Motor control device, electric actuator, and electric power steering device

Abstract

To suppress vibration at disturbance suppression in a high band.SOLUTION: A motor control device comprises: a command value calculation unit that calculates a voltage command value on the basis of a differential value between a current command value and an actual current value; a disturbance suppression unit that calculates a suppression value for at least suppressing torque disturbance on the basis of the actual current value and a rotation angle of a motor, the suppression value to be added to the current command value; and a characteristic conversion unit that acts on the voltage command value for the purpose of converting on the feedback control the electric characteristics of the motor reflected to feedback control.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a motor control device, an electric actuator, and an electric power steering device. [Background technology]

[0002] 2. Description of the Related Art Conventionally, motor control devices equipped with a disturbance suppressor that suppresses disturbances (noise) entering a motor control system are known. For example, Patent Document 1 proposes a motor control device equipped with a disturbance observer that suppresses torque disturbances. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-163370 Summary of the Invention [Problem to be solved by the invention]

[0004] However, if the disturbance suppression band is set to a high band so that the disturbance suppressor can suppress the disturbance even when the motor is rotating at high speed, while the disturbance is suppressed, the stability (phase margin) of the current control system decreases, causing vibrations at the phase margin frequency. Therefore, an object of the present invention is to suppress vibrations when suppressing disturbances in a high frequency band. [Means for solving the problem]

[0005] In order to solve the above problem, one aspect of the motor control device according to the present invention includes a command value calculation unit that calculates a voltage command value based on a difference value between a current command value and an actual current value; a disturbance suppression unit that calculates a suppression value to be added to the current command value based on the actual current value and a rotational angle of the motor in order to suppress at least torque disturbance; and a characteristic conversion unit that acts on the voltage command value in order to convert the electrical characteristics of the motor reflected in feedback control in the feedback control.

[0006] As a result of detailed investigations by the inventors of the present invention, it was found that the main factor affecting stability is the electrical characteristics of the motor. The motor control device described above can change the electrical characteristics of the motor to the desired electrical characteristics during control, thereby suppressing vibrations during disturbance suppression in the desired frequency range, including the high frequency range.

[0007] In the motor control device, it is preferable that the command value calculation unit calculates a q-axis voltage command value and a d-axis voltage command value, and the characteristic conversion unit acts on each of the q-axis voltage command value and the d-axis voltage command value. Since the influence of the back electromotive force differs between the q-axis and the d-axis, desired electrical characteristics are realized by acting in accordance with the respective voltage command values.

[0008] In the motor control device, the characteristic conversion unit converts a gain G LR but, G LR ={(Ls+R)(Js+D)+K E K T} / {(L0s+R0)(Js+D)+K E K T} however, s: Laplace operator L[H]: Inductance of the motor R [Ω]: Resistance of the motor J [kgm 2 ]: Inertia of the motor D [Nm / (rad / s)]: Viscosity of the motor K E [V / (rad / s)]: EMF constant of the motor K T [Nm / A]: Torque constant of the motor L0[H]: Desired inductance R0 [Ω]: Desired resistance It is preferable that the formula be represented by the following formula: The gain G expressed by the above formula LR This allows the desired inductance L0 and resistance R0 to be realized in controlling the q axis.

[0009] In the motor control device, the characteristic conversion unit converts a gain G LR but, G LR =(Ls+R) / (L0s+R0) however, s: Laplace operator L[H]: Inductance of the motor R [Ω]: Resistance of the motor L0[H]: Desired inductance R0 [Ω]: Desired resistance It is preferable that the formula be represented by the following formula: The gain G expressed by the above formula LR This allows the desired inductance L0 and resistance R0 to be realized in terms of d-axis control.

[0010] In order to solve the above problem, one aspect of the electric actuator according to the present invention includes any one of the motor control devices described above, and a motor to which a voltage controlled by the motor control device is applied. With such an electric actuator, vibrations are suppressed when disturbances are suppressed in a high frequency range, so that an actual current flows through the motor in accordance with the current command value, thereby obtaining a desired output.

[0011] In order to solve the above problem, one aspect of an electric power steering device according to the present invention includes any of the motor control devices described above, a motor to which a voltage controlled by the motor control device is applied, and a power steering mechanism driven by the motor. According to such an electric power steering device, an actual current flows to the motor in accordance with the current command value, and a desired output is obtained, so that the steering assist accuracy is high. [Effects of the Invention]

[0012] According to the present invention, it is possible to suppress vibrations during disturbance suppression in a high frequency band. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a configuration diagram schematically illustrating an embodiment of an electric power steering device. [Figure 2] FIG. 2 is a functional block diagram illustrating an example of a functional configuration of a control unit. [Figure 3] FIG. 2 is a functional block diagram showing an example of a functional configuration of a voltage command value calculation unit. [Figure 4] FIG. 2 is a block diagram showing a specific functional configuration of a rotation speed estimation unit. [Figure 5] This is a block diagram including the LR conversion unit and the electrical, magnetic, and mechanical characteristics of the motor. [Figure 6] This is a block diagram in which the electrical, magnetic, and mechanical characteristics shown in Figure 5 are summarized in one block. [Figure 7] FIG. 10 is a diagram showing post-conversion characteristics that combine the LR conversion unit and the electric, magnetic, and mechanical characteristics of the motor. [Figure 8] FIG. 10 is a diagram showing the characteristics of the LR converter on the d axis. [Figure 9] FIG. 10 is a diagram showing the converted characteristics of the LR conversion unit on the d-axis and the electrical characteristics of the motor. [Figure 10] FIG. 4 is a diagram showing an approximation of a transfer function in the control system shown in FIG. [Figure 11] 10 is a graph showing a change in stability of a control system due to a change in inductance. [Figure 12] 10 is a graph showing a change in stability of a control system due to a change in resistance. [Figure 13] 10 is a graph showing a change in stability of a control system when conversion of inductance and resistance is combined. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art, more detailed description than necessary may be omitted. For example, detailed description of already well-known matters or redundant description of substantially identical configurations may be omitted. Furthermore, elements shown in earlier-described figures may be appropriately referenced in the description of later figures.

[0015] In this specification, an embodiment of the present disclosure will be described using as an example an electric actuator that supplies power from a power source to a three-phase motor having three-phase (A, B, and C) windings. However, the scope of the present disclosure also includes an electric actuator that supplies power from a power source to an n-phase motor having n-phase (n is an integer equal to or greater than 4) windings, such as four or five phases.

[0016] FIG. 1 is a schematic diagram showing the configuration of an embodiment of an electric power steering device. The electric power steering device 100 of this embodiment is equipped with a steering mechanism having a steering wheel 1, a column shaft 2, a reduction gear 3, universal joints 4A and 4B, a pinion-rack mechanism 5, and a tie rod 6 for the steered wheels. The electric power steering device 100 also includes a torque sensor 10, a motor 20, a control unit 30, an ignition key 11, a vehicle speed sensor 12, and a battery 14. The combination of the motor 20 and the control unit 30 corresponds to one embodiment of the electric actuator of the present invention, and the control unit 30 corresponds to one embodiment of the motor control device of the present invention. The steering mechanism is driven by the motor 20.

[0017] A column shaft 2 of the steering wheel 1 is connected to a tie rod 6 of the steered wheels via a reduction gear 3, universal joints 4A and 4B, and a pinion rack mechanism 5. A torque sensor 10 that detects the steering torque of the steering wheel 1 is provided on the column shaft 2, and a motor 20 that assists the steering force of the steering wheel 1 is connected to the column shaft 2 via the reduction gear 3. The torque sensor 10 detects the steering torque Th transmitted from the steering wheel 1 due to the driver's steering operation.

[0018] A control unit (ECU) 30 that controls the power steering device 100 is supplied with power from a battery 14, which is a power source, and also receives an ignition key signal from an ignition key 11. The control unit 30 calculates a steering assist torque using an assist map or the like based on the steering torque Th detected by the torque sensor 10 and the vehicle speed Vh detected by the vehicle speed sensor 12. Then, the control unit 30 controls the current I supplied to the motor 20 so as to generate the calculated assist torque. A voltage controlled by the control unit 30 is applied to the motor 20, and the current I is controlled by the controlled voltage. The assist torque generated by driving the motor 20 is applied to the steering system as an assist force for the driver's steering operation (steering assist force), allowing the driver to operate the steering wheel with less force.

[0019] The quality of the steering feel is determined by the amount of assist torque generated from the steering torque Th output by steering and the vehicle speed Vh. Furthermore, the performance of the electric power steering device is greatly affected by the accuracy with which the current I required to generate the assist torque is passed to the motor 20.

[0020] The control unit 30 includes, for example, a processor and peripheral components such as a storage device. The computer may include a processor, such as a CPU (Central Processing Unit) or an MPU (Micro-Processing Unit). The storage device may include any of a semiconductor storage device, a magnetic storage device, and an optical storage device. The storage device may include a register, a cache memory, a memory such as a ROM (Read Only Memory) used as a main memory, and a RAM (Random Access Memory).

[0021] The control unit 30 may be configured with dedicated hardware, which will be described below, for executing each information processing. For example, the control unit 30 may include a functional logic circuit configured in a general-purpose semiconductor integrated circuit, such as a programmable logic device (PLD) such as a field-programmable gate array (FPGA).

[0022] FIG. 2 is a functional block diagram showing an example of the functional configuration of the control unit 30. The control unit 30 includes a current command value calculation unit 40, a voltage command value calculation unit 45, a two-phase / three-phase conversion unit 46, a PWM (Pulse Width Modulation) control unit 47, an inverter 48, and a three-phase / two-phase conversion unit 49, and drives the motor 20 by vector control. The motor 20 is, for example, a three-phase motor. The functions of the current command value calculation unit 40, the voltage command value calculation unit 45, the two-phase / three-phase conversion unit 46, the PWM control unit 47, and the three-phase / two-phase conversion unit 49 are realized, for example, by the processor of the control unit 30 executing a computer program stored in a storage device.

[0023] The current command value calculation unit 40 calculates current command values ​​Iq0 and Id0 that indicate the currents of the d and q axes that should be applied to the motor 20, respectively, based on the steering torque Th and the vehicle speed Vh. On the other hand, the currents i a, ib, ic flowing through each phase of the motor 20 are detected by current sensors 60, 61, 62 provided in each layer, and the detected currents i a, ib, ic are converted into actual current values ​​id, iq of the dq2 axes by the 3-phase / 2-phase conversion unit 49 and fed back.

[0024] The current command values ​​Iq0, Id0 and the fed back actual current values ​​id, iq are also input to a voltage command value calculation unit 45. The voltage command value calculation unit 45 calculates voltage command values ​​vq, vd such that the difference between the current command values ​​Iq0, Id0 and the actual current values ​​id, iq becomes 0. A two-phase / three-phase conversion unit 46 converts the voltage command values ​​vd, vq into three-phase voltage command values ​​va, vb, vc.

[0025] The PWM control unit 47 generates PWM-controlled gate signals based on the three-phase voltage command values ​​va, vb, and vc. The inverter 48 is driven by the gate signals generated by the PWM control unit 47 and applies voltages indicated by the three-phase voltage command values ​​va, vb, and vc to the respective phases of the motor 20. As a result, the motor 20 is supplied with currents indicated by the current command values ​​Iq0 and Id0.

[0026] The resolver 63 detects the motor angle (rotation angle) θ of the motor 20, and the detected motor angle θ is fed back to the current command value calculation unit 40 and used for vector control. A motor rotation angle sensor may be used instead of the resolver 63. Note that the rotation angular velocity ω of the motor 20 calculated based on changes in the motor angle θ may be input to the current command value calculation unit 40 together with the motor angle θ or instead of the motor angle θ.

[0027] Fig. 3 is a functional block diagram showing an example of the functional configuration of the voltage command value calculation unit 45. Fig. 3 also shows a model of the motor 20. Fig. 3 shows the control function for the q axis as a representative, but the voltage command value calculation unit 45 also has a similar control function for the d axis. The function of the motor 20 is to determine the electrical characteristics 21 and the torque constant K T , mechanical property 23, integral element 24, and EMF (back electromotive force) coefficient K E and

[0028] An actual current is generated when a voltage is input to the electrical characteristic 21 of the motor 20. The voltage value input to the electrical characteristic 21 includes voltage noise. The gain of the electrical characteristic 21 is expressed as 1 / (Ls+R) where L is an inductance [H] and R is a resistance [Ω]. The actual current is detected by current sensors 60, 61, and 62, and the detected value includes current detection noise. Actual current and torque constant K T [Nm / A] acts to generate motor torque.

[0029] The angular velocity of the motor 20 is generated by inputting the motor torque to the mechanical characteristic 23. The gain of the mechanical characteristic 23 is the inertia J [kgm 2 ] and viscosity D [Nm / (rad / s)], which can be expressed as 1 / (Js+D). The angular velocity of the motor 20 passes through the integral element 24 to become the motor angle θ. The motor angle θ is detected by the resolver 63 (or the motor rotation angle sensor), and the detected value contains angle detection noise.

[0030] EMF coefficient K for angular velocity E The action of [V / (rad / s)] generates a back electromotive force, and the back electromotive force is reflected in the input of the electrical characteristic 21. The voltage command value calculation unit 45 includes a control band setting unit 70, a PID (Proportional Integral Differential) control unit 71, a low-pass filter 72, a first delay element 73, an LR conversion unit 74, a second delay element 75, and a disturbance suppression unit 76.

[0031] The control band setting unit 70 receives the current command value Iq0 and applies a gain G ref By applying the gain G ref teeth, G ref =ω ref / (s+ω ref ) however, s: Laplace operator ω ref[rad / s]: Current control bandwidth It is expressed as:

[0032] The PID control unit 71 receives the difference Δq between the current command value Iq0 and the q-axis actual current value iq, and calculates the voltage command value vq by PID control based on the difference Δq. PID teeth, G PID ={ω c L+(R / 2)}[1+{ω c / (2s)}+{s / (2ω c )}] however, s: Laplace operator ω c [rad / s]: Disturbance suppression band L[H]: Inductance of the motor R [Ω]: resistance of the motor It is expressed as:

[0033] The low-pass filter 72 cuts out current detection noise contained in the q-axis actual current value iq. The gain G LPF teeth, G LPF =ω LPF / (s+ω LPF ) however, s: Laplace operator ω LPF [rad / s]: cutoff frequency It is expressed as:

[0034] The first delay element 73 functions as a back electromotive force suppressor by feedback with a delay. The gain G dly teeth, G dly =e -Tdly·s however, Tdly [μs]: Current control period It is expressed as:

[0035] The LR converter 74 acts on the voltage command value to convert the electrical characteristics of the motor 20 reflected in the feedback control into the desired electrical characteristics in the feedback control. LR More on this later. The second delay element 75 represents a delay in the feedback loop. The gain G DLY teeth, G DLY =e -TDLY·s however, TDLY [μs]: calculation time from current detection by the current sensors 60, 61, and 62 to duty reflection in the output of the inverter 48 It is expressed as:

[0036] The disturbance suppression unit 76 calculates a suppression value to be added to the current command value Iq0 to suppress control disturbances, based on the q-axis actual current value iq and the motor angle θ. The disturbance suppression unit 76 includes a rotation speed estimator 80, a torque disturbance estimator 81, a torque disturbance suppression unit 82, and a high-pass filter 83. The rotation speed estimator 80 estimates the rotation speed of the motor 20 from the q-axis actual current value iq and the motor angle θ. The rotation speed estimator 80 provides a smooth estimated rotation speed value.

[0037] FIG. 4 is a block diagram showing a specific functional configuration of the rotation speed estimation unit 80. As shown in FIG. The functional blocks shown in FIG. 4 correspond to the following formulas (1) and (2).

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[0038] Returning to Figure 3, the explanation continues. The transfer function Gω in the rotation speed estimation unit 80 is expressed by the matrix T in the following equation (3).

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[0039] The torque disturbance estimation unit 81 estimates the torque disturbance from the q-axis actual current value iq and the estimated rotation speed value. TRQ is expressed by the matrix T in the following equation (4).

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[0040] The torque disturbance suppression unit 82 calculates a suppression value for suppressing the estimated torque disturbance. cmp is expressed by the following formula (5).

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[0041] The high-pass filter 83 acts on the torque disturbance suppression value to remove the DC component of the torque disturbance. The action of the high-pass filter 83 realizes a function similar to a notch filter that suppresses disturbances of a specific frequency. The gain G of the high-pass filter 83 HPF is the cutoff frequency ω HPF By G HPF =s / (s+ω HPF ) The disturbance suppression unit 76 can accurately suppress torque disturbances by estimating the torque disturbances, and can also suppress voltage noise, current detection noise, and angle detection noise. c When is set to a high frequency band, disturbance suppression by the disturbance suppressor 76 can be achieved even in the high rotation range of the motor 20. On the other hand, the disturbance suppression band ω c If is set to a high band, oscillations are likely to occur in the feedback control of the voltage command value calculation unit 45, so the voltage command value calculation unit 45 incorporates a configuration for improving the stability of control.

[0042] As a result of detailed studies by the inventors of the present invention, it was found that the main factor affecting the stability of voltage command value calculation unit 45 is electrical characteristics 21 of motor 20. However, electrical characteristics 21 of motor 20 are inseparable from the specifications required of motor 20, and it is difficult to change the hardware of motor 20. Therefore, an LR converter 74 is incorporated to realize desired electrical characteristics in the feedback control of voltage command value calculation unit 45. Since voltage command value calculation unit 45 calculates a q-axis voltage command value vq and a d-axis voltage command value vd, LR converter 74 acts on each of the q-axis voltage command value vq and the d-axis voltage command value vd.

[0043] FIG. 5 is a block diagram including the LR conversion unit 74 and the electric, magnetic and mechanical characteristics 26 of the motor 20. As shown in FIG. The motor 20 has the elements shown in FIG. 3 as the electrical, magnetic, and mechanical characteristics 26. In q-axis control, a back electromotive force is added between the LR converter 74 and the electrical characteristics 21 of the motor 20, so the LR converter 74 must be designed with this back electromotive force in mind. The back electromotive force added to the input side of the electrical characteristics 21 is calculated based on the electrical characteristics 21, the torque constant K T , mechanical properties 23 and EMF coefficient K E Since the above factors all have a bearing on the design of the LR converter 74, the above factors are all relevant to the design of the LR converter 74.

[0044] FIG. 6 is a block diagram in which the electrical, magnetic and mechanical characteristics 26 shown in FIG. 5 are collected into one block. The electrical characteristics 21 and torque constant K shown in Figure 5 T , mechanical properties 23 and EMF coefficient K E The gain of the electrical, magnetic and mechanical characteristics 26 is k T / {(Ls+R)(Js+D)+k E k T The corresponding gain of the LR converter 74 is expressed as {(Ls+R)(Js+D)+k E k T} / {(L0s+R0)(Js+D)+k E k T} is required. In other words, the gain G acting on the q-axis voltage command value LR teeth, G LR ={(Ls+R)(Js+D)+K E K T} / {(L0s+R0)(Js+D)+K E K T} however, s: Laplace operator L[H]: Inductance of the motor R [Ω]: Resistance of the motor J [kgm 2 ]: Inertia of the motor D [Nm / (rad / s)]: Viscosity of the motor K E [V / (rad / s)]: EMF constant of the motor K T [Nm / A]: Torque constant of the motor L0[H]: Desired inductance R0 [Ω]: Desired resistance It is expressed as:

[0045] FIG. 7 is a diagram showing the converted characteristics obtained by combining the LR conversion section 74 and the electric / magnetic / mechanical characteristics 26. In FIG. The gain of the post-conversion characteristic 27 obtained by combining the LR conversion unit 74 and the electric, magnetic, and mechanical characteristic 26 is k T / {(L0s+R0) (Js+D)+k E k T}. It can be confirmed that the gain of the post-conversion characteristic 27 is a characteristic in which the inductance L and resistance R in the electric-magnetic-mechanical characteristic 26 shown in FIG. 6 are converted into the desired inductance L0 and resistance R0. In other words, the desired LR characteristic is realized in the control of the q axis by the LR conversion unit 74 having the gain shown in FIG. 6.

[0046] In the case of the LR converter 74 on the d axis, it is not necessary to take the back electromotive force into consideration. FIG. 8 is a diagram showing the characteristics of the LR converter 74 on the d axis, and FIG. 9 is a diagram showing the post-conversion characteristics combining the LR converter 74 on the d axis and the electrical characteristics 21 of the motor 20. In the control of the d-axis, since the back electromotive force is not added to the input of the electrical characteristic 21 of the motor 20, the gain of the LR conversion unit 74 is calculated as (Ls+R) / (L0s+R0) for the gain of the electrical characteristic 21, 1 / (Ls+R). In other words, the gain G acting on the d-axis voltage command value LR but, G LR =(Ls+R) / (L0s+R0) however, s: Laplace operator L[H]: Inductance of the motor R [Ω]: Resistance of the motor L0[H]: Desired inductance R0 [Ω]: Desired resistance It is expressed as: 9, the converted characteristic 27 has a gain of 1 / (L0s+R0), which confirms that the inductance L and resistance R in the electrical characteristic 21 have been converted into the desired inductance L0 and resistance R0. In other words, the desired LR characteristic is realized in the control of the d-axis by the LR conversion unit 74 having the gain shown in FIG.

[0047] FIG. 10 is a diagram showing an approximation formula of a transfer function in the control system shown in FIG. The transfer function in the control system is roughly divided into a characteristic compensation portion of the disturbance suppression unit 76, a loop transfer function portion of the current control system, and a sensitivity function portion. The characteristic compensation portion of the disturbance suppression unit 76 represents characteristic compensation of the mechanical system in the disturbance suppression unit 76, and includes a portion corresponding to the mechanical system on the actual machine side and a portion corresponding to the mechanical system on the control side. The mechanical system on the actual machine side is the mechanical characteristics 23 of the motor 20 itself, and the mechanical system on the control side is the mechanical characteristics set for control.

[0048] The loop transfer function portion of the current control system includes the actual portion of the motor 20, the portion of the LR conversion portion 74, and the main portion of the control from the PID control portion 71 to the second delay element 75. Since the LR converter 74 is included in the open-loop transfer function of the current control system, the combination of the actual device part and the LR converter 74 part becomes the actual device part in terms of control. The sensitivity function portion is approximately zero for voltage noise Δv, and exhibits HPF characteristics for current detection noise Δi, torque disturbance Δτ, and angle detection noise Δθ. Therefore, it can be seen that the control system shown in Figure 3 achieves noise suppression for all types of noise. As explained below, converting the motor's control characteristics to the desired characteristics improves the stability of the control system, achieving noise suppression even in the high rotation speed range.

[0049] FIG. 11 is a graph showing the change in stability of the control system due to the change in inductance. The horizontal axis in FIG. 11 is a logarithmic axis indicating frequency, and the vertical axis in FIG. 11 indicates amplitude in the upper graph and phase in the lower graph. In the graph, the thin solid line shows the characteristics before conversion, the thick solid line shows the characteristics when the inductance is halved, and the dotted line shows the characteristics when the inductance is doubled. It can be seen that inductance is sensitive mainly to the resonant frequency of the hardware, and that when the inductance is small, the phase advances and the stability of the control system (particularly the phase margin) increases.

[0050] FIG. 12 is a graph showing the change in stability of the control system due to the change in resistance. In FIG. 12, the horizontal axis is also a pair of axes showing frequency, and the upper vertical axis shows amplitude and the lower vertical axis shows phase. In the graph, the thin solid line shows the characteristics before conversion, the thick solid line shows the characteristics when the resistance is doubled, and the dotted line shows the characteristics when the inductance is halved. It can be seen that the inductance is mainly sensitive to the damping coefficient, and as the resistance increases, the phase advances and the stability of the control system increases.

[0051] FIG. 13 is a graph showing the change in stability of the control system when inductance and resistance conversion are combined. In FIG. 13 as well, the horizontal axis is a pair of axes showing frequency, and the upper vertical axis shows amplitude and the lower vertical axis shows phase. In the graph, the thin solid line shows the characteristics before conversion, and the thick solid line shows the characteristics when the inductance is halved and the resistance is doubled. It can be seen that the combination of inductance and resistance conversion further advances the phase, further increasing the stability of the control system.

[0052] By increasing the stability of the control system (particularly the phase margin), an electric actuator equipped with the motor 20 and the control unit 30 can obtain a desired output by causing an actual current to flow through the motor 20 in accordance with the current command value even during high-speed operation. Also, in the electric power steering device 100 shown in Fig. 1, the motor 20 can obtain a desired output even during high-speed operation, resulting in high steering assist accuracy.

[0053] Although the above description shows an example of application to a power steering device, the electric actuator and motor control device of the present invention can be applied to a wide range of fields, such as vehicle drive systems and robots, etc. In other words, the embodiments and scope of application of the present invention are not limited to power steering devices. [Explanation of symbols]

[0054] 100...electric power steering device, 1...steering wheel, 2...column shaft, 3...Reduction gear, 4A, 4B...Universal joint, 5...Pinion rack mechanism, 6...steered wheel tie rod, 10...torque sensor, 11...ignition key, 12... vehicle speed sensor, 14... battery, 20... motor, 30... control unit, 40...current command value calculation unit, 45...voltage command value calculation unit, 46...2-phase / 3-phase conversion unit, 47...PWM control unit, 48...inverter, 49...3-phase / 2-phase conversion unit, 60, 61, 62...current sensors, 63...resolver, 70...control band setting unit, 71... PID control unit, 72... low-pass filter, 73... first delay element, 74...LR conversion unit, 75...second delay element, 76...disturbance suppression unit, 80...rotation speed estimation unit, 81...torque disturbance estimation unit, 82...torque disturbance suppression unit, 83...high-pass filter

Claims

1. a command value calculation unit that calculates a voltage command value based on a difference between a current command value and an actual current value; a disturbance suppression unit that calculates a suppression value to be added to the current command value based on the actual current value and a rotation angle of the motor in order to suppress at least torque disturbance; a characteristic conversion unit that acts on the voltage command value to convert the electrical characteristics of the motor reflected in feedback control on the feedback control; Equipped with the command value calculation unit calculates a q-axis voltage command value and a d-axis voltage command value; the characteristic conversion unit acts on each of the q-axis voltage command value and the d-axis voltage command value; Motor control device.

2. The characteristic conversion unit is configured to convert a gain G ＬＲ but, G ＬＲ ={(Ls+R)(Js+D)+K Ｅ K Ｔ } / {(L ０ s+R ０ )(Js+D)+K Ｅ K Ｔ } however, s: Laplace operator L [H]: Inductance of the motor R [Ω]: Resistance of the motor J [kgm ２ ]: Inertia of the above motor D [Nm / (rad / s)]: Viscosity of the motor K Ｅ [V / (rad / s)]: EMF constant of the motor K Ｔ [Nm / A]: torque constant of the motor L ０ [H]: Desired inductance R ０ [Ω]: Desired resistance 2. The motor control device according to claim 1, wherein:

3. The characteristic conversion unit applies a gain G ＬＲ but, G ＬＲ =(Ls+R) / (L ０ s+R ０ ) however, s: Laplace operator L [H]: Inductance of the motor R [Ω]: Resistance of the motor L ０ [H]: Desired inductance R ０ [Ω]: Desired resistance 2. The motor control device according to claim 1, wherein:

4. The motor control device according to any one of claims 1 to 3; a motor to which a voltage controlled by the motor control device is applied; An electric actuator equipped with

5. The motor control device according to any one of claims 1 to 3; a motor to which a voltage controlled by the motor control device is applied; a steering mechanism driven by the motor; An electric power steering device equipped with

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