JP2007033412A - Position detector error parameter extraction device and position detector with error correction function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an error parameter extraction device for a position detector suitable for accurately performing angle detection.
SOLUTION: Five sampling values a _{1 to} a ₅ and b _{1 to} b ₅ are acquired for resolver signals cos θ and sin θ, and based on the acquired sampling values a _{1 to} a ₅ and b _{1 to} b ₅ , an equation is obtained. According to (1) to (7), error parameters r, c, d, and δ for correcting the offset, phase error, and amplitude difference are calculated, and the rotation angle is calculated based on the calculated error parameters r, c, d, and δ. The position θ is corrected.
[Selection] Figure 2

Description

  The present invention relates to an error parameter extraction device for a position detector and a position detector having an error correction function, and in particular, includes an error parameter extraction device for an angle detector and an error correction function suitable for accurately performing angle detection. It relates to a position detector.

  A resolver is used as a sensor for detecting the rotation angle of the rotor. The resolver is rotatably attached to a rotating shaft such as a motor, and the reluctance between the rotor and the stator changes depending on the position of the rotor, and a resolver signal having a voltage corresponding to the change is output. Since the resolver signal from the resolver is analog, a resolver digital converter (RDC: Resolver Digital Converter) for converting this into a digital signal is prepared.

  The resolver includes a two-phase resolver that outputs two resolver signals whose phases are different by 90 °. When a two-phase resolver is used, the RDC detects the rotation angle position of the rotation shaft as position detection data based on two resolver signals obtained from the resolver. Ideally, the resolver signal is a sinusoidal waveform with no error. However, in reality, an amplitude difference, an offset, and a phase error are generated in the resolver signal due to variations in the shape of the rotor, coil characteristics, variations in the gap between the rotor and the stator, and the like.

Conventionally, as a technique for performing correction in consideration of an error of a resolver signal, for example, a correction method of a position detector described in Patent Document 1, an angle detection device described in Patent Document 2, and a phase error of a resolver described in Patent Document 3 Compensation methods are known.
Patent Documents 1 and 2 disclose a technique for correcting an amplitude difference between resolver signals, and Patent Document 3 discloses a technique for correcting a phase error of a resolver signal.
JP 2003-166803 A JP 2004-177273 A JP 59-148812 A

  In the inventions described in Patent Documents 1 and 2, since the position detection data is detected by correcting the amplitude difference of the resolver signal, accurate angle detection can be performed even if the amplitude difference occurs in the resolver signal. However, not only the amplitude difference but also an offset occurs in the resolver signal. In the case of the VR type resolver, since the excitation winding and the detection winding are wound around the same stator, an offset is generated in the output signal due to the influence of leakage magnetic flux. In the case of using a two-phase resolver, the rotational angle position is detected by taking the amplitude ratio of the two resolver signals. If only the amplitude difference is corrected, if an offset occurs, an error will occur at most angular positions. Therefore, the inventions described in Patent Documents 1 and 2 have a problem that the angle cannot be accurately detected when an offset occurs.

The invention described in Patent Document 3 performs correction in consideration of the phase error of the resolver signal. However, when an offset occurs, there is the same problem as described above. Further, since the resolver signal is corrected by a circuit and position detection data is detected based on the corrected resolver signal, the corrected resolver signal includes a circuit error even if the phase error is reduced.
Such a problem is assumed not only when an offset occurs in the resolver signal but also when a phase error and an amplitude difference occur at the same time. That is, in the inventions described in Patent Documents 1 and 2, the influence of the amplitude difference can be reduced, but the detection accuracy is lowered due to the effect of the phase error. Although it can be reduced, the detection accuracy decreases due to the influence of the amplitude difference.
Therefore, the present invention has been made paying attention to such an unsolved problem of the conventional technology, and is an error parameter extraction device for a position detector and an error correction suitable for accurately performing angle detection. An object of the present invention is to provide a position detector having a function.

  In order to achieve the above object, an error parameter extracting apparatus for a position detector according to claim 1 according to the present invention outputs two position detection signals having different phases that change according to the rotation angle of the rotor. An apparatus comprising: a position detector that receives the position detection signal from a resolver, and detects a rotational angle position of the rotor based on the input position detection signal; and an error parameter extraction device applied to the position detector. The position detector includes sampling value acquisition means for acquiring at least two sampling values having different rotational angle positions for each of the two position detection signals, and the at least two sampling values. A first input / output means for receiving the error parameter from the error parameter extracting device; A memory for storing parameters; and a rotation angle position correction unit for correcting a rotation angle position of the rotor based on the sampling value acquired by the sampling value acquisition unit and the error parameter of the memory; The apparatus receives the sampling value transmitted from the first input / output means, and based on the received sampling value, second input / output means for transmitting the error parameter to the position detector, Error parameter calculation means for calculating an error parameter for correcting an error between the two position detection signals.

With such a configuration, in the position detector, the sampling value acquisition unit acquires at least two sampling values having different rotation angle positions for each of the two position detection signals, and the first input / output The acquired sampling value is transmitted to the error parameter extracting device by the means.
In the error parameter extraction device, when the sampling value is received by the second input / output unit, the error parameter calculation unit calculates an error parameter for correcting an error between the two position detection signals based on the received sampling value. The Then, the calculated error parameter is transmitted to the position detector by the second input / output means.
In the position detector, when the error parameter is received by the first input / output means, the received error parameter is stored in the memory. Then, the rotation angle position correction unit corrects the rotation angle position of the rotor based on the acquired sampling value and the error parameter of the memory.

Furthermore, the error parameter extracting device for the position detector according to claim 2 according to the present invention is the error parameter extracting device for the position detector according to claim 1, wherein the sampling value acquisition means has an arbitrary rotation angle position that is different. get the sampled values a ₁ ~a _n and b ₁ ~b _n one by at least two, the error parameter-calculating means, the sampling value a ₁ acquired by the sampling value obtaining means ~a _n and b ₁ ~b _n Based on the above, an error parameter for correcting an error between the two position detection signals is calculated by the following two equations.
a _i = A cos θ _i + c
b _i = Bsin (θ _i + δ) + d
Where i = 1,..., N
With such a configuration, the sampling value obtaining means, the sampling value a ₁ ~a _n and b ₁ ~b _n is acquired, the error parameter by calculating means, the obtained sampled values a ₁ ~a _n and b ₁ Based on ˜b _n , the error parameter is calculated by the above two formulas.

Furthermore, the error parameter extracting device for the position detector according to claim 3 according to the present invention is the error parameter extracting device for the position detector according to claim 2, wherein n is an integer of 2 or more, and the error parameter calculating means Is based on the sampling values a _{1 to} a _n and b _{1 to} b _n according to the equations when c = 0, d = 0 and δ = 0 in the two equations. An error parameter for correcting the amplitude difference is calculated, or the amplitude difference between the two position detection signals is corrected by the equation when c = 0, d = 0 and A = B in the two equations. An error parameter for calculating the error is calculated.

In such a configuration, when error parameter calculation means sets c = 0, d = 0, and δ = 0 in the above two formulas based on the sampling values a _{1 to} a _n and b _{1 to} b _n. The error parameter for correcting the amplitude difference between the two position detection signals is calculated by the following equation. Alternatively, an error parameter for correcting the amplitude difference between the two position detection signals is calculated by an expression when c = 0, d = 0, and A = B in the two expressions.

Furthermore, the error parameter extracting device for a position detector according to claim 4 according to the present invention is the error parameter extracting device for a position detector according to claim 2, wherein n is an integer of 3 or more, and the error parameter calculating means is on the basis of the sampled values a ₁ ~a _n and b ₁ ~b _n, the equation in the case of the c = 0 and d = 0 in the two equations, the amplitude difference of the two position detection signals and the phase An error parameter for correcting an error is calculated, or an error parameter for correcting an offset between the two position detection signals is calculated using an equation when A = B and δ = 0 in the two equations. calculate.

With such a configuration, the error parameter-calculating means, based on the sampling values a ₁ ~a _n and b ₁ ~b _n, error parameters for correcting the amplitude difference and the phase error of the two position detection signals Calculated. Alternatively, an error parameter for correcting the offset of the two position detection signals is calculated by an expression when A = B and δ = 0 in the two expressions.

Furthermore, the error parameter extracting device for the position detector according to claim 5 according to the present invention is the error parameter extracting device for the position detector according to claim 2, wherein n is an integer of 4 or more, and the error parameter calculating means is on the basis of the sampled values a ₁ ~a _n and b ₁ ~b _n, the equation in the case of the a = B in the two formulas, for correcting an offset and the phase error of the two position detection signals Or an error parameter for correcting an offset and an amplitude difference between the two position detection signals is calculated using an equation when δ = 0 in the two equations.

With such a configuration, the error parameter-calculating means, based on the sampling values a ₁ ~a _n and b ₁ ~b _n, the equation in the case of the A = B in two equations, two position detection signals An error parameter for correcting the offset and phase error is calculated. Alternatively, an error parameter for correcting an offset and an amplitude difference between the two position detection signals is calculated by an expression when δ = 0 in the two expressions.

Furthermore, the error parameter extracting device for the position detector according to claim 6 according to the present invention is the error parameter extracting device for the position detector according to claim 2, wherein n is an integer of 5 or more, and the error parameter calculating means is on the basis of the sampled values a ₁ ~a _n and b ₁ ~b _n, wherein the two equations to calculate the error parameters for correcting an offset, phase error and amplitude difference of the two position detection signals .
With such a configuration, the error parameter-calculating means, based on the sampling values a ₁ ~a _n and b ₁ ~b _n, the two equations, the two position detection signal offset, phase error and amplitude difference An error parameter for correction is calculated.

  On the other hand, in order to achieve the above object, a position detector having an error correction function according to claim 7 of the present invention outputs two position detection signals having different phases that change in accordance with the rotation angle of the rotor. A position detector that receives the position detection signal from a two-phase resolver and detects the rotation angle position of the rotor based on the input position detection signal, and obtains a sampling value for each of the two position detection signals. Sampling value acquisition means for acquiring, sampling value selection means for selecting and storing at least two sampling values having different rotational angle positions from the sampling value, and the at least 2 stored by the sampling value selection means An error parameter for calculating an error parameter for correcting an error between the two position detection signals based on each sampling value. Based on the parameter calculation means, the memory for storing the error parameters, the sampling values of the two position detection signals acquired by the sampling value acquisition means and the error parameters of the memory, the rotational angle position of the rotor is corrected. Rotation angle position correction means.

If it is such a structure, a sampling value will be acquired about each of two position detection signals by a sampling value acquisition means, and arbitrary at least 2 from which a rotation angle position differs from the acquired sampling value by a sampling value selection means Each sampling value is selected and saved. Next, an error parameter for correcting an error between the two position detection signals is calculated by the error parameter calculation means based on at least two stored sampling values, and the calculated error parameter is stored in the memory. The Then, the rotation angle position correction unit corrects the rotation angle position of the rotor based on the acquired sampling values of the two position detection signals and the error parameter of the memory.
On the other hand, in order to achieve the above object, a motor control device according to an eighth aspect of the present invention includes the position detector according to any one of the first to seventh aspects.

As described above, according to the error parameter extracting device of the position detector according to claim 1 or the position detector having the error correction function according to claim 7 according to the present invention, the error parameter for correcting the error. Since the rotational angle position is corrected based on the above, an effect is obtained that it is possible to perform accurate angle detection even if an error occurs in the position detection signal, as compared with the conventional case. Further, since correction by the circuit is not performed, an effect that the circuit error of the position detection signal can be reduced is also obtained.
Furthermore, according to the error parameter extraction apparatus for a position detector according to claim 2 of the present invention, the error parameter for correcting the error can be accurately calculated, so that more accurate angle detection can be performed. The effect of being able to be obtained.

Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 to FIG. 5 are diagrams showing a first embodiment of a position detector having an error parameter extracting device and an error correction function of a position detector according to the present invention.
First, the configuration of the error parameter extracting apparatus for the position detector according to the present invention will be described.
FIG. 1 is a block diagram showing a configuration of an error parameter extraction apparatus for a position detector.

  As shown in FIG. 1, the position parameter error parameter extraction apparatus includes a two-phase resolver 10 rotatably attached to a rotation shaft such as a motor, and a rotation angle of the rotation shaft based on an output signal from the resolver 10. An RDC 20 that detects a position as position detection data and an error parameter extraction device 30 that calculates an error parameter based on an output signal from the RDC 20 are configured.

  The resolver 10 is composed of a cylindrical stator and a rotor that grips the rotation shaft and is rotatably disposed in the stator, and the reluctance between the rotor and the stator varies depending on the position of the rotor, The fundamental wave component of the reluctance change per rotation of the rotor is configured to be one cycle. That is, the thickness of the rotor is changed so that the inner diameter center of the rotor coincides with the inner diameter center of the stator and the outer shape center of the rotor is decentered from the inner diameter center by a certain amount of eccentricity. It changes according to the position. For this reason, the resolver 10 outputs a resolver signal cosθ that changes in accordance with the rotation angle of the rotating shaft and a resolver signal sinθ that is 90 ° out of phase with respect to the resolver signal cosθ.

The RDC 20 includes an excitation signal generation unit that outputs an excitation signal sinωt to the resolver 10 and a parameter storage unit that stores error parameters. In addition, the resolver signals cos θ and sin θ are sampled at five different rotational angle positions by rotating the rotor, and five sampled values a _{1 to} a ₅ and b _{1 to} b ₅ are obtained. Then, these ten sampling values are sent to the error parameter extraction device 30.
The error parameter extraction device 30 acquires the sampling values a _{1 to} a ₅ and b _{1 to} b ₅ of the resolver signals cos θ and sin θ from the RDC 20, respectively, and based on the acquired sampling values, the offset and phase of the resolver signals cos θ and sin θ. An error parameter for correcting the error and the amplitude difference is calculated, and the calculated error parameter is stored in the RDC 20.

Next, processing of the error parameter extraction device 30 will be described.
FIG. 2 is a flowchart showing an error parameter calculation process executed by the error parameter extraction device 30.
When the error parameter calculation process is executed by the error parameter extraction device 30, as shown in FIG. 2, first, the process proceeds to step S100.
In step S100, a sampling value acquisition request is output to the RDC 20, and the process proceeds to step S102, where the sampling values a and b of the resolver signals cos θ and sin θ are acquired from the RDC 20, and the process proceeds to step S106.

In step S106, it is determined whether or not _five sampling values a _{1 to} a ₅ and b _{1 to} b ₅ have been acquired for the resolver signals cos θ and sin θ, and the five sampling values a _{1 to} a ₅ , b ₁ to When it is determined that b ₅ has been acquired (Yes), the process proceeds to step S108.
In step S108, based on the acquired sampling values a _{1 to} a ₅ and b _{1 to} b ₅ , error parameters are calculated as follows.
Assuming that the offset, phase error, and amplitude difference are included in the resolver signal, the two resolver signals are expressed by the following equations (1) and (2). In the following expressions (1) and (2), c and d are offsets, δ is a phase error, and A and B are different amplitudes.
a = A cos θ + c (1)
b = Bsin (θ + δ) + d (2)

Substituting the sampling values a _{1 to} a ₅ and b _{1 to} b ₅ into the above equations (1) and (2), the following equation (3) is obtained.
a ₁ = A cos θ ₁ + c, b ₁ = B sin (θ ₁ + δ) + d
a ₂ = Acos θ ₂ + c, b ₂ = B sin (θ ₂ + δ) + d
a ₃ = Acos θ ₃ + c, b ₃ = B sin (θ ₃ + δ) + d
a ₄ = Acos θ ₄ + c, b ₄ = B sin (θ ₄ + δ) + d
a ₅ = A cos θ ₅ + c, b ₅ = B sin (θ ₅ + δ) + d (3)

Here, when r = A / B and b _i = B sin θ _i cos δ + B cos θ _i sin δ + d (i = 1 to 5), the following expression (4) is obtained.
^{_{(A 1 -c) 2 + (}} r / cosδ) 2 {b 1 -d- (a 1 -c) sinδ / r} 2 = A 2
(A ₂ −c) ² + (r / cos δ) ² {b ₂ −d− (a ₂ −c) sin δ / r} ² = A ²
(A ₃ −c) ² + (r / cos δ) ² {b ₃ −d− (a ₃ −c) sin δ / r} ² = A ²
(A ₄ −c) ² + (r / cos δ) ² {b ₄ −d− (a ₄ −c) sin δ / r} ² = A ²
(A ₅ −c) ² + (r / cos δ) ² {b ₅ −d− (a ₅ −c) sin δ / r} ² = A ² (4)

Here, when w = c−drsin δ, x = dr ² −crsin δ, y = r ² , and z = rsin δ, a quaternary linear simultaneous equation such as the following equation (5) is obtained.
2 (a ₁ −a ₂ ) w + 2 (b ₁ −b ₂ ) x− (b ₁ ² −b ₂ ² ) y + 2 (a ₁ b ₁ −a ₂ b ₂ ) z = a ₁ ² −a ₂ ²
2 (a ₂ −a ₃ ) w + 2 (b ₂ −b ₃ ) x− (b ₂ ² −b ₃ ² ) y + 2 (a ₂ b ₂ −a ₃ b ₃ ) z = a ₂ ² −a ₃ ²
2 (a ₃ −a ₄ ) w + 2 (b ₃ −b ₄ ) x− (b ₃ ² −b ₄ ² ) y + 2 (a ₃ b ₃ −a ₄ b ₄ ) z = a ₃ ² −a ₄ ²
2 (a ₄ −a ₅ ) w + 2 (b ₄ −b ₅ ) x− (b ₄ ² −b ₅ ² ) y + 2 (a ₄ b ₄ −a ₅ b ₅ ) z = a ₄ ² −a ₅ ² . 5)
Solving the above equation (5), w, x, y, and z can be obtained. The quaternary linear simultaneous equations can be solved by a known calculation method.

Since r = A / B = y ^1/2 , sin δ = z / r, δ = sin ⁻¹ z / r, and cos δ = {1− (z / r) ² } ^1/2 , the above equation (5) Substituting w, x, y, and z obtained by the above equation, a simultaneous equation having c and d in the following equation (6) as unknowns is obtained.
c-zd = w
-Zc + yd = x (6)

Therefore, the following equation (7) is obtained from the above equation (6).
c = (wy + yz) / (yz- ² )
d = (x + wz) / (y−z ² ) (7)
C and d can be obtained from the above equation (7). r, c, d, and δ are error parameters.
Next, the process proceeds to step S110, where the calculated error parameters r, c, d, and δ are sent to and stored in the RDC 20, and a series of processing is terminated and the original processing is restored.
On the other hand, when it is determined in step S106 that the five sampling values a _{1 to} a ₅ and b _{1 to} b ₅ have not yet been acquired (No), the process proceeds to step S100.

Next, processing of the RDC 20 will be described.
First, the error parameter saving process will be described.
FIG. 3 is a flowchart showing an error parameter storage process executed by the RDC 20.
When the error parameter storage process is executed by the RDC 20, as shown in FIG. 3, first, the process proceeds to step S150.
In step S150, a sampling value acquisition request is received, the process proceeds to step S152, the resolver signals cos θ and sin θ are simultaneously sampled to obtain sampling values a and b, and the process proceeds to step S154 where the acquired sampling value a , B are transmitted to the error parameter extracting device 30, and the process proceeds to step S156.

In step S156, it is determined whether or not five sets of sampling values a and b have been transmitted. If it is determined that five sets of sampling values a and b have been transmitted (Yes), the process proceeds to step S158 and error parameters are set. The process proceeds to step S160, where the received error parameter is stored in the parameter storage unit, a series of processes is terminated, and the original process is restored.
On the other hand, when it is determined in step S156 that five sets of sampling values a and b are not transmitted (No), the process proceeds to step S150.

Next, the rotation angle position calculation process will be described.
FIG. 4 is a flowchart showing the rotation angle position calculation process executed by the RDC 20.
When the rotation angle position calculation process is executed by the RDC 20, as shown in FIG. 4, first, the process proceeds to step S200.
In step S200, the sampling timer is started, and the process proceeds to step S202, where it is determined whether the sampling timing is reached based on the sampling timer. If it is determined that the sampling timing is reached (Yes), the process proceeds to step S204. To do.
In step S204, the resolver signals cos θ and sin θ are simultaneously sampled to obtain sampling values a and b, and the process proceeds to step S208.

In step S208, the rotation angle position θ is calculated based on the error parameters r, c, d, δ of the parameter storage unit and the acquired sampling values a, b. The rotation angle position θ (t) at the sampling timing t can be calculated by the following equation (8). In the following equation (8), r, c, d, and δ are error parameters, and a (t) and b (t) are sampling values a and b acquired at the sampling timing t.
θ (t) = tan ⁻¹ [{r (b (t) −d) / (a (t) −c) −sinδ} / cosδ] (8)

The offset, phase error, and amplitude difference can be corrected by the above equation (8).
Next, the process proceeds to step S210, where the calculated rotation angle position θ is output as position detection data, a series of processes are terminated, and the original process is restored.
On the other hand, when it is determined in step S202 that the sampling timing is not reached (No), the process waits in step S202 until the sampling timing is reached.

Next, the operation of the present embodiment will be described.
First, prior to the actual operation of the RDC 20, the RDC 20 is subjected to a test operation at the time of manufacture or the like.
In the error parameter extraction device 30, a sampling value acquisition request is output to the RDC 20 through step S100.
In the RDC 20, when an acquisition request is input, the resolver signals cos θ and sin θ are sampled simultaneously, and the sampling values a and b are output to the error parameter extraction device 30.

In the error parameter extraction device 30, the sampling values are repeatedly acquired until _five sampling values a _{1 to} a ₅ and b _{1 to} b ₅ are acquired at different rotation angle positions for the resolver signals cos θ and sin θ. When the required number of sampling values is acquired, the offset, phase is obtained by the above equations (1) to (7) based on the acquired sampling values a _{1 to} a ₅ and b _{1 to} b ₅ through step S108. Error parameters r, c, d, and δ for correcting the error and the amplitude difference are calculated. Then, through step S110, the calculated error parameters r, c, d, and δ are stored in the RDC 20.

Next, the RDC 20 is put into actual operation.
In the RDC 20, when the sampling timing comes, the resolver signals cos θ and sin θ are sampled simultaneously through step S204, and the sampling values a and b are obtained. Then, through steps S208 and S210, the rotational angle position θ is calculated by the above equation (8) based on the error parameters r, c, d, δ of the parameter storage unit and the acquired sampling values a, b. The rotation angle position θ is output as position detection data.

FIG. 5 is a diagram illustrating a rotational position calculation result when the resolver signals cos θ and sin θ include errors of A = 30000, B = 29900, c = 4000, d = −1000, and δ = 3 °.
When 360 ° is divided into 65536 (16 bits), the rotation angle position is distorted downward in a region where the absolute position of the rotor is small, and distorted upward in a region where the absolute position of the rotor is large, as indicated by n ^. This is an influence due to an offset, a phase error, and an amplitude difference, and indicates that the rotational angle position cannot be accurately calculated for a distorted region.

On the other hand, when r = 1.111111, c = 4000, d = −1000, and δ = 0.05236 [rad] are calculated as error parameters and the rotation angle position is corrected, the rotation angle position is the rotor as indicated by n. The absolute position and the rotational angle position of the lens were almost 1: 1. It can be said that the correction according to the present invention is effective. Note that Δn is the difference between n and n ^.
In this way, in the present embodiment, five sampling values a _{1 to} a ₅ and b _{1 to} b ₅ are acquired for the resolver signals cos θ and sin θ, and the acquired sampling values a _{1 to} a ₅ , b ₁ to Based on b ₅ , the error parameters r, c, d, and δ for correcting the offset, phase error, and amplitude difference are calculated by the above equations (1) to (7), and the calculated error parameters r, c, The rotational angle position θ is corrected based on d and δ.

As a result, the rotational angle position is corrected based on the error parameters for correcting the offset, phase error, and amplitude difference. Therefore, even if an offset, phase error, and amplitude difference occur in the position detection signal as compared with the conventional case. , Accurate angle detection can be performed. In addition, since correction by the circuit is not performed, the circuit error of the position detection signal can be reduced.
In the first embodiment, steps S102 and S110 correspond to the second input / output means according to claim 1, and step S108 corresponds to the error parameter calculation means according to claims 1 to 6, S152 corresponds to the sampling value acquisition means according to claim 1 or 2, and steps S154 and S158 correspond to the first input / output means according to claim 1. Step S208 corresponds to the rotational angle position correcting means described in claim 1.

Next, a second embodiment of the present invention will be described with reference to the drawings. FIG. 6 is a diagram showing a second embodiment of a position detector having an error parameter extracting device and an error correction function of a position detector according to the present invention.
In the present embodiment, the position detector error parameter extracting apparatus and the position detector having an error correction function according to the present invention are applied to the case of correcting the rotational angle position based on the error parameter. The difference from the first embodiment is that the error parameter is calculated by the RDC 20. Hereinafter, only the parts different from the first embodiment will be described, and the same parts as those in the first embodiment will be denoted by the same reference numerals and the description thereof will be omitted.

First, the processing of the RDC 20 will be described.
FIG. 6 is a flowchart showing a rotation angle position calculation process executed by the RDC 20.
When the rotation angle position calculation process is executed by the RDC 20, as shown in FIG. 6, first, the process proceeds to step S300.
In step S300, it is determined whether or not the error parameter is stored in the parameter storage unit. When it is determined that the error parameter is not stored (No), the process proceeds to step S302 and is similar to steps S102 to S110. The error parameter calculation process is executed, and the process proceeds to step S200. Then, after steps S200 to S210, the series of processes is terminated and the original process is restored.
On the other hand, when it is determined in step S300 that the error parameter is stored (Yes), the process proceeds to step S200.

Next, the operation of the present embodiment will be described.
In the RDC 20, the resolver signals cos θ and sin θ are simultaneously sampled through step S302, and five sampling values a _{1 to} a ₅ and b _{1 to} b ₅ are obtained. When the required number of sampling values is acquired, the offset, phase error, and amplitude difference are calculated by the above formulas (1) to (7) based on the acquired sampling values a _{1 to} a ₅ and b _{1 to} b _5. Error parameters r, c, d, and δ for correction are calculated. The calculated error parameters r, c, d, and δ are stored in the RDC 20.

Note that during the actual operation of the RDC 20, as in the first embodiment, based on the error parameters r, c, d, δ of the parameter storage unit and the acquired sampling values a, b, The rotation angle position θ is calculated by 8).
In the second embodiment, step S302 corresponds to the error parameter calculation means according to claim 7, and step S208 corresponds to the rotation angle position correction means according to claim 7.

Next, a third embodiment of the present invention will be described with reference to the drawings. The offset, amplitude, or phase error may be negligible depending on the design, manufacturing error status, operating conditions, and other circumstances of the resolver 10 and RDC 20, and therefore the manufacturing error status, operating status. By calculating only the necessary error parameters according to other environments, the calculation load can be reduced as compared with the case where the four error parameters are always calculated. FIG. 7 is a diagram showing a third embodiment of a position detector having an error parameter extracting device and an error correction function of a position detector according to the present invention.
In this embodiment, the error parameter calculation apparatus of the position detector according to the present invention and the position detector having an error correction function are different in error parameter calculation processing based on the magnitude of the offset, phase error, or amplitude difference. It applies to the case.

First, the processing of the RDC 20 will be described.
FIG. 7 is a flowchart showing the case classification of error parameter calculation processing executed by the RDC 20.
When the error parameter calculation process is executed by the error parameter extraction device 30, as shown in FIG. 7, first, the process proceeds to step S406, where it is determined whether or not the offset is a predetermined value or more. When it is determined that the offset is greater than or equal to a predetermined value (Yes), the process proceeds to step S408, where it is determined whether or not the phase error is greater than or equal to a predetermined value, and the phase error is determined in advance. When it is determined that the value is greater than or equal to the value (Yes), the process proceeds to step S410.

In step S410, it is determined whether or not the amplitude difference is equal to or greater than a predetermined value. When it is determined that the amplitude difference is equal to or greater than a predetermined value (Yes), the process proceeds to step S412, and 1 error parameter calculation processing is executed, a series of processing is terminated, and the original processing is restored. The first error parameter calculation process is performed as follows. That is, a first error parameter calculation process for calculating an error parameter for correcting an offset, a phase error, and an amplitude difference is executed. In the first error parameter calculation process, five sampling values a _{1 to} a ₅ and b _{1 to} b ₅ are acquired for the resolver signals cos θ and sin θ, and the acquired sampling values a _{1 to} a ₅ and b _{1 to} b ₅ are obtained. Based on the above equations (1) to (7), the error parameters r, c, d, and δ are calculated, and the calculated error parameters r, c, d, and δ are stored in the parameter storage unit.

On the other hand, when it is determined in step S410 that the amplitude difference is less than the predetermined value (No), the process proceeds to step S414.
In step S414, a second error parameter calculation process for calculating an error parameter for correcting the offset and phase error is executed. In the second error parameter calculation process, four sampling values a _{1 to} a ₄ and b _{1 to} b ₄ are acquired for the resolver signals cos θ and sin θ, and the acquired sampling values a _{1 to} a ₄ and b _{1 to} b ₄ are obtained. Based on the following equation (9), error parameters c, d, and δ are calculated, and the calculated error parameters c, d, and δ are stored in the parameter storage unit. The error parameters c, d, and δ can be obtained from the following equation (9) in the same manner as the above equations (4) to (7).
a ₁ = cos θ ₁ + c, b ₁ = sin (θ ₁ + δ) + d
a ₂ = cos θ ₂ + c, b ₂ = sin (θ ₂ + δ) + d
a ₃ = cos θ ₃ + c, b ₃ = sin (θ ₃ + δ) + d
a ₄ = cos θ ₄ + c, b ₄ = sin (θ ₄ + δ) + d (9)
When the process of step S414 ends, the series of processes ends and returns to the original process.

On the other hand, when it is determined in step S408 that the phase error is less than the predetermined value (No), the process proceeds to step S416, where it is determined whether the amplitude difference is greater than or equal to a predetermined value. When it is determined that the value is equal to or greater than the predetermined value (Yes), the process proceeds to step S418.
In step S418, a third error parameter calculation process for calculating an error parameter for correcting the offset and the amplitude difference is executed. In the third error parameter calculation process, four sampling values a _{1 to} a ₄ and b _{1 to} b ₄ are acquired for the resolver signals cos θ and sin θ, and the acquired sampling values a _{1 to} a ₄ and b _{1 to} b ₄ are obtained. Based on the following equation (10), error parameters r, c, d are calculated, and the calculated error parameters r, c, d are stored in the parameter storage unit. The error parameters r, c, and d can be obtained from the following equation (10) in the same manner as the above equations (4) to (7).
_{a 1 = Acosθ 1 + c,} b 1 = Bsinθ 1 + d
a ₂ = A cos θ ₂ + c, b ₂ = B sin θ ₂ + d
a ₃ = A cos θ ₃ + c, b ₃ = B sin θ ₃ + d
a ₄ = A cos θ ₄ + c, b ₄ = B sin θ ₄ + d (10)
When the process of step S418 ends, the series of processes ends and the original process is restored.

On the other hand, when it is determined in step S416 that the amplitude difference is less than the predetermined value (No), the process proceeds to step S420.
In step S420, a fourth error parameter calculation process for calculating an error parameter for correcting the offset is executed. In the fourth error parameter calculation process, three sampling values a _{1 to} a ₃ and b _{1 to} b ₃ are acquired for the resolver signals cos θ and sin θ, and the acquired sampling values a _{1 to} a ₃ and b _{1 to} b ₃ are obtained. Based on the following equation (11), the error parameters c and d are calculated, and the calculated error parameters c and d are stored in the parameter storage unit. The error parameters c and d can be obtained from the following equation (11) in the same manner as the above equations (4) to (7).
a ₁ = A cos θ ₁ + c, b ₁ = A sin θ ₁ + d
a ₂ = A cos θ ₂ + c, b ₂ = A sin θ ₂ + d
a ₃ = A cos θ ₃ + c, b ₃ = A sin θ ₃ + d (11)
When the process of step S420 is completed, the series of processes is terminated and the original process is restored.

  On the other hand, when it is determined in step S406 that the offset is less than the predetermined value (No), the process proceeds to step S422 to determine whether or not the phase error is equal to or greater than a predetermined value. When it is determined that the value is equal to or greater than the predetermined value (Yes), the process proceeds to step S424, where it is determined whether the amplitude difference is equal to or greater than a predetermined value, and the amplitude difference is equal to or greater than the predetermined value. When it is determined that (Yes), the process proceeds to step S426.

In step S426, a fifth error parameter calculation process for calculating an error parameter for correcting the phase error and the amplitude difference is executed. In the fifth error parameter calculation process, three sampling values a _{1 to} a ₃ and b _{1 to} b ₃ are acquired for the resolver signals cos θ and sin θ, and the acquired sampling values a _{1 to} a ₃ and b _{1 to} b ₃ are obtained. Based on the following equation (12), error parameters r and δ are calculated, and the calculated error parameters r and δ are stored in the parameter storage unit. The error parameters r and δ can be obtained from the following equation (12) in the same manner as the above equations (4) to (7).
_{a 1 = Acosθ 1, b 1} = Bsin (θ 1 + δ)
_{a 2 = Acosθ 2, b 2} = Bsin (θ 2 + δ)
a ₃ = A cos θ ₃ , b ₃ = B sin (θ ₃ + δ) (12)
When the process of step S426 ends, the series of processes ends and the original process is restored.

On the other hand, when it is determined in step S424 that the amplitude difference is less than the predetermined value (No), the process proceeds to step S428.
In step S428, a sixth error parameter calculation process for calculating an error parameter for correcting the phase error is executed. In the sixth error parameter calculation process, two sampling values a ₁ , a ₂ , b ₁ , and b ₂ are acquired for the resolver signals cos θ and sin θ, and the acquired sampling values a ₁ , a ₂ , b ₁ , and b ₂ are obtained. Based on the following equation (13), the error parameter δ is calculated, and the calculated error parameter δ is stored in the parameter storage unit. The error parameter δ can be obtained from the following equation (13) in the same manner as the above equations (4) to (7).
_{a 1 = Acosθ 1, b 1} = Asin (θ 1 + δ)
a ₂ = A cos θ ₂ , b ₂ = A sin (θ ₂ + δ) (13)
When the process of step S428 ends, the series of processes ends and returns to the original process.

On the other hand, when it is determined in step S422 that the phase error is less than the predetermined value (No), the process proceeds to step S430, where it is determined whether the amplitude difference is greater than or equal to a predetermined value. When it is determined that the value is equal to or greater than the predetermined value (Yes), the process proceeds to step S432.
In step S432, a seventh error parameter calculation process for calculating an error parameter for correcting the amplitude difference is executed. In the seventh error parameter calculation process, two sampling values a ₁ , a ₂ , b ₁ , and b ₂ are acquired for the resolver signals cos θ and sin θ, and the acquired sampling values a ₁ , a ₂ , b ₁ , and b ₂ are obtained. Based on the following equation (14), the error parameter r is calculated, and the calculated error parameter r is stored in the parameter storage unit. The error parameter r can be obtained from the following equation (14) in the same manner as the above equations (4) to (7).
a ₁ = Acosθ ₁ , b ₁ = Bsinθ ₁
a ₂ = A cos θ ₂ , b ₂ = B sin θ ₂ (14)
When the process of step S432 is completed, the series of processes is terminated and the original process is restored.
On the other hand, when it is determined in step S430 that the amplitude difference is less than the predetermined value (No), the series of processes is terminated and the original process is restored.

Next, the operation of the present embodiment will be described.
In the RDC 20, when the offset, the phase error, and the amplitude difference are large, five sampling values a _{1 to} a ₅ and b _{1 to} b ₅ are acquired through step S412 and the acquired sampling values a _{1 to} a ₅ are acquired. , B _{1 to} b ₅ , error parameters r, c, d, and δ for correcting the offset, phase error, and amplitude difference are calculated by the above equations (1) to (7).

Moreover, the RDC 20, the offset and the phase error is large, if the amplitude difference is small, through step S414, 4 pieces of sampling values _{a 1 ~a 4, b 1 ~b} 4 is obtained, the obtained sampled value a _{Based on 1 to} a ₄ and b _{1 to} b ₄ , error parameters c, d, and δ for correcting the offset and phase error are calculated by the above equation (9).
Further, in the RDC 20, when the offset and the amplitude difference are large and the phase error is small, the four sampling values a _{1 to} a ₄ and b _{1 to} b ₄ are acquired through step S418, and the acquired sampling value a _{Based on 1 to} a ₄ and b _{1 to} b ₄ , error parameters r, c, and d for correcting the offset and the amplitude difference are calculated by the above equation (10).

Further, in the RDC 20, when the offset is large and the phase error and the amplitude difference are small, the three sampling values a _{1 to} a ₃ and b _{1 to} b ₃ are acquired through step S420, and the acquired sampling value a _{Based on 1 to} a ₃ and b _{1 to} b ₃ , error parameters c and d for correcting the offset are calculated by the above equation (11).
Further, in the RDC 20, when the phase error and the amplitude difference are large and the offset is small, the three sampling values a _{1 to} a ₃ and b _{1 to} b ₃ are acquired through step S426, and the acquired sampling value a _{Based on 1 to} a ₃ and b _{1 to} b ₃ , error parameters r and δ for correcting the phase error and the amplitude difference are calculated by the above equation (12).

Further, in the RDC 20, when the phase error is large and the offset and the amplitude difference are small, two sampling values a ₁ , a ₂ , b ₁ , and b ₂ are acquired through step S428, and the acquired sampling value a _{Based on 1} , a ₂ , b ₁ , and b ₂ , an error parameter δ for correcting the phase error is calculated by the above equation (13).
Further, in the RDC 20, when the amplitude difference is large and the offset and phase error are small, the two sampling values a ₁ , a ₂ , b ₁ , and b ₂ are acquired through step S432, and the acquired sampling value a _{Based on 1} , a ₂ , b ₁ , b ₂ , an error parameter r for correcting the amplitude difference is calculated by the above equation (14).

Thus, in this embodiment, when the offset, phase error, or amplitude difference is greater than or equal to a predetermined value, only the error parameter for correcting an error that is greater than or equal to the predetermined value is calculated. It is like that.
Needless to say, the calculation in the second to seventh error parameter calculation processing is easier than the calculation in the first error parameter calculation processing, that is, the calculation developed by the above formulas (3) to (7). In calculating the correction of the angular position, it is only necessary to set the error parameter r to 1 and others to 0 in the above equation (8).

In the first embodiment, the error parameter for correcting the offset, phase error, and amplitude difference is calculated. However, the present invention is not limited to this, and any one of the offset, phase error, and amplitude difference is calculated. An error parameter for correcting such an error may be calculated.
In the second embodiment, the rotation angle position calculation process shown in the flowchart of FIG. 6 is executed. However, the present invention is not limited to this, and the rotation angle position calculation shown in the flowcharts of FIGS. It can also be configured to perform processing.

FIG. 8 is a flowchart in which the error parameter can be automatically updated in parallel with the rotation angle position calculation process shown in FIG.
8 is executed in the RDC 20, the process proceeds to step S500, where r = 1, c = d = δ = 0, f _all = 0, the process proceeds to step S502, and sampling is performed. The timer is started, the process proceeds to step S504, the timer interrupt is permitted, and the process proceeds to step S506.

At step S506, the sampled values a ₁ ~a _n, whether b ₁ ~b _n are aligned, f _all is determined by "1" or "0", the sampling value a ₁ ~a _n, b ₁ When it is determined that .about.b _n are prepared (Yes), the process proceeds to step S508, an error parameter calculation process is executed, and the process proceeds to step S510.
At step S510, to complete the update by storing the calculated error parameter in the parameter storage unit, the process proceeds to step S512, the oldest sampled values a _old, clears b _old, and f _all = 0, step S514 Migrate to

In step S514, it is determined whether or not the process has ended. When it is determined that the process has ended (Yes), the series of processes ends.
On the other hand, in step S514, when the process is determined not to terminate (No), and in step S506, the sampled values a ₁ ~a _n, when it is determined that b ₁ ~b _n are not aligned (No) Both The process proceeds to step S506.

Next, the timer interrupt process will be described.
FIG. 9 is a flowchart showing the timer interrupt process.
When the timer interrupt process is started by permitting the timer interrupt in step S504, the process proceeds to step S550, the sampling values a (t) and b (t) are simultaneously acquired, and the process proceeds to step S552. The rotation angle position θ (t) is calculated based on the sampling values a (t), b (t) and the error parameter, the process proceeds to step S554, and the calculated rotation angle position θ (t) is output, step S556. Migrate to

In step S556, it determines whether the sampled value a ₁ ~a _n to update the error parameters, the b ₁ ~b _n are aligned, sampled values _{a 1 ~a n, b 1 ~b} n is equipped When it is determined that there is no (No), the process proceeds to step S558.
In step S558, it is determined whether | a _last −a (t) |> α or | b _last −b (t) |> α is satisfied, and when it is determined that either is satisfied (Yes), Proceeding to step S560, the sampling values a (t) and b (t) are stored as a _last and b _last , and the process proceeds to step S562.

In step S562, when determining whether the sampled values a ₁ ~a _n, is b ₁ ~b _n are aligned, it is determined that the sampled values a ₁ ~a _n, is b ₁ ~b _n are aligned (Yes ) Goes to step S564, sets f _all = 1, ends the series of processes, and returns to the original process.
On the other hand, in step S556, when it is determined that the sampled values a ₁ ~a _n, is b ₁ ~b _n are aligned (Yes), at step S562, the sampled values a ₁ ~a _n, is b ₁ ~b _n aligned When it is determined that it is not (No), in step S558, when it is determined that | a _last −a (t) |> α or | b _last −b (t) |> α is not satisfied (No) Then, the series of processes is terminated and the original process is restored.

  In the first to third embodiments, two position detection signals having different phases are acquired from the two-phase resolver 10, and an error parameter is calculated based on the acquired position detection signals. However, the present invention is not limited to this, and three or more position detection signals having different phases may be acquired from a resolver having three or more phases, and an error parameter may be calculated based on the acquired position detection signals.

It is a block diagram which shows the structure of the error parameter extraction apparatus of a position detector. 4 is a flowchart showing an error parameter calculation process executed by the error parameter extraction device 30. 5 is a flowchart showing an error parameter storage process executed by the RDC 20; 7 is a flowchart showing a rotation angle position calculation process executed by the RDC 20. It is a figure which shows the rotational position calculation result in case the error of A = 30000, B = 29900, c = 4000, d = -1000, and δ = 3 ° is included in resolver signals cosθ and sinθ. 7 is a flowchart showing a rotation angle position calculation process executed by the RDC 20. 5 is a flowchart showing a case classification of error parameter calculation processing executed by the RDC 20; It is a flowchart which can update an error parameter automatically in parallel with the rotation angle position calculation process shown in FIG. It is a flowchart which shows a timer interruption process.

Explanation of symbols

10 Resolver 20 RDC
30 Error parameter extraction device

Claims (8)

The position detection signal is input from a two-phase resolver that outputs two position detection signals having different phases that change according to the rotation angle of the rotor, and the rotation angle position of the rotor is determined based on the input position detection signal. A device comprising a position detector for detection and an error parameter extraction device applied to the position detector,
The position detector includes sampling value acquisition means for acquiring at least two sampling values having different rotational angle positions for each of the two position detection signals, and the at least two sampling values as the error parameter. A first input / output unit for transmitting to the extraction device and receiving the error parameter from the error parameter extraction device; a memory for storing the error parameter; a sampling value acquired by the sampling value acquisition unit; and an error parameter of the memory Rotation angle position correction means for correcting the rotation angle position of the rotor based on
The error parameter extracting device receives the sampling value transmitted from the first input / output unit, and transmits a second input / output unit that transmits the error parameter to the position detector. An error parameter extraction device for a position detector, comprising: error parameter calculation means for calculating an error parameter for correcting an error between the two position detection signals based on the error parameter calculation means. In claim 1,
The sampling value obtaining means, the rotational angular position obtains the sampled values a ₁ ~a _n and b ₁ ~b _n of twos different arbitrary least,
The error parameter calculation means, based on the obtained sampling value a ₁ ~a _n and b ₁ ~b _n at the sampling value obtaining means, the following two equations, correcting an error of the two position detection signals An error parameter extracting device for a position detector, characterized in that an error parameter for calculating the position is calculated.
a _i = A cos θ _i + c
b _i = Bsin (θ _i + δ) + d
Where i = 1,..., N In claim 2,
n is an integer greater than or equal to 2,
The error parameter calculation means, on the basis of the sampled values a ₁ ~a _n and b ₁ ~b _n, the equation in the case of the c = 0, d = 0 and [delta] = 0 in the two equations, the two An error parameter for correcting an amplitude difference between the two position detection signals is calculated, or the two position detection signals are calculated according to an expression when c = 0, d = 0, and A = B in the two expressions. An error parameter extracting device for a position detector, characterized in that an error parameter for correcting an amplitude difference of the position detector is calculated. In claim 2,
n is an integer greater than or equal to 3,
The error parameter calculation means, on the basis of the sampled values a ₁ ~a _n and b ₁ ~b _n, wherein the equation in the case of the c = 0 and d = 0 in the two equations, the two position detection signals An error parameter for correcting an amplitude difference and a phase error between the two position detection signals is calculated, or an offset between the two position detection signals is corrected by an equation when A = B and δ = 0 in the two equations. An error parameter extracting device for a position detector, characterized in that an error parameter for calculating the position is calculated. In claim 2,
n is an integer greater than or equal to 4,
The error parameter calculation means, on the basis of the sampled values a ₁ ~a _n and b ₁ ~b _n, the equation in the case of the A = B in the two equations, the two position detection signals of the offset and the phase Calculate an error parameter for correcting an error, or calculate an error parameter for correcting an offset and an amplitude difference between the two position detection signals based on an equation when δ = 0 in the two equations. An error parameter extracting device for a position detector. In claim 2,
n is an integer greater than or equal to 5,
The error parameter calculation means, on the basis of the sampled values a ₁ ~a _n and b ₁ ~b _n, by the two equations, the two position detection signal offset, for correcting the phase error and amplitude difference An error parameter extracting apparatus for a position detector, characterized by calculating an error parameter. The position detection signal is input from a two-phase resolver that outputs two position detection signals having different phases that change according to the rotation angle of the rotor, and the rotation angle position of the rotor is determined based on the input position detection signal. A position detector for detecting,
Sampling value acquisition means for acquiring a sampling value for each of the two position detection signals; sampling value selection means for selecting and storing at least two sampling values having different rotational angle positions from the sampling value; Error parameter calculation means for calculating an error parameter for correcting an error between the two position detection signals based on the at least two sampling values stored by the sampling value selection means, and storing the error parameter And a rotation angle position correction means for correcting the rotation angle position of the rotor based on the sampling values of the two position detection signals acquired by the sampling value acquisition means and the error parameter of the memory. A position detector having an error correction function characterized by the above.   A motor control device comprising the position detector according to claim 1.

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