JPH08183443A - Braking pressure control device for vehicle - Google Patents

Abstract

PURPOSE: To appropriately detect the abnormality of a brake sensor even during the execution of braking pressure control. CONSTITUTION: A brake sensor 13 detects whether braking operation is performed by a driver and outputs a brake signal indicating to that effect. An ECU 20 controls the braking pressure of wheels into either a pressure reducing state or a pressure intensifying state in order to dissolve wheel lock generated in association with the braking operation of the driver. At this time larger braking pressure is distributed to the front wheel side than the rear wheel side. The ECU 20 judges the generation of abnormality to the brake sensor 13 if the brake sensor 13 is off in the case of the front wheel speed being lowered large in relation to the rear wheel speed. The ECU 20 suspends the detection of sensor abnormality at the time of cylinder cut off operation of an engine and at the operating time of a parking brake. When the vehicle speed is the specified speed or less and a vehicle is in an accelerating state, the ECU 20 informs the driver of the information of sensor abnormality by lighting an alarm lamp.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle brake pressure control device for performing anti-skid control (hereinafter referred to as ABS control), traction control (hereinafter referred to as TRC control), and the like.

[0002]

2. Description of the Related Art In a device for performing brake pressure control such as ABS control or TRC control, the control command is determined according to a brake signal indicating whether or not a driver has performed a brake operation. Therefore, if the brake signal is not correctly output, the control accuracy may be greatly affected, and various methods for detecting an abnormality of the brake sensor have been proposed conventionally (for example, Japanese Patent Laid-Open No. 5-149417). ).

[0003]

However, the conventional abnormality detecting method mainly discloses a detecting method during normal braking, such as simply detecting the presence or absence of a brake sensor signal when the vehicle is rapidly decelerating. No specific detection method for implementing ABS control or TRC control is disclosed.

The present invention has been made in view of the above problems, and an object thereof is to provide a vehicle brake pressure capable of appropriately detecting an abnormality of a brake sensor even when executing brake pressure control. It is to provide a control device.

[0005]

In order to achieve the above object, the invention according to claim 1 is a brake sensor which detects the presence or absence of a brake operation by a driver and outputs a brake signal to that effect. A brake that controls the brake pressure of the wheel to at least one of the reduced pressure state and the increased pressure state in order to cancel the wheel lock due to the brake operation by the driver, and distributes a larger brake pressure to the front wheel side than to the rear wheel side. A pressure control means, a wheel speed difference detection means for detecting a wheel speed difference between the front wheel side and the rear wheel side, and a brake signal indicating that the brake operation is performed when the wheel speed difference becomes large as the front wheel speed decreases. If the above is not output, an abnormality detecting means for determining that an abnormality has occurred in the brake sensor is provided.

According to a second aspect of the present invention, in the first aspect of the present invention, the abnormality detecting means is configured to stop the abnormality detection when the engine is running with reduced cylinders. According to a third aspect of the invention, in the first aspect of the invention, the abnormality detecting means is configured to stop the abnormality detection when the parking brake of the vehicle is used.

According to the present invention, a brake sensor for detecting the presence / absence of a brake operation by the driver and outputting a brake signal to that effect, and a brake operation by the driver when a predetermined control condition is satisfied. In order to eliminate the accompanying wheel lock, the brake pressure control means for controlling the brake pressure of the wheel to at least one of the reduced pressure state and the increased pressure state and the brake when the control condition of the brake pressure control means is satisfied a predetermined number of times. The gist is to provide an abnormality detecting means for determining that an abnormality has occurred in the brake sensor unless a brake signal indicating that an operation has been performed is output.

According to a fifth aspect of the present invention, a brake sensor that detects the presence or absence of a brake operation by the driver and outputs a brake signal to that effect, and at least the acceleration slip of the wheels except when the driver operates the brake. In order to solve the above problem, a brake pressure control means for applying a brake pressure to a wheel cylinder on the drive wheel side, a driven wheel speed detection means for detecting a driven wheel speed of a vehicle, and a decrease in the driven wheel speed during the brake pressure control. The gist is to provide an abnormality detecting unit that determines that an abnormality has occurred in the brake sensor if the brake signal indicating the brake operation is not output when the amount exceeds a predetermined value.

According to a sixth aspect of the present invention, a brake sensor that detects the presence or absence of a brake operation by the driver and outputs a brake signal indicating that, and a vehicle travel distance or a maximum vehicle speed after the ignition key of the vehicle is turned on. When the vehicle traveling distance or the maximum vehicle speed detected by the measuring means reaches a predetermined value, the brake signal indicating that there is a brake operation has not been output by then, the brake The gist of the present invention is to include an abnormality detecting unit that determines that an abnormality has occurred in the sensor.

In the invention described in claim 7, claims 1 to 6 are provided.
In any one of the inventions described above, the slip determination level is low when an abnormality of the brake sensor is determined by the antiskid control means having a plurality of control start criteria with different slip determination levels and the abnormality detection means. And a control start reference changing means for changing the control start reference.

According to the invention described in claim 8, claims 1 to 6 are provided.
In any one of the inventions, when an acceleration slip occurs, a traction control unit that applies a brake pressure to each wheel by the supply pressure of the pump, and an abnormality of the brake sensor is determined by the abnormality detection unit, the traction And a control prohibiting means for prohibiting the brake pressure control by the control means.

In the invention described in claim 9, claims 1 to 8 are provided.
In any one of the inventions, when an abnormality of the brake sensor is determined by the abnormality detection means, an abnormality information storage means for storing the abnormality information, and an informing means for informing the driver of the abnormality information And notification control means for controlling the notification means so as to notify the abnormality information stored in the abnormality information storage means when a predetermined vehicle driving condition is satisfied.

According to a tenth aspect of the present invention, in the ninth aspect of the present invention, the vehicle driving condition of the notification control means is that the vehicle speed is equal to or lower than a predetermined speed or the vehicle is in a non-decelerated state. At least one of

According to an eleventh aspect of the invention, in the invention of the ninth aspect, the vehicle operating condition of the notification control means includes that the engine is started.

[0015]

According to the first aspect of the invention, the brake sensor detects the presence / absence of a brake operation by the driver and outputs a brake signal to that effect. The brake pressure control means controls the brake pressure of the wheels to at least one of the reduced pressure state and the increased pressure state in order to cancel the wheel lock caused by the driver's brake operation, and the front wheel side is larger than the rear wheel side. Distribute brake pressure. The wheel speed difference detecting means detects a wheel speed difference between the front wheel side and the rear wheel side. The abnormality detecting means determines that an abnormality has occurred in the brake sensor if the brake signal indicating that the brake operation is performed is not output when the wheel speed difference becomes large as the front wheel speed decreases. That is, in the brake pressure control for distributing the brake pressure as described above, the speed reduction amount of the front wheels becomes larger than the speed reduction amount of the rear wheels due to the brake operation by the driver. Therefore, the abnormality of the brake sensor can be easily detected from the difference between the front and rear wheel speeds.

According to the second aspect of the invention, the abnormality detecting means suspends the abnormality detection during the engine cut-off cylinder operation.
That is, when the reduced cylinder operation is performed, the engine brake due to the fuel cut may act to reduce the drive wheel speed, and in the invention of claim 1, there is a possibility that a sensor abnormality is erroneously detected particularly in the case of a front-wheel drive vehicle. Therefore, erroneous detection is prevented by stopping the abnormality detection during the reduced cylinder operation.

According to the third aspect of the present invention, the abnormality detecting means stops the abnormality detection when the parking brake of the vehicle is used. This configuration prevents erroneous detection when using the parking brake.

According to the invention described in claim 4, the brake sensor detects whether or not the driver operates the brake,
A brake signal indicating that is output. The brake pressure control means controls the brake pressure of the wheels to at least one of the reduced pressure state and the increased pressure state in order to cancel the wheel lock caused by the brake operation by the driver when a predetermined control condition is satisfied. The abnormality detecting means determines that an abnormality has occurred in the brake sensor if a brake signal indicating that a brake operation is performed is not output when the control condition of the brake pressure control means is satisfied a predetermined number of times. That is, the fact that the control condition of the brake pressure control means is satisfied has a high possibility that the driver has performed the brake operation, and the abnormality of the brake sensor can be easily detected from the number of times the condition is satisfied and the presence of the brake signal. . It should be noted that increasing the number of times the condition is satisfied will prevent erroneous detection.

According to the fifth aspect of the invention, the brake sensor detects whether or not the driver has operated the brake,
A brake signal indicating that is output. Brake pressure control means, except when the driver is operating the brake,
Brake pressure is applied to the wheel cylinder on the drive wheel side in order to eliminate at least the acceleration slip of the wheel. The driven wheel speed detecting means detects the driven wheel speed of the vehicle. The abnormality detecting means determines that an abnormality has occurred in the brake sensor when the brake signal indicating that the brake operation is performed is not output when the amount of decrease in the driven wheel speed during the brake pressure control exceeds a predetermined value. That is, the execution of the brake pressure control (for example, traction control) corresponds to the occurrence of the acceleration slip, and the decrease of the driven wheel speed at this time is highly likely that the driver performed the brake operation.
Therefore, an abnormality of the brake sensor can be easily detected from the amount of decrease in the driven wheel speed.

According to the sixth aspect of the invention, the brake sensor detects whether or not the driver has operated the brake,
A brake signal indicating that is output. The measuring means measures a vehicle traveling distance or a maximum vehicle speed after the ignition key of the vehicle is turned on. When the vehicle traveled distance or the maximum vehicle speed detected by the measuring means reaches a predetermined value, the abnormality detecting means generates an abnormality in the brake sensor unless the brake signal indicating that the brake operation is performed is output by that time. It is judged that it did. That is, it is unlikely that the driver does not perform the brake operation at all when the vehicle actually travels. Therefore, an abnormality of the brake sensor can be easily detected by the above method.

According to the seventh aspect of the present invention, the control start reference changing means controls the anti-skid control means so that the slip determination level becomes low when the abnormality detection means determines that the brake sensor is abnormal. Change the starting criteria. In this case, the anti-skid control is started at a lower slip determination level even if the presence of the brake operation cannot be detected when the brake sensor is abnormal. Therefore, the control is started at an early timing, and the occurrence of wheel lock is suppressed with a margin.

According to the eighth aspect of the invention, the traction control means applies the brake pressure to each wheel by the supply pressure of the pump when the acceleration slip occurs. The control prohibiting means prohibits the brake pressure control by the traction control means when the abnormality detecting means determines that the brake sensor is abnormal. In this case, even if the brake operation cannot be detected when the brake sensor is abnormal, the required master cylinder pressure is quickly transmitted to the wheel cylinder of each wheel, and proper braking operation is ensured.

According to the ninth aspect of the present invention, the abnormality information storage means stores the abnormality information when the abnormality detection means determines that the brake sensor is abnormal. The notification control unit controls the notification unit to notify the abnormality information stored in the abnormality information storage unit when a predetermined vehicle driving condition is satisfied. The abnormality information is notified to the driver by the control of the notification means. In this case, even if a sensor abnormality is detected, the abnormality information is not unconditionally (immediately) notified to the driver, but is notified after a predetermined vehicle driving condition is satisfied. The confusion given to people is avoided.

According to the tenth aspect of the present invention, the vehicle operating condition of the notification control means includes at least one of a vehicle speed not higher than a predetermined speed and a vehicle not being decelerated.

According to the eleventh aspect of the invention, the vehicle operating condition of the notification control means includes that the engine is being started. Also in claims 10 and 11, the confusion of the driver due to the abnormality information is avoided.

[0026]

【Example】

(First Embodiment) A first embodiment in which the present invention is embodied in a brake pressure control device for a front wheel drive type four-wheel vehicle will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the outline of the brake pressure control device in this embodiment. As shown in Figure 1,
The brake pedal 1 is connected to a vacuum booster (hereinafter referred to as V / B) 2 for boosting the pedaling force of the pedal 1, and the V / B 2 is connected to a tandem master cylinder (hereinafter referred to as M / B). 3) is connected.
A brake actuator 6 is connected to the two hydraulic paths 4 and 5 provided in the M / C 3, and a hydraulic pump 7 is attached to the brake actuator 6. The brake actuator 6 is composed of a known hydraulic circuit having at least various solenoid valves capable of switching between a pressure increasing state and a pressure reducing state. The brake actuator 6 and the hydraulic pump 7 are electronic control units (hereinafter referred to as ECUs) 20.
It is driven according to the control command from. And M / C3
Alternatively, the brake fluid supplied by the hydraulic pump 7 is passed through the brake actuator 6 and the hydraulic paths 8 and 9 to each wheel F.
L, FR, RL, RR wheel cylinders (hereinafter W /
C) 10FL, 10FR, 10RL, 10RR.

Wheel speed sensors 11FL, 11FR, 11RL, 11 for detecting the rotational speeds of the wheels are provided on the respective wheels FL to RR.
Each RR is provided. These wheel speed sensors 1
As 1FL to 11RR, sensors of electromagnetic pickup type or photoelectric conversion type are used. Each wheel speed sensor 11FL
The detection signal from ~ 11RR is input to the ECU 20 and the EC
U20 performs ABS control (anti-skid control) that suppresses wheel lock that occurs during vehicle braking and TRC control (traction control) that suppresses wheel acceleration slip that occurs during vehicle acceleration based on the rotational speed information of each wheel. Run. During the ABS control, the brake pressure is distributed so that the brake pressure on the front wheel side is larger than the brake pressure on the rear wheel side as shown in FIG. 2, so that the stability of the vehicle is ensured.

In addition to the detection signals from the wheel speed sensors 11FL to 11RR, the ECU 20 detects a brake sensor 13 for detecting whether or not the brake pedal 1 is operated, and an operation amount of an accelerator pedal (not shown). It operates by receiving a detection signal from the accelerator sensor 14 or the like. An instrument panel (not shown) inside the vehicle is provided with a warning lamp 15 for notifying the driver of abnormality information of the brake sensor 13.

The ECU 20 comprises a microcomputer mainly composed of a CPU, a ROM, a RAM and the like, and is provided with a communication device for transmitting and receiving detection data and control data of various sensors. In this embodiment, the ECU 20 constitutes the brake pressure control means, the wheel speed difference detection means, the abnormality detection means, the abnormality information storage means and the notification control means, and the warning lamp 15 constitutes the notification means.

Next, the unique operation and effect of this embodiment will be described with reference to FIGS. Here, FIG.
FIG. 6 is a flowchart showing a sensor abnormality detection routine executed by the CU 20 in a predetermined cycle (for example, every 5 ms). FIG.
This is an abnormality warning routine executed every (ms). In addition,
The flow shown in FIG. 3 is OF due to disconnection of the brake sensor 13
F abnormality is detected. In the same flow, F1 =
1, F2 = 1 indicates a sensor abnormality and F1 = 0, F2
The abnormality determination flags F1 and F2, which indicate that the sensor is normal when = 0, are used. The states of the abnormality determination flags F1 and F2 are stored and retained in the memory in the ECU 20 as abnormality information regardless of whether the ignition key is on or off.

Now, when the routine of FIG. 3 is started,
First, in step 100, the ECU 20 determines the abnormality determination flag F
It is determined whether or not either 1 or F2 is "1", and if this is affirmatively determined, this processing is immediately terminated. Also,
If the determination in step 100 is negative, the ECU 20 proceeds to step 101.

In step 101, the ECU 20 determines the average wheel speed VRave of the left and right rear wheels RL, RR and the left and right front wheels FL, F.
It is determined whether the difference between R and the average wheel speed VFave is greater than a predetermined determination value ε, and whether the state has continued for a predetermined time or more. Here, step 10
If 1 is affirmatively determined, the brake pressure on the front wheels increases due to the execution of the ABS control, and as shown in FIG. 4, the average wheel speed VFave on the front wheels side is compared to the average wheel speed VRave on the rear wheels side. As mentioned above, it shows that it has decreased. FIG.
Then, at time t1, affirmative determination is made at step 101.

If step 101 is answered in the affirmative, EC
The U20 proceeds to step 102 and determines whether or not the sensor abnormality detection condition is satisfied. Here, the sensor abnormality detection condition includes that the engine is not in the reduced cylinder operation state and that the parking brake (not shown) is not operating. That is, in a front-wheel drive vehicle, if engine braking is performed by fuel cut during reduced cylinder operation, the wheel speed of the front wheels (driving wheels) may decrease regardless of the brake operation by the driver. Further, when the parking brake is operated while the vehicle is traveling, the braking force by the parking brake acts on the front wheels, resulting in a decrease in the front wheel speed. In such a case, regardless of whether the brake sensor 13 is turned on or off, a speed difference between the front and rear wheels occurs, so that a sensor abnormality is not detected, the negative determination is made in step 102, and the process directly proceeds to step 106.

If step 102 is answered in the affirmative, EC
The U20 proceeds to step 103 and determines whether or not the brake sensor 13 is turned on. In this case, if step 103 is positive, the ECU 20 resets the abnormality determination flag F1 to “0” in step 104, and proceeds to the subsequent step 106. That is, the ECU 20 determines that the brake sensor 13 is normal. Also, step 1
If the determination of 03 is negative, the ECU 20 determines that the brake sensor 13 is in the OFF abnormality, and proceeds to step 105. The ECU 20 sets the abnormality determination flag F1 to "1" in step 105, and ends this processing.

After that, the ECU 20 determines in step 106 whether or not the wheel slip ratio S is larger than a predetermined ABS start reference value SS and whether or not the state has continued for a predetermined time or longer. . Where step 1
If the determination of 06 is affirmative, the depression speed of the brake pedal 1 causes the rotational speed of one of the wheels to decrease with respect to the vehicle body speed as shown in FIG. Indicates that the value SS has been reached.
In FIG. 5, step 106 is positively determined at time t2.

If step 106 is answered in the affirmative, E
The CU 20 continues the step 107 to the brake sensor 13
It is determined whether or not is turned on. In this case, if step 107 is positively determined, the ECU 20 determines that step 1
In step 08, the abnormality determination flag F1 is reset to "0", and this processing ends. If the determination in step 107 is negative, the ECU 20 proceeds to step 109, sets the abnormality determination flag F2 to "1", and ends this processing.

On the other hand, in the routine of FIG.
In step 200, it is determined whether or not any of the abnormality determination flags F1 and F2 is "1". In addition, the ECU 2
0 means that the estimated vehicle speed VT0 is 30 km / step 201.
Whether or not the vehicle body acceleration GT0 is larger than "0", that is, whether or not the vehicle is in the non-decelerated state is detected in the following step 202.

If the determinations at steps 200 to 202 are affirmative, the ECU 20 determines at step 203
Then, the warning lamp 15 is turned on to notify the driver of the sensor abnormality information.

As described above, in the brake pressure control system of the present embodiment, it is possible to easily detect the abnormality of the brake sensor 13 by utilizing the wheel speed difference between the front and rear wheels caused by the ABS control. In this case, the brake sensor 13 is operated during the reduced cylinder operation of the engine or the operation of the parking brake.
Since the detection of the abnormality is stopped, it is possible to prevent the erroneous detection of the sensor abnormality.

Further, in this embodiment, the abnormality information is notified to the driver when a predetermined vehicle driving condition (the vehicle is in the low speed range and in the non-deceleration state) is satisfied. Therefore, it is unlikely that the driver will be surprised or confused by the notification of the abnormality information, and the abnormality information can be notified to the driver at an appropriate timing.

On the other hand, in the brake pressure control system of the first embodiment, the control method of ABS control and TRC control is changed as follows when the sensor is abnormal. That is, in this control device, as shown in FIG. 7, two types of ABS control start criteria having different slip determination levels are set.
That is, in FIG. 7, the first start reference K1 is the ABS control start reference when the brake signal is ON, and the second start reference K2 (the wheel speed is the wheel speed is higher than the start reference K1). The value on the K1 side is larger, but the slip determination level is lower on the K1 side) is the ABS control start reference when the brake signal is off.

Then, the ECU 20 selects one of the start criteria according to the on / off state of the brake signal, and selects A
Implement BS control. When it is determined that the brake sensor 13 is abnormal, the ECU 20 always sets the ABS control start reference to the first reference regardless of whether the brake signal is on or off.
The starting criterion K1 is In this case, the brake sensor 13
Even if the brake operation is not detected when the
The S control is started at a lower slip determination level. Therefore, the control is started at an early timing, and the occurrence of wheel lock is suppressed with a margin. Here, ECU
An anti-skid control unit and a control start reference changing unit are constituted by 20.

Further, in the present brake pressure control device, when it is determined that the brake sensor 13 is abnormal, the TR
C control is prohibited. In this case, even if the brake operation is not detected when the brake sensor 13 is abnormal, the required master cylinder pressure is quickly transmitted to the W / C 10FL to 10RR of each wheel, and proper braking operation can be secured. Here, the ECU 20 constitutes a traction control means and a control prohibition means.

(Second Embodiment) Next, a brake pressure control device according to a second embodiment will be described focusing on the difference from the first embodiment. In this embodiment, the same device as that of the first embodiment is used, and the abnormality detection method of the brake sensor 13 is changed to the contents described in "Claim 4". In the second embodiment, the ECU 20 constitutes the brake pressure control means and the abnormality detection means.

That is, the ECU 20 sets the brake pressure of the wheel to at least the reduced pressure state or the increased pressure state when the predetermined ABS control condition (the ABS start condition accompanying the decrease of the wheel speed during the brake operation by the driver) is satisfied. Crab control and wheel lock suppression. In addition, the ECU 2
When the ABS control condition is satisfied a predetermined number of times, 0 determines that an abnormality has occurred in the brake sensor 13 unless a brake signal indicating that the brake operation is performed is output.

In this case, the fact that the ABS control condition is satisfied is highly likely that the driver has operated the brake, and the brake sensor is determined based on the number of times the condition is satisfied (for example, 1 to 10 times) and the presence or absence of the brake signal. The 13 abnormalities can be easily detected. Note that erroneous detection can be prevented by increasing the number of times the condition is satisfied.

(Third Embodiment) Next, a brake pressure control device according to a third embodiment will be described. In this embodiment, the same device as that of the first embodiment is used, and the abnormality detection method of the brake sensor 13 is changed to the content described in "Claim 5". In the third embodiment, the ECU 20 constitutes a brake pressure control means, a driven wheel speed detection means and an abnormality detection means.

That is, the ECU 20 controls the driven wheels RL and RR.
The driven wheel speed is detected from the detection results of the wheel speed sensors 11RL and 11RR on the side. Then, when the amount of decrease in the driven wheel speed during TRC control exceeds a predetermined value, the ECU 20
If the brake signal indicating that the brake operation is performed is not output, it is determined that an abnormality has occurred in the brake sensor 13. In short, the execution of the TRC control usually corresponds to the occurrence of the acceleration slip, and the decrease in the driven wheel speed at this time is highly likely that the driver has performed the brake operation.
Therefore, the brake sensor 1 is calculated from the amount of decrease in the driven wheel speed.
The abnormality 3 can be easily detected.

(Fourth Embodiment) Next, a brake pressure control device according to a fourth embodiment will be described. In this embodiment, the same device as that of the first embodiment is used, and the abnormality detection method of the brake sensor 13 is changed to the contents described in "Claim 6". In the fourth embodiment, the ECU 20 constitutes measuring means and abnormality detecting means.

That is, the ECU 20 measures the distance traveled by the vehicle or the maximum vehicle speed after the ignition key of the vehicle is turned on. Then, the ECU 20 determines that an abnormality has occurred in the brake sensor 13 when the vehicle mileage or the maximum vehicle speed has reached a predetermined value and a brake signal indicating that a brake operation has been performed has not been output by then. . In short, when the vehicle travel distance reaches a predetermined value (for example, 5 km) or the maximum speed reaches a predetermined speed (for example, 60 km / h) during actual traveling of the vehicle, the driver operates the brakes by that time. It is very unlikely that nothing happened. Therefore, the abnormality of the brake sensor 13 can be easily detected by the above method.

The present invention can be embodied in the following modes in addition to the above embodiments. (1) In the first embodiment, if the vehicle is in the low speed range and is in the acceleration state, the driver is warned of the abnormal information because the vehicle driving condition is satisfied (the process of FIG. 6). Good. For example, when the engine is started, the vehicle driving condition may be set, and the driver may be warned of the abnormality information according to the ON operation of the ignition key when the vehicle is started.

(2) In the above embodiment, the alarm means is constituted by the warning lamp 15, but this may be changed to another means such as a buzzer or a message display device. (3) In the above embodiment, the TR after the abnormal sensor is detected.
Although it is described that the C control is prohibited, the TRC control pattern may be changed when the sensor is abnormal.

That is, during TRC control, the brake signal =
When it is turned on and when a sensor abnormality is determined, the W / C1 of each wheel is changed from M / C3 during TRC control.
The TRC control pattern is changed so as to prevent excess brake fluid from flowing into 0FL to 10RR. That is, TR
During C control, the W / C 10FL, 10 on the drive wheels FL, FR side from the hydraulic pump 7 via the brake actuator 6
A large amount of brake fluid is being supplied to the FR. Therefore, when the brake operation is performed in accordance with the brake operation by the driver in the above state, the brake oil used during the TRC control is discharged and the new brake oil is supplied from the M / C 3.
Various problems such as pedal bottoming (with the bottom of the brake pedal 1) occur.

On the other hand, in this configuration, for example, the supply pressure of the hydraulic pump 7 is always set to be equal to or higher than the supply pressure of M / C3 and M / C3.
The above problem is solved by preventing excess brake fluid from flowing from C3 to W / C10FL to 10RR. Further, in this configuration, since the above-mentioned control change is performed when the sensor abnormality is detected, even if the presence of the brake operation cannot be detected when the brake sensor 13 is abnormal, the above problems can be avoided. Furthermore, the transition from the TRC control to the normal braking operation (including the ABS control) can be appropriately performed.

[0056]

According to the first aspect of the invention, it is possible to easily detect the abnormality of the brake sensor from the difference between the front and rear wheel speeds during the brake pressure control.

According to the invention described in claims 2 and 3, it is possible to prevent erroneous detection of sensor abnormality. According to the invention described in claim 4, the abnormality of the brake sensor can be easily detected from the number of times the brake pressure control condition is satisfied and the presence or absence of the brake signal.

According to the fifth aspect of the invention, the abnormality of the brake sensor can be easily detected from the amount of decrease in the speed of the driven wheels when the brake pressure control is executed. According to the invention described in claim 6, it is possible to easily detect the abnormality of the brake sensor from the vehicle traveling distance or the maximum vehicle speed after the ignition key of the vehicle is turned on.

According to the seventh and eighth aspects of the present invention, it is possible to perform the appropriate brake pressure control even when the abnormality of the brake sensor occurs. According to the invention described in claims 9 to 11, the excellent effect of being able to notify the driver of the abnormality information at an appropriate timing is exhibited.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a vehicle braking control device according to an embodiment.

FIG. 2 is a diagram showing a front and rear distribution of brake pressure.

FIG. 3 is a flowchart showing a sensor abnormality detection routine.

FIG. 4 is a time chart showing changes in front wheel speed and rear wheel speed.

FIG. 5 is a time chart showing changes in vehicle speed and wheel speed.

FIG. 6 is a flowchart showing an abnormality warning routine.

FIG. 7 is a time chart showing a reference for starting ABS control.

[Explanation of symbols]

3 ... Master cylinder (M / C), 7 ... Hydraulic pump, 10
FL-10RR ... Wheel cylinder (W / C), 13 ... Brake sensor, 15 ... Warning lamp as notification means, 20
... Brake pressure control means, wheel speed difference detection means, abnormality detection means, driven wheel speed detection means, measurement means, anti-skid control means, control start reference changing means, traction control means, control prohibition means, abnormality information storage means, notification An electronic control unit (ECU) as a control means.

Claims (11)

[Claims] 1. A brake sensor that detects the presence or absence of a brake operation by the driver and outputs a brake signal indicating that, and at least the brake pressure of the wheel is reduced in order to cancel the wheel lock due to the brake operation by the driver. State or increased pressure state, and a brake pressure control means that distributes a larger brake pressure to the front wheel side than to the rear wheel side, and a wheel speed difference that detects the wheel speed difference between the front wheel side and the rear wheel side. Detection means, and an abnormality detection means for determining that an abnormality has occurred in the brake sensor unless a brake signal indicating that the brake operation is present is output when the wheel speed difference becomes large as the front wheel speed decreases. A brake pressure control device for a vehicle, comprising: 2. The abnormality detection device for a brake sensor according to claim 1, wherein the abnormality detection means suspends the abnormality detection when the engine is running with reduced cylinders. 3. The abnormality detection device for a brake sensor according to claim 1, wherein the abnormality detection means stops the abnormality detection when the parking brake of the vehicle is used. 4. A brake sensor that detects the presence or absence of a brake operation by a driver and outputs a brake signal indicating that, and when a predetermined control condition is satisfied, to eliminate wheel lock due to the brake operation by the driver. , A brake pressure control means for controlling the brake pressure of the wheel to at least one of the depressurized state and the increased pressure state, and when the control condition of the brake pressure control means is satisfied a predetermined number of times, a brake signal indicating that there is a brake operation is generated. A brake pressure control device for a vehicle, comprising: abnormality detecting means for determining that an abnormality has occurred in the brake sensor if no output is provided. 5. A brake sensor that detects the presence or absence of a brake operation by a driver and outputs a brake signal indicating that, and a drive wheel for eliminating at least acceleration slip of the wheel except when the driver operates the brake. Brake pressure control means for applying a brake pressure to the side wheel cylinder, driven wheel speed detection means for detecting the driven wheel speed of the vehicle, and the amount of decrease in the driven wheel speed during the brake pressure control exceeds a predetermined value. At this time, the vehicle brake pressure control device is provided with: an abnormality detection unit that determines that an abnormality has occurred in the brake sensor if a brake signal indicating that the brake operation is present is not output. 6. A brake sensor that detects the presence or absence of a brake operation by a driver and outputs a brake signal indicating that, and a measuring unit that measures the vehicle travel distance or the maximum vehicle speed after the ignition key of the vehicle is turned on. When the vehicle mileage or the maximum vehicle speed detected by the measuring means reaches a predetermined value, if the brake signal indicating that the brake operation is present has not been output by then, an abnormality has occurred in the brake sensor. A brake pressure control device for a vehicle, comprising: an abnormality detecting means for determining. 7. An anti-skid control means having a plurality of control start criteria having different slip determination levels, and the slip determination level being lowered when the abnormality of the brake sensor is determined by the abnormality detection means. 7. The vehicle brake pressure control device according to claim 1, further comprising a control start reference changing unit that changes the control start reference. 8. A traction control means for applying a brake pressure to each wheel by a supply pressure of a pump when an acceleration slip occurs, and a brake by the traction control means when an abnormality of a brake sensor is determined by the abnormality detection means. 7. A control inhibiting means for inhibiting pressure control.
The brake pressure control device for a vehicle according to any one of 1. 9. An abnormality information storage unit that stores the abnormality information when the abnormality detection unit determines an abnormality of the brake sensor, an informing unit for informing the driver of the abnormality information, and the abnormality. 9. The vehicle according to any one of claims 1 to 8, further comprising notification control means for controlling the notification means so as to notify the abnormality information stored in the information storage means when a predetermined vehicle driving condition is satisfied. Brake pressure control device. 10. The vehicle operating conditions of the notification control means are:
The vehicle brake pressure control device according to claim 9, comprising at least one of a vehicle speed being equal to or lower than a predetermined speed and a vehicle being in a non-decelerated state. 11. The vehicle operating conditions of the notification control means are:
The brake pressure control device for a vehicle according to claim 9, wherein the brake pressure control device is for when the engine is started.