JP2885309B2 - Electric power steering device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric power steering apparatus in which the power of an electric motor is directly applied to a steering system to reduce the steering force of a driver and to stabilize the behavior of a vehicle.

[0002]

2. Description of the Related Art In an electric power steering apparatus of the prior application, driving of an electric motor is controlled based on a deviation between a signal corresponding to a steering torque and a braking signal corresponding to a steering speed, and power generated by the motor (steering assist force) is generated. In addition to reducing the steering force of the driver by adding it to the steering system, the applicant has provided a damper function to increase or decrease the power of the electric motor in accordance with the steering speed of the steering system to stabilize the vehicle behavior. It has been proposed as Japanese Patent Application No. 5-305625 (hereinafter referred to as a prior application).

An outline of the configuration and operation of the electric power steering apparatus of the prior application will be described. FIG. 10 is an overall configuration diagram of the electric power steering device of the prior application, and FIG. 11 is a block diagram of a main part of the electric power steering device of the prior application.

In FIG. 10, an electric power steering system 1 of the prior application includes a steering wheel 2, a steering shaft 3, a hypoid gear 4, a pinion 5a, and a rack shaft 5.
The steering speed acting on the rack & pinion mechanism 5, the tie rod 6, the front wheel 7 of the steered wheels, the electric motor 8 for generating the steering assist force, and the steering wheel 2 is detected and converted into an electric signal corresponding to the steering speed. A steering speed sensor 9 for outputting the obtained steering speed signal N, a steering torque sensor 10 for detecting a steering torque acting on the steering wheel 2 and outputting a steering torque signal T converted into an electric signal corresponding to the steering torque, a vehicle speed And a control means 1 for driving and controlling the electric motor 8 based on the steering speed signal N, the steering torque signal T, and the vehicle speed signal V, which output a vehicle speed signal V converted into an electric signal corresponding to the vehicle speed.
2, a motor driving means 13 and a motor current detecting means 14 are provided.

When the steering wheel 2 is steered, a steering speed sensor 9 and a steering torque sensor 10 provided on the steering shaft 3 detect the steering speed and the steering torque, respectively, and convert the steering speed signal N and the steering torque into electric signals. The signal T is supplied to the control device 12. In addition, the rotational torque applied to the steering shaft 3 is determined by the rotational force of the pinion 5a via the rack and pinion mechanism 5 as the rack shaft 5b.
And the steering of the front wheel 7 is changed via the tie rod 6.

On the other hand, the vehicle speed sensor 11 detects the speed of the vehicle, converts it into a corresponding electric signal, and sends a vehicle speed signal V to the control means 12. The control means 12 supplies a control voltage signal V _O to the motor driving means 13 based on the steering speed signal N, the steering torque signal T and the vehicle speed signal V, and
3 the control voltage signal is supplied to the motor voltage V _M corresponding to V _O to drive the motor 8, the steering assist torque motor 8 is obtained by boosting via the hypoid gear 4 and the motor torque generated (assist torque) Is applied to the steering shaft 3 to reduce the steering torque applied to the steering wheel 2 and to provide a damper function to increase or decrease the power of the electric motor in accordance with the steering speed of the steering system, thereby stabilizing the vehicle behavior. Have been.

[0007] In FIG. 11, the control means 12 of the electric power steering 1 of the prior application is based on the steering torque signal T from the steering torque sensor 10 and the vehicle speed signal V from the vehicle speed sensor 11, as shown in FIG. steering torque signal of the vehicle speed signal V as a parameter showing (T) - assist current signal (I _a) the steering torque control signal generating means 15 for converting the assist current signal I _a characteristic diagram, a steering speed signal from the steering speed sensor 9 N and the vehicle speed signal V from the vehicle speed sensor 11
(N) -braking current signal ( _ID ) using the vehicle speed signal V shown in FIG.
Steering damper control signal generating means 16, a deviation calculating means 17 calculates the deviation between the assist current signal I _A braking current signal I _D and outputs a target current signal I _MS which converts the braking current signal I _D of the characteristic diagram, the target current signal I _MS and motor current detecting means 14 is an electric motor detected current detection signal I _MD deviation determining means 18 for outputting a deviation signal ΔI deviation by calculating the (value corresponding to the motor current I _M), the deviation signal ΔI Control means 1 for providing a control voltage signal V _O mixed with an ON signal and a PWM signal to the motor driving means 13 based on the
9 is provided.

The steering torque control signal generating means 15 is a ROM
Includes a memory etc., it is saved preset plurality of characteristic data, (a) 1 single assist current signal (I _A) of such a vehicle speed signal V as a parameter as shown in FIG characteristic data of FIG. 12 are combined You.

[0009] Steering damper control signal generating means 16
Has a memory such as a ROM, in which a plurality of preset characteristic data are stored, and one braking current signal ( _ID ) using the vehicle speed signal V as a parameter as shown in FIG.
The characteristic data is synthesized.

The deviation calculating means 17 generates an assist current signal I _A
And the braking current signal I _D deviation (I _A -I _D) a by computing is configured to output the target current signal I _MS for controlling the driving of the motor 8, the target current signal I _MS steering torque signal T,
It is generated so as to match the average driver's steering feeling corresponding to the vehicle speed signal V and the steering speed signal N.

The target current signal _IMS and the motor current detection signal I
_MD is calculated by the deviation determining means 18 the deviation (I _MS -I _MD) is the control voltage signal V _O from the drive control unit 19 based on the deviation signal ΔI is provided to the motor drive unit 13. The drive control means 19 is constituted by control means for PID control or H infinity control. The drive control unit 19 is configured to control deviation signal so that the motor current I _M becomes equal to the target current signal I _MS [Delta] I a (I _MS -I _MD) to 0 (ΔI = 0).

As described above, in the electric power steering apparatus 1 of the prior application, the control means 12 includes the steering torque control signal generating means 15 and the steering damper control signal generating means 16
The provided, each steering torque signal T, corresponds to the steering speed N and the vehicle speed V, the generated assist current signal I _A and the brake current signal I _D to match the steering feeling of the average driver, the brake current signal I _D since the assist current signal I _a correction to the target current signal I _MS is adapted to be obtained as a damper, an electric power steering apparatus 1 that matches the steering feeling of the average driver is provided.

[0013]

Although the electric power steering apparatus of the prior application matches the steering feeling of an average driver, the steering feeling of a sporty driving other than the average driver, for example, has a responsive feeling. An average power steering feeling is not suitable for a driver who likes a ring or a driver who likes a light steering feeling, and an electric power steering device that can obtain a steering feeling that meets the driver's preference is desired.

The present invention has been made to solve such a problem, and an object of the present invention is to provide an electric power steering device capable of setting a standard, sporty, and light steering feeling according to a driver's preference. .

[0015]

In order to solve the above problems, an electric power steering apparatus according to the present invention is provided with a steering characteristic setting switch operable by a driver, and the control means is based on switch information from the steering characteristic setting switch. And changing the characteristics of the steering speed component signal.

Further, in the electric power steering apparatus according to the present invention, the control means is provided with a steering speed component signal selecting means for storing steering speed component signal data having a plurality of characteristics, and corresponds to the switch information of the steering characteristic setting switch. One of the characteristics of the obtained steering speed component signal data is selected.

Further, in the electric power steering apparatus according to the present invention, the control means is provided with a steering torque component signal selecting means for storing steering torque component signal data having a plurality of characteristics, and corresponds to the switch information of the steering characteristic setting switch. One of the characteristics of the obtained steering torque component signal data is selected.

Further, in the electric power steering apparatus according to the present invention, the control means is provided with a steering state detecting means for detecting a going state and a returning state of the steering system,
One of the characteristics of the steering speed component signal data corresponding to the forward state or the return state of the steering system is selected based on the signal detected by the steering state detecting means and the switch information.

Further, the electric power steering apparatus according to the present invention is provided with a vehicle speed sensor for detecting the speed of the vehicle, and generates a steering speed component signal based on the vehicle speed signal and the steering speed signal detected by the vehicle speed sensor. And

[0020]

Since the electric power steering apparatus according to the present invention has the steering characteristic setting switch operable by the driver, the control means changes the characteristic of the steering speed component signal based on the switch information from the steering characteristic setting switch. Therefore, the steering characteristics can be selected.

Further, in the electric power steering apparatus according to the present invention, since the control means includes the steering speed component signal selecting means for storing the steering speed component signal data having a plurality of characteristics, the switch information of the steering characteristic setting switch is provided. One of the characteristics of the steering speed component signal data corresponding to the above can be selected.

Further, in the electric power steering apparatus according to the present invention, since the control means includes the steering torque component signal selecting means for storing steering torque component signal data having a plurality of characteristics, the switch information of the steering characteristic setting switch is provided. One of the characteristics of the steering torque component signal data corresponding to the above can be selected.

In the electric power steering apparatus according to the present invention, since the control means includes the steering state detecting means for detecting the forward and return states of the steering system, the signal and switch information detected by the steering state detecting means are provided. , One of the characteristics of the steering speed component signal data corresponding to the forward state or the return state of the steering system can be selected.

Further, since the electric power steering apparatus according to the present invention is provided with a vehicle speed sensor for detecting the speed of the vehicle, a steering speed component signal can be generated based on the vehicle speed signal and the steering speed signal, and the steering characteristic of the vehicle speed response is obtained. Can be set.

[0025]

Embodiments of the present invention will be described below with reference to the accompanying drawings. In the following description, the steering torque component signal and the steering speed component signal are referred to as an assist signal and a braking signal, respectively, and are represented as an assist current signal and a braking current signal, which are current signals. FIG. 1 is an overall configuration diagram of an electric power steering device according to the present invention. In FIG. 1, the electric power steering apparatus 20 shown in FIG. 10 includes a steering characteristic setting switch 21 and a control means 22 provided with a braking current signal selecting means for storing braking signal data having a plurality of characteristics. Different from the device 1.

FIG. 2 is a block diagram of a main part of the electric power steering apparatus according to the present invention. 2, the electric power steering apparatus 20 includes a steering speed sensor 9, a steering torque sensor 10, a vehicle speed sensor 11, a steering characteristic setting switch 21, a control unit 22, a motor driving unit 13, a motor 8, and a motor current detecting unit 14. .

The steering characteristic setting switch 21 is configured by a driver, for example, a push button switch, a slide switch, a lever switch, or the like. The steering characteristic (standard characteristic, sports characteristic,
Lighting characteristics) are set, and switch information S corresponding to the setting is provided to the control means 22.

The control means 22 is based on a microprocessor and has various arithmetic functions, memory functions and processing functions.
And software such as a program for executing a sequence or an instruction, and includes an assist current signal selecting unit 23, a braking current signal selecting unit 24, a target current setting unit 25, a deviation determining unit 18, and a drive control unit 19.

The assist current signal selecting means 23 has a memory such as a ROM, and is one steering torque signal (T) -assist current signal using a vehicle speed signal V as a parameter as shown in FIG. (I _a) the characteristic data storing, reading the assist current signal data corresponding based on the vehicle speed signal V steering torque signal T and the vehicle speed sensor 11 steering torque sensor 10 detects detects the target assist current signal I _a It is provided to the current setting means 25.

The braking current signal selection means 24 has a memory such as a ROM, stores a plurality of steering speed signal (N) -braking current signal ( _ID ) characteristic data using a vehicle speed signal V set in advance as a parameter, and stores the data. Selects one characteristic from a plurality of characteristics based on the switch information S from the steering characteristic setting switch 21 set by the user, and selects the steering speed signal N and the steering speed signal N detected by the steering speed sensor 9 from the selected characteristic data. Based on the vehicle speed signal V detected by the vehicle speed sensor 11, corresponding braking current signal data is read, and the braking current signal _ID is provided to the target current setting means 25.

FIG. 3 is a block diagram showing a main part of a braking current signal selecting means of the electric power steering apparatus according to the present invention. In this embodiment, two storage means for storing braking current data characteristics are provided, and one of the characteristics stored in each storage means can be selected based on the switch information S. The braking current signal selecting means 24
Data access means 26A and 26B, braking current data storage means 27A and 27B, and braking current switching means 28 are provided. The data access means 26A takes in the steering speed signal N and the vehicle speed signal V, sends an access signal to the braking current data storage means 27A, and outputs the steering speed signal N and the vehicle speed signal V preset in the braking current data storage means 27A. The corresponding braking current data is read, and the braking current signal _ID1 is read.
Is provided to the braking current switching means 28.

The data access means 26B has a steering speed signal N and a vehicle speed signal V similarly to the data access means 26A.
Uptake, sends an access signal to the braking current data storage unit 27B, is set in advance in the braking current data storage unit 27B, reads the braking current data corresponding to the steering speed signal N and the vehicle speed signal V, the brake current signal I _D2 Is provided to the braking current switching means 28.

Braking current data storage means 27A and 27
B includes a memory such as a ROM, and uses a vehicle speed signal V as a parameter, and a braking current signal I for a steering speed signal N.
_D1 and _ID2 data are set in advance, and braking current data _ID1 and _ID2 corresponding to the steering speed signal N and the vehicle speed signal V are output based on the access signals supplied from the data access means 26A and 26B, respectively.

FIG. 4 shows a characteristic diagram of the steering speed signal (N) -braking current signal ( _ID ) using the vehicle speed V as a parameter.
(A) shows a characteristic diagram of the braking current signal I _D1 stored in the braking current data storage means 27A, and (b) shows a braking current signal I _D1 stored in the braking current data storage means 27B.
The characteristic diagram of _D2 is shown. For example, FIG. 7A shows characteristics corresponding to the average driver steering (standard), and the braking current signal _ID1 corresponding to the steering speed signal N is equal to the vehicle speed signal V.
(V _L: low vehicle speed range, V _M: Medium speed region, V _H: high vehicle speed range) are set to increase as increases, high-speed running is set larger the damping in the high vehicle speed region (V _H) When the steering wheel operation is sometimes fast (the steering speed N is large), the steering assist force is small and an appropriate steering force is applied.

On the other hand, FIG. 3B shows characteristics corresponding to a driver who prefers light steering during high-speed running.
In the low vehicle speed region (V _L ), the braking current signal I _D2 corresponding to (a) is substantially equal to the characteristic shown in FIG. By setting the braking current signal I _D2 in the region V _H ) smaller than the braking current signal I _D1 to reduce damping,
The steering characteristics during high-speed running are light and light.

The braking current switching means 28 is constituted by a switch circuit or the like which can be switched by software, and selects the braking current signal I _D1 or the braking current signal I _D2 based on the switch information S for selecting the steering characteristic, and Signal _ID ( _ID1 , _ID2 )
Is provided to the target current setting means 25 of FIG.

The target current setting unit 25 includes a deviation calculation function, the assist current signal I _A supplied from the assist current signal setting unit 23, the braking current signal is provided from the braking current selecting means 24 I _D (I _D1, It calculates a deviation (I _a -I _D) of I _D2), and outputs a target current signal I _MS to the deviation determining means 18.

The deviation determining means 18 is constituted by a subtractor or the like, the target current signal I _MS and the motor current detection signal I _MD deviations from the motor current detecting means 14 provided in the negative feedback loop (I _MS -
I _MD ) and outputs the deviation signal ΔI to the drive control means 19.

As described above, the control means 22 includes the braking current signal selecting means 24, and based on the switch information S corresponding to the steering characteristic set by the driver from the steering characteristic setting switch 21, the steering speed using the vehicle speed signal V as a parameter. two braking current corresponding to the _{N I D (I D1, I} D2) selecting one of the characteristics, so that damping controlling the assist current signal I _a braking current signal I _D1 or braking current signal I _D2, driver For example, an average (standard) steering characteristic or a light steering characteristic can be selected according to the user's preference.

FIG. 5 is a block diagram of a main part of another embodiment of the electric power steering apparatus according to the present invention. In this embodiment, the control means 30 includes an assist current signal selecting means 31 having a plurality of characteristics, a steering state detecting means 32 for detecting a steering state and a return state, and a plurality of steering states corresponding to the steering state and the return state. 2 in that a braking current signal selecting means 33 having the following characteristic is provided.

The assist current signal selecting means 31 includes a memory such as a ROM for storing a plurality of assist current signal I _A characteristic data, the steering torque signal T, from among a plurality of characteristics based on the vehicle speed signal V and the switch information S elect a single characteristic corresponding to the switch information S, it provides an assist current signal I _a which is selected in the target current setting means 25.

The steering state detecting means 32 has a comparator or a comparison function of a software configuration. Based on the direction code F of the steering torque signal T and the direction code G of the steering speed signal N, the direction code F matches the direction code G ( F = G), it is determined that the steering is in the forward state, and the forward state determination signal S _TS . If the direction code F and the direction code G do not match (F ≠ G), it is determined that the steering is in the return state, and the return state is determined. The determination signal S _TR is sent to the braking current signal selection means 33, respectively.

The braking current signal selecting means 33 has a memory such as a ROM for storing a plurality of braking current _ID characteristic data corresponding to the steering going state and the returning state, and includes a steering speed signal N, a vehicle speed signal V and switch information S.
From the plurality of characteristics, one characteristic corresponding to each of the steering forward state and the return state corresponding to the switch information S is selected, and the braking current signal I _{DS in the} selected forward state or the braking current in the selected return state is selected. The signal _IDR is provided to the target current setting means 25.

FIG. 6 shows a block diagram of the assist current signal selecting means and the braking current signal selecting means. The assist current signal selecting unit 31 includes an assist current data access unit 31A, an assist current data storage unit 31B, and an assist current switching unit 31C.

The assist current signal selecting means 31 takes in a steering torque signal T and the vehicle speed signal V, a plurality of access current signals I _A characteristic corresponding to the steering torque signal T and the vehicle speed signal V to access the assist current data storage unit 31B read, for example, outputs an access current signal I _A1, I _A2, I _A3 of the three characteristics which differ corresponding to the same steering torque signal T and the vehicle speed signal V to the assist current switching means 31C.

The assist current data storage means 31B has the RO
For example, access current signal data I _A1 , I _A2 , and I _A3 having three different characteristics corresponding to the same steering torque signal T and vehicle speed signal V set in advance are stored.

The assist current switching means 31C is constituted by a switch (SWA) of software control or software configuration, and switches the switch based on the switch information S from the steering characteristic setting switch 21 corresponding to the steering characteristic set by the driver to access. One of the current signals _IA1 , _IA2 and _IA3 is selected.

The steering torque signal in which the vehicle speed signal V as a parameter in FIG. 7 (T) - showing the assist current signal (I _A) characteristic diagram. For example, FIG. 10A shows a characteristic (access current signal _IA1 characteristic) in which the steering torque is adjusted to the average (standard) driver's preference, and FIG. 10B shows the characteristic of FIG. Characteristics (access current signal _IA2 characteristics), in which the steering torque during high-speed running is set heavy.
FIG. 3C shows a characteristic (access current signal _IA3 characteristic) in which the steering torque during parking and low-speed traveling is set to be heavy, and the steering torque during high-speed traveling is set to be even greater.

The braking current signal selecting means 33 includes a going braking current data accessing means 34A, a going braking current data storing means 34B, and a returning braking current data accessing means 3
5A, return braking current data storage means 35B, braking current switching means 33A and 33B, steering state switching means 3
6 is provided.

Outgoing braking current data access means 34
A, the return braking current data access means 35A takes in the steering speed signal N and the vehicle speed signal V, and accesses the outgoing braking current data storage means 34B and the return braking current data storage means 35B to access the steering speed signal N and the vehicle speed. A plurality of outgoing braking current signal I _DS characteristics and return braking current signal I _DR characteristics corresponding to the signal V are read out, and, for example, three outgoing braking currents corresponding to the same steering speed signal N and vehicle speed signal V are read out. The signals I _DS1 , I _DS2 , I _{DS 3} and the return braking current signals I _DR1 , I _DR2 , I of the three characteristics
_DR3 is output to the braking current switching means 33A and 33B, respectively.

The going braking current data storage means 34B stores R
For example, outgoing braking current signal data I _DS1 , I _DS2 , I _{DS3 having} three different characteristics corresponding to the same steering speed signal N and vehicle speed signal V set in advance and configured with a memory such as OM.
Save.

The return braking current data storage means 35B is also constructed of a memory such as a ROM similarly to the outward braking current data storage means 34B, and corresponds to the same preset steering speed signal N and vehicle speed signal V. One of the time characteristic of the return brake current signal data I _{DR 1,} stores the I _DR2, I _DR3.

[0053] steering speed signal of the vehicle speed signal V as a parameter in FIG. 8 (N) - forward during braking current signal (I _DS) characteristic diagram,
FIG. 9 shows a characteristic diagram of the steering speed signal (N) -return braking current signal ( _IDR ) using the vehicle speed signal V as a parameter. 8 (a) to 8 (c), three outgoing braking current ( _IDS1 , _IDS2 , _IDS3 ) characteristics in FIG. 8 and FIGS. 9 (a) to 9 (c).
By combining the three return braking current ( _IDR1 , _IDR2 , _IDR3 ) characteristics shown in the figure, a steering characteristic according to the driver's preference can be obtained.

For example, the combination of the I _DS1 characteristic and the I _DR1 characteristic is such that when the steering wheel is turned (going), the increase in the going braking current signal I _DS1 is reduced in accordance with the increase in the vehicle speed signal V, and At the time of the returning operation (at the time of returning), the returning braking current signal I _DR1 is set so as to increase and stabilize.

The combination of the I _DS2 characteristic and the I _DR2 characteristic is
When the steering wheel is turned (going), the going braking current signal I _DS2 is increased in response to the increase of the vehicle speed signal V to emphasize the feeling of response, and when returning the steering wheel (going back), the returning braking is performed. Good return characteristics are realized by _reducing the increase of the current signal _IDR2 .

[0056] Furthermore, the combination of I _DS3 characteristics and I _DR3 characteristics, the I _DS3 characteristics substantially equal to the I _DS2 characteristics, I _DR3
By setting the characteristic to be smaller than the _IDS2 characteristic, the return characteristic is strengthened, and a steering characteristic suitable for sport running can be obtained.

The control current switching means 33A, 33B are constituted by switches (SWB, SWC) of software control or software configuration. The control current switching means 33A switches the switch SW (B) based on the switch information S from the steering characteristic setting switch 21 corresponding to the steering characteristic set by the driver, and outputs the in-going braking current signals I _DS1 , I _DS2 , I _DS3. one selected from the supply to the steering state switching means 36 as forward braking current signal I _DS. Control current switching means 3
Similarly, 3B (SWC) switches the switch SW (C) based on the switch information S, selects one of the return braking current signals I _DR1 , I _DR2 , and I _DR3 , and returns the return braking current signal I _{DR3. It} is supplied to the steering state switching means 36 as _DR .

[0058] Steering state switching means 36 is constituted by a switch (SWD) of software control or software configurations, based on the forward state determination signal S _TS or return state determination signal S _TR steering state detecting means 32 detects that shown in FIG. 5 changeover switch SWD Te, in the case of forward state determination signal S _TS is selected forward braking current signals I _DS, whereas in the case of the return state determination signal S _TR to select the braking current signal I _DR when return forward One of the hourly braking current signal I _{DS and the} returning braking current signal I _DR is provided to the target current setting means 25 as the braking current signal _ID .

As described above, the control means 30 includes the assist current signal selecting means 31, the steering state detecting means 32, and the braking current signal selecting means 33, and the plurality of assist current signal setting means 31 set based on the switch information S. with selecting one characteristic from the assist current signal I _a characteristic, the braking current forward braking current signals of a plurality of characteristics set to the signal selecting means 33 I _DS and more characteristics of the return time of braking current signal I _DR braking current signal I _D selected one characteristic respectively, the further forward braking current signal I _DS or return time of braking current signal I _DR by forward state or return state steering state detecting means 32 detects from the
Selected as, assist current signal I _A and the braking current signal I _D
Since the auxiliary steering torque is generated based on the deviation of the steering wheel, it is possible to set the steering characteristics according to the driver's preference including the forward and return states of the steering operation.

[0060] In the embodiment of FIGS. 2 and 5 feeds back the motor current detection signal I _MD detected by the motor current detecting means 14, a deviation signal between the target current signal I _MS and the motor current detection signal I _MD ΔI (= has been configured to drive and control the electric motor 8 on the basis of the I _MS -I _MD), remove the feedback loop may be configured to control an open loop of only the target current signal I _MS. Further, a steering speed sensor for detecting the steering speed of the steering system may be estimated from the rotation speed of the electric motor 8. Further, the present invention can be applied to the invention described in JP-A-61-169368.

[0061]

As described above, the electric power steering apparatus according to the present invention is provided with the steering characteristic setting switch operable by the driver, and the control means controls the steering speed component signal based on the switch information from the steering characteristic setting switch. Can be changed and the steering characteristic can be selected, so that the driver can determine the steering characteristic according to his / her preference.

Further, in the electric power steering apparatus according to the present invention, the control means is provided with a steering speed component signal selecting means for storing steering speed component signal data having a plurality of characteristics, and corresponds to the switch information of the steering characteristic setting switch. Since one of the characteristics of the calculated steering speed component signal data can be selected, it is possible to select a steering characteristic suitable for the driver's preference.

Further, in the electric power steering apparatus according to the present invention, the control means is provided with a steering torque component signal selecting means for storing steering torque component signal data having a plurality of characteristics, and corresponds to the switch information of the steering characteristic setting switch. Since one of the characteristics of the obtained steering torque component signal data can be selected, it is possible to set a fine steering characteristic that meets the driver's preference.

Further, in the electric power steering apparatus according to the present invention, the control means is provided with a steering state detecting means for detecting a going state and a returning state of the steering system,
One of the characteristics of the steering speed component signal data corresponding to the forward state or the return state of the steering system can be selected based on the signal detected by the steering state detecting means and the switch information, so that a finer steering characteristic is set. be able to.

Further, the electric power steering apparatus according to the present invention is provided with a vehicle speed sensor for detecting the speed of the vehicle, and generates a steering speed component signal based on the vehicle speed signal and the steering speed signal. Properties can be set.

Accordingly, it is possible to provide a highly convenient electric power steering apparatus capable of setting fine steering characteristics according to the driver's preference with a single vehicle.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an electric power steering device according to the present invention.

FIG. 2 is a block diagram of a main part of an electric power steering apparatus according to the present invention.

FIG. 3 is a block diagram of a main part of a braking current signal selecting means of the electric power steering device according to the present invention.

FIG. 4 is a steering speed signal (N) using a vehicle speed V as a parameter.
-Characteristic diagram of braking current signal ( _ID )

FIG. 5 is a block diagram of a main part of another embodiment of the electric power steering apparatus according to the present invention.

FIG. 6 is a block diagram of an assist current signal selecting unit and a braking current signal selecting unit;

[7] a steering torque signal and vehicle speed signal V as a parameter (T) - assist current signal (I _A) characteristic diagram

[8] steering speed signal of the vehicle speed signal V as a parameter (N) - forward during braking current signal (I _DS) characteristic diagram

FIG. 9 is a characteristic diagram of a steering speed signal (N) -return braking current signal ( _IDR ) using a vehicle speed signal V as a parameter.

FIG. 10 is an overall configuration diagram of an electric power steering device of the prior application.

FIG. 11 is a block diagram of a main part of the electric power steering device of the prior application.

[12] the steering torque signal (T) - assist current signal (I _A) characteristic view and the steering speed signal (N) - braking current signal (I _D) characteristic diagram

[Explanation of symbols]

1, 20: electric power steering device, 2: steering wheel, 3: steering shaft, 4: hypoid gear, 5: rack and pinion mechanism, 5a: pinion, 5b
... Rack shaft, 6 ... Tie rod, 7 ... Front wheel, 8 ... Electric motor,
9: steering speed sensor, 10: steering torque sensor, 11 ...
Vehicle speed sensors, 12, 22, 30 ... control means, 13 ... motor drive means, 14 ... motor current detection means, 15 ... steering torque control signal generation means, 16 ... steering damper control signal generation means, 17 ... deviation calculation means, 18 ... Deviation determining means, 19 ... Drive control means, 21 ... Steering characteristic setting switch, 23,31 ... Assist current signal selecting means, 24,3
3 ... braking current signal selecting means, 25 ... target current setting means,
26A, 26B ... data access means, 27A, 27B
... braking current data storage means, 28 ... braking current switching means,
31A: Assist current data access means, 31B: Assist current data storage means, 31C: Assist current switching means, 32: Steering state detection means, 33A, 33
B: braking current switching means, 34A: going braking current data access means, 34B: going braking current data storage means, 35A: returning braking current data accessing means, 35
B ... back braking current data storage unit, 36 ... steering state switching means, F, G ... Direction code, I _A ... assist current signal, I _D ... braking current signal, I _DS ... braking current signal forward state, I _DR … Return state braking current signal, I _M … Motor current, I _MD … Motor current detection signal, I _MS … Target current signal, ΔI… Deviation signal, N… Steering speed signal, S _TS … Going state determination signal, S _TR ... return state determination signal, T ... steering torque signal, V ... vehicle speed signal, V _M ... motor voltage, V _O ... control voltage signal.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI B62D 13:00

Claims (5)

(57) [Claims] 1. A steering torque sensor for detecting a steering torque applied to a steering system of a vehicle, a steering speed sensor for detecting a steering speed of the steering system, an electric motor for providing an assist torque to the steering system, and the steering torque. Control means for controlling the driving of the electric motor based on a deviation of a steering torque component signal corresponding to the steering speed and a steering speed component signal corresponding to the steering speed. An electric power steering apparatus, further comprising a switch, wherein the control unit changes a characteristic of the steering speed component signal based on switch information from the steering characteristic setting switch. 2. The steering speed component signal data corresponding to switch information of the steering characteristic setting switch, wherein the control unit includes a steering speed component signal selection unit that stores the steering speed component signal data having a plurality of characteristics. Characteristic 1
The electric power steering apparatus according to claim 1, wherein one of the power steering apparatuses is selected. 3. A steering torque component signal selecting means for storing said steering torque component signal data having a plurality of characteristics in said control means, wherein said steering torque component signal data corresponding to switch information of said steering characteristic setting switch is provided. The electric power steering apparatus according to claim 1, wherein one of the following characteristics is selected. 4. The control means includes a steering state detecting means for detecting a forward state and a return state of a steering system, and based on a signal detected by the steering state detecting means and the switch information, a steering state of the steering system or a switch state. 2. The method according to claim 1, wherein one of the characteristics of the steering speed component signal data corresponding to a return state is selected.
An electric power steering device as described in the above. 5. The vehicle according to claim 1, further comprising a vehicle speed sensor for detecting a speed of the vehicle, wherein the steering speed component signal is generated based on the vehicle speed signal detected by the vehicle speed sensor and the steering speed signal. Electric power steering device.