JPH09325029A - Device for correcting geomagnetism sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To calculate azimuth correctly by correcting and converting into such a output value that is in a parallel condition to horizontal surface, by using angle of inclination and corrected value calculated by a specific formula even when an earth magnetism sensor is inclined against the horizontal durface. SOLUTION: In a step S1, a vehicle body is directed toward true north by controling the output of vehicle body and its steering system, and the vehicle is stopped automatically in a step S2, and then a gradient angle β1 of the vehicle body outputted from a inclination sensor and Y coil output VY1 of an geomagnetism sensor are stored in a step S3. Next, a jack-up of vehicle body is requested through display of operation panel in a step S4, and a message of pressing a jack-up completion button is indicated on the operation panel, then pressing of the button is checked in a step 5. When it is confirmed, the system advances to a step 6 to store T coil output VY2 of the magnetism sensor at that time. Then, in a step 7, a gradient correction value K corresponding to Z-axis-direction element M2 can be calculated according to a formula by using pitch angles β1 and β2 and Y coil outputs VY1 and VY2 .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a correction device for a geomagnetic sensor that corrects an error in orientation calculation based on the output of a geomagnetic sensor.

[0002]

2. Description of the Related Art In general, geomagnetic sensors used in an automobile navigation system, an autonomous traveling control system of an autonomous vehicle which is autonomously traveling unmanned, are orthogonal to each other.
A two-axis geomagnetic sensor equipped with two magnetic detection coils. With this two-axis geomagnetic sensor, each of the two magnetic detection coils observes in an X, Y, Z orthogonal coordinate system with the XY plane as the horizontal plane. X-axis direction component of the geomagnetic vector and Y
The axial component is detected, and the azimuth angle can be calculated by the ratio of the output values of the magnetic detection coils.

When calculating the azimuth angle by the geomagnetic sensor, it is necessary to calibrate the geomagnetic sensor in advance in order to correct the influence of the magnetization of the vehicle body and the surrounding magnetic field. Center and gain (diameter in each axial direction) of the circular output locus of each X- and Y-axis magnetic detection coil observed when the geomagnetic sensor is fixed on the ground and it is rotated once on a horizontal and flat road surface. The calibration can be performed by obtaining

Techniques relating to the calibration of the above-mentioned two-axis type geomagnetic sensor are disclosed in Japanese Patent Laid-Open No. 4-110717 and Japanese Patent Laid-Open No. 4-346020.
When the geomagnetic sensor cannot be continuously rotated, the center of the output locus and the gain are estimated from the data of three or more points, and when the geomagnetic sensor can be continuously rotated, X,
A technique such as obtaining the center of the output locus and the gain from each maximum value and each minimum value of the Y coil is adopted.

[0005]

However, an unmanned autonomous vehicle or the like that does not always travel on a flat surface does not always travel on a flat ground, and such an autonomous vehicle is equipped with the above-mentioned two-axis geomagnetic sensor. When calculating the traveling direction by tilting the vehicle body on a sloping ground, the geomagnetic sensor fixed to the vehicle body detects other components corresponding to the horizontal component of the geomagnetic vector, which causes an azimuth calculation error. .

The azimuth calculation error due to this inclination is a triaxial geomagnetic sensor capable of detecting a geomagnetic vector component in the Z-axis direction, which is a direction perpendicular to the vehicle body, in addition to the X- and Y-direction magnetic detection axes. Although this can be solved by using, the triaxial geomagnetic sensor is extremely expensive as compared with the biaxial geomagnetic sensor described above, resulting in an increase in cost. Further, since the three-axis geomagnetic sensor requires three-dimensional calibration, it is difficult to perform calibration in a vehicle mounted state, which is not practical.

The present invention has been made in view of the above circumstances, and enables inclination correction for a relatively inexpensive biaxial geomagnetic sensor without using an expensive and triaxial geomagnetic sensor that is difficult to calibrate. It is an object of the present invention to provide a correction device for a geomagnetic sensor that can eliminate a direction calculation error due to inclination.

[0008]

SUMMARY OF THE INVENTION The present invention is a correction device for a geomagnetic sensor that detects only two-axis components of a geomagnetic vector in three-dimensional spatial coordinates, wherein the vertical component of the geomagnetic vector is detected by the geomagnetic sensor. Inclination correction value calculating means for estimating the inclination angle based on the inclination angle when inclined with respect to the horizontal plane and the output value of the geomagnetic sensor, and the geomagnetism when the geomagnetic sensor is inclined with respect to the horizontal plane. An inclination correction means is provided for converting the output value of the sensor into an output value when the geomagnetic sensor is in a state parallel to the horizontal plane, based on the inclination angle and the inclination correction value.

That is, the vertical component of the geomagnetic vector estimated based on the tilt angle when the geomagnetic sensor is tilted with respect to the horizontal plane and the output value of the geomagnetic sensor is obtained in advance as a tilt correction value, and the geomagnetic sensor is placed on the horizontal plane. Even when tilted, the tilt angle and the tilt correction value are converted into an output value when the geomagnetic sensor is in a state parallel to the horizontal plane, and accurate azimuth calculation is possible.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. 2 to 6 show the first embodiment of the present invention.
FIG. 2 shows a form, FIG. 2 is a flowchart of a tilt correction calibration processing routine, FIG. 3 is a flowchart of an azimuth calculation routine, FIG. 4 is a block diagram of an autonomous running control system, and FIG. 5 is an external view of an autonomous running vehicle equipped with a geomagnetic sensor. , Fig. 6
FIG. 6 is an explanatory diagram showing a relationship between a coordinate system and a geomagnetic vector.

In FIG. 5, reference numeral 1 denotes an autonomous traveling work vehicle which is self-propelled and is unmanned. In the present embodiment, it is a lawn mowing work vehicle for performing grass and lawn mowing work on a golf course or the like. This lawnmower vehicle 1 is driven by an engine and the steering angles of the front and rear wheels are independently controlled.
A cutting blade mechanism 2 such as a mower for carrying out grass and lawn mowing work is provided, a dead reckoning sensor for measuring the current position based on a traveling history from a reference position, and an obstacle for detecting a traveling obstacle. Equipped with a sensor for object detection,
It is equipped with various sensors and actuators for driving and steering control.

As the dead reckoning sensor, a geomagnetic sensor 3 provided at the rear of the lawnmower 1 and wheel encoders 4a and 4b provided at the left and right rear wheels are provided, and the obstacle detecting sensor is provided. As for the contactless type sensors 5a and 5b, which are ultrasonic sensors or optical sensors, are attached to the front and rear parts of the lawnmower work vehicle 1,
Switch type contact sensors 6a and 6b are attached to the front and rear ends of the lawnmower working vehicle 1.

In order to detect the horizontal component of the geomagnetic vector, the geomagnetic sensor 3 has an X-coil for north-south detection and a Y-coil for east-west detection that are orthogonal to each other on the magnetic core of a ring-shaped core around which an exciting coil is wound. It is a well-known two-axis type sensor that is wound and arranged. For this two-axis type geomagnetic sensor 3,
An inclination sensor 7 for detecting a roll angle and a pitch angle of the vehicle body is installed in the lower center of the vehicle body in order to perform inclination correction described later.

That is, in general, in order to calculate the azimuth by a biaxial type geomagnetic sensor, each X, Y observed when the geomagnetic sensor is fixed to the vehicle body is rotated once on a horizontal and flat road surface. By performing a well-known calibration to find the center of the output circle of the coil, AC errors due to the disturbance of the geomagnetic field and the influence of the surrounding external magnetic field are removed. When the vehicle body is tilted due to the inclination of, the output of the geomagnetic sensor changes according to the inclination of the vehicle body, and a large error occurs in the azimuth calculated based on the output of the geomagnetic sensor.

For this reason, in the present invention, in addition to the normal calibration, the tilt sensor 7 is used to perform the tilt correction calibration for the two-axis geomagnetic sensor 3, and the expensive three-axis sensor is used. It is possible to ensure the same precision as that of the geomagnetic sensor of the mold.

The calibration of the geomagnetic sensor 3 is performed by the on-vehicle controller 20 shown in FIG.
The control device 20 corrects the traveling direction of the lawnmower working vehicle 1 detected by the geomagnetic sensor 3 in accordance with an error from the target direction to control autonomous traveling. Prior to the start of autonomous traveling control, the geomagnetic field is controlled. The sensor 3 can be calibrated. That is, the above-mentioned respective sensors and actuators described later are connected to the control device 20, and the inclination correction value calculating means according to the present invention,
The functions of the tilt correction means and other control means are realized.

The details of the control device 20 will be described below. The control device 20 is composed of, for example, a plurality of microcomputers, and the dead reckoning position detection unit 21, to which the geomagnetic sensor 3 and the wheel encoders 4a and 4b are connected, the contactless sensors 5a and 5b, and the contact sensor 6a. , 6b are connected to the obstacle detection unit 22, a traveling control unit 23 that controls autonomous traveling of the lawnmower work vehicle 1 based on signals from the detection units 21 and 22, and work data referred to by the traveling control unit 23. Data storage unit 24 that stores maps, maps, and the like, a vehicle control unit 25 that performs vehicle control according to an instruction from the traveling control unit 23, and each mechanical unit of the lawnmower work vehicle 1 based on the output from the vehicle control unit 25. A drive control unit 26, a steering control unit 27, a cutting blade control unit 28, and the like are provided for driving the. Further, the control device 20 is connected to an operation panel 13 including a display and operation switches arranged on an instrument panel of the lawnmower working vehicle 1 for manually operating the lawnmower working vehicle 1. 29 are provided.

In the dead reckoning position detecting unit 21, the output pulses from the wheel encoders 4a and 4b are integrated to obtain a traveling distance, and the traveling distance is made to correspond to the change in the traveling direction detected by the geomagnetic sensor 3. By accumulating, the traveling history from the reference point is calculated and the current position of the own vehicle is measured. Further, the obstacle detection unit 22 detects an unpredictable obstacle by the non-contact type sensors 5a and 5b and the contact type sensors 6a and 6b, and outputs a detection signal to the travel control unit 23.

On the basis of the information from the dead reckoning position detecting section 21, the running control section 23 runs a map of the working data storage section 24 (work contents and terrain data of a work area for grass and lawn mowing work, etc.). (Reference map), the amount of error between the current position of the vehicle and the target position is calculated, and a travel route instruction and a vehicle control instruction are determined in order to correct the amount of the error and output to the vehicle control unit 25. In addition, the obstacle detection unit 2
When an obstacle is detected by the signal from 2, the instruction to avoid the obstacle or stop the vehicle is given.

The work data storage unit 24 stores fixed data such as terrain data of a work area where grass and lawn mowing work are performed, data obtained by processing signals from each sensor, calibration data of the geomagnetic sensor 3, positioning by dead reckoning. Work data and the like during control execution of data and the like are stored.

The vehicle control unit 25 converts the instruction from the traveling control unit 23 into a specific control instruction amount, and the control instruction amount is driven by the drive control unit 26, the steering control unit 27, and the cutting blade control unit 28. Output to. Thereby, the drive control unit 2
6 drives a travel control actuator 8 such as a throttle actuator, a speed change actuator, a forward / reverse switching actuator, a brake actuator, etc. for adjusting the throttle opening to control the engine output, and controls a hydraulic pump 9 to control each. Generates hydraulic pressure to drive the function part.

In the steering control unit 27, the front wheel steering hydraulic control valve 11a and the rear wheel steering hydraulic control valve 11b are based on the inputs from the front wheel steering angle sensor 10a and the rear wheel steering angle sensor 10b provided in the steering system. The steering control (steering amount feedback control) is performed via the cutting blade control unit 28, and the cutting blade control unit 28 performs servo control of the cutting blade mechanism unit 2 via the cutting blade control hydraulic control valve 12.

Further, the terminal control section 29 is an input / output interface for processing input signals from the operation switches of the operation panel 13 and display output signals to the display, and communication for processing signals from a handy terminal (not shown). Interface, etc.,
A command signal corresponding to the operation input is output to the traveling control unit 23.

In this embodiment, the operation panel 13 connected to the terminal control unit 29 is provided with operation switches for executing the calibration of the geomagnetic sensor 3, and the operation switch 13 is operated via the terminal control unit 29. The geomagnetic sensor 3 can be calibrated at any time by manual operation.

For example, before moving the lawnmower work vehicle 1 to a work area on a sloping ground by manned operation and turning on a calibration switch provided on the operation panel 13 before starting unmanned work traveling in this work area. Thus, the geomagnetic sensor can be calibrated. It is also possible to input a command from a handy terminal (not shown) to perform calibration.

As described above, the control unit 20 executes the inclination correction calibration by the pitch / roll of the vehicle body as the calibration of the geomagnetic sensor 3 in addition to the calibration on the ordinary flat ground as described above. This tilt correction calibration is a process that involves coordinate conversion of the geomagnetic vector in the three-dimensional space, and the tilt correction calibration will be described below.

First, as shown in FIG. 6, an X, Y, Z orthogonal coordinate system (hereinafter referred to as a horizontal coordinate system) whose horizontal plane is the XY plane is assumed. When the geomagnetic vector M observed in this horizontal coordinate system has a dip angle F and an azimuth angle α, each component Mx, My, Mz in the X, Y, Z axis directions of the geomagnetic vector M is
It can be expressed by the following equations (1) to (3).

Mx = | M | cosFsinα (1) My = | M | cosFcosα (2) Mz = | M | sinF (3) Therefore, when the vehicle body is in the horizontal state parallel to the X and Y planes, By the X and Y coils of the biaxial geomagnetic sensor 3,
An azimuth angle α is obtained by the following equation (4) by detecting the X-axis direction component Mx and the Y-axis direction component My that are obtained by decomposing the projection component of the geomagnetic vector M on the XY plane into the X-axis direction and the Y-axis direction. be able to.

Α = arctan (Mx / My) (4) On the other hand, the geomagnetic sensor 3 fixed to the vehicle body is inclined.
Also in the state of being inclined with respect to the horizontal plane, the detected values of the X and Y coils of the geomagnetic sensor 3 do not match the X-axis direction component Mx and the Y-axis direction component My of the geomagnetic vector M observed in the horizontal coordinate system, Azimuth calculation error occurs.

That is, when the vehicle body front-rear direction is the Y axis direction, the vehicle body width direction is the X axis direction, the pitch angle as the vehicle body front-rear direction inclination angle is β, and the roll angle as the vehicle body width direction inclination angle is γ, In the two-axis type geomagnetic sensor 3 fixed to the vehicle body, a geomagnetic vector M observed in a coordinate system in which the horizontal coordinate system is rotated by a pitch angle β and a roll angle γ (hereinafter referred to as a pitch / roll rotational coordinate system). X-axis component M of
The x ′ and Y-axis direction component My ′ will be detected.

The geomagnetic vector [Mx'My'Mz '] observed in the pitch-roll rotational coordinate system is the same as the geomagnetic vector [MxMyMz] observed in the horizontal coordinate system.
Transformation matrix R by pitch rotation expressed by the following equation (5)
It can be expressed by the expression (7) obtained by multiplying x and the conversion matrix Ry by the roll rotation expressed by the following expression (6).

[0032] Further, by expanding the above equation (7), the X-axis direction component Mx and the Y-axis direction component My of the geomagnetic vector M observed in the horizontal coordinate system can be expressed by the following equations (8) and (9). .

Mx = (Mx ′ + Mysinβsinγ + Mzcosβsinγ) / cosγ (8) My = (My ′ + Mzsinβ) / cosβ (9) In the above formulas (8) and (9), the pitch angle measured by the tilt sensor 7 is represented. β and roll angle γ, X-axis direction component M in the pitch / roll rotational coordinate system measured by the geomagnetic sensor 3
In addition to x ′ and Y-axis direction component My ′, normally, a Z-axis direction component Mz in a horizontal coordinate system that cannot be measured by the biaxial geomagnetic sensor 3 is included. This Z-axis direction component Mz is the same as the above (3)
As is clear from the equation, it is a vertical component component of the earth's magnetism corresponding to the dip angle F, which is originally a constant value in the same region, but in reality, the magnetic force due to the magnetization of the vehicle body is vector-added. Since it is a different value, calibration is required.

Therefore, in the present invention, the Y coil output of the geomagnetic sensor 3 is measured at different pitch angles and is applied to the equation (9) to obtain the Z-axis direction component Mz in the horizontal coordinate system. That is, if the Y-axis direction components of the pitch / roll rotational coordinate system at the pitch angles β1 and β2 are My1 and My2, respectively, the Y-axis direction component My of the horizontal coordinate system according to the above equation (9) is My.
Can be expressed by the following equations (10) and (11).

My = (My1 + Mzsinβ1) / cosβ1 (10) My = (My2 + Mzsinβ2) / cosβ2 (11) Then, the above equations (10) and (11) are combined to establish the Z-axis direction component Mz.
Equation (12) below is obtained, and by applying the Z-axis direction component Mz obtained by this equation (12) to the above equations (8) and (9), the azimuth angle can be obtained by the above equation (4). It is possible to obtain α.

Mz = (My2cosβ1-My1cosβ2) / (sinβ1cosβ2-cosβ1sinβ2) (12) The equations (10) and (11) have smaller errors as the absolute values of the Y-axis direction components My1 and My2 increase. Therefore, it is desirable to perform the measurement in the northward direction in which the Y coil output of the geomagnetic sensor 3 becomes the largest.

Next, the processing relating to the tilt correction calibration of the geomagnetic sensor 3 executed by the control device 20 will be described with reference to the flowcharts of FIGS. Note that it is assumed that the normal calibration on a flat ground has already been performed. The calibration on the flat ground is described in detail in Japanese Patent Application No. 8-120430 by the present applicant.

In the inclination correction calibration processing routine of FIG. 2, first, in step S1, the engine output is controlled and the steering system is controlled via the throttle actuator that constitutes one of the traveling control actuators 8 of the lawnmower working vehicle 1. Then, the vehicle body is turned to turn the vehicle body direction to true north, the vehicle automatically stops in step S2, and in step S3, the vehicle body tilt angle (pitch angle) β1 based on the output from the tilt sensor 7 is output.
And the Y coil output Vy1 of the geomagnetic sensor 3 are stored.

Next, in step S4, the operation panel 1
A message prompting the jack-up of the vehicle body and pressing the jack-up end button of the operation panel 13 after the jack-up is displayed on the display 3 and whether the jack-up end button of the operation panel 13 is pressed in step S5. Check whether or not.

Then, the driver manually jacks up the vehicle body in accordance with the display message on the operation panel 13 and repeats the loop for displaying the message of step S5 until the jackup end button is pressed, and the jackup end button is pushed. When pressed, the above step S5
To step S6, the pitch angle β2 of the vehicle body at the time of jacking up (an angular difference of about 5 degrees from the pitch angle β1) and the Y coil output V of the geomagnetic sensor 3 at that time
Remember y2 and.

After that, the process proceeds to step S7, in which two pitch angles β1 and β2 before and after jacking up and two Y coil outputs Vy1 and Vy2 are used, and the following formula (12) is followed.
From equation (13), Z of the geomagnetic vector in the horizontal coordinate system
An inclination correction value K corresponding to the axial component Mz is calculated. Then, the inclination correction value K is stored in the work data storage unit 24, and the routine ends.

K = (Vy2cosβ1-Vy1cosβ2) / (sinβ1cosβ2-cosβ1sinβ2) (13) The tilt correction value K obtained by the above tilt correction calibration processing is used to tilt-correct the output of the geomagnetic sensor 3 to obtain the azimuth angle. The process of calculating the is performed by the azimuth calculation routine of FIG.

In this azimuth calculation routine, step S11
When the X, Y coil outputs Vx ′, Vy ′ are obtained from the geomagnetic sensor 3, the pitch angle β and the roll angle γ are obtained from the tilt sensor 7 in step S12, the process proceeds to step S13, and the tilt stored in the work data storage unit 24 is calculated. Corresponding to each X, Y axis direction component Mx, My of the geomagnetic vector in the horizontal coordinate system by the following equations (14) and (15) according to the above equations (8) and (9) using the correction value K The corrected output values Vx and Vy are calculated.

Vx = (Vx ′ + Vysinβsinγ + Kcosβsinγ) / cosγ (14) Vy = (Vy ′ + Ksinβ) / cosβ (15) Then, the process proceeds to step S14, using the correction value output values Vx and Vy, and the above (4 The azimuth angle α is obtained by the following equation (16) according to the equation), stored in the work data storage unit 24, and the routine ends.

Α = arctan (Vx / Vy) (16) As a result, the inclination of the biaxial geomagnetic sensor 3 can be accurately corrected without using an expensive triaxial geomagnetic sensor. It is possible to eliminate the azimuth calculation error during traveling and expand the control range and improve the controllability in the navigation system and the autonomous traveling control system.

7 and 8 relate to the second embodiment of the present invention. FIG. 7 is a flowchart of a tilt correction calibration processing routine, and FIG. 8 is a block diagram of an autonomous traveling control system.

In this embodiment, the vehicle body jack-up for tilt correction in the first embodiment described above is automated by providing the lawnmower work vehicle 1 with a jack-up mechanism. The jack-up mechanism is actuated by the hydraulic pressure from the hydraulic pump 9, for example, and controls the jack-up hydraulic control valve 14 via the drive control unit 26 to jack up the vehicle body, as shown in FIG.

Therefore, in the inclination correction calibration process of the present embodiment, in step S21 of FIG. 7, the drive system and steering system of the lawnmower working vehicle 1 are controlled to turn the vehicle body, as in the first embodiment described above. If you turn the body direction to true north, step
After automatically stopping in S22, the pitch angle β1 of the vehicle body by the output from the tilt sensor 7 and the Y coil output Vy1 of the geomagnetic sensor 3 are stored in Step S23, and then the jack-up hydraulic control valve 14 is driven in Step S24. Then, hydraulic pressure is supplied to the jack-up mechanism to automatically jack up the vehicle body.

Then, in step S25, the pitch angle β2 of the vehicle body at the time of jacking up and the geomagnetic sensor 3 at that time
After memorizing the Y coil output Vy2, the jack-up hydraulic control valve 14 is switched to relieve the hydraulic pressure to the jack-up mechanism to release the jack-up, and the process proceeds to step S26, in the same manner as in the first embodiment. One pitch angle β1,
Using β2 and the two Y coil outputs Vy1 and Vy2, the tilt correction value K is calculated by the above equation (13), the tilt correction value K is stored in the work data storage unit 24, and the routine ends.

In this embodiment, not only is it possible to eliminate the error in the direction calculation when the two-axis type geomagnetic sensor 3 travels on a slope, but it is also possible to completely automatically calibrate the geomagnetic sensor 3 and By linking with autonomous traveling control, it is possible to accurately calculate the heading under all traveling conditions and to realize a more advanced control system.

[0051]

As described above, according to the present invention, the tilt when the geomagnetic sensor is tilted with respect to the horizontal plane with respect to the geomagnetic sensor that detects only the two-axis components in the three-dimensional spatial coordinates of the geomagnetic vector. The vertical component of the geomagnetic vector estimated based on the angle and the output value of the geomagnetic sensor is obtained in advance as the inclination correction value, and even when the geomagnetic sensor is inclined with respect to the horizontal plane, the inclination angle and the inclination correction value are used to determine the geomagnetism. Since the output value is corrected when the sensor is parallel to the horizontal plane, accurate tilt correction for the biaxial geomagnetic sensor 3 is possible without using a triaxial geomagnetic sensor that is expensive and difficult to calibrate. It is possible to eliminate azimuth calculation error on sloping land,
It is possible to expand the control range and improve the controllability of the navigation system and the autonomous traveling control system.

[Brief description of drawings]

FIG. 1 is a basic configuration diagram of the present invention.

FIG. 2 is a flowchart of a tilt correction calibration processing routine according to the first embodiment of the present invention.

FIG. 3 is the same as the above, a flowchart of a bearing calculation routine.

FIG. 4 is a block diagram of the autonomous traveling control system of the above.

[Fig. 5] Same as above, an external view of an autonomous vehicle equipped with a geomagnetic sensor.

FIG. 6 is an explanatory diagram showing the relationship between the coordinate system and the geomagnetic vector.

FIG. 7 is a flowchart of a tilt correction calibration processing routine according to the second embodiment of the present invention.

FIG. 8 is a block diagram of the autonomous traveling control system of the above.

[Explanation of symbols]

3 ... Geomagnetic sensor M ... Geomagnetic vector Mz ... Z-axis direction component (vertical direction component) of the geomagnetic vector in the horizontal coordinate system β ... Pitch angle (tilt angle) γ ... Roll angle (tilt angle) Vx, Vy ... Geomagnetic sensor Output value K ... Tilt correction value

Claims (1)

[Claims] 1. A correction device for a geomagnetic sensor that detects only two-axis components of a geomagnetic vector in three-dimensional space coordinates, wherein a vertical component of the geomagnetic vector is obtained when the geomagnetic sensor is tilted with respect to a horizontal plane. An inclination correction value calculating means for estimating the inclination value and an output value of the geomagnetic sensor and setting an inclination correction value, and an output value of the geomagnetic sensor when the geomagnetic sensor is inclined with respect to a horizontal plane. A correction device for a geomagnetic sensor, comprising: an inclination correction means for converting and correcting an output value when the geomagnetic sensor is in a state parallel to a horizontal plane based on an angle and the inclination correction value.