JPH0680035A - Driving force allocating integrated control device for front and rear wheel and left and right wheel - Google Patents

Abstract

PURPOSE:To improve driving performance and a steering characteristic when a vehicle turns by arranging the first integrated control means to carry out correction control, to which a front wheel allocation quantity is added according to an over-steering moment detected quantity, on the front and rear wheel driving force allocation control system side when the over-steering moment is detected. CONSTITUTION:When a vehicle turns such as when it turns in high (mu) road acceleration, and when the over-steering moment is caused by control to increase turning outer ring side driving force allocation on the left and right wheel driving force allocation control system 4 side or when being in a condition where the occurrence is expected, an over-steering moment condition is detected by an over-steering moment detecting means 18a. When the over-steering moment is detected, correction control to which a front wheel allocation quantity is added according to an over-steering moment detected quantity, is carried out on the front and rear wheel driving force allocation control system 7 side by means of the first integrated control means 18a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a front / rear wheel and left / right wheel driving force comprehensive control device applied to a vehicle equipped with both a front / rear wheel driving force distribution control system and a left / right wheel driving force distribution control system.

[0002]

2. Description of the Related Art Conventionally, as a drive force distribution integrated control device for front and rear wheels and left and right wheels, for example, JP-A-62-292529 is known.
The device described in the publication is known.

[0003] According to this conventional source, front and rear wheel drive force distribution control systems which control the drive force distribution to the front wheels by the magnitude of the clutch engagement force, and the difference which controls the differential limiting torque by the magnitude of the clutch engagement force. In vehicles equipped with both the dynamic limit torque control system and the clutch engaging force used in both systems, when one of them is increased, the other is also increased to effectively suppress the drive wheel slip and to improve the stack escapeability. Techniques for improving and accelerating on low friction coefficient roads are shown.

[0004]

However, in such a conventional front-rear wheel and left-right wheel driving force distribution comprehensive control device, the two clutch engaging forces are simply interlocked with each other to positively It is a device that is not designed to control the steering characteristics, so even if the drive performance is improved to some extent,
Understeer as a steer characteristic when turning at high lateral acceleration.
Steer characteristics or oversteer characteristics may occur.

The present invention has been made in view of the above-mentioned problems, and front and rear wheels applied to a vehicle equipped with both the front and rear wheel driving force distribution control system and the left and right wheel driving force distribution control system. An object of the present invention is to achieve both improvement of drive performance and improvement of steer characteristics when turning, in a comprehensive control device for distributing drive force to the left and right wheels.

[0006]

In order to solve the above-mentioned problems, according to the integrated driving force distribution control device for the front and rear wheels and the left and right wheels according to claim 1, oversteer by control on the side of the left and right wheel driving force distribution control system during turning. A first comprehensive control means is provided for causing the front and rear wheel drive force distribution control system side to perform a correction control in which a front wheel distribution amount is added according to an oversteer moment detection amount when a moment is generated or when a moment is expected to occur.

That is, as shown in the claim correspondence diagram of FIG. 1 (a), the front and rear wheel drive force distribution control system a for controlling the drive force distribution to the front and rear wheels according to the predetermined vehicle state, and the predetermined vehicle state The left and right wheel drive force distribution control system b that controls the drive force distribution to the left and right wheels according to the above, and when the oversteer moment is generated or expected due to the control on the side of the left and right wheel drive force distribution control system b during turning. Oversteer moment detecting means c for detecting the time when the state is
When the oversteer moment is detected, the front / rear wheel driving force distribution control system a side performs the correction control including the front wheel distribution amount according to the detected amount of oversteer moment.

In order to solve the above-mentioned problems, the integrated drive force distribution control device for the front and rear wheels and the left and right wheels according to claim 2,
When the understeer moment is generated or expected to occur due to the control on the front / rear wheel drive force distribution control system side, the left / right wheel drive force distribution control system side performs correction control including the turning outer wheel distribution amount according to the detected understeer moment. A second total control means is provided.

That is, as shown in the claim correspondence diagram of FIG. 1 (b), the front and rear wheel drive force distribution control system a for controlling the drive force distribution to the front and rear wheels according to the running state of the vehicle, and the running state of the vehicle The left and right wheel drive force distribution control system b that controls the drive force distribution to the left and right wheels in accordance with the above, and when the understeer moment occurs or is expected to occur due to control on the side of the front and rear wheel drive force distribution control system a during turning. Understeer moment detecting means e for detecting the time when the vehicle is in the state of being controlled, and when the understeer moment is detected, the right and left wheel drive force distribution control system b And a second total control means f to be performed in step 1.

[0010]

The operation of the present invention will be described.

During high-μ road acceleration turning, etc., during steering, when the oversteer moment is generated or is expected to occur due to the control for increasing the driving force distribution on the left and right wheel driving force distribution control system b side. In the state, the oversteer moment detecting means c detects the oversteer moment state. When the oversteer moment is detected, the first comprehensive control means d performs the correction control including the front wheel distribution amount according to the oversteer moment detection amount on the front and rear wheel driving force distribution control system a side.

Therefore, an understeer moment is generated by adding the front wheel distribution amount by the correction control on the front and rear wheel drive force distribution control system a side, and this understeer moment is generated by the left and right wheel drive force distribution control system b.
The oversteer moment generated by the control on the side is canceled, and the steer characteristic of the vehicle is corrected in the neutral steer direction. Since the basic control of the front and rear wheel driving force distribution control system a and the left and right wheel driving force distribution control system b is not changed, the improvement of the driving performance by these driving force distribution control is ensured as it is. .

The operation of the invention according to claim 2 will be described.

A state in which an understeer moment occurs or is expected to occur due to control for increasing the driving force distribution to the front wheels on the front and rear wheel driving force distribution control system a during turning, such as when turning on a low μ road. In the case of, the understeer moment detecting means e detects the understeer moment state. Then, when the understeer moment is detected, the second comprehensive control means f performs the correction control including the turning outer wheel distribution amount according to the detected understeer moment on the left and right wheel driving force distribution control system b side.

Therefore, an oversteer moment is generated by the turning outer wheel distribution amount being added by the correction control on the left and right wheel drive force distribution control system b side, and this oversteer moment is generated by the front and rear wheel drive force distribution control system a.
The understeer moment generated by the control on the side is canceled, and the steer characteristic of the vehicle is corrected in the neutral steer direction. The front and rear wheel driving force distribution control system a
Since the basic control of the left and right wheel driving force distribution control system b is not changed, the improvement of the driving performance by the driving force distribution control is ensured as it is.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) First, the structure will be described.

FIG. 2 is an overall system diagram of a rear-wheel drive-based four-wheel drive vehicle to which the front-rear wheel and left-right wheel driving force distribution integrated control device of the first embodiment corresponding to the first aspect of the present invention is applied. Is.

In FIG. 2, the driving force from the engine 1 and the transmission 2 is transmitted from the rear propeller shaft 3 to the left and right rear wheels 5 and 6 via the electronically controlled LSD 4.
It is transmitted from the rear propeller shaft 3 to the left and right front wheels 10 and 11 via the ETS transfer 7, the front propeller shaft 8 and the front differential 9.

A hydraulic unit 12 is provided in the electric control LSD 4.
The left and right rear wheels 5, 6 depending on the clutch control pressure applied from the
A differential limiting clutch 13 that generates a differential limiting torque between is included.

The ETS transfer 7 is connected to the front wheel 1 according to the clutch control pressure applied from the hydraulic unit 12.
A transfer clutch 14 that generates a transmission driving torque to 0 and 11 is built in.

The hydraulic unit 12 includes a hydraulic source 15 and an E
It has a TS control valve 16 and a CSD control valve 17.

The ETS control valve 16 is controlled by a command from the ETS control unit 18a of the controller 18 to generate a clutch control pressure for the transfer clutch 14 (corresponding to a front / rear wheel driving force distribution control system).

The CSD control valve 17 is controlled by a command from the CSD control section 18b of the controller 18, and produces clutch control pressure to the limited differential clutch 13 (corresponding to a left and right wheel drive force distribution control system).

The controller 18 includes the left front wheel rotation speed N _FL from the left front wheel rotation sensor 19, the right front wheel rotation speed N _FR from the right front wheel rotation sensor 20, and the left rear wheel rotation sensor 21.
From the left rear wheel rotation speed N _RL , the right rear wheel rotation sensor 22 from the right rear wheel rotation speed N _RR , the lateral acceleration Y _G from the lateral acceleration sensor 23, and the accelerator opening degree from the accelerator opening degree sensor 24. θ and the switch signal from the brake switch 25 are input.

Further, between the ETS control unit 18a and the CSD control unit 18b in the controller 18, information on the ETS clutch torque T _ETS and the CSD clutch torque T _CSD is exchanged with each other.

Next, the operation will be described.

(A) Front / rear wheel drive force distribution control operation FIG. 3 is a flow chart showing the flow of the front / rear wheel drive force distribution control operation performed by the ETS controller 18a of the controller 18 (oversteer moment detection means and first
Equivalent to total control means).

In step 30, the left front wheel rotation speed N _FL , the right front wheel rotation speed N _FR , the left rear wheel rotation speed N _RL, and the right rear wheel rotation speed N _RR.
And lateral acceleration Y _G and CSD clutch torque T _CSD are read. The CSD clutch torque T _CSD may be given according to the accelerator opening degree and the accelerator opening speed as in the second embodiment described later, or other values such as the left and right wheel rotational speed difference and the lateral acceleration. It may be given by a control law including control elements.

In step 31, the left front wheel rotation speed N _FL , the right front wheel rotation speed N _FR , the left rear wheel rotation speed N _RL, and the right rear wheel rotation speed N _RR.
From left front wheel speed V _WFL and right front wheel speed V _WFR and left rear wheel speed V respectively
_WRL and right rear wheel speed V _WRR are calculated.

In step 32, the front wheel speed V _WF is calculated by the average value of the left front wheel speed V _WFL and the right front wheel speed V _WFR, and the rear wheel speed is calculated by the average value of the left rear wheel speed V _WRL and the right rear wheel speed V _WRR. Wheel speed V _WR is calculated.

In step 33, the rear wheel speed V _WR and the front wheel speed V _WR
The front and rear wheel rotation speed difference ΔV is calculated from the difference with _WF .

At step 34, ET is performed by the lateral acceleration Y _G.
The proportional gain Kdv in the S basic control is calculated. As shown in FIG. 4, the proportional gain Kdv has a maximum value in a region where the lateral acceleration Y _G is equal to or less than a predetermined value, and when the lateral acceleration Y _G exceeds the predetermined value,
It is given as a value that gradually decreases as the lateral acceleration Y _G increases.

At step 35, lateral acceleration Y _G , CSD clutch torque T _CSD , CSD clutch torque differential value T
_The differential limiting torque sensitive gain Kgd is calculated by _CSD 'by the following formula.

Kgd = Kxx.multidot. (Kdiff1 + Kdiff2) where the coefficient Kxx is the lateral acceleration as shown in FIG. 5 (a).
The value is 0 until Y _G reaches a predetermined value Y _GO, and is a value that rises in a higher-order function when it exceeds the predetermined value Y _GO .

The first gain Kdiff1 is given as a value proportional to the magnitude of the CSD clutch torque T _CSD , as shown in FIG. 5 (b).

As shown in FIG. 5 (c), the second gain Kdiff2 is given as a positive value proportional to the CSD clutch torque differential value T _CSD 'when the CSD clutch torque differential value T _CSD ' is positive, and a negative value proportional to the negative value. To be

That is, when the lateral acceleration is large and the differential limiting torque is large, or when the lateral acceleration is large and the increasing change of the differential limiting torque is large, the oversteer moment is easily generated.
The differential steering torque sensitive gain Kgd is given as a high value according to the ease of oversteering moment.

At step 36, it is judged if the differential limited torque sensitive gain Kgd is larger than the set value Kgdo which is considered to cause the oversteer moment.

In step 37, the ETS clutch torque T _ETS is proportional gain Kdv and differential limiting torque sensitive gain K.
It is calculated by the following formula from gd and the front-rear wheel rotation speed difference ΔV.

T _ETS = (Kdv + Kgd) ΔV In step 38, the ETS clutch torque T _ETS is calculated by the following equation from the proportional gain Kdv and the front and rear wheel rotation speed difference ΔV.

T _ETS = Kdv · ΔV In step 39, step 37 or step 38
The ETS clutch torque T _ETS obtained in the above is converted into an obtained current value I _ETS .

In step 40, the current value I _ETS is output to the ETS control valve 16 of the hydraulic unit 12.

(B) When the occurrence of oversteer moment due to differential limiting is small When the differential limiting torque is small or the differential limiting torque differential value is small even during straight traveling or turning, step 3
The differential limiting torque sensitive gain Kgd at 5 is set to a small value, and it is determined NO at step 36.

Therefore, in the flowchart of FIG. 3, step 30 → step 31 → step 32 → step 33 → step 34 → step 35 → step 36.
→ Step 38 → Step 39 → Step 40, and in Step 38, the ETS clutch torque T
_{The ETS} is calculated from the proportional gain Kdv and the front / rear wheel rotation speed difference ΔV, and so-called basic front / rear wheel driving force distribution control is performed.

This front and rear wheel drive force distribution control is a control that increases the transmission torque to the front wheel side as the occurrence of rear wheel slip increases, so that it is possible to achieve both 4WD drive performance and running of a rear wheel drive vehicle. Further, since the control is such that the proportional gain Kdv is lowered as the lateral acceleration increases, ideal turning performance can be realized by weak understeer to weak oversteer on any road surface.

(C) When an oversteer moment is generated due to the differential limitation When acceleration is performed on a high μ road with a large accelerator depression amount or accelerator depression speed, when the lateral acceleration is large and the differential limiting torque is large, or When the acceleration is large and the increase in the differential limiting torque is large, the oversteer moment is likely to occur. Therefore, in step 35, the differential limiting torque sensitive gain Kgd is set to a high value according to the ease of the oversteer moment. It is determined NO in 36.

Therefore, in the flowchart of FIG. 3, step 30 → step 31 → step 32 → step 33 → step 34 → step 35 → step 36.
→ Step 37 → Step 39 → Step 40, and in Step 37, the ETS clutch torque T
_ETS is proportional gain Kdv, differential limiting torque sensitive gain Kgd
And the front-rear wheel rotational speed difference ΔV, and the ETS is obtained by adding the differential torque limiting correction torque (Kgd · ΔV) to the clutch torque (Kdv · ΔV) by the so-called basic front-rear wheel driving force distribution control. Clutch torque T
Front / rear wheel drive force distribution control is performed to obtain _ETS . When the lateral acceleration is large, such as when accelerating on a high μ road, the proportional gain due to the basic control is small, and there is plenty of room for the front and rear wheel drive force distribution control system to increase the transmission drive torque to the front wheels. .

The correction torque (Kgd · ΔV) corresponding to the differential limiting torque in the front-rear wheel driving force distribution control is such that the differential limiting torque sensitive gain Kgd is the lateral acceleration Y _G and the CSD clutch torque T.
By calculating the _CSD and CSD clutch torque differential value T _CSD ', it becomes a value according to the oversteer moment that may be generated by the differential limiting control, and this differential limiting torque corresponding correction torque (Kgd · ΔV) is Front wheels 10,1
An understeer moment is generated by being added to the drive torque transmitted to 1, and this understeer moment cancels the oversteer moment generated by the differential limiting control, and the steer characteristic of the vehicle is corrected in the neutral steer direction.

Further, the clutch torque (Kdv · ΔV) by the basic front / rear wheel drive force distribution control is given on the side of the front / rear wheel drive force distribution control system, and the control on the side of the differential limiting control does not change at all. Therefore, the improvement of the driving performance by the driving force distribution control of the front and rear wheels and the left and right wheels can be ensured as it is.

Next, the effect will be described.

(1) Front-rear wheel and left-right wheel drive force comprehensive control device applied to a rear-wheel drive-based four-wheel drive vehicle equipped with both the front-rear wheel drive force distribution control system and the differential limiting torque control system When turning, when oversteer moment is expected to occur due to control on the differential limiting torque side,
Since the front and rear wheel drive force distribution control system performs correction control by adding a correction torque (Kgd · ΔV) corresponding to the differential limiting torque corresponding to the differential limiting torque sensitive gain Kgd,
It is possible to achieve both improved drive performance and improved steer characteristics during turning.

(2) The occurrence of oversteer moment in the differential limiting torque control is predicted by the lateral acceleration Y _G , the CSD clutch torque T _CSD , and the CSD clutch torque differential value T _CSD ', and the oversteer moment amount is integrated. Since the differential limiting torque sensitive gain Kgd is used to obtain the oversteer moment or to obtain the amount of oversteer moment only by the lateral acceleration Y _G which is the turning information and the CSD clutch torque T _CSD which is the differential limiting information. By comparison, the CSD clutch torque differential value T
By adding _CSD ', it is possible to anticipate the occurrence of oversteer moment at an early stage, and it is possible to obtain an accurate amount of oversteer moment, so that the steer characteristic can be greatly improved.

(Second Embodiment) A total driving force distribution control system for front and rear wheels and left and right wheels according to a second embodiment of the present invention will be described.

First, the structure will be described.

The overall system to which the device of the second embodiment is applied is the same as that of FIG. 2 showing the overall system to which the device of the first embodiment is applied, and therefore, illustration and description thereof will be omitted.

Next, the operation will be described.

(A) Differential limiting torque control operation FIG. 6 is a flowchart showing the flow of the differential limiting torque control operation performed by the CSD control section 18b of the controller 18 (understeer moment detecting means and second step).
Equivalent to total control means).

At step 60, the lateral acceleration Y _G , accelerator opening θ and ETS clutch torque T _ETS are read.
The ETS clutch torque T _ETS may be given by the control law of the above-mentioned first embodiment, or may be given by the control law including other control elements.

At step 61, the accelerator opening speed θ'is calculated by the differential calculation processing of the accelerator opening θ.

[0061] At step 62, the accelerator opening proportional gain Ka is calculated by the lateral acceleration Y _G. This accelerator opening proportional gain Ka is zero until the lateral acceleration Y _G reaches a predetermined value,
It is given as a value that suddenly increases when it exceeds a predetermined value.

[0062] At step 63, the basic accelerator opening speed proportional gain Ka 'is calculated by the lateral acceleration Y _G. The basic accelerator opening speed proportional gain Ka 'is given as a value that is zero until the lateral acceleration Y _G reaches a predetermined value and that increases rapidly when the lateral acceleration Y _G exceeds the predetermined value.

In step 64, the correction gain Ke 'is calculated from the ETS clutch torque T _ETS . The correction gain Ke ′ is given as a value that is zero until the ETS clutch torque T _ETS reaches a predetermined value and that increases rapidly when the ETS clutch torque T _ETS exceeds the predetermined value.

In step 65, it is judged whether or not the lateral acceleration Y _G is larger than a set value a (for example, a = 0.7 G) which is considered to cause an understeer moment.

In step 66, the accelerator opening speed proportional gain Kx is calculated by the sum of the basic accelerator opening speed proportional gain Ka 'and the correction gain Ke'.

At step 67, the basic accelerator opening speed proportional gain Ka 'is kept unchanged and the accelerator opening speed proportional gain Kx is kept.
It is said that

In step 68, the CSD clutch torque T _CSD is calculated by the following formula from the accelerator opening proportional gain Ka, the accelerator opening θ, the accelerator opening speed proportional gain Kx and the accelerator opening speed θ '.

T _CSD = Ka * θ + Kx * θ 'At step 69, the CSD clutch torque T _CSD obtained at step 68 is converted into an obtained current value I _CSD .

In step 70, the current value I _CSD is output to the CSD control valve 17 of the hydraulic unit 12.

(B) When the occurrence of the understeer moment due to the ETS control is small When the lateral acceleration Y _G is small even during straight traveling or turning, it is judged NO in step 66.

Therefore, in the flowchart of FIG. 6, step 60 → step 61 → step 62 → step 63 → step 64 → step 65 → step 67.
→ Step 68 → Step 69 → Step 70, and in Step 67, the basic accelerator opening speed proportional gain Ka ′ is directly used as the accelerator opening speed proportional gain Kx, and so-called basic differential limiting torque control is performed. .

In this differential limiting torque control, the differential limiting torque is increased in proportion to the accelerator opening and the accelerator opening speed, and the control gain is increased as the lateral acceleration increases. Since the control increases the transmission torque to the outer wheel side, it is possible to improve the oversteer response at the initial stage of acceleration, that is, the response of accelerator control.

(C) When an understeer moment is generated by the ETS control The road surface is slippery and the driving wheel slip is large so that the low μ
Large ETS clutch torque T, such as when turning the road
_{When ETS} is given, in step 64,
The correction gain Ke ′ is calculated according to the magnitude of the ETS clutch torque T _ETS , and the turning determination step, step 65.
Is determined to be YES.

Therefore, in the flowchart of FIG. 6, step 60 → step 61 → step 62 → step 63 → step 64 → step 65 → step 66.
→ Step 68 → Step 69 → Step 70. In Step 66, the value obtained by adding the correction gain Ke 'to the basic accelerator opening speed proportional gain Ka' is set as the accelerator opening speed proportional gain Kx, which is the basic differential limiting torque. ETS to the control clutch torque (Ka * θ + Ka '* θ')
The differential limiting torque control is performed so that the CSD clutch torque T _{CSD to} which the torque corresponding correction torque (Ke '* θ') is added is obtained. When the accelerator opening speed is low, such as when turning on a low μ road, the proportional gain Ka 'by the basic control is small, and there is a sufficient margin for increasing the differential limiting torque on the differential limiting torque control system side.

In the ETS torque-corresponding correction torque (Ke '* θ') in this differential limiting torque control, the correction gain Ke 'is E.
By calculating with the TS clutch torque T _ETS , E
It corresponds to the understeer moment that may be generated by the TS control, and this ETS torque-corresponding correction torque (Ke '* θ') is transmitted to the side of the left and right rear wheels 5 and 6 that is the outer turning wheel. Is applied to generate an oversteer moment, the oversteer moment cancels the understeer moment generated by the ETS control, and the steering characteristic of the vehicle is corrected in the neutral steer direction.

Further, the basic clutch torque (Ka * θ + Ka ′ * θ ′) is applied on the differential limiting torque control system side, and the control on the front / rear wheel drive force distribution control system side does not change at all. Therefore, the improvement of the driving performance by the driving force distribution control of the front and rear wheels and the left and right wheels can be ensured as it is.

Next, the effect will be described.

(1) Front-rear wheel and left-right wheel drive force comprehensive control device applied to a rear-wheel drive-based four-wheel drive vehicle equipped with both the front-rear wheel drive force distribution control system and the differential limiting torque control system At the time of turning, when the understeer moment is expected to occur due to the control on the front and rear wheel drive force distribution control system side, the correction control that adds the ETS torque corresponding correction torque (Ke '* θ') according to the correction gain Ke 'is Since the device is performed on the side of the dynamic limiting torque control system, it is possible to achieve both improvement of drive performance and improvement of steer characteristics during turning.

(2) Since the gain of the accelerator opening speed θ'is corrected with respect to the expected occurrence of an understeer moment due to the magnitude of the ETS clutch torque T _ETS , the accelerator in which a sudden change in steer characteristic becomes a problem It is possible to effectively improve the steer characteristic during turning acceleration while stepping on.

Although the embodiment has been described above with reference to the drawings, the specific structure is not limited to this embodiment.

For example, the first embodiment device and the second embodiment device are integrated controls in which when one control system is in the control limit direction, the other control system side compensates the steer characteristic. The device of the first embodiment and the device of the second embodiment may be mounted on the same vehicle and applied.

In the embodiment, the example of application to the rear wheel drive-based four-wheel drive vehicle is shown, but the invention can also be applied to the front wheel drive-based four-wheel drive vehicle. In this case, in order to obtain the understeer characteristic in the front / rear wheel drive force distribution control, the clutch torque is weakened to control in the front wheel drive direction.

In the first embodiment, the occurrence of the oversteer moment is expected, and in the second embodiment, the occurrence of the understeer moment is expected. However, in any case, the direct or indirect detection of the drive torque causes An example in which the occurrence of an oversteer moment or an understeer moment is detected may be used.

[0084]

According to the present invention, the driving force of the front and rear wheels and the driving force of the left and right wheels applied to a vehicle equipped with both the front and rear wheel driving force distribution control system and the left and right wheel driving force distribution control system. In the integrated distribution control device, when the oversteer moment occurs or is expected to occur due to the control on the left and right wheel drive force distribution control system during turning, the front and rear wheel drive correction control that adds the front wheel distribution amount according to the oversteer moment detection amount Since the first total control means to be performed on the side of the force distribution control system is provided, it is possible to obtain an effect that both improvement of drive performance and improvement of steer characteristics can be achieved at the time of turning.

According to the second aspect of the present invention, the front and rear wheels and the left and right wheels are combined for driving force distribution applied to a vehicle equipped with both the front and rear wheels driving force distribution control system and the left and right wheels driving force distribution control system. In the control device, when the understeer moment occurs or is expected to occur due to the control on the front / rear wheel drive force distribution control system side during turning, the correction control that adds the turning outer wheel distribution amount according to the detected understeer moment is applied to the left and right wheel drive forces. Since the second comprehensive control means is provided on the side of the distribution control system, it is possible to achieve an improvement in drive performance and an improvement in steer characteristics at the time of turning.

[Brief description of drawings]

1 (a) is a claim correspondence diagram showing a front and rear wheel and left / right wheel driving force distribution integrated control device of the present invention corresponding to claim 1; FIG. 1 (b) is claim 1; FIG. 6 is a diagram showing the claims corresponding to the front and rear wheels and the left and right wheels driving force distribution integrated control device according to the present invention.

FIG. 2 is an overall system diagram showing a rear-wheel drive-based four-wheel drive vehicle to which the front-rear wheel and left-right wheel driving force distribution comprehensive control device of the first embodiment is applied.

FIG. 3 is a flow chart showing a flow of front and rear wheel driving force distribution control operation performed by an ETS control unit of the controller of the first embodiment device.

FIG. 4 is a proportional gain characteristic diagram in ETS basic control.

5A is a characteristic diagram of a coefficient Kxx according to a lateral acceleration Y _G , and FIG. 5B is a characteristic diagram of a first gain Kdiff1 according to a CSD clutch torque T _CSD . 5 (c) is C
Second gain K according to SD clutch torque differential value T _CSD '
It is a characteristic diagram of diff2.

FIG. 6 is a flowchart showing a flow of a differential limiting torque control operation performed by a CSD control unit of the controller of the second embodiment device.

[Explanation of symbols]

 a front and rear wheel drive force distribution control system b left and right wheel drive force distribution control system c oversteer moment detection means d first comprehensive control means e understeer moment detection means f second comprehensive control means

Claims (2)

[Claims] 1. A front / rear wheel drive force distribution control system for controlling drive force distribution to front and rear wheels according to a predetermined vehicle state, and left and right wheels for controlling drive force distribution to left and right wheels according to a predetermined vehicle state. A driving force distribution control system, oversteer moment detecting means for detecting when an oversteer moment occurs or is expected to occur due to control on the side of the left and right wheel driving force distribution control system during turning, and an oversteer moment The front / rear wheel driving force distribution control system, the front / rear wheel driving force distribution control system performs a correction control in which the front wheel distribution amount is added according to the detected oversteer moment. Integrated control device for driving force distribution between wheels and left and right wheels. 2. A front and rear wheel drive force distribution control system for controlling drive force distribution to front and rear wheels according to a running state of a vehicle, and left and right wheels for controlling drive force distribution to left and right wheels according to a running state of the vehicle. A driving force distribution control system, understeer moment detection means for detecting when an understeer moment occurs or is expected to occur under control of the front and rear wheel drive force distribution control system during turning, and an understeer moment And a second comprehensive control means for causing the left and right wheel drive force distribution control system side to perform a correction control in which a turning outer wheel distribution amount is added in accordance with an understeer moment detection amount. Integrated control device for front and rear wheels and left and right wheels.