JP2011149724A - Rotation angle detection device, rotating electric machine, and electric power steering device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that the second harmonic effect cannot be completely removed because the phase is not taken into account although the magnitude of the second harmonic is known, and that the structure is complicated because the correction of a zero point parameter and the correction of the second harmonic are performed by separate means in a conventional calibration device for rotation angle detection. <P>SOLUTION: The rotation angle detection device has an axial double angle of N (N is a positive integer), for detecting a rotation angle using sinusoidal two-phase output signals having phases shifted from each other. The rotation angle detection device includes a correction means for adding a correction value that is constant with respect to the rotation angle to at least one of two-phase output signals Esin, Ecos, as a means for canceling an angle error N-th order component (angle error of mechanical angle 360 degrees period is taken as the first-order) generated depending on the amplitude and phase of the second harmonic component when the two-phase output signals are denoted as Esin, Ecos and when the DC components of the Esin, Ecos and the N-th order components of the Esin, Ecos are taken as the fundamental wave components. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a rotation angle detection device such as a resolver, a rotating electrical machine device including the rotation angle detection device, and an electric power steering device. Specifically, a rotation angle detection device capable of reducing the angle error by removing the influence of the direct current component and the harmonic component contained in the output signal and improving the accuracy of angle detection, the rotating electrical machine device including the same, and the electric motor The present invention relates to a power steering device.

  For the purpose of detecting the rotation angle of a vehicle motor, a resolver that is inexpensive and superior in environmental resistance as compared with an optical encoder is generally used. Due to the manufacturing variations of resolvers, the output signal may contain harmonic components and have a distorted waveform. If angle detection is performed from an output signal including distortion, an angle error occurs, and the accuracy of rotation angle detection decreases. For such a problem, for example, Patent Document 1 proposes a signal calibration apparatus that digitally processes an output signal including distortion and removes the distortion.

JP-A-4-96131

  In the signal calibration apparatus of Patent Document 1, although the magnitude of the second harmonic is known, there is a problem that the phase cannot be considered, and the influence of the second harmonic cannot be completely removed. It was. Further, in the signal calibration apparatus of Patent Document 1, since the zero point parameter correction and the second harmonic correction are performed by different means, there is a problem that the structure becomes complicated.

  The present invention has been made to improve the above-described problems, and a rotation angle detection device capable of reducing an angle error in consideration of the phase of the second harmonic, a rotating electrical machine device including the same, and An electric power steering apparatus is proposed.

  The rotation angle detection device according to the present invention outputs a rotation angle signal representing a rotation angle using a sinusoidal two-phase output signal having a shaft multiplication angle of N (N is a positive integer) and shifted in phase from each other. A rotation angle detection device, where the two-phase output signals are Esin and Ecos, respectively, and the second harmonic when the Esin and Ecos DC components and the Nth order component of Esin and Ecos are the fundamental wave components. As means for canceling the angular error N-order component when the angular error of the mechanical angle of 360 degrees, which is generated depending on the amplitude and phase of the component, is primary, a correction amount that is constant with respect to the rotation angle is defined as Esin And correction means for adding to at least one of Ecos.

  A rotating electrical machine apparatus according to the present invention is a rotating electrical machine apparatus including the rotation angle detection device, and includes a rotating electrical machine and a controller integrated with the rotating electrical machine, and the controller includes the correction unit. A correction amount that the correction means adds to at least one of the two-phase output signals Esin and Ecos in a state where the controller and the rotary electric machine are combined. It is calculated based on the measured output signals Esin and Ecos, and the storage device stores the correction amount.

An electric power steering apparatus according to the present invention includes a rotating electrical machine, a rotational angle detection device that generates a rotational angle signal representing a rotational angle of a rotor of the rotating electrical machine, and a controller that controls driving of the rotating electrical machine. An electric power steering device for a vehicle in which a rotor of the rotating electrical machine is coupled to a steering wheel of a vehicle, wherein the rotation angle detection device has an axial multiplication angle of N (N is a positive integer), A signal processing unit that outputs a rotation angle signal representing a rotation angle of the rotor using a shifted sinusoidal two-phase output signal;
This signal processing unit, when the two-phase output signal is Esin, Ecos,
As means for canceling the angular error N-order component when the angular error of the mechanical angle of 360 degrees is the primary, a correction amount that is constant with respect to the rotational angle of the rotor is set to at least one of Esin and Ecos. Having correction means for adding,
The correction amount is based on the amplitude and phase of the second harmonic component when the two-phase output signals Esin and Ecos are DC components and the N-order component of the two-phase output signals Esin and Ecos is the fundamental component. The controller has a storage device, and the storage device stores the correction amount.

  According to the rotation angle detection device of the present invention, the angle error N-order component when the angle error of the mechanical angle of 360 degrees is made primary is greatly reduced, and the angle detection accuracy can be greatly improved. In addition, the amplitude of the second harmonic component when the DC component and the Nth-order component of Esin and Ecos are used as the fundamental component simply by adding a correction amount that is constant with respect to the rotation angle to at least one of Esin and Ecos. Therefore, the effect of the apparatus can be simplified as compared with the conventional technique in which the second harmonic component of the output signal is corrected.

  Further, according to the rotating electrical machine apparatus of the present invention, even if an angle error occurs in the two-phase output signal, a correction amount can be added to at least one of the output signals Esin and Ecos. As a result, the torque pulsation of the rotating electrical machine can be reduced, and a rotating electrical machine apparatus with low vibration and low noise can be obtained.

  In addition, according to the electric power steering apparatus of the present invention, it is possible to greatly reduce the angle error caused by a plurality of factors with a simple configuration. In addition, since the angle error of the rotation angle detection device can be greatly reduced, the torque pulsation of the rotating electrical machine is reduced, and a good steering feeling can be obtained. Since only the correction amount needs to be stored in the storage device, there is an effect that a necessary storage capacity is reduced as compared with the conventional technique.

FIG. 1 is a cross-sectional view of a resolver used as a signal generator in Embodiment 1 of the rotation angle detection device according to the present invention. FIG. 2 is an explanatory diagram of the winding of the resolver used in the first embodiment. FIG. 3 is an explanatory diagram showing a voltage waveform of the excitation winding and output winding of the resolver used in the first embodiment and a signal waveform obtained from the voltage waveform. FIG. 4 is an explanatory diagram of signal waveforms of the resolver used in the first embodiment. FIG. 5 is an explanatory diagram showing the frequency analysis result of the signal waveform of the resolver used in the first embodiment. FIG. 6 is an explanatory diagram of a Lissajous waveform of a resolver signal according to the first embodiment. FIG. 7 is an explanatory diagram of a Lissajous waveform of the resolver signal according to the first embodiment. FIG. 8 is an explanatory diagram of a Lissajous waveform of the resolver signal according to the first embodiment. FIG. 9 is a diagram in which the angle error according to the first embodiment is regarded as a vector quantity and plotted according to amplitude and phase. FIG. 10 is an explanatory diagram regarding the center shift of the Lissajous waveform of the resolver signal according to the first embodiment. FIG. 11 is an explanatory diagram of an angle error waveform according to a conventional example. FIG. 12 is an explanatory diagram of an angle error waveform according to the first embodiment. FIG. 13 is an explanatory diagram showing the frequency analysis result of the angle error waveform according to the first embodiment. FIG. 14 is a block diagram showing a signal processing unit in the first embodiment. FIG. 15 is a perspective view of a magnetic sensor used as a signal generator in Embodiment 2 of the rotation angle detection device according to the present invention. FIG. 16 is an explanatory diagram of a waveform of an output signal of the magnetic sensor used in the second embodiment. FIG. 17 is a block diagram showing a signal processing unit in Embodiment 3 of the rotation angle detection device according to the present invention. FIG. 18 is an explanatory diagram showing the effect of reducing the angle error according to the first to third embodiments. FIG. 19 is a configuration diagram of a fourth embodiment of the rotating electrical machine apparatus according to the present invention. FIG. 20 is a cross-sectional view of the rotating electrical machine in the fourth embodiment. FIG. 21 is a configuration diagram of Embodiment 5 of the electric power steering apparatus according to the present invention.

  Next, several embodiments of a rotation angle detection device, a rotating electrical machine device, and an electric power steering device according to the present invention will be described with reference to the drawings.

Embodiment 1 FIG.
Embodiment 1 of the rotation angle detection device according to the present invention is a rotation angle detection device 100, which is configured by combining a signal generation device 200 and a signal processing unit 300. For the signal generator 200, a resolver or a magnetic sensor is used, but in the first embodiment, a resolver 210 is used. The rotation angle detection apparatus 100 according to the first embodiment is configured to reduce an angle error using a resolver 210. First, the resolver 210 used as the signal generator 200 will be described, and then the signal processing unit 300 will be described.

  FIG. 1 is a cross-sectional view showing a resolver 210 used as a signal generation device 200 in the rotation angle detection device 100 of the first embodiment. Specifically, the resolver 210 is a variable reluctance type resolver. The resolver 210 has a stator 1 and a rotor 2. The stator 1 is formed in a cylindrical shape, and a plurality of magnetic poles 1a are formed on the inner periphery thereof at equal angular intervals, and a winding 3 is disposed on each magnetic pole 1a. The rotor 2 is disposed on the inner periphery of the stator 1 so as to face each magnetic pole 1a, and is attached to the rotating shaft 2a. FIG. 1 is a cross-sectional view in a plane perpendicular to the rotating shaft 2a, and details of an insulator for the winding 3, a connection portion of the winding 3, a connector, and the like are omitted.

  The windings 3 arranged on each magnetic pole 1a are respectively composed of an excitation winding 3a, a first output winding 3b, and a second output winding 3c. There are various connection modes for the excitation winding 3a, the first output winding 3b, and the second output winding 3c arranged in each magnetic pole 1a. For example, the excitation winding arranged in each magnetic pole 1a. The wires 3a are connected in series with each other, the first output windings 3a arranged on each magnetic pole 1a are also connected in series with each other, and the second output windings 3b arranged on each magnetic pole 1a are also connected in series with each other. The The rotor 2 has such a shape that the gap permeance with each magnetic pole 1 a of the stator 1 varies depending on the rotation angle of the rotor 2. In FIG. 1, the rotor 2 is formed in a shape in which the gap permeance pulsates four times in the rotation range of 360 degrees in mechanical angle, and operates as a 4 × resolver, that is, a resolver with a shaft angle multiplier N = 4.

  FIG. 2 is an explanatory diagram of the winding 3 of the resolver 210. An excitation power source 4 is connected to the excitation winding 3a, an AC voltage is applied, and an excitation current flows. The frequency of the excitation voltage of the excitation power supply 4 is, for example, 10 (kHz). The number of turns and the arrangement of the first output winding 3b and the second output winding 3c are determined so as to form a phase difference of 90 electrical degrees. FIG. 2 is a schematic diagram showing the first output winding 3b and the second output winding 3c arranged in directions orthogonal to each other to facilitate understanding of the winding structure of the resolver 210. Since the first output winding 3b and the second output winding 3c have a phase difference of 90 degrees in electrical angle, their output voltages E1 and E2 have a relationship between SIN and COS. Hereinafter, it is assumed that the output voltage E1 of the first output winding 3b corresponds to SIN, and the output voltage E2 of the second output winding 3c corresponds to COS. When the rotor 2 rotates, output voltages E1 and E2 having an amplitude corresponding to the rotation angle of the rotor 2 appear in the first output winding 3b and the second output winding 3c.

FIG. 3 shows an output voltage waveform representing the output voltages E1 and E2 generated by the excitation winding 3a and the output windings 3b and 3c, and an output signal waveform extracted from the output voltage waveforms of the output windings 3b and 3c. FIG. 6 is an output voltage waveform and an output signal waveform measured when the rotor 2 of the resolver 210 is rotating at a constant speed. FIG. 3A shows an excitation voltage waveform 5 of the excitation winding 3a. FIG. 3B shows an output voltage waveform 6 representing the output voltage E1 generated at the first output winding 3b, and an output signal waveform 7 extracted from the output voltage waveform 6. FIG. 3C shows an output voltage waveform 8 representing the output voltage E2 generated in the second output winding 3c, and an output signal waveform 9 extracted from the output voltage waveform 8. 3A, 3 </ b> B, and 3 </ b> C is the rotation angle of the rotor 2, and is represented by the electrical angle of the resolver 210. The relationship between the electrical angle and the mechanical angle of the resolver 210 is as follows. When the shaft multiple angle is N (N is a positive integer),
(Electrical angle) = (shaft double angle N) x (mechanical angle)
It becomes the relationship.

  The excitation voltage waveform 5 shown in FIG. 3A is a waveform in which the amplitude does not change depending on the rotation angle of the rotor 2 because an AC voltage having a constant amplitude is applied from the excitation power supply 4. The output voltage waveform 6 shown in FIG. 3B is an induced voltage waveform induced in the first output winding 3 b by the excitation voltage waveform 5, and the output signal waveform 7 is the output voltage waveform 6 and the excitation voltage waveform 5. This is a signal waveform in which the peak value of the output voltage waveform 6 is detected in synchronization with the frequency. The output signal waveform 7 is a waveform obtained by extracting the envelope of the output voltage waveform 6. The output signal waveform 7 corresponds to the SIN signal of the resolver 210. The output voltage waveform 8 shown in FIG. 3C is an induced voltage waveform that is induced in the second output winding 3 c by the excitation voltage waveform 5, and the output signal waveform 9 is the output voltage waveform 8 and the excitation voltage waveform 5. This is a signal waveform in which the peak value of the output voltage waveform 8 is detected in synchronization with the frequency. The output signal waveform 9 corresponds to the COS signal of the resolver 210. The output signal waveforms 7 and 9 are extracted from the output voltage waveforms 6 and 8 representing the output voltages E1 and E2 by the signal extraction means 15 of FIGS. 14 and 17 included in the signal processing means 300.

  Although the output signal waveforms 7 and 9 detect the peak values of the output voltage waveforms 6 and 8 here, the present invention is not limited to this. For noise countermeasures, a value estimated from a plurality of detection points spaced at time intervals may be used, or the peak value may be detected by making the output voltage waveform a trapezoidal wave. The rotation angle can be detected from the output signal waveforms 7 and 9, that is, the SIN signal and COS signal of the resolver 210, and this can be realized, for example, by obtaining the arctangent of the SIN signal and the COS signal.

Next, as a specific example of the output signal waveforms 7 and 9 representing the output voltages E1 and E2, output signal waveforms when the resolver 210 is configured as a 4 × resolver are shown in FIG. FIG. 4 shows output signal waveforms of the output windings 3b and 3c when the resolver 210 is a 4 × resolver, and the horizontal axis represents the rotation angle of the rotor 2 of the resolver 210 in mechanical angle. An output signal waveform 7a corresponding to the SIN signal obtained from the output voltage waveform 6 of the first output winding 3b and an output signal waveform 9a corresponding to the COS signal obtained from the output voltage waveform 8 of the second output winding 3c are: Both have sinusoidal waveforms, and pulsate within the range of 360 ° mechanical angle, the number of times that coincides with the shaft angle multiplier N (four times in this example). The output signal waveform 7a and the output signal waveform 9a are out of phase with each other, and the phase difference is 22.5 degrees mechanical angle, that is, the electrical angle of the resolver 210.
4 × 22.5 = 90 degrees.

  In the case of an ideal resolver, the output signal waveform 7a and the output signal waveform 9a are sine waves that do not include harmonic components. However, in an actual machine, the waveform is distorted, and the distortion of the waveform is an angular error. It may cause. FIG. 5 shows the result of frequency analysis of the output signal waveform 7a corresponding to the SIN signal of FIG. 4 and the output signal waveform 9a corresponding to the COS signal. Since the resolver 210 is a 4 × resolver, the fourth-order component is the fundamental wave component, but other order components can be seen. Here, attention is focused on a zero-order component (DC component) and an eighth-order component (2N-order component) as large components other than the fourth-order component. Since the 4th order component is the fundamental wave component, the 8th order component is the 2Nth order component and is the second harmonic component with respect to the fundamental wave.

When the output signal waveform 7 or 7a, 9 or 9a output from the resolver 210 having a shaft angle multiplier N is set to Esin and Ecos, and normalized by the amplitude of the Nth order component that is the fundamental wave component, The output signals Esin (θ) and Ecos (θ) expressed as a function of the rotation angle θ of the rotor 2 are ideally
Esin (θ) = sinNθ (1)
Ecos (θ) = cosNθ (2)
Can be expressed as In the expressions (1) and (2), N is an axial double angle.

When the two-phase output signals Esin and Ecos are output signals E′sin and E′cos including a fundamental wave component and a zero-order component (DC component), the output signal E expressed as a function of the rotation angle θ of the rotor 2 'sin (θ), E'cos (θ) is
E'sin (θ) = sinNθ + es (3)
E'cos (θ) = cosNθ + ec (4)
Can be expressed as The output signals E′sin and E′cos in Expressions (3) and (4) do not include components other than the fundamental wave component (fourth order component) and the zeroth order component. In the expressions (3) and (4), es and ec are constant values and are arbitrary real numbers. When the output signals E′sin and E′cos include a zeroth order component, an angular error Nth order component having a mechanical angle of 360 ° as a first order is generated. When this angular error N-order component is ε (rad) in terms of the electrical angle of the resolver 210, the angular error N-order component ε is expressed by the following equation (5) from Equations (1), (2), (3), and (4). Can be approximated.

ただし、式（５）のξについて、cosξ、sinξは次の式（６）とした。

However, for ξ in the equation (5), cos ξ and sin ξ are set to the following equation (6).

On the other hand, when the two-phase output signals Esin and Ecos are output signals E ″ sin and E ″ cos including a fundamental wave component and a 2N-order component (second harmonic component), the rotation angle θ of the rotor 2 is The output signals E ″ sin (θ) and E ″ cos (θ) expressed as functions are expressed as follows. The amplitude of the 2N order component is es2N and ec2N, and the phases are α2N and β2N.
E ″ sin (θ) = sinNθ + es2N × sin (2Nθ + α2N) (7)
E''cos （θ） = cosNθ + ec2N × sin (2Nθ + β2N) (8)
Can be expressed as The output signals E ″ sin and E ″ cos in Expressions (7) and (8) do not include components other than the fundamental wave component (fourth order component) and the 2N order component (second harmonic component). At this time, an N-order component and a 3N-order component are generally generated as the angle error. However, the angle error N-order component is approximately expressed by the following equations (1), (2), (7), and (8). Equation (9) can be written.

  In Equation (9), ζ is a phase and is a value determined by amplitudes es2N and ec2N and phases α2N and β2N. As described above, the cause of the angular error N-order component of the resolver 210 includes a zero-order component (DC component) and a 2N-order component (second harmonic component) included in the output signals Esin and Ecos.

  6 shows the SIN signal extracted from the first output winding 3b of the resolver 210, that is, the output signal Esin on the vertical axis, and the COS signal extracted from the second output winding 3c, that is, the output signal Ecos on the horizontal axis. This is a Lissajous waveform. When the output signals Esin and Ecos are the output signals E′sin and E′cos including the zeroth order component (DC component) as in the equations (3) and (4), the Lissajous waveform 10a shown in FIG. Become. In the Lissajous waveform 10a, a center shift occurs. The center of the Lissajous waveform 10a shown in FIG. 6 is shifted from the origin, and is shifted to the position of the Lissajous center 11a. When the rotation angle is obtained from such a Lissajous waveform 10a, the angular error N-order component is included when the angular error of the mechanical angle of 360 degrees is set to the first order as shown in the equation (5) as the angular error. .

  Next, when the output signals Esin and Ecos are output signals E ″ sin and E ″ cos including a 2N-order component (second harmonic component) as in the equations (7) and (8), The Lissajous waveform 10b shown in FIG. 7 is obtained. The vertical axis in FIG. 7 is the SIN signal extracted from the first output winding 3b of the resolver 210, that is, the output signal Esin, as in FIG. 6, and the horizontal axis is from the second output winding 3c in the resolver 210. The extracted COS signal, that is, the output signal Ecos. It can be seen that the Lissajous waveform 10b is a waveform distorted from a circle. However, since the output signals E ″ sin and E ″ cos have no zero-order component, the center 11b of the Lissajous waveform 10b coincides with the origin. When the rotation angle is obtained from such a Lissajous waveform 10b, an angular error N-order component is included when the angular error of a mechanical angle of 360 degrees is set as the primary as shown in the equation (9) as an angular error. It will be.

  Further, when the output signals Esin and Ecos include both the 0th order component (DC component) and the 2Nth order component (second harmonic component), the Lissajous wave 10c shown in FIG. 8 is obtained. In FIG. 8, it is assumed that the output signals Esin and Ecos include a fundamental wave component, a zero-order component (DC component), and a 2N-order component (second harmonic component), and no other components. The Lissajous waveform 10c in FIG. 8 is distorted instead of circular, and the center 11c of the Lissajous waveform 10c is deviated from the origin. When the rotation angle is obtained from such a Lissajous waveform 10c, an angular error obtained by synthesizing the angular error Nth order component represented by Expression (9) in addition to the angular error Nth order component represented by Expression (5) is obtained. In an actual machine, there is almost no state where there is no center shift or no 2N-order component (second harmonic), and a Lissajous waveform 11c as shown in FIG. is there. Therefore, it is considered that the angle error cannot be reduced simply by correcting the center shift and moving to the origin.

  Further, according to FIGS. 1 and 2 of Patent Document 1, the zero point parameter calculation means and the second harmonic error correction parameter calculation means are provided separately, and the normalization means and the second harmonic removal means are further provided. There is a problem that it is provided separately and the configuration is complicated. In addition, although the magnitude of the second harmonic is known, there is a problem that the phase cannot be considered, and the influence of the second harmonic cannot be completely removed. Further, when there is no center deviation of the cosine signal, max (x) = min (x) and gx = 0, and when there is no center deviation of the sine signal, max (y) = min (y) and gy = 0. Therefore, in this case, the equations (1) and (2) described in Patent Document 1 become constants and do not make sense, and there is a problem that the rotation angle cannot be detected properly.

  The present invention has been made in order to improve the above-described problems, and the rotational angle detection device according to the present invention can simultaneously reduce angular errors caused by a plurality of factors with a simple configuration. The contents will be described below.

FIG. 9 is a diagram in which the angular error Nth order component is regarded as a vector quantity and plotted according to the amplitude and phase. In FIG. 9, the horizontal axis is X, the vertical axis is Y (the unit is rad of resolver electrical angle), and the angular error ε (rad) of the Nth order component is expressed by the following equation (10).
ε = E_N × sin (Nθ + η) (10)
In Equation (10), E_N is an arbitrary real number, η is an arbitrary real number, and θ is a rotation angle of the rotor 2 (mechanical angle radians). The angle error ε in the equation (10) is equal to the angle error caused by the 0th-order component (DC component) of the output signals Esin and Ecos expressed by the equation (5) and the output signals Esin and Ecos expressed by the equation (9). This is equal to the sum of the angular error caused by the 2Nth order component (second harmonic component) when the Nth order component is the fundamental wave component. In FIG. 9, the angular error Nth order component is represented by a vector 12c, and this vector 12c has a size from the origin to the point (X, Y). The X value corresponding to the X axis of the point (X, Y) and the Y value corresponding to the Y axis were defined as the following equations (11) and (12).
X = E_N × cosη (11)
Y = E_N × sinη (12)
The length of the vector 12c is E_N, and the angle 13c formed with the X axis coincides with η.

  As described above, the cause of the angular error N-order component of the resolver 210 is that the zero-order component (DC component) of the output signals Esin and Ecos and the N-order component of the output signals Esin and Ecos are the fundamental wave components. There is a 2N order component (second harmonic component). The angular error Nth order component can be regarded as a composition of angular errors caused by these two components. Assume that the Nth-order component of the angle error due to the zeroth-order component of the output signals Esin and Ecos is a vector 12a of an angle 13a (referred to as ξ in equation (5)) formed with the X axis, and the second-order of the output signals Esin and Ecos. Assuming that the angular error Nth order component due to the component is a vector 12b of an angle 13b (referred to as ζ in the equation (9)) formed with the X axis, the vector 12c of the angular error Nth order component of the resolver 210 is the vector 12a. And the vector 12b.

  In order to reduce the angular error N-order component represented by the vector 12c, the resolver output signals Esin and Ecos may be corrected so as to generate an angular error that cancels the vector 12c. In other words, the vector (X, Y), that is, the vector (−X, −Y) obtained by inverting the vector 12c, that is, the vector 12d is generated, and the output signals Esin and Ecos may be corrected by the vector 12d.

  Here, the angular error Nth order component is generated from the 0th order component and the 2Nth order component of the output signals Esin and Ecos. Focusing on the equations (5) and (6), an arbitrary amplitude can be obtained by moving the Lissajous center. It is understood that it is possible to generate an N-order component of the phase angle error. Based on this understanding, the present invention reduces the angular error Nth order component indicated by the vector 12c resulting from both the 0th order component and the 2Nth order component of the output signals Esin and Ecos by moving the Lissajous center. Therefore, a correction value corresponding to the vector 12d is generated, and the correction value corresponding to the vector 12d is added to the output signals Esin and Ecos. Therefore, the 0th-order component of the output signals Esin and Ecos for generating the vector (−X, −Y), that is, the vector 12d is obtained.

Consider the cases of equations (3) and (4). In the case of these formulas (3) and (4), the Lissajous center shifts from the origin and moves to the point (ec, es) when considering the normalized plane of the COS and SIN signals. Since the angular error Nth order component at this time is expressed by equations (5) and (6), the angular error Nth order component corresponds to the vector (ec, es) from equations (10), (11), and (12). It will be. Therefore, to convert the angle error vector (Xe, Ye) to the Lissajous center shift (Xc, Yc),
Xc = −Xe, Yc = Ye (13)
And it is sufficient. The reason why Xe is minus in equation (13) is because cosξ in equation (6) is minus. Therefore, the vector (−X, −Y) for reducing the angular error Nth order component, that is, the Lissajous center shift (Xc, Yc) for generating the vector 12d, that is, the 0th order component of the output signals Esin and Ecos,
Xc = X, Yc = -Y (14)
It becomes. From the above, if the Lissajous center is moved by (X, -Y) from the original Lissajous center, the angular error Nth order component can be canceled. This vector is called an error correction vector.

  The above will be described using a Lissajous waveform. FIG. 10 shows a Lissajous waveform. The horizontal axis shows the COS signal and the vertical axis shows the SIN signal normalized. For simplicity, the Lissajous distortion due to harmonics is omitted and shown in a circle. In the Lissajous waveform 10d, the output signals Esin and Ecos include a zero-order component, and the Lissajous center 11d is deviated from the origin. The angular error caused by the center shift of the Lissajous waveform 10d corresponds to the vector 12a in FIG. Furthermore, if the 2N order component is included in the output signals Esin and Ecos and the Lissajous is distorted, the angle error generated thereby corresponds to the vector 12b in FIG. The vector 12c, which is the sum of these vectors, becomes the angular error Nth-order component, and the vector for canceling this becomes (−X, −Y), that is, the vector 12d. The zero-order component of the output signals Esin and Ecos that generate the vector 12d is obtained from the equation (14), and the vector 14 in FIG. 10 corresponds to it. If the Lissajous center is moved to the vector 11e obtained by adding the error correction vector 14 to the original Lissajous center vector 11d, the angular error Nth order component can be greatly reduced.

In other words, it is as follows. The angular error Nth order component obtained from the output signals Esin and Ecos of the output windings 3b and 3c is expressed by equation (10), and the fundamental component of the output signals Esin and Ecos (one rotation of the rotor 2 is one cycle). When the amplitude of the N component when the component is the first order is Esin0 and Ecos0 (unit: V),
Correction values that are constant with respect to the rotation angle of the rotor 2 are added to the output signals Esin and Ecos,
Esin0 × E_N × cosη (unit: V),
-Ecos0 × E_N × sinη (Unit: V)
Are added to the output signal Esin, Ecos DC component (0th order component) and Esin, Ecos second harmonic component (2N order component) amplitude and phase dependent angle error Nth order component is greatly reduced It will be possible.

If the output signals Esin and Ecos of the output windings 3b and 3c are standardized and discussed, when the output signals Esin and Ecos are normalized by the fundamental component amplitudes Esin0 and Ecos0, respectively, the output signals Esin and Ecos are As a correction value that is constant with respect to the rotation angle of the rotor 2,
E_N × cosη
−E_N × sinη
The same effect can be obtained by adding each of.

  Further, the angular error Nth order component represented by Expression (10) is obtained by adding the angular error Nth order component represented by Expression (5) and the angular error Nth order component represented by Expression (9). The correction values which are added to the output signals Esin and Ecos and become constant with respect to the rotation angle of the rotor 2 are the angle error N-order component expressed by the equation (5) and the angle error N expressed by the equation (9). It can also be calculated as the sum of the next components. In this case, the DC components of the two-phase output signals Esin and Ecos are es and ec (es and ec are arbitrary real numbers), and the amplitude of the second harmonic component of the two-phase output signals Esin and Ecos is es2N and ec2N (Es2N, ec2N are arbitrary real numbers) and the phase of the second harmonic component is α2N, β2N (α2N, β2N are arbitrary real numbers), the correction amount is the DC components es, ec, It is calculated from the amplitudes es2N and ec2N and the phases α2N and β2N.

  In order to verify the effect of the above method, we examined the reduction of the angle error using the Lissajous waveform. The output signals Esin and Ecos of the output windings 3b and 3c of the resolver 210 configured as a 4X resolver were measured to obtain an angle error waveform. The obtained angle error waveform is shown in FIG. FIG. 11 is an explanatory diagram of an angle error waveform according to a conventional example, and the horizontal axis represents the rotation angle of the rotor 2 in mechanical angle. Waveform A is the original angle error waveform. This waveform A is obtained by converting the output signals Esin and Ecos into angle information as it is without correcting the output signals Esin and Ecos and taking the difference from the true angle. A component that pulsates four times in one rotation of the rotor 2 is seen. This is the angular error Nth-order component (N is an axial multiple angle, here N = 4).

  First, for the purpose of reducing the angular error Nth order component, processing for moving the center shift of the Lissajous waveform to the origin corresponding to only the 0th order component (DC component) of the output signals Esin and Ecos was performed. The result is the angle error waveform B in FIG. 11. This angle error waveform B is a waveform corresponding to the conventional example, and the case where only the center shift of the Lissajous waveform shown in FIG. 6 is moved to the origin is performed. It is a waveform. In the angle error waveform B, although a change is observed in the error waveform, the fourth-order component is hardly reduced, and the amplitude of the angle error does not change much. This is because the Lissajous waveform is distorted, and the output signals Esin and Ecos contain an 8th-order (2Nth-order) component in addition to the 0th-order component as shown in FIG. By moving the Lissajous center to the origin, the fourth-order angle error component (the Nth-order angle error component) due to the zeroth-order component of the output signals Esin and Ecos can be reduced, but the eighth order (2N of the output signals Esin and Ecos). This is because the quaternary component of angular error due to the (next) component could not be reduced. That is, the angle error cannot be sufficiently reduced only by correcting the Lissajous center deviation corresponding to only the zeroth order component (DC component) of the output signals Esin and Ecos.

  Next, as shown in FIG. 10, according to the present invention, the angle error caused by both the zero-order component (DC component) and the eighth-order component (2N-order component) of the output signals Esin and Ecos is considered. Thus, a method of shifting the center of the Lissajous waveform was applied. The results are shown in FIG. FIG. 12 is an explanatory diagram of the angle error waveform according to the first embodiment of the present invention. Angular error waveform C is a waveform corresponding to the first embodiment of the present invention. The angular error quaternary component is greatly reduced, and the peak value (pp value) of the angle error can be reduced to about ½.

  In order to confirm the effect in detail, the result of frequency analysis of the angle error is shown in FIG. FIG. 13 is an explanatory diagram showing the frequency analysis result of the angle error waveform according to the first embodiment. The horizontal axis of FIG. 13 is the order of the angle error, and the vertical axis is the angle error from 0 value to the peak value. (0−p). In FIG. 13, the white bar graph shows the angle error corresponding to the original angle error waveform A, the hatched bar graph shows the angle error corresponding to the angle error waveform B of the conventional example, and the black bar graph shows this It is an angle error corresponding to the angle error waveform C according to the first embodiment of the invention. The angular error quaternary (Nth order) component cannot be reduced in the conventional example, but is significantly reduced in the first embodiment of the present invention. In the first embodiment of the present invention, the fourth-order component of the original angular error waveform A can be reduced to only 3%. In this example, since there is an angular error eighth-order component, the angle error has a pp value of about half, but if the resolver has almost no angular error eighth-order component, the effect of the present invention is further exhibited. It will be possible.

  FIG. 14 is a block diagram showing a specific example of the signal processing unit 300 used in the rotation angle detection device 100 of the first embodiment. In FIG. 14, the signal processing unit 300 is configured as a signal processing unit 310. The signal processing unit 310 is used in combination with a signal generator 200, for example, a resolver 210. The signal processing unit 310 includes a signal extraction unit 15, a correction unit 16, an angle calculation unit 17, and a Lissajous center correction amount output unit 18. These signal extraction means 15, correction means 16, angle calculation means 17, and Lissajous center correction amount output means 18 are configured using, for example, a microcomputer. Output voltages E1 and E2 of the output windings 3b and 3c of the resolver 210 having a shaft angle multiplier N are input to the signal extraction means 15. The signal extraction unit 15 extracts the two-phase output signals Esin and Ecos from the output voltages E1 and E2, and outputs the output signals Esin and Ecos to the correction unit 16. The Lissajous waveform center correction amount output means 18 calculates a Lissajous center correction vector amount from the 0th order component and the 2Nth order component included in the output signals Esin and Ecos, and the correction amounts Esin0 × E_N × cosη and Ecos0 × E_N × sin η is calculated, and these correction amounts are output to the correction means 16. The correction unit 16 receives the correction values Esin0 × E_N × cos η and Ecos0 × E_N × sin η obtained by the correction amount output unit 18, and receives the correction amounts Esin0 × E_N × cos η and Ecos 0 × in the output signals Esin and Ecos. Add E_N x sin η and move the center of the Lissajous waveform. In other words, correction amounts Esin0 × E_N × cosη and Ecos0 × E_N × sinη are added to the output signals Esin and Ecos as zero-order components, respectively.

In other words, the angle error ε (rad) of the resolver 210 is
ε = E_N × sin (Nθ + η) (10) (repost)
When the correction means 16 outputs the output signals Esin and Ecos,
Esin0 × E_N × cosη (unit: V),
-Ecos0 × E_N × sinη (Unit: V)
Are respectively added. However, Esin0 and Ecos0 (unit: V) are the amplitudes of the fundamental wave signal of the resolver signal (the N-order component when the component having one rotation of the rotor 2 as one cycle is primary). The correction values Esin0 × E_N × cosη and Ecos0 × E_N × sinη to be added to the output signals Esin and Ecos may be calculated while monitoring the output signals Esin and Ecos in real time, or measured in advance. A correction value calculated from the output signals Esin and Ecos may be stored in a storage device. The output signals Esin and Ecos obtained by adding the correction signals Esin0 × E_N × cosη and Ecos0 × E_N × sinη are converted into the rotation angle θ of the rotor 2 by the angle calculating unit 17. Is done. The angle calculation means 17 calculates the rotation angle θ by, for example, obtaining the arc tangent, tan-1 (Esin / Ecos), from the output signals Esin and Ecos output from the correction means 16.

In FIG. 1 of Patent Document 1, zero point parameter calculation means, normalization means, and second harmonic error correction for the angle error caused by the 0th order and the 2N order angle error of the signal waveform. Parameter calculation means and second harmonic elimination means are provided. In this case, the process of reducing the angle error is complicated, and it is necessary to deal with the 0th-order component and the 2Nth-order component of the signal waveform (the second harmonic is used in Patent Document 1), which increases the calculation load. There was a problem of ending up. However, with the configuration of the present invention, it is possible to deal with both the angle error caused by the 0th order component and the angle error caused by the 2Nth order component of the signal waveform only by moving the center of the Lissajous waveform. That is, the angle error caused by a plurality of factors can be simultaneously reduced with a simple configuration. Accordingly, the angle error reduction process is simplified, and the calculation load can be reduced. Since the calculation load is reduced, when driving a motor equipped with the resolver 210, there is also an effect that the cost of the CPU used for the controller can be reduced.
In addition, since the phase of the 2N-order component of the output signals Esin and Ecos can be considered, there is an effect that the influence of the 2N-order component can be almost completely removed. Further, when the Lissajous waveform has no center deviation and coincides with the origin, there is a problem that the patent document 1 cannot detect the angle. However, in the present invention, the angle can be detected without any problem.

  In the first embodiment, the resolver 210 having a shaft angle multiplier N = 4 is shown, but the present invention is not limited to this. The present invention can be applied at an arbitrary shaft angle multiplier N (N is a positive integer).

As described above, the rotation angle detection device 100 outputs a rotation angle signal representing a rotation angle using a sinusoidal two-phase output signal having a shaft multiplication angle of N (N is a positive integer) and out of phase with each other. And
When the two-phase output signal is Esin and Ecos, respectively, it depends on the amplitude and phase of the second harmonic component when the DC component of Esin and Ecos and the Nth component of Esin and Ecos are the fundamental wave components. As a means for canceling the angular error Nth order component when the angular error of the mechanical angle of 360 ° is generated as a first order, a correction value that is constant with respect to the rotation angle is added to at least one of Esin and Ecos By including the correcting means 16 for performing the rotation, the angular error N-order component can be greatly reduced, and the rotation angle detecting device 100 with a small angular error can be obtained.

  In the first embodiment, the variable reluctance resolver 210 is used as the signal generator 200, but the present invention is not limited to this. The same effect can be obtained with a brushless resolver, and it goes without saying that the same effect can be obtained with other configurations as long as the angle detection signal has a relationship between SIN and COS.

  The Lissajous center correction amount output means 18 of the signal processing unit 310 is configured to calculate correction amounts Esin0 × E_N × cosη and Ecos0 × E_N × sinη and output these correction amounts to the correction means 16. The Lissajous center correction amount output means 18 calculates the individual correction elements Esin0, E_N, sinη and cosη constituting the correction amounts Esin0 × E_N × cosη and Ecos0 × E_N × sinη, and the correction means 16 It is also possible to calculate correction amounts Esin0 × E_N × cos η and Ecos0 × E_N × sin η based on the individual correction elements and add these correction amounts to the output signals Esin and Ecos.

Embodiment 2. FIG.
FIG. 15 is a perspective view showing a magnetic sensor 220 used in Embodiment 2 of the rotation angle detection device according to the present invention. This magnetic sensor 220 constitutes the signal generator 200 and is used in place of the resolver 210 in the first embodiment. In this magnetic sensor 220, the cylindrical permanent magnet 20 magnetized so that the N pole and the S pole are switched in a certain region (a region of 180 degrees that bisects the circumference in FIG. 15) The permanent magnet 20 and the shaft 21 are both rotatable freely. A hall sensor 22 is arranged so as to face the permanent magnet 20 via a gap. The hall sensor 22 includes two hall elements arranged at rotational positions different from each other by 90 degrees in the rotational direction of the shaft 21. As the permanent magnet 20 rotates, the magnetic field in the vicinity of the Hall sensor 22 changes, and the Hall voltage of each Hall element of the Hall sensor 22 changes in a sine wave shape.

  Since this magnetic sensor 220 does not use the excitation winding 3a unlike the resolver 210, the output signals Esin and Ecos can be directly output from the hall sensor 22 without using the signal extraction means 15 of FIG. it can. Therefore, when this magnetic sensor 220 is used, the signal extraction means 15 of the signal processing unit 300 is omitted. The waveform of the output signal of each Hall element of the hall sensor 22 is shown in FIG. The two-phase sinusoidal output signals 7b and 9b have waveforms that are 90 degrees out of phase with each other. The output signal 7b is a SIN signal, that is, Esin, and the output signal 9b is a COS signal, that is, Ecos. When the output signals 7b and 9b include the 0th order component and the second harmonic component, an angular error Nth order component is generated. A signal obtained by eliminating the signal extraction unit 15 shown in FIG. The present invention can achieve the same effect even in a rotation angle detection device that combines the processing units 300.

Embodiment 3 FIG.
In the first embodiment, in the resolver 210 with an axial multiplication angle of N, a method of moving the center of the Lissajous waveform in order to remove the angular error Nth order component caused by the 0th order component and the 2Nth order component of the output signals Esin and Ecos, and The configuration was described. In the first embodiment, the angular error Nth-order component can be reduced, but when the other components are large, the angle error pp value cannot be sufficiently reduced. For example, when the amplitudes of the fundamental wave components of Esin and Ecos are different, a 2Nth-order angular error component is generated, and means for correcting this angular error 2Nth-order component may be provided.

  FIG. 17 is a block diagram showing a signal processing unit 320 used in Embodiment 3 of the rotation angle detection device according to the present invention. This signal processing unit 320 constitutes the signal processing unit 300 and is used in combination with, for example, the resolver 210 used in the first embodiment. This signal processing unit 320 is obtained by adding an amplitude correction amount output means 19 to the signal processing unit 310 used in the first embodiment.

  In this signal processing unit 320, the two-phase output signals Esin and Ecos extracted by the signal extraction means 15 from the output voltages E 1 and E 2 of the output windings 3 b and 3 c of the resolver 210 having a shaft angle multiplier N are sent to the correction means 16. It is done. The Lissajous waveform center correction amount output means 18 calculates a Lissajous center correction amount Esin0 × E_N × cosη and Ecos0 × E_N × sinη from the 0th order component and the 2Nth order component included in the output signals Esin and Ecos. The correction amount is output to the correction means 16. The correction unit 16 receives the correction values Esin0 × E_N × cos η and Ecos0 × E_N × sin η obtained by the correction amount output unit 18, and receives the correction amounts Esin0 × E_N × cos η and Ecos 0 × in the output signals Esin and Ecos. Add E_N x sin η and move the center of the Lissajous waveform. In other words, correction amounts Esin0 × E_N × cosη and Ecos0 × E_N × sinη are added to the output signals Esin and Ecos as zero-order components, respectively.

In other words, the angle error ε of the resolver 210 (rad of the resolver electrical angle) is
ε = E_N × sin (Nθ + η) (10) (repost)
When the correction means 16 outputs the output signals Esin and Ecos,
Esin0 × E_N × cosη (unit: V),
-Ecos0 × E_N × sinη (Unit: V)
Are respectively added. However, Esin0 and Ecos0 (unit: V) are the amplitudes of the fundamental components of the output signals Esin and Ecos (the Nth order component when the component having one cycle of the rotor 2 as one cycle is the first order). The correction amount added to the output signals Esin and Ecos may be calculated while monitoring the output signals Esin and Ecos in real time, or the correction amount calculated from the output signal measured in advance is stored in the storage device. It may be a method to keep.

  Further, the signal processing unit 320 is provided with output signal amplitude correction amount output means 19. This amplitude correction amount output means 19 multiplies one or both of the output signals Esin and Ecos when the amplitudes of the fundamental wave components of the output signals Esin and Ecos are different between Esin and Ecos. An amplitude correction amount is calculated, and this amplitude correction amount is output to the correction means 16. This amplitude correction amount is a constant that is multiplied by one or both of the output signals Esin and Ecos. The correction means 16 performs a process of adding correction amounts Esin0 × E_N × cosη (unit: V) and −Ecos0 × E_N × sinη (unit: V) to the output signals Esin and Ecos, and any one of the output signals Esin and Ecos. Either or both are multiplied by the amplitude correction amount to perform processing for matching the amplitudes of the fundamental components of the output signals Esin and Ecos. Then, the signals Esin and Ecos output from the correction unit 16 are converted into the rotor rotation angle θ by the angle calculation unit 17. For example, the angle calculation means 17 calculates the rotation angle θ by obtaining the arc tangent, tan-1 (Esin / Ecos), of the signals Esin and Ecos output from the correction means 16. When the signal processing unit 320 is combined with the magnetic sensor 220, the signal extraction means 15 is omitted.

  By using the signal processing unit 320 having such a configuration, it is possible to remove the 2N-order component of the angle error, and the effect of reducing the angle detection error is greater than that of the first embodiment. Further, the angle error can be reduced with a simpler configuration than that of FIG. 1 of Patent Document 1, and the angle error reduction process is simplified, and the calculation load can be reduced. Since the calculation load is reduced, when driving a motor equipped with the resolver 210, there is also an effect that the cost of the CPU used for the controller can be reduced.

  FIG. 18 is a diagram comparing angle errors in order to explain the effect of the third embodiment. The vertical axis in FIG. 18 is a value obtained by normalizing the pp value of the angle error with the original angle error waveform indicated by the waveform A in FIGS. The bar graph a is an angle error corresponding to the waveform A indicating the original angle error waveform, and is normalized and has a size of 1.000. A bar graph b corresponds to the waveform B in FIG. 11 showing the conventional example, and is an angle error when the center shift of the Lissajous is moved to the origin, and the size is 0.997. The bar graph c is an angle error when the Lissajous center is moved in consideration of the 0th order component and the 2Nth order component of the output signal described in the first embodiment, and the magnitude is 0.554. The bar graph d is obtained by applying both the method of moving the Lissajous center in consideration of the 0th and 2Nth order components of the output signal and the method of combining the amplitudes of the output signals Esin and Ecos described in the third embodiment. And the size is 0.357. It can be seen that the angular error is reduced to about ½ in the first embodiment, and the angular error is reduced to about 36% in the third embodiment.

Embodiment 4 FIG.
FIG. 19 shows Embodiment 4 of the rotating electrical machine apparatus according to the present invention. The rotating electrical machine apparatus 400 according to the fourth embodiment is configured by integrally combining a rotating electrical machine 410 with a controller 430. The rotating electric machine 410 is specifically a permanent magnet type motor, and is configured by incorporating the signal generator 200, for example, the resolver 210 or the magnetic sensor 220. The controller 430 includes a signal processing unit 300 and a storage device 350. The signal processing unit 300 is configured using the rotation angle signal processing unit 310 in the first embodiment or the signal processing unit 320 in the third embodiment. The storage device 350 is incorporated in the controller 430 together with the signal processing unit 300. The storage device 350 stores the correction amount output from the Lissajous center correction amount output unit 18 in the signal processing unit 300 and supplies the correction amount to the correction unit 16. When the signal processing unit 300 includes the signal processing unit 320 according to the third embodiment, the storage device 350 includes the amplitude correction amount output unit 19 together with the correction amount output from the Lissajous center correction amount output unit 18. The output amplitude correction amount is stored and supplied to the correction means 16. The signal generation device 200, the signal processing unit 300, and the storage device 350 constitute the rotation angle detection device 100.

  FIG. 20 is a cross-sectional view showing a permanent magnet type motor 420 used as the rotating electrical machine 410. FIG. 20 shows a sectional view on a plane parallel to the rotation axis of the permanent magnet type motor 420. The permanent magnet type motor 420 includes a rotor 430, a stator 440, and a signal generator 200. The signal generator 200 is, for example, a resolver 210. A permanent magnet 432 is provided on the surface of the rotor core 431 of the rotor 430. A shaft 433 is press-fitted into the rotor core 431, and the shaft 433 is supported by a stator 440 via bearings 441 and 442 so as to be rotatable. The rotor 430 is provided with a resolver 210 that generates two-phase output voltages E1 and E2.

  The resolver 210 fixes the stator 1 to the stator 440, and the rotor 2 is fixed to the shaft 433. A winding 3 is disposed on the stator 1. The stator core 443 of the stator 440 is provided so as to face the permanent magnet 432 through a gap. The stator core 443 may be configured, for example, by laminating electromagnetic steel plates or may be configured by a dust core. An armature winding 444 is wound around the stator core 443. The stator 440 is fixed to the frame 450 by press-fitting or shrink fitting, and the frame 450 is further fixed to the housing 460.

  In such a permanent magnet type motor 420, the rotor 430 is rotated by energizing the armature winding 444. When an angle error occurs in the resolver 210, the rotation angle of the rotor 2 cannot be detected correctly, and the phase of the current supplied to the armature winding 444 deviates from the ideal phase. Since the angular error pulsates, the phase of the current also pulsates accordingly, resulting in torque pulsation. In the resolver 210 having a shaft angle multiplier N, there is an angle error Nth order component when the angular error of the 360 degree mechanical angle of the rotor 2 is taken as a first order component, and the torque pulsation also shows an Nth order component and a double order 2Nth order component. . When torque pulsation occurs, noise and vibration increase. Therefore, it is necessary to reduce torque pulsation when used in an electric power steering apparatus that requires quietness.

  With such a configuration, even if an angle error occurs in the resolver 210, a correction amount can be added to at least one of the output signals Esin and Ecos, so that the angular error Nth-order component can be sufficiently reduced. As a result, the torque pulsation of the permanent magnet type motor 420 can be reduced, and the permanent magnet type motor 420 with low vibration and low noise can be obtained.

  Correction values Esin0 × E_N × cosη (unit: V) and −Ecos0 × E_N × sinη (unit: V) stored in the storage device 350 are calculated by the correction amount output means 18 while monitoring the output signals Esin and Ecos in real time. Alternatively, a correction value calculated from the output signals Esin and Ecos measured in advance may be used. If the correction values calculated from the output signals Esin and Ecos measured in advance are stored, it is possible to reduce the calculation load of the angle calculation and to reduce the calculation device. With an arrangement that is simpler than that of Patent Document 1, it is possible to significantly reduce the angle error caused by a plurality of factors.

  Further, since the permanent magnet type motor 420 and the controller 430 are integrated, even if the angular error of the resolver 210 mounted on the permanent magnet type motor 420 varies, the output signals Esin and Ecos measured in advance are measured. If the correction value calculated from the above is stored, it is possible to reduce the influence of variation and obtain a motor with small torque pulsation.

Embodiment 5 FIG.
FIG. 21 is a block diagram showing Embodiment 5 of the electric power steering apparatus according to the present invention. The electric power steering apparatus 500 according to the fifth embodiment is configured using the rotating electrical machine apparatus 400 according to the fourth embodiment.

  In FIG. 21, the electric power steering apparatus 500 is provided with a column shaft 503 for transmitting a steering force from a steering wheel 502 of an automobile. The column shaft 503 is connected with a gear 504 (for example, only a gear box is omitted in the figure, which is a worm gear), and the output (torque) of the permanent magnet type motor 420 driven by the controller 430 is connected to the column shaft 503. , The number of revolutions) is transmitted while changing the direction of rotation to a right angle, and at the same time, the speed is reduced to increase the assist torque. The handle joint 505 transmits the steering force and also changes the rotation direction. A steering gear 506 (details are omitted in the figure, only the gear box is shown) decelerates the rotation of the column shaft 503, and at the same time, converts it into a linear motion of the rack 507 to obtain a required displacement. The wheels are moved by the linear movement of the rack 507, and the direction of the vehicle can be changed.

  In such an electric power steering apparatus 500, the resolver 210 that is lower in cost and superior in environmental resistance than the optical encoder is often used as the rotation angle detection apparatus 100 of the permanent magnet type motor 420. However, when an angle error occurs in the resolver 210, torque pulsation of the order corresponding to the order of the angle error occurs, which causes noise and vibration, and a good steering feeling cannot be obtained.

  When the output signals of the first output winding 3b and the second output winding 3c of the resolver 210 whose shaft double angle is N (N is a positive integer) are Esin and Ecos, respectively, the mechanical angle of the resolver 210 is 360 degrees. Correction means Esin0 × E_N × cos η (unit: V), −Ecos0 × E_N × sin η (unit: V) which are constant with respect to the rotation angle of the resolver 210, as means for canceling the N-order component of the angular error when the angular error is primary. The correction means 16 for adding the unit (V) to at least one of Esin and Ecos is provided, and this constant correction value is the same as that described in the previous embodiments, Esin, the DC component of Ecos, and Esin. The Nth-order component of Ecos is determined from the amplitude and phase of the second harmonic when the fundamental wave component is used. Further, the controller 430 includes a storage device 350, and the storage device 350 stores the correction value to be added to the output signals Esin and Ecos.

  With such a configuration, it is possible to significantly reduce the angle error caused by a plurality of factors with a simple configuration. In addition, since the angle error of the rotation angle detection device 100 can be significantly reduced, the torque pulsation of the permanent magnet type motor 420 is reduced, and a good steering feeling can be obtained. When the signal processing unit 310 of the first embodiment is used, the storage device 350 has two correction values, that is, a correction value Esin0 × E_N × cosη (unit: V) that is constant with respect to the rotation angle of the resolver 210, Since it is only necessary to store -Ecos0 × E_N × sin η (unit: V), there is also an effect that a necessary storage capacity can be reduced as compared with the conventional case.

  Further, before assembling the permanent magnet type motor 420 and the controller 430 to the vehicle, correction amounts Esin0 × E_N × cosη (unit: V) and −Ecos0 × E_N × sinη (unit: V) for reducing the angle error are stored. In this case, even if a variation occurs in the angle error of the rotation angle detection device 100 provided in the permanent magnet type motor 420, if the correction value calculated from the output signals Esin and Ecos measured in advance is stored, the variation will occur. There is also an effect that an electric power steering device with a small torque pulsation can be obtained without being influenced by the above.

  The rotation angle detection device according to the present invention can be used, for example, as a rotation angle detection device for a rotating electrical machine, and the rotation electrical machine device according to the present invention can be used, for example, in an electric power steering device for a vehicle. The electric power steering apparatus according to the present invention can be used in a vehicle.

100: rotation angle detector, 200: signal generator, 210: resolver,
220: Magnetic sensor, 300, 310, 320: Signal processing unit,
350: storage device 400, rotating electrical machine device, 410: rotating electrical machine,
420: Permanent magnet type motor, 430: Controller
500: Electric power steering device,
1: stator, 2: rotor, 3a: excitation winding, 3b: first output winding,
3c: second output winding, 3: winding, 4: excitation power supply, 5: excitation voltage waveform,
6: voltage waveform of the first output winding, 7: output signal of the first output winding,
16: Correction means, 17: Angle calculation means, 18: Lissajous center correction amount output means,
19: Amplitude correction amount output means.

Claims (10)

A rotation angle detection device that outputs a rotation angle signal representing a rotation angle using a sinusoidal two-phase output signal having a shaft angle multiplier of N (N is a positive integer) and out of phase with each other,
When the two-phase output signal is Esin and Ecos, respectively, it depends on the amplitude and phase of the second harmonic component when the DC component of Esin and Ecos and the Nth component of Esin and Ecos are the fundamental wave components. As a means to cancel the angular error N-order component when the angular error of the mechanical angle of 360 degrees is generated as a first order, a correction amount that is constant with respect to the rotation angle is added to at least one of Esin and Ecos A rotation angle detection device comprising correction means for performing the correction.   The rotation angle detection device according to claim 1, comprising a signal generation device and a signal processing unit, wherein the signal generation device is provided between an excitation winding and a stator having a two-phase output winding, and the stator. A rotor that varies the gap permeance according to the rotation angle, the two-phase output winding generates a two-phase output voltage, and the signal processing unit is based on the two-phase output voltage, A rotation angle detection device that generates the two-phase output signals Esin and Ecos and outputs a rotation angle signal representing a rotation angle of the rotor. The rotation angle detection device according to claim 1, wherein an angular error Nth order component obtained from the two-phase output signals Esin and Ecos is expressed as follows:
ε = E_N × sin (Nθ + η) (Unit: electrical angle radians)
Where E_N is an arbitrary real number, η is an arbitrary real number, θ is a rotation angle (mechanical angle radians),
When the amplitudes of the fundamental waves of the two-phase output signals Esin and Ecos are set to Esin0 and Ecos0 (unit (V)), the correction means adds the correction amount to the two-phase output signals Esin and Ecos as the correction amount,
Esin0 × E_N × cosη (unit (V)),
-Ecos0 × E_N × sinη (Unit (V))
Are added, respectively. The rotation angle detection device according to claim 1, wherein an angular error N-order component obtained from the two-phase output signals Esin and Ecos is expressed as follows:
ε = E_N × sin (Nθ + η) (Unit: electrical angle radians)
Where E_N is an arbitrary real number, η is an arbitrary real number, θ is a rotation angle (mechanical angle radians),
The amplitudes of the fundamental components of the two-phase output signals Esin and Ecos are Esin0 and Ecos0 (unit is (V)),
When the two-phase output signals Esin and Ecos are normalized by the amplitude of the fundamental component with Esin0 and Ecos0, respectively, the correction means converts the two-phase output signals Esin and Ecos into the correction amounts as
E_N × cosη,
−E_N × sinη
Are added, respectively.   2. The rotation angle detecting device according to claim 1, wherein DC components of the two-phase output signals Esin and Ecos are es and ec (es and ec are arbitrary real numbers), and the two-phase output signals Esin and Ecos When the amplitude of the second harmonic component is es2N and ec2N (es2N and ec2N are arbitrary real numbers) and the phase of the second harmonic component is α2N and β2N (α2N and β2N are arbitrary real numbers), the correction is performed. A rotation angle detection device characterized in that a quantity is calculated from the DC components es, ec, the amplitudes es2N, ec2N, and the phases α2N, β2N. The rotation angle detection device according to claim 1, further comprising a signal processing unit, the signal processing unit having a correction amount output means and a rotation angle calculation means together with the correction means,
A first vector representing an angular error N-order component caused by the DC component of the two-phase output signals Esin and Ecos and an angular error N-order component caused by the second harmonic component of the two-phase output signals Esin and Ecos. When the sum of the vector with the second vector to be represented is the third vector representing the angular error Nth order component,
The correction amount output means obtains an error correction vector for moving the Lissajous center as the correction amount from the fourth vector obtained by inverting the third vector,
The correction means adds the error correction vector to the two-phase output signals Esin and Ecos to correct the Lissajous center,
The rotation angle calculation unit outputs the rotation angle signal based on the two-phase output signals Esin and Ecos added with the error correction vector.   2. The rotation angle detection device according to claim 1, further comprising amplitude correction amount output means for matching the amplitudes of the two-phase output signals Esin and Ecos. A rotating electrical machine apparatus including the rotation angle detecting device according to claim 1, comprising a rotating electrical machine and a controller combined with the rotating electrical machine,
The controller includes the correction unit and a storage device, and drives and controls the rotating electrical machine.
The correction amount that the correction means adds to at least one of the two-phase output signals Esin and Ecos is calculated based on the output signals Esin and Ecos measured in a state where the controller and the rotating electrical machine are combined. ,
The rotating electrical machine apparatus, wherein the storage device stores the correction amount. A rotating electrical machine, a rotational angle detection device that generates a rotational angle signal representing the rotational angle of the rotor of the rotating electrical machine, and a controller that controls the driving of the rotating electrical machine, the rotor of the rotating electrical machine being a steering wheel of a vehicle An electric power steering device for a vehicle coupled to
The rotation angle detection device outputs a rotation angle signal representing a rotation angle of the rotor by using a sinusoidal two-phase output signal having a shaft multiplication angle of N (N is a positive integer) and shifted in phase from each other. A signal processing unit
This signal processing unit, when the two-phase output signal is Esin, Ecos,
As means for canceling the angular error N-order component when the angular error of the mechanical angle of 360 degrees is the primary, a correction amount that is constant with respect to the rotational angle of the rotor is set to at least one of Esin and Ecos. Having correction means for adding,
The correction amount is based on the amplitude and phase of the second harmonic component when the two-phase output signals Esin and Ecos are DC components and the N-order component of the two-phase output signals Esin and Ecos is the fundamental component. Determined,
The controller includes a storage device, and the storage device stores the correction amount.   10. The electric power steering apparatus according to claim 9, wherein the correction amount is stored in the storage device before being assembled to a vehicle.

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