JP2019144056A - Rotation angle detector, motor controller, electric power steering device, and rotation angle detection method - Google Patents

Abstract

To provide a rotation angle detector, a motor controller, an electric power steering device, and a rotation angle detection method with which it is possible to maintain high detection accuracy.SOLUTION: The gain of a first sine wave signal is corrected to obtain a second sine wave signal on the basis of the maximum or minimum value of the first sine wave signal when the revolution speed of a motor is less than or equal to an upper-limit threshold. The gain of a first cosine wave signal is corrected to obtain a second cosine wave signal on the basis of the maximum or minimum value of the first cosine wave signal when the revolution speed of a motor is less than or equal to an upper-limit threshold. The gain of a third sine wave signal derived by adding the second cosine wave signal and the second sine wave signal is corrected to obtain a fourth sine wave signal on the basis of the maximum or minimum value of the third sine wave signal. The gain of a third cosine wave signal derived by subtracting the second sine wave signal from the second cosine wave signal is corrected to obtain a fourth cosine wave signal on the basis of the maximum or minimum value of the third cosine wave signal. The rotation angle of the motor is calculated on the basis of the fourth sine wave signal and the fourth cosine wave signal.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.

  In order to reduce the steering force of vehicles such as passenger cars and trucks, there is a so-called electric power steering (EPS) device that assists steering by a motor. The electric power steering apparatus has a steering assist control function for applying an assist steering force generated by a motor to a vehicle steering mechanism. In such an electric power steering apparatus, in order to perform current control of the 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 magnetoresistive elements connected in series at a predetermined interval in the direction parallel to the rotation axis of a magnetized 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).

JP2015-87137A

  When using a magnetoresistive element as a sensor, a DC offset component is superimposed on the output of the sensor. Moreover, 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. In general, calibration is performed so as to correct an offset voltage, a gain error, a phase shift, and the like before shipment in a state where a sensor is incorporated in a motor. However, the offset voltage and gain error generated in the sensor output change due to temperature drift, and increase as the temperature rises. For this reason, there is a possibility that the detection accuracy is lowered under a temperature condition different from that at the time of calibration before shipment. In addition, these errors may increase due to changes over time, and the detection accuracy may decrease. In particular, since the magnetoresistive element is a highly sensitive semiconductor element, output fluctuation due to such temperature characteristics and aging cannot 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 capable of maintaining high detection accuracy. It is an object.

  In order to achieve the above object, a rotation angle detection device according to an aspect of the present invention includes 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 for outputting a differential cosine wave signal including a positive phase cosine wave signal and a negative phase cosine wave signal obtained by inverting the phase of the positive phase cosine wave signal as a position detection signal of the motor, and the position detection A position detection unit for detecting the position of the motor based on the signal; and a storage unit, wherein the position detection unit calculates a difference between the positive phase sine wave signal and the negative phase sine wave signal as a first sine wave. A difference calculation 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 a maximum of the first sine wave signal stored in the storage unit Based on the value or the minimum value, the gain of the first sine wave signal is corrected. Outputs a second sine wave signal and outputs a second cosine wave signal obtained by correcting the gain of the first cosine wave signal based on the maximum value or the minimum value of the first cosine wave signal stored in the storage unit. A first gain correction unit that adds the second cosine wave signal and the second sine wave signal to generate a third sine wave signal, and the maximum of the third sine wave signal stored in the storage unit A fourth sine wave signal in which the gain of the third sine wave signal is corrected based on the value or the minimum value, and a third cosine wave signal obtained by subtracting the second sine wave signal from the second cosine wave signal. And 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 the maximum value or the minimum value of the third cosine wave signal stored in the storage unit And based on the fourth sine wave signal and the fourth cosine wave signal, An angle calculation unit that calculates a rotation angle of the motor and calculates a rotation number of the motor based on the rotation angle of the motor, wherein the first gain correction unit corresponds to at least the rotation number of the motor The maximum value and the minimum value of the first sine wave signal and the maximum value and the minimum value of the first cosine wave signal are updated.

  According to the above configuration, the rotation angle detection device can be calibrated based on the position detection signal detected in real time. Thereby, it can suppress that detection accuracy falls by temperature drift or a time-dependent change, and can maintain high detection accuracy.

  As a desirable mode of the rotation angle detection device, the first gain correction unit may be configured to store the first sine wave stored in the storage unit when the rotation speed of the motor is equal to or lower than an upper limit threshold value of the rotation speed of the motor. It is preferable to update the maximum and minimum values of the signal and the maximum and minimum values of the first cosine wave signal.

  Thereby, when the rotation speed of the motor is equal to or lower than the upper limit threshold, the gains of the first sine wave signal and the first cosine wave signal are corrected to obtain the second sine wave signal and the second cosine wave signal. The maximum value and minimum value of the 1 sine wave signal and the maximum value and minimum value of the first cosine wave signal are updated.

  As a desirable mode of the rotation angle detection device, the first gain correction unit is configured to detect the first sine wave when the value of the first sine wave signal is 0 or more when the zero point of the first cosine wave signal is detected. The value of the signal is stored in the storage unit as the maximum value of the first sine wave signal, and when the zero point of the first cosine wave signal is detected, the value of the first sine wave signal is less than zero. The value of the first sine wave signal is stored in the storage unit as the minimum value of the first sine wave signal, and when the zero point of the first sine wave signal is detected, the value of the first cosine wave signal is 0 or more. The value of the first cosine wave signal at a certain time is stored in the storage unit as the maximum value of the first cosine wave signal, and when the zero point of the first sine wave signal is detected, the value of the first cosine wave signal is stored. The value of the first cosine wave signal when is less than 0 is the first cosine wave signal. Stored in the storage unit as the minimum value.

  Thereby, by detecting the maximum value or the minimum value of the first sine wave signal or the maximum value or the minimum value of the first cosine wave signal, the number of rotations of the motor is set to be equal to or lower than the upper limit threshold value, thereby further improving the detection accuracy. Can be increased.

  As a desirable mode of the rotation angle detection device, when the zero point of the first cosine wave signal is detected, the value of the first sine wave signal is 0 or more, and the value of the first cosine wave signal is the first cosine wave signal. When the maximum value of the cosine wave signal is not less than the lower limit value and not more than the upper limit value, 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 the first cosine wave signal is stored. When the zero point is detected, the value of the first sine wave signal is less than 0, and the value of the first sine wave signal is not less than the lower limit value and not more than the upper limit value of the minimum value of the first sine wave signal. In this case, the 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 value of the first cosine wave signal is detected when the zero point of the first sine wave signal is detected. Is greater than or equal to 0, and the value of the first cosine wave signal is lower than the maximum value of the first cosine wave signal. When the value is not less than the upper limit value and not more than the upper limit value, 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 zero point of the first sine wave signal is detected, When the value of the first cosine wave signal is less than 0 and the value of the first cosine wave signal is not less than the lower limit value and not more than the upper limit value of the minimum value of the first cosine wave signal, the first cosine wave signal The value of the signal is stored in the storage unit as the minimum value of the first cosine wave signal.

  Thereby, in addition to setting the number of revolutions of the motor to be equal to or lower than the upper limit threshold, the maximum value and minimum value of the first sine wave signal, or the upper limit value and lower limit value of the maximum value and minimum value of the first cosine wave signal are provided. Thus, learning of abnormal values can be prevented.

  As a desirable mode of the rotation angle detection device, the difference calculation unit may be configured such that the positive phase sine wave signal is less than a lower limit threshold value of the positive phase sine wave signal or an upper limit threshold value of the positive phase sine wave signal. If it is larger, it is determined that the input value of the positive phase sine wave signal is abnormal, and the negative phase sine wave signal is less than a lower limit threshold of the negative phase sine wave signal, or an upper limit of the negative phase sine wave signal When it is larger than the threshold value, it is determined that the input value of the negative-phase sine wave signal is abnormal, and the positive-phase cosine wave signal is less than a lower-limit threshold value of the positive-phase cosine wave signal, or the positive-phase cosine wave signal When the signal is larger than the upper limit threshold value of the signal, it is determined that the input value of the positive phase cosine wave signal is abnormal, and the negative phase cosine wave signal is less than the lower limit threshold value of the negative phase cosine wave signal, or When the phase cosine wave signal is larger than the upper threshold, the phase cosine wave signal It is preferable to determine that the force abnormalities.

  Thereby, an input value abnormality of the positive phase sine wave signal, an input value abnormality of the negative phase sine wave signal, an input value abnormality of the positive phase cosine wave signal, and an input value abnormality of the negative phase cosine wave signal can be detected.

  As a desirable mode of the rotation angle detection device, the difference calculation unit is configured such that the sine wave signal offset voltage is less than a lower limit threshold value of the sine wave signal offset voltage or is higher than an upper limit threshold value of the sine wave signal offset voltage. If it is larger, it is determined that the offset voltage value of the sine wave signal offset voltage is abnormal, and the cosine wave signal offset voltage is less than a lower limit threshold of the cosine wave signal offset voltage, or the cosine wave signal offset voltage When it is larger than the upper limit threshold value, it is preferable to determine that the offset voltage value of the cosine wave signal offset voltage is abnormal.

  Thereby, the offset voltage value abnormality of the sine wave signal offset voltage and the offset voltage value abnormality of the cosine wave signal offset voltage can be detected.

  As a desirable mode of the rotation angle detection device, the first gain correction unit is configured to detect the first sine wave when the value of the first sine wave signal is 0 or more when the zero point of the first cosine wave signal is detected. The maximum value of the first sine 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 greater than the upper limit value of the maximum value of the first sine wave signal. When the zero point of the first cosine wave signal is detected, the value of the first sine wave signal when the value of the first sine wave signal is less than 0 is the value of the first sine wave signal. When it is less than the lower limit value of the minimum value or larger than the upper limit value of the minimum value of the first sine wave signal, it is determined that the minimum value of the first sine wave signal is abnormal, The first cosine when the value of the first cosine wave signal is 0 or more when the zero point is detected. When the value of the wave signal is less than the lower limit value of the maximum value of the first cosine wave signal or greater than the upper limit value of the maximum value of the first cosine wave signal, the maximum value of the first cosine wave signal When the zero point of the first sine wave signal is detected, the value of the first cosine wave signal when the value of the first cosine wave signal is less than 0 is the first cosine wave signal. It is preferable to determine that the minimum value of the first cosine wave signal is abnormal when it is less than the lower limit value of the minimum value or larger than the upper limit value of the minimum value of the first cosine wave signal.

  Thereby, the maximum value abnormality of the first sine wave signal, the minimum value abnormality of the first sine wave signal, the maximum value abnormality of the first cosine wave signal, and the minimum value abnormality of the first cosine wave signal can be detected.

  As a desirable mode of the rotation angle detection device, the second gain correction unit may detect the third sine wave when the value of the third sine wave signal is 0 or more when the zero point of the third cosine wave signal is detected. When the value of the third sine wave signal is less than 0 when the zero value of the third cosine wave signal is detected, the value of the signal is stored in the storage unit as the maximum value of the third sine wave signal. The value of the third sine wave signal is stored in the storage unit as the minimum value of the third sine wave signal, and when the zero point of the third sine wave signal is detected, the value of the third cosine wave signal is 0 or more. In some cases, the value of the third cosine wave signal is stored in the storage unit as the maximum value of the third cosine wave signal, and the value of the third cosine wave signal is detected when the zero point of the third sine wave signal is detected. Is less than 0, the value of the third cosine wave signal is set to the third cosine wave signal. It is preferably stored in the storage unit as the minimum value.

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

  In order to achieve the above object, a motor control device according to an aspect of the present invention includes the rotation angle detection device, and drives and controls the motor using the rotation angle.

  Thereby, it is possible to drive and control the motor 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, and the motor is provided on a column shaft or a rack of a steering, and torque control of the steering force of the steering is performed. To do.

  Thereby, the accuracy of the steering assist control in the electric power steering apparatus can be increased.

  Thereby, the electric power steering device can perform processing according to the failure determination result of the rotation angle detection device.

  In order to achieve the above object, a rotation angle detection method according to one aspect of the present invention includes a positive phase sine wave signal output from a position detection sensor as a motor position detection signal and a phase inversion of the positive phase sine wave signal. A differential sine wave signal including a negative phase sine wave signal, and a differential cosine wave signal including a positive phase cosine wave signal and a negative phase 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, wherein a difference between the positive phase sine wave signal and the negative phase sine wave signal is a first sine wave signal, and the positive phase cosine wave signal and the reverse phase A step of setting a difference from the phase cosine wave signal as a first cosine wave signal, and a maximum value or a minimum value of the first sine wave signal when the rotation speed of the motor is equal to or lower than an upper limit threshold value of the rotation speed of the motor. To correct the gain of the first sine wave signal and Based on the maximum value or the minimum value of the first cosine wave signal when the rotation speed of the motor is equal to or less than the upper limit threshold value of the rotation speed of the motor, From the step of correcting the gain to obtain a second cosine wave signal, the step of adding the second cosine wave signal and the second sine wave signal to obtain a third sine wave signal, and the second cosine wave signal Subtracting the second sine wave signal to obtain a third cosine wave signal and correcting the gain of the third sine wave signal based on the maximum value or the minimum value of the third sine wave signal A step of making a wave signal, a step of correcting a gain of the third cosine wave signal based on the maximum value or the minimum value of the third cosine wave signal, and making a fourth cosine wave signal, and the fourth sine wave signal And the rotation of the motor based on the fourth cosine wave signal. A calculating a square, a.

  As a result, the rotation angle detection device can be calibrated based on the position detection signal detected in real time. Thereby, it can suppress that detection accuracy falls by temperature drift or a time-dependent change, and can maintain high detection accuracy. Further, the maximum value and the minimum value of the first sine wave signal used when obtaining the second sine wave signal and the second cosine wave signal by correcting the gains of the first sine wave signal and the first cosine wave signal, or The detection accuracy can be further improved by setting the rotation speed of the motor when detecting the maximum value or the minimum value of one cosine wave signal to be equal to or lower than the upper limit threshold value.

  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 that can maintain high detection accuracy.

FIG. 1 is a diagram illustrating a configuration of an electric power steering apparatus according to an embodiment. FIG. 2 is a schematic diagram illustrating a hardware configuration of a control unit that controls the electric power steering apparatus according to the embodiment. FIG. 3 is a functional block diagram illustrating a functional configuration of a control unit that controls the electric power steering apparatus according to the embodiment. FIG. 4 is a schematic diagram of a position detection sensor in the embodiment. FIG. 5 is a diagram illustrating the relationship between the position detection signal and the phase angle. FIG. 6 shows the motor control current when the U-phase current, V-phase current, and W-phase current of the three-phase brushless motor are controlled in the three-phase brushless motor using the electrical angle detected by the position detector. It is a figure which shows the relationship between an electrical angle. FIG. 7 is a diagram illustrating an example of a schematic block configuration of the rotation angle detection device according to the embodiment. FIG. 8 is a diagram illustrating an example of an equivalent block of the differential operation unit. FIG. 9 is a first diagram illustrating a difference calculation concept in the equivalent block shown in FIG. 8 of the differential calculation unit. FIG. 10 is a second diagram for explaining the concept of difference calculation in the equivalent block shown in FIG. 8 of the differential operation unit. FIG. 11 is a third diagram for explaining the concept of difference calculation in the equivalent block shown in FIG. 8 of the differential operation unit. FIG. 12 is a fourth diagram illustrating a difference calculation concept 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 concept of detecting 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 the phase conversion process when no phase shift occurs in the second sine wave signal and the second cosine wave signal. FIG. 16 is a vector diagram after the phase conversion process when a phase shift of α occurs in the second sine wave signal and the second cosine wave signal. FIG. 17 is a diagram illustrating an example of an equivalent block of the second gain correction unit. FIG. 18 is a diagram for explaining the concept of detecting 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 embodiment. FIG. 20 is a diagram illustrating an example of each piece of information stored in the EEPROM. FIG. 21 is a flowchart illustrating an example of the input abnormality determination process. FIG. 22 is a flowchart illustrating an example of the maximum value detection process and the minimum value detection process of the first sine wave signal and the first cosine wave signal. FIG. 23 is a flowchart illustrating an example of the maximum value detection process and the minimum value detection process of the third sine wave signal and the third cosine wave signal. FIG. 24 is a diagram illustrating a configuration example in which only two position detection sensors are provided. FIG. 25 is a diagram illustrating a configuration example in which two motors, two position detection sensors, and two position detection units are provided. FIG. 26 is a flowchart illustrating an example of a failure determination processing procedure of the rotation angle detection device according to the embodiment. FIG. 27 is a flowchart illustrating an example of the abnormality detection process.

  DESCRIPTION OF EMBODIMENTS Hereinafter, modes for carrying out the invention (hereinafter referred to as embodiments) will be described in detail with reference to the drawings. In addition, this invention is not limited by the following embodiment. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those in a so-called equivalent range. Furthermore, the constituent elements disclosed in the following embodiments can be appropriately combined.

  FIG. 1 is a diagram illustrating a configuration of an electric power steering apparatus according to an embodiment. The electric power steering apparatus 100 includes a motor 20 that applies an auxiliary steering force to the steering mechanism of the vehicle, and drives and controls the motor 20 based on a steering auxiliary command value calculated using at least a steering torque and a vehicle speed for the steering mechanism. To do.

  Thus, the electric power steering apparatus 100 is mounted on a vehicle and assists the operation of the handle wheel 1 (hereinafter also referred to as “steering”) by the driver of the vehicle. A column shaft 2 of the handle wheel 1 is connected to a tie rod 6 of a steered wheel via a reduction gear 3, universal joints 4a and 4b, and a rack and pinion mechanism 5. The column shaft 2 is provided with a torque sensor 10 that detects the steering torque T of the handle wheel 1. 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 handle 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 that controls the electric power steering apparatus 100 is supplied with electric power from the battery 14 via a power supply relay 13 incorporated therein, and is transmitted from the ignition switch 11. Receive the ignition signal. Further, the control unit 30 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 so that the current detection value of the motor 20 follows the current command value based on the value of the current (current detection value) supplied to the motor 20 and the current command value. Thus, the control unit 30 is a device that controls the electric power steering device 100 (a control device for the electric power steering device).

  FIG. 2 is a schematic diagram illustrating a hardware configuration of a control unit that controls the electric power steering apparatus according to the embodiment. As shown in FIG. 2, the control unit 30 includes a power 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 CPU (Central Processing Unit) 101, a RAM (Random Access Memory) 102 as a first storage device, a ROM (Read Only Memory) 103 as a second storage device, an EEPROM ( 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 provided, and these are connected to a bus 108. The CPU 101 corresponds to a processing device, and controls the electric power steering device 100 by executing a computer program for control of the electric power steering device 100 (hereinafter referred to as a control program) stored in the ROM 103.

  The ROM 103 stores a control program and data used for control of the electric power steering apparatus 100. The RAM 102 is used as a work memory for operating the control program. The EEPROM 104 stores control data and the like input / 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 turned on, and is overwritten in the EEPROM 104 at a predetermined timing.

  The ROM 103, the RAM 102, the EEPROM 104, and the like are storage devices that store information, and are storage devices (primary storage devices) that can be directly accessed by the CPU 101.

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

  Moreover, in this embodiment, RAM102 functions as a 2nd memory | storage part which memorize | stores the update value of the various data in the rotation angle detection process mentioned later.

  The A / D converter 106 converts each input value to the control unit 30 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 vehicle speed V signal (vehicle speed pulse) from the vehicle speed sensor 12.

  The PWM controller 107 outputs a PWM control signal for each phase of UVW based on the current command value for 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 current Im supplied to the motor 20 and outputs it to the A / D converter 106.

The position detection unit 17 reads the position detection signal output from the position detection sensor 25 and outputs the rotation angle θ ₁ or the electrical angle θ ₂ of the motor 20. 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 by a circuit, or may be realized by the control computer 110 illustrated in FIG. 2, more specifically, the CPU 101. Details of the correction method of the position detection signal in the position detection sensor 25 and the position detection unit 17 will be described later.

  FIG. 3 is a functional block diagram illustrating a functional configuration of a control unit that controls the electric power steering apparatus according to the embodiment. The 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 includes 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 Im approaches 0, the integral control and derivative control and proportional control 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 according to the duty ratio D calculated by the current control unit 31b. The motor current detection circuit 16 detects the current Im flowing through the motor 20.

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

  FIG. 4 is a schematic diagram of a position detection sensor in the embodiment. In the present embodiment, as shown in FIG. 4, the position detection sensor 25 includes a one-pole rotating magnet 251 having N and S poles provided at an end of a motor shaft (rotating shaft) 20 a, and the rotating magnet. And an MR sensor 252 that is disposed in the axial direction (in the direction of the axial center X of the motor shaft (rotating shaft) 20a) from 251 via a gap having a predetermined interval.

  The MR sensor 252 is configured using an MR (Magneto Resistance) element (magnetoresistance element). An example of the MR sensor 252 is a TMR sensor using a tunnel magnetoresistance effect (Tunnel Magneto Resistance Effect). In addition to the TMR sensor, the MR sensor 252 may be an AMR (Anisotropic Magneto Resistive) sensor or a GMR (Giant Magnetoresistive Effect) sensor. The present disclosure is not limited by the type of the MR sensor 252.

  The MR sensor 252 outputs a position detection signal corresponding to a change in the magnetic field generated when the rotating magnet 251 rotates together with the motor shaft (rotating shaft) 20a about the axis X of the motor shaft (rotating 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 position detection signals. 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 illustrating the relationship between the position detection signal and the phase angle. 5A shows an ideal waveform of the positive-phase sine wave signal Sinθ ₁ +, and FIG. 5B shows an ideal waveform of the negative-phase sine wave signal Sinθ ₁ −. Yes. Further, (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 −. Show. Further, (e) shown in FIG. 5 shows the rotation angle (mechanical angle) θ ₁ of the motor 20.

As shown in FIG. 5, in this embodiment, since the number of magnetic poles of the rotating magnet 251 is 1, one cycle Tm of the rotation angle (mechanical angle) θ ₁ of the motor 20 and one cycle of the electrical angle of the MR sensor 252. Te matches. That is, the MR sensor 252 shown in FIG. 4 detects one cycle Te of the electrical angle of the MR sensor 252 in one cycle Tm of the rotation angle (mechanical angle) θ ₁ of the motor 20. The position detection sensor 25 is not limited to the above-described configuration as long as it can output a differential sine wave signal and a differential cosine wave signal. For example, the rotation angle (mechanical angle) θ _{1 of the} motor 20 is not limited thereto. For one period Tm, a differential sine wave signal and a differential cosine wave signal for a plurality of periods in electrical angle may be output.

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

  As shown in FIG. 6, the U-phase current, V-phase current, and W-phase current of the three-phase brushless motor have waveforms that 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 of the motor 20 detected by the position detection unit 17. In the example shown in FIG. 6, an example is shown in which control is performed so that the electric angle 0 [deg] is the current control start position and the phase of the U phase is 0 [deg].

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

  FIG. 7 is a diagram illustrating an example of a schematic block configuration of the rotation angle detection device according to the embodiment. As illustrated in FIG. 7, the rotation angle detection device 200 according to the 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 −, and outputs a first sine wave signal Sinθ _1f . Further, the sine wave difference calculation unit 1711 includes a later-described normal phase sine wave signal input value abnormality detection flag ERR1-1, a negative phase sine wave signal input value abnormality detection flag ERR1-2, and a sine wave signal offset voltage value abnormality detection flag. It has a function of setting or resetting ERR3-1.

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 −, and outputs a first cosine wave signal Cosθ _1f . Further, the cosine wave difference calculation unit 1712 includes a positive phase cosine wave signal input value abnormality detection flag ERR2-1, a negative phase cosine wave signal input value abnormality detection flag ERR2-2, and a cosine wave signal offset voltage value abnormality detection flag which will be described later. It has a function of setting or resetting ERR3-2.

  The differential operation unit 171 receives the differential differential sine wave signal and differential cosine wave signal, which are analog signals and are subjected to A / D conversion by sampling the differential sine wave signal and differential cosine wave signal which are analog signals. The

  FIG. 8 is a diagram illustrating an example of an equivalent block of the differential operation unit. FIG. 9 is a first diagram illustrating a difference calculation concept in the equivalent block shown in FIG. 8 of the differential calculation unit. FIG. 10 is a second diagram for explaining the concept of difference calculation in the equivalent block shown in FIG. 8 of the differential operation unit. FIG. 11 is a third diagram for explaining the concept of difference calculation in the equivalent block shown in FIG. 8 of the differential operation unit. FIG. 12 is a fourth diagram illustrating a difference calculation concept 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 sinusoidal signal offset voltage _{Dif Sin1} superimposed. Further, as shown in FIG. 10, a cosine wave signal offset voltage Dif _Cos1 is superimposed on the positive phase cosine wave signal Cosθ ₁ + and the negative phase cosine wave signal Cosθ ₁ − which are differential cosine wave signals.

Sinusoidal signal 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 positive phase sine wave signals obtained by subtracting the sine wave signal offset voltage _{Dif Sin1} Sinθ _1d +, the following (2) expressed by the formula, a sinusoidal signal offset voltage _{Dif Sin1} reversed-phase sine wave signal sin [theta _1d obtained by subtracting the - is It can be expressed by the following equation (3).

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

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

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

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

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

Based on the positive phase sine wave signal Sinθ _1d +, the first sine wave signal Sinθ _1f = (Sinθ _1d +) = (− (Sinθ _1d −)), and subtracting equation (5) from equation (4) above, The following equation (6) is obtained.

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

Further, the cosine wave signal offset voltage Dif _Cos1 is expressed 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 positive phase cosine wave signal Cos? _1d obtained by subtracting the cosine wave signal offset voltage _{Dif Cos 1} +, the following (8) expressed by the formula, the cosine wave signal offset voltage _{Dif Cos 1} reverse-phase cosine wave signal Cos? _1d obtained by subtracting the - is It can be expressed by the following equation (9).

(Cosθ _1d +) = (Cosθ ₁ +) − Dif _Cos1 (8)

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

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

(Cos θ _1d +) = (Cos θ ₁ +) / 2− (Cos θ ₁ −) / 2 (10)

(Cos θ _1d −) = − ((Cos θ ₁ +) / 2− (Cos θ ₁ −) / 2) (11)

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

(Cos θ _1f ) × 2 = (Cos θ ₁ +) − (Cos θ ₁ −) (12)

In the present 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, and differential positive phase cosine wave signal Cos? _{1 +} and the negative phase cosine wave signal is a cosine wave signal Cos? ₁ - to get on each double resolution. Accordingly, the first sine wave signal Sinθ _1f is obtained by subtracting the negative phase sine wave signal Sinθ ₁ − from the normal phase sine wave signal Sinθ ₁ + using the following equation (6 ′) (see FIG. 11). ). Further, the first cosine wave signal Cosθ _1f is obtained by subtracting the negative phase cosine wave signal Cosθ ₁ − from the positive phase cosine wave signal Cosθ ₁ + using the following equation (12 ′) (see FIG. 12). .

Sinθ _1f = (Sinθ ₁ +) − (Sinθ 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 sine wave difference calculation unit 1711 detects an input value abnormality of the positive phase sine wave signal Sinθ ₁ +.

Specifically, the sine wave difference calculation unit 1711 has, for example, a value of the positive phase sine wave signal Sinθ ₁ + equal to or higher than a lower limit threshold (eg, 0.3 V) in terms of an analog value and an upper limit threshold (eg, 4.7 V). ) If it is within the following range, it is determined to be normal, and if the value of the positive phase sine wave signal Sinθ ₁ + is less than the lower limit threshold in terms of analog value or larger than the upper limit threshold, the positive phase sine wave It is determined that the input value of the signal Sinθ ₁ + is abnormal. When the sine wave difference calculation unit 1711 detects an input value abnormality of the positive phase sine wave signal Sinθ ₁ +, the positive phase sine wave signal input value abnormality detection flag ERR1-1 is set.

Further, the sine wave difference calculation unit 1711 detects an input value abnormality of the negative-phase sine wave signal Sinθ ₁ −.

Specifically, the sine wave difference calculation unit 1711 has, for example, the value of the anti-phase sine wave signal Sinθ ₁ − equal to or higher than a lower limit threshold (eg, 0.3 V) in terms of analog value and an upper limit threshold (eg, 4.7 V). ) If it is within the following range, it is determined to be normal, and if the value of the anti-phase sine wave signal Sinθ ₁ − is less than the lower limit threshold in terms of analog value or greater than the upper limit threshold, the anti-phase sine wave It is determined that the input value of the signal Sinθ ₁ − is abnormal. When the sine wave difference calculation unit 1711 detects an input value abnormality of the negative phase sine wave signal Sinθ ₁ −, the negative phase sine wave signal input value abnormality detection flag ERR1-2 is set.

Further, sine wave difference calculation unit 1711 detects the abnormality of the sinusoidal signal offset voltage _{Dif Sin1} calculated by the above equation (1).

Specifically, sinusoidal difference calculation unit 1711, for example, the value of the sine wave signal offset voltage _{Dif Sin1} Whereas midpoint theoretical 2.5V to 5V in analog value terms, the lower threshold (e.g., 2.3V) or more and the upper limit threshold (e.g., 2.7V) as long as it is within the range below were determined to be normal, if the value of the sine wave signal offset voltage Dif _Sin1 is less than the lower threshold for an analog value terms, or, than the upper threshold value If also large, it is determined that the offset voltage abnormalities of the sinusoidal signal offset voltage _{Dif Sin1.} Sinusoidal difference calculation unit 1711, when detecting the offset voltage abnormalities of the sinusoidal signal offset voltage _{Dif Sin1,} sets the sine wave signal offset voltage abnormality detection flag ERR3-1.

Further, the cosine wave difference calculation unit 1712 detects an input value abnormality of the positive phase cosine wave signal Cosθ ₁ +.

Specifically, the cosine wave difference calculation unit 1712 has, for example, a value of the positive phase cosine wave signal Cosθ ₁ + equal to or higher than a lower limit threshold (for example, 0.3 V) in analog value conversion, and an upper limit threshold (for example, 4.7 V). ) If it is within the following range, it is determined as normal, and if the value of the positive phase cosine wave signal Cosθ ₁ + is less than the lower limit threshold value or converted to an analog value, or greater than the upper limit threshold value, the positive phase cosine wave It is determined that the input value of the signal Cosθ ₁ + is abnormal. When detecting an input value abnormality of the positive phase cosine wave signal Cosθ ₁ +, the cosine wave difference calculation unit 1712 sets a positive phase cosine wave signal input value abnormality detection flag ERR2-1.

Further, the cosine wave difference calculation unit 1712 detects an input value abnormality of the anti-phase cosine wave signal Cosθ ₁ −.

Specifically, the cosine wave difference calculation unit 1712 has, for example, the value of the anti-phase cosine wave signal Cosθ ₁ − equal to or higher than the lower limit threshold (for example, 0.3 V) in terms of analog value and the upper limit threshold (for example, 4.7 V). ) If it is within the following range, it is determined to be normal, and if the value of the anti-phase cosine wave signal Cosθ ₁ − is less than the lower limit threshold in terms of analog value or greater than the upper limit threshold, the anti-phase cosine wave It is determined that the input value of the signal Cosθ ₁ − is abnormal. The cosine wave difference calculation unit 1712 sets an anti-phase cosine wave signal input value abnormality detection flag ERR2-2 when detecting an input value abnormality of the anti-phase cosine wave signal Cosθ ₁ −.

The cosine wave difference calculation unit 1712 detects an abnormality in the cosine wave signal offset voltage Dif _Cos1 calculated by the above equation (7).

Specifically, the cosine wave difference calculation unit 1712, for example, is equal to or higher than a lower threshold (for example, 2.3 V) with respect to a midpoint theoretical value of 2.5 V in terms of analog value _when the value of the cosine wave signal offset voltage Dif _Cos1 is 5 V. And, if it is within the range of the upper threshold (for example, 2.7 V) or less, it is determined as normal, and the value of the cosine wave signal offset voltage Dif _Cos1 is less than the lower threshold in terms of analog value, or from the upper threshold Is larger, it is determined that the offset voltage value of the cosine wave signal offset voltage Dif _Cos1 is abnormal. Cosine difference calculation unit 1712, when detecting the offset voltage abnormalities of the cosine wave signal offset voltage _{Dif Cos 1,} sets the cosine wave signal offset voltage value anomaly detection flag ERR3-2.

  The first gain correction unit 172 includes a first sine wave gain correction unit 1721, a first cosine wave gain correction unit 1722, and a rotation speed threshold value determination unit 1723.

The first sine wave gain correction unit 1721 outputs a second sine wave signal Sinθ _1g obtained by correcting the gain of the first sine wave signal Sinθ _1f . The first sine wave gain correction unit 1721 has a function of setting or resetting a sine wave signal maximum value abnormality detection flag ERR4-1 and a sine wave signal minimum value abnormality detection flag ERR4-2, which will be described later.

The first cosine wave gain correction unit 1722 outputs a second cosine wave signal Cosθ _1g obtained by correcting the gain of the first cosine wave signal Cosθ _1f . The first cosine wave gain correction unit 1722 has a function of setting or resetting a cosine wave signal maximum value abnormality detection flag ERR5-1 and a cosine wave signal minimum value abnormality detection flag ERR5-2, which will be described later.

The rotation speed threshold determination unit 1723 determines the maximum value and minimum value of the first sine wave signal Sinθ _1f and the first value based on the rotation speed ω of the motor 20 calculated by a rotation number calculation unit 1744 of the angle calculation unit 174 described later. The update permission condition for the maximum value and the minimum value of the cosine wave signal Cosθ _1f is determined.

Specifically, for example, if the rotational speed ω of the motor 20 is equal to or lower than an upper limit threshold (for example, 200 rpm), the first gain correction unit 172 sets the maximum and minimum values of the first sine wave signal Sinθ _1f , and the first When updating of the maximum value and the minimum value of the 1 cosine wave signal Cosθ _1f is permitted and the rotational speed ω of the motor 20 is larger than the upper limit threshold, the maximum value and the minimum value of the first sine wave signal Sinθ _1f , and The updating of the maximum value and the minimum value of the first cosine wave signal Cosθ _1f is prohibited.

  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 concept of detecting 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 corrects the gain 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.

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

Sinθ _1g L = Sinθ _1f × ((− 1) / (MIN (Sinθ _1f ))) (14)

The first sine wave gain correction unit 1721 converts the sine wave signal Sinθ _1g U into the second sine wave signal Sinθ _1g and the first sine wave signal Sinθ _1g when the value of the first sine wave signal Sinθ _1f is 0 or more. _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, 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 Sinθ _1f is 0 or more, When the value of the first sine wave signal Sinθ _1f is less than 0, the second sine wave signal Sinθ _1g is calculated using the following equation (14 ′).

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

Sinθ _1g = Sinθ _1f × ((− 1) / (MIN (Sinθ _1f ))) (14 ′)

Thereby, the second sine wave signal Sinθ _1g in which the gain of the first sine wave signal Sinθ _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 Figure 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.

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

Cos θ _1g L = Cos θ _1f × ((− 1) / (MIN (Cos θ _1f ))) (16)

Then, when the value of the first cosine wave signal Cosθ _1f is 0 or more, the first cosine wave gain correction unit 1722 sets the cosine wave signal Cosθ _1g U as the second cosine wave signal Cosθ _1g and the first cosine wave signal Cosθ. _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, 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 Cosθ _1f is 0 or more, When the value of the first cosine wave signal Cosθ _1f is less than 0, the second cosine wave signal Cosθ _1g is calculated using the following equation (16 ′).

Cos θ _1g = Cos θ _1f × (1 / (MAX (Cos θ _1f ))) (15 ′)

Cos θ _1g = Cos θ _1f × ((− 1) / (MIN (Cos θ _1f ))) (16 ′)

Thereby, the second cosine wave signal Cosθ _1g in which the gain of the first cosine wave signal Cosθ _1f is corrected is obtained.

The first sine wave gain correction unit 1721, a first sine of 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) The abnormality of the maximum value of the wave signal Sinθ _1f is detected.

Specifically, the first sine wave gain correction unit 1721, for example, 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) If the maximum value of the first sine wave signal Sinθ _1f is equal to or higher than the lower limit value (eg, 3.2 V) and equal to or lower than the upper limit value (eg, 4.4 V), the first cosine wave signal is determined to be normal. the value of the first sine-wave signal sin [theta _1f at the zero point detection of cos [theta] _1f is 0 or whether the maximum value of the first sine-wave signal sin [theta _1f when (Sinθ _1f ≧ 0) is is less than the lower limit, or upper If larger than the value, it is determined that the maximum value of the first sine wave signal Sinθ _1f is abnormal. The first sine wave gain correction unit 1721 sets the sine wave signal maximum value abnormality detection flag ERR4-1 when detecting the maximum value abnormality of the first sine wave signal Sinθ _1f . At this time, the first sine wave gain correction unit 1721 does not update the maximum value of the first sine wave signal Sinθ _1f .

The first sine wave gain correction unit 1721, a first sine of 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) The abnormality of the minimum value of the wave signal Sinθ _1f is detected.

Specifically, the first sine wave gain correction unit 1721, for example, 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) If the minimum value of the first sine wave signal Sinθ _1f is equal to or higher than the lower limit value (for example, −4.4 V) and equal to or lower than the upper limit value (for example, −3.2 V), the first cosine is determined. less than the value of the first sine-wave signal sin [theta _1f at the zero point detection wave signal Cos? _1f is zero or a minimum value of the first sine-wave signal sin [theta _1f when a (sin [theta _1f <0) is less than the lower limit value, Or when larger than an upper limit, it determines with the minimum value abnormality of 1st sine wave signal Sin (theta) _1f . The first sine wave gain correction unit 1721 sets a sine wave signal minimum value abnormality detection flag ERR4-2 when detecting a minimum value abnormality of the first sine wave signal Sinθ _1f . At this time, the first sine wave gain correction unit 1721 does not update the minimum value of the first sine wave signal Sinθ _1f .

The first cosine wave gain correction unit 1722, the first cosine of 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 abnormality of the maximum value of the wave signal Cosθ _1f is detected.

Specifically, the first cosine-wave gain correction unit 1722, for example, 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) If the maximum value of the first cosine wave signal Cosθ _1f is not less than the lower limit (eg, 3.2 V) and not more than the upper limit (eg, 4.4 V), the first sine wave signal is determined to be normal. the value of the first cosine wave signal Cos? _1f at the zero point detection of sin [theta _1f is 0 or whether the maximum value of the first cosine wave signal Cos? _1f when (Cos? _1f ≧ 0) is is less than the lower limit, or upper If it is larger than the value, it is determined that the maximum value of the first cosine wave signal Cosθ _1f is abnormal. The first cosine wave gain correction unit 1722 sets the cosine wave signal maximum value abnormality detection flag ERR5-1 when detecting the maximum value abnormality of the first cosine wave signal Cosθ _1f . At this time, the first cosine wave gain correction unit 1722 does not update the maximum value of the first cosine wave signal Cosθ _1f .

The first cosine wave gain correction unit 1722, the first cosine of 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) The abnormality of the minimum value of the wave signal Cosθ _1f is detected.

Specifically, the first cosine-wave gain correction unit 1722, for example, 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) If the minimum value of the first cosine wave signal Cosθ _1f is equal to or higher than the lower limit value (for example, −4.4V) and equal to or lower than the upper limit value (for example, −3.2V), the first sine is determined. or minimum of the first cosine wave signal Cos? _1f when the value of the first cosine wave signal Cos? _1f is smaller than 0 (Cosθ _1f <0) at the time of the zero point detection wave signal sin [theta _1f is less than the lower limit, Alternatively, when the value is larger than the upper limit value, it is determined that the minimum value of the first cosine wave signal Cosθ _1f is abnormal. The first cosine wave gain correction unit 1722 sets the cosine wave signal minimum value abnormality detection flag ERR5-2 when detecting the minimum value abnormality of the first cosine wave signal Cosθ _1f . At this time, the first cosine wave gain correction unit 1722 does not update the minimum value of the first cosine wave signal Cosθ _1f .

  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 a 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 calculate the second cosine wave. A third cosine wave signal V _C-S obtained by phase conversion of the signal Cosθ _1g 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 the phase conversion process when no phase shift occurs in the second sine wave signal and the second cosine wave signal. FIG. 16 is a vector diagram after the phase conversion process 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} is changed to 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 by +45+ (α / 2) deg phase with respect to the second cosine wave signal Cosθ _1g . 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 deg.

As shown in FIG. 15, when there is no phase shift between the second sine wave signal Sinθ _1g and the second cosine wave signal Cosθ _1g , the vector (Cosθ _1g + Sinθ _1g ) of the above equation (17) and the above The size of the vector (Cosθ _1g −Sinθ _1g ) in the equation (18) is the same.

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

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

Thus, the phase shift α of the second sine-wave signal sin [theta _{1 g} and the second cosine wave signal Cos? _{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 illustrating an example of an equivalent block of the second gain correction unit. FIG. 18 is a diagram for explaining the concept of detecting 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.

When the value of the third sine wave signal V _{C + S} when the zero point of the third cosine wave signal V _C-S is detected is 0 or more (V _{C + S} ≧ 0), the second sine wave gain correction unit 1731 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 corrects the gain of the third sine wave signal V _{C + S} using the following equations (19) and (20), and the sine wave signal V1 _{C +} SU and the sine wave signal V1 _{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 equal to or greater than 0, the second sine wave gain correction unit 1731 converts the sine wave signal V1 _{C + S} U into the fourth sine wave signal V1 _{C + S,} and the third sine wave signal V 1 _When the value of _{C + S} is less than 0, the sine wave signal V1 _{C + S} L is set as the fourth sine wave signal V1 _{C + S.}

That is, the second sine wave gain correction unit 1731 calculates the fourth sine wave signal V1 _{C + S} using the following equation (19 ′) when the value of the third sine wave signal V _{C + S} is 0 or more, When the value of the third sine wave signal V _{C + S} is less than 0, the fourth sine wave signal V1 _{C + S} is calculated using the following equation (20 ′).

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

V1 _{C + S} = V _{C + S} × ((− 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 when the zero point of the third sine wave signal V _{C + S} is detected is 0 or more (V _C−S ≧ 0), 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 V1 _C-S U and the cosine wave. The signal V1 _C-S L is obtained.

V1 _C−S U = V _C−S × (1 / (MAX (V _C−S ))) (21)

V1 _C−S L = V _C−S × ((− 1) / (MIN (V _C−S ))) (22)

The second cosine wave gain correction unit 1732 sets the cosine wave signal V1 _C-S U as the fourth cosine wave signal V1 _C-S when 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 cosine wave signal V1 _C-S L is set as the fourth cosine wave signal V1 _C-S .

That is, when the value of the third cosine wave signal V _C-S is equal to or greater than 0, the second cosine wave gain correction unit 1732 uses the following equation (21 ′) to calculate the fourth cosine wave signal V1 _C-S. When the value of the third cosine wave signal V _C-S is less than 0, the fourth cosine wave signal V1 _C-S is calculated using the following equation (22 ′).

V1 _C−S = V _C−S × (1 / (MAX (V _C−S ))) (21 ′)

V1 _C−S = V _C−S × ((− 1) / (MIN (V _C−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, a motor electrical angle calculation unit 1743, and a rotation number calculation unit 1744.

The arc tangent calculation unit 1741 calculates an angle θ _1h within a range of −90 deg <θ _1h <+90 deg using the following equation (23).

θ _1h = arctan (V1 _{C + S} / V1 _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 To do. Further, the quadrant determination unit 1742 advances the phase by 45 degrees delayed by the second gain correction unit 173.

When the fourth cosine wave signal V1 _C−S is equal to or greater than 0 (V1 _C−S ≧ 0), the quadrant determination unit 1742 uses the following equation (24) to calculate the motor within the range of 0 deg <θ ₁ <360 deg. A rotation angle θ _{1 of} 20 is calculated.

θ ₁ = θ _1h −45 deg (24)

Further, when the fourth cosine wave signal V1 _C-S is less than 0 (V1 _C-S <0), the quadrant determination unit 1742 uses the following equation (25) to satisfy the range of 0 deg <θ ₁ <360 deg. It calculates a rotation angle theta ₁ of the motor 20 in.

θ ₁ = (θ _1h +180 deg) −45 deg (25)

The motor electrical angle calculation unit 1743 calculates an electrical angle θ ₂ corresponding to the number of magnetic pole pairs of the motor 20 based on the rotation angle θ ₁ of the motor 20 calculated by the quadrant determination unit 1742. When the number of magnetic pole pairs of the motor 20 is four, the rotation angle θ ₁ is divided into four, the difference from the current control start position is corrected, and the electric angle θ ₂ for four cycles is calculated.

The rotation speed calculation unit 1744 calculates the rotation speed ω of the motor 20 based on the rotation angle θ ₁ of the motor 20. Specifically, the rotational speed calculation unit 1744 calculates the rotational speed ω of the motor 20 with reference to, for example, the amount of change in ₁ ms units of the rotational angle θ ₁ of the motor 20. At this time, for example, when the processing period in the rotation angle detection process described later, in other words, the sampling period of the A / D conversion process in the previous stage of the difference calculation unit 171 is 250 μs, the rotation angle θ of the motor 20 for four periods. ₁ is referred to. The unit time for calculating the rotation speed ω of the motor 20 is not limited to 1 ms.

  Next, the rotation angle detection process in the rotation angle detection apparatus 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 embodiment.

  In the present embodiment, the rotation angle detection device 200 is calibrated in real time during actual operation of actually running the vehicle. Thereby, it can suppress that detection accuracy falls by temperature drift or a time-dependent change, and can maintain high detection accuracy. Hereinafter, real-time calibration at the time of actual operation described above will be described.

  FIG. 20 is a diagram illustrating an example of each piece of information stored in the EEPROM.

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 the first cosine wave signal Cos? _1f of the first sine-wave signal sin [theta _1f the initial value MAX1Ref of), the initial value of 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 Cosθ _1f) MIN1Ref, the third sinusoidal signal _{V C + S} The maximum value MAX (V _{C + S} ) and the initial value MAX2Ref of the maximum value MAX (V _C−S ) of the third cosine wave signal V _C−S , the minimum value MIN (V _{C + S} ) of the third sine wave signal V _{C + S} and the third value The initial value MIN2Ref of the minimum value MIN (V _C-S ) of the cosine wave signal V _C-S is stored.

Moreover, EEPROM 104 in the (first storage unit), an upper limit value MAX1Lim_H and the lower limit value of the maximum value MAX of the first sine-wave signal sin [theta _1f (sin [theta _1f) and a maximum value MAX (Cos? _1f) of the first cosine wave signal Cos? _1f MAX1Lim_L, the upper limit 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 are stored.

Moreover, EEPROM 104 in the (first storage unit), positive-phase sine wave signal sin [theta ₁ +, reverse-phase sine wave signal sin [theta ₁ -, positive phase cosine wave signal Cos? ₁ +, and the negative phase cosine wave signal Cos? ₁ - maximum threshold Lim_H and lower threshold Lim_L, upper threshold DifLim_H and lower threshold DifLim_L sinusoidal signals offset voltage _{Dif Sin1} and cosine-wave signal offset voltage _{Dif Cos 1,} upper threshold RS_H the rotational speed ω of the motor 20 is stored.

  Each information stored in the EEPROM 104 may be numerical data or may be a discrete value such as digital data.

In actual operation, upon receiving the ignition signal transmitted from the ignition switch 11, the CPU 101 reads MAX1Ref, MIN1Ref, MAX2Ref, MIN2Ref stored in the EEPROM 104 (first storage unit), and stores it in 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 It is written as the value of the maximum value of the signal _{V C + S MAX (V C} + S) and a maximum value MAX of the third cosine wave signal _{V C-S (V C-} S), MIN2Ref minimum value of the third sinusoidal signal _{V C + S,} respectively Written as the value of MIN (V _{C + S} ) and the minimum value MIN (V _C−S ) of the third cosine wave signal V _C-S The

  In the present embodiment, the rotation angle detection process in the rotation angle detection device 200 is performed every 250 μs, for example. That is, the sampling period of the A / D conversion process in the previous stage of the difference calculation unit 171 is 250 μs. Note that the sampling period of the A / D conversion process in the previous stage of the difference calculation unit 171 is an example, and is not limited to 250 μs.

  In the rotation angle detection process shown in FIG. 19, the position detection unit 17 first performs an input abnormality determination process (step S1). FIG. 21 is a flowchart illustrating an example of the input abnormality determination process.

The position detection unit 17 outputs a differential sine wave signal (positive phase sine wave signal Sinθ ₁ +, a negative phase sine wave signal Sinθ ₁ −) and a differential cosine wave signal (positive phase cosine wave signal) output from the position detection sensor 25. Cos θ ₁ + and anti-phase cosine wave signal Cos θ ₁ −) are acquired by sampling (step S10).

Difference calculation unit 171, a positive-phase sine wave signal sin [theta ₁ + from EEPROM 104, reverse-phase sine wave signal sin [theta ₁ -, positive phase cosine wave signal Cos? ₁ +, and the negative phase cosine wave signal Cos? ₁ - upper threshold Lim_H and lower Read the threshold value Lim_L.

The sine wave difference calculation unit 1711 determines whether or not the input value of the positive phase sine wave signal Sinθ ₁ + is equal to or higher than the lower limit threshold Lim_L and lower than the upper limit threshold Lim_H (Lim_L ≦ Sinθ ₁ + ≦ Lim_H). (Step S11).

When the input value of the positive phase sine wave signal Sinθ ₁ + is equal to or higher than the lower limit threshold Lim_L and equal to or lower than the upper limit threshold Lim_H (Lim_L ≦ Sinθ ₁ + ≦ Lim_H) (step S11; Yes), a sine wave difference calculation unit 1711 determines that the input value of the positive phase sine wave signal Sinθ ₁ + is normal, and resets the positive phase sine wave signal input value abnormality detection flag ERR1-1 (step S11a).

When the input value of the positive phase sine wave signal Sinθ ₁ + is less than the lower limit threshold Lim_L or larger than the upper limit threshold Lim_H (step S11; No), the sine wave difference calculation unit 1711 outputs the positive phase sine wave signal. It is determined that the input value of Sinθ ₁ + is abnormal, and the positive phase sine wave signal input value abnormality detection flag ERR1-1 is set (step S11b).

Subsequently, the sine wave difference calculation unit 1711 determines whether or not the input value of the negative-phase sine wave signal Sinθ ₁ − is equal to or greater than the lower limit threshold Lim_L and equal to or less than the upper limit threshold Lim_H (Lim_L ≦ Sinθ ₁ − ≦ Lim_H). Is determined (step S12).

When the input value of the negative-phase sine wave signal Sinθ ₁ − is greater than or equal to the lower limit threshold Lim_L and less than or equal to the upper limit threshold Lim_H (Lim_L ≦ Sinθ ₁ − ≦ Lim_H) (step S12; Yes), the sine wave difference calculation unit 1711 determines that the input value of the negative-phase sine wave signal Sinθ ₁ − is normal, and resets the negative-phase sine wave signal input value abnormality detection flag ERR1-2 (step S12a).

When the input value of the negative phase sine wave signal Sinθ ₁ − is less than the lower limit threshold Lim_L or larger than the upper limit threshold Lim_H (step S12; No), the sine wave difference calculation unit 1711 outputs the negative phase sine wave signal. It is determined that the input value of Sinθ ₁ − is abnormal, and the negative phase sine wave signal input value abnormality detection flag ERR1-2 is set (step S12b).

Subsequently, the cosine wave difference calculation unit 1712 determines whether or not the value of the positive phase cosine wave signal Cosθ ₁ + is equal to or greater than the lower limit threshold Lim_L and equal to or less than the upper limit threshold Lim_H (Lim_L ≦ Cosθ ₁ + ≦ Lim_H). Is determined (step S13).

When the value of the positive phase cosine wave signal Cosθ ₁ + is not less than the lower limit threshold Lim_L and not more than the upper limit threshold Lim_H (Lim_L ≦ Cosθ ₁ + ≦ Lim_H) (step S13; Yes), the cosine wave difference calculation unit 1712 Determines that the input value of the positive phase cosine wave signal Cosθ ₁ + is normal, and resets the positive phase cosine wave signal input value abnormality detection flag ERR2-1 (step S13a).

When the value of the positive phase cosine wave signal Cosθ ₁ + is less than the lower limit threshold Lim_L or larger than the upper limit threshold Lim_H (step S13; No), the cosine wave difference calculation unit 1712 outputs the positive phase cosine wave signal Cosθ. ₁ + a is determined as an input value abnormality, setting the positive-phase cosine wave signal input value abnormality detection flag ERR2-1 (step S13b).

Subsequently, the cosine wave difference calculation unit 1712 determines whether or not the value of the anti-phase cosine wave signal Cosθ ₁ − is equal to or higher than the lower limit threshold Lim_L and lower than or equal to the upper limit threshold Lim_H (Lim_L ≦ Cosθ ₁ − ≦ Lim_H). Is determined (step S14).

When the value of the negative-phase cosine wave signal Cosθ ₁ − is equal to or higher than the lower limit threshold Lim_L and equal to or lower than the upper limit threshold Lim_H (Lim_L ≦ Cosθ ₁ − ≦ Lim_H) (step S14; Yes), the cosine wave difference calculation unit 1712 Determines that the input value of the anti-phase cosine wave signal Cosθ ₁ − is normal, and resets the anti-phase cosine wave signal input value abnormality detection flag ERR2-2 (step S14a).

When the value of the anti-phase cosine wave signal Cosθ ₁ − is less than the lower limit threshold Lim_L or larger than the upper limit threshold Lim_H (step S14; No), the cosine wave difference calculation unit 1712 outputs the anti-phase cosine wave signal Cosθ. _It is determined that the input value is abnormal as _1- , and the anti-phase cosine wave signal input value abnormality detection flag ERR2-2 is set (step S14b).

Then, the difference calculation unit 171 reads the upper threshold DifLim_H and lower threshold DifLim_L sinusoidal signals offset voltage _{Dif Sin1} and cosine-wave signal offset voltage _{Dif Cos 1} from EEPROM 104. Sinusoidal difference calculation unit 1711, using the above equation (1), to calculate a sinusoidal signal offset voltage _{Dif Sin1} (step S15).

Sinusoidal difference calculation unit 1711 determines the value of the sine wave signal offset voltage _{Dif Sin1} is, is at the lower threshold DifLim_L above, and, whether the upper limit threshold DifLim_H below _{(DifLim_L ≦ Dif Sin1 ≦ DifLim_H)} ( step S16).

The value of the sine wave signal offset voltage _{Dif Sin1} is, is at the lower threshold DifLim_L above, and, when it is less than the upper limit threshold _{DifLim_H (DifLim_L ≦ Dif Sin1 ≦ DifLim_H} ) ( step S16; Yes), the sinusoidal difference calculation unit 1711, offset voltage value of the sine wave signal offset voltage _{Dif Sin1} is determined to be normal, and resets the sinusoidal signal offset voltage abnormality detection flag ERR3-1 (step S16a).

The value of the sine wave signal offset voltage _{Dif Sin1} is either less than the lower threshold DifLim_L, or, when larger than the upper threshold DifLim_H (step S16; No), the sinusoidal difference calculation unit 1711, the sine wave signal offset voltage _{Dif Sin1} And the sine wave signal offset voltage value abnormality detection flag ERR3-1 is set (step S16b).

Subsequently, the cosine wave difference calculation unit 1712 calculates the cosine wave signal offset voltage Dif _Cos1 using the above equation (7) (step S17).

The cosine wave difference calculation unit 1712 determines whether or not the value of the cosine wave signal offset voltage Dif _Cos1 is equal to or higher than the lower limit threshold DifLim_L and equal to or lower than the upper limit threshold DifLim_H (DifLim_L ≦ Dif _Cos1 ≦ DifLim_H) (step) S18).

When the value of the cosine wave signal offset voltage Dif _Cos1 is equal to or higher than the lower limit threshold DifLim_L and equal to or lower than the upper limit threshold DifLim_H (DifLim_L ≦ Dif _{Cos 1} ≦ DifLim_H) (step S18; Yes), the cosine wave difference calculation unit 1712 It is determined that the offset voltage value of the cosine wave signal offset voltage Dif _Cos1 is normal, the cosine wave signal offset voltage value abnormality detection flag ERR3-2 is reset (step S18a), and the process returns to the rotation angle detection processing procedure shown in FIG.

When the value of the cosine wave signal offset voltage Dif _Cos1 is less than the lower limit threshold value DifLim_L or larger than the upper limit threshold value DifLim_H (step S18; No), the cosine wave difference calculation unit 1712 outputs the cosine wave signal offset voltage Dif _Cos1. , The cosine wave signal offset voltage value abnormality detection flag ERR3-2 is set (step S18b), and the process returns to the rotation angle detection processing procedure shown in FIG.

The sine wave difference calculation unit 1711 of the difference calculation unit 171 calculates the first sine wave signal Sinθ _1f using the above-described equation (6 ′), and the cosine wave difference calculation unit 1712 of the difference calculation unit 171 described above. The first cosine wave signal Cosθ _1f is calculated using equation (12 ′) (step S101).

Next, the position detection unit 17 performs the maximum value detection process and a minimum value detection process of the first sine-wave signal sin [theta _1f and the first cosine wave signal Cos? _1f (step S2). FIG. 22 is a flowchart illustrating an example of the maximum value detection process and the minimum value detection process of the first sine wave signal and the first cosine wave signal.

  The first gain correction unit 172 reads the upper limit threshold value RS_H of the rotational speed ω of the motor 20 from the EEPROM 104. The rotation speed threshold determination unit 1723 of the first gain correction unit 172 determines whether the rotation speed ω of the motor 20 is equal to or lower than the upper limit threshold RS_H (ω ≦ RS_H) (step S20).

When the rotation speed ω of the motor 20 is greater than the upper threshold RS_H (step S20; No), the rotational speed threshold value determination unit 1723, rotational speed ω of the motor 20 is the maximum value MAX (sin [theta _1f of the first sine-wave signal sin [theta _1f ) and the minimum value MIN (Sinθ _1f), determines that the update condition outside of the maximum value MAX of the first cosine wave signal Cos? _1f (Cos? _1f) and the minimum value MIN (Cos? _1f), the rotation angle detection processing procedure shown in FIG. 19 Return to. That is, the maximum value MAX (Sinθ _1f) and the minimum value MIN (Sinθ _1f) of the rotational speed of the motor 20 is first sine-wave signal sin [theta _1f, the maximum value MAX (Cos? _1f) and the minimum value of the first cosine wave signal Cos? _1f MIN when it is determined that the update condition outside (Cos? _1f), the maximum value MAX (Sinθ _1f) and the minimum value MIN of the first sine-wave signal Sinθ _1f (Sinθ _1f), the maximum value of the first cosine wave signal Cos? _1f The MAX (Cos θ _1f ) and the minimum value MIN (Cos θ _1f ) are not updated.

When the rotational speed ω of the motor 20 is equal to or lower than the upper limit threshold RS_H (ω ≦ RS_H) (step S20; Yes), the rotational speed threshold determination unit 1723 indicates that the rotational speed ω of the motor 20 is the maximum of the first sine wave signal Sinθ _1f . the value MAX (sin [theta _1f) and the minimum value MIN (Sinθ _1f), determines that the update condition is satisfied of the maximum value MAX of the first cosine wave signal Cosθ _1f (Cosθ _1f) and the minimum value MIN (Cos? _1f), and the first sine maximum value MAX wave signal Sinθ _1f (Sinθ _1f) and the minimum value MIN (Sinθ _1f), to allow updating of the maximum value MAX (Cos? _1f) and the minimum value MIN of the first cosine wave signal Cosθ _1f (Cosθ _1f).

Subsequently, the first gain correction unit 172 detects the zero point (Cos θ _1f = 0) of the first cosine wave signal Cos θ _1f (step S21). When the zero point of the first cosine wave signal Cosθ _1f is not detected (step S21; No), the process proceeds to step S25.

Upon detecting the zero point of the first cosine wave signal Cos? _1f (step S21; 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 Is greater than or equal to 0 (Sinθ _1f ≧ 0) (step S22).

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 S22; 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 S22a).

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 S22a; Yes), the first gain correction portion 172, the value of the first sine-wave signal sin [theta _1f maximum value MAX of the first sine-wave signal Sinθ _1f (Sinθ _1f) as the upper RAM102 Is updated (step S23a), and the process proceeds to step S25.

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 sin [theta _1f (Step S22a; No), the first sine wave gain correction unit 1721 of the first gain correction unit 172 determines that the maximum value of the first sine wave signal Sinθ _1f is abnormal, and detects a sine wave signal maximum value abnormality detection flag ERR4-1. Is set (step S24a), and the process proceeds to step S25. That is, when it is determined that the maximum value of the first sine wave signal Sinθ _1f is abnormal, the maximum value MAX (Sinθ _1f ) of the first sine wave signal Sinθ _1f is not updated.

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 S22; 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 (step S22b).

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 S22b; Yes), the first gain correction portion 172, the value of the first sine-wave signal sin [theta _1f minimum value MIN of the first sine-wave signal Sinθ _1f (Sinθ _1f) as the upper RAM102 Is updated (step S23b), and the process proceeds to step S25.

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 S22b; No), the first sine wave gain correction unit 1721 of the first gain correction unit 172 determines that the minimum value of the first sine wave signal Sinθ _1f is abnormal and detects a sine wave signal minimum value abnormality detection flag ERR4-2. Is set (step S24b), and the process proceeds to step S25. That is, when it is determined that the minimum value of the first sine wave signal Sinθ _1f is abnormal, the minimum value MIN (Sinθ _1f ) of the first sine wave signal Sinθ _1f is not updated.

Subsequently, the first gain correction unit 172 detects the zero point (Sinθ _1f = 0) of the first sine wave signal Sinθ _1f (step S25). When the zero point of the first sine wave signal Sinθ _1f is not detected (step S25; No), the process returns to the rotation angle detection processing procedure shown in FIG.

Upon detecting the zero point of the first sine-wave signal sin [theta _1f (step S25; 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 Is greater than or equal to 0 (Cos θ _1f ≧ 0) (step S26).

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 S26; 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 S26a).

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 S26a; Yes), the first gain correction portion 172, the value of the first cosine wave signal Cos? _1f maximum value MAX of the first cosine wave signal Cos? _1f (Cos? _1f) as the upper RAM102 Is updated (step S27a), and the process returns to the rotation angle detection processing procedure shown in FIG.

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 S26a; No), the first cosine wave gain correction unit 1722 of the first gain correction unit 172 determines that the maximum value of the first cosine wave signal Cosθ _1f is abnormal and detects the cosine wave signal maximum value abnormality detection flag ERR5-1. Is set (step S28a), and the process returns to the rotation angle detection processing procedure shown in FIG. That is, when it is determined that the maximum value of the first cosine wave signal Cosθ _1f is abnormal, the maximum value MAX (Cosθ _1f ) of the first cosine wave signal Cosθ _1f is not updated.

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 S26; 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 (step S26b).

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 S26b; Yes), the first gain correction portion 172, the value of the first cosine wave signal Cos? _1f minimum value MIN of the first cosine wave signal Cos? _1f (Cos? _1f) as the upper RAM102 Is updated (step S27b), and the process returns to the rotation angle detection processing procedure shown in FIG.

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 S26b; No), the first cosine wave gain correction unit 1722 of the first gain correction unit 172 determines that the minimum value of the first cosine wave signal Cosθ _1f is abnormal and detects the cosine wave signal minimum value abnormality detection flag ERR5-2. Is set (step S28b), and the process returns to the rotation angle detection processing procedure shown in FIG. That is, when it is determined that the minimum value of the first cosine wave signal Cosθ _1f is abnormal, the minimum value MIN (Cosθ _1f ) of the first cosine wave signal Cosθ _1f is not updated.

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 ≧ 0). It is determined whether or not (step S102a).

When the value of the first sine wave signal Sinθ _1f is greater than or equal to 0 (Sinθ _1f ≧ 0) (step S102a; Yes), the first sine wave gain correction unit 1721 uses the equation (13 ′) described above to calculate A 2-sine wave signal Sinθ _1g is calculated (step S103a).

When the value of the first sine wave signal Sinθ _1f is less than 0 (Sinθ _1f <0) (step S102a; No), the first sine wave gain correction unit 1721 uses the equation (14 ′) described above to calculate A two sine 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 or not the value of the first cosine wave signal Cosθ _1f is greater than or equal to 0 (Cosθ _1f ≧ 0) (step S102b).

When the value of the first cosine wave signal Cosθ _1f is equal to or greater than 0 (Cosθ _1f ≧ 0) (step S102b; Yes), the first cosine wave gain correction unit 1722 uses the equation (15 ′) described above to The two cosine wave signal Cosθ _1g is calculated (step S103b).

When the value of the first cosine wave signal Cosθ _1f is less than 0 (Cosθ _1f <0) (step S102b; No), the first cosine wave gain correction unit 1722 uses the equation (16 ′) described above to calculate The two cosine wave signal Cosθ _1g is calculated (step S104b).

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-described equation (17), and also described above (18 ) Is used to calculate a third cosine wave signal V _C-S obtained by phase conversion of the second cosine wave signal Cosθ _1g (step S105).

Subsequently, the position detection unit 17 performs maximum value detection processing and minimum value detection processing of the third sine wave signal V _{C + S} and the third cosine wave signal V _C-S (step S3). FIG. 23 is a flowchart illustrating an example of the maximum value detection process and the minimum value detection process of the third sine wave signal and the third cosine wave signal.

The second gain correction unit 173 detects the zero point (V _C−S = 0) of the third cosine wave signal V _C−S (step S31). If not detected zero point of the third cosine wave signal _{V C-S} (step S31; No), the process proceeds to step S35.

When the zero point of the third cosine wave signal V _C-S is detected (step S31; Yes), the second gain correction unit 173 detects the third sine wave signal when the zero point of the third cosine wave signal V _C-S is detected. It is determined whether or not the value of V _{C + S} is 0 or more (V _{C + S} ≧ 0) (step S32).

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) (step S32; 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 S33), and the process proceeds to step S35.

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 S32; 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 S34), and the process proceeds to step S35.

Subsequently, the second gain correction unit 173 detects the zero point (V _{C + S} = 0) of the third sine wave signal V _{C + S} (step S35). When the zero point of the third sine wave signal V _{C + S} is not detected (step S35; No), the process returns to the rotation angle detection processing procedure shown in FIG.

When the zero point of the third sine wave signal V _{C + S} is detected (step S35; 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 is greater than or equal to 0 (V _C−S ≧ 0) (step S36).

When the value of the third cosine wave signal V _C-S when the zero point of the third sine wave signal V _{C + S} is detected is 0 or more (V _C-S ≧ 0) (step S36; Yes), the second gain correction unit 173, the value of the third cosine wave signal _{V C-S} and updates the data in the RAM102 as the maximum value MAX of the third cosine wave signal _{V C-S (V C-} S) ( step S37), FIG. 19 The procedure returns to the rotation angle detection processing procedure shown.

When the value of the third cosine wave signal V _C-S when the zero point of the third sine wave signal V _{C + S} is detected is less than 0 (V _C-S <0) (step S36; No), the second gain correction unit 173, the value of the third cosine wave signal _{V C-S} and updates the data in the RAM102 as the minimum value MIN of the third cosine wave signal _{V C-S (V C-} S) ( step S38), FIG. 19 The procedure returns to the rotation angle detection processing procedure shown.

In the above step S3, the maximum value of the third sinusoidal signal _{V C + S MAX (V C} + S), the minimum value MIN _{(V C +} S) of the third sinusoidal signal _{V C + S,} the third cosine wave signal _{V C-S} Although an example in which the maximum value MAX (V _C-S ) and the minimum value MIN (V _C-S ) of the third cosine wave signal V _C-S are updated is shown, the maximum value MAX of the third sine wave signal V _{C + S} is shown. _{(V C +} S), the minimum value MIN of the third sinusoidal signal _{V C + S (V C +} S), the maximum value of the third cosine wave signal _{V C-S MAX (V C} -S), and the third cosine wave signal _{V C-} the value of _S the minimum value MIN of (V _C-S) will vary with change in the phase difference, which has a low temperature dependence, less secular change. Therefore, 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} and _{(V C-S)} as the initial value MAX2Ref, third sine wave signal V _{C +} minimum value MIN of _{S (V C + S)} and a maximum value MAX of the third cosine wave signal _{V C-S} and _{(V C-S)} may be a mode that does not update the initial value MIN2Ref.

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). It is determined whether or not (step S106a).

When the value of the third sine wave signal V _{C + S} is equal to or greater than 0 (V _{C + S} ≧ 0) (step S106a; Yes), the second sine wave gain correction unit 1731 uses the equation (19 ′) described above to calculate A 4-sine wave signal V1 _{C + S} is calculated (step S107a).

When the value of the third sine wave signal V _{C + S} is less than 0 (V _{C + S} <0) (step S106a; No), the second sine wave gain correction unit 1731 uses the equation (20 ′) described above to calculate A 4-sine wave signal V1 _{C + S} is calculated (step S108a).

The second cosine wave gain correction unit 1732 of the second gain correction unit 173 determines whether or not the value of the third cosine wave signal V _C-S is 0 or more (V _C−S ≧ 0) (step S106b). ).

When the value of the third cosine wave signal V _C-S is equal to or greater than 0 (V _C−S ≧ 0) (step S106b; Yes), the second cosine wave gain correction unit 1732 calculates the above-described equation (21 ′). The fourth cosine wave signal V1C _-S is calculated by using (Step S107b).

When the value of the third cosine wave signal V _C-S is less than 0 (V _C-S <0) (step S106b; No), the second cosine wave gain correction unit 1732 uses the expression (22 ′) described above. The fourth cosine wave signal V1C _-S is calculated by using (Step S108b).

The arc tangent calculation unit 1741 of the angle calculation unit 174 calculates the angle θ _1h within the range of −90 deg <θ _1h <+90 deg using the above-described equation (23) (step S109).

The quadrant determination unit 1742 of the angle calculation unit 174 determines whether or not the fourth cosine wave signal V1 _C-S is 0 or more (V1 _C−S ≧ 0) (step S110).

When the fourth cosine wave signal V1 _C-S is equal to or greater than 0 (V1 _C-S ≧ 0) (step S110; Yes), the quadrant determination unit 1742 uses the above-described equation (24), and 0 deg <θ ₁ The rotation angle θ ₁ of the motor 20 within the range of <360 deg is calculated (step S111).

When the fourth cosine wave signal V1 _C-S is less than 0 (V1 _C-S <0) (step S110; No), the quadrant determination unit 1742 uses the above-described equation (25), and 0 deg <θ ₁ The rotation angle θ ₁ of the motor 20 within the range of <360 deg is calculated (step S112).

Based on the rotation angle θ ₁ of the motor 20 calculated by the quadrant determination unit 1742, the motor electrical angle calculation unit 1743 calculates an electrical angle θ ₂ corresponding to the number of magnetic pole pairs of the motor 20 and offset adjusted to the reference point for current control. (Step S113).

The processing up to S113 above steps S1, a predetermined sampling period (e.g., 250 [mu] s) by repeatedly executing, since electrical angle theta ₂ which corresponds to the magnetic pole logarithm of the motor 20 in real time is corrected, Ya temperature drift A decrease in detection accuracy due to a change with time can be suppressed, and high detection accuracy can be maintained.

In addition, in the example mentioned above, although the rotation angle detection apparatus 200 demonstrated the aspect which outputs the electrical angle (theta) ₂ of the motor 20, as shown in FIG.2 and FIG.7, the rotation angle (theta) ₁ of the motor 20 is output. An aspect may be sufficient.

  Next, a failure determination process of the rotation angle detection device 200 in the electric power steering apparatus 100 using the rotation angle detection device 200 according to the embodiment will be described.

  The control computer 110 includes a positive phase sine wave signal input value abnormality detection flag ERR1-1 and a negative phase sine wave signal input value abnormality detection flag ERR1-2 that are set or reset by the sine wave difference calculation unit 1711 of the difference calculation unit 171. And the sine wave signal offset voltage value abnormality detection flag ERR3-1, and by detecting the number of times of detection detection of each abnormality detection flag, a failure of the rotation angle detection device 200 is detected and predetermined error processing is performed. It has a function.

  Further, the control computer 110 includes a positive phase cosine wave signal input value abnormality detection flag ERR2-1 and a negative phase cosine wave signal input value abnormality detection flag ERR2 that are set or reset by the cosine wave difference calculation unit 1712 of the difference calculation unit 171. -2 and cosine wave signal offset voltage value abnormality detection flag ERR3-2, and by detecting the number of times of detection detection of each abnormality detection flag, a failure of rotation angle detection device 200 is detected, and predetermined error processing is performed. It has a function to perform.

  The control computer 110 also sets the sine wave signal maximum value abnormality detection flag ERR4-1 and the sine wave signal minimum value abnormality detection flag ERR4 that are set or reset by the first sine wave gain correction unit 1721 of the first gain correction unit 172. 2 is monitored, and the failure detection of the rotation angle detection device 200 is detected by counting the number of times the abnormality detection flag is set, and a predetermined error process is performed.

  Further, the control computer 110 sets the cosine wave signal maximum value abnormality detection flag ERR5-1 and the cosine wave signal minimum value abnormality detection flag ERR5 that are set or reset by the first cosine wave gain correction unit 1722 of the first gain correction unit 172. -2 is monitored, and the malfunction detection flag is detected by counting the number of times the abnormality detection flag is set, and a predetermined error process is performed.

  FIG. 24 is a diagram illustrating a configuration example in which only two position detection sensors are provided. FIG. 25 is a diagram illustrating a configuration example in which two motors, two position detection sensors, and two position detection units are provided.

  As the error processing performed by the control computer 110, for example, as shown in FIG. 24, in the configuration in which the two position detection sensors 25-1 and 25-2 are provided, the rotation described above using the position detection sensor 25-1. If a failure is determined while the angle detection process is being performed, the rotation angle detection process may be continued using the position detection sensor 25-2.

  For example, as shown in FIG. 25, the drive system 300-1, including the motor 20-1, the position detection sensor 25-1, and the position detection unit 17-1, the motor 20-2, and the position detection sensor 25-. 2 and the drive system 300-2 including the position detection unit 17-2, normally 100% assist control is performed in both the drive system 300-1 and the drive system 300-2. However, when a failure is detected in the rotation angle detection device 200-1 of the drive system 300-1, position detection in the drive system 300-1 is stopped, and 50% assist control is performed only by the drive system 300-2. It is possible to continue. Similarly, when a failure is detected in the rotation angle detection device 200-2 of the drive system 300-2, position detection in the drive system 300-2 is stopped, and 50% assist is provided only in the drive system 300-1. It is conceivable to continue the control.

  It is also conceivable to stop the assist control when the rotation angle detection process cannot be performed.

  The error processing described above is an example, and the present invention is not limited to these.

  Hereinafter, the failure determination process of the rotation angle detection device 200 according to the present embodiment will be described. FIG. 26 is a flowchart illustrating an example of a failure determination processing procedure of the rotation angle detection device according to the embodiment.

  In the following description, the above-described normal phase sine wave signal input value abnormality detection flag ERR1-1, negative phase sine wave signal input value abnormality detection flag ERR1-2, sine wave signal offset voltage value abnormality detection flag ERR3-1, positive phase Cosine wave signal input value abnormality detection flag ERR2-1, reverse phase cosine wave signal input value abnormality detection flag ERR2-2, cosine wave signal offset voltage value abnormality detection flag ERR3-2, sine wave signal maximum value abnormality detection flag ERR4-1 The sine wave signal minimum value abnormality detection flag ERR4-2, the cosine wave signal maximum value abnormality detection flag ERR5-1, and the cosine wave signal minimum value abnormality detection flag ERR5-2 are collectively referred to as “abnormality detection flag ERRx”. x represents the number of abnormality detection flags, and is an integer from 1 to n. Although the ten abnormality detection flags described above have been described in the present embodiment, other abnormality detection flags indicating a failure of the rotation angle detection device 200 may be included. Further, when any one of the abnormality detection flags ERRx is indicated, it is referred to as “abnormality detection flag ERRp”. p is an integer from 1 to n.

  In the failure determination process shown in FIG. 26, the control computer 110 first performs an abnormality detection process of monitoring each abnormality detection flag ERRp and detecting an abnormality of the rotation angle detection device 200 (step S4). FIG. 27 is a flowchart illustrating an example of the abnormality detection process.

  The control computer 110 performs the abnormality detection process shown in FIG. 27 for each abnormality detection flag ERRp. The EEPROM 104 of the control computer 110 stores an upper limit value Npth of the consecutive occurrence count Np for each abnormality detection flag ERRp (hereinafter, simply referred to as “anomaly detection flag ERRp consecutive occurrence count upper limit value”).

  The control computer 110 monitors the abnormality detection flag ERRp and determines whether or not the abnormality detection flag ERRp has been set (step S41).

  If the abnormality detection flag ERRp is not set (step S41; No), the control computer 110 resets the number Np of consecutive occurrences of the abnormality detection flag ERRp (Np = 0), and continuously generates the abnormality detection flag ERRp. (Hereinafter simply referred to as “ERRp continuous occurrence flag”) is reset (step S42), and the process of step S41 is repeated.

  If the abnormality detection flag ERRp is set (step S41; Yes), the control computer 110 increments the number Np of consecutive occurrences of the abnormality detection flag ERRp (Np = Np + 1) (step S43), and then detects abnormality. It is determined whether or not the number of consecutive occurrences Np of the flag ERRp is equal to or greater than the upper limit Npth of the abnormality detection flag ERRp (Np ≧ Npth) (step S44).

  If the abnormality detection flag ERRp continuous occurrence count Np is less than the abnormality detection flag ERRp continuous occurrence count upper limit Npth (Np <Npth) (step S44; No), the processing returns to step S41.

  If the abnormality detection flag ERRp continuous occurrence count Np is equal to or greater than the abnormality detection flag ERRp continuous occurrence count upper limit Npth (Np ≧ Npth) (step S44; Yes), the control computer 110 sets the ERRp continuous occurrence flag ( Step S45) and the process returns to the failure determination processing procedure shown in FIG.

  The control computer 110 determines whether or not the ERRp continuous occurrence flag is set in any one or more of the abnormality detection flags ERRx (step S201). If the ERRp continuous occurrence flag is not set (step S201; No), the process of step S4 is repeated.

  If the ERRp continuous occurrence flag is set (step S201; Yes), the control computer 110 performs the predetermined error process described above (step S202), and ends the failure determination process.

  Note that the value of the abnormality detection flag ERRp continuous occurrence count upper limit value Npth may be set differently for each abnormality detection flag ERRp, or a plurality of types of abnormality detection flags ERRp share the same value. May be.

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), and the upper limit value, the initial value, the lower limit value, and the maximum value MAX _{(V C +} S) of the third sinusoidal signal _{V C + S} of the maximum value MAX (Cos? _1f) of the first cosine wave signal Cos? _1f, minimum value MIN of the third sinusoidal signal _{V C + S (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 third cosine wave signal _{V C-S} ( The initial value of V _C-S ) and the value of each abnormality detection flag ERRp continuous occurrence count upper limit value Npth are shown as being stored in the EEPROM 104 (first storage unit). A mode may be provided in which the first storage unit is stored. 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 signal _{V C + S} minimum value MIN of _{(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-S (V C-} S) is Although an example of storing in the RAM 102 (second storage unit) is shown, a mode in which a second storage unit is provided in addition to the RAM 102 and stored in the second storage unit may be used. The present disclosure is not limited by the configuration of the second storage unit.

  Further, in the above-described embodiment, an example in which the rotation angle detection device 200 is calibrated in real time during actual operation in which the vehicle actually travels has been shown, but in conjunction with this, before shipping the electric power steering device 100, A configuration in which initial calibration of the rotation angle detection device 200 is performed in a state where the position detection sensor 25 is incorporated in the motor 20 may be employed.

1 Handle wheel (steering)
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, 17-1, 17-2 Position detection unit 20, 20-1, 20 -2 Motor 20a Motor shaft 25, 25-1, 25-2 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 Computer for Control (MCU)
171 Difference calculation unit 172 First gain correction unit 173 Second gain correction unit 174 Angle calculation unit 200, 200-1, 200-2 Rotation angle detection device 251 Rotating magnet 252 MR sensor 300-1, 300-2 Drive system 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 1723 Rotational speed threshold determination 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 determination unit

Claims (11)

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 negative phase obtained by inverting the phase of the positive phase cosine wave signal and the positive phase cosine wave signal. A position detection sensor that outputs a differential cosine wave signal including a cosine wave signal as a motor position detection signal;
A position detection unit for detecting the position of the motor based on the position detection signal;
A storage unit;
With
The position detector 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. A difference calculation unit to
Based on the maximum value or the minimum value of the first sine wave signal stored in the storage unit, a second sine wave signal obtained by correcting the gain of the first sine wave signal is output and stored in the storage unit A first gain correction unit that outputs a second cosine wave signal obtained by correcting a gain of the first cosine wave signal based on a maximum value or a minimum value of the first cosine wave signal;
Adding the second cosine wave signal and the second sine wave signal to generate a third sine wave signal, based on the maximum value or the minimum value of the third sine wave signal stored in the storage unit, A fourth sine wave signal obtained by correcting the gain of the third sine wave signal is output, and a third cosine wave signal is generated by subtracting the second sine wave signal from the second cosine wave signal. A second gain correction unit for outputting a fourth cosine wave signal obtained by correcting the gain of the third cosine wave signal based on the stored maximum value or minimum value of the third cosine wave signal;
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, and calculates a rotation speed of the motor based on the rotation angle of the motor;
With
The first gain correction unit updates the maximum value and the minimum value of the first sine wave signal and the maximum value and the minimum value of the first cosine wave signal according to at least the rotational speed of the motor. Detection device. The first gain correction unit includes:
When the rotation speed of the motor is equal to or lower than the upper limit threshold of the rotation speed of the motor, the maximum value and the minimum value of the first sine wave signal stored in the storage unit, and the first cosine wave signal The rotation angle detection device according to claim 1, wherein the maximum value and the minimum value are updated. The first gain correction unit includes:
When the zero point of the first cosine wave signal is detected, the value of the first sine wave signal when the value of the first sine wave signal is 0 or more is set as the maximum value of the first sine wave signal. Remember
When the zero point of the first cosine wave signal is detected, the value of the first sine wave signal when the value of the first sine wave signal is less than 0 is set as the minimum value of the first sine wave signal. Remember
When the zero point of the first sine wave signal is detected, the value of the first cosine wave signal when the value of the first cosine wave signal is 0 or more is set as the maximum value of the first cosine wave signal as the storage unit. Remember
When the zero point of the first sine wave signal is detected, the value of the first cosine wave signal when the value of the first cosine wave signal is less than 0 is set as the minimum value of the first cosine wave signal as the storage unit. The rotation angle detection device according to claim 2. The first gain correction unit includes:
When the zero point of the first cosine wave signal is detected, the value of the first sine wave signal is 0 or more, and the value of the first cosine wave signal is a lower limit value of the maximum value of the first cosine wave signal. When the value is not more than the upper limit value, the value of the first sine wave signal is stored in the storage unit as the maximum value of the first sine wave signal,
When the zero point of the first cosine wave signal is detected, the value of the first sine wave signal is less than 0, and the value of the first sine wave signal is the lower limit of the minimum value of the first sine wave signal. When the value is not more than the upper limit value, the value of the first sine wave signal is stored in the storage unit as the minimum value of the first sine wave signal,
When the zero point of the first sine wave signal is detected, the value of the first cosine wave signal is 0 or more, and the value of the first cosine wave signal is a lower limit value of the maximum value of the first cosine wave signal. When the value is not more than the upper limit, the value of the first cosine wave signal is stored in the storage unit as the maximum value of the first cosine wave signal,
When the zero point of the first sine wave signal is detected, the value of the first cosine wave signal is less than 0, and the value of the first cosine wave signal is a lower limit value of the minimum value of the first cosine wave signal. The rotation angle detection device according to claim 2, wherein the value of the first cosine wave signal is stored in the storage unit as the minimum value of the first cosine wave signal when the value is not more than the upper limit value. The difference calculator is
When the positive phase sine wave signal is less than the lower limit threshold value of the positive phase sine wave signal or larger than the upper limit threshold value of the positive phase sine wave signal, Judgment,
When the negative phase sine wave signal is less than the lower limit threshold value of the negative phase sine wave signal or larger than the upper limit threshold value of the negative phase sine wave signal, Judgment,
When the positive phase cosine wave signal is less than the lower limit threshold value of the positive phase cosine wave signal or larger than the upper limit threshold value of the positive phase cosine wave signal, the input value abnormality of the positive phase cosine wave signal is Judgment,
When the negative-phase cosine wave signal is less than the lower-limit threshold value of the negative-phase cosine wave signal or greater than the upper-limit threshold value of the negative-phase cosine wave signal, The rotation angle detection device according to any one of claims 1 to 4, wherein the determination is made. The difference calculator is
A sine wave signal offset voltage, which is half the sum of the positive phase sine wave signal and the negative phase sine wave signal, is less than a lower limit threshold of the sine wave signal offset voltage, or the sine wave signal offset voltage Is determined to be an offset voltage value abnormality of the sine wave signal offset voltage,
A cosine wave signal offset voltage which is a half value of the sum of the positive phase cosine wave signal and the negative phase cosine wave signal is less than a lower limit threshold of the cosine wave signal offset voltage, or the cosine wave signal offset voltage. The rotation angle detection device according to any one of claims 1 to 5, wherein an offset voltage value abnormality of the cosine wave signal offset voltage is determined when the value is larger than an upper limit threshold value. The first gain correction unit includes:
When the zero point of the first cosine wave signal is detected, the value of the first sine wave signal when the value of the first sine wave signal is 0 or more is the lower limit value of the maximum value of the first sine wave signal. If it is less than or greater than the upper limit of the maximum value of the first sine wave signal, it is determined that the maximum value of the first sine wave signal is abnormal,
When the zero point of the first cosine wave signal is detected, the value of the first sine wave signal when the value of the first sine wave signal is less than 0 is the lower limit value of the minimum value of the first sine wave signal. If it is less than or greater than the upper limit of the minimum value of the first sine wave signal, determine that the minimum value of the first sine wave signal is abnormal,
When the zero point of the first sine wave signal is detected, the value of the first cosine wave signal when the value of the first cosine wave signal is 0 or more is the lower limit value of the maximum value of the first cosine wave signal. Or less than the upper limit value of the maximum value of the first cosine wave signal, it is determined that the maximum value of the first cosine wave signal is abnormal,
When the zero point of the first sine wave signal is detected, the value of the first cosine wave signal when the value of the first cosine wave signal is less than 0 is the lower limit value of the minimum value of the first cosine wave signal. It is determined that the minimum value of the first cosine wave signal is abnormal when it is less than or greater 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 is
When the zero point of the third cosine wave signal is detected and the value of the third sine wave signal is 0 or more, the value of the third sine wave signal is set as the maximum value of the third sine wave signal. Remember
When the zero point of the third cosine wave signal is detected and the value of the third sine wave signal is less than 0, the value of the third sine wave signal is set as the minimum value of the third sine wave signal. Remember
When the zero point of the third sine wave signal is detected, and the value of the third cosine wave signal is 0 or more, the value of the third cosine wave signal is set as the maximum value of the third cosine wave signal. Remember
When the zero point of the third sine wave signal is detected, if the value of the third cosine wave signal is less than 0, the value of the third cosine wave signal is set as the minimum value of the third cosine wave signal as the storage unit. The rotation angle detection device according to any one of claims 1 to 7. A rotation angle detection device according to any one of claims 1 to 8, comprising:
A motor control device that drives and controls the motor using the rotation angle. A motor control device according to claim 9,
The electric power steering device, wherein the motor is provided on a column shaft or a rack of the steering and torque-controls the steering force of the steering. 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 output from the position detection sensor as a motor position detection signal A rotation angle detection method for detecting a position of the motor based on a differential cosine wave signal including a signal and a negative cosine wave signal obtained by inverting the phase of the positive phase cosine wave signal,
A difference between the positive phase sine wave signal and the negative phase sine wave signal as a first sine wave signal;
A difference between the positive phase cosine wave signal and the negative phase cosine wave signal as a first cosine wave signal;
Based on the maximum value or the minimum value of the first sine wave signal when the rotation speed of the motor is equal to or lower than the upper limit threshold value of the rotation speed of the motor, the gain of the first sine wave signal is corrected and the second sine wave is corrected. A step of making a wave signal;
Based on the maximum value or the minimum value of the first cosine wave signal when the rotation speed of the motor is equal to or lower than the upper limit threshold value of the rotation speed of the motor, the gain of the first cosine wave signal is corrected and the second cosine wave is corrected. A step of making a wave signal;
Adding the second cosine wave signal and the second sine wave signal to form 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 a gain of the third cosine wave signal based on a maximum value or a 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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