JP2019124670A - Rotation angle detection device, motor control device, electric power steering device, and rotation angle detection method - Google Patents

Abstract

To provide a rotation angle detection device, motor control device, electric power steering device and rotation angle detection method that can maintain high detection accuracy.SOLUTION: On the basis of a maximum value or a minimum value of a first sinusoidal signal serving a differential between a positive phase sinusoidal signal and a reversed phase sinusoidal signal, a second sinusoidal signal is obtained that has a gain of the first sinusoidal signal corrected. On the basis of a maximum value or a minimum value of a first cosine wave signal serving a differential between a positive phase cosine wave signal and a reversed phase cosine wave, a second cosine wave signal is obtained that has a gain of the first cosine wave signal corrected. On he basis of a maximum value or a minimum value of a third sinusoidal signal adding the second cosine wave signal and the second sinusoidal signal, a fourth sinusoidal signal is obtained that has a gain of the third sinusoidal signal corrected. On the basis of a maximum value or a minimum value of a third cosine wave signal subtracting the second sinusoidal signal from the second cosine wave signal, a fourth cosine wave signal is obtained that has a gain of the third cosine wave signal corrected. On the basis of the fourth sinusoidal signal and the fourth cosine wave signal, a rotation angle of a motor is calculated.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a rotation angle detection device, a motor control device, an electric power steering device, and a rotation angle detection method.

  There is a so-called electric power steering (EPS) device that assists steering with a motor in order to reduce the steering force of vehicles such as passenger cars and trucks. The electric power steering apparatus has a steering assist control function of applying an assist steering force generated by a motor to a steering mechanism of a vehicle. In such an electric power steering apparatus, in order to perform current control of a brushless motor, it is necessary to detect the position (rotation angle) of the motor with high accuracy using a sensor. For example, the voltage at the connection point between two series-connected magnetoresistive elements arranged at predetermined intervals in a direction parallel to the rotation axis of the magnetizing rotor in which a plurality of N poles and S poles are alternately arranged on the outer peripheral surface A configuration for performing position detection using a differential output voltage) is disclosed (for example, Patent Document 1).

JP, 2015-87137, A

  When the magnetoresistive element is used as a sensor, a DC offset component is superimposed on the output of the sensor. In addition, a gain error or a phase shift of the sensor may occur due to a mounting error of the rotating magnet or a manufacturing error of the sensor. It is general to perform calibration so as to correct offset voltage, gain error, phase shift and the like before shipping in a state where the sensor is incorporated in the motor. However, the offset voltage or gain error occurring at the output of the sensor changes due to temperature drift and increases as the temperature rises. For this reason, detection accuracy may decrease under temperature conditions different from those at the time of calibration before shipping. In addition, these errors may increase due to the change with time, and the detection accuracy may decrease. In particular, since the magnetoresistive element is a highly sensitive semiconductor element, the output fluctuation due to such temperature characteristics and aging can not be ignored.

  The present invention has been made in view of the above problems, and provides a rotation angle detection device, a motor control device, an electric power steering device, and a rotation angle detection method that can maintain high detection accuracy. It is an object.

  In order to achieve the above object, a rotation angle detection device according to one aspect of the present invention is a differential sine wave signal including a positive phase sine wave signal and a negative phase sine wave signal obtained by inverting the phase of the positive phase sine wave signal. And a position detection sensor that outputs, as a motor position detection signal, a differential cosine wave signal including a positive phase cosine wave signal and an antiphase cosine wave signal obtained by inverting the phase of the positive phase cosine wave signal, and the position detection A position detection unit that detects the position of the motor based on a signal, and the position detection unit outputs a difference between the positive phase sine wave signal and the negative phase sine wave signal as a first sine wave signal A difference calculating unit that outputs a difference between the positive phase cosine wave signal and the negative phase cosine wave signal as a first cosine wave signal; and the first sine based on a maximum value or a minimum value of the first sine wave signal. Output a second sine wave signal with the gain of the wave signal corrected A first gain correction unit that outputs a second cosine wave signal in which a gain of the first cosine wave signal is corrected based on a maximum value or a minimum value of the first cosine wave signal; a second cosine wave signal; A second sine wave signal is added to generate a third sine wave signal, and a gain of the third sine wave signal is corrected based on the maximum value or the minimum value of the third sine wave signal. And outputting a third cosine wave signal by subtracting the second sine wave signal from the second cosine wave signal, and generating the third cosine wave based on the maximum value or the minimum value of the third cosine wave signal. A second gain correction unit that outputs a fourth cosine wave signal obtained by correcting the gain of the signal; and an angle calculation unit that calculates a rotation angle of the motor based on the fourth sine wave signal and the fourth cosine wave signal; Equipped with

  According to the above configuration, calibration of the rotation angle detection device can be performed based on the position detection signal detected in real time. As a result, reduction in detection accuracy due to temperature drift or temporal change can be suppressed, and high detection accuracy can be maintained.

  As a desirable mode of the rotation angle detection device, the maximum value and the minimum value of the first sine wave signal, the maximum value and the minimum value of the first cosine wave signal, the maximum value and the minimum value of the third sine wave signal, and It is preferable to provide a storage unit that stores the maximum value and the minimum value of the third cosine wave signal.

  Thereby, the rotation angle detection process can be performed using the latest data detected in real time.

  As a desirable mode of the rotation angle detection device, the first gain correction unit detects a zero point of the first cosine wave signal, and the value of the first sine wave signal is 0 or more at the time of the zero point detection. When the value of the first sine wave signal is stored in the storage unit as the maximum value of the first sine wave signal, and when the value of the first sine wave signal is less than 0, the value of the first sine wave signal A value is stored in the storage unit as the minimum value of the first sine wave signal, and the zero point of the first sine wave signal is detected, and the value of the first cosine wave signal is zero or more at the time of the zero point detection. When the value of the first cosine wave signal is stored in the storage unit as the maximum value of the first cosine wave signal, and when the value of the first cosine wave signal is less than 0, the first cosine wave Preferably, the value of the signal is stored in the storage unit as the minimum value of the first cosine wave signal. There.

  Thereby, the maximum value or the minimum value of the first sine wave signal for obtaining the second sine wave signal can be obtained in real time. Also, the maximum value or the minimum value of the first cosine wave signal for obtaining the second cosine wave signal can be obtained in real time.

  As a desirable mode of the rotation angle detection device, the storage unit may be configured to set the upper limit value and the lower limit value of the maximum value of the first sine wave signal and the first cosine wave signal, and the first sine wave signal and the first cosine. The upper limit value and the lower limit value of the minimum value of the wave signal are stored, and the first gain correction unit detects the zero point of the first cosine wave signal, and the zero point of the first sine wave signal is detected. When the value is 0 or more, the value of the first sine wave signal is not less than the lower limit value of the maximum value of the first sine wave signal and not more than the upper limit value of the maximum value of the first sine wave signal. In one case, the value of the first sine wave signal is stored as the maximum value of the first sine wave signal in the storage unit, and when the value of the first sine wave signal is less than 0, the first sine wave is stored. The value of the signal is equal to or greater than the lower limit value of the minimum value of the first sine wave signal; The value of the first sine wave signal is stored as the minimum value of the first sine wave signal in the storage unit when the value is equal to or less than the upper limit value of the minimum value of the sine wave signal, and the zero point of the first sine wave signal is stored. When the value of the first cosine wave signal is 0 or more at the time of detecting the zero point, the value of the first cosine wave signal is equal to or more than the lower limit value of the maximum value of the first cosine wave signal. And the value of the first cosine wave signal is stored as the maximum value of the first cosine wave signal in the storage unit when the first cosine wave signal is equal to or less than the upper limit value of the maximum value of the first cosine wave signal; When the value of the 1 cosine wave signal is less than 0, the value of the first cosine wave signal is not less than the lower limit value of the minimum value of the first cosine wave signal, and the minimum value of the first cosine wave signal And storing the value of the first cosine wave signal as the minimum value of the first cosine wave signal when the value is equal to or less than the upper limit value of It is preferably stored in.

  Thereby, the maximum value of the first sine wave signal can be acquired in a state where the value of the first sine wave signal does not deviate from the upper limit value and the lower limit value of the maximum value of the first sine wave signal. In addition, the minimum value of the first sine wave signal can be acquired in a state where the value of the first sine wave signal does not deviate from the upper limit value and the lower limit value of the minimum value of the first sine wave signal. Further, the maximum value of the first cosine wave signal can be obtained in a state where the value of the first cosine wave signal does not deviate from the upper limit value and the lower limit value of the maximum value of the first cosine wave signal. Further, the minimum value of the first cosine wave signal can be obtained in a state where the value of the first cosine wave signal does not deviate from the upper limit value and the lower limit value of the minimum value of the first cosine wave signal. Thus, even when the value of the first sine wave signal or the first cosine wave signal becomes an abnormal value due to noise or the like, the rotation angle detection processing can be performed normally.

  As a desirable mode of the rotation angle detection device, the storage unit is configured to receive an initial value of the maximum value of the first sine wave signal and the first cosine wave signal and a minimum value of the first sine wave signal and the first cosine wave signal. The first gain correction unit further stores the first sine wave when the value of the first sine wave signal is 0 or more at the time of detecting the zero point of the first cosine wave signal. When the value of the signal is less than the lower limit value of the maximum value of the first sine wave signal or larger than the upper limit value of the maximum value of the first sine wave signal, the maximum value of the first sine wave signal The initial value of the value is stored as the maximum value of the first sine wave signal in the storage unit, and when the value of the first sine wave signal is less than 0, the value of the first sine wave signal is the first value. Less than the lower limit value of the minimum value of the sine wave signal, or above the minimum value of the first sine wave signal If larger than the value, the initial value of the minimum value of the first sine wave signal is stored in the storage unit as the minimum value of the first sine wave signal, and the zero point of the first sine wave signal is detected; When the value of the first cosine wave signal is 0 or more, the value of the first cosine wave signal is less than the lower limit value of the maximum value of the first cosine wave signal, or the first cosine wave signal And storing the initial value of the maximum value of the first cosine wave signal as the maximum value of the first cosine wave signal in the storage unit when the value is larger than the upper limit value of the maximum value of the first cosine wave signal; Is less than 0, the value of the first cosine wave signal is less than the lower limit value of the minimum value of the first cosine wave signal, or higher than the upper limit value of the minimum value of the first cosine wave signal When it is large, the initial value of the minimum value of the first cosine wave signal is taken as the minimum value of the first cosine wave signal. It is preferably stored in 憶部.

  Thus, when the value of the first sine wave signal deviates from the upper limit value and the lower limit value of the maximum value of the first sine wave signal, the initial value of the maximum value of the first sine wave signal is set to the first sine wave. It can be applied as the maximum value of the wave signal. When the value of the first sine wave signal deviates from the upper limit value and the lower limit value of the minimum value of the first sine wave signal, the initial value of the minimum value of the first sine wave signal is set to the first sine wave It can be applied as the minimum value of the signal. When the value of the first cosine wave signal deviates from the upper limit value and the lower limit value of the maximum value of the first cosine wave signal, the initial value of the maximum value of the first cosine wave signal is set to the first cosine wave It can be applied as the maximum value of the signal. When the value of the first cosine wave signal deviates from the upper limit value and the lower limit value of the minimum value of the first cosine wave signal, the initial value of the minimum value of the first cosine wave signal is set to the first cosine wave It can be applied as the minimum value of the signal. Thus, even when the value of the first sine wave signal or the first cosine wave signal becomes an abnormal value due to noise or the like, the rotation angle detection processing can be performed normally.

  As a desirable mode of the rotation angle detection device, the second gain correction unit detects a zero point of the third cosine wave signal, and the value of the third sine wave signal is 0 or more at the time of the detection of the zero point. When the value of the third sine wave signal is stored in the storage unit as the maximum value of the third sine wave signal, and when the value of the third sine wave signal is less than 0, the third sine wave signal A value is stored in the storage unit as the minimum value of the third sine wave signal, a zero point of the third sine wave signal is detected, and the value of the third cosine wave signal is zero or more at the time of the zero point detection. And storing the value of the third cosine wave signal as the maximum value of the third cosine wave signal in the storage unit, and when the value of the third cosine wave signal is less than 0, the third cosine wave It is preferable to store the value of the signal in the storage unit as the minimum value of the third cosine wave signal. There.

  Thereby, the maximum value or the minimum value of the third sine wave signal for obtaining the fourth sine wave signal can be obtained in real time. Also, the maximum value or the minimum value of the third cosine wave signal for obtaining the fourth cosine wave signal can be obtained in real time.

  As a desirable mode of the rotation angle detection device, the storage unit may be configured to set the upper limit value and the lower limit value of the maximum value of the third sine wave signal and the third cosine wave signal, and the third sine wave signal and the third cosine wave. The upper limit value and the lower limit value of the minimum value of the wave signal are stored, and the second gain correction unit detects the zero point of the third cosine wave signal, and at the time of the detection of the zero point, the third sine wave signal When the value is 0 or more, the value of the third sine wave signal is not less than the lower limit value of the maximum value of the third sine wave signal, and not more than the upper limit value of the maximum value of the third sine wave signal. In some cases, the value of the third sine wave signal is stored in the storage unit as the maximum value of the third sine wave signal, and the value of the third sine wave signal is less than 0, the third sine wave The value of the signal is equal to or greater than the lower limit value of the minimum value of the third sine wave signal, and the third value The value of the third sine wave signal is stored as the minimum value of the third sine wave signal in the storage unit when the value is equal to or less than the upper limit value of the minimum value of the sine wave signal, and the zero point of the third sine wave signal is stored. Is detected, and the value of the third cosine wave signal is equal to or greater than the lower limit value of the maximum value of the third cosine wave signal when the value of the third cosine wave signal is 0 or more at the time of detecting the zero point. And the value of the third cosine wave signal is stored as the maximum value of the third cosine wave signal in the storage unit when the value of the third cosine wave signal is equal to or less than the upper limit value of the maximum value of the third cosine wave signal; When the value of the 3 cosine wave signal is less than 0, the value of the third cosine wave signal is not less than the lower limit value of the minimum value of the third cosine wave signal, and the minimum value of the third cosine wave signal And storing the value of the third cosine wave signal as the minimum value of the third cosine wave signal when the value is equal to or less than the upper limit value of It is preferably stored in.

  Thus, the maximum value of the third sine wave signal can be obtained in a state where the value of the third sine wave signal does not deviate from the upper limit value and the lower limit value of the maximum value of the third sine wave signal. In addition, the minimum value of the third sine wave signal can be obtained in a state where the value of the third sine wave signal does not deviate from the upper limit value and the lower limit value of the minimum value of the third sine wave signal. Further, the maximum value of the third cosine wave signal can be acquired in a state where the value of the third cosine wave signal does not deviate from the upper limit value and the lower limit value of the maximum value of the third cosine wave signal. Further, the minimum value of the third cosine wave signal can be acquired in a state where the value of the third cosine wave signal does not deviate from the upper limit value and the lower limit value of the minimum value of the third cosine wave signal. Thus, even when the value of the third sine wave signal or the third cosine wave signal becomes an abnormal value due to noise or the like, the rotation angle detection processing can be performed normally.

  As a desirable mode of the rotation angle detection device, the storage unit is configured to receive an initial value of maximum values of the third sine wave signal and the third cosine wave signal, and a minimum value of the third sine wave signal and the third cosine wave signal. And the second gain correction unit, when the zero point of the third cosine wave signal is detected, when the value of the third sine wave signal is 0 or more, the third sine wave is stored. When the value of the signal is less than the lower limit value of the maximum value of the third sine wave signal or larger than the upper limit value of the maximum value of the third sine wave signal, the maximum value of the third sine wave signal The initial value of the value is stored in the storage unit as the maximum value of the third sine wave signal, and when the value of the third sine wave signal is less than 0, the value of the third sine wave signal is the third value. Less than the lower limit value of the minimum value of the sine wave signal, or above the minimum value of the third sine wave signal If larger than the value, the initial value of the minimum value of the third sine wave signal is stored in the storage unit as the minimum value of the third sine wave signal, and the zero point of the third sine wave signal is detected; When the value of the third cosine wave signal is 0 or more, the value of the third cosine wave signal is less than the lower limit value of the maximum value of the third cosine wave signal, or the third cosine wave signal And storing the initial value of the maximum value of the third cosine wave signal as the maximum value of the third cosine wave signal in the storage section when the value is larger than the upper limit value of the maximum value of the third cosine wave signal; Is less than 0, the value of the third cosine wave signal is less than the lower limit value of the minimum value of the third cosine wave signal, or higher than the upper limit value of the minimum value of the third cosine wave signal When it is large, the initial value of the minimum value of the third cosine wave signal is set as the minimum value of the third cosine wave signal. It is preferably stored in 憶部.

  Thus, when the value of the third sine wave signal deviates from the upper limit value and the lower limit value of the maximum value of the third sine wave signal, the initial value of the maximum value of the third sine wave signal is the third sine wave. It can be applied as the maximum value of the wave signal. When the value of the third sine wave signal deviates from the upper limit value and the lower limit value of the minimum value of the third sine wave signal, the initial value of the minimum value of the third sine wave signal is set to the third sine wave It can be applied as the minimum value of the signal. When the value of the third cosine wave signal deviates from the upper limit value and the lower limit value of the maximum value of the third cosine wave signal, the initial value of the maximum value of the third cosine wave signal is set to the third cosine wave It can be applied as the maximum value of the signal. When the value of the third cosine wave signal deviates from the upper limit value and the lower limit value of the minimum value of the third cosine wave signal, the initial value of the minimum value of the third cosine wave signal is set to the third cosine wave It can be applied as the minimum value of the signal. Thus, even when the value of the third sine wave signal or the third cosine wave signal becomes an abnormal value due to noise or the like, the rotation angle detection processing can be performed normally.

As a desirable mode of the rotation angle detection device, when the difference operation unit sets the positive phase sine wave signal as Sinθ ₁ +, the negative phase sine wave signal as Sin θ ₁ −, and the first sine wave signal as Sin θ _1f , The first sine wave signal Sinθ _1f is calculated using the following equation (1), the positive phase cosine wave signal is Cosθ ₁ +, the negative phase cosine wave signal is Cosθ ₁ −, the first cosine wave signal is when the cos [theta] _1f, using the following equation (2), it is preferable to calculate the first cosine wave signal cos [theta] _1f.

Sin θ _1f = (Sin θ ₁ +)-(Sin θ _1- ) (1)

Cos θ _1f = (Cos θ ₁ +) − (Cos θ ₁ −) (2)

  As a result, the first sine wave signal and the first cosine wave signal in which the middle point is zero potential, that is, the offset voltage is removed are obtained.

As a desirable mode of the rotation angle detection device, the first gain correction unit sets the maximum value of the first sine wave signal Sinθ _1f to MAX (Sinθ _1f ), sets the second sine wave signal to Sinθ _1g, and the first sine when the value of the wave signal sin [theta _1f is 0 or more, using the following equation (3), it calculates the second sine-wave signal sin [theta _{1 g,} when the value of the first sine-wave signal sin [theta _1f is less than 0 Preferably, the second sine wave signal Sinθ _{1 g} is calculated using the following equation (4).

Sinθ _1g = Sinθ _1f × (1 / (MAX (Sinθ _1f ))) (3)

Sinθ _1g = Sinθ _1f × ((-1) / (MIN (Sinθ _1f ))) (4)

  Thereby, the second sine wave signal in which the gain of the first sine wave signal is corrected is obtained.

As a desirable mode of the rotation angle detection device, the first gain correction unit may set the maximum value of the first cosine wave signal Cosθ 1 _f to MAX (Cos θ _1f ), the second cosine wave signal to Cos θ _1g, and the first cosine when the value of the wave signal Cos? _1f is 0 or more, using the following equation (5), calculates the second cosine wave signal Cos? _{1 g,} when the value of the first cosine wave signal Cos? _1f is less than 0 It is preferable to calculate the second cosine wave signal Cosθ _{1 g} using the following equation (6).

Cosθ _1g = Cosθ _1f × (1 / (MAX (Cosθ _1f ))) (5)

Cosθ _1g = Cosθ _1f × ((-1) / (MIN (Cosθ _1f ))) (6)

  Thereby, a second cosine wave signal in which the gain of the first cosine wave signal is corrected is obtained.

As a desirable mode of the rotation angle detection device, when the third sine wave signal is V _{C + S} , the second gain correction unit calculates the third sine wave signal V _{C + S} using the following equation (7). When the third cosine wave signal is V _{C -S} , it is preferable to calculate the third cosine wave signal V _{C -S} using the following equation (8).

_{V C + S = Cosθ 1g +} Sinθ 1g ··· (7)

V _C-S = Cosθ _1g- Sinθ _1g (8)

  Thereby, the phase shift of the second sine wave signal and the second cosine wave signal is corrected.

As a desirable mode of the rotation angle detection device, the second gain correction unit may set the maximum value of the third sine wave signal V _{C + S} to MAX (V _{C + S 2} ), the fourth sine wave signal to V 1 _{C + S,} and the third sine wave. When the value of the wave signal V _{C + S} is 0 or more, the fourth sine wave signal V 1 _{C + S} is calculated using the following equation (9), and the value of the third sine wave signal V _{C + S} is less than 0 Preferably, the fourth sine wave signal V1 _{C + S} is calculated using the following equation (10).

V1 _{C + S} = V _{C + S} x (1 / (MAX (V _{C + S} ))) (9)

V1 _{C + S} = V _{C + S} x ((-1) / (MIN (V _{C + S} ))) (10)

  Thereby, the fourth sine wave signal in which the gain of the third sine wave signal is corrected is obtained.

As a desirable mode of the rotation angle detection device, the second gain correction unit may set the maximum value of the third cosine wave signal V _C-S to MAX (V _C-S ) and the fourth cosine wave signal to V 1 _C-S. When the value of the third cosine wave signal V _C-S is 0 or more, the fourth cosine wave signal V 1 _C-S is calculated using the following equation (11), and the third cosine wave signal When the value of V _C-S is less than 0, it is preferable to calculate the fourth cosine wave signal V 1 _C-S using the following equation (12).

V1 _C-S = V _C-S x (1 / (MAX (V _C-S ))) (11)

V1C _-S = VC _-S * ((-1) / (MIN (VC _-S ))) (12)

  Thereby, the fourth cosine wave signal in which the gain of the third cosine wave signal is corrected is obtained.

As a desirable mode of the rotation angle detection device, the angle calculation unit calculates the angle θ _{1 h} using the following equation (13), assuming that the angle within the range of −90 deg <θ _{1 h} <+90 deg is θ _{1 h.} The rotational angle of the motor within the range of 0 deg <θ ₁ <360 deg is θ _1, and the fourth cosine wave signal V 1 _C-S is 0 or more, the motor using the following equation (14) calculating a rotation angle theta ₁ of, when the fourth cosine wave signal V1 _C-S is less than 0, using the following equation (15), it is preferable to calculate the rotation angle theta ₁ of the motor.

θ _1h = arctan (V _{C + S} / V 1 _C-S ) (13)

θ ₁ = θ _{1 h} −45 deg (14)

θ ₁ = (θ _{1 h} +180 deg) −45 deg (15)

  Thereby, the rotation angle of the motor can be advanced by the phase 45 deg delayed by the second gain correction unit.

  In order to achieve the above-mentioned object, a motor control device concerning one mode of the present invention is provided with the above-mentioned rotation angle detection device, and drive-controls the above-mentioned motor using the above-mentioned rotation angle.

  Thereby, the drive control of the motor can be performed with high accuracy.

  In order to achieve the above object, an electric power steering apparatus according to an aspect of the present invention includes the motor control apparatus, wherein the motor is provided on a column axis or a rack of steering, and torque control of steering power of the steering is performed. Do.

  Thus, the accuracy of the steering assist control in the electric power steering apparatus can be enhanced.

  In order to achieve the above object, according to one aspect of the present invention, there is provided a rotation angle detection method comprising: inverting a positive-phase sinusoidal signal and a positive-phase sinusoidal signal output from a position detection sensor as a position detection signal of a motor. A differential sine wave signal including a reversed phase sine wave signal, and a differential cosine wave signal including a positive phase cosine wave signal and an antiphase cosine wave signal obtained by inverting the phase of the positive phase cosine wave signal; A rotation angle detection method for detecting a position of a motor, comprising: setting a difference between the positive phase sine wave signal and the negative phase sine wave signal as a first sine wave signal; and inverting the positive phase cosine wave signal and the reverse phase The second sine wave signal is corrected by correcting the gain of the first sine wave signal based on the step of setting the difference from the cosine wave signal as the first cosine wave signal and the maximum value or the minimum value of the first sine wave signal. And the maximum value or the minimum value of the first cosine wave signal And correcting the gain of the first cosine wave signal to obtain a second cosine wave signal, and adding the second cosine wave signal and the second sine wave signal to generate a third sine wave signal. And subtracting the second sine wave signal from the second cosine wave signal to obtain a third cosine wave signal, and the third sine wave signal based on the maximum value or the minimum value of the third sine wave signal. Correcting the gain of the third cosine wave signal based on the step of correcting the gain of the second sine wave signal and the maximum value or the minimum value of the third cosine wave signal to obtain the fourth cosine wave signal Calculating the rotation angle of the motor based on the fourth sine wave signal and the fourth cosine wave signal.

  Thereby, based on the position detection signal detected in real time, calibration of a rotation angle detection apparatus can be implemented. As a result, reduction in detection accuracy due to temperature drift or temporal change can be suppressed, and high detection accuracy can be maintained.

  According to the present invention, it is possible to provide a rotation angle detection device, a motor control device, an electric power steering device, and a rotation angle detection method capable of maintaining high detection accuracy.

FIG. 1 is a diagram showing the configuration of the electric power steering apparatus according to the first embodiment. FIG. 2 is a schematic view showing a hardware configuration of a control unit that controls the electric power steering apparatus according to the first embodiment. FIG. 3 is a functional block diagram showing a functional configuration of a control unit that controls the electric power steering apparatus according to the first embodiment. FIG. 4 is a schematic view of the position detection sensor in the first embodiment. FIG. 5 is a diagram showing the relationship between the position detection signal and the phase angle. FIG. 6 shows a motor control current when controlling the U-phase current, V-phase current and W-phase current of the 3-phase brushless motor using the electrical angle detected by the position detection unit in the 3-phase brushless motor It is a figure which shows the relationship between and an electrical angle. FIG. 7 is a diagram showing an example of a schematic block configuration of the rotation angle detection device according to the first embodiment. FIG. 8 is a diagram showing an example of an equivalent block of the differential operation unit. FIG. 9 is a first diagram for explaining the concept of difference calculation in the equivalent block shown in FIG. 8 of the differential calculation unit. FIG. 10 is a second diagram for explaining the concept of the difference operation in the equivalent block shown in FIG. 8 of the differential operation unit. FIG. 11 is a third diagram for explaining the concept of the difference operation in the equivalent block shown in FIG. 8 of the differential operation unit. FIG. 12 is a fourth diagram for explaining the concept of difference calculation in the equivalent block shown in FIG. 8 of the differential calculation unit. FIG. 13 is a diagram illustrating an example of an equivalent block of the first gain correction unit. FIG. 14 is a diagram for explaining the detection concept of the maximum value or the minimum value of the first sine wave signal and the first cosine wave signal in the equivalent block shown in FIG. 13 of the first gain correction unit. FIG. 15 is a vector diagram after phase conversion processing when no phase shift occurs in the second sine wave signal and the second cosine wave signal. FIG. 16 is a vector diagram after phase conversion processing when a phase shift of α occurs in the second sine wave signal and the second cosine wave signal. FIG. 17 is a diagram showing an example of an equivalent block of the second gain correction unit. FIG. 18 is a diagram for explaining the detection concept of the maximum value or the minimum value of the third sine wave signal and the third cosine wave signal in the equivalent block shown in FIG. 17 of the second gain correction unit. FIG. 19 is a flowchart illustrating an example of a rotation angle detection processing procedure in the rotation angle detection device according to the first embodiment. FIG. 20 is a flowchart illustrating an example of an interrupt processing procedure for detecting the maximum value or the minimum value of the first sine wave signal in the rotation angle detection device according to the first embodiment. FIG. 21 is a flowchart illustrating an example of an interrupt processing procedure for detecting the maximum value or the minimum value of the first cosine wave signal in the rotation angle detection device according to the first embodiment. FIG. 22 is a flowchart illustrating an example of an interrupt processing procedure for detecting the maximum value or the minimum value of the third sine wave signal in the rotation angle detection device according to the first embodiment. FIG. 23 is a flowchart illustrating an example of an interrupt processing procedure for detecting the maximum value or the minimum value of the third cosine wave signal in the rotation angle detection device according to the first embodiment. FIG. 24 is a diagram showing an example of the upper limit value, the initial value, and the lower limit value of the maximum value of the first sine wave signal and the first cosine wave signal stored in the EEPROM. FIG. 25 is a diagram showing an example of the upper limit value, the initial value, and the lower limit value of the minimum value of the first sine wave signal and the first cosine wave signal stored in the EEPROM. FIG. 26 is a diagram showing an example of the upper limit value, the initial value, and the lower limit value of the maximum values of the third sine wave signal and the third cosine wave signal stored in the EEPROM. FIG. 27 is a diagram showing an example of the upper limit value, the initial value, and the lower limit value of the minimum value of the third sine wave signal and the third cosine wave signal stored in the EEPROM. FIG. 28 is a flowchart illustrating an example of an interrupt processing procedure for detecting the maximum value or the minimum value of the first sine wave signal in the rotation angle detection device according to the second embodiment. FIG. 29 is a flowchart illustrating an example of an interrupt processing procedure for detecting the maximum value or the minimum value of the first cosine wave signal in the rotation angle detection device according to the second embodiment. FIG. 30 is a flowchart illustrating an example of an interrupt processing procedure for detecting the maximum value or the minimum value of the third sine wave signal in the rotation angle detection device according to the second embodiment. FIG. 31 is a flowchart illustrating an example of an interrupt processing procedure for detecting the maximum value or the minimum value of the third cosine wave signal in the rotation angle detection device according to the second embodiment. FIG. 32 is a flowchart illustrating an example of an interrupt processing procedure for detecting the maximum value or the minimum value of the first sine wave signal in the rotation angle detection device according to the modification of the second embodiment. FIG. 33 is a flowchart illustrating an example of an interrupt processing procedure for detecting the maximum value or the minimum value of the first cosine wave signal in the rotation angle detection device according to the modification of the second embodiment. FIG. 34 is a flowchart showing an example of an interrupt processing procedure for detecting the maximum value or the minimum value of the third sine wave signal in the rotation angle detection device according to the modification of the second embodiment. FIG. 35 is a flowchart illustrating an example of an interrupt processing procedure for detecting the maximum value or the minimum value of the third cosine wave signal in the rotation angle detection device according to the modification of the second embodiment.

  Hereinafter, modes for carrying out the invention (hereinafter referred to as embodiments) will be described in detail with reference to the drawings. Note that the present invention is not limited by the following embodiments. Further, constituent elements in the following embodiments include those which can be easily conceived by those skilled in the art, substantially the same ones, and so-called equivalent ranges. Furthermore, the components disclosed in the following embodiments can be combined as appropriate.

(Embodiment 1)
FIG. 1 is a diagram showing the configuration of the electric power steering apparatus according to the first embodiment. The electric power steering apparatus 100 has a motor 20 for applying an auxiliary steering force to a steering mechanism of a vehicle, and controls driving of the motor 20 based on a steering assist command value calculated using at least a steering torque and a vehicle speed for the steering mechanism. Do.

  As described above, the electric power steering apparatus 100 is mounted on a vehicle to assist the driver of the vehicle to operate the steering wheel 1 (hereinafter, also referred to as “steering”). A column shaft 2 of the steering wheel 1 is connected to a tie rod 6 of a steered wheel via a reduction gear 3, universal joints 4 a and 4 b, and a rack and pinion mechanism 5. The column shaft 2 is provided with a torque sensor 10 for detecting the steering torque T of the steering wheel 1. Further, a reduction gear 3 is attached to the column shaft 2. The reduction gear 3 increases the torque generated by the motor 20 and transmits it to the column shaft 2. With such a structure, the steering force of the steering wheel 1 is assisted by the torque generated by the motor 20.

  In the present embodiment, the electric power steering apparatus 100 is a column assist type apparatus that transmits the torque of the motor 20 to the column shaft 2.

  The motor 20 is, for example, a brushless motor. An ECU (Electronic Control Unit, hereinafter referred to as a control unit) 30 for controlling the electric power steering apparatus 100 receives supply of power from the battery 14 via a power supply relay 13 built therein, and is transmitted from the ignition switch 11 Receive an ignition signal. The control unit 30 also calculates a current command value of the motor 20 based on the steering torque T detected by the torque sensor 10 and the vehicle speed (vehicle speed) V detected by the vehicle speed sensor 12. The control unit 30 drives and controls the motor 20 based on the value (current detection value) of the current supplied to the motor 20 and the current command value so that the current detection value of the motor 20 follows the current command value. As described above, the control unit 30 is a device that controls the electric power steering device 100 (a control device of the electric power steering device).

  FIG. 2 is a schematic view showing a hardware configuration of a control unit that controls the electric power steering apparatus according to the first embodiment. As shown in FIG. 2, the control unit 30 includes a power supply relay 13, a control computer (MCU) 110, a motor drive circuit 15, a motor current detection circuit 16, a position detection unit 17 and the like. A control computer 110 of the electric power steering apparatus 100 includes a central processing unit (CPU) 101, a random access memory (RAM) 102 as a first storage device, a read only memory (ROM) 103 as a second storage device, and an EEPROM (read only memory). An Electrically Erasable Programmable ROM (ROM) 104, an interface (I / F) 105, an A / D (Analog / Digital) converter 106, a PWM (Pulse Width Modulation) controller 107, and the like are connected to the bus 108. The CPU 101 corresponds to a processing device and executes the computer program for control of the electric power steering apparatus 100 stored in the ROM 103 (hereinafter referred to as a control program) to control the electric power steering apparatus 100.

  The ROM 103 stores control programs and data used to control the electric power steering apparatus 100. The RAM 102 is also used as a work memory for operating the control program. The EEPROM 104 stores control data and the like input and output by the control program. The control data is used on the control program developed in the RAM 102 after the control unit 30 is powered on, and is overwritten on the EEPROM 104 at a predetermined timing.

  The ROM 103, the RAM 102, the EEPROM 104, and the like are storage devices for storing information, and are storage devices (primary storage devices) to which the CPU 101 can directly access.

  In the present embodiment, the EEPROM 104 functions as a first storage unit that stores initial values of various data in rotation angle detection processing described later.

  Further, in the present embodiment, the RAM 102 functions as a second storage unit that stores update values of various data in a rotation angle detection process described later.

A / D converter 106, inputs the steering torque T, the rotation angle theta ₁ of the signal of the motor 20 from the current detection value Im and the position detection unit 17 of the motor 20 from the motor current detecting circuit 16 and the like from the torque sensor 10 And convert it into a digital signal. The interface 105 is connected to an in-vehicle network such as a CAN (Controller Area Network). The interface 105 is for receiving a signal (vehicle speed pulse) of the vehicle speed V from the vehicle speed sensor 12.

  The PWM controller 107 outputs a PWM control signal of each phase of UVW based on the current command value to the motor 20. The motor drive circuit 15 is configured by an inverter circuit or the like, and drives the motor 20 based on a signal output from the PWM controller 107. The motor current detection circuit 16 detects the value (current detection value) Im of the current supplied to the motor 20 and outputs it to the A / D converter 106.

Position detecting section 17, the position detection signal output from the position detection sensor 25, performs a rotation angle detection process for obtaining the rotation angle theta ₁ of the motor 20, and outputs it to the A / D converter 106. In the present embodiment, the position detection unit 17 corrects the position detection signal output from the position detection sensor 25 and performs rotation angle detection processing based on the corrected signal. The position detection unit 17 may be configured as a circuit, or may be implemented as the control computer 110 shown in FIG. 2, more specifically, the CPU 101. Details of the correction method of the position detection signal in the position sensor 25 and the position detection unit 17 will be described later.

  FIG. 3 is a functional block diagram showing a functional configuration of a control unit that controls the electric power steering apparatus according to the first embodiment. Control of the electric power steering apparatus 100 will be described with reference to FIG. As shown in FIG. 3, the control unit 30 has an assist function unit 31.

The assist function unit 31 has a current command value calculation unit 31a and a current control unit 31b. The current command value calculation unit 31a calculates a current command value I corresponding to the steering torque T and the vehicle speed V. The current control unit 31b, based on the electrical angle theta ₂ of the motor 20 output from the position detection unit 17, so that the deviation between the current command value I and the current detection value Im approaches zero, proportional control and differential control and integral At least one of the control is performed, and the duty ratio D of the gate drive signal of the motor drive circuit 15 is calculated so that the current Im controlled to approach the current command value I is generated. The motor drive circuit 15 outputs, to the motor 20, a current subjected to PWM control in accordance with the duty ratio D calculated by the current control unit 31b. The motor current detection circuit 16 detects the current Im flowing in the motor 20.

  The assist function unit 31 shown in FIG. 3 is realized by the control computer 110 shown in FIG. 2, more specifically, the CPU 101. The position detection unit 17 will be described later.

  FIG. 4 is a schematic view of the position detection sensor in the first embodiment. In the present embodiment, as shown in FIG. 4, the position detection sensor 25 is a one-pole rotating magnet 251 comprising an N pole and an S pole provided at the end of a motor shaft (rotating shaft) 20a; And an MR sensor 252 disposed with an air gap at a predetermined interval in the axial direction (direction of the axis X of the motor shaft (rotational shaft) 20a) from the point 251.

  The MR sensor 252 is configured using an MR (Magneto Resistance) element (a magnetoresistive element). An example of the MR sensor 252 is a TMR sensor using a tunnel magnetoresistive effect (Tunnel Magneto Resistance Effect). The MR sensor 252 may be an AMR (Anisotropic Magneto Resistive) sensor or a GMR (Giant Magnetoresistance Effect) sensor other than a TMR sensor. The present disclosure is not limited by the type of the MR sensor 252.

  The MR sensor 252 outputs a position detection signal according to the change of the magnetic field generated when the rotary magnet 251 rotates around the axial center X of the motor shaft (rotational shaft) 20a together with the motor shaft (rotational shaft) 20a.

In the present embodiment, the MR sensor 252 outputs a differential sine wave signal and a differential cosine wave signal, which are analog signals, as a position detection signal. Differential sinusoidal signal, a positive-phase sine wave signal sin [theta ₁ +, the positive phase sine wave signal sin [theta ₁ + phase inverted reverse-phase sine wave signal sin [theta ₁ - and a. Differential cosine wave signal, the positive-phase cosine wave signal Cos? ₁ +, the positive phase cosine wave signal Cos? ₁ + phase inverted reverse-phase cosine wave signal Cos? ₁ - and a.

FIG. 5 is a diagram showing the relationship between the position detection signal and the phase angle. (A) shown in FIG. 5 shows an ideal waveform of the positive phase sine wave signal Sinθ ₁ +, and (b) shown in FIG. 5 shows an ideal waveform of the antiphase sine wave signal Sinθ ₁ − There is. Also, (c) shown in FIG. 5 shows an ideal waveform of the positive phase cosine wave signal Cosθ ₁ +, and (d) shown in FIG. 5 shows an ideal waveform of the negative phase cosine wave signal Cosθ ₁ − It shows. Also, shown in FIG. 5 (e) shows the rotation angle (mechanical angle) theta ₁ of the motor 20.

As shown in FIG. 5, in the present embodiment, since the number of poles of the rotating magnet 251 is 1, and 1 cycle Tm of mechanical angle theta ₁ of the motor 20, and one period Te of the electrical angle of the MR sensor 252 matches Do. That, MR sensor 252 shown in Figure 4, in one cycle Tm of mechanical angle theta ₁ of the motor 20, to detect one cycle Te of the electrical angle of the MR sensor 252. The position detecting sensor 25, if the output can be a differential sine wave signal and the differential cosine wave signal is not limited to the above-described configuration, for example, one period Tm of mechanical angle theta ₁ of the motor 20 On the other hand, a configuration capable of outputting a differential sine wave signal and a differential cosine wave signal for a plurality of periods in electrical angle may be employed.

  FIG. 6 shows a motor control current when controlling the U-phase current, V-phase current and W-phase current of the 3-phase brushless motor using the electrical angle detected by the position detection unit in the 3-phase brushless motor It is a figure which shows the relationship between and an electrical angle.

  As shown in FIG. 6, the U-phase current, the V-phase current, and the W-phase current of the three-phase brushless motor have waveforms which are 120 degrees out of phase with each other.

  The current control unit 31 b of the assist function unit 31 performs current control of the motor 20 using the electrical angle detected by the position detection unit 17. The example shown in FIG. 6 shows an example in which 0 [deg] of the electrical angle is set as the current control start position, and control is performed so that the phase of the U phase becomes 0 [deg].

  In current control of the motor 20, an electrical angle is required for each of the magnetic pole pairs of the motor 20. When the number of magnetic poles of the motor 20 is 4, the position detection unit 17 divides the rotation angle of the motor 20 into an electrical angle corresponding to the number of magnetic poles of the motor 20 and outputs it to the current control unit 31b of the assist function unit 31. Do.

  FIG. 7 is a diagram showing an example of a schematic block configuration of the rotation angle detection device according to the first embodiment. As shown in FIG. 7, the rotation angle detection device 200 according to the first embodiment includes a position detection sensor 25 and a position detection unit 17.

  As shown in FIG. 7, in the present embodiment, the position detection unit 17 includes a difference calculation unit 171, a first gain correction unit 172, a second gain correction unit 173, and an angle calculation unit 174. .

  The difference calculation unit 171 includes a sine wave difference calculation unit 1711 and a cosine wave difference calculation unit 1712.

The sine wave difference calculation unit 1711 calculates a difference between the positive phase sine wave signal Sinθ ₁ + and the negative phase sine wave signal Sinθ ₁ − to output a first sine wave signal Sinθ 1 _f .

The cosine wave difference calculation unit 1712 calculates a difference between the positive phase cosine wave signal Cosθ ₁ + and the negative phase cosine wave signal Cosθ ₁ − to output a first cosine wave signal Cosθ _1f .

  The differential computing unit 171 receives differential sine wave signals and differential cosine wave signals of discrete values obtained by sampling and processing A / D converted differential sine wave signals and differential cosine wave signals as analog signals. Ru.

  FIG. 8 is a diagram showing an example of an equivalent block of the differential operation unit. FIG. 9 is a first diagram for explaining the concept of difference calculation in the equivalent block shown in FIG. 8 of the differential calculation unit. FIG. 10 is a second diagram for explaining the concept of the difference operation in the equivalent block shown in FIG. 8 of the differential operation unit. FIG. 11 is a third diagram for explaining the concept of the difference operation in the equivalent block shown in FIG. 8 of the differential operation unit. FIG. 12 is a fourth diagram for explaining the concept of difference calculation in the equivalent block shown in FIG. 8 of the differential calculation unit.

As shown in FIG. 9, the positive phase sine wave signal which is a differential sinusoidal signal sin [theta ₁ + and the negative phase sine wave signal sin [theta ₁ -, the offset voltage _{Dif Sin1} is superimposed. Further, as shown in FIG. 10, the offset voltage Dif _Cos1 is superimposed on the positive phase cosine wave signal Cosθ ₁ + and the negative phase cosine wave signal Cos θ ₁ − which are differential cosine wave signals.

Offset voltage _{Dif Sin1,} as shown in the following equation (1), positive-phase sine wave signal sin [theta ₁ + and the negative-phase sine wave signal sin [theta ₁ - is represented by the half of the value obtained by adding the.

_{(Dif Sin1) = ((Sinθ} 1 +) + (Sinθ 1 -)) / 2 ··· (1)

On the other hand, the offset voltage _Dif positive phase sine wave signal sin [theta _1d + is obtained by subtracting the _Sin1, represented by the following equation (2), reversed-phase sine wave signal sin [theta _1d obtained by subtracting the offset voltage _{Dif Sin1} - the following (3) It can be expressed by a formula.

_{(Sinθ 1d +) = (Sinθ} 1 +) - Dif Sin1 ··· (2)

_{(Sinθ 1d -) = (Sinθ} 1 -) - Dif Sin1 ··· (3)

  Substituting the above equation (1) into the equations (2) and (3), the following equations (4) and (5) are obtained.

(Sinθ _1d +) = (Sinθ ₁ +) / 2− (Sinθ ₁ −) / 2 (4)

(Sinθ _1d −) = − ((Sinθ ₁ +) / 2− (Sinθ ₁ −) / 2) (5)

Assuming that the first sine wave signal Sinθ _1f = (Sinθ _1d +) = (− (Sinθ _1d −)) with the positive phase sine wave signal Sinθ _1d + as a reference, and the equation (5) is subtracted from the equation (4), The following equation (6) is obtained.

(Sinθ _1f ) × 2 = (Sinθ ₁ +) − (Sinθ ₁ −) (6)

Further, the offset voltage Dif _Cos1 is represented by a half value of a value obtained by adding the positive phase cosine wave signal Cosθ ₁ + and the negative phase cosine wave signal Cosθ ₁ − as shown in the following equation (7).

_{(Dif Cos1) = ((Cosθ} 1 +) + (Cosθ 1 -)) / 2 ··· (7)

On the other hand, the offset voltage _Dif positive phase sine wave signal Cos? _1d + is obtained by subtracting the _{Cos 1,} represented by the following equation (8), reversed-phase cosine wave signal Cos? _1d obtained by subtracting the offset voltage _{Dif Cos 1} - the following (9) It can be expressed by a formula.

(Cos θ _1d +) = (Cos θ ₁ +) − Dif _{Cos 1} (8)

(Cos θ _1d −) = (Cos θ ₁ −) − Dif _{Cos 1} (9)

  By substituting the equation (7) into the equations (8) and (9), the following equations (10) and (11) are obtained.

(Cosθ _1d +) = (Cosθ ₁ +) / 2− (Cosθ ₁ −) / 2 (10)

(Cosθ _1d −) = − ((Cosθ ₁ +) / 2− (Cosθ ₁ −) / 2) (11)

Assuming that the first cosine wave signal Cosθ _1f = (Cosθ _1d +) = (− (Cosθ _1d −)) with the positive phase cosine wave signal Cosθ _1d + as a reference, and the equation (11) is subtracted from the equation (10), The following equation (12) is obtained.

(Cosθ _1f ) × 2 = (Cosθ ₁ +) − (Cosθ ₁ −) (12)

In this embodiment, when the differential sine wave signal and the differential cosine wave signal are sampled, the positive phase sine wave signal Sinθ ₁ + and the negative phase sine wave signal Sinθ ₁ −, which are differential sine wave signals, are differentially processed. The positive phase cosine wave signal Cosθ ₁ + and the negative phase cosine wave signal Cosθ ₁ − which are cosine wave signals are acquired with a resolution of 2 times. Thereby, the first sine wave signal Sinθ _1f is obtained by subtracting the antiphase sine wave signal Sinθ ₁ − from the positive phase sine wave signal Sinθ ₁ + using the following equation (6 ′) (see FIG. 11). ). Further, the first cosine wave signal Cosθ 1 _f is obtained by subtracting the antiphase cosine wave signal Cosθ ₁ − from the positive phase cosine wave signal Cosθ ₁ + using the following equation (12 ′) (see FIG. 12) .

Sin θ _1f = (Sin θ ₁ +)-(Sin θ _1- ) (6 ')

Cos θ _1f = (Cos θ ₁ +) − (Cos θ ₁ −) (12 ′)

Thus, zero potential midpoint, i.e., the first sine-wave signal sin [theta _1f and the first cosine wave signal Cos? _1f the offset voltage is removed can be obtained.

  The first gain correction unit 172 includes a first sine wave gain correction unit 1721 and a first cosine wave gain correction unit 1722.

The first sine wave gain correction unit 1721 outputs the second sine-wave signal sin [theta _{1 g} obtained by correcting the gain of the first sine-wave signal sin [theta _1f.

First cosine-wave gain correction unit 1722 outputs the second cosine wave signal Cos? _{1 g} obtained by correcting the gain of the first cosine wave signal Cos? _1f.

  FIG. 13 is a diagram illustrating an example of an equivalent block of the first gain correction unit. FIG. 14 is a diagram for explaining the detection concept of the maximum value or the minimum value of the first sine wave signal and the first cosine wave signal in the equivalent block shown in FIG. 13 of the first gain correction unit.

The first gain correction portion 172 detects the zero point of the first cosine wave signal Cos? _1f first cosine wave signal Cos? _1f is zero potential.

The first sine wave gain correction unit 1721, when the value of the first sine-wave signal sin [theta _1f at the zero point detection of the first cosine wave signal Cos? _1f is 0 or more (sin [theta _1f ≧ 0), the first sine wave the value of the signal sin [theta _1f detects the maximum value MAX of the first sine-wave signal Sinθ _1f (Sinθ _1f), the value of the first sine-wave signal sin [theta _1f at the zero point detection of the first cosine wave signal Cos? _1f is less than 0 when a (Sinθ _1f <0), to detect the value of the first sine-wave signal sin [theta _1f as the minimum value MIN of the first sine-wave signal Sinθ _1f (Sinθ _1f) (see FIG. 14).

The first sine wave gain correction unit 1721 performs gain correction of the first sine wave signal Sinθ _1f using the following equations (13) and (14), and the sine wave signal Sinθ _1g U and the sine wave signal Sinθ _1g L Ask for

Sin θ _1g U = Sin θ _1f × (1 / (MAX (Sin θ _1f ))) (13)

Sin θ _1g L = Sin θ _1f × ((-1) / (MIN (Sin θ _1f ))) (14)

The first sine wave gain correction unit 1721, when the value of the first sine-wave signal sin [theta _1f is greater than or equal to 0, the sine wave signal sin [theta _{1 g} U and the second sine-wave signal sin [theta _{1 g,} the first sine-wave signal sin [theta _When the value of _1f is less than 0, the sine wave signal Sinθ _1g L is set as the second sine wave signal Sinθ _1g .

That is, when the value of the first sine wave signal Sinθ _1f is 0 or more, the first sine wave gain correction unit 1721 calculates the second sine wave signal Sinθ _1g using the following equation (13 ′), when the value of the first sine-wave signal sin [theta _1f is less than 0, with (14 ') below, it calculates a second sine-wave signal sin [theta _{1 g.}

Sinθ _1g = Sinθ _1f × (1 / (MAX (Sinθ _1f ))) (13 ')

Sinθ _1g = Sinθ _1f × ((-1) / (MIN (Sinθ _1f ))) (14 ')

Thus, the second sine-wave signal sin [theta _{1 g} the gain of the first sine-wave signal sin [theta _1f is corrected is obtained.

The first gain correction portion 172 detects the zero point of the first sine-wave signal sin [theta _1f first sine-wave signal sin [theta _1f becomes zero potential.

First cosine-wave gain correction unit 1722, when the value of the first cosine wave signal Cos? _1f at the zero point detection of the first sine-wave signal sin [theta _1f is 0 or more (Cos? _1f ≧ 0), the first cosine wave the value of the signal Cos? _1f detects the maximum value MAX of the first cosine wave signal Cosθ _1f (Cosθ _1f), the value of the first cosine wave signal Cos? _1f at the zero point detection of the first sine-wave signal sin [theta _1f is less than 0 when a (Cosθ _1f <0), to detect the value of the first cosine wave signal Cos? _1f as the minimum value MIN of the first cosine wave signal Cosθ _1f (Cosθ _1f) (see FIG. 14).

The first cosine wave gain correction unit 1722 performs gain correction of the first cosine wave signal Cosθ _1f using the following equations (15) and (16), and the cosine wave signal Cosθ _1g U and the cosine wave signal Cosθ _1g L Ask for

Cos θ _{1 g} U = Cos θ _{1 f} × (1 / (MAX (Cos θ 1 _f ))) (15)

Cos θ _{1 g} L = Cos θ _{1 f} × ((-1) / (MIN (Cos θ 1 _f ))) (16)

The first cosine wave gain correction unit 1722, when the value of the first cosine wave signal Cos? _1f is greater than or equal to 0, the cosine wave signal Cos? _{1 g} U as the second cosine wave signal Cos? _{1 g,} the first cosine wave signal Cos? _When the value of _1f is less than 0, the cosine wave signal Cosθ _1g L is set as the second cosine wave signal Cosθ _1g .

That is, when the value of the first cosine wave signal Cosθ _1f is 0 or more, the first cosine wave gain correction unit 1722 calculates the second cosine wave signal Cosθ _1g using the following equation (15 ′), when the value of the first cosine wave signal Cos? _1f is less than 0, with (16 ') below, calculates a second cosine wave signal Cos? _{1 g.}

Cosθ _1g = Cosθ _1f × (1 / (MAX (Cosθ _1f ))) (15 ')

Cosθ _1g = Cosθ _1f × ((-1) / (MIN (Cosθ _1f ))) (16 ')

Thus, the second cosine wave signal Cos? _{1 g} the gain of the first cosine wave signal Cos? _1f is corrected is obtained.

  The second gain correction unit 173 includes a second sine wave gain correction unit 1731, a second cosine wave gain correction unit 1732, and a phase conversion unit 1733.

The phase conversion unit 1733 calculates the third sine wave signal V _{C + S} obtained by phase-converting the second sine wave signal Sinθ _1g using the following equation (17), and uses the following equation (18) to obtain the second cosine wave A third cosine wave signal V _C-S obtained by phase-converting the signal Cosθ _{1 g} is calculated.

_{V C + S = Cosθ 1g +} Sinθ 1g ··· (17)

V _C-S = Cosθ _1g- Sinθ _1g (18)

  FIG. 15 is a vector diagram after phase conversion processing when no phase shift occurs in the second sine wave signal and the second cosine wave signal. FIG. 16 is a vector diagram after phase conversion processing when a phase shift of α occurs in the second sine wave signal and the second cosine wave signal.

When a phase shift of α occurs between the second sine wave signal Sinθ _1g and the second cosine wave signal Cosθ _1g , as shown in FIG. 16, the third sine wave signal V _{C + S} becomes the second sine wave signal Sinθ _1g . On the other hand, the + 45- (α / 2) deg phase is delayed, and the third cosine wave signal V _{C -S} is delayed +45+ (α / 2) deg phase with respect to the second cosine wave signal Cos θ _{1 g} . That is, the third sine wave signal V _{C + S} and the third cosine wave signal V _C-S have a phase difference of 90 degrees.

As shown in FIG. 15, when the phase shift does not occur in the second sine-wave signal sin [theta _{1 g} and the second cosine wave signal Cos? _{1 g,} the above equation (17) of the vector (Cos? _{1 g} + sin [theta _{1 g),} above It equals equation (18) the magnitude of the vector (Cos? _{1 g} -sin _{1 g)} of.

On the other hand, as shown in FIG. 16, when occurring a phase shift of α to the second sine-wave signal sin [theta _{1 g} and the second cosine wave signal Cos? _{1 g,} the above equation (17) of the vector (Cos? _{1 g} + sin [theta _{1 g} ) Becomes larger than the vector (Cosθ _1g −Sinθ _1g ) of the above equation (18).

In this embodiment, gain correction is performed on the third sine wave signal V _{C + S} that is the result of the above equation (17) and the third cosine wave signal V _C-S that is the result of the above equation (18). By doing this, the vectors of the fourth sine wave signal V1 _{C + S} after gain correction and the vectors of the fourth cosine wave signal V1 _C-S are corrected to be equal.

Thereby, the phase shift α of the second sine wave signal Sinθ _{1 g} and the second cosine wave signal Cos θ _{1 g} is corrected.

The second sine wave gain correction unit 1731 outputs a fourth sine wave signal V1 _{C + S} obtained by correcting the gain of the third sine wave signal V _{C + S.}

The second cosine wave gain correction unit 1732 outputs a fourth cosine wave signal V1 _C-S obtained by correcting the gain of the third cosine wave signal V _C-S .

  FIG. 17 is a diagram showing an example of an equivalent block of the second gain correction unit. FIG. 18 is a diagram for explaining the detection concept of the maximum value or the minimum value of the third sine wave signal and the third cosine wave signal in the equivalent block shown in FIG. 17 of the second gain correction unit.

The second gain correction unit 173 detects the zero point of the third cosine wave signal V _C-S in which the third cosine wave signal V _C-S becomes zero potential.

The second sine wave gain correction unit 1731, when the value of the third sinusoidal signal _{V C + S} at the zero point detection of the third cosine wave signal _{V C-S} is 0 or more _{(V C + S ≧ 0)} , the third detecting the value of the sine wave signal _{V C + S} as the maximum value MAX of the third sinusoidal signal _{V C + S (V C +} S), the third sinusoidal signal _{V C + S} at the zero point detection of the third cosine wave signal _{V C-S} when the value is less than _{0 (V C + S <0} ), to detect the value of the third sine wave signal _{V C + S} as the minimum value MIN of the third sinusoidal signal _{V C + S (V C +} S) ( see Figure 18).

The second sine wave gain correction unit 1731 performs gain correction of the third sine wave signal V _{C + S} using the following equations (19) and (20), and the sine wave signal V 1 _{C + S} U and the sine wave signal V 1 _{C + S} L Ask for

V1 _{C + S} U = V _{C + S} × (1 / (MAX (V _{C + S} ))) (19)

V1 _{C + S} L = V _{C + S} * ((-1) / (MIN (V _{C + S} ))) (20)

Then, when the value of the third sine wave signal V _{C + S} is 0 or more, the second sine wave gain correction unit 1731 sets the sine wave signal V _{1 C + S} U as the fourth sine wave signal V 1 _{C + S,} and the third sine wave signal V _When the value of _{C + S} is less than 0, the sine wave signal V1 _{C +} SL is set as the fourth sine wave signal V1 _{C + S.}

That is, when the value of the third sine wave signal V _{C + S} is 0 or more, the second sine wave gain correction unit 1731 calculates the fourth sine wave signal V 1 _{C + S} using the following equation (19 ′), When the value of the third sine wave signal V _{C + S} is less than 0, the fourth sine wave signal V 1 _{C + S} is calculated using the following equation (20 ′).

V1 _{C + S} = V _{C + S} x (1 / (MAX (V _{C + S} ))) (19 ')

V1 _{C + S} = V _{C + S} x ((-1) / (MIN (V _{C + S} ))) (20 ')

Thereby, the fourth sine wave signal V1 _{C + S} in which the gain of the third sine wave signal V _{C + S} is corrected is obtained.

The second gain correction unit 173 detects the zero point of the third sinusoidal signal V _{C + S} of the third sinusoidal signal V _{C + S} becomes zero potential.

When the value of the third cosine wave signal V _C-S at the time of detecting the zero point of the third sine wave signal V _{C + S} is 0 or more (V _{C -S} 00), the second cosine wave gain correction unit 1732 is relevant. third detects the value of the cosine wave signal _{V C-S} as the maximum value MAX of the third cosine wave signal _{V C-S (V C-} S), the third at the zero point detection of the third sinusoidal signal _{V C + S} when the value of the cosine wave signal _{V C-S} is less than _{0 (V C-S <0} ), the minimum value MIN of values of the third cosine wave signal _{V C-S} third cosine wave signal _{V C-S} It is detected as (V _C−S ) (see FIG. 18).

The second cosine wave gain correction unit 1732 performs gain correction of the third cosine wave signal V _C-S using the following equations (21) and (22), and the cosine wave signal V 1 _C-S U and the cosine wave The signals V1 _C-S L are determined.

V1 _C-S U = V _C-S x (1 / (MAX (V _C-S ))) (21)

V1 _C-S L = V _C-S x ((-1) / (MIN (V _C-S ))) (22)

Then, when the value of the third cosine wave signal V _C-S is 0 or more, the second cosine wave gain correction unit 1732 sets the cosine wave signal V 1 _C-S U as the fourth cosine wave signal V 1 _C-S , When the value of the third cosine wave signal V _C-S is less than 0, the cosine wave signal V 1 _C-S L is made the fourth cosine wave signal V 1 _C-S .

That is, when the value of the third cosine wave signal V _C-S is 0 or more, the second cosine wave gain correction unit 1732 uses the following equation (21 ') to calculate the fourth cosine wave signal V 1 _C-S When the value of the third cosine wave signal V _C-S is less than 0, the fourth cosine wave signal V 1 _C-S is calculated using the following equation (22 ′).

V1 _C-S = V _C-S x (1 / (MAX (V _C-S ))) (21 ')

V1C _-S = VC _-S * ((-1) / (MIN (VC _-S ))) (22 ')

Thereby, the fourth cosine wave signal V1 _C-S in which the gain of the third cosine wave signal V _C-S is corrected is obtained.

  The angle calculation unit 174 includes an arctangent calculation unit 1741, a quadrant determination unit 1742, and a motor electrical angle calculation unit 1743.

The arctangent calculation unit 1741 calculates an angle θ _{1 h} within a range of −90 deg <θ _{1 h} <+90 deg using the following equation (23).

θ _{1 h} = arctan (V _{1 C + S} / V 1 _C−S ) (23)

Quadrant determination unit 1742, converts the angle theta _1h within the scope of -90deg <θ _1h <+ 90deg calculated by arctangent calculation unit 1741, the rotation angle theta ₁ of the motor 20 in the 0 deg <theta ₁ <range of 360deg Do. Further, the quadrant determination unit 1742 causes the second gain correction unit 173 to advance the phase 45 deg delayed.

When the fourth cosine wave signal V1 _C-S is 0 or more (V1 _C-S 0 0), the quadrant determining unit 1742 uses the following equation (24) to determine that the motor within the range of 0 deg <θ ₁ <360 deg. It calculates a rotation angle theta ₁ of 20.

θ ₁ = θ _{1 h} −45 deg (24)

In addition, when the fourth cosine wave signal V1 _C-S is less than 0 (V1 _C-S <0), the quadrant determining unit 1742 uses the following equation (25) to satisfy 0 deg <θ ₁ <360 deg. The rotation angle θ ₁ of the motor 20 at ₁ is calculated.

θ ₁ = (θ _{1 h} +180 deg) −45 deg (25)

Motor electric angle calculating unit 1743, based on the rotational angle theta ₁ of the motor 20 calculated by the quadrant determining unit 1742, calculates the electric angle theta ₂ which corresponds to the magnetic pole logarithm of the motor 20. If the pole logarithm of the motor 20 is four, the rotation angle theta ₁ 4 divided and calculates an electrical angle theta ₂ of the 4 cycles.

  Next, rotation angle detection processing in the rotation angle detection device 200 according to the present embodiment will be described. FIG. 19 is a flowchart illustrating an example of a rotation angle detection processing procedure in the rotation angle detection device according to the first embodiment. FIG. 20 is a flowchart illustrating an example of an interrupt processing procedure for detecting the maximum value or the minimum value of the first sine wave signal in the rotation angle detection device according to the first embodiment. FIG. 21 is a flowchart illustrating an example of an interrupt processing procedure for detecting the maximum value or the minimum value of the first cosine wave signal in the rotation angle detection device according to the first embodiment. FIG. 22 is a flowchart illustrating an example of an interrupt processing procedure for detecting the maximum value or the minimum value of the third sine wave signal in the rotation angle detection device according to the first embodiment. FIG. 23 is a flowchart illustrating an example of an interrupt processing procedure for detecting the maximum value or the minimum value of the third cosine wave signal in the rotation angle detection device according to the first embodiment.

  In the present embodiment, calibration of the rotation angle detection device 200 is performed in real time at the time of actual operation in which the vehicle is actually driven. As a result, reduction in detection accuracy due to temperature drift or temporal change can be suppressed, and high detection accuracy can be maintained. Hereinafter, the above-described real-time calibration in actual operation will be described.

EEPROM104 The (first storage unit), for example, room temperature (e.g., 25 degrees) in the maximum value MAX (Cos? _1f of the maximum value MAX (sin [theta _1f) and a first cosine wave signal Cos? _1f of the first sine-wave signal sin [theta _1f the initial value of) MAX1ref, the minimum value MIN (sin [theta _1f) and the initial value MIN1ref, the maximum value of the third sine wave signal of the minimum value MIN of the first cosine wave signal Cosθ _1f (Cosθ _1f) of the first sine-wave signal sin [theta _1f V _{C +} initial value MAX2ref of the maximum value MAX of _{S (V C + S)} and a maximum value MAX _{(V C-S)} of the third cosine wave signal _{V C-S,} the minimum value MIN of the maximum value _{V C + S} of the third sinusoidal signal ( V _{C + S),} and a third initial value MIN2ref of the minimum value MIN of the cosine wave signal _{V C-S (V C-} S) are stored.

At the time of actual operation, when the CPU 101 receives the ignition signal transmitted from the ignition switch 11, it reads MAX1ref, MIN1ref, MAX2ref, MIN2ref stored in the EEPROM 104 (first storage unit), and sends it to the RAM 102 (second storage unit). Write. At this time, RAM 102 in the (second storage section), as the value of the maximum value MAX of the first sine-wave signal Sinθ _1f MAX1ref respectively (sin [theta _1f) and a maximum value MAX (Cos? _1f) of the first cosine wave signal Cos? _1f written, MIN1ref is written as the value of the minimum value MIN of the first sine-wave signal sin [theta _1f respectively (sin [theta _1f) and the minimum value MIN (Cos? _1f) of the first cosine wave signal Cos? _1f, third sine wave MAX2ref each written as the value of the maximum value MAX of the maximum value _{V C + S} of the signal _{(V C + S)} and a maximum value MAX of the third cosine wave signal _{V C-S (V C-} S), the maximum of the third sine wave signal MIN2ref respectively values of _{V C +} minimum value MIN _{(V C + S)} of _S and the third cosine wave signal _{V C-S} minimum value MIN of _{(V C-S)} Written as

The position detection unit 17 detects differential sine wave signals (positive-phase sine wave signal Sinθ ₁ +, reverse-phase sine wave signal Sinθ ₁ −) and differential cosine wave signals (positive-phase cosine wave signal) output from the position detection sensor 25. The cos θ ₁ +, anti-phase cosine wave signal Cos θ ₁ −) is sampled and acquired (step S100). The sine wave difference calculation unit 1711 of the difference calculation unit 171 calculates the first sine wave signal Sinθ 1 _f using the above-described equation (6 ′) (step S101 a). Further, the cosine wave difference calculation unit 1712 of the difference calculation unit 171 calculates the first cosine wave signal Cosθ 1 _f using the above-described equation (12 ′) (step S101 b).

  While performing the rotation angle detection process, the first gain correction unit 172 always carries out the interrupt processing procedure shown in FIG.

The first gain correction portion 172 detects the zero point of the first cosine wave signal Cos? _1f the (Cosθ _1f = 0) (step S201). If not detected zero point of the first cosine wave signal Cos? _1f (step S201; No), until detection of the zero point of the first cosine wave signal Cos? _1f, repeats the processing of step S201.

Upon detecting the zero point of the first cosine wave signal Cos? _1f (step S201; Yes), the first gain correction portion 172, the value of the first sine-wave signal sin [theta _1f at the zero point detection of the first cosine wave signal Cos? _1f Whether or not 0 or more (Sin θ _1f 0 0) is determined (step S202).

When the value of the first sine-wave signal sin [theta _1f at the zero point detection of the first cosine wave signal Cos? _1f is 0 or more (Sinθ _1f ≧ 0) (step S202; Yes), the first gain correction portion 172, the the value of 1 sine wave signal sin [theta _1f updates the maximum value MAX data on RAM102 as (sin [theta _1f) of the first sine-wave signal sin [theta _1f (step S203), the process returns to step S201.

When the value of the first sine-wave signal sin [theta _1f at the zero point detection of the first cosine wave signal Cos? _1f is smaller than 0 (Sinθ _1f <0) (step S202; No), the first gain correction portion 172, the the value of 1 sine wave signal sin [theta _1f updates the minimum value MIN data on RAM102 as (sin [theta _1f) of the first sine-wave signal sin [theta _1f (step S204), the process returns to step S201.

  The first gain correction unit 172 always carries out the interrupt processing procedure shown in FIG. 21 while performing the rotation angle detection processing.

The first gain correction portion 172 detects the zero point of the first sine-wave signal sin [theta _1f the (Sinθ _1f = 0) (step S301). If not detected zero point of the first sine-wave signal sin [theta _1f (step S301; No), until detection of the zero point of the first sine-wave signal sin [theta _1f, it repeats the processing of step S301.

Upon detecting the zero point of the first sine-wave signal sin [theta _1f (step S301; Yes), the first gain correction portion 172, the value of the first cosine wave signal Cos? _1f at the zero point detection of the first sine-wave signal sin [theta _1f It is determined whether or not 0 or more (Cos θ _1f 0 0) (step S302).

When the value of the first cosine wave signal Cos? _1f at the zero point detection of the first sine-wave signal sin [theta _1f is 0 or more (Cosθ _1f ≧ 0) (step S302; Yes), the first gain correction portion 172, the the value of 1 cosine wave signal Cos? _1f maximum value MAX of the first cosine wave signal Cosθ _1f (Cosθ _1f) as to update the data in the RAM 102 (step S303), the process returns to step S301.

When the value of the first cosine wave signal Cos? _1f at the zero point detection of the first sine-wave signal sin [theta _1f is smaller than 0 (Cosθ _1f <0) (step S302; No), the first gain correction portion 172, the the value of 1 cosine wave signal Cos? _1f minimum value MIN of the first cosine wave signal Cosθ _1f (Cosθ _1f) as to update the data in the RAM 102 (step S304), the process returns to step S301.

Returning to the rotation angle detection processing procedure shown in FIG. 19, the first sine wave gain correction unit 1721 of the first gain correction unit 172 determines whether the value of the first sine wave signal Sinθ _1f is 0 or more (Sinθ _1f 00) It is determined whether or not it is (step S102a).

When the value of the first sine-wave signal sin [theta _1f is 0 or more (sin [theta _1f ≧ 0) (step S102a; Yes), the first sine wave gain correction unit 1721, using the above-described (13 ') below, the A two-sinusoidal wave signal Sinθ _1g is calculated (step S103a).

When the value of the first sine-wave signal sin [theta _1f is smaller than 0 (sin [theta _1f <0) (step S102a; No), the first sine wave gain correction unit 1721, using the above-described (14 ') where the A two-sinusoidal wave signal Sinθ _1g is calculated (step S104a).

The first cosine wave gain correction unit 1722 of the first gain correction unit 172 determines whether the value of the first cosine wave signal Cos θ 1 _f is 0 or more (Cos θ 1 _{f f} 0) (step S102 b).

When the value of the first cosine wave signal Cosθ 1 _f is 0 or more (Cos θ _1f 0 0) (step S102 b; Yes), the first cosine wave gain correction unit 1722 uses the above-mentioned equation (15 ′) to calculate The 2 cosine wave signal Cosθ _1g is calculated (step S103 b).

When the value of the first cosine wave signal Cosθ _1f is less than 0 (Cosθ _1f <0) (step S102 b; No), the first cosine wave gain correction unit 1722 uses the above-mentioned equation (16 ′) to calculate The two cosine wave signal Cosθ _1g is calculated (step S104 b).

The phase conversion unit 1733 of the second gain correction unit 173 calculates the third sine wave signal V _{C + S} obtained by phase-converting the second sine wave signal Sinθ _1g using the above-mentioned equation (17), and (18 The third cosine wave signal V _C-S obtained by phase-converting the second cosine wave signal Cosθ _{1 g} is calculated using the equation (step S105).

  While performing the rotation angle detection process, the second gain correction unit 173 always carries out the interrupt processing procedure shown in FIG.

The second gain correction unit 173 detects the zero point (V _{C -S} = 0) of the third cosine wave signal V _{C -S} (step S401). When the zero point of the third cosine wave signal V _C-S is not detected (step S401; No), the process of step S401 is repeated until the zero point of the third cosine wave signal V _C-S is detected.

When the zero point of the third cosine wave signal V _C-S is detected (step S 401; Yes), the second gain correction unit 173 detects the third sine wave signal at the time of detecting the zero point of the third cosine wave signal V _C-S It is determined whether the value of V _{C + S} is 0 or more (V _{C + S S} 0) (step S402).

When the value of the third sine wave signal V _{C + S} at the time of detecting the zero point of the third cosine wave signal V _C-S is 0 or more (V _{C + S} 0 0) (step S402; Yes), the second gain correction unit 173 , the value of the third sinusoidal signal _{V C + S} updates the data on the RAM102 as the maximum value MAX of the third sinusoidal signal _{V C + S (V C +} S) ( step S403), the process returns to step S401.

When the value of the third sine wave signal V _{C + S} at the time of detecting the zero point of the third cosine wave signal V _C-S is less than 0 (V _{C + S} <0) (step S402; No), the second gain correction unit 173 , the value of the third sinusoidal signal _{V C + S} updates the data on the RAM102 as the minimum value MIN of the third sinusoidal signal _{V C + S (V C +} S) ( step S404), the process returns to step S401.

  While performing the rotation angle detection process, the second gain correction unit 173 always carries out the interrupt processing procedure shown in FIG.

The second gain correction unit 173 detects the zero point (V _{C + S} = 0) of the third sine wave signal V _{C + S} (step S 501). When the zero point of the third sine wave signal V _{C + S} is not detected (step S501; No), the process of step S501 is repeated until the zero point of the third sine wave signal V _{C + S} is detected.

When the zero point of the third sine wave signal V _{C + S} is detected (step S501; Yes), the second gain correction unit 173 detects the third cosine wave signal V _C-S when the zero point of the third sine wave signal V _{C + S} is detected. It is determined whether or not the value of V is 0 or more (V _{C -S} 0 0) (step S502).

When the value of the third cosine wave signal V _C-S at the time of detecting the zero point of the third sine wave signal V _{C + S} is 0 or more (V _{C -S} ≧ 0) (step S502; Yes), the second gain correction unit 173, the value of the third cosine wave signal _{V C-S} updates the maximum value MAX _{(V C-S)} data on RAM102 as the third cosine wave signal _{V C-S} (step S503), step S501 Return to processing.

When the value of the third cosine wave signal V _C-S at the time of detecting the zero point of the third sine wave signal V _{C + S} is less than 0 (V _{C -S} <0) (step S502; No), the second gain correction unit 173, the value of the third cosine wave signal _{V C-S} and updates the minimum value MIN _{(V C-S)} data on RAM102 as the third cosine wave signal _{V C-S} (step S504), step S501 Return to processing.

Returning to the rotation angle detection processing procedure shown in FIG. 19, the second sine wave gain correction unit 1731 of the second gain correction unit 173 determines whether the value of the third sine wave signal V _{C + S} is 0 or more (V _{C + S} 0 0) It is determined whether or not it is (step S106a).

When the value of the third sine wave signal V _{C + S} is 0 or more (V _{C + S} 0 0) (step S106 a; Yes), the second sine wave gain correction unit 1731 uses the equation (19 ′) described above to The four sine wave signals V1 _{C + S} are calculated (step S107a).

When the value of the third sine wave signal V _{C + S} is less than 0 (V _{C + S} <0) (step S106 a; No), the second sine wave gain correction unit 1731 uses the above equation (20 ′) to calculate The four sine wave signals V1 _{C + S} are calculated (step S108a).

The second cosine wave gain correction unit 1732 of the second gain correction unit 173 determines whether the value of the third cosine wave signal V _C-S is 0 or more (V _{C-S S} 0) (step S106 b ).

When the value of the third cosine wave signal V _C-S is 0 or more (V _C-S 0 0) (step S106 b; Yes), the second cosine wave gain correction unit 1732 calculates the above-mentioned equation (21 ') The fourth cosine wave signal V1 _C-S is calculated using (step S107 b).

When the value of the third cosine wave signal V _C-S is less than 0 (V _C-S <0) (step S106 b; No), the second cosine wave gain correction unit 1732 calculates the above-mentioned equation (22 ') The fourth cosine wave signal V1 _C-S is calculated using (step S108 b).

The arctangent calculation unit 1741 of the angle calculation unit 174 calculates the angle θ1 _h within the range of −90 deg <θ _{1 h} <+90 deg using the above-mentioned equation (23) (step S109).

The quadrant determining unit 1742 of the angle calculating unit 174 determines whether the fourth cosine wave signal V1C _-S is 0 or more (V1C _-S− 0) (step S110).

When the fourth cosine wave signal V1C _-S is 0 or more (V1C _-S ≧ 0) (step S110; Yes), the quadrant determining unit 1742 uses the above-mentioned equation (24) to satisfy 0deg <θ _1. <calculates a rotation angle theta ₁ of the motor 20 in the range of 360 deg (step S111).

When the fourth cosine wave signal V1C _-S is less than 0 (V1C _-S <0) (step S110; No), the quadrant determining unit 1742 uses the above-mentioned equation (25) to obtain 0deg <θ _1. <calculates a rotation angle theta ₁ of the motor 20 in the range of 360 deg (step S112).

  Then, the position detection unit 17 outputs the calculated rotation angle θ1 of the motor 20 (Step S113), returns to the process of Step S100, and repeats the processes of Step S100 to Step S113.

By the rotation angle detection process procedure described above, the rotation angle theta ₁ of the motor 20 in real time is corrected, can be detected accurately by the temperature drift or aging to suppress the decrease, maintain a high detection accuracy can Can.

  The rotation angle detection device 200 constitutes a motor control device that drives and controls the motor 20.

  Further, the motor control device constitutes an electric power steering device 100.

As described above, the rotation angle detection apparatus 200, the motor control apparatus, and the electric power steering apparatus 100 according to the _first embodiment include the difference including the positive phase sine wave signal Sinθ ₁ + and the negative phase sine wave signal Sinθ ₁ − A position detection sensor 25 which outputs a differential cosine wave signal including a moving sine wave signal, a positive phase cosine wave signal Cosθ ₁ + and a negative phase cosine wave signal Cosθ ₁ − as a position detection signal of the motor 20; A position detection unit 17 that detects the position of the motor 20 based on the detection signal, and a first storage unit (EEPROM 104) and a second storage unit (RAM 102) are provided. Position detecting unit 17 includes a positive-phase sine wave signal sin [theta ₁ + and the negative-phase sine wave signal sin [theta ₁ - outputting the difference between the first sine-wave signal sin [theta _1f, positive phase cosine wave signal Cos? ₁ + anti-phase cosine wave signal Cos? ₁ - the difference calculation unit 171 for outputting the difference as the first cosine wave signal Cos? _1f and, based on the maximum value of the first sine-wave signal Sinθ _1f MAX (Sinθ _1f) or the minimum value MIN (Sinθ _1f) outputs a second sine-wave signal sin [theta _{1 g} obtained by correcting the gain of the first sine-wave signal sin [theta _1f, based on the maximum value of the first cosine wave signal Cosθ _1f MAX (Cosθ _1f) or the minimum value MIN (Cos? _1f) A first gain correction unit 172 that outputs a second cosine wave signal Cosθ _1g obtained by correcting the gain of the first cosine wave signal Cosθ _1f ;
By adding a second cosine wave signal Cos? _{1 g} and the second sine-wave signal sin [theta _{1 g} to generate a third sinusoidal signal _{V C + S,} the maximum value MAX _{(V C + S)} or the minimum value MIN of the third sinusoidal signal _{V C + S} Based on (V _{C + S} ), the fourth sine wave signal V 1 _{C + S obtained} by correcting the gain of the third sine wave signal V _{C + S} is output, and the second sine wave signal _S in θ _{1 g} is subtracted from the second cosine wave signal Cos θ _{1 g} . generating a third cosine wave signal _{V C-S,} based on the maximum value of the third cosine wave signal _{V C-S MAX (V C} -S) or the minimum value MIN _{(V C-S),} the third cosine wave signal a second gain correction portion 173 for outputting a fourth cosine wave signal _{V1 C-S} obtained by correcting the gain of V _C-S, based on the fourth sine wave signal _{V1 C + S,} and the fourth cosine wave signal _{V1 C-S,} the motor angle calculating part for calculating a rotation angle theta ₁ of 20 It includes a 74, a.

  According to the above configuration, calibration of the rotation angle detection device 200 can be performed based on the position detection signal detected in real time. As a result, reduction in detection accuracy due to temperature drift or temporal change can be suppressed, and high detection accuracy can be maintained.

Specifically, the first gain correction unit 172 detects the zero point of the first cosine wave signal Cosθ 1 _f , and when the value of the first sine wave signal Sinθ 1 _f is 0 or more at the time of the detection of the zero point. the value of the first sine-wave signal sin [theta _1f stores the maximum value MAX of the first sine-wave signal sin [theta _1f second storage section as (Sinθ _1f) (RAM102), the value of the first sine-wave signal sin [theta _1f is less than 0 sometimes, it stores the value of the first sine-wave signal sin [theta _1f to the minimum value MIN (Sinθ _1f) as a second storage unit of the first sine-wave signal Sinθ _1f (RAM102). The first gain correction portion 172 detects the zero point of the first sine-wave signal sin [theta _1f, during the zero-point detection, the first cosine wave signal at the zero point detection of the first sine-wave signal sin [theta _1f Cos? when the value of _1f is 0 or more, storing the value of the first cosine wave signal Cos? _1f the maximum value MAX (Cos? _1f) as a second storage unit of the first cosine wave signal Cos? _1f (RAM 102), first when the value of the cosine wave signal Cos? _1f is less than 0, stores the value of the first cosine wave signal Cos? _1f to the minimum value MIN (Cos? _1f) as a second storage unit of the first cosine wave signal Cos? _1f (RAM 102) Do.

Thereby, the maximum value MAX (Sinθ _1f ) or the minimum value MIN (Sinθ _1f ) of the first sine wave signal Sinθ _1f for obtaining the second sine wave signal Sinθ _1g can be acquired in real time. Further, the maximum value MAX (Cosθ _1f ) or the minimum value MIN (Cosθ _1f ) of the first cosine wave signal Cosθ _1f for obtaining the second cosine wave signal Cosθ _1g can be acquired in real time.

Further, specifically, the second gain correction portion 173, in detecting the zero point of the third cosine wave signal V _C-S, at the time of the zero-point detection, the value of the third sinusoidal signal V _{C + S} is 0 or more At one point, and stores the value of the third sine wave signal _{V C + S} in the second storage unit as the maximum value MAX _{(V C + S)} of the third sinusoidal signal _{V C + S} (RAM102), third cosine wave signal _{V C-S} when the value of the third sinusoidal signal _{V C + S} at the zero point detection is less than 0, the value of the third sine wave signal _{V C + S} as the minimum value MIN of the third sinusoidal signal _{V C + S (V C +} S) 2) Store in the storage unit (RAM 102). In addition, the second gain correction unit 173 detects the zero point of the third sine wave signal V _{C + S} , and when the value of the third cosine wave signal V _C-S is 0 or more at the time of the zero point detection, the value of the third cosine wave signal _{V C-S} stored in the second memory as the maximum value MAX of the third cosine wave signal _{V C-S (V C-} S) (RAM102), third sinusoidal signal _{V C + S} minimum value MIN when the values of the third cosine wave signal V _C-S at the zero point detection is less than 0, the value of the third cosine wave signal V _C-S of the third cosine wave signal V _C-S It stores in the second storage unit (RAM 102) as (V _C−S ).

As a result, it is possible to obtain the maximum value MAX (V _{C + S} ) or the minimum value MIN (V _{C + S} ) of the third sine wave signal V _{C + S} for obtaining the fourth sine wave signal V 1 _{C + S} in real time. Also, to obtain the maximum value MAX (V _C-S ) or the minimum value MIN (V _C-S ) of the third cosine wave signal V _C-S for obtaining the fourth cosine wave signal V 1 _C-S in real time Can.

  The motor control device according to the first embodiment can drive and control the motor 20 with high accuracy by controlling the drive of the motor 20 using the rotation angle of the motor 20 calculated with high accuracy.

  In the electric power steering apparatus 100 according to the first embodiment, the motor 20 controlled by the motor control apparatus according to the first embodiment is provided on the column shaft 2 of the steering 1 so that the steering assist of the electric power steering apparatus 100 is performed. Control accuracy can be increased.

The rotation angle detecting method according to the first embodiment, output from the position detection sensor 25 as a position detection signal of the motor, the positive-phase sine wave signal sin [theta _{1 +} and the negative-phase sine wave signal sin [theta ₁ - and the differential comprising sine wave signal, and the positive-phase cosine wave signal Cos? _{1 +} and the negative-phase cosine wave signal Cos? ₁ - based on differential cosine wave signal and a, a rotation angle detecting method for detecting the position of the motor 20, a positive comprising the steps of a difference between the first sine-wave signal sin [theta _1f, positive phase cosine wave signal Cos? ₁ + and the negative-phase cosine wave signal Cos? ₁ - - phase sine wave signal sin [theta ₁ + and the negative-phase sine wave signal sin [theta ₁ and the method comprising the difference between the first cosine wave signal Cos? _1f, based on the maximum value MAX (Sinθ _1f) or the minimum value MIN of the first sine-wave signal Sinθ _1f (Sinθ _1f), the first sine-wave signal sin [theta _1f A step of the second sine-wave signal sin [theta _{1 g} of the gain is corrected on the basis of the maximum value of the first cosine wave signal Cosθ _1f MAX (Cosθ _1f) or the minimum value MIN (Cos? _1f), the first cosine wave signal Cos? a step of the second cosine wave signal Cos? _{1 g} by correcting the gain of _1f, a step of the second cosine wave signal Cos? _{1 g} by adding the second sinusoidal signal sin [theta _{1 g} third sinusoidal signal _{V C + S} the steps of the third cosine wave signal _{V C-S} from the second cosine wave signal Cos? _{1 g} by subtracting the second sine-wave signal sin [theta _{1 g,} the maximum value of the third sinusoidal signal _{V C + S MAX (V C} + S) , or based on the minimum value MIN _{(V C + S),} the steps of the fourth sine wave signal _{V1 C + S} to correct the gain of the third sinusoidal signal _{V C + S,} the maximum value of the third cosine wave signal _{V C-S} Based on AX _{(V C-S)} or the minimum value MIN _{(V C-S),} the steps of the fourth cosine wave signal _{V1 C-S} to correct the gain of the third cosine wave signal _{V C-S,} the 4 based on the sine wave signal _{V1 C + S,} and the fourth cosine wave signal _{V1 C-S,} having a step of calculating a rotation angle theta ₁ of the motor 20.

  Thus, calibration of the rotation angle detection device 200 can be performed based on the position detection signal detected in real time. As a result, reduction in detection accuracy due to temperature drift or temporal change can be suppressed, and high detection accuracy can be maintained.

Second Embodiment
In the present embodiment, the maximum value MAX of the first sine-wave signal Sinθ _1f (Sinθ _1f) and a maximum value MAX (Cos? _1f) of the first cosine wave signal Cos? _1f, the minimum value MIN of the first sine-wave signal sin [theta _1f (sin [theta _1f) and the minimum value MIN of the first cosine wave signal Cos? _1f (Cos? _1f), the third sinusoidal signal _{V C +} maximum value MAX _{(V C + S} of _S) and the maximum value MAX of the third cosine wave signal _{V C-S (V C-S),} the minimum value MIN of the minimum value MIN _{(V C + S),} and the third cosine wave signal _{V C-S} of the third sinusoidal signal _{V C + S (V C-} S), for, respectively upper and lower limit values An example will be described in which each value on the RAM 102 is not updated when each value exceeds the upper limit value or the lower limit value.

  FIG. 24 is a diagram showing an example of the upper limit value, the initial value, and the lower limit value of the maximum value of the first sine wave signal and the first cosine wave signal stored in the EEPROM. FIG. 25 is a diagram showing an example of the upper limit value, the initial value, and the lower limit value of the minimum value of the first sine wave signal and the first cosine wave signal stored in the EEPROM. FIG. 26 is a diagram showing an example of the upper limit value, the initial value, and the lower limit value of the maximum values of the third sine wave signal and the third cosine wave signal stored in the EEPROM. FIG. 27 is a diagram showing an example of the upper limit value, the initial value, and the lower limit value of the minimum value of the third sine wave signal and the third cosine wave signal stored in the EEPROM. The upper limit value, the initial value, and the lower limit value of each value stored in the EEPROM 104 may be numerical data or discrete values such as digital data.

  FIG. 28 is a flowchart illustrating an example of an interrupt processing procedure for detecting the maximum value or the minimum value of the first sine wave signal in the rotation angle detection device according to the second embodiment. FIG. 29 is a flowchart illustrating an example of an interrupt processing procedure for detecting the maximum value or the minimum value of the first cosine wave signal in the rotation angle detection device according to the second embodiment. FIG. 30 is a flowchart illustrating an example of an interrupt processing procedure for detecting the maximum value or the minimum value of the third sine wave signal in the rotation angle detection device according to the second embodiment. FIG. 31 is a flowchart illustrating an example of an interrupt processing procedure for detecting the maximum value or the minimum value of the third cosine wave signal in the rotation angle detection device according to the second embodiment. The configuration of the rotation angle detection device according to the present embodiment and the rotation angle detection processing procedure are the same as in the first embodiment, and thus the description thereof is omitted here. The description of the same processing as that of the first embodiment is omitted.

  The first gain correction unit 172 always carries out the interrupt processing procedure shown in FIG. 28 while performing the above-described rotation angle detection processing.

When the value of the first sine-wave signal sin [theta _1f at the zero point detection of the first cosine wave signal Cos? _1f is 0 or more (Sinθ _1f ≧ 0) (step S202; Yes), the first gain correction unit 172, EEPROM 104 from reading the upper limit value MAX1Lim_H and the lower limit value MAX1Lim_L of the maximum value MAX of the first sine-wave signal Sinθ _1f (Sinθ _1f) and a maximum value MAX (Cos? _1f) of the first cosine wave signal Cos? _1f, a first sine-wave signal sin [theta _1f or values, and the lower limit value MAX1Lim_L or more of the maximum value of the first sine-wave signal sin [theta _1f, and an upper limit value of the maximum value of the first sine-wave signal Sinθ _1f MAX1Lim_H below (MAX1Lim_L ≦ Sinθ _1f ≦ MAX1Lim_H) It is determined whether or not (step S202-1).

The value of the first sine-wave signal sin [theta _1f is, and the lower limit value MAX1Lim_L or more of the maximum value of the first sine-wave signal sin [theta _1f, and the upper limit value of the maximum value of the first sine-wave signal Sinθ _1f MAX1Lim_H below (MAX1Lim_L ≦ Sinθ when _1f ≦ MAX1Lim_H) is (step S202-1; Yes), the first gain correction portion 172, the value of the first sine-wave signal sin [theta _1f as the maximum value MAX of the first sine-wave signal Sinθ _1f (Sinθ _1f) The data on the RAM 102 is updated (step S203), and the process returns to step S201.

The value of the first sine-wave signal sin [theta _1f is, the maximum value of either less than the lower limit MAX1Lim_L the first sine-wave signal sin [theta _1f, or, when larger than the upper limit value MAX1Lim_H of the maximum value of the first sine-wave signal Sinshita1f ( Step S202-1: No) The first gain correction unit 172 does not update the value of the maximum value MAX (Sinθ _1f ) of the first sine wave signal Sinθ _1f on the RAM 102, and returns to the process of step S201.

When the value of the first sine-wave signal sin [theta _1f at the zero point detection of the first cosine wave signal Cos? _1f is smaller than 0 (Sinθ _1f <0) (step S202; No), the first gain correction unit 172, EEPROM 104 from reading the upper limit value MIN1Lim_H and the lower limit value MIN1Lim_L the minimum value MIN of the first sine-wave signal Sinθ _1f (Sinθ _1f) and the minimum value MIN (Cos? _1f) of the first cosine wave signal Cos? _1f, a first sine-wave signal sin [theta _1f or values, and the lower limit value MIN1Lim_L than the minimum value of the first sine-wave signal sin [theta _1f, and an upper limit value of the minimum value of the first sine-wave signal Sinθ _1f MIN1Lim_H below (MIN1Lim_L ≦ Sinθ _1f ≦ MIN1Lim_H) It is determined whether or not it is (step S202-2).

The value of the first sine-wave signal sin [theta _1f is, and the lower limit value MIN1Lim_L than the minimum value of the first sine-wave signal sin [theta _1f, and the upper limit value of the minimum value of the first sine-wave signal Sinθ _1f MIN1Lim_H below (MIN1Lim_L ≦ Sinθ when _1f ≦ MIN1Lim_H) is (step S202-2; Yes), the first gain correction portion 172, the value of the first sine-wave signal sin [theta _1f as the minimum value MIN of the first sine-wave signal Sinθ _1f (Sinθ _1f) The data on the RAM 102 is updated (step S204), and the process returns to step S201.

The value of the first sine-wave signal sin [theta _1f is, the minimum value of either less than the lower limit MIN1Lim_L the first sine-wave signal sin [theta _1f, or, when larger than the upper limit value MIN1Lim_H the minimum value of the first sine-wave signal sin [theta _1f (Step S202-2; No), the first gain correction unit 172 does not update the value of the minimum value MIN (Sinθ _1f ) of the first sine wave signal Sinθ _1f on the RAM 102, and returns to the process of step S201.

  While performing the above-described rotation angle detection process, the first gain correction unit 172 always carries out the interrupt processing procedure shown in FIG.

When the value of the first cosine wave signal Cos? _1f at the zero point detection of the first sine-wave signal sin [theta _1f is 0 or more (Cosθ _1f ≧ 0) (step S302; Yes), the first gain correction unit 172, EEPROM 104 from reading the upper limit value MAX1Lim_H and the lower limit value MAX1Lim_L of the maximum value MAX of the first sine-wave signal Sinθ _1f (Sinθ _1f) and a maximum value MAX (Cos? _1f) of the first cosine wave signal Cos? _1f, the first cosine wave signal Cos? _1f or values, and the lower limit value MAX1Lim_L or more of the maximum value of the first cosine wave signal Cos? _1f, and an upper limit value of the maximum value of the first cosine wave signal Cosθ _1f MAX1Lim_H below (MAX1Lim_L ≦ Cosθ _1f ≦ MAX1Lim_H) It is determined whether or not (step S302-1).

The value of the first cosine wave signal Cos? _1f is, and the lower limit value MAX1Lim_L or more of the maximum value of the first cosine wave signal Cos? _1f, and the upper limit value of the maximum value of the first cosine wave signal Cosθ _1f MAX1Lim_H below (MAX1Lim_L ≦ Cosθ when _1f ≦ MAX1Lim_H) is (step S302-1; Yes), the first gain correction portion 172, the value of the first cosine wave signal Cos? _1f as the maximum value MAX of the first cosine wave signal Cos? _1f (Cos? _1f) The data on the RAM 102 is updated (step S303), and the process returns to step S301.

The value of the first cosine wave signal Cos? _1f is either less than the lower limit MAX1Lim_L of the maximum value of the first cosine wave signal Cos? _1f, or, when larger than the upper limit value MAX1Lim_H of the maximum value of the first cosine wave signal Cos? _1f (step S302-1; No), the first gain correction unit 172 does not update the value of the maximum value MAX of the first cosine wave signal Cos? _1f on RAM 102 (Cos? _1f), the process returns to step S301.

When the value of the first cosine wave signal Cos? _1f at the zero point detection of the first sine-wave signal sin [theta _1f is smaller than 0 (Cosθ _1f <0) (step S302; No), the first gain correction unit 172, EEPROM 104 from reading the upper limit value MIN1Lim_H and the lower limit value MIN1Lim_L the minimum value MIN of the first sine-wave signal Sinθ _1f (Sinθ _1f) and the minimum value MIN (Cos? _1f) of the first cosine wave signal Cos? _1f, the first cosine wave signal Cos? _1f or values, and the lower limit value MIN1Lim_L than the minimum value of the first cosine wave signal Cos? _1f, and an upper limit value of the minimum value of the first cosine wave signal Cosθ _1f MIN1Lim_H below (MIN1Lim_L ≦ Cosθ _1f ≦ MIN1Lim_H) It is determined whether or not it is (step S302-2).

The value of the first cosine wave signal Cos? _1f is, and the lower limit value MIN1Lim_L than the minimum value of the first cosine wave signal Cos? _1f, and the upper limit value of the minimum value of the first cosine wave signal Cosθ _1f MIN1Lim_H below (MIN1Lim_L ≦ Cosθ when _1f ≦ MIN1Lim_H) is (step S302-2; Yes), the first gain correction portion 172, the value of the first cosine wave signal Cos? _1f as the minimum value MIN of the first cosine wave signal Cos? _1f (Cos? _1f) The data on the RAM 102 is updated (step S304), and the process returns to step S301.

The value of the first cosine wave signal Cos? _1f is either less than the lower limit MIN1Lim_L the minimum value of the first cosine wave signal Cos? _1f, or, when larger than the upper limit value MIN1Lim_H the minimum value of the first cosine wave signal Cos? _1f (step S302-2; No), the first gain correction unit 172 does not update the value of the minimum value MIN of the first cosine wave signal Cos? _1f on RAM 102 (Cos? _1f), the process returns to step S301.

  While performing the above-described rotation angle detection processing, the second gain correction unit 173 always carries out the interrupt processing procedure shown in FIG.

When the value of the third sine wave signal V _{C + S} at the time of detecting the zero point of the third cosine wave signal V _C-S is 0 or more (V _{C + S} 0 0) (step S402; Yes), the second gain correction unit 173 reads the upper limit value MAX2Lim_H and the lower limit value MAX2Lim_L of the maximum value MAX of the third sinusoidal signal _{V C + S} from EEPROM104 _{(V C + S)} and a maximum value MAX of the third cosine wave signal _{V C-S (V C-} S), the 3 the value of the sine wave signal _{V C + S} is, and the third lower limit value of the maximum value of the sine wave signal _{V C + S} MAX2Lim_L or more and the upper limit value of the maximum value of the third sinusoidal signal _{V C + S} MAX2Lim_H below (MAX2Lim_L ≦ _{V C + S} It is determined whether or not ≦ MAX2Lim_H (step S402-1).

The value of the third sinusoidal signal _{V C + S} is, and the third lower limit value of the maximum value of the sine wave signal _{V C + S} MAX2Lim_L or more and the upper limit value of the maximum value of the third sinusoidal signal _{V C + S} MAX2Lim_H below (MAX2Lim_L ≦ V _{C + S} ≦ MAX2Lim_H) is when a (step S402-1; Yes), the second gain correction unit 173, the value of the third sinusoidal signal _{V C + S} as a third sine wave signal _{V C +} the maximum value of _S MAX _{(V C + S)} The data on the RAM 102 is updated (step S403), and the process returns to step S401.

The value of the third sinusoidal signal _{V C + S} is either less than the lower limit MAX2Lim_L of the maximum value of the third sinusoidal signal _{V C + S,} or, when larger than the upper limit value MAX2Lim_H of the maximum value of the third sinusoidal signal _{V C + S} (Step S402-1; No), the second gain correction unit 173 does not update the value of the maximum value MAX (V _{C + S} ) of the third sine wave signal V _{C + S} on the RAM 102, and returns to the process of step S401.

When the value of the third sine wave signal V _{C + S} at the time of detecting the zero point of the third cosine wave signal V _C-S is less than 0 (V _{C + S} <0) (step S402; No), the second gain correction unit 173 reads the upper limit value MIN2Lim_H and the lower limit value MIN2Lim_L the minimum value MIN of the third sinusoidal signal _{V C + S} from EEPROM104 _{(V C + S)} and the minimum value MIN of the third cosine wave signal _{V C-S (V C-} S), the 3 the value of the sine wave signal _{V C + S} is, and the third lower limit value of the minimum value of the sine wave signal _{V C + S} MIN2Lim_L or more and the upper limit value of the minimum value of the third sinusoidal signal _{V C + S} MIN2Lim_H below (MIN2Lim_L ≦ _{V C + S} It is determined whether or not MIN MIN2LimH) (step S402-2).

The value of the third sinusoidal signal _{V C + S} is, and the third lower limit value of the minimum value of the sine wave signal _{V C + S} MIN2Lim_L or more and the upper limit value of the minimum value of the third sinusoidal signal _{V C + S} MIN2Lim_H below (MIN2Lim_L ≦ V _{C + S} ≦ MIN2Lim_H) is when a (step S402-2; Yes), the second gain correction unit 173, the minimum value MIN of values of the third sinusoidal signal _{V C + S} third sinusoidal signal _{V C + S (V C +} S) The data on the RAM 102 is updated (step S404), and the process returns to step S401.

The value of the third sinusoidal signal _{V C + S} is either less than the lower limit MIN2Lim_L the minimum value of the third sinusoidal signal _{V C + S,} or, when larger than the upper limit value MIN2Lim_H the minimum value of the third sinusoidal signal _{V C + S} (Step S402-2; No), the second gain correction unit 173 does not update the value of the minimum value MIN (V _{C + S} ) of the third sine wave signal V _{C + S} on the RAM 102, and returns to the process of step S401.

  The second gain correction unit 173 constantly executes the interrupt processing procedure shown in FIG. 31 while performing the above-described rotation angle detection processing.

When the value of the third cosine wave signal V _C-S at the time of detecting the zero point of the third sine wave signal V _{C + S} is 0 or more (V _{C -S} ≧ 0) (step S502; Yes), the second gain correction unit 173 reads the upper limit value MAX2Lim_H and the lower limit value MAX2Lim_L of the maximum value MAX of the third sinusoidal signal _{V C + S} from EEPROM104 _{(V C + S)} and a maximum value MAX of the third cosine wave signal _{V C-S (V C-} S) , the value of the third cosine wave signal _{V C-S} is, and the lower limit value MAX2Lim_L or more of the maximum value of the third cosine wave signal _{V C-S,} and the upper limit of the maximum value of the third cosine wave signal _{V C-S} It is determined whether the value is less than or equal to MAX2Lim_H (MAX2Lim_L CVC _-S ≦ MAX2Lim_H) (step S502-1).

The third value of the cosine wave signal _{V C-S} is, and the lower limit value MAX2Lim_L or more of the maximum value of the third cosine wave signal _{V C-S,} and the upper limit value of the maximum value of the third cosine wave signal _{V C-S} When MAX2Lim_H or less (MAX2Lim_L ≦ VC _-S ≦ MAX2Lim_H) (step S502-1; Yes), the second gain correction unit 173 determines the value of the third cosine wave signal V _C-S as the third cosine wave signal V the maximum value of the _{C-S MAX (V C-} S) as to update the data in the RAM 102 (step S503), the process returns to step S501.

The third value of the cosine wave signal _{V C-S} is either less than the lower limit MAX2Lim_L of the maximum value of the third cosine wave signal _{V C-S,} or the upper limit of the maximum value of the third cosine wave signal _{V C-S} When the value is larger than the value MAX2Lim_H (step S502-1; No), the second gain correction unit 173 updates the value of the maximum value MAX (V _{C -S} ) of the third cosine wave signal V _{C -S} on the RAM 102. Then, the process returns to the process of step S501.

When the value of the third cosine wave signal V _C-S at the time of detecting the zero point of the third sine wave signal V _{C + S} is less than 0 (V _{C -S} <0) (step S502; No), the second gain correction unit 173 reads the upper limit value MIN2Lim_H and the lower limit value MIN2Lim_L the minimum value MIN of the third sinusoidal signal _{V C + S} from EEPROM104 _{(V C + S)} and the minimum value MIN of the third cosine wave signal _{V C-S (V C-} S) , the value of the third cosine wave signal _{V C-S} is, and the lower limit value MIN2Lim_L than the minimum value of the third cosine wave signal _{V C-S,} and the upper limit of the minimum value of the third cosine wave signal _{V C-S} It is determined whether or not the value is less than or equal to the value MIN2Lim_H (MIN2Lim_L ≦ VC _-S ≦ MIN2Lim_H) (step S502-2).

The third value of the cosine wave signal _{V C-S} is, and the lower limit value MIN2Lim_L than the minimum value of the third cosine wave signal _{V C-S,} and the upper limit value of the minimum value of the third cosine wave signal _{V C-S} When MIN2Lim_H or less (MIN2Lim_L ≦ VC _-S ≦ MIN2Lim_H) (step S502-2; Yes), the second gain correction unit 173 calculates the value of the third cosine wave signal V _C-S as the third cosine wave signal V minimum value MIN of the _{C-S (V C-S} ) as to update the data in the RAM 102 (step S504), the process returns to step S501.

The third value of the cosine wave signal _{V C-S} is either less than the lower limit MIN2Lim_L the minimum value of the third cosine wave signal _{V C-S,} or the upper limit of the minimum value of the third cosine wave signal _{V C-S} When the value is larger than the value MIN2Lim_H (step S502-2; No), the second gain correction unit 173 updates the value of the minimum value MIN (V _{C -S} ) of the third cosine wave signal V _{C -S} on the RAM 102. Then, the process returns to the process of step S501.

28, 29 described above, FIG. 30, the interrupt processing procedure shown in FIG. 31, the maximum value MAX (sin [theta _1f) of the first sine-wave signal sin [theta _1f, the maximum value MAX of the first cosine wave signal Cos? _1f (Cos? _1f), the minimum value MIN (sin [theta _1f of the first sine-wave signal sin [theta _1f), the minimum value MIN (Cos? _1f of the first cosine wave signal Cos? _1f), the maximum value of the third sinusoidal signal _{V C + S MAX (V C} + S) , the maximum value of the third cosine wave signal _{V C-S MAX (V C} -S), the minimum value MIN of the minimum value MIN _{(V C +} S), the third cosine wave signal _{V C-S} of the third sinusoidal signal _{V C + S} Even when each value of (V _C−S ) becomes an abnormal value due to noise or the like, the rotation angle detection processing can be performed normally.

(Modification)
In a variation of the second embodiment, the maximum value MAX of the first sine-wave signal Sinθ _1f (Sinθ _1f), the minimum value MIN (Sinθ _1f), the maximum value of the first cosine wave signal Cos? _1f of the first sine-wave signal sin [theta _1f MAX (Cosθ _1f ), the minimum value MIN (Cosθ _1f ) of the first cosine wave signal Cosθ _1f , the maximum value MAX (V _{C + S} ) of the third sine wave signal V _{C + S} , the minimum value MIN (third Q) of the third sine wave signal V _{C + S} V _{C +} S), the maximum value of the third cosine wave signal _{V C-S MAX (V C} -S), the upper limit value is the value of the minimum value MIN of the third cosine wave signal _{V C-S (V C-} S) or When the lower limit value is exceeded, an example in which the initial value of each value is applied will be described.

  FIG. 32 is a flowchart illustrating an example of an interrupt processing procedure for detecting the maximum value or the minimum value of the first sine wave signal in the rotation angle detection device according to the modification of the second embodiment. FIG. 33 is a flowchart illustrating an example of an interrupt processing procedure for detecting the maximum value or the minimum value of the first cosine wave signal in the rotation angle detection device according to the modification of the second embodiment. FIG. 34 is a flowchart showing an example of an interrupt processing procedure for detecting the maximum value or the minimum value of the third sine wave signal in the rotation angle detection device according to the modification of the second embodiment. FIG. 35 is a flowchart illustrating an example of an interrupt processing procedure for detecting the maximum value or the minimum value of the third cosine wave signal in the rotation angle detection device according to the modification of the second embodiment.

  The first gain correction unit 172 always carries out the interrupt processing procedure shown in FIG. 32 while performing the above-described rotation angle detection processing.

The value of the first sine-wave signal sin [theta _1f is, and the lower limit value MAX1Lim_L or more of the maximum value MAX of the first sine-wave signal Sinθ _1f (Sinθ _1f), and the maximum value MAX (sin [theta _1f of the first sine-wave signal sin [theta _1f ) limit MAX1Lim_H follows (when a MAX1Lim_L ≦ Sinθ _1f ≦ MAX1Lim_H) (step S202-1; Yes), the first gain correction portion 172, the value of the first sine-wave signal sin [theta _1f first sine-wave signal sin [theta maximum value MAX of _{1f (Sinθ 1f)} as to update the data in the RAM 102 (step S203a), the process returns to step S201.

The value of the first sine-wave signal sin [theta _1f is, the maximum value MAX or less than the lower limit value MAX1Lim_L of (sin [theta _1f) of the first sine-wave signal sin [theta _1f, or the maximum value MAX of the first sine-wave signal sin [theta _1f (sin [theta when greater than the upper limit value MAX1Lim_H of _1f) (step S202-1; No), the first gain correction portion 172, the maximum value MAX (sin [theta _1f of the first sine-wave signal sin [theta _1f from EEPROM 104) and a first cosine wave signal cos [theta] _1f maximum value MAX (cos [theta] _1f) initial value and updates the data on the RAM102 as read by the maximum value MAX of the first sine-wave signal Sinθ _1f (Sinθ _1f) MAX1ref of (step S203b), the process of step S201 Return.

The first value of the sine wave signal sin [theta _1f is not less than the lower limit value MIN1Lim_L the minimum value MIN of the first sine-wave signal Sinθ _1f (Sinθ _1f), and the minimum value MIN (sin [theta _1f of the first sine-wave signal sin [theta _1f ) limit MIN1Lim_H follows (when a MIN1Lim_L ≦ Sinθ _1f ≦ MIN1Lim_H) (step S202-2; Yes), the first gain correction portion 172, the value of the first sine-wave signal sin [theta _1f first sine-wave signal sin [theta _1f minimum value MIN of the (sin [theta _1f) as to update the data in the RAM 102 (step S204a), the process returns to step S201.

The value of the first sine-wave signal sin [theta _1f is, the minimum value MIN or less than the lower limit value MIN1Lim_L of (sin [theta _1f) of the first sine-wave signal sin [theta _1f, or the minimum value MIN of the first sine-wave signal sin [theta _1f (sin [theta when greater than the upper limit value MIN1Lim_H of _1f) (step S202-2; No), the first gain correction portion 172, the minimum value MIN (sin [theta _1f of the first sine-wave signal sin [theta _1f from EEPROM 104) and a first cosine wave signal cos [theta] _1f minimum value MIN (cos [theta] _1f) initial value and updates the data in the RAM102 as the minimum value MIN of the first sine-wave signal sin [theta _1f reads (Sinθ _1f) MIN1ref of (step S204b), the process of step S201 Return.

  While performing the above-described rotation angle detection process, the first gain correction unit 172 always carries out the interrupt processing procedure shown in FIG.

The value of the first cosine wave signal Cos? _1f is, and the lower limit value MAX1Lim_L or more of the maximum value MAX of the first cosine wave signal Cosθ _1f (Cosθ _1f), and the maximum value MAX (Cos? _1f of the first cosine wave signal Cos? _1f ) limit MAX1Lim_H follows (when a MAX1Lim_L ≦ Cosθ _1f ≦ MAX1Lim_H) (step S302-1; Yes), the first gain correction portion 172, the value of the first cosine wave signal Cos? _1f first cosine wave signal Cos? maximum value MAX of _1f (Cos? _1f) as to update the data in the RAM 102 (step S 303 a), the process returns to step S301.

The value of the first cosine wave signal Cos? _1f is, the maximum value MAX or less than the lower limit value MAX1Lim_L of (Cos? _1f) of the first cosine wave signal Cos? _1f, or the maximum value MAX of the first cosine wave signal Cos? _1f (Cos? when greater than the upper limit value MAX1Lim_H of _1f) (step S302-1; No), the first gain correction portion 172, the maximum value MAX (sin [theta _1f of the first sine-wave signal sin [theta _1f from EEPROM 104) and a first cosine wave signal cos [theta] _1f maximum value MAX (cos [theta] _1f) initial value and updates the data on the RAM102 as read by the maximum value MAX of the first cosine wave signal Cosθ _1f (Cosθ _1f) MAX1ref of (step S303b), the process of step S301 Return.

The first value of the cosine wave signal Cos? _1f is, and the lower limit value MIN1Lim_L more minimum value MIN of the first cosine wave signal Cosθ _1f (Cosθ _1f), and the minimum value MIN (Cos? _1f of the first cosine wave signal Cos? _1f ) limit MIN1Lim_H follows (when a MIN1Lim_L ≦ Cosθ _1f ≦ MIN1Lim_H) (step S302-2; Yes), the first gain correction portion 172, the value of the first cosine wave signal Cos? _1f first cosine wave signal Cos? _1f minimum value MIN of (Cos? _1f) as to update the data in the RAM 102 (step S304a), the process returns to step S301.

The value of the first cosine wave signal Cos? _1f is, the minimum value MIN or less than the lower limit value MIN1Lim_L of (Cos? _1f) of the first cosine wave signal Cos? _1f, or the minimum value MIN of the first cosine wave signal Cos? _1f (Cos? when greater than the upper limit value MIN1Lim_H of _1f) (step S302-2; No), the first gain correction portion 172, the minimum value MIN (sin [theta _1f of the first sine-wave signal sin [theta _1f from EEPROM 104) and a first cosine wave signal cos [theta] _1f minimum value MIN (cos [theta] _1f) initial value and updates the data on the RAM102 as read by the minimum value MIN of the first cosine wave signal Cosθ _1f (Cosθ _1f) MIN1ref of (step S304b), the process of step S301 Return.

  The second gain correction unit 173 constantly executes the interrupt processing procedure shown in FIG. 34 while performing the above-described rotation angle detection processing.

The third value of the sine wave signal _{V C + S} is, and the third maximum value MAX _{(V C + S)} of the sine wave signal _{V C + S} lower limit MAX2Lim_L more, and the maximum value of the third sinusoidal signal _{V C + S MAX (V C} + S Is equal to or less than the upper limit value MAX2Lim_H (MAX2Lim_L ≦ VC _{+ S} ≦ MAX2Lim_H) (step S402-1; Yes), the second gain correction unit 173 sets the value of the third sine wave signal VC _{+ S} to the third sine wave signal V _{C + S} maximum value MAX of _{(V C + S)} as to update the data in the RAM 102 (step S403a), the process returns to step S401.

The value of the third sinusoidal signal _{V C + S} is a third or less than the lower limit value MAX2Lim_L sinusoidal signal _{V C + S} maximum value MAX of _{(V C + S),} or the maximum value MAX (V third sinusoidal signal _{V C + S} when greater than the upper limit value MAX2Lim_H of _{C + S)} (step S402-1; No), the second gain correction unit 173 from EEPROM104 maximum value MAX of the third sinusoidal signal _{V C + S (V C +} S) , and the third cosine wave signal update the V _C-S maximum value MAX _{(V C-S)} of the initial value data on RAM102 as the maximum value of the third sinusoidal signal _{V C + S} reads MAX2ref MAX _{(V C + S)} in (step S403b), step It returns to the process of S401.

The value of the third sinusoidal signal _{V C + S} is, and the third lower limit MIN2Lim_L more sinusoidal signal _{V C + S} minimum value MIN of _{(V C + S),} and the minimum value MIN of the third sinusoidal signal _{V C + S (V C +} S If the second gain correction unit 173 determines that the value of the third sine wave signal V _{C + S} is equal to or less than the upper limit value MIN2Lim_H (MIN2Lim_L ≦ Vc _{+ S} ≦ MIN2Lim_H) (step S402-2; Yes) minimum value MIN of _{C + S (V C + S} ) as to update the data in the RAM 102 (step S404a), the process returns to step S401.

The value of the third sinusoidal signal _{V C + S} is either less than the lower limit MIN2Lim_L the minimum value MIN of the third sinusoidal signal _{V C + S (V C +} S), or the minimum value MIN (V third sinusoidal signal _{V C + S} when greater than the upper limit value MIN2Lim_H of _{C + S)} (step S402-2; No), the second gain correction unit 173 from EEPROM104 minimum value MIN of the third sinusoidal signal _{V C + S (V C +} S) , and the third cosine wave signal update the V _C-S minimum value MIN _{(V C-S)} of the initial value data on RAM102 as the minimum value of the third sinusoidal signal _{V C + S} reads MIN2ref MIN _{(V C + S)} in (step S404b), step It returns to the process of S401.

  The second gain correction unit 173 always carries out the interrupt processing procedure shown in FIG. 35 while performing the above-described rotation angle detection processing.

The value of the third cosine wave signal _{V C-S} is, and the third lower limit MAX2Lim_L or more of the maximum value MAX of the cosine wave signal _{V C-S (V C-} S), and the third cosine wave signal _{V C-} when _S is a maximum value MAX of _{(V C-S)} upper limit MAX2Lim_H follows _{(MAX2Lim_L ≦ V C-S ≦} MAX2Lim_H) ( step S502-1; Yes), the second gain correction portion 173, a third cosine wave signal _V value of _C-S the third cosine wave signal _{V C-S} maximum value MAX of _{(V C-S)} as to update the data in the RAM 102 (step S503a), the process returns to step S501.

If the value of the third cosine wave signal _{V C-S} is less than the lower limit value MAX2Lim_L of the maximum value of the third cosine wave signal _{V C-S MAX (V C} -S), or the third cosine wave signal _{V C} When it is larger than the upper limit value MAX2Lim_H of the maximum value MAX (Vc _-S ) of _-S (step S502-1; No), the second gain correction unit 173 determines the maximum value MAX of the third sine wave signal Vc _{+ S} from the EEPROM 104. _{(V C + S),} and the third cosine wave signal _{V C-S} maximum value MAX _{(V C-S)} reads out the initial value MAX2ref the third cosine wave signal _{V C-S} maximum value MAX of _{(V C-S)} Then, the data on the RAM 102 is updated as (step S503 b), and the process returns to step S501.

The value of the third cosine wave signal _{V C-S} is, and the third cosine wave signal _{V C-S} minimum value MIN of _{(V C-S)} lower limit MIN2Lim_L above, and, third cosine wave signal _{V C- If} the upper limit value MIN2Lim_H of the minimum value MIN (V _C−S ) of _S is equal to or less than MIN2Lim_L ≦ V _C−S ≦ MIN2Lim_H (step S502-2; Yes), the second gain correction unit 173 calculates the third cosine wave signal _V value of _C-S the third cosine wave signal _{V C-S} minimum value MIN of _{(V C-S)} as to update the data in the RAM 102 (step S504a), the process returns to step S501.

If the value of the third cosine wave signal _{V C-S} is less than the lower limit value MIN2Lim_L the minimum value MIN of the third cosine wave signal _{V C-S (V C-} S), or the third cosine wave signal _{V C} When it is larger than the upper limit value MIN2Lim_H of the minimum value MIN (Vc _-S ) of _-S (step S502-2; No), the second gain correction unit 173 determines the minimum value MIN of the third sine wave signal Vc _{+ S} from the EEPROM 104. _{(V C + S),} and the third cosine wave signal _{V C-S} minimum value MIN _{(V C-S)} reads out the initial value MIN2ref the third cosine wave signal _{V C-S} minimum value MIN of _{(V C-S)} Then, the data on the RAM 102 is updated as (step S504 b), and the process returns to step S501.

Also in the interrupt processing procedure shown in FIG. 32, FIG. 33, FIG. 34, and FIG. 35, similarly to the interrupt processing procedure shown in FIG. 28, FIG. 29, FIG. sin [theta maximum value MAX (sin [theta _1f) of _1f, the maximum value MAX of the first cosine wave signal Cosθ _1f (Cosθ _1f), the minimum value MIN (Sinθ _1f) of the first sine-wave signal sin [theta _1f, the first cosine wave signal Cos? _1f the minimum value MIN of (Cos? _1f), the maximum value of the third sinusoidal signal _{V C + S MAX (V C} + S), the maximum value MAX _{(V C-S)} of the third cosine wave signal _{V C-S,} the third sine wave signal V _{C + S} minimum value MIN of _{(V C +} S), the minimum value the values of MIN _{(V C-S)} of the third cosine wave signal _{V C-S} is, even when an abnormal value due to noise or the like, the rotation angle normally Perform detection processing Can.

In the embodiment described above, the maximum value MAX of the first sine-wave signal Sinθ _1f (Sinθ _1f), the minimum value MIN (Cos? _1f), the minimum value of the first sine-wave signal sin [theta _1f of the first cosine wave signal Cos? _1f MIN (Sinθ _1f), the maximum value MAX (Cos? _1f) of the first cosine wave signal Cos? _1f, the maximum value MAX _{(V C +} S) of the third sinusoidal signal _{V C + S,} the minimum value MIN of the third sinusoidal signal _{V C + S} ( V _{C +} S), the upper limit of the third cosine wave signal _V maximum value MAX _{(V C-S} of the _C-S), and the minimum value MIN of the third cosine wave signal _{V C-S (V C-} S), the initial value Although the lower limit value is an example stored in the EEPROM 104 (first storage unit), the first storage unit may be provided in addition to the EEPROM 104 and may be stored in the first storage unit. The present disclosure is not limited by the configuration of the first storage unit.

Further, in the above embodiment, the rotation angle detection process described above, the maximum value MAX (Sinθ _1f) of the first sine-wave signal sin [theta _1f, the minimum value MIN (Cos? _1f) of the first cosine wave signal Cos? _1f, first minimum value MIN of the sine wave signal Sinθ _1f (Sinθ _1f), the maximum value MAX of the first cosine wave signal Cosθ _1f (Cosθ _1f), the maximum value of the third sine wave signal _{V S MAX (V C + S} ), the third sine wave minimum value MIN of the signal _{V S (V C + S)} , the maximum value MAX of the third cosine wave signal _{V C (V C-S)} , the minimum value MIN of the third cosine wave signal _{V C (V C-S)} is, RAM 102 Although the example stored in (the second storage unit) has been shown, a second storage unit may be provided in addition to the RAM 102 and may be stored in the second storage unit. The present disclosure is not limited by the configuration of the second storage unit.

  In the embodiment described above, an example of performing calibration of the rotation angle detection device 200 in real time at the time of actual operation in which the vehicle is actually traveled has been shown. In a state where the position detection sensor 25 is incorporated in the motor 20, the initial calibration of the rotation angle detection device 200 may be performed.

1 steering wheel (steering)
Reference Signs List 2 column shaft 3 reduction gear 4a, 4b universal joint 10 torque sensor 11 ignition switch 12 vehicle speed sensor 14 battery 15 motor drive circuit 16 motor current detection circuit 17 position detection unit 20 motor 20a motor shaft 25 position detection sensor 30 control unit (ECU)
31 Assist function unit 31a Current command value calculation unit 31b Current control unit 100 Electric power steering (EPS) device 101 CPU
102 RAM (second storage unit)
103 ROM
104 EEPROM (first storage unit)
105 interface 106 A / D converter 107 PWM controller 110 control computer (MCU)
171 difference calculation unit 172 first gain correction unit 173 second gain correction unit 174 angle calculation unit 200 rotation angle detection device 251 rotary magnet 252 MR sensor 1711 sine wave difference calculation unit 1712 cosine wave difference calculation unit 1721 first sine wave gain correction Unit 1722 First cosine wave gain correction unit 1731 Second sine wave gain correction unit 1732 Second cosine wave gain correction unit 1733 Phase conversion unit 1741 Inverse tangent calculation unit 1742 Quadrant judgment unit

Claims (18)

A differential sine wave signal including a positive phase sine wave signal and a negative phase sine wave signal obtained by inverting the phase of the positive phase sine wave signal, and a positive phase cosine wave signal and a negative phase obtained by inverting the positive phase cosine wave signal A position detection sensor that outputs a differential cosine wave signal including a cosine wave signal as a position detection signal of a motor;
A position detection unit that detects the position of the motor based on the position detection signal;
Equipped with
The position detection unit is
The difference between the positive phase sine wave signal and the negative phase sine wave signal is output as a first sine wave signal, and the difference between the positive phase cosine wave signal and the negative phase cosine wave signal is output as a first cosine wave signal The difference calculation unit to
While outputting the 2nd sine wave signal which corrected the gain of the 1st sine wave signal based on the maximum value or the minimum value of the 1st sine wave signal, based on the maximum value or the minimum value of the 1st cosine wave signal A first gain correction unit that outputs a second cosine wave signal obtained by correcting the gain of the first cosine wave signal;
The second cosine wave signal and the second sine wave signal are added to generate a third sine wave signal, and the gain of the third sine wave signal is generated based on the maximum value or the minimum value of the third sine wave signal. To generate a third cosine wave signal by subtracting the second sine wave signal from the second cosine wave signal and generating a third cosine wave signal; A second gain correction unit that outputs a fourth cosine wave signal obtained by correcting the gain of the third cosine wave signal based on a value;
An angle calculation unit that calculates a rotation angle of the motor based on the fourth sine wave signal and the fourth cosine wave signal;
Rotation angle detection device. Maximum value and minimum value of the first sine wave signal, maximum value and minimum value of the first cosine wave signal, maximum value and minimum value of the third sine wave signal, and maximum value of the third cosine wave signal The rotation angle detection device according to claim 1, further comprising a storage unit that stores the minimum value and the minimum value. The first gain correction unit
The zero point of the first cosine wave signal is detected, and when the zero point is detected, when the value of the first sine wave signal is 0 or more, the value of the first sine wave signal is detected as the first sine wave signal. Of the first sine wave signal is stored as the minimum value of the first sine wave signal when the value of the first sine wave signal is less than 0. And
The zero point of the first sine wave signal is detected, and when the value of the first cosine wave signal is 0 or more when the zero point is detected, the value of the first cosine wave signal is set to the first cosine wave signal. Is stored in the storage unit as the maximum value of the first cosine wave signal, and when the value of the first cosine wave signal is less than 0, the value of the first cosine wave signal is stored in the storage unit as the minimum value of the first cosine wave signal The rotation angle detection device according to claim 2. The storage unit is
The upper limit value and the lower limit value of the maximum value of the first sine wave signal and the first cosine wave signal, and the upper limit value and the lower limit value of the minimum value of the first sine wave signal and the first cosine wave signal are stored. ,
The first gain correction unit
The zero point of the first cosine wave signal is detected, and when the value of the first sine wave signal is 0 or more at the time of the detection of the zero point, the value of the first sine wave signal is the first sine wave When it is not less than the lower limit value of the maximum value of the signal and not more than the upper limit value of the maximum value of the first sine wave signal, the value of the first sine wave signal is set as the maximum value of the first sine wave signal. When the value of the first sine wave signal stored in the storage unit is less than 0, the value of the first sine wave signal is equal to or more than the lower limit value of the minimum value of the first sine wave signal, and Storing the value of the first sine wave signal as the minimum value of the first sine wave signal in the storage unit when the value is equal to or less than the upper limit value of the minimum value of the first sine wave signal;
The zero point of the first sine wave signal is detected, and when the value of the first cosine wave signal is 0 or more when the zero point is detected, the value of the first cosine wave signal is the first cosine wave. When the value is not less than the lower limit value of the maximum value of the signal and not more than the upper limit value of the maximum value of the first cosine wave signal, the value of the first cosine wave signal is taken as the maximum value of the first cosine wave signal. When the value of the first cosine wave signal stored in the storage unit is less than 0, the value of the first cosine wave signal is not less than the lower limit value of the minimum value of the first cosine wave signal, and The rotation according to claim 2, wherein the value of the first cosine wave signal is stored as the minimum value of the first cosine wave signal when the value is equal to or less than the upper limit value of the minimum value of the first cosine wave signal. Angle detector. The storage unit is
The initial value of the maximum value of the first sine wave signal and the first cosine wave signal, and the initial value of the minimum value of the first sine wave signal and the first cosine wave signal are further stored.
The first gain correction unit
At the time of detecting the zero point of the first cosine wave signal, when the value of the first sine wave signal is 0 or more, the value of the first sine wave signal is the lower limit value of the maximum value of the first sine wave signal. The initial value of the maximum value of the first sine wave signal is stored as the maximum value of the first sine wave signal when the value is less than or larger than the upper limit value of the maximum value of the first sine wave signal. , And when the value of the first sine wave signal is less than 0, the value of the first sine wave signal is less than the lower limit value of the minimum value of the first sine wave signal, or The initial value of the minimum value of the first sine wave signal is stored as the minimum value of the first sine wave signal in the storage unit when the value is larger than the upper limit value of the minimum value of the first sine wave signal,
At the time of detecting the zero point of the first sine wave signal, when the value of the first cosine wave signal is 0 or more, the value of the first cosine wave signal is the lower limit value of the maximum value of the first cosine wave signal. The initial value of the maximum value of the first cosine wave signal is stored as the maximum value of the first cosine wave signal when the value is less than or larger than the upper limit value of the maximum value of the first cosine wave signal. , And when the value of the first cosine wave signal is less than 0, the value of the first cosine wave signal is less than the lower limit value of the minimum value of the first cosine wave signal, or The initial value of the minimum value of the first cosine wave signal is stored as the minimum value of the first cosine wave signal in the storage unit when the value is larger than the upper limit value of the minimum value of the first cosine wave signal. The rotation angle detection device described. The second gain correction unit
The zero point of the third cosine wave signal is detected, and when the zero point is detected, when the value of the third sine wave signal is 0 or more, the value of the third sine wave signal is set to the third sine wave signal. Of the third sine wave signal is stored as the minimum value of the third sine wave signal when the value of the third sine wave signal is less than 0. And
The zero point of the third sine wave signal is detected, and when the value of the third cosine wave signal is 0 or more at the time of the detection of the zero point, the value of the third cosine wave signal is set to the third cosine wave signal. Of the third cosine wave signal is stored as the minimum value of the third cosine wave signal when the value of the third cosine wave signal is less than 0. The rotation angle detection device according to any one of claims 2 to 5. The storage unit is
The upper limit value and the lower limit value of the maximum value of the third sine wave signal and the third cosine wave signal, and the upper limit value and the lower limit value of the minimum value of the third sine wave signal and the third cosine wave signal are stored. ,
The second gain correction unit
The zero point of the third cosine wave signal is detected, and when the value of the third sine wave signal is 0 or more at the time of the detection of the zero point, the value of the third sine wave signal is the third sine wave When it is not less than the lower limit value of the maximum value of the signal and not more than the upper limit value of the maximum value of the third sine wave signal, the value of the third sine wave signal is regarded as the maximum value of the third sine wave signal. When the value of the third sine wave signal stored in the storage unit is less than 0, the value of the third sine wave signal is equal to or more than the lower limit value of the minimum value of the third sine wave signal, and And storing the value of the third sine wave signal as the minimum value of the third sine wave signal in the storage unit when the value is equal to or less than the upper limit value of the minimum value of the third sine wave signal;
The zero point of the third sine wave signal is detected, and when the value of the third cosine wave signal is 0 or more at the time of the detection of the zero point, the value of the third cosine wave signal is the third cosine wave. When the value is not less than the lower limit value of the maximum value of the signal and not more than the upper limit value of the maximum value of the third cosine wave signal, the value of the third cosine wave signal is set as the maximum value of the third cosine wave signal. When the value of the third cosine wave signal stored in the storage unit is less than 0, the value of the third cosine wave signal is not less than the lower limit value of the minimum value of the third cosine wave signal, and When the value is equal to or less than the upper limit value of the minimum value of the third cosine wave signal, the value of the third cosine wave signal is stored as the minimum value of the third cosine wave signal in the storage unit. The rotation angle detection device according to any one of the above. The storage unit is
An initial value of maximum values of the third sine wave signal and the third cosine wave signal, and an initial value of minimum values of the third sine wave signal and the third cosine wave signal are further stored;
The second gain correction unit
At the time of detecting the zero point of the third cosine wave signal, when the value of the third sine wave signal is 0 or more, the value of the third sine wave signal is the lower limit value of the maximum value of the third sine wave signal. When it is less than or larger than the upper limit value of the maximum value of the third sine wave signal, the initial value of the maximum value of the third sine wave signal is stored as the maximum value of the third sine wave signal. , And when the value of the third sine wave signal is less than 0, the value of the third sine wave signal is less than the lower limit of the minimum value of the third sine wave signal, or The initial value of the minimum value of the third sine wave signal is stored in the storage unit as the minimum value of the third sine wave signal when the value is larger than the upper limit value of the minimum value of the third sine wave signal,
At the time of detecting the zero point of the third sine wave signal, when the value of the third cosine wave signal is 0 or more, the value of the third cosine wave signal is the lower limit value of the maximum value of the third cosine wave signal. If it is less than or greater than the upper limit value of the maximum value of the third cosine wave signal, the initial value of the maximum value of the third cosine wave signal is stored as the maximum value of the third cosine wave signal. And the value of the third cosine wave signal is less than the lower limit value of the minimum value of the third cosine wave signal when the value of the third cosine wave signal is less than 0, or The initial value of the minimum value of the third cosine wave signal is stored in the storage unit as the minimum value of the third cosine wave signal when the value is larger than the upper limit value of the minimum value of the third cosine wave signal. The rotation angle detection device described. The difference calculation unit
Assuming that the positive phase sine wave signal is Sinθ ₁ +, the opposite phase sine wave signal is Sinθ ₁ −, and the first sine wave signal is Sinθ _1f , the first sine wave signal is calculated using the following equation (1) Calculate Sin θ _1f ,
Assuming that the positive phase cosine wave signal is Cos θ ₁ +, the negative phase cosine wave signal is Cos θ ₁ −, and the first cosine wave signal is Cos θ 1 _f , the first cosine wave signal is calculated using the following equation (2) The rotation angle detection device according to any one of claims 1 to 8, which calculates Cos θ _1f .
Sin θ _1f = (Sin θ ₁ +)-(Sin θ _1- ) (1)
Cos θ _1f = (Cos θ ₁ +) − (Cos θ ₁ −) (2) The first gain correction unit
The maximum value of the first sine-wave signal Sinθ _1f MAX (Sinθ _1f), said second sine-wave signal and sin [theta _{1 g,} when the value of the first sine-wave signal sin [theta _1f is greater than or equal to 0, the following equation (3 To calculate the second sine wave signal Sinθ _1g, and when the value of the first sine wave signal Sinθ _1f is less than 0, the second sine wave signal Sinθ is calculated using the following equation (4): The rotation angle detection device according to any one of claims 1 to 9, which calculates _{1 g} .
Sinθ _1g = Sinθ _1f × (1 / (MAX (Sinθ _1f ))) (3)
Sinθ _1g = Sinθ _1f × ((-1) / (MIN (Sinθ _1f ))) (4) The first gain correction unit
The maximum value of the first cosine wave signal Cosθ _1f MAX (Cosθ _1f), the second cosine wave signal and Cos? _{1 g,} when the value of the first cosine wave signal Cos? _1f is greater than or equal to 0, the following equation (5 And calculating the second cosine wave signal Cosθ _1g, and when the value of the first cosine wave signal Cosθ _1f is less than 0, the second cosine wave signal Cosθ is calculated using the following equation (6) The rotation angle detection device according to any one of claims 1 to 10, wherein 1 _g is calculated.
Cosθ _1g = Cosθ _1f × (1 / (MAX (Cosθ _1f ))) (5)
Cosθ _1g = Cosθ _1f × ((-1) / (MIN (Cosθ _1f ))) (6) The second gain correction unit
When the third sine wave signal is V _{C + S} , the third sine wave signal V _{C + S} is calculated using the following equation (7), and the third cosine wave signal is V _C-S: The rotation angle detection device according to claim 11, wherein the third cosine wave signal V _C-S is calculated using the equation (8).
_{V C + S = Cosθ 1g +} Sinθ 1g ··· (7)
V _C-S = Cosθ _1g- Sinθ _1g (8) The second gain correction unit
When the maximum value of the third sine wave signal V _{C + S} is MAX (V _{C + S} ), the fourth sine wave signal is V 1 _{C + S,} and the value of the third sine wave signal V _{C + S} is 0 or more, the following equation (9 To calculate the fourth sine wave signal V1 _{C + S,} and when the value of the third sine wave signal V.sub.C _{+ S} is less than 0, the fourth sine wave signal V1 is calculated using the following equation (10). The rotation angle detection device according to claim 12, which calculates _{C + S.}
V1 _{C + S} = V _{C + S} x (1 / (MAX (V _{C + S} ))) (9)
V1 _{C + S} = V _{C + S} x ((-1) / (MIN (V _{C + S} ))) (10) The second gain correction unit
The maximum value of the third cosine wave signal V _C-S is MAX (V _C-S ), the fourth cosine wave signal is V 1 _C-S, and the value of the third cosine wave signal V _C-S is 0 or more When the value of the third cosine wave signal V _{C -S} is less than 0, the fourth cosine wave signal V 1 _{C -S} is calculated using the following equation (11). The rotation angle detection device according to claim 12 or 13, wherein the fourth cosine wave signal V1C _-S is calculated using.
V1 _C-S = V _C-S x (1 / (MAX (V _C-S ))) (11)
V1C _-S = VC _-S * ((-1) / (MIN (VC _-S ))) (12) The angle calculation unit
-90deg <when the angle theta _1h in the range of theta _1h <+ 90deg, using the following equation (13), calculates the angle theta _1h, the rotation of the motor in the range of 0deg <θ ₁ <360deg Assuming that the angle is θ ₁ and the fourth cosine wave signal V 1 _C-S is 0 or more, the rotation angle θ _{1 of the} motor is calculated using the following equation (14), and the fourth cosine wave signal The rotation angle detection device according to claim 14, wherein when the V1C _-S is less than 0, the rotation angle? _{1 of the} motor is calculated using the following equation (15).
θ _1h = arctan (V _{1 C + S} / V 1 _C−S ) (13)
θ ₁ = θ _{1 h} −45 deg (14)
θ ₁ = (θ _{1 h} +180 deg) −45 deg (15) A rotation angle detection device according to any one of claims 1 to 15, comprising:
A motor control device that drives and controls the motor using the rotation angle. The motor control device according to claim 16,
The motor is provided on a column axis or a rack of steering, and performs torque control of the steering force of the steering. A differential sine wave signal including a positive phase sine wave signal output from a position detection sensor as a position detection signal of a motor and a negative phase sine wave signal obtained by inverting the phase of the positive phase sine wave signal, and a positive phase cosine wave A rotation angle detection method for detecting the position of the motor based on a differential cosine wave signal including a signal and an antiphase cosine wave signal obtained by inverting the phase of the positive phase cosine wave signal.
Setting the difference between the positive phase sine wave signal and the negative phase sine wave signal as a first sine wave signal;
Setting a difference between the positive phase cosine wave signal and the negative phase cosine wave signal as a first cosine wave signal;
Correcting the gain of the first sine wave signal to a second sine wave signal based on the maximum value or the minimum value of the first sine wave signal;
Correcting the gain of the first cosine wave signal based on the maximum value or the minimum value of the first cosine wave signal to obtain a second cosine wave signal;
Adding the second cosine wave signal and the second sine wave signal to obtain a third sine wave signal;
Subtracting the second sine wave signal from the second cosine wave signal to obtain a third cosine wave signal;
Correcting the gain of the third sine wave signal based on the maximum value or the minimum value of the third sine wave signal to obtain a fourth sine wave signal;
Correcting the gain of the third cosine wave signal based on the maximum value or the minimum value of the third cosine wave signal to obtain a fourth cosine wave signal;
Calculating a rotation angle of the motor based on the fourth sine wave signal and the fourth cosine wave signal;
A rotation angle detection method.

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