JP5353195B2 - Motor control device and electric power steering device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor controller, which can suppress the dispersion of motor torque, and an electric motive power steering gear. <P>SOLUTION: A motor 30 includes three magnetic sensors 33u, 33v, and 33w, which can detect three-phase magnetic force &phiv;u, &phiv;v, and &phiv;w in three directions that parallel circumferential center lines Lu, Lv, and Lw, at intervals of 120&deg; in electrical angle besides being on the circumferential center lines Lu, Lv, and Lw, in each stator tooth 31b of a stator 31. Since the magnetic force &phiv;u, &phiv;v, and &phiv;w in the three directions are detected, so that they may include rotor magnetic force &phiv;fa generated by a rotor 32 and stator magnetic force &phiv;di and &phiv;qi, by these three magnetic sensors 33u, 33v, and 33w, the motor torque Tq output actually by the motor 30 can be obtained, based on these rotor magnetic force &phiv;fa and stator magnetic force &phiv;di and &phiv;qi. ECU 40 controls the motor 30, by supplying each coil of the stator 31 with a voltage according to this motor torque Tq and a torque command Tq*. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a motor control device and an electric power steering device.

2. Description of the Related Art Conventionally, as a motor control device that assists steering by a steering wheel of a vehicle, for example, a control device for an electric power steering device shown in Patent Document 1 is known. The control device performs PI control processing based on the d-axis current command value and q-axis current command value set from the detected steering torque and the like, and the d-axis current and q-axis current input by the feedback system. This is executed to generate a d-axis voltage command value and a q-axis voltage command value. The control device converts both voltage command values into voltage command values for each phase, and outputs a PWM signal corresponding to the voltage command value for each phase to the motor drive means to control the motor (motor).
JP 2006-256550 A

6A is a block diagram for explaining current feedback control related to the d-axis current Id, and FIG. 6B is a block diagram for explaining current feedback control related to the q-axis current Iq.
The current feedback control as described above will be described in detail. As shown in FIG. 6 (A), voltage conversion is performed for the deviation between the d-axis current Id and the d-axis current command value Id * calculated by the adder. The unit 101 multiplies the gain Ki to convert it to the d-axis voltage Vd. The d-axis current Id is calculated by dividing the d-axis voltage Vd by the impedance of the motor by the current converter 102. Then, the d-axis stator magnetic force φdi is calculated by multiplying the d-axis current Id by the number of turns p of the coil by the magnetic force conversion unit 103. Further, the d-axis current Id calculated by the current conversion unit 102 is output to the adding unit, and current feedback calculation processing is performed. In the normal control, the d-axis current command value Id * is set to 0 (zero) so that the d-axis stator magnetic force φdi is set to 0 (zero). In the field weakening control, the rotor magnetic force φfa generated by the rotor is weakened. The d-axis current command value Id * is set so as to generate such a d-axis stator magnetic force φdi.

  Further, as shown in FIG. 6B, the difference between the q-axis current Iq and the q-axis current command value Iq * calculated by the adding unit is multiplied by the gain Ki by the voltage conversion unit 104 to obtain the q-axis. Convert to voltage Vq. The q-axis current Iq is calculated by dividing the q-axis voltage Vq by the motor impedance by the current converter 105. Then, the q-axis stator magnetic force φqi is calculated by multiplying the q-axis current Iq by the number of turns p of the coil by the magnetic force conversion unit 106. Further, the q-axis current Iq calculated by the current conversion unit 105 is output to the addition unit, and current feedback calculation processing is performed. Then, the motor torque Tq obtained by multiplying the q-axis stator magnetic force φqi by the rotor magnetic force φfa by the torque conversion unit 107 is the torque that is actually output from the motor.

  By the way, since the rotor magnetic force φfa varies depending on the manufacturing state, operating temperature, change with time, etc., even if the current feedback control as described above is performed, the motor torque actually output by the motor varies. In this case, there is a problem that it is difficult to output the desired motor torque without variation.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a motor control device and an electric power steering device that can suppress variations in motor torque.

To achieve the above object, patents motor control apparatus according to claim 1 according to the claims, the stator three-phase coils (S ₁ to S ₁₂₎ is having a plurality of teeth wound respectively (31b) ( 31) and a motor control device (40, 60) for driving and controlling a motor (30) having a rotor (32) having a plurality of magnetic poles, the motor including a circumferential center line (Lu) of each tooth. , Lv, Lw) and three magnetic sensors (33u, 33v, 33w) capable of detecting a magnetic force (φu, φv, φw) in a direction along the circumferential center line at an electrical angle interval of 120 degrees , A rotation angle detecting means for detecting a rotation angle of the rotor, and a q-axis magnetic force obtained by converting magnetic forces in three directions detected by the three magnetic sensors based on the rotation angles and a magnetic force is generated in the stator. Not in front A voltage corresponding to a deviation between a motor torque (Tq) obtained by multiplication with a rotor magnetic force detected and stored in advance by each magnetic sensor and a torque command value (Tq *) set based on a driving situation, A technical feature is that the motor is controlled by supplying the coil.

  The motor controlled by the motor control device according to claim 1 can detect a magnetic force in a direction along the circumferential center line at 120 degrees intervals on the circumferential center line among the teeth of the stator. Three magnetic sensors are provided. Since these three magnetic sensors detect the magnetic force in three directions so as to include the rotor magnetic force generated by the rotor and the stator magnetic force, the motor torque actually output by the motor is obtained based on the rotor magnetic force and the stator magnetic force. . The motor control device controls the motor by supplying a voltage corresponding to the motor torque and a torque command value set based on the driving condition to each coil.

As a result, it is possible to drive and control the motor according to torque based on magnetic force feedback of each detected magnetic force instead of current feedback.
Therefore, even when the rotor magnetic force generated by the rotor varies, variations in motor torque output from the motor can be suppressed.

In particular, the motor that is driven and controlled by the motor control device is provided with a rotation angle detecting means for detecting the rotation angle of the rotor. The motor control device converts the magnetic force in three directions with an electrical angle detected by three magnetic sensors at intervals of 120 degrees, that is, the U-phase magnetic force, the V-phase magnetic force, and the W-phase magnetic force, based on the rotation angle. The motor torque that is actually output by the motor is calculated by multiplying the q-axis magnetic force with the rotor magnetic force that is detected and stored in advance by each magnetic sensor in a state where no magnetic force is generated in the stator. . By controlling the motor by supplying a voltage according to the motor torque calculated in this way and the torque command value set based on the driving situation to each coil, the torque based on the magnetic feedback of the q-axis magnetic force is obtained. Accordingly, since the motor is driven and controlled, variations in motor torque output from the motor can be reliably suppressed even when the rotor magnetic force varies.

In electric power steering apparatus according to claim 2 detects the steering state, to assist the steering by generating the motor controlled by the motor control device according an assist force corresponding to the steering state to claim 1. As a result, it is possible to realize an electric power steering apparatus that enjoys the effects and advantages of the invention of claim 1, such as the ability to suppress variations in motor torque output from the motor. Therefore, by adopting such a motor and a motor control device, it is possible to obtain a good steering feeling in which variations in motor torque are suppressed.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. First, the configuration of the electric power steering apparatus according to the present embodiment will be described with reference to FIGS. FIG. 1A is a configuration diagram showing an example of the overall configuration of an electric power steering apparatus 20 according to an embodiment of the present invention, and FIG. 1B is a circuit block showing an example of an electrical configuration of an ECU or the like. FIG.

  The electric power steering apparatus 20 mainly includes a steering wheel 21, a steering shaft 22, a pinion input shaft 23, a steering sensor 24, a speed reducer 27, a rack and pinion 28, a rod 29, a motor 30, a motor rotation angle sensor 25, It is comprised from ECU40 grade | etc.,.

  As shown in FIG. 1A, one end side of a steering shaft 22 is connected to the steering wheel 21, and the input side of a steering sensor 24 is connected to the other end side of the steering shaft 22. Further, one end side of the pinion input shaft 23 of the rack and pinion 28 is connected to the output side of the steering sensor 24. The steering sensor 24 includes a torsion bar (not shown) and two resolvers attached to both ends of the torsion bar so as to sandwich the torsion bar. The input / output receives one end of the torsion bar and outputs the other end. By detecting the torsion bar twist amount and the like generated between the two resolvers, the steering torque Ts and the steering angle by the steering wheel 21 can be detected.

  A reduction gear 27 is coupled to the pinion input shaft 23 connected to the output side of the steering sensor 24, and assist force output from the motor 30 is transmitted to the pinion input shaft 23 via the reduction gear 27. It is configured to be able to.

  That is, although not shown in the drawings, the speed reducer 27 as a power transmission mechanism is configured such that the motor gear attached to the output shaft of the motor 30 and the speed reduction gear of the speed reducer 27 can mesh with each other. When the output shaft 30 rotates, the reduction gear of the reducer 27 rotates at a predetermined reduction ratio, so that the driving force (assist force) by the motor 30 can be transmitted to the pinion input shaft 23.

  A motor rotation angle sensor 25 capable of detecting the rotation angle (motor rotation angle θm) of the motor 30 is attached to the motor 30, and a signal corresponding to the motor rotation angle θm detected by the motor rotation angle sensor 25. Can be output to the ECU 40.

On the other hand, on the other end side of the pinion input shaft 23, a pinion gear that can be engaged with a rack groove of a rack shaft (not shown) constituting the rack and pinion 28 is formed.
In this rack and pinion 28, the rotational motion of the pinion input shaft 23 can be converted into the linear motion of the rack shaft, and rods 29 are connected to both ends of the rack shaft. Steering wheels FR and FL are connected via a knuckle (not shown). Thus, when the pinion input shaft 23 rotates, the actual steering angle of the steered wheels FR, FL can be changed via the rack and pinion 28, the rod 29, etc., so that the rotation amount and the rotation direction of the pinion input shaft 23 can be changed. The steered wheels FR and FL can be steered.

Here, the configuration of the motor 30 according to the present embodiment will be described in detail with reference to FIG. FIG. 2 is a cross-sectional view of the motor 30 in the circumferential direction.
As shown in FIG. 2, the motor 30 is mainly composed of a stator 31 fixed to the inner peripheral surface of a housing (not shown), a rotor 32 disposed inside the stator 31, and the like, and a three-phase 10 pole 12 slot. This is a brushless motor.

The stator 31 includes 12 stator teeth 31b that are arranged at equal intervals in the circumferential direction. The stator 31 can be divided into 10 poles and 12 slots, and 12 coils are wound around the stator teeth 31b by concentrated winding. and a _S 1 _{to S 12} of the winding. Windings _S 1 _{to S 12} is, _{S 1,} S _2, S 3 clockwise equal intervals viewed from the axial direction one side, ... _are arranged such that the _{S 12} (see FIG. 2).

The windings S ₇ and S ₈ connected in series with the windings S ₁ and S ₂ connected in series function as U-phase windings (U ⁺ , U ⁻ ) and are connected in series. The windings S ₉ and S ₁₀ connected in series with the windings S ₃ and S ₄ connected in parallel function as V-phase windings (V ⁺ , V ⁻ ) and are connected in series. The windings S ₁₁ and S ₁₂ connected in series with the lines S ₅ and S ₆ are connected in parallel and function as W-phase windings (W ⁺ , W ⁻ ). Note that U ⁺ and U ⁻ are wound in opposite directions in the U-phase winding, and “ ⁺ ” and “ ⁻ ” are wound in opposite directions in the other-phase windings. Indicates.

  As shown in FIG. 2, three magnetic sensors 33u, 33v, and 33w are disposed on the circumferential center lines Lu, Lv, and Lw of the stator teeth 31b at intervals of 120 degrees in electrical angle among the stator teeth 31b. Is provided. The magnetic sensor 33u detects a U-phase magnetic force φu that is a magnetic force in a direction along the circumferential center line Lu, and the magnetic sensor 33v detects a V-phase magnetic force φv that is a magnetic force in a direction along the circumferential center line Lv. The magnetic sensors 33w are respectively arranged so as to detect a W-phase magnetic force φw that is a magnetic force in a direction along the circumferential center line Lw.

  The rotor 32 is arranged inside the stator 31 so as to form a certain distance (air gap) with the inner peripheral surface of the stator core 31a. The rotor 32 includes a shaft 32a that is rotatably supported by a bearing (not shown), a rotor yoke 32b that is fixed to the shaft 32a so as not to rotate relative to the shaft 32a, and an N pole that is equidistant in the circumferential direction on the outer peripheral surface of the rotor yoke 32b. And ten permanent magnets 32c alternately arranged with S poles.

  Next, the electrical configuration of the ECU 40 that controls the drive of the motor 30 will be described with reference to FIG. As shown in FIG. 1B, the ECU 40 is mainly configured by an MPU 60, an interface I / F 42, a motor drive circuit 50, and the like. The interface I / F 42 and the motor are connected to the MPU 60 through an input / output bus. A drive circuit 50 and the like are connected. The ECU 40 and the MPU 60 together with the motor rotation angle sensor 25 correspond to an example of a “motor control device” in the claims.

  The MPU 60 is composed of, for example, a microcomputer, a memory (ROM, RAM, EEPROM, etc.), etc., and has a function of executing basic motor control of the electric power steering apparatus 20 by a predetermined computer program. . That is, the MPU 60 sets the steering torque Ts detected by the steering sensor 24, the three-phase magnetic forces φu, φv, φw detected by the magnetic sensors 33u to 33w, the motor rotation angle θm detected by the motor rotation angle sensor 25, and the like. Based on this, the motor 30 is vector-controlled.

  The interface I / F 42 is a function for inputting various sensor signals input from the magnetic sensors 33u to 33w, the steering sensor 24, the motor rotation angle sensor 25, and the like to a predetermined port of the MPU 60 via an A / D converter or the like. Etc.

  The motor drive circuit 50 has a function of converting electric power supplied from the DC power source Batt into controllable three-phase AC power (see FIG. 4), and includes a PWM circuit and a switching circuit.

  Thereby, the ECU 40 generates motor torque suitable for the steering state based on the steering torque Ts, the three-phase magnetic forces φu, φv, φw, the motor rotation angle θm, and the like by PI control (proportional integral control) described later. Therefore, the electric power steering apparatus 20 can assist the steering of the driver by the steering wheel 21.

  Next, control processing for the motor 30 by the ECU 40 will be described with reference to FIGS. 3 and 4. FIG. 3 is an explanatory diagram illustrating the relationship among the U-phase magnetic force φu, the V-phase magnetic force φv, and the W-phase magnetic force φw, the d-axis magnetic force φd, and the q-axis stator magnetic force φqi. FIG. 4 is a functional block diagram relating to the PI control system of the motor 30 according to the present embodiment.

First, the d-axis magnetic force φd and the q-axis stator magnetic force φqi calculated by magnetic force feedback control, which is a characteristic part of the present invention, will be described with reference to FIG.
As illustrated in FIG. 3, the three-direction U-phase magnetic force φu, V-phase magnetic force φv, and W-phase magnetic force φw detected by the magnetic force sensors 33u, 33v, and 33w are d-axis-direction magnetic forces d. It is decomposed (converted) into an axial magnetic force φd and a q-axis magnetic force φq that is a magnetic force in the q-axis direction. Here, the d-axis magnetic force φd is an added value of the d-axis stator magnetic force φdi that is the magnetic force generated by the stator 31 and the rotor magnetic force φfa that is the magnetic force generated by the rotor 32. The rotor magnetic force φfa is detected by each of the magnetic sensors 33u, 33v, 33w when the voltage command value is 0 (zero) V and the stator 31 does not generate magnetic flux. And so on. In addition, since the q-axis magnetic force φq is a magnetic force generated only by the stator 31, it is hereinafter referred to as a q-axis stator magnetic force φqi.

Next, the calculation processing of the PI control system for the motor 30 by the ECU 40 will be described with reference to FIG.
As shown in FIG. 4, a signal corresponding to the steering torque Ts input from the steering sensor 24 to the MPU 60 is input to the phase compensation unit 61 after noise components are removed by a filter circuit (not shown). The phase compensator 61 performs a process of advancing the phase in order to increase the responsiveness to the output of the steering sensor 24, and then outputs a phase-compensated torque signal to the assist controller 62.

  In the assist control unit 62, the d-axis magnetic force command value φd * generated by the motor 30 and the torque command value Tq * are generated in order to assist the steering force based on the detected torque based on the torque signal input from the phase compensation unit 61. It is set by a predetermined map or arithmetic expression. The d-axis magnetic force command value φd * and the torque command value Tq * set in this way are output to an adding unit positioned in front of the PI control units 63 and 64, respectively.

  In the addition unit located in the preceding stage of the PI control unit 63, the d-axis magnetic force command value φd * output from the assist control unit 62 and the d-axis magnetic force φd of the motor 30 fed back from a three-phase two-phase conversion unit 67 described later. A difference calculation process for obtaining a deviation from is performed. In addition, the adding unit located in the preceding stage of the PI control unit 64 calculates a difference between a torque command value Tq * output from the assist control unit 62 and a motor torque Tq fed back from a torque conversion unit 69 described later. Processing is done. Thereby, the deviation between the d-axis magnetic force command value φd * and the d-axis magnetic force φd and the deviation between the torque command value Tq * and the motor torque Tq are calculated and output to the PI control units 63 and 64, respectively.

  In the PI control units 63 and 64, proportional-integral control is performed. That is, the PI control unit 63 performs a proportional integration calculation based on the deviation between the d-axis magnetic force command value φd * and the d-axis magnetic force φd output from the previous addition unit, and a predetermined proportional sensitivity and integral gain. Processing to output the d-axis voltage command value Vd * to the two-phase / three-phase converter 65 is performed as an integral value correction operation until the target value is reached. That is, the PI control unit 63 performs feedback calculation processing together with the addition unit.

  The PI control unit 64 performs proportional-integral calculation based on the deviation between the torque command value Tq * and the motor torque Tq, and a predetermined proportional sensitivity and integral gain, and corrects the integral value until the target value is reached. A process of outputting the q-axis voltage command value Vq * to the two-phase / three-phase converter 65 is performed.

  In the two-phase / three-phase conversion unit 65, the d-axis voltage command value Vd * and the q-axis voltage command value Vq * input from the PI control units 63 and 64 are dq-inverted (three-phase conversion) to obtain the voltage of each phase. Processing for calculating the command values Vu *, Vv *, Vw * is performed. The voltage command values reversely converted by the two-phase / three-phase conversion unit 65 are output to the PWM conversion unit 66 as a U-phase voltage command value Vu *, a V-phase voltage command value Vv *, and a W-phase voltage command value Vw *. The PWM conversion unit 66 performs a process of converting the voltage command values Vu *, Vv *, Vw * of each phase into PWM command values PWMu *, PWMv *, PWMw * for each phase.

  In the motor drive circuit 50, on the basis of the PWM signals PWMu *, PWMv *, and PWMw * of each phase output from the PWM converter 66, switching circuits (not shown) are turned on / off for each of the U phase, V phase, and W phase. As a result, the motor drive circuit 50 converts the DC power supplied from the DC power supply Batt into three-phase AC power and supplies the drive power to the motor 30. Therefore, the motor suitable for the steering state detected by the steering sensor 24. Torque is generated in the motor 30.

  Further, the U-phase magnetic force φu, the V-phase magnetic force φv, and the W-phase magnetic force φw generated in each phase of the stator 31 are detected by the magnetic sensors 33u, 33v, and 33w and output to the three-phase / two-phase converter 67.

  The motor rotation angle calculation unit 68 performs a process of calculating the motor rotation angle θm based on a signal corresponding to the motor rotation angle input from the motor rotation angle sensor 25. The motor rotation angle θm thus calculated is output to the three-phase / two-phase converter 67.

  The three-phase / two-phase converter 67 receives the U-phase magnetic force φu, the V-phase magnetic force φv, and the W-phase magnetic force φw input from the magnetic sensors 33u, 33v, 33w, and the motor rotation angle θm input from the motor rotation angle calculation unit 68. Is subjected to dq conversion (two-phase conversion) to calculate the d-axis magnetic force φd and the q-axis stator magnetic force φqi.

  The d-axis magnetic force φd converted by the three-phase / two-phase converter 67 is fed back to the adder located in the previous stage of the PI controller 63. Further, the q-axis stator magnetic force φqi is multiplied by the rotor magnetic force φfa by the torque conversion unit 69 and is fed back as a motor torque Tq to an addition unit located in the preceding stage of the PI control unit 63. Thereby, as described above, the feedback calculation processing by the PI control units 63 and 64 becomes possible.

By performing such vector control of the motor 30 by the MPU 60, the electric power steering apparatus 20 can be controlled.
Here, the magnetic feedback control described above will be described in detail with reference to FIGS. FIG. 5A is a block diagram for explaining magnetic force feedback control related to the d-axis magnetic force φd, and FIG. 5B is a block diagram for explaining magnetic force feedback control related to the q-axis stator magnetic force φqi. .

  First, magnetic feedback regarding the d-axis magnetic force φd will be described. As shown in FIG. 5A, voltage conversion is performed on the deviation between the d-axis magnetic force φd and the d-axis magnetic force command value φd * calculated by the adder. The unit 71 multiplies the gain Kφ and converts it to the d-axis voltage Vd. The d-axis current Id is calculated by dividing the d-axis voltage Vd by the impedance of the motor 30 by the current converter 72. Then, the d-axis stator magnetic force φdi is calculated by multiplying the d-axis current Id by the number of turns p of the coil by the magnetic force conversion unit 73. Then, the d-axis magnetic force φd, which is an added value of the d-axis stator magnetic force φdi and the rotor magnetic force φfa, is output to the adding unit, and magnetic force feedback calculation processing is performed.

  Next, the magnetic force feedback related to the q-axis stator magnetic force φqi will be described. As shown in FIG. 5B, the voltage conversion unit with respect to the deviation between the motor torque Tq calculated by the addition unit and the torque command value Tq *, as shown in FIG. A gain Kφ is multiplied by 81 and converted to a q-axis voltage Vq. The q-axis current Iq is calculated by dividing the q-axis voltage Vq by the motor impedance by the current converter 82. The q-axis stator magnetic force φqi is calculated by multiplying the q-axis current Iq by the number of turns p of the coil by the magnetic force conversion unit 83. Then, the motor torque Tq obtained by multiplying the q-axis stator magnetic force φqi by the rotor magnetic force φfa by the first torque converting unit 84 is output to the adding unit, and the magnetic force feedback calculation process is performed. In addition, the motor torque Tq obtained by multiplying the q-axis stator magnetic force φqi by the rotor magnetic force φfa by the second torque converter 85 is the torque that is actually output from the motor.

  As described above, the magnetic force feedback control is performed by detecting the rotor magnetic force φfa, the d-axis stator magnetic force φdi, and the q-axis stator magnetic force φqi by the magnetic sensors 33u, 33v, and 33w, so that even when the rotor magnetic force φfa varies. The motor torque Tq output from the motor 30 can be made constant.

  As described above, the motor 30 that is driven and controlled by the ECU 40 according to the present embodiment includes 120 degrees in electrical angle on the circumferential center lines Lu, Lv, and Lw among the stator teeth 31b of the stator 31. Three magnetic sensors 33u, 33v, and 33w capable of detecting three-phase magnetic forces φu, φv, and φw in three directions along the circumferential centerlines Lu, Lv, and Lw are provided at intervals. The three magnetic sensors 33u, 33v, 33w detect the three-direction magnetic forces φu, φv, φw so as to include the rotor magnetic force φfa generated by the rotor 32 and the stator magnetic forces φdi, φqi. A motor torque Tq that is actually output from the motor 30 is obtained based on the stator magnetic forces φdi and φqi. The ECU 40 controls the motor 30 by supplying a voltage corresponding to the motor torque Tq and a torque command value Tq * set based on the driving condition to each coil of the stator 31.

  More specifically, the ECU 40 obtains the U-phase magnetic force φu, the V-phase magnetic force φv, and the W-phase magnetic force φw, which are magnetic forces in three directions with an electrical angle detected by the three magnetic sensors 33u, 33v, and 33w at intervals of 120 degrees. Based on the motor rotation angle θm, it is converted into a d-axis stator magnetic force φdi and a q-axis stator magnetic force φqi, and the motor torque Tq actually output by the motor 30 is calculated by multiplying the q-axis stator magnetic force φqi and the rotor magnetic force φfa. . The ECU 40 controls the motor 30 by supplying a voltage corresponding to the motor torque Tq calculated in this way and the torque command value Tq * set based on the driving condition to each coil of the stator 31.

Accordingly, it is possible to drive and control the motor 30 according to torque based on magnetic force feedback of each detected magnetic force instead of current feedback.
Therefore, variation in the motor torque Tq output from the motor 30 can be suppressed even when the rotor magnetic force φfa generated by the rotor 32 varies.

  In the electric power steering apparatus 20 according to the present embodiment, the steering state is detected, and an assist force corresponding to the steering state is generated by the motor 30 controlled by the ECU 40 to assist the steering. Thereby, it is possible to realize an electric power steering apparatus that enjoys operations and effects such as the ability to suppress variations in motor torque Tq output from the motor 30. Therefore, by adopting such a motor 30 and ECU 40, it is possible to obtain a good steering feeling in which variations in motor torque Tq are suppressed.

In addition, this invention is not limited to the said embodiment, You may actualize as follows, and even in that case, an effect | action and effect equivalent to the said embodiment are acquired.
(1) The motor 30 is not limited to a three-phase, 10-pole, 12-slot brushless motor, and may employ a rotor having a magnetic pole different from 10 poles or a stator having a stator tooth different from 12 slots. Good. At this time, the magnetic sensors 33u, 33v, and 33w are provided so as to be able to detect the magnetic force in the direction along the circumferential center line at an electrical angle of 120 degrees on the circumferential center line among the stator teeth of the stator 31. Thus, U-phase magnetic force φu, V-phase magnetic force φv, and W-phase magnetic force φw, which are magnetic forces in three directions, are detected.

(2) In the above embodiment, as shown in FIG. 1, a so-called column-type electric power steering apparatus 20 that can transmit the assist force output from the motor 30 to the pinion input shaft 23 via the speed reducer 27. However, the motor control device and the electric power steering device according to the present invention are not limited to this example. For example, the rack and pinion 28 includes a motor and a speed reducer, and outputs from the motor. You may apply to what is called a rack-type electric power steering device which can transmit assist force to be transmitted to a rack mechanism via a reduction gear. Also, a so-called rack parallel type electric power steering device in which the rack shaft and the motor are arranged in parallel, a so-called pinion type electric power steering device in which the motor is arranged in the pinion portion having the pinion input shaft 23, or You may apply to what is called a dual pinion type electric power steering device.

FIG. 1A is a block diagram showing an example of the overall configuration of an electric power steering apparatus according to an embodiment of the present invention, and FIG. 1B is a circuit block diagram showing a configuration example of an ECU and the like. . It is a circumferential direction sectional view of a motor. It is explanatory drawing which illustrates the relationship between U-phase magnetic force, V-phase magnetic force, and W-phase magnetic force, d-axis magnetic force, and q-axis stator magnetic force. It is a functional block diagram regarding the PI control system of the motor which concerns on this embodiment. FIG. 5A is a block diagram for explaining magnetic force feedback control regarding the d-axis magnetic force, and FIG. 5B is a block diagram for explaining magnetic force feedback control regarding the q-axis stator magnetic force. FIG. 6A is a block diagram for explaining current feedback control related to the d-axis current, and FIG. 6B is a block diagram for explaining current feedback control related to the q-axis current.

Explanation of symbols

DESCRIPTION OF SYMBOLS 20 ... Electric power steering device 25 ... Motor rotation angle sensor (rotation angle detection means)
30 ... Motor 31 ... Stator 31b ... Stator teeth (teeth)
32 ... Rotor 33u, 33v, 33w ... Magnetic sensor 40 ... ECU (motor control device)
60 ... MPU (motor control unit)
Lu, Lv, Lw ... circumferential center line S ₁ to S _{12 ...} winding (coil)
Tq: Motor torque Tq *: Torque command value θm: Motor rotation angle (rotation angle)
φu… U phase magnetic force φv… V phase magnetic force φw… W phase magnetic force φd… d-axis magnetic force φdi—d-axis stator magnetic force φd * —d-axis magnetic force command value φqi—q-axis stator magnetic force φfa—rotor magnetic force

Claims (2)

A motor control device that drives and controls a motor including a stator having a plurality of teeth each wound with a three-phase coil and a rotor having a plurality of magnetic poles,
The motor includes three magnetic sensors that are capable of detecting a magnetic force in a direction along the circumferential center line at an electrical angle of 120 degrees on the circumferential center line of the teeth .
Rotation angle detection means for detecting the rotation angle of the rotor,
The q-axis magnetic force obtained by converting the magnetic forces in the three directions detected by the three magnetic sensors based on the rotation angle and the magnetic sensors are detected and stored in advance in a state where no magnetic force is generated in the stator. A motor that controls the motor by supplying a voltage corresponding to a deviation between a motor torque obtained by multiplication with a rotor magnetic force and a torque command value set based on a driving state to each of the coils. Control device. An electric power steering apparatus that detects a steering state and assists steering by generating an assist force according to the steering state by the motor controlled by the motor control device according to claim 1 .

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