JP2007161006A - Electric power steering control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric power steering control device capable of enhancing steering performance such as the stability and the steering feeling of a vehicle without being affected by the disturbance. <P>SOLUTION: The electric power steering control device comprises a torque sensor 1 for measuring the steering torque when a driver performs the steering, a phase compensator 2 for improving the frequency characteristic by performing the phase compensation of the steering torque Ts, a vibration suppression control means 15 for suppressing the vibration of the steering system, and a main auxiliary torque controller 3 for operating the main auxiliary torque current for assisting the steering torque based on the phase-compensated steering torque Ts. A first local torque control means 18 locally increases the gain to the specified frequency range, and performs the local torque control for enhancing the disturbance suppression characteristic. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electric power steering control device that assists a steering force with a motor, and more particularly to a novel technique for improving steering performance such as vehicle stability and steering feeling without being affected by disturbance. It is.

Generally, an electric power steering control device arranges a motor so as to mesh with a steering mechanism, measures a steering torque generated when a driver rotates a steering wheel, and supplies a current corresponding to the measured torque value to the motor. Thus, the motor is driven to rotate, and a required auxiliary torque for assisting the steering torque by the driver is generated.
In this type of device, not only the main auxiliary torque control that controls the basic auxiliary force according to the steering torque, but also some compensation controls to improve the steering performance such as vehicle stability and steering feeling. Has been introduced.

For example, conventionally, an electric power steering control device with improved steering feeling has been disclosed (see, for example, Patent Document 1).
In Patent Document 1, the steering torque measured by the steering torque sensor is phase-compensated by the phase compensation means, the auxiliary torque corresponding to the signal after the phase compensation is generated by the motor, and the constant of the phase compensation means is set to the detection value of the vehicle speed sensor. By changing according to the above, the auxiliary force and responsiveness required according to the vehicle speed are satisfied, and an appropriate steering feeling is ensured.

However, in the above configuration, as shown in FIG. 10, for example, the disturbance suppression characteristic deteriorates in a specific frequency region.
FIG. 10 is an explanatory diagram showing frequency characteristics of the phase compensator (software) in the conventional apparatus described in Patent Document 1. In FIG.
In FIG. 10, the upper part shows the frequency characteristic of the phase θ [°], and the lower part shows the frequency characteristic of the gain G [dB].
Further, the phase θ and the gain G are parameters of a vehicle speed signal consisting of a high speed VH (one-dot chain line), a medium speed VM (dotted line), and a low speed VL (solid line) as parameters, respectively (frequency of steering [rotation speed] Corresponding to the above).

As is clear from FIG. 10, the gain G is reduced compared to the DC gain (0 [dB]) in a specific frequency region, and the drop in the gain G is particularly significant at high speed VH (one-dot chain line). . Needless to say, the higher the gain G, the higher the disturbance suppression effect.
That is, in FIG. 10, the magnitude of the gain G correlates with the disturbance suppression effect, but it can be seen that the gain G decreases compared to the DC gain in a specific frequency region. The same applies to other compensation controls.

JP-A-8-91236 JP 2000-168600 A

  In the conventional electric power steering control device, although the steering performance corresponding to the vehicle speed is realized, there is a problem that the gain decreases in a specific frequency region and the disturbance suppression characteristic is deteriorated.

  The present invention has been made to solve the above-described problems, and a local gain is obtained using local torque control for a frequency region in which the gain of the frequency characteristic is smaller than a predetermined value with respect to the DC gain. An object of the present invention is to obtain an electric power steering control device that enables each compensation control without deteriorating disturbance suppression characteristics in a specific frequency region.

  An electric power steering control device according to the present invention includes a steering torque measuring means for measuring a steering torque applied to a steering system from a driver, a motor for generating auxiliary torque for the steering system, and a motor for detecting a motor driving current flowing through the motor. An electric power steering control device comprising current detection means and target current calculation means for calculating a target value of a motor drive current as a target current, wherein the target current calculation means is a main auxiliary torque control current according to a steering torque. And a plurality of frequency characteristic compensation means for compensating frequency characteristics when the steering torque is input and the auxiliary torque is output, and at least one of the plurality of frequency characteristic compensation means is included. One is constituted by local torque control means, and the local torque control means is used when the local torque control means is disabled. In smaller specific frequency range above a predetermined value to the DC gain gain becomes a target of the frequency characteristics of, and increases the gain of the local torque control means.

  According to the present invention, by using the local torque control, it is possible to increase the gain in the specific frequency region and improve the disturbance suppression characteristic in the specific frequency region that has been deteriorated by each frequency characteristic compensation unit.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below with reference to the drawings.
1 is a block diagram showing an electric power steering control apparatus according to Embodiment 1 of the present invention.
Since the above problem can be solved only by software, FIG. 1 mainly shows the software function of the microcomputer. Regarding the hardware of the electric power steering apparatus, since the conventional configuration can be used, detailed description is omitted here.

In FIG. 1, a torque sensor 1 is provided in a steering mechanism (not shown) of a vehicle, measures a steering torque Ts given from a driver to a steering system (steering mechanism), and sets a detected value of the steering torque Ts as a target. Input to the current calculation means 30.
The target current calculation means 30 calculates a target current io corresponding to the auxiliary torque Tc to be generated from the motor 6 according to the output value of the torque sensor 1 (detected value of the steering torque Ts).

The current detector 7 detects the motor drive current im flowing through the motor 6 and inputs it to the current controller 5 and the target current calculation means 30.
The current controller 5 determines a drive voltage command to be applied to the input terminal of the motor 6 so that the motor drive current im detected by the current detector 7 matches the target current io calculated by the target current calculation means 30. A value is set and output as a drive signal (for example, a PWM signal).
The motor 6 is driven by a drive signal from the current controller 5 and generates an auxiliary torque Tc for the steering system.

The target current calculation means 30 is constituted by microcomputer software, and includes a phase compensator 2, a main auxiliary torque controller 3, an addition calculator 4, vibration suppression control means 15, and first local torque control means. (Hereinafter simply referred to as “local torque control means”) 18.
The phase compensator 2, the vibration suppression control means 15 and the local torque control means 18 each function as a frequency characteristic compensation means, and compensate the frequency characteristics when the steering torque Ts is input and the auxiliary torque Tc is output.

The phase compensator 2 performs phase compensation on the steering torque Ts (output value of the torque sensor 1) to improve the frequency characteristic of the steering torque Ts.
The main auxiliary torque controller 3 calculates a main auxiliary torque control current ic for assisting the steering torque Ts based on the phase-compensated steering torque Ts.

The vibration suppression control means 15 includes a steering torque HPF (high pass filter) 8, a drive current HPF (high pass filter) 9, a motor rotation angular velocity observer 10, an angular velocity controller 11, an integrator 12, and an angle controller 13. And an adder 14 to calculate a vibration suppression control current ib for suppressing the vibration of the steering system.
The local torque control means 18 has a measured steering torque BPF (bandpass filter) and a local torque controller 17.

In the vibration suppression control means 15, the steering torque HPF 8 outputs an HPF signal obtained by removing the steering frequency component from the steering torque Ts detected by the torque sensor 1, and the drive current HPF 9 is the motor drive detected by the current controller 5. An HPF signal obtained by removing the steering frequency component from the current im is output.
The motor rotational angular velocity observer 10 estimates and calculates the rotational vibration angular velocity Vm of the motor 6 based on the HPF signals (vibration components) output from the steering torque HPF8 and the drive current HPF9.

The angular velocity controller 11 calculates an angular velocity control current ia for controlling the angular velocity of steering based on the motor rotational vibration angular velocity Vm output from the motor rotational angular velocity observer 10.
The integrator 12 calculates the rotational vibration angle Rm of the motor 6 based on the motor rotational vibration angular velocity Vm, and the angle controller 13 controls the angle of the steering based on the rotational vibration angle Rm of the motor 6. The current ir is calculated.
The adder 14 adds the angular velocity control current ia calculated by the angular velocity controller 11 and the angle control current ir calculated by the angle controller 13 and outputs a vibration suppression control current ib.

  Here, the motor rotational angular velocity observer 10 is configured with respect to a vibration equation when the moment of inertia of the motor is an inertia term and the rigidity of the torque sensor is a spring term, as described in Patent Document 2, for example. .

In the local torque control means 18, the measured steering torque BPF 16 extracts a first specific frequency component (hereinafter simply referred to as “characteristic frequency component”) from the steering torque Ts detected by the torque sensor 1 and outputs a BPF signal. .
Further, the local torque controller 17 calculates a first local torque control current (hereinafter simply referred to as “local torque control current”) ic1 in accordance with the BPF signal (characteristic frequency component) from the measured steering torque BPF 16.

  The addition calculator 4 includes a main auxiliary torque control current ic calculated by the main auxiliary torque controller 3, a vibration suppression control current ib calculated by the vibration suppression control means 15, and a local torque calculated by the local torque control means 18. The target current io is calculated by adding the torque control current ic1.

As shown in FIG. 1, in the electric power steering control device, the main auxiliary torque controller 3 calculates the basic main auxiliary torque control current ic by the main auxiliary torque controller 3 in accordance with the steering torque Ts from the torque sensor 1. I have control.
In order to improve steering performance such as vehicle stability and steering feeling, vibration suppression control means 15 and local torque control means 18 are introduced as frequency characteristic compensation means.

However, although the control using the frequency characteristic compensation means has a target compensation effect, as described above, the gain is reduced and the disturbance suppression characteristic is deteriorated in the specific frequency region as described above.
FIG. 2 is an explanatory diagram showing frequency characteristics when the steering torque Ts of the electric power steering control device is input and the auxiliary torque Tc is output.

  As is clear from FIG. 2, in the case of “no control” (see the dashed curve) by the frequency characteristic compensation means (local torque control means), in a specific frequency region (for example, 7 [Hz] to 40 [Hz]). It can be seen that a gain decrease of about 4 (= 28-24) [dB] occurs from the DC gain (28 [dB]).

That is, the frequency characteristic compensation means such as the phase compensator 2 and the vibration suppression control means 15 improve the steering performance such as the stability of the vehicle and the steering feeling, and realize the target compensation effect. As indicated by the broken line “without local torque control” in FIG. 2, the gain of the frequency characteristic when the steering torque Ts is input and the auxiliary torque Tc is output is reduced with respect to the DC gain in a specific frequency region. End up.
As described above, the higher the gain, the higher the disturbance suppression effect. Therefore, for example, it is understood that the state of “with local torque control” (see the dotted curve) by the local torque control means 18 is desirable.

Therefore, the local torque control means 18 has the measured steering torque Ts as an input and the auxiliary torque Tc as an output in a state where the local torque control means 18 is invalid (a configuration before the local torque control means 18 is introduced). In view of the frequency characteristics at that time (see, for example, the dashed curve in FIG. 2), the local torque control current ic1 for increasing the gain is output in a specific frequency region where the gain is smaller than a predetermined value with respect to the DC gain. .
The predetermined value means an absolute value and a relative value of the amount of change from the DC gain.

  First, when designing the circuit of the local torque control means 18, the control amount (local torque control current ic1) and the control frequency region of the local torque control means 18 are selected based on the frequency characteristics of each frequency characteristic compensation means, and the control frequency region is determined accordingly. Then, the constants of the measured steering torque BPF 16 and the local torque controller 17 are set.

As a result, the measured steering torque BPF 16 extracts a specific frequency component from the steering torque Ts and outputs it as a BPF signal.
Further, the local torque controller 17 outputs a local torque control current ic1 based on a calculation according to the BPF signal from the measured steering torque BPF16.
The control result by the local torque control current ic1 is as shown by “with control” (dotted line curve) in FIG.

  As described above, by using the local torque control by the local torque control means 18, the gain is increased in the specific frequency area, and the disturbance suppression characteristic in the specific frequency area that has been deteriorated by each frequency characteristic compensation means (see the broken line curve). Can be improved.

Next, the operation of the electric power steering control apparatus according to Embodiment 1 of the present invention shown in FIG. 1 will be described with reference to the flowchart of FIG.
The first embodiment of the present invention is different from the prior art in that the local torque control means 18 is provided in order to improve the disturbance suppression characteristics deteriorated in the specific frequency region by various compensation control means, and This is because an algorithm by the torque control means 18 is added.

  On the other hand, regarding the control of the motor drive current im, general control such as PID current feedback control or open loop control based on the target current io and the motor rotation signal can be applied, and digital control or analog control is possible. Either method can be executed.

In FIG. 3, the target current calculation means 30 comprising a microcomputer first reads the detected value of the steering torque Ts output from the torque sensor 1 and stores it in the memory (step S101).
Similarly, the detected value of the motor drive current im output from the current detector 7 is read and stored in the memory (step S102).

Further, the phase compensator 2 reads the steering torque Ts stored in the memory, performs a phase compensation calculation on the steering torque Ts, and stores the output value of the phase compensator 2 in the memory as a phase compensation value (step). S103).
The main auxiliary torque controller 3 reads the phase compensation value stored in the memory, obtains the main auxiliary torque control current ic based on, for example, map calculation, and stores it in the memory (step S104).

Next, the steering torque HPF8 in the vibration suppression control means 15 reads the detected value of the steering torque Ts stored in the memory, and passes the steering torque Ts through a high-pass filter, thereby removing the steering frequency component from the steering torque Ts. The value is stored in the memory as the output value of the steering torque HPF8 (step S105).
Similarly, the drive current HPF 9 reads the detected value of the motor drive current im stored in the memory, and passes the motor drive current im through a high-pass filter, thereby driving the value obtained by removing the steering frequency component from the motor drive current im. The output value of the current HPF 9 is stored in the memory (step S106).

Subsequently, the rotational angular velocity observer 10 reads the output values (vibration components) of the steering torque HPF8 and the drive current HPF9 stored in the memory, estimates and calculates the motor rotational vibration angular velocity Vm, and stores it in the memory (step S107). ).
Further, the integrator 12 integrates the motor rotational vibration angular velocity Vm (estimated value) stored in the memory to estimate the motor rotational vibration angle Rm and store it in the memory (step S108).

Further, the angular velocity controller 11 calculates the angular velocity control current ia by reading the motor rotational vibration angular velocity Vm stored in the memory and multiplying by a preset gain, and stores it in the memory (step S109).
Similarly, the angle controller 13 calculates the angle control current ir by reading the motor rotation vibration angle Rm (estimated value) stored in the memory and multiplying by a preset gain, and stores it in the memory. (Step S110).
Subsequently, the adder 14 adds the angular velocity control current ia and the angle control current ir stored in the memory, and stores them in the memory as the vibration suppression control current ib (step S111).

Next, the measured steering torque BPF 16 in the local torque control means 18 reads the steering torque Ts stored in the memory, passes it through a bandpass filter, extracts a specific frequency component, and then outputs it as an output value of the measured steering torque BPF 16. Store in the memory (step S112).
Subsequently, the local torque controller 17 reads the output value (specific frequency component) of the measured steering torque BPF 16 stored in the memory, and multiplies it by a preset gain (a value for compensating for the gain reduction). Thus, the local torque control current ic1 is calculated and stored in the memory (step S113).

Here, the local torque control means 18 constituted by the measured steering torque BPF 16 and the local torque controller 17 is based on the frequency characteristics of each frequency characteristic compensation means, and the control frequency area (specific frequency area) and the control amount (for compensation). (Gain) is selected.
In the local torque control means 18, the constants of the measured steering torque BPF 16 and the local torque controller 17 are set in advance according to the values of the control frequency region (specific frequency region) and the control amount (compensation gain). Yes.

Finally, the addition calculator 4 calculates the target current io by adding all the main auxiliary torque control current ic, vibration suppression control current ib, and local torque control current ic1 stored in the memory, and stores them in the memory. (Step S114), the processing routine of FIG. 3 is terminated.
Hereinafter, the target current io of the motor 6 is calculated by repeating the processing operations of steps S101 to S114 for each control sampling.

  As described above, the electric power steering control apparatus according to the first embodiment of the present invention includes the torque sensor 1 that measures the steering torque Ts that is applied from the driver to the steering system, and the motor that generates the auxiliary torque Tc for the steering system. 6, a motor current detector 7 that detects a motor drive current im flowing through the motor 6, and a target current calculation means 30 that calculates a target value of the motor drive current im as a target current io.

  The target current calculation means 30 has the phase compensator 2 and the main auxiliary torque control means 3 for calculating the main auxiliary torque control current ic according to the steering torque Ts, and the steering torque Ts as an input and the auxiliary torque Tc as an output. The phase compensator 2 for compensating the frequency characteristics at that time, the vibration suppression control means 15 and the local torque control means 18 (a plurality of frequency characteristic compensation means) are provided.

  At least one of the plurality of frequency characteristic compensation means is constituted by the local torque control means 18, and the local torque control means 18 receives the steering torque Ts when the local torque control means 18 is invalidated as an input and the auxiliary torque Tc. The gain of the local torque control means 18 is increased in a specific frequency region in which the gain of the frequency characteristic when the output is set to be an output is smaller than a predetermined value with respect to the target DC gain.

Further, the target current calculation means 30 includes an addition calculator 4, and the addition calculator 4 includes a main auxiliary torque control current ic, a vibration suppression control current ib, and a local torque control current ic1 (of a plurality of frequency characteristic compensation means). The target current io is calculated by adding the output value.
The local torque control means 18 includes a measured steering torque BPF 16 (specific frequency component extraction means) and a local torque controller 17 (local torque control amount calculation means).
The measured steering torque BPF 16 extracts a specific frequency component in a specific frequency region from the steering torque Ts as a BPF signal, and the local torque controller 17 calculates a local torque control current ic1 according to the specific frequency component.

In this way, the local torque control means 18 is provided, and the frequency characteristic gain when the steering torque Ts is input and the auxiliary torque Tc is output without redesigning each frequency characteristic compensation means is a predetermined value with respect to the DC gain. By performing local torque control for increasing the gain in a specific frequency region that is smaller than the above, the desired compensation effect of each frequency characteristic compensation unit without deteriorating the disturbance suppression characteristic by the vibration suppression control unit 15 Can be obtained.
The design of the local torque control means 18 is easily realized by selecting the control amount and the control frequency region from the frequency characteristics of each frequency characteristic compensation means using the specific frequency component extracted from the steering torque Ts as an input signal. be able to.

Therefore, without redesigning each frequency characteristic compensation means (phase compensator 2, vibration suppression control means 15, etc.), only the local torque control by the local torque control means 18 is added, and the steering torque Ts is input and the auxiliary torque Tc is input. Can improve the frequency characteristics.
Even in a specific frequency region, the steering performance (vehicle stability, steering feeling, etc.) can be improved using each frequency characteristic compensation means without deteriorating the disturbance suppression characteristic.

  Further, a specific frequency component is extracted based on the steering torque Ts indicating the direct state quantity of the steering system, and the control amount and the control frequency region are obtained from the frequency characteristics of each frequency characteristic compensation means using the steering torque Ts as an input signal. By selecting, local torque control can be designed easily.

  In the first embodiment, the main auxiliary torque current ic is obtained by map calculation, and the angular velocity control current ia, the angle control current ir, and the local torque control current ic1 are obtained by gain multiplication. Each of ic, angular velocity control current ia, angle control current ir, and local torque control current ic1 can be obtained by any calculation method of map calculation or gain multiplication.

Further, although the phase compensator 2 is constituted by a digital circuit, it may be constituted by an analog circuit.
Further, the phase compensator 2 may be composed of a plurality of stages of phase compensators in which both digital circuits and analog circuits are combined.
In this case, in the process of reading the steering torque Ts in FIG. 3 (step S101), a value obtained by phase compensation of the detected value of the steering torque Ts by the analog circuit is read and stored in the memory.
Further, when the phase compensator 2 is composed of only an analog circuit, the phase compensation calculation process (step S103) in FIG. 3 is not required.

Further, although the phase compensator 2 is inserted in the previous stage of the main auxiliary torque controller 3, the phase compensator 2 may be omitted and the main auxiliary torque control current ic may be obtained directly from the steering torque Ts.
In this case, the phase compensation process (step S103) in FIG. 3 is not necessary, and the main auxiliary torque current ic is calculated from the steering torque Ts in step S104.

Further, as the specific frequency extracting means for extracting the specific frequency component from the steering torque Ts, the measurement steering torque BPF 16 (band pass filter) is used, but a filter circuit combining HPF (high pass filter) and LPF (low pass filter) is used. You may use, or you may use the phase compensation means which combined the delay phase compensator and the advance phase compensator.
As described above, when the HPF, LPF, lagging phase compensator, and leading phase compensator are used as the specific frequency extracting means, the frequency characteristics and the frequency characteristics of each frequency characteristic compensating means are the same as when the measured steering torque BPF16 is used. Each circuit constant is set based on the constant of the compensator.

  Further, as shown in FIG. 1, the case where the local torque control is applied to the apparatus having the phase compensator 2 and the vibration suppression control means 15 as the frequency characteristic compensation means other than the local torque control means 18 has been described. It goes without saying that the same local torque control can be applied to any apparatus that includes any one of the frequency characteristic compensation means that causes the disturbance suppression characteristic to deteriorate in the specific frequency region.

  Further, an addition calculator 4 for calculating the target current io is provided, and the main auxiliary torque control current ic from the main auxiliary torque controller 3, the angular velocity control current ia from the angular velocity controller 11, and the angle from the angle controller 13. The control current ir and the local torque control current ic1 from the local torque controller 17 are added, but a compensation current controller including a conventional viscosity compensation controller, friction compensation controller, and inertia compensation controller is added. The target current io may be calculated by further adding the control current value.

  Further, the motor rotational vibration angular velocity Vm is estimated and calculated by the motor rotational angular velocity observer 10, and the motor rotational vibration angular velocity Rm is calculated by integrating the motor rotational vibration angular velocity Vm. However, instead of estimating the motor rotational vibration angular velocity Vm, the motor rotational vibration angular velocity Vm is calculated. You may use the actual value by a rotational angular velocity sensor (for example, a tacho generator etc.).

  As described above, when the motor rotation angular velocity sensor is used, the vibration suppression control means 15 is provided with the motor rotation angular velocity HPF (high pass filter), and reading processing of the motor drive current im in FIG. 3 (step S102). ), The detection value of the motor rotational angular velocity sensor is read and stored in the memory, and the process of passing the steering torque Ts through the steering torque HPF8 (step S105) is not necessary.

  In this case, in the process of passing the motor drive current im through the drive current HPF9 (step S106), the detected value of the motor rotation angular velocity sensor stored in the memory is passed through the motor rotation angular velocity HPF to remove the steering frequency component. Thereafter, the measured value of the motor rotational vibration angular velocity is stored in the memory, and the calculation processing (step S107) of the motor rotational vibration angular velocity Vm becomes unnecessary.

  Further, in this case, in the calculation process (step S108) of the motor rotational vibration angle Rm, the integrator 12 integrates the measured value of the motor rotational vibration angular velocity stored in the memory, and the measured value of the motor rotational vibration angle Rm. In the calculation processing of the angular velocity control current ia (step S109), the angular velocity control current ia is calculated from the measured value of the motor rotational vibration angular velocity. In the calculation processing of the angle control current ir (step S110), the motor rotation is calculated. The angle control current ir is calculated from the measured value of the vibration angle.

Further, instead of the motor rotation angular velocity sensor, a motor rotation angle sensor (for example, a rotary encoder) may be used, and the detected value (motor rotation angle) of the motor rotation angle sensor may be differentially processed to obtain the motor rotation angular velocity.
In this case, a motor rotation angle HPF (high pass filter) and a differentiator are provided in the vibration suppression control means 15, and in step S102, the detection value (motor rotation angle) of the motor rotation angle sensor is read and stored in the memory. Step S105 is not necessary.

In this case, in step S106, the motor rotation angle stored in the memory is passed through the motor rotation angle HPF to remove the steering frequency component, and then stored in the memory as a measured value of the motor rotation vibration angle. Step S107 becomes unnecessary.
In Step S108, the motor rotational vibration angle stored in the memory is differentiated by the differentiator, and the motor rotational vibration angular velocity is calculated and stored in the memory.

In this case, in step S109, the angular velocity control current ia is calculated from the motor rotational vibration angular velocity Vm based on the measured value of the motor rotational angle. In step S110, the angle control current ir is calculated from the motor rotational vibration angle (measured value). Will be calculated.
Furthermore, although both the angular velocity controller 11 and the angle controller 13 are used in the first embodiment, only one of them may be used.

Embodiment 2. FIG.
In the first embodiment (FIG. 1), the local torque control means 18 is provided, a specific frequency component is extracted from the steering torque Ts as a BPF signal by the measured steering torque BPF 16, and the BPF signal is output by the local torque controller 17. As shown in FIG. 4, for example, a motor rotation angle sensor 19 is provided, and a second local torque related to the motor rotation angle sensor 19 is provided in the target current calculation means 30 as shown in FIG. Control means (hereinafter simply referred to as “local torque control means”) 23 may be added.

FIG. 4 is a block diagram showing an electric power steering control apparatus according to Embodiment 2 of the present invention. Components similar to those described above (see FIG. 1) are denoted by the same reference numerals as those described above or after the reference numerals. A detailed description is omitted with “A”.
In FIG. 4, the current detector 7 is connected to a motor rotation angle sensor 19 that detects a motor rotation angle Rs.

The target current calculation means 30A includes an additional local torque control means 23 in addition to the configuration described above (FIG. 1).
The local torque control means 23 includes a steering torque calculator 20, a calculated steering torque BPF 21 (specific frequency component extraction means), and a local torque controller 22 (local torque control amount calculation means), and a second local torque control. A current (hereinafter simply referred to as “local torque control current”) ic2 is calculated.

The steering torque calculator 20 calculates a calculated steering torque Tsc by multiplying the motor rotation angle Rs detected by the motor rotation angle sensor 19 by a coefficient and converting the motor rotation angle into a dimension of the steering torque Ts.
The calculated steering torque BPF 21 extracts a second specific frequency component (hereinafter simply referred to as “characteristic frequency component”) in the specific frequency region from the calculated steering torque Tsc, and outputs a BPF signal.
The local torque controller 22 calculates a local torque control current ic2 in accordance with the BPF signal (characteristic frequency component) from the calculated steering torque BPF 21 and inputs it to the addition calculator 4A.

  In the steering torque calculator 20 in the local torque control means 23, in order to calculate the calculated steering torque Tsc converted into the dimension of the steering torque Ts by multiplying the motor rotation angle Rs (detected value) by a coefficient, for example, the above-mentioned The technique disclosed in Patent Document 2 is used.

Further, the local torque control means 18 and 23 receive the steering torque Ts (measured value) in the state where the local torque control means 18 and 23 are disabled (a configuration before the local torque control means 18 and 23 are introduced). In view of the frequency characteristics when the auxiliary torque Tc is output (see, for example, the dashed curve in FIG. 2), a local frequency for increasing the gain in a specific frequency region where the gain is smaller than a predetermined value with respect to the DC gain. Torque control currents ic1 and ic2 are output.
The predetermined value means an absolute value and a relative value of the amount of change from the DC gain, as described above.

  The control amount and control frequency region of the local torque control means 18, 23 are selected based on the frequency characteristics of other frequency characteristic compensation means (phase compensator 2 and vibration suppression control means 15). That is, the constants of the measured steering torque BPF 16, the local torque controller 17, the calculated steering torque BPF 21, and the local torque controller 22 are set in advance according to the selected control amount and control frequency region.

  The addition calculator 4A includes a main auxiliary torque control current ic calculated by the main auxiliary torque controller 3, a vibration suppression control current ib calculated by the vibration suppression control means 15, and a local torque calculated by the local torque control means 18. The target current io is calculated by adding the torque control current ic1 and the local torque control current ic2 calculated by the local torque control means 23.

Next, the operation of the electric power steering control apparatus according to Embodiment 2 of the present invention shown in FIG. 4 will be described with reference to the flowchart of FIG.
In FIG. 5, the same processes (steps S101 to S113) as those described above (see FIG. 3) are denoted by the same reference numerals as those described above and will not be described in detail.
Steps S216 to S218 are processes similar to steps S112 to S114 described above.

In this case as well, as described above, the description is limited to the algorithm until the target current io is calculated by the target current calculation means 30A.
In FIG. 5, the process from the process for reading the steering torque Ts (step S101) to the process for calculating the local torque control current ic1 (step S113) is the same as described above.

Next, the local torque control means 23 in the target current calculation means 30A reads the motor rotation angle Rs (detection value) from the motor rotation angle sensor 19 and stores it in the memory (step S214).
Subsequently, the steering torque calculator 20 reads the motor rotation angle Rs stored in the memory, multiplies the motor rotation angle Rs by a coefficient, and converts it into a dimension of the steering torque Ts, thereby calculating the calculated steering torque Tsc. And stored in the memory (step S215).

Next, the calculated steering torque BPF21 reads the calculated steering torque Tsc stored in the memory, extracts a specific frequency component through a band pass filter, and stores it in the memory as a BPF signal (step S216).
The local torque controller 22 reads the BPF signal (specific frequency component), calculates the local torque control current ic2 by multiplying the gain for compensating for the reduction, and stores it in the memory (step S217).

  Here, as described above, the control amount and the control frequency region of the local torque control means 23 are selected based on the frequency characteristics of each frequency characteristic compensation means, and the constants of the arithmetic steering torque BPF 21 and the local torque controller 22 are selected. Is preset according to the selected control amount and control frequency range.

Finally, the addition computing unit 4A adds the main auxiliary torque control current ic, the vibration suppression control current ib, and the local torque control currents ic1 and ic2 stored in the memory, and stores them in the memory as the target current io (step S218). Then, the processing routine of FIG.
Hereinafter, the target current io of the motor 6 is calculated by repeating the processing operations of steps S101 to S113 and S214 to S218 for each control sampling.

As described above, the electric power steering control apparatus according to Embodiment 2 of the present invention includes the motor rotation angle sensor 19 that detects the rotation angle Rs of the motor 6 in addition to the above-described configuration.
The target current calculation means 30 </ b> A further includes local torque control means 23 including a steering torque calculator 20, a calculated steering torque BPF 21, and a local torque controller 22.

The steering torque calculator 20 multiplies the motor rotation angle Rs by a coefficient to convert the rotation angle into the dimension of the steering torque to calculate the calculated steering torque Tsc. The calculated steering torque BPF 21 calculates the specific frequency from the calculated steering torque Tsc. The specific frequency component of the region is extracted, and the local torque controller 22 calculates the local torque control current ic2 according to the specific frequency component extracted by the calculation steering torque BPF21.
The addition calculator 4A adds the main auxiliary torque control current ic, the vibration suppression control current ib, and the local torque control currents ic1 and ic2 to calculate the target current io.

  Thereby, the signals used for the local torque control are not limited to the steering torque Ts, but the measured values (the steering torque Ts and the motor rotation angle) of the torque sensor 1 and the motor rotation angle sensor 19 (or the motor rotation angular velocity sensor). Rs) and an estimated calculation value (motor rotational vibration angular velocity Vm) of the motor rotational angular velocity observer 10 can be further appropriately selected and used in advance in a frequency region where local torque control is applied. Local torque control can be realized, and disturbance suppression characteristics can be further improved.

In the second embodiment, the calculation steering torque BPF21 is used as the specific frequency component extraction means for extracting the specific frequency component from the calculation steering torque Tsc. However, the HPF (high pass filter) and the LPF (low pass filter) are used. May be used, or a phase compensation means combining a delayed phase compensator and a leading phase compensator may be used.
As described above, when the HPF, LPF, lagging phase compensator, and leading phase compensator are used as the specific frequency extracting means, the frequency characteristics and the frequency characteristics of each frequency characteristic compensating means are the same as when the measured steering torque BPF16 is used. Each circuit constant is set based on the constant of the compensator.

  Further, in order to improve the disturbance suppression characteristic in the specific frequency region, both the local torque control means 18 and 23 are used, but only the local torque control means 23 may be used.

Further, the motor rotation angle sensor 19 is used to measure the motor rotation angle Rs, and the steering torque calculator 20 multiplies the motor rotation angle Rs (measured value) by a coefficient, which is converted into the dimension of the steering torque Ts for calculation steering. Although the torque Tsc is calculated, a motor rotation angular velocity sensor (for example, a tachometer generator) and an integrator may be used as the motor rotation angle detection means.
In this case, the motor rotation angular velocity is measured by the motor rotation angular velocity sensor, and the motor rotation angle is calculated by integrating the motor rotation angular velocity.

  Further, even if the motor rotation angular velocity is estimated by the motor rotation angular velocity observer 10, the estimated motor rotation angular velocity is further integrated to calculate the motor rotation angle, and the value of the motor rotation angle is input to the steering torque calculator 20. Good.

Embodiment 3 FIG.
In the first embodiment (FIG. 1), the constant calculation for the phase compensator 2 and the local torque control means 18 is not considered. However, for example, as shown in FIG. 6, the phase compensator 2B and the local torque control means. In order to calculate the constant for 18B, a phase compensator constant calculator 25 and a local torque constant calculator 26 based on the vehicle speed Vs may be provided.

FIG. 6 is a block diagram showing an electric power steering control apparatus according to Embodiment 3 of the present invention. Components similar to those described above (see FIG. 1) are denoted by the same reference numerals as those described above or after the reference numerals. Detailed description is omitted with “B”.
In FIG. 6, the point different from the above is that the control amount and the control frequency region of the phase compensator 2B and the local torque control means 18B are not constant but variably set.

In this case, in addition to the above-described configuration, a vehicle speed sensor 24 is connected to the target current calculation means 30B, and the vehicle speed sensor 24 detects the vehicle speed Vs of the vehicle on which the electric power steering control device is mounted and detects the target. Input to the current calculation means 30B.
The target current calculation means 30B includes a phase compensator constant calculator 25 and a local torque constant calculator 26.

The phase compensator constant calculator 25 calculates the constant Kp of the phase compensator 2B (frequency characteristic compensation means other than the local torque control means) based on the vehicle speed Vs, and determines the control amount and control frequency region of the phase compensator 2B. Variable setting.
The phase compensator 2B, for which the constant Kp is set by the phase compensator constant calculator 25, improves the frequency characteristic of the steering torque Ts by compensating the phase of the steering torque Ts.
The constant Kp calculated by the phase compensator constant calculator 25 is also input to the local torque constant calculator 26.

The local torque constant calculator 26 calculates the control amount and control frequency region of the local torque control means 18B based on the constant Kp calculated by the phase compensator constant calculator 25.
That is, the local torque constant calculator 26 calculates and outputs the constant of the local torque control means 18B according to the change in the frequency characteristics of the frequency characteristic compensation means other than the local torque control means.
Thereby, the constants of the measured steering torque BPF 16B and the local torque controller 17B in the local torque control means 18B are changed according to the calculation result of the local torque constant calculator 26.

In the target current calculation means 30B, when the constant of the phase compensator 2B for improving the frequency characteristic of the steering torque Ts by compensating the phase of the steering torque Ts is variably set, the change of the frequency characteristic of the phase compensator 2B Accordingly, the frequency characteristics when the steering torque Ts is input and the auxiliary torque Tc is output also change.
Therefore, the local torque control means 18B is configured by the measurement steering torque BPF 16B and the local torque controller 17B whose constants are variably set so that the control amount and the control frequency region are changed according to the change of the phase compensator 2B. ing.

  The constants of the measured steering torque BPF 16B and the local torque controller 17B are changed in accordance with the calculation result output from the local torque constant calculator 26, and the local torque control means 18B determines the local torque control current based on the changed constant. ic1 is generated.

Next, the operation of the electric power steering control apparatus according to Embodiment 3 of the present invention shown in FIG. 6 will be described with reference to the flowchart of FIG.
In FIG. 7, the same processes (steps S101, S102, S104 to S111, S114) as those described above (see FIG. 3) are denoted by the same reference numerals, and detailed description thereof is omitted.
Steps S312 and S313 are processes similar to steps S112 and S113 described above.

In this case as well, the description will be limited to the algorithm until the target current io is calculated by the target current calculating means 30B.
In FIG. 7, first, the reading process (steps S101 and S102) of the steering torque Ts and the motor drive current im is the same as described above.
Subsequently, the vehicle speed Vs (detected value) is read from the vehicle speed sensor 24 and stored in the memory (step S303).

Next, the phase compensator constant calculator 25 calculates the constant Kp of the phase compensator 2B according to the vehicle speed Vs stored in the memory, and stores it in the memory as the calculated value (calculation result) of the phase compensator constant (calculation result). Step S304).
Further, the local torque constant calculator 26 calculates the constant Kt of the local torque control means 18B according to the phase compensator constant Kp stored in the memory, and stores it in the memory as the local torque control means constant (step S305). .

Next, the phase compensator 2B reads the phase compensator constant Kp (calculated value) stored in the memory, variably sets the constant compensator 2B as its own constant, and reads the steering torque Ts stored in the memory. A phase compensation calculation is performed on the signal and the calculation result is stored in the memory as a phase compensation value (step S306).
Thereafter, similarly to the above, the process from the main auxiliary torque control current ic calculation process (step S104) to the vibration suppression control current ib calculation process (step S111) is executed.

  Next, the measured steering torque BPF 16B reads the local torque control means constant Kt (calculated value) stored in the memory, variably sets it as its own constant, and also reads the steering torque Ts stored in the memory, The specific frequency component is extracted through the filter and stored in the memory as the BPF signal output (step S312).

  Hereinafter, the local torque controller 17B reads the gain based on the local torque control means constant Kt (calculated value), variably sets it as its own gain, reads the BPF signal from the measured steering torque BPF 16B, and variably sets it. The local torque control current ic1 is calculated by multiplying the gain and stored in the memory (step S313).

Finally, the addition calculator 4 adds the main auxiliary torque control current ic, the vibration suppression control current ib, and the local torque control current ic1 stored in the memory, and stores them in the memory as the target current io (step S114). The processing routine of FIG. 7 is terminated.
Hereinafter, the target current io of the motor 6 is calculated by repeating the processing operations of steps S101, S102, S303 to S306, S104 to S111, S312, S313, and S114 for each control sampling.

  As described above, the electric power steering control device according to Embodiment 3 of the present invention includes the vehicle speed sensor 24 that detects the vehicle speed Vs. The target current calculation means 30B includes a phase compensator constant calculator 25 that calculates a constant of the phase compensator 2B based on the vehicle speed Vs, and a phase compensator 2B (frequency characteristic compensation means other than the local torque control means 18B). A local torque constant calculator 26 for calculating a constant of the local torque control means 18B according to a change in frequency characteristics is provided.

Furthermore, the constant of the local torque control means 18B is changed according to the calculation result (constant Kt) of the local torque constant calculator 26.
As described above, by appropriately setting the constant of the local torque control means 18B, appropriate local torque control is realized in accordance with the change in frequency characteristics when the steering torque Ts is input and the auxiliary torque Tc is output. Can do.

  In the third embodiment, the present invention is applied to the case where the local torque control is performed using only the local torque control unit 18B. However, as in the second embodiment, the local torque control unit 23 is used, or Needless to say, the present invention is also applicable to the case where two local torque control means 18 and 23 are used.

The phase compensator constant calculator 25 calculates the phase compensation constant Kp according to the vehicle speed Vs, variably sets the constant of the phase compensator 2B (frequency characteristic compensation control means), and receives the steering torque Ts as an auxiliary. Although the present invention is applied to a device that changes the frequency characteristics when torque is output, for example, the vibration suppression control means 15 may be selected as the frequency characteristic compensation means in which the constant is variably set.
In this case, the signal for changing the frequency characteristics of the phase compensator 2B and the vibration suppression control means 15 is, for example, a map gain between the steering torque Ts and the main auxiliary torque controller 3.

Embodiment 4 FIG.
In the first to third embodiments (FIGS. 1, 4, and 6), the main auxiliary torque controller 3 controls the main auxiliary torque based on the steering torque Ts phase-compensated by the phase compensators 2 and 2B. Although the current ic is calculated, for example, as shown in FIG. 8, third local torque control means (hereinafter simply referred to as “local torque control means”) including the local torque phase compensator 27 is provided in the preceding stage of the main auxiliary torque controller 3. 28) may be further provided.

FIG. 8 is a block diagram showing an electric power steering control apparatus according to Embodiment 4 of the present invention, and shows a configuration when local torque control means 28 is added to Embodiment 3 (FIG. 6) described above. .
In FIG. 8, the same parts as those described above (see FIGS. 1 and 6) are denoted by the same reference numerals as those described above, or “C” after the reference numerals, and detailed description thereof is omitted.
In this case, the local torque control means 28 further compensates the phase of the phase compensation value from the phase compensator 2B. The constant of the local torque control means 28 is variably set according to the constant Kt from the local torque constant calculator 26C.

In the first to third embodiments, the main auxiliary torque controller 3 calculates the main auxiliary torque control current ic based on the steering torque Ts phase-compensated by the phase compensators 2 and 2B. Main auxiliary torque control current ic, vibration suppression control current ib and local torque control signals ic1, ic2 from vibration suppression control means 15 and local torque control means 18, 18B, 23 connected in parallel to main auxiliary torque controller 3, Is added to calculate the target current io.
On the other hand, in the fourth embodiment (FIG. 8) of the present invention, the local torque control means 28 is further connected in series to the main auxiliary torque controller 3.

In FIG. 8, the phase compensator 2B calculates the phase compensation value by compensating the phase of the steering torque Ts in order to stabilize the control system of the auxiliary torque Tc, and the local torque phase compensator 27 (local torque control means 28). ) Further compensates the phase compensation value corresponding to the phase-compensated steering torque Ts and inputs the phase compensation value to the main auxiliary torque controller 3.
The main auxiliary torque controller 3 calculates the main auxiliary torque control current ic according to the local torque phase compensation value (third local torque control current) ip from the local torque phase compensator 27.
As a result, local torque control with improved disturbance suppression characteristics that have deteriorated in a specific frequency region is realized.

At this time, the local torque constant calculator 26C performs local torque control in a specific frequency region where the gain of the frequency characteristic when the steering torque Ts is input and the auxiliary torque Tc is output is smaller than the DC gain by a predetermined value or more. Constants Kt and Ktp (control amount and control frequency region) are calculated so that the gains of the means 18B and 28 are increased.
That is, the local torque constant calculator 26C selects and outputs the constant Kt for the measured steering torque BPF 16B and the local torque controller 17B and the constant Ktp for the local torque phase compensator 27.

Next, the operation of the electric power steering control apparatus according to Embodiment 4 of the present invention shown in FIG. 8 will be described with reference to the flowchart of FIG.
In FIG. 8, the same processes as those described above (see FIGS. 3 and 7) (steps S101, S102, S303, S304, S306, S105 to S111, S312, S313, and S114) are denoted by the same reference numerals as described above. Detailed description is omitted.
Steps S405 and S408 are processes similar to steps S305 and S104 described above.

In this case as well, the description is limited to the algorithm until the target current io is calculated by the target current calculation means 30C as described above.
In FIG. 9, first, the process for reading the steering torque Ts, the motor drive current im, and the vehicle speed Vs (steps S101, S102, S303) and the process for calculating the phase compensator constant Kp (step S304) are the same as described above.

Subsequently, the local torque constant calculator 26C calculates the constants Kt and Ktp of the local torque control means 18B and 27 according to the phase compensator constant Kp stored in the memory, and stores them in the memory as local torque control means constants. (Step S405).
Further, the phase compensator 2B reads the phase compensator constant Kp stored in the memory, sets it as its own constant, reads the steering torque Ts stored in the memory, performs the phase compensation calculation, and obtains the phase compensation value. Store in the memory (step S306).

Subsequently, the local torque phase compensator 27 constituting the local torque means 28 reads the local torque control means constant Ktp stored in the memory, sets it as its own constant, and reads the phase compensation value stored in the memory. To further compensate the phase (step S407).
That is, the local torque phase compensator 27 extracts the specific frequency component by phase compensating the phase compensation value so that the gain of the specific frequency component increases with respect to the DC gain, and then the third local torque control current (hereinafter referred to as the third local torque control current). Ip is simply stored in the memory as a local torque phase compensation value.

Next, the main auxiliary torque controller 3 reads the local torque phase compensation value (local torque control current) ip stored in the memory, calculates a map of the main auxiliary torque control current ic from the local torque phase compensation value ip, and stores the memory. (Step S408).
Thereafter, similarly to the above, processing by the vibration suppression control means 15, the local torque control means 18B, and the addition calculator 4 (steps S105 to S111, S312, S313, S114) is performed to calculate the target current io.
Further, the target current io of the motor 6 is calculated by repeating the above processing operation every control sampling.

  As described above, the target current calculation unit 30C according to Embodiment 4 of the present invention includes the phase compensator 2B that calculates the phase compensation value by phase compensation of the steering torque Ts and the local torque phase compensator 27. And a torque control means 28. The local torque phase compensation means 27 calculates the local torque phase compensation value (local torque control current) ip by phase compensating the phase compensation value from the phase compensator 2B, and is the main auxiliary. It inputs to a torque control means.

At this time, the phase compensator 2B has constants (control amounts and frequency regions) set according to the phase compensator constant Kp, and the local torque phase compensator 27 (local torque control means 28) has a local torque control means constant Ktp. The constants (control amount and frequency domain) are set according to.
In the local torque control means 18B, constants (control amount and frequency region) are set according to the local torque control means constant Kt.
Thus, even in a system in which the frequency characteristics change by changing the constants of the local torque control means 18B and 28 in accordance with the change in the constant Kp of each frequency characteristic compensation means, an appropriate local torque corresponding to the change is obtained. Control can be realized.

It is a block diagram which shows the structure of the electric power steering control apparatus which concerns on Embodiment 1 of this invention. It is explanatory drawing which shows the gain of the frequency characteristic of the electric power steering control apparatus concerning Embodiment 1 of this invention. It is a flowchart which shows the algorithm of Embodiment 1 of this invention. It is a block diagram which shows the structure of the electric power steering control apparatus which concerns on Embodiment 2 of this invention. It is a flowchart which shows the algorithm of Embodiment 2 of this invention. It is a block diagram which shows the structure of the electric power steering control apparatus which concerns on Embodiment 3 of this invention. It is a flowchart which shows the algorithm of Embodiment 3 of this invention. It is a block diagram which shows the structure of the electric power steering control apparatus which concerns on Embodiment 4 of this invention. It is a flowchart which shows the algorithm of Embodiment 4 of this invention. It is explanatory drawing which shows the frequency characteristic of the phase compensator of the software in a conventional apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Torque sensor (steering torque measuring means) 2, 2B Phase compensator, 3 Main auxiliary torque controller, 4, 4A Addition calculator, 5 Current controller, 6 Motor, 7 Current detector, 8 Steering torque HPF, 9 Drive current HPF, 10 Motor rotation angular velocity observer, 11 Angular velocity controller, 12 Integrator, 13 Angle controller, 14 Adder, 15 Vibration suppression control means, 16, 16B Measurement steering torque BPF, 17, 17B, 22 Local torque control , 18, 18B first local torque control means, 19 motor rotation angle sensor, 20 steering torque calculator, 21 calculated steering torque BPF, 23 second local torque control means, 24 vehicle speed sensor, 25 phase compensator constant calculation Means 26, 26C Local torque constant calculator, 27 Local torque phase compensator, 28 Third local torque controller , 30, 30A, 30B, 30C target current calculation means, ia angular velocity control current, ib vibration suppression control current, ic main auxiliary torque control current, ic1 first local torque control current, im motor drive current, io target current, ip First local torque control current (local torque phase compensation value), ir angle control current, Rm motor rotation vibration angle, Tc auxiliary torque, Ts steering torque, Tsc calculation steering torque, Vm motor rotation vibration angular velocity, Vs vehicle speed.

Claims (6)

Steering torque measuring means for measuring the steering torque applied from the driver to the steering system;
A motor for generating an auxiliary torque for the steering system;
Motor current detecting means for detecting a motor driving current flowing in the motor;
An electric power steering control device comprising: target current calculation means for calculating a target value of the motor drive current as a target current;
The target current calculation means includes
Main auxiliary torque control means for calculating a main auxiliary torque control current according to the steering torque;
A plurality of frequency characteristic compensation means for compensating frequency characteristics when the steering torque is input and the auxiliary torque is output;
At least one of the plurality of frequency characteristic compensation means is constituted by a local torque control means,
The local torque control means sets the gain of the local torque control means in a specific frequency region in which the gain of the frequency characteristics when the local torque control means is disabled is smaller than a predetermined value with respect to a target DC gain. An electric power steering control device characterized by being increased.   2. The target current calculation means includes an addition calculator for calculating the target current by adding the main auxiliary torque control current and output values of the plurality of frequency characteristic compensation means. Electric power steering control device. The local torque control means includes a first local torque control means including a specific frequency component extraction means and a local torque control amount calculation means,
The specific frequency component extracting means extracts a first specific frequency component in the specific frequency region from the steering torque,
The local torque control amount calculation means calculates a first local torque control current according to the first specific frequency component,
The electric power steering control device according to claim 2, wherein the addition calculator calculates the target current by adding the main auxiliary torque control current and the first local torque control current. Motor rotation angle detection means for detecting the rotation angle of the motor;
The local torque control means includes second local torque control means including steering torque calculation means, specific frequency component extraction means, and local torque control amount calculation means,
The steering torque calculation means multiplies the rotation angle of the motor by a coefficient, converts the rotation angle into a dimension of the steering torque, and calculates a calculation steering torque.
The specific frequency component extracting means extracts a second specific frequency component in the specific frequency region from the calculated steering torque,
The local torque control amount calculation means calculates a second local torque control current according to the second specific frequency component,
4. The electric power according to claim 2, wherein the addition computing unit calculates the target current by adding the main auxiliary torque control current and the second local torque control current. 5. Steering control device. The target current calculation means includes
A local torque constant calculating means for calculating a constant of the local torque control means according to a change in frequency characteristics of the frequency characteristic compensating means other than the local torque control means;
The electric power steering control device according to any one of claims 1 to 4, wherein the constant of the local torque control means is changed according to a calculation result of the local torque constant calculation means. . The target current calculation means includes a phase compensator for calculating a phase compensation value by phase compensating the steering torque,
The local torque control means includes third local torque control means having local torque phase compensation means,
The local torque phase compensation means calculates a third local torque control current by phase compensating the phase compensation value and inputs the third local torque control current to the main auxiliary torque control means. The electric power steering control device according to any one of 5 to 5.

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