JP2002037048A - Braking device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize the stable behavior of a vehicle by improving the turning- round performance of the vehicle in the initial period of turning particularly on a low μ road. SOLUTION: In the initial period of turning, braking force applied to wheels 21FL-21RL is regulated so that the rising speed of turning-round action becomes the predetermined set value (a broken line becomes a continuous line) regardless of the road surface μ. In the latter period of turning, braking force applied to the wheels 21FL-21RL is regulated to generate a yaw rate corresponding to the road surface μ, to the vehicle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle having braking means provided on each wheel, and braking force adjusting means for controlling the braking means to individually adjust the braking force applied to each wheel. To a braking device.

[0002]

2. Description of the Related Art Conventionally, as a braking device for a vehicle of this kind, a braking means provided on each wheel, and a braking force adjustment for controlling the braking means to individually adjust the braking force applied to each wheel. There is known an apparatus which includes means for controlling the yaw behavior of the vehicle by controlling the braking force applied to each wheel (see, for example, Japanese Patent Application Laid-Open No. 9-24812). In this vehicle, when the deviation between the target yaw rate set based on the steering angle and the actual yaw rate generated in the vehicle is equal to or greater than a predetermined value, the braking force applied to the turning outer wheel is adjusted during turning. Try to avoid spin.

[0003]

By the way, in the initial stage of turning of a vehicle on a road surface having a low friction coefficient (low μ road), it takes a long time from the driver turning the rudder until the vehicle actually starts turning. turn into. That is, the turning property is deteriorated.

For example, FIG. 17 shows a time change of a yaw rate (actual yaw rate) generated in a vehicle, and shows a time change of a yaw rate on a low μ road indicated by a broken line and a time change of a yaw rate on a high μ road indicated by an alternate long and short dash line. By comparison,
On the low μ road, it can be seen that the rising speed of the yaw rate (the rising speed of the turning operation) in the initial stage of turning is small. As described above, on a low μ road, the turning operation of the vehicle in the initial stage of turning is delayed as compared with the high μ road, and therefore, the driver may perform the correction steering for further turning the steering further. If such correction steering is performed, the steering angle becomes too large, so that the steering must be turned in the opposite direction in response to the response of the vehicle behavior. Therefore, by performing the above-described correction steering, the turning of the rudder is repeated, and as a result, there is a disadvantage that the behavior of the vehicle becomes unstable.

The present invention has been made in view of such circumstances, and an object of the present invention is to improve the turning performance of a vehicle particularly at the beginning of a turn on a low μ road. To realize stable vehicle behavior.

[0006]

In order to achieve the above object, the rising speed of the turning operation (turning behavior) at the beginning of turning of the vehicle is set to a preset value regardless of the road surface friction coefficient.

Specifically, the invention according to claim 1 comprises a braking means provided on each wheel, and a braking force adjusting means for controlling the braking means and individually adjusting the braking force applied to each wheel. It is intended for a vehicle braking device equipped with the same.

The yaw rate detecting means for detecting the yaw rate occurring in the vehicle, the steering angle detecting means for detecting the steering angle of the vehicle, and the yaw rate detected by the yaw rate detecting means and the steering angle detecting means. Control means for controlling the braking force adjusting means so that the rising speed of the turning operation in the initial stage of turning of the vehicle becomes a preset value regardless of the road surface friction coefficient based on the steering angle thus set. That is a specific matter. Here, the “set value” of the rising speed of the turning operation at the beginning of turning of the vehicle may be, for example, the rising speed of the turning operation of the vehicle at the beginning of turning on a high μ road.

According to the first aspect of the present invention, the control means controls the braking force adjusting means based on the yaw rate detected by the yaw rate detecting means and the steering angle detected by the steering angle detecting means, that is, the braking of the turning inner wheel. By controlling the braking force adjusting means so that the means is operated, a yaw moment is generated in the vehicle, and the rising speed (turning speed of the yaw rate) of the turning operation in the initial stage of turning of the vehicle is independent of the road surface friction coefficient. The value is set to a preset value.

Thus, even on a low μ road, the turning operation of the vehicle in response to the driver's steering is not delayed, and the high μ
A turning operation similar to the turning operation of the vehicle on the road is obtained. As a result, the driver does not perform the correction steering, and as a result, the vehicle behavior becomes stable.

As described above, even when the turning operation at the initial stage of the turn, that is, when the transient turning operation is controlled, the yaw rate generated in the vehicle during the steady turn such as the latter half of the turn is not a yaw rate corresponding to the friction coefficient of the road surface. Will be unstable.

Therefore, the control means is provided with a braking force adjusting means in a later stage of the turning of the vehicle such that the yaw rate generated in the vehicle becomes a set value set in accordance with the road surface friction coefficient. Preferably, it is configured to control.

According to the second aspect of the invention, at the beginning of turning of the vehicle, a predetermined turning operation is performed irrespective of the friction coefficient of the road surface, while in the later stage of turning, a yaw rate corresponding to the friction coefficient of the road surface is generated. The state is obtained. Thereby, a more stable turning is realized.

According to a third aspect of the present invention, there is provided a vehicle side slip angle detecting means for detecting a vehicle body side slip angle, and the control means includes a yaw rate detected by the yaw rate detecting means and a steering detected by the steering angle detecting means. The braking force is adjusted based on the vehicle angle and the vehicle body slip angle detected by the vehicle body slip angle detecting means so that the rising speed of the turning operation at the initial stage of turning of the vehicle becomes a preset value regardless of the road surface friction coefficient. It is a specific matter to configure to control the means.

According to the third aspect of the invention, in addition to the functions and effects of the first or second aspect of the invention,
Since the turning operation of the vehicle is controlled based on the yaw rate, the steering angle, and the vehicle body slip angle detected by the vehicle body slip angle detection means, the vehicle behavior is further stabilized.

In the case where the rising speed of the turning operation at the beginning of turning is controlled by applying a braking force to each wheel, the control intervention becomes frequent or the total amount of control performed becomes large. As a result, a fade phenomenon of the braking means (brake) may be easily caused.

Therefore, an object of the present invention is to reduce the frequency or amount of operation of the braking means.
A so-called tuck-in, in which the vehicle turns inward with the load movement, is used, and the automatic transmission is shifted down to generate the load movement.

More specifically, the automatic transmission is provided with a speed changeover means for performing a speed change control, and the control means is controlled by a braking force adjusting means at the beginning of turning of the vehicle, or the automatic transmission is operated by a downshift. In this case, the control of the speed change switching means is performed as described above.

According to the fourth aspect of the present invention, the control means shifts down the automatic transmission through the speed changeover means,
The rise speed of the turning operation in the initial stage of turning is set to a predetermined value due to the tack-in caused by this. Also, only when the rising speed of the turning operation does not reach the predetermined value even by this tack-in, in addition to the control of the automatic transmission, the braking device is controlled through the braking force adjusting device to reduce the rising speed of the turning operation. Set to a predetermined value. As a result, the number of actuations and the actuation amount (actuation time) of the braking means are reduced and the fade phenomenon is avoided, while improving the turning performance.

The invention according to claim 5 also utilizes the tuck-in. Specifically, the invention is provided with an engine output adjusting means for adjusting the output torque of the engine, and the control means is provided for turning the vehicle. It is a specific matter that an initial stage is configured to control the braking force adjusting unit or to control the engine output adjusting unit so that the output torque of the engine decreases.

According to the fifth aspect of the invention, when the engine output adjusting means reduces the output torque of the engine, the load shifts and the tack-in occurs as described above. Therefore, the control means controls the engine output adjusting means instead of the control of the braking force adjusting means or together with the control of the braking force adjusting means. The number of actuations and the amount of actuation of the braking means are reduced by the amount of actuation of the means. as a result,
The fading phenomenon can be avoided.

Here, the engine output adjusting means is configured to adjust the output torque of the engine by adjusting the throttle opening of the engine, for example, as set forth in claim 6, and the control means is controlled by the driver May be configured to control the engine output adjusting means when the driver is depressing the accelerator pedal.

In this case, a shift switching means for controlling a shift of the automatic transmission is provided, as described in claim 7.
The control means may be configured to control the shift changeover means so that the automatic transmission shifts down when the driver does not depress the accelerator pedal.

According to the present invention, when the driver is depressing the accelerator pedal, the throttle opening is adjusted by controlling the engine output adjusting means while the accelerator pedal is depressed. When the operation is not being performed (when the throttle valve is closed), the downshift of the automatic transmission is performed under the control of the shift switching means. This causes a tack-in,
The rising speed of the turning operation at the beginning of turning is set as a set value. Even when the throttle opening control and the shift control are performed, only when the rising speed of the turning operation does not reach the set value, the braking means is controlled in addition to the throttle opening control and the shift control, and the turning operation is performed. Set the rising speed as the set value. As a result, the number of actuations and the amount of actuation of the braking means are greatly reduced, and the fade phenomenon is reliably avoided.

Further, as set forth in claim 8, a notifying means for notifying the driver that the control means is operating may be provided.

In the case where the notification to the driver is performed in this manner, the mode of notification to the driver is changed when the intervention frequency of the control or the total amount of executed control exceeds a predetermined value. It may be configured as follows.

According to the ninth aspect of the present invention, when the intervention frequency of the control or the total amount of the executed control exceeds a predetermined value, a fade phenomenon of the braking means may occur. Make a change and notify the driver accordingly. As a result, the driver's attention is drawn, and the driver operates without control intervention. As a result, the number of control interventions or the control amount is reduced, and the fade phenomenon is avoided.

According to a tenth aspect of the present invention, the control means is configured to suppress the control when the intervention frequency of the control or the total amount of the executed control exceeds a predetermined value. is there.

According to the tenth aspect of the present invention, when the intervention frequency of the control or the total amount of the executed control exceeds a predetermined value, that is, when there is a possibility that a fade phenomenon may occur,
Since the control means suppresses the control, the above-described fade phenomenon is avoided.

The suppression of the control is, specifically, as follows.
According to an eleventh aspect, the control means is configured to perform control when a deviation between a target yaw rate set based on the steering angle and an actual yaw rate generated in the vehicle is equal to or larger than a threshold value. The threshold value may be set higher as the control intervention frequency or the total amount of executed control is larger.

According to the eleventh aspect of the present invention, as the control intervention frequency or the total amount of executed control increases, the control start threshold value increases, and the control intervention frequency can be reduced.

Further, unlike the invention described in claim 11,
For example, the control means may be configured to reduce the control amount as the control intervention frequency or the total amount of executed control increases.

According to the twelfth aspect of the present invention, the control amount (for example, the brake hydraulic pressure amount) becomes smaller as the intervention frequency of the control or the total amount of executed control becomes larger, so that the control amount is reduced.

Further, the control means may be configured to stop the control when the intervention frequency of the control or the total amount of the executed control is equal to or more than a predetermined value.

According to the thirteenth aspect of the present invention, when the intervention frequency of the control or the total amount of the executed control exceeds a predetermined value, the control is stopped, so that the fade phenomenon is reliably avoided.

When the control by the control means is stopped in this way, a notification means for notifying the driver of the control stop of the control means may be provided.

According to the fourteenth aspect of the present invention, the notifying unit notifies the driver of the suspension of the control by the control unit, so that the driver is alerted.

Further, for example, the control means may be configured so as to stop the control with a predetermined time delay from when the notification means notifies the control means of the stop of the control.

According to the fifteenth aspect of the present invention, the control means stops the control with a predetermined time delay from the time when the notification is made by the notification means. Therefore, the driver recognizes that the control is to be stopped and then stops the control. Therefore, there is ample time to drive the vehicle in accordance with the requirements, and safety is improved.

[0040]

As described above, according to the vehicle braking device of the present invention, the rising speed of the turning operation at the beginning of turning of the vehicle is a preset value irrespective of the road surface friction coefficient. The turning operation of the vehicle is not delayed even on the μ road, and as a result, the behavior of the vehicle can be stabilized without the driver performing the corrective steering.

On the other hand, in the later stage of the turn, a yaw rate corresponding to the friction coefficient of the road surface is generated in the vehicle, so that a stable turn can be realized.

By controlling the turning operation by tack-in using the automatic transmission control means and the engine output adjusting means, the frequency and amount of operation of the braking means are reduced, and the fade phenomenon of the braking means is avoided. be able to.

Further, when the intervention frequency of the braking means or the control amount is large, the control frequency is suppressed or the control is stopped, so that the intervention frequency and the control amount of the braking means are reduced, and the fade phenomenon of the braking means is avoided. be able to.

In addition, the notifying means notifies the driver of the operation state of the control means, so that the driver's attention is drawn and the stability and safety of the vehicle can be improved.

[0045]

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

<First Embodiment> FIG. 1 shows a vehicle equipped with a vehicle braking device according to a first embodiment of the present invention, wherein 1 is a vehicle body, and 2, 2,... 21FR,
21FL, 21RR, 21RL, four sets of hydraulic brakes individually provided as braking means, 3 a pressurizing unit for supplying pressurized liquid to each of these brakes 2, 4 a pressurizing unit 3 Unit that distributes the pressure fluid supplied from the
The pressure unit 3 and the HU
4 constitutes braking force adjusting means. Reference numeral 5 denotes a controller as control means for controlling the operation of each of the brakes 2 via the pressurizing unit 3 and the HU 4.
Are wheel speed sensors for detecting the wheel speeds of the wheels 21, 71 are lateral G sensors for detecting lateral acceleration acting on the vehicle body 1, and 72 are acting on the vehicle body 1. The yaw rate sensor 73 detects the actual yaw rate γ.
Is a steering angle sensor as a steering angle detecting means for detecting the steering angle.
Are wheel cylinder pressure sensors for detecting the wheel cylinder pressure of each wheel 21;
Reference numerals 4,... Denote brake pad temperature sensors for detecting the temperature of the brake pads of the brakes 2 of the respective wheels 21. In addition, 10 is a master cylinder, 11 is an engine, 12
Is a continuously variable transmission (CVT: Continuous) as an automatic transmission.
ly Variable Transmission), and this CVT12
Is of a toroidal type.

The brakes 2, 2,... Are a brake 2 for the right front wheel 21FR and a left rear wheel 21R, as shown in FIG.
L is connected to the master cylinder 10 by a first hydraulic line 22a, while the brake 2 of the left front wheel 21FL and the brake 2 of the right rear wheel 21RR are different from the first hydraulic line 22a. The hydraulic cylinder 22b is connected to the master cylinder 10, thereby forming two independent brake systems of the so-called X-pipe type. Then, the wheels 21FR, 21FR, 2
A braking force is applied to 1FL,.

The pressurizing unit 3 includes 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 for detecting the hydraulic pressure between the two. And
In response to a command from the controller 5, the cut valve 3
2a and 32b are closed, so that the hydraulic pumps 31a and 32b are independent of the brake operation by the driver.
Are configured to be supplied to the brakes 2, 2,... Via the HU4. Also,
The HU 4 is connected to the first hydraulic line 22a or the second hydraulic line 2
A pressurizing valve 41 for pressurizing each brake 2 with a pressurized liquid supplied via a pressure tank 2b, and a depressurizing valve 43 for connecting each brake 2 to a reservoir tank 42 for depressurizing the brake.
43... Each of the pressurizing valves 41 and the depressurizing valves 4
By adjusting the opening degree of the brake 3, the hydraulic pressure applied to each of the brakes 2 is increased or decreased, and the braking force is increased or decreased.

Next, an outline of the turning control of the vehicle by the controller 5 will be described with reference to FIG. 17. The controller 5 changes the yaw rate on a low μ road as shown by the solid line in FIG. Thus, the control of the brake 2 of each wheel 21 is performed. That is, in the initial stage of the turn, the rising speed of the yaw rate (the changing speed of the yaw rate) becomes as indicated by the broken line in FIG.
Is controlled so as to be the same as the yaw rate change speed on the high μ road (see the dashed line in the figure). On the other hand, in the later stage of turning, the yaw rate according to the road surface μ (yaw rate on low μ road <yaw rate on high μ road)
Is caused in the vehicle.

Next, the turning operation control by the controller 5 will be described with reference to the flowchart shown in FIG. First, in step S11, the wheel speed detected by the wheel speed sensor 21, the vehicle speed V calculated based on the wheel speed, the steering angle δ detected by the steering angle sensor 73, and the actual yaw rate detected by the yaw rate sensor 72. The sensor data of γ, the lateral acceleration detected by the lateral G sensor 71, and the wheel cylinder pressure detected by the wheel cylinder pressure sensor 23 are obtained.

Next, at step S12, the road surface μ
And the vehicle body side slip angle β is estimated. For example, the road surface μ may be estimated from the wheel speed, and the vehicle body side slip angle β may be estimated from the actual yaw rate γ and the lateral acceleration. Therefore, in the present embodiment, the yaw rate sensor 72,
The lateral G sensor 71 and the controller 5 constitute a vehicle body side slip angle detecting means.

In step S13, the target yaw rate Tr
Calculate γ. The target yaw rate Trγ is, as shown in FIG. 4, a steering angle δ passed through a delay filter G (s) set based on a response time of the turning operation of the vehicle with respect to steering.
Multiply by and set.

Here, the delay filter G (s) is set based on the response time of the turning operation on the high μ road, whereby the rising speed of the target yaw rate Trγ at the initial stage of turning is high. Is set in the same manner as the rising speed.

The above gain (target yaw rate Trγ)
/ Steering angle δ) is set in consideration of the vehicle speed V and the road surface μ.
Specifically, as shown in FIG. 5, a reference value α is set so that a gain is given for each road surface μ. Also, the vehicle speed V
(Refer to the dashed line in the figure). Thus, for example, when the road surface friction coefficient is μ0, the gain becomes α · μ0, and the target yaw rate T
rγ is set to Trγ = α · μ0 · δ. In this way, in the later stage of the turn, the target yaw rate Trγ is set to a value corresponding to the road surface μ.

The setting of the gain is not limited to the above. For example, a plurality of road surface μ representative values (for example, road surface μ = 0.2 (small), 0.4 (medium), 0.6
(Large) prepares a map of vehicle speed V and gain,
The gain may be set by using this map. In this way, the calculation time of the target yaw rate Trγ can be reduced.

After the target yaw rate Trγ has been calculated in this way, in step S14, a target yaw moment M_target required to realize the target yaw rate Trγ is calculated. This is because, as shown in FIG. 6, a gain of 1 is set to the target yaw rate Trγ so that the actual yaw rate γ can quickly follow the target yaw rate Trγ.
(Feed forward) and the actual yaw rate γ and the vehicle body side slip angle β to stabilize the behavior of the vehicle.
Is multiplied by a gain 3 (feedback), and a term obtained by multiplying the integral value of the deviation e between the target yaw rate Trγ and the actual yaw rate γ by a gain 4 is set as a target yaw moment M_target. Here, the gain 4 is corrected by a value obtained by multiplying the actual yaw rate γ and the vehicle body side slip angle β by the gain 2 so as to reduce the error.

Thus, the target yaw moment M_t
If the target is calculated, in step S15,
A target wheel cylinder oil pressure applied to the brakes 2 of the respective wheels 21 required to generate the target yaw moment M_target is calculated. Specifically, as shown in FIG. 7, first, M_f and M_r are calculated from the target yaw moment M_target by M_f + M_r = M_targ.
Set to be et. As shown in FIG. 8, M_f is a moment obtained from a distance L_f from the position of the center of gravity to the front inner wheel (in FIG. 8, left turning) and a braking force F_f generated on the front inner wheel. Is the distance L_ from the position of the center of gravity to the rear wheel in the turn.
r and a braking force F_r generated on the rear wheel in the turning.

When M_f and M_r are set, the braking torque required to realize the moments M_f and M_r is set. Next, the hydraulic pressure of each wheel is set based on the set braking torque. This may be set in consideration of the detection result of the wheel cylinder pressure sensor 23.

When the target wheel cylinder pressure of each of the wheels 21FR to 21RL is calculated in this manner, step S1 is executed.
At 6, the control permission is determined. The control permission determination conditions are as follows: the steering speed is a predetermined value or more, the vehicle speed V is a predetermined value or more (for example, 40 km / h or more), the road surface μ is a predetermined value or less (for example, 0.6 or less which is a wet road), and the control system is Four conditions are set as to whether a failure has occurred.

Then, in step S17, it is determined whether or not to permit the control. If all the above conditions (1) to (5) are satisfied and the control is to be permitted (YES), the control of the wheel cylinder pressure (brake 2, 2,...), But not permitted
If so, the process ends without proceeding to step S18.

In this way, the rising speed of the target yaw rate Trγ in the initial stage of turning is set in the same manner as the rising speed on the high μ road, and the target yaw rate Trγ is set.
are controlled so as to be γ, the rising speed of the turning operation at the beginning of turning is made similar to the rising speed of the turning operation on the high μ road. That is, the turning characteristics of the vehicle can be obtained on the low μ road as well as on the high μ road, so that the behavior of the vehicle can be stabilized without the driver performing the corrective steering.

On the other hand, the target yaw rate T in the latter half of the turn
By controlling the brakes 2, 2,... so that rγ is set to a value corresponding to the road surface μ and to reach the target yaw rate Trγ, a stable turning according to the road surface μ can be realized.

<Second Embodiment> FIGS. 9A to 9C are flowcharts of control by a controller 5 according to a second embodiment of the present invention. In the second embodiment, brakes 2, 2,. In addition to controlling the turning motion,
The control of the turning operation using the tack-in by the output torque control of the engine 11 and the shift control of the CVT 12 is performed. Since the configuration of the vehicle according to the present embodiment is substantially the same as that of the first embodiment, the same members are denoted by the same reference numerals, and description thereof will be omitted. Only different portions will be described.

In the second embodiment, as shown in FIG. 10, both the throttle valve 13a directly connected to the accelerator pedal 15 and the electric throttle 13b whose opening is controlled by the motor 16 are connected to the engine 11
The driving of the motor 16 is performed as follows.
It is controlled by the controller 5. Therefore, the electric throttle 13b and the motor 16 constitute an engine output adjusting means for adjusting the output torque of the engine.

The controller 5 controls the speed of the CVT 12 in addition to the operation of the brakes 2, 2,....
The transmission switching means is also used as a control means for controlling the transmission switching means.

Next, the turning operation control by the controller 5 will be described with reference to flowcharts shown in FIGS. 9A to 9C. Steps S21 to S24 in this flowchart are the same as steps S11 to S14 in FIG. Since they are the same, the description is omitted.

In step S25 (the next step after the target yaw moment M_target is set) in the flowchart shown in FIG. 9B, the accelerator pedal 15 is turned on.
It is determined whether or not it has been performed. The accelerator pedal is ON,
That is, if the driver has depressed the accelerator pedal 15 (YES), the process proceeds to step S26, where the yaw moment M1 of the tack-in generated by closing the electric throttle 13b is calculated, the electric throttle 13b is closed and the CVT 12 is closed. The yaw moment M2 of the tack-in generated by downshifting is calculated.

Next, in step S27, it is determined whether or not the target yaw moment M_target <M1.
When M_target <M1 is YES, closing the electric throttle 13b causes the target yaw moment M_tar.
Since a yaw moment greater than “get” is generated, step S2 is performed to control only the brakes 2, 2,.
Proceed to 14 (see FIG. 9C) to calculate the target wheel cylinder oil pressure for each wheel.

On the other hand, in step S27, M_t
If NO is satisfied, the process proceeds to step S28, and it is determined whether or not the target yaw moment M_target> M2. If M_target> M2 is YES, the process proceeds to step S29, where the electric throttle 1
3b and the control of both the CVT 12 are determined, and the target yaw moment M_target is newly set as M_target = M_target-M2. On the other hand, in the above step S28, M_target
If NO in step S2, the process proceeds to step S210, in which it is determined that only the electric throttle 13b is to be controlled, and a new target yaw moment M_target is set as M_target = M_target-M1.

If it is determined in step S25 that the accelerator pedal 15 is OFF (NO in step S25), the process proceeds to step S25.
In step 211, the yaw moment M3 of the tack-in caused by shifting down the CVT 12 is calculated. Then, in step S212, it is determined whether or not the target yaw moment M_target <M3. If YES in M_target <M3, it is determined that only the control of the brakes 2, 2,.
On the other hand, if M_target ≧ M3 is NO, the process proceeds to step S213 to determine execution of the control of the CVT 12, and M_target = M_target.
The target yaw moment M_tar is newly set as t-M3.
Set get.

When the means for generating the tack-in is selected in this way, the yaw moment for which the target yaw moment M_target cannot be realized by executing these means is controlled by controlling the brakes 2, 2,. Will be caused by

That is, in step S214, the target wheel cylinder pressure of each wheel 21 is calculated based on the newly set target yaw moment M_target or the target yaw moment M_target set in step S24, and control is performed in step S215. The permission is determined. If YES in step S216 to permit the control, step S217 is performed.
In the above, the selected tack-in control means, that is, the execution of the control for closing the electric throttle 13b or the CVT 1
2, or both the closing of the electric throttle 13 b and the shifting control of the CVT 12, and a step S 2.
At 18, wheel cylinder pressure control is executed. On the other hand, if NO in step S216 that control is not permitted,
The process ends without performing steps S217 and S218.

As described above, in the case of the second embodiment, the turning operation of the vehicle is controlled by using the output torque control of the engine 11 and the tack-in generated by performing the shift control of the CVT 12. It is possible to reduce the operation frequency or the operation amount of 2,. As a result, the fade phenomenon of the brakes 2, 2,... Can be reliably avoided.

Even if the shift control is performed in this manner, the automatic transmission is of the toroidal type CVT 12, so that responsiveness is good and shift shock can be reduced, thereby preventing the driver from feeling uncomfortable. be able to.

In this embodiment, the automatic transmission is CVT
Although it is set to 12, it may be AT (Automatic Transmission). Further, the CVT 12 is not limited to the toroidal type.

The output torque of the engine 11 is adjusted by the opening degree of the electric throttle 13b. However, the present invention is not limited to this.
The output torque of the engine 11 may be adjusted by a known method.

<Third Embodiment> FIG. 11 is a flowchart for setting a control start threshold value according to a third embodiment of the present invention. In the third embodiment, brakes 2, 2,. If the control intervention frequency or control amount is large,
The control is suppressed or the control is stopped.

Since the structure of the vehicle in the third embodiment is substantially the same as that of the first embodiment, the same members are denoted by the same reference numerals, and description thereof will be omitted. Only different parts will be described. In the third embodiment, when the control is stopped or when the control is suppressed, a notifying unit for notifying the driver to that effect is provided. As shown in FIG. 12, the notification means is constituted by a notification lamp 81 which can be changed to blue / yellow / red for lighting, and is used during normal control (stop of control and control ) Is illuminated in blue while control is suppressed, and illuminated in yellow when control is suppressed, and further illuminated in red when control is suspended. As described above, the notification lamp 81 is configured to change the notification mode for the driver according to the control situation. The lighting control of the notification lamp 81 is performed by the controller 5.

The controller 5 according to the third embodiment
Is the same as the control flowchart of the controller 5 in the first embodiment (see FIG. 3), and the setting of the control start threshold value is performed in the control permission step in step S16. In the first embodiment, the steering speed is equal to or more than a predetermined value, the vehicle speed V is equal to or more than a predetermined value (for example, 40 km / h or more), the road surface μ is equal to or less than a predetermined value (for example, 0.6 or less which is a wet road), and the control system is The control is started when the four conditions of whether or not the failure is satisfied are satisfied. In the third embodiment, however, the deviation between the target yaw rate Trγ and the actual yaw rate γ is satisfied. Is different from the first embodiment in that control is started when the value is larger than the threshold value.

In the flowchart for setting the control start threshold value (threshold value for the deviation between the target yaw rate Trγ and the actual yaw rate γ) shown in FIG. 11, first, the brake pad temperature sensor 24 detects in step S31. It is determined whether or not the brake pad temperature is higher than a preset threshold value (brake pad temperature> threshold value).
This is to determine whether the total control amount is large or not. If the brake pad temperature ≦ the threshold value is NO, the process proceeds to step S32, and the control amounts of the brakes 2, 2,. As there is no need to suppress control intervention,
Set the control start threshold to small. Thus, the control is started even when the deviation between the target yaw rate Trγ and the actual yaw rate γ is small.

On the other hand, brake pad temperature> threshold value Y
In the case of ES, the process proceeds to step S33, where the brake 2,
2. It is determined whether or not the control intervention frequency is high. This may be determined by, for example, the total control amount per predetermined time, or may be determined by the number of control interventions from the stop state of the vehicle (vehicle speed V = 0) to the next stop state. If the intervention frequency is large, ie, YES, the control amount and the intervention frequency are both large, and if the control is further repeated, a fade phenomenon of the brakes 2, 2,... May occur. To determine to stop the control.

If it is determined in step S33 that the intervention frequency is low, the process proceeds to step S35, in which it is determined whether or not the traveling road is a snowy road. This determination may be made based on, for example, the road surface μ and the outside air temperature. Y which is a snowy road
In the case of ES, the process proceeds to step S32, and the control start threshold value is set to a small value for the purpose of positively intervening the control in order to improve the turning performance of the vehicle.

On the other hand, if NO in step S35, that is, if the road is not a snowy road, the flow advances to step S36 to determine whether or not the traveling road is a wet road. This determination may be made, for example, based on the operation of the wiper. If the road is a wet road, the flow proceeds to step S37, and control intervention is required because the road surface μ is relatively low.
In order to reduce the intervention frequency, the control start threshold is set to medium.

On the other hand, if NO in step S36, that is, if the road is not a wet road, the flow advances to step S38 to determine whether or not the running road is a mountain road. This determination is made, for example, by GPS (Gl
obalPositioning System) and map information. When the road is a mountain road, the process proceeds to step S39, in which control intervention is not so necessary, but the control start threshold value is set to a large value for the purpose of assisting the driving because there are many up-down and lane circuits. As a result, the control is started only when the deviation between the target yaw rate Trγ and the actual yaw rate γ is large.

On the other hand, if the result of step S38 is NO, that is, the road is not a mountain road, the running conditions do not require control, and the control amounts of the brakes 2, 2,... Are large. Abort.

After setting the control start threshold value and determining to stop the control in this way, in step S17 (see FIG. 3), the steering speed is equal to or higher than the predetermined value, and the vehicle speed V is equal to or higher than the predetermined value (for example, 40 km / h). Above), the condition that the control system has not failed is satisfied and the target yaw rate T
If the deviation between rγ and the actual yaw rate γ is larger than the set threshold value, control is permitted and step S18 is performed.
Then, while the wheel cylinder pressure is controlled, if the control is not permitted in step S17, the process ends without proceeding to step S18. Further, also in the case where the control is stopped in step S34, the process ends without proceeding to step S18.

During normal control (the threshold value for starting control is small), the notification lamp 81 lights in blue to notify the driver that normal control is being performed, while starting control. When the control is suppressed by changing the threshold value to medium or large, it lights up in yellow to notify that the control is in the suppression state. Then, when the control is stopped, it is lit in red to notify the driver of the control stop.

When the controller 5 stops the control, as shown in FIG. 13, after the driver is informed of the stop of the control (after the notification lamp 81 lights up in red), a predetermined period of time elapses. After the lapse of Δt, the control is actually stopped.

On the other hand, if a predetermined time elapses after the control is stopped or the temperature of the brake pad falls below the threshold value, the controller 5 cancels the control stop and returns to the normal control. It is configured to return.
When returning to the normal control, the notification lamp 81 is lit in blue, so that the driver can recognize that the suspension of the control has been released. Also,
When returning to the normal control, the threshold value of the control start is gradually reduced after the notification by the driver is performed, so that the control is not suddenly started.

As described above, in the case of the third embodiment, the temperature of the brake pad (total amount of control performed) and the brake pad 2
2, to change the threshold value for starting the control based on the intervention frequency of the control or to stop the control,
The fade phenomenon of 2,... Can be avoided beforehand.

Further, since the driver is notified according to the control situation such as the change of the control start threshold value or the suspension of the control, the driver's attention is raised and the stability of the vehicle is improved. And safety can be further improved.

Further, when the control is stopped, a delay time Δt from when the notification to the driver is performed to when the control is actually stopped is set. There is a margin of time until the operation adapted to the control suspension is performed, and safety can be improved. On the other hand, when the control is returned from the control suspended state, the control start threshold is gradually reduced after the notification to the driver is made, so that the driver's discomfort can be reduced.

The notifying means is not limited to the notifying lamp 81.
For example, a speaker may be provided so as to notify the change of the threshold value or the suspension of the control by voice.
Further, the fact that the control has been stopped may be notified by a warning sound or an operation sound instead of the voice. In addition, the driver may be notified of the suspension of the control, for example, by vibrating the steering wheel or the seat.

<First Modification> In the third embodiment, the frequency of control intervention is reduced by changing the control start threshold value for the purpose of avoiding the fade phenomenon of the brakes 2, 2,. However, in this first modified example,
By reducing the operation amount (control amount) of the brakes 2, 2,..., The fade phenomenon of the brakes 2, 2,.

That is, FIG. 14 shows a flowchart for setting the brake pressure gain according to the first modified example. The control flowchart for the controller 5 in the first modified example is also the same as the control flowchart for the controller 5 in the third embodiment (FIG. 14). The setting of the brake pressure gain is performed in the control permission step in step S16.

The flowchart for setting the brake pressure gain is shown in the flowchart for setting the threshold value for starting control (FIG. 12).
Only the contents of step S32, step S37, and step S39 are different, and therefore, the description of the other steps is omitted.

That is, if it is determined in step S41 that the brake pad temperature ≦ the threshold value is NO or if the process proceeds to step S42 in which it is determined that the road is a snowy road, the brake pressure gain is set to normal (100%). . Thereby, the brake pressure is applied as usual.

On the other hand, if it is determined in step S43 that the operation frequency of the control is high, or if it is determined in step S48 that the road is not a mountain road and the process proceeds to step S44, the brake pressure gain is set to 0% to stop the control.

When the process proceeds to step S47 on the basis of the wet road in step S46, the brake pressure gain is set to 70% (medium) in order to reduce the brake amount. Further, when the process proceeds to step S49 assuming that the road is a mountain road in step S48, the brake pressure gain is set to 50% (small) in order to further reduce the brake amount.
As described above, when the brake pressure gain is changed based on the brake pad temperature and the control intervention frequency, the control amount is changed (reduced), so that the brake pad temperature rise is avoided, and the brakes 2, 2,. The fade phenomenon can be avoided beforehand. Note that the value (70, 50%) of the brake pressure gain may be appropriately adjusted.

<Second Modification> In a second modification, as in the third embodiment and the first modification, the controller 5 suppresses the control and stops the control based on the control intervention frequency or the control amount. In addition to the operation, a manual switch 9 (FIG.
Reference).

That is, the driver can operate the manual switch 9 to change the control start threshold value or the brake pressure gain. The manual switch 9 allows the normal control and the snow road specification (control start). Threshold is small or brake pressure gain is large), wet road specification (control start threshold is medium or brake pressure gain is medium), mountain road specification (control start threshold is large or brake pressure gain is small), It is possible to switch to five specifications of control suspension.

In the second modification, the notification lamp 81 does not change the notification mode in accordance with the operation state of the controller 5, but in accordance with the brake pad temperature and the intervention frequency of the brakes 2, 2,... Thus, the notification mode is changed. In other words, when the brake pad temperature is low or the frequency of intervention of the brake control is low, it lights up in blue, while when the brake pad temperature is medium or the frequency of intervention of the brake control is medium, it lights up in yellow. When the brake pad temperature is high or the frequency of brake control intervention is high, the light is lit in red. Thus, the driver can operate the manual switch 9 according to the notification mode of the notification lamp 81. Further, by changing the notification mode according to the brake pad temperature and the frequency of intervention of the brakes 2, 2,..., The driver's attention is raised, and as a result, safer driving is realized.

When the driver stops the control by operating the manual switch 9, as shown in FIG. 15, when the manual switch 9 is turned off, the controller 5 immediately stops the control. ing.
Conversely, when the driver returns the control by operating the manual switch 9, the manual switch 9
Is turned on, the controller 5 is configured to immediately return to the control. Thus, unlike the case where the controller 5 decides to suspend or return the control, when the control is suspended or returned by the driver's will, the controller 5 controls the manual switch 9 in response to the operation of the manual switch 9. Immediate suspension or return can prevent the driver from feeling uncomfortable.

The notification means is not limited to the notification lamp 81. For example, as shown in FIG. 16, for example, four substantially trapezoidal segments 82a to 82d which are individually turned on and off extend in the vertical direction. The display may be performed by the display device 82 that displays the arranged segment rows. When the brake pad temperature is low or the frequency of intervention of the brake control is low, only the lowermost segment 82d is lit, for example, in blue, while when the brake pad temperature is medium, When the intervention frequency is medium, the lower two segments 82c and 82d are lit, for example, in yellow. Further, when the brake pad temperature rises or the frequency of intervention of the brake control increases, the lower three segments 82b to 82d are lit, for example, in yellow. When the brake pad temperature is high or the frequency of intervention of the brake control is high, all the segments 82a to 82d are configured to be illuminated, for example, in red, so that the driver can control the frequency of the intervention or the control. The amount may be notified stepwise.

Note that this display device 82 may be a notifying means instead of the notifying lamp 81 in the third embodiment. That is, the number of lighting and the lighting color of the segments 82a to 82d may be changed in accordance with the state of control by the controller 5.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a vehicle to which a vehicle braking 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 control flowchart by a controller according to the first embodiment.

FIG. 4 is a block diagram illustrating a method for calculating a target yaw rate.

FIG. 5 is a diagram illustrating a method of setting a gain of a target yaw rate.

FIG. 6 is a block diagram illustrating a method for calculating a target yaw moment.

FIG. 7 is a flowchart relating to calculation of a target wheel cylinder pressure.

FIG. 8 is an explanatory diagram showing distribution of a braking force applied to each wheel.

FIG. 9A is a part of a control flowchart by the controller according to the second embodiment.

FIG. 9B is a part of a control flowchart by the controller according to the second embodiment.

FIG. 9C is a part of a control flowchart by the controller according to the second embodiment.

FIG. 10 is a schematic diagram showing a configuration of an engine intake system according to a second embodiment.

FIG. 11 is a flowchart for setting a control start threshold value according to the third embodiment.

FIG. 12 is a diagram showing a notification lamp.

FIG. 13 is a time chart showing a control switching mode when the controller stops control or returns control.

FIG. 14 is a flowchart for setting a brake pressure gain according to a first modified example.

FIG. 15 is a diagram corresponding to FIG. 13, showing a control mode when the driver stops control or returns control.

FIG. 16 illustrates a display device.

FIG. 17 is a diagram showing a time change of a yaw rate on a high μ road and a low μ road.

[Explanation of symbols]

2 Brake (braking means) 3 Pressurizing unit (braking force adjusting means) 4 Hydraulic unit (braking force adjusting means) 5 Controller (control means) 12 CVT (automatic transmission) 15 Accelerator pedal 16 Motor (engine output adjusting means) 21) Wheels 72 Yaw rate sensor (yaw rate detecting means) 73 Steering angle sensor (steering angle detecting means) 81 Notification lamp (notifying means) 82 Display device (notifying means) 13b Electric throttle (engine output adjusting means)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F16H 61/16 F16H 61/16 (72) Inventor Toru Yoshioka 3-1, Fuchu-cho, Shinchi, Aki-gun, Hiroshima Mazda Incorporated F-term (reference) 3D041 AA40 AA48 AA80 AB01 AC01 AC15 AC18 AC19 AC26 AD10 AD50 AD51 AE03 AE04 AE32 AE39 AE41 AF01 3D046 BB23 BB25 BB28 BB29 CC02 DD04 EE01 FF05 GG02 GG06 HH08 MMH3H05HHH LLH LL NB01 SB10 TB03 TB07 TB11 TB13 VB02Z VB05Z VB07W VC03W VD02W VD11W VD14W VE05W VE06W

Claims (15)

[Claims] A braking system for a vehicle, comprising: braking means provided on each wheel; and braking force adjusting means for controlling the braking means to individually adjust a braking force applied to each wheel. A yaw rate detecting means for detecting a yaw rate occurring in the vehicle; a steering angle detecting means for detecting a steering angle of the vehicle; a yaw rate detected by the yaw rate detecting means and a steering angle detected by the steering angle detecting means. Control means for controlling the braking force adjusting means so that the rising speed of the turning operation in the initial stage of turning of the vehicle becomes a preset value regardless of the road surface friction coefficient. Characteristic vehicle braking device. 2. The control device according to claim 1, wherein the control device controls the braking force adjusting device such that a yaw rate generated in the vehicle becomes a set value set in accordance with a road surface friction coefficient in a later period of the turning of the vehicle. A braking device for a vehicle, wherein the braking device is configured as described above. 3. The vehicle according to claim 1, further comprising a vehicle body slip angle detecting means for detecting a vehicle body skid angle, wherein the control means comprises a yaw rate detected by the yaw rate detecting means and a steering detected by the steering angle detecting means. The braking force is adjusted based on the vehicle angle and the vehicle body slip angle detected by the vehicle body slip angle detecting means so that the rising speed of the turning operation at the initial stage of turning of the vehicle becomes a preset value regardless of the road surface friction coefficient. A vehicle braking device configured to control the means. 4. The automatic transmission according to claim 1, further comprising a speed changeover means for performing a speed change control of the automatic transmission, wherein the control means controls the braking force adjusting means or shifts down the automatic transmission at an early stage of turning of the vehicle. The vehicle braking device is configured to control the shift switching means as described above. 5. The vehicle according to claim 1, further comprising an engine output adjusting means for adjusting an output torque of the engine, wherein the control means controls the braking force adjusting means or reduces the output torque of the engine at an early stage of turning of the vehicle. The vehicle braking device is configured to control the engine output adjusting means as described above. 6. The engine output adjusting means according to claim 5, wherein the engine output adjusting means adjusts the output torque of the engine by adjusting the throttle opening of the engine. A vehicle braking device configured to control the engine output adjusting means when the vehicle is being depressed. 7. The automatic transmission according to claim 6, further comprising a speed changeover means for performing a speed change control of the automatic transmission, wherein the control means shifts down the automatic transmission when the driver does not depress the accelerator pedal. A braking device for a vehicle, characterized in that the braking device is configured to control the shift switching means as described above. 8. The vehicle braking device according to claim 1, further comprising a notifying unit that notifies a driver that the control unit is operating. 9. The information processing device according to claim 8, wherein the notification means is configured to change a notification mode to the driver when the control intervention frequency or the total amount of control performed is equal to or more than a predetermined value. Vehicle braking device. 10. The vehicle according to claim 1, wherein the control means is configured to suppress the control when the intervention frequency of the control or the total amount of executed control is equal to or more than a predetermined value. Braking device. 11. The control device according to claim 10, wherein the control means performs control when a deviation between a target yaw rate set based on the steering angle and an actual yaw rate generated in the vehicle is equal to or larger than a threshold value. A braking device for a vehicle, wherein the threshold value is increased as the control intervention frequency or the total amount of executed control increases. 12. The vehicle braking device according to claim 10, wherein the control means is configured to reduce the control amount as the intervention frequency of the control or the total amount of control performed increases. 13. The vehicle according to claim 10, wherein the control unit is configured to stop the control when the intervention frequency of the control or the total amount of the executed control exceeds a predetermined value. Braking device. 14. The vehicle braking device according to claim 13, further comprising: a notifying unit that notifies a driver of control suspension of the control unit to the driver. 15. The vehicle braking system according to claim 14, wherein the control unit is configured to stop the control with a predetermined time delay after the notification unit notifies the control unit of the stop of the control. apparatus.