JP2016185785A - Electric power steering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology capable of inexpensively reducing a burden of a driver during a vehicle body skidding.SOLUTION: An electric power steering device includes: a basic target current calculating portion which sets a basic target current becoming a base of a target current supplied to an electric motor on the basis of steering torque detected by a torque sensor 109; a basic vehicle body skidding base correcting current which becomes a base of a vehicle body skidding correcting current for correcting the basic target current according to the steering torque detected by the torque sensor; a vehicle body skidding correcting current calculating portion 28 which sets a vehicle body skidding correcting current on the basis of steering difference between an estimated steering angle estimated by difference between rotation speed of left side wheels disposed on the left side of the vehicle and right side wheels disposed on the right side, and a detected steering angle detected by a steering angle sensor 180; and a target current deciding portion which decides a target current on the basis of the basic target current set by the basic target current calculating portion and the vehicle body skidding correcting current set by the vehicle body skidding correcting current calculating portion 28.SELECTED DRAWING: Figure 6

Description

  The present invention relates to an electric power steering apparatus.

In recent years, an electric power steering device that reduces the driver's steering force when steering the vehicle has been proposed with a technology that reduces the driver's fatigue when the vehicle is flowing when the vehicle is traveling on a road surface with a lateral slope. Has been.
For example, the electric power steering apparatus described in Patent Document 1 is configured as follows. That is, in an electric power steering device for a vehicle that controls an assist amount by a steering motor in accordance with a steering torque detected by a steering torque sensor, a yaw rate sensor that detects a yaw rate of the vehicle, and a steering angle that detects a steering angle of a steering wheel A sensor is provided. When the yaw rate detected by the yaw rate sensor is near zero, the steering torque detected by the steering torque sensor is equal to or greater than a predetermined value, and the steering angle detected by the steering angle sensor is equal to or greater than a predetermined value, The assist amount is increased from the normal assist amount.

JP 2007-168617 A

An expensive yaw rate sensor is required to determine whether or not the vehicle is in the steering state for suppressing the vehicle body flow using the yaw rate sensor. Therefore, it is desirable to reduce the burden on the driver when the vehicle body flows without using an expensive yaw rate sensor.
An object of the present invention is to provide an electric power steering device that can reduce a burden on a driver when the vehicle body flows at low cost.

  For this purpose, the present invention provides an electric motor for applying an assisting force for steering a steering wheel of a vehicle, torque detecting means for detecting a steering torque of the steering wheel, and a steering angle which is a rotation angle of the steering wheel. Rudder angle detecting means for detecting, basic target current setting means for setting a basic target current as a base of a target current to be supplied to the electric motor based on the steering torque detected by the torque detecting means, and the torque detecting means A basic correction current that is a basis of a correction current that corrects the basic target current according to the detected steering torque, a rotation speed of a left wheel disposed on the left side of the vehicle, and a rotation speed of a right wheel disposed on the right side The correction current is calculated based on the estimated steering angle estimated based on the difference between the steering angle and the detected steering angle detected by the steering angle detection means. Correction current calculation means for determining, and target current determination means for determining the target current based on the basic target current set by the basic target current setting means and the correction current set by the correction current calculation means, An electric power steering apparatus comprising:

Here, when the steering angle deviation is equal to or less than a predetermined value, the correction current calculation unit may correct the correction current so that the correction current increases as the steering angle deviation increases.
In addition, the correction current calculation means calculates the correction current when the steering direction of the steering wheel obtained based on the steering torque detected by the torque detection means is opposite to the deviation direction of the steering angle deviation. You may correct | amend so that it may become zero.

Further, the correction current calculation means may correct the basic correction current according to the detected steering angle detected by the steering angle detection means.
The correction current calculation unit may correct the basic correction current according to a change speed of the detected steering angle detected by the steering angle detection unit.
Further, the correction current calculation means may correct the basic correction current according to the steering torque detected by the torque detection means.
The correction current calculation means may correct the basic correction current according to a vehicle speed that is a moving speed of the vehicle.

  According to the present invention, it is possible to reduce the burden on the driver when the vehicle body flows at low cost.

It is a figure showing the schematic structure of the electric power steering device concerning an embodiment. It is a schematic block diagram of a control apparatus. It is a schematic block diagram of a control part. It is a schematic block diagram of a basic target current calculation part. It is the schematic of the control map which shows a response | compatibility with steering torque, vehicle speed, and base current. It is a schematic block diagram of a vehicle body flow correction | amendment electric current calculation part. It is the schematic of the control map which shows a response | compatibility with a steering torque and a basic vehicle body flow base correction | amendment electric current. It is a schematic block diagram of a steering angle estimation part. It is the schematic of the control map which shows a response | compatibility with a vehicle speed adjustment coefficient and a vehicle speed. It is the schematic of the control map which shows a response | compatibility with a steering angle deviation gain and the absolute value of a steering angle deviation. It is the schematic of the control map which shows a response | compatibility with a steering angle correction coefficient and the absolute value of a detected steering angle. It is the schematic of the control map which shows a response | compatibility with a steering angular velocity correction coefficient and the absolute value of a steering angular velocity. It is the schematic of the control map which shows a response | compatibility with a torque correction coefficient and the absolute value of steering torque. It is the schematic of the control map which shows a response | compatibility with a vehicle speed correction coefficient and a vehicle speed.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is a diagram illustrating a schematic configuration of an electric power steering apparatus 100 according to an embodiment.
Electric power steering device 100 (hereinafter, also simply referred to as “steering device 100”) is a steering device for arbitrarily changing the traveling direction of a vehicle, and in this embodiment, an automobile as an example of the vehicle. 1 illustrates the configuration applied to 1.

  The steering device 100 includes a wheel-like steering wheel 101 that is operated by a driver to change the traveling direction of the automobile 1, and a steering shaft 102 that is provided integrally with the steering wheel 101. Yes. The steering device 100 includes an upper connecting shaft 103 connected to the steering shaft 102 via a universal joint 103a, and a lower connecting shaft 108 connected to the upper connecting shaft 103 via a universal joint 103b. . The lower connecting shaft 108 rotates in conjunction with the rotation of the steering wheel 101.

  Steering device 100 includes tie rod 104 coupled to each of left front wheel 151 and right front wheel 152 as rolling wheels, and rack shaft 105 coupled to tie rod 104. Further, the steering device 100 includes a pinion 106 a that constitutes a rack and pinion mechanism together with rack teeth 105 a formed on the rack shaft 105. The pinion 106 a is formed at the lower end portion of the pinion shaft 106. The rack shaft 105, the pinion shaft 106, and the like function as a transmission mechanism that transmits the rotational operation force of the steering wheel 101 as the rolling power of the left front wheel 151 and the right front wheel 152. The pinion shaft 106 applies a driving force (rack axial force) for rolling the left front wheel 151 and the right front wheel 152 to the rack shaft 105 that rolls the left front wheel 151 and the right front wheel 152 by rotating.

  The steering device 100 also includes a steering gear box 107 that houses the pinion shaft 106. The pinion shaft 106 is connected to the lower connection shaft 108 via the torsion bar 112 in the steering gear box 107. The steering gear box 107 has a steering torque T applied to the steering wheel 101 based on the relative rotation angle between the lower connecting shaft 108 and the pinion shaft 106, in other words, based on the twist amount of the torsion bar 112. A torque sensor 109 is provided as an example of torque detecting means for detecting the torque.

  The steering device 100 also includes an electric motor 110 supported by the steering gear box 107, and a speed reduction mechanism 111 that reduces the driving force of the electric motor 110 and transmits it to the pinion shaft 106. The speed reduction mechanism 111 includes, for example, a worm wheel (not shown) fixed to the pinion shaft 106, a worm gear (not shown) fixed to the output shaft of the electric motor 110, and the like. The electric motor 110 applies a driving force for rolling the left front wheel 151 and the right front wheel 152 to the rack shaft 105 by applying a rotational driving force to the pinion shaft 106. The electric motor 110 according to the present embodiment is a three-phase brushless motor having a resolver 120 that outputs a rotation angle signal θs linked to a motor rotation angle θm that is the rotation angle of the electric motor 110.

  Further, the steering device 100 includes a steering angle sensor 180 as an example of a steering angle detection unit that detects a steering angle that is a rotation angle of the steering wheel (handle) 101. The steering angle sensor 180 is attached to the steering shaft 102 itself and rotates in synchronization with the steering shaft 102, and a second rotating member (not shown) that rotates in conjunction with the rotation of the first rotating member. And a magnetoresistive element (not shown) for detecting a change in the magnetic field of the magnetized portion fixed to the second rotating member. The steering angle sensor 180 outputs sine wave and cosine wave signals corresponding to the rotation angle of the steering wheel 101.

  In addition, the steering device 100 includes a control device 10 that controls the operation of the electric motor 110. The control device 10 includes a CPU that performs arithmetic processing when controlling the electric motor 110, a ROM that stores programs executed by the CPU, various data, and the like, and a RAM that is used as a working memory of the CPU, and the like. It is equipped with.

  The control device 10 includes a torque signal Td obtained by converting the steering torque T detected by the torque sensor 109 described above into an output signal, and a detected steering angle θa detected by the steering angle sensor 180 converted into an output signal. The steering angle signal θas and the rotation angle signal θs from the resolver 120 are input. The value of the steering torque T is set to be positive when the torsion bar 112 is twisted by rotating the steering wheel 101 leftward from the neutral state where the torsion bar 112 is not twisted. Has been. Further, the value of the detected steering angle θa is set to be positive when the driver rotates the steering wheel 101 in the left direction from the state where the steering wheel 101 is not rotating.

  In addition, the control device 10 includes a vehicle speed sensor that detects a vehicle speed Vc that is a moving speed of the automobile 1 via a network (CAN) that performs communication for sending signals for controlling various devices mounted on the automobile 1. A vehicle speed signal v which is an output signal from 170 is input.

  In addition, an output signal from a wheel speed sensor 190 that detects the rotational speeds of the four wheels arranged on the front, rear, left, and right sides of the automobile 1 is input to the control device 10 via a network (CAN). The wheel speed sensor 190 includes a left front wheel speed sensor 191 (see FIG. 8) that detects the rotational speed of the left front wheel 151 disposed in front of the left side of the automobile 1, and the rotational speed of the right front wheel 152 disposed in front of the right side. And a right front wheel speed sensor 192 (see FIG. 8). Further, the wheel speed sensor 190 detects the rotational speed of the left rear wheel speed sensor 193 (see FIG. 8) that detects the rotational speed of the left rear wheel disposed after the left side, and detects the rotational speed of the right rear wheel disposed after the right side. And a right rear wheel speed sensor 194 (see FIG. 8).

  As will be described later, the steering device 100 configured as described above basically drives the electric motor 110 based on the steering torque T detected by the torque sensor 109, and generates the generated torque of the electric motor 110 as the pinion shaft 106. To communicate. Thereby, the torque generated by the electric motor 110 assists the driver's steering force applied to the steering wheel 101.

Next, the control device 10 will be described.
FIG. 2 is a schematic configuration diagram of the control device 10.
The control device 10 includes a target current calculation unit 20 that calculates (sets) a target current It to be supplied to the electric motor 110, and a control unit 30 that performs feedback control based on the target current It calculated by the target current calculation unit 20. It has.
Further, the control device 10 calculates the motor rotation speed Nm based on the motor rotation angle calculation unit 71 that calculates the motor rotation angle θm of the electric motor 110 and the motor rotation angle θm calculated by the motor rotation angle calculation unit 71. And a motor rotation speed calculation unit 72 for calculating.

  The target current calculation unit 20 is a basic target current setting unit that calculates (sets) a basic target current Itf that is the basis of the target current It supplied to the electric motor 110 based on the torque signal Td and the vehicle speed signal v. A target current calculation unit 27 is provided. The target current calculation unit 20 includes a vehicle body flow correction current calculation unit 28 as an example of a correction current setting unit that calculates (sets) a vehicle body flow correction current Ir that is a current corresponding to the vehicle body flow of the automobile 1. . The target current calculation unit 20 finally determines the target current It based on the basic target current Itf calculated by the basic target current calculation unit 27 and the vehicle body flow correction current Ir calculated by the vehicle body flow correction current calculation unit 28. A target current determining unit 29 is provided as an example of the target current determining means.

Then, the target current calculation unit 20 repeatedly executes the processing described later by the basic target current calculation unit 27, the vehicle body flow correction current calculation unit 28, and the target current determination unit 29 every predetermined time (for example, 4 milliseconds). Thus, the target current It supplied to the electric motor 110 is calculated (set).
The basic target current calculation unit 27, the vehicle body flow correction current calculation unit 28, and the target current determination unit 29 will be described in detail later.

FIG. 3 is a schematic configuration diagram of the control unit 30.
As shown in FIG. 3, the control unit 30 includes a motor drive control unit 31 that controls the operation of the electric motor 110, a motor drive unit 32 that drives the electric motor 110, and an actual current Im that actually flows through the electric motor 110. And a motor current detection unit 33 for detection.
The motor drive control unit 31 is based on a deviation between the target current It finally determined by the target current calculation unit 20 and the actual current Im supplied to the electric motor 110 detected by the motor current detection unit 33. A feedback (F / B) control unit 40 that performs feedback control, and a PWM signal generation unit 60 that generates a PWM (pulse width modulation) signal for PWM driving the electric motor 110.

  The feedback control unit 40 includes a deviation calculating unit 41 for obtaining a deviation between the target current It finally determined by the target current calculating unit 20 and the actual current Im detected by the motor current detecting unit 33, and the deviation is A feedback (F / B) processing unit 42 that performs feedback processing so as to be zero is provided.

The feedback (F / B) processing unit 42 performs feedback control so that the target current It and the actual current Im match. For example, the feedback (F / B) processing unit 42 is proportional to the deviation calculated by the deviation calculating unit 41. Is proportionally processed, integrated by an integral element, and these values are added by an addition operation unit.
The PWM signal generation unit 60 generates a PWM signal for driving the electric motor 110 by PWM (pulse width modulation) based on the output value from the feedback control unit 40, and outputs the generated PWM signal.

The motor drive unit 32 is a so-called inverter, and includes, for example, six independent transistors (FETs) as switching elements. Three of the six transistors are a positive line of a power source, an electric coil of each phase, The other three transistors are connected to the electric coil of each phase and the negative side (ground) line of the power source. Then, the driving of the electric motor 110 is controlled by driving the gates of two transistors selected from the six and switching the transistors.
The motor current detection unit 33 detects the value of the actual current Im flowing through the electric motor 110 from the voltage generated at both ends of the shunt resistor connected to the motor drive unit 32.

The motor rotation angle calculation unit 71 (see FIG. 2) calculates the motor rotation angle θm based on the rotation angle signal θs from the resolver 120.
The motor rotation speed calculation unit 72 (see FIG. 2) calculates the motor rotation speed Nm of the electric motor 110 based on the motor rotation angle θm calculated by the motor rotation angle calculation unit 71.

Next, the basic target current calculation unit 27 of the target current calculation unit 20 will be described in detail.
FIG. 4 is a schematic configuration diagram of the basic target current calculation unit 27.
The basic target current calculation unit 27 calculates a base current calculation unit 21 that calculates a base current Ib that is a base for setting the basic target current Itf, and an inertia compensation current Is that cancels the moment of inertia of the electric motor 110. An inertia compensation current calculation unit 22 and a damper compensation current calculation unit 23 that calculates a damper compensation current Id that limits the rotation of the electric motor 110 are provided. The basic target current calculation unit 27 determines a basic target current Itf based on the values calculated by the base current calculation unit 21, the inertia compensation current calculation unit 22, and the damper compensation current calculation unit 23. 25. In addition, the basic target current calculation unit 27 includes a phase compensation unit 26 that compensates for the phase of the steering torque T detected by the torque sensor 109.
The basic target current calculator 27 receives a torque signal Td, a vehicle speed signal v, a motor rotation speed signal Nms obtained by converting the motor rotation speed Nm into an output signal, and the like.

FIG. 5 is a schematic diagram of a control map showing the correspondence between the steering torque T, the vehicle speed Vc, and the base current Ib.
The base current calculation unit 21 calculates a base current Ib based on the torque signal Ts obtained by phase compensation of the torque signal Td by the phase compensation unit 26 and the vehicle speed signal v from the vehicle speed sensor 170. That is, the base current calculation unit 21 calculates the base current Ib according to the phase-compensated steering torque T and the vehicle speed Vc. The base current calculation unit 21 is, for example, a phase-compensated steering torque T (torque signal Ts), vehicle speed Vc (vehicle speed signal v), and base current that are created in advance based on empirical rules and stored in the ROM. The base current Ib is calculated by substituting the steering torque T (torque signal Ts) and the vehicle speed Vc (vehicle speed signal v) into the control map illustrated in FIG. 5 showing the correspondence with Ib.

  The inertia compensation current calculation unit 22 calculates an inertia compensation current Is for canceling the moment of inertia of the electric motor 110 and the system based on the torque signal Ts and the vehicle speed signal v. That is, the inertia compensation current calculation unit 22 calculates the inertia compensation current Is according to the steering torque T (torque signal Ts) and the vehicle speed Vc (vehicle speed signal v). Note that the inertia compensation current calculation unit 22 generates, for example, the steering torque T (torque signal Ts), the vehicle speed Vc (vehicle speed signal v), and the inertia compensation current Is, which are previously created based on empirical rules and stored in the ROM. The inertia compensation current Is is calculated by substituting the steering torque T (torque signal Ts) and the vehicle speed Vc (vehicle speed signal v) into the control map indicating the correspondence between the two.

  The damper compensation current calculation unit 23 calculates a damper compensation current Id for limiting the rotation of the electric motor 110 based on the torque signal Ts, the vehicle speed signal v, and the motor rotation speed signal Nms of the electric motor 110. That is, the damper compensation current calculation unit 23 performs the damper compensation current according to the steering torque T (torque signal Ts), the vehicle speed Vc (vehicle speed signal v), and the motor rotation speed Nm (motor rotation speed signal Nms) of the electric motor 110. Id is calculated. Note that the damper compensation current calculation unit 23, for example, a steering torque T (torque signal Ts), a vehicle speed Vc (vehicle speed signal v), and a motor rotation speed Nm (prepared based on empirical rules in advance and stored in the ROM). In the control map indicating the correspondence between the motor rotation speed signal Nms) and the damper compensation current Id, the steering torque T (torque signal Ts), the vehicle speed Vc (vehicle speed signal v), and the motor rotation speed Nm (motor rotation speed signal Nms) are displayed. By substituting, the damper compensation current Id is calculated.

  The basic target current determination unit 25 includes a base current Ib calculated by the base current calculation unit 21, an inertia compensation current Is calculated by the inertia compensation current calculation unit 22, and a damper calculated by the damper compensation current calculation unit 23. A basic target current Itf is determined based on the compensation current Id. For example, the basic target current determination unit 25 determines the current obtained by adding the inertia compensation current Is to the base current Ib and subtracting the damper compensation current Id as the basic target current Itf.

<Configuration of Vehicle Body Flow Correction Current Calculation Unit 28>
Next, the vehicle body flow correction current calculation unit 28 will be described in detail.
FIG. 6 is a schematic configuration diagram of the vehicle body flow correction current calculation unit 28.
A vehicle body flow correction current calculation unit 28 calculates a basic vehicle body flow base correction current Irbb that is a base for setting a basic vehicle body flow correction current Irb to be described later based on the steering torque T detected by the torque sensor 109. A vehicle body flow base correction current calculation unit 280 is provided.
Further, the vehicle body flow correction current calculation unit 28 detects the steering angle estimation unit 281 that estimates the steering angle from the difference between the left and right wheel speeds, the estimated steering angle θc estimated by the steering angle estimation unit 281, and the steering angle sensor 180. A steering angle deviation calculating unit 282 for calculating a steering angle deviation Δθ with respect to the detected steering angle θa.

The vehicle body flow correction current calculation unit 28 adjusts the basic vehicle body flow base correction current Irbb calculated by the basic vehicle body flow base correction current calculation unit 280 based on the steering angle deviation Δθ calculated by the steering angle deviation calculation unit 282. Is provided with a steering angle deviation gain setting unit 283 for setting the steering angle deviation gain GΔθ.
The vehicle body flow correction current calculation unit 28 includes a multiplication unit 284 that multiplies the steering torque T detected by the torque sensor 109 and the steering angle deviation Δθ calculated by the steering angle deviation calculation unit 282.
The vehicle body flow correction current calculation unit 28 multiplies the basic vehicle body flow base correction current Irbb calculated by the basic vehicle body flow base correction current calculation unit 280 and the steering angle deviation gain GΔθ set by the steering angle deviation gain setting unit 283. A basic vehicle body flow correction current calculation unit 285 is provided that sets a basic vehicle body flow correction current Irb that is the basis of the vehicle body flow correction current Ir based on the value obtained by multiplication by the unit 284.

The vehicle body flow correction current calculation unit 28 sets a steering angle correction coefficient Kθ for correcting the basic vehicle body flow correction current Irb in accordance with the detected steering angle θa detected by the steering angle sensor 180. A setting unit 286 is provided.
Further, the vehicle body flow correction current calculation unit 28 corrects the basic vehicle body flow correction current Irb in accordance with the steering angular velocity Vθ that is the change speed of the detected steering angle θa detected by the steering angle sensor 180. A steering angular speed correction coefficient setting unit 287 for setting Kvθ is provided.

Further, the vehicle body flow correction current calculation unit 28 includes a torque correction coefficient setting unit 288 that sets a torque correction coefficient Kt for correcting the basic vehicle body flow correction current Irb in accordance with the steering torque T detected by the torque sensor 109. I have.
The vehicle body flow correction current calculation unit 28 includes a vehicle speed correction coefficient setting unit 289 that sets a vehicle speed correction coefficient Kvc for correcting the basic vehicle body flow correction current Irb in accordance with the vehicle speed Vc detected by the vehicle speed sensor 170. ing.

The vehicle body flow correction current calculation unit 28 adds the steering angle correction coefficient Kθ set by the steering angle correction coefficient setting unit 286 to the basic vehicle body flow correction current Irb calculated by the basic vehicle body flow correction current calculation unit 285, and the steering angular speed correction. The temporary vehicle body is obtained by multiplying the steering angular speed correction coefficient Kvθ set by the coefficient setting section 287, the torque correction coefficient Kt set by the torque correction coefficient setting section 288, and the vehicle speed correction coefficient Kvc set by the vehicle speed correction coefficient setting section 289. A provisional vehicle body flow correction current calculation unit 290 that calculates the flow correction current Irf is provided.
Further, the vehicle body flow correction current calculation unit 28 averages a plurality of values of the temporary vehicle body flow correction current Irf calculated by the temporary vehicle body flow correction current calculation unit 290 and outputs the averaged value as the vehicle body flow correction current Ir. An averaging unit 291 is provided.

  The vehicle body flow correction current calculation unit 28 includes a basic vehicle body flow base correction current calculation unit 280, a steering angle estimation unit 281, a steering angle deviation calculation unit 282, a steering angle deviation gain setting unit 283, a multiplication unit 284, and a basic vehicle body flow correction. A current calculation unit 285, a steering angle correction coefficient setting unit 286, a steering angular speed correction coefficient setting unit 287, a torque correction coefficient setting unit 288, a vehicle speed correction coefficient setting unit 289, a temporary vehicle body flow correction current calculation unit 290, and an averaging unit 291 will be described later. The vehicle body flow correction current Ir is calculated (set) by repeatedly executing the processing to be performed every predetermined time (for example, 4 milliseconds).

(Configuration of Basic Body Flow Base Correction Current Calculation Unit 280)
FIG. 7 is a schematic diagram of a control map showing the correspondence between the steering torque T and the basic vehicle body flow base correction current Irbb.
The basic vehicle body flow base correction current calculation unit 280 calculates a basic vehicle body flow base correction current Irbb corresponding to the steering torque T detected by the torque sensor 109. The basic vehicle body flow base correction current calculation unit 280 is exemplified in FIG. 7 showing the correspondence between the steering torque T and the basic vehicle body flow base correction current Irbb, which is created based on an empirical rule and stored in the ROM in advance. The basic vehicle body flow base correction current Irbb is calculated by substituting the steering torque T into the control map.
In FIG. 7, the absolute value of the basic vehicle body flow base correction current Irbb is set to increase as the absolute value | T | of the steering torque T increases.

(Configuration of the rudder angle estimation unit 281)
FIG. 8 is a schematic configuration diagram of the rudder angle estimation unit 281.
The steering angle estimation unit 281 includes a wheel speed difference calculation unit 281a that calculates a wheel speed difference ΔVh between the rotation speed of the wheel disposed on the left side of the automobile 1 and the rotation speed of the wheel disposed on the right side, and a wheel speed difference calculation. A steering angle conversion unit 281b that converts the wheel speed difference ΔVh calculated by the unit 281a into a steering angle.
Further, the steering angle estimation unit 281 sets a vehicle speed adjustment coefficient that sets a vehicle speed adjustment coefficient Kva for adjusting the converted steering angle θe converted by the steering angle conversion unit 281b according to the vehicle speed Vc detected by the vehicle speed sensor 170. A portion 281c is provided.
Further, the steering angle estimation unit 281 calculates the temporary estimated steering angle θcf by multiplying the converted steering angle θe converted by the steering angle conversion unit 281b and the vehicle speed adjustment coefficient Kva set by the vehicle speed adjustment coefficient setting unit 281c. An estimated rudder angle calculation unit 281d is provided.
The rudder angle estimation unit 281 averages a plurality of values of the temporary estimated rudder angle θcf calculated by the temporary estimated rudder angle calculation unit 281d, and outputs an averaged value as the estimated rudder angle θc. The control unit 281e is provided.

  The wheel speed difference calculation unit 281a includes a right front wheel speed Vh2 that is the rotational speed of the right front wheel 152 detected by the right front wheel speed sensor 192 and a right rear wheel (not shown) detected by the right rear wheel speed sensor 194. From the value obtained by adding the right rear wheel speed Vh4 that is the rotational speed, the left front wheel speed Vh1 that is the rotational speed of the left front wheel 151 detected by the left front wheel speed sensor 191 and the left rear wheel speed sensor 193 are detected. The wheel speed difference ΔVh is calculated by subtracting the left rear wheel speed Vh3 which is the rotational speed of the left rear wheel (not shown) (ΔVh = Vh2 + Vh4−Vh1−Vh3).

  The steering angle conversion unit 281b has a correlation between the wheel speed difference ΔVh between the rotational speed of the wheel disposed on the left side of the automobile 1 and the rotational speed of the wheel disposed on the right side and the steering angle in advance. The wheel speed difference ΔVh is converted into a steering angle by multiplying the determined conversion coefficient α by the wheel speed difference ΔVh calculated by the wheel speed difference calculation unit 281a. When the rudder angle converted by the rudder angle conversion unit 281b is the converted rudder angle θe, the converted rudder angle θe = ΔVh × α.

The vehicle speed adjustment coefficient setting unit 281c sets a vehicle speed adjustment coefficient Kva for adjusting the converted steering angle θe converted by the steering angle conversion unit 281b according to the vehicle speed Vc.
FIG. 9 is a schematic diagram of a control map showing the correspondence between the vehicle speed adjustment coefficient Kva and the vehicle speed Vc.
The vehicle speed adjustment coefficient setting unit 281c sets the vehicle speed adjustment coefficient Kva based on the vehicle speed Vc detected by the vehicle speed sensor 170. The vehicle speed adjustment coefficient setting unit 281c, for example, sets the vehicle speed Vc on the control map illustrated in FIG. 9 that shows the correspondence between the vehicle speed adjustment coefficient Kva and the vehicle speed Vc, which is previously created based on an empirical rule and stored in the ROM. By substituting, the vehicle speed adjustment coefficient Kva is calculated. By the multiplication with the vehicle speed adjustment coefficient Kva, the reduction characteristic of the converted steering angle θe due to the wheel speed difference ΔVh in the low speed and high speed ranges is corrected. The vehicle speed adjustment coefficient Kva0 in the low speed and high speed ranges is set in advance to a value larger than 1. It can be exemplified that Kva0 is 5.

The temporary estimated rudder angle calculation unit 281d calculates the temporary estimated rudder angle θcf by multiplying the converted rudder angle θe converted by the rudder angle conversion unit 281b and the vehicle speed adjustment coefficient Kva set by the vehicle speed adjustment coefficient setting unit 281c ( θcf = θe × Kva).
The estimated rudder angle averaging unit 281e averages the values of the past N estimated temporary rudder angles θcf calculated by the temporary estimated rudder angle calculating unit 281d repeatedly executing at predetermined time intervals. . The estimated rudder angle averaging unit 281e can be exemplified as an FIR filter. N can be exemplified as 100.
The steering angle estimation unit 281 configured as described above is such that, for example, when the automobile 1 is traveling on an inclined road surface, the vehicle body is inclined, and the rotational speed of the wheels arranged on the left side of the automobile 1 and the wheels arranged on the right side. The steering angle corresponding to the wheel speed difference ΔVh is estimated in view of the fact that the wheel speed difference ΔVh with respect to the rotation speed of the vehicle is not zero.

(Configuration of Rudder Angle Deviation Calculation Unit 282)
The steering angle deviation calculation unit 282 calculates the steering angle deviation Δθ by subtracting the estimated steering angle θc estimated by the steering angle estimation unit 281 from the detected steering angle θa detected by the steering angle sensor 180 (Δθ = Θa−θc).

(Configuration of Rudder Angle Deviation Gain Setting Unit 283)
FIG. 10 is a schematic diagram of a control map showing the correspondence between the steering angle deviation gain GΔθ and the absolute value | Δθ | of the steering angle deviation Δθ.
The steering angle deviation gain setting unit 283 sets the steering angle deviation gain GΔθ based on the steering angle deviation Δθ calculated by the steering angle deviation calculation unit 282. The rudder angle deviation gain setting unit 283 calculates the absolute value | Δθ | of the rudder angle deviation Δθ and, for example, the rudder angle deviation gain GΔθ and the rudder angle, which are previously created based on empirical rules and stored in the ROM. The steering angle deviation gain GΔθ is calculated by substituting the absolute value | Δθ | of the steering angle deviation Δθ into the control map illustrated in FIG. 10 showing the correspondence with the absolute value | Δθ | of the deviation Δθ.

  In FIG. 10, when the absolute value | Δθ | of the steering angle deviation Δθ is smaller than a predetermined first reference steering angle deviation Δθ1, the steering angle increases as the absolute value | Δθ | of the steering angle deviation Δθ increases. The deviation gain GΔθ is set to gradually increase from zero. When the absolute value | Δθ | of the steering angle deviation Δθ is larger than a predetermined second reference steering angle deviation Δθ2, the steering angle deviation gain GΔθ is set to 1. When the absolute value | Δθ | of the steering angle deviation Δθ is equal to or greater than the first reference steering angle deviation Δθ1 and equal to or smaller than the second reference steering angle deviation Δθ2, the steering angle deviation gain GΔθ is equal to the first steering angle deviation gain GΔθ. The reference steering angle deviation Δθ1 is set so as to gradually decrease from the value when the reference steering angle deviation Δθ1 is reached. In the region where the absolute value | Δθ | of the steering angle deviation Δθ is smaller than the first reference steering angle deviation Δθ1, the absolute value | Δθ | when the steering angle deviation gain GΔθ is 1 is the third reference steering angle. Assuming that the deviation is Δθ3, in FIG. 10, when the absolute value | Δθ | is less than the third reference steering angle deviation Δθ3, the steering angle deviation gain GΔθ is less than 1, and the absolute value | Δθ | is the third reference steering angle deviation Δθ3. In this case, the steering angle deviation gain GΔθ is set to be 1 or more.

(Configuration of Multiplication Unit 284)
The multiplier 284 multiplies the steering torque T detected by the torque sensor 109 and the steering angle deviation Δθ calculated by the steering angle deviation calculator 282.
The multiplication unit 284 multiplies the steering torque T and the steering angle deviation Δθ so that the steering direction in which the steering torque T is applied and the deviation direction of the steering angle deviation Δθ obtained by subtracting the estimated steering angle θc from the detected steering angle θa. The sign of the value obtained by multiplication is determined according to (the detected steering angle θa> the estimated steering angle θc is positive, the detected steering angle θa <the estimated steering angle θc is negative). For example, when the steering direction and the deviation direction have the same sign, the sign of the value obtained by multiplication by the multiplication unit 284 is positive, and when the steering direction and the deviation direction have different signs, the multiplication unit 284 The sign of the value obtained by multiplying is negative.

(Configuration of basic vehicle body flow correction current calculation unit 285)
When the value calculated by the multiplication unit 284 is positive, that is, when the steering direction and the deviation direction have the same sign, the basic vehicle body flow correction current calculation unit 285 calculates the basic vehicle body flow correction current Irb as the basic vehicle body flow correction current Irb. The basic vehicle body flow base correction current Irbb calculated by the flow base correction current calculation unit 280 is set to a value obtained by multiplying the steering angle deviation gain GΔθ set by the steering angle deviation gain setting unit 283. On the other hand, the basic vehicle body flow correction current calculation unit 285 sets the basic vehicle body flow correction current Irb to zero when the value calculated by the multiplication unit 284 is negative, that is, when the steering direction and the deviation direction have different signs. Set to.
This is because when the steering direction and the deviation direction have the same sign, the vehicle body is flowing, and it is considered that an assist force for suppressing the vehicle body flow is necessary. This is because the driver is steered for turning and the like, and it is considered that the assist force for suppressing the vehicle body flow is unnecessary. In other words, it is for preventing unnecessary assist force from being applied due to erroneous determination.

(Configuration of rudder angle correction coefficient setting unit 286)
The steering angle correction coefficient setting unit 286 sets a steering angle correction coefficient Kθ for correcting the basic vehicle body flow correction current Irb calculated by the basic vehicle body flow correction current calculation unit 285 according to the detected steering angle θa. To do.
FIG. 11 is a schematic diagram of a control map showing the correspondence between the steering angle correction coefficient Kθ and the absolute value | θa | of the detected steering angle θa.
The steering angle correction coefficient setting unit 286 sets the steering angle correction coefficient Kθ based on the detected steering angle θa detected by the steering angle sensor 180. The steering angle correction coefficient setting unit 286, for example, in the control map illustrated in FIG. 11 showing the correspondence between the steering angle correction coefficient Kθ and the detected steering angle θa, which is created based on an empirical rule and stored in the ROM in advance. Then, the steering angle correction coefficient Kθ is calculated by substituting the absolute value | θa | of the detected steering angle θa.

  The steering angle correction coefficient Kθ is set so that the vehicle body flow correction current Ir becomes small when the absolute value of the rotation angle of the steering wheel 101 by the driver is larger than a predetermined reference steering angle θ0. That is, ideally, when the absolute value | θa | of the detected steering angle θa is equal to or smaller than the reference steering angle θ0, the steering angle correction coefficient Kθ is 1, and the absolute value | θa | of the detected steering angle θa is the reference steering angle. When the angle is larger than θ0, the steering angle correction coefficient Kθ is set to zero after gradually decreasing from 1 to zero. This is because when the absolute value | θa | of the detected steering angle θa is larger than the reference steering angle θ0, it is considered that the driver is intentionally rotating the steering wheel 101 to turn the automobile 1. This is to prevent the operation of the driver from being hindered. As shown in FIG. 11, when the absolute value | θa | of the detected steering angle θa is near the reference steering angle θ0, the steering angle correction coefficient Kθ increases as the absolute value | θa | of the detected steering angle θa increases. When the steering angle correction coefficient Kθ is set to gradually decrease from 1, and the absolute value | θa | of the detected steering angle θa increases, the steering angle correction coefficient Kθ gradually approaches zero. Is set to

(Configuration of rudder angular velocity correction coefficient setting unit 287)
The rudder angular velocity correction coefficient setting unit 287 calculates the rudder angular velocity Vθ by differentiating the detected rudder angle θa detected by the rudder angle sensor 180, and the basic vehicle body calculated by the basic vehicle body flow correction current calculation unit 285. A steering angular velocity correction coefficient Kvθ is set for correcting the flow correction current Irb in accordance with the steering angular velocity Vθ.
FIG. 12 is a schematic diagram of a control map showing the correspondence between the steering angular velocity correction coefficient Kvθ and the absolute value | Vθ | of the steering angular velocity Vθ.
The steering angular speed correction coefficient setting unit 287 sets the steering angular speed correction coefficient Kvθ based on the calculated steering angular speed Vθ. The steering angular velocity correction coefficient setting unit 287 is shown in FIG. 12, for example, showing the correspondence between the steering angular velocity correction coefficient Kvθ and the absolute value | Vθ | The steering angular velocity correction coefficient Kvθ is calculated by substituting the absolute value | Vθ | of the calculated steering angular velocity Vθ into the illustrated control map.

  The steering angular velocity correction coefficient Kvθ is set so that the vehicle body flow correction current Ir becomes small when the absolute value of the rotational speed of the steering wheel 101 by the driver is larger than a predetermined reference steering angular velocity Vθ0. That is, ideally, when the absolute value | Vθ | of the steering angular velocity Vθ is equal to or less than the reference steering angular velocity Vθ0, the steering angular velocity correction coefficient Kvθ is 1, and the absolute value | Vθ | of the steering angular velocity Vθ is the reference steering angular velocity Vθ0. If larger, the steering angular speed correction coefficient Kvθ is gradually reduced from 1 to zero and then set to zero. This is because when the absolute value | Vθ | of the steering angular velocity Vθ is larger than the reference steering angular velocity Vθ0, it is considered that the driver intentionally rotates the steering wheel 101 to turn the automobile 1. This is so as not to hinder the operation of the person. As shown in FIG. 12, when the absolute value | Vθ | of the steering angular velocity Vθ is near the reference steering angular velocity Vθ0, the steering angular velocity correction coefficient Kvθ is increased from 1 as the absolute value | Vθ | of the steering angular velocity Vθ increases. When the steering angular speed correction coefficient Kvθ is near zero, the steering angular speed correction coefficient Kvθ is gradually set closer to zero as the absolute value | Vθ | of the steering angular speed Vθ increases. ing.

(Configuration of torque correction coefficient setting unit 288)
The torque correction coefficient setting unit 288 sets a torque correction coefficient Kt for correcting the basic vehicle body flow correction current Irb calculated by the basic vehicle body flow correction current calculation unit 285 according to the steering torque T.
FIG. 13 is a schematic diagram of a control map showing the correspondence between the torque correction coefficient Kt and the absolute value | T | of the steering torque T.
The torque correction coefficient setting unit 288 sets a torque correction coefficient Kt based on the steering torque T detected by the torque sensor 109. For example, the torque correction coefficient setting unit 288 is illustrated in FIG. 13 showing the correspondence between the torque correction coefficient Kt and the absolute value | T | of the steering torque T, which is previously created based on empirical rules and stored in the ROM. The torque correction coefficient Kt is calculated by substituting the absolute value | T | of the steering torque T into the control map.

  The torque correction coefficient Kt is set so that the vehicle body flow correction current Ir becomes smaller when the operation load on the steering wheel 101 by the driver is larger than a predetermined reference torque T0. That is, ideally, when the absolute value | T | of the steering torque T is less than or equal to the reference torque T0, the torque correction coefficient Kt is 1, and the absolute value | T | of the steering torque T is greater than the reference torque T0. The torque correction coefficient Kt is set to zero after gradually decreasing from 1 to zero. This is because when the absolute value | T | of the steering torque T is larger than the reference torque T0, it is considered that the driver is intentionally rotating the steering wheel 101 to turn the automobile 1. This is so as not to disturb the operation. As shown in FIG. 13, when the absolute value | T | of the steering torque T is near the reference torque T0, the torque correction coefficient Kt is set to gradually decrease from 1 as the steering torque T increases. When the torque correction coefficient Kt is near zero, the torque correction coefficient Kt is set to gradually approach zero as the absolute value | T | of the steering torque T increases.

(Configuration of vehicle speed correction coefficient setting unit 289)
The vehicle speed correction coefficient setting unit 289 sets a vehicle speed correction coefficient Kvc for correcting the basic vehicle body flow correction current Irb calculated by the basic vehicle body flow correction current calculation unit 285 according to the vehicle speed Vc.
FIG. 14 is a schematic diagram of a control map showing the correspondence between the vehicle speed correction coefficient Kvc and the vehicle speed Vc.
The vehicle speed correction coefficient setting unit 289 sets a vehicle speed correction coefficient Kvc based on the vehicle speed Vc detected by the vehicle speed sensor 170. The vehicle speed correction coefficient setting unit 289, for example, sets the vehicle speed Vc on the control map illustrated in FIG. 14 that shows the correspondence between the vehicle speed correction coefficient Kvc and the vehicle speed Vc, which is previously created based on an empirical rule and stored in the ROM. By substituting, the vehicle speed correction coefficient Kvc is calculated. In FIG. 14, the vehicle speed correction coefficient Kvc is set so that the vehicle body flow correction current Ir becomes small when the automobile 1 is low speed and high speed.

(Configuration of Temporary Vehicle Body Flow Correction Current Calculation Unit 290)
The temporary vehicle body flow correction current calculation unit 290 includes a basic vehicle body flow correction current Irb calculated by the basic vehicle body flow correction current calculation unit 285, a steering angle correction coefficient Kθ set by the steering angle correction coefficient setting unit 286, and a steering angular velocity correction coefficient. The provisional vehicle body flow is obtained by multiplying the steering angular velocity correction coefficient Kvθ calculated by the setting unit 287, the torque correction coefficient Kt set by the torque correction coefficient setting unit 288, and the vehicle speed correction coefficient Kvc set by the vehicle speed correction coefficient setting unit 289. The correction current Irf is determined (Irf = Irb × Kθ × Kvθ × Kt × Kvc).

(Configuration of averaging unit 291)
The averaging unit 291 averages values for the past N vehicle body flow correction currents Irf calculated by the temporary vehicle body flow correction current calculation unit 290 repeatedly executed at predetermined time intervals. The converted value is output as the vehicle body flow correction current Ir. The averaging unit 291 can be exemplified as an FIR filter. N can be exemplified as 100.

  In the vehicle body flow correction current calculation unit 28 configured as described above, the steering angle estimation unit 281 estimates the steering angle corresponding to the wheel speed difference ΔVh, and the steering angle deviation calculation unit 282 detects the steering angle sensor 180. A rudder angle deviation Δθ between the detected rudder angle θa and the estimated rudder angle θc is calculated. This steering angle deviation Δθ is considered to correspond to the steering angle that is actually operated and rotated by the driver to travel straight on an inclined road surface, for example. In other words, it is considered that the driver is applying a force to rotate the steering wheel 101 by a considerable amount of the steering angle deviation Δθ. In view of such matters, the basic vehicle body flow base correction current Irbb calculated by the basic vehicle body flow base correction current calculation unit 280 so that the vehicle body flow correction current Ir becomes a current amount that reduces the driver load corresponding to the steering angle deviation Δθ. Is adjusted with a steering angle deviation gain GΔθ determined based on the steering angle deviation Δθ.

Here, in FIG. 10, when the absolute value | Δθ | of the steering angle deviation Δθ is less than the third reference steering angle deviation Δθ3, the steering angle deviation gain GΔθ is set to be less than 1. This is because in a small region where the absolute value | Δθ | of the steering angle deviation Δθ is less than the third reference steering angle deviation Δθ3, the steering angle deviation Δθ may occur due to noise included in output values from various sensors. In such a case, it is not appropriate to set the vehicle body flow correction current Ir.
On the other hand, the steering angle deviation gain GΔθ is set to 1 in a region where the absolute value | Δθ | of the steering angle deviation Δθ is larger than the second reference steering angle deviation Δθ2. This is because in a region where the absolute value | Δθ | is larger than the second reference steering angle deviation Δθ2, there is a high possibility that the driver is turning the steering wheel 101 to turn, but the steering angle deviation gain cannot be determined. This is because the correction using various correction coefficients is left to the correction if it is necessary to perform the correction without performing the adjustment with GΔθ.
In the region where the absolute value | Δθ | of the steering angle deviation Δθ is larger than the third reference steering angle deviation Δθ3 and smaller than the second reference steering angle deviation Δθ2, the steering angle deviation gain GΔθ is set larger than 1. In the region where the absolute value | Δθ | is larger than the third reference rudder angle deviation Δθ3 and smaller than the second reference rudder angle deviation Δθ2, it is possible that the driver keeps the steering by applying a force smaller than the force required for turning. The basic vehicle body flow base correction current Irbb is likely to be insufficient with the basic vehicle body flow base correction current Irbb corresponding to the steering torque T detected by the torque sensor 109. This is to amplify.

Further, in the vehicle body flow correction current calculation unit 28 according to the present embodiment, the averaging unit 291 averages the past N values of the provisional vehicle body flow correction current Irf from the current time, so that the torque sensor 109 and the like The noise of the output signals from various sensors is removed to improve the signal resolution.
Further, in the vehicle body flow correction current calculating unit 28 according to the present embodiment, the estimated rudder angle averaging unit 281e averages the past N values of the temporary estimated rudder angle θcf from the current time point, whereby the wheel speed sensor The noise of the output signal from 190 is removed to improve the signal resolution.
Further, in the vehicle body flow correction current calculation unit 28 according to the present embodiment, a basic vehicle body flow correction current calculation unit using the steering angle correction coefficient Kθ, the steering angular speed correction coefficient Kvθ, the torque correction coefficient Kt, the vehicle speed correction coefficient Kvc, and the like. The basic vehicle body flow correction current Irb calculated at 285 is corrected to determine the temporary vehicle body flow correction current Irf. This prevents the driver's operation from being obstructed when the driver is intentionally turning the steering wheel 101 to turn the automobile 1.

  Then, the target current determination unit 29 according to the present embodiment adds the basic target current Itf calculated by the basic target current calculation unit 27 and the vehicle body flow correction current Ir calculated by the vehicle body flow correction current calculation unit 28. Is determined as the final target current It.

  In the target current calculation unit 20 configured as described above, even when the driver needs a load associated with the vehicle body flow, for example, when the vehicle travels straight on an inclined road surface, the electric motor 110 loads the load associated with the vehicle body flow. Since it assists, a driver | operator's burden can be eased. That is, for example, in a case where the vehicle body flow correction current calculation unit 28 is not provided, such as when the vehicle travels straight on an inclined road surface, in a situation where the driver must continue to hold the steering by applying force to the steering wheel 101. In addition, since the vehicle body flow correction current Ir is added to the target current It, the electric motor 110 assists the force required for the steering. Further, if the force is required for turning (left turn or right turn), as shown in FIG. 5, the steering torque T is such that the absolute value of the base current Ib is greater than zero, so the assist force is applied to the electric motor 110 by the basic target current Itf. Arise. In the target current calculation unit 20 according to the present embodiment, a scene in which the steering must be maintained by applying a force smaller than the force required for turning, such as the region of the steering torque T where the base current Ib is zero. However, since the vehicle body flow correction current Ir is added to the target current It, the burden on the driver can be reduced.

  In the vehicle body flow correction current calculation unit 28 according to the present embodiment, based on the left-right difference in the rotational speed of the wheel detected by the wheel speed sensor 190 provided in the automobile 1 for use in conventional ABS or the like. The vehicle body flow correction current Ir is determined by grasping the vehicle body flow. Therefore, it is not necessary to separately provide a yaw rate sensor to grasp the vehicle body flow. Therefore, according to the steering device 100 according to the present embodiment, it is possible to reduce the burden on the driver when the vehicle body flows at low cost.

  In the embodiment described above, the basic vehicle body flow correction current Irb calculated by the basic vehicle body flow correction current calculation unit 285 is used as the steering angle correction coefficient Kθ, the steering angular speed correction coefficient Kvθ, the torque correction coefficient Kt, and the vehicle speed correction. Although correction is performed using the coefficient Kvc, the present invention is not particularly limited to such a mode. The temporary vehicle body flow correction current calculation unit 290 of the vehicle body flow correction current calculation unit 28 includes the basic vehicle body flow correction current Irb calculated by the basic vehicle body flow correction current calculation unit 285, the steering angle correction coefficient Kθ, the steering angular speed correction coefficient Kvθ, and the torque. A value obtained by multiplying at least one of the correction coefficient Kt and the vehicle speed correction coefficient Kvc may be determined as the temporary vehicle body flow correction current Irf.

DESCRIPTION OF SYMBOLS 10 ... Control apparatus, 20 ... Target current calculation part, 21 ... Base current calculation part, 27 ... Basic target current calculation part, 28 ... Body flow correction current calculation part, 29 ... Target current determination part, 30 ... Control part, 100 ... Electric power steering device 110 110 Electric motor 281 Steering angle estimation unit 282 Steering angle deviation calculation unit 283 Steering angle deviation gain setting unit 284 Multiplication unit 285 Basic flow correction current calculation unit 286 ... Steering angle correction coefficient setting unit, 287 ... Steering angular velocity correction coefficient setting part, 288 ... Torque correction coefficient setting part, 289 ... Vehicle speed correction coefficient setting part, 290 ... Temporary vehicle body flow correction current calculation part, 291 ... Averaging part

Claims (7)

An electric motor for applying an assisting force to the steering wheel of the vehicle;
Torque detecting means for detecting a steering torque of the steering wheel;
Rudder angle detecting means for detecting a rudder angle which is a rotation angle of the steering wheel;
Basic target current setting means for setting a basic target current serving as a base of a target current supplied to the electric motor based on the steering torque detected by the torque detection means;
A basic correction current that is the basis of a correction current that corrects the basic target current according to the steering torque detected by the torque detection means, the rotational speed of the left wheel arranged on the left side of the vehicle, and the right side arranged on the right side Correction current calculation means for setting the correction current based on the estimated steering angle estimated based on the difference between the rotational speed of the wheel and the detected steering angle detected by the steering angle detection means;
Target current determining means for determining the target current based on the basic target current set by the basic target current setting means and the correction current set by the correction current calculation means;
An electric power steering apparatus comprising: The correction current calculation means corrects the correction current so that the correction current increases as the steering angle deviation increases when the steering angle deviation is equal to or less than a predetermined value. The electric power steering device described in 1. The correction current calculation means determines that the correction current is zero when the steering direction of the steering wheel obtained based on the steering torque detected by the torque detection means is opposite to the deviation direction of the steering angle deviation. It correct | amends so that it may become. The electric power steering apparatus of Claim 1 or 2 characterized by the above-mentioned. The electric power steering according to any one of claims 1 to 3, wherein the correction current calculation means corrects the basic correction current in accordance with the detected steering angle detected by the steering angle detection means. apparatus. The said correction | amendment electric current calculation means correct | amends the said basic correction electric current according to the change speed of the said detected steering angle detected by the said steering angle detection means, The any one of Claim 1 to 4 characterized by the above-mentioned. Electric power steering device. 6. The electric power steering apparatus according to claim 1, wherein the correction current calculation unit corrects the basic correction current in accordance with a steering torque detected by the torque detection unit. The electric power steering apparatus according to any one of claims 1 to 6, wherein the correction current calculation unit corrects the basic correction current according to a vehicle speed that is a moving speed of the vehicle.

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