JP2000255442A - Cooperative control device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately carry out the operation inhibition of motor-driven power steering equipment in a cooperative control device used for a vehicle and reducing a torque steering phenomenon by applying cooperative control to driving force.braking force distributing equipment and motor-driven power steering equipment. SOLUTION: A first electronic control unit U1 enumerates a current correction value ΔI for reducing a torque steering phenomenon and applies the current correction value ΔI to a second electronic control unit U2. The second electronic control unit U2 drives a motor 27 in motor-driven power steering equipment, using a correction target current IMS obtained by correcting a target current IMS, using correction value ΔI. A driving inhibition determining means M12 receiving a correction motor real current IM' obtained by correcting a motor real current IM, using the current correction value ΔI determines development of abnormality in a control system when the motor-driven power steering equipment is in an assistance inhibition region in which are direction of the correction motor real current IM' and that of steering torque TQ are in the reverse directions, and inhibits the driving of a motor 27.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving force / braking force distribution device for distributing a driving force or a braking force between left and right wheels or between front and rear wheels, and an electric power steering device for applying a steering assist torque to a steering system. The present invention also relates to a cooperative control device for a vehicle, which further comprises

[0002]

2. Description of the Related Art A yaw in a turning direction is provided by making a ratio of distributing a driving force of an engine to left and right driving wheels variable and increasing a driving force distributed to a turning outer wheel and reducing a driving force distributed to a turning inner wheel. Techniques for increasing the turning performance by generating a moment are known. In a vehicle equipped with such a driving force distribution device, when the driving force distributed to the left and right driving wheels is changed, there is a problem that an undesired steering force is generated in the left and right driving wheels also serving as the steering wheels (torque steer phenomenon). ). In order to reduce the torque steer phenomenon, an electric power steering device provided in a vehicle is used, and the electric power steering device generates a steering assist torque that cancels the undesired steering force.
It has already been proposed by the present applicant (Japanese Patent Application No. 9-302).
No. 155).

Further, in a vehicle provided with an electric power steering device, an actual motor current flowing through a motor of the electric power steering device and a steering torque are set to prevent generation of an undesirable steering assist torque due to an abnormality of the control means. A device that prohibits driving of the motor of the electric power steering device when the steering torque detected by the detection means is in a preset assist prohibition region has already been proposed by the present applicant (Japanese Patent Application No. 10-3700).
No. 99).

[0004]

When the vehicle includes both the driving force distribution device and the electric power steering device, the actual current of the motor of the electric power steering device is a current for assisting the driver's steering operation. And a current component for reducing the torque steer phenomenon. Therefore, when the assist prohibition region is searched based on the actual motor current, the operation of the electric power steering device is prohibited when the operation of the electric power steering device is necessary due to the influence of the current component for reducing the torque steer phenomenon, The operation may be permitted when the operation of the electric power steering device is unnecessary.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is directed to a vehicle cooperative control device for cooperatively controlling a driving / braking force distribution device and an electric power steering device to reduce a torque steer phenomenon. An object of the present invention is to enable the operation of a device to be properly prohibited.

[0006]

According to the first aspect of the present invention, there is provided a driving force / braking force for distributing a driving force or a braking force between left and right wheels or between front and rear wheels. An electric power steering device having a distribution device, first control means for controlling operation of the driving force / braking force distribution device, and a motor for applying a steering assist torque to a steering system;
A second control means for calculating a motor control signal for driving the motor based on at least the steering torque detected by the steering torque detection means,
The first control means can calculate a correction signal for correcting the motor control signal based on the control amount of the driving force / braking force distribution device, and the second control means can correct the motor control signal with the correction signal. A motor for driving a motor based on a motor control signal and prohibiting driving of the motor based on a corrected motor actual current and a steering torque obtained by correcting a motor actual current detected by current detection means with a correction signal. A cooperative control device is proposed.

According to the above arrangement, the motor control signal calculated by the second control means of the electric power steering device is corrected by the correction signal calculated by the first control means based on the control amount of the driving force / braking force distribution device. The second control means drives the motor of the electric power steering device based on the corrected motor control signal, so that it is possible to simultaneously assist the driver's steering operation and reduce the torque steering phenomenon. can do. Moreover, the second control means prohibits the driving of the motor of the electric power steering device based on the corrected motor actual current obtained by correcting the motor actual current with the correction signal and the steering torque. Regardless of this, the operation of the electric power steering device can be accurately prohibited.

According to the invention described in claim 2,
A driving force / braking force distribution device for distributing a driving force or a braking force between the left and right wheels or the front and rear wheels, a first control means for controlling the operation of the driving force / braking force distribution device, and a steering assist torque to a steering system. An electric power steering device having a motor to be added, and a second control means for calculating a motor control signal for driving the motor based on at least the steering torque detected by the steering torque detection means, The first control means can calculate a correction signal for correcting the motor control signal based on the control amount of the driving force / braking force distribution device, and the second control means can correct the motor control signal with the correction signal. The motor is driven based on the motor control signal, and the motor drive signal for driving the motor is corrected based on the correction motor drive signal and the steering torque. Cooperative control apparatus for a vehicle and inhibits the driving of the motor Te is proposed.

According to the above configuration, the motor control signal calculated by the second control means of the electric power steering device is corrected by the correction signal calculated by the first control means based on the control amount of the driving force / braking force distribution device. The second control means drives the motor of the electric power steering device based on the corrected motor control signal, so that it is possible to simultaneously assist the driver's steering operation and reduce the torque steering phenomenon. can do. In addition, the second control means inhibits driving of the motor of the electric power steering device based on the corrected motor drive signal obtained by correcting the motor drive signal with the correction signal and the steering torque. Regardless of this, the operation of the electric power steering device can be accurately prohibited.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on embodiments of the present invention shown in the accompanying drawings.

1 to 9 show a first embodiment of the present invention. FIG. 1 is a diagram showing a structure of a driving force distribution device, FIG. 2 is a block diagram showing a circuit configuration of a first electronic control unit, FIG.
FIG. 4 is a diagram illustrating the operation of the driving force distribution device during a right turn in a medium-low vehicle speed range, FIG. 4 is a diagram illustrating the operation of the driving force distribution device during a left turn in a medium-low vehicle speed range, and FIG. FIG. 6 is a block diagram illustrating a circuit configuration of a second electronic control unit, FIG. 7 is a diagram illustrating a relationship between a steering torque and an absolute value of a difference between torque distribution amounts, and FIG. FIG. 9 is a diagram showing a map for searching for a steering torque correction amount from the absolute value of the difference between the amounts, and FIG. 9 is a diagram showing a map for searching for an operation prohibition region of the electric power steering device.

As shown in FIG. 1, the front engine
Front mounted on the front of the vehicle
The transmission M is connected to the right end of the engine E
After the engine E and transmission M
The driving force distribution device T is disposed in the section. Driving force distribution device T
Drive shaft extending left and right from the left and right edges of the
A_LAnd right drive shaft A_RTo the left front
Wheel W_FLAnd right front wheel W _FRIs connected. Driving force distribution device
T constitutes the driving force / braking force distribution device of the present invention.

The driving force distribution device T includes a differential device D to which driving force is transmitted from an external gear 3 meshing with an input gear 2 provided on an input shaft 1 extending from a transmission M.
The differential device D is composed of a double pinion type planetary gear mechanism, and a ring gear 4 formed integrally with the external gear 3.
A sun gear 5 disposed coaxially inside the ring gear 4, an outer planetary gear 6 meshing with the ring gear 4, and an inner planetary gear 7 meshing with the sun gear 5; Consists of The differential device D is
While the ring gear 4 functions as an input element,
The sun gear 5 functioning as one output element is a left output shaft 9
Is connected to the left front wheel W _FL via _L, and the addition planetary carrier 8 functioning as the other output element is connected to the right front wheel W _FR via the right output shaft 9 _R.

The carrier member 11 rotatably supported on the outer periphery of the left output shaft 9 _L is provided with four pinion shafts 12 arranged at 90 ° intervals in the circumferential direction. The triple pinion member 16 integrally formed with the two pinions 14 and the third pinion 15 is attached to each of the pinion shafts 12.
Are rotatably supported.

A first sun gear 17 rotatably supported on the outer periphery of the left output shaft 9 _L and meshing with the first pinion 13.
Are connected to the planetary carrier 8 of the differential D.
The second sun gear 18 fixed to the outer periphery of the left output shaft 9 _L
Meshes with the second pinion 14. Further, the left output shaft 9
_A third sun gear 19 rotatably supported on the outer periphery of _L meshes with the third pinion 15.

The numbers of teeth of the first pinion 13, the second pinion 14, the third pinion 15, the first sun gear 17, the second sun gear 18, and the third sun gear 19 in the embodiment are as follows.

The number of teeth of the first pinion 13 Z ₂ = 17 The number of teeth of the second pinion 14 Z ₄ = 17 The number of teeth of the third pinion 15 Z ₆ = 34 The number of teeth of the first sun gear 17 Z ₁ = 32 The second sun gear Number of teeth of 18 Z ₃ = 28 Number of teeth of third sun gear 19 Z ₅ = 32

A third sun gear 19 can be connected to the casing 20 via a left hydraulic clutch C _L, and the rotational speed of the carrier member 11 is increased by the engagement of the left hydraulic clutch C _L. The carrier member 11 can be coupled to the casing 20 via a right hydraulic clutch C _R, the rotational speed of the carrier member 11 is reduced by engagement of the right hydraulic clutch C _R. And the right hydraulic clutch C _R and the left hydraulic clutch C _L is controlled by the first electronic control unit U ₁ including a microcomputer. First electronic control unit U ₁ constitutes the first control means of the present invention.

As shown in FIG. 2, the first electronic control unit U _1, the engine torque detecting means S ₁ for detecting the engine torque T _E, an engine rotational speed detecting means for detecting a rotational speed Ne of the engine E S _2, a vehicle speed detecting means S ₃ for detecting the vehicle speed V, steering angle detecting means S for detecting a steering angle θ
The signal from ₄ is input. First electronic control unit U
₁ is arithmetic processing based on signals from the respective detecting means S ₁ to S ₄ on a predetermined program, the left hydraulic clutch C _L
And controls the right hydraulic clutch C _R.

The first electronic control unit U ₁ includes a drive shaft torque calculating means M 1 and a gear ratio calculating means M 2
Right and left distribution correction coefficient calculation means M3, target yaw rate calculation means M4, lateral acceleration calculation means M5, left and right distribution correction coefficient calculation means M6, left and right front wheel torque calculation means M7
And a correction current calculating means M8.

The drive shaft torque calculating means M1
The gear ratio Ni obtained by the gear ratio calculating means M2 from the engine speed Ne and the vehicle speed V is calculated based on the engine torque T.
By multiplying _E , the drive shaft torque T _D
(That is, the sum of the torque transmitted to the left and right front wheels W _FL , W _FR ). The engine torque T _E is can be obtained from the intake pressure (or accelerator opening) and the engine speed Ne, the torque detecting means and the vehicle provided drive shaft torque T _D to a power transmission system in addition to the above-mentioned From the longitudinal acceleration. Further, the vehicle speed V may be obtained optically using a spatial filter other than the wheel speed, or may be obtained using a Doppler radar.

The right and left distribution correction factor calculating means M3 is the first right and left distribution correction coefficient K _T with a map search based on the drive shaft torque T _D, the second based on the vehicle speed V
A map search is performed for the left-right distribution correction coefficient K _V. Target yaw rate calculating means M4 are both retrieved from the map steering angle component Y ₁ of the target yaw rate Y based on the steering angle theta, the vehicle speed component Y ₂ of the target yaw rate Y and the map search on the basis of the vehicle speed V, the their steering angle component by multiplying the Y ₁ and the vehicle speed component Y ₂ calculates the target yaw rate Y. Lateral acceleration calculation means M5
Calculates the lateral acceleration Y _G by multiplying the target yaw rate Y by the vehicle speed V.
6, right and left distribution on the basis of the lateral acceleration Y _G correction coefficient G
Search by map.

In the left and right front wheel torque calculating means M7, the torque distribution amount T _L to be distributed to the left front wheel W _FL and the torque distribution amount T _R to be distributed to the right front wheel W _FR are calculated based on the following equation. Is calculated.

T _L = (T _D / 2) × (1 + K _W × K _T × K _V × G) (1) T _R = (T _D / 2) × (1−K _W × K _T × K _V) × G) (2) where K _T and K _V are the left and right distribution correction coefficients obtained by the left and right distribution correction coefficient calculation means M3, G is the left and right distribution correction coefficient obtained by the left and right distribution correction coefficient calculation means M6, and K _W Is a constant.

(1 ± K _W × K _T × K _V × G) on the right side of the equations (1) and (2) are the left and right front wheels W _FL , W _FR.
A torque distribution ratio between the front wheels W _FL , W _FR increases by a predetermined amount, and the torque distribution of the other front wheels W _FL , W _FR decreases by the predetermined amount. .

The left and right front wheels W _FL as described above, W _FR torque distribution amount to be allocated to T _L, the T _R is calculated, the left and right front wheels W _FL, W _FR to the distributed torques T _L, T _The left hydraulic clutch _CL and the right hydraulic clutch _CR are controlled so that _R is transmitted.

The correction current calculating means M8 will be described later in detail.

Thus, the first electronic control unit U₁from
According to the command, the right hydraulic clutch C_R
And left hydraulic clutch C_LAre disengaged together.
Thereby, the carrier member 11 and the third sun gear 19
Of the left drive shaft 9_LDry right
Bu shaft 9_R, Planetary carrier 8 and differential device D
The carrier member 11 and the carrier member 11 are all rotated together. This
At the time, as indicated by the hatched arrow in FIG.
The torque of the gin E is transmitted from the differential D to the left and right front wheels W. _FL, W_FR
Transmitted evenly.

[0029] Now, when turning right in the low speed range in the vehicle, engages the right hydraulic clutch C _R in accordance with a command from the first electronic control unit U _1, as shown in FIG. 3, the casing of the carrier member 11 Stop by connecting to 20. At this time, the left output shaft 9 _L integral with the left front wheel W _FL and the right output shaft 9 _R integral with the right front wheel W _FR (that is, the planetary carrier 8 of the differential device D) are connected to the second sun gear 18, 2 pinion 1
4, because it is attached via a first pinion 13 and the first sun gear 17, the rotation speed N _L of the left front wheel W _FL is accelerated in the following relationship with respect to the rotational speed N _R of the right front wheel W _FR You.

N _L / N _R = (Z ₄ / Z ₃ ) × (Z ₁ / Z ₂ ) = 1.143 (3)

As described above, the rotation speed N of the left front wheel W _FL
When _L is increased relative to the rotational rate N _R of the right front wheel W _FR, as indicated by the hatched arrow in FIG. 3, turning outer part of the torque of an inner wheel right front wheel W _FR Left front wheel W _FL
Can be transmitted to

The carrier member 11 is connected to the right hydraulic clutch C
Instead of stopping by _R, if reducing the rotational speed of the carrier member 11 by appropriately adjusting the engagement force of the right hydraulic clutch C _R, the right front wheel W _FR and rotation speed N _L of the left front wheel W _FL in accordance with the deceleration can Hayashi increased relative to the rotational speed N _R, to transmit any torque from the right front wheel W _FR as a turning-inner to the left front wheel W _FL is the outer turning wheel.

On the other hand, when the vehicle is turning left in the middle to low vehicle speed range,
Is the first electronic control unit U as shown in FIG.₁from
Commanded left hydraulic clutch C_LAre engaged with the third pinion
15 is connected to the casing 20 via the third sun gear 19
Is done. As a result, the left output shaft 9 _LThe rotation speed of the
The rotation speed of the rear member 11 is increased, and the right front wheel W_FRRotation speed
N_RIs the front left wheel W_FLRotation speed N_LTo the following equation
Speeded up.

N _R / N _L = {1- (Z ₅ / Z ₆ ) × (Z ₂ / Z ₁ )} {1- (Z ₅ / Z ₆ ) × (Z ₄ / Z ₃ )} = 1 .167 (4)

As described above, the rotation speed N of the right front wheel W _FR
When _R is increasing relative to the rotational rate N _L of the left front wheel W _FL, as indicated by the hatched arrow in FIG. 4, the pivot part of the torque of a turning inner front left wheel W _FL outer Right front wheel W _FR
Can be transmitted to In this case, when accelerating the rotation speed of the carrier member 11 by appropriately adjusting the engagement force of the left hydraulic clutch C _L, left front wheel W _FL rotation speed N _R of the right front wheel W _FR in accordance with the speed increasing The rotation speed is increased with respect to the rotation speed N _L , and an arbitrary torque can be transmitted from the left front wheel W _{FL as the} turning inner wheel to the right front wheel W _FR as the turning outer wheel. Thus, when the vehicle is running at a low speed, it is possible to improve the turning performance by transmitting a larger torque to the outer turning wheel than to the turning inner wheel.
During high-speed running, it is possible to reduce the torque transmitted to the turning outer wheel as compared with the case of the medium-to-low speed running, or to improve the running stability by transmitting torque from the turning outer wheel to the turning inner wheel. And those in the first electronic control right and left distribution correction factor calculating means M3 of the unit U _1,
It is achieved by setting the map of the second right and left distribution correction coefficient K _V with respect to the vehicle speed V.

As is clear from the comparison of the equations (3) and (4), the first pinion 13, the second pinion 14, the third pinion 15, the first sun gear 17, and the second sun gear 18
And the number of teeth of by a set as described above third sun gear 19, the speed increasing ratio from the right front wheel W _FR to the left front wheel W _FL (about 1.143), increasing from the left front wheel W _FL to the right front wheel W _FR The speed factor (about 1.167) can be made substantially equal.

When the driving force distributed from the engine E to the left and right front wheels W _FL and W _FR via the driving force distribution device T changes, so-called torque steer is applied to the left and right front wheels W _FL and W _FR as the steered wheels. An undesirable steering force is generated by the phenomenon. In a vehicle equipped with the electric power steering device S, when a torque steer phenomenon occurs due to the operation of the driving force distribution device T, the electric power steering device S is operated so as to cancel the steering force due to the torque steer phenomenon, and the vehicle is driven in the reverse direction. By generating the steering assist torque, the torque steer phenomenon can be reduced.

As is apparent from FIG. 2, the first electronic control unit
U₁The right and left front wheel torque
Left and right front wheels W calculated by calculation means M7_FL, W_FRDistributed to
Torque distribution amount T_L, T_RIs entered. Torque stay
The steering force generated by the phenomenon_FL, W_FRTo
Torque distribution amount T to be distributed_L, T_RIs the absolute value of the difference
| T_L-T_R| And the speed determined by the geometry of the steering system
Since it is proportional to the club radius R, the correction current calculating means M8
Is the steering torque correction amount ΔT_QTo ΔT_Q= K × | T_L-T_R| × R (5) Here, K is a conversion coefficient. Further correction current
The calculating means M8 calculates the steering torque correction amount ΔT_QWill be described later
The motor 27 of the electric power steering device S to be driven
Is converted into a current correction amount ΔI. This current correction amount ΔI is
It corresponds to the correction signal of the present invention, and
The ring device S determines the steering torque correction amount ΔT _QEquivalent to
Steering torque (that is, steering torque generated by the torque steer phenomenon)
A steering torque that can negate steering force)
Equivalent to flow. And calculated by the correction current calculating means M8.
The current correction amount ΔI controls the electric power steering device S
Second electronic control unit U_TwoIs input to

[0039] In Thus, when the steering operation in the same direction as the steering force of the driver by the operation of the driving force distribution device T acts on the steering torque correction amount ΔT from the steering torque T _Q
The corrected steering torque T _Q ′ is calculated by subtracting _Q, and when a steering force in a direction opposite to the driver's steering operation is applied, the steering torque correction amount ΔT _Q is added to the steering torque T _Q to perform the corrected steering. By calculating the torque T _Q ′,
The torque steer phenomenon accompanying the operation of the driving force distribution device T can be reduced.

It should be noted that the steering torque correction amount ΔT _Q is calculated by the above (5)
Instead of calculating based on the formula, it is also possible to search from a map based on the absolute value | T _L −T _R | of the difference between the steering torque T _Q and the torque distribution amount. That is, the absolute value | T _L −T _R | of the difference between the steering torque T _Q and the torque distribution amount.
7, the relationship shown by the dashed line when the amount of torque steer increases due to changes in the road surface friction coefficient, etc., and the relationship shown by the dashed line when the amount of torque steer decreases. Becomes Therefore, the absolute value | T _L -T of the difference between the input steering torque T _Q and the torque distribution amount
_R | is closest to the three characteristic lines in FIG. 7, a characteristic line corresponding to the characteristic line specified in FIG. 7 is selected from the map in FIG. 8, and the characteristic line is selected. By applying the absolute value | T _L −T _R | of the difference between the torque distribution amounts to search the steering torque correction amount ΔT _Q , the torque steer phenomenon can be reduced more effectively.

Next, the steering system of the vehicle will be described with reference to FIG.

The steering torque input to the steering wheel 21 by the driver is transmitted to the rack 2 via the steering shaft 22, the connecting shaft 23 and the pinion 24.
5 and the reciprocating motion of the rack 25 is transmitted to the left and right front wheels W _FL and W _FR via the left and right tie rods 26 and 26 to steer the front wheels W _FL and W _FR . The electric power steering device S provided in the steering system includes a driving gear 28 provided on an output shaft of a motor 27, a driven gear 29 meshing with the driving gear 28, a screw shaft 30 integrated with the driven gear 29, A nut 31 meshed with the screw shaft 30 and connected to the rack 25;

The second electronic control unit U ₂ constituting the second control means of the present invention does not independently control the operation of the electric power steering device S, but the driving force distribution device T
The operation of the electric power steering device S is coordinated with the operation of the electric power steering device S.

As shown in FIG. 6, the second electronic control unit U ₂ comprises a target current setting means M9 and a drive control means M10.
, Drive inhibition means M11 and drive inhibition determination means M12
, A subtraction means 33 and an addition means 34.

The target current setting means M9 includes a vehicle speed detecting means S
₃ and the vehicle speed V input from, based on the steering torque T _Q inputted from the steering torque detecting means S _5, the target current I for driving the motor 27 of the electric power steering system S
Map search for _MS . The target current _IMS is set so as to increase as the steering torque T _Q increases, and to increase as the vehicle speed V decreases. With this characteristic, the steering assist torque corresponding to the driving state of the vehicle is set. Can be generated.

[0046] and the target current I _MS to the target current setting means M9 is output, a current correction value ΔI of the first electronic control unit U ₁ outputs is inputted to the subtraction unit 33, where the target current I
_The current correction value ΔI is subtracted from _MS to obtain a correction target current I _MS ′
(= I _MS -ΔI) is calculated. The driving force distribution device T
When the steering force acts in the same direction as the driver's steering operation, the target current I
By subtracting the current correction amount ΔI from the _MS to calculate the corrected target current I _MS ', but when the steering operation direction opposite the steering force of the driver acts, by adding the current correction amount ΔI to the target current I _MS In some cases, the correction target current _IMS ′ may be calculated. The target current I _MS corresponds to the motor control signal of the present invention, the current correction value ΔI corresponds to the correction signal of the present invention, the corrected target current I _MS 'corresponds to the correction motor control signal of the present invention.

The drive control means M10 outputs the correction target current I _MS '.
Into a motor drive signal V _D , and the motor drive signal V _D
D is output to the drive inhibiting means M11. Drive prohibition means M1
1, when the drive inhibit signal from the drive inhibition determining means M12 is not input, by driving the motor 27 in the motor voltage V _M to output the motor drive signal V _D directly to the motor driver 32, the electric power steering system S To generate steering assist torque. Thus, the correction target current I calculated from the target current I _MS and the current correction amount ΔI
By controlling the electric power steering device S based on _MS ', it is possible to simultaneously perform the steering assist of the driver, which is an essential function of the electric power steering device S, and reduce the torque steer phenomenon.

On the other hand, when an abnormal situation such as a failure of the control system occurs, a drive inhibition signal is input from the drive inhibition determination means M12 to the drive inhibition means M11, and the drive inhibition means M11
Is adapted to prevent the prohibit output of the motor drive signal V _D prohibits operation of the electric power steering apparatus S, an electric power steering device S generates an unexpected auxiliary steering torque of the driver .

The adding means 34 includes a first electronic control unit U
_The correction motor actual current I _M ′ is calculated by adding the current correction amount ΔI output by ₁ and the motor actual current I _M supplied to the motor 27 detected by the current detecting means S ₆ . In the case where the subtraction unit 33 performs an addition without subtraction, addition means 34 will calculate the correct actual motor current I _M 'by subtracting the current correction amount ΔI from the actual motor current I _M. Detected by the steering torque detecting means S ₅ steering torque T _Q and correcting the actual motor current I _M calculated in the adding means 34 'is input drive inhibition determining means M12, these steering torque T _Q and correcting the actual motor current I _M ′ To determine whether to prohibit the driving of the electric power steering device S.

FIG. 9 is a map for making the above determination. This map is originally a vehicle that does not have the driving force distribution device T, that is, does not perform the cooperative control of the electric power steering device S and the driving force distribution device T. This is set for the vehicle. Here, the horizontal axis is the steering torque detecting means S
_The vertical axis represents the steering torque T _Q detected in step ₅ ,
₆ represents the actual motor current I _M detected in FIG. The region where the steering torque T _Q on the right side of the horizontal axis origin is (+) corresponds to the case where the steering torque in the right turning direction is input to the steering wheel 21, and the steering torque T on the left side of the horizontal axis origin. The region where _Q is (-) corresponds to the case where the steering torque in the left turning direction is input to the steering wheel 21. The region where the motor actual current I _M above the origin on the vertical axis is (+) corresponds to the case where the motor 27 outputs torque in the right-turn direction, and the motor actual current I _M below the origin on the vertical axis is lower. The region where I _M is (-) corresponds to the case where the motor 27 outputs the torque in the left turning direction. And when the steering torque T _Q and the actual motor current I _M is in the assist inhibition region indicated by hatching, drive inhibition determining means M12 outputs a command for prohibiting the driving of the motor 27 to drive inhibition means M11.

[0051] For example, the driver despite not performing the steering operation, the second electronic control unit U ₂
When the motor 27 by the failure is driven in the rightward turning direction by the large current, actual motor current I _M at this time is in a positive (+) region. By the motor 27 is freely driven in the rightward turning direction, the driver to try to straight vehicle by adding a strong steering torque T _Q from the left turn direction to the steering wheel 21, the steering torque detecting means S
Steering torque T _{Q where 5} is detected (-) becomes b region.
As a result, the motor actual current I _M and the steering torque T _Q have a relationship indicated by a point P in FIG. 9 and enter the assist prohibition region indicated by hatching, and the drive prohibition determining means M12 issues a command to prohibit driving of the motor 27. By outputting, it is possible to prevent the electric power steering device S from generating an undesirable steering assist torque.

The above description applies to a vehicle that does not perform cooperative control of the electric power steering device S and the driving force distribution device T. However, the following problem occurs in a vehicle that performs cooperative control. That is, in a vehicle that performs cooperative control, the actual motor current _IM includes a current component for assisting the driver's steering operation and a current component for reducing the torque steer phenomenon.
If the map of FIG. 9 that does not consider the current component for reducing the torque steer phenomenon is used as it is, an erroneous determination occurs and the operation of the electric power steering apparatus S is prohibited when the operation is required, The operation may be permitted when the operation of the steering device S is unnecessary.

[0053] To avoid this, it may be used a three-dimensional map in which the current component in the parameters for reducing the torque steer phenomenon in addition to the steering torque T _Q and the actual motor current I _M, In this way Not only does the map become complicated, but it becomes necessary to prepare different maps for vehicles that perform cooperative control and vehicles that do not perform cooperative control.

Therefore, in the present embodiment, in a vehicle that performs cooperative control, a current component for reducing the torque steer phenomenon is removed from the actual motor current I _M , that is, a vehicle for substantially assisting the driver's steering operation. The correction motor actual current I _M ′ corresponding to the current component is applied to the map of FIG. 9 to determine the prohibition of driving, whereby the appropriate map can be accurately obtained without using the map of the vehicle that does not perform the cooperative control. It is possible to make an appropriate judgment.

Next, a second embodiment of the present invention will be described with reference to FIG.

In the first embodiment described above, the actual motor current I _M is used to determine whether the driving of the motor 27 of the electric power steering device S is prohibited, but the motor driving signal V _D output by the driving control means M10 is because of a proportional relationship between the actual motor current I _M, in this embodiment so as to obtain the same effect as the first embodiment using a motor drive signal V _D in place of the actual motor current I _M .

Specifically, the adding means 34 of the first embodiment
(See FIG. 6).
The motor drive signal output by the drive control means M10 to the means 35
Issue V_DAnd the first electronic control unit U_TwoThe correction signal output by
The signal ΔV is input. This correction signal ΔV is equal to the target current I
_MSCurrent correction value ΔI for correcting the motor drive signal V
_DIs converted to correspond to. Addition means 35
Is the motor drive signal V_DTo the correction signal ΔV (or
Is subtracted) and the corrected motor drive signal V_D′
Correction motor drive signal V_D'To the drive inhibition determination means M12.
Output. The correction inhibition motor M12 includes the correction motor
Drive signal V_D'In addition to the driving torque detecting means S_Fivefrom
Drive torque T_QIs input, and there is a correction motor drive signal
V_D'And drive torque T_QIs in the assist prohibited area
It is determined whether or not. The map used at that time is the first
Substantially the same as the map used in the examples (see FIG. 9)
And the vertical axis represents the motor actual current I._MFrom the motor drive signal
Issue V_DIt is equivalent to what was changed to.

[0058] In Thus, the second embodiment also, the drive prohibition of the motor 27 based on the corrected motor driving signal V _D 'obtained by removing the signal component to reduce torque steer phenomenon from the motor drive signal V _D By making the determination, it is possible to make an accurate determination while directly using the map of the vehicle that does not perform cooperative control for the determination.

Although the embodiments of the present invention have been described in detail, various design changes can be made in the present invention without departing from the gist thereof.

For example, the driving force distribution device according to the present invention is not limited to a device for distributing driving force between left and right wheels, but may be a device for distributing driving force between front and rear wheels. Further, the present invention can be applied to a system in which braking force is distributed between left and right wheels or between front and rear wheels.

[0061]

As described above, according to the first aspect of the present invention, the motor control signal calculated by the second control means of the electric power steering device is used by the first control means to calculate the driving force and the driving force.
Since a correction motor control signal is calculated by correcting with a correction signal calculated based on the control amount of the braking force distribution device, and the second control means drives the motor of the electric power steering device based on the correction motor control signal, It is possible to simultaneously assist the driver's steering operation and reduce the torque steer phenomenon. Moreover, the second control means prohibits the driving of the motor of the electric power steering device based on the corrected motor actual current obtained by correcting the motor actual current with the correction signal and the steering torque. Regardless of this, the operation of the electric power steering device can be accurately prohibited.

According to the second aspect of the present invention,
The motor control signal calculated by the second control means of the electric power steering device is corrected by the correction signal calculated based on the control amount of the driving force / braking force distribution device by the first control means to calculate a corrected motor control signal. Since the second control means drives the motor of the electric power steering device based on the corrected motor control signal, it is possible to simultaneously assist the steering operation of the driver and reduce the torque steer phenomenon. In addition, the second control means inhibits driving of the motor of the electric power steering device based on the corrected motor drive signal obtained by correcting the motor drive signal with the correction signal and the steering torque. Regardless of this, the operation of the electric power steering device can be accurately prohibited.

[Brief description of the drawings]

FIG. 1 is a diagram showing a structure of a driving force distribution device.

FIG. 2 is a block diagram showing a circuit configuration of a first electronic control unit.

FIG. 3 is a diagram showing an operation of the driving force distribution device during a right turn in a middle to low vehicle speed range.

FIG. 4 is a diagram showing an operation of the driving force distribution device during a left turn in a middle to low vehicle speed range.

FIG. 5 is a diagram showing the structure of an electric power steering device.

FIG. 6 is a block diagram showing a circuit configuration of a second electronic control unit.

FIG. 7 is a diagram showing a relationship between an absolute value of a difference between a steering torque and a torque distribution amount.

FIG. 8 is a diagram showing a map for retrieving a steering torque correction amount from an absolute value of a difference between torque distribution amounts.

FIG. 9 is a diagram showing a map for searching an operation prohibition region of the electric power steering device.

FIG. 10 is a block diagram showing a circuit configuration of a second electronic control unit according to a second embodiment of the present invention.

[Explanation of symbols]

I _M actual motor current I _M 'corrected motor actual current I _MS target current (motor control signal) I _MS ' corrected target current (corrected motor control signal) ΔI current correction amount (corrected signal) S electric power steering device S ₅ steering torque Detecting means S ₆ Current detecting means T Driving force distribution device (Driving force / braking force distribution device) T _Q Steering torque U ₁ First electronic control unit (First control device) U ₂ Second electronic control unit (Second control device) ) V _D motor drive signal V _D 'corrected motor driving signal ΔV correction signal 27 motor

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Tatsuhiro Tomari 1-4-1 Chuo, Wako-shi, Saitama Pref. Honda Research Institute, Inc. (72) Inventor Masakatsu Hori 1-4-1 Chuo, Wako-shi, Saitama Inside Honda R & D Co., Ltd. (72) Inventor Shinji Okuma 1-4-1 Chuo, Wako-shi, Saitama Prefecture Inside Honda R & D Co., Ltd. (72) Akihiro Iwasaki 1-4-1 Chuo, Wako-shi, Saitama Pref. Inside Honda R & D Co., Ltd. (72) Inventor Koji Shibata 1-4-1 Chuo, Wako-shi, Saitama F-term inside Honda R & D Co., Ltd. 3D032 CC16 DA03 DA15 DA23 DA25 DA29 DA33 DA48 DA49 DA64 DB02 DB03 DC08 DD02 DE09 EA01 EB11 EC23 EC24 FF05 GG01 3D033 CA03 CA11 CA13 CA16 CA20 CA21 CA31 CA32 3D036 GA02 GA32 GA42 GB09 GG28 GG31 GG35 GG43 GG44 GH20 GH22 GH25 GJ01

Claims (2)

[Claims] A driving force / braking force distribution device (T) for distributing a driving force or a braking force between left and right wheels or between front and rear wheels.
An electric power steering device (S) having first control means (U ₁ ) for controlling the operation of the driving force / braking force distribution device (T), and a motor (27) for applying a steering assist torque to the steering system. at least a steering torque detecting means second control means for calculating a motor motor control signal for driving the (27) (I _MS) on the basis of the detected steering torque (T _Q) in the (S ₅₎ (U ₂₎
Wherein the first control means (U ₁ ) controls the motor control signal ( _IMS ) based on the control amount of the driving force / braking force distribution device (T).
The is possible calculate a correction signal for correcting ([Delta] I), the second control unit (U ₂₎ is, the motor control signal (I _MS) a correction signal correcting the motor control signal corrected by (ΔI) (I _MS ') Based on the actual motor current (I) detected by the current detecting means (S ₆ ).
A vehicle cooperative control device for prohibiting driving of a motor (27) based on a corrected motor actual current ( _IM ') obtained by correcting _M ) with a correction signal (ΔI) and a steering torque (T _Q ). 2. A driving force / braking force distribution device (T) for distributing a driving force or a braking force between left and right wheels or between front and rear wheels.
An electric power steering device (S) having first control means (U ₁ ) for controlling the operation of the driving force / braking force distribution device (T), and a motor (27) for applying a steering assist torque to the steering system. at least a steering torque detecting means second control means for calculating a motor motor control signal for driving the (27) (I _MS) on the basis of the detected steering torque (T _Q) in the (S ₅₎ (U ₂₎
Wherein the first control means (U ₁ ) controls the motor control signal ( _IMS ) based on the control amount of the driving force / braking force distribution device (T).
The is possible calculate a correction signal for correcting ([Delta] I), the second control unit (U ₂₎ is, the motor control signal (I _MS) a correction signal correcting the motor control signal corrected by (ΔI) (I _MS ') A motor drive signal (V _D ) for driving the motor (27) and for driving the motor (27) based on the
Is corrected by the correction signal (ΔI).
_D ′) and the steering torque (T _Q ) based on the motor (2
7) A cooperative control device for a vehicle, wherein the driving of 7) is prohibited.