JP2019028037A - Rotation angle sensor calibration method, module calibration method, calibration parameter generation device, rotation angle sensor, rotation angle sensor module and program - Google Patents

Abstract

To provide a rotation angle sensor calibration method.SOLUTION: A rotation angle sensor calibration method, which detects a magnetic field in an X-axis direction on an XY plane and a magnetic field in Y-axis direction thereon, and detects a rotation angle on the XY plane of a rotary magnet rotating around an axis of a rotary axis, comprises: an installation step of installing a rotation angle sensor on the XY plane; a magnetic field application step of, on the XY plane, applying the magnetic field in a N (N is an integer more than 3) direction different in a direction by an angle having 360 degrees equally divided into N to a rotation angle sensor, respectively; an acquisition step of acquiring at least a two-system output signal to be output in response to respective applications of the magnetic field in the N direction from the rotation angle sensor; a calculation step of calculating a calibration parameter calibrating the rotation angle sensor on the basis of the at least two-system output signal; and a storage step of causing the calibration parameter to be stored in a storage part of the rotation angle sensor.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a rotation angle sensor calibration method, a rotation angle sensor module calibration method, a calibration parameter generation device, a rotation angle sensor, a rotation angle sensor module, and a program.

Conventionally, a non-contact rotation angle sensor that detects a change in a magnetic field in the X direction and the Y direction and detects a rotation angle of a rotating magnet based on the detection result is known (for example, see Patent Document 1).
Patent Document 1 Japanese Patent Application Laid-Open No. 2006-061708

  Conventional rotational angle sensors may have angular non-linearity errors, and it is desirable to implement angular nonlinearity error adjustment and calibration in an easy way.

  In the first aspect of the present invention, the rotation angle for detecting the rotation angle in the XY plane of the rotating magnet rotating around the axis of the rotation axis by detecting the magnetic field in the X-axis direction and the magnetic field in the Y-axis direction on the XY plane. A method for calibrating a sensor, which is a magnetic field in an N direction (N is an integer of 3 or more) in which the direction differs by an angle equal to 360 degrees divided into N on the XY plane and an installation stage where the rotation angle sensor is installed on the XY plane. Are applied to the rotation angle sensor, respectively, an acquisition step for acquiring at least two output signals output from the rotation angle sensor in response to the application of the N-direction magnetic field, and at least two systems. A rotation angle sensor comprising: a calculation step for calculating a calibration parameter for calibrating the rotation angle sensor on the basis of the output signal; and a storage step for storing the calibration parameter in a storage unit of the rotation angle sensor. To provide a service method of calibration.

  In the second aspect of the present invention, by detecting a rotating magnet rotating around the rotation axis, a magnetic field in the X-axis direction and a magnetic field in the Y-axis direction on the XY plane, the rotation angle of the rotating magnet in the XY plane is determined. A rotation angle sensor module for detecting a rotation angle sensor module, wherein the rotation angle sensor module is calibrated by the rotation angle sensor calibration method according to the first aspect of the present invention. Provide a method.

  In the third aspect of the present invention, the rotation angle sensor detects the rotation angle in the XY plane of the rotating magnet that rotates around the rotation axis by detecting the magnetic field in the X-axis direction and the magnetic field in the Y-axis direction on the XY plane. An acquisition unit that acquires at least two systems of output signals, a calculation unit that calculates a calibration parameter for calibrating the rotation angle sensor based on the output signals of at least two systems, and a calibration parameter that is supplied to the storage unit of the rotation angle sensor And a parameter supply unit that stores the magnetic field in the N direction (N is an integer of 3 or more) in different directions by an angle obtained by equally dividing 360 degrees into N on the XY plane. Provided is a calibration parameter generation device that acquires an output signal output in response to each application from a rotation angle sensor.

  In the fourth aspect of the present invention, the first sensor that converts the magnetic fields in the X-axis direction and the Y-axis direction and outputs output signals in the X-axis direction and the Y-axis direction, and the X-axis direction and the Y-axis direction. A second sensor that converts the magnetic field of the magnetic field and outputs output signals in the X-axis direction and the Y-axis direction, and a storage unit that stores the calibration parameters generated by the calibration parameter generation device according to the third aspect of the present invention. Based on the calibration parameters, errors in the output signals in the X-axis direction and the Y-axis direction of at least two systems output from the first sensor and the second sensor are corrected, and error correction signals in the X-axis direction and the Y-axis direction are respectively obtained. A rotation angle sensor is provided that includes an error correction unit that outputs and an angle signal calculation unit that calculates a corrected angle signal based on error correction signals in the X-axis direction and the Y-axis direction.

  According to a fifth aspect of the present invention, there is provided a rotation angle sensor module comprising the rotation angle sensor according to the fourth aspect of the present invention and a rotating magnet having a rotation axis in a direction substantially perpendicular to the XY plane.

  In a sixth aspect of the present invention, a program for causing a computer to execute the rotation angle sensor calibration method according to the first aspect of the present invention is provided.

  According to a seventh aspect of the present invention, there is provided a program for causing a computer to execute the rotation angle sensor module calibration method according to the second aspect of the present invention.

  The summary of the invention does not enumerate all the features of the present invention. In addition, a sub-combination of these feature groups can also be an invention.

An example of the rotation angle sensor module 300 is shown together with the calibration parameter generation device 200. An example of a structure of the rotating magnet 410 and the rotation angle sensor 100 is shown. An example in which the first Hall element pair 111 according to the present embodiment detects a magnetic field in the X-axis direction is shown. An example of a circuit structure of the rotation angle sensor 100 and the calibration parameter production | generation apparatus 200 is shown. It is a figure for demonstrating the sensor position shift which is a factor of an angle nonlinearity error. It is a figure for demonstrating the rotation axis shift | offset | difference which is a factor of an angle nonlinearity error. An example of an operation flow of the calibration parameter generation apparatus 200 is shown. A magnetic field application device 30 is shown together with a rotation angle sensor 100 and a calibration parameter generation device 200. An example of an operation flow of the calibration parameter generation apparatus 200 is shown. An example of an operation flow of the calibration parameter generation apparatus 200 is shown. It is a figure for demonstrating the error component of angle signal (phi) ((theta)) and amplitude signal mag. It is a figure for demonstrating the relationship between the real part of _Hmag and an imaginary part. The relationship between a Dy coordinate and the coefficient of sin2 (theta) of MAG is shown. The relationship between the Dy coordinate and the coefficient of cos θ of MAG is shown. The relationship between the Dy coordinate and the coefficient of sin θ of INL is shown. The angle dependence of the angle nonlinearity error in the case of having a sensor position shift and a rotation axis shift is shown. An example of the structure of the rotation angle sensor 100 which concerns on another Example is shown. An example of the structure of the rotation angle sensor module 500 which concerns on a comparative example is shown. An example of the circuit structure of the rotation angle sensor module 500 which concerns on a comparative example is shown. An example of a hardware configuration of a computer 1900 functioning as the calibration parameter generation device 200 is shown.

  Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. In addition, not all the combinations of features described in the embodiments are essential for the solving means of the invention.

  FIG. 1 shows an example of a rotation angle sensor module 300 together with a calibration parameter generation device 200. The rotation angle sensor module 300 includes the rotation angle sensor 100, a rotating magnet 410, a rotating shaft 412, and a motor 420. In this specification, the surface of the substrate on which the rotation angle sensor 100 is formed is an XY plane having an X axis and a Y axis, and an axis perpendicular to the XY plane is a Z axis. That is, the X, Y, and Z axes are coordinate systems orthogonal to each other.

  The rotating magnet 410 rotates around the rotating shaft 412. For example, the rotating magnet 410 has a ring shape and rotates on a plane substantially parallel to the XY plane. The rotating magnet 410 may be divided into two regions each having a semi-ring shape in cross section substantially parallel to the XY plane, and forms a magnet in which one region is an S pole and the other region is an N pole. The rotating magnet 410 generates a rotating magnetic field in the rotation angle sensor 100 by rotating on a plane substantially parallel to the XY plane.

  The rotating shaft 412 is formed by extending in a direction substantially perpendicular to the XY plane. That is, the rotation shaft 412 rotates around the Z axis. The rotating shaft 412 has one end connected to the rotating magnet 410 and the other end connected to the motor 420.

  The motor 420 rotates the rotation shaft 412 around the Z axis. Thereby, the motor 420 rotates the rotating magnet 410 around the Z axis.

  The rotation angle sensor 100 detects the magnetic field in the X-axis direction and the magnetic field in the Y-axis direction on the XY plane, and detects the rotation angle on the XY plane of the rotating magnet 410 that rotates about the rotation axis 412. The rotation angle sensor 100 of this example is disposed laterally on the rotating magnet 410. The lateral arrangement of the rotation angle sensor 100 means that the rotation angle sensor 100 is provided in the radial direction of the rotating magnet 410. That is, the rotation angle sensor 100 is provided on the same XY plane as the rotary magnet 410.

  The rotation angle sensor module 300 of this example includes a rotation angle sensor 100 that is disposed laterally on a rotating magnet 410. Therefore, the rotation angle sensor module 300 can reduce the height as compared with the case where the rotation angle sensor 100 is arranged vertically. Thereby, size reduction of the rotation angle sensor module 300 is realized.

  FIG. 2 shows an example of the configuration of the rotating magnet 410 and the rotation angle sensor 100. The rotation angle sensor 100 detects the rotation angle of the rotating magnet 410 that rotates about the rotating shaft 412 in a non-contact manner. The rotation angle sensor 100 includes a substrate 10, a first sensor 110, a second sensor 120, and a magnetic convergence plate 130.

  The substrate 10 is formed of a semiconductor such as silicon and includes a semiconductor circuit and a semiconductor element. The substrate 10 may be an IC chip. In this case, the substrate 10 includes a terminal and is electrically connected to an external substrate, circuit, wiring, and the like.

  The first sensor 110 and the second sensor 120 are provided at positions where the rotation angle of the rotating magnet 410 can be detected without contact. The first sensor 110 and the second sensor 120 of this example are disposed laterally with respect to the rotating magnet 410. That is, the first sensor 110 and the second sensor 120 are formed in the same XY plane as the rotating magnet 410. The first sensor 110 and the second sensor 120 of this example are arranged on the outer side of the rotating magnet 410 in the radial direction.

  Further, the first sensor 110 and the second sensor 120 are provided at a predetermined distance in parallel with the tangential direction of the rotating magnet 410. The distance between the first sensor 110 and the second sensor 120 is not particularly limited. In one example, the distance between the first sensor 110 and the second sensor 120 refers to the distance between the center of the first sensor 110 and the center of the second sensor 120. The distance between the first sensor 110 and the second sensor 120 may be smaller than the diameter of the rotating magnet 410 and may be smaller than the radius of the rotating magnet 410. Further, it is desirable that the distances of the first sensor 110 and the second sensor 120 to the rotation shaft 412 are equal to each other.

  The first sensor 110 and the second sensor 120 detect a magnetic field in the X direction and a magnetic field in the Y direction, respectively. The first sensor 110 of this example includes a first Hall element pair 111 and a second Hall element pair 116. The second sensor 120 includes a third Hall element pair 121 and a fourth Hall element pair 126.

  The first Hall element pair 111 detects a magnetic field in the X-axis direction. The first Hall element pair 111 is formed on the substrate 10 and connected to a circuit or the like formed on the substrate 10. The first hall element pair 111 includes a first hall element 112 and a second hall element 113.

  The first hall element 112 and the second hall element 113 are arranged in parallel with the X axis. As an example, the first Hall element 112 and the second Hall element 113 are elements that generate an electromotive force (Hall effect) in the Y-axis direction according to a magnetic field input in the Z-axis direction when a current flows in the X-axis direction. . The first hall element 112 and the second hall element 113 may be formed of a semiconductor or the like. As an example, the first Hall element 112 and the second Hall element 113 are arranged on the substrate 10 in line symmetry with respect to an axis parallel to the Y axis.

  The second Hall element pair 116 detects a magnetic field in the Y-axis direction. Similar to the first Hall element pair 111, the second Hall element pair 116 is formed on the substrate 10 and connected to a circuit or the like formed on the substrate 10. The second Hall element pair 116 in this example includes a third Hall element 117 and a fourth Hall element 118.

  The third Hall element 117 and the fourth Hall element 118 are arranged in parallel with the Y axis. For example, the third Hall element 117 and the fourth Hall element 118 are elements that generate an electromotive force (Hall effect) in the X-axis direction corresponding to a magnetic field input in the Z-axis direction when a current is passed in the Y-axis direction. . As an example, the third Hall element 117 and the fourth Hall element 118 are arranged in line symmetry with respect to an axis parallel to the X axis on the substrate 10.

  Note that the first Hall element pair 111 and the second Hall element pair 116 may be alternately energized in the X-axis direction and in the Y-axis direction to cancel the offset output. Such an offset canceling method is known as a spinning current method. The third Hall element pair 121 and the fourth Hall element pair 126 included in the second sensor 120 are also arranged in the same manner as the first Hall element pair 111 and the second Hall element pair 116 included in the first sensor 110.

  The third Hall element pair 121 detects a magnetic field in the X-axis direction. The third Hall element pair 121 is formed on the substrate 10 and connected to a circuit or the like formed on the substrate 10. The third Hall element pair 121 includes a first Hall element 122 and a second Hall element 123.

  The first Hall element 122 and the second Hall element 123 are arranged in parallel with the X axis. As an example, the first Hall element 122 and the second Hall element 123 are elements that generate an electromotive force (Hall effect) in the Y-axis direction corresponding to a magnetic field input in the Z-axis direction when a current flows in the X-axis direction. . The first hall element 122 and the second hall element 123 may be formed of a semiconductor or the like. As an example, the first Hall element 122 and the second Hall element 123 are arranged in line symmetry with respect to an axis parallel to the Y axis on the substrate 10.

  The fourth Hall element pair 126 detects a magnetic field in the Y-axis direction. Similarly to the third Hall element pair 121, the fourth Hall element pair 126 is formed on the substrate 10 and connected to a circuit or the like formed on the substrate 10. The fourth Hall element pair 126 in this example includes a third Hall element 127 and a fourth Hall element 128.

  The third Hall element 127 and the fourth Hall element 128 are arranged in parallel with the Y axis. As an example, the third Hall element 127 and the fourth Hall element 128 are elements that generate an electromotive force (Hall effect) in the X-axis direction corresponding to a magnetic field input in the Z-axis direction when a current flows in the Y-axis direction. . As an example, the third Hall element 127 and the fourth Hall element 128 are arranged in line symmetry with respect to an axis parallel to the X axis on the substrate 10.

The rotation angle sensor 100 generates angle signals (Φ ₁ (θ), Φ ₂ (θ)) based on the Hall electromotive force signals (Vx, Vy) from the first sensor 110 and the second sensor 120. The rotation angle sensor 100 outputs the generated angle signals (Φ ₁ (θ), Φ ₂ (θ)) to the outside. That is, the rotation angle sensor 100 of this example outputs two systems of angle signals (Φ ₁ (θ), Φ ₂ (θ)) based on the first sensor 110 and the second sensor 120. Two types of angle signals (Φ ₁ (θ), Φ ₂ (θ)) are output according to the rotation angle θ of the rotating magnet 410.

  FIG. 3 shows an example when the first Hall element pair 111 according to the present embodiment detects a magnetic field in the X-axis direction. On the substrate 10 of this example, a magnetic converging plate 130 is formed.

  The magnetic flux concentrating plate 130 is disposed above each Hall element pair and bends the magnetic field input to the rotation angle sensor 100. The magnetic converging plate 130 is formed of a magnetic material or the like, for example, each Hall element having a sensitivity in the Z-axis direction by bending a magnetic field in the X-axis direction and / or the Y-axis direction so as to generate a component in the Z-axis direction. Let the pair input. The magnetic flux concentrating plate 130 may be formed on the upper surface of the substrate 10, or alternatively, may be formed above the substrate 10 via an insulating layer or the like.

Here, the magnetic field vector H (H _X , H _Y , H _Z ) input to the rotation angle sensor 100 is bent by the magnetic converging plate 130 and input to the first Hall element 112, the magnetic flux density vector B (Hall, X 1). Is expressed by the following equation using the magnetic permeability Mu (Hall, X1) at the position of the first Hall element 112. Here, the magnetic permeability Mu (Hall, X1) is a second-order tensor (matrix with 3 rows and 3 columns).

Similarly, the magnetic flux density vector B (Hall, X2) input to the second Hall element 113 is expressed by the following equation using the magnetic permeability Mu (Hall, X2) at the position of the second Hall element 113.

The first hall element 112 and the second hall element 113 detect a magnetic field in the Z-axis direction. Therefore, the first Hall element 112 and the second Hall element 113, as shown in the following equation, thereby to detect the magnetic flux density B _Z of the Z-axis direction that is bent by the magnetic flux concentrator 130.

Here, an example in which a magnetic field vector H _in (H _X , 0, 0) _{in the} + X-axis direction is input above the rotation angle sensor 100 will be described. As an example, the magnetic converging plate 130 bends the input magnetic field as shown by a magnetic flux density vector B in the drawing, and causes the first Hall element 112 to input a magnetic flux in the + Z-axis direction.

Further, since the magnetic permeability of the magnetic flux concentrating plate 130 made of a magnetic material or the like is higher than the magnetic permeability of air, the magnetic flux in the magnetic converging plate 130 is compared with the magnetic flux density in the air. Density increases. For example, the magnetic flux density in the Z-axis direction at the position of the first Hall element 112 is approximately 1. as compared with the magnetic flux density obtained by multiplying the input magnetic field _HZ by the air permeability μ, as shown by the following equation. About 4 times higher.

Similarly, as an example, the magnetic flux concentrating plate 130 causes the second Hall element 113 to generate a magnetic flux in the −Z-axis direction, and the magnetic flux density in the Z-axis direction at the position of the second Hall element 113 is expressed by the following equation.

  The first Hall element 112 and the second Hall element 113 thus generate Hall electromotive force according to the magnetic flux density input in the Z-axis direction. Here, when the 1st Hall element 112 and the 2nd Hall element 113 are formed with substantially the same shape and the substantially same material, each magnetic sensitivity becomes substantially equal. In addition, since the magnetic flux densities input to the first Hall element 112 and the second Hall element 113 are opposite to each other, the generated Hall electromotive forces have different signs.

Therefore, when the magnetic sensitivity is S, the Hall electromotive force signal V _X of the first Hall element pair 111 is converted into the Hall electromotive force V _sig (Hall, X1) of the first Hall element 112 and the Hall electromotive force of the second Hall element 113. It can be defined as the following equation, which is the difference between the power V _sig (Hall, X2).

Thus, the rotation angle sensor 100 outputs the Hall electromotive force according to the magnetic field vector H _in (H _X , 0, 0) input in the X-axis direction by calculating the Hall electromotive force signal V _X. be able to. Further, since the Hall electromotive force signal V _X is the difference between the Hall electromotive forces of the Hall elements, the first Hall element 112 and the second Hall element 113 are in the same direction (+ Z axis direction or −Z axis direction), and The Hall electromotive force generated by the magnetic field having substantially the same absolute value is canceled out and becomes substantially zero.

That is, the rotation angle sensor 100 calculates the Hall electromotive force signal V _X , so that even if a magnetic field vector H _XZ (H _X , 0, H _Z ) in a direction parallel to the XZ plane is input, The Hall electromotive force corresponding to the magnetic field vector component H _X (H _X , 0, 0) can be calculated. The first Hall element 112 and the second Hall element 113 are not sensitive to the magnetic field in the Y-axis direction, and the magnetic focusing plate 130 ideally converts the magnetic field in the Y-axis direction into the Z-axis direction. do not do. Therefore, the rotation angle sensor 100 calculates the Hall electromotive force signal V _X so that the three orthogonal components are not zero (in any direction) magnetic field vectors H _XYZ (H _X , H _Y , H _Z ). Is input, it is possible to detect the Hall electromotive force according to the component H _X (H _X , 0, 0) of the magnetic field vector in the X-axis direction.

Similarly, the second Hall element pair 116 arranged in the Y-axis direction can calculate a magnetic field in the Y-axis direction. That is, the rotation angle sensor 100 uses the second Hall element pair 116 to calculate the Hall electromotive force signal V _Y of the following expression, thereby inputting the magnetic field vector H _XYZ (H _X , H _Y , H _Z ). However, it is possible to calculate the Hall electromotive force according to the component H _Y (0, H _Y , 0) of the magnetic field vector in the Y-axis direction.

Similarly, the first Hall element 112 and the second Hall element 113 generate Hall electromotive force according to the magnetic flux density input in the Z-axis direction. Then, the Hall electromotive force signal _{V Z} of the first hall element pair 111, Hall electromotive force _V sig of the first Hall element 112 (Hall, X1) and Hall electromotive force _V sig of the second Hall element 113 (Hall, X2) May be calculated as the sum of. The rotation angle sensor 100 of the present embodiment will describe an example in which the Hall electromotive force signals V _X and V _Y are output, and the Hall electromotive force signal V _Z will be omitted, but the rotation angle sensor 100 is not related to the Hall electromotive force signal. for even V _Z, it may be output like the Hall electromotive force signal _{V X} and _{V Y.}

As described above, the rotation angle sensor 100 is based on the output signals of the first Hall element pair 111 and the second Hall element pair 116, and the X-axis component of the input magnetic field vector H _XYZ (H _X , H _Y , H _Z ). Hall electromotive force signals V _X and V _Y corresponding to H _X (H _X , 0,0) and Y axis component H _Y (0, H _Y , 0) are output. That is, the rotation angle sensor 100 can calculate the Hall electromotive force corresponding to the magnetic field in the direction parallel to the XY plane by decomposing it into an X-axis component and a Y-axis component.

In this example, the case where the first Hall element pair 111 and the second Hall element pair 116 detect a magnetic field in a direction parallel to the XY plane has been described. However, the third Hall element pair 121 and the fourth Hall element pair 126 are described. In the same manner, a magnetic field in a direction parallel to the XY plane can be detected. In other words, the rotation angle sensor 100 is based on the output signals of the third Hall element pair 121 and the fourth Hall element pair 126, and the X-axis component H _X (H _X ) of the input magnetic field vector H _XYZ (H _X , H _Y , H _Z ). Hall electromotive force signals V _X and V _Y corresponding to H _X , 0,0) and Y axis component H _Y (0, H _Y , 0) are output.

The rotation angle sensor 100 detects, for example, a magnetic field caused by rotation of a rotating magnet 410 having a rotation axis parallel to the Z axis in a plane parallel to the XY plane, and outputs a Hall electromotive force signal corresponding to the rotation angle. Can do. For example, the rotation angle sensor 100 receives a rotating magnetic field expressed by the following equation. Here, H ₀ is the amplitude value of the magnetic field, and is a constant that may be normalized (for example, 1) when calculating the rotation angle θ.

As an example, the rotation angle sensor 100 outputs a Hall electromotive force signal (V _X , V _Y ) represented by the following equations for a rotating magnetic field such as the above equation. Here, A _x and A _y are amplitude values of each signal, θ is a rotation angle of the rotating magnet 410, α is a non-orthogonality error between signals, and V _{os_x} and V _{os_y} are offsets of each signal.

The amplitude values A _x and A _{y of} each signal, the non-orthogonality error α between the signals, and the offsets V _{os_x} and V _{os_y} of each signal are errors caused by the rotation angle sensor 100. Therefore, these errors can be trimmed before shipment.

Using the Hall electromotive force signals (V _X , V _Y ) as described above, the angle signal φ (θ) corresponding to the rotation angle θ of the rotating magnet 410 can be calculated by the following equation as an example.

  Here, it has been described that the rotation angle sensor 100 detects a magnetic field in a plane parallel to the XY plane, but a change in a magnetic field in another plane may be detected. Since the rotation angle sensor 100 can also detect the magnetic field in the Z-axis direction, for example, the rotation angle sensor 100 detects the magnetic field due to the rotation of the rotating magnet 410 with the rotation axis 412 parallel to the Y-axis in the plane parallel to the XZ plane. The Hall electromotive force signal corresponding to the rotation angle θ can be output. Similarly, the rotation angle sensor 100 detects a magnetic field generated by rotation of a rotating magnet 410 having a rotation axis 412 parallel to the X axis in a plane parallel to the YZ plane, and generates a Hall electromotive force signal corresponding to the rotation angle θ. It can also be output.

  Further, since the rotation angle sensor 100 can detect a three-dimensional magnetic field of the XYZ axes, it detects a magnetic field due to rotation in a plane that can be expressed by the XYZ axes, and outputs a Hall electromotive force signal corresponding to the rotation angle θ. can do. An example in which the rotation angle sensor 100 according to the present embodiment outputs a Hall electromotive force signal expressed by Equation (9) will be described.

  FIG. 4 shows an example of the circuit configuration of the rotation angle sensor 100 and the calibration parameter generation device 200. The rotation angle sensor 100 includes a first sensor 110, a second sensor 120, an X-axis signal output unit 140, a Y-axis signal output unit 150, an error correction unit 160, an angle signal calculation unit 170, and an input / output unit. 180 and a storage unit 190.

  Each component of the rotation angle sensor 100 may be formed on the same substrate 10. For example, the X-axis signal output unit 140, the Y-axis signal output unit 150, the error correction unit 160, the angle signal calculation unit 170, the input / output unit 180, and the storage unit 190 are formed inside the substrate 10.

The X-axis signal output unit 140 magnetoelectrically converts a magnetic field in the X-axis direction and outputs an output signal in the X-axis direction as an output signal. The X-axis signal output unit 140 of this example outputs two systems of output signals V _x1 (θ) and V _x2 (θ). The X-axis signal output unit 140 includes an amplification unit 142 and an AD conversion unit 144.

  The amplifying unit 142 is connected to the first Hall element pair 111 and the third Hall element pair 121, and amplifies the received Hall electromotive force signal with a predetermined amplification degree. The amplification unit 142 supplies the amplified Hall electromotive force signal to the AD conversion unit 144.

The AD converter 144 is connected to the amplifier 142 and converts the received Hall electromotive force signal into a digital signal. The AD conversion unit 144 of this example is an Xch AD converter. The AD conversion unit 144 supplies the converted digital signal to the error correction unit 160 as two systems of output signals V _x1 (θ) and V _x2 (θ).

The Y-axis signal output unit 150 magnetoelectrically converts a magnetic field in the Y-axis direction and outputs an output signal in the Y-axis direction as an output signal. The Y-axis signal output unit 150 of this example outputs two systems of output signals V _y1 (θ) and V _y2 (θ). The Y-axis signal output unit 150 includes an amplification unit 152 and an AD conversion unit 154.

  The amplifying unit 152 is connected to the second Hall element pair 116 and the fourth Hall element pair 126, and amplifies the received Hall electromotive force signal with a predetermined amplification degree. The amplification unit 152 supplies the amplified Hall electromotive force signal to the AD conversion unit 154.

The AD conversion unit 154 is connected to the amplification unit 152 and converts the received Hall electromotive force signal into a digital signal. The AD converter 154 of this example is a Ych AD converter. The AD conversion unit 154 supplies the converted digital signal to the error correction unit 160 as two systems of output signals V _y1 (θ) and V _y2 (θ).

In this way, the X-axis signal output unit 140 and the Y-axis signal output unit 150 output at least two systems of output signals (V _x1 , V _x2 , V _y1 , V _y2 ). The X-axis signal output unit 140 of this example outputs two systems of output signals V _x1 (θ) and V _x2 (θ) to the error correction unit 160. In addition, the Y-axis signal output unit 150 of the present example outputs two systems of output signals V _y1 (θ) and V _y2 (θ) to the error correction unit 160.

The error correction unit 160 outputs error correction signals in the X-axis direction and the Y-axis direction, respectively, based on predetermined calibration parameters. The error correction unit 160 is connected to the X-axis signal output unit 140 and the Y-axis signal output unit 150, and receives output signals (V _x1 , V _x2 , V _y1 , V _y2 ) in the X-axis direction and the Y-axis direction. The error correction unit 160 is connected to the storage unit 190 and reads calibration parameters from the storage unit 190. Thereby, the error correction unit 160 corrects the output signals (V _x1 , V _x2 , V _y1 , V _y2 ) with the calibration parameters. The error correction unit 160 supplies the corrected output signals (V _x1 , V _x2 , V _y1 , V _y2 ) to the angle signal calculation unit 170 as error correction signals.

The angle signal calculation unit 170 receives the error correction signal from the error correction unit 160. The angle signal calculation unit 170 calculates angle signals (Φ ₁ (θ), Φ ₂ (θ)) based on the received error correction signal. When the error correction signal is an appropriately corrected signal, the angle signal calculation unit 170 outputs angle signals (Φ ₁ (θ), Φ ₂ (θ)) that substantially match the rotation angle θ.

In one example, the angle signal calculation unit 170 calculates the angle signals (Φ ₁ (θ), Φ ₂ (θ)) by calculating Expression (10) or an equivalent expression. For example, the angle signal calculation unit 170 may include a calculation circuit or the like such as a CORDIC (COORDINATE ROTATION DIGITAL COMPUTER) circuit based on a trigonometric function calculation model. The CORDIC circuit executes a predetermined CORDIC algorithm.

When the ideal Hall electromotive force signal (V _X , V _Y ) is obtained in the equation (9), the angle signal calculation unit 170 has an angle signal (Φ ₁ (Φ ₁ ) that substantially matches the rotation angle θ of the rotating magnet 410. θ) and Φ ₂ (θ)) are output. An ideal Hall electromotive force signal (V _X , V _Y ) is obtained when, for example, V _{os_x} and V _{os_y} are substantially zero, A _x is substantially equal to A _y , and α is substantially zero. It is the case.

On the other hand, when the ideal Hall electromotive force signals (V _X , V _Y ) cannot be obtained, the angle signals (Φ ₁ (θ), Φ ₂ (θ)) output by the angle signal calculation unit 170 are the rotation angles θ And the difference between φ (θ) and θ (φ (θ) −θ) is an angle nonlinearity error of the rotation angle sensor 100. The case where an ideal Hall electromotive force signal (V _X , V _Y ) cannot be obtained means that at least one of offset V _os — _x , V _os — _y , amplitude difference (A _x −A _y ), and non-orthogonality error α This is a case where one is not substantially zero. For example, the angle non-linearity error is caused by an assembly error of the rotation angle sensor module 300.

  The input / output unit 180 is connected to an external device or the like, and exchanges calibration parameters with the external device or the like. The input / output unit 180 may be an interface circuit of the rotation angle sensor 100. In this case, in addition to the calibration parameters, other parameters and data used in the rotation angle sensor 100 may be exchanged. The input / output unit 180 supplies calibration parameters received from the outside to the storage unit 190. Further, the input / output unit 180 supplies the calibration parameters stored in the storage unit 190 to the outside.

The storage unit 190 stores calibration parameters. At least one calibration parameter for calibrating the error of the angle signal calculated by the rotation angle sensor 100 is stored. Calibration parameters, the offset V _{Os_x} the X-axis _{direction, Y} axis direction of the offset V _{Os_y,} mismatch of the magnetic sensitivity, and among the angular nonlinear error based on non-orthogonality errors alpha, include parameters to reduce at least one error It's okay.

  The calibration parameter generation device 200 is connected to the input / output unit 180 and generates a calibration parameter. The calibration parameter generation device 200 of this example includes an acquisition unit 210, a calculation unit 220, and a parameter supply unit 230.

The acquisition unit 210 acquires an output signal from the rotation angle sensor 100. The acquisition unit 210 of this example is connected to the X-axis signal output unit 140 and the Y-axis signal output unit 150 and acquires output signals (V _x1 , V _x2 , V _y1 , V _y2 ). The acquisition unit 210 may store the acquired output signals (V _x1 , V _x2 , V _y1 , V _y2 ) in the storage unit 190 or the like inside the calibration parameter generation device 200.

The calculation unit 220 is connected to the acquisition unit 210 or the storage unit 190 and receives output signals (V _x1 , V _x2 , V _y1 , V _y2 ). The calculation unit 220 calculates calibration parameters for calibrating the rotation angle sensor 100 based on the output signals (V _x1 , V _x2 , V _y1 , V _y2 ). In one example, the calculation unit 220 calibrates based on the difference between the output signals (V _x1 , V _x2 ) output from the first sensor 110 and the output signals (V _y1 , V _y2 ) output from the second sensor 120. Calculate the parameters. The difference between the output signal _{(V x1,} V _x2) and the output signal _{(V y1,} V _y2), and a signal based on the output signal _{(V x1,} V _x2), based on the output signal _{(V y1,} V _y2) Includes the difference from the signal. Thereby, the calculation unit 220 can calculate a calibration parameter based on a signal that depends on the distance between the first sensor 110 and the second sensor 120. A method for calculating the calibration parameter will be described later.

The calculation unit 220 calculates a calibration parameter based on the angle signal φ (θ _n ) and without using the angle θ _n . Thereby, the calculation part 220 can calculate a calibration parameter, without using the encoder for detecting angle (theta) _n .

  The parameter supply unit 230 is connected to the calculation unit 220 and receives calibration parameters from the calculation unit 220. Further, the parameter supply unit 230 supplies the received calibration parameter to the rotation angle sensor 100. The parameter supply unit 230 of this example is connected to the input / output unit 180 and transmits calibration parameters to the input / output unit 180.

  Further, the parameter supply unit 230 may control whether to supply calibration parameters to the rotation angle sensor 100. For example, when the calibration parameter is stored in the storage unit 190, the parameter supply unit 230 transmits the calibration parameter to the rotation angle sensor 100 only when the calibration parameter needs to be updated.

  FIG. 5 is a diagram for explaining the sensor position deviation which is a factor of the angle nonlinearity error. The rotation angle sensor 100 of this example has a positional deviation (Dx, Dy). The displacement (Dx, Dy) indicates the sensor position when the center of the rotating magnet 410 is the origin. For example, the positional deviation (Dx, Dy) may occur during assembly of the rotation angle sensor 100 and may cause an angular nonlinearity error.

  FIG. 6 is a diagram for explaining the rotational axis deviation which is a factor of the angle nonlinearity error. The N pole S pole direction of the rotating magnet 410 is defined as the D direction (in this example, the X axis direction). In the XY plane, the direction orthogonal to the D direction is defined as the Q direction (in this example, the Y axis direction). In this case, the deviation of the rotating shaft 412 is (Ed, Eq). The deviation (Ed, Eq) of the rotation shaft 412 occurs not only due to the assembly process of the rotation angle sensor module 300 but also due to uneven magnetization of the magnet in the rotation magnet 410. The eccentricity of the rotation angle sensor 100 may occur due to the deviation (Ed, Eq) of the rotation shaft 412.

  FIG. 7 shows an example of the operation flow of the calibration parameter generation apparatus 200. The calibration parameter generation device 200 generates calibration parameters by executing steps S100 to S130.

  First, the rotation angle sensor 100 is installed on the XY plane (S100). Here, the XY plane on which the rotation angle sensor 100 is installed is a plane substantially parallel to the direction of the magnetic field detected by the rotation angle sensor 100. Further, it is desirable that the plane is substantially coincident with the plane formed by the direction of the magnetic field detected by the rotation angle sensor 100.

Next, a magnetic field is applied to the rotation angle sensor 100, and the calibration parameter generation device 200 acquires output signals (V _x1 , V _x2 , V _y1 , V _y2 ) of the rotation angle sensor 100 (S110). Here, the magnetic field applied to the rotation angle sensor 100 is a magnetic field in the N direction (N is an integer of 3 or more) whose direction is different by an angle obtained by equally dividing 360 degrees into N on the XY plane. For example, the rotation angle sensor 100 is applied with magnetic fields in three directions on the XY plane having angles of 0 °, 120 °, and 240 ° with respect to predetermined directions on the XY plane. An example of an apparatus for applying such a magnetic field will be described with reference to FIG.

  FIG. 8 shows the magnetic field application device 30 together with the rotation angle sensor 100 and the calibration parameter generation device 200. The magnetic field application device 30 of this example shows an example in which magnetic fields in four directions whose directions are different from each other by an angle (90 °) obtained by dividing 360 degrees into four are applied to the rotation angle sensor 100. The magnetic field application device 30 includes a first coil unit 42, a second coil unit 44, a third coil unit 46, and a fourth coil unit 48.

  The first coil portion 42 and the third coil portion 46 may be Helmholtz coils formed of substantially the same shape and material and having substantially the same central axis. In this example, an example is shown in which the central axes of the first coil portion 42 and the third coil portion 46 are arranged substantially parallel to the Y-axis direction. The first coil unit 42 and the third coil unit 46 switch and apply magnetic fields in the + Y axis direction and the −Y axis direction to the rotation angle sensor 100 according to the direction of the flowing current. The first coil portion 42 and the third coil portion 46 can adjust the magnitude of the magnetic field to be applied by controlling the magnitude of the flowing current. That is, the first coil unit 42 and the third coil unit 46 apply a magnetic field having angles of about 90 ° and about 270 ° to the rotation angle sensor 100 with respect to the + X axis direction.

  The second coil portion 44 and the fourth coil portion 48 may be Helmholtz coils formed of substantially the same shape and material and having substantially the same central axis. In this example, an example is shown in which the central axes of the second coil portion 44 and the fourth coil portion 48 are arranged substantially parallel to the X-axis direction. The second coil unit 44 and the fourth coil unit 48 switch and apply magnetic fields in the + X axis direction and the −X axis direction to the rotation angle sensor 100 according to the direction of the flowing current. That is, the second coil unit 44 and the fourth coil unit 48 apply a magnetic field having angles of approximately 0 ° and approximately 180 ° to the rotation angle sensor 100 with respect to the + X axis direction.

  In this example, the rotation angle sensor 100 is arranged at the intersection of the central axes of the first coil portion 42 and the third coil portion 46 and the central axes of the second coil portion 44 and the fourth coil portion 48. Show. As described above, the magnetic field application device 30 has a magnetic field in the N direction (N is an integer of 3 or more) having different directions by an angle obtained by equally dividing 360 degrees into N on the XY plane according to the arrangement of the plurality of coil units. Can be applied to the rotation angle sensor 100, respectively.

The acquisition unit 210 outputs a magnetic field in the N direction (N is an integer of 3 or more) having different directions by an angle obtained by equally dividing 360 degrees into N on the XY plane in response to each applied to the rotation angle sensor 100. Output signals (V _x1 , V _x2 , V _y1 , V _y2 ) are acquired from the rotation angle sensor 100. For example, the acquisition unit 210 is output corresponding to each angle θ _n (n = 0, 1, 2,..., N−1) of the magnetic field in the N direction with respect to a predetermined direction on the XY plane. At least two systems of output signals in the X-axis direction and the Y-axis direction (V _X1 (θ _n ), V _X2 (θ _n ), V _Y1 (θ _n ), V _Y2 (θ _n )) are acquired.

Next, the calculation unit 220 is based on at least two systems of output signals (V _X1 (θ _n ), V _X2 (θ _n ), V _Y1 (θ _n ), V _Y2 (θ _n )). A calibration parameter for calibrating is calculated (S120). Then, the parameter supply unit 230 supplies the calibration parameter calculated by the calculation unit 220 to the storage unit 190 of the rotation angle sensor 100 for storage (S130). As described above, the rotation angle sensor module 300 of this example applies a magnetic field in a plurality of predetermined directions to the rotation angle sensor 100 using the magnetic field application device 30, and the angular nonlinearity error of the rotation angle sensor 100. Calibration parameters can be generated that correct for.

FIG. 9 shows an example of an operation flow of the calibration parameter generation apparatus 200. The acquisition unit 210 acquires two systems of output signals (V _x1 , V _x2 , V _y1 , V _y2 ) according to the rotation of the rotating magnet 410 (S210). The calculation unit 220 calculates calibration parameters for even harmonics (S220). Step S220 is an example of a first calculation stage. The parameter supply unit 230 supplies the calibration parameter calculated by the calculation unit 220 to the rotation angle sensor 100 (S225). As a result, the calculation unit 220 performs angular nonlinearity caused by the positional deviation (Dx, Dy) of the rotation angle sensor 100. Calibrate the sex error. When the rotation angle sensor 100 is disposed horizontally, it is preferable to first calibrate a relatively large error component due to positional deviation (Dx, Dy) as shown in FIG. When the error component is originally small, the calculation unit 220 may calculate all the calibration parameters by one rotation of the rotating magnet 410.

In addition, after the parameter supply unit 230 supplies the calibration parameters (S225), if necessary, the output signals (V _x1 , V _x2 , V _y1 , V _y2 ) of two systems are acquired (S210). May be. Thereby, even when the error component of the even-numbered harmonic wave is large, it can be expected that the error is gradually reduced while improving the calculation accuracy by performing calibration of the same component a plurality of times. Therefore, the calculation unit 220 can calculate the calibration parameter with high accuracy without using the true magnet angle θ by the encoder.

  Next, the magnitude relationship of the deviation (Ed, Eq) of the rotation shaft 412 is compared (S230). For example, the calculation unit 220 determines whether or not the deviation (Ed, Eq) of the rotation shaft 412 is greater than zero. Step S230 is an example of a comparison stage. The calculation unit 220 selects a calibration parameter calculation method according to the magnitude of the deviation (Ed, Eq) of the rotating shaft 412. For example, the calculation unit 220 determines whether or not to calculate odd-numbered harmonic calibration parameters according to the magnitude relationship of the deviation components of the rotation shaft 412.

  In the case of Ed, Eq> 0, the calculation unit 220 calculates an odd-numbered harmonic calibration parameter (S240). That is, the calculation unit 220 calculates the calibration parameter using both the even and odd harmonics. Step S240 is an example of a second calculation stage executed after the comparison stage.

  On the other hand, if Ed, Eq> 0 is not satisfied, a method for calculating the calibration parameter of the odd harmonic is determined according to the magnitude of the deviation (Ed, Eq) of the rotating shaft 412 (S235). For example, when Ed >> Eq≈0 or Eq >> Ed≈0, the calculation unit 220 uses an even-numbered harmonic calculation method. The calculation unit 220 may calculate the calibration parameter based on the cosine wave component when Ed >> Eq≈0, and may calculate the calibration parameter based on the sine wave component when Eq >> Ed≈0. Further, in the case of Ed, Eq≈0, the deviation (Ed, Eq) of the rotating shaft 412 is small, so that it is not necessary to further correct the odd harmonics.

  The parameter supply unit 230 supplies the calibration parameter calculated by the calculation unit 220 to the rotation angle sensor 100 (S250). Note that after the parameter supply unit 230 supplies the calibration parameters (S250), the process may return to the step (S210) depending on the occurrence of an error due to variations in the sensor position or the axis deviation.

  FIG. 10 shows an example of an operation flow of the calibration parameter generation apparatus 200. In the operation flow of this example, a correction algorithm when it is determined that Ed, Eq> 0 in step S230 will be mainly described. The calibration parameter is calculated for each of the first sensor 110 and the second sensor 120. The sensor 1 and the sensor 2 are the 1st sensor 110 and the 2nd sensor 120 as an example.

The acquisition unit 210 acquires output signals (V _x1 , V _x2 , V _y1 , V _y2 ) from the first sensor 110 and the second sensor 120 according to the rotation of the rotating magnet 410 (S310, S315). For example, as described above, the rotation angle sensor 100 outputs the Hall electromotive force signal (Vx, Vy) represented by the equation (9) with respect to the rotating magnetic field.

  The calculation unit 220 performs Fourier series expansion on the amplitude error MAG for each of the first sensor 110 and the second sensor 120 (S320, S325). MAG is calculated from the amplitude signal mag of the first sensor 110 and the second sensor 120 as an error component of the amplitude signal. In this way, the coefficient of the functional expression regarding MAG is calculated. Further, the difference between the output angles of the first sensor 110 and the second sensor 120 is calculated, and Fourier series expansion is performed (S330).

For example, the amplitude signal mag is expressed by the following equation using the Hall electromotive force signal (Vx, Vy).

  FIG. 11 is a diagram for explaining error components of the angle signal φ (θ) and the amplitude signal mag. The vertical axis represents the Hall electromotive force signal (Vy), and the horizontal axis represents the Hall electromotive force signal (Vx). A broken line indicates an ideal rotation vector (Vx, Vy) = (cos (θ), sin (θ)).

ＭＡＧ（θ）は、規格化されているので１が理想値である。ＩＮＬ（θ）は、０が理想値である。但し、ＭＡＧ（θ）およびＩＮＬ（θ）は、ＩＣ内の誤差や、組み立て時の位置ずれ等により４次以上の誤差を含む。なお、本例では、４次までのＭＡＧ（θ）およびＩＮＬ（θ）について示したが、理論上は、ＭＡＧ（θ）およびＩＮＬ（θ）の次数が５次以上であってもよい。 MAG appears as a deviation in the normal direction with respect to the rotation vector. The angle error INL appears as a tangential shift with respect to the rotation vector (Vx, Vy). For example, MAG (θ) and INL (θ) are represented by the following equations, respectively.

Since MAG (θ) is standardized, 1 is an ideal value. As for INL (θ), 0 is an ideal value. However, MAG (θ) and INL (θ) include fourth-order or higher errors due to errors in the IC, positional deviations during assembly, and the like. In this example, MAG (θ) and INL (θ) up to the fourth order are shown, but theoretically, the orders of MAG (θ) and INL (θ) may be the fifth order or more.

  The rotation angle sensor 100 of this example is provided apart from the center of the rotating magnet 410 by a certain distance, and the first sensor 110 and the second sensor 120 are arranged in parallel to the tangential direction of the rotating magnet 410. Thereby, the rotation angle sensor 100 can calculate the difference between the two systems of the MAG signal and the INL signal.

  In one example, the calibration parameter generation apparatus 200 estimates INL for each component by using calibration parameters based on a signal output from the rotation angle sensor 100. When the rotation vector is converted to a complex plane, the real part of the rotation vector becomes a normal component and the imaginary part becomes a tangential component, so the relationship between the real part and the imaginary part of the rotation vector including an error is the correlation between INL and MAG. It becomes. For example, the calibration parameter is the product of MAG and INL correlation coefficient (INL / MAG) and MAG.

ここで、Ｄ＝Ｄｘ＋ｉＤｙ、Ｅ＝Ｅｄ＋ｉＥｑであり、α，β，γは実数である。Ｈ_ｍａｇの実数部は、理想ＭＡＧ信号を１としたときの実装誤差を含んだＭＡＧ信号を示す。また、Ｈ_ｍａｇの虚数部は、ＩＮＬを示す。本明細書において、較正パラメータ生成装置２００が実装要因の誤差（Ｄｘ，Ｄｙ，Ｅｄ，Ｅｑ）を含む場合を、非軸端配置と称する。また、較正パラメータ生成装置２００が実装要因の誤差（Ｄｘ，Ｄｙ，Ｅｄ，Ｅｑ）を含まない場合や、これらの誤差を無視できる場合を軸端配置と称する。 FIG. 12 is a diagram for explaining the relationship between the real part and the imaginary part of H _mag . H _mag is represented by the following equation.

Here, D = Dx + iDy, E = Ed + iEq, and α, β, and γ are real numbers. The real part of H _mag indicates a MAG signal including a mounting error when the ideal MAG signal is 1. The imaginary part of H _mag indicates INL. In this specification, the case where the calibration parameter generation device 200 includes errors (Dx, Dy, Ed, Eq) of mounting factors is referred to as non-axial end arrangement. A case where the calibration parameter generation apparatus 200 does not include mounting factor errors (Dx, Dy, Ed, Eq) or a case where these errors can be ignored is referred to as a shaft end arrangement.

  In the non-axis end arrangement, the error (Dx, Dy, Ed, Eq) of the mounting factor is dominant. In the equation (13), the Hall electromotive force signal (Vx, Vy) at the sensor position including the error of these mounting factors is normalized with the ideal MAG signal as 1 when there is no mounting error.

  Next, the calculation unit 220 calculates a correlation coefficient between MAG and INL by calculating an angle error / amplitude error (INL / MAG) for the even multiple component. The calculation unit 220 estimates the angular error of the even harmonics from the product of the even harmonics of the MAG and the correlation coefficient. Furthermore, the calculation unit 220 estimates the Y positions of the first sensor 110 and the second sensor 120 (S340).

Here, a method for estimating the error component of even-numbered harmonics will be described. For even harmonics, MAG (θ) and INL (θ) are expressed by the following equations.

When a positional deviation (Dx, Dy) occurs, a second-order error appears in MAG and INL from Equation (14). Further, even-numbered harmonic errors such as a quadruple cycle and a six-fold cycle have the same tendency. The coefficient of MAG is calculated by expanding the normalized MAG (θ _n ) into a Fourier series. θ _n is one cycle from θ ₀ to θ _N−1 when magnetic field data is acquired for each angle obtained by equally dividing 360 ° by the rotation angle of the rotating magnet 410 into N.

（数１５）式および（数１６）式を用いると、規格化したＭＡＧ（θ_ｎ）は次式で示される。

フーリエ級数展開のリファレンス角度は、回転角センサ１００の角度信号φをθに代入することで近似される。即ち、本例の較正パラメータ生成装置２００は、較正パラメータを算出するために、回転磁石４１０の角度θが不要である。したがって、較正パラメータを算出するための計算が簡略化される。但し、較正パラメータ生成装置２００は、回転磁石４１０の角度θを用いて較正パラメータを算出することもできる。

By using (Expression 15) and (Expression 16), normalized MAG (θ _n ) is expressed by the following expression.

The reference angle of the Fourier series expansion is approximated by substituting the angle signal φ of the rotation angle sensor 100 into θ. That is, the calibration parameter generating apparatus 200 of this example does not need the angle θ of the rotating magnet 410 in order to calculate the calibration parameter. Therefore, the calculation for calculating the calibration parameter is simplified. However, the calibration parameter generation device 200 can also calculate the calibration parameter using the angle θ of the rotating magnet 410.

The calibration parameter generating apparatus 200 of this example calculates the angle signal φ of the rotation angle sensor 100 assuming the angle θ of the rotating magnet 410. For example, the calibration parameter generation apparatus 200 acquires φ (θ _n ) at regular intervals and acquires a MAG signal for each φ (θ _n ) for one period in order to improve the accuracy of approximation. The MAG signal differs for each φ (θ _n ), but is approximated by integration.

From the above, the amount of MAG change including the mounting position error between the two sensors is Δdy = D _y1 −D _y2 in the case of the coefficient change of MAGsin 2θ, and the output of the first sensor 110 is φ ₁ the angle theta _{1_n,} when the sensor 1 output puts the theta _{2_n} the angle of the magnet o'clock phi _2, the following expression holds.

そして、２系統センサ間のそれぞれの実装位置誤差を含んだＩＮＬの変化量は、ＩＮＬｃｏｓ２θの係数変化の場合、次式で示される。

Next, INL is expressed by the following equation.

The amount of change in INL including each mounting position error between the two systems of sensors is expressed by the following equation in the case of a change in the coefficient of INLcos 2θ.

Here, although φ ₁ (θ _n ) −φ ₂ (θ _n ) can be calculated, when calculating without using the angle θ of the rotating magnet 410, in order to increase the approximation accuracy at the time of Fourier series expansion, Calculate the formula.

The calibration parameter generating apparatus 200 includes a formula developed a difference between φ ₂ (θ _1n) in the case of φ ₁ (θ _1n) has data acquisition to be at equal intervals _{φ 1 (θ 1n), φ} 2 ( The approximation accuracy is improved by taking the average of the expression obtained by developing the difference from φ ₁ (θ _2n ) with φ ₂ (θ _2n ) when data is acquired so that θ _2n ) is equally spaced.

  Here, since d · 2DxΔDy and d ′ · 2DxΔDy are respectively calculated, the correlation coefficient d ′ / d between the cos 2θ component of the INL and the sin 2θ component of the MAG is approximately calculated by taking the ratio of the two. The correlation coefficient between the sin 2θ component of INL and the cos 2θ component of MAG is c ′ / c≈−d ′ / d.

Therefore, the angle of the double cycle of each of the two sensors is calculated from the product of the coefficient (c (D _x2 -D _y2 ), d (2DxDy)) of the MAG (θ) of each of the two sensors and the correlation coefficient. Error calibration parameters can be calculated.

FIG. 13 shows the relationship between the Dy coordinates and the coefficient of sin 2θ of MAG. The coefficient of sin 2θ of the MAG in this example is d (2DxDy). The calculation unit 220 estimates the Dy coordinate of the sensor from the error coefficient of the sine wave having a double period. When the respective Dy coordinates of the first sensor 110 and second sensor 120 and _{D y1} and _{D y2,} factor _{D 1} and _{D 2} of sin2θ of MAG, respectively represented by the following formula.
D ₁ = d (2D _x D _y1 )
D ₂ = d (2D _x D _y2 )

Here, since the coefficient ratio D ₁ / D ₂ for the first sensor 110 and the second sensor 120 and the coordinate ratio D _y1 / D _y2 coincide, using ΔDy, D _y1 and D _y2 are respectively expressed by the following equations: Indicated by

  The value of ΔDy may be an arbitrary value. However, when the actual distance is known in the metric system as the value of ΔDy, the calculation unit 220 can calculate the Dy coordinates in units of meters. As described above, the calculation unit 220 of this example can calculate the Dy coordinates of the first sensor 110 and the second sensor 120 without using the angle θ of the rotating magnet 410.

  Next, the calculation part 220 estimates the position of Dy = 0 from the Y coordinate of the 1st sensor 110 and the 2nd sensor 120, and the odd multiple component of MAG. Further, the calculation unit 220 estimates the angle error of the odd-numbered harmonics in combination with the calculation of the angle error / amplitude error (INL / MAG) (S350).

ここで、ＭＡＧ（θ）について、ｃｏｓθの係数をＡとし、ｓｉｎθの係数をＢとする。また、ＩＮＬ（θ）について、ｓｉｎθの係数をＡ'とし、ｃｏｓθの係数をＢ'とする。この場合、Ａ、Ａ'、Ｂ、Ｂ'について次式が成り立つ。

For example, an error component of odd harmonics is estimated by the following method. For example, for an error of 1 time period, MAG and INL are expressed by the following equations.

Here, for MAG (θ), the coefficient of cos θ is A, and the coefficient of sin θ is B. For INL (θ), the coefficient of sin θ is A ′, and the coefficient of cos θ is B ′. In this case, the following expressions hold for A, A ′, B, and B ′.

  If the normalized MAG and INL have an error of 1 time period, the real part and the imaginary part of the primary error of the rotating magnetic field are extracted and the coefficients A, A ′, B, B ′ as shown in the above equation. Can guide you. The theory of this example can be applied not only to a 1-fold period but also to errors of other odd-numbered harmonics such as a 3-fold period and a 5-fold period.

When Ed, Eq> 0, the calculation unit 220 calculates the difference between MAG and INL between the two systems of sensors.

  The calculation unit 220 calculates b ′ / b and b ′ / a by taking a ratio for each term that requires Ed and each term that requires Eq. Further, the error of 1 time period including the Dx coordinate of the sensor is estimated by the following method.

FIG. 14 shows the relationship between the Dy coordinate and the coefficient of cos θ of MAG. The coefficient of cos θ of the MAG in this example is (a · DxEd + b · DyEq). The calculation unit 220 estimates the Dx coordinate of the sensor from the error coefficient of the cosine wave having a 1-cycle. _Assuming that the coefficients A of the first sensor 110 and the second sensor 120 are D _y1 and D _y2 , the coefficients A ₁ and A ₂ of cos θ of the MAG are respectively expressed by the following equations.
A ₁ = (a · DxEd + b · D _y1 Eq)
A ₂ = (a · DxEd + b · D _y2 Eq)

Here, when the coordinates Dy on the horizontal axis, intercept _{A 0} becomes ADxEd. Further, the following equation holds from the inclination when the coordinate Dy is taken on the horizontal axis.

以上の通り、算出部２２０は、ａＤｘＥｄを算出し、Ｄｘ座標を推定できる。 Substituting the calculated D _y2 into the equation (28), the following equation is established.

As described above, the calculation unit 220 can calculate aDxEd and estimate Dx coordinates.

FIG. 15 shows the relationship between the Dy coordinate and the coefficient of sin θ of INL. The coefficient of sin θ of INL in this example is −b ′ · (DxEd−DyEq). The calculation unit 220 calculates a coefficient in the case of Dy = 0 from the error coefficient of the sinusoidal wave with a 1-cycle. When Dy = 0, the relationship between the MAG and INL error of 1 time period is expressed by the following equation.

Here, the correlation coefficients b ′ / b and b ′ / a are calculated from the difference between the first sensor 110 and the second sensor 120. Therefore, the calculation unit 220 calculates the INL _{0 in} the case of Dy = 0 from the product of the cos θ coefficient (a · DxEd) and the sin θ coefficient (−b · DxEq) in the case of Dy = 0 and the correlation coefficient. , Sin coefficient and cos coefficient can be calculated respectively. For INL ₀ , the coefficient of sin θ is F, and the calculated values of D _y1 and D _y2 are used for plotting. The calculation unit 220 can calculate A ₁ ′ and A ₂ ′ that are INL coefficients of the sensor position.

A ₁ ′ −A ₂ ′ is calculated as A ₁ ′ −A ₂ ′ = b ′ · (ΔDyEq) because it is the amount of change in the sin θ component of the INL between the sensors. Therefore, the calculation unit 220 can calculate the angular error A ′ having a 1-fold period, and can similarly calculate B ′.

ここで、Ａ＝（ａ・ＤｘＥｄ＋ｂ・ＤｙＥｑ）、Ｂ＝（−ｂ・ＤｘＥｑ＋ａ・ＤｙＥｄ）とする。 In the case of Ed, Eq≈0, the calculation result may diverge.

Here, it is assumed that A = (a · DxEd + b · DyEq) and B = (− b · DxEq + a · DyEd).

  The calculating unit 220 calculates the coefficient A of the cosine signal and the coefficient B of the sine signal of the 1-fold period by expanding the Fourier series of the signal obtained by normalizing the magnetic field amplitude signal MAG.

Ｅｄ≒０の場合、次式が成り立つ。

Next, consider the case of Eq≈0 and Ed≈0.
When Eq≈0, the following equation holds.

When Ed≈0, the following equation holds.

  In the case of non-axial end arrangement, particularly Dx >> Dy, A >> B is satisfied under the condition of Eq≈0. Further, when Ed≈0, B >> A holds. Further, when Ed, Eq≈0, A≈B≈0 holds. Thus, the calculation unit 220 can divide the values of Ed and Eq into cases by comparing A and B. For example, the calculation unit 220 compares A and B, thereby performing the comparison in step S230 and selecting a branch of the operation flow. Thereby, the calculation unit 220 can avoid the problem that the denominator becomes ≈0 and the calibration parameter diverges when taking the ratio. In the case of Ed, Eq≈0, the angle error of the 1-fold period is smaller than the angle error of the even-numbered harmonics, and therefore correction using the odd-numbered harmonics is not necessary.

Next, a method of estimating the error component of the odd harmonic will be described for Ed >> Eq≈0. In this case, MAG and INL are expressed by the following equations.

このように、算出部２２０は、比を取ることで相関係数ｂ'／ａを算出できる。 In the case of Ed >> Eq≈0 and A >> B, the error of 1 time period is expressed by the above equation. The theory of this example can be applied not only to a 1-fold period but also to an error of an odd-numbered harmonic such as a 3-fold period or a 5-fold period. The calculation unit 220 calculates an average of the MAG between the two systems of sensors and the difference between the respective output angles.

Thus, the calculation unit 220 can calculate the correlation coefficient b ′ / a by taking the ratio.

  The calculation unit 220 can calculate the calibration parameter of the angular error of the cosine function having a 1-fold period of INL from the product of the MAG sin coefficient (α · DyEd) and the correlation coefficient. Further, the calculation unit 220 can calculate the calibration parameter of the angular error of the sinusoidal function having a period of 1 from the result obtained by multiplying the product of the cos coefficient (α · DxEd) of the MAG and the correlation coefficient by −1.

Ｅｑ＞＞Ｅｄ≒０、Ｂ＞＞Ａの場合、１倍周期の誤差は上式のようになる。本例の理論は、１倍周期のみならず、３倍周期や５倍周期といった奇数倍波の誤差に適用できる。算出部２２０は、２系統のセンサ間のＭＡＧとそれぞれの出力角度の差分を平均したものを算出する。

このように、算出部２２０は、比を取ることで相関係数ｂ'／ｂを算出できる。 Next, a method of estimating the error component of the odd harmonic will be described for Eq >> Ed≈0.

In the case of Eq >> Ed≈0 and B >> A, the error of 1 time period is expressed by the above equation. The theory of this example can be applied not only to a 1-fold period but also to an error of an odd-numbered harmonic such as a 3-fold period or a 5-fold period. The calculating part 220 calculates what averaged the difference of MAG between two systems of sensors, and each output angle.

Thus, the calculation unit 220 can calculate the correlation coefficient b ′ / b by taking the ratio.

  The calculation unit 220 calculates a calibration parameter of an angular error of a sinusoidal function having a 1-fold cycle of INL from the product of the cos coefficient (b · DyEq) of the MAG and the correlation coefficient. Further, the calculation unit 220 calculates a calibration parameter for the angular error of the cosine function having a period of 1 from the result obtained by multiplying the product of the MAG sin coefficient (−b · DxEq) and the correlation coefficient by −1.

  The parameter supply unit 230 supplies calibration parameters (for example, angle error parameters) estimated for each frequency component to the storage unit 190 for storage (S360). The error correction unit 160 corrects the error using the estimated angle error (S370). As a result, the angle signal calculation unit 170 outputs a signal after calibration (S380).

The calibration parameter generating apparatus 200 of this embodiment, without using the angle θ of the rotating magnet 410 can calculate the calibration parameters from the output signal of the rotation angle sensor _{100 (V x1, V x2,} V y1, V y2). The calibration parameter generation device 200 of this example can correct the angle θ of the rotating magnet 410 as unnecessary in the non-axial end arrangement.

FIG. 16 shows the angle dependence of the angle nonlinearity error when there is a sensor position shift and a rotational axis shift. The vertical axis represents the angle nonlinearity error (°), and the horizontal axis represents the angle θ (°) of the rotating magnet 410. If the angle error parameters estimated for each component are a ′ to h ′, INL (θ) is expressed by the following equation.

The angle signal φ (θ _n ) has an angular non-linearity error caused by a positional deviation and a rotational axis deviation. For example, in the case of horizontal arrangement, a position error is large and a component that fluctuates in a double cycle is dominant. It becomes. In the angle signal φ (θ _n ), the angle non-orthogonality error is corrected using the parameters a ′ to h ′. For example, the angle signal φ ′ ₁ (θ ₁ ) obtained by correcting the angle signal φ (θ _n ) for the first sensor 110 is expressed by the following equation.

From the result of this example, it can be seen that the angle non-orthogonality error of the corrected angle signal φ ′ ₁ (θ ₁ ) is significantly reduced as compared with the angle signal φ (θ _n ). The rotation angle sensor 100 may correct each of the first sensor 110 and the second sensor 120.

  FIG. 17 shows an example of the configuration of the rotation angle sensor 100 according to another embodiment. The rotation angle sensor 100 of this example is different from the rotation angle sensor 100 shown in FIG. 4 in that an acquisition unit 210, a calculation unit 220, and a parameter supply unit 230 are provided. That is, the acquisition unit 210, the calculation unit 220, and the parameter supply unit 230 are formed on the same substrate as the substrate 10 on which the first sensor 110 and the second sensor 120 are formed. In addition, each structure of the rotation angle sensor 100 of this example may operate | move similarly to each structure of the rotation angle sensor 100 and the calibration parameter production | generation apparatus 200 shown in FIG.

  FIG. 18 shows an example of the configuration of a rotation angle sensor module 500 according to a comparative example. FIG. 19 shows an example of a circuit configuration of the rotation angle sensor module 500 according to the comparative example.

  The rotation angle sensor module 500 has only one first sensor 110. That is, the rotation angle sensor module 500 has only one system for sensors that detect a magnetic field in the X-axis direction and a magnetic field in the Y-axis direction. Therefore, the rotation angle sensor module 500 needs to use the angle θ of the rotating magnet 410 in order to calculate the calibration parameter. The rotation angle sensor module 500 needs to be provided with an encoder in order to measure the absolute angle θ of the rotating magnet 410. Advanced adjustment such as control of the motor 420 is required.

On the other hand, the rotation angle sensor module 300 has two signal systems for outputting X-axis and Y-axis magnetic field detectors and angle signals. Therefore, the rotation angle sensor module 300 can calculate the calibration parameter only from the output signals (V _x1 , V _x2 , V _y1 , V _y2 ). That is, the rotation angle sensor module 300 can calibrate the rotation angle sensor 100 without using information on the angle θ of the rotating magnet 410. Thereby, the rotation angle sensor module 300 can realize automatic correction on the rotation angle sensor 100 side. Further, the rotation angle sensor module 300 does not require advanced control of the motor 420.

  In addition, the calibration parameter generation apparatus 200 of the present example can generate a calibration parameter with a third or higher order error. Therefore, the rotation angle sensor module 300 realizes calibration of the rotation angle sensor 100 with high accuracy.

  Furthermore, the rotation angle sensor module 300 can reduce not only the angle non-linearity error inherent to the rotation angle sensor 100 but also the angle non-linearity error caused by the axis deviation of the rotating magnet 410. In other words, the rotation angle sensor module 300 can correct even a non-axial end arrangement with a large magnetic field distortion, thereby improving the degree of freedom of arrangement.

  FIG. 20 shows an example of a hardware configuration of a computer 1900 that functions as the calibration parameter generation apparatus 200. A computer 1900 according to this embodiment is connected to a CPU peripheral unit having a CPU 2000, a RAM 2020, a graphic controller 2075, and a display device 2080 that are connected to each other by a host controller 2082, and to the host controller 2082 by an input / output controller 2084. An input / output unit having a communication interface 2030, a hard disk drive 2040, and a DVD drive 2060; a legacy input / output unit having a ROM 2010, a flexible disk drive 2050, and an input / output chip 2070 connected to the input / output controller 2084; Is provided.

  The host controller 2082 connects the RAM 2020 to the CPU 2000 and the graphic controller 2075 that access the RAM 2020 at a high transfer rate. The CPU 2000 operates based on programs stored in the ROM 2010 and the RAM 2020 and controls each unit. The graphic controller 2075 acquires image data generated by the CPU 2000 or the like on a frame buffer provided in the RAM 2020 and displays it on the display device 2080. Instead of this, the graphic controller 2075 may include a frame buffer for storing image data generated by the CPU 2000 or the like.

  The input / output controller 2084 connects the host controller 2082 to the communication interface 2030, the hard disk drive 2040, and the DVD drive 2060, which are relatively high-speed input / output devices. The communication interface 2030 communicates with other devices via a network. The hard disk drive 2040 stores programs and data used by the CPU 2000 in the computer 1900. The DVD drive 2060 reads a program or data from the DVD-ROM 2095 and provides it to the hard disk drive 2040 via the RAM 2020.

  The input / output controller 2084 is connected to the ROM 2010, the flexible disk drive 2050, and the relatively low-speed input / output device of the input / output chip 2070. The ROM 2010 stores a boot program that the computer 1900 executes at startup and / or a program that depends on the hardware of the computer 1900. The flexible disk drive 2050 reads a program or data from the flexible disk 2090 and provides it to the hard disk drive 2040 via the RAM 2020. The input / output chip 2070 connects the flexible disk drive 2050 to the input / output controller 2084 and inputs / outputs various input / output devices via, for example, a parallel port, a serial port, a keyboard port, a mouse port, and the like. Connect to controller 2084.

  A program provided to the hard disk drive 2040 via the RAM 2020 is stored in a recording medium such as the flexible disk 2090, the DVD-ROM 2095, or an IC card and provided by the user. The program is read from the recording medium, installed in the hard disk drive 2040 in the computer 1900 via the RAM 2020, and executed by the CPU 2000.

  The program is installed in the computer 1900, and causes the computer 1900 to function as the acquisition unit 210, the calculation unit 220, and the parameter supply unit 230.

  The information processing described in the program is read into the computer 1900, whereby the acquisition unit 210, the calculation unit 220, and the parameter supply unit 230, which are specific means in which the software and the various hardware resources described above cooperate. Function as. And by this specific means, the calculation or processing of information according to the purpose of use of the computer 1900 in the present embodiment is realized, whereby the specific calibration parameter generation device 200 according to the purpose of use is constructed.

  As an example, when communication is performed between the computer 1900 and an external device or the like, the CPU 2000 executes a communication program loaded on the RAM 2020 and executes a communication interface based on the processing content described in the communication program. A communication process is instructed to 2030. Under the control of the CPU 2000, the communication interface 2030 reads transmission data stored in a transmission buffer area or the like provided on a storage device such as the RAM 2020, the hard disk drive 2040, the flexible disk 2090, or the DVD-ROM 2095, and sends it to the network. The reception data transmitted or received from the network is written into a reception buffer area or the like provided on the storage device. As described above, the communication interface 2030 may transfer transmission / reception data to / from the storage device by the DMA (Direct Memory Access) method. Instead, the CPU 2000 transfers the storage device or the communication interface 2030 as the transfer source. The transmission / reception data may be transferred by reading the data from the data and writing the data to the communication interface 2030 or the storage device of the transfer destination.

  In addition, the CPU 2000 includes all or necessary portions of files or databases stored in an external storage device such as the hard disk drive 2040, DVD drive 2060 (DVD-ROM 2095), and flexible disk drive 2050 (flexible disk 2090). Are read into the RAM 2020 by DMA transfer or the like, and various processes are performed on the data on the RAM 2020. Then, CPU 2000 writes the processed data back to the external storage device by DMA transfer or the like. In such processing, since the RAM 2020 can be regarded as temporarily holding the contents of the external storage device, in the present embodiment, the RAM 2020 and the external storage device are collectively referred to as a memory, a storage unit, or a storage device. Various types of information such as various programs, data, tables, and databases in the present embodiment are stored on such a storage device and are subjected to information processing. Note that the CPU 2000 can also store a part of the RAM 2020 in the cache memory and perform reading and writing on the cache memory. Even in such a form, the cache memory bears a part of the function of the RAM 2020. Therefore, in the present embodiment, the cache memory is also included in the RAM 2020, the memory, and / or the storage device unless otherwise indicated. To do.

  In addition, the CPU 2000 performs various operations, such as various operations, information processing, condition determination, information search / replacement, etc., described in the present embodiment, specified for the data read from the RAM 2020 by the instruction sequence of the program. Is written back to the RAM 2020. For example, when performing the condition determination, the CPU 2000 determines whether the various variables shown in the present embodiment satisfy the conditions such as large, small, above, below, equal, etc., compared to other variables or constants. When the condition is satisfied (or not satisfied), the program branches to a different instruction sequence or calls a subroutine.

  Further, the CPU 2000 can search for information stored in a file or database in the storage device. For example, in the case where a plurality of entries in which the attribute value of the second attribute is associated with the attribute value of the first attribute are stored in the storage device, the CPU 2000 displays the plurality of entries stored in the storage device. The entry that matches the condition in which the attribute value of the first attribute is specified is retrieved, and the attribute value of the second attribute that is stored in the entry is read, thereby associating with the first attribute that satisfies the predetermined condition The attribute value of the specified second attribute can be obtained.

  The program or module shown above may be stored in an external recording medium. As a recording medium, in addition to the flexible disk 2090 and the DVD-ROM 2095, an optical recording medium such as a DVD, Blu-ray (registered trademark), or a CD, a magneto-optical recording medium such as an MO, a tape medium, a semiconductor such as an IC card, etc. A memory or the like can be used. Further, a storage device such as a hard disk or a RAM provided in a server system connected to a dedicated communication network or the Internet may be used as a recording medium, and the program may be provided to the computer 1900 via the network.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

  The order of execution of each process such as operations, procedures, steps, and stages in the apparatus, system, program, and method shown in the claims, the description, and the drawings is particularly “before” or “prior to”. It should be noted that the output can be realized in any order unless the output of the previous process is used in the subsequent process. Regarding the operation flow in the claims, the description, and the drawings, even if it is described using “first”, “next”, etc. for convenience, it means that it is essential to carry out in this order. It is not a thing.

DESCRIPTION OF SYMBOLS 10 ... Board | substrate, 30 ... Magnetic field application apparatus, 42 ... 1st coil part, 44 ... 2nd coil part, 46 ... 3rd coil part, 48 ... 4th coil part, DESCRIPTION OF SYMBOLS 100 ... Rotation angle sensor, 110 ... 1st sensor, 111 ... 1st Hall element pair, 112 ... 1st Hall element, 113 ... 2nd Hall element, 116 ... 2nd Hall element pair, 117 ... third Hall element, 118 ... fourth Hall element, 120 ... second sensor, 121 ... third Hall element pair, 122 ... first Hall element, 123 ... 2nd Hall element, 126 ... 4th Hall element pair, 127 ... 3rd Hall element, 128 ... 4th Hall element, 130 ... Magnetic focusing plate, 140 ... X-axis signal Output unit, 142... Amplification unit, 144... AD conversion unit, 150. Output unit 152... Amplification unit 154... AD conversion unit 160. Error correction unit 170. Angle signal calculation unit 180. DESCRIPTION OF SYMBOLS 200 ... Calibration parameter production | generation apparatus, 210 ... Acquisition part, 220 ... Calculation part, 230 ... Parameter supply part, 300 ... Rotation angle sensor module, 410 ... Rotation magnet, 412 ... Rotating shaft, 420 ... motor, 500 ... rotation angle sensor module, 1900 ... computer, 2000 ... CPU, 2010 ... ROM, 2020 ... RAM, 2030 ... communication interface, 2040: hard disk drive, 2050: flexible disk drive, 2060 ... DVD drive, 2070 ... input / output chip, 20 5: graphic controller, 2080 ... display device, 2082 ... the host controller, 2084 ... input and output controller, 2090 ... flexible disk, 2095 ··· DVD-ROM

Claims (20)

A rotation angle sensor calibration method for detecting a rotation angle in the XY plane of a rotating magnet that rotates around an axis of a rotation axis by detecting a magnetic field in an X-axis direction and a magnetic field in a Y-axis direction on an XY plane,
An installation step of installing the rotation angle sensor on the XY plane and a magnetic field in N directions (N is an integer of 3 or more) having different directions by an angle equal to 360 degrees divided into N on the XY plane Applying a magnetic field to each of the sensors;
An acquisition step of acquiring at least two systems of output signals from the rotation angle sensor that are output in response to application of the magnetic field in the N direction, respectively;
A calculation step of calculating a calibration parameter for calibrating the rotation angle sensor based on the output signals of the at least two systems;
Storing the calibration parameter in the storage unit of the rotation angle sensor;
A method for calibrating a rotation angle sensor. The rotation angle sensor has a first sensor and a second sensor,
The rotation angle sensor calibration method according to claim 1, wherein the calculation step calculates the calibration parameter based on a difference between an output signal output from the first sensor and an output signal output from the second sensor. . The rotation angle sensor calibration method according to claim 2, wherein the first sensor and the second sensor are provided in parallel with a tangential direction of the rotating magnet on an outer side in a radial direction of the rotating magnet. In the obtaining step, the rotation angle output corresponding to each angle θ _n (n = 0, 1,..., N−1) of the rotating magnet with respect to a predetermined direction on the XY plane. Obtain N angle signals φ (θ _n ) of the sensor,
4. The rotation angle sensor according to claim 1, wherein the calculating step calculates the calibration parameter based on the angle signal φ (θ _n ) and without using the angle θ _n . 5. Calibration method. The calculating step includes
A first calculation step of calculating calibration parameters of even harmonics for the at least two systems of output signals;
After the first calculation step, a comparison step of comparing the magnitude relationship of the deviation component of the rotation axis;
After the comparison step, a second calculation step of calculating an odd harmonic calibration parameter for the at least two output signals;
The rotation angle sensor calibration method according to any one of claims 1 to 4. The rotation angle sensor calibration method according to claim 5, wherein in the comparison step, it is determined whether or not to execute the second calculation step according to a magnitude relation of a deviation component of the rotation axis. The acquisition step is output corresponding to each angle θ _n (n = 0, 1,..., N−1) of the magnetic field in the N direction with respect to a predetermined direction on the XY plane. Obtaining the output signals of the rotation angle sensor in the X-axis direction and the Y-axis direction;
The said calculation step calculates the said calibration parameter using the correlation coefficient of the angle error and amplitude error of the said output signal of the said X-axis direction and the said Y-axis direction. The rotation angle sensor calibration method described. A rotation magnet that rotates around a rotation axis, and a rotation angle sensor that detects a rotation angle of the rotation magnet in the XY plane by detecting a magnetic field in the X-axis direction and a magnetic field in the Y-axis direction on the XY plane. A method for calibrating an angular sensor module, comprising:
A calibration method for a rotation angle sensor module, wherein the rotation angle sensor is calibrated by the rotation angle sensor calibration method according to claim 1. Detects the magnetic field in the X-axis direction and the magnetic field in the Y-axis direction on the XY plane, and obtains output signals of at least two systems of rotation angle sensors that detect the rotation angle in the XY plane of the rotating magnet rotating around the rotation axis An acquisition unit to
A calculation unit for calculating a calibration parameter for calibrating the rotation angle sensor based on the output signals of the at least two systems;
A parameter supply unit that supplies the calibration parameter to the storage unit of the rotation angle sensor and stores the calibration parameter;
With
The acquisition unit outputs a magnetic field in an N direction (N is an integer of 3 or more) having different directions by an angle obtained by dividing 360 degrees into N on the XY plane in response to application to the rotation angle sensor. A calibration parameter generation device that obtains an output signal to be obtained from the rotation angle sensor. The rotation angle sensor has a first sensor and a second sensor,
The calibration parameter generation device according to claim 9, wherein the calculation unit calculates the calibration parameter based on a difference between an output signal output from the first sensor and an output signal output from the second sensor. The calibration parameter generation device according to claim 10, wherein the first sensor and the second sensor are provided in parallel to a tangential direction of the rotating magnet outside the radial direction of the rotating magnet. The acquisition unit is output corresponding to each angle θ _n (n = 0, 1,..., N−1) of the magnetic field in the N direction with respect to a predetermined direction on the XY plane. Obtain N angle signals φ (θ _n ) of the rotation angle sensor,
The calibration parameter generation device according to any one of claims 9 to 11, wherein the calculation unit calculates the calibration parameter based on the angle signal φ (θ _n ) and without using the angle θ _n. . The calculation unit calculates calibration parameters of even harmonics for the at least two systems of output signals,
After calculating the calibration parameters of the even harmonics, compare the magnitude relationship of the rotational axis deviation component,
The calibration parameter generation device according to any one of claims 9 to 12, wherein after comparing the magnitude relationship of the deviation component of the rotation axis, calibration parameters for odd harmonics are calculated for the at least two systems of output signals. The calibration parameter generation device according to claim 13, wherein the calculation unit determines whether or not to calculate a calibration parameter of the odd-numbered harmonics according to a magnitude relationship of the deviation component of the rotation axis. The acquisition unit is output corresponding to each angle θ _n (n = 0, 1, 2,..., N−1) of the magnetic field in the N direction with respect to a predetermined direction on the XY plane. Obtaining the output signals of the rotation angle sensor in the X-axis direction and the Y-axis direction,
The calculation unit calculates the calibration parameter using a correlation coefficient between an angle error and an amplitude error of the output signal in the X-axis direction and the Y-axis direction. The calibration parameter generator described. A first sensor that converts magnetic fields in the X-axis direction and the Y-axis direction and outputs output signals in the X-axis direction and the Y-axis direction;
A second sensor that converts the magnetic fields in the X-axis direction and the Y-axis direction and outputs output signals in the X-axis direction and the Y-axis direction;
A storage unit for storing calibration parameters generated by the calibration parameter generation device according to any one of claims 9 to 15,
Based on the calibration parameters, errors in the output signals of the at least two systems output from the first sensor and the second sensor in the X-axis direction and the Y-axis direction are corrected to correct the X-axis direction and the Y-axis. An error correction unit that outputs an error correction signal for each direction;
An angle signal calculation unit that calculates a corrected angle signal based on the error correction signals in the X-axis direction and the Y-axis direction;
A rotation angle sensor. The rotation angle sensor according to claim 16, wherein the first sensor and the second sensor are provided in parallel to a tangential direction of the rotary magnet on an outer side in a radial direction of the rotary magnet. A rotation angle sensor according to claim 16 or 17,
A rotating magnet having a rotation axis in a direction substantially perpendicular to the XY plane;
A rotation angle sensor module.   The program which makes a computer perform the calibration method of the rotation angle sensor as described in any one of Claim 1 to 7.   The program which makes a computer perform the calibration method of the rotation angle sensor module of Claim 8.

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