JP2599944B2 - Automatic steering system for work vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention travels a work vehicle such as a tractor, a rice transplanter, a lawn mower, or the like that performs various ground work by traveling in a work place along a predetermined route. The present invention relates to a device that automatically steers to make it work.

(Prior art)

BACKGROUND ART Conventionally, there is known a working vehicle equipped with an automatic steering device by teaching regeneration control in various ground work such as plowing and crushing work in a field by a tractor, lawn mowing work in a garden by a lawnmower, and the like, traveling in a work place. . These vehicles teach in advance by manually or automatically steering a part of the work place, the outer periphery, or the entire runway, and a travel route in the work place is set based on the teaching information. Along the route, ground work is performed by the automatic steering device.

[Problems to be Solved by the Invention] However, in the automatic steering device as described above, in the worst case, when the work vehicle climbs on a ridge or an obstacle in a field during ground work and becomes unable to steer, and the worst case, There was a risk that the utility vehicle would fall.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide an automatic steering device that can prevent a danger of being unable to steer or falling due to excessive inclination during automatic steering after teaching. And

[Means for solving the problem]

An automatic steering device for a working vehicle according to the present invention is an automatic steering device for a working vehicle that performs ground work along a runway taught in advance in a work place. A tilt detector for detecting a tilt amount in a direction, a maximum tilt amount storage means for calculating and storing a maximum tilt amount of the working vehicle detected by the tilt detector during the teaching, and for automatic steering. While performing ground work, the inclination amount is detected by the inclination detector, and the comparison unit compares the inclination amount with the maximum inclination amount. The comparison unit determines that the inclination amount is larger than the maximum inclination amount. Means for performing a predetermined operation when it is determined that

[Action]

In the present invention, the maximum tilt amount calculated and stored by the tilt detector at the time of teaching is compared with the tilt amount detected during ground work during automatic steering, and the tilt amount is calculated from the maximum tilt amount. When it is large, the occurrence of danger is prevented beforehand by the predetermined operation of the work vehicle.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the drawings showing the embodiments. FIG. 1 is a left side view of a tractor equipped with an automatic steering device for a working vehicle according to the present invention (hereinafter referred to as the present device).

In FIG. 1, reference numeral 1 denotes an airframe supported by a pair of left and right front wheels 2, 2 and rear wheels 3, 3. The direction of the front wheels 2, 2 is changed in accordance with the turning operation of the steering handle 4 by the driver sitting on the driver's seat 12 installed on the rear upper side of the body 1, and the direction of the front wheels 2, 2 is changed. The body 1 is steered accordingly, and when automatic steering is performed by the apparatus of the present invention, as will be described later, the steering hydraulic cylinder 27 (third cylinder) is used.
(See the figure.) The direction in which the pressure oil is supplied to the cylinder 27 is electrically switched to change the operation direction of the cylinder 27, so that the direction can also be changed. The rear wheels 3,3 are the fuselage 1
The power generated by the power unit 5 mounted on the front of the
The airframe 1 is rotated by being transmitted via the rear wheel 51, and the body 1 travels in a field, which is a work place, by the rotation of the rear wheels 3,3. Roller 7 as a working machine is attached to the body 1 so as to be able to move up and down in accordance with the vertical movement of a three-point link mechanism 6 attached to the rear part of the body 1, and power is transmitted from the power unit 5. When the vehicle is dropped into a field, the operation cultivates and crushes the field.

FIG. 2 is a schematic perspective view showing the configuration of the tilt detector. The left side of the driver's seat 20 is in the traveling direction of the body 1 (or a direction orthogonal to the traveling direction), that is, before and after (or left and right) of the body 1.
An inclination detector 9a (or 9b) for detecting the amount of inclination in the direction is fixed. The tilt detector 9a (or 9b) has a potentiometer 90 mounted on a pivot shaft 92 of a weight 91 vertically suspended so as to be swingable in the front-rear (or left-right) direction of the body 1. When the casing 93 of the detectors 9a and 9b falls with the body 1, the weight
The tilt amount of the body 1 is detected as a change in the output voltage of the potentiometer 90 corresponding to a change in the tilt amount of the weight body 91 by utilizing the relative tilt of the weight 91. The output potential of the tilt detector 9a (or 9b)
Is higher than the reference value when the aircraft 1 is tilted with the front part (or left side) facing upward when the vehicle is in a horizontal state.

FIG. 3 is a block diagram showing a configuration of the direction detector.
An azimuth detector 8 for detecting the azimuth of the body 1 in the traveling direction is fixed to the upper center of the rotary 7. As the azimuth detector 8, a geomagnetic sensor formed by winding a pair of detection windings 81 and 82 orthogonal to each other so as to surround the toroidal core 80 from the outside is used, and the toroidal core 80 is oscillated by an oscillator. When AC excitation is performed at a predetermined frequency and a reference voltage is applied to the detection windings 81 and 82, the voltage induced in the detection windings 81 and 82 is maximum when the directions of the geomagnetism are orthogonal to each other. The circuit described in Sensor Technology, Vol. 5, No. 4 (April, 1985) is constructed by utilizing the following. Since the frequency components of the output voltages of the detection windings 81 and 82 are twice the frequency of the exciting current of the toroidal core 80, each output voltage is synchronously detected with reference to twice the frequency oscillated by the oscillator. And output as an output through a separate integrating circuit and amplifier. The detection winding 8 thus taken out
The output voltage of 1,82 is given to a steering control unit 30 described later, and the steering control unit 30 uses the arc tangent of the ratio of these two outputs to set the azimuth of the geomagnetism as an absolute reference. The installation direction of the detector 8, in other words, the traveling direction of the aircraft 1 is calculated.

Boundary detectors 10l and 10r are attached to the upper front portions of the left and right side surfaces of the hood covering the power unit 5, respectively. Both of the boundary detectors 10l and 10r have their detection areas slightly ahead of the front end of the body 1 and the distance between the left and right detection areas according to the width of a working machine such as a rotary 7 attached to the rear of the body 1. Installed so that it can be changed.

The boundary detectors 10l and 10r incorporate a light-emitting element and a light-receiving element, and project light emitted from the former onto a test object,
The reflected light from the test object is captured by the latter, and a voltage signal corresponding to the amount of received light is output.

FIG. 4 is a block diagram of a control system of the device of the present invention, which is shown together with a plan view of a steering mechanism of the front wheels 2, 2.

In the figure, reference numeral 20 denotes a front axle fixed to a lower portion of the body 1 with its longitudinal direction being the left-right direction. Knuckle arms 22 respectively supporting left and right front wheels 2, 2 are provided at both left and right ends of the front axle 20. , 22 each with a separate kingpin 2
It is pivotally supported around 1,21 so that it can rotate freely in the horizontal plane. The knuckle arms 22 and 22 have respective front ends at the front of a rotating plate 24 that rotates in a horizontal plane around a pivot 23 erected on the upper part of the front axle 20 via separate link members 25 and 25. The steering hydraulic cylinder 27 is attached by locking the distal end of the piston rod to the distal end of an arm 26 projecting leftward in the middle of the rotary plate 24. ing.
Accordingly, when the hydraulic cylinder 27 performs the advance operation (or the retreat operation), the rotation plate 24 rotates clockwise (or counterclockwise) in FIG. The front wheels 2, 2 are transmitted to the left and right knuckle arms 22, 22 via 25, 25, and are steered right (or left) together with the respective knuckle arms 22, 22.

A steering angle detector 15 using a potentiometer is provided at the position of the king pin 21.
15 outputs a positive voltage according to the amount of rotation of the king pin 21, that is, a steering voltage of the front wheel 2 when the vehicle is steered to the right with respect to straight traveling, and outputs a negative voltage when the vehicle is steered to the left. I do.

Furthermore, at the positions of the knuckle arms 22, 22 on the left and right,
Travel distance detectors 16l and 16r using reed switches are provided, and by detecting the magnetic material attached to the front wheels 2, 2, the rotation speed of the front wheels 2, 2 is detected, and the detected left and right rotation speeds are detected. Are averaged, thereby calculating the mileage.

When the hydraulic oil generated by the hydraulic pump 29 is supplied to the hydraulic cylinder 27 via a four-port, three-position switching type electromagnetic directional control valve V, and the solenoid Sl of the electromagnetic directional switching valve V is excited The hydraulic oil from the hydraulic pump 27 is supplied to the retreat-side oil chamber of the hydraulic cylinder 27, and the front wheels 2, 2 are steered to the left by the operation of the steering mechanism as described above. When the V solenoid Sr is excited, the front wheels 2,
2 is steered to the right. Further, when the solenoid Sl and the solenoid Sr are both demagnetized and the electromagnetic directional control valve V is at its neutral position, the front wheels 2, 2 are maintained at the current steering angle.

On the other hand, the forward and backward movement of the body 1 is performed by the transmission 51,
The transmission 51 is provided with a transmission lever 52 disposed on the front right side of the driver's seat.
The speed is changed by Also, at the proximal pivot of the transmission lever 52,
A shift motor 50, which is lever driving means for rotating the lever 52, is mounted coaxially with a pivot shaft of the shift lever 52, and the transmission 51 is rotated by the shift motor 50 or manual rotation of the shift lever 52. The forward and backward movement is made.

Reference numeral 30 denotes the azimuth detector 8, the inclination detectors 9a, 9
b, the traveling distance detectors 16l, 16r and the boundary detectors 10l, 10r
This is a steering control unit that operates as described later based on the detection result of, and steers the aircraft 1 by exciting the solenoid Sl or the solenoid Sr of the electromagnetic direction control valve V.

The steering control unit 30 is connected to a power supply via a key switch 31 for starting the engine, and is operable only when the engine is in a driving state.

The input port a ₁ of the steering control unit 30, and an automatic switch 32 for turning on is connected when the driver seated in the driver's seat 12 for commanding the operation start to the steering control unit 30, the switch input ports a ₁ in accordance with the 32-on is adapted to turn on a high level.

Also the input port a ₂ and input port a ₃ of the steering control unit 30, the base end portion of the traveling state selection lever 9 arranged on the steerable position by the driver sitting in the driver's seat 12, the lever A teaching travel switch 33 and an automatic steering switch 34 using micro switches arranged to be turned on in accordance with the locking position of No. 9 are connected respectively, and both the automatic switch 32 and the teaching travel switch 33 are connected. When the input port a ₂ is turned on, the input port a ₂ turns to a high level, and when the automatic switch 32 and the automatic steering switch 34 are turned on, the input port a ₃
Turns to a high level. The traveling state selection lever 9 includes a locking position where the teaching travel switch 33 is turned on, a locking position where the automatic steering switch 34 is turned on, and locking of a reversing operation in which both switches are turned off. The driver has three locking positions, and the driver seated on the driver's seat 12 rotates the lever 9 to change the locking position, so that the steering control unit 30 will be described later. Do 3
The following operation contents can be selected.

The outputs of the boundary detectors 10l and 10r are connected to changeover switches 11l and 11r that are operated in conjunction with each other.
11l and 11r distribute the outputs of the boundary detectors 10l and 10r to the input of the buffer amplifier 44 and the input of the potentiometer 46, respectively.

The potentiometer 46 is adjusted so as to output 1/2 of the input voltage, and the output has the same gain as that of the buffer amplifier 44 and is supplied to another buffer amplifier 45.

The outputs of the buffer amplifiers 44 and 45 are input to the differential amplifier 43, and the output of the differential amplifier 43 is one input of the differential amplifier 42. The output of the steering angle detector 15 is provided to another input terminal of the error amplifier 42 via a polarity inverter 40, and the output of the differential amplifier 42 is supplied to the input terminal of the error amplifier 42 via a polarity inverter 60. is input to the input port a ₄ of the control unit 30.

The output signal E of the differential amplifier 42 input to the control unit 30
Is compared with the comparison reference values E ₁ (positive) and E ₂ (negative), respectively, and E> E ₁
Turning output ports b ₁ so as to energize the solenoid Sr electromagnetic directional switching valve V is in the high level, and turns to the high level the output port b ₂ so as to energize the solenoid Sl when E <E _2, further E ₂ when <when E <of E ₁ is an output port b _1, b ₂ are both low level.

Front wheels 2,2 when Thus to E> E ₁ is steered to the right, E <E ₂
When the is steered to the left, it is not steered in E ₂ <E <When E _1.

The polarity inverters 40 and 41 operate when the changeover switches 11l and 11r are switched to the side that supplies the output from the boundary detector 10l to the potentiometer 46, and invert the polarity of the input signal, and conversely, Buffer amplifier 4
In the case where the input signal is switched to the input side, the input signal does not operate and the input signal is passed as it is.

Then, the input port a ₅ the running distance detector 16l, 16r
The steering control unit 30 detects the left and right rotation speeds within a predetermined time, and calculates the average rotation speed.
Pa is obtained, and the mileage is calculated based on Pa.

The input ports a ₆ and a ₇ are supplied with output voltages from the two detection windings 81 and 82 of the azimuth detector 8, respectively, and the steering control unit 30 calculates the input voltage based on an arithmetic expression stored in advance. The traveling direction of the body 1 is calculated from the arc tangent of the ratio between these output voltages.

Further comprising using a potentiometer to the input port a _8, a ₉ tilt detector 9a, are given respective output voltages of 9b.

Then, according to signals input to the input ports a ₄ , a ₈ and a ₉ , automatic steering control is performed according to a boundary between an already-worked area and an un-worked area, which will be described later, and the input ports a ₅ , a ₆ , a _7, a ₈ and a ₉
, An automatic steering control based on the teaching and the storage thereof is performed.

On the other hand, the output ports b ₁ and b ₂ of the steering control unit 30 are respectively connected to the solenoid Sr and the solenoid Sl of the electromagnetic directional control valve V via separate excitation circuits (not shown),
Solenoid Sr (or solenoid Sl) is excited according to the high level output of output port b ₁ (or output port b2),
The hydraulic cylinder 27 is configured to advance (or retreat), and the front wheels 2, 2 are steered rightward (or leftward) by the above-described operation of the steering mechanism.

The output ports b ₃ and b ₄ are connected to a shift motor 50 that shifts the shift lever 52, and the output port b ₃ (or b ₄ )
In the forward (or reverse) direction in accordance with the high-level output of the shift lever 10, and shifts the speed change lever 10 from the forward (or reverse) position to the reverse (or neutral) position.

Now, the operation of the device of the present invention configured as described above will be described.

FIG. 5 is a partial plan view of the field showing the running state of the tractor, and FIG. 6 is a flowchart at the start of steering control.

In the automatic steering according to the present invention, first, as shown in FIG. 5, the driver operates the steering wheel 4 to move the aircraft 1 along the one side in the field while working with the rotary 7. In one stroke, teaching travel is performed in which the steering control unit 30 stores the traveling direction and travel distance of the machine body 1 during this work as a teaching travel route. Next, turn around and work area CTD
The tractor is automatically steered following the boundary INT of the unworked area UCT. When performing the automatic steering based on the following, when the boundary INT cannot be detected, the body 1 compares the azimuth data stored by the teaching traveling with the azimuth data of the azimuth detector 8, and Until the boundary can be detected, the vehicle is automatically steered based on the azimuth data stored by the teaching travel. When performing this automatic steering, the driver first turns on the automatic switch 32 and operates the automatic switch 32. Control unit 30
Command to start the operation, and then rotate the traveling state selection lever 9 to lock it at a locking position for selecting the teaching traveling. When the teaching traveling switch 33 is turned on, the teaching Make a run. After the completion of the teaching traveling, the driver rotates the traveling state selection lever 9 and locks the driving state selection lever 9 at a locking position where the automatic steering switch 34 is turned on.
Automatic steering by the operation of the steering control unit 30 is started.

When the key switch 31 is turned on and connected to the power source, the steering control unit 30 performs, as shown in the flowchart of FIG.
First the automatic switch by its input ports a ₁ level
Check the on / off status of 32. And has an automatic switch 32 is turned off, when the input port a ₁ is at low level,
Steering control unit 30 resets its memory, registers and all flags, waits until the automatic switch 32 is turned on, also has an automatic switch 32 is turned on, the input port a ₁ is a high level If, by then the input port a ₂ and input port a ₃ levels examined off states of the teaching travel switch 33 and the automatic steering switch 34, the teaching travel switch 33 is turned on, the input port a ₂ is a high level when it is, according to the teachings running subroutine will be described later, also has an automatic steering switch 34 is turned on, when the input port a ₃ is a high level, according to the automatic steering subroutine will be described later, further teaches the travel switch 33 and the automatic steering When both the direction switches 34 are in the OFF state, they operate in accordance with the direction subroutine described later. As described above, the automatic steering switch 34 and the teaching travel switch 33 are disposed so as to be turned on at different locking positions of the single traveling state selection lever 9, so that they are both turned on. The driver turns the automatic switch 32 on and off and turns the running state selection lever 9 to turn the steering control unit 30 to follow the turning subroutine, the teaching driving subroutine, and the automatic steering subroutine. Can be ordered.

The above-mentioned teaching traveling is performed only from the base point indicated by the circle in the upper left part of the field shown in FIG.

FIG. 7 shows a flowchart of such teaching traveling, FIG. 8 shows a flowchart of an azimuth detecting subroutine, FIG. 9 shows a flowchart of a distance calculating subroutine, and FIG. 10 shows a flowchart of a maximum tilt amount calculating subroutine. .

Above conditions are satisfied, when a transition is made to the teaching running subroutine, steering control unit 30 is the maximum slope of the front and rear of the machine body 1 and the left-right direction Ca _MAX, and a predetermined distance L _a per azimuth detection and calculation of the Cb _MAX And write them to the storage device.

The azimuth data of the azimuth detector 8 is read a predetermined number of times is the azimuth detection subroutine determines the orientation S _i of a certain distance by the average. Distance calculation subroutine respective right and left distance detector 16l, rotational speed Pl output from 16r, a certain time T ₂ counted Pr, left and right rotational speed Pl, calculates the average rotational speed Pa of Pr, per rotation Distance l, average rotation speed Pa and fixed time T ₂
Obtain a speed V _i and a _{(V i = Pa × l /} T 2), determine the traveling distance L by integrating the speed at the time. The L calculated in addition to the distance L _s from the base point to determine the distance from the base point of each point.

Write store next distance obtained L _s and the orientation S _i in the storage device. This is done every predetermined distance L _a to the machine body 1 by the driver to lock the running state selection lever 9 to EKO position.

FIG. 11 is a flowchart showing the automatic steering control. When the first turning is completed and the teaching traveling is completed, the driver turns the automatic steering switch 34 by turning the traveling state selecting lever 9 by turning the lever. Set to a lock position that can be turned on Next, the steering control unit 30 calculates the inclination amount Ca in the front-rear direction and the inclination amount Cb in
Are compared with the maximum inclination amounts Ca _MAX and Cb _{MAX in} the respective directions stored in the teaching travel, and the inclination amount C
a shift, either Cb is the maximum inclination amount Ca _MAX, steering control unit 30 exceeds Cb _MAX interrupts the automatic steering, the forward rotation of the shift motor 50 the high level output is performed to the output port b ₁ The lever 52 is shifted from the forward to the reverse, the body 1 retreats in the direction opposite to the tilt direction, and after a certain period of time, the power unit 5 stops and the tractor stops.

In this way, when the vehicle climbs over an obstacle such as a ridge during automatic steering and exceeds the maximum inclination amount Ca _MAX , Cb _MAX during teaching, the aircraft 1
Prevents the danger of falling over by a predetermined operation.

Further, both of the inclination amounts Ca and Cb are equal to the maximum inclination amount Ca.
_MAX, when not exceeding Cb _MAX, the boundary detector 10l, and detects a boundary INT by 10r, automatically steering so as to follow it. For example, when the vehicle is steered following the boundary INT from top to bottom in FIG. 5, that is, when the work area CTD exists on the right side of the body 1, the changeover switches 11l and 11r shown in FIG. Switching is performed, and the output of the right boundary detector 10r is switched to the input side of the buffer amplifier 44.

Now, assuming that the outputs of the boundary detectors 10l and 10r are A and B and the gains of the buffer amplifiers 44 and 45 are k, the output to the differential amplifier 43 is 1/2 kA and kB, and the gain of the differential amplifier 43 is Assuming that k ′ and k · k ′ = K, the output C of the differential amplifier 43 is as follows.

C = K (B-1 / 2A) The left boundary detector always uses the unworked area UCT as the detection area, whereas the right boundary detector 10r uses the already-worked area CTD.
The first case where only the unworked area UCT is detected, the second case where only the unworked area UCT is detected, and the third case where both are included as the detection area including the boundary INT can be considered.

Since the surface of the already-worked area CTD has severe irregularities and the light projected on the surface is scattered, the output of the boundary detector having the already-worked area CTD as a detection area is almost zero. Therefore, in the first case B
= 0, A = B in the second case, and B = 0 in the third case
ＡA. In particular, when the boundary detector 10r is located above the boundary INT and its detection area includes half of the unworked area UCT and half of the already-worked area CTD, B = 1 / 2A. That is, when the output signal C of the differential amplifier 16 is 0, it indicates that the vehicle is traveling along the boundary INT, and when the output signal C is positive, the front part of the body 1 in FIG. This indicates that the front of the body 1 is shifted to the left, that is, to the already-worked area CTD side in FIG. It is shown that.

On the other hand, since the output signal D from the steering angle detector 15 is a voltage corresponding to the left and right steering angles with respect to the forward movement of the front wheels 2, 2, the gains k and K are set in association with the output signal D. ,
The output signal E = CD of the differential amplifier 42 is equal to the front wheel 2,
The required steering angle change amount from the state of 2 is obtained. The output signal E is compared with the reference voltage values E ₁ and E _{2 as} described above, and the steering is controlled.

Also, at this time, if the boundary INT becomes undetectable and automatic steering following the boundary INT becomes impossible, the azimuth data S _Mi stored in the teaching travel described above is read, and the same distance from the base point in the direction data is stored. Direction data S _Mi and detected direction data S _i
Are compared, and the output port of the steering control unit 30 is
or either b ₁ or b ₂ is a high level output, or both MigiSusumu the body 1 without being output, forehand or directly steering.

When the automatic steering is opposite to the traveling direction of the teaching travel, that is, when the vehicle is automatically steered from top to bottom in FIG. 5, the stored azimuth data S _Mi is read from the opposite direction.

Due to these, even if the work vehicle automatically steered according to the boundary INT can not detect the boundary INT in the middle,
The automatic steering is not interrupted, and the vehicle follows the azimuth of the first travel taught.

This automatic steering control is also performed until the driver locks the traveling state selection lever 9 at the turning position, similarly to the above-described teaching traveling.

In the present embodiment, a geomagnetic sensor using a toroidal core is used as the direction detector for detecting the traveling direction. However, for example, a photo interrupter, a lead, etc. A large number of switches and the like are arranged, and the rotational position of the magnetic needle is detected by these,
An azimuth detector for specifying the traveling direction of the airframe 1 with respect to the azimuth of geomagnetism may be used.

Further, in the present embodiment, a tilt detector having a potentiometer mounted on a pivot shaft of a weight body is used as the tilt detector.However, the present invention is not limited to this. Any device can be used as long as the amount of inclination can be detected, for example, by applying a change in the output value.

Further, in the present embodiment, the case where the present invention device is mounted on the tractor has been described. However, it goes without saying that the present invention device can be applied to other work vehicles such as rice transplanters, harvesters, lawnmowers and the like. No.

〔effect〕

As described in detail above, in the apparatus of the present invention, the maximum inclination amount is calculated and stored during teaching traveling, and the tractor rides on an obstacle or the like by comparing the inclination amount detected during automatic steering with the maximum inclination amount, When the inclination amount exceeds the maximum inclination amount, the automatic steering is interrupted and stopped after retreating for a predetermined time,
It has excellent effects such as preventing a danger such as falling down and providing a safe working environment.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an embodiment of the present invention. FIG. 1 is a left side view of a tractor equipped with the device of the present invention, and FIG. 2 is a schematic diagram showing a configuration of a tilt detector. FIG. 3 is a block diagram showing a configuration of the azimuth detector, FIG. 4 is a block diagram showing a configuration of the device of the present invention, FIG. 5 is a partial plan view of a field showing a running state of the tractor, FIG. FIG. 11 to FIG. 11 are flowcharts showing the operation contents of the device of the present invention. 1 ... body, 2 ... front wheel, 3 ... rear wheel, 7 ... rotary, 8a, 8b ... direction detector, 9a, 9b ... tilt detector, 10l,
10r …… Boundary detector, 16l, 16r …… Driving distance detector, 27…
... Hydraulic cylinder, 30 ... Steering control unit, 50 ... Shift motor

Claims (1)

(57) [Claims] 1. An automatic steering apparatus for a working vehicle that performs ground work along a runway taught in advance in a working place, wherein a slope detecting a traveling direction of the working vehicle and a tilt amount in a direction orthogonal to the traveling direction. A maximum inclination amount storage means for calculating and storing a maximum inclination amount of the working vehicle detected by the inclination detector during the teaching, and A comparing unit that detects the amount of inclination with a detector and compares the amount of inclination with the maximum amount of inclination. When the comparing unit determines that the amount of inclination is greater than the maximum amount of inclination, a predetermined operation is performed. An automatic steering device for a working vehicle, comprising: