JPH06191418A - Electric vehicle - Google Patents

Abstract

PURPOSE:To give an alarm that the residual capacity is reduced to a driver by making the auxiliary steering force fed from an electric power steering device different from that by that time, when the residual capacity of a battery power source for running is reduced. And to reduce the power consumption by reducing the auxiliary steering force when the residual capacity is reduced. CONSTITUTION:An electric motor control signal generating means 5A generates an electric motor control signal TK to generate an auxiliary steering force depending on the detecting outputs 2a and 3a of a steering torque detecting means 2 and a steering rotating direction detecting means 3. The residual capacity of a battery power source for running is detected by a running power source residual capacity detecting means 4, and depending on the detecting signal 4a, an auxiliary steering force correcting means 5B corrects the electric motor control signal TK and feeds a corrected control signal TH to an electric motor driving means 6. The auxiliary steering force correcting means 5B corrects the auxiliary steering force to the reducing side corresponding to the reduction of the residual capacity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric vehicle equipped with an electric power steering device, and more particularly to an electric vehicle adapted to inform a driver by a change in steering feeling that the capacity of a driving power source has decreased. Regarding

[0002]

2. Description of the Related Art An electric motor capable of supplying a predetermined auxiliary steering force regardless of fluctuations in the power supply voltage by correcting the control signal of the electric motor based on the power supply voltage supplied to the electric motor that generates the auxiliary steering force. Type power steering device,
The applicant of the present invention has proposed it in JP-A-62-34849.

[0003]

Electric vehicles, particularly those using a lead battery or the like as an energy source, have a practically very short travel distance per charge as compared with conventional gasoline vehicles. On the other hand, if a large number of batteries are installed to extend the mileage, the weight of the vehicle will increase, but considering the recent trend toward easy drive, it is necessary to install a power steering device. It is expected to become mainstream.

Since the electric vehicle has a short mileage per charge, in consideration of return from the destination and emergency evacuation after a considerable amount of electric energy is consumed, the remaining power capacity meter (of a gasoline vehicle) It is not enough to display the amount of remaining energy to the driver by means of a fuel gauge (equivalent to a fuel gauge), and it is better to be able to warn of the decrease in the amount of energy carried by some other means. Also,
When the remaining capacity is low, we want to save energy as much as possible within the range that does not impair the basic functions of the vehicle.

The present invention has been made in order to meet such a demand, and when the remaining capacity of the traveling battery power source becomes small, the auxiliary steering force supplied from the electric power steering device is different from that before. The first purpose is to give a warning to the driver that the remaining capacity is reduced by tightening.
A second object is to reduce the power consumption of the electric power steering device by reducing the auxiliary steering force when the remaining capacity becomes small.

[0006]

In order to solve the above problems, an electric vehicle according to a first aspect of the present invention is directed to a running power source remaining capacity detecting means for detecting the remaining capacity of a running battery power source, and this running power source remaining capacity detection. An auxiliary steering force correction means for correcting the auxiliary steering force by correcting the electric power supplied to the electric motor for generating the auxiliary steering force of the electric power steering device based on the remaining capacity detected by the means. To do.

An electric vehicle according to a second aspect of the present invention is characterized by comprising auxiliary steering force correction means for correcting the auxiliary steering force to the decreasing side when the remaining capacity of the battery power source for traveling decreases.

[0008]

In the electric vehicle according to the present invention, the auxiliary steering force correcting means supplies the auxiliary steering force supplied from the electric power steering device based on the remaining capacity of the traveling battery power source detected by the traveling power source remaining capacity detecting means. To correct. Therefore, since the driver is warned that the remaining capacity is low as a change in the steering force, the warning can be given more reliably than with the visual display means such as the remaining capacity meter.

In the electric vehicle according to the second aspect, the auxiliary steering force is corrected to the decreasing side when the remaining capacity of the traveling secondary battery power source decreases. As a result, the power consumption of the electric power steering device can be reduced.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a block diagram of an essential part of an electric power steering control device for an electric vehicle according to the present invention. This electric power steering apparatus 1 includes a steering torque detecting means 2 for detecting a steering torque of a steering wheel (not shown), a steering rotation direction detecting means 3 for detecting a steering rotation direction, and a secondary battery power source for running an electric vehicle. A running power source remaining capacity detecting means 4 for detecting the remaining capacity; a control means 5;
The electric motor drive means 6 drives an electric motor that generates a steering assist force based on the output of the control means 5.

The running power remaining capacity detecting means 4 is used for running 2
It is configured to detect and output the power supply voltage when power is supplied from the secondary battery power supply to the traveling motor.For example, when charging the traveling power supply during regenerative braking, The detection of the power supply voltage is stopped, and the power supply voltage at the time of power supply to the traveling motor is output.

The control means 5 is a motor control signal generation means 5
A and auxiliary steering force correction means 5B are provided. The electric motor control signal generating means 5A receives the steering torque detection output 2a and the steering rotation direction detection output 3a as input, and refers to a table registered in advance to generate an auxiliary steering force required for the current steering operation from the electric motor. The motor control signal TK for supplying the electric power is output.

The auxiliary steering force correcting means 5B is output from the electric motor control signal generating means 5A when the remaining capacity exceeds a preset capacity based on the detection output 4a of the traveling power remaining capacity detecting means 4. The electric motor control signal TK is supplied to the electric motor drive means 6 as it is, and when the remaining capacity is equal to or less than the preset capacity, the correction control signal TH obtained by performing a predetermined correction on the electric motor control signal TK is output. Configured to do so.

FIG. 2 is a graph showing the correction characteristics of the steering assist force correction means. The horizontal axis represents the remaining capacity of the traveling power source in percentage, and the vertical axis represents the correction coefficient of the electric power supplied to the auxiliary steering force generating electric motor. FIG. 2 shows a plurality of correction characteristic examples in one graph. Characteristic A is such that, when the remaining capacity of the traveling power source becomes less than 40%, for example, the correction coefficient K is decreased in proportion to the decrease of the remaining capacity, so that the steering feeling is increased according to the decrease of the remaining capacity. is there. Characteristic B is for making the steering feel different when the remaining capacity of the driving power supply is 40% or more and less than 40%, characteristic C is for decreasing the correction coefficient K with a gentle curve, and characteristic D is for The correction coefficient K is decreased stepwise in multiple steps in accordance with the decrease in the remaining capacity.

In any of the characteristics, when the remaining capacity of the traveling power source reaches a preset remaining capacity, the electric power supplied to the electric motor for generating the auxiliary steering force is gradually or stepwise reduced,
The range is set so that the steering feeling (auxiliary steering force) does not change abruptly, and the driver can detect a change in the effectiveness of the power steering device (weight of steering wheel operation). Therefore, it is possible to notify the driver of the decrease in the remaining capacity of the power source for traveling without looking at the visual display means such as the remaining capacity meter, and the correction is to reduce the power supplied to the power steering device. Therefore, energy consumption can be suppressed.

FIG. 3 is a sectional view showing a specific structural example of the electric power steering apparatus. In FIG. 3, 1 is an electric power steering apparatus for an electric vehicle, 7 is a steering column, 8 is a stator, and 9 and 10 are an input shaft and an output shaft which are coaxially arranged. The inner end of the input shaft 9 is rotatably supported in the inner end of the output shaft 10 via a bearing 11, while the inner ends of the input shaft 9 are rotated by the torsion bar 1.
2, the input shaft 9 is connected to the bearings 11 and 13,
The output shaft 10 is rotatably supported by bearings 14 and 15, respectively.

Further, a steering rotation direction sensor 16 is provided around the input shaft 9, a steering torque sensor 17 is provided around a fitting portion between the input shaft 9 and the output shaft 10, and a steering torque sensor 17 is provided around the output shaft 10. A control device that drives and controls the electric motor 18 based on the detection signals from the installed electric motor 18 and deceleration mechanism 19, the steering rotation direction sensor 16 and the steering torque detection sensor 17, and the detection signal from the traveling power source remaining amount detection means 4. 20 and 20 are provided.

The steering rotation direction sensor 16 is composed of a DC generator 16a fixed to the outer periphery of the steering column 7. The DC generator 16a has a rotation shaft arranged along the axis of the input shaft 9, and a belt groove 9 formed on the outer periphery of the input shaft 9 corresponding to a pulley 16b attached to the shaft end.
a is formed. This belt groove 9a and pulley 16b
A belt 16c is suspended around the DC power generator 16a, and the DC generator 16a rotates as the input shaft 9 rotates, and a detection signal corresponding to the rotation direction and rotation speed of the input shaft 9 is output.

The steering torque sensor 17 includes a cylindrical movable iron core 17a provided on the outer periphery of the fitting portion of the input shaft 9 and the output shaft 10 so as to be displaceable in the axial direction, and a coil portion 17b fixed to the inner periphery of the steering column. It consists of a differential transformer. The movable iron core 17a is provided with each protrusion 10a of the output shaft 10.
The pin 17e protruding from the
The movable iron core 17a is provided with elongated holes 17g and 17h which are engaged with the pins 17f projectingly provided on the input shaft 9 while being displaced from each other.
When the angular difference between the input shaft 9 and the output shaft 10 in the circumferential direction occurs, the input shaft 9 and the output shaft 10 are displaced in the axial direction due to their engagement relationship, and this displacement amount corresponds to the steering torque applied to the input shaft 9. .

The movable iron core 17a is made of a magnetic material at its central portion, and magnetic material 17i of good conductor is integrally provided at both ends. Further, the movable iron core 17a is biased from the right end by a spring 17j made of a non-magnetic material, and the pins 17e, 17f.
Lost motion due to the gap between the long holes 17g and 17h is prevented. The coil portion 17b arranged around the movable iron core 17a outputs a primary coil 17k to which an AC signal such as a pulse is input and an output signal corresponding to the displacement of the movable iron core 17a, and is arranged on both sides of the primary coil 17k. It is composed of a pair of secondary coils 17l and 17m provided.

Therefore, as the torsion bar 12 is twisted, the angular difference between the input shaft 9 and the output shaft 10 becomes the axial displacement of the movable iron core 17a, which is converted into an electric signal by the secondary coils 17l, 17m and output.

The electric motor 18 includes a stator 8 integrally provided on the steering column 7, at least a pair of magnets 8a fixed to the inner peripheral surface of the stator 8, and the output shaft 1.
The rotor 18a is rotatably arranged around 0, and the brush 18d is radially pressed in the brush holder 18b fixed to the stator 8 by the slip ring 18c.

The rotor 18a includes a bearing 21 and a bearing 22.
A laminated core 18 having a cylindrical shaft 18e rotatably supported by
f, the multiple winding 18g is sequentially and integrally wound, and the magnet 8a
A minute gap is provided on the outer periphery of the iron core 18f.
Further, the cylindrical shaft 18e is provided with a commutator 18h connected to the multiplex winding 18g, and a brush 18d is pressed against it.

The speed reduction mechanism 19 comprises two stages of planetary mechanisms 23 and 24 arranged around the output shaft 10. The planetary mechanism 23 at the front stage is provided on the inner peripheral surface of the case 25, and
5 is a ring roller 27 elastically supported by a spring 26 on a contact portion 25a formed between the stator 5 and the stator 8.
And is engaged with the other end side (left end side in the figure) of the cylinder shaft 18e so as to be movable in the cylinder axis direction and integrally rotatable in the circumferential direction, and friction surfaces 28b ... Are formed on the outer periphery thereof. And the sun roller 28 and the friction surface 29b provided on the outer periphery of the sun roller 28.
Is formed of a planetary roller 29 and a first carrier member 30 that pivotally supports the planetary roller 29.

The planetary mechanism 24 at the latter stage has a sun roller 31 having a friction surface on the outer circumference of a ring roller 27 which is commonly used and a first carrier member 30 which is fitted around the output shaft 5 and which is integrally connected. And a planetary roller 32 interposed between them and having an outer periphery as a friction surface, and this planetary roller 32
And a second carrier member 33 that pivotally supports. This second
The carrier member 33 has an inner end portion attached to a ring body 34 which is attached to the rear end portion of the output shaft 10, and the ring body 34 is attached to a support member 35 attached to the case 25 side by a bearing 15.
The output shaft 10 is rotatably supported via a shaft and is connected to the rear end of the output shaft 10 by spline coupling.

Ring roller 27, sun rollers 28, 3
1 and each planetary roller 29, 32 are made of metal (for example, iron, aluminum, etc.), and each friction surface has a groove having a substantially V-shaped cross section that can be fitted to each other.
Of these, the ring roller 27 and the planetary rollers 29, 3
2 is axially divided at each apex of the substantially V-shaped groove indicated by reference numerals 27b ..., 29b ..., 32b ..., and each of the divided dividing members 27a ..., 29a ..., 32a. It is provided so as to be movable in the axial direction.

In such a configuration, steering torque is applied to the input shaft 9, torque is transmitted from the input shaft 9 to the output shaft 10 via the torsion bar 12, and steering is performed by the steering torque detection sensor 17 and the steering rotation direction sensor 16. When the torque and the steering direction are detected, the control device 20
Signal processing is performed by the brushes, the control voltage is supplied to the multiplex winding 18g via the brush 18d, and the electric motor 18 is rotated in the same direction as the steering torque. Rotor 18 of electric motor 18
The rotation torque of a is reduced by the reduction mechanism 19, and the output shaft 1 is transmitted via the planetary mechanism 23 in the front stage and the planetary mechanism 24 in the rear stage.
Transmitted to 0.

FIG. 4 is a block diagram showing a specific example of the control device. The control device 20 constitutes the control means 5 shown in FIG. 1, and includes an A / D converter 20a and a microcomputer (MCU) 20b. The microcomputer 20b is used to configure the motor control signal generation means 5A and the correction means 5B shown in FIG.
The microcomputer 20b includes an input / output port, a memory, a calculation unit, a control unit, a clock generator, and the like.

This electric vehicle is equipped with a battery power supply 42 for general electric equipment, which is independent of the battery power supply 41 for traveling, and the electric motor 18 for generating the auxiliary steering force is supplied from the battery power supply 42 for general electric equipment. . In addition, the traveling battery power source 41
Is set to be higher than the voltage of the general-purpose electrical equipment battery power source 42, and in this embodiment, the voltage is stepped down via the down converter 46 to supply the voltage to the general-purpose electrical equipment battery power source 42 to drive the traveling battery. From the power supply 41 to the general-purpose electrical equipment battery power supply 4
2 is configured to be rechargeable. Further, the stabilized power supply VCC is supplied from the general electric equipment battery power supply 42 to the control device 20 and the like via the constant voltage circuit 43. The traveling motor drive control unit 45 is configured to adjust the electric power supplied to the traveling motor 44 based on accelerator information, brake information, and the like (not shown).

The power supply voltage of the traveling battery power supply 41 is detected by the traveling power supply remaining amount detecting means 4, and its detection output S5 is A /
It is supplied to the D converter 20a. The traveling power source remaining amount detecting means 4 is composed of a resistance voltage divider or the like.

The running power remaining amount detecting means 4 is
The battery power source voltage is maintained when electric power is being supplied from the traveling power source 41 to the traveling motor 44, and power supply to the traveling motor 44 is stopped, and the traveling motor 4
When the traveling battery power supply 41 is charged from the 4 side by regenerative braking or the like, the signal 4a relating to the held battery power supply voltage may be output.

Further, the control device 2 is provided only when the information relating to the operating state of the electric vehicle is given to the control device 20 and the electric power is supplied from the traveling battery power source 41 to the traveling motor 44.
In the case of 0, the detection output 4a of the traveling power remaining capacity detecting means 4 may be taken in via the A / D converter 20a.

The steering torque detecting means 2 appropriately steers the steering torque sensor 17 shown in FIG. 3 and a signal obtained by dividing the clock pulse CP of the microcomputer 20b into a rectangular wave or sine wave alternating current. Torque sensor 17
Drive unit 2a for supplying to the primary coil 17k of
And each secondary coil 17 corresponding to the displacement of the movable iron core 17a.
Rectifier circuits 2b and 2c for rectifying the respective electric signals obtained from 1 and 17m, and low pass filters for removing a high frequency component contained in the rectified outputs of the rectifier circuits 2b and 2c to obtain a stable DC voltage. (LPF) 2d and 2e.

The steering rotation direction detecting means 3 includes a DC generator 16a which constitutes the steering rotation direction sensor 16 and subtraction circuits 3a and 3b which subtract the output of the DC generator 16a and detect the direction and size thereof. , A low-pass filter 3 for converting each output of each subtraction circuit 3a, 3b into a stable DC voltage
It is composed of c and 3d.

The microcomputer 20b detects the detection outputs S1 and S2 of the steering torque detecting means 2, the detection outputs S3 and S4 of the steering rotation direction detecting means 3, and the remaining power supply for traveling based on a program stored in advance. The detection output S5 of the detection means 4 is fetched as corresponding digital information via the A / D converter 20a, and the processing described later is performed to perform the motor rotation direction designating signals T1, T2 and the PWM signal T.
3 is supplied to the motor driving means 6.

The electric motor driving means 6 is a drive unit 6
a and four semiconductor power switching elements 6b to 6e connected in a two-phase bridge. Drive unit 6
a, for example, when the right rotation is designated based on the motor rotation direction designation signals T1 and T2, drives the switching element 6b into the conductive state and also drives the switching element 6e based on the PWM signal T3. When the left rotation is designated, the switching element 6c is driven to the conductive state and the switching element 6d is driven to switch based on the PWM signal T3, so that the polarity of the current supplied to the electric motor 18 is The electric power is controlled to control the rotation direction of the electric motor 18 and the auxiliary steering force (rotation speed and torque) supplied from the electric motor.

Next, the operation based on the above configuration will be described.
FIG. 5 is a flowchart showing the operation of the control device. When a key switch of an ignition key (not shown) is turned on, power is supplied to the control device 20 and other circuits to start control. First, the microcomputer 20b
Clears the data in each register and RAM in step P1, and sequentially reads the steering torque detection signals S1 and S2 via the A / D converter 20a in step P2 to read S1-S.
2 is calculated, and this is designated as steering torque T.

Since the steering torque sensor 17 is composed of a differential transformer, the detection signals S1 and S2 and the steering torque T have the relationship shown in FIG. In step P3, in order to determine the acting direction of the steering torque T, it is determined whether it is positive or negative. If it is positive or zero, the flag F is set to 0 in step P4 and the process proceeds to step P6. If it is negative, the flag F is set to 1 in step 5 and
Absolute value conversion, that is, processing of T = -T is performed. Here, the flag F indicates the sign of the steering torque T, that is, the acting direction.

In step P6, the contents of the conversion table 1 are read from the memory by using the absolute value of the steering torque T as an address. In the memory, as shown in FIG. 7, the armature current IM of the electric motor 18 corresponding to the absolute value T of the steering torque.
And the resistance RM of the armature winding, the brush, the wiring, and the like, that is, the conversion table 1 that stores the duty conversion value D (T) of RM · IM. Therefore,
In step P7, the contents of the memory corresponding to the address based on the absolute value T of the steering torque, that is, the duty conversion value D (T) of RM / IM is read out, and the flow advances to step P7.

At step P7, the value of the flag F is discriminated so as to give a code to the read duty conversion value D (T). If the flag F is 0, the steering torque is zero or positive, so the duty conversion value D (T) is transferred as it is. If the flag F is 1, the steering torque is negative, so the routine proceeds to step P8, where the duty conversion is performed. The value D (T) is transferred and stored as a negative value, and the process proceeds to step P9.

In step P9, the detection signals S3 and S4 of the steering rotation direction detecting means 3 are sequentially read, S3-S4 are calculated, and this is set as the steering rotation speed S. Here, the detection signals S3 and S4 of the steering rotation direction detecting means 16 and the steering rotation speed S have the relationship shown in FIG.

In step S10, it is determined whether the steering rotational speed S is in the positive or negative direction. If the steering rotation speed S is positive or zero, the flag F is set to 0 in step P11. If the steering rotation speed S is negative, step P1
In step 2, the flag F is set to 1, and absolute value conversion, that is, S = -S, is performed.

In step P13, the contents of the conversion table 2 are read from the memory with the absolute value S of the steering rotation speed as an address. As shown in FIG. 9, in the memory, the induced electromotive force constant Vk of the electric motor 18 is set in order to determine the rotational speed SM of the electric motor 18 corresponding to the absolute value S of the steering rotational speed.
Of the rotational speed SM, that is, a conversion table 2 in which the duty conversion value D (S) of Vk · SM is stored. Therefore, the content of the memory corresponding to the address by the absolute value S of the steering rotation speed, that is, the duty conversion value of the rotation speed SM is read.

In step P14, the value of the flag F is determined in order to give a code to the read duty conversion value D (S). If the flag F is 0, the steering rotation speed is positive or zero, so the duty conversion value D (S) is transferred as it is. If the flag F is 1, the steering rotation speed is negative, so the routine proceeds to step P15. Converted value D
(S) is transferred as a negative value and stored.

Then, in step P16, the steering torque T
Is added to the duty conversion value D (T) based on the steering rotation speed S, and this value is set to TK.

After Step P17, Step P16
A process for correcting the control signal TK obtained in step 1 is performed based on the remaining capacity of the traveling battery power supply 41. First, in step P17, the detection output 4 of the running power remaining capacity detecting means 4 is detected.
a is read via the A / D converter 20a, and then in step P18, the contents of the conversion table 3 are read from the memory using the read value V as an address. In the memory, as shown in FIG.
The correction coefficient K set in advance corresponding to the power supply voltage V of 1 is stored. Then, in step P19, the correction coefficient K is multiplied by the control signal TK obtained in step P16 to make a correction, and the multiplication result signal K · TK is obtained.

In step P20, the sign of the multiplication result signal K · TK is determined in order to determine the acting direction of the auxiliary torque to be output. If the multiplication result signal K · TK is positive or zero, it is further determined in step P21 whether it is positive or zero. If it is zero, the rotation direction control signal T1 is determined in step P22.
And T2 are both set to 0, and if positive, the rotation direction control signal T1 is set to 1 and the rotation direction control signal T2 is set to 0 in step P23, and the rotation direction control signals T1 and T2 are output in step P25. At the same time, the absolute value of the multiplication result signal K · TK is output as the correction control signal TH.

On the other hand, when the value of the multiplication result signal K · TK is negative, the rotation direction control signal T1 is set to 0 and the rotation direction control signal T2 is set to 1 in step P24, and the direction of the steering assist torque is set in step P25. The rotation direction control signals T1 and T2 of the electric motor 18 shown are output, and the correction control signal TH related to the absolute value of the steering assist torque is output and supplied to the electric motor drive means 6.

As shown in FIG. 10, the traveling battery power source 4 is used.
When the remaining capacity of 1 becomes less than the predetermined amount, the correction coefficient K becomes 1
Since it is set to a smaller value, the correction control signal TH becomes a smaller value as the remaining capacity of the traveling battery power source 41 decreases, and the electric power supplied from the electric motor drive control means 6 to the electric motor 18 is decreased. As a result, the auxiliary steering force is reduced.

Therefore, the driver can know that the remaining capacity of the traveling battery power source 41 is decreasing due to the heavy steering operation. Further, since the electric power supplied to the electric motor 18 for generating the steering assist force is reduced as the remaining capacity of the traveling battery power source 41 decreases, the traveling battery power source 41 via the down converter 46 supplies the general electrical equipment battery power source. The power for charging 42 is also reduced, and the power consumption of the traveling battery power source 41 and the general electrical equipment battery power source 42 is reduced.

In this embodiment, the traveling battery power source 41 is used.
Although the configuration for detecting the remaining capacity of the battery power supply by detecting the power supply voltage of is described, the remaining capacity may be detected by detecting the discharge current from the traveling battery power supply 41 and integrating the discharge current. Good. Further, when the traveling battery power supply 41 is charged during regenerative braking or the like, the charged current may be corrected to manage the remaining capacity.

[0052]

As described above, in the electric vehicle according to the first aspect of the invention, the auxiliary steering force of the electric power steering device is made different according to the remaining capacity of the battery power source for traveling, so the battery power source for traveling is set. The remaining capacity can be notified to the driver as a change in the steering force, and the driver can be more surely warned that the remaining capacity has decreased than with a visual display means such as a remaining capacity meter.

In the electric vehicle according to the second aspect, the auxiliary steering force is corrected to the decreasing side when the remaining capacity of the traveling battery power source decreases, so that the basic function of the vehicle is not impaired. The power consumption can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram of an essential part of an electric power steering apparatus for an electric vehicle according to the present invention.

FIG. 2 is a graph showing correction characteristics of auxiliary steering force correction means.

FIG. 3 is a cross-sectional view showing a specific structural example of an electric power steering device.

FIG. 4 is a block configuration diagram showing a specific example of a control device.

FIG. 5 is a flowchart showing the operation of the control device.

FIG. 6 is a graph showing detection characteristics of steering torque detection means.

FIG. 7 is a graph showing a relationship between a steering torque detection value and a duty conversion value.

FIG. 8 is a graph showing the detection characteristics of steering rotation direction detection means.

FIG. 9 is a graph showing a relationship between a steering rotation detection value and a duty conversion value.

FIG. 10 is a graph showing a relationship between a detected voltage value of a battery power source for traveling and a correction coefficient.

[Explanation of symbols]

 1 Electric Power Steering Device 2 Steering Torque Detecting Means 3 Steering Rotation Direction Detecting Means 4 Driving Power Remaining Amount Detecting Means 5 Control Means 5A Electric Motor Control Signal Generating Means 5B Auxiliary Steering Force Correcting Means 6 Electric Motor Driving Means 41 Driving Battery Power TH Correction control signal TK Motor control signal

Claims (2)

[Claims] 1. In an electric vehicle equipped with an electric power steering device, a running power remaining capacity detecting means for detecting a remaining capacity of a running battery power source of the electric vehicle, and a running power remaining capacity detecting means for detecting the remaining capacity. And an auxiliary steering force correction means for correcting the auxiliary steering force by correcting the electric power supplied to the electric motor for generating the auxiliary steering force of the electric power steering device based on the remaining capacity. Automobile. 2. The auxiliary steering force correcting means is configured to correct the auxiliary steering force to a decreasing side when the remaining capacity of the traveling battery power source decreases. Electric car.