DE112017000564T5 - Angle detection device and method - Google Patents

Abstract

An error in a detection angle of an angle detection device is adjusted with a simple circuit configuration. An angle detection apparatus and method for detecting an angle is provided, wherein the angle detection apparatus for detecting the angle of a magnetic field includes: a first delta-sigma modulation unit for outputting a first modulation signal by applying delta-sigma modulation to a first magnetic field detection signal; which corresponds to a first directional component of the magnetic field; a second delta-sigma modulation unit for outputting a second modulation signal by applying a delta-sigma modulation to the second magnetic field detection signal corresponding to a second directional component of the magnetic field; and a loop control unit for making the detection angle follow by a loop control the first modulation signal and the second modulation signal, wherein the loop control unit includes a phase difference detection unit for detecting a phase difference of the detection angle with respect to one indicated by the first modulation signal and the second modulation signal Has angle; and a phase difference detection unit adjusts an error in the detection angle with respect to the angle of the magnetic field.

Description

BACKGROUND

TECHNICAL AREA

The present invention relates to an angle detection apparatus and a method for detecting an angle.

STATE OF THE ART

Conventionally, contactless

• Patentdokument 1: Japanisches Patent Nr. 5043878
• Patentdokument 2: Japanisches Patent Nr. 5342045
• Patentdokument 3: Japanisches Patent Nr. 5449417
• Patentdokument 4: Japanisches Patent Nr. 5687223
• Patentdokument 5: Japanisches Patent Nr. 4111813

Rotation angle sensors have been known for detecting rotation angles of rotating magnets based on detection results of detecting a change of magnetic fields in the X direction and in the Y direction. Also, such rotation angle sensors have non-linear angle errors due to sensitivity mismatches, offset errors, and sensitivities of other axes, etc., so that error adjustment, etc. have been performed (for example, see Patent Documents 1 to 5).

• Patent Document 1: Japanese Patent No. 5043878
• Patent Document 2: Japanese Patent No. 5342045
• Patent Document 3: Japanese Patent No. 5449417
• Patent Document 4: Japanese Patent No. 5687223
• Patent Document 5: Japanese Patent No. 4111813

For example, in conventional adjustments of non-linear angle errors described in patent documents 3, 4 and 5, it is proposed that AD conversion units, such as a delta-sigma modulator, cause nonlinear errors (eg offsets, sensitivity mismatches, other axis sensitivities). However, such a correction in the analog circuit, for example, correction within the delta-sigma modulator, causes the oversampling effect to decrease and causes folding noise.

Also, for signal processing according to the delta-sigma modulator, it can be assumed that after the modulation signal outputted by a decimation filter is made into multi-bit digital data, an operation is performed between the multi-bit data on the causes of the non-linear angle errors to correct. However, when the correction of the rotation angle sensor is performed after the decimal filter, the higher the resolution, the more multi-bit operations are required, so that particularly when an operation is performed using a circuit such as a multiplier, the circuit scale is made to increase , Generally, although depending on the circuit configurations, a 16 by 16 bit multiplier requires about 10 times the number of gates of a 1 by 16 bit multiplier and causes the circuit area to increase. Thus, a rotation angle sensor having a high resolution with a small nonlinear angle error and low noise is provided, while the increase in the circuit area is prevented.

[General Revelation]

(Item 1) An angle detection device can detect an angle of a magnetic field.

The angle detection device may include a first delta-sigma detection unit for outputting a first modulation pop by applying delta-sigma modulation to the first magnetic field detection signal corresponding to a first directional component of the magnetic field.

The angle detection device may include a second delta-sigma modulation unit for outputting a second modulation signal by applying delta-sigma modulation to the second magnetic field detection signal corresponding to a second directional component of the magnetic field.

The angle detection device may include a loop control unit for causing the detection angle to follow the first modulation signal and the second modulation signal by a loop control.

The loop control unit may include a phase difference detection unit for detecting a phase difference of the detection angle with respect to an angle indicated by the first modulation signal and the second modulation signal.

The phase difference detection unit may detect an error in the detection angle with respect to the angle of the magnetic field.

(Item 2) The phase difference detection unit may output a phase difference signal indicating the phase difference based on the first modulation signal and the second modulation signal, and the first feedback signal and the second feedback signal according to the detection angle.

The phase difference detection unit may adjust at least one of the first feedback signal, the second feedback signal and the phase difference signal so that the error becomes smaller.

(Item 3) The phase difference detection unit may operate the outer product of a set of the first modulation signal and the second modulation signal and a set of the first feedback signal and the second feedback signal to output a phase difference signal.

(Item 4) The phase difference detection unit may include a first angle adder unit for adding a first adjustment angle to the detection angle.

The phase difference detection unit may include a first amplitude adjustment unit for generating a first feedback signal to adjust the amplitude errors in the first modulation signal and the second modulation signal using the angle output from the first angle adding unit.

(Item 5) The phase difference detection unit may include a first angle subtracting unit for subtracting the first adjustment angle from the detection angle.

The first amplitude adjusting unit may generate the first feedback signal for adjusting the amplitude error in the first modulation signal and the second modulation signal using a sine value corresponding to the angle output from the first angle adding unit and a sine value corresponding to an angle corresponds to that output from the first angle subtracting unit.

(Item 6) The angle detection device may include a memory unit that can receive as the input an address based on an angle and output a sine value and a cosine value corresponding to the angle as data corresponding to the corresponding angles.

The first angle adding unit and the first angle subtracting unit may be connected to the storage unit at different cycles, an address based on the angle obtained by adding the first adjusting angle to the detecting angle, and an address based on the angle is determined by subtracting the first adjustment angle from the detection angle.

The first amplitude adjusting unit may receive from the storage unit at different cycles the sine value corresponding to the angle output from the first angle adding unit and the sine value corresponding to the angle output from the first angle subtracting unit.

The first amplitude adjusting unit may generate a first feedback signal for adjusting amplitude errors in the first modulation signal and the second modulation signal.

(Item 7) The phase difference detection unit may include a second angle adding unit for adding a second adjustment angle to the detection angle.

The phase difference detection unit may include a second amplitude adjustment unit for generating a second feedback signal for adjusting the amplitude errors in the first modulation signal and the second modulation signal using the angle output from the second angle adding unit.

(Item 8) The phase difference detection unit may include a second angle subtracting unit for subtracting the second adjustment angle from the detection angle. The second amplitude adjusting unit may generate the second feedback signal for adjusting the amplitude errors in the first modulation signal and the second modulation signal using a cosine value corresponding to the angle output from the second angle adding unit and a cosine value corresponding to the angle output from the second angle subtracting unit.

(Item 9) The phase difference detection unit may include an offset adjusting unit for multiplying the first feedback signal by the first offset adjustment value to adjust the offset of the first modulation signal and adding or subtracting the result to or from the phase difference.

(Item 10) The offset adjustment unit may add or subtract to or from the phase difference the result obtained by multiplying, per bit, the first feedback signal and the bitstream whose bits all have the same weighting as the first offset adjustment value.

(Item 11) The offset adjusting unit may multiply the second feedback signal by the second offset adjustment value to adjust the offset of the second modulation signal and to add or subtract the result to or from the phase difference.

(Item 12) The phase difference detection unit may include a third angle adding unit for adding a third adjustment angle to the detection angle.

The phase difference detection unit may include a third angle subtracting unit for subtracting the third adjustment angle from the detection angle.

The phase difference detecting unit may include, for adjusting another axis sensitivity between the first modulation signal and the second modulation signal, another axis sensitivity adjusting unit for generating a first feedback signal using a resultant detection angle obtained by adding the third adjustment value to the detection angle , and a second feedback signal using a resulting detection angle obtained by subtracting the third adjustment angle from the detection angle.

(Item 13) The other axis sensitivity adjusting unit may generate a first feedback signal based on a sine value corresponding to the resulting detection angle, which is obtained by adding the third adjustment angle to the detection angle.

The other axis sensitivity adjusting unit may generate a second feedback signal based on a cosine value corresponding to the resulting detection angle obtained by subtracting the third adjustment angle from the detection angle.

(Item 14) The phase difference detecting unit may include a per-bit sequential receive operation unit as an input of a bit stream of the first modulation signal and a bit stream of the second modulation signal to extract an outer product per bit between the bit stream of the first modulation signal and the bit stream of the first modulation signal second modulation signal and a set of the first feedback signal and the second feedback signal to operate.

(Item 15) The loop control unit may include a loop filter to allow the passage of frequency components having a predetermined frequency or lower in the phase difference.

The loop control unit may include an angle updating unit for increasing or decreasing the detection angle corresponding to the phase difference that has passed through the loop filter.

(Item 16) The phase difference detection unit may include a first magnetic detection unit that outputs the first magnetic field detection signal corresponding to the first directional component of the magnetic field. The angle detection device may include a second magnetic detection unit for outputting the second magnetic field detection signal corresponding to the second directional component of the magnetic field.

(Item 17) A method can adjust an error in the detection angle of the angle detection device to detect the angle of the magnetic field.

The method may include outputting a modulation signal by applying delta-sigma modulation to the first magnetic field detection signal corresponding to the first directional component of the magnetic field.

The method may include outputting a second modulation signal by applying delta-sigma modulation to the second magnetic field detection signal corresponding to the second directional component of the magnetic field.

The method may include causing the detection angle to follow the first modulation signal and the second modulation signal by a loop control.

To cause the detection angle to follow may include detecting a phase difference of the detection angle with respect to the angle indicated by the first modulation signal and the second modulation signal.

The detection of the phase difference can adjust the error in the detection angle with respect to the angle of the magnetic field.

(Item 18) The angle detection device can detect an angle of a magnetic field.

The angle detection device may include a first delta-sigma modulation unit for outputting a first modulation signal by applying delta-sigma modulation to the first magnetic field detection signal corresponding to a first directional component of the magnetic field. The angle detection device may include a second delta-sigma modulation unit for outputting a second modulation signal by applying delta-sigma modulation to the second magnetic field detection signal corresponding to a second directional component of the magnetic field.

The angle detection device may include a loop control unit for causing the detection angle to follow the first modulation signal and the second modulation signal by a loop control.

The loop control unit may adjust an error in the detection angle with respect to the angle of the magnetic field using a preset adjustment value.

(Item 19) A method can adjust an error in the detection angle of the angle detection device for detecting the angle of the magnetic field.

The method may include outputting a first modulation signal by applying delta-sigma modulation to the first magnetic field detection signal corresponding to the first directional component of the magnetic field.

The method may include outputting a second modulation signal by applying delta-sigma modulation to the second magnetic field detection signal corresponding to the second directional component of the magnetic field.

The method may include causing the detection angle to follow the first modulation signal and the second modulation signal by a loop control.

Making the detection angle follow can adjust the error in the detection angle with respect to the angle of the magnetic field using a preset adjustment value.

The summary statement does not necessarily describe all necessary features of the embodiments of the present invention. The present invention may also be a sub-combination of the features described above.

list of figures

• 1 FIG. 12 shows an exemplary configuration of a rotation angle sensor 1000 according to the present embodiment.
• 2 illustrates a first example configuration of an angle detection device 10 according to the present embodiment.
• 3 11 illustrates a first example of a first magnetic field detection signal Vx and a second magnetic field detection signal Vy output from a first magnetic sensor unit 30 and a second magnetic sensor unit 32 according to the present embodiment.
• 4 illustrates a second example configuration of the angle detection device 10 according to the present embodiment.
• 5 illustrates a third example configuration of the angle detection device 10 according to the present embodiment.
• 6 FIG. 12 illustrates a second example of the first magnetic field detection signal Vx and the second magnetic field detection signal Vy output from the first magnetic sensor unit 30 and the second magnetic sensor unit 32 according to the present embodiment.
• 7 illustrates a fourth example configuration of the angle detection device 10 according to the present embodiment.
• 8th FIG. 11 illustrates a third example of the first magnetic field detection signal Vx and the second magnetic field detection signal Vy output from the first magnetic sensor unit 30 and the second magnetic sensor unit 32 according to the present embodiment.
• 9 illustrates a fifth example configuration of the angle detection device 10 according to the present embodiment.
• 10 illustrates a first modification example of the phase difference detection unit 210 according to the present embodiment.
• 11 illustrates a second modification example of the phase difference detection unit 210 according to the present embodiment.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, (some) embodiment (s) of the present invention will be described. The embodiment (s) do not limit the invention according to the claims, and all combinations of the features described in the embodiment (s) are not necessarily essential to means provided by aspects of the invention.

1 shows an example configuration of a rotation angle sensor 1000 according to the present embodiment. The rotation angle sensor 1000 detects contactlessly a rotation angle of a magnetic field, which rotates about a rotation axis. 1 Fig. 15 shows an example for detecting a rotation angle of a magnetic field rotating on a plane parallel to the XY plane. The rotation angle sensor 1000 includes an angle detection device 10 and a rotary magnet 20 ,

The angle detection device 10 detects a rotation angle of a rotational magnetic field passing through the rotary magnet 20 is produced. The angle detection device 10 As an example, a semiconductor chip, etc., having integrated circuits or the like. In this case, the angle detection device becomes 10 is formed of semiconductors such as silicon and includes semiconductor circuits, semiconductor elements and the like. The angle detection device 10 includes a plurality of terminals and is electrically connected to external substrates, circuits and wirings, etc. Detailed configurations of the angle detection device 10 are described below.

The rotary magnet 20 generates the rotational magnetic field. The rotary magnet 20 has a magnet 22 , an axis of rotation 24 and a motor 26 on. The magnet 22 rotates around the axis of rotation 24 , 1 shows an example in which the magnet 22 along the Z-axis of the angle detection device 10 is provided. The magnet 22 has a disk shape as an example and rotates on a plane approximately parallel to the XY plane. The magnet 22 can be divided into two regions whose cross-sections are approximately semicircular in shape approximately parallel to the XY plane to form a magnet in which one of two semi-circular regions is the S pole and the other region is the N pole.

The magnet 22 generates a rotational magnetic field by rotating on the plane approximately parallel to the XY plane, such as by Equation 1 in the angle detection device 10 expressed. Here, B represents an absolute value of a magnetic field generated by the angle detection device 10 is detected. In the present embodiment, B is considered to be approximately constant to be handled as a constant. Also, θ represents an angle of a magnetic field direction of the rotational magnetic field with respect to a predetermined direction or a reference direction on a plane where the magnetic field rotates. $$\begin{array}{l}\text{Bx}\left(\mathrm{\theta }\right)=\text{B}\cdot \text{cos}\mathrm{\theta }\\ \text{by}\left(\mathrm{\theta }\right)=\text{B}\cdot \text{sin}\mathrm{\theta }\end{array}$$

The rotation axis 24 is provided in a direction approximately perpendicular to the XY plane. One end of the rotation axis 24 is with the magnet 22 connected and the other end of the same is with the engine 26 connected. The motor 26 rotates the rotation axis 24 and the magnet 22 that with the rotation axis 24 connected is. In such a way, the rotation angle sensor becomes 1000 formed by assembling the angle detection device 10 for detecting the magnetic field parallel to the XY plane and the rotating magnet 20 for rotating the magnet about the Z-axis.

The angle detection device 10 For example, detects a first directional component and a second directional component on the XY plane of the rotational magnetic field, each through the rotary magnet 20 are generated and calculates the rotation angle θ of the rotary magnet 20 at a time of detection based on the first direction component and the second direction component, and outputs the resulting rotation angle θ. Here, the first direction and the second direction are not limited as long as they are different directions from each other. It should be noted that it is desirable that the first direction and the second direction are two directions intersecting each other orthogonally on the XY plane. The present embodiment will be described where the first direction is the X-axis direction and the second is the Y-axis direction.

2 illustrates a first example configuration of an angle detection device 10 according to the present embodiment. The angle detection device 10 detects an angle of a magnetic field being input. The angle detection device 10 includes a first magnetic sensor unit in the first example configuration 30 , a second magnetic sensor unit 32 , a first amplification unit 40 , a second amplification unit 42 , a first delta-sigma modulation unit 50 , a second delta-sigma modulation unit 52 and a loop control unit 100 ,

The first magnetic sensor unit 30 outputs a first magnetic field detection signal Vx corresponding to the first directional component of the incoming magnetic field. The second magnetic sensor unit 32 outputs a second magnetic field detection signal Vy corresponding to the second directional component of the incoming magnetic field. The first magnetic sensor unit 30 and the second magnetic sensor unit 32 Both have magnetic sensors for detecting a magnetic field in one direction. For example, the first magnetic sensor unit outputs 30 the first magnetic field detection signal Vx corresponding to the magnetic field Bx (θ) as expressed by equation (1), and outputs the second magnetic sensor unit 32 the second magnetic field detection signal Vy corresponding to the magnetic field By (θ) as expressed by Equation (1). The first magnetic sensor unit 30 and the second magnetic sensor unit 32 Both preferably output detection signals that are proportional to incoming magnetic fields.

Each of the first magnetic sensor unit 30 and the second magnetic sensor unit 32 For example, a Hall element, a magnetic resistance element (MR), a giant magnetoresistance element (GMR), Tunnel effect magnetoresistance element (TMR), a magnetic impedance element (MI element) and / or an inductance sensor, etc. Also, each of the first magnetic sensor unit 30 and the second magnetic sensor unit 32 further comprising a magnetic convergence plate for converging the incoming magnetic field.

The first reinforcement unit 40 amplifies the first magnetic field detection signal Vx coming from the first magnetic sensor unit 30 is issued. The first reinforcement unit 40 provides the amplified signal to the first delta-sigma modulation unit 50 , It should be noted that when the rotation angle of the magnetic field is detected, an amplitude value of the incoming magnetic field may be standardized, where that by the first amplifying unit 40 amplified signal is considered to be approximately equal to the magnetic field Bx (θ) and that through the second amplifying unit 42 amplified signal is considered approximately equal to the magnetic field By (θ). That is, it is assumed that the angle θ of the rotational magnetic field is represented by using the first magnetic field detection signal Vx and the second magnetic field detection signal Vy.

The first delta-sigma modulation unit 50 applies a delta-sigma modulation to the first magnetic field detection signal Vx corresponding to the first direction component of the incoming magnetic field and outputs a first modulation signal. The second delta-sigma modulation unit 52 applies a delta sigma modulation to the second magnetic field detection signal Vy corresponding to the second directional component of the incoming magnetic field and outputs a second modulation signal. The first delta-sigma modulation unit 50 and the second delta-sigma modulation unit 52 As an example, both output bitstreams as a modulation signal with a predetermined number of 1-bit data.

It should be noted that the bitstream contains the predetermined number of 1-bit data and is such a signal that an integrated value of the 1-bit data is proportional to or approximately coincident with the amplitude value of the incoming signal. That is, the first delta-sigma modulation unit 50 as the first modulation signal outputs a bit stream corresponding to the magnetic field Bx (θ) and the second delta-sigma modulation unit 52 when the second modulation signal outputs a bit current corresponding to the magnetic field By (θ).

The loop control unit 100 receives the first modulation signal and the second modulation signal respectively from the first delta-sigma modulation unit 50 and the second delta-sigma modulation unit 52 and outputs, as a detection angle φ, angle information corresponding to the first received modulation signal and the second modulation signal. The loop control unit 100 may update the detection angle φ sequentially in accordance with a clock signal, etc., and output the resulting updated detection angle φ. The loop control unit 100 may cause the detection angle to follow the first modulation signal and the second modulation signal by loop control to update the detection angle φ and output the resulting updated detection angle φ. The loop control unit 100 has a phase difference detection unit 110 , a loop filter 140 and an angle updating unit 150 on.

The phase difference detection unit 110 Detects a phase difference of the detection angle φ with respect to the angle θ, which is indicated by the first modulation signal and the second modulation signal. The phase difference detection unit 110 detects the phase difference between the detection angle φ coming from the loop control unit 100 and the angle information θ corresponding to the first modulation signal and the second modulation signal, and then outputs the loop control unit 100 the phase difference for updating the detection angle. The phase difference detection unit 110 includes a storage unit 120 and an outer product operation unit 130 ,

The storage unit 120 may, as an input, receive an address based on an angle and output a sine value and a cosine value corresponding to the angle as data corresponding to the respective angles. The storage unit 120 stores sine values and cosine values each corresponding to a plurality of angles. The storage unit 120 can store sine values and cosine values for corresponding addresses corresponding to the plurality of angles. The storage unit 120 For example, as input, receives a detection angle derived from the loop control unit 100 is output and includes a conversion unit for converting the input detection angle into an address corresponding to the detection angle. That is, the storage unit 120 sin φ and cos φ according to the incoming detection angle φ outputs.

The storage unit 120 delivers to the outer product operation unit 130 a sin φ value and a cos φ corresponding to the incoming detection angle φ as a first feedback signal and a second feedback signal, respectively. The storage unit 120 For example, as an input of π / 2 radian (or an address value corresponding to π / 2 radians), it supplies 1 as the first feedback signal and 0 as the second feedback signal. The storage unit 120 may output the first feedback signal and the second feedback signal with digital values of predetermined numbers of bits.

The outer product operation unit 130 an outer product P, which is expressed by the following equation, operates by using the first feedback signal and the second feedback signal derived from the memory unit 120 are output, and the first modulation signal and the second modulation signal. It is to be noted that it is assumed that the first modulation signal is expressed by B · cos θ and the second modulation signal is expressed by B · sin θ. $$\begin{array}{l}\text{P = -B}\cdot \text{cos}\mathrm{\theta }\cdot \text{sin}\mathrm{\phi \; +}\text{B}\cdot \text{sin}\mathrm{\theta }\cdot \text{cos}\mathrm{\phi }\\ \mathrm{=}\text{B}\cdot \text{sin}\left(\mathrm{\theta }-\mathrm{\phi }\right)\\ \cong \text{B}\cdot \left(\mathrm{\theta }-\mathrm{\phi }\right)\end{array}$$

The outer product operation unit 130 includes, for example, a first multiplier unit 132 , a second multiplier unit 134 and a subtracting unit 136 , The first multiplier unit 132 multiplies the first modulation signal and the first feedback signal to calculate B · cos θ · sin φ. The second multiplier unit 134 multiplies the second modulation signal and the second feedback signal to calculate B · sin θ · cos φ. The subtraction unit 136 operates the outer product P expressed by Equation (2) by subtracting the product passing through the first multiplying unit 132 is calculated from the product by the second multiplier unit 134 is calculated. In such a way, the phase difference detection unit develops 110 the outer product of a set of the first modulation signal and the second modulation signal, and a set of the first feedback signal and the second feedback signal, and outputs the result as the phase difference signal.

Here is the loop control unit 100 the detection angle φ so as to follow the angle θ indicated by the first modulation signal and the second modulation signal, and thus the value of θ · φ is such a small value that the approximation sin (θ · φ) ≅ ( θ · φ) can be satisfied. Thus, as expressed by equation (2), the outer product P may be obtained by operation through the outer product operation unit 130 is determined to be approximated as B · (θ-φ), a value proportional to the phase difference of the detection angle φ with respect to the angle θ. The value B is a constant, and therefore, the phase difference detection unit results 110 in detecting the phase difference (θ-φ) between the angle θ and the detection angle φ. The phase difference detection unit 110 supplies the detected phase difference to the loop filter 140 ,

The loop filter 140 allows the passage of frequency components having a predetermined frequency or lower in the phase difference obtained from the phase difference detection unit 110 be received. The loop filter 140 can be a low-pass filter. The loop filter 140 can reduce quantization noise generated by the first delta-sigma modulation unit 50 and the second delta-sigma modulation unit 52 is produced. Also, when the first magnetic field detection signal Vx and the second magnetic field detection signal Vy generated from the first magnetic sensor unit 30 and the second magnetic sensor unit 32 output, modulated, and DC offset signals included in the first magnetic field detection signal Vx and the second magnetic field detection signal Vy are converted into harmonic components, the loop filter may be output 140 also reduce the harmonic component.

The angle update unit 150 increases or decreases the detection angle φ according to the phase difference (θ-φ) that has passed through the loop filter. The angle update unit 150 updates the detection angle φ so that the phase difference (θ-φ) comes closer to zero. The angle update unit 150 For example, it may include two integration units, and in this case, the loop control unit 100 a type 2 servo circuit including two integration units in a closed loop circuit. The angle update unit 150 includes as an example two integration units and a DCO (Digitally Controlled Oscillator) circuit.

When the incoming signal of the phase difference (θ-φ) to the angle updating unit 150 For example, a signal which is detected by operation using the first modulation signal and the second modulation signal of the bit stream, the first integration unit in the angle updating unit 150 integrate the phase difference signal to produce a phase difference signal per clock. Also, the phase difference per clock (that is, per unit time) has a dimension of angular velocity ω (rad / s), which is the time differential of the angle. In this case, the angle update unit returns 150 a signal of the wind speed ω to the DCO circuit and outputs a frequency signal corresponding to the angular velocity ω, and the second integration unit integrates the frequency signal to generate the detection angle φ.

It should be noted that the second integration unit may include an up and down counter to perform count-up and count-down operations, and integrate a count of the frequency signals for that time into the count values up to the previous time to produce the detection angle φ , That is, by integrating the phase difference (θ-φ) for that time to the detection angle φ for the previous time, the angle updating unit 150 calculates the detection angle φ closer than the rotation angle -θ of the magnetic field for that time.

As described above, the angle detection device 10 according to the present embodiment by a feedback loop through the loop control unit 100 give a more accurate detection angle φ, which is made to follow the angle θ. In the feedback loop, the loop control unit couples 100 to the outer product operation unit 130 the sine wave signal sin (φ) and the cosine wave signal cos (φ) corresponding to the detection angle φ to multiply with the first modulation signal and the second modulation signal.

Here, when the first modulation signal and the second modulation signal are signed bit streams where values of either +1 or -1 are temporarily aligned, the outer product P expressed by Equation (2) becomes any one of the values P1 to P4 such as expressed by the following equation, corresponding to bit values of the first modulation signal and the second modulation signal. It should be noted that it is assumed that the bit value of the first modulation signal is S1 and the bit value of the second modulation signal is S2. $$\begin{array}{ccc}\text{P}1=-\text{B}\cdot \text{sin}\mathrm{\phi }+\text{B}\cdot \text{cos}\mathrm{\phi }.& \text{S1 = + 1}\text{.}& \text{S2 = + 1}\\ \text{P2}=\text{B}\cdot \text{sin}\mathrm{\phi }+\text{B}\cdot \text{cos}\mathrm{\phi }.& \text{S1 = -1}\text{.}& \text{S2 = + 1}\\ \text{P3}=-\text{B}\cdot \text{sin}\mathrm{\phi -}\text{B}\cdot \text{cos}\mathrm{\phi }.& \text{S1 = + 1}\text{.}& \text{S2 = -1}\\ \text{P4}=\text{B}\cdot \text{sin}\mathrm{\phi -}\text{B}\cdot \text{cos}\mathrm{\phi }.& \text{S1 = -1}\text{.}& \text{S2 = -1}\end{array}$$

That is, by supplying the first modulating signal and the second modulating signal to the outer product operation unit 130 in the form of the bitstream, the angle detection device 10 calculate the outer product P by adding or subtracting the first feedback signal and the second feedback signal. That is, the outer product operation unit 130 sequentially receiving, per bit as an input, a bitstream of the first modulation signal and a bitstream of the second modulation signal, and performing adding or subtracting to operate the outer product, per bit, between the bitstream of the first modulation signal and the bitstream of the second modulation signal and a set of the first feedback signal and the second feedback signal. This allows the outer product operation unit 130 as alternatives to the first multiplication unit 132 and the second multiplication unit 134 use an adder and a subtracter to scale down a mounting surface.

In such an angle detection device 10 For example, the detection angle φ may include errors such as sensitivity mismatches, offset errors, other axis sensitivities, and the like. In this case, the angle detection device has 10 measured these errors during their production step and / or under a condition where the detection operation has not been performed to adjust the error of the detection angle φ according to the measured result. However, when such a non-linear angle error adjustment is performed on an analog circuit, for example, the delta-sigma modulation unit, etc., the oversampling effect for causing the convolution noise is lowered, and thus the adjustment is not suitable for lowering its noise.

Thus, the loop control unit adjusts 200 According to the present embodiment, the non-linear angle error to realize the lowering of the noise so that the adjustment by the analog signal can not be realized, and the high-resolution is realized. Also, it is possible to prevent the circuit scale from increasing as the resolution becomes higher by adjusting the non-linear angle error without using the multiplier. That is, the loop control unit 200 the error in the detection angle φ with respect to the angle θ of the magnetic field is adjusted by adding and subtracting using a preset adjustment value. The angle detection device 10 that is such a loop control unit 200 will be described next.

3 FIG. 11 illustrates a first example of a first magnetic field detection signal Vx and a second magnetic field detection signal Vy generated from a first magnetic sensor unit 30 and a second magnetic sensor unit 32 according to the present embodiment. In 3 The horizontal axis represents the first magnetic field detection signal Vx of the first magnetic sensor unit 30 which detects the first direction (X-axis direction), and the vertical axis represents the second magnetic field detection signal Vy of the second magnetic sensor unit 32 which detects the second direction (Y-axis direction). A signal indicated by the broken line is an ideal magnetic field detection signal having an approximately circular shape on the XY plane. It means that 3 an example shows where it is assumed in that the ideal first magnetic field detection signal Vx is expressed by B · cos θ and the ideal second magnetic field detection signal Vy is expressed by B · sin θ.

A signal indicated by the solid line shows a magnetic field detection signal in the case where a mismatch in the magnet sensitivities in the first magnetic sensor unit 30 and the second magnetic sensor unit 32 occurs. 3 shows a magnetic field detection signal in the case where the first magnetic sensor unit 30 larger than the second magnetic sensor unit 32 in the magnetic sensitivity is. In this case, the first magnetic field detection signal Vx may be expressed by B · A · cos θ, where A> 1. In such a case, when mis-adjustments in the magnetic sensitivity in the first magnetic sensor unit 30 and the second magnetic sensor unit 32 occur, the angle detection device 10 do not spend the exact detection angle φ.

For example, when the angle θ of the rotational magnetic field falls within the range 0 <θ <π / 2 (and π <θ <3π / 2), the first magnetic field detection signal Vx is larger than the second magnetic field detection signal Vy, and thus the angle detection device outputs 10 a detection angle φ that is smaller than θ. Similarly, when the angle θ of the rotational magnetic field falls within the range: π / 2 <θ <π (and 3π / 2 <θ <2π), the first magnetic field detection signal Vx is smaller than the second magnetic field detection signal Vy, and thus the angle detection device outputs 10 the detection angle φ, which is greater than θ.

More specifically, the outer product P expressed by Equation (2) will be like the following equation. Here, since θ≅φ, it is assumed that sin (θ-φ) = 0 and 2 · cos φ · sin θ = sin 2θ. $$\begin{array}{l}\text{P = -B}\cdot \text{A}\cdot \text{cos}\mathrm{\theta }\cdot \text{sin}\mathrm{\phi \; +}\text{B}\cdot \text{sin}\mathrm{\theta }\cdot \text{cos}\mathrm{\phi }\\ \mathrm{=}\text{B}\cdot \left\{-\text{A}\cdot \text{cos}\mathrm{\theta }\cdot \text{sin}\mathrm{\phi }+\text{sin}\mathrm{\theta }\cdot \text{cos}\mathrm{\phi }\right\}\\ \text{= B}\cdot \left\{\text{A}\cdot \text{sin}\left(\mathrm{\theta }-\mathrm{\phi }\right)+\left(1-\text{A}\right)\cdot \text{sin}\mathrm{\theta }\cdot \text{cos}\mathrm{\phi }\right\}\\ \cong -0.5\cdot \text{B}\cdot \left(-1+\text{A}\right)\cdot \text{sin}2\mathrm{\theta }\end{array}$$

As described above, there is a case where the outer product P still has a certain value even if the phase difference (θ-φ) is zero, resulting in that the detection angle φ is an error corresponding to the magnetic field mismatch. Contains sensitivity. When the first magnetic field detection signal Vx having a correction value 1 / A is multiplied to adjust such an angle error, the first magnetic field detection signal Vx B · cos θ to be able to express the outer product P in equation ( 2 ) to calculate. That is, the adjustment of the angle error is enabled by adding a multiplication circuit for multiplying the first magnetic field detection signal Vx by the correction value 1 / A , However, the multiplication circuit has a large mounting area, which may cause the circuit scale to increase.

Thus, to adjust the angle error without using the multiplication circuit, first the first feedback signal is multiplied by a correction value β to calculate the outer product P. $$\text{P}=\text{B}\cdot \text{A}\cdot \text{cos}\mathrm{\theta }\cdot \text{sin}\mathrm{\phi }\cdot \text{cos}\mathrm{\beta }+\text{B}\cdot \text{sin}\mathrm{\theta }\cdot \text{cos}\mathrm{\phi }$$

Here, A = 1 / cos α. It should be noted that A cos β are values both close to 1 and therefore the approximation can be made: α≅β, that is, cos β / cos α ≅ 1. Thus, equation (5) is expressed as the following equation , $$\begin{array}{l}\text{P = -B}\cdot \text{cos}\mathrm{\theta }\cdot \text{sin}\mathrm{\phi }\cdot \text{cos}\mathrm{\beta \; /}\text{cos}\mathrm{\alpha \; +}\text{B}\cdot \text{sin}\mathrm{\theta }\cdot \text{cos}\mathrm{\phi }\\ \cong -\text{B}\cdot \text{cos}\mathrm{\theta }\cdot \text{sin}\mathrm{\phi }+\text{B}\cdot \text{sin}\mathrm{\theta }\cdot \text{cos}\mathrm{\phi }\\ \text{= B}\cdot \text{sin}\left(\mathrm{\theta }-\mathrm{\phi }\right)\\ \cong \text{B}\cdot \left(\mathrm{\theta }-\mathrm{\phi }\right)\end{array}$$

As described above, by making the phase difference (θ-φ) zero, as in equation (2), using the corrected value β, the external product P can be made zero. Thus, the angle detection device 10 reduce the angular error corresponding to the magnetic sensitivity mismatch by making the detection angle φ follow θ.

Next, transforming the multiplication into Equation 5 becomes as follows. $$\begin{array}{l}\text{P}=-\text{B}\cdot \text{A}\cdot \text{cos}\mathrm{\theta }\cdot \text{sin}\mathrm{\phi }\cdot \text{cos}\mathrm{\beta }+\text{B}\cdot \text{sin}\mathrm{\theta }\cdot \text{cos}\mathrm{\phi }\\ \mathrm{=\; -}\text{B}\cdot \text{A}\cdot \text{cos}\mathrm{\theta }\cdot \left\{\text{sin}\left(\mathrm{\phi }\text{+}\mathrm{\beta }\right)\text{+ sin}\left(\mathrm{\phi }-\mathrm{\beta }\right)\right\}/2\\ +\text{B}\cdot \text{sin}\mathrm{\theta }\cdot \text{cos}\mathrm{\phi }\end{array}$$

Equation 7 indicates that multiplications such as sin φ · cos β can be derived from additions such as sin (φ + β) + sin (φ-β). The loop control unit 200 According to the present embodiment, the error is adjusted without using the multiplication circuit, using a circuit for performing the operation in Equation 7.

4 illustrates a second exemplary configuration of the angle detection device 10 according to the present embodiment. In the angle detection device 10 in the second example configuration, operations that are approximately the same as those of the angle detection device 10 in the in 2 shown in the first example configuration, with the same reference numerals and the description will not be repeated. The angle detection device 10 in the second example configuration, the loop control unit includes 200 , The loop control unit 200 has a phase difference detection unit 210 , the loop filter 140 and the angle updating unit 150 on. The loop filter 140 and the angle updating unit 150 are in 2 described, the description will not be repeated here.

The phase difference detection unit 210 adjusts the error in the detection angle φ with respect to the angle θ of the magnetic field. The phase difference detection unit 210 can perform the adjustment so that the error of the detection angle φ becomes smaller. 4 shows an example where the phase difference detection unit 210 adjusted an angle error in the case where the first magnetic sensor unit 30 larger than the second magnetic sensor unit 32 at the magnetic sensitivity is. That is, the phase difference detection unit 210 outputs a phase difference signal indicative of the phase difference based on the first modulation signal and the second modulation signal and the first feedback signal and the second feedback signal in accordance with the detection angle φ, and adjusts the first feedback signal. The phase difference detection unit 210 includes the storage unit 120 , the outer product operation unit 130 , a correction value storage unit 220 , a first adding and subtracting unit 230 and a first amplitude adjusting unit 240 ,

The correction value storage unit 220 stores a correction value β which adjusts the error at the detection angle φ. The correction value storage unit 220 can store + β and - β. It is to be noted that in the present embodiment, the correction value β is regarded as a first adjustment angle.

The first adding and subtracting unit 230 adds and subtracts the detection angle φ based on the first adjustment angle β in the correction value storage unit 220 , The first adding and subtracting unit 230 includes a first angular adder unit 232 and a first angle subtracting unit 234 , The first angular adder unit 232 adds the first adjustment angle β to the detection angle φ. The first angular adder unit 232 supplies the addition result (φ + β) to the memory unit 120 , The first angle subtraction unit 234 subtracts the first adjusted angle β from the detection angle φ. The first angle subtraction unit 234 supplies the subtraction result (φ-β) to the memory unit 120 ,

The first angular adder unit 232 and the first angle subtraction unit 234 can assign an address based on the angles to the storage unit 120 deliver. Also, the first angular adder unit 232 and the first angle subtraction unit 234 on the storage unit 120 at different cycles, enter an address based on the angle obtained by adding the first adjustment value β to the detection angle φ, and an address based on the angle obtained by subtracting the first adjustment angle β from the detection angle φ. That is, the first adding and subtracting unit 230 sequentially the storage unit 120 Address values based on the angles corresponding to the clock signal, etc.

The storage unit 120 there, in addition to the in 2 described operations, the sine wave signal corresponding to an angle which is determined by the detection angle φ and the first adjustment angle β out. That is, the storage unit 120 respectively, a value of a sine wave signal sin (φ + β) corresponding to the result of addition (φ + β) of the first angular adder unit 232 , a value of a sine wave signal sin (φ-β) corresponding to the subtraction result (φ-β) of the first angle subtracting unit 234 and outputs a value of a cosine wave signal cos φ corresponding to the detection angle φ. It should be noted that, as in 2 , the value of the cosine wave signal cos φ becomes the second feedback signal.

The first amplitude adjustment unit 240 generates the first feedback signal to adjust the amplitude errors in the first modulation signal and the second modulation signal, using the angles derived from the first angular adder unit 232 and the first angular subtraction unit 234 be issued. The first amplitude adjustment unit 240 generates the first feedback signal for adjusting the amplitude errors in the first modulation signal and the second modulation signal using a sine value corresponding to an angle derived from the first angular adder unit 232 and a sine value corresponding to the angle obtained from the first angle subtracting unit 234 is issued.

Also, the first amplitude adjustment unit 240 generate the first feedback signal for adjusting the amplitude error in the first modulation signal and the second modulation signal, receiving, at different cycles, from the memory unit 120 of the sine value corresponding to that of the first angular adder unit 232 output angle and the sine value corresponding to those from the first angle subtraction unit 234 output angle. The first amplitude adjustment unit 240 includes an adder unit 242 and an amplification unit 244 ,

The adding unit 242 adds values of sin (φ + β) and sin (φ-β) coming from the memory unit 120 be received. The reinforcement unit 244 amplifies the addition result of the adder unit 242 at a predetermined fixed magnification. The reinforcement unit 244 can the addition result of the adding unit 242 for example, by a factor of 0.5. That is, the first amplitude adjustment unit 240 when the first feedback signal generates a signal which is obtained by dividing a sum of sin (φ + β) and sin (φ-β) by two. Thereby, the first feedback signal becomes {sin (φ + β) + sin (φ-β)} / 2. It should be noted that the operation of multiplying by 0.5 times in the digital operation may be performed by bit shifting, so that the area is not increased.

The outer product operation unit 130 operates the outer product P using the first feedback signal and the second feedback signal and the first modulation signal and the second modulation signal. Here, the first feedback signal {sin (φ + β) + sin (φ-β)} / 2, so that the outer product operation unit 130 in the present embodiment, the outer product P expressed by Equation 7 operates. Also, the outer product P expressed by Equation 7 may be approximated to the phase difference (θ-φ) as expressed by Equation 6. Thus, by the outer product operation unit 130 the operation result of the outer product P the loop filter 140 feeds, the loop control unit 200 output the detection angle φ following the angle θ of the rotational magnetic field.

It should be noted that the outer product operation unit 130 the outer product P, as in 2 can be calculated by adding or subtracting the first feedback signal and the second feedback signal. Thus, the phase difference detection unit 210 calculate the outer product P by adding and subtracting based on the detection angle φ and the first adjustment angle β. Also, the phase difference detection unit 210 use the sine wave signal stored in the memory unit 120 is stored as the sine wave signal sin (φ) + β) and the sine wave signal sin (φ-β) used to generate the first feedback signal. That is, the phase difference detection unit 210 Used data in which the address value is shifted from the detection angle φ by the first adjustment angle β, and thus the outer product P without increasing the data to be stored in the memory unit 120 to calculate.

Thus, the loop control unit 200 According to the present embodiment, the angular error corresponding to the magnetic sensitivity mismatch can be adjusted while preventing an increase in the circuit scale and data to be handled. The angle detection device 10 in 4 includes such loop control unit 200 Thus, a contactless rotation angle sensor may be provided where the sensitivity mismatch is reduced while preventing an increase in circuit scale and also in data for handling.

An example where the angle detection device 10 According to the present embodiment described above, the angle error for the mismatch in the magnetic sensitivity is adjusted when the first magnetic sensor unit 30 larger than the second magnetic sensor unit 32 in the magnetic sensitivity is will be described. Alternatively, the angle detection device 10 adjust the angular error for the mismatch in the magnetic sensitivity when the first magnetic sensor unit 30 smaller than the second magnetic sensor unit 32 at the magnetic sensitivity. In this case, the external product P expressed by the equation 4 is expressed as the following equation. $$\begin{array}{l}\text{P}=-\text{B}\cdot \text{cos}\mathrm{\theta }\cdot \text{sin}\mathrm{\phi }+\text{B}\cdot \text{A}\cdot \text{sin}\mathrm{\theta }\cdot \text{cos}\mathrm{\phi }\\ \mathrm{=}\text{B}\cdot \left\{\text{A}\cdot \text{sin}\left(\mathrm{\theta }-\mathrm{\phi }\right)+\left(-1+\text{A}\right)\cdot \text{cos}\mathrm{\theta }\cdot \text{sin}\mathrm{\phi }\right\}\\ \cong 0.5\cdot \text{B}\cdot \left(-1+\text{A}\right)\cdot \text{sin}2\mathrm{\theta }\end{array}$$

Even in this case, the outer product P is calculated by multiplying the second feedback signal by the correction value cos β. In such a way, by using the corrective value cos β as in Equation 6, the external product P can be made zero by making the phase difference (θ-φ) zero. Thus, the angle detection device 10 reduce the angular error corresponding to the magnetic sensitivity mismatch by making the detection angle φ follow θ. $$\begin{array}{l}\text{P = -B}\cdot \text{cos}\mathrm{\theta }\cdot \text{sin}\mathrm{\phi \; +}\text{B}\cdot \text{A}\cdot \text{sin}\mathrm{\theta }\cdot \text{cos}\mathrm{\phi }\cdot \text{cos}\mathrm{\beta }\\ \cong -\text{B}\cdot \text{cos}\mathrm{\theta }\cdot \text{sin}\mathrm{\phi }+\text{B}\cdot \text{sin}\mathrm{\theta }\cdot \text{cos}\mathrm{\phi }\\ \text{= B}\cdot \text{sin}\left(\mathrm{\theta }-\mathrm{\phi }\right)\\ \cong \text{B}\cdot \left(\mathrm{\theta }-\mathrm{\phi }\right)\end{array}$$

Also, equation (9) can be transformed as follows. $$\begin{array}{l}\text{P}=-\text{B}\cdot \text{cos}\mathrm{\theta }\cdot \text{sin}\mathrm{\phi }+\text{B}\cdot \text{A}\cdot \text{sin}\mathrm{\theta }\cdot \text{cos}\mathrm{\phi }\cdot \text{cos}\mathrm{\beta }\\ \mathrm{=\; -}\text{B}\cdot \text{cos}\mathrm{\theta }\cdot \text{sin}\mathrm{\phi }\\ \mathrm{+}\text{B}\cdot \text{A}\cdot \text{sin}\mathrm{\theta }\cdot \left\{\text{cos}\left(\mathrm{\phi }+\mathrm{\beta }\right)+\text{cos}\left(\mathrm{\phi -\beta }\right)\right\}/2\end{array}$$

Equation 10 states that multiplications such as cos φ · cos β can be derived from addition such as cos (φ + β) + cos (φ-β). The loop control unit 200 According to the present embodiment, the angle error corresponding to the magnetic sensitivity mismatch can be reduced by using a circuit for performing the operation in Equation 10. Such a loop control unit 200 will be described next.

5 illustrates a third example configuration of the angle detection device 10 according to the present embodiment. In the angle detection device 10 In the third example embodiment, operations are approximately the same as those of the angle detection device 10 in the first example configuration and the second example configuration that in 2 respectively. 4 are shown, the same reference numerals and the description will not be repeated. The loop control unit 200 in the third example configuration, the phase difference detection unit 210 , the loop filter 140 and the angle updating unit 150 on. The loop filter 140 and the angle updating unit 150 are in 2 described and the description is not repeated here.

5 shows an example where the phase difference detection unit 210 adjusted an angle error in the case where the first magnetic sensor unit 30 smaller than the second magnetic sensor unit 32 at Magnetic Sensitivity. That is, the phase difference detection unit 210 outputs a phase difference signal indicative of the phase difference based on the first modulation signal and the second modulation signal, and the first feedback signal and the second feedback signal corresponding to the detection angle φ, and adjusts the second feedback signal. The phase difference detection unit 210 includes the storage unit 120 , the outer product operation unit 130 , the correction value storage unit 220 , a second adding and subtracting unit 330 and a second amplitude adjusting unit 340 ,

The correction value storage unit 220 stores a second adjustment angle β. The second adding and subtracting unit 330 adds and subtracts the detection angle φ based on the second adjustment angle β in the correction value storage unit 220 , The second adding and subtracting unit 330 includes a second angle adding unit 332 and a second angle subtractor unit 334 , The second angle adding unit 332 adds the second adjustment angle β to the detection angle φ. The second angle adding unit 332 supplies the addition result (φ + β) to the memory unit 120 , The second angle subtractor unit 334 subtracts the second adjustment angle β from the detection angle φ. The second angle subtractor unit 334 supplies the subtraction result (φ-β) to the memory unit 120 ,

The second angle adding unit 332 and the second angle subtractor unit 334 can send an address, based on the angles, to the storage unit 120 deliver. Also, the second angle adding unit 332 and the second angle subtractor unit 334 to the storage unit 120 in different cycles, input an address based on the angle obtained by adding the second adjustment angle β to the detection angle φ, and an address based on the angle obtained by subtracting the second adjustment angle β from the detection angle φ. That is, the second adding and subtracting unit 330 sequentially the storage unit 120 Can supply address values based on the angles corresponding to the clock signal, etc.

The storage unit 120 In addition to the in 2 described operations, the cosine wave signal corresponding to an angle which is determined by the detection angle φ and the second adjustment angle β from. That is, the storage unit 120 respectively, a value of a cosine wave signal cos (φ + β) corresponding to the addition result (φ + β) of the second angle adding unit 332 , an angle of a cosine wave signal cos (φ-β) corresponding to the subtraction result (φ-β) of the second angle subtracting unit 334 and outputs a value of a sine wave signal sin (φ) corresponding to the detection angle φ. It should be noted that, as in 2 the value of the sine wave signal sin (φ) becomes the first feedback signal.

The second amplitude adjustment unit 340 generates the second feedback signal to adjust the amplitude error in the first modulation signal and in the second modulation signal using the angles derived from the second angle adding unit 332 and the second angle subtracting unit 334 be issued. The second amplitude adjustment unit 340 generates the second feedback signal for adjusting the amplitude error in the first modulation signal and the second modulation signal using a cosine value corresponding to that from the second angle adding unit 332 and a cosine value corresponding to that from the second angle subtractor unit 334 output angle. The second amplitude adjustment unit 340 includes an adder unit 342 and an amplification unit 344 ,

The adding unit 342 adds values of cos (φ + β) and cos (φ-β) coming from the memory unit 120 be received. The reinforcement unit 344 amplifies the addition result of the adder unit 342 at a predetermined fixed magnification. The reinforcement unit 344 can the addition result of the adding unit 342 For example, increase by a factor of 0.5. That is, the second amplitude adjustment unit 340 when the second feedback signal produces a signal which is obtained by dividing a sum of cos (φ + β) and cos (φ-β) by two. Thereby, the second feedback signal becomes {cos (φ + β) + cos (φ-β)} / 2. It should be noted that the operation of multiplying by 0.5 times in the digital operation can be performed by bit shifting so that the area is not made to grow.

The outer product operation unit 130 operates on the outer product P using the first feedback signal and the second feedback signal and the first modulation signal and the second modulation signal. Here, the second feedback signal {cos (φ + β) + cos (φ-β)} / 2, so that the outer product operation unit 130 in the present embodiment, the outer product P expressed by Equation 10 operates. Also, the external product P expressed by Equation 10 can be approximated to a value based on the phase difference (θ-φ) as expressed by Equation 9. Thus, by the outer product operation unit 130 showing the operation result of the outer product P of the loop filters 140 feeds the loop control unit 200 output the detection angle φ following the angle θ of the rotational magnetic field.

It should be noted that the outer product operation unit 130 the outer product P can calculate, as in 2 by adding or subtracting the first feedback signal and the second feedback signal. Also uses the phase difference detection unit 210 Data in which the address value is shifted from the detection angle φ by the second adjustment angle β, and thus can calculate the outer product P without multiplying the data stored in the storage unit 120 to save. Thus, the loop control unit 200 according to the present embodiment, adjust the angular error corresponding to the magnetic sensitivity mismatch while preventing an increase in the circuit size and also in the data to be handled.

An example where the angle detection device 10 According to the present embodiment described above, the angular error for the misregistration in the magnetic sensitivity is adjusted will be described. Alternatively, the angle detection device 10 adjust the angle error for the offset error. First, the offset error will be described next.

6 illustrates a second example in the first magnetic field detection signal Vx and in the second magnetic field detection signal Vy derived from the first magnetic sensor unit 30 and the second magnetic sensor unit 32 according to the present embodiment. In 6 The horizontal axis represents the first magnetic field detection signal Vx of the first magnetic sensor unit 30 which detects the first direction (X-axis direction) and the vertical axis represents the second magnetic field detection signal Vy of the second magnetic sensor unit 32 which detects the second direction (Y-axis direction). A signal indicated by the broken line is an ideal magnetic field detection signal having an approximately circular shape on the XY plane. It means that 6 shows an example in which it is assumed that the ideal first magnetic field detection signal Vx is expressed by B · cos θ and the ideal magnetic field detection signal Vy is expressed by B · sin θ.

A signal indicated by the solid line shows a magnetic field detection signal in the case where the offset error in the first magnetic sensor unit 30 and the second magnetic sensor unit 32 occur. 6 shows a magnetic field detection signal in the case where offset errors are included as: + Ox in the first magnetic field detection signal Vx; and + Oy in the first magnetic field detection signal Vx. When such offset errors in the first magnetic sensor unit 30 and the second magnetic sensor unit 32 occur, the angle detection device 10 do not spend the exact detection angle φ.

More specifically, the outer product P expressed by Equation 2 will be like the following equation. Here that θ≅φ, it is assumed that sin (θ-φ) = 0. $$\begin{array}{l}\text{P}=-\left(\text{B}\cdot \text{cos}\mathrm{\theta }+\text{Ox}\right)\cdot \text{sin}\mathrm{\phi }+\left(\text{B}\cdot \text{sin}\mathrm{\theta }+\text{Oy}\right)\cdot \text{cos}\mathrm{\phi }\\ \mathrm{=}\text{B}\cdot \text{sin}\left(\mathrm{\theta }-\mathrm{\phi }\right)-\text{Ox}\cdot \text{sin}\mathrm{\phi }+\text{Oy}\cdot \text{cos}\mathrm{\phi }\\ \cong \text{Oy}\cdot \text{cos}\mathrm{\phi }-\text{Ox}\cdot \text{sin}\mathrm{\phi }\end{array}$$

As described above, there is a case where the outer product P still has some value even if the phase difference (θ-φ) is zero, resulting in that the detection angle φ includes an angle error corresponding to the offset error. Thus, the angle detection device adjusts 10 According to the present embodiment, the angular error by reducing Oy · cos φ · Ox · sin φ, which is caused by the offset error, from the outer product P.

7 illustrates a fourth example configuration of the angle detection device 10 according to the present embodiment. In the angle detection device 10 In the fourth example configuration, operations are approximately the same as those of the angle detection device 10 in the in 2 In the first example configuration shown, the same reference numbers are given and the description will not be repeated. The angle detection device 10 in the fourth example configuration includes the loop control unit 200 ,

The loop control unit 200 has the phase difference detection unit 210 , the loop filter 140 and the angle updating unit 150 on. The loop filter 140 and the angle updating unit 150 are in 2 described and the description is not repeated here.

7 shows an example in which the phase difference detection unit 210 the offset error of the first magnetic sensor unit 30 and the second magnetic sensor unit 32 adjusted. That is, the phase difference detection unit 210 outputs a phase difference signal indicative of the phase difference based on the first modulation signal and the second modulation signal and the first feedback signal and the second feedback signal in accordance with the detection angle φ, and adjusts the phase difference signal. The phase difference detection unit 210 includes the storage unit 120 , the outer product operation unit 130 , the correction value storage unit 220 and an offset adjustment unit 410 ,

The storage unit 120 delivers in addition to the in 2 described operation to the offset adjustment unit 410 a value of the cosine wave signal cos φ and a value of the sine wave signal sin φ corresponding to the detection angle φ. The outer product operation unit 130 , as in 2 described, processes the outer product P using the first feedback signal and the second feedback signal and the first modulation signal and the second modulation signal. The outer product operation unit 130 gives the outer product P expressed by Equation 11.

The correction value storage unit 220 stores correction values Ox and Oy which adjust the error at the detection angle φ. It should be noted that in the present embodiment, the correction value Ox is regarded as the first offset adjustment value, and the correction value Oy is regarded as the second offset adjustment value.

The offset adjustment unit 410 may multiply the first feedback signal by the first offset adjustment value to adjust the offset of the first modulation signal and to add or subtract the result to or from the phase difference. Here, the phase difference represents the operation result of Equation 7. In addition, the offset adjustment unit 410 also multiply the second feedback signal by the second offset adjustment value to adjust the offset of the second modulation signal and to add or subtract the result to or from the phase difference. The offset adjustment unit 410 includes as an example a first multiplying unit 412 , a second multiplier unit 414 and an adding unit 416 ,

The first multiplier unit 412 multiplies a value of sin φ coming from the memory unit 120 is received with one from the correction value storage unit 220 received first offset adjustment value. The second multiplier unit 414 multiplies a value of cos φ coming from the storage unit 120 is received with one from the correction value storage unit 220 received second offset adjustment value. The adding unit 416 adds a multiplication result of the first multiplying unit 412 to the operation result of the outer product P, which is the outer product operation unit 130 Will be received. Also, the adder unit subtracts 416 a multiplication result of the second multiplying unit 414 from the result of operation of the outer product P coming out of the outer product operation unit 130 Will be received.

This adjusts the offset adjustment unit 410 by operation through the outer product operation unit 130 determined outer product P to an adjustment value P ', which is expressed by the following equation. $$\begin{array}{l}\text{P}\text{'}=\text{P}+\text{Ox}\cdot \text{sin}\mathrm{\phi }\cdot \text{Oy}\cdot \text{cos}\mathrm{\phi }\\ \mathrm{=}\text{B sin}\left(\mathrm{\theta }\cdot \mathrm{\phi }\right)\\ \cong \text{B}\cdot \left(\mathrm{\theta }\cdot \mathrm{\phi }\right)\end{array}$$

That is, the offset adjustment unit 410 can adjust the adjustment value P 'to be approximately coincident with a value based on the phase difference (θ-φ). Thus, in that the phase difference detection unit 210 the operation result of the adjustment value P 'of the loop filters 140 feeds, the loop control unit 200 output the detection angle φ following the angle θ of the rotational magnetic field.

It should be noted that it will be described that the offset adjustment unit 410 the offset error using the first multiplier unit 412 and the second multiplier unit 414 adjusted. In In this case, since two more multiplier circuits are added, the mounting area of the angle detection device 10 be increased. Thus, the correction value storage unit 220 the first offset adjustment value and the second offset adjustment value of the offset adjustment unit 410 in the bitstream. The correction value storage unit 220 For example, as the first offset adjustment value, the bitstream whose bits are all the same direction as that equivalent to the correction value Ox is provided. Similarly, the correction value storage unit 220 as the second offset adjustment value, supply the bit stream whose bits all have the same weighting, which is equivalent to the correction value Oy.

In this case, the offset adjustment unit adds 410 to the phase difference, the result obtained by multiplying per bit of the bit stream of the correction value storage unit 220 received first Offsetjustierwerts with the feedback signal is determined. Similarly, the offset adjustment unit subtracts 410 from the phase difference, the result obtained by multiplying, per bit, the bit stream of the from the correction value storage unit 220 received second offset adjustment value is determined with the second feedback signal.

The multiplication that uses the bitstream provided by the offset adjustment unit 410 10, described above, may be performed by processing the addition or subtraction, similarly to the operation of calculating the outer product P by adding or subtracting the outer product operation unit 130 , in the 2 is described. Thus, the offset adjustment unit 410 adjust the offset error while preventing the mounting surface from rising. Thus, the loop control unit 200 According to the present embodiment, adjusting the error in the detection angle corresponding to the offset error while preventing the circuit scale from being increased.

An example in which the angle detection device 10 According to the present embodiment described above, the errors in the detection angle corresponding to the misregistration in the magnetic sensitivity and the offset error are adjusted. Alternatively, the angle detection device 10 adjust the error at the detection angle according to the other axis sensitivity. First, the other axis sensitivity will be described next.

8th illustrates a third example of the first magnetic field detection signal Vx and the second magnetic field detection signal Vy derived from the first magnetic sensor unit 30 and the second magnetic sensor unit 32 according to the present embodiment. In 8th The horizontal axis represents the first magnetic field detection signal Vx of the first magnetic sensor unit 30 which detects the first direction (X-axis direction), and the vertical axis represents the second magnetic field detection signal Vy of the second magnetic sensor unit 32 which detects the second direction (Y-axis direction). A signal indicated by the broken line is an ideal magnetic field detection signal having an approximately circular shape on the XY plane. It means that 8th an example shows where it is assumed that the ideal first magnetic field detection signal Vx is expressed by B · cos θ and the ideal second magnetic field detection signal Vy is expressed by B · sin θ.

A signal indicated by the solid line shows a magnetic field detection signal in the case where other axis sensitivities in the first magnetic sensor unit 30 and the second magnetic sensor unit 32 occur. 8th shows a magnetic field detection signal in the case where the other axis sensitivity is included, such as: + B · γ · sin θ in the first magnetic field detection signal Vx; and + B · γ · cos θ in the first magnetic field detection signal Vx. In such cases, if other axis sensitivities in the first magnetic sensor unit 30 and the second magnetic sensor unit 32 occur, the angle detection device 10 do not spend the exact detection angle φ.

Here, the magnetic field detection signal in the case where the other axis sensitivity is included therein is approximated as the following equation. If the angle error corresponding to the other axis sensitivity is approximately 5 degrees or less, the accuracy of such approach can be expected to be high. $$\begin{array}{l}\text{Vx}=\text{B}\cdot \left(\text{cos}\mathrm{\theta }+\mathrm{\gamma }\cdot \text{sin}\mathrm{\theta }\right)\\ \cong \text{B}\cdot \left(\text{cos}\mathrm{\gamma }\cdot \text{cos}\mathrm{\theta \; +}\text{sin}\mathrm{\gamma }\cdot \text{sin}\mathrm{\theta }\right)\\ =\text{B}\cdot \text{cos}\left(\mathrm{\theta }-\mathrm{\gamma }\right)\\ \text{Vy}=\text{B}\cdot \left(\text{sin}\mathrm{\theta }+\mathrm{\gamma }\cdot \text{cos}\mathrm{\theta }\right)\\ \cong \text{B}\cdot \left(\text{cos}\mathrm{\gamma }\cdot \text{sin}\mathrm{\theta \; +}\text{sin}\mathrm{\gamma }\cdot \text{cos}\mathrm{\theta }\right)\\ =\text{B}\cdot \text{sin}\left(\mathrm{\theta \; +\; \gamma }\right)\end{array}$$

In this case, the external product P expressed by Equation 2 is calculated as the following equation, where an approximation is made: γ≅0 is made. $$\begin{array}{l}\text{P}=-\text{B}\cdot \text{cos}\left(\mathrm{\theta }-\mathrm{\gamma }\right)\cdot \text{sin}\mathrm{\phi }+\text{B}\cdot \text{sin}\left(\mathrm{\theta }+\mathrm{\gamma }\right)\cdot \text{cos}\mathrm{\phi }\\ \mathrm{=}\text{B}\cdot [-0.5\cdot \left\{\text{sin}\left(\mathrm{\theta }-\mathrm{\gamma }+\mathrm{\phi }\right)-\text{sin}\left(\mathrm{\theta }-\mathrm{\gamma }-\mathrm{\phi }\right)\right\}\\ +0.5\cdot \left\{\text{sin}\left(\mathrm{\theta }+\mathrm{\gamma }+\mathrm{\phi }\right)+\text{sin}\left(\mathrm{\theta }+\mathrm{\gamma }-\mathrm{\phi }\right)\right\}]\\ =\text{B}\cdot [0.5\cdot \left\{\text{-sin}\left(\mathrm{\theta }+\mathrm{\phi -\gamma }\right)\text{+ sin}\left(\mathrm{\theta \; +\; \gamma \; +\; \phi }\right)\right\}\\ +0.5\cdot \left\{\text{sin}\left(\mathrm{\theta -\phi -\gamma }\right)+\text{sin}\left(\mathrm{\theta -\phi \; +\; \gamma }\right)\right\}]\\ =\text{B}\cdot \left\{\text{cos}\left(\mathrm{\theta }+\mathrm{\phi }\right)\cdot \text{sin}\mathrm{\gamma }+\text{sin}\left(\mathrm{\theta }-\mathrm{\phi }\right)\cdot \text{cos}\mathrm{\gamma }\right\}\\ \cong \text{B}\cdot \left\{\text{cos}\left(\mathrm{\theta }+\mathrm{\phi }\right)\cdot \mathrm{\gamma }+\text{sin}\left(\mathrm{\theta }-\mathrm{\phi }\right)\cdot 1\right\}\\ =\text{B}\cdot \mathrm{\gamma }\cdot \text{cos 2}\mathrm{\theta }\end{array}$$

As described above, there is a case where the outer product P still has some value even if the phase difference (θ-φ) is zero, resulting in that the detection angle φ includes an angle error corresponding to the other axis sensitivity. Thus, the angle detection device adjusts 10 According to the present embodiment, the angle error corresponding to the other axis sensitivity is reduced.

The angle detection device 10 For example, as an example, the phases of the first feedback signal and the second feedback signal may be adjusted using δ as the following equation.

Here an approximation is made: γ≅δ≅0. $$\begin{array}{l}\text{P = -B}\cdot \text{cos}\left(\mathrm{\theta }-\mathrm{\gamma }\right)\cdot \text{sin}\left(\mathrm{\phi }+\mathrm{\delta }\right)\\ +\text{B}\cdot \text{sin}\left(\mathrm{\theta }+\mathrm{\gamma }\right)\cdot \text{cos}\left(\mathrm{\phi }-\mathrm{\delta }\right)\\ =\text{B}\cdot [-0.5\cdot \left\{\text{sin}\left(\mathrm{\theta }-\mathrm{\gamma }+\mathrm{\phi }+\mathrm{\delta }\right)-\text{sin}\left(\mathrm{\theta }-\mathrm{\gamma }-\mathrm{\phi }-\mathrm{\delta }\right)\right\}\\ +0.5\cdot \left\{\text{sin}\left(\mathrm{\theta }+\mathrm{\gamma }+\mathrm{\phi }-\mathrm{\delta }\right)+\text{sin}\left(\mathrm{\theta }+\mathrm{\gamma }-\mathrm{\phi }+\mathrm{\delta }\right)\right\}]\\ =\text{B}\cdot [0.5\cdot \left\{-\text{sin}\left(\mathrm{\theta }+\mathrm{\phi }-\mathrm{\gamma }+\mathrm{\delta }\right)+\text{sin}\left(\mathrm{\theta }+\mathrm{\gamma }+\mathrm{\phi }-\mathrm{\delta }\right)\right\}\\ +.05\cdot \left\{\text{sin}\left(\mathrm{\theta }-\mathrm{\phi }-\mathrm{\gamma }-\mathrm{\delta }\right)+\text{sin}\left(\mathrm{\theta }-\mathrm{\phi }+\mathrm{\gamma }+\mathrm{\delta }\right)\right\}]\\ =\text{B}\cdot \left\{\text{cos}\left(\mathrm{\theta }+\mathrm{\phi }\right)\cdot \text{sin}\left(\mathrm{\gamma }-\mathrm{\delta }\right)+\text{sin}\left(\mathrm{\theta }-\mathrm{\phi }\right)\cdot \text{cos}\left(\mathrm{\gamma }+\mathrm{\delta }\right)\right\}\\ \cong \text{B}\cdot \left\{\text{cos}\left(\mathrm{\theta }+\mathrm{\phi }\right)\cdot 0+\text{sin}\left(\mathrm{\theta }-\mathrm{\phi }\right)\cdot 1\right\}\\ =\mathrm{{\rm B}}\cdot \text{sin}\left(\mathrm{\theta }-\mathrm{\phi }\right)\\ \cong \text{B}\cdot \left(\mathrm{\theta }-\mathrm{\phi }\right)\end{array}$$

As described above, by making the phase difference (θ-φ) zero, as in Equation 6, using the correction value δ, the outer product P can be made zero. Thus, the angle detection device 10 reduce the angular error corresponding to the other axis sensitivity by making the detection angle φ to follow θ. The angle detection device 10 According to the present embodiment, the angle error corresponding to the other axis sensitivity can be reduced by using a circuit for performing the operation in Equation 15. Such an angle detection device 10 will be described next.

9 illustrates a fifth example configuration of the angle detection device 10 according to the present embodiment. In the angle detection device 10 in the fifth example configuration, operations which are approximately the same as those in the angle detection apparatus 10 in the in 2 shown the first example configuration, the same reference numerals and the description will not be repeated. The angle detection device 10 in the fifth example configuration, the loop control unit includes 200 , The loop control unit 200 has the phase difference detection unit 210 , the loop filter 140 and the angle updating unit 150 on. The loop filter 140 and the angle updating unit 150 are in 2 described, the description will not be repeated here.

9 shows an example in which the phase difference detection unit 210 the other axis sensitivities of the first magnetic sensor unit 30 and the second magnetic sensor unit 32 adjusted. That is, the phase difference detection unit 210 outputs a phase difference signal indicative of the phase difference based on the first modulation signal and the second modulation signal, and the first feedback signal and the second feedback signal corresponding to the workpiece table 4 , and adjusts the first feedback signal and the second feedback signal. The phase difference detection unit 210 includes the storage unit 120 , the outer product operation unit 130 , the correction value storage unit 220 and another axis sensitivity adjustment unit 410 ,

The correction value storage unit 220 stores a correction value δ which adjusts the error in the detection angle φ. The correction value storage unit 220 can store values of + δ or -δ. It is to be noted that in the present embodiment, the correction value δ is regarded as a third adjustment value.

The other axis sensitivity adjustment unit 510 adds and subtracts the detection angle φ based on the third adjustment angle δ in the correction value storage unit 220 , The other axis sensitivity adjustment unit 510 includes a third angle adding unit 512 and a third angle subtracting unit 514 , the third angle adding unit 512 adds the third adjustment angle δ to the detection angle φ. The third angle adding unit 512 supplies the addition result (φ + δ) to the memory unit 120 , The third angle subtraction unit 514 subtracts the third adjustment angle δ from the detection angle φ. The third angle subtraction unit 514 supplies the subtraction result (φ-δ) to the memory unit 120 ,

The third angle adding unit 512 and the third angle subtracting unit 514 can send an address, based on the angles, to the storage unit 120 deliver. Also, the third angle adding unit 512 and the third angle subtracting unit 514 on the storage unit 120 at different cycles, based on the angle obtained by adding the third adjustment angle δ to the detection angle φ and an address based on the angle obtained by subtracting the third adjustment angle δ from the detection angle φ. That is, the difference axis sensitivity adjustment unit 510 to the storage unit 120 Address values based on the angles corresponding to the clock signal.

The storage unit 120 outputs a sine value and a cosine value corresponding to an angle determined by the detection angle φ and the third adjustment angle δ. That is, the storage unit 120 each a value of sin (φ + δ) corresponding to the addition result (φ + δ) of the third angle adding unit 512 and a value of cos (φ-δ) corresponding to the subtraction result (φ-δ) of the third angle subtracting unit 514 outputs.

That is, to adjust the other axis sensitivity between the first modulation signal and the second modulation signal, that the other different-axis sensitivity adjustment unit 510 generates a first feedback signal using a resultant detection angle φ + δ obtained by adding the third adjustment angle δ to the detection angle, and a second feedback signal using a resultant detection angle φ-δ obtained by subtracting the third adjustment angle δ from the detection angle. Also generates the other axis sensitivity adjustment unit 510 a first feedback signal based on a sine value corresponding to a resulting detection angle φ + δ, which is obtained by adding the third adjustment angle δ to the detection angle, and a second feedback signal based on a cosine value corresponding to the resulting detection angle φ-δ which detects is obtained by subtracting the third adjustment angle δ from the detection angle. 9 shows an example where the other axis sensitivity adjustment unit 510 sin (φ + δ) as the first feedback signal from the memory unit 120 and cos (φ-δ) as the second feedback signal from the memory unit 120 outputs.

The outer product operation unit 130 operates the outer product P using the first feedback signal and the second feedback signal and the first modulation signal and the second modulation signal. In the outer product operation unit 130 in the present embodiment, the other axis sensitivity adjusting unit adjusts 510 the first feedback signal and the second feedback signal based on the third adjustment angle δ such that the outer product operation unit 130 the outer product P expressed by Equation 15 operates. Thus, by allowing the outer product operation unit 130 the operation result of the outer product P of the loop filters 140 feeds the loop controller 200 output the detection angle φ following the angle θ of the rotational magnetic field.

It should be noted that the outer product operation unit 130 the outer product P, as in 2 described by adding or subtracting the first feedback signal and the second feedback signal. Also uses the other axis sensitivity adjustment unit 510 Data in which the address value is shifted from the detection angle φ by the third adjustment angle δ and thus can adjust the first feedback signal and the second feedback signal without storing the data in the memory unit 120 to grow. Thus, the loop control unit 200 according to the present embodiment, adjust the angle error corresponding to the other axis sensitivity while preventing an increase in the circuit scale and also in the data to be handled.

An example where the angle detection device 10 According to the present embodiment described above, each of the errors in the detection angle corresponding to any misregistration in the magnetic sensitivity, the offset error and the other axis sensitivity is adjusted. Alternatively or additionally, the angle detection device 10 adjust two or more errors from the errors in the detection angle corresponding to any of mismatch in the magnetic sensitivity, offset error, and other axis sensitivity. A phase difference detection unit 210 used in such an angle detection device 10 is provided will be described next.

10 illustrates a first modification example of the phase difference detection unit 210 according to the present embodiment. In the phase difference detection unit 210 In the first modification example, operations which are approximately the same as those of FIG 4 . 7 and 9 shown phase difference detection unit 210 , the same reference numerals and the description will not be repeated. The phase difference detection unit 210 In the first modification example, the storage unit includes 120 , the outer product operation unit 130 , the correction value storage unit 220 , the first adding and subtracting unit 230 , the first amplitude adjustment unit 240 , the offset adjustment unit 410 and the other axis sensitivity adjustment unit 510 ,

The correction value storage unit 220 stores the first adjustment angle β, the first offset adjustment value Ox, the second offset adjustment value Oy, and the third adjustment angle δ. The correction value storage unit 220 respectively supplies the first adjustment angle β to the first adding and subtracting unit 230 , the first offset adjustment value Ox, and the second offset adjustment value Oy to the offset adjusting unit 410 and the third adjustment angle δ to the other axis sensitivity adjusting unit 510 ,

The first adding and subtracting unit 230 and the first amplitude adjustment unit 240 can, as in 4 described, adjust the angular error corresponding to the mismatch in the magnetic sensitivity by adjusting the first feedback signal. The offset adjustment unit 410 adjusted, as in 7 described, the angle error corresponding to the offset error by adjusting the outer product P, which is determined by the operation by the outer product operation unit 130 , The other axis sensitivity adjustment unit 510 adjusted, as in 9 described, the angle error corresponding to the other axis sensitivity by adjusting the first feedback signal and the second feedback signal.

Thus, the phase difference detection unit 210 According to the present embodiment, each of the errors in the detection angle corresponding to the mismatch in the magnetic sensitivity, the offset error and the other Achsensensitivität adjust. It should be noted that 10 shows an example in which the phase difference detection unit 210 adjusts the angular error in the case where the first direction is greater than the second direction in the magnetic sensitivity. Alternatively, the phase difference detection unit 210 adjust the angle error in the case where the magnetic sensitivity in the first direction is smaller than that of the second direction. Such a phase difference detection unit 210 will be described next.

11 illustrates a second modification example of the phase difference detection unit 210 according to the present embodiment. In the phase difference detection unit 210 In the second modification example, operations are approximately the same as those of the phase difference detection unit 210 , in the 5 . 7 and 9 is shown, the same reference numerals and the description will not be repeated. The phase difference detection unit 210 In the second modification example, the storage unit includes 120 , the outer product operation unit 130 , the correction value storage unit 220 , the second adding and subtracting unit 330 , the second amplitude adjustment unit 340 , the offset adjustment unit 410 and the other axis sensitivity adjustment unit 510 ,

That is, the phase difference detection unit 210 in the second modification example as alternatives to the first adding and subtracting unit 230 and the first amplitude adjustment unit 240 the phase difference detection unit 210 in the first modification example in FIG 10 the second adding and subtracting unit 330 and the second amplitude adjusting unit 240 contains. The correction value storage unit 220 stores the second adjustment angle β and the correction value storage unit 220 supplies the second adjustment angle β to the second adding and subtracting unit 330 , The second adding and subtracting unit 330 and the second amplitude adjusting unit 340 can, as in 5 described adjust the angle error corresponding to the magnetic sensitivity mismatch by adjusting the second feedback signal. The other operations of the phase difference detection unit 210 in the second modification example are approximately the same as those of the phase difference detection unit 210 in the first in 10 shown modification example and the description will not be repeated here.

As described above, the phase difference detection unit 210 According to the present embodiment, each of the errors in the detection angle corresponding to the mismatch in the magnetic sensitivity, the offset error and the other axis sensitivity adjust. It should be noted that it is described that the in 10 and 11 described phase difference detection unit 210 adjusts the angular error corresponding to the magnetic sensitivity mismatch by adjusting the first feedback signal and / or the second feedback signal. Alternatively, the phase difference detection unit 210 the first adding and subtracting unit 230 , the first amplitude adjustment unit 240 , the second adding and subtraction 330 and the second amplitude adjusting unit 340 contain.

In this case, the phase difference detection unit 210 according to the magnitude of the magnetic sensitivity in the first direction and in the second direction between adjusting the first feedback signal by the first adding and subtracting unit 230 and the first amplitude adjusting unit 240 and adjusting the second feedback signal by the second adding and subtracting unit 330 and the second amplitude adjusting unit 340 switch. As a result, the phase difference detection unit 210 respectively adjust the errors in the detection angle corresponding to the mismatch in the two types of magnetic sensitivities, the offset error, and the other axis sensitivity.

While the embodiments of the present invention have been described, the technical scope of the invention is not limited by the embodiments described above. It will be apparent to those skilled in the art that various changes and improvements may be added to the embodiments described above. It is also apparent from the scope of the claims that the embodiments to which such changes and improvements are added may be included within the technical scope of the invention.

The operations, procedures, steps and stages in each process, embodiment or diagram performed by a device, a system, a program and a method as set forth in the claims may be performed in any order as long as the order does not pass through Are indicated "before", "before" or the like and unless the output from the previous process is used in the later process. Even if the process flow is described using phrases such as "first" or "next" in the claims, embodiments or diagrams, it does not necessarily mean that the process must be performed in that order.

LIST OF REFERENCE NUMBERS

10 angle detection device; 20 rotating magnet; 22 magnet; 24 rotation axis; 26 engine; 30 first magnetic sensor unit; 32 second magnetic sensor unit; 40 first gain unit; 42 second amplification unit; 50 first delta-sigma modulation unit; 52 second delta-sigma modulation unit; 100 loop control unit; 110 phase difference detection unit; 120 storage unit; 130 outer product operation unit; 132 first multiplier unit; 134 second multiplier unit; 136 subtraction unit; 140 loop filter; 150 angle updating unit; 200 loop control unit; 210 phase difference detection unit; 220 correction value storage unit; 230 first adding and subtracting unit; 232 first angular adder unit; 234 first angular subtraction unit; 240 first amplitude adjustment unit; 242 adding unit; 244 amplification unit; 330 second adding and subtracting unit; 332 second angle adding unit; 334 second angle subtracting unit; 340 second amplitude adjustment unit; 342 adding unit; 344 amplification unit; 410 offset adjustment unit; 412 first multiplier unit; 414 second multiplier unit; 416 adding unit; 510 other axis sensitivity adjustment unit; 512 third angle adding unit; 514 third angle subtracting unit; 1000 rotation angle sensor

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• JP 5043878 [0002]
• JP 5342045 [0002]
• JP 5449417 [0002]
• JP 5687223 [0002]
• JP 4111813 [0002]

Claims (19)

An angle detecting device for detecting an angle of a magnetic field, comprising: a first delta-sigma modulation unit for applying delta-sigma modulation to a first magnetic field detection signal corresponding to a first directional component of a magnetic field to output a first modulation signal; a second delta-sigma modulation unit for applying delta-sigma modulation to a second magnetic field detection signal corresponding to a second directional component of a magnetic field to output a second modulation signal; and a loop control unit for making a detection angle follow the first modulation signal and the second modulation signal by loop control, wherein the loop control unit includes a phase difference detection unit for detecting a phase difference of the detection angle with respect to an angle indicated by the first modulation signal and the second modulation signal; and the phase difference detection unit adjusts an error in the detection angle with respect to an angle of the magnetic field. Winkeldetektionsvorrichtung according to Claim 1 wherein the phase difference detection unit outputs a phase difference signal indicative of the phase difference based on the first modulation signal and the second modulation signal, and a first feedback signal and a second feedback signal corresponding to the detection angle; and adjusting at least one of the first feedback signal, the second feedback signal, and the phase difference signal to make the error smaller. Winkeldetektionsvorrichtung according to Claim 2 wherein the phase difference detection unit operates on an outer product of a set of the first modulation signal and the second modulation signal, and outputs the phase difference signal. Winkeldetektionsvorrichtung according to Claim 2 or 3 wherein the phase difference detection unit includes: a first angle adder unit for adding a first adjustment angle to the detection angle; and a first amplitude adjusting unit for generating the first feedback signal to adjust amplitude errors in the first modulation signal and the second modulation signal using an angle output from the first angular adder unit. Winkeldetektionsvorrichtung according to Claim 4 wherein the phase difference detection unit further includes a first angle subtracting unit for subtracting the first adjustment angle from the detection angle; and the first amplitude adjusting unit generates a first feedback signal for adjusting amplitude errors in the first modulation signal and the second modulation signal using a sine value corresponding to an angle output from the first angular adder unit and a sine value corresponding to an angle is output from the first angle subtracting unit. Winkeldetektionsvorrichtung according to Claim 5 , further comprising a memory unit that can receive an address based on an angle as an input and output as data corresponding to respective angles, a sine value and a cosine value corresponding to the angle, wherein the first angle adder unit and the first angle subtracting unit at the memory unit at different cycles, input an address based on an angle obtained by adding the first adjustment angle to the detection angle and an address based on an angle obtained by subtracting the first adjustment angle from the detection angle; and the first amplitude adjusting unit receives, at different cycles from the storage unit, a sine value corresponding to an angle output from the first angular adder unit and a sine value corresponding to an angle output from the first angle subtracting unit to receive the first feedback signal Adjusting amplitude errors in the first modulation signal and in the second modulation signal to generate. Angle detection device according to one of Claims 2 to 6 wherein the phase difference detection unit includes: a second angle adder unit for adding a second adjustment angle to the detection angle; and a second amplitude adjusting unit for generating the second feedback signal for adjusting amplitude errors in the first modulation signal and in the second modulation signal using an angle output from the second angular adder unit. Winkeldetektionsvorrichtung according to Claim 7 wherein the phase difference detection unit further includes a second angle subtracting unit for subtracting the second adjustment angle from the detection angle; and the second amplitude adjusting unit includes a second feedback signal for adjusting amplitude errors in the first modulation signal and the second modulation signal using a cosine value corresponding to an angle output from the second angle adder unit and a cosine value corresponding to an angle derived from the second angle subtracting unit output is generated. Angle detection device according to one of Claims 2 to 8th wherein the phase difference detection unit further includes an offset adjusting unit for multiplying the first feedback signal by a first offset adjustment value to adjust an offset of the first modulation signal, and adding or subtracting a resultant to or from the phase difference. Winkeldetektionsvorrichtung according to Claim 9 wherein the offset adjustment unit multiplies, per bit, the first feedback signal and a bitstream whose bits have the same weighting as the first offset adjustment value, and adds or subtracts a result to or from the phase difference. Winkeldetektionsvorrichtung according to Claim 9 or 10 wherein the offset adjusting unit multiplies the second feedback signal by a second offset adjustment value to adjust an offset of the second modulation signal, and to add or subtract a result to or from the phase difference. Angle detection device according to one of Claims 2 to 11 wherein the phase difference detection unit includes: a third angle adder unit for adding a third adjustment angle to the detection angle; a third angle subtracting unit for subtracting a third adjustment angle from the detection angle; and another axis sensitivity adjusting unit for adjusting another axis sensitivity between the first modulation signal and the second modulation signal to generate the first feedback signal using a result detection angle obtained by adding the third adjustment angle to the detection angle and the second feedback signal using a result detection angle obtained by subtracting the third adjustment angle from the detection angle. Winkeldetektionsvorrichtung according to Claim 12 wherein the other axis-sensitivity adjusting unit calculates the first feedback signal based on a sine value corresponding to a result-detection angle obtained by adding the third adjustment angle to the detection angle and the second feedback signal based on a cosine value corresponding to a result-detection angle obtained by subtracting third adjustment angle of the detection angle is determined generated. Angle detection device according to one of Claims 2 to 13 wherein the phase difference detection unit includes an outer product operation unit for sequentially receiving, per bit as an input, a bit stream of the first modulation signal and a bit stream of the second modulation signal to process an outer product, per bit, between the bit stream of the first modulation signal and the first modulation signal Bitstream of the second modulation signal and a set of the first feedback signal and the second feedback signal. Winkeldetektionsvorrichtung according to Claim 14 wherein the loop control unit comprises: a loop filter for allowing passage of a frequency component having a predetermined frequency or lower at the phase difference; and an angle updating unit for increasing or decreasing the detection angle in accordance with the phase difference that has passed through the loop filter. Angle detection device according to one of Claims 1 to 15 further comprising: a first magnetic sensor unit for outputting the first magnetic field detection signal corresponding to the first directional component of a magnetic field; and a second magnetic sensor unit for outputting the second magnetic field detection signal corresponding to the second directional component of a magnetic field. A method for adjusting an error at a detection angle of an angle detection device for detecting an angle of a magnetic field, comprising: Applying delta-sigma modulation to a first magnetic field detection signal corresponding to a first directional component of a magnetic field to output a first modulation signal; Applying delta-sigma modulation to a second magnetic field detection signal corresponding to a second directional component of a magnetic field to output a second modulation signal; and Bringing the detection angle to follow the first modulation signal and the second modulation signal, by a loop control, wherein causing a detection angle to follow, comprising detecting a phase difference of the detection angle with respect to an angle indicated by the first modulation signal and the second modulation signal; and detecting a phase difference adjusts an error in the detection angle with respect to an angle of the magnetic field. An angle detection device for detecting an angle of a magnetic field, comprising: a first delta-sigma modulation unit for applying a delta-sigma modulation to a first magnetic field detection signal corresponding to a first one Direction component of a magnetic field corresponds to output a first modulation signal; a second delta-sigma modulation unit for applying delta-sigma modulation to a second magnetic field detection signal corresponding to a second directional component of a magnetic field to output a second modulation signal; and a loop control unit for making a detection angle follow the first modulation signal and the second modulation signal by loop control, wherein the loop control unit adjusts an error in the detection angle with respect to an angle of the magnetic field by using a preset adjustment value. A method for adjusting an error in the detection angle of an angle detection device for detecting an angle of a magnetic field, comprising: Applying delta-sigma modulation to a first magnetic field detection signal corresponding to a first directional component of a magnetic field to output a first modulation signal; Applying delta-sigma modulation to a second magnetic field detection signal corresponding to a second directional component of a magnetic field to output a second modulation signal; and Bringing a detection angle to follow the first modulation signal and the second modulation signal by a loop control, wherein bringing a detection angle to follow adjusts an error in the detection angle with respect to an angle of the magnetic field using a preset adjustment value.

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