JPH0942971A - Body of vehicle azimuth detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To precisely detect the azimuth of the body of vehicle to the at most by correcting the fluctuation of a value detected by a geomagnetic sensor due to the inclination of the body. SOLUTION: A geomagnetic sensor 23 is attached to the body of vehicle to detect magnetic force in two directions. x, y, orthogonal to each other in a plane view. The inclination angles θx, θy of the geomagnetic sensor 23 to a horizontal plane are detected, so that an azimuth calculating means which finds the azimuth angle θh of the body on the basis of a ratio of magnetic forces Hx, Hy in two orthogonal directions x, y detected by the geomagnetic sensor 23 finds the azimuth of the body in accordance with the inclination angle information in the condition that the geomagnetic sensor 23 is located in a adequately set attitude to the horizontal plane.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle body provided with a geomagnetic sensor for detecting magnetic forces in two directions orthogonal to each other in a plan view, and the vehicle body is constructed according to a ratio of magnetic forces in two orthogonal directions detected by the geomagnetic sensor. The present invention relates to a vehicle body azimuth detecting device provided with azimuth calculating means for obtaining the azimuth.

[0002]

2. Description of the Related Art Such a vehicle body orientation detecting device is required together with information on the vehicle body position as information for guiding control when, for example, guiding and traveling an automatic traveling rice planting work vehicle along a predetermined route in a field. It is installed in the work vehicle or the like in order to obtain information on the proper vehicle body direction. Since the direction of the magnetic force due to the geomagnetism is the north-south direction in plan view, two magnetic forces orthogonal to each other in plan view (for example, a magnetic force along the longitudinal direction of the vehicle body and a magnetic force along the lateral direction of the vehicle body) are applied to the geomagnetic sensor. And the azimuth of the vehicle body is obtained from the ratio of the magnetic forces as an azimuth with the reference angle 0 in the east direction (for example, Japanese Patent Laid-Open No. 6-149355).
Reference).

[0003]

However, the vehicle body may be tilted from the horizontal state due to the unevenness of the farm scene or the vehicle body structure of the working vehicle during traveling.
The direction of the vehicle body is calculated without considering the fact that the magnetic force passing through the geomagnetic sensor changes due to the inclination of the vehicle body and the detected value changes. Therefore, under a working condition in which the vehicle body is steeply inclined, the error in the vehicle body direction detection value also becomes large, and there is a possibility that the work vehicle cannot be guided and run along the set route in an appropriate state.

The present invention has been made in view of the above circumstances, and an object of the present invention is to correct fluctuations in the detected value of the geomagnetic sensor due to tilting of the vehicle body in order to solve the above-mentioned problems of the prior art. It is to be able to detect the direction as accurately as possible.

[0005]

A first characteristic configuration of a vehicle body azimuth detecting apparatus according to the present invention is provided with an inclination angle detecting means for detecting an inclination angle of the geomagnetic sensor with respect to a horizontal plane.
The azimuth calculating means is configured to obtain the azimuth of the vehicle body in a state where the geomagnetic sensor is positioned in a set proper posture with respect to a horizontal plane, based on the detection information of the inclination angle detecting means.

A second characteristic configuration is the same as the first characteristic configuration, wherein the azimuth calculation means is in two orthogonal directions detected by the geomagnetic sensor based on the detection information of the inclination angle detection means. Is corrected to a value in a state in which the geomagnetic sensor is positioned in a set proper posture with respect to the horizontal plane, and the orientation of the vehicle body is obtained based on the corrected magnetic force ratio. .

A third characteristic configuration is the first or second aspect described above.
In the characteristic configuration of the above, the inclination angle detecting means is configured to detect a pitching angle around an axis along the lateral direction of the vehicle body and a rolling angle around the axis along the longitudinal direction of the vehicle, and the azimuth calculating means comprises: Magnetic force in two orthogonal directions detected by the geomagnetic sensor is rotated about an axis along the lateral direction of the vehicle body so that the pitching angle becomes zero.
Further, the rotation processing is performed around the axis along the longitudinal direction of the vehicle body so that the rolling angle becomes zero, and the geomagnetic sensor is corrected to a value in a state in which the geomagnetic sensor is in a set proper posture with respect to the horizontal plane. There is a point.

A fourth characteristic configuration is the same as the third characteristic configuration, wherein the geomagnetic sensor has two magnetic forces in the two directions orthogonal to each other in the vehicle longitudinal direction and the vehicle lateral direction.
The azimuth calculating means is configured to detect two magnetic forces, and the azimuth calculating means detects the magnetic field in the vehicle longitudinal direction and the vehicle lateral direction detected by the geomagnetic sensor before and after a change when the inclination angle of the vehicle body is changed by a set angle. From each magnetic force, a magnetic force along the vertical direction of the vehicle body is obtained, and in the rotation processing, the three magnetic forces in the vehicle longitudinal direction, the vehicle lateral direction, and the vehicle body vertical direction are set by the geomagnetic sensor in an appropriate posture with respect to the horizontal plane. The point is that it is configured to correct to the value in the state of being turned on.

[0009]

According to the first characteristic configuration of the vehicle body direction detecting apparatus according to the present invention, the geomagnetic sensor attached to the vehicle body so as to detect the magnetic forces in two directions orthogonal to each other in plan view is inclined with respect to the horizontal plane. When the geomagnetic sensor is not in the proper setting posture, the inclination angle of the geomagnetic sensor with respect to the horizontal plane is detected, and the inclination angle detection information is used to detect, for example, the orthogonal 2 detected by the geomagnetic sensor not in the proper setting posture. The vehicle body orientation obtained by the ratio of the magnetic forces in the directions is corrected to obtain the vehicle body orientation in the state where the geomagnetic sensor is in the set proper posture with respect to the horizontal plane.

Further, according to the second characteristic constitution, in the first characteristic constitution, the orthogonal 2 detected by the geomagnetic sensor which is not positioned in the set proper posture with respect to the horizontal plane.
The magnetic force in the direction is corrected to a value in the state where the geomagnetic sensor is in the set proper posture with respect to the horizontal plane using the inclination angle detection information, and the geomagnetic sensor is obtained by the ratio of the magnetic forces in the two orthogonal directions after the correction. The vehicle body orientation in a state in which is positioned in the set proper posture with respect to the horizontal plane is obtained.

According to the third characteristic constitution, in the first or second characteristic constitution, the inclination angle of the geomagnetic sensor with respect to the horizontal plane is the pitching angle around the axis along the lateral direction of the vehicle body and the longitudinal direction of the vehicle body. The magnetic force in two orthogonal directions detected by a geomagnetic sensor that is not positioned in a proper posture with respect to the horizontal plane is detected as a rolling angle around the axis along which the pitching angle becomes zero. A value in a state in which the geomagnetic sensor is rotated around the axis along the axis and along the axis along the longitudinal direction of the vehicle body so that the rolling angle becomes zero, and the geomagnetic sensor is positioned in the proper posture with respect to the horizontal plane. The vehicle body orientation in a state in which the geomagnetic sensor is positioned in the set proper posture with respect to the horizontal plane is obtained from the corrected ratio of the magnetic forces in the two orthogonal directions.

According to the fourth characteristic constitution, in the third characteristic constitution, two magnetic forces along the vehicle longitudinal direction and the vehicle lateral width direction are detected as magnetic forces in two orthogonal directions, and The magnetic force along the vertical direction of the vehicle body is obtained from the magnetic forces in the vehicle front-rear direction and the vehicle body lateral width direction before and after the change when the inclination angle is changed by the set angle. Then, the three magnetic forces in the vehicle body front-rear direction, the vehicle body width direction, and the vehicle body vertical direction cause the geomagnetic sensor to set a proper posture with respect to the horizontal plane by the rotation process for reducing the pitching angle to zero and the rotation process for reducing the rolling angle to zero. Is corrected to the value in the state in which the geomagnetic sensor is positioned in a set proper posture with respect to the horizontal plane by the corrected ratio of the magnetic forces in the vehicle longitudinal direction and the vehicle lateral direction. Is required.

[0013]

According to the first characteristic configuration of the vehicle body direction detecting apparatus according to the present invention, the inclination angle detection information is used even if the vehicle body is inclined and the geomagnetic sensor is not positioned in the set proper posture with respect to the horizontal plane. It becomes possible to detect the vehicle body orientation in the state of being set in the proper posture with respect to the horizontal plane by performing the correction processing and the like, and thus using the vehicle body orientation information as guidance control information, for example, for rice planting, etc. The work vehicle can now be guided and run in a proper state along a set route in the work site.

Further, according to the second characteristic configuration, after the detected value of the magnetic force by the geomagnetic sensor which is not positioned in the set proper posture with respect to the horizontal plane is corrected to the value in the set proper posture by the inclination angle detection information. Since the vehicle body azimuth in the set proper posture state is obtained by the ratio of the magnetic forces in the two orthogonal directions in a plan view, for example, the vehicle body azimuth obtained from the detected value of the magnetic force of the geomagnetic sensor not in the set proper posture is used as the inclination angle. Compared to the case where the vehicle body azimuth in the set proper posture state is obtained by making a correction based on the detection information, the contents of the correction process can be easily understood, and the setting of the correction coefficient and the like can be simplified. Suitable means for carrying out are obtained.

According to the third characteristic configuration, the process of correcting the detected value of the magnetic force by the geomagnetic sensor which is not positioned in the set proper posture with respect to the horizontal plane to the value in the set proper posture,
Since the rotation process is performed around each axis along the vehicle body width direction and the vehicle body front-rear direction so that the pitching angle and the rolling angle are zero, the geomagnetic sensor, that is, the inclination of the vehicle body is normally detected as the pitching angle or the rolling angle. Therefore, the magnetic force detection value of the geomagnetic sensor can be appropriately corrected, and a suitable means for implementing the first or second characteristic configuration can be obtained.

According to the fourth characteristic configuration, the detected values of the magnetic force along the vehicle body width direction and the vehicle body front-rear direction by the geomagnetic sensor which are not located in the set proper posture with respect to the horizontal plane are set to the values in the set proper posture. In the correction process, the magnetic force in the vehicle body vertical direction is used in addition to the vehicle body width direction and the vehicle body front-rear direction. Therefore, for example, the correction process can be performed with higher accuracy compared to using only two magnetic forces in the vehicle body width direction and the vehicle body front-rear direction. Therefore, a suitable means for implementing the third characteristic configuration can be obtained.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION A case where the vehicle body direction detecting device of the present invention is installed in an automatic traveling work vehicle A for rice transplanting will be described below with reference to the drawings. As shown in FIG.
A rectangular farm field F is set, and in the farm field F, the work vehicle A travels while working along each work path L as a plurality of guide paths arranged in the lateral direction along the field longitudinal direction. 180 at adjacent work strokes at the end of each work stroke L
The automatic tracking-type guidance control device B on the ground side performs guidance control so as to travel the entire range of the field F by repeating the reciprocating traveling in which the vehicle travels in a turning direction and then travels in the opposite direction in the work stroke L. .

Reference pole P for displaying the reference position of the field F
1 and P2 are installed at the ridges at the longitudinal center positions of both long sides of the field F (sides indicated by k1, k2 and sides indicated by k3, k4). As shown in FIG. 2, each reference pole is composed of a cylindrical light reflecting plate 28 supported by a support 27 at a predetermined height above the ground, and the light reflecting plate 28 directs incident light into the incident direction. It has the property of being reflected to. In FIG. 1, k
0 is the entrance of the work vehicle A to the field F, kd is the work vehicle A
Is a default position that indicates the standard work starting position for. In addition, the side on one end side in the longitudinal direction of the field F (k1, k in FIG. 1)
The center position (side indicated by 4) is set to the installation position of the automatic tracking guidance control device B.

As shown in FIG. 3, in the work vehicle A, a light bulb 20 as a light emitting body is installed at the tip of a column 19 standing upright on the work vehicle A. A reflection sheet 19a is formed to reflect the beam light b for distance detection projected from the laser length measuring device 13 on the side of the automatic tracking guidance control device B toward the incident direction. The light bulb 20 is continuously turned on by a power source (not shown).

The automatic tracking type guidance control device B is provided with an image sensor S as an image pickup means for picking up an image of a predetermined range including the light bulb 20, and a laser length measuring device 13 for detecting the distance to the light bulb 20. The projection direction of the detection light b is set along the imaging direction of the image sensor S. The image sensor S and the laser length-measuring device 13 are integrally fixedly installed on the installation base 9, and the rotation motor 11 for rotating the installation base 9 around the vertical axis θ and the installation base 9 horizontally. A swinging motor 12 that swings around the axis φ is provided. Therefore, the turning motor 11 and the swinging motor 12 constitute imaging angle adjusting means 11 and 12 for adjusting the imaging angle of the image sensor S. The turning motor 11 and the swinging motor 12 have encoders 11a and 12a built therein (see FIG. 5), and the image pickup angle of the image sensor S is detected based on the information of the encoders 11a and 12a. It is supposed to be done.

As shown in FIG. 4, the image sensor S
Is composed of an electric zoom lens 14 that constitutes an optical system, and a monochrome CCD sensor 15 equipped with an electronic shutter that is an imaging unit. The electric zoom lens 14 includes a focus drive motor 33, a first potentiometer 34 which is a focus position detection sensor, a zoom drive motor 35,
Second potentiometer 36 which is a zoom position detection sensor
Are provided. Then, the light from the electric bulb 20 that has passed through the electric zoom lens 14 and the optical filter 24 provided on the rear side of the electric zoom lens 14 is configured to form an image on a CCD element 27 which is an imaging element provided in the CCD sensor 15. ing. The optical filter 24 is used for the light bulb 20.
The transmittance is increased with respect to the emission wavelength of.

Referring to FIG. 5, the control configuration of the automatic tracking type guidance control device B will be described. An imaging angle controller 49, an image sensor controller 50, a laser length measuring device controller 51, and these controllers 49, 50. , 51 is provided to control the main controller C. The image pickup angle controller 49 receives image pickup angle information of the image sensor S from the encoders 11a and 12a, and outputs drive signals for the turning motor 11 and the swinging motor 12. The image sensor controller 50 receives the image pickup information of the CCD sensor 15 and the detection information of the first potentiometer 34 and the second potentiometer 36, and also receives the CCD sensor 15, the focus drive motor 33, and the zoom drive motor 35. The drive signal for is output. Distance detection information from the laser length measuring device 13 is input to the laser length measuring device controller 51.

Using the image sensor controller 50, based on the image pickup information of the image sensor S,
Image processing means T for detecting the position of the light bulb 20 in the image pickup screen of the image sensor S is configured. That is, as shown in FIG. 6, the image pickup screen 2 of the image sensor S
With the center point O of 9 as the origin, the center of gravity position G of the area corresponding to the light bulb 20 is set with the screen horizontal direction set to the X ′ axis (right direction is plus) and the screen vertical direction is Y ′ axis (upward is plus). Then, the deviations X and Y between the center of gravity position G and the screen center point O are detected, and the deviations X and Y are used as the position information of the light bulb 20 within the imaging screen. In this example, the deviation Y in the Y′-axis direction is almost 0, and only the deviation X in the X′-axis direction is shown.

The main controller C is configured to change and adjust the imaging magnification of the image sensor S based on the distance information to the light bulb 20 detected by the laser length measuring device 13. That is, the electric zoom 1 increases the imaging magnification as the distance to the light bulb 20 increases and decreases the imaging magnification as the distance to the light bulb 20 decreases.
By moving the lens position of No. 4, the size of the light bulb 20 in the imaging screen is maintained at an appropriate size. Furthermore, compared to when the moving direction of the light bulb 20 is horizontal in the image capturing screen, when the moving direction is the perspective direction, that is, the position of the light bulb 20 in the image capturing screen does not change much and the distance is changed. The zoom control speed is increased when only the change is made so that the delay of the tracking control is minimized.

The main controller C captures the light bulb 20 at a predetermined position in the image pickup screen of the image sensor S, specifically, at the center point O of the image pickup screen 29.
Tracking control for operating the turning motor 11 and the swinging motor 12 is performed. This tracking control will be described below. Since it takes a predetermined processing time to detect the position within the screen by the image processing means T, as shown in FIG. 7, the position of the light bulb 20 (in the figure, the vertical axis .theta. (Indicated by angles around) is obtained as the position at discrete, spaced detection points. In the figure, the light bulb 20 has a current angle detection time t.
It is located at an angle θ2 around the vertical axis θ at an angle detection time t2 two points before 0, and at an angle θ1 around the vertical axis θ at an angle detection time t1 one before the current angle detection time t0. It is assumed that the vehicle is moving on the locus J so as to be positioned at the angle θ0 around the vertical axis θ at the current angle detection time t0. It should be noted that the angle about the vertical axis θ is positive in the clockwise direction (clockwise) when viewed from above, and the angular position around the horizontal axis φ of the light bulb 20 does not change. From the above, the change rate θv of the angular position around the vertical axis θ of the light bulb 20 from the angle detection time t1 one before the current angle detection time t0 to the current angle detection time t0 is given by the following formula (1). To be

[0026]

## EQU1 ## θv = (θ0−θ1) / (t0−t1) (1)

Therefore, in order to capture the light bulb 20 at the center point O of the screen at the next angle detection time point after the current angle detection time point t0, X'detected by the image processing means T.
Considering the correction amount for the deviation X (FIG. 6) in the axial direction and the rate of change θv in the angular position around the vertical axis θ, the turning amount Δθ around the vertical axis θ is expressed by the following equation (2). Then, the turning motor 11 is operated with the turning amount Δθ.
Note that a1 and a2 are predetermined gain coefficients (a1> 0,
a2> 0).

[0028]

[Formula 2] Δθ = a1 · X + a2 · θv (2)

As shown in FIG. 5, the automatic tracking type guidance control device B is provided with a ground-side transceiver 10 for transmitting and receiving control information to and from the work vehicle A, which is connected to the main controller C. The reference position detecting means PK for detecting the reference position of the field F displayed by the reference poles P1 and P2.
And a ground side information storage means R for storing ground side information including the arrangement positions of the reference poles P1 and P2. As the ground side information, the coordinates of the reference poles P1 and P2, the coordinates of the corners k1, k2, k3 and k4 of the field F, the position of the doorway k0, and the work process L information (process width, process length, process) (Number, etc.), coordinates of the default position kd, etc. are stored.

The reference position detecting means PK detects the distance to the light reflecting plate 28 with the projection direction of the detection light set toward the light reflecting plate 28 of the reference poles P1 and P2. It is configured by using the instrument 13, the laser length measuring device controller 51 and the main controller C. Further, the ground side information storage means R is configured by using the main controller C.

Then, the main controller C in the automatic tracking type guidance control device B is arranged so that the reference position detecting means PK is used.
The position of the work vehicle A is measured while tracking the work vehicle A based on the position of the self in each field F determined based on the detection information of the above and the storage information of the ground side information storage means R. Specifically, the self position, that is, the installation position of the automatic tracking type guidance control device B is obtained from the installation position information of the reference poles P1 and P2 and the distance information to the reference poles P1 and P2 which are known in advance, and the image is obtained. The position of the light bulb 20 in the image pickup screen of the image sensor S by the processing means T and the encoder 11
The position of the work vehicle A is detected from the image pickup angle information of the image sensor S by a and 12a.

Then, the main controller C controls the movement of the work vehicle A based on the vehicle body direction information from the work vehicle A received by the transceiver 10 on the ground side and the obtained vehicle body position information. The guidance control information is obtained, and the guidance control information is transmitted to the work vehicle A side through the transceiver 10 on the ground side.

Next, referring to FIG. 8, the control configuration of the work vehicle A side will be described. A work vehicle controller SC utilizing a microcomputer is provided, and the work vehicle controller SC is provided with the transceiver 10 on the ground side. A transmitter / receiver 16 on the side of the work vehicle for transmitting / receiving information to / from is connected.
In addition, from the work vehicle controller SC, a traveling motor 17 for operating the traveling transmission 18 and a steering motor 2 for operating the steering device 22.
1 and a drive signal to the working device actuator 26 for operating the working device 25 (in the case of a rice transplanter, raising and lowering the planting device).

A geomagnetic sensor 23 for detecting magnetic forces in two directions orthogonal to each other in plan view is attached to the vehicle body. Specifically, as shown in FIG. 10, the geomagnetic sensor 23 uses two magnetic forces H along the vehicle body front-rear direction (y direction) and the vehicle body lateral width direction (x direction) as the two orthogonal magnetic forces.
It is configured to detect y and Hx. In the figure,
H is the vector of the magnetic force due to the geomagnetism, and Hxy is the magnetic force in the horizontal plane, but the magnetic force Hz along the vehicle body vertical direction (z direction) cannot be directly detected by the geomagnetic sensor 23. And the detection information of this geomagnetic sensor 23 is
It is input to the work vehicle controller SC.

A specific structure of the geomagnetic sensor 23 will be described with reference to FIG. High magnetic permeability toroidal coil 1
The excitation coil 2 is wound around the coil, and a pair of output coils 3 and 4 wound in the diametrical directions (the above-mentioned y and x directions) orthogonal to each other are provided in the flux gate system.
With the vehicle body front-back direction as the y direction and the vehicle body width direction as the x direction,
The toroidal coil 1 is attached to the vehicle body in a posture in which the axial center z direction is upward in the vertical direction (this posture is referred to as a proper setting posture with respect to the horizontal plane of the geomagnetic sensor 23). An alternating current with a sufficiently large amplitude is made to flow from the oscillator 5 to the exciting coil 2 via the driver 6, and the toroidal coil 1 has an alternating magnetic field of positive and negative symmetrical waveform in which the peaks and valleys of the sine wave are clamped by the saturation characteristic. Is occurring. Then, since the directions of the electromotive forces generated at the diametrically opposite ends of the toroidal coil 1 in the respective output coils 3 and 4 are opposite and of equal magnitude, no voltage is induced in the output coils 3 and 4.

However, for example, when an external DC magnetic force (geomagnetism) is applied to the output coil 3 from a direction perpendicular to the output coil (x direction), if the direction of the AC magnetic field by the exciting coil 2 and the direction of the geomagnetism match at one end side, at the other end side. Since the directions are opposite, the amount of electromotive force clamped by the saturation characteristic of the toroidal coil 1 is large on one end side and is small on the other end side. Therefore, the amount of electromotive force generated on both end sides of the output coil 3 is reduced. The balance is lost. As a result, an AC voltage is induced in the output coil 3. On the other hand, since the influence of the geomagnetism does not appear in the output coil 4 provided in the direction perpendicular to the output coil 3, no voltage is induced. Contrary to the above, the direction (y
Direction), an AC voltage is induced in the output coil 4 and no voltage is induced in the output coil 3. Then, the AC voltage induced in the output coils 3 and 4 passes through the respective filter amplifiers 7 and detectors 8,
It is taken out as DC voltages Vx and Vy.

Utilizing the work vehicle controller SC, the magnetic forces in two orthogonal directions detected by the geomagnetic sensor 23, that is, the magnetic force Hy along the vehicle front-rear direction (y direction) and the magnetic force Hx along the vehicle lateral direction (x direction). The azimuth calculation means 100 for obtaining the azimuth of the vehicle body is configured by the ratio Hy / Hx of.
The azimuth θh of the vehicle body is 90 degrees (π / 2 radians) when the front side of the vehicle is facing north.
From the above ratio Hy / Hx with the angle east facing 0, the following formula (3)
(See FIG. 10). However, this azimuth angle θh is the azimuth of the vehicle when the vehicle is in a horizontal state, that is, the azimuth of the vehicle when the geomagnetic sensor 23 is in the set proper posture with respect to the horizontal plane.

[0038]

Hx = Hxy · cos θh, Hy = Hxy · sin θh θh = tan ⁻¹ (Hy / Hx) + π / 2 (3)

Therefore, as shown in FIG. 8, as the inclination angle detecting means for detecting the inclination angle of the geomagnetic sensor 23 with respect to the horizontal plane, the pitching for detecting the pitching angle θx around the axis along the vehicle body lateral width direction (x direction). Corner detection sensor 3
2 and a rolling angle detection sensor 31 that detects a rolling angle θy around an axis along the vehicle front-rear direction (y direction). Then, each detection information of both the sensors 31 and 32 is input to the work vehicle controller SC. It should be noted that the detected values of the pitching angle θx and the rolling angle θy are set to an angle of 0 when the vehicle body is in a horizontal state as shown in FIG. Take in the angle direction.

Then, the azimuth calculating means 100 causes the geomagnetic sensor 23 to set a proper posture with respect to the horizontal plane based on the detection information of the tilt angle detecting means (the pitching angle detecting sensor 32 and the rolling angle detecting sensor 31). The orientation of the vehicle body in the state of being positioned is obtained, that is, the magnetic forces in the two orthogonal directions detected by the geomagnetic sensor 23 based on the detection information of the both angle detection sensors 31 and 32 (when the vehicle body is inclined). Value) is corrected to a value (value when the vehicle body is not tilted) when the geomagnetic sensor 23 is positioned in the set proper posture with respect to the horizontal plane, and the corrected magnetic force ratio Hy / Hx It is configured to determine the direction of the vehicle body.

Specifically, first, as shown in FIG.
The azimuth calculating means 100 changes the tilt angle of the vehicle body before and after the change when the set angle α is changed so that, for example, a pitching angle is generated around the axis along the vehicle body lateral width direction (x direction) from the horizontal state. From each magnetic force in the longitudinal direction of the vehicle body and the lateral direction of the vehicle body detected by the geomagnetic sensor 23 (Hx, Hy before tilting and Hx ′, Hy ′ after tilting), follow the vertical direction of the vehicle body by the following formula (3). Calculate the magnetic force Hz. In this example, since the angle of inclination is about the axis along the lateral direction of the vehicle body (x direction), the magnetic forces Hx and Hx ′ in the lateral direction of the vehicle body before and after the inclination have the same value, but the vehicle body is inclined. The direction of the vehicle body width (x
It is possible to incline in any direction, without being limited to the periphery of the axis along the (direction). Hyz is a projection component of the geomagnetic force H on the yz plane. Here, since the magnetic forces Hx, Hy, and Hz in the x, y, and z directions are obtained, the magnitude of the geomagnetic force H is calculated from the three magnetic forces Hx, Hy, and Hz as shown in equation (4). You can do it.

[0042]

(Equation 4)

After that, the magnetic forces Hx and Hy detected by the geomagnetic sensor 23 in the longitudinal direction of the vehicle body and the lateral direction of the vehicle body.
And the magnitude of the magnetic force H of the geomagnetism obtained above (this value may be considered not to change in the range traveling in the field F), the magnetic force Hz in the vertical direction of the vehicle body at any time is reduced. It can be obtained by calculation using the equation (5).

[0044]

(Equation 5)

The correction is performed by the vehicle front-back direction,
Three magnetic forces in the vehicle body width direction and the vehicle body vertical direction, that is, magnetic forces Hx and Hy in two orthogonal directions (vehicle body width direction and vehicle body vertical direction) detected by the geomagnetic sensor 23 and calculated as described above. The obtained magnetic force Hz in the vertical direction of the vehicle body is rotationally processed about the axis along the lateral direction of the vehicle body so that the pitching angle θx becomes zero, and the rolling angle θy, as shown in the following formula (6). Is rotated around the axis along the longitudinal direction of the vehicle body so as to be zero, and is corrected to a value in a state where the geomagnetic sensor 23 is positioned in the set proper posture with respect to the horizontal plane.

[0046]

(Equation 6)

Then, the work vehicle controller SC is
The information of the vehicle body azimuth angle θh obtained as described above is transmitted from the transceiver 16 on the work vehicle side to the transceiver 10 on the ground side, and the automatic tracking guidance is received by the transceiver 16 on the work vehicle A side. Based on the guidance control information from the control device B, the steering control is performed so that the work vehicle A is moved along each work stroke L.

Next, the work vehicle A by the automatic tracking type guidance control device B will be described with reference to the flow charts shown in FIGS.
The specific configuration of the position measurement and the guided traveling of the work vehicle A will be described.

First, after the automatic tracking guidance control device B is installed at the guidance position of the field F (center position of the side indicated by k1 and k4 shown in FIG. 1),
In the main routine (FIG. 12), the map file of the current field F1 is selected and read from the ground side information (hereinafter referred to as a map file) stored in the ground side information storage means R. Then, based on the map file information, the reference position detecting means PK described above recognizes its own installation position.

Next, the light bulb 20 of the work vehicle A is operated at the center point O of the image pickup screen of the image sensor S to detect the position of the work vehicle A from the azimuth information and the distance information.
The first trajectory data (stored in rows) is read and the deviation between the trajectory and the vehicle body position is calculated. If the track deviation is not within the set value (for example, 1 m), the next track data is read, and the track data is sequentially read and the track deviation is calculated until the track deviation falls within the set value. Here, even if all track data in the file is read, if the track deviation does not fall within the set value, the current car body position is judged to be inappropriate, so move it manually to the track you want to guide, or Default position k
The vehicle body position is changed by moving it to d. Then, the position of the work vehicle A after the movement is detected, the orbit data is read and the orbit deviation is calculated again. When the orbit data within which the orbit deviation falls within the set value is found, the orbit and vehicle body position are determined. It is displayed on a TV monitor (not shown).
Looking at this display, when the operator or the like commands the start of guidance, the vehicle guidance along the trajectory is started, while if the guidance is not started, the flow from the change of the vehicle position is repeated.

In the vehicle body guidance (FIG. 13), the trajectory data is set in the calculation buffer and then the laser length measuring device 1 is used.
3 (abbreviated as PSR) and the image processing means T (VS) using the image sensor controller 50.
Data is requested to (abbreviated as X). Where VSX
Processing takes time, so after waiting for the time until the processing is completed, the distance data from the PSR, the in-screen position data from the VSX, and the imaging angle controller 4
The imaging angle data of the encoders 11a and 12a is read from 9. Then, the azimuth angle is determined from the in-screen position data and the imaging angle data, the vehicle body position is calculated from the azimuth angle and the distance data, and the control amount for automatic tracking is obtained. Activate the tracking operation.

Next, it is checked whether or not the calculated vehicle position is located at the end of the track. If it is not the end of the track, the vehicle body azimuth data is received from the work vehicle A, the steering angle of the vehicle body is calculated from the vehicle body azimuth angle and the deviation of the vehicle body position with respect to the track, and the steering angle data, and Guidance control information for other gear shifting operations and operation of working machines (planting devices, etc.) is transmitted to the work vehicle A. On the other hand, if it is at the end of the track, the next track data is read and the flow from the reception of the vehicle body azimuth data of the work vehicle A is repeated based on the track data. When the processing for the data in the file has been completed by the reading of the next track data, the processing for guiding the vehicle body is completed, and the process returns to the main routine.

In the vehicle body side control (FIG. 14), the geomagnetic data of the geomagnetic sensor 23, the inclination angle data of the rolling angle detection sensor 31 and the pitching angle detection sensor 32 are obtained, and the geomagnetic data is corrected by the inclination angle data. Then, the azimuth angle of the vehicle body is obtained from the corrected geomagnetic data, and the azimuth data is transmitted to the ground-based automatic tracking guidance control device B. Then, the guidance control data from the ground side is received, and each control of steering, speed change, and working machine operation is performed according to the control information.

[Other Embodiments] In the above embodiment, the two directions which are orthogonal to each other in plan view, which are the magnetic force detection directions of the geomagnetic sensor 23, are set to the vehicle body front-rear direction and the vehicle body lateral width direction. However, the present invention is not limited to this. 4 in the longitudinal direction of the vehicle
It may be set in two directions of 5 degrees orthogonal to each other.

In the above embodiment, the geomagnetic sensor 23 is of the flux gate type, but other geomagnetic sensor such as a Hall element may be used.

In the above-described embodiment, the geomagnetic sensor 23 is constructed as a two-dimensional type that detects magnetic forces in two orthogonal directions, but other than this, a three-dimensional type sensor that detects magnetic forces in three orthogonal directions may be used. In this three-dimensional geomagnetic sensor, for example, three magnetic forces in the vehicle lateral direction (x direction), the vehicle longitudinal direction (y direction), and the vehicle vertical direction (z direction) are directly detected. There is no need to calculate the magnitude of the magnetic force in advance and calculate the remaining magnetic force in the vertical direction of the vehicle body from the magnitude of the magnetic force and the detected values in the vehicle body width direction and the vehicle body front-back direction, as in a two-dimensional geomagnetic sensor. .

In the above embodiment, the inclination angle of the geomagnetic sensor 23 with respect to the horizontal plane is detected as the pitching angle and the rolling angle. However, the present invention is not limited to this, and the pitching angle and the rolling angle are not limited to the above for simplification of the processing. It is also possible to detect only one and correct one of the tilt angles. In addition to the above, the inclination angle with respect to the horizontal plane may be detected by the maximum inclination direction and the inclination angle in that direction. In this case, the inclination angle correction of the detected magnetic force is
It is performed by a process of rotating an inclination angle in the direction around an axis along a direction orthogonal to the maximum inclination direction.

In the above embodiment, the detected value of the magnetic force by the geomagnetic sensor 23 which is not located in the set proper posture with respect to the horizontal plane is corrected to the value of the magnetic force in the state set in the proper set posture, and after the correction. Although the azimuth angle is obtained from the ratio of the magnetic forces, the present invention is not limited to this. For example, the azimuth angle is tentatively obtained from the ratio of the magnetic forces in the inclined state, and the correction factor stored in the memory in advance is stored in the tentative azimuth angle. Alternatively, the corrected azimuth angle may be obtained. Also, when the value of the magnetic force is corrected, the magnetic force correction coefficient for each inclination angle data stored in the memory in advance is used instead of the rotation processing to return the inclination angle each time as in the above embodiment. You may make it multiply by the detection value of.

Incidentally, reference numerals are written in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configuration of the attached drawings by the entry.

[Brief description of drawings]

FIG. 1 is a plan view showing guided traveling of a work vehicle in a field on the ground side.

FIG. 2 is a side view of means for indicating a reference position in a field.

FIG. 3 is an external view showing a work vehicle and an automatic tracking type guidance control device.

FIG. 4 is a cross-sectional side view showing the configuration of the image pickup means.

FIG. 5 is a block diagram showing a control configuration of an automatic tracking type guidance control device.

FIG. 6 is an explanatory diagram of a process for detecting the position of a light emitter in the image pickup screen.

FIG. 7 is an explanatory diagram of tracking control.

FIG. 8 is a block diagram showing a control configuration on the work vehicle side.

FIG. 9 is a perspective view and a control block diagram showing the configuration of the geomagnetic sensor.

FIG. 10 is an explanatory diagram showing direction detection of a geomagnetic sensor.

FIG. 11 is an explanatory diagram of geomagnetic detection by a geomagnetic sensor.

FIG. 12 is a flowchart illustrating a control operation.

FIG. 13 is a flowchart illustrating a control operation.

FIG. 14 is a flowchart illustrating a control operation.

[Explanation of symbols]

 23 geomagnetic sensor 100 azimuth calculation means 31, 32 inclination angle detection means

Claims (4)

[Claims] 1. A geomagnetic sensor (23) for detecting magnetic forces in two directions orthogonal to each other in a plan view is attached to a vehicle body, and the vehicle body is obtained by a ratio of magnetic forces in the two orthogonal directions detected by the geomagnetic sensor (23). A vehicle body azimuth detecting device provided with an azimuth calculating means (100) for obtaining an azimuth of the geomagnetic sensor, wherein inclination angle detecting means (31, 32) for detecting an inclination angle of the geomagnetic sensor (23) with respect to a horizontal plane is provided. The azimuth calculation means (100) determines the vehicle body azimuth in a state where the geomagnetic sensor (23) is positioned in the set proper posture with respect to the horizontal plane based on the detection information of the inclination angle detection means (31, 32). The vehicle body direction detection device configured in. 2. The azimuth calculation means (100), based on the detection information of the inclination angle detection means (31, 32), magnetic forces in two orthogonal directions detected by the geomagnetic sensor (23), The geomagnetic sensor (23) is corrected to a value in a state in which the geomagnetic sensor (23) is positioned in a set proper posture with respect to the horizontal plane, and the orientation of the vehicle body is obtained from the corrected magnetic force ratio. Car body direction detector. 3. The inclination angle detecting means (31, 32) is
The azimuth calculating means (100) is configured to detect a pitching angle around an axis along the lateral direction of the vehicle body and a rolling angle around an axis along the longitudinal direction of the vehicle.
3) The magnetic forces in the two orthogonal directions detected in 3) are rotated around the axis along the lateral direction of the vehicle body so that the pitching angle becomes zero and the rolling angle becomes zero so that the rolling angle becomes zero. The rotation processing is performed around an axis along the direction, and the geomagnetic sensor (23) is configured to be corrected to a value in a state in which the geomagnetic sensor (23) is positioned in a set proper posture with respect to the horizontal plane. Body direction detector. 4. The geomagnetic sensor (23) is configured to detect two magnetic forces along the vehicle body front-rear direction and the vehicle body lateral width direction as the magnetic forces in the two orthogonal directions, and the azimuth calculation means (100). , The magnetic force along the vertical direction of the vehicle body is obtained from the magnetic forces in the vehicle longitudinal direction and the vehicle lateral width direction detected by the geomagnetic sensor (23) before and after the change when the inclination angle of the vehicle body is changed by a set angle. In the rotation process, the three magnetic forces in the vehicle front-rear direction, the vehicle body lateral direction, and the vehicle body vertical direction are corrected to values when the geomagnetic sensor (23) is positioned in the set proper posture with respect to the horizontal plane. The vehicle body azimuth detecting device according to claim 3, wherein