JP3079538B2 - Comprehensive control system for auxiliary steering angle and braking / driving force - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an integrated control device for auxiliary steering angle and braking / driving force.

2. Description of the Related Art Conventionally, as a rear wheel steering angle control device which is an example of an auxiliary steering angle control device, for example, a device described in JP-A-59-77968 is known. At low vehicle speed or when the front wheel steering angle is large, the rear wheels are steered in the opposite phase, and at high vehicle speed or when the front wheel steering angle is small, the rear wheels are steered in phase. The contents to improve the steering performance are shown.

Conventionally, as a driving force distribution control device for a four-wheel drive vehicle, which is an example of a braking / driving force control device, for example, Japanese Unexamined Patent Publication No.
A device described in Japanese Patent No. 157437 is known, and in this conventional source, when a driving wheel slip occurs, the driving force distribution to the driven wheels is increased to control the driving force distribution in the four-wheel drive direction, and the vehicle is quickly started. The contents to improve the driving performance and the running stability at the time of acceleration, acceleration and the like are shown.

(Problems to be Solved by the Invention) However, when the rear wheel steering angle control device and the driving force distribution control device for a four-wheel drive vehicle are simultaneously mounted on one vehicle, the rear wheel steering angle control sensitivity and the driving force If the distribution control sensitivity is set independently, and the rear wheel steering angle control and the driving force distribution control are performed independently of each other based on the set sensitivity,
Originally, this point is not considered at all even though the vehicle state area where the control effect of the auxiliary steering angle control is large and the vehicle state area where the control effect of the braking / driving force control are large are different.
The total control effect of both control devices is not optimal.

In addition, when the rear wheel steering angle control and the driving force distribution control are performed simultaneously, the control amount is the same as when the vehicle is mounted alone and the total energy consumption is reduced even in the vehicle state where one control effect is small. When the total energy consumption is limited due to reasons such as fuel efficiency in a vehicle equipped with a plurality of control devices as described above, the control amount on the side where the control effect is large may be limited. .

Therefore, it is conceivable to simply perform cooperative control to improve a certain performance or perform control to compensate for the other performance degradation by changing one control and link the controls with each other. In this case, the effect can be obtained only for this purpose, and the optimization of the total control effect cannot be achieved.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problem. In a general control device for a vehicle in which an auxiliary steering angle control device and a braking / driving force control device are simultaneously mounted, control is performed when both control devices are simultaneously operated. It is an object of the present invention to optimize the total control effect of both control devices while preventing the control amount from being restricted on the side of the device having a large effect.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the integrated control device for auxiliary steering angle and braking / driving force according to the present invention has a vehicle state region in which the control effect of the auxiliary steering angle control is large, A vehicle state area having a large control effect is distinguished by the same parameter including at least the longitudinal acceleration, and the control sensitivity is changed according to the magnitude of the control effect.

That is, as shown in the claim correspondence diagram of FIG. 1, in the invention of claim 1, an auxiliary steering angle control device a for controlling at least one of the front wheels or the rear wheels during steering of the front wheels, and a control for each wheel. a longitudinal force control device b for controlling at least one of power or driving force, and longitudinal acceleration detecting means c for detecting a longitudinal acceleration X _G acting on the vehicle, multiplying the basic control amount arithmetic expression to obtain the target control amount when defining the values and the control sensitivity, when the value of the longitudinal acceleration detection value is smaller is set smaller the larger longitudinal force control sensitivity alpha _T auxiliary steering angle control sensitivity alpha _S, the value of the longitudinal acceleration detection value increases Accordingly, characterized in that it comprises a and a general control sensitivity setting means e for setting the auxiliary steering angle control sensitivity alpha _S decrease by braking-driving force control sensitivity alpha _T increases.

According to the second aspect of the present invention, an auxiliary steering angle control device a for controlling at least one of the front wheels and the rear wheels during steering of the front wheels, and a braking / driving device for controlling at least one of the braking force or the driving force of each wheel. a force control unit b, and the longitudinal acceleration detection means c for detecting a longitudinal acceleration X _G acting on the vehicle, the lateral acceleration detecting means d for detecting a lateral acceleration Y _G acting on the vehicle,
When the value to be multiplied by the basic control amount is defined as the control sensitivity in the equation for obtaining the target control amount, the sum of the square of the longitudinal acceleration detection value and the square of the lateral acceleration detection value (X _G ² + Y _G ² ) is calculated, When the calculated value of the sum of the squares (X _G ² + Y _G ² ) is equal to or less than a predetermined value, the auxiliary steering angle control sensitivity α _S is set to a large constant value and the braking / driving force control sensitivity α _T is set to a small constant value. , When the calculated value of the sum of squares (X _G ² + Y _G ² ) exceeds a predetermined value, the ratio of the longitudinal acceleration detection value to the lateral acceleration detection value (α _T / α _S )
When the calculated ratio (α _T / α _S ) is small, the auxiliary steering angle control sensitivity α _S is increased and the braking / driving force control sensitivity α _T is increased.
Control sensitivity setting means e for setting the auxiliary steering angle control sensitivity α _S to be smaller and the braking / driving force control sensitivity α _T to be larger as the value of the calculated ratio (α _T / α _S ) becomes larger. And is characterized by having.

(Operation) According to the first aspect of the present invention, when the vehicle travels, when the value to be multiplied by the basic control amount in the arithmetic expression for obtaining the target control amount is defined as the control sensitivity, when the value of the longitudinal acceleration detection value detected from the longitudinal acceleration detecting means c is small is set auxiliary steering angle control sensitivity alpha _S is large, the braking-driving force control sensitivity alpha _T is set small.
Then, set the auxiliary steering angle control sensitivity alpha _S is small according to the value of the longitudinal acceleration detection value increases, the braking-driving force control sensitivity alpha _T is set larger.

According to the second aspect of the present invention, when the control sensitivity is defined as a value obtained by multiplying the basic control amount by an arithmetic expression for obtaining the target control amount, the longitudinal acceleration is determined by the total control sensitivity setting means e during vehicle running. The sum of the square of the detection value and the square of the lateral acceleration detection value (X _G ² + Y _G ² ) is calculated, and the sum of the squares (X _G ² + Y
Calculated value of _G ²⁾ is at a predetermined value or less, the auxiliary steering angle control sensitivity alpha _S is longitudinal force control sensitivity alpha _T while being set to a predetermined value is set to a small constant value. When the calculated value of the sum of squares (X _G ² + Y _G ² ) exceeds a predetermined value, the ratio of the longitudinal acceleration detection value to the lateral acceleration detection value (α _T /
α _S ) is calculated, and when the calculated ratio (α _T / α _S ) is small, the auxiliary steering angle control sensitivity α _S is set large, and the braking / driving force control sensitivity α _T is set small. As the value of the ratio (α _T / α _S ) increases, the auxiliary steering angle control sensitivity α _S is set smaller, and the braking / driving force control sensitivity α _T
Is set large.

That is, both the control sensitivities α _S and α _T are changed using X _G or (X _G ² + Y _G ² ) as a parameter.
This is for the following reason.

Since the braking / driving force control is a slip ratio control based on the distribution of the driving force or the braking force, the driving effect or the braking force is large, the control effect is large in a region where the slip ratio is large, and the region where the control effect is large is the longitudinal acceleration. Is a large area.

The auxiliary steering angle control has an effect in the cornering power characteristic of the tire from the linear region to the non-linear region, but since the effect of other control devices is large in the non-linear region, the control effect is relatively large in the linear region of the tire characteristic, The region where the control effect is large can be regarded as a region where the longitudinal acceleration and the lateral acceleration where the wheel load movement is small are small.

Therefore, it is possible to areas distinguished according to the magnitude of the control effect by X _G or a ^{_{(X G 2 + Y G 2}} ) as parameters,
The X _G or ^{_{(X G 2 + Y G 2}} ) during running value is small, that the auxiliary steering angle control sensitivity alpha _S is relatively enhanced with respect to the longitudinal force control sensitivity alpha _T, the braking-driving force control Therefore, the change in the cornering power of the front and rear wheels due to the control is suppressed to a small value, and the auxiliary steering angle control having a large control effect is sufficiently utilized. And
When the vehicle travels with a large value of X _G or (X _G ² + Y _G ² ), the braking / driving force control sensitivity α _T is set to be relatively higher than the auxiliary steering angle control sensitivity α _S , so that the auxiliary steering angle control is performed. As a result, the change in wheel slip rate due to the change in wheel load can be kept small, and the braking / driving force control with a large control effect can be fully utilized, and the total control effect of both control devices a and b can be reduced. Optimization is achieved.

Further, even if the total energy consumption is limited due to reasons such as fuel efficiency, etc., both control sensitivities α _S , α _T change control reduces the energy consumption on the side of the device having a small control effect, so both control devices a, b Among them, the control amount limitation on the side of the device having a large control effect is prevented.

First Embodiment First, the configuration will be described.

FIG. 2 shows a front and rear wheel steering angle control device (an example of an auxiliary steering angle control device), a front and rear wheel driving force distribution control device (an example of a braking / driving force control device), and an active suspension control device (an example of a wheel load distribution control device). FIG. 1 is an overall system diagram showing a vehicle simultaneously mounted with the above.

The vehicle equipped with each control system is a torque split four-wheel drive vehicle based on a rear wheel drive, and the right and left rear wheels 1R, 1L are equipped with an engine 2, a transmission 3, a rear propeller shaft 4, a rear differential 5, Engine driving force is transmitted via rear drive shafts 6R and 6L.

The engine driving force is transmitted to the left and right front wheels 7R, 7L from a transfer 8 provided in the middle of the rear propeller shaft 4 via a front propeller shaft 9, a front differential 10, and left and right front drive shafts 11R, 11L.

Further, between the front steering gear device 12 for steering the front wheels 7R, 7L and the left and right rear wheels 1R, 1L, front and rear wheel steering for giving an auxiliary steering angle to the front wheels 7R, 7L and the rear wheels 1R, 1L by a piston stroke by supply hydraulic pressure. A front wheel hydraulic power cylinder 13 and a rear wheel hydraulic power cylinder 14 are provided as angle control actuators.

The transfer 8 has a built-in hydraulic multi-plate clutch 15 as a front and rear wheel drive force distribution control actuator that applies a variable transmission torque to the front wheels by controlling the engagement pressure.

Further, between the sprung and unsprung portions of each wheel, a hydraulic cylinder 16 as an active suspension control actuator for actively suppressing the swing of the vehicle body by independently controlling the supply hydraulic pressure.
FR, 16FL, 16RR, 16RL are provided.

The supply hydraulic pressure to the front wheel hydraulic power cylinder 13 and the rear wheel hydraulic power cylinder 14 is controlled by a front wheel hydraulic control valve 17F.
And a valve operation control command from the steering angle control controller 18 for the rear wheel hydraulic control valve 17R.A detection signal is input to the steering angle control controller 18 from a front wheel steering angle sensor 19, a vehicle speed sensor 20, and the like. In addition, model adaptation control of yaw rate for obtaining a desired yaw rate response at the time of turning, phase inversion control for achieving both steering response and steering stability, and the like are performed.

The control of the supply hydraulic pressure to the hydraulic multi-plate clutch 15 is performed by a valve operation control command from the driving force distribution controller 22 to the driving force distribution control valve 21, and the driving force distribution controller 22 includes a right front wheel rotation sensor 23, Left front wheel rotation sensor 24, Right rear wheel rotation sensor 25, Left rear wheel rotation sensor 2
6, Detection signals from the lateral acceleration sensor 27 etc. are input and the driving force distribution is changed from rear wheel drive (0: 100) to rigid 4WD (50:50)
By the above-described front and rear wheel driving force distribution control that continuously controls the vehicle, for example, while starting or accelerating, the driving wheel distribution is reduced by reducing the driving force distribution to the front wheels during turning to reduce rear wheel driving tendency. For example, control for improving both driving performance and turning performance is performed.

The hydraulic pressure supplied to the hydraulic cylinders 16FR, 16FL, 16RR, 16RL is controlled by a right front wheel control valve 28FR, a left front wheel control valve 28FL,
The suspension control controller 29 controls the right rear wheel control valve 28RR and the left rear wheel control valve 28RL according to valve operation control commands. The suspension control controller 29 includes a vertical acceleration sensor 30, a lateral acceleration sensor 2
7, detection signals from the longitudinal acceleration sensor 31, the vehicle height sensor 32, and the like are input, and for example, vehicle body vertical restraint control, vehicle body roll restraint control, vehicle pitching restraint control, vehicle height change restraint control, etc. Done.

And the longitudinal acceleration sensor 31 (longitudinal acceleration detecting means)
And the detection signal from the lateral acceleration sensor 27 (lateral acceleration detecting means) and the switch signal from the manual switch 33 are input to determine the magnitude of the control effect according to the vehicle state (X _G ² +
Y _G ² ) and (X _G / Y _G ) are distinguished as parameters, and the auxiliary steering angle control sensitivity α _S , the driving force distribution control sensitivity α _T, and the wheel load distribution control sensitivity α _R that are optimal for the vehicle state at that time are determined. There is provided a general control controller 34 (general control sensitivity setting means) which outputs the obtained control sensitivities α _S , α _T , α _R to the respective controllers 18, 22, 29.

The manual switch 33 is a switch for changing the control characteristic mode in order to reflect the driver's intention and preference. In the embodiment, two modes, a mode A for emphasizing driving force characteristics and a mode B for turning characteristics, are set. I have.

FIG. 3 shows a specific example of the front and rear wheel steering angle control system, FIG. 4 shows a specific example of the front and rear wheel driving force distribution system, and FIG.
The figure shows a specific example of an active suspension control system, all of which are well known and detailed description is omitted.

Next, a basic concept regarding control sensitivity setting in the present embodiment will be described.

^{_{(I) (X G 2 + Y G}} 2), (X G / Y G) first reason for a parameter for distinguishing the magnitude region of the control ^{_{effect, (X G 2 + Y G}} 2), (X G / Y G) each control sensitivity alpha _S as a parameter for distinguishing the magnitude region of the control effect, α _T, α _R
Is changed and set for the following reason.

・ Since the braking / driving force control is a slip ratio control based on the distribution of the driving force or the braking force, the driving force or the braking force is large, and the control effect is large in a region where the slip ratio is large. It can be called an acceleration region or a deceleration region where the acceleration is large.

In the wheel load distribution control, since the cornering power of the tire is controlled by controlling the amount of load movement between the left and right wheels (or between the front and rear wheels), the control effect is large in an area where the load movement is large.

That is, it is a region where the lateral acceleration and the longitudinal acceleration are large.
However, emphasis is placed on lateral acceleration rather than longitudinal acceleration, since lateral acceleration often occurs more steadily.

・ Auxiliary steering angle control has an effect on the cornering power characteristics of the tire from the linear range to the non-linear range, but since the effect of other control devices is large in the non-linear range, the control effect is relatively large in the linear region of the tire characteristics. The region where the control effect is large can be regarded as a region where the longitudinal acceleration and the lateral acceleration where the wheel load movement is small are small.

Accordingly, FIG. 6 is a conceptual diagram showing a vehicle state region having a large control effect by the respective control sensitivities α _S , α _T , and α _R.

(B) Problems when control sensitivity is fixed value a) Problems in the area where (X _G ² + Y _G ² ) is good at assisting steering angle control ・ About braking / driving force control Basically, control is not performed in this area. It is unnecessary and wastes power, and despite the fact that it is desired to increase the auxiliary steering angle control effect by applying a lot of power (for example, oil pressure in hydraulic control) to the auxiliary steering angle control, due to reasons such as fuel efficiency, Since the total output is limited, the power required by the auxiliary steering angle control device cannot be obtained.

In terms of performance, the cornering power of the front and rear wheels changes in conjunction with the change in the braking / driving force, and the control effect of the auxiliary steering angle control device that controls the cornering power as if there is no change is impaired.

・ About wheel load distribution control The point that the power is wasted and the power of the auxiliary steering angle control device cannot be obtained is the same as the braking / driving force control.

In terms of performance, the independent control of the auxiliary steering angle control is controlled by assuming that the steering characteristic has a constant value, but the steering characteristic changes due to the wheel load distribution control (specifically, the front and rear cornering powers). ), The characteristic originally intended by the auxiliary steering angle control cannot be obtained.

b) (X _G ² + Y _G ² ) is good at wheel load distribution control,
Problems in the area where (X _G / Y _G ) is small ・ Auxiliary steering angle control The point that the power is wasted and the power of the wheel load distribution control device cannot be obtained is the same as the others.

In terms of performance, for example, the side slip angle of the tire changes due to the control of the auxiliary steering angle, the direction of the lateral force and the longitudinal force acting on the tire changes, and the moving amount of the wheel load changes (rear wheel movement). , The sideslip angle is directed toward the inside of the turn, the wheel load on the front inner wheel decreases, and the wheel load on the rear outer wheel increases.)

Therefore, the state before the control of the wheel load distribution control is different depending on the presence or absence of the auxiliary steering angle control, and the intended control in the wheel load distribution control cannot be appropriately performed.

・ About braking / driving force control The point that the power is wasted and the power of the wheel load distribution control device cannot be obtained is the same as the others.

In terms of performance, for example, in the front and rear wheel driving force distribution control, the slip ratio of the front and rear wheels fluctuates to change the driving force distribution. Despite the desire to optimize the cornering force generated by each wheel by controlling the steering characteristic by the wheel load distribution control, the cornering force deviates from the optimum value due to the change in the slip ratio.

c) (X _G ² + Y _G ² ) which is good at braking / driving force control is large, and (X _G
Problems in the region where / Y _G ) is large ・ Auxiliary steering angle control The point that the power is wasted and the power of the braking / driving force control device cannot be obtained is the same as the others.

In terms of performance, for example, the side slip angle of the tire changes due to the control of the auxiliary steering angle, the direction of the lateral force and the longitudinal force acting on the tire changes, and the moving amount of the wheel load changes (rear wheel movement). , The sideslip angle is directed toward the inside of the turn, the wheel load on the front inner wheel decreases, and the front inner wheel spins.)

Therefore, the slip ratio of each wheel changes due to the change in the wheel load, and finally, the difference between the front and rear wheel rotational speeds differs depending on the presence or absence of the auxiliary steering angle control, so that the intended control cannot be performed.

・ About wheel load distribution control The point that the power is wasted and the power of the wheel load distribution control device cannot be obtained is the same as the others.

In terms of performance, for example, when the wheel load of one wheel decreases due to the wheel load distribution control, the slip rate of the tire increases, and in the worst case, the tire slips and the difference in the rotational speed of the front and rear wheels becomes the wheel load. Since it changes depending on the presence or absence of the distribution control, the desired control cannot be performed.

 Next, the operation will be described.

FIG. 7 is a flow chart showing the flow of the control sensitivity setting processing operation in the general control controller 34 which sets the respective control sensitivities α _S , α _T , α _R and outputs them to the controllers 18, 22, 29.
Hereinafter, each step will be described.

In step 101, a switch signal from the manual switch 33 and sensor signals from the longitudinal acceleration sensor 31 and the lateral acceleration sensor 27 are read.

In step 102, the square of the longitudinal acceleration X _G and the lateral acceleration Y _G
Is calculated.

In step 103, it is determined whether the value of (X _G ² + Y _G ² ) is equal to or greater than a predetermined value.

If the value of (X _G ² + Y _G ² ) is less than the predetermined value, the process proceeds to step 108, where the auxiliary steering angle control sensitivity α _S , the driving force distribution control sensitivity α _T , and the wheel load distribution control sensitivity α _R Is α
_S1, alpha _T1, sets the alpha _R1.

Here, α _T1 and α _R1 are set to extremely small values with respect to α _{S1 so} that the auxiliary steering angle control effect is increased.
For example, α _S1 = 1 and α _T1 , α _R1 ≒ 0 may be set.

On the other hand, if it is determined in step 103 that the value of (X _G ² + Y _G ² ) is equal to or greater than the predetermined value, the process proceeds to step 104 and subsequent steps.

In step 104, (X
The values of the auxiliary steering angle control sensitivity α _S and the control gain K _S are calculated from the auxiliary steering angle control sensitivity characteristic map and the control gain characteristic map for the value of _G ² + Y _G ² ).

Although these characteristic map is selected by characteristic mode by manual switch 33, basically, the auxiliary steering angle control sensitivity alpha _{S ^{is, (X G 2 + Y G}} 2) Higher the smaller increase (right downward ), The control gain K _S is (X _G ² + Y _G ² )
The characteristic is set to increase (increase right) as the value increases.

In step 105, the value of (X _G / Y _G ) is calculated.

In step 106, (X
The values of the driving force distribution basic control sensitivity α _TO and the wheel load distribution basic control sensitivity α _RO are calculated from the driving force distribution control sensitivity characteristic map and the wheel load distribution control sensitivity characteristic map for the value of _G / Y _G ).

It should be noted that these characteristic maps are selected in the characteristic mode by the manual switch 33. Basically, the driving force distribution basic control sensitivity α _TO increases as the value of (X _G / Y _G ) increases (increases to the right). ), Wheel load distribution basic control sensitivity α
_RO is set so that it becomes smaller (lower right) as the value of (X _G / Y _G ) becomes larger.

In step 107, the basic control sensitivities α _TO and α _RO obtained in step 106 are corrected by the following equation, and the driving force distribution control sensitivity α _T and the wheel load distribution control sensitivity α _R are calculated.

α _T = α _TO · K _S α _R = α _RO · K _{S In} step 109, the control sensitivities α _S , α _T , α obtained in step 104 and step 107 or step 108 are obtained.
_R is output to the steering angle controller 18, the driving force distribution controller 22, and the suspension control controller 29, respectively.

Based on the settings of the control sensitivities α _S , α _T , and α _R described above, the controllers 18, 22, and 29 perform the following control.

As shown in the following equation, the steering angle control controller 18 multiplies the basic control steering angles f _sf and f _sr by the auxiliary steering angle control sensitivity α _S to obtain the front wheel auxiliary steering angle target value δ _F ^* and the rear wheel is an auxiliary steering angle target value [delta] _R ^*, the target value δ _F ^*, δ _R ^*
Is output to the front wheel steering angle control valve 17F and the rear wheel steering angle control valve 17R.

^{_{δ F * = α S · f}} sf (θ, V) δ R * = α S · f sr (θ, V) in the driving force distribution controller 22, as shown in the following formula, the basic front wheel side driving force distribution ratio the value obtained by multiplying the driving force distribution control sensitivity alpha _T to f _T is the driving force distribution wheel ratio target value T _F ^*
A command signal for obtaining the target value T _F ^* is output to the driving force distribution control valve 21.

T _F ^* = α _T · f _T (ΔN, Y _G ) where ΔN is the difference between the front and rear wheel rotation speeds, and the rear wheel rotation speed Nr and the front wheel rotation are determined by signals from the rotation sensors 23, 24, 25, and 26. The speed Nf is obtained by the following equation which takes the difference between them.

ΔN = Nr−Nf In the suspension control controller 29, as shown in the following equation, the value obtained by multiplying the basic wheel load distribution ratio f _R by the wheel load distribution control sensitivity α _R is equal to the wheel load distribution ratio target value R _S ^* . Is done.

R _S ^* = α _R · f _R (Z _G , X _G , Y _G , S) As described above, the front and rear wheels corresponding to the embodiment of the integrated control device for auxiliary steering angle and braking / driving force according to the present invention. When the steering angle control and the front and rear wheel drive force distribution control are viewed, the following effects are exhibited.

By using (X _G ² + Y _G ² ) as a parameter, areas can be distinguished according to the magnitude of the control effect, and as shown in the characteristic map of FIG. 8, the value of (X _G ² + Y _G ² ) is small. during running, the auxiliary steering angle control sensitivity alpha _S is turned into the relatively elevated with respect to the driving force distribution control sensitivity alpha _T, the driving force distribution control changes in the cornering power of the accompanying front and rear wheels is suppressed small Therefore, the front and rear wheel steering angle control having a large control effect is sufficiently utilized.

Further, when the vehicle travels with a large value of (X _G ² + Y _G ² ), the driving force distribution control sensitivity α _T is set relatively higher than the auxiliary steering angle control sensitivity α _S , so that the front and rear wheel steering angle control is performed. As a result, the change in the slip ratio of each wheel is suppressed to a small degree by the change in the wheel load distribution accompanying the driving force distribution, and the driving force distribution control having a large control effect is sufficiently utilized.

That is, optimization of the total control effect by the control devices for the auxiliary steering angle and the driving force distribution is achieved.

Even if the total energy consumption is limited due to reasons such as fuel consumption, the energy consumption on the side of the device where the control effect is small is reduced by the change control of the two control sensitivities α _S and α _T. The control amount limitation on the side of the control device having the greater control effect is prevented.

A manual switch 33 is provided to enable selection of either the driving force characteristic emphasis mode A or the turning performance emphasis mode B, as shown in FIGS. 8 and 9, to meet the driver's preference and traveling road surface. In this way, the performance of the mounting device can be brought out.

Second Embodiment Next, a description will be given of an auxiliary steering angle and braking / driving force comprehensive control device according to a second embodiment corresponding to the first aspect of the present invention.

The first embodiment, since a system including a wheel load distribution control device, an example of determining the magnitude of the control sensitivity by both of the longitudinal acceleration X _G and the lateral acceleration Y _G, the second embodiment auxiliary a vehicle in which two devices with steering angle control apparatus as longitudinal force control device is mounted at the same time, as described in claim 1, without detecting the lateral acceleration Y _G, only longitudinal acceleration X _G It detected and is an example of to set the auxiliary steering angle control sensitivity alpha _S and the driving force distribution control sensitivity alpha _T.

In terms of the configuration, the suspension control system is omitted from the apparatus of the first embodiment, and the other configuration is not changed.

Next, FIG. 10 shows a general controller 34 of the second embodiment.
Each step will be described below with reference to a flowchart showing the flow of the control sensitivity setting processing operation performed in step (a).

In step 201, the loaded acceleration X _G longitudinal from the acceleration sensor 31 before and after.

In step 202, the auxiliary steering angle control sensitivity alpha _S and the driving force distribution control sensitivity alpha _T is determined according to control sensitivity characteristics map that is described in the stearyl frame based on the longitudinal acceleration X _G.

That is, in the low longitudinal acceleration zone driving force distribution control sensitivity alpha _T than the auxiliary steering angle control sensitivity alpha _S is the value of increased, the drive force distribution control sensitivity alpha _T than the auxiliary steering angle control sensitivity alpha _S in the high longitudinal acceleration region is Higher value.

In step 203, the two control sensitivities α _S and α _T determined in step 202 are output to the steering angle control controller 18 and the driving force distribution controller 22.

Therefore, as in the first embodiment, the total control effect of the two control devices is optimized while preventing the control amount from being limited on the side of the device having a large control effect when both control devices operate simultaneously. I can do it.

As described above, the embodiments have been described based on the drawings. However, the specific configuration is not limited to the embodiments, and even if there is a design change or the like without departing from the gist of the present invention, it is included in the present invention. .

For example, in the embodiment, the example of the characteristic (FIG. 8) where the control sensitivities α _S and α _T intersect is shown. However, the two characteristics do not always need to intersect, and as shown in FIG. 9, (X _G ² + Y _G ² ), the characteristic graph of (α _T / α _S ) is described as (X _G ² + Y
_G ²⁾ value becomes larger (α _T / α _S driving force distribution control sensitivity and the auxiliary steering angle control sensitivity alpha _S such that the value becomes _large) alpha
_{If T} is set, it is included in the present invention. That is, (α _T /
If the graph of α _S ) satisfies that the graph is a graph of upward-sloping characteristics, each control sensitivity characteristic map satisfies the claim whether it is convex upward or downward.

Further, in the present embodiment, the system including the wheel load distribution control device has been described. However, it is needless to say that the present invention can be applied to a vehicle not equipped with the wheel load distribution control device. The present invention can be applied to a vehicle in which a braking / driving force control device is similarly mounted.

Further, as an auxiliary steering angle control device, an example has been described in which the steering angle is controlled for both the front and rear wheels in the embodiment, but a device for controlling the auxiliary steering angle only for the rear wheel or the front wheel may be used.

Also, as the braking / driving force control device, an example of the front and rear wheel driving force distribution device has been described, but a left / right driving force distribution control device, a traction control device for directly controlling the driving force of each wheel, and a braking force for each wheel are controlled. An anti-lock braking system or the like may be used.

(Effects of the Invention) As described above, according to the first aspect of the present invention, in the overall control device for a vehicle in which the auxiliary steering angle control device and the braking / driving force control device are simultaneously mounted, the auxiliary steering angle Since the vehicle state area where the control effect of the control is large and the vehicle state area where the control effect of the braking / driving force control is large are distinguished by using the longitudinal acceleration as a parameter, and the control sensitivity is changed according to the magnitude of the control effect, both means are used. It is possible to obtain an effect that the total control effect of the two control devices can be optimized while preventing the control amount from being limited on the device side having the large control effect when the control devices are simultaneously operated.

According to a second aspect of the present invention, there is provided an integrated control system for a vehicle in which an auxiliary steering angle control device and a braking / driving force control device are simultaneously mounted. The vehicle state area where the control effect of the force control is large is distinguished from the sum of the square of the longitudinal acceleration and the square of the lateral acceleration as a parameter, and the control sensitivity is changed according to the magnitude of the control effect. The effect is obtained that the total control effect of the two control devices can be optimized while preventing the control amount from being limited on the side of the device having a large control effect during the simultaneous operation.

[Brief description of the drawings]

FIG. 1 is a claim correspondence diagram showing an integrated control device for auxiliary steering angle and braking / driving force according to the present invention, and FIG. 2 is a front / rear wheel steering angle control device (an example of an auxiliary steering angle control device) and front / rear wheel driving force distribution control. FIG. 3 is an overall system diagram showing a vehicle equipped with a device (an example of a braking / driving force control device) and an active suspension control device (an example of a wheel load distribution control device). FIG. 3 shows a specific example of a front and rear wheel steering angle control device. FIG. 4, FIG. 4 is a diagram showing a specific example of the front and rear wheel driving force distribution control device, FIG. 5 is a diagram showing a specific example of the active suspension control device, and FIG. FIG. 7 is a flowchart showing the flow of the control sensitivity setting processing operation in the integrated controller of the first embodiment, and FIG. 8 is (X _G ² +
FIG. 9 is a characteristic map of the auxiliary steering angle control sensitivity and the driving force distribution control sensitivity with respect to the value of Y _G ² ), FIG. 9 is a control sensitivity ratio characteristic graph, and FIG. 10 is the control sensitivity of the integrated controller of the second embodiment. It is a flowchart which shows the flow of a setting process operation. a: auxiliary steering angle control device b: braking / driving force control device c: longitudinal acceleration detecting means d: lateral acceleration detecting means e: total control sensitivity setting means

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI B62D 101: 00 103: 00 113: 00 (56) References JP-A-1-119439 (JP, A) JP-A-2-227339 (JP, A) Japanese Utility Model 1-62965 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60K 41/00 B60T 8/58 B62D 6/00 B62D 7/00 B60K 17 / 348 B60K 23/08

Claims (2)

(57) [Claims] An auxiliary steering angle control device for controlling at least one of a front wheel and a rear wheel during steering of a front wheel; a braking / driving force control device for controlling at least one of a braking force and a driving force of each wheel; A longitudinal acceleration detecting means for detecting the longitudinal acceleration acting on the vehicle; and a control sensitivity when a value to be multiplied by the basic control amount in an arithmetic expression for obtaining a target control amount is defined as a control sensitivity. Comprehensive control sensitivity setting means for increasing the control sensitivity and decreasing the braking / driving force control sensitivity, and decreasing the auxiliary steering angle control sensitivity and increasing the braking / driving force control sensitivity as the longitudinal acceleration detection value increases. A total control device for auxiliary steering angle and braking / driving force, characterized by being provided. 2. An auxiliary steering angle control device for controlling a steering angle of at least one of a front wheel and a rear wheel during front wheel steering; a braking / driving force control device for controlling at least one of a braking force and a driving force of each wheel; Longitudinal acceleration detecting means for detecting longitudinal acceleration acting on the vehicle, lateral acceleration detecting means for detecting lateral acceleration acting on the vehicle, and a control sensitivity is defined as a value to be multiplied by the basic control amount in an arithmetic expression for obtaining a target control amount. When the sum of the square of the longitudinal acceleration detection value and the square of the lateral acceleration detection value is calculated, and when the calculated value of the sum of the squares is equal to or smaller than a predetermined value, the auxiliary steering angle control sensitivity is set to a large constant value and the braking / driving force is set. The control sensitivity is set to a small constant value, and when the calculated value of the sum of squares exceeds a predetermined value, the ratio of the longitudinal acceleration detection value to the lateral acceleration detection value is calculated. Square system A total control sensitivity setting means for setting the control sensitivity to be large and the braking / driving force control sensitivity to be small, and setting the auxiliary steering angle control sensitivity to be small and setting the braking / driving force control sensitivity to be large as the calculated ratio value becomes large. A total control device for auxiliary steering angle and braking / driving force, characterized by being provided.