Control device, steering device, control method, and program

Abstract

To provide a control device and the like capable of suppressing vibration of a steering wheel caused by unevenness of a road surface and unbalance of wheels.SOLUTION: A control device that controls driving of a motor capable of outputting an assist torque for a steering torque based on a torque signal Td output from a torque sensor 109 capable of detecting the steering torque for a steering wheel extracts a signal for a disturbance vibration generated in the steering wheel due to an external factor from the torque signal Td, advances a phase of an extraction signal Te that is the extracted signal, and controls driving of the motor so as to output the assist torque based on an advance angle signal Ta obtained by advancing the phase of the extraction signal.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a control device, a steering device, a control method, and a program. [Background technology]

[0002] In recent years, steering devices have been proposed that aim to stabilize steering wheels and improve steering performance. For example, the steering device described in Patent Document 1 controls an electric motor so that movement of the steering mechanism is suppressed in response to a reverse input from the road surface when traveling on rough roads such as sand and gravel or unpaved roads. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-121610 Summary of the Invention [Problem to be solved by the invention]

[0004] Since unevenness in the road surface or wheel imbalance can cause vibrations in the steering wheel in the rotational direction, it is desirable to suppress vibrations in the steering wheel caused by unevenness in the road surface or wheel imbalance. An object of the present invention is to provide a control device and the like that can suppress vibrations of a steering wheel caused by unevenness of the road surface or imbalance of the wheels. [Means for solving the problem]

[0005] The present invention, which was completed with this object in mind, is a control device that controls the drive of a motor that can output an assist torque for a steering torque applied to a steering wheel, based on a torque signal output from a torque sensor that can detect the steering torque applied to the steering wheel. The control device extracts from the torque signal a signal representing a disturbance vibration that occurs in the steering wheel due to an external factor, advances the phase of the extracted signal, and controls the drive of the motor to output the assist torque based on an advance signal obtained by advancing the phase of the extracted signal. [Effects of the Invention]

[0006] According to the present invention, vibrations of the steering wheel caused by unevenness of the road surface or imbalance of the wheels can be suppressed. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a diagram showing a schematic configuration of an electric power steering device according to an embodiment; [Figure 2] FIG. 2 is a diagram illustrating an example of a schematic configuration of a control device. [Figure 3] FIG. 2 is a diagram illustrating an example of a schematic configuration of a target current setting unit. [Figure 4] FIG. 2 is a diagram illustrating an example of a schematic configuration of a suppression current setting unit. [Figure 5] 5A and 5B are diagrams illustrating an example of a torque signal, an extraction signal, and an advance angle signal. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a diagram showing a schematic configuration of an electric power steering device 100 according to an embodiment. FIG. 2 is a diagram showing an example of a schematic configuration of the control device 10. As shown in FIG. The electric power steering device 100 (hereinafter sometimes simply referred to as "steering device 100") is a steering device for arbitrarily changing the traveling direction of a vehicle 1. The vehicle 1 can be exemplified as an automobile.

[0009] The steering device 100 includes a steering wheel 101 that is operated by the driver to change the direction of travel of the vehicle 1, and a steering shaft 102 that is integral with the steering wheel 101. The steering device 100 also includes a first connecting shaft 103 that is connected to the steering shaft 102 via a universal joint 103a, and a second connecting shaft 104 that is connected to the first connecting shaft 103 via a universal joint 103b. The second connecting shaft 104 rotates in conjunction with the rotation of the steering wheel 101.

[0010] The steering device 100 also includes tie rods 105 connected to left and right wheels (e.g., front wheels) 150, which serve as rolling wheels, and a rack shaft 106 connected to the tie rod 105. The steering device 100 also includes a pinion 107a that, together with rack teeth 106a formed on the rack shaft 106, constitutes a rack-pinion mechanism. The pinion 107a is formed at the lower end of a pinion shaft 107. The pinion shaft 107 applies a driving force to the rack shaft 106, which rotates to cause the wheels 150 to roll, thereby causing the wheels 150 to roll. The rack shaft 106, pinion shaft 107, etc. function as a transmission mechanism that transmits the rotational operating force of the steering wheel 101 as a rolling force for the wheels 150.

[0011] The steering device 100 also has a steering gear box 130 that houses a pinion shaft 107. The pinion shaft 107 is connected to the second connecting shaft 104 via a torsion bar 108 inside the steering gear box 130. A torque sensor 109 is provided inside the steering gear box 130 and is capable of detecting the steering torque applied to the steering wheel 101 based on the relative rotation angle between the second connecting shaft 104 and the pinion shaft 107. The torque sensor 109 can be, for example, a sensor that can detect the steering torque based on the amount of torsion of the torsion bar 108. The torque sensor 109 also detects disturbance torque transmitted to the pinion shaft 107 via the wheels 150.

[0012] The steering device 100 also includes a motor 110 supported by a steering gearbox 130, and a speed reduction mechanism 111 that reduces the driving force of the motor 110 and transmits it to the pinion shaft 107. The speed reduction mechanism 111 is composed of, for example, a worm wheel (not shown) fixed to the pinion shaft 107, and a worm gear (not shown) fixed to the output shaft of the motor 110. The motor 110 applies a rotational driving force to the pinion shaft 107, thereby applying a driving force to the rack shaft 106 that causes the wheels 150 to roll. The motor 110 can be, for example, a three-phase brushless motor.

[0013] The steering device 100 also includes a control device 10 that controls the operation of the motor 110. An output signal from the torque sensor 109 described above is input to the control device 10. Also, output signals from a vehicle speed sensor 170 that detects the vehicle speed Vc, which is the moving speed of the vehicle 1, and the like are input to the control device 10 via a communication network (in other words, a CAN) that transmits signals for controlling various devices mounted on the vehicle 1.

[0014] The steering device 100 configured as described above drives the motor 110 based on the torque T detected by the torque sensor 109, and transmits the torque generated by the motor 110 to the pinion shaft 107. As a result, the torque generated by the motor 110 assists the steering force applied to the steering wheel 101 by the driver.

[0015] Next, the control device 10 will be described. The control device 10 is an arithmetic and logic operation circuit that includes a CPU, a ROM, a RAM, a backup RAM, and the like. The control device 10 receives inputs such as a torque signal Td, which is an output signal converted from the detected torque T detected by the torque sensor 109 described above, and a vehicle speed signal v, which is an output signal converted from the vehicle speed Vc detected by the vehicle speed sensor 170.

[0016] The control device 10 has a target current setting unit 20 that sets a target current It to be supplied to the motor 110 based on the torque signal Td, the vehicle speed signal v, etc., and a drive control unit 30 that performs feedback control, etc. based on the target current It set by the target current setting unit 20.

[0017] Next, the target current setting unit 20 will be described in detail. FIG. 3 is a diagram showing an example of a schematic configuration of the target current setting unit 20. As shown in FIG. The target current setting unit 20 includes a first setting unit 21 that sets a base current Ib that serves as a base for setting the target current It, and a second setting unit 22 that sets an inertia compensation current Is that cancels out the inertia moment of the motor 110. The target current setting unit 20 also includes a third setting unit 23 that sets a damper compensation current Id that limits the rotation of the motor 110. The target current setting unit 20 also includes a provisional determination unit 25 that determines a provisional target current Itf that is a provisional target current based on the values ​​set by the first setting unit 21, the second setting unit 22, and the third setting unit 23. The target current setting unit 20 also includes a phase compensation unit 26 that compensates for the phase of the detected torque T detected by the torque sensor 109.

[0018] The target current setting unit 20 also includes a suppression current setting unit 27 that sets a disturbance suppression current Ir, which is a current that suppresses vibrations in the rotational direction (hereinafter, may be referred to as "disturbance vibrations") that occur in the steering wheel 101 due to unevenness of the road surface or imbalance of the wheels 150. The target current setting unit 20 also includes a final determination unit 28 that finally determines the target current It based on the tentative target current Itf determined by the tentative determination unit 25 and the disturbance suppression current Ir set by the suppression current setting unit 27.

[0019] The torque signal Td and the vehicle speed signal v are input to the target current setting unit 20. The rotation speed signal Nms, which is obtained by converting the rotation speed Nm of the motor 110 into an output signal, is also input to the target current setting unit 20. The rotation speed Nm of the motor 110 can be calculated based on an output signal from a resolver that detects the rotation position of the rotor of the motor 110, which is, for example, a three-phase brushless motor.

[0020] The first setting unit 21 sets the base current Ib based on the torque signal Ts obtained by phase compensation of the torque signal Td by the phase compensation unit 26, the vehicle speed signal v from the vehicle speed sensor 170, and a control map created in advance. In other words, the first setting unit 21 sets the base current Ib according to the detected torque T and the vehicle speed Vc. The second setting unit 22 sets an inertia compensation current Is for canceling the inertia moment of the motor 110 and the system based on the torque signal Ts and the vehicle speed signal v. In other words, the second setting unit 22 sets the inertia compensation current Is according to the detected torque T and the vehicle speed Vc. The third setting unit 23 sets the damper compensation current Id that limits the rotation of the motor 110 based on the torque signal Ts, the vehicle speed signal v, and the rotation speed signal Nms of the motor 110. In other words, the third setting unit 23 sets the damper compensation current Id according to the detected torque T, the vehicle speed Vc, and the rotation speed Nm of the motor 110.

[0021] The tentative determination unit 25 determines the tentative target current Itf based on the base current Ib set by the first setting unit 21, the inertia compensation current Is set by the second setting unit 22, and the damper compensation current Id set by the third setting unit 23. For example, the tentative determination unit 25 determines the tentative target current Itf as a value obtained by adding the inertia compensation current Is to the base current Ib and subtracting the damper compensation current Id from it. The suppression current setting unit 27 will be described in detail later.

[0022] The final determination unit 28 finally determines the target current It based on the tentative target current Itf determined by the tentative determination unit 25 and the disturbance suppression current Ir set by the suppression current setting unit 27. The final determination unit 28 according to this embodiment determines the value obtained by adding the disturbance suppression current Ir set by the suppression current setting unit 27 to the tentative target current Itf determined by the tentative determination unit 25 as the target current It.

[0023] (Drive control unit 30) The drive control unit 30 has a motor drive control unit (not shown) that controls the operation of the motor 110, a motor drive unit (not shown) that drives the motor 110, and a motor current detection unit (not shown) that detects the actual current that actually flows through the motor 110. The motor drive control unit has a feedback control unit (not shown) that performs feedback processing so that the difference between the target current It set by the target current setting unit 20 and the actual current supplied to the motor 110 detected by the motor current detection unit becomes 0. The motor drive control unit also has a PWM signal generation unit (not shown) that generates a PWM signal for PWM driving the motor 110.

[0024] The motor drive unit is a so-called inverter, and includes, for example, six independent transistors (FETs) as switching elements. Three of the six transistors are connected between the positive line of the power supply and the electric coil of each phase, and the other three transistors are connected between the electric coil of each phase and the negative (ground) line of the power supply. The drive of the motor 110 is controlled by driving the gates of two selected transistors from the six to cause these transistors to perform switching operations. The motor current detector detects the value of the actual current flowing through the motor 110 from the voltage generated across a shunt resistor connected to the motor driver.

[0025] Next, the suppression current setting unit 27 will be described in detail. The suppression current setting unit 27 sets the disturbance suppression current Ir, which is a current for canceling, by the motor 110, vibrations (in other words, disturbance vibrations) transmitted to the steering wheel 101 due to unevenness of the road surface or imbalance of the wheels 150. In other words, the disturbance suppression current Ir is a current for driving the motor 110 so as to apply a rotational torque in the opposite direction to the rotational torque transmitted to the pinion shaft 107 via the wheels 150, the rack shaft 106, etc. due to unevenness of the road surface or imbalance of the wheels 150.

[0026] FIG. 4 is a diagram showing an example of a schematic configuration of the suppression current setting unit 27. As shown in FIG. Fig. 5 is a diagram showing an example of the torque signal Td, the extraction signal Te, and the advance angle signal Ta. Fig. 5 shows an example of the torque signal Td when the driver rotates the steering wheel 101 in one direction (for example, rightward) from the neutral position, returns it to the neutral position, and then rotates it in the other direction (for example, leftward) and returns it to the neutral position.

[0027] The suppression current setting unit 27 includes an extraction unit 270 that extracts components of a predetermined frequency band from the torque signal Td from the torque sensor 109. The suppression current setting unit 27 also includes a compensation unit 273 that advances the phase of the torque signal Td (hereinafter, may be referred to as "extracted signal Te") extracted by the extraction unit 270. The suppression current setting unit 27 also includes a determination unit 274 that determines the disturbance suppression current Ir.

[0028] The extraction unit 270 has a filter 271 that passes only signals in a predetermined frequency band centered on a center frequency Frc among the torque signals Td from the torque sensor 109 and does not pass (in other words, attenuates) signals of other frequencies. The extraction unit 270 also has a center setting unit 272 that sets the center frequency Frc of the filter 271 in accordance with the vehicle speed Vc.

[0029] The filter 271 can be exemplified as a band-pass filter that passes only signals in a predetermined frequency band (e.g., 3 Hz) centered on a center frequency Frc and does not pass (in other words, attenuates) signals of other frequencies. The filter 271 can be configured, for example, by an analog circuit or a program executed by a CPU. The center frequency Frc is set by a center setting unit 272.

[0030] The center setting unit 272 determines the center frequency Frc of the filter 271 based on the vehicle speed signal v. That is, the center setting unit 272 sets the center frequency Frc according to the vehicle speed Vc. Note that the center setting unit 272 sets the center frequency Frc by, for example, substituting the vehicle speed Vc into a control map that indicates the correspondence between the vehicle speed Vc and the center frequency Frc and that has been created in advance based on empirical rules and stored in ROM.

[0031] Since one period of the disturbance vibration is considered to be one rotation of the wheel 150, the frequency of the disturbance vibration depends on the rotation speed of the wheel 150 and increases in proportion to the rotation speed of the wheel 150. The diameter of the wheel 150 differs depending on the vehicle model. Furthermore, the diameter of the wheel 150 differs depending on the specifications even for the same vehicle model. Meanwhile, the rotation speed of the wheel 150 at which the disturbance vibration occurs differs depending on the vehicle model and specifications, but is generally considered to occur within a predetermined range of rotation speed. Therefore, the frequency of the disturbance vibration is low in vehicles with a large diameter of the wheel 150. On the other hand, the frequency of the disturbance vibration is high in vehicles with a small diameter of the wheel 150. The frequency of the disturbance vibration can be, for example, 8 Hz to 15 Hz.

[0032] In consideration of these matters, the control map showing the correspondence between the vehicle speed Vc and the center frequency Frc of the filter 271 is set so that the vehicle speed Vc and the center frequency Frc are proportional in a vehicle speed range where disturbance vibrations are likely to occur. The center frequency Frc in a vehicle speed range lower than the vehicle speed range where disturbance vibrations are likely to occur is set to the center frequency Frc at the minimum vehicle speed within the vehicle speed range where disturbance vibrations are likely to occur. Furthermore, the center frequency Frc in a vehicle speed range higher than the vehicle speed range where disturbance vibrations are likely to occur is set to the center frequency Frc at the maximum vehicle speed within the vehicle speed range where disturbance vibrations are likely to occur.

[0033] For example, after the steering device 100 according to the present embodiment is mounted on the vehicle 1, the center setting unit 272 determines the vehicle speed Vc at which disturbance vibration occurs and sets the center frequency Frc by substituting the determined vehicle speed Vc into the control map. Then, the center setting unit 272 sets the set center frequency Frc as the center frequency Frc of the filter 271. For example, the center setting unit 272 can exemplarily set the center frequency Frc to 10 Hz when the vehicle speed Vc is 80 km / h.

[0034] The center setting unit 272 may, for example, acquire the vehicle identification information of the vehicle and acquire the vehicle speed Vc at which disturbance vibration occurs corresponding to the acquired identification information by reading it from a ROM. The center setting unit 272 may, for example, grasp the vehicle speed Vc at which disturbance vibration occurs based on a value input by an operator who sets the steering device 100.

[0035] With the above-described configuration, the extraction unit 270 passes only signals of a predetermined frequency band centered on the center frequency Frc set by the center setting unit 272 from the torque signal Td from the torque sensor 109, thereby extracting with high precision the signal of the frequency of the disturbance vibration. The extraction unit 270 may perform arithmetic processing to extract the frequency components of the disturbance vibration from the detected torque T. For example, the extraction unit 270 may read the torque T detected by the torque sensor 109 at regular time intervals (for example, every 4 milliseconds) and extract the components in a predetermined frequency band.

[0036] The compensation unit 273 advances the phase of the extraction signal Te extracted by the extraction unit 270. In this way, the compensation unit 273 is a phase-lead compensator that advances the phase of the extraction signal Te of the specific frequency band passed through the filter 271. Furthermore, the compensation unit 273 determines the angle by which to advance the phase based on the vehicle speed signal v, and advances the phase of the extraction signal Te by the determined angle. First, the compensation unit 273 determines an angle according to the vehicle speed Vc. For example, the compensation unit 273 sets the angle by substituting the vehicle speed Vc into a control map that is created in advance based on empirical rules and stored in ROM and indicates the correspondence between the phase advance angle and the vehicle speed Vc.

[0037] In the control map, the angle by which the phase is advanced is set to be greater as the vehicle speed Vc is higher. This is because, as a result of extensive research by the present inventors and others, they found that the higher the frequency of the torque signal Td, the more the phase lags relative to the torque to be detected. However, since a larger phase advance angle can actually cause instability, the upper limit of the phase advance angle is set to 90 degrees. For example, the phase advance angle can be 45 degrees when the vehicle speed Vc is 80 km / h. Therefore, when the vehicle speed Vc is 80 km / h, the center frequency Frc is 10 Hz, and the compensation unit 273 advances the phase of the extraction signal Te by 45 degrees.

[0038] The determination unit 274 determines the value obtained by multiplying the extracted signal Te (hereinafter, sometimes referred to as the "advance angle signal Ta") after the phase has been advanced by the compensation unit 273 by a coefficient predetermined for each vehicle model and specification as the disturbance suppression current Ir.

[0039] The suppression current setting unit 27 stores the disturbance suppression current Ir determined by the above-described method in a storage area such as a RAM. Then, the final determination unit 28 determines the sum of the tentative target current Itf and the disturbance suppression current Ir stored in a storage area such as a RAM as the target current It.

[0040] In the steering device 100 configured as described above, the target current It includes the disturbance suppression current Ir, which is a current for canceling disturbance vibrations by the motor 110. Therefore, it is possible to suppress vibrations transmitted to the steering wheel 101 due to unevenness of the road surface or imbalance of the wheels 150 from being transmitted to the driver.

[0041] Furthermore, in the target current setting unit 20 configured as described above, the target current It is always determined as the current obtained by adding the disturbance suppression current Ir to the tentative target current Itf. Therefore, when no disturbance vibration is occurring, it is desirable to set the disturbance suppression current Ir to zero. The filter 271 of the suppression current setting unit 27 according to this embodiment passes only signals in a predetermined frequency band centered on a center frequency Frc corresponding to the vehicle speed Vc at which disturbance vibration is expected to occur, and does not pass signals of other frequencies. Therefore, compared to extracting signals of disturbance vibration frequencies using a filter that passes signals in a specific frequency band (e.g., 8 to 15 Hz) without changing the center frequency Frc according to the vehicle speed Vc, it is possible to prevent unnecessary application of the disturbance suppression current Ir. As a result, it is possible to prevent deterioration of the steering feel when no disturbance vibration is occurring.

[0042] As described above, the control device 10 is a device that controls the driving of the motor 110, which is capable of outputting an assist torque for the steering torque, based on the torque signal Td output from the torque sensor 109, which is capable of detecting the steering torque for the steering wheel 101. The control device 10 then extracts, from the torque signal Td, a signal regarding disturbance vibrations that occur in the steering wheel 101 due to external factors (for example, unevenness of the road surface or imbalance of the wheels 150). The control device 10 also advances the phase of the extracted signal, that is, the extraction signal Te, and controls the driving of the motor 110 so as to output an assist torque based on the advance signal Ta obtained by advancing the phase of the extraction signal Te (in other words, it supplies the target current It to which the disturbance suppression current Ir has been added). In addition, the control method performed by the control device 10 extracts a signal regarding disturbance vibration from the torque signal Td, advances the phase of the extracted signal, that is, the extraction signal Te, and controls the driving of the motor 110 so as to output an assist torque based on the advance signal Ta obtained by advancing the phase of the extraction signal Te.

[0043] According to the control device 10 configured as described above, disturbance vibrations can be suppressed with higher accuracy than when the drive of the motor 110 is controlled so as to output an assist torque based on the extraction signal Te rather than the advance signal Ta.

[0044] Here, the control device 10 determines the frequency of the extraction signal Te according to the vehicle speed Vc. This makes it possible to prevent the application of an unnecessary disturbance suppression current Ir in a frequency band where the driver's normal steering frequency does not cause disturbance vibration, thereby preventing the steering feeling from deteriorating when no disturbance vibration occurs.

[0045] Furthermore, the control device 10 determines the angle by which the phase of the extraction signal Te is advanced in accordance with the vehicle speed Vc, thereby enabling the phase of the disturbance suppression current Ir to be matched with the phase of the disturbance vibration with high precision. For example, the control device 10 advances the phase of the extraction signal Te by 1 to 90 degrees to generate the advance angle signal Ta. In other words, the control device 10 does not advance the phase of the extraction signal Te by more than 90 degrees. This makes it possible to prevent the steering feeling from worsening due to the application of the disturbance suppression current Ir.

[0046] The control device 10 adds a disturbance suppression current Ir (an example of a suppression current) for suppressing disturbance vibrations determined based on the advance signal Ta to a current (for example, a tentative target current Itf) determined based on the torque signal Td, and determines this current as the target current It to be supplied to the motor 110. This makes it possible to effectively suppress disturbance vibrations while maintaining the assistance for normal steering by the driver.

[0047] Furthermore, the processing performed by the control device 10 described above can be realized by the cooperation of software and hardware resources. In this case, the CPU of the control device 10 executes a program that realizes each function of the device, thereby realizing each function. For example, a non-transitory computer-readable recording medium on which a program is recorded is provided to the control device 10, and the CPU of the control device 10 reads the program stored in the recording medium. Alternatively, the CPU of the control device 10 downloads the program via a network. In these cases, the program read from the recording medium or the downloaded program itself realizes the functions of the above-described embodiments, and the program itself and the recording medium on which it is recorded constitute the present invention.

[0048] The program that realizes the functions of the control device 10 causes the computer to execute an extraction function of extracting a signal regarding disturbance vibration from a torque signal Td output from a torque sensor 109 that can detect the steering torque applied to the steering wheel 101. The program also causes the computer to execute a function of advancing the phase of an extracted signal Te, which is the extracted signal, and a function of controlling the drive of a motor 110 that can output an assist torque for the steering torque, based on an advance signal Ta that is the phase advanced from the extracted signal Te.

[0049] In the above-described embodiment, a sensor that detects the steering torque applied to the steering wheel 101 and the disturbance torque transmitted to the pinion shaft 107 via the wheels 150 is used as the torque sensor 109, which detects the steering torque based on the amount of torsion of the torsion bar 108, but is not particularly limited to this. For example, a magnetostrictive sensor that detects torque based on changes in magnetic properties caused by magnetostriction may also be used.

[0050] In the above-described embodiment, the control for suppressing disturbance vibrations is applied to a pinion-type electric power steering system, but this is not a limitation and may be applied to other types of electric power steering devices, such as a double-pinion type or a rack-assist type. [Explanation of symbols]

[0051] 10...control device, 20...target current setting unit, 21...first setting unit, 22...second setting unit, 23...third setting unit, 25...temporary determination unit, 27...suppression current setting unit, 28...final determination unit, 30...drive control unit, 100...electric power steering device, 101...steering wheel, 109...torque sensor, 110...motor, 270...extraction unit, 271...filter, 272...center setting unit, 273...compensation unit, 274...determination unit, Ta...advance angle signal, Td...torque signal, Te...extraction signal

Claims

1. A control device that controls driving of a motor that can output an assist torque for a steering torque on a steering wheel based on a torque signal output from a torque sensor that can detect the steering torque, extracting a signal relating to a disturbance vibration occurring in the steering wheel due to an external factor from the torque signal; Advance the phase of the extracted signal, controlling the driving of the motor so as to output the assist torque based on an advance signal obtained by advancing the phase of the extracted signal; Control device.

2. determining the frequency of the extracted signal in accordance with the vehicle speed; The control device according to claim 1 .

3. determining an angle by which the phase of the extracted signal is advanced in accordance with the vehicle speed; The control device according to claim 1 .

4. The phase of the extracted signal is advanced by 1 to 90 degrees to obtain the lead angle signal. The control device according to claim 3 .

5. a current determined based on the torque signal plus a suppression current for suppressing the disturbance vibration determined based on the advance angle signal, the sum of which is set as a target current to be supplied to the motor; The control device according to claim 1 .

6. a value obtained by multiplying the advance signal by a predetermined coefficient is set as the suppression current; The control device according to claim 5 .

7. a torque sensor capable of detecting a steering torque applied to a steering wheel; a motor capable of outputting an assist torque for the steering torque; a control device that controls the driving of the motor based on a torque signal output from the torque sensor; Equipped with the control device extracts, from the torque signal, a signal regarding a disturbance vibration occurring in the steering wheel due to an external factor; Advance the phase of the extracted signal, controlling the driving of the motor so as to output the assist torque based on an advance signal obtained by advancing the phase of the extracted signal; Steering device.

8. A control method for controlling drive of a motor capable of outputting an assist torque for a steering torque on a steering wheel, based on a torque signal output from a torque sensor capable of detecting the steering torque, the method comprising: extracting a signal relating to a disturbance vibration occurring in the steering wheel due to an external factor from the torque signal; Advance the phase of the extracted signal, controlling the driving of the motor so as to output the assist torque based on an advance signal obtained by advancing the phase of the extracted signal; Control method.

9. On the computer, an extraction function for extracting a signal relating to a disturbance vibration occurring in the steering wheel due to an external factor from a torque signal output from a torque sensor capable of detecting a steering torque applied to the steering wheel; a function of advancing the phase of the extracted signal, which is the extracted signal; a function of controlling the driving of a motor capable of outputting an assist torque for the steering torque based on an advance signal obtained by advancing the phase of the extracted signal; A program that executes the following.

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