JP2019132603A - Rotation detection circuit, rotation detection apparatus, and rotation detection method - Google Patents

Abstract

To solve a problem for providing a rotation detection method to correct a phase error without monitoring the phase error.SOLUTION: A phase detection circuit is provided with: an addition unit for adding a first sinusoidal signal received from a first sensor and a second sinusoidal signal received from a second sensor outputting a second sinusoidal signal with a second phase together to output a third sinusoidal signal with a third phase; a subtraction unit for subtracting the first sinusoidal signal from the second sinusoidal signal to output a fourth sinusoidal signal with a phase difference of 1/4 period from the third sinusoidal signal; a phase calculation unit for calculating the third phase from the third sinusoidal signal and the fourth sinusoidal signal; a phase difference determination unit for determines a phase difference between the third phase and the first phase, on the basis of the third sinusoidal signal and/or the fourth sinusoidal signal; and an angle output unit for outputting a fourth phase obtained by adding a phase difference between the calculated third phase and the first phase, and the third phase.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a rotation detection circuit, a rotation detection device, and a rotation detection method.

  2. Description of the Related Art A rotation detector that detects a rotational position of a rotor based on a two-phase signal having a 90-degree phase difference from two sensors is known. In such a rotation detector, a phase error may occur in the two-phase signal due to an assembly error or the like. On the other hand, a method is known in which the rotation angle obtained by adjusting the phase error is obtained by monitoring the phase error (for example, Patent Document 1).

However, according to this method, it is necessary to monitor the phase error during the rotation detection.
Patent Document 1 Japanese Unexamined Patent Application Publication No. 2012-32313

  In view of the above problems, it is an object to provide a rotation detection circuit, a rotation detection device, and a rotation detection method that correct a phase error without monitoring the phase error.

  In the first aspect of the present invention, the first sine wave signal received from the first sensor that outputs the first sine wave signal of the first phase based on the rotational position of the rotor, and the rotation of the rotor Based on the position, a second sine wave signal received from a second sensor that outputs a second sine wave signal having a second phase different from the first phase is added to obtain a third sine wave signal having a third phase. An adder for outputting, a subtractor for subtracting the first sine wave signal from the second sine wave signal and outputting a fourth sine wave signal having a phase different from the third sine wave signal by ¼ period, Based on at least one of the third sine wave signal and the fourth sine wave signal, the phase calculation unit that calculates the third phase from the wave signal and the fourth sine wave signal, A phase difference determination unit for determining a phase difference, a phase difference between the calculated third phase and the first phase, and An angle output unit for outputting the fourth phase obtained by adding the third phase, to provide a rotation detecting circuit comprising a. Moreover, in a 1st aspect, the rotation detection apparatus provided with the said rotation detection circuit, a 1st sensor, and a 2nd sensor, and the rotation detection method using the said rotation detection apparatus are also provided.

  It should be noted that the above summary of the invention does not enumerate all the necessary features of the present invention. In addition, a sub-combination of these feature groups can also be an invention.

The block diagram which concerns on an example of the rotation detection apparatus 10 of this embodiment is shown. The block diagram which concerns on an example of the signal correction | amendment part 140 of this embodiment is shown. A block diagram concerning an example of phase error cancellation part 150 of this embodiment is shown. The block diagram which concerns on an example of the angle adjustment part 160 of this embodiment is shown. An example of the processing flow of the rotation detection method of this embodiment is shown.

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

  FIG. 1 is a block diagram according to an example of the rotation detection device 10 of the present embodiment. The rotation detection device 10 according to the present embodiment receives a two-phase signal related to the rotational position of a rotor such as a motor from two sensors, and cancels the phase error by calculation without monitoring the phase error of the two-phase signal. This identifies the exact rotational position of the rotor. The rotation detection device 10 includes a motor 110, a motor control circuit 120, a first sensor 122, a second sensor 124, and a rotation detection circuit 130. The rotation detection device 10 does not include the motor 110 and / or the motor control circuit 120, and these may be separately provided outside the rotation detection device 10.

  The motor 110 is supplied with electric power from the power source and rotates the rotor. A magnet such as a multipolar magnet ring for detecting the rotational position may be attached to the rotor.

  The motor control circuit 120 controls the rotation operation of the motor 110. The motor control circuit 120 may control the rotational operation of the motor 110 based on information on the rotational position of the rotor obtained from the rotation detection circuit 130 described later.

  The first sensor 122 outputs a first sine wave signal VA having a first phase based on the rotational position of the rotor that rotates the motor 110. The second sensor 124 outputs a second sine wave signal VB having a second phase different from the first phase based on the rotational position of the rotor that rotates the motor 110. The first sensor 122 and the second sensor 124 may be magnetic sensors that output detection results of magnetic fields generated from the magnets of the rotor. As an example, the first sensor 122 and the second sensor 124 may be Hall elements that detect a magnetic field of a multipolar magnet ring attached to the rotor.

  The first sensor 122 and the second sensor 124 may be disposed at a position shifted by 90 degrees about the rotation axis of the rotor, whereby the first phase and the second phase are ¼ period (ie, 90 degrees). In addition to a quarter cycle, the first phase and the second phase include a shift corresponding to a phase error due to an assembly error or the like. The first sensor 122 and the second sensor 124 output the first sine wave signal VA and the second sine wave signal VB to the rotation detection circuit 130.

  The rotation detection circuit 130 eliminates the phase error included in the first sine wave signal VA and the second sine wave signal VB, calculates the rotational position of the rotor, and outputs the calculated rotational position. The rotation detection circuit 130 includes a signal correction unit 140, a phase error cancellation unit 150, and an angle adjustment unit 160. Hereinafter, these configurations and functions will be described with reference to FIGS.

  FIG. 2 is a block diagram according to an example of the signal correction unit 140 of the present embodiment. The signal correction unit 140 corrects the offset and gain of the first sine wave signal VA and the second sine wave signal VB, thereby ensuring the accuracy of the process of calculating the subsequent rotational position. The signal correction unit 140 includes an AD converter 141, an AD converter 142, an offset / gain calculation unit 143, a first offset correction unit 145, a second offset correction unit 146, a first gain correction unit 147, and a second gain correction unit 148. including. Note that the signal correction unit 140 may not include a part of these, and may include other circuits.

  The AD converter 141 receives the first sine wave signal VA, which is an analog signal, from the first sensor 122 and periodically samples them to convert the first sine wave signal VA into a digital signal. The AD converter 141 outputs a first sine wave signal (hereinafter referred to as a digital signal A0) corresponding to the first sine wave signal VA to the offset / gain calculation unit 143 and the first offset correction unit 145.

  The AD converter 142 receives the second sine wave signal VB, which is an analog signal, from the second sensor 124 and periodically samples them to convert the second sine wave signal VB into a digital signal. The AD converter 142 outputs a second sine wave signal (hereinafter, referred to as a digital signal B0) corresponding to the second sine wave signal VB to the offset / gain calculation unit 143 and the second offset correction unit 146.

  The offset / gain calculation unit 143 calculates an offset correction amount and a gain correction amount to be applied to the digital signal A0 and the digital signal B0. For example, the offset / gain calculation unit 143 calculates the difference between the average of the digital signal A0 during a certain period and 0, and the difference between the average of the digital signal B0 during a certain period and 0. The offset / gain calculation unit 143 may provide these deviations as the offset correction amount for the digital signal A0 and the offset correction amount for the digital signal B0 to the first offset correction unit 145 and the second offset correction unit 146, respectively. .

For example, the offset / gain calculation unit 143 calculates the amplitude H ₁ of the digital signal A 0 and the amplitude H ₂ of the digital signal B 0. For example, the offset / gain calculation unit 143 acquires the digital signal A0 and the digital signal B0 of a certain period, from their maximum value and the minimum value, the amplitude of H ₂ amplitudes H ₁ and the digital signal B0 of the digital signal A0 decide.

Then, the offset / gain calculation unit 143 determines the gain correction amount r ₁ for the digital signal A 0 and the gain correction amount r ₂ for the digital signal B 0 so that r ₁ / r ₂ = H ₂ / H _1. It's okay. The offset / gain calculation unit 143 provides the gain correction amount r ₁ and the gain correction amount r ₂ to the first gain correction unit 147 and the second gain correction unit 148, respectively. Further, the offset / gain calculation unit 143 may provide the gain correction amount r ₁ and the gain correction amount r ₂ to the phase difference determination unit 162 described later.

Instead, the offset / gain calculation unit 143 calculates the ratio of the amplitude of the digital signal A0 to the digital signal B0 (H ₁ / H ₂ ) or its reciprocal (H ₂ / H ₁ ) with respect to the digital signal B0 or the digital signal A0. The gain correction amount may be calculated. In this case, the offset / gain calculation unit 143 may provide the gain correction amount only to one of the second gain correction unit 148 and the first gain correction unit 147.

  The first offset correction unit 145 performs output offset correction of the first sine wave signal. For example, the first offset correction unit 145 performs offset correction of the digital signal A0 based on the offset correction amount obtained from the offset / gain calculation unit 143. The first offset correction unit 145 outputs the correction signal A1 after the offset correction to the first gain correction unit 147.

  The second offset correction unit 146 performs output offset correction of the second sine wave signal. For example, the second offset correction unit 146 performs offset correction of the digital signal B0 based on the offset correction amount obtained from the offset / gain calculation unit 143. The second offset correction unit 146 outputs the correction signal B1 after the offset correction to the second gain correction unit 148.

The first gain correction unit 147 performs gain correction of the first sine wave signal. For example, the first gain correction portion 147, based on the gain correction amount r ₁ obtained from the offset / gain calculation unit 143 performs gain correction of the digital signal A1. The first gain correction unit 147 outputs the correction signal A2 after gain correction to the phase error cancellation unit 150.

The second gain correction unit 148 performs gain correction of the second sine wave signal. For example, the second gain correction portion 148, based on the gain correction amount r ₂ obtained from the offset / gain calculation unit 143 performs gain correction of the digital signal B1. The second gain correction unit 148 outputs the correction signal B2 after gain correction to the phase error cancellation unit 150.

  When the offset / gain calculation unit 143 calculates the gain correction amount of only one of the digital signal A0 and the digital signal B0, the gain correction amount is calculated from the first gain correction unit 147 and the second gain correction unit 148. One of the processing of the digital signal that was not done may be omitted.

  FIG. 3 is a block diagram according to an example of the phase error canceling unit 150 of the present embodiment. The phase error cancellation unit 150 receives the correction signal A2 and the correction signal B2 from the signal correction unit 140, and cancels the phase error included in the correction signal A2 and the correction signal B2. The phase error cancellation unit 150 includes an addition unit 151, a subtraction unit 152, a gain calculation unit 153, a third gain correction unit 154, a fourth gain correction unit 155, and a phase calculation unit 157. The phase error canceling unit 150 may not include a part of these, and may include other circuits.

  The adder 151 adds the first sine wave signal output from the first sensor 122 and the second sine wave signal output from the second sensor 124 to output a third sine wave signal having a third phase. To do. For example, the adding unit 151 adds a correction signal A2 that is a first sine wave signal that has been offset / gain corrected and a correction signal B2 that is a second sine wave signal that has been offset / gain corrected. The value is output as the third sine wave signal A3. The adder 151 supplies the third sine wave signal A3 to the gain calculator 153 and the third gain corrector 154.

…数式１
ここで、αは、

…数式２

…数式３
により定義される。 Here, represents the correction signal A2 in Kcosshita, representing a correction signal B2 at Ksin (θ + θ _off). θ _off corresponds to the phase error. In this case, the third sine wave signal A3 can be expressed as K (2 (1 + sin θ _off )) ^1/2 cos (θ−α)) by the following formula 1.

... Formula 1
Where α is

... Formula 2

... Formula 3
Defined by

  The subtracting unit 152 subtracts the first sine wave signal from the second sine wave signal and outputs a fourth sine wave signal having a phase that is ¼ period different from the third sine wave signal. For example, the subtraction unit 152 outputs a digital value obtained by subtracting the correction signal A2 from the correction signal B2 as the fourth sine wave signal B3. The subtraction unit 152 supplies the fourth sine wave signal B3 to the gain calculation unit 153 and the fourth gain correction unit 155.

…数式４
なお、第３正弦波信号Ａ３と同様に、αは数式２及び数式３により定義される。 Here, the fourth sine wave signal B3 can be expressed as K (2 (1-sin θ _off )) ^1/2 sin (θ-α)) by the following mathematical formula 4.

... Formula 4
As in the third sine wave signal A3, α is defined by Equation 2 and Equation 3.

The gain calculation unit 153 calculates a gain correction amount for aligning the amplitudes of the third sine wave signal A3 and the fourth sine wave signal B3. For example, the gain calculation unit 153 sets the gain correction amount r _{3 of} the third sine wave signal A3 so that r ₃ × (1 + sin θ _off ) ^1/2 and r ₄ × (1-sin θ _off ) ^1/2 are equal. , and to determine the gain correction amount _{r 4} of the fourth sine wave signal B3.

As an example, the gain calculation unit 153 obtains the third sine wave signal A3 for a period of time a fourth sine wave signal B3, the amplitude H of the amplitude H ₃ and the fourth sinusoidal signal B3 of the third sine wave signal A3 ₄ is determined. Next, the gain calculation unit 153 may determine the gain correction amount r ₃ and the gain correction amount r ₄ so that r ₃ / r ₄ = H ₄ / H ₃ .

The gain calculation unit 153 provides the gain correction amount r ₃ to the third gain correction unit 154 and provides the gain correction amount r ₄ to the fourth gain correction unit 155. Further, the gain calculation unit 153 includes (1) an amplitude H _{3 of} the third sine wave signal A3, (2) an amplitude H _{4 of} the fourth sine wave signal B3, and (3) an amplitude H _{3 of} the third sine wave signal A3. The angle adjustment unit 160 is provided with at least one of the amplitude H _{4 of} the fourth sine wave signal B ₃ and (4) the gain correction amount r ₃ and the gain correction amount r ₄ or the ratio of both.

As another example, the gain calculation unit 153 calculates the ratio of the amplitude of the third sine wave signal A3 to the fourth sine wave signal B3 (H ₃ / H ₄ ) or its inverse (H ₄ / H ₃ ) as the fourth sine wave. The gain correction amount for the signal B3 or the third sine wave signal A3 may be calculated. In this case, the gain calculation unit 153 may provide the gain correction amount only to one of the fourth gain correction unit 155 or the third gain correction unit 154.

The third gain correction unit 154 performs gain correction of the third sine wave signal. For example, the third gain correcting unit 154, based on the gain correction amount r ₃ obtained from the gain calculation unit 153 performs gain correction of the third sine wave signal A3. The third gain correction unit 154 outputs the gain-corrected third sine wave signal A4 to the phase calculation unit 157.

The fourth gain correction unit 155 performs gain correction of the fourth sine wave signal. For example, the fourth gain correction unit 155, based on the gain correction amount r ₄ obtained from the gain calculation unit 153 performs gain correction of the fourth sine wave signal B3. The fourth gain correction unit 155 outputs the gain-corrected fourth sine wave signal B4 to the phase calculation unit 157.

…数式５ The phase calculation unit 157 calculates a third phase from the third sine wave signal and the fourth sine wave signal. For example, the phase calculation unit 157 calculates the third phase θ0 by calculating the arc tangent of the gain-corrected third sine wave signal A4 divided by the gain-corrected fourth sine wave signal B4. As an example, θ0 is expressed by Equation 5 below.

... Formula 5

  Thereby, the phase calculation unit 157 calculates (θ−α) as the third phase. The phase calculation unit 157 may calculate the third phase by calculation, or may determine the third phase by referring to a lookup table. The phase calculation unit 157 provides the third phase to the angle adjustment unit 160.

FIG. 4 is a block diagram according to an example of the angle adjustment unit 160 of the present embodiment. The angle adjustment unit 160 receives the third phase, the gain correction amount r ₃ / r _{4 and the} like from the phase error cancellation unit 150, and calculates and outputs the rotational position of the rotor of the motor 110 based on these. The angle adjustment unit 160 includes a phase difference determination unit 162 and an angle output unit 164. The angle adjustment unit 160 may not include a part of these, and may include other circuits.

The phase difference determination unit 162 determines the phase difference between the third phase and the first phase based on at least one of the third sine wave signal and the fourth sine wave signal. For example, the phase difference determination unit 162 receives (1) the amplitude H _{3 of} the third sine wave signal A3 received from the gain calculation unit 153, (2) the amplitude H _{4 of} the fourth sine wave signal B3, and (3) the third sine. amplitude _{H 4} amplitude _{H 3} and the fourth sine wave signal B3 of the wave signal A3, and, (4) the gain correction amount _{r 3} and the gain correction amount _{r 4} or the ratio, based on at least one of the, first The phase difference α between the phase 3 and the first phase is determined.

For example, the phase difference determination unit 162, at least one of the amplitude H ₄ amplitude H ₃ and the fourth sinusoidal signal B3 of the third sine wave signal A3, may determine the phase difference alpha. As an example, the phase difference determination unit 162, from the ratio of the amplitude _{H 4} amplitude _{H 3} and the fourth sinusoidal signal B3 of the third sinusoidal signal _{A3 (H 4 / H 3)} , may determine the phase difference α . Specifically, the phase difference determination unit 162 calculates H ₄ / H ₃ to obtain [(1−sin _off ) / (1 + sin _off )] ^1/2 . This is equal to sin α / cos α = tan α. The phase difference determination unit 162 may further determine the phase difference α by performing a process such as calculating an arctangent for H ₄ / H ₃ or referring to a lookup table. Here, the phase difference determination unit 162 may use the gain correction amount ratio r ₃ / r ₄ instead of H ₄ / H ₃ .

As another example, the phase difference determination unit 162 acquires information about the amplitudes K of the correction signals A2 and B2 from the offset / gain calculation unit 143 and the like of the signal correction unit 140, and calculates K (2 (1 + sinθ the amplitude _{H 3,} denoted ^{_off)) 1/2} after dividing the amplitude K√2, squared, it calculates the sin _{[theta] off} by subtracting 1, this is substituted into equation 2 or equation 3, sin α or cos α may be calculated. Further, the phase difference determination unit 162 may calculate sin α or cos α by the same method using the amplitude H ₄ instead of the amplitude H ₃ . Thereafter, the phase difference determination unit 162 may calculate the phase difference α by calculating an arc sine or arc cosine with respect to sin α or cos α, or referring to a lookup table.

  The angle output unit 164 outputs a fourth phase θ1 obtained by adding the phase difference α between the third phase and the first phase calculated by the phase difference determination unit 162 and the third phase θ0. The angle output unit 164 provides the motor control circuit 120 with the fourth phase θ1 as the most recent rotational position of the motor 110.

As described above, the rotation detection circuit 130 of this embodiment does not monitor the phase error θ _off included in the output signals of the first sensor 122 and the second sensor 124 as needed, and the phase error cancellation unit 150 and the angle adjustment unit 160. Can be removed by the four arithmetic operations. For this reason, according to the rotation detection circuit 130 of the present embodiment, it is not necessary to assemble the first sensor 122 and the second sensor 124 in the rotation detection device 10 with high accuracy.

Further, according to the rotation detection circuit 130 of the present embodiment, it is not necessary to acquire and store a phase error for one rotation in advance, so that a large memory capacity is not required to cancel the phase error θ _off. . Therefore, according to the rotation detection device 10 of the present embodiment, the device manufacturing cost can be reduced and the space of the device can be saved.

  Note that the rotation detection device 10 and the rotation detection circuit 130 may have other circuits or parts not shown in FIGS.

  FIG. 5 shows an example of a processing flow of a rotation detection method by the rotation detection device 10 of the present embodiment. The rotation detection device 10 can accurately detect the rotation position of the motor by performing the processing of S110 to S180 of FIG. For convenience of explanation, the processing of S110 to S180 will be described in order, but these processing may be executed in parallel like a pipeline.

  First, in S110, the first sensor 122 and the second sensor 124 each output a sine wave signal to the signal correction unit 140 based on the rotational position of the rotor of the motor 110. For example, the first sensor 122 outputs a first sine wave signal VA having a first phase. The second sensor 124 outputs a second sine wave signal VB having a second phase. Here, the first sine wave signal VA may be a signal including a sin component of phase θ, and the second sine wave signal VB may be a signal including a cos component of phase θ (that is, a sin component of phase θ + 90 degrees). .

  Next, in S120, each of the AD converter 141 and the AD converter 142 of the signal correction unit 140 converts the first sine wave signal VA and the second sine wave signal VB into digital signals. The AD converter 141 outputs a digital signal A0 obtained by digitizing the first sine wave signal VA to the offset / gain calculation unit 143 and the first offset correction unit 145. The AD converter 142 outputs a digital signal B0 obtained by digitizing the second sine wave signal VB to the offset / gain calculation unit 143 and the second offset correction unit 146.

  Next, in S130, the signal correction unit 140 performs offset correction of the digital signal A0 and the digital signal B0. Specifically, the offset / gain calculation unit 143 calculates an offset correction amount for the digital signal A0 and an offset correction amount for the digital signal B0, and these are calculated as the first offset correction unit 145 and the second offset correction unit 146, respectively. To provide.

  The first offset correction unit 145 and the second offset correction unit 146 correct the digital signal A0 and the digital signal B0 with the given offset correction amount, respectively. The first offset correction unit 145 and the second offset correction unit 146 output the correction signal A1 and the correction signal B1 subjected to the offset correction to the first gain correction unit 147 and the second gain correction unit 148.

  Next, in S140, the signal correction unit 140 performs gain correction of the correction signal A1 and the correction signal B1. Specifically, the offset / gain calculation unit 143 calculates the gain correction amount for the correction signal A1 and the gain correction amount for the correction signal B1, respectively, and these are calculated as the first gain correction unit 147 and the second gain correction unit 148, respectively. To provide.

  The first gain correction unit 147 and the second gain correction unit 148 correct the correction signal A1 and the correction signal B1 with the given gain correction amount, respectively. The first gain correction unit 147 and the second gain correction unit 148 provide the gain-corrected correction signal A2 and correction signal B2 to the addition unit 151 and the subtraction unit 152 of the phase error cancellation unit 150.

  Next, in S150, the phase error canceling unit 150 cancels the phase error between the first sine wave signal and the second sine wave signal. For example, the addition unit 151 adds the correction signal A2 and the correction signal B2, and the subtraction unit 152 subtracts the correction signal A2 from the correction signal B2. The adding unit 151 outputs the third sine wave signal A3 as an addition result to the gain calculating unit 153 and the third gain correcting unit 154. The subtraction unit 152 outputs the fourth sine wave signal B3 as a subtraction result to the gain calculation unit 153 and the fourth gain correction unit 155.

  Next, in S160, the phase error canceling unit 150 performs gain adjustment of the third sine wave signal A3 and the fourth sine wave signal B3. For example, the gain calculation unit 153 calculates a gain correction amount for aligning the amplitudes of the third sine wave signal A3 and the fourth sine wave signal B3, and sets the respective gain correction amounts as the third gain correction unit 154 and the fourth gain. This is supplied to the correction unit 155.

  The third gain correction unit 154 and the fourth gain correction unit 155 perform gain correction of the third sine wave signal A3 and the fourth sine wave signal B3 with the respective gain correction amounts. The third gain correction unit 154 and the fourth gain correction unit 155 output the third sine wave signal A4 and the fourth sine wave signal B4 after gain correction to the phase calculation unit 157.

  Next, in S170, the phase calculation unit 157 calculates the third phase θ0 represented by θ−α from the gain-corrected third sine wave signal A4 and fourth sine wave signal B4. The phase calculation unit 157 calculates the third phase θ0 by, for example, calculating the arctangent of the ratio of the fourth sine wave signal B4 to the gain-corrected third sine wave signal A4. The phase calculation unit 157 provides the calculated third phase θ0 to the angle output unit 164.

Next, in S180, the angle adjustment unit 160, and a third ratio of the amplitude _{H 4} amplitude _{H 3} and the fourth sine wave signal B3 of the sinusoidal signal A3 _(H 4 / H _3), etc., third phase θ0 From this, a fourth phase θ1 represented by θ0 + α is calculated. For example, the phase difference determination unit 162 (1) the amplitude H _{3 of} the third sine wave signal A3, (2) the amplitude H _{4 of} the fourth sine wave signal B3, and (3) the amplitude H _{3 of} the third sine wave signal A3. The phase difference α is determined from the amplitude H _{4 of} the fourth sine wave signal B3, or (4) the gain correction amount r ₃ and the gain correction amount r ₄ or the ratio thereof. The phase difference determination unit 162 provides the determined phase difference α to the angle output unit 164.

  Next, the angle output unit 164 calculates the fourth phase θ1 by adding the third phase θ0 and the phase difference α. The angle output unit 164 outputs the fourth phase θ1 as the rotational position of the rotor of the motor 110.

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

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

DESCRIPTION OF SYMBOLS 10 Rotation detection apparatus 110 Motor 120 Motor control circuit 122 1st sensor 124 2nd sensor 130 Rotation detection circuit 140 Signal correction part 141 AD converter 142 AD converter 143 Offset / gain calculation part 145 1st offset correction part 146 2nd offset correction part 147 First gain correction unit 148 Second gain correction unit 150 Phase error cancellation unit 151 Addition unit 152 Subtraction unit 153 Gain calculation unit 154 Third gain correction unit 155 Fourth gain correction unit 157 Phase calculation unit 160 Angle adjustment unit 162 Phase difference Determination unit 164 Angle output unit

Claims (15)

Based on the rotation position of the rotor, the first sine wave signal output from the first sensor that outputs the first sine wave signal of the first phase, and the rotation position of the rotor, the first An adder that adds the second sine wave signal output from the second sensor that outputs a second sine wave signal having a second phase different from the first phase and outputs a third sine wave signal having a third phase When,
A subtracting unit that subtracts the first sine wave signal from the second sine wave signal and outputs a fourth sine wave signal having a phase different from the third sine wave signal by a quarter period;
A phase calculation unit for calculating the third phase from the third sine wave signal and the fourth sine wave signal;
A phase difference determining unit that determines a phase difference between the third phase and the first phase based on at least one of the third sine wave signal and the fourth sine wave signal;
An angle output unit that outputs a phase difference between the calculated third phase and the first phase, and a fourth phase obtained by adding the third phase;
A rotation detection circuit comprising: The phase calculation unit calculates the third phase by calculating an arctangent of the third sine wave signal divided by the fourth sine wave signal;
The rotation detection circuit according to claim 1. The phase difference determining unit determines the phase difference from at least one of an amplitude of the third sine wave signal and an amplitude of the fourth sine wave signal;
The rotation detection circuit according to claim 1. The phase difference determining unit determines the phase difference from a ratio of an amplitude of the third sine wave signal and an amplitude of the fourth sine wave signal;
The rotation detection circuit according to claim 3. A first offset correction unit that performs output offset correction of the first sine wave signal;
A second offset correction unit that performs output offset correction of the second sine wave signal;
Further comprising
The rotation detection circuit according to claim 1. A first gain correction unit that performs gain correction of the first sine wave signal;
A second gain correction unit that performs gain correction of the second sine wave signal;
Further comprising
The rotation detection circuit according to claim 5. A third gain correction unit that performs gain correction of the third sine wave signal;
A fourth gain correction unit that performs gain correction of the fourth sine wave signal;
Further comprising
The rotation detection circuit according to claim 6. The rotation detection circuit according to any one of claims 1 to 7,
The first sensor; and
The second sensor;
A rotation detection device comprising: Outputting a first sine wave signal of a first phase from a first sensor based on the rotational position of the rotor;
Outputting a second sine wave signal having a second phase different from the first phase based on a rotational position of the rotor from a second sensor;
An adding step of adding the first sine wave signal and the second sine wave signal to output a third sine wave signal having a third phase;
Subtracting the first sine wave signal from the second sine wave signal to output a fourth sine wave signal having a phase different from the third sine wave signal by ¼ period;
A phase calculating step of calculating the third phase from the third sine wave signal and the fourth sine wave signal;
A phase difference determination step for determining a phase difference between the third phase and the first phase based on at least one of the third sine wave signal and the fourth sine wave signal;
An angle output step of outputting a phase difference between the calculated third phase and the first phase, and a fourth phase obtained by adding the third phase;
A rotation detection method comprising: The phase calculating step includes a step of calculating the third phase by calculating an arctangent of the third sine wave signal divided by the fourth sine wave signal.
The rotation detection method according to claim 9. The phase difference determining step determines the phase difference from at least one of an amplitude of the third sine wave signal and an amplitude of the fourth sine wave signal;
The rotation detection method according to claim 9 or 10. The phase difference determining step determines the phase difference from a ratio of an amplitude of the third sine wave signal and an amplitude of the fourth sine wave signal.
The rotation detection method according to claim 11. A first offset correction stage for performing an output offset correction of the first sine wave signal;
A second offset correction stage for performing an output offset correction of the second sine wave signal;
Further comprising
The rotation detection method according to any one of claims 9 to 12. A first gain correction stage for performing gain correction of the first sine wave signal;
A second gain correction stage for performing gain correction of the second sine wave signal;
Further comprising
The rotation detection method according to claim 13. A third gain correction stage for performing gain correction of the third sine wave signal;
A fourth gain correction stage for performing gain correction of the fourth sine wave signal;
Further comprising
The rotation detection method according to claim 14.

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