JPH10264796A - Vehicle attitude control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent vehicle acceleration or deceleration from being hindered for no reason by inhibiting unnecessary attitude control on a split road and to enhance safety by preventing excessive deviation of the turning attitude of the vehicle. SOLUTION: An SCS controller controlling the turning attitude of a vehicle by imparting braking forces separately to the front and rear right and left wheels of the vehicle is equipped with a split road detecting part which, from the amount of deviation between the right and left wheel speeds, detects that the vehicle is running on a split road. When the vehicle is determined (SC2) to be traveling on a split road, yaw-rate control is inhibited (SC10), and a switch criterion threshold K3 is set at a large value to delay switching to sideslip angle control (SC4). The control gain G2 of the sideslip angle control may be set to increase (SC6), or the hysteresis of a wheel speed sensor, a lateral acceleration sensor, a yaw-rate sensor, and a steering angle sensor may be decreased (SC8).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle attitude control device for controlling a turning attitude of a vehicle so as to converge toward a target traveling direction, and more particularly, to a split road in which the turning attitude of the vehicle necessarily collapses. It relates to suppression of unnecessary posture control.

[0002]

2. Description of the Related Art Conventionally, there has been known a vehicle attitude control device which detects a vehicle state quantity representing a turning attitude of a vehicle with respect to a traveling direction and controls the attitude of the vehicle based on the detected vehicle state quantity. (For example, see Japanese Patent Application Laid-Open No. 7-23262).
No. 9). Such a vehicle attitude control device generally includes a braking unit configured to be able to independently apply a braking force to each of the front, rear, left, and right wheels of the vehicle, and a predetermined vehicle detected by various state quantity sensors. The turning posture of the vehicle is determined based on the state quantity, and the operation control of the braking means is performed in accordance with the result of the determination. The control applied to each of the wheels by the operation control of the braking means is configured. The turning posture of the vehicle is controlled by changing the power and applying a required yaw moment to the vehicle.

[0003]

Incidentally, the vehicle has a high friction coefficient on one side of the road where one of the left and right wheels rolls, as well as a normal road having a substantially uniform friction coefficient on the road. The vehicle may travel on a so-called split road having a low friction coefficient on the other side of the road surface on which the other wheel rolls. And
In this case, the driving force or the braking force acting on each of the left and right sides of the vehicle is different depending on the level of the friction coefficient of the road surface, so that the vehicle necessarily travels in a state in which the posture is lost. For example, on a split road where the friction coefficient on the left side is lower than that on the right side, the driving force acting on the left side of the vehicle is relatively smaller than the driving force acting on the right side, so that the vehicle inevitably moves in the traveling direction. On the other hand, the vehicle will run with a slant toward the left. On the other hand, in the conventional attitude control device, the attitude control for applying the braking force to the right wheel of the vehicle and applying the clockwise yaw moment to the vehicle is performed. As a result, the application of the braking force is performed. As a result, the driving force is unduly limited, and the vehicle cannot be sufficiently accelerated. That is, on the split road, it is considered desirable to allow a certain degree of collapse of the turning posture of the vehicle. On the other hand, also on the split road, it is necessary to prevent an excessive collapse of the turning posture of the vehicle by posture control as in the related art.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a vehicle in a split road where the turning posture of a vehicle is inevitably collapsed.
An object of the present invention is to prevent unduly hindering acceleration and deceleration of the vehicle by suppressing unnecessary posture control, and also to prevent an excessive collapse of the turning posture of the vehicle.

[0005]

In order to achieve the above object, the invention according to claim 1 comprises a braking means which is capable of individually applying a braking force to each of the front, rear, left and right wheels of a vehicle,
A vehicle having attitude control means for controlling the operation of the braking means and applying braking force to each of the wheels independently so as to control the turning attitude of the vehicle so as to converge toward a target traveling direction. Is assumed. In this vehicle, a wheel speed detecting means for detecting a rotation speed of each wheel, and the vehicle has a high friction coefficient on one road surface on which one of left and right wheels rolls and the other wheel rolls. A split road detecting unit that detects that the vehicle is traveling on a split road having a low friction coefficient on the other side of the road based on a deviation amount of rotation speeds of the left and right wheels detected by the wheel speed detecting unit; When the vehicle is traveling on a split road, the control unit suppresses the control by the attitude control unit when the split road detection unit detects the traveling state.

[0006] In the case of the above configuration, the fact that the vehicle is traveling on the split road is detected by the split detecting means on the basis of the difference between the rotational speeds of the left and right wheels. The control is suppressed by the control suppression means. For this reason, it is possible to suppress the operation control of the braking means by the attitude control means and suppress the control of applying the braking force against the driver's request for acceleration or deceleration to the vehicle. In other words, the vehicle is allowed to inevitably disturb the turning posture of the vehicle on the split road, so that it is possible to suppress unduly hindering the acceleration and deceleration of the vehicle on the split road.

According to a second aspect of the present invention, in the first aspect of the invention, there is provided an accelerator operation amount detecting means for detecting an accelerator operation amount by a driver, and the limit control means is detected by the accelerator operation amount detecting means. The control by the attitude control means is more strongly suppressed as the accelerator operation amount is larger.

In the above configuration, in addition to the operation according to the first aspect of the present invention, as the accelerator operation amount detected by the accelerator operation amount detecting means is larger, the operation control of the braking means by the attitude control means is more strongly suppressed. You. Therefore, as the driver's request for acceleration increases, the operation of the braking means against the driver's will can be suppressed more strongly, whereby the vehicle can be sufficiently accelerated in response to the driver's accelerator operation. It becomes possible to.

According to a third aspect of the present invention, in the first aspect of the present invention, a brake operation amount detecting means for detecting a brake operation amount by a driver is provided, and the control by the attitude control means is performed as the restriction control means. The configuration is such that the greater the brake operation amount detected by the brake operation amount detection means, the more strongly the brake operation amount is suppressed.

In the above configuration, in addition to the operation according to the first aspect of the present invention, as the brake operation amount detected by the brake operation amount detection unit increases, the operation control of the braking unit by the attitude control unit is more strongly suppressed. Become so. Therefore, as the driver's request for deceleration becomes stronger, the operation of the braking means contrary to the driver's intention can be more strongly suppressed, whereby the vehicle can be sufficiently decelerated in accordance with the driver's braking operation. It becomes possible to.

According to a fourth aspect of the present invention, in the first aspect of the present invention, there is provided a vehicle body side slip angle detecting means for detecting a vehicle body side slip angle with respect to the front-rear direction of the vehicle. When the deviation amount between the detected body slip angle and the target slip angle corresponding to the target traveling direction is equal to or larger than a set amount, the braking means is configured to converge the vehicle body slip angle of the vehicle to the target slip angle. And a side slip angle control unit for performing a side slip angle control for correcting the turning posture of the vehicle by controlling the operation of the vehicle. And, when the split road detecting unit detects that the vehicle is traveling on the split road,
It is configured to include a sideslip angle control suppression unit that delays the start of the sideslip angle control by the sideslip angle control unit.

In the case of the above configuration, the configuration of the attitude control means and the control suppression means in the first aspect of the invention is specified. That is, the attitude control means performs side slip angle control so as to suppress at least a deviation of the turning attitude of the vehicle from the target traveling direction to a predetermined amount or less. When the vehicle is traveling, the start of the sideslip angle control is delayed by the sideslip angle control suppression unit. Then, due to the delay of the start of the side slip angle control, the side slip angle control is not performed on the split road until the turning posture of the vehicle is relatively largely collapsed, so that the control by the posture control means is surely suppressed. Will be possible. In addition, when the turning posture of the vehicle further collapses, the turning posture of the vehicle is corrected by the side slip angle control.
Excessive collapse of the turning posture of the vehicle can be prevented while satisfying the driver's acceleration / deceleration request.

According to a fifth aspect of the present invention, in the invention of the fourth aspect, when the split road detecting means detects that the vehicle is traveling on a split road, the control of the sideslip angle control by the sideslip angle control section. A control amount change correction means for changing and correcting the amount to the large value side is provided.

In the above configuration, in addition to the operation according to the fourth aspect of the present invention, when it is detected that the vehicle is traveling on a split road, the sideslip angle control is performed until the turning posture of the vehicle is relatively largely collapsed. Even if the execution of the above is delayed, once the above-mentioned sideslip angle control is executed, the control amount of the sideslip angle control has been changed and corrected to the large value side, so that a large yaw moment is applied to the vehicle by that amount, and It is possible to quickly correct the turning posture of the vehicle.

According to a sixth aspect of the present invention, there is provided the vehicle body side slip angle detecting means according to the fourth aspect of the present invention, wherein a state quantity sensor for detecting a predetermined vehicle state quantity representing a turning posture of the vehicle with respect to the traveling direction, And a sideslip angle calculator for calculating a vehicle sideslip angle based on an input signal value input from the sensor. And a control suppression unit, comprising: a hysteresis change setting unit configured to change and set the hysteresis in the state quantity sensor to a small value side when the split road detection unit detects that the vehicle is traveling on a split road. Is what you do.

In the above configuration, in addition to the operation according to the fourth aspect, when the split road detecting means detects that the vehicle is traveling on the split road, the hysteresis in the state quantity sensor is small. Therefore, the input signal value input from the state quantity sensor to the sideslip angle calculation unit changes finely and responsively in response to the change in the turning posture of the vehicle. For this reason, the calculated value of the vehicle body side slip angle calculated by the side slip angle calculation unit changes finely in accordance with the change of the actual vehicle body side slip angle of the vehicle. It becomes possible to correct the turning posture of the vehicle more precisely by making the sideslip angle control performed based on the finer details.

According to a seventh aspect of the present invention, there is provided the state quantity sensor according to the sixth aspect, wherein the state quantity sensor detects a rotational speed of each wheel, and a lateral acceleration acting on the vehicle in the left-right direction. It comprises a lateral G sensor, a yaw rate sensor for detecting the yaw rate acting on the vehicle, and a steering angle sensor for detecting the steering angle of the steering.

In the case of the above configuration, the configuration of the state quantity sensor according to the present invention is specifically specified.

According to an eighth aspect of the present invention, in the first aspect of the invention, there is provided a yaw rate detecting means for detecting a yaw rate of the vehicle, and the attitude control means is provided with a yaw rate detected by the yaw rate detecting means in a target traveling direction. A yaw rate control unit for controlling the operation of the braking means so as to apply a yaw moment to the vehicle body so as to converge to a corresponding target yaw rate is provided. And, when the split road detecting unit detects that the vehicle is traveling on the split road,
A yaw rate control prohibition unit for prohibiting the execution of the yaw rate control by the yaw rate control unit is provided.

In the case of the above configuration, the configuration of the attitude control means and the control suppression means in the first aspect of the invention is specified. That is, the attitude control means controls the turning attitude of the vehicle so that the yaw rate of the vehicle converges to the target yaw rate by at least the yaw rate control, and the control suppression means operates when the vehicle travels on the split road. The execution of the yaw rate control is prohibited when the vehicle is in the state. By prohibiting the execution of the yaw rate control, the control by the attitude control means is surely suppressed.

According to a ninth aspect of the present invention, in the first aspect of the present invention, the control suppressing means controls the control by the attitude control means when the split road detecting means detects that the vehicle is running on the split road. A control amount change setting unit for changing and setting the amount to the small value side is provided.

In the case of the above configuration, the configuration of the control suppressing means in the first aspect of the invention is specifically specified. That is, when the vehicle is traveling on a split road, the control amount by the attitude control means is changed and set to a small value side, whereby the control by the attitude control means can be reliably suppressed.

[0023]

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

FIG. 1 shows a vehicle 1 to which a vehicle attitude control device (hereinafter, simply referred to as SCS) according to an embodiment of the present invention is applied. 4 sets of hydraulic brakes respectively arranged on the four wheels 21FR, 21FL, 21RR, 21RL of the vehicle, 3 is a pressurizing unit for supplying pressurized liquid to each of the brakes 2, 4 is a pressurizing unit 3 is supplied to the brakes 2, 2,
, And a hydraulic unit (hereinafter simply referred to as HU) for distributing and supplying these brakes 2, 2,.
The pressurizing unit 3 and the HU 4 constitute a braking unit. Reference numeral 5 denotes an SCS controller as attitude control means for controlling the operation of each of the brakes 2 via the pressurizing unit 3 and the HU 4. Wheels 6, 6,... A wheel speed sensor as speed detecting means, a lateral G sensor 7 for detecting a lateral acceleration y ″ acting on the vehicle 1, and a yaw rate detection 8 detecting a yaw rate ψ ′ acting on the vehicle 1 A yaw rate sensor as means, a steering angle sensor 9 for detecting a steering angle θH of the steering wheel, a master cylinder 10, an engine 11, an automatic transmission (AT) 12, a rotation speed 13 of the engine 11, E to adjust the fuel injection amount according to the intake air amount, etc.
It is a GI controller.

As shown in FIG. 2, the brakes 2, 2,... Are connected to the master cylinder 10 by the first hydraulic line 22a, where the brake 2 of the right front wheel 21FR and the brake 2 of the left rear wheel 21RL are connected. , Brake 2 for left front wheel 21FL
And the brake 2 of the right rear wheel 21RR are connected to the first hydraulic line 2
2a, is connected to the master cylinder 10 by a second hydraulic line 22b different from that of the master cylinder 10.
Two independent brake systems of the piping type are configured. And the brake pedal 1 by the driver
The braking force is applied to the wheels 21FR, 21FL,...

The pressurizing unit 3 comprises the first and second
Hydraulic pumps 31a, 31b connected to the hydraulic lines 22a, 22b, respectively, and these hydraulic pumps 31a, 31b
b and cut valves 32a and 32b respectively provided in the first and second hydraulic lines 22a and 22b so that the master cylinder 10 can be connected and disconnected, and the cut valves 32a and 32b and the master cylinder 10 And a hydraulic pressure sensor 33 as a brake operation amount detecting means for detecting a hydraulic pressure between the two. And the SCS controller 5
The cut valves 32a and 32b are closed in response to a command from the hydraulic pumps 31a and 31b, so that the hydraulic fluid discharged from the hydraulic pumps 31a and 31b is supplied to the brake 2 via the HU 4 regardless of the brake operation by the driver. , 2, ... are supplied. In addition, the HU4 is
As shown in FIG. 2, each of the brake valves 2 is pressurized by a hydraulic fluid supplied through the first hydraulic pipeline 22a or the second hydraulic pipeline 22b.
Is connected to the reservoir tank 42 to reduce the pressure.
3, 43... Then, the opening degree of each of the above-described pressurizing valves 41 and each of the depressurizing valves 43 is increased / decreased / changed and adjusted in accordance with a command from the SCS controller 5, whereby
The hydraulic pressure supplied to each of the brakes 2 is increased or decreased so that the braking force is increased or decreased.

The SCS controller 5 turns the vehicle 1 based on input signals from the wheel speed sensors 6, 6,..., The lateral G sensor 7, the yaw rate sensor 8, and the steering angle sensor 9, as shown in FIG. The posture is determined, and the operation of the pressurizing unit 3 and the HU 4 is controlled in accordance with the result of the determination. The operation of the pressurizing unit 3 and the HU 4 causes the front, rear, left and right wheels 21FR, 21FL,. By independently applying the braking force, SCS control for converging the turning posture of the vehicle 1 toward the target traveling direction is performed. Further, the SCS controller 5 includes:
The brake operation amount of the driver is detected based on the brake pressure P detected by the hydraulic pressure sensor 33, and the operation of the pressurizing unit 3 and the HU 4 is controlled according to the brake operation amount.

The SCS controller 5 specifically includes a vehicle state quantity calculating section 51 as a vehicle body side slip angle calculating section.
A target state quantity calculation unit 52, a control intervention determination unit 53,
A basic control unit 54; a split road detection unit 55 as a split road detection unit; a yaw rate control prohibition unit 56; a sideslip angle control suppression unit 57; and a control amount correction unit as a control amount change correction unit. And a hysteresis change setting unit 59. The vehicle state quantity calculating unit 51, the wheel speed sensors 6, 6,..., The lateral G sensor 7, the yaw rate sensor 8, and the steering angle sensor 9 constitute a vehicle body side slip angle detecting means, and the yaw rate control is prohibited. The control unit includes the unit 56, the side slip angle control suppression unit 57, and the hysteresis change setting unit 59.

The state quantity calculation unit 51 is configured to perform a turning posture with respect to the traveling direction of the vehicle 1 based on input signal values from the wheel speed sensors 6, 6,..., The lateral G sensor 7, the yaw rate sensor 8 and the steering angle sensor 9. And the target state quantity calculation unit 52
Is similarly configured to calculate a target state quantity corresponding to the target traveling direction. Further, the control intervention determination unit 53 is configured to make a control intervention determination of the SCS control based on a state quantity deviation between the vehicle state quantity and the target state quantity. The basic control unit 54 calculates the amount of braking force applied to each of the wheels 21FR, 21FL,... In order to apply a required yaw moment corresponding to the state quantity deviation to the vehicle 1. A yaw rate control unit 54a for performing a yaw rate control for smoothly changing the turning posture of the vehicle 1 so as to follow a driver's driving operation (mainly steering), and a skidding for quickly correcting the turning posture of the vehicle 1. And a sideslip angle control unit 54b for performing angle control.

The split road detecting section 55 detects the wheel speeds v1, v detected by the wheel speed sensors 6, 6,.
, Is configured to detect that the vehicle 1 is traveling on a split road when the deviation between the left and right wheel speeds is equal to or greater than a predetermined amount. When it is detected that the vehicle 1 is traveling on a split road, the yaw rate control prohibiting unit 56 prohibits the yaw rate control by the yaw rate control unit 54a. When it is detected that the vehicle 1 is traveling on a split road, the side slip angle control suppression unit 57 increases a later-described switching determination threshold value K3 set in the control intervention determination unit 53 by increasing it. Thus, the start of the sideslip angle control by the sideslip angle control unit 54b is configured to be delayed, and the degree of the delay is changed according to the level of the brake pressure P detected by the hydraulic pressure sensor 33. It has become. Further, the control amount correction unit 58 detects when the vehicle 1 is traveling on a split road,
The control amount of the side slip angle control is configured to be changed according to the level of the brake pressure P. In addition, the hysteresis change setting unit 59 determines that the vehicle 1 is traveling on a split road. When detected, the hysteresis of the wheel speed sensors 6, 6,..., The lateral acceleration sensor 7, the yaw rate sensor 8, and the steering angle sensor 9 are configured to be changed to the smaller value side.

It should be noted that the SCS controller 5
In addition to S control, the well-known ABS (Anti-Skid Brake
System) Control and TCS (Traction Control System)
The ABS also controls the wheels 21FR,
This system limits the braking force applied to the wheels 21FR, 21FL,... To prevent the brake lock of the wheels 21FR, 21FL,.
This is a system that limits the driving torque for driving the FL to prevent those slips.

FIG. 4 shows an outline of the basic control by the SCS controller 5. In this basic control, first, when the driver gets into the vehicle and turns on the ignition key, the SCS controller 5 proceeds to step SA1. 5 and the EGI controller 13 are initialized, and the calculated values and the like stored in the previous processing are cleared. In step SA2, after the origin of the wheel speed sensors 6, 6,... Has been corrected, signal inputs to the SCS controller 5 are received from these sensors, and based on these input signals, the vehicle body of the vehicle is determined in step SA3. A common vehicle state quantity such as speed, vehicle deceleration, and vehicle speed at each wheel position is calculated.

Subsequently, control calculation of SCS control is performed in step SA4. That is, in step SA41, as the vehicle state quantity, the SCS body speed Vscs, the body side slip angle β,
The wheel slip ratio and slip angle of each wheel, the vertical load of each wheel, the wheel load factor of each wheel, and the road surface friction coefficient μ are calculated. In step SA42, the target yaw rate ψ′TR and the target sideslip angle βTR are set as target state quantities. Is calculated. Then, in step SA43, an intervention is determined for the yaw rate control or the side slip angle control on the basis of the calculation result. When it is determined that the control intervention is necessary, the process proceeds to step SA44. In this step SA44, the wheels 21FR, 21FL,
.. And the braking force applied to each of the selected wheels 21 is calculated. Then, based on the calculated braking force, in step SA45, the control output amount to the pressurizing unit 3 and the HU4, that is, the pressurizing valve 4 of each brake 2
, And the respective valve openings of the pressure reducing valves 43, 43,... Are calculated.

Further, in step SA5, a control target value and a control output amount necessary for the ABS control are calculated, and in step S5
In A6, a control target value and a control output amount required for the TCS control are calculated, and then, in step SA7, the respective calculation results of the ABS control, the TCS control, and the SCS control are arbitrated by a predetermined method, and the pressurization is performed. The control output amount to the unit 3 and the HU 4 is determined. Then, in step SA8, the pressure units 3 and HU4 are operated to control the degree of opening of each of the pressure valves 41 and the pressure reduction valves 43.
The brakes 2, 2, ... of the wheels 21FR, 21FL ...
Control the hydraulic pressure supplied to the wheels 21FR, 21FL
The required braking force is applied to. Finally, step SA9
Perform a fail-safe determination as to whether the wheel speed sensors 6, 6,... And the pressurizing unit 3 are operating normally, and thereafter return to step SA1.

In the above flow chart, step SA41 corresponds to the state quantity calculating section 51, SA42 corresponds to the target state quantity calculating section 52, step SA43 corresponds to the control intervention determining section 53, and step SA44 corresponds to the basic control. It corresponds to the part 54 respectively.

-SCS Control- Hereinafter, the details of the SCS control will be described with reference to FIGS. Note that the calculation of the ABS control in step SA5 and the calculation of the TCS control in step SA6 are well known, and a description thereof will be omitted.

FIG. 5 shows the vehicle speed Vscs, the vehicle body side slip angle β, the vertical load of each wheel, and step S41 in FIG.
Calculation of the slip ratio of each wheel, the slip angle of each wheel, the wheel load ratio of each wheel, and the road surface friction coefficient μ, and step S in FIG.
The calculation of the target side slip angle βTR and the target yaw rate ψ′TR in A42 is shown. That is, in step SB2,
Wheel speed v1 of wheel 21FR, wheel speed v2 of wheel 21FL, wheel speed v3 of wheel 21RR, wheel speed v4 of wheel 21RL, lateral acceleration y "of vehicle 1, yaw rate ψ 'of vehicle 1, steering angle of steering Step S is input.
At B4, the vehicle speed Vscs is calculated based on the wheel speeds v1, v2,..., And at Step SB6, the wheel speed v1 is calculated.
, V2,... And the lateral acceleration y ″. In step SB8, the vehicle body speed Vscs, the wheel speeds v1, v2,. Then, the vehicle body side slip angle β is calculated based on the yaw rate ψ ′ and the steering angle θH. Here, when the vehicle 1 is traveling on a split road, the hysteresis of the wheel speed sensors 6, 6,..., The lateral acceleration sensor 7, the yaw rate sensor 8, and the steering angle sensor 9 are changed to a small value side as described later. As a result, the vehicle body side slip angle β calculated in step SB8 is changed to the vehicle 1
Changes in response to the actual change in the vehicle sideslip angle.

Step SB1 following step SB8
0, the wheel speeds v1, v2,...
s, the vehicle side slip angle β, the yaw rate ψ ', and the steering angle θ
The slip ratio and the slip angle of each wheel are calculated based on H, and in step SB12, the wheels 21FR and 21FR are determined based on the vertical load of each wheel and the slip ratio and the slip angle.
For each of 1FL,..., A wheel load ratio, which is a ratio of the current gripping force to the total gripping force that the tires 23, 23,. And step SB
In step 14, a road surface friction coefficient μ is calculated based on the wheel load factor and the lateral acceleration y ″, and in step SB16,
A target yaw rate ψ'TR and a target sideslip angle βTR are calculated based on the road friction coefficient μ, the vehicle speed Vscs, and the steering angle θH.

In the flow chart shown in FIG. 5, steps SB2 to SB14 correspond to the state quantity calculator 51, and step SB16 corresponds to the target state quantity calculator 52.

FIG. 6 shows the SCS control after the SCS control intervention determination in step SA43 in FIG. 4. In step SB18, the yaw rate deviation amount (| ψ′TR−) between the yaw rate ψ ′ and the target yaw rate ψ′TR ψ '|), and
The side slip angle deviation amount (| βTR−β |) between the vehicle body side slip angle β and the target side slip angle βTR is determined as an intervention determination threshold value K1 or K2, respectively, which is set in advance for determining the intervention of the yaw rate control of the SCS. Compare with When the yaw rate deviation amount is equal to or greater than the intervention determination threshold value K1 or the side slip angle deviation amount is equal to or greater than the intervention determination threshold value K2, the deviation of the turning posture of the vehicle 1 with respect to the target traveling direction is determined. It is determined that the SCS control intervention is necessary and the process proceeds to step SB20. On the other hand, the yaw rate deviation amount is smaller than the intervention determination threshold value K1, and the side slip angle deviation amount is determined to be intervention. If the value is smaller than the threshold value K2, it is determined that the SCS control intervention is not required, and the process returns. In step SB20, the side slip angle deviation amount (| βTR−β |) is set to a switching determination threshold value K3 (K3> K2) as a preset amount for determining the switching of the SCS to the side slip angle control. Compare. The value of the switching determination threshold value K3 is set to be increased when it is detected that the vehicle 1 is traveling on a split road, as described later. , The switching to the side slip angle control is delayed.

If the side slip angle deviation is smaller than the switching determination threshold value K3, the flow advances to step SB22 to set the target yaw rate ψ'TR as the SCS control target value, and then to step SB24. , The SCS control amount ψ′amt as the control amount in the yaw rate control is changed to the yaw rate deviation amount (| ψ′TR−ψ ′).
|) And the control gain G1. That is, ψ′amt = G1 × | ψ′TR−ψ ′ | That is, while it is determined that the change in the turning posture of the vehicle 1 is relatively small and in a stable state (SB20), the yaw rate of the vehicle 1 ψ ′ Is applied to the vehicle so that the yaw moment is relatively small and proportional to the yaw rate deviation amount (| ψ′TR−ψ ′ |) so that the target yaw rate ψ′TR corresponding to the driving operation of the driver is converged. SB22,
SB24), the yaw rate control for smoothly changing the turning posture of the vehicle 1 so as to follow the driving operation of the driver is performed.

On the other hand, if the side slip angle deviation amount (| βTR−β |) is equal to or greater than the switching determination threshold value K3 in step SB20, the process proceeds to step SB26, where the target side slip angle βTR is set as the SCS control target value. Step SB after setting
Then, at step SB28, the SCS control amount βamt actually used for the SCS control is calculated by multiplying the side slip angle deviation amount (| βTR−β |) by the control gain G2. That is, βamt = G2 × | βTR−β | That is, when it is determined that the turning posture of the vehicle 1 is about to collapse (SB20), the vehicle body side slip angle β is relatively large and converges to the target side slip angle βTR. By making the yaw moment proportional to the above-mentioned side slip angle deviation amount (| βTR−β |) act on the vehicle (SB26, SB28), the skid angle control for quickly correcting the turning posture of the vehicle 1 is performed. I have to. Here, the value of the control gain G2 is changed and set to a large value when it is detected that the vehicle 1 is traveling on a split road, as described later. When the vehicle 1 is traveling on a split road surface, the SCS control amount βamt in the side slip angle control is increased and corrected.

Then, in step SB30 following step SB24 or step SB28, it is determined whether or not a failure has occurred in the pressurizing unit 3 or the HU4. If it is determined that a failure has occurred, the process proceeds to step SB32. The SCS control is stopped and the process returns. On the other hand, if the failure is not determined in step SB30, the process proceeds to step S30.
Proceeding to B34, the above SCS control, ABS control and TC
The calculation results of the S control are arbitrated by a predetermined method. An outline of the arbitration will be described. If the ABS control is performed when the SCS control is performed, the AB control is performed.
By correcting the control amount of the S control based on the SCS control amount ψ′amt or βamt, the S control is performed while giving priority to the ABS control.
When the CS control is performed and the TCS control is performed when the SCS control is performed,
The operation of the pressurizing unit 3 and the HU 4 for the TCS control is stopped to perform the SCS control.

Subsequently, at step SB36, SC
Based on the S control amount ψ′amt or βamt, the wheels 21FR, 21FL,... For applying the braking force for SCS control are selected, and the braking forces to be applied to these wheels 21FR, 21FL,. If the yaw rate control increases the yaw rate ψ 'of the vehicle 1 clockwise in the yaw rate control, and corrects the turning posture of the vehicle toward the right side in the sideslip angle control, the wheel selection and the calculation of the braking force will be briefly described. , The SCS control amount に 対 し ′ with respect to the right front wheel 21FR or the right front and rear wheels 21FR and 21RR.
By applying a braking force corresponding to amt or βamt, a clockwise yaw moment is applied to the vehicle. Conversely, when the yaw rate ψ ′ of the vehicle 1 is increased counterclockwise, or when the turning posture of the vehicle is to be corrected to the left side, the SCS is applied to the left front wheel 21FL or the left and right front wheels 21FL and 21RL. Control amount ψ'am
A counterclockwise yaw moment is applied to the vehicle by applying a braking force corresponding to t or βamt.

Then, in step SB38 following step SB36, the control output amounts to the pressurizing unit 3 and the HU 4 for applying the required braking force to the wheels 21FR, 21FL,... Selected in step SB36, respectively. That is, the pressurizing valve 4 of the brakes 2, 2,.
, 41,... And the pressure-reducing valves 43, 43,... Are calculated, and in step SB40, the calculated control outputs are output to the pressurizing unit 3 and the HU 4 to perform SCS control. Execute, then return.

In the above flowchart shown in FIG. 6, steps SB18 and SB20 correspond to the control intervention determination section 53, and step SB2
Steps SB2 and SB24 correspond to the yaw rate controller 54a, and steps SB26 and SB28 correspond to the sideslip angle controller 54b.

FIG. 7 shows a special SCS control for traveling on a split road. In step SC2, wheel speed sensors 6, 6,.
It is determined whether or not the vehicle 1 is traveling on a split road based on the wheel speeds v1, v2,.
That is, the wheel speed v1 of the right front wheel 21FR and the left front wheel 21
The amount of deviation between the FL wheel speed v2 and the right rear wheel 21RR
While the difference between the wheel speed v3 of the left rear wheel 21RL and the wheel speed v4 of the left rear wheel 21RL (hereinafter, simply referred to as left and right wheel speed difference) is smaller than a predetermined amount, it is assumed that the vehicle 1 is not traveling on the split road. If the difference between the left and right wheel speeds is equal to or greater than the predetermined amount, the process returns to step SC4, determining that the vehicle 1 is traveling on a split road.

In step SC4, the control intervention determining section 53
The change setting of the switching determination threshold value K3 in the switching determination (SB20) to the side slip angle control is performed by reading from the threshold value setting map M1. In the threshold value setting map M1, the switching determination threshold value K3 is set in advance with respect to the relationship between the left and right wheel speed deviation amount and the brake pressure P. The threshold value K3 is set to a constant value in a region where the left and right wheel speed deviations are relatively small, and increases with an increase in the left and right wheel speed deviations in a region where the left and right wheel speed deviations are relatively large. It is set and the degree of the increase is set to increase as the brake pressure P increases. In other words, the start of the side slip angle control is delayed as the difference between the left and right wheel speeds increases and as the brake pressure P increases.

Subsequently, in SC6, the sideslip angle control unit 54b
The setting of the control gain G2 in the calculation of the SCS control amount βamt (SB28) by the control gain setting map M
Perform by reading from 2. The control gain setting map M2 is a map in which the control gain G2 is set in advance in a relationship between the left and right wheel speed deviation amounts and the brake pressure P.
In the control gain setting map M2, the control gain G2 is set to a constant value in a region where the left and right wheel speed deviation is relatively small, while the control gain G2 is set to a constant value in a region where the left and right wheel speed deviation is relatively large. It is set to increase with an increase in the speed deviation amount, and the degree of the increase is set to increase as the brake pressure P increases. In other words, the larger the difference between the left and right wheel speeds is,
The higher the brake pressure P is, the more the SCS control amount βamt is corrected to increase.

Then, SC8 following the above step SC6
, The hysteresis in each of the wheel speed sensors 6, 6,..., The lateral acceleration sensor 7, the yaw rate sensor 8, and the steering angle sensor 9 is changed and set to a small value side so as to decrease by 20%. By changing the setting of the hysteresis, the vehicle body side slip angle β calculated by the state quantity calculation unit 51 is calculated.
However, since it changes more finely with respect to a change in the actual vehicle body skid angle of the vehicle 1, the skid angle control is performed more finely. Finally, step SC
At 10, the yaw rate control (SB22, SB24) in the yaw rate control unit 54a is prohibited, and thereafter,
To return. By prohibiting the yaw rate control, the SCS control is not performed while it is determined that the change in the turning posture of the vehicle 1 is relatively small and stable (SB20).

In the above flow chart, step SC2 is performed by the split path detecting section 55 in step S2.
C4 corresponds to the sideslip angle control suppression unit 57, respectively. Step SC6 corresponds to the control amount correction unit 58, step SC8 corresponds to the hysteresis change setting unit 59, and step SC10 corresponds to the yaw rate control prohibition unit 56.

According to the vehicle attitude control device of the embodiment, when it is detected based on the left and right wheel speed deviations that the vehicle 1 is traveling on the split road (SC2), the yaw rate control is performed. In addition to being prohibited (SC10), the start of the sideslip angle control is delayed (SC4). For this reason, while the change in the turning posture of the vehicle 1 is relatively small and in a stable state, the SCS control can be prevented from being performed by allowing the vehicle to necessarily incline in the turning posture on the split road, Thus, unnecessary SCS control on the split road can be prevented, and the vehicle 1 can be sufficiently accelerated or decelerated in response to a driver's acceleration request or deceleration request.

At this time, as the brake pressure P detected by the hydraulic pressure sensor 33 is higher, that is, as the driver's deceleration request is stronger, the start of the side slip angle control is delayed (SC4). On the other hand, when the driver decides to quickly decelerate the vehicle, the vehicle can be sufficiently decelerated in accordance with the driver's braking operation. Further, on the split road, the control gain G2 in the side slip angle control is changed and set to a large value side (SC6), and the SCS control amount βamt is increased and corrected. Therefore, when the side slip angle control is executed, A larger yaw moment is applied to the vehicle 1 than when the vehicle 1 is traveling on a normal road other than the split road, so that the turning posture can be quickly corrected, whereby the turning posture of the vehicle 1 is excessively collapsed. Can be prevented.

In addition, on the split road, the hysteresis of each of the wheel speed sensors 6, 6,..., The lateral acceleration sensor 7, the yaw rate sensor 8, and the steering angle sensor 9 is reduced by 20% (SC8). Therefore, the calculation of the SCS control amount βamt is performed finely accordingly. Therefore, the skid angle control can be made finer, and thereby the posture of the vehicle can be corrected more accurately.

<Other Embodiments> The present invention is not limited to the above-described embodiments, but includes various other embodiments. That is, while the vehicle 1 is traveling on a split road, the yaw rate control is prohibited and the side slip angle control is delayed. However, the present invention is not limited to this. It may be prohibited. Further, a control amount change setting unit for reducing the control amount of the yaw rate control or the side slip angle control may be provided.

In the above-described embodiment, the SCS control is more strongly suppressed by increasing the threshold value K3 for determining the switch to the side slip angle control in accordance with the increase in the brake operation amount of the driver. However, the SCS control may be more strongly suppressed by, for example, decreasing the control gain G2 of the side slip angle control in accordance with the increase in the brake operation amount.

In the above embodiment, the brake operation amount of the driver is detected based on the brake pressure P detected by the hydraulic pressure sensor 33. However, the present invention is not limited to this. For example, the brake pedal depression angle is detected. Thus, the brake operation amount of the driver may be detected.

In the above embodiment, the SCS control is strongly suppressed as the driver's brake operation amount increases. However, the present invention is not limited to this. For example, an accelerator operation amount detecting means for detecting the driver's accelerator operation amount may be provided. The SCS control may be more strongly suppressed as the accelerator operation amount detected by the accelerator operation amount detector increases.

[0059]

As described above, according to the vehicle attitude control apparatus of the first aspect, when the vehicle is traveling on a split road, the attitude control of the vehicle by the attitude control means is suppressed. By doing so, it is possible to allow the vehicle to inevitably disturb the turning posture of the vehicle on the split road and suppress unduly hindering acceleration and deceleration of the vehicle.

According to the second aspect of the present invention, in addition to the effect of the first aspect of the invention, the control by the attitude control means can be suppressed more as the driver's acceleration request becomes stronger. When the driver determines that the vehicle is to be accelerated in a hurry, the vehicle can be sufficiently accelerated according to the accelerator operation.

According to the third aspect of the present invention, in addition to the effect of the first aspect of the invention, the control by the attitude control means can be suppressed more strongly as the driver's deceleration request becomes stronger. When the driver determines that he wants to decelerate the vehicle in a hurry, the vehicle can be sufficiently decelerated according to the brake operation.

According to the fourth aspect of the present invention, when the vehicle is traveling on a split road, the start of the side slip angle control is delayed so that the side slip angle control is performed until the turning posture of the vehicle is relatively largely collapsed. Thus, the control by the attitude control means can be reliably suppressed, and the excessive turning attitude of the vehicle can be prevented.

According to the fifth aspect of the present invention, in addition to the effect of the fourth aspect of the present invention, the control amount of the side slip angle control is changed and corrected to a large value side, and a correspondingly large yaw moment is applied to the vehicle. By doing so, the turning posture of the vehicle can be quickly corrected.

According to the sixth aspect of the invention, in addition to the effect of the fourth aspect of the present invention, by changing and setting the hysteresis in the state quantity sensor to a small value side, the side slip angle control can be performed by changing the attitude of the vehicle. The turning posture of the vehicle can be more accurately corrected.

According to the invention of claim 7, the configuration of the state quantity sensor in the invention of claim 6 is specified.

According to the eighth aspect of the invention, when the vehicle is traveling on a split road, the control by the attitude control means can be reliably suppressed by inhibiting the yaw rate control.

According to the ninth aspect of the present invention, when the vehicle is traveling on a split road, the control amount by the attitude control means is changed and set to a small value side, so that the attitude control means Control can be reliably suppressed.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a vehicle to which a vehicle attitude control device according to an embodiment of the present invention is applied.

FIG. 2 is a diagram showing a hydraulic system of a brake.

FIG. 3 is a block diagram illustrating a configuration of an SCS controller.

FIG. 4 is a flowchart showing an outline of basic control.

FIG. 5 is a flowchart illustrating processing in a state quantity calculation unit and a target state quantity calculation unit.

FIG. 6 is a flowchart showing SCS control after control intervention determination.

FIG. 7 is a flowchart showing special SCS control on a split road.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Vehicle 2,2 ... Brake (braking means) 3 Pressurizing unit (braking means) 4 Hydraulic unit (braking means) 5 SCS controller (attitude control means) 6,6, ... Wheel speed sensor (wheel speed detecting means) 7 Lateral G sensor 8 Yaw rate sensor (yaw rate detecting means) 9 Steering angle sensor 21FR, 21FL, 21RR, 21RL Wheel 33 Hydraulic pressure sensor (brake operation amount detecting means) 51 State quantity calculating section (side slip angle calculating section) 54a Yaw rate controlling section 54b Side slip angle control unit 55 Split road detection unit (split road detection unit) 56 Yaw rate control prohibition unit 57 Side slip angle control suppression unit 58 Control amount correction unit (Control amount change correction unit) 59 Hysteresis change setting unit P Brake pressure (Brake operation) Amount) v1, v2, v3, v4 Wheel speed (wheel rotation speed, predetermined vehicle state quantity) y ″ car Both lateral accelerations (predetermined vehicle state quantity) β Body side slip angle βTR Target side slip angle θH Steering steering angle (steering operation amount, predetermined vehicle state quantity) ψ ′ Vehicle yaw rate (detected yaw rate, predetermined vehicle state quantity) ψ ´TR target yaw rate

Continued on the front page (72) Inventor Tetsuya Tachihata 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Co., Ltd.

Claims (9)

[Claims] 1. A braking means configured to be capable of individually applying a braking force to each of front, rear, left and right wheels of a vehicle, and independently applying braking force to each of the wheels by controlling the operation of the braking means. A posture control device for controlling the turning posture of the vehicle so as to converge toward the target traveling direction by performing a vehicle speed control device that detects a rotation speed of each wheel; That the vehicle is traveling on a split road having a high friction coefficient on one side of the road surface on which one of the left and right wheels rolls and a low friction coefficient on the other side of the road surface on which the other wheel rolls, Split road detecting means for detecting based on the deviation between the rotational speeds of the left and right wheels detected by the wheel speed detecting means; and when the split road detecting means detects that the vehicle is traveling on a split road. And a control suppressing means for suppressing the control by the attitude control means. 2. An accelerator operation amount detecting device according to claim 1, further comprising an accelerator operation amount detecting means for detecting an accelerator operation amount by a driver, wherein the control suppressing means controls the control by the attitude control means by the accelerator operation detected by the accelerator operation amount detecting means. An attitude control device for a vehicle, wherein the attitude control device is configured to strongly suppress the larger the amount. 3. A brake operation amount detecting device according to claim 1, further comprising a brake operation amount detecting device for detecting a brake operation amount by a driver, wherein the control suppressing device controls the control by the attitude control device by the brake operation detected by the brake operation amount detecting device. An attitude control device for a vehicle, wherein the attitude control device is configured to strongly suppress the larger the amount. 4. The vehicle according to claim 1, further comprising a vehicle body slip angle detecting means for detecting a vehicle body skid angle with respect to a front-rear direction of the vehicle, wherein the attitude control means includes a vehicle slip angle detected by the vehicle body skid angle detecting means and a target. When the deviation amount from the target sideslip angle corresponding to the traveling direction becomes equal to or greater than a set amount, the operation of the braking means is controlled by controlling the operation of the braking means so that the vehicle body sideslip angle of the vehicle converges on the target sideslip angle. A side-slip angle control unit for performing a side-slip angle control for correcting a turning posture, wherein the control suppression unit is configured to perform the side-slip angle control unit when the split road detection unit detects that the vehicle is traveling on a split road. An attitude control device for a vehicle, comprising: a side slip angle control suppression unit that delays execution of a side slip angle control by the vehicle. 5. The method according to claim 4, wherein when the split road detecting means detects that the vehicle is traveling on a split road, the control amount of the sideslip angle control by the sideslip angle control unit is changed and corrected to a large value side. An attitude control device for a vehicle, comprising a control amount change correction unit. 6. The vehicle body side slip angle detecting means according to claim 4, wherein the vehicle body side slip angle detecting means detects a predetermined vehicle state quantity representing a turning posture of the vehicle with respect to the traveling direction, and an input signal value input from the state quantity sensor. A side slip angle calculating unit that calculates a vehicle body side slip angle based on the vehicle speed.The control suppression unit detects the vehicle running on the split road when the split road detection unit detects the vehicle. An attitude control device for a vehicle, comprising: a hysteresis change setting unit that changes and sets hysteresis to a small value side. 7. The vehicle according to claim 6, wherein the state quantity sensor includes: a wheel speed sensor that detects a rotation speed of each wheel; a lateral G sensor that detects a lateral acceleration acting on the vehicle in a left-right direction; An attitude control device for a vehicle, comprising: a yaw rate sensor for detecting an operating yaw rate; and a steering angle sensor for detecting a steering angle of a steering. 8. A vehicle according to claim 1, further comprising: a yaw rate detecting means for detecting a yaw rate of the vehicle, wherein the attitude control means causes the yaw rate detected by the yaw rate detecting means to converge to a target yaw rate corresponding to a target traveling direction. The vehicle includes a yaw rate control unit that controls the operation of the braking unit to apply a yaw moment to the vehicle body. The control suppression unit detects that the vehicle is traveling on a split road by the split road detection unit. And a yaw rate control prohibition unit for prohibiting the execution of the yaw rate control by the yaw rate control unit. 9. The control suppression means according to claim 1, wherein the control amount is changed and set to a small value side when the split road detection means detects that the vehicle is traveling on a split road. An attitude control device for a vehicle, comprising a control amount change setting unit.