JPH10185608A - Attitude detection apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an attitude detection apparatus small and always capable of detecting attitude information of an object to be detected with high precision at any place on the earth. SOLUTION: An attitude information detecting section 2 which detects attitude information of an object to be detected, and an arithmetic processing section 3 which calculates, by operations, angle information according to the attitude of the object to be detected based on attitude information detected by this attitude information detecting section 2, are provided, and this arithmetic processing section 3 is so constituted that it provides correcting section 33 which enables correction of angle information by providing the correction to the referring attitude information gained in the attitude information detecting section 2, considering geomagnetism.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a posture detecting device for detecting the posture (inclination angle, rotation angle, etc.) of an object or a person, for example, a display on a screen (display) according to the operation (posture) of the person. The present invention relates to a posture detection device suitable for use in a head-mounted display bodily sensation game for controlling the position, inclination angle, rotation angle, and the like of an object, posture control of a robot, a fully automatic traveling system, a navigation system, and the like.

[0002]

2. Description of the Related Art FIG.
FIG. 26 is a schematic perspective view showing an example of an axis motion sensor. The three-axis motion sensor 100 shown in FIG.
Tilt angle sensor 103, magnetic sensor 104, and CPU 10
5. Here, the tilt angle sensor 103 is disposed on the substrate 101 and the magnetic sensor 10
4 and the CPU 105 are arranged on the substrate 102. The overall dimensions are length 50 mm, width 40 mm, height 5
It is about 0 mm.

Here, the tilt angle sensor 103 has a built-in liquid such as a silicon liquid and a pendulum. When an object to be detected such as an attached object or a person is tilted with respect to the surface of the ground, the resistance of the liquid is measured. The magnetic sensor 104 has a mechanism that causes a change in the value or a change in the position of the pendulum. The magnetic sensor 104 detects geomagnetism (a geomagnetic vector).

[0004] The CPU 105 includes a tilt angle sensor 10.
The tilt angle of the object to be detected is calculated based on the change in the resistance value of the liquid and the change in the position of the pendulum obtained in step 3, and the rotation angle of the object to be detected is calculated based on the geomagnetism detected by the geomagnetic sensor 104. Things. Thereby, the above 3
For example, as shown in FIG. 26A, the axis motion sensor sets the surface horizontal plane to an XY plane (here, the X axis direction is left and right, and the Y axis direction is front and rear), and the vertical direction to the surface horizontal plane ( Assuming the Z axis and the coordinate system as the (up and down) directions, the inclination angle sensor 103 detects the rotation (tilt) angle of the detection object about the X axis [pitch: see FIGS. Around rotation (tilt) angle [Roll: FIG. 26
(B), see FIG. 27 (c)].
4, the rotation angle around the Z axis [Yaw angle: FIG.
(B) and FIG. 27 (a)] can be detected, and three-axis information of the pitch, roll, and yaw angle (posture information of the detection target) can be obtained. However, in this case,
It is defined to detect the iodine angle with magnetic north as absolute 0 degrees.

[0005]

However, such a conventional three-axis motion sensor 100 has the following problems. The geomagnetism detected by the magnetic sensor 104 has deviations and inclinations for each region (latitude and longitude of the earth) and different horizontal forces, so that a different depression angle (an angle formed by a surface horizontal plane and a geomagnetic vector) occurs for each region. Therefore, if the yaw angle detected by using the geomagnetism is not corrected in consideration of the geomagnetic deviation, the inclination, and the horizontal force in each region, a reversal phenomenon of the yaw angle occurs.

Since the liquid sensor and the mechanical (pendulum) method are used for the tilt sensor 103, it takes time for the change of the liquid and the pendulum to stabilize, and the data is not stable. Unreliable data may be output for a certain period of time.
Therefore, when the three-axis motion sensor 100 is used for a screen pointing device, a seasickness phenomenon or the like occurs on a display screen, and when the three-axis motion sensor 100 is used for a positioning device, a wrong direction indication or the like occurs.

Since the liquid sensor and the mechanical (pendulum) sensor are used for the tilt sensor 103, the size of the entire sensor 100 is increased. The present invention has been made in view of such a problem, and provides a posture detecting device which is small and can always detect posture information of a detection target object with high accuracy in any region on the earth. With the goal.

[0008]

According to a first aspect of the present invention, there is provided an attitude detecting apparatus for detecting an attitude of an object to be detected, and an attitude information detecting section for detecting an attitude of the object to be detected. An arithmetic processing unit that calculates angle information according to the attitude of the detected object based on the attitude information is provided, and the arithmetic processing unit considers geomagnetism for the attitude information obtained by the attitude information detection unit. It is characterized by comprising a correction unit capable of correcting the angle information by performing the correction described above.

According to a second aspect of the present invention, there is provided an attitude detecting apparatus according to the first aspect, wherein the attitude information detecting section detects a magnetic field intensity due to terrestrial magnetism;
An inclination detection unit that detects an inclination of the detected object with respect to the surface horizontal plane, and a calculation processing unit calculates rotation angle information of the detected object on the surface horizontal plane based on the detection result of the magnetic detection unit by calculation. A rotation angle calculation unit for calculating, and a tilt angle calculation unit for calculating tilt angle information of the detected object with respect to the surface horizontal plane based on the detection result of the tilt detection unit, and the correction unit calculates the tilt angle. The rotation angle information obtained by the rotation angle calculation unit is corrected by converting the magnetic field intensity information detected by the magnetic detection unit based on the inclination angle information obtained by the unit into magnetic field intensity information on the surface horizontal plane. It is characterized by being constituted so that it can be performed.

According to a third aspect of the present invention, there is provided the attitude detecting apparatus according to the second aspect, wherein the magnetic detecting section has a first sheet-like coil member having an annular coil pattern functioning as an exciting coil. A linear coil pattern for detecting a saturation state of the magnetic field, the linear coil pattern being disposed on one surface side of the first sheet coil member so as to cross the annular coil pattern of the first sheet coil member; A second sheet-like coil member, and a linear coil pattern for detecting a saturated state of the magnetic field. The second coil member is disposed such that the linear coil pattern intersects the linear coil pattern of the second sheet-like coil member. It is characterized by comprising a third sheet-shaped coil member disposed on one surface side of the sheet-shaped coil member.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a view schematically showing the appearance of a three-axis motion sensor as a posture detecting device according to an embodiment of the present invention, FIG. 2 is a view as viewed from an arrow A in FIG. 1, and FIG. 1 to 3, 1 is a three-axis motion sensor, 2A is a substrate-type fluxgate sensor, 2B is an inclination sensor, and 3 is C
PU, 4 is a control board on which the above-mentioned inclination sensor 2B, CPU 3 and the like are arranged, 5 is an external connection terminal, and 6 is a column for connecting the flux gate sensor 2A and the control board 4 so as to keep them parallel. .

Focusing on the function, the three-axis motion sensor 1 of the present embodiment is configured as shown in FIG. 4. In the present embodiment, the pitch of the detection target to which the sensor 1 is attached is set. , Roll, yaw angle [Fig.
(See (a) to FIG. 27 (c)]). The attitude information detecting section 2 for detecting attitude information includes a flux gate sensor 2A and an inclination sensor 2B.

Here, the flux gate sensor (magnetic detection unit) 2A detects the magnetic field intensity due to the terrestrial magnetism, and the inclination sensor (inclination detection unit) 2B detects the inclination of the object to be detected with respect to the surface horizontal plane. And CP
The U (arithmetic processing unit) 3 calculates angle information (pitch, roll, yaw angle) corresponding to the posture of the detection target based on the posture information detected by the sensors 2A and 2B. However, here, each sensor 2A, 2A
The above-mentioned yaw angle can be corrected by performing a correction in consideration of the geomagnetism on the information obtained in B.

For this reason, as shown in FIG. 4, the CPU 3 includes an inclination angle calculator 31, a rotation angle calculator 32, and a correction unit 33.
Is the yaw angle (rotation angle information) of the detected object on the surface horizontal plane based on the detection result of the flux gate sensor 2A.
Is calculated by the calculation.
Calculates the pitch and roll (inclination angle information) of the detection target object with respect to the horizontal surface based on the detection result of the inclination sensor 2B by calculation.

The correction section 33 converts the magnetic field strength information detected by the flux gate sensor 2A based on the pitch and roll obtained by the above-described inclination angle calculation section 32 on a horizontal surface of the surface by coordinate conversion processing described later. The yaw angle obtained in the rotation angle calculator 31 is corrected by converting the information into the magnetic field strength information. Next, FIG. 5 is a diagram schematically showing the configuration of the above-described flux gate sensor 2A. As shown in FIG. 5, the flux gate sensor 2A of the present embodiment has two epoxy substrates 6 each. , 7, 8 and an amorphous core 9 formed in a ring shape and supplied with a current to function as an exciting coil. Here,
The epoxy substrates 6 ', 7, 8 are made of glass.

As shown in FIG. 5, a linear coil pattern 10 for detecting the saturation state of the magnetic field is formed on the epoxy substrate (third sheet coil member) 6 'by etching. And the epoxy substrate (second
On the sheet-shaped coil member 7, a similar linear coil pattern 11 is formed by etching in a direction intersecting (perpendicular to) the coil pattern 10.

On the epoxy substrate 8, a plurality of linear coil patterns 12 are formed in a ring shape by etching, and the amorphous core (first sheet-shaped coil member) 9 has an etching like a toroidal coil. A pattern is formed so as to function as an exciting coil. Here, each of the above-mentioned etching (coil) patterns is formed such that its etching width is on the order of several microns.

That is, the flux gate sensor 2A of the present embodiment has the amorphous core 9 and the linear coil pattern 11, and the linear coil pattern 11 traverses the coil pattern of the amorphous core 9. And a linear coil pattern 10 disposed on one side of the epoxy substrate 7 such that the linear coil pattern 10 intersects the linear coil pattern 11 of the epoxy substrate 7. And an epoxy substrate 6 '.

Thus, the present fluxgate sensor 2
A shows linear coil patterns 10 and 1 intersecting each other with information on magnetic field strength generated when the amorphous core 9 is excited.
By measuring at 1, the geomagnetic directionality can be obtained. As described above, the flux gate sensor 2A of the present embodiment does not require the conventional winding technology for forming a coil by forming a coil pattern required as a magnetic sensor by using the etching technology. There is no variation in sensitivity due to wire irregularities or winding pressure, and the accuracy can be controlled on the order of microns. As a result, the fluxgate sensor 2A is formed extremely thin while maintaining the magnetic detection performance, and the size of the entire three-axis motion sensor 1 is greatly reduced.

The above-mentioned amorphous core 9 does not necessarily need to be formed in a ring shape as shown in FIG. 5, but may be formed in another shape such as a flat plate shape. The epoxy substrates 6 ', 7, and 8 may be made of plastic instead of glass as long as they can be etched. Next, FIG. 6 is a block diagram showing a configuration of a main part of the above-described tilt sensor 2B. As shown in FIG. 6, the tilt sensor 2B according to the present embodiment includes independent fixed pole plates 21 and 22. A center electrode 24 mounted on a main beam 23 operable in response to an applied acceleration;
4, two capacitors (CS1, CS2) are formed.

Thus, in the tilt sensor 2B, as shown in FIG. 7, for example, the main beam 23 is activated when acceleration is applied to the tilt sensor 2B when the object to be detected is tilted with respect to the horizontal surface. Then, the above 2
A mismatch occurs between the two capacitance values CS1 and CS2. As a result, a current corresponding to the inclination with respect to the surface horizontal plane flows through the center electrode plate 24. If this current value is supplied to the CPU 3 as inclination detection information, the above-described inclination angle calculation is performed. The required inclination angle information (pitch, roll) is detected in the section 32.

That is, the tilt sensor 2B is designed to be integrated as an IC by enabling the tilt information to be detected by utilizing the change in capacitance as described above.
The size of the entire axis motion sensor 1 is greatly reduced. The dimensions of the three-axis motion sensor 1 are 45 mm in length and 30 m in width as shown in FIG.
m and a height of about 8.5 mm.

Hereinafter, the operation of the three-axis motion sensor 1 according to the present embodiment configured as described above will be described with reference to the flowchart (steps S1 to S5) shown in FIG. First, the flux gate sensor 2A detects the magnetic field intensity due to the terrestrial magnetism (Step S1).
Then, the detected magnetic field strength information is provided to the CPU 3, and the CPU 3 calculates the yaw angle by the rotation angle calculation unit 31 based on the magnetic field strength information. There is a difference, a deviation, a horizontal force, and the like, and geomagnetism cannot be detected depending on the inclination angle of the flux gate sensor 2A.
3 is used to perform a correction process.

This correction process is performed based on tilt detection information obtained by the tilt sensor 2B. Tilt sensor 2B
When the object to be detected to which the three-axis motion sensor 1 is attached is inclined with respect to the horizontal surface, inclination detection information such as a current value corresponding to the inclination is obtained (step S2). The obtained information is supplied to the CPU 3 and the CPU 3
In 3, the pitch and roll are calculated by a predetermined calculation based on the tilt detection information and output by the tilt calculator 32 (step S3).

The correction section 33 calculates the pitch,
By performing the following coordinate conversion process based on the roll, the magnetic field intensity information detected by the flux gate sensor 2A is converted into magnetic field intensity information on the surface horizontal plane (coordinate conversion), and these inclinations and deviations are converted. Then, a state where there is no influence of the horizontal force is set (step S4). As a result, the rotation angle calculation unit 3
In step 1, arithmetic processing is performed based on the corrected magnetic field strength information, and a correct and accurate yaw angle is always calculated (step S5).

Here, the above-described coordinate conversion processing will be described in detail. (A) General operation method of coordinate transformation For example, as shown in FIG. 8, a fixed coordinate system set in space is (xh, yh, zh), and this coordinate system is φ, yh around the xh axis. It is assumed that the coordinate system when rotated about the axis by θ is (x, y, z). However, the sign of each rotation angle is set as shown in FIG.

First, in this (xh, yh, zh) coordinate system, the magnetic flux vector H (→) = (HXH, HYH, HZ)
H). In the (x, y, z) coordinate system, the vector H (→) is expressed as H (→) = (HX, HY, HZ). Therefore, the conversion from the (xh, yh, zh) coordinate system to the (x, y, z) coordinate system is

[0028]

(Equation 1)

## EQU2 ## Conversely, (x, y, z)
The transformation from the coordinate system to the (xh, yh, zh) coordinate system is

[0030]

(Equation 2)

## EQU1 ## As an actual state, (xh,
yh, zh) coordinate system on the ground surface (gravity is "-z"
(Direction), the (x, y, z) coordinate system can be considered, for example, a ship. At this time, if the vector H (→) is considered to be geomagnetism, it can be approximated as HZH 0 (3). Therefore, the magnitude of the vector H (→), that is, the horizontal amplitude of the fluxgate sensor 2A, φ,
Once θ is known, HZ can be calculated from equation (1).

HZ = −HXH sin θ + HYH · cos θ · sin φ (4) By expanding the equation (2) of the matrix, HXH = HX cos θ + HY sin θ · sin φ−HZ sin θ · cos φ (5) HYH = HY · cos φ + HZ · sin φ · .. (6) HZH = HX sin θ−HY cos θ · sin φ + HZ cos θ · cos φ (7)

Cos φ = C1, cos θ = C2, sin
Assuming that φ = S1 and sin θ = S2, the equation (4) is replaced by
HXH = HX · C2 + HY · S2 · S1 − (− HXH · S2 + HYH · C2 · S1) · C1 · S2 = HX · C2 + HY · S1 · S2 + HXH · C1 · S2 ² -HYH · C1 · C2 · S1 · S2 ... (8) By substituting equation (4) into equation (6), HYH = HY · C1 + (− HYH · S2 + HYH · C2 · S1) · S1 = HY · C1−HXH · S1 · S2 + HYH · C2 · S1 ² ... (9) When formula (8) is rearranged for HXH,

[0034]

(Equation 3)

When formula (9) is rearranged for HXH,

[0036]

(Equation 4)

By combining equations (10) and (11), HY
Arranging about H,

[0038]

(Equation 5)

When formula (8) is rearranged for HYH,

[0040]

(Equation 6)

When formula (9) is arranged for HYH,

[0042]

(Equation 7)

By combining equations (13) and (14), HX
Arranging about H,

[0044]

(Equation 8)

When recalculated from equations (7) and (3),

[0046]

(Equation 9)

Substituting equation (16) into equation (5) and rearranging,

[0048]

(Equation 10)

Here, C2 ² + S2 ² = cos ² θ +
From sin ² = 1, HXH = HX / C2 (17) Substituting equation (16) into equation (6) and rearranging:

[0050]

[Equation 11]

Next, the reverse conversion formula is reestablished. HXH = HX · C2-HZ · S2 (19) HYH = HX · S1 · S2-HY · C1 + HZ · C1 · C2 (20) HZH = HX · C1 · S2-HY · S1 + HZ · C1 · C2 (21) When HZH = 0 in equation (21), HZ is obtained.

[0052]

(Equation 12)

Substituting equation (22) into equation (19) and rearranging,

[0054]

(Equation 13)

Substituting equation (22) into equation (20) and rearranging,

[0056]

[Equation 14]

(B) Basic Definition A coordinate system (xh, yh, z
h) is a reference coordinate system. This reference coordinate system is shown in FIG.
0 (a) and φ around the xh axis as shown in FIG.
Let the coordinate system rotated by (x ′, y ′, z ′) be the coordinate system 1. At this time, the vector p (→) is expressed as p (→) = (xh, yh, zh) in the reference coordinate system, and p (→ h) in the coordinate system 1.
If (→) = (x ′, y ′, z ′), the relationship between them is expressed in a matrix expression.

[0058]

(Equation 15)

Is expressed as follows. Next, a coordinate system (x, y, z) obtained by rotating the reference coordinate system by θ with respect to the y ′ axis as shown in FIGS. 11A and 11B is referred to as a coordinate system 2. At this time, the vector p (→) is expressed as p in the coordinate system 2.
Expressing (→) = (x, y, z), the matrix expression of the relationship between the coordinate system 1 and the coordinate system 2 is

[0060]

(Equation 16)

Is expressed as follows. From the equations (25) and (26), the relationship between the reference coordinate system and the coordinate system 2 is

[0062]

[Equation 17]

Is obtained. This is an equation in which the signs of φ and θ are opposite to those in equation (1). Hereinafter, consideration will be given based on this equation (27).
Next, considering the inverse transformation from the coordinate system 2 to the coordinate system 1 for the vector p (→),

[0064]

(Equation 18)

The inverse transformation from the coordinate system 1 to the reference coordinate system is as follows.

[0066]

[Equation 19]

Is obtained. Therefore, the conversion from the coordinate system 2 to the reference coordinate system is performed according to equations (28) and (29).

[0068]

(Equation 20)

Is obtained. (C) Angle Expression of Tilt Sensor Next, as shown in FIG. 12B, a case where the above-described tilt sensor 2B is attached to the origin of the coordinate system 2 will be considered. It is assumed that the z (-) direction is the direction of gravity in the reference coordinate system as shown in FIG. At this time, when the output of the inclination sensor 2B is expressed as x-axis rotation angle: u y-axis rotation angle: v, these angles u and v are expressed as (xh, yh ) It can be considered as an angle between an x-y axis and an intersection line when the plane crosses the (x, z) plane and the (y, z) plane of the coordinate system 2.

U: the angle between the intersection of the (xh, yh) plane and the (y, z) plane and the y axis v: the intersection between the (xh, yh) plane and the (x, z) plane and x
Consider the relationship between these u and v and φ and θ used in the above coordinate transformation. First, when φ = 0 and θ = 0, since the coordinate system 2 matches the reference coordinate system, it is clear that u = 0 and v = 0.

Next, consider a case where the inclination sensor 2B is attached to the center of the coordinate system 1 rotated by φ about the x-axis. In this case, it can be intuitively said that u = −φ. Here, considering a unit vector (length 1) perpendicular to the (xh, yh) plane, it is considered that u and v can be obtained by obtaining an angle with the z ′ axis after coordinate conversion. Equation (2
5)

[0072]

(Equation 21)

∴ x ′ = 0, y ′ = sin φ, z ′ = cos θ (31) At this time, as shown in FIG. 13, the angle between the z ′ axis and the y ′, z ′ components of the vector is u = −tan ⁻¹ (y ′ / z ′) = ⁻ tan ⁻¹ (sin φ / cos φ) = ⁻ tan ⁻¹ (tan φ) = − φ (32) Then, y ′ Consider a case where the inclination sensor 2B is attached to the center of the coordinate system 2 rotated by θ about the axis. In this case, v = 0 can be said intuitively. Similarly, when u and v are determined in consideration of the unit vector,
From equation (27),

[0074]

(Equation 22)

Ｘ x = −cos θ · sin θ, y = sin θ, z = cos φ · cos θ (33) As shown in FIG. 14, when the slopes of the y and z components are obtained from the z axis, u = −tan ^{− 1} (y / z) = ⁻ tan ⁻¹ [sin φ / (cos φ · cos θ)] = ⁻ tan ⁻¹ (tan φ / cos θ) (34) Similarly, as shown in FIG. When the slope of the z component is obtained, v = −tan ⁻¹ (x / z) = − tan ⁻¹ [− (cos φ · sin θ) / (cos φ · cos θ)] = ⁻ tan ⁻¹ (−sin θ / cos θ) = −tan ⁻¹ (−tan θ) = θ (35)

(D) Conversion of Geomagnetic Vector from Coordinate System 2 to Reference Coordinate System Assuming that the geomagnetic vector is (xh, yh, 0), from equation (25), x = xh · cos θ + yh · sin φ · sin θ (36) y = yh · cosφ (37) z = xh · sinθ−yh · sinφ · cosθ (38) From equation (34), yh = y / cosφ (39) From Expressions (36) and (39), x = xh · cos θ + y · sin φ · sin θ / cos φ ∴xh · cos θ = x−y · sin φ · sin θ / (cos φ · cos θ) ∴xh = (x / cos θ) −y · Tanφ · tanθ (40)

As another approach, from equation (30), xh = x · cos θ + z · sin θ (41) yh = x · sin φ · sin θ + y · cos φ−z · sin φ · cos θ (42) zh = −x · cosφ · sinθ + y · sinφ + z · cosφ · sinθ (43) Since zh = 0 now, 0 = −x · cosφ · sin
From θ + y · sin φ + z · cos φ · sin θ,

[0078]

(Equation 23)

From equations (41) and (44),

[0080]

(Equation 24)

This is the same result as in equation (40). From equations (42) and (44),

[0082]

(Equation 25)

This also has the same result as equation (39).
When φ and θ are replaced by u and v, the geomagnetic vector [the detection value (x, y) of the fluxgate sensor 2A] is coordinated to the reference coordinate system (surface horizontal plane) by the detection value (u, v) of the inclination angle sensor 2B. Can be converted. From equation (34), tan (u) = − tan φ / cos θ ∴tan φ = −cos θ · tan (u) (47) This is substituted into equation (46), and from equation (35), xh = x / Cos (v) + cos (v) · tan (u) · tan (v) · y (48) Further, Expression (47) is simplified, and φ = u · cosθ (49) By substituting this into equation (39), yh = y / cos (u · cosv) (50) The rotation angle calculator 31 of the CPU 3 calculates the magnetic field intensity of the terrestrial magnetism corrected by the coordinate conversion as described above. The yaw angle is calculated based on the information.

The above coordinate conversion may be performed by the following calculation. That is, as shown in FIG. 16, the coordinate system to which the inclination sensor 2B is attached is (x, y, z). In this case, the actual horizontal plane is yz
The angle u between the line of intersection and the y-axis when traversing the plane is considered as output data of the tilt sensor. Similarly, the angle v between the intersection line when the horizontal plane crosses the xz plane and the x-axis is considered as output data of the tilt sensor. In this case, the direction from the x and y axes is positive in the z axis (+) direction, and the point where the x and y axes coincide with the intersection line is 0.

Here, the reference coordinate system (x
h, yh, zh), the xh, yh plane coincides with the horizontal plane. At this time, attention is paid to the relationship between the z axis and the zh axis. As shown in FIG. 17A, the angle between the line connecting z-zh and the x-axis when looking down from above the z-axis is α.
However, when the value coincides with the x-axis, the value is 0, and the value from the x-axis (+) to the y-axis (+) is +. Also, as shown in FIG.
The angle between the z axis and the zh axis is denoted by β. Then, FIG.
As shown in FIGS. 18A and 18B, when α is 0, it matches v, and when α is 90 degrees, it matches u.

Here, the relationship between u and v and α and β is obtained.
A unit vector of length 1 that matches the zh axis (0, 0, 1)
think of. The angle between the shadow of the vector on the x and z planes and the z axis is v, and the angle between the shadow on the yz plane and the z axis is u. When this vector is expressed by (x, y, z) coordinates, as shown in FIG. 19, the length between the z-axis component and the vector vertex is sin β, and the length of the z-axis component is cos β. Therefore, x = sinβ · cosα y = sinβ · sinα (51) z = cosβ From this, FIGS. 20, 21 (a) and 21
As can be seen from (b), tan (−v) = sinβ · cosα / cosβ (52) tan (−u) = sinβ · sinα / cosβ (53) Equations (52) and (53) ), Cosα = tan (−v) / tanβ (54) sinα = tan (−u) / tanβ (55) By dividing equation (55) by equation (54), tanα = Tan (-u) / tan (-v) ∴α = tan ^-1 [tan (-u) / tan (-v)] When the equations (54) and (55) are squared and added, cos ^{2 α + sin 2 α = tan 2} (-v) / tan 2 β + tan 2 (-u) / tan 2 β ∴ 1 = ^{[tan 2 (-v) + tan 2} (-u) ] ^{/ tan 2 β tan 2 β =} tan ² (−u) + tan ² (−v) tan β = (tan ² (−u) + tan ² (−v)) ^{1 /} 2∴β = tan ⁻¹ [(tan ² (−u) + tan ² (−v)) ^1/2 ] (56)

Next, the z axis is made to coincide with the zh axis. Consider a coordinate system (x ′, y ′, z ′) in which the z-axis is rotated by α. At this time, the zh axis is on the x'z 'plane. (X,
Consider an arbitrary vector n (→) on (y, z). n
Assuming that (→) takes the value of (x, y, z) in the (x, y, z) coordinate system, x ′ = x · cos α + y · sin α y in the (x ′, y ′, z ′) coordinate system. '= −x · sin α + y · cos α (57) z ′ = z In a matrix expression,

[0088]

(Equation 26)

## EQU11 ## Next, as shown in FIGS. 22 and 23, the coordinates rotated β with respect to the y ′ axis are represented by (x ″, y ″,
z ″), x ″ = x ′ · cos β−z ′ · sin β y ″ = y ′ (59) z ″ = x ′ · sin β + z ′ · cos β In the matrix expression,

[0090]

[Equation 27]

Is obtained. Further, when the z ″ axis is rotated by −α, the reference coordinate system is (xh, yh, zh). Xh = x ″ · cosα−y ″ · sinα yh = x ″ · sinα + y ″ · cosα (61) ) Zh = 0 In matrix expression

[0092]

[Equation 28]

Is obtained. From the above, when (xh, yh, zh) is obtained from the (x, y, z) coordinates,

[0094]

(Equation 29)

When expanded, xh = x · (cos ² α · cos β + sin ² α) + y · (cos α · cos β · sin α−sin α · cos α) −z · cos α · sin β yh = x · (sin α · cos β · cos α−cos α · Sin α) + y · (sin ² α · cos β + cos ² α)-z · sin α · sin β zh = x · sin β · cos α + y · sin α · sin β + z · cos β · · · · · · ^{2 α · cosβ + sin 2 α} -cos 2 α -sin 2 α + 1) + y · cosα · sinα (cosβ-1) -z · cosα · sinβ = x · ^{[cos 2 α · (cosβ-1} ) +1 ] + ... (Omitted hereafter) = x + cosα · [x · cosα (cosβ−1) + y · sinα (cosβ−1) −z · sinβ] (64) ∴yh = x · cosα · sinα ( cosβ-1) + y (sin 2 α · cosβ + cos 2 α-cos 2 α-sin 2 α + 1) = x · cosα · sinα (cosβ-1) + y [sin ² α (cosβ- 1) +1] + z · sinα · sinβ = y + sinα [x · cosα (cosβ−1) + y · sin (cosβ−1) −z · sinβ] (65) From equations (64) and (65), The correction term Δx of x and the correction term Δy of y are respectively expressed as follows: Δx = cosα [x · cosα (cosβ−1) + y · sinα (cosβ−1) −z · sinβ] (66) Δy = sinα [ x · cosα (cosβ−1) + y · sin (cosβ−1) −z · sinβ] (67) Here, if ΔT is defined as ΔT = x · cosα (cosβ−1) + y · sin (cosβ−1) −z · sinβ (68), Expressions (64) and (65) are expressed as xh = x + Δx = x + cosα · ΔT (69) yh = y + Δy = y + sinα · ΔT (70) Here, if zh ≠ 0, equation (63)
More, zh = x · sinβ · cosαy · sinα · sinβ + z · cosβ ∴ -z = x (cosα · sinβ / cosβ) + y (sinα · sinβ / cosβ) -zh / cosβ -z · sinβ = x (cosα · sin 2 β / cosβ) + y (sinα · sin 2 β / cosβ) -zh · sinβ / cosβ

[0096]

[Equation 30]

From the above,

[0098]

(Equation 31)

## EQU10 ## As described above, according to the three-axis motion sensor 1 of the present embodiment, the correction unit 33 of the CPU 3 performs the correction in consideration of the terrestrial magnetism on the rotation angle information obtained by the flux gate sensor 2A, thereby detecting the rotation angle information. Since the rotation angle (yaw angle) information of the object can be corrected, the attitude (angle information) of the object to be detected is always irrespective of the geomagnetic deviation, inclination, and horizontal force, that is, in any area of the earth's surface. ) Can be accurately and accurately detected, which greatly contributes to the improvement of the reliability of the present sensor 1 device.

Specifically, the magnetic field intensity information detected by the fluxgate sensor 2A is converted into magnetic field intensity information on a horizontal surface based on the pitch and roll (detected value of the inclination sensor 2B) of the object to be detected. As a result, the yaw angle information of the detection target obtained based on the magnetic field strength information due to the terrestrial magnetism is corrected, so that the yaw angle reversal phenomenon due to the terrestrial magnetism deviation, inclination, horizontal force, etc. is reliably prevented, and the pitch And the roll can always obtain an accurate yaw angle of the object to be detected, which further contributes to the improvement of the reliability of the sensor 1.

Further, in the three-axis motion sensor 1 of the present embodiment, the flux gate sensor 2A is formed extremely thin as described above, and the tilt sensor 2B is formed into an IC to reduce the size. It is downsized. The three-axis motion sensor 1 according to the present embodiment
Has a flux gate sensor 2A and a tilt sensor 2B as the posture information detecting unit 2 as shown in FIG. 4, but may be configured as a two-axis motion sensor including only the tilt sensor 2B. Further, the flux gate sensor 2A and the tilt sensor 2B do not necessarily need to use the special ones described above, and may use normal ones.

[0102]

As described above in detail, according to the attitude detecting apparatus of the first aspect of the present invention, the correction section of the arithmetic processing section detects the terrestrial magnetism with respect to the attitude information obtained by the attitude information detecting section. The angle information obtained in accordance with the posture of the detection target object can be corrected by performing the correction in consideration of the correction, and therefore, irrespective of the geomagnetic deviation, the inclination, and the horizontal force,
In any area of the ground surface, the attitude (angle information) of the detection target can always be detected accurately and accurately, which greatly contributes to the improvement of the reliability of the present apparatus.

Further, according to the attitude detecting apparatus of the present invention, the magnetic field intensity information detected by the magnetic detection unit is detected on the surface horizontal plane based on the inclination angle information of the object to be detected with respect to the surface horizontal plane. By converting to magnetic field strength information,
Since the rotation angle information of the detected object obtained based on the magnetic field intensity information due to the geomagnetism is corrected, it is possible to reliably prevent the rotation angle information from being reversed due to the deviation, inclination, horizontal force, etc. of the geomagnetism, In addition, accurate rotation angle information of the object to be detected can always be obtained, which further contributes to improvement of the reliability of the present apparatus.

Further, according to the attitude detecting apparatus of the present invention, the magnetic detecting section has a sheet-like coil member having an annular coil pattern functioning as an exciting coil, and a linear coil pattern. Since the configuration is provided with the sheet-shaped coil member, the configuration is extremely thinned while maintaining the magnetic detection performance, which greatly contributes to downsizing of the entire posture detection device.

[Brief description of the drawings]

FIG. 1 is a diagram schematically illustrating an appearance of a three-axis motion sensor as a posture detection device according to an embodiment of the present invention.

FIG. 2 is a view taken in the direction of arrow A in FIG.

FIG. 3 is a view taken in the direction of arrow B in FIG. 1;

FIG. 4 is a functional block diagram of the three-axis motion sensor of the embodiment.

FIG. 5 is a diagram schematically showing a configuration of a flux gate sensor used in the three-axis motion sensor of the embodiment.

FIG. 6 is a block diagram illustrating a configuration of a main part of a tilt sensor used in the three-axis motion sensor according to the embodiment.

FIG. 7 is a diagram for explaining the operation of the tilt sensor according to the embodiment.

FIG. 8 is a diagram illustrating a coordinate conversion process in the three-axis motion sensor according to the embodiment.

FIG. 9 is a diagram illustrating a coordinate conversion process in the three-axis motion sensor according to the embodiment.

FIGS. 10A and 10B are diagrams illustrating a coordinate conversion process in the three-axis motion sensor according to the present embodiment.

FIGS. 11A and 11B are diagrams illustrating a coordinate conversion process in the three-axis motion sensor according to the present embodiment.

FIGS. 12A and 12B are diagrams for explaining a coordinate conversion process in the three-axis motion sensor according to the present embodiment.

FIG. 13 is a diagram for explaining a coordinate conversion process in the three-axis motion sensor of the embodiment.

FIG. 14 is a diagram illustrating a coordinate conversion process in the three-axis motion sensor according to the embodiment.

FIG. 15 is a diagram illustrating a coordinate conversion process in the three-axis motion sensor according to the embodiment.

FIG. 16 is a diagram for explaining a coordinate conversion process in the three-axis motion sensor of the embodiment.

FIGS. 17A and 17B are diagrams for explaining a coordinate conversion process in the three-axis motion sensor according to the present embodiment.

FIGS. 18A and 18B are diagrams for explaining a coordinate conversion process in the three-axis motion sensor according to the present embodiment.

FIG. 19 is a diagram illustrating a coordinate conversion process in the three-axis motion sensor according to the embodiment.

FIG. 20 is a diagram illustrating a coordinate conversion process in the three-axis motion sensor according to the embodiment.

FIGS. 21A and 21B are diagrams for explaining a coordinate conversion process in the three-axis motion sensor according to the present embodiment.

FIG. 22 is a diagram illustrating a coordinate conversion process in the three-axis motion sensor according to the embodiment.

FIG. 23 is a diagram illustrating a coordinate conversion process in the three-axis motion sensor according to the embodiment.

FIG. 24 is a flowchart illustrating the operation of the three-axis motion sensor according to the present embodiment.

FIG. 25 is a schematic perspective view showing an example of a three-axis motion sensor as a conventional posture detecting device.

26 (a) and (b) are pitch, roll,
It is a figure for explaining a yaw angle.

27 (a) to (c) are pitch, roll,
It is a figure for explaining a yaw angle.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 3-axis motion sensor (posture detection apparatus) 2 Posture information detection part 2A Flux gate sensor (magnetic detection part) 2B Inclination sensor (tilt detection part) 3 CPU (arithmetic processing part) 4 Control board 5 External connection terminal part 6 Post 6 ', 7,8 Epoxy substrate 9 Amorphous core 10-12 Linear coil pattern 21,22 Fixed electrode plate 23 Main beam 24 Center electrode plate 31 Rotation angle calculator 32 Tilt angle calculator 33 Correction unit

Claims (3)

[Claims] 1. An attitude information detecting section for detecting attitude information of an object to be detected, and based on the attitude information detected by the attitude information detecting section,
An arithmetic processing unit for calculating angle information according to the attitude of the detected object by calculation, wherein the arithmetic processing unit corrects the attitude information obtained by the attitude information detection unit in consideration of geomagnetism And a correction unit that can correct the angle information by performing the correction. 2. The apparatus according to claim 1, wherein the attitude information detecting section includes: a magnetic detecting section for detecting a magnetic field intensity due to terrestrial magnetism; and an inclination detecting section for detecting an inclination of the detected object with respect to a horizontal surface. A rotation angle calculator for calculating rotation angle information of the detection target on the surface horizontal plane based on the detection result of the magnetic detection unit; and the detection target based on the detection result of the tilt detection unit. A tilt angle calculating unit for calculating tilt angle information of the object with respect to the surface horizontal plane by calculation; and the correction unit detects the tilt angle information based on the tilt angle information obtained by the tilt angle calculating unit. By converting the obtained magnetic field strength information into magnetic field strength information on the ground surface horizontal plane, it is characterized in that it is configured to be able to correct the rotation angle information obtained in the rotation angle calculation unit, Claim 1 posture detection device as claimed. 3. A magnetic sensor comprising: a first sheet-like coil member having an annular coil pattern functioning as an exciting coil; and a linear coil pattern for detecting a saturation state of a magnetic field. A second sheet-shaped coil member disposed on both sides of the first sheet-shaped coil member so as to cross the annular coil pattern of the first sheet-shaped coil member; and a linear shape for detecting a saturation state of a magnetic field. The second sheet-like coil member has a coil pattern so that the linear coil pattern intersects the linear coil pattern.
3. The attitude detecting device according to claim 2, further comprising a third sheet-shaped coil member disposed on one surface side of the sheet-shaped coil member.