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

Abstract

A motor control device is provided with: a current command value calculation unit (41) that calculates a current command value for driving a motor; a current value detection unit (48) that detects a current flowing through the motor; a current control unit (52) that outputs a first voltage command value on the basis of the deviation between a current command value and a current detection value, which is the detection value of the current detected by the current value detection unit (48); a voltage disturbance suppression unit (53) that adds the output of the delay element (55) to the first voltage command value to calculate a second voltage command value, and inputs the second voltage command value to the delay element (55); and a drive circuit (47) that drives the motor on the basis of the second voltage command value.

Description

Technical Field

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

[0002] Patent Document 1 below describes a technique in which a reverse voltage is estimated based on a reverse voltage constant and a motor rotation speed, and a correction value for canceling the reverse voltage is added to a voltage command value to compensate for the reverse voltage (hereinafter sometimes referred to as "feedforward reverse voltage compensation").

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2017-175834 Summary of the invention

[0006] Problems to be solved by the invention

[0007] Feedforward reverse voltage compensation has the following problem: it has low robustness against disturbance factors such as deviations caused by individual differences in the motors used, temperature changes, and changes in physical properties caused by aging.

[0008] An object of the present invention is to provide a motor control device having improved robustness against disturbance factors such as variations due to individual differences in motors used, temperature changes, and changes in physical properties due to aging.

[0009] Means for solving problems

[0010] In order to achieve the above-mentioned purpose, a motor control device of one embodiment of the present invention comprises: a current command value calculation unit, which calculates a current command value for driving a motor; a current value detection unit, which detects the current flowing through the motor; a current control unit, which outputs a first voltage command value based on the deviation between a current detection value as a detection value of the current detected by the current value detection unit and the current command value; a voltage interference suppression unit, which adds the output of a delay element to the first voltage command value to calculate a second voltage command value, and inputs the second voltage command value to the delay element; and a drive circuit, which drives the motor based on the second voltage command value.

[0011] According to another aspect of the present invention, there is provided an electric actuator product including the above-mentioned motor control device and a motor controlled by the motor control device.

[0012] According to still another aspect of the present invention, there is provided an electric power steering device including the above-mentioned motor control device and a motor controlled by the motor control device, wherein the motor applies a steering assist force to a steering system of a vehicle.

[0013] Effects of the Invention

[0014] According to the present invention, it is possible to provide a motor control device having improved robustness against disturbance factors such as variations due to individual differences in motors used, temperature changes, and changes in physical properties due to aging. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic structural diagram showing an example of an electric power steering device according to an embodiment.

[0016] Figure 2 Yes means Figure 1 A block diagram showing an example of a functional configuration of a steering assist function of the controller described above.

[0017] Figure 3 This is a block diagram expressing a first example of a system for driving a motor using a current command value using a transfer function.

[0018] Figure 4 (a) and (b) are Figure 3 A Bode plot of an example of frequency characteristics when the numerator of the common term of the transfer function of the system is set to 1.

[0019] Figure 5 (a) and (b) are Figure 3 A Bode diagram of an example of a control filter 52 is shown.

[0020] Figure 6 (a) and (b) are Figure 3 A Bode plot of an example of a transfer function obtained by dividing the numerator of the common term of the transfer function of the system by the transfer functions of the delay element 56 and the filter 54.

[0021] Figure 7 (a) and (b) are Bode plots of an example of a transfer function of a component in which a disturbance voltage Δv affects a motor current i.

[0022] Figure 8 (a) and (b) are Bode diagrams showing simulation results of the comparative example.

[0023] Fig. 9 (a) and (b) are Bode diagrams showing simulation results of the embodiment.

[0024] Fig.10 This is a block diagram expressing a second example of a system for driving a motor using a current command value using a transfer function.

[0025] Fig.11 This is a block diagram expressing a third example of a system for driving a motor using a current command value using a transfer function.

[0026] Fig.12 This is a schematic structural diagram showing an example of a linear motion table device using the motor control device of the present invention. DETAILED DESCRIPTION

[0027] Embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0028] In addition, the embodiments of the present invention shown below illustrate devices and methods for implementing the technical concept of the present invention, but the technical concept of the present invention does not limit the structure and configuration of the components to the following contents. The technical concept of the present invention can be modified in various ways within the technical scope specified by the technical solution described in the claims.

[0029] (structure)

[0030] Figure 1 The schematic structural diagram of an example of an electric power steering device according to an embodiment is shown. A steering shaft (steering shaft, handle shaft) 2 of a steering wheel (steering handle) 1 is connected to steered wheels 8L, 8R via a reduction gear (worm gear) 3 constituting a reduction mechanism, universal joints 4a, 4b, a pinion rack mechanism 5, tie rods 6a, 6b, and further via hub units 7a, 7b.

[0031] The rack and pinion mechanism 5 includes a pinion 5a connected to a pinion shaft to which the steering force is transmitted from the universal joint 4b and a rack 5b meshing with the pinion 5a. The rack 5b converts the rotational motion transmitted to the pinion 5a into a linear motion in the vehicle width direction.

[0032] The steering shaft 2 is provided with a torque sensor 10 for detecting a steering torque Th. In addition, the steering shaft 2 is provided with a steering angle sensor 14 for detecting a steering angle θh of the steering wheel 1 .

[0033] A motor 20 assisting the steering force of the steering wheel 1 is connected to the steering shaft 2 via a reduction gear 3. A controller 30 controlling an electric power steering (EPS) device is supplied with power from a battery 13 and receives an ignition key signal via an ignition key 11.

[0034] In addition, the unit for applying the steering assist force is not limited to the motor, and various actuators can be used.

[0035] The controller 30 is an electronic control unit (ECU) that calculates a current command value for an auxiliary control command based on the steering torque Th detected by the torque sensor 10, the vehicle speed Vh detected by the vehicle speed sensor 12, and the steering angle θh detected by the steering angle sensor 14, and controls the current supplied to the motor 20 by obtaining a voltage control command value Vref by compensating the current command value.

[0036] The steering angle sensor 14 is not essential, and the steering angle θh may be calculated by adding a rotation angle obtained from a rotation angle sensor that detects the rotation angle of the rotating shaft of the motor 20 and a torsion angle of the torsion bar of the torque sensor 10 .

[0037] In addition, the steering angle of the steered wheels 8L, 8R may be used instead of the steering angle θh. For example, the steering angle may be detected by detecting the displacement of the rack 5b.

[0038] The controller 30 may include, for example, a computer including a processor and peripheral components such as a storage device. The processor may be, for example, a CPU (Central Processing Unit) or an MPU (Micro-Processing Unit).

[0039] 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 ROM (Read Only Memory) used as a main storage device, and a RAM (Random Access Memory) and other memories.

[0040] The functions of the controller 30 described below are implemented, for example, by a processor of the controller 30 executing a computer program stored in a storage device.

[0041] In addition, the controller 30 may be formed by dedicated hardware for executing each information processing described below.

[0042] For example, the controller 30 may include a functional logic circuit set in a general-purpose semiconductor integrated circuit. For example, the controller 30 may include a programmable logic device (PLD) such as a field programmable gate array (FPGA).

[0043] Next, refer to Figure 2 , an example of the functional structure of the steering assist function based on the controller 30 is described.

[0044] The steering torque Th and the vehicle speed Vh are input to the current command value calculation unit 41 which calculates the current command value Iref0. The current command value calculation unit 41 calculates the current command value Iref0 as the control target value of the current supplied to the motor 20 based on the input steering torque Th and the vehicle speed Vh using an assist map or the like.

[0045] The adder 42A adds the compensation signal CM from the compensation signal generating unit 44 to the current command value Iref0 to calculate the current command value Iref=Iref0+CM, and inputs the current command value Iref to the current limiting unit 43. The compensation signal CM is added to compensate for the characteristics related to the steering system, and the convergence, inertia characteristics, etc. are improved. The compensation signal generating unit 44 calculates the compensation signal CM by adding the convergence 44-1, the inertia 44-2, and the automatic self-aligning torque (SAT) 44-3 through adders 44-4 and 44-5.

[0046] The current command value Irefm, whose maximum current is limited by the current limiting unit 43, is input to the subtractor 42B to calculate the deviation ΔI (=Irefm-Im) from the motor current value Im fed back, and the deviation ΔI is input to the PI (proportional integral) control unit 45 for improving the characteristics of the steering action. The voltage control command value Vref, whose characteristics are improved by the PI control unit 45, is input to the PWM control unit 46, and the motor 20 is PWM driven via the inverter 47 as a driving unit. The current value Im of the motor 20 is detected by the motor current detector 48 and fed back to the subtractor 42B.

[0047] In addition, the controller 30 can calculate the q-axis current command value as a torque generating component and the d-axis current command value as a magnetic field generating component as the current command value Iref, and perform vector control to generate a voltage command value based on the deviation between the q-axis motor current detection value and the q-axis current command value, and the deviation between the d-axis motor current detection value and the d-axis current command value.

[0048] Figure 3 This is a block diagram of a system that uses a transfer function to express the current command value Iref to drive the motor 20. The current command value Iref is input to a subtractor 51 via a control filter (Gref(s)) 50, and the subtractor 51 calculates the deviation between the output of the control filter 50 and the current value Im of the motor 20 detected by the motor current detector 48. The control filter (A(s)) 52 calculates a first voltage command value based on the deviation between the output of the control filter 50 and the current value Im of the motor 20, and inputs it to an adder 53. The control filter 52 is an example of a "current control unit" described in the claims.

[0049] The adder 53 calculates the second voltage command value by adding the output of the adder 53 delayed by the delay element (Gdly) 55 to the first voltage command value and integrating the first voltage command value. The adder 53 is an example of a "voltage disturbance suppression unit" described in the claims.

[0050] The delay element 55 may be, for example, a delay element that provides a delay equivalent to the control period of the current control of the motor current of the motor 20 by the controller 30. For example, the adder 53 calculates the second voltage command value by adding the output value of the adder 53 in the previous cycle in the current control to the first voltage command value in this cycle.

[0051] The output of the adder 53 is passed through a filter (G LPF (s)) 54 is input to the delay element 55 and the delay element (GDLY) 56. That is, the filter 54 is a filter that reduces the noise of the added value of the first voltage command value and the output of the delay element 55. The filter 54 may be, for example, a low-pass filter. If the detection noise of the current value Im of the motor 20 detected by the motor current detector 48 can be ignored, the filter 54 may be omitted.

[0052] The delay element 56 may be a delay element that provides a delay equivalent to the hardware delay of the controller 30. For example, the delay of the delay element 56 may be a delay from when the motor current detector 48 detects the current value Im of the motor 20 to when the PWM control unit 46 outputs the PWM using the detected current value Im.

[0053] The calculation unit 57 subtracts the reverse voltage EMF of the motor from the output of the delay element 56 and adds the interference voltage ΔV. The calculation unit 57 models the influence of the reverse voltage EMF actually generated in the motor on the output (control voltage) from the delay element 56 .

[0054] The calculation result of the calculation unit 57 is converted into a motor current i by dividing the impedance E(s)=L·s+R of the motor 20 by the electrical characteristic unit (1 / E(s)) 58 of the motor 20. The constants L and R are the inductance and resistance of the motor 20, respectively.

[0055] The motor current i is converted into torque τ by multiplying the torque coefficient (Kt) 59. The torque τ is converted into the motor rotation angle θ by the mechanical characteristic unit (1 / M(s)) 61. The denominator of the transfer function of the mechanical characteristic unit 61 is, for example, M(s)=Js 2 +(D+G CF )s+K, constants J, D, G CF , K are the motor's inertia moment, viscosity coefficient, Coulomb friction coefficient, and spring coefficient, respectively.

[0056] The reverse voltage generating unit (s·Ke) 62 generates a reverse voltage EMF having a magnitude equal to the product of the time differential of the motor rotation angle θ (ie, the motor rotation speed) and the reverse voltage constant Ke.

[0057] The motor current i is detected by the motor current detector 48 and fed back to the subtracter 51 , but is fed back as the motor current Im=i+Δi by mixing the current detection error Δi in the adder 60 .

[0058] The transfer function that takes the current command value Iref, the disturbance voltage Δv, the current detection error Δi, the disturbance torque Δτ, and the disturbance angle Δθ of the motor rotation angle as input and outputs the motor current i is given by the following equation (1).

[0059] [Mathematical formula 1]

[0060]

[0061] In addition, the term on the right side of the above formula (1) is [Formula 2]

[0062]

[0063] The portion of is sometimes referred to as "input vector" in the following description. In addition, the portion indicating the influence of the physical characteristics of the motor 20 common to each term of the input vector on the right side of the above equation (1) is

[0064] [Mathematical formula 3]

[0065]

[0066] In the following description, it is sometimes described as a "common term". In addition, the part of the right-hand side term of the above formula (1) that represents the influence of the input vector on each term

[0067] [Formula 4]

[0068]

[0069] In the following description, it may be described as a “sensitivity vector.” In the above equation (1), it is assumed that the influence of the disturbance angle Δθ can be ignored, and the component of the sensitivity vector for the disturbance angle Δθ is assumed to be “0”.

[0070] In this embodiment, the transfer function characteristics of the control filter 52 are set as follows: the numerator of the common term of the above equation (1) is divided by the transfer function (GDLY) of the delay element 56 and the transfer function (G LPF (s)) and the transfer function

[0071] [Formula 5]

[0072]

[0073] The frequency response of the motor current i has a small change (i.e., it has a gentle (flat) frequency characteristic), and the interference voltage Δv affects the transfer function of the component of the motor current i.

[0074] [Mathematical formula 6]

[0075]

[0076] It has the characteristics of a high-pass filter (that is, it has the characteristics of attenuating low-frequency components).

[0077] The transfer function of the control filter (A(s)) 52 can be set as shown in the following equation, for example.

[0078] [Formula 7]

[0079]

[0080] The above equation is an example of a PID (proportional, integral, differential) controller, and the characteristics of the transfer function of the control filter 52 can be appropriately adjusted by changing the parameters Kp, ζ, and ωc, for example.

[0081] When the transfer function of the control filter 52 is set in this manner, the numerator of the common term is divided by the transfer function of the delay element 56 (GDLY) and the transfer function of the filter 54 (G LPF (s)) reduces the fluctuation of the frequency response of the transfer function obtained, and can achieve good response characteristics that are less likely to be affected by the frequency of the current command value Iref.

[0082] In addition, when vector control is performed, the interference term between the reverse voltage, the d-axis component, and the q-axis component is processed as a low-frequency signal (e.g., 10 [Hz] or less) of the same degree as the steering cycle of the steering wheel 1 on the dq-axis rotating coordinate system. Therefore, the transfer function of the component in which the interference voltage Δv affects the motor current i has the characteristics of a high-pass filter with a cutoff frequency that attenuates the low-frequency component, thereby suppressing the influence of the reverse voltage and other interference voltages.

[0083] For example, when the numerator of the common term of the transfer function of the above formula (1) is set to 1, [Mathematical formula 8]

[0084]

[0085] In having Figure 4 (a) and Figure 4 In the case of the frequency characteristics shown in (b), in order to divide the numerator of the common term by the transfer function (GDLY, G LPF(s)) and the transfer function

[0086] [Mathematical formula 9]

[0087]

[0088] The frequency response variation of the control filter 52 is reduced, and the transfer function A(s) is set to have the same Figure 4 (a) and Figure 4 The frequency characteristics are opposite to those illustrated in (b).

[0089] Figure 5 (a) and Figure 5 (b) is a Bode diagram of an example of a control filter 52 set to have a characteristic opposite to the frequency characteristic of the denominator of the common term.

[0090] When the frequency characteristic of the control filter 52 is set as Figure 5 (a) and Figure 5 As shown in (b), the numerator of the common term is divided by the transfer function of the delay element 56 and the filter 54 (GDLY, G LPF (s)) and the frequency characteristics of the transfer function are as follows Figure 6 (a) and Figure 6 as shown in (b).

[0091] like Figure 6 (a) and Figure 6 As shown in (b), the numerator of the common term is suppressed by dividing the transfer function (GDLY, G LPF (s)) to reduce the fluctuation of the frequency response of the transfer function obtained, and achieve a relatively flat frequency characteristic.

[0092] In addition, when the frequency characteristic of the control filter 52 is set as Figure 5 (a) and Figure 5 As shown in (b), the transfer function of the component of the interference voltage Δv affecting the motor current i is

[0093] [Formula 10]

[0094]

[0095] like Figure 7 (a) and Figure 7 By making the transfer function of the component in which the disturbance voltage Δv affects the motor current i have the characteristics of a high-pass filter, the influence on the reverse voltage and other disturbance voltages can be suppressed as described above.

[0096] Next, refer to Figure 8 (a) Figure 8 (b) and Fig. 9 (a) Fig. 9 (b) describes the effects of the implementation scheme. Figure 8 (a) and Figure 8 (b) is a Bode diagram showing the simulation result of the frequency characteristic of the motor current i with respect to the current command value Iref when the conventional feedforward type reverse voltage compensation is performed as a comparative example. Fig. 9 (a) and Fig. 9 (b) is a Bode diagram showing a simulation result of the frequency characteristic of the motor current i with respect to the current command value Iref when the controller 30 of the embodiment performs motor current control.

[0097] The solid line represents the reference frequency characteristic, the dotted line represents the frequency characteristic at room temperature, the dotted line represents the frequency characteristic at -40 degrees, and the single-dot chain line represents the frequency characteristic at 100 degrees.

[0098] Compare Figure 8 (a) and Fig. 9 It can be seen from (a) that, in the case of conventional feedforward type reverse voltage compensation, a gain reduction occurs in the frequency band below 100 Hz due to the influence of the pass-free filter that suppresses the influence of current detection noise, but in the case of the motor current control of the implementation method, the gain reduction in the frequency band below 100 Hz is suppressed.

[0099] It is also known that when the motor current control of the embodiment is performed, the gain change accompanying the temperature change in the low frequency band is suppressed. In addition, the higher the temperature, the more the gain change is suppressed. Electric actuator products and electric power steering devices generate heat by themselves due to power-on, so most of them operate at normal temperature conditions or high temperature conditions compared to extremely low temperature conditions. The characteristics of the motor current control of the embodiment are in the operating state.

[0100] (Variant 1)

[0101] Fig.10 FIG. 2 is a block diagram showing a second example of a system for driving the motor 20 by the current command value Iref using a transfer function. Figure 3 The filter in (G LPF (s)) 54 independently includes a filter (G) for reducing the noise of the output (ie, the first voltage command value) of the control filter (A(s)) 52. LPF (s)) 54a and a filter (G) for reducing noise at the output of the delay element (Gdly) 55 LPF (s))54b.

[0102] For example, a filter 54a may be configured between the control filter 52 and the adder 53, and a filter 54b may be configured between the delay element 55 and the adder 53, whereby the adder 53 adds the first voltage command value whose noise is reduced by the filter 54a and the output of the delay element 55 whose noise is reduced by the filter 54b to calculate the second voltage command value.

[0103] In addition, a filter 54a may be arranged before the control filter 52, and the output of the subtractor 51 whose noise is reduced by the filter 54a may be input to the control filter 52. In such a configuration, the noise of the output of the control filter 52 (ie, the first voltage command value) can be reduced by the filter 54a.

[0104] Similarly, a filter 54b may be arranged before the delay element 55, and the output of the adder 53 whose noise is reduced by the filter 54b may be input to the delay element 55. In such a configuration, the noise of the output of the delay element 55 can be reduced by the filter 54b.

[0105] (Variant 2)

[0106] Fig.11 This is a block diagram expressing a third example of a system for driving the motor 20 by the current command value Iref using a transfer function.

[0107] Can replace Fig.10 The control filter (A(s)) 52 in the circuit is configured such that a control filter (A(s)) 52a identical to the control filter 52 is provided at the front stage of the subtractor 51 (i.e., between the control filter (Gref(s)) 50 and the subtractor 51), and a control filter (A(s)) 52b identical to the control filter 52 is provided in the feedback path of the current value Im detected by the motor current detector 48 (i.e., between the motor current detector 48 and the subtractor 51). Even in this configuration, Fig.10 The transfer functions of the systems shown are equivalent.

[0108] In addition, instead of the filter (GLPF (s)) 54a, a filter (GLPF (s)) 54a for reducing the noise of the output of the control filter 52a and a filter (GLPF (s)) 54a for reducing the noise of the output of the control filter 52b may be independently provided. The filter 54a1 reduces the noise of the current command value Iref, and the filter 54a2 reduces the noise of the current detection value Im.

[0109] The connection order of the control filter 50, the control filter 52a and the filter 54a is not limited to Fig.11For example, a filter 54a may be provided at the subsequent stage of the control filter 50 of the input current command value Iref, and a control filter 52a may be provided at the subsequent stage of the filter 54a, and the output of the control filter 52a may be input to the subtractor 51.

[0110] In addition, the control filter 50 can be set at the subsequent stage of the control filter 52a of the input current command value Iref, and the filter 54a1 can be set at the subsequent stage of the control filter 50, and the output of the filter 54a1 can be input to the subtractor 51. Alternatively, the filter 54a1 can be set at the subsequent stage of the control filter 52a of the input current command value Iref, and the control filter 50 can be set at the subsequent stage of the filter 54a1, and the output of the control filter 50 can be input to the subtractor 51.

[0111] In addition, the control filter 50 can be set at the subsequent stage of the filter 54a of the input current command value Iref, and the control filter 52a can be set at the subsequent stage of the control filter 50, and the output of the control filter 52a can be input to the subtractor 51. Alternatively, the control filter 52a can be set at the subsequent stage of the filter 54a of the input current command value Iref, and the control filter 50 can be set at the subsequent stage of the control filter 52a, and the output of the control filter 50 can be input to the subtractor 51.

[0112] In addition, the arrangement order of the control filter 52b and the filter 54a in the feedback path of the current value Im is not limited to Fig.11 In the same order, the current value Im detected by the motor current detector 48 may be input to the filter 54a, a control filter 52b may be provided at the rear stage of the filter 54a, and the output of the control filter 52b may be input to the subtractor 51.

[0113] In addition, the control filter (A(s)) and the filter (G LPF (s)) are both arranged in the preceding stage of the subtractor 51 and in the feedback path of the current value Im, but only the control filter (A(s)) and the filter (G LPF One of the filters (s)) is arranged at the preceding stage of the subtractor 51 and in the feedback path of the current value Im, and the other filter is arranged at the subsequent stage of the subtractor 51.

[0114] (Effects of Embodiments)

[0115] (1) The motor control device of the embodiment includes: a current command value calculation unit 41, which calculates a current command value Iref for driving the motor 20; a current value detection unit 48, which detects the current flowing through the motor 20; a control filter 52, which outputs a first voltage command value based on the deviation between a current detection value Im, which is a detection value of the current detected by the current value detection unit 48, and the current command value Iref; an adder 53, which adds the first voltage command value and the output of the delay element 55 to calculate a second voltage command value, and inputs the second voltage command value to the delay element 55; and an inverter 47, which drives the motor 20 based on the second voltage command value.

[0116] In the conventional feedforward type, a model of motor characteristics such as the reverse voltage constant is required, but this is not used in the present invention. Therefore, even if the reverse voltage constant changes due to deviations caused by individual differences in the motors used, temperature changes, changes in physical properties due to aging, etc., the resulting interference voltage can be suppressed, thereby improving the robustness against interference factors.

[0117] In addition, the motor speed used in the conventional feedforward type reverse voltage compensation is calculated based on the sampling value of the motor angle, and therefore may be affected by detection errors, detection noise, etc., resulting in estimation errors. However, in the present invention, since the motor speed is not used to suppress the interference voltage, the influence of the detection error and detection noise of the motor speed can be avoided.

[0118] In addition, when the voltage command value is calculated by vector control as described above, the current command value calculation unit 41 can calculate the d-axis current command value and the q-axis current command value. Then, the current detection value Im can be converted into the q-axis motor current detection value and the d-axis motor current detection value. The control filter (current control unit) 52 can calculate the first voltage command value based on the deviation between the q-axis motor current detection value and the q-axis current command value, and the deviation between the d-axis motor current detection value and the d-axis current command value.

[0119] (2) The control filter 52 may have the characteristics of a high-pass filter for the interference voltage applied to the motor 20 .

[0120] As described above, the interference terms between the reverse voltage and the d-axis component and the q-axis component are processed as low-frequency signals of the same degree as the steering cycle of the steering wheel 1 in the dq-axis rotation coordinate system. The control filter 52 has the characteristics of a high-pass filter with respect to the interference voltage, thereby being able to suppress the influence of the reverse voltage and other interference voltages.

[0121] (Variation Example)

[0122] The motor control device of the present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the gist of the present invention.

[0123] For example, in the above-mentioned embodiment, as an application example of the motor control device of the present invention, the electric power steering device 10 having the motor control device is illustrated, but the application scope of the motor control device of the present invention is not limited to this, and can be applied to various mechanical devices using the motor control device.

[0124] Fig.12 This is a schematic structural diagram showing an example of a linear motion table device using the motor control device of the present invention.

[0125] The linear motion table device includes a feed screw device, a table 71 , two linear guides (linear motion guide devices), and a base 74 .

[0126] The feed screw device includes a screw shaft 70, a nut 76, and a motor 77. The screw shaft 70 is inserted into the nut 76. The feed screw mechanism of the feed screw device is a ball screw in which the spiral groove of the screw shaft 70 and the spiral groove of the nut 76 are in point contact via balls (rolling elements). The motor 77 is coupled to one axial end of the screw shaft 70.

[0127] The two linear guides each have a guide rail 72, two sliders (moving bodies) 73, and a plurality of rolling bodies. In the linear guide, the guide rail 72 and the slider 73 each have a track surface that forms a rolling path for the rolling body at a position facing each other. The two track surfaces extend in the longitudinal direction of the guide rail 72, and the slider 73 moves linearly along the guide rail 72 by means of the rolling body rolling in the rolling path under load.

[0128] Linear guides are arranged at both ends of the base 74 in a direction perpendicular to the moving direction Y of the table 71 , and a feed screw device is arranged between the two linear guides. The guide rail 72 and the screw shaft 70 are arranged parallel to the moving direction Y of the table 71 .

[0129] With this arrangement, the guide rail 72 is fixed to the base 74. The screw shaft 70 has rolling bearings mounted on both axial ends thereof, and housings 75 are fixed to the outer rings of the rolling bearings. Each housing 75 is fixed to the base 74. Thus, the screw shaft 70 is supported rotatably relative to the base 74.

[0130] The worktable 71 is disposed above the two sliders 73 of each linear guide and the nut 76 of the feed screw device, and is directly fixed to the sliders 73 and fixed to the nut 76 via a bracket. That is, the two sliders 73 of each linear guide and the feed screw device 76 are fixed to one surface of the worktable 71.

[0131] In this linear motion table, when the motor 77 is driven to operate the feed screw device, the screw shaft 70 rotates, and the nut 76 performs linear motion through the ball screw mechanism. In response, the table 71 performs linear motion while being guided by the linear guide.

[0132] The controller 78 sets a current command value for driving the motor 77 , and calculates a voltage control command value Vref based on the current command value through the same processing as the controller 30 of the above-described embodiment, thereby controlling the current supplied to the motor 20 .

[0133] Description of Reference Numerals

[0134] 1…steering wheel, 2…steering shaft, 3…reduction gear, 4a, 4b…universal joint, 5…pinion-rack mechanism, 5a…pinion, 5b…rack, 6a, 6b…tie rod, 7a, 7b…hub unit, 8L, 8R…steering wheel, 10…torque sensor, 11…ignition key, 12…vehicle speed sensor, 13…battery, 14…steering angle sensor, 20…steering assist motor, 20, 77…motor, 30, 78…controller, 41…current command value calculation unit, 42A, 44-4, 44-5, 53…adder, 42B, 51…subtractor, 43…current limiter, 44…compensation signal generator, 44-1…collector Convergence, 44-2...Inertia, 44-3...Automatic return torque, 45...(Proportional-integral) control unit, 46...PWM control unit, 47...Inverter, 48...Motor current detector, 50, 52, 52a, 52b...Control filter, 53...Voltage interference suppression unit, 54, 54a, 54a1, 54a2, 54b...Filter, 55, 56...Delay element, 57...Calculation unit, 58...Electrical characteristic unit, 59...Torque coefficient, 60...Addition unit, 61...Mechanical characteristic unit, 62...Reverse voltage generation unit, 70...Screw shaft, 71...Working table, 72...Guide rail, 73...Slider, 74...Base, 75...Housing, 76...Nut.

Claims

1. A motor control device, characterized in that: The motor control device comprises: a current command value calculation unit that calculates a current command value for driving the motor; a current value detection unit that detects a current flowing through the motor; a current control unit that outputs a first voltage command value based on a deviation between a current detection value, which is a detection value of the current detected by the current value detection unit, and the current command value; a voltage disturbance suppression unit that adds the output of the delay element to the first voltage command value to calculate a second voltage command value, and inputs the second voltage command value to the delay element; as well as A drive circuit drives the motor based on the second voltage command value.

2. The motor control device according to claim 1, characterized in that: The motor control device includes a first filter that reduces noise of the second voltage command value.

3. The motor control device according to claim 2, characterized in that: The first filter is a filter that reduces noise of a sum of the first voltage command value and the output of the delay element.

4. The motor control device according to claim 3, characterized in that: The output of the first filter is input to the delay element.

5. The motor control device according to claim 2, characterized in that: The first filter independently includes a second filter for reducing noise of the first voltage command value and a third filter for reducing noise of the output of the delay element. The voltage disturbance suppression unit calculates the second voltage command value by adding the first voltage command value whose noise is reduced by the second filter and the output of the delay element whose noise is reduced by the third filter.

6. The motor control device according to claim 1, characterized in that: The motor control device may include a filter that reduces noise of the current command value, a filter that reduces noise of the current detection value, and a filter that reduces noise of an output of the delay element, respectively and independently.

7. The motor control device according to claim 1, characterized in that: The current control unit has a high-pass filter characteristic for an interference voltage applied to the motor.

8. The motor control device according to claim 1, characterized in that: The current control unit has characteristics of proportional control, integral control, and differential control for the deviation.

9. An electric actuator product, characterized in that: The electric actuator product has: The motor control device according to any one of claims 1 to 8; and A motor controlled by the motor control device.

10. An electric power steering device, characterized in that: The electric power steering device comprises: The motor control device according to any one of claims 1 to 8; and a motor controlled by the motor control device, The motor applies a steering assist force to a steering system of the vehicle.

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