fan clutch for interrupting power transmission to the blower 7, and a dynamic injection pump. Signals are output by connecting the terminals of the relays 115 that permit the operation of 13 respectively.

At the input port of the other MPU 102, the terminal of the automatic mode setting switch 46, the output signal terminal of each channel of the receiver 111, and the main speed change lever of the traveling speed change mechanism 11 are in the retracted position. Is attached to the front of the front bumper of the traveling vehicle 1 to stop traveling when an obstacle comes into contact with the terminal of the restraining switch 91 that detects the For touch sensor 11
6 terminals, a terminal of a stroke sensor 117 for detecting the maximum protruding position of the stroke of the piston rod of the hydraulic cylinder 17 for steering, and terminals of magnetic sensors 26a, 26b for detecting an AC magnetic field from the induction cable 27. ,
Although not shown, a spray for adjusting the direction of the spray nozzle groups 6 on the left and right sides on a plane intersecting with the traveling direction axis of the traveling vehicle 1 in order to effectively spray the chemicals on the standing trees on the sloped surface of the mountain. A terminal of a switch 118 for operating the nozzle orientation changing actuator and a rotation speed detector 11 of the engine 10.
9 is connected to each of the terminals to input a signal. Also,
The output port of the MPU 102 has terminals for the operation permitting relay 120 of the engine 10 and various pilot lamps 121.
, A terminal of the monitor lamp 122, a terminal of an automatic mode lamp 47 for confirming the state in the automatic mode, a terminal 28 of an electromagnetic solenoid of the control valve 28 for steering.
The R and 28L terminals are connected to each other to output a signal.

In the transmitter 110, a signal from an input section equipped with a plurality of operation buttons for various operation commands is added to a receiver 111 by adding an FM modulation (frequency modulation) signal to a carrier wave (radio wave). The number of channels in the embodiment is seven, including the channels of the reception monitor signal. On the other hand, the receiver 111 includes an automatic frequency controller (AFC) for stabilizing the center frequency and a local oscillator, amplifies radio waves received by an antenna provided in a traveling vehicle with a high frequency amplifier, and uses a frequency mixer and an intermediate frequency. Amplifier, FM
Various output devices such as a control valve 29 for the traveling clutch device and the braking device, an engine operation permission relay 115, and motors 37a, 38a, 39a for spraying a chemical liquid are input to the control device 100 via a wave detector and a low frequency amplifier. A predetermined signal is output to.

Next, the wireless remote operation will be described.
After the engine is started in the manual mode and the control mode is switched to the automatic mode, the transmitter 110 is turned on, and the radio wave (carrier wave) of the reception monitor signal is continuously transmitted to the receiver 111. To be done. When a predetermined operation button among the plurality of buttons on the transmitter 110 is pressed, the corresponding channel (CH1 to C
In H6), a command signal is sent to the receiver 111 and a signal is input to the microcomputer units 101 and 102. Therefore, each microcomputer unit starts running (starting) on a predetermined control loop, and the blower ( Switching motors 37a, 3 for driving the fan 7 and starting spraying of the left nozzle 6, the right nozzle 6, and the upper nozzle 6.
8a and 39a are turned on. Then, when the start operation button is pressed while the shift button is being pressed, traveling can be stopped and remote operation can be performed. In addition,
It is also possible to set so that other operation commands can be issued by pressing other operation buttons while pressing the shift button. This makes it possible to set a large number of operation items with a small number of operation buttons.
0 can be configured and the most frequently used operations are
The operation can be performed by operating one operation button, and the one that is rarely used can be divided into two-button operation.

Next, during the remote operation or the like, when the input of the reception monitor signal to the control device 100 is continuously interrupted for 2 to 5 seconds (when the signal does not reach), a radio signal is transmitted. Process as non-delivery mode. In the wireless signal non-arrival mode, the traveling vehicle 1 is stopped, the blower (fan) 7 of the spray unit 5 is stopped, and the chemical liquid spray is stopped (only the travel stop is performed when the spray operation is not executed).

As described above, when the input interruption time of the reception monitor signal is not less than the fixed time, the radio signal non-delivery mode is controlled for the first time, and the antenna and the transmitter of the receiver in the traveling vehicle are running. Even if the reception monitor signal cannot be received for a moment due to the presence of a bush of trees between the vehicle and the antenna of the traveling vehicle 1
There is no need to stop the work, and work can be facilitated. On the other hand, when the input of the reception monitor signal is interrupted for a certain length of time, the traveling is stopped from the viewpoint of eliminating the danger of runaway and ensuring safety.

The cause of the non-delivery of the reception monitor signal (radio signal non-delivery) is also a power supply failure (battery consumption) on the transmitter 110 side, a transmission circuit failure, a reception circuit failure on the receiver 111 side, and the like. possible. The electromagnetic induction signal generator 150 of the present invention will be described with reference to FIG. 8 (functional block diagram) and FIG. 9 (outer perspective view). In the waterproof case 151, a rechargeable battery (power source) 152 will be described. A sine wave of a predetermined frequency (1.5 kHz in the embodiment) generated by the sine wave generator 153 is detachably arranged and is input to the constant current output circuit (amplifier) 154 to cause the analog switch 155 to have a predetermined current value. It outputs to a pair of output terminals 156 and 157 via. In that case, one output terminal 156 is directly connected to one terminal of the induction cable 27, and a predetermined capacitance C is provided between the analog switch 155 and the other output terminal 157.
Capacitor 158 is connected to the other output terminal 15
7 and the other terminal of the induction cable 27 are connected.

The output voltage monitoring circuit 159 monitors the current value output from the constant current output circuit 154 within a predetermined value range, and the power supply voltage monitoring circuit 160 uses a battery (power source). The output voltage monitoring circuit 15 monitors whether the voltage of the output voltage is less than or equal to a predetermined value.
9 and the discriminant value of the power supply voltage monitoring circuit 160 deviates from the permissible range, the alarm circuit 161 is activated and the alarm lamp 162 is activated.
Lights up (flashes) and operates. Also, the output voltage monitoring circuit 15
The discriminant value in 9 deviates from the permissible range (for example, in the case where a normal electromagnetic induction signal cannot be generated, such as a disconnection accident of the induction cable 27, an induction route (work route) is too long, and the output voltage decreases). Sometimes output terminals 156, 15
The output from 7 is cut off. Further, the power supply voltage monitoring circuit 160 is configured to operate when the power supply switch 163 for turning on / off the power supply is turned on, and a warning lamp is provided when the power supply voltage is low (the battery level is low). Keep 164 active. In addition, according to the work route (induction cable 27), the route changeover switch 165 provided on the front surface of the case 151 is changed over so as to switch the output to either of the two pairs of output terminals (see FIG. 9). ). Terminal 1 in Figure 9
66 is a charging terminal for the battery 152.

In the embodiment, for example, an induction cable 27
Is 3 mm ² in cross section and has a length of 1200 m, the pure electric resistance value of the induction cable 27 is R = 6.7.
Ohm. Further, it is assumed that the electromagnetic induction signal generator 150 needs to have a capacity (a current value supplied to the induction cable 27 is 187 mA (milliamperes)). Now, as shown in FIG. 10, consider the case where an alternating current of frequency f = 1.5 kHz is supplied to the RLC series circuit 167. Here, from the capability (current, voltage) of the electromagnetic induction signal generator 150,
It is assumed that it is necessary to suppress the impedance (composite resistance) Z ≦ 10Ω (the resistance value is small).

In this case, the impedance (combined resistance) in the RLC series circuit 167 is 10 Ω ≧ Z = √
In the formula of [R ² + (ωL−1 / ωC) ² ], inductance (coil component) L = 0, R = 6.7 Ω, ω = 2πf
Therefore, the electric capacitance C of the capacitor 158 at that time is
When calculating (micro farad, μF), C ≧ 14.3μ
It becomes F.

Therefore, the electromagnetic induction signal generator 150
When the electric capacitance C of the capacitor 158 to be mounted in advance is set to a value slightly larger than 14.3 μF and C = 22 μF, the above equation Z ≧ √ [R ² + (ωL-1 / ωC) ² ]
When Z = 10Ω, R = 6.7Ω, C = 22μF is substituted, the inductance (coil component) L is calculated.
It becomes 30 μH (micro Henry).

Therefore, the above-mentioned thickness and length (electrical resistance value)
When a sinusoidal alternating current of about 187 mA (milliamperes) is flowed using the induction cable 27 of No. 1, if inductance (coil component) L ≦ 1230 μH (micro Henry),
The guide cable 27 can be laid along a zigzag work path. In other words, if the capacitor 158 having the above-mentioned capacitance value is connected in series to the circuit of the electromagnetic induction signal generator 150 and the induction cable 27, the inductance (coil component) will be apparent due to the laying of the induction cable 27. The decrease in the above electric resistance value will be canceled by the component of the capacitor, and even if the load that can keep the output current value from the electromagnetic induction signal generator 150 constant is small, The apparent electric resistance value (impedance) Z on the load side (induction cable) can be reduced and the work route (induction route) can be lengthened.

[0030]

In summary, the electromagnetic induction signal generator for an automatic vehicle according to the present invention is for generating a predetermined AC magnetic field so as to automatically control the automatic vehicle to steer along an induction cable. On the output side of the output circuit in the electromagnetic induction signal generator that supplies alternating current to the induction cable,
Since a capacitor with a predetermined electric capacity is installed in series with the induction cable, connect a capacitor with a predetermined electric capacity value to the circuit of the electromagnetic induction signal generator and the induction cable in series. In this case, the component of the capacitor cancels out the decrease in the apparent electrical resistance value due to the inductance (coil component) that is always generated when the induction cable is laid along the zigzag work route. Therefore, even if the output current value from the electromagnetic induction signal generator is small, the apparent electric resistance value (impedance) Z on the load side (induction cable) is reduced to lengthen the work route (induction route). There is an effect that can be taken.

[Brief description of drawings]

FIG. 1 is a side view of a drug spraying machine.

FIG. 2 is a plan view of the medicine spraying machine.

FIG. 3 is a schematic plan view of a steering device 14.

FIG. 4 is a control hydraulic circuit diagram of a steering device and the like.

FIG. 5 is a mechanism block diagram of a spraying unit.

FIG. 6 is a functional block diagram of a control device.

7A is an explanatory diagram showing a positional relationship between an AC magnetic field generated from an induction cable and a magnetic sensor in the traveling vehicle 1, and FIG. 7B shows a relationship between an output of the magnetic sensor due to lateral displacement of the magnetic sensor with respect to the induction cable. It is an explanatory view shown.

FIG. 8 is a block diagram showing a connection state between an electromagnetic induction signal generator and an induction cable.

FIG. 9 is an external perspective view of an electromagnetic induction signal generator.

FIG. 10 is an RLC circuit diagram.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Traveling vehicle 6 Spray nozzle 7 Blower 10 Engine 11 Travel speed change mechanism 12 Power transmission mechanism 13 Dynamic injection pump 14 Steering device 16 Hydraulic circuit 26a, 26b Magnetic sensor 27 Induction cable 28 Automatic steering control valve 29 Control valve 100 Control device 101, 102 MPU 110 Transmitter 111 Receiver 150 Electromagnetic induction signal generator 154 Constant current output circuit 155 Analog switch 156, 157 Output terminal 158 Capacitor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yukio Murai 1-32 Chayamachi, Kita-ku, Osaka Yanmar Agricultural Machinery Co., Ltd.

Claims (1)

[Claims] 1. An output side of an output circuit of an electromagnetic induction signal generator for supplying an alternating current to an induction cable for generating a predetermined alternating magnetic field so as to automatically steer an automatically traveling vehicle along the induction cable. An electromagnetic induction signal generator for an automatic vehicle, wherein a capacitor having a predetermined electric capacity is provided so as to be connected in series to an induction cable.