JP2015133868A - Motor controller, motor-driven actuator system, and motor control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to start in a short period of time operating a brushless motor whose rotation is controlled by an estimated value of a rotor angle on the basis of an inductance variation.SOLUTION: A rotor is rotated to a rotation end position at a time of starting operation of a brushless motor, and an estimated value of a rotor angle is calculated on the basis of a polarity of a magnetic pole axis univocally determined by an actual value of the rotor angle when the rotation is regulated by an inductance variation and a stopper.

Description

  The present invention relates to a motor control device, an electric actuator system, and a motor control method.

  A technique (sensorless motor drive control) for driving a brushless motor (hereinafter referred to as a motor) without using an angular position detection device of a rotor is known. In sensorless motor drive control, the rotor angle (magnetic pole position) is estimated. When the rotor is stopped or at a low speed, the rotor angle is estimated based on the fluctuation of the motor inductance.

  For example, in Patent Document 1, a harmonic voltage for position detection is superimposed on a command signal, a differential current of a harmonic current flowing in the motor at that time is detected, and an arithmetic process using the harmonic voltage and the differential current is performed. Thus, the inductance is calculated, and the estimated value of the rotor angle is calculated based on the fluctuation of the inductance. Here, as shown in the schematic diagram of FIG. 5, when the rotor angle is θ, the period of the rotor angle θ is 360 °, whereas the variation period of the inductance is 180 °, which is half. For this reason, when the estimated value of the rotor angle is calculated using the inductance, it is not possible to identify the rotor angle whose phase is different by 180 °. For example, as shown in FIG. 5, when the rotor angle estimated from the inductance is 45 °, the actual rotor angle θ may be 45 ° or 225 °. That is, when the inductance period corresponds to the rotor angle of 270 ° to 90 °, the actual value of the rotor angle and the estimated value of the rotor angle are within the range of the actual value of the rotor angle of 90 ° to 270 °. It is calculated with a 180 ° deviation (that is, with the magnetic poles reversed).

  Therefore, in order to solve such a problem, Patent Document 2 describes that the actual value of the rotor angle agrees with the estimated value of the rotor angle by performing a process of determining the direction of the magnetic pole before starting the control of the motor. Is disclosed. In the method of Patent Literature 2, when a magnetic field is generated by flowing a current in the magnetic pole direction (estimated d-axis) estimated based on a variation in inductance, the direction of the magnetic field generated by the current is the same as the direction of the magnetic field generated by the magnet. Utilizing the fact that the state of the motor current flowing in each phase of the motor changes between the saturation state of a certain magnetic flux and the non-saturation state of the magnetic flux in which the direction of the magnetic field generated by the current and the direction of the magnetic field generated by the magnet is opposite, This change is discriminated to determine the direction of the magnetic pole of the rotor (the polarity of the magnetic pole axis). According to such a method of Patent Document 2, as shown in FIG. 5, the relationship between the d-axis estimated by the magnetic pole discrimination and the polarity of the magnetic pole is discriminated by coincidence or inversion, thereby estimating from the inductance, for example. When the rotor angle indicates 45 °, it is determined whether the actual rotor angle θ is 45 ° or 225 °.

Japanese Patent Laid-Open No. 2006-121782 JP 2002-78392 A

  However, in the method of Patent Document 2, it is necessary to always perform the process of determining the direction of the magnetic pole before starting the motor control, and it takes time to start the motor control.

  The present invention has been made in view of the above-described problems, and an object thereof is to enable a brushless motor whose rotation is controlled by an estimated value of a rotor angle based on an inductance variation to be started in a short time.

  As a means for solving the above-mentioned problem, the first invention is a brushless in which the rotation of the rotor is restricted at the rotation end position by the stopper and the rotor is biased toward the rotation end position by the biasing means. A motor control device that performs sensorless vector control for estimating a magnetic pole position based on a change in inductance of a motor, and determines a polarity of a magnetic pole axis that is uniquely determined by an actual value of a rotor angle when rotation is restricted by the stopper. An initial setting unit for storing, an angle estimation unit for calculating an estimated value of a rotor angle based on inductance variation and the polarity of the magnetic pole axis stored in the initial setting unit, and the rotor angle obtained by the angle estimation unit And an inverter that generates an actual voltage to be applied to the brushless motor based on the estimated value.

  According to a second aspect of the present invention, there is provided a brushless motor in which the rotation of the rotor is restricted at the rotation end position by the stopper and the rotor is biased toward the rotation end position by the biasing means based on the variation in inductance. Is a motor control device that performs sensorless vector control to estimate the initial value of the rotor angle when rotation is restricted by the stopper, and calculates the estimated value of the rotor angle based on the inductance variation And an inverter that generates an actual voltage to be applied to the brushless motor based on the estimated value of the rotor angle obtained by the angle estimation unit, wherein the angle estimation unit has θ ^ (n + 1) The updated value of the estimated value of the rotor angle, ω ^ (n + 1) is the updated value of the estimated value of the rotor angular velocity, and Δt is the low value in the previous control cycle. The elapsed time from the calculation of the estimated angle value, θ ^ (n) is the estimated value of the rotor angle in the previous control period, ω ^ (n) is the estimated value of the rotor angular speed in the previous control period, and K1 and K2 are The estimated value of the rotor angle is calculated by the following equation (1) in which the calculation gain, θe (n) indicates the phase difference estimated value in the previous control cycle, and the actual value of the rotor angle stored in the initial setting unit is expressed by the equation It is θ ^ (0) when n = 0 in (1), and the angle estimation unit employs a configuration in which the estimated value of the rotor angle is calculated using the actual value as an initial value.

  According to a third invention, in the first or second invention, a configuration is adopted in which the actual voltage is generated to cause the rotor to generate a driving force in a direction toward the rotation end position when the brushless motor is started.

  According to a fourth aspect of the present invention, there is provided an electric actuator having a brushless motor in which the rotation of the rotor is restricted by the stopper at the rotation end position and the rotor is biased toward the rotation end position by the biasing means. An electric actuator system including a motor control device that performs vector control of a motor based on a variation in inductance, and includes the motor control device according to any one of the first to third inventions as the motor control device. Is adopted.

  In a fifth aspect based on the fourth aspect, the stopper is configured such that the actual value of the rotor angle at the rotation end position is in a range of 45 ° centered on the actual value of the rotor angle at which the polarity of the magnetic pole axis is reversed. A configuration is adopted in which it is provided at a position that is set to avoid this.

  According to a sixth aspect of the present invention, there is provided a brushless motor in which the rotation of the rotor is restricted at the rotation end position by the stopper and the rotor is biased toward the rotation end position by the biasing means. A motor control method for performing sensorless vector control for estimating the actual rotation angle when the brushless motor is started and the rotor is rotated to the rotation end position and the rotation is restricted by the inductance variation and the stopper. A configuration is adopted in which the estimated value of the rotor angle is calculated based on the polarity of the magnetic pole axis that is uniquely determined by the value.

  According to the present invention, when the brushless motor is started, the rotor angle at the start is always constant by rotating the rotor to the rotation end position where the rotation is restricted by the stopper. For this reason, the polarity of the magnetic pole axis in the rotor rotated to the rotation end position is uniquely determined. Therefore, the brushless motor can be accurately controlled by calculating the estimated value of the rotor angle at the start based on the polarity of the magnetic pole shaft in the rotor rotated to the rotation end position. According to the present invention, the brushless motor can be controlled in a short time because there is no need to perform the process of determining the direction of the magnetic pole.

It is a functional block diagram which shows schematic structure of the electric actuator system in one Embodiment of this invention. It is a longitudinal section showing a schematic structure of an electric actuator with which an electric actuator system in one embodiment of the present invention is provided. It is the perspective view which illustrated the main-body part and stopper of a plunger with which the electric actuator system in one Embodiment of this invention is provided. It is a principal part enlarged view of the electric actuator with which the electric actuator system in one Embodiment of this invention is provided. It is explanatory drawing which shows the relationship between the d-axis estimated by the magnetic pole discrimination | determination, and the polarity of a magnetic pole.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment of a motor control device, an electric actuator system and a motor control method according to the present invention will be described with reference to the drawings. In the following drawings, the scale of each member is appropriately changed in order to make each member a recognizable size.

  FIG. 1 is a functional block diagram showing a schematic configuration of the electric actuator system S of the present embodiment. As shown in this figure, the electric actuator system S of this embodiment includes a motor control device 1 and an electric actuator 20.

  First, the electric actuator 20 will be described. FIG. 2 is a longitudinal sectional view showing a schematic configuration of the electric actuator 20. As shown in this figure, the electric actuator 20 includes a casing 21, a motor 22, a ball screw 23, a plunger 24, a stopper 25, a compression spring 26 (biasing means), a reservoir tank 27, and a detection unit. 28.

  The casing 21 is a metal container that houses the motor 22, the ball screw 23, the plunger 24, and the like. A discharge hole 21 a for pushing hydraulic oil to the outside of the casing 21 is provided at the end of the casing 21. In addition, a filling chamber 21b continuous to the discharge hole 21a is provided inside the casing 21, and the filling chamber 21b is filled with hydraulic oil. Further, the casing 21 is formed with a port 21c opened so as to face the filling chamber 21b, and the reservoir tank 27 is connected to the filling chamber 21b via the port 21c. The port 21c is provided at a position where the plunger 24 is closed by a main body 24a of the plunger 24 described later when the plunger 24 is moved by being pushed by the ball screw 23 (ie, pushed to the right in FIG. 2).

  The motor 22 is a brushless DC motor accommodated in the casing 21 in the vicinity of the end opposite to the discharge hole 21a. The motor 22 has a stator 22a and a rotor 22b. The stator 22a is fixed in an annular shape with respect to the inner wall surface of the casing 21, and includes an armature 22c made of a coil and an insulator 22d that supports the armature 22c. In the present embodiment, a three-phase (U, V, W) armature 22c is provided. The rotor 22 b is supported by a bearing so as to be surrounded by the stator 22 a and is connected to the ball screw 23. The rotor 22b has a plurality of permanent magnets 22e arranged to face the stator 22a. Such a permanent magnet 22e forms an N pole and an S pole with respect to the rotor 22b. The rotor 22b is rotationally driven by forming a magnetic field by energizing the armature 22c of the stator 22a.

  In the following description, the magnetic pole axis means an axis connecting these N pole and S pole. Further, the polarity of the magnetic pole axis means the polarities of two end portions existing on the magnetic pole axis (that is, whether it is N pole or S pole), and means the direction of the magnetic pole axis.

  The ball screw 23 is a rod-like member extending in the axial direction of the rotor 22b, and is screwed with the rotor 22b via the ball 23a. The ball screw 23 is linearly moved in the longitudinal direction by the rotation of the rotor 22b.

  The plunger 24 is fixed to the tip of the ball screw 23 and is moved in the axial direction of the rotor 22b as the ball screw 23 moves. The plunger 24 includes a main body portion 24a, a seal ring 24b, and a valve mechanism 24c.

  The main body 24 a is a columnar member that is fixed to the ball screw 23. The main body 24a includes a filling chamber 24d that is filled with hydraulic oil at the center in the moving direction. FIG. 3 is a perspective view illustrating the main body 24 a of the plunger 24 and the stopper 25. As shown in this figure, as shown in FIG. 3, a slit 24e through which the stopper 25 is inserted is provided in the ceiling and bottom of the filling chamber 24d. The slit 24e extends in the direction so that the main body 24a can move in the axial direction of the rotor 22b. Further, a through hole 24f into which the cylindrical member 24g of the valve mechanism 24c is slidably fitted is provided at the distal end portion of the main body 24a. As shown in FIG. 2 (and FIG. 4 to be described later), the plunger 24 is restricted from moving when the end of the slit 24e on the discharge hole 21a side contacts the stopper 25.

  The seal ring 24b is attached to the outer peripheral surface side of the main body portion 24a, and prevents hydraulic oil from leaking to the motor 22 side through the gap between the plunger 24 and the casing 21.

  The valve mechanism 24c includes a cylindrical member 24g, a support portion 24h, and a compression spring 24i. The cylindrical member 24g is a bottomed cylindrical member, and is slidably fitted into the through hole 24f of the main body 24a with the bottom (right end in FIG. 2) facing the discharge hole 21a. The cylindrical member 24g is longer than the through hole 24f, and the opening end side is in contact with the stopper 25. In addition, a through hole 24j that communicates the outside and the inside of the cylindrical member 24g is provided near the bottom of the cylindrical member 24g. The support portion 24h is a bottomed cylindrical member fixed to the tip of the main body portion 24a, and a through hole 24k is provided in the bottom portion (right end portion in FIG. 2). The support portion 24h holds the compression spring 24i accommodated therein with the cylindrical member 24g. The compression spring 24i is disposed between the bottom of the support portion 24h and the cylindrical member 24g, and always urges the cylindrical member 24g toward the stopper 25.

  The stopper 25 is fixed to the casing 21 and is provided so as to pass through the body 24a of the plunger 24 in the vertical direction through the slit 24e of the plunger 24 as described above. The stopper 25 defines the movement end position of the plunger 24 that is biased toward the motor 22 by the compression spring 24i. When the end of the slit 24e comes into contact with the stopper 25, the plunger 24 is stopped at the movement end position. In addition, when the movement of the plunger 24 is restricted by the stopper 25, the rotation of the rotor 22b of the motor 22 connected to the plunger 24 via the ball screw 23 is also restricted. That is, the stopper 25 also defines the rotation end position of the rotor 22b. That is, in the electric actuator 20 of this embodiment, the rotation of the rotor 22b is restricted by the stopper 25 at the rotation end position.

  The compression spring 26 is accommodated in the filling chamber 21b, and urges the plunger 24 toward the motor 22 side. That is, the compression spring 26 urges the plunger 24 in a direction in which the rotor 22b moves toward the rotation end position. The reservoir tank 27 is a tank that stores hydraulic oil, and is connected to the filling chamber 21b via the port 21c. The detector 28 detects the position of the plunger 24 (that is, the stroke position) and outputs the result as a stroke position detection signal Sa.

  In the electric actuator 20 having such a configuration, the rotor 22b of the motor 22 is rotated so that the ball screw 23 is moved to the motor 22 side, and the plunger 24 is pulled to a position where it is stopped by the stopper 25 (movement end position). 4A, when the cylindrical member 24g is pressed from the stopper 25, the compression spring 24i is contracted, and the through hole 24j formed in the cylindrical member 24g is formed in the filling chamber 21b (supported). Exposed to the inside of the portion 24h). Further, the port 21c is opened. As a result, the filling chamber 21b, the reservoir tank 27, and the filling chamber 24d of the main body 24a are connected, and no hydraulic pressure is generated. Since the plunger 24 is urged toward the motor 22 by the compression spring 26, the state shown in FIG. 4A (that is, the state where no hydraulic pressure is generated) is obtained by reducing the torque in the motor 22 to zero or minute. It becomes. Further, in the electric actuator 20, the motor controller 1 generates the actual voltage so that the driving force in the direction toward the rotation end position is generated in the rotor 22b when the motor 22 is started, so that the plunger 24 is reliably stopped by the stopper. It can be pulled to a position where it is stopped by 25.

  On the other hand, when the rotor 22b of the motor 22 is rotated so that the ball screw 23 is moved toward the discharge hole 21a, the plunger 24 is moved toward the discharge hole 21a as shown in FIG. Thus, the cylindrical member 24g is pushed back to the motor 22 side by the compression spring 24i, and the through hole 24j formed in the cylindrical member 24g is closed by the main body 24a. The port 21c is also closed. As a result, the filling chamber 21b is isolated from the reservoir tank 27 and the filling chamber 24d of the main body 24a, and the hydraulic pressure is generated by the movement of the plunger 24 toward the discharge hole 21a.

  Next, the motor control device 1 will be described. As described above, the motor 22 of the electric actuator 20 whose rotation is controlled by the motor control device 1 includes the rotor 22b including the permanent magnet 22e and the three phases (U, V, W) arranged around the rotor 22b. It is a brushless DC motor provided with the armature 22c. The motor control device 1 performs feedback control on the current flowing through the armature 22 c of the motor 22. The motor control device 1 has an armature (d-axis armature) provided on the d-axis with the direction perpendicular to the magnetic flux direction of the field pole of the rotor 22b of the motor 22 as the d-axis and the motor 22 on the d-axis. And an equivalent circuit having an armature (q-axis armature) provided on the q-axis for vector control.

  Such a motor control device 1 includes, for example, an on-vehicle ECU (engine control unit), and stores a storage unit that stores various programs and data necessary for calculation, an arithmetic processing unit that performs various calculations, these storage units, and an arithmetic unit. It consists of hardware such as a substrate on which the processing unit is mounted.

  As shown in FIG. 1, the motor control device 1 includes a command angle calculation unit 2, a first subtraction unit 3, a position control unit 4, a second subtraction unit 5, a speed control unit 6, and a third subtraction unit. 7, current / non-interference control unit 8, control switching unit 9, addition unit 10, inverse dq conversion unit 11, inverter 12, position detection signal generation unit 13, angle estimation unit 14, dq A conversion unit 15, an actual angle calculation unit 16, an actual angular velocity calculation unit 17, and an initial setting unit 18 are provided.

  The command angle calculation unit 2 receives a stroke position command signal Sb (command signal), which is a command signal for designating the stroke position of the plunger 24 of the electric actuator, from the outside, and the rotor command angle based on the stroke position command signal Sb. θ * is calculated. The rotor command angle θ * indicates the rotor angle when the plunger 24 is disposed at the stroke position based on the stroke position command signal Sb. The first subtraction unit 3 calculates a difference value between the rotor command angle θ * calculated by the command angle calculation unit 2 and the rotor actual angle θm (actual value of the rotor angle) calculated by the actual angle calculation unit 16. . The actual rotor angle θm indicates an actual value of the rotor angle based on the stroke position detection signal Sa output from the detection unit 28.

  The position control unit 4 receives the difference value calculated by the first subtraction unit 3 and calculates a rotor command angular velocity ω * (rotor angular velocity command value) based on the difference value. The position control unit 4 is represented by, for example, a PID element Kp + Ki / S + KDS. The second subtraction unit 5 calculates a difference value between the rotor command angular velocity ω * calculated by the position control unit 4 and the rotor actual angular velocity ωm (actual value of the rotor angular velocity) calculated by the actual angular velocity calculation unit 17. The actual rotor angular velocity ωm indicates an actual value of the rotor angular velocity calculated based on the actual rotor angle θm.

  The speed control unit 6 receives the difference value calculated by the second subtraction unit 5 and calculates the d-axis command current Id * and the q-axis command current Iq * based on the difference value. The speed control unit 6 is represented by a PID element, for example.

  The third subtraction unit 7 calculates a difference value between the d-axis command current Id * calculated by the speed control unit 6 and the d-axis estimated actual current Id ^ calculated by the dq conversion unit 15. The third subtraction unit 7 calculates a difference value between the q-axis command current Iq * calculated by the speed control unit 6 and the q-axis estimated actual current Iq ^ calculated by the dq conversion unit 15. The d-axis estimated actual current Id ^ and the q-axis estimated actual current Iq ^ are supplied to the d-axis armature with the U-phase actual current Iu, V-phase actual current Iv, and W-phase actual current Iw output from the inverter 12. And a current supplied to the q-axis armature. The d-axis estimated actual current Id ^ is a current supplied to the d-axis armature, and the q-axis estimated actual current Iq ^ is a current supplied to the q-axis armature.

  The current / non-interference control unit 8 performs a PI process on the difference value calculated by the third subtraction unit 7 and further performs a process of canceling the influence of the speed electromotive force that interferes between the d-axis and the q-axis. D-axis command voltage Vd * and q-axis command voltage Vq * are calculated.

  The control switching unit 9 performs mode switching between the butting mode and the position control mode. In the abutting mode, an appropriate torque shaft current Id * for driving the plunger 24 in the direction of abutting against the position of the stopper 25 is input to the third subtracting unit 7. In the position control mode, the output of the speed control unit 6 is output to the third subtraction unit 7 as it is. The control switching unit 9 switches the mode of the control switching unit 9 from the abutting mode to the position control mode or from the position control mode to the abutting mode based on an external command.

  The addition unit 10 superimposes the d-axis detection voltage Vhd generated by the position detection signal generation unit 13 on the d-axis command voltage Vd * calculated by the current / non-interference control unit 8. The adding unit 10 superimposes the q-axis detection voltage Vhq generated by the position detection signal generation unit 13 on the q-axis command voltage Vq * calculated by the current / non-interference control unit 8.

  The inverse dq converter 11 converts the d-axis command voltage Vd * superimposed with the d-axis detection voltage Vhd and the q-axis command voltage Vq * superimposed with the q-axis detection voltage Vhq into U, V, This is converted into a command voltage to be applied to the W three-phase armature 22c. The command voltage applied to the U-phase armature is the U-phase command voltage Vu *, the command voltage applied to the V-phase armature is the V-phase command voltage Vv *, and the command voltage applied to the W-phase armature is W The phase command voltage is Vw *.

  The inverter 12 is an actual voltage that is actually applied to the armature 22c of the motor 22 in accordance with the U-phase command voltage Vu *, the V-phase command voltage Vv *, and the W-phase command voltage Vw * obtained by the inverse dq converter 11. And the actual voltage is applied to the armature 22 c of the motor 22. The inverter 12 generates a U-phase actual voltage Vu that is an actual voltage that is actually applied to the U-phase armature 22c of the motor 22 according to the U-phase command voltage Vu *, and according to the V-phase command voltage Vv *. A V-phase actual voltage Vv that is an actual voltage actually applied to the V-phase armature 22c of the motor 22 is generated, and is actually applied to the W-phase armature 22c of the motor 22 in accordance with the W-phase command voltage Vw *. A W-phase actual voltage Vw that is an actual voltage is generated.

  The inverter 12 detects the actual current supplied to the motor 22 and outputs the value. The inverter 12 supplies the U-phase armature 22c with the actual current supplied to the U-phase armature 22c, the V-phase armature 22c with the actual current supplied to the V-phase armature 22c, and the W-phase armature 22c. The supplied actual current is output as a W-phase actual current Iw.

  The position detection signal generator 13 generates a d-axis detection voltage Vhd and a q-axis detection voltage Vhq used for estimating the rotor angle of the motor 22. These d-axis detection voltage Vhd and q-axis detection voltage Vhq have three cycles of the motor control device 1 (T11, t12, T13) as one cycle and each phase (d-axis detection voltage Vhd and This is a harmonic voltage whose output pattern is set so that the sum of the output voltages of the q-axis detection voltage Vhq) becomes zero. Note that three control cycles do not necessarily have to be one period.

  The angle estimation unit 14 includes a rotor command angular velocity ω * calculated by the position control unit 4, a d-axis detection voltage Vhd and a q-axis detection voltage Vhq generated by the position detection signal generation unit 13, and a dp conversion unit. The d-axis estimated actual current Id ^ and the q-axis estimated actual current Iq ^ obtained at 15 and the rotor actual angular velocity ωm calculated by the actual angular velocity calculating unit 17 are input.

  The angle estimation unit 14 obtains a sine reference value Vsdq, a cosine reference value Vcdq, and an inductance reference value L0 based on these input values, and further estimates a phase difference between the rotor estimated angle θ ^ and the rotor actual angle θm. The value θe is obtained, and the rotor estimated angle θ ^ is updated using an observer. Here, the angle estimation unit 14 determines that θ ^ (n + 1) is the updated value of the rotor estimated angle, ω ^ (n + 1) is the updated value of the estimated rotor angular velocity, and Δt is the time from the calculation of the estimated rotor angle in the previous control cycle. Elapsed time, θ ^ (n) is the estimated rotor angle in the previous control cycle, ω ^ (n) is the estimated rotor angular velocity in the previous control cycle, K1 and K2 are calculation gains, and θe (n) is in the previous control cycle. The estimated rotor angle θ ^ is calculated by the above equation (1) indicating the estimated phase difference value. The angle estimating unit 14 calculates the estimated rotor angle θ ^ based on the polarity of the magnetic pole axis stored in the initial setting unit 18 when the electric actuator 20 is started (that is, when the motor 22 is started).

  The dq conversion unit 15 includes a d-axis estimated actual current Id ^ that supplies the U-phase actual current Iu, the V-phase actual current Iv, and the W-phase actual current Iw output from the inverter 12 to the d-axis armature, Conversion to q-axis estimated actual current Iq ^ supplied to the q-axis armature. Here, the dq converter 15 uses the inverse matrix of the determinant of the inverse dq converter 11 to convert the U-phase actual current Iu, the V-phase actual current Iv, and the W-phase actual current Iw into the d-axis estimation actual. The current Id ^ and the q-axis estimated actual current Iq ^ are converted.

  The actual angle calculation unit 16 receives the stroke position detection signal Sa from the detection unit 28 and calculates the rotor actual angle θm based on the actual stroke position. The actual angular velocity calculator 17 receives the rotor actual angle θm calculated by the actual angle calculator 16 and calculates the rotor actual angular velocity ωm from the rotor actual angle θm. Here, the actual angular velocity calculation unit 17 calculates the rotor actual angular velocity ωm by, for example, differentiating the value of the rotor actual angle θm with time.

  The initial setting unit 18 stores the polarity of the magnetic pole shaft that is uniquely determined by the actual rotor angle when the rotation is restricted by the stopper 25 of the electric actuator 20. That is, the initial setting unit 18 stores in advance the polarity of the magnetic pole axis of the rotor 22b stopped at the rotation end position by the stopper 25 (that is, the direction of the end of the magnetic pole axis on the N pole side). Alternatively, the rotor actual angle θ0 when the rotor 22b is at the rotation end position is stored.

  When the electric actuator 20 is started, the abutting mode is entered, and an appropriate torque shaft current Id * for rotating the rotor 22b to the rotation end position is input to the third subtracting unit 7 to input a U-phase command. A voltage Vu, a V-phase command voltage Vv, and a W-phase command voltage Vw are generated.

  The calculation method of the d-axis command voltage Vd * and the q-axis command voltage Vq * in the current / non-interference control unit 8 and the d-axis command voltage Vd * and the q-axis command voltage Vq * in the inverse dq conversion unit 11 Phase command voltage Vu *, conversion method to V phase command voltage Vv * and W phase command voltage Vw *, sine reference value Vsdq, cosine reference value Vcdq, inductance reference value L0, phase difference estimated value θe in angle estimator 14 and Since the calculation method of the rotor estimated angle θ ^ and the like is detailed in the above-mentioned Patent Document 1 and the like, description thereof is omitted here. The vector control method is described in detail in "Theory and Design of AC Servo System: Hidehiko Sugimoto, General Electronic Publishing".

  In the electric actuator system S having such a configuration, at the time of starting, the U-phase actual voltage Vu, the V-phase actual voltage Vv, and the W-phase actual voltage Vw are generated based on the abutting mode, and each armature 22c of the motor 22 is generated. To be applied. As a result, the rotor 22b is rotated to the rotation end position.

  Subsequently, based on the polarity of the magnetic pole axis stored in the initial setting unit 18 or the rotor actual angle θ0 at the rotation end position, the angle estimation unit 14 performs the rotor estimated angle θ using the observer represented by the above equation (1). ^ Is calculated. At this time, the initial value θ ^ (0) used for estimating the rotor angle is usually 0 ° or 180 ° depending on the polarity of the magnetic pole axis. However, the actual rotor angle θ0 is preferably used. The convergence calculation can be completed in a short period of time, and the estimated rotor angle θ ^ can be determined in a short period of time.

  As described above, the angle estimation unit 14 determines the rotor angle when the rotation is restricted by the stopper 25 based on the polarity of the magnetic pole axis stored in the inductance variation and initial setting unit 18 or the actual angle θ0, that is, the rotor at the start. After calculating the estimated value of the angle, the electric actuator system S can be freely operated by inputting the stroke position command signal Sb to the command angle calculation unit 2 thereafter. Here, at each start, the rotor angle when the rotation is restricted by the stopper 25 is estimated, such as wear or deformation of the stopper 25, aging deterioration of parts of the electric actuator 20, dimensional error for each product, or the like. This is because it is assumed that the actual rotor angle at the end position varies.

  According to such an electric actuator system S of the present embodiment, when the motor 22 is started, the rotor 22b is rotated to the rotation end position where the rotation is restricted by the stopper 25. It becomes constant. For this reason, the polarity of the magnetic pole axis in the rotor 22b rotated to the rotation end position is uniquely determined. Therefore, the motor 22 can be accurately controlled by calculating the estimated rotor angle θ ^ at the start based on the polarity of the magnetic pole axis in the rotor 22b rotated to the rotation end position. According to the electric actuator system S of the present embodiment as described above, it is not necessary to perform the process of determining the direction of the magnetic poles, so that the motor 22 can be controlled in a short time.

  In the present embodiment, the stopper 25 is provided at a position where the rotor actual angle θ0 at the rotation end position is set to avoid a range of 45 ° centering on the rotor actual angle at which the polarity of the magnetic pole axis is reversed. It is desirable that For example, when the polarity of the magnetic pole axis is reversed at the rotor actual angles of 90 ° and 270 °, if the rotor actual angle θ0 at the rotation end position is in the vicinity of 90 ° or 270 °, the components of the electric actuator 20 Even if the actual rotor angle at the rotation end position is slightly deviated due to aging deterioration or dimensional error for each product, the actual polarity of the magnetic pole axis is different from the polarity of the magnetic pole axis stored in the initial setting unit 18. there is a possibility. Therefore, in such a case, it is desirable to set the position of the stopper 25 while avoiding the range where the rotor actual angle θ0 at the rotation end position is 90 ° and 45 ° centering on 270 °.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the said embodiment. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the spirit of the present invention.

  For example, in the above embodiment, the angle estimation unit 14 uses the rotor actual angular velocity ωm calculated by the actual angular velocity calculation unit 17 as a feedback signal to the second subtraction unit 5 and the current / non-interference control unit 8. However, it is also possible to use the estimated rotor speed ω ^ as a feedback signal to the second subtraction unit 5 and the current / non-interference control unit 8 without using the rotor actual angular velocity ωm.

  S: Electric actuator system, 1 ... Motor controller, 2 ... Command angle calculation unit, 3 ... First subtraction unit, 4 ... Position control unit, 5 ... Second subtraction unit, 6 ... Speed control , 7... 3rd subtraction unit, 8... Current / non-interference control unit, 9... Control switching unit, 10... Addition unit, 11. Detection signal generation unit, 14 ... angle estimation unit, 15 ... dq conversion unit, 16 ... real angle calculation unit, 17 ... real angular velocity calculation unit, 18 ... initial setting unit, S0 ... command signal, Sa ...... Stroke position detection signal, Sb ... Stroke position command signal, 20 ... Electric actuator, 21 ... Case, 21a ... Discharge hole, 21b ... Filling chamber, 21c ... Port, 22 ... Motor, 22a ... Stator, 22b ... Rotor, 22c ... Armature, 2 d: Insulator, 22e: Permanent magnet, 23: Ball screw, 23a ... Ball, 24 ... Plunger, 24a ... Main body, 24b ... Seal ring, 24c ... Valve mechanism, 24d ... Filling chamber, 24e …… slit, 24f …… through hole, 24g …… cylindrical member, 24h …… support portion, 24i …… compression spring, 24j …… through hole, 24k …… through hole, 25 …… stopper, 26 …… compression Spring, 27 ... Reservoir tank, 28 ... Detector

Claims (6)

Sensorless vector control for estimating the magnetic pole position based on the fluctuation of the inductance of the brushless motor in which the rotation of the rotor is restricted by the stopper at the rotation end position and the rotor is biased toward the rotation end position by the biasing means. A motor control device for performing
An initial setting unit that stores the polarity of the magnetic pole shaft that is uniquely determined by the actual value of the rotor angle when rotation is restricted by the stopper;
An angle estimator that calculates an estimated value of the rotor angle based on the inductance variation and the polarity of the magnetic pole axis stored in the initial setting unit;
A motor control device comprising: an inverter that generates an actual voltage to be applied to a brushless motor based on the estimated value of the rotor angle obtained by the angle estimation unit. Sensorless vector control for estimating the magnetic pole position based on the fluctuation of the inductance of the brushless motor in which the rotation of the rotor is restricted by the stopper at the rotation end position and the rotor is biased toward the rotation end position by the biasing means. A motor control device for performing
An initial setting unit that stores an actual value of the rotor angle when rotation is restricted by the stopper;
An angle estimator that calculates an estimated value of the rotor angle based on the inductance variation;
An inverter that generates an actual voltage to be applied to the brushless motor based on the estimated value of the rotor angle obtained by the angle estimation unit;
The angle estimator calculates θ ^ (n + 1) as an updated value of the estimated value of the rotor angle, ω ^ (n + 1) as an updated value of the estimated value of the rotor angular velocity, and Δt as an estimated value of the rotor angle in the previous control cycle. The elapsed time from the time, θ ^ (n) is the estimated value of the rotor angle in the previous control cycle, ω ^ (n) is the estimated value of the rotor angular velocity in the previous control cycle, K1 and K2 are the calculation gains, θe (n ) Calculates the estimated value of the rotor angle by the following equation (1) indicating the estimated phase difference value in the previous control cycle,
The actual value of the rotor angle stored in the initial setting unit is θ ^ (0) when n = 0 in Equation (1), and the angle estimation unit estimates the rotor angle using the actual value as an initial value. A motor control device that calculates a value.

  3. The motor control device according to claim 1, wherein the actual voltage is generated to cause the rotor to generate a driving force in a direction toward the rotation end position when the brushless motor is started. 4. An electric actuator having a brushless motor in which the rotation of the rotor is restricted by the stopper at the rotation end position and the rotor is urged toward the rotation end position by the urging means, and the brushless motor is changed in inductance. An electric actuator system comprising a motor control device that performs vector control based on the vector,
An electric actuator system comprising the motor control device according to claim 1 as the motor control device.   The stopper is provided at a position where the actual value of the rotor angle at the rotation end position is set to avoid a range of 45 ° centering on the actual value of the rotor angle at which the polarity of the magnetic pole axis is reversed. The electric actuator system according to claim 4. Sensorless vector control for estimating the magnetic pole position based on the fluctuation of the inductance of the brushless motor in which the rotation of the rotor is restricted by the stopper at the rotation end position and the rotor is biased toward the rotation end position by the biasing means. A motor control method for performing
When starting the brushless motor, the rotor is rotated based on the polarity of the magnetic pole shaft that is uniquely determined by the actual value of the rotor angle when the rotor is rotated to the rotation end position and the rotation is restricted by the stopper. The motor control method characterized by calculating the estimated value of.

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