JP2004074984A - Electric power steering device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the steering load for a driver in reversing the operating direction of an operation member. <P>SOLUTION: A basic target current value is determined on the basis of the steering torque T and a speed of car V. A corrected target current value is determined by adding various correction values to the basic target current value in an adding part 25. An electric motor M is driven and controlled on the basis of the corrected target current value. A turn controlling part 24 creates a correction value to reduce high steering load caused by the inertia of the electric motor M and a steering mechanism 3 in steering to reverse the steering direction of the steering wheel 1. Concretely, when the reversing of the steering direction is detected, the correction value is determined on the basis of the steering acceleration at that time, and the change of a steering angle or the steering torque from the detection of the reversing. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electric power steering device configured to transmit a driving force generated by an electric motor to a steering mechanism to assist steering.
[0002]
[Prior art]
2. Description of the Related Art An electric power steering apparatus that assists steering by mechanically transmitting a driving force of an electric motor to a steering mechanism has been conventionally used. The electric motor is controlled based on a target current value set according to the steering torque applied to the steering wheel, whereby a steering assist force corresponding to the steering torque is given to the steering mechanism.
[0003]
Since the inertia of the steering mechanism itself and the inertia of an electric motor mechanically coupled to the steering mechanism become a load during steering, inertia compensation control for reducing the steering load due to these inertia may be adopted. Specifically, for example, the rotational angular acceleration of the electric motor is obtained, and inertia compensation control is achieved by adding an inertial compensation current corresponding to the rotational angular acceleration to the target current value.
Further, in order to improve a response delay caused by inertia of the steering mechanism and the electric motor, a torque differential value which is a differential value of the steering torque is obtained, and a compensation current corresponding to the torque differential value is added to the target current value. Thus, the responsiveness compensation control may be performed.
[0004]
[Problems to be solved by the invention]
The driver receives the strongest inertia of the steering mechanism and the electric motor at the time of turning back to reverse the operation direction of the steering wheel. The influence of this inertia is greater as the steering speed at the time of turning back is higher, and the steering becomes heavier than the natural range of weight.
This phenomenon cannot be improved by the inertia compensation control or the responsiveness compensation control described above.
[0005]
Therefore, an object of the present invention is to provide an electric power steering device capable of reducing the driver's steering load when the operation direction of the operation member is reversed, thereby improving the steering feeling. is there.
[0006]
Means for Solving the Problems and Effects of the Invention
According to the first aspect of the present invention, a driving force generated by an electric motor (M) controlled according to an operation amount of an operation member (1) is transmitted to a steering mechanism (3). An electric power steering device for assisting steering, comprising: an operation amount detection means (5) for detecting an operation amount of the operation member; and a target drive value of the electric motor according to the operation amount detected by the operation amount detection means. Basic target drive value setting means (11) for setting a basic target drive value which is a basic value of the above, operation acceleration detection means (15) for detecting the operation acceleration of the operation member, and inversion of the operation direction of the operation member. An inversion detecting means (31) for detecting, and when the inversion of the operation direction of the operating member is detected by the inversion detection means, the basic target drive is detected in accordance with the operation acceleration detected by the operation acceleration detection means. Correction means (25, 32, 33, 34, 40) for correcting the basic target drive value set by the value setting means to obtain a target drive value for controlling the electric motor, and a target calculated by the correction means. A motor drive means (20) for driving the electric motor based on a drive value. It should be noted that the alphanumeric characters in parentheses indicate corresponding components and the like in embodiments described later. Hereinafter, the same applies in this section.
[0007]
According to the present invention, when the reversal of the operation direction of the operation member is detected, the target drive value for controlling the electric motor is obtained by correcting the basic target drive value according to the operation acceleration at that time. . As a result, the target current value can be increased according to the operation acceleration at the time of the reverse steering, so that at the time of the reverse steering, the steering load caused by the inertia of the electric motor and the steering mechanism can be reduced, and the favorable steering can be achieved. Feeling can be realized.
[0008]
The operation amount detection means may detect an operation torque applied to the operation member as an operation amount.
Further, the operation acceleration detecting means may be a means for differentiating the output of the operation angle sensor (6) for detecting the operation angle of the operation member with second order time. In the case where an operation speed detection means (14) for obtaining an operation speed by differentiating the output of the operation angle sensor by the first order time is provided, the operation acceleration detection means sets the output of the operation speed detection means to one. The operation acceleration may be obtained by differentiating the floor time.
[0009]
For example, for the operation of the operation member in one direction, the first sign (positive or negative) is commonly given to the operation speed and the operation amount at that time, and for the operation of the operation member in the other direction. Assuming that a second sign (negative or positive) is commonly given to the operation speed and the operation amount therewith, the inversion detecting means reverses the operation direction when the operation speed and the operation amount have different signs. May be detected.
In addition, the correcting means is configured to increase the steering assist force (steering assist force in the operation direction after the reversal) applied to the steering mechanism as the absolute value of the operation acceleration at the time when the reversal of the operation direction is detected is increased. It is preferable to correct the basic target drive value.
[0010]
According to a second aspect of the present invention, the correction means includes a basic correction value corresponding to an operation acceleration detected by the operation acceleration detection means when the inversion of the operation direction of the operation member is detected by the inversion detection means. A basic correction value setting means (32) to be set; and an operation angle change amount detecting means (32) for detecting an operation angle change amount of the operation member from the time when the inversion of the operation direction of the operation member is detected by the inversion detection means ( 33) correcting the basic target drive value by correcting the basic correction value set by the basic correction value setting means according to the operation angle change amount detected by the operation angle change amount detection means. Correction value calculating means for obtaining a correction value; and means for correcting the basic target drive value based on the correction value obtained by the correction value calculating means. An electric power steering apparatus according to claim 1, wherein.
[0011]
According to this configuration, the operation angle change amount after the inversion of the operation direction is detected is detected. Therefore, by setting a basic correction value based on the operation acceleration when the operation direction is reversed, and further correcting the basic correction value based on the amount of change in the operation angle, in the initial and subsequent periods when the operation direction is reversed, An appropriate correction value can be set. Therefore, by correcting the basic target drive value based on this correction value, it is possible to set an appropriate target drive value, effectively compensate for the influence of inertia of the electric motor or the like, and obtain an excellent steering feeling. Can be realized.
[0012]
The basic correction value setting means may set, for example, a basic correction value such that the absolute value of the operation acceleration at the time when the reversal of the operation direction is detected is increased as the absolute value of the operation acceleration is increased.
Further, the correction value calculation means includes gain setting means (34) for setting a gain according to the amount of change in the operation angle, and multiplication means (35) for multiplying the set gain by the basic correction value. There may be. The gain takes an upper limit value when the operation angle change amount is zero, for example, and decreases to a predetermined lower limit value (for example, zero) as the absolute value of the operation angle change amount increases to a predetermined threshold value. It may be set so that it goes. As a result, at the beginning when the operation direction is reversed, the basic target drive value can be largely corrected to strongly compensate for the large inertia associated with the return steering, and thereafter, the correction amount can be gradually reduced.
[0013]
For example, when the operation speed detecting means for detecting the operation speed of the operating member is provided, the operation angle change amount detecting means detects the operation speed from the time when the inversion detecting means detects the reversal of the operation direction. An operation speed integrating means (33) for integrating the operation speed detected by the detecting means can be constituted. In this case, the operation speed integrated value corresponds to the operation angle change amount.
According to a third aspect of the present invention, the correction means includes a basic correction value corresponding to an operation acceleration detected by the operation acceleration detection means when the inversion of the operation direction of the operation member is detected by the inversion detection means. The basic target drive value is corrected by correcting the basic correction value set by the basic correction value setting means according to the operation amount detected by the basic correction value setting means (32) and the operation amount detected by the operation amount detection means. Correction value calculating means (35, 40) for obtaining a correction value for correction; and means (25) for correcting the basic target drive value based on the correction value obtained by the correction value calculating means. The electric power steering apparatus according to claim 1, wherein:
[0014]
According to this configuration, since the basic correction value is corrected in accordance with the operation amount (for example, operation torque) detected by the operation amount detection means, appropriate steering assistance can be performed according to the steering load at the time of reverse steering. Can be.
For example, the correction value calculating means may include gain setting means (40) for setting a gain according to the operation amount, and multiplication means (35) for multiplying the set gain by the basic correction value. Good. It is preferable that the gain is set to be larger, for example, as the absolute value of the operation amount is larger. More specifically, for example, it is preferable to set the gain so as to increase in a range equal to or less than a predetermined upper limit value as the absolute value of the steering torque increases. However, when the steering torque takes a value within a predetermined dead zone near zero, the gain is preferably set to zero.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a block diagram showing an electric configuration of an electric power steering apparatus according to one embodiment of the present invention. A steering torque applied to a steering wheel 1 as an operation member is transmitted to a steering mechanism 3 via a steering shaft 2. A driving force generated from the electric motor M is mechanically transmitted to the steering mechanism 3 as a steering assist force via a gear mechanism or by a direct drive method.
[0016]
The steering shaft 2 is divided into an input shaft 2A connected to the steering wheel 1 and an output shaft 2B connected to the steering mechanism 3. The input shaft 2A and the output shaft 2B are connected to a torsion bar 4. Are connected to each other. The torsion bar 4 twists according to the steering torque T applied to the steering wheel 1, and the direction and amount of the twist are detected by a torque sensor 5. The output signal of the torque sensor 5 is input to the controller 10 (ECU).
[0017]
The controller 10 includes, in addition to the output signal of the torque sensor 5, a steering angle sensor 6 for detecting a steering angle θ as a rotation angle of the steering wheel 1, and a vehicle speed V of a vehicle equipped with the electric power steering device. Each output signal from the vehicle speed sensor 7 to be detected is also input.
The controller 10 sets a target current value according to the steering torque T detected by the torque sensor 5 and the vehicle speed V detected by the vehicle speed sensor 7, and controls the motor driver 20 based on the target current value. An appropriate drive current is given to the electric motor M. As a result, a steering assist force corresponding to the steering torque T and the vehicle speed V is given to the steering mechanism 3.
[0018]
The controller 10 includes a basic target current value setting unit 11 that sets a basic target current value according to the steering torque T and the vehicle speed V by a program process performed by a microcomputer provided therein, and the basic target current value setting unit 11. By correcting the basic target current value set by the user, each function of the correction unit 12 for setting an appropriate target current value is realized. The motor driver 20 including a power transistor and the like is controlled based on the target current value set by the correction unit 12, and power is supplied from the motor driver 20 to the electric motor M.
[0019]
The correction unit 12 includes a responsiveness compensation control unit 21 that generates a correction value for compensating a response delay caused by the inertia of the steering mechanism 3 and the electric motor M, and a steering operation that is performed by the inertia of the steering mechanism 3 and the electric motor M. In consideration of the influence of the inertia moment of the electric motor M and the inertia compensation control unit 22 that generates a correction value for reducing the load, the motor current value is reduced during rotation or the electric motor M is stopped. A damping control unit 23 for generating a correction value for increasing a motor current value in the reverse rotation direction, and an inertia of the steering mechanism 3 and the electric motor M at the time of reverse steering in which the operation direction of the steering wheel 1 is reversed. And a return control unit 24 for reducing a large steering burden caused by the above. The return control unit 24 generates a correction value for reducing the steering load that cannot be compensated for by the normal inertia compensation control by the inertia compensation control unit 22 during the return steering.
[0020]
Furthermore, the correction unit 12 sets the correction values generated by the responsiveness compensation control unit 21, the inertia compensation control unit 22, the damping control unit 23, and the switching control unit 24 to the basic target current value set by the basic target current value setting unit 11. , An adder 25 that corrects the basic target current value.
On the other hand, the controller 10 obtains a torque differential value calculation unit 13 that obtains a torque differential value by time-differentiating the steering torque T detected by the torque sensor 5, and time-differentiates the steering angle θ detected by the steering angle sensor 6. A steering speed calculating unit 14 for calculating a steering speed (steering angular speed), and a steering acceleration calculating unit 15 for calculating a steering acceleration (steering angular acceleration) by further differentiating the steering speed calculated by the steering speed calculating unit 14 with time. have. These function processing portions are realized by program processing executed by a microcomputer provided in the controller 10.
[0021]
The torque differential value obtained by the torque differential value calculation unit 13 is input to the responsiveness compensation control unit 21. The responsiveness compensation control unit 21 is further provided with a vehicle speed V detected by the vehicle speed sensor 7 so that a correction value for responsiveness compensation is obtained based on the torque differential value and the vehicle speed V. It has become. This correction value is determined such that, for example, the larger the torque differential value, the larger the value, and the larger the vehicle speed V, the smaller the value.
[0022]
The steering acceleration calculated by the steering acceleration calculator 15 and the vehicle speed V detected by the vehicle speed sensor 7 are input to the inertia compensation controller 22. For example, the inertia compensation control unit 22 generates a correction value that increases as the steering acceleration increases and decreases as the vehicle speed V increases.
The steering speed calculated by the steering speed calculation unit 14 and the vehicle speed V detected by the vehicle speed sensor 7 are input to the damping control unit 23. The correction value generated by the damping control unit 23 has a sign different from that of the basic target current value set by the basic target current value setting unit 11, and its absolute value increases as the absolute value of the steering speed increases. It is increased as the vehicle speed V increases.
[0023]
The steering control calculated by the steering acceleration calculating unit 15, the vehicle speed V detected by the vehicle speed sensor 7, and the steering torque T detected by the torque sensor 5 are input to the switching control unit 24.
FIG. 2 is a diagram for explaining the operation of the basic target current value setting unit 11, and shows the relationship between the steering torque T and the basic target current value. As the steering torque T, for example, the torque for steering in the right direction has a positive value, and the torque for steering in the left direction has a negative value. Further, the basic target current value is a positive value when the electric motor M is to generate a steering assist force for rightward steering, and when the electric motor M is to generate a steering assist force for leftward steering. Negative value.
[0024]
The basic target current value has a positive value for a positive value of the steering torque, and has a negative value for a negative value of the steering torque. When the steering torque is a minute value in the range of -T1 to T1 (for example, T1 = 0.4 Nm) (torque dead zone), the basic target current value is set to zero. The absolute value of the basic target current value is set to be smaller as the vehicle speed V detected by the vehicle speed sensor 7 is higher. As a result, a large steering assist force can be generated during low-speed running, and the steering assist force can be reduced during high-speed running.
[0025]
FIG. 3 is a block diagram for explaining a configuration example of the switching control unit 24. The turning control unit 24 detects that the steering direction of the steering wheel 1 has been inverted, that is, the inversion detecting unit 31 for detecting that the turning steering has been performed, and the inversion detecting unit 31 detects the inversion of the steering direction. A basic correction value setting unit 32 that sets a basic correction value based on the steering acceleration at the time of the steering operation, a steering speed integration unit 33 that starts integration of the steering speed from the time when the inversion detection unit 31 detects the inversion of the steering direction, A gain setting section for setting a steering speed integrated value sensitive gain in accordance with the integrated value of the steering speed in the steering speed integrating section 33; and a basic correction value setting section for setting the steering speed integrated value sensitive gain set by the gain setting section. And a multiplication unit 35 that generates a correction value for switching control by multiplying the basic correction value set by 32.
[0026]
FIG. 4 is a diagram illustrating an example of the relationship between the steering angle and the steering torque when the steering wheel 1 is operated left and right. When the steering wheel 1 is turned from the left side to the right side and then back, the relationship between the steering angle θ and the steering torque T changes as shown by the arrow in FIG. That is, when the steering wheel 1 is turned from the left side (θ <0) to the right side (θ> 0) through the steering angle midpoint (θ = 0), the relationship between the steering angle θ and the steering torque T is represented by a curve. It looks like LR. Then, when turning back on the right side, the relationship between the steering angle θ and the steering torque T shows a change like a curve LL. When the steering speed is higher, the curve changes as indicated by the curves LR1 and LL1, and the steering load at the time of turning back increases.
[0027]
After a turning point IL at which the steering wheel 1 is turned from the right to the left, the steering angle θ decreases. Therefore, immediately after the start of the turning-back steering (the first quadrant portion of the curve LL), the steering speed becomes a negative value, whereas the steering torque T becomes a positive value, and the signs of the two are different. .
Similarly, after the turning point IR at which the steering wheel 1 is turned from the left to the right, the steering angle θ increases. Therefore, immediately after the start of the reverse steering (the third quadrant portion of the curve LR), the steering speed becomes a positive value, while the steering torque T becomes a negative value, and the signs of the two are different. .
[0028]
Therefore, the reversal detection unit 31 monitors whether the sign of the steering torque T and the sign of the steering speed match or not, and if they do not match, determines that the steering direction has been reversed.
Therefore, the basic correction value setting unit 32 sets the basic correction value based on the steering acceleration at the turning points IL and IR.
Further, the steering speed accumulating unit 33 accumulates the steering speeds after the inversion detecting unit 31 detects the reversal of the steering direction, so that the steering angle change amount from the turning points IL and IR is obtained.
[0029]
FIG. 5 is a diagram illustrating an example of setting a basic correction value by the basic correction value setting unit 32. As shown by a solid line or a two-dot chain line in FIG. 5, the basic correction value setting unit 32 sets a basic correction value having a larger absolute value as the absolute value of the steering acceleration at the time when the reversal of the steering direction is detected. However, when the steering acceleration at the time of detecting the reversal of the steering direction is a predetermined minute value near zero, the basic correction value is set to zero. The sign of the basic correction value is the same as the sign of the steering acceleration. That is, the basic correction value is set so as to increase the steering assist force in the steering direction after being reversed by the reverse steering.
[0030]
The basic correction value may be set so as to change non-linearly with respect to the steering acceleration at the time of inversion detection as shown by a solid line in FIG. May be set to change linearly with respect to the steering acceleration.
Note that the basic correction value setting unit 32 can be configured using a memory that stores a table corresponding to the characteristic as shown in FIG. 5, or can perform a function operation for realizing the characteristic as shown in FIG. Can also be realized.
[0031]
FIG. 6 is a diagram illustrating an example of setting of the steering speed integrated value sensitive gain by the gain setting unit 34. The integrated steering speed value is a positive value if the steering direction after being reversed by the reverse steering is rightward, and a negative value if the steering direction is leftward. The steering speed integrated value sensitive gain takes an upper limit (for example, “1”) when the steering speed integrated value is zero, and decreases with an increase in the absolute value of the steering speed integrated value. When the absolute value reaches a predetermined threshold, it is set to a lower limit (for example, “0”).
[0032]
Of course, the characteristic of the steering speed integrated value sensitive gain may be different between rightward steering and leftward steering.
Since the basic correction value has a sign corresponding to the steering acceleration, the steering speed integrated value sensitive gain is a positive value regardless of the sign of the steering speed integrated value.
The gain setting unit 34 can be configured using a memory that stores a table corresponding to the characteristics as shown in FIG. 6, or allows the microcomputer to execute a function operation for realizing the characteristics as shown in FIG. It can also be realized by:
[0033]
By setting the basic correction value and the steering speed integrated value sensitive gain as described above, when the steering direction is reversed, the larger the steering acceleration at that time, the larger the basic correction value is set, and further, the steering direction is reversed. As the absolute value of the amount of change in the steering angle after this operation (the absolute value of the integrated steering speed value) increases, the steering speed integrated value sensitive gain decreases. As a result, at the time of reverse steering, a larger correction value can be added to the basic target current value as the steering acceleration is larger, and the correction value takes a large value at the beginning of the reverse steering and gradually decreases thereafter. Go. As a result, it is possible to reduce the driver's steering burden during the reverse steering and to realize a natural steering feeling.
[0034]
FIG. 7 is a block diagram illustrating another configuration example of the switching control unit 24. 7, parts corresponding to the respective parts shown in FIG. 3 described above are denoted by the same reference numerals as in FIG.
In this configuration example, the gain to be multiplied by the basic correction value set by the basic correction value setting unit 32 is set by the steering torque sensitive gain setting unit 40 based on the steering torque T. The steering torque sensitive gain set by the steering torque sensitive gain setting unit 40 is multiplied by the basic correction value set by the basic correction value setting unit 32 in the multiplication unit 35. As a result, the correction value for the switching control is obtained. Is required.
[0035]
FIG. 8 is a diagram illustrating a characteristic example of the steering torque sensitive gain set by the steering torque sensitive gain setting unit 40. In this example, as the absolute value of the steering torque T increases, the steering torque responsive gain changes linearly within a range equal to or less than a predetermined upper limit (for example, “1”). However, when the steering torque T takes a value within a predetermined dead zone near zero, the steering torque sensitive gain is set to zero.
Since the basic correction value has a sign corresponding to the steering acceleration, the steering torque sensitive gain is a positive value regardless of the sign of the steering torque.
[0036]
According to such a configuration, immediately after the reversal of the steering direction is detected, since the basic correction value according to the steering acceleration at that time is set and the steering torque T is large, the output is output from the multiplication unit 35. The correction value takes a large value. Then, when the steering torque T gradually decreases after the steering direction is reversed, the correction value decreases accordingly. In this way, it is possible to effectively reduce the driver's steering load at the time of reverse steering, and to realize a natural steering feeling.
[0037]
As described above, one embodiment of the present invention has been described, but the present invention can be embodied in other forms. For example, in the above-described embodiment, the target current value is used as the target drive value for controlling the electric motor M, but the target voltage value and the assist torque target value that is the target value of the steering assist force are used as the target drive value. May be used.
In addition, various design changes can be made within the scope of the matters described in the claims.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an electrical configuration of an electric power steering device according to an embodiment of the present invention.
FIG. 2 is a diagram for explaining the operation of a basic target current value setting unit, and shows a relationship between a steering torque and a basic target current value.
FIG. 3 is a block diagram illustrating a configuration example of a switching control unit.
FIG. 4 is a diagram illustrating an example of a relationship between a steering angle and a steering torque when a steering wheel is operated left and right.
FIG. 5 is a diagram showing a setting example of a basic correction value.
FIG. 6 is a diagram showing a setting example of a steering speed integrated value sensitive gain.
FIG. 7 is a block diagram illustrating another configuration example of the switching control unit;
FIG. 8 is a diagram illustrating a characteristic example of a steering torque sensitive gain.
[Explanation of symbols]
Reference Signs List 1 steering wheel 2 steering shaft 2A input shaft 2B output shaft 3 steering mechanism 4 torsion bar 5 torque sensor 6 steering angle sensor 7 vehicle speed sensor 10 controller 11 basic target current value setting unit 12 correction unit 13 torque differential value calculation unit 14 steering speed calculation Unit 15 steering acceleration calculation unit 20 motor driver 21 responsiveness compensation control unit 22 inertia compensation control unit 23 damping control unit 24 switching control unit 25 addition unit 31 inversion detection unit 32 basic correction value setting unit 33 steering speed integration unit 34 gain setting unit 35 Multiplying unit 40 Steering torque sensitive gain setting unit M Electric motor

Claims (3)

An electric power steering device that transmits a driving force generated by an electric motor controlled according to an operation amount of an operation member to a steering mechanism to assist in steering,
Operation amount detection means for detecting an operation amount of the operation member,
Basic target drive value setting means for setting a basic target drive value that is a basic value of the target drive value of the electric motor according to the operation amount detected by the operation amount detection means;
Operation acceleration detection means for detecting an operation acceleration of the operation member;
Reversal detecting means for detecting reversal of the operation direction of the operation member,
When the inversion of the operation direction of the operation member is detected by the inversion detection means, the basic target drive value set by the basic target drive value setting means is corrected according to the operation acceleration detected by the operation acceleration detection means. Correction means for obtaining a target drive value for controlling the electric motor,
An electric power steering apparatus comprising: a motor driving unit that drives the electric motor based on a target driving value obtained by the correction unit. The correction means,
Basic correction value setting means for setting a basic correction value according to the operation acceleration detected by the operation acceleration detection means when the inversion of the operation direction of the operation member is detected by the inversion detection means;
Operation angle change amount detection means for detecting an operation angle change amount of the operation member from a point in time when the inversion of the operation direction of the operation member is detected by the inversion detection means,
A correction value for correcting the basic target drive value is obtained by correcting the basic correction value set by the basic correction value setting means according to the operation angle change amount detected by the operation angle change amount detection means. Correction value calculating means,
2. The electric power steering apparatus according to claim 1, further comprising: means for correcting the basic target drive value based on the correction value obtained by the correction value calculation means. The correction means,
Basic correction value setting means for setting a basic correction value according to the operation acceleration detected by the operation acceleration detection means when the inversion of the operation direction of the operation member is detected by the inversion detection means;
Correction value calculating means for obtaining a correction value for correcting the basic target drive value by correcting the basic correction value set by the basic correction value setting means in accordance with the operation amount detected by the operation amount detecting means When,
2. The electric power steering apparatus according to claim 1, further comprising: means for correcting the basic target drive value based on the correction value obtained by the correction value calculation means.

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