JP2008216266A - Rotary angle measuring instrument and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an azimuthal angle measuring instrument, a rotary angle measuring instrument, an azimuthal angle measuring program, a rotary angle measuring program, an azimuthal angle measuring method, and a rotary angle measuring method, for accurately measuring an azimuthal angle irrespective of a place of measurement and suitable for cost reduction. <P>SOLUTION: Inclination angle data is calculated from triaxial earth magnetism data obtained when the azimuthal angle measuring instrument is set at a known inclination angle and from triaxial earth magnetism data obtained when the instrument is set at an inclination angle for an ordinarily used attitude. The inclination angle data is used to correct an azimuthal angle. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rotation angle measurement device, a rotation angle measurement program, and a rotation angle measurement method. In particular, the present invention relates to a rotation angle measurement device, a rotation angle measurement program, and a rotation angle measurement method that can accurately measure the azimuth angle regardless of the measurement location and are suitable for reducing costs.

FIG. 8 shows the geomagnetic component in the ground coordinate system (xg, yg, zg).
The ground coordinate axes xg, yg, and zg are oriented in the north-south direction, the east-west direction, and the vertical direction, respectively. The components Mxg, Myg, and Mzg of the geomagnetic total magnetic force M in the ground coordinate axes xg, yg, and zg directions are the north-south component and the east-west direction, respectively. A component and a geomagnetic component called a vertical component force, and a component parallel to the xg? Yg plane is called a horizontal component force. Further, an angle D formed between the horizontal component force and the xg axis is called a declination, and an angle I formed between the geomagnetic total magnetic force M and the horizontal component force is called a dip angle. In general, the north direction indicated by the compass is the direction of horizontal component force and is called magnetic north.
Conventionally, as a technique for measuring an azimuth angle, there are the following two azimuth angle measurement apparatuses.
The first azimuth measuring device includes a biaxial magnetic sensor that detects geomagnetic components in directions orthogonal to each other, places the azimuth measuring device on a horizontal plane, and calculates the azimuth based on the biaxial output obtained from the magnetic sensor. It comes to measure.

Next, the configuration of the second azimuth measuring device will be described with reference to FIGS.
FIG. 9 is a perspective view showing a magnetic sensor mounting structure in a conventional azimuth measuring device.
In FIG. 9, the second azimuth measuring device includes an x-axis magnetic sensor HEx that detects a geomagnetic component in the x-axis direction with the vertical direction of the azimuth measuring device as the x-axis, and the horizontal direction of the azimuth measuring device as the y-axis. The y-axis magnetic sensor HEy for detecting the geomagnetic component in the y-axis direction and the z-axis magnetic sensor HEz for detecting the geomagnetic component in the z-axis direction with the thickness direction of the azimuth measuring device as the z-axis are provided. The x-axis magnetic sensor HEEx, the y-axis magnetic sensor HEy, and the z-axis magnetic sensor HEz are composed of Hall elements and the like, and are arranged so that each magnetosensitive surface is perpendicular to each axis, and the geomagnetic component in each axis direction is A sensor signal of a corresponding magnitude is output.

FIG. 10 is a perspective view showing a mounting structure of an inclination angle sensor in a conventional azimuth measuring device.
In FIG. 10, the second azimuth measuring device is provided with an inclination angle sensor 17 for detecting an inclination angle η of the y axis with respect to the xg? Yg plane and an inclination angle φ of the x axis with respect to the xg? Yg plane. The tilt angle sensor 17 outputs a sensor signal having a magnitude corresponding to the tilt angle η and a sensor signal having a magnitude corresponding to the tilt angle φ.

FIG. 11 is a block diagram showing a configuration of a conventional azimuth measuring device.
In FIG. 11, the second azimuth measuring device includes a triaxial magnetic sensor 11, a magnetic sensor drive power supply unit 12, a multiplexer unit 13, a magnetic sensor amplification unit 14, a magnetic sensor A / D conversion unit 15, and sensitivity / offset correction. A unit 16, an inclination angle sensor 17, an inclination angle sensor amplification unit 18, an inclination angle sensor A / D conversion unit 19, a measurement data correction unit 20, and an azimuth angle calculation unit 21 are provided.

The three-axis magnetic sensor 11 is provided with an x-axis magnetic sensor HEEx, a y-axis magnetic sensor HEy, and a z-axis magnetic sensor HEz.
The multiplexer unit 13 is for switching between the x-axis magnetic sensor HEEx, the y-axis magnetic sensor HEy, and the z-axis magnetic sensor HEz. The multiplexer unit 13 converts the drive voltage output from the magnetic sensor drive power supply unit 12 into the x-axis magnetic sensor HEEx, The sensor signals applied to the y-axis magnetic sensor HEy and the z-axis magnetic sensor HEz, respectively, and output from the x-axis magnetic sensor HEx, the y-axis magnetic sensor HEy, and the z-axis magnetic sensor HEz are time-divided to the magnetic sensor amplifier 14. Output.

The magnetic sensor A / D converter 15 A / D converts sensor signals from the x-axis magnetic sensor HEx, the y-axis magnetic sensor HEy, and the z-axis magnetic sensor HEz, and converts the converted digital data into x-axis geomagnetic measurement data, The y-axis geomagnetism measurement data and the z-axis geomagnetism measurement data are output to the sensitivity / offset correction unit 16.
The sensitivity / offset correction unit 16 is based on the x-axis geomagnetism measurement data, the y-axis geomagnetism measurement data, and the z-axis geomagnetism measurement data from the magnetic sensor A / D conversion unit 15, and the x-axis magnetic sensor HEx and the y-axis magnetic sensor HEy. The offset and sensitivity correction coefficient of the z-axis magnetic sensor HEz are calculated, and the x-axis geomagnetic measurement data, the y-axis geomagnetic measurement data, and the z-axis geomagnetic measurement data are corrected based on the calculated offset and sensitivity correction coefficient.

The tilt angle sensor A / D conversion unit 19 A / D converts the sensor signal from the tilt angle sensor 17 and outputs the converted digital data to the measurement data correction unit 20 as tilt angle measurement data.
The measurement data correction unit 20 is based on the tilt angle measurement data from the tilt angle sensor A / D conversion unit 19, and x-axis geomagnetism measurement data, y-axis geomagnetism measurement data, and z-axis geomagnetism measurement from the sensitivity / offset correction unit 16. Correct the data.

The azimuth calculation unit 21 calculates the azimuth based on the x-axis geomagnetic measurement data, the y-axis geomagnetic measurement data, and the z-axis geomagnetic measurement data from the measurement data correction unit 20.
As a technique close to the second azimuth measuring device, for example, there is an azimuth output device disclosed in Patent Document 1.
The azimuth | direction output apparatus of patent document 1 is the azimuth | direction where the measurement error by the non-horizontal state was corrected using geomagnetic information X, Y, Z from a three-dimensional geomagnetic sensor, and inclination amount (alpha), (beta) detected by the inclination sensor. θmg is calculated. Further, the true direction θtr is calculated using the declination value D from the declination value output unit, and the calculated true direction θtr is presented.

Thereby, it is possible to perform azimuth measurement without an error due to tilt even in a non-horizontal state and to present a true azimuth.
Moreover, the invention of patent document 2, the invention of patent document 3, and the invention of patent document 4 are proposed as information using the magnitude | size of the geomagnetism of a measurement area | region, and the information of a dip.
JP-A-8-278137 JP 63-027711 A JP 2003-156335 A JP 2003-166825 A

However, in the conventional first azimuth measuring device, it is necessary to place the azimuth measuring device on a horizontal plane, and therefore, the problem that the azimuth angle cannot be accurately measured in a place where the level cannot be secured. was there.
In the second conventional azimuth measuring device, it is not necessary to place the azimuth measuring device on a horizontal plane, but instead, it is necessary to measure the inclination angles η and φ of the azimuth measuring device. An inclination angle sensor 17, an inclination angle sensor amplification unit 18, and an inclination angle sensor A / D conversion unit 19 are provided. Therefore, there is a problem that the cost increases.
Accordingly, the present invention provides a rotation angle measurement device, a rotation angle measurement program, and a rotation angle measurement method that can accurately measure the azimuth angle regardless of the measurement location and are suitable for reducing costs. Objective.

The following invention is provided to solve the above-mentioned conventional problems.
The rotation angle measuring device according to claim 1 of the present invention is a three-axis magnetic detection means for detecting magnetic components in directions orthogonal to each other, and three or more different magnets rotated around one straight line as a rotation axis. Rotation angle calculation means for calculating rotation angle data of the rotation and the rotation axis based on three or more different three-axis output data detected by the magnetic detection means in the posture state of the detection means. It is characterized by.

  With such a configuration, for example, when the user measures the environmental magnetic field while holding the rotation angle measurement device, magnetic components in directions orthogonal to each other are detected by the magnetic detection means. The magnetic detection means detects three or more different three-axis output data in three or more different posture states. Then, the rotation angle data and the rotation axis of rotation are calculated based on three or more different three-axis output data by the rotation angle calculation means.

  According to a second aspect of the present invention, there is provided the rotation angle measuring apparatus according to the present invention, wherein the three-axis magnetic detection means for detecting magnetic components in directions orthogonal to each other, and the first posture state of the magnetic detection means are set as the magnetic state. A coordinate system of the magnetic detection means for detecting a component, and the first posture state rotated around one coordinate axis of a three-axis coordinate system in which the relative relationship between the three coordinate axes and the coordinate origin is known; A different posture state of the magnetic detection means is set as a second posture state, the first three-axis output data detected by the magnetic detection means in the first posture state, and the magnetism in the second posture state. Rotation angle calculation means for calculating the rotation angle data of the rotation and the rotation axis based on second triaxial output data different from the first triaxial output data detected by the detection means. It is characterized by being That.

  With such a configuration, for example, when the user measures the azimuth while holding the rotation angle measurement device in hand, the magnetic components in the directions orthogonal to each other are detected by the magnetic detection means. The first posture state of the rotation angle measuring device is expressed by a coordinate system of a magnetic detection means for detecting a magnetic component, and one coordinate axis of a three-axis coordinate system in which the relative relationship between the three coordinate axes and the coordinate origin is known. When the posture state of the rotation angle measuring device different from the first posture state rotated as the rotation axis is set to the second posture state, the first three axes that are magnetic components in the first posture state are detected by the magnetic detection means. Second triaxial output data different from the first triaxial output data which is the output data and the magnetic component in the second posture state is detected. Then, the rotation angle calculation means calculates rotation angle data and a rotation axis based on the first three-axis output data and the second three-axis output data.

A rotation angle measurement program according to a third aspect of the present invention is a program for causing a computer that can use a three-axis magnetic detection means for detecting magnetic components in directions orthogonal to each other to be executed. Rotation angle data of the rotation based on three or more different three-axis output data detected by the magnetic detection means in the posture state of three or more different magnetic detection means rotated about one straight line as a rotation axis And a program for causing the computer to execute processing for realizing a rotation angle calculation means for calculating the rotation axis.
If it is such a structure, when a program will be read by computer and a computer will perform a process by the read program, the effect | action equivalent to the rotation angle measuring device of Claim 1 which concerns on this invention will be acquired.

An azimuth angle measuring method according to claim 4 of the present invention is a program for causing a computer that can use three-axis magnetic detection means for detecting magnetic components in directions orthogonal to each other to be executed, and The first posture state of the magnetic detection means is defined as one coordinate axis of a coordinate system of the magnetic detection means for detecting the magnetic component, a three-axis coordinate system in which the relative relationship between the three coordinate axes and the coordinate origin is known. The first attitude state detected by the magnetic detection means in the first attitude state is defined as the attitude state of the magnetic detection means different from the first attitude state rotated about the rotation axis. Based on the output data and the second three-axis output data different from the first three-axis output data detected by the magnetic detection means in the second posture state, the rotation angle data and the rotation of the rotation Characterized in that it is a program for executing a process to realize the rotation angle calculating means for calculating the computer.
If it is such a structure, when a program will be read by computer and a computer will perform a process by the read program, the effect | action equivalent to the rotation angle measuring device of Claim 2 which concerns on this invention will be acquired.

  According to a fifth aspect of the present invention, there is provided a rotation angle measuring method according to the fifth aspect of the present invention, which uses three axes of magnetic detection means for detecting magnetic components in directions orthogonal to each other and rotates three straight axes as a rotation axis. A three-axis output data acquisition step of acquiring three or more different three-axis output data detected by the magnetic detection means in the different posture states of the magnetic detection means, and three or more different three axes And a rotation angle calculation step of calculating the rotation angle data of the rotation and the rotation axis based on the output data.

  According to a sixth aspect of the present invention, there is provided a rotation angle measuring method according to the present invention, wherein the first posture state of the magnetic detection means is determined using a triaxial magnetic detection means for detecting magnetic components in directions orthogonal to each other. The first coordinate system is rotated about one coordinate axis of a coordinate system of the magnetic detection means for detecting the magnetic component and a three-axis coordinate system in which the relative relationship between the coordinate axes of the three axes and the coordinate origin is known. A first three-axis output data acquisition step of acquiring a first three-axis output data by the magnetic detection unit in the first posture state, wherein the posture state of the magnetic detection unit different from the posture state is set as a second posture state. A second three-axis output data acquisition step of acquiring second three-axis output data different from the first three-axis output data by the magnetic detection means in the second posture state, and the first three Axis output data and the second three-axis output Based on the data, and characterized in that it comprises a rotation angle calculating step of calculating the rotation angle data and the rotation axis of the rotation.

An embodiment of the present invention will be described with reference to the drawings.
An embodiment of an azimuth measuring device, an azimuth measuring program, and an azimuth measuring method according to the present invention will be described with reference to FIGS.
FIG. 1 is a perspective view showing a mounting structure of a magnetic sensor in an azimuth measuring apparatus 100 according to the present invention.
As shown in FIG. 1, the azimuth measuring device 100 includes an x-axis magnetic sensor HEx that detects a geomagnetic component in the x-axis direction with the vertical direction of the azimuth measuring device 100 as the x-axis, and the lateral direction of the azimuth measuring device 100. A y-axis magnetic sensor HEy that detects the geomagnetic component in the y-axis direction as the y-axis and a z-axis magnetic sensor HEz that detects the geomagnetic component in the z-axis direction with the thickness direction of the azimuth measuring device 100 as the z-axis are provided. . The x-axis magnetic sensor HEEx, the y-axis magnetic sensor HEy, and the z-axis magnetic sensor HEz are composed of Hall elements and the like, and are arranged so that each magnetosensitive surface is perpendicular to each axis, and the geomagnetic component in each axis direction is A sensor signal of a corresponding magnitude is output.

FIG. 2 is a diagram showing a posture state of the azimuth measuring apparatus 100 according to the present invention.
As shown in FIG. 2, when the ground coordinate system is (xg, yg, zg) and the three-axis coordinate system of the azimuth measuring device 100 (hereinafter referred to as the measuring device coordinate system) is (x, y, z). The attitude state of the azimuth measuring apparatus 100 is represented by an inclination angle α, an inclination angle η, and an azimuth angle θ.
Here, assuming that the measurement device coordinate system and the ground coordinate system match first, the azimuth angle measurement device 100 is first left around the z axis of the measurement device coordinate system, looking at the origin from the z-axis positive direction. Rotate around the y axis of the measuring device coordinate system, then rotate it around the y axis in the positive direction of the y axis and rotate it clockwise by the angle α, and finally around the x axis of the measuring device coordinate system In addition, when the origin is viewed from the x-axis positive direction and rotated counterclockwise by an angle η, θ is referred to as an azimuth angle, and α and η are referred to as inclination angles.

The azimuth angle θ is an angle formed by an axis formed by projecting the xg axis of the ground coordinate system and the x axis of the measurement apparatus coordinate system onto the zg-yg plane of the ground coordinate system, and the inclination angle α is the x of the measurement apparatus coordinate system. The angle formed between the axis projected on the zg-yg plane of the ground coordinate system and the x axis, and the inclination angle η is a rotation angle from a predetermined reference position around the x axis.
Here, the azimuth measuring device 100 is rotated (−α) around the y-axis of the measuring device coordinate system, and the xy plane of the measuring device coordinate system matches the xg-yg plane of the ground coordinate system. Sometimes, the azimuth measuring device 100 is a reference position.

FIG. 3 is a block diagram showing a configuration of the azimuth measuring apparatus 100 according to the present invention.
As shown in FIG. 3, the azimuth measuring apparatus 100 includes a three-axis magnetic sensor 31, a magnetic sensor drive power supply unit 32, a multiplexer unit 33, a magnetic sensor amplification unit 34, a magnetic sensor A / D conversion unit 35, a sensitivity / offset. A correction unit 36, an inclination angle information calculation unit 37, an inclination angle information storage unit 38, an inclination angle correction calculation unit 39, and an azimuth angle calculation unit 40 are provided.
The triaxial magnetic sensor 31 is provided with an x axis magnetic sensor HEEx, a y axis magnetic sensor HEy, and a z axis magnetic sensor HEz.

  The multiplexer unit 33 is for switching between the x-axis magnetic sensor HEEx, the y-axis magnetic sensor HEy, and the z-axis magnetic sensor HEz. The multiplexer unit 33 converts the drive voltage output from the magnetic sensor drive power supply unit 32 into the x-axis magnetic sensor HEEx, The sensor signals that are applied to the y-axis magnetic sensor HEy and the z-axis magnetic sensor HEz, respectively, and output from the x-axis magnetic sensor HEx, the y-axis magnetic sensor HEy, and the z-axis magnetic sensor HEz are time-divided to the magnetic sensor amplifier 34. Output.

The magnetic sensor amplifier 34 amplifies sensor signals from the x-axis magnetic sensor HEEx, the y-axis magnetic sensor HEy, and the z-axis magnetic sensor HEz and outputs the amplified signal to the magnetic sensor A / D converter 35.
The magnetic sensor A / D conversion unit 35 performs A / D conversion on the sensor signals from the x-axis magnetic sensor HEx, the y-axis magnetic sensor HEy, and the z-axis magnetic sensor HEz amplified by the magnetic sensor amplification unit 34, and converts the converted digital signal. The data is output to the sensitivity / offset correction unit 36 as x-axis geomagnetic measurement data, y-axis geomagnetic measurement data, and z-axis geomagnetic measurement data, respectively.

  The sensitivity / offset correction unit 36 is based on the x-axis geomagnetism measurement data, the y-axis geomagnetism measurement data, and the z-axis geomagnetism measurement data from the magnetic sensor A / D conversion unit 35. The offset and sensitivity correction coefficient of the z-axis magnetic sensor HEz are calculated, and the x-axis geomagnetic measurement data, the y-axis geomagnetic measurement data, and the z-axis geomagnetic measurement data are corrected based on the calculated offset and sensitivity correction coefficient.

The tilt angle information calculation unit 37 calculates an angle difference Δα from the reference tilt angle based on the x-axis geomagnetic measurement data, the y-axis geomagnetic measurement data, and the z-axis geomagnetic measurement data from the sensitivity / offset correction unit 36. The inclination angle α is calculated based on the calculated angle difference Δα and the reference inclination angle, and the inclination angle information indicating the calculated inclination angle α is stored in the inclination angle information storage unit 38.
The tilt angle correction calculation unit 39 corrects the x-axis geomagnetic measurement data, the y-axis geomagnetic measurement data, and the z-axis geomagnetic measurement data from the sensitivity / offset correction unit 36 based on the tilt angle information in the tilt angle information storage unit 38. .
The azimuth angle calculation unit 40 calculates the azimuth angle θ based on the x-axis geomagnetic measurement data, the y-axis geomagnetic measurement data, and the z-axis geomagnetic measurement data from the tilt angle correction calculation unit 39.

Next, details of a method for calculating the angle difference Δα, the inclination angle α, and the azimuth angle θ will be described with reference to FIGS.
FIG. 4 is a diagram for determining the posture state of the azimuth measuring apparatus 100. As shown in FIG. 4, in the azimuth measuring apparatus 100, the attitude state of the azimuth measuring apparatus is determined by the azimuth angle θ and the inclination angle α. Note that the y-axis is always parallel to the xg? Yg plane, and when the tilt angle α is 90 °, the x-axis and zg-axis are assumed to be parallel. Then, between the ground coordinate system (xg, yg, zg) and the measuring device coordinate system (x, y, z), coordinates as shown in the following formula (1) are excluded, except for the translation component due to the difference in the origin. The conversion formula is established.

  Further, the components Mxg, Myg, Mzg of the ground coordinate system of the geomagnetic total magnetic force M described in FIG. 8 are expressed by the following equations (2), (3), and (4).

  Therefore, the components Mx, My, Mz of the measuring device coordinate system of the geomagnetic total magnetic force M, that is, the three-axis output data Mx, My, Mz of the three-axis magnetic sensor 31 are expressed by the following equations (5), (6), and (7 ).

Here, as shown in FIG. 4, with the azimuth angle θ fixed, geomagnetism is measured at a known tilt angle α ₀ and tilt angle α ₁ at which the azimuth angle is desired to be measured. The triaxial component data obtained by the geomagnetism measurement at the known tilt angle α ₀ is obtained as the geomagnetism measurement data M _x0 , M _y0 , M _z0, and obtained by the geomagnetism measurement at the tilt angle α1 for which the azimuth angle θ is to be measured. The obtained three-axis component data is represented as geomagnetic measurement data M _x1 , M _y1 , M _z1 .
As described above, the operation of changing the attitude state of the azimuth angle measuring apparatus 100 from the inclination angle α ₀ to the inclination angle α ₁ while fixing the azimuth angle θ is a straight line parallel to the y axis and passing through the origin. The rotation operation around this rotation axis. That is, this rotation operation changes the components in the x direction and the z direction, but does not change the component in the y direction.

FIG. 5 is a diagram illustrating an example of an operation for changing the posture state of the azimuth measuring apparatus 100.
As shown in FIG. 5, an operation for changing the posture state of the azimuth measuring device 100 can be easily performed by changing the elbow angle while the user is facing a certain direction. Further, a more practical operation is to start the azimuth measuring device 100 from a horizontal posture state, and to bring the operation screen of the azimuth measuring device 100 to an angle that is easy for the user to see, the posture state of the azimuth measuring device 100 It is an operation to change.
If the angle difference Δα between the two different inclination angles α ₀ and α ₁ described above is Δα = α ₁ −α ₀ , the geomagnetic measurement data M _x0 , My ₀ , M _z0 and the geomagnetic measurement The data M _x1 , M _y1 , and M _z1 satisfy the following formula (8).

  That is, when the formula (8) is transformed, the following formulas (9) and (10) are obtained.

Therefore, the angle difference Δα can be obtained from the equations (9) and (10).
Further, the inclination angle α is obtained based on the angle difference Δα and the known inclination angle α by the following equation (11).

  With respect to the geomagnetism measurement data Mx, My, and Mz when the azimuth measuring apparatus 100 faces the direction to be measured while the inclination angle α (= α) calculated by the above-described method is fixed, the following equation (12) Thus, the geomagnetic measurement data Mx ′, My ′, Mz ′ corrected for the tilt angle can be obtained.

  By substituting the equations (5), (6), and (7) into the equation (12), the following equations (13), (14), and (15) are obtained.

  Therefore, the azimuth angle (θ−D), that is, the azimuth angle θ based on the magnetic north direction can be obtained by the following equation (16).

Next, the operation of the present embodiment will be described.
As shown in FIG. 5, when measuring the azimuth angle θ (or θ? D) of the azimuth measuring device 100, the user holds the azimuth measuring device 100 in his hand and performs an operation of starting the acquisition of the tilt angle information. . First, the user fixes the posture state of the azimuth measuring apparatus 100 to a known (eg, horizontal) inclination angle α ₀ by setting the elbow to an angle α ₀ , and the known inclination angle α _{0 is set} to the azimuth measuring apparatus 100. To measure geomagnetism. The geomagnetic measurement data M _x0 , M _y0 , M _z0 obtained by the measurement are sent to the tilt angle information calculation unit 37 in FIG. Further, the input tilt angle α ₀ is stored in the tilt angle information storage unit 38.

Next, as shown in FIG. 5, the user changes the elbow to the angle α ₁ , so that the orientation state of the azimuth measuring apparatus 100 is fixed while the azimuth when the tilt angle α ₀ is measured is fixed. The geomagnetism is measured by fixing the angle to the inclination angle α ₁ (usually the posture state in which the azimuth angle θ is measured). The geomagnetic measurement data M _x1 , M _y1 , and M _z1 obtained by the measurement are sent to the inclination angle information calculation unit 37 in FIG.

Next, the tilt angle information calculation unit 37 uses the above-described equations (9) and (10) to obtain the geomagnetic measurement data M _x0 , M _y0 , M _z0 obtained at the known tilt angle α ₀ , and the azimuth. Based on the geomagnetic measurement data M _x1 , M _y1 , M _z1 obtained at the inclination angle α ₁ at which the angle θ is to be measured, the angle difference Δα of the inclination angle is calculated, and a known inclination is calculated using equation (11). The inclination angle α ₁ is calculated based on the angle α ₀ and the angle difference Δα between the inclination angles. The tilt angle α ₁ that is the calculated tilt angle information is stored in the tilt angle storage unit 38. Here, the azimuth measuring device 100 displays a notification that the tilt angle information has been obtained, and the azimuth angle θ at the tilt angle α (= α ₁ ) to be measured can be measured.

Next, when measuring the azimuth angle θ, the user measures the azimuth angle θ described above by rotating the elbow at a tilt angle α (= α) and rotating around the height axis passing through the elbow. The azimuth measuring device 100 is positioned in the desired direction, and an operation for starting azimuth measurement is performed. First, when geomagnetism is measured, the obtained geomagnetism measurement data Mx, My, Mz are sent to the tilt angle correction calculation unit 39 shown in FIG. Here, the geomagnetic measurement data M _x1 , M _y1 , M _z1 measured at the second inclination angle α ₁ can be used as they are. At this time, it is not necessary to measure geomagnetism. Then, the inclination angle correction calculation unit 39, the above equation (12) geomagnetic measured data M _x corrected tilt angle by _{', M y', M z} ' are calculated, the azimuth angle calculation unit 40 of FIG. 1 Sent. The azimuth angle θ is calculated by the azimuth angle calculation unit 40 using the above equation (16).

Thus, in this embodiment, the user is held in the hand of the azimuth measuring device 100, by changing the angle of the elbow, and the known tilt angle alpha _0, in the inclination angle alpha ₁ Tokyo to be measured azimuth Geomagnetic measurement data is acquired from the triaxial magnetic sensor 31, the angle difference Δα of the inclination angle is calculated, and the inclination angle α ₁ is calculated based on the calculated angle difference Δα and the inclination angle α ₀ . Then, while the elbow is fixed at the inclination angle α (= α ₁ ), the user rotates around the height direction axis passing through the elbow, and acquires the geomagnetic measurement data from the triaxial magnetic sensor 31 again. The azimuth angle θ is calculated based on α. Here, when the geomagnetic measurement data M _x1 , M _y1 and M _z1 measured at the inclination angle α ₁ are used as they are, the inclination angle α (==) is not acquired again from the triaxial magnetic sensor 31. The azimuth angle θ is calculated based on α ₁ ).
As a result, the attitude state of the azimuth measuring device 100 is changed while the angle θ between the xg axis of the ground coordinate system and the axis projected on the xg-yg plane of the ground coordinate system is fixed. The inclination angle α can be measured simply by making it.

Next, an embodiment of a rotation angle measurement device, a rotation angle measurement program, and a rotation angle measurement method will be described with reference to FIG.
FIG. 6 is a block diagram showing the configuration of the rotation angle measuring apparatus 200 according to the present invention.
As shown in FIG. 6, the rotation angle measuring apparatus 200 includes a three-axis magnetic sensor 51, a magnetic sensor drive power supply unit 52, a multiplexer unit 53, a magnetic sensor amplification unit 54, a magnetic sensor A / D conversion unit 55, sensitivity / offset correction. A unit 56 and a rotation angle calculation unit 57 are provided.
The triaxial magnetic sensor 51 is provided with an x axis magnetic sensor HEEx, a y axis magnetic sensor HEy, and a z axis magnetic sensor HEz.

  The multiplexer unit 53 is for switching between the x-axis magnetic sensor HEEx, the y-axis magnetic sensor HEy, and the z-axis magnetic sensor HEz. The multiplexer 53 converts the drive voltage output from the magnetic sensor drive power supply unit 52 into the x-axis magnetic sensor HEEx, The sensor signals that are applied to the y-axis magnetic sensor HEy and the z-axis magnetic sensor HEz, respectively, and output from the x-axis magnetic sensor HEx, the y-axis magnetic sensor HEy, and the z-axis magnetic sensor HEz are time-divided to the magnetic sensor amplifier 54. Output.

The magnetic sensor amplifier 54 amplifies the sensor signals from the x-axis magnetic sensor HEEx, the y-axis magnetic sensor HEy, and the z-axis magnetic sensor HEz and outputs the amplified signal to the magnetic sensor A / D converter 55.
The magnetic sensor A / D conversion unit 55 performs A / D conversion on the sensor signals from the x-axis magnetic sensor HEx, the y-axis magnetic sensor HEy, and the z-axis magnetic sensor HEz amplified by the magnetic sensor amplification unit 54, and converts the converted digital signal. The data is output to the sensitivity / offset correction unit 56 as x-axis geomagnetic measurement data, y-axis geomagnetic measurement data, and z-axis geomagnetic measurement data, respectively.

The sensitivity / offset correction unit 56 is based on the x-axis geomagnetism measurement data, the y-axis geomagnetism measurement data, and the z-axis geomagnetism measurement data from the magnetic sensor A / D conversion unit 55, and the x-axis magnetic sensor HEx and the y-axis magnetic sensor HEy. The offset and sensitivity correction coefficient of the z-axis magnetic sensor HEz are calculated, and the x-axis geomagnetic measurement data, the y-axis geomagnetic measurement data, and the z-axis geomagnetic measurement data are corrected based on the calculated offset and sensitivity correction coefficient.
The rotation angle calculation unit 57 calculates the rotation angle Δα around the rotation axis based on the x-axis geomagnetism measurement data, the y-axis geomagnetism measurement data, and the z-axis geomagnetism measurement data from the sensitivity / offset correction unit 56.

Next, the details of the calculation method of the rotation angle will be described with reference to FIG.
First, an example of a calculation method of the rotation angle when the geomagnetic measurement data is measured by the triaxial magnetic sensor 51 in three different posture states of the rotation angle measuring device 200 will be described.
When the rotation angle measuring device 200 is rotated about the rotation axis (1, φ _A , θ _A ) represented by the polar coordinate system, the geomagnetic measurement data measured by the three-axis magnetic sensor 51 before the rotation is M, If the geomagnetic measurement data measured by the rotated three-axis magnetic sensor 51 is M ′, the relationship between the geomagnetic measurement data M and the geomagnetic measurement data M ′ satisfies the following expression (17). Here, the geomagnetic measurement data M and the geomagnetic measurement data M ′ are represented by three-dimensional vectors. The transformation matrix T is expressed by the following equations (18), (19), and (20).

The relationship between the geomagnetic measurement data M and the geomagnetic measurement data M ′ described above is a point obtained by rotating the point M in the three-dimensional space (−α) around the rotation axis (1, φ _A , θ _A ). This is the same as the relationship between the point M and the point M ′ when M ′.
Accordingly, the rotation shaft _{(1, φ A, θ A} ) when the alpha ₁₂ rotates the rotational angle measuring device 200 around the geomagnetic measurement data measured by the three-axis magnetic sensor 51 before rotation and M _1, after the rotation When the geomagnetic measurement data measured by the three-axis magnetic sensor 51 is M _2, and the rotation angle measuring device 200 is further rotated α ₂₃ around the rotation axis (1, φ _A , θ _A ), the three axes after rotation When the geomagnetic measurement data measured by the magnetic sensor 51 and M _3, the magnetic measurement data M _1, the relationship of the magnetic measurement data M ₂ and the magnetic measurement data M ₃ are, the point M ₁ on the three-dimensional space, the rotation shaft ( 1, a point rotated by (−α ₁₂ ) around (φ _A , θ _A ) as a point M _2, and a point further rotated (−α ₂₃ ) around a rotation axis (1, φ _A , θ _A ) the point M ₁ when the point M _3, is the same as the relationship between the point M ₂ and point M _3.

In FIG. 7, a point obtained by rotating the point M in the three-dimensional space (−α ₁₂ ) around the rotation axis (1, φ _1A , θ _A ) is defined as a point M ₂ , and the rotation axis (1, φ _A is a diagram showing the relationship between (-.alpha. ₂₃₎ points M ₁ when the point is rotated to a point M _3, points M ₂ and point M ₃ around theta _a). As shown in FIG. 7, the point M ₁ , the point M _2, and the point M ₃ are on the same plane and further on the circumference of one circle. The rotation axes (1, φ _A , θ _A ) are normals of a plane formed by the points M ₁ , M _2, and M ₃ passing through the coordinate origin of the three-dimensional space, and these normals are Pass through the center point of the circle.
The normal vector n of the plane formed by the points M ₁ , M ₂ and M ₃ , that is, the rotation axis n represented by the three-axis orthogonal coordinate system is represented by the following equation (21).

  Therefore, an arbitrary point x on the plane is represented by the following expression (22), and the center point C of the circle is represented by the following expression (23).

Accordingly, the rotation shaft _{(1, φ A, θ A} ) when rotated alpha _ij rotational angle measuring device 200 around the geomagnetic measurement data measured by the three-axis magnetic sensor 51 before rotation and M _i, after rotation When the geomagnetic measurement data measured by the three-axis magnetic sensor 51 is M _j , the rotation angle α _ij is obtained by the following equations (24) and (25).

Next, an example of a calculation method of the rotation angle when the geomagnetic measurement data is measured by the triaxial magnetic sensor 51 in four or more different posture states of the rotation angle measuring device 200 will be described.
As described above, the relationship between the geomagnetic measured data M _i and the geomagnetic measured data M _j is the point M _i rotary shaft _{(1, φ A, θ A} ) when the point M _j points rotated about the Since the relationship between the point M _i and the point M _j is the same, the equation of the plane created by the point M _i associated with the measured geomagnetic measurement data M _i is expressed as x + by + cz + d = 0, ax + y + cz + d = 0, or Assuming that ax + by + z + d = 0, unknowns a, b, c, and d are obtained by the method of least squares. Here, the plane equation is generally expressed by ax + by + cz + d = 0, but at least one of the unknowns a, b, c, and d is 1. That is, an appropriate three geomagnetic measured data M _i measured into equation (21), x component of the normal vector n, y component, or the absolute value of z component coefficients large enough component than 0, Set to 1.
The point M _i, 'when the point M _i' point M _i of the points projected on a plane determined is represented by the following equation (26).

  Since the normal vector is n = (a, b, c), the center point C of the circle is expressed by the following equation (27).

Accordingly, the rotation shaft _{(1, φ A, θ A} ) when rotated alpha _ij rotational angle measuring device 200 around the geomagnetic measurement data measured by the three-axis magnetic sensor 51 before rotation and M _i, after rotation When the geomagnetic measurement data measured by the three-axis magnetic sensor 51 is M _j , the rotation angle α _ij is obtained by the following equations (28) and (29).

Next, an example of a calculation method of the rotation angle when the relative relationship between the coordinate axis and the coordinate origin of the arbitrary coordinate system X _rot and the measurement apparatus coordinate system X _M is known will be described. Here, the measurement device coordinate system X _M is a three-axis coordinate system of the rotation angle measurement device 200.
It is assumed that the coordinate system X _rot and the measurement apparatus coordinate system X _M satisfy the following expressions (30) and (31).

That is, the coordinate system X _rot is a coordinate formed by first rotating the measurement apparatus coordinate system X _M around the z axis by θ, then rotating around the y axis, and finally rotating around the x axis by η. It is a system.
The geomagnetic measurement data measured by the three-axis magnetic sensor 51 in the first posture of the rotary angle measuring device 200 and M _1, the rotation axis of any one of the coordinate axes of the coordinate system X _rot, the coordinate system X _rot and When the measuring device coordinate system X _M is rotated α, the geomagnetic measurement data measured by the three-axis magnetic sensor 51 is M _2, and a value obtained by converting the geomagnetic measurement data M ₁ into the coordinate system X _rot is converted into a converted value. _Assuming that M _rot1 and the value obtained by coordinate transformation of the geomagnetic measurement data M ₂ to the coordinate system X _rot are the converted value M _rot2 , the converted value M _rot1 and the converted value M _rot2 are _expressed by the following equations (32) and (33). Is done.

Here, the relationship between the conversion value M _rot1 and the conversion value M _rot2 is expressed by the following equations (34) and (37) when the x-axis is a rotation axis, and when the y-axis is a rotation axis, the following equation ( 35) and (38), and when the z-axis is a rotation axis, they are represented by the following equations (36) and (39).

Using equation (32) and (33), M ₁ and geomagnetism measuring data geomagnetic measurement data calculated conversion value M _rot and converted value M _ROT2 than M _2, the converted value M _rot and the conversion value M _ROT2 A component whose component change between them is 0 or a sufficiently small value is obtained. The coordinate axis representing the obtained component becomes the rotation axis.
The rotation angle α is obtained using any one of the equations (37), (38), or (39) corresponding to the obtained rotation axis.

Next, the operation of the present embodiment will be described.
When measuring the rotation angle Δα of the rotation angle measurement device 200, the user holds the rotation angle measurement device 200 in his hand and performs an operation for starting the acquisition of the tilt angle information. First, the user fixes the posture state of the rotation angle measurement device 200 to a known (eg, horizontal) inclination angle α ₀ by setting the elbow to an angle α ₀ , and the known inclination angle α _{0 is set} to the rotation angle measurement device 200. To measure geomagnetism. The geomagnetic measurement data M _x0 , M _y0 , and M _z0 obtained by the measurement are sent to the tilt angle information calculation unit 57 in FIG.

Next, by changing the elbow to the angle α ₁ , the user fixes the posture state of the rotation angle measuring device 200 to the tilt angle α ₁ while fixing the azimuth angle when the tilt angle α ₀ is measured, Measure geomagnetism. The geomagnetic measurement data M _x1 , M _y1 , and M _z1 obtained by the measurement are sent to the tilt angle information calculation unit 57 in FIG.
Next, the tilt angle information calculation unit 57 uses the above-described equations (9) and (10) to obtain the geomagnetic measurement data M _x0 , M _y0 , M _z0 and the tilt angle obtained at the known tilt angle α ₀ . Based on the geomagnetic measurement data M _x1 , M _y1 and M _z1 obtained at α ₁ , the angle difference Δα of the tilt angle, that is, the rotation angle Δα is calculated.

In the embodiment of the rotation angle measurement device, rotation angle measurement program, and rotation angle measurement method described above, the three-axis magnetic sensor 51 corresponds to the magnetic detection means according to claim 1, 2, 3, 4, 5, or 6. The rotation angle calculation unit 57 corresponds to the rotation angle calculation means described in claim 1, 2, 3, or 4.
In the above-described embodiment, as shown in FIG. 2, the tilt angle (α) is changed, but the twist angle is calculated by a similar theory when the twist angle (η) is changed. can do.

In the above-described embodiment, as shown in FIG. 2, the ground coordinate system (xg, yg, zg) is the two axes on the horizontal plane and the vertical axis, but any ground coordinate system may be used. The rotation angle (θ, α, η) can be calculated by a similar theory.
In the above-described embodiment, the case where Hall elements are used as the triaxial magnetic sensor 31 and the triaxial magnetic sensor 51 has been described as an example, but the axial magnetic sensor 31 and the triaxial magnetic sensor 51 are not necessarily Hall elements. For example, a fluxgate sensor or the like may be used.

  In the embodiments of the azimuth measuring device, the azimuth measuring program, and the azimuth measuring method described above, the sensitivity / offset correction calculation unit 36, the tilt angle information calculation unit 37, the tilt angle correction calculation unit 39, and the azimuth calculation. The processing performed by the unit 40 may be realized by hardware, or the azimuth measuring device 100 may be configured as a computer in which a CPU, a ROM, and a RAM are connected by a bus, and the CPU may execute the processing. In this case, the control program stored in advance in the ROM may be executed, or the program may be read from the information recording medium storing the program showing these procedures and executed. May be.

  In the embodiment of the rotation angle measurement device, rotation angle measurement program, and rotation angle measurement method described above, the processing performed by the sensitivity / offset correction calculation unit 56 and the rotation angle calculation unit 57 may be realized by hardware. The rotation angle measuring device 200 may be configured as a computer in which a CPU, a ROM, and a RAM are connected by a bus, and the CPU may execute the processing. In this case, the control program stored in advance in the ROM may be executed, or the program may be read from the information recording medium storing the program showing these procedures and executed. May be.

Here, the information recording medium is a semiconductor recording medium such as RAM or ROM, a magnetic storage type recording medium such as FD or HD, an optical reading type recording medium such as CD, CDV, LD, or DVD, or a magnetic storage such as MO. Any type / optical reading type recording medium, including any information recording medium that can be read by a computer, regardless of electronic, magnetic, optical, or other reading methods.
In addition, the above-mentioned embodiment is for description and does not limit the scope of the present invention. Accordingly, those skilled in the art can employ embodiments in which each or all of these elements are replaced by equivalents thereof, and these embodiments are also included in the scope of the present invention.

It is a perspective view which shows the attachment structure of the magnetic sensor in the azimuth measuring device which concerns on this invention. It is a figure which shows the attitude | position state of the azimuth measuring device which concerns on this invention. It is a block diagram which shows the structure of the azimuth measuring device which concerns on this invention. It is a figure which defines the attitude | position state of an azimuth measuring device. It is a figure which shows an example of operation which changes the attitude | position state of an azimuth measuring device. It is a block diagram which shows the structure of the rotation angle measuring device which concerns on this invention. Point M _1, is a diagram showing the relationship of the point M ₂ and point M _3. The geomagnetic component in the ground coordinate system (xg, yg, zg) is shown. It is a perspective view which shows the attachment structure of the magnetic sensor in the conventional azimuth measuring device. It is a perspective view which shows the attachment structure of the inclination angle sensor in the conventional azimuth measuring device. It is a block diagram which shows the structure of the conventional azimuth measuring device.

Explanation of symbols

11, 31, 51 3-axis magnetic sensor HEx x-axis Hall element HEy y-axis Hall element HEz z-axis Hall element 12, 32, 52 Magnetic sensor drive power supply unit 13, 33, 53 Multiplexer unit 14, 34, 54 Magnetic sensor amplifier unit 15, 35, 55 Magnetic sensor A / D conversion unit 16, 36, 56 Sensitivity / offset correction unit 37 Inclination angle calculation unit 38 Inclination angle information storage unit 20, 39 Measurement data correction unit 21, 40 Azimuth angle calculation unit 57 Rotation angle Calculation unit

Claims (6)

Triaxial magnetic detection means for detecting magnetic components in directions orthogonal to each other;
The rotation angle of the rotation based on three or more different three-axis output data detected by the magnetic detection means in the posture state of three or more different magnetic detection means rotated about one straight line as a rotation axis Rotation angle calculating means for calculating data and the rotation axis;
A rotation angle measuring device comprising: Triaxial magnetic detection means for detecting magnetic components in directions orthogonal to each other;
The first posture state of the magnetic detection means is defined as one of a coordinate system of the magnetic detection means for detecting the magnetic component and one of a three-axis coordinate system in which the relative relationship between the three coordinate axes and the coordinate origin is known. The posture state of the magnetic detection means different from the first posture state rotated about the coordinate axis as a rotation axis is set as a second posture state,
The first three-axis output data detected by the magnetic detection means in the first posture state is different from the first three-axis output data detected by the magnetic detection means in the second posture state. Rotation angle calculation means for calculating rotation angle data of the rotation and the rotation axis based on second triaxial output data;
A rotation angle measuring device comprising: A program for causing a computer capable of using three-axis magnetic detection means for detecting magnetic components in directions orthogonal to each other to execute the method,
The rotation angle of the rotation based on three or more different three-axis output data detected by the magnetic detection means in the posture state of three or more different magnetic detection means rotated about one straight line as a rotation axis A rotation angle measurement program, which is a program for causing the computer to execute processing for realizing rotation angle calculation means for calculating data and the rotation axis. A program for causing a computer capable of using three-axis magnetic detection means for detecting magnetic components in directions orthogonal to each other to execute the method,
The first posture state of the magnetic detection means is defined as one of a coordinate system of the magnetic detection means for detecting the magnetic component and one of a three-axis coordinate system in which the relative relationship between the three coordinate axes and the coordinate origin is known. The posture state of the magnetic detection means different from the first posture state rotated about the coordinate axis as a rotation axis is set as a second posture state,
The first three-axis output data detected by the magnetic detection means in the first posture state is different from the first three-axis output data detected by the magnetic detection means in the second posture state. The rotation angle is a program for causing the computer to execute processing for realizing the rotation angle calculation means for calculating the rotation angle data and the rotation axis based on the second three-axis output data. Measurement program. Utilizing a triaxial magnetic detection means for detecting magnetic components in directions perpendicular to each other,
A three-axis output data acquisition step of acquiring three or more different three-axis output data detected by the magnetic detection means in a posture state of three or more different magnetic detection means rotated about one straight line as a rotation axis When,
A rotation angle calculation step of calculating rotation angle data of the rotation and the rotation axis based on three or more different three-axis output data;
A rotation angle measuring method characterized by comprising: Utilizing a triaxial magnetic detection means for detecting magnetic components in directions perpendicular to each other,
The first posture state of the magnetic detection means is defined as one of a coordinate system of the magnetic detection means for detecting the magnetic component and one of a three-axis coordinate system in which the relative relationship between the three coordinate axes and the coordinate origin is known. The posture state of the magnetic detection means different from the first posture state rotated about the coordinate axis as a rotation axis is set as a second posture state,
A first three-axis output data acquisition step of acquiring first three-axis output data by the magnetic detection means in the first posture state;
A second triaxial output data acquisition step of acquiring second triaxial output data different from the first triaxial output data by the magnetic detection means in the second posture state;
A rotation angle calculation step of calculating rotation angle data of the rotation and the rotation axis based on the first three-axis output data and the second three-axis output data;
A rotation angle measuring method characterized by comprising:

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