JP3713728B2 - Brake pressure detection device and brake system abnormality detection device using the same - Google Patents

Description

[0001]
[Industrial application fields]
The present invention is used in a brake device including a vacuum booster that introduces an intake negative pressure of an engine and boosts a brake operation force in accordance with a difference between the negative pressure and an atmospheric pressure. And a brake system abnormality detection device using the same.
[0002]
[Prior art]
In general, in a brake device for a vehicle, brake oil is pumped from a master cylinder in accordance with a brake operation by a driver, and a brake force is applied to the wheel cylinder of each wheel by the brake oil. In recent years, there has been a demand for a technique for detecting a brake pressure applied from a master cylinder to a wheel cylinder and grasping, for example, a brake pressure control state or an abnormal state of a brake system using the detection result.
[0003]
[Problems to be solved by the invention]
However, although there is a demand for the above, in reality there are few specific and effective technologies as a new technology for detecting the brake pressure, and mainly a pressure sensor disposed in a hydraulic path connecting the master cylinder and the wheel cylinder. The brake pressure was detected from the detection result of the sensor.
[0004]
Therefore, the present invention is made to meet the above-mentioned demand, and the object is as follows. That is, the first object of the present invention is to provide a brake pressure detecting device having a novel configuration and capable of easily detecting a brake pressure, targeting a brake device using a vacuum booster. It is a second object of the present invention to provide a brake system abnormality detection device that can accurately detect a brake system abnormality using the brake pressure detected by the pressure detection device.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the present invention is configured to detect the brake pressure from the characteristics of the vacuum booster for boosting the brake operation force by the driver. In other words, the vacuum-type booster of the present invention include those which introduce a negative intake pressure of the engine, to boost the brake operating force in accordance with the difference between the atmospheric pressure to be introduced in accordance with the operation of the intake negative pressure and the brake pedal When the brake pedal is operated, the intake negative pressure level introduced into the booster temporarily changes.
[0006]
Therefore, in the brake pressure detection device according to claim 1, a negative pressure detecting means for detecting the intake negative pressure is introduced into the vacuum-type booster, according to a change of the detected intake negative pressure by the negative pressure detection means And a brake pressure estimating means for estimating the brake pressure.
[0007]
According to a second aspect of the present invention, the brake pressure detecting device according to the first aspect is characterized in that the negative pressure detecting means is an intake pipe negative pressure sensor disposed in an intake pipe of an engine.
[0008]
According to a third aspect of the present invention, there is provided a brake system abnormality detection device using the brake pressure detection device according to the first aspect, wherein an actual deceleration detecting means for detecting an actual deceleration of the vehicle, and the brake pressure An estimated deceleration calculating means for calculating an estimated deceleration of the vehicle based on the brake pressure estimated by the estimating means; and if the difference between the actual deceleration and the estimated deceleration exceeds a predetermined value, the vacuum booster And a booster abnormality detecting means for determining that an abnormality has occurred.
[0009]
According to a fourth aspect of the present invention, there is provided a brake system abnormality detecting device using the brake pressure detecting device according to the first aspect, the brake sensor for detecting presence or absence of a brake operation by a driver, and the brake pressure estimating means. The present invention is provided with a sensor abnormality detecting means for determining that an abnormality has occurred in the brake sensor when the brake operation by the brake sensor is not detected even when the brake pressure estimated by the above reaches a predetermined value.
[0010]
[Action]
According to the brake pressure detecting device of the first aspect, the negative pressure detecting means detects the intake negative pressure introduced into the vacuum booster. The brake pressure estimating means estimates the brake pressure according to the intake negative pressure detected by the negative pressure detecting means. That is, as described above, in the vacuum booster, since the intake negative pressure level to be introduced changes during a brake operation, the brake pressure is easily detected according to the above configuration.
[0011]
According to the brake pressure detecting device of the second aspect, it is not necessary to newly provide a negative pressure sensor by detecting the negative pressure introduced into the vacuum booster by the intake pipe negative pressure sensor.
[0012]
According to the brake system abnormality detection device of the third aspect, the actual deceleration detecting means detects the actual deceleration of the vehicle. The estimated deceleration detecting means calculates an estimated deceleration of the vehicle based on the brake pressure estimated by the brake pressure estimating means. The booster abnormality detection means determines that an abnormality has occurred in the vacuum booster when the difference between the actual deceleration and the estimated deceleration exceeds a predetermined value. That is, when an abnormality occurs in the vacuum booster and the negative pressure does not change despite the brake operation, the estimated vehicle deceleration obtained from the brake pressure value does not correspond to the actual vehicle deceleration. Therefore, the abnormality of the vacuum booster is easily detected from the difference between the estimated deceleration and the actual deceleration.
[0013]
According to the brake system abnormality detection device of the fourth aspect, the brake sensor detects the presence or absence of the brake operation by the driver. The sensor abnormality detection means determines that an abnormality has occurred in the brake sensor when the brake operation by the brake sensor is not detected even when the brake pressure estimated by the brake pressure estimation means reaches a predetermined value. That is, the brake pressure is detected according to a temporary change in the negative pressure at the time of the brake operation, but an abnormality of the brake sensor can be easily detected by using this brake pressure data.
[0014]
【Example】
(First embodiment)
Hereinafter, a first embodiment in which the present invention is embodied in a braking control device for a rear wheel drive four-wheel vehicle will be described with reference to the drawings.
[0015]
FIG. 1 is a configuration diagram illustrating an outline of a vehicle brake control device according to the present embodiment. As shown in FIG. 1, a vacuum booster (hereinafter referred to as V / B) 2 for boosting the depression force of the pedal 1 is connected to the brake pedal 1, and the tandem type is connected to the V / B2. A master cylinder (hereinafter referred to as M / C) 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 configured by a known hydraulic circuit having various electromagnetic valves that can switch at least between a pressure increasing state and a pressure reducing state. The brake actuator 6 and the hydraulic pump 7 are driven in response to a control command from an electronic control unit (hereinafter referred to as ECU) 40. The brake oil supplied by the M / C 3 or the hydraulic pump 7 passes through the brake actuator 6 and the hydraulic paths 8 and 9, and the wheel cylinders (hereinafter referred to as W / C) 10FL of the wheels FL, FR, RL, and RR. , 10FR, 10RL, 10RR.
[0016]
Each wheel FL to RR is provided with a wheel speed sensor 11FL, 11FR, 11RL, 11RR for detecting the rotation speed of the wheel. As these wheel speed sensors 11FL to 11RR, electromagnetic pickup type or photoelectric conversion type sensors are used. Detection signals from the wheel speed sensors 11FL to 11RR are input to the ECU 40, and the ECU 40 controls anti-skid control (hereinafter referred to as ABS control) that suppresses the wheel lock generated during vehicle braking based on the rotational speed information of each wheel. In addition, traction control (hereinafter referred to as TRC control) that suppresses the acceleration slip of the wheel that has occurred during vehicle acceleration is executed.
[0017]
In the engine 13, a surge tank 15 provided in the intake pipe 14 is provided with an intake pipe negative pressure sensor 16 for detecting the intake pipe negative pressure. A detection signal of the intake pipe negative pressure sensor 16 is input to the ECU 40. In this embodiment, the intake pipe negative pressure sensor 16 constitutes a negative pressure detecting means.
[0018]
In addition to the detection signals from the wheel speed sensors 11FL to 11RR, the ECU 40 detects a brake sensor 17 that detects whether the brake pedal 1 is operated or an accelerator sensor 18 that detects an operation amount of an accelerator pedal (not shown). Operates in response to detection signals from the The ECU 40 includes a microcomputer mainly composed of a CPU, ROM, RAM, and the like, and includes a communication device that transmits and receives sensor detection data and control data. In this embodiment, the ECU 40 comprises negative pressure detection means, brake pressure estimation means, actual deceleration detection means, estimated deceleration calculation means, booster abnormality detection means, and sensor abnormality detection means.
[0019]
Next, the configuration and operation of V / B2 will be described with reference to FIG.
In FIG. 2, the V / B 2 has a first power cylinder 21a and a second power cylinder 21b. Inside each of the power cylinders 21a and 21b, diaphragms 22a and 22b have constant pressure chambers 23a and variable pressure chambers 24a, Each is divided into a constant pressure chamber 23b and a variable pressure chamber 24b. The outer peripheries of the diaphragms 22a and 22b are fixed to the outer wall of the V / B2. An intake negative pressure of the engine 13 is introduced into the constant pressure chambers 23 a and 23 b through the negative pressure port 25, and atmospheric pressure is introduced into the variable pressure chambers 24 a and 24 b through the filter 26. A check valve is provided in a negative pressure pipe (not shown) connecting the negative pressure port 25 and the intake pipe 14 of the engine 13 so that the airtightness of the constant pressure chambers 23a and 23b is maintained. The valve operating rod 27 moves in the left-right direction in the figure according to the depression operation of the brake pedal 1, and the booster piston rod 28 outputs the pedal operation amount boosted by the V / B2 to the M / C3 as the V / B output. introduce.
[0020]
The operation of V / B2 will be described in detail.
When the brake pedal 1 is depressed, the valve operating rod 27 advances to the left in the figure while pushing the air valve 29, and the control valve 30 pressed against the air valve 29 by the control valve spring 31 also advances to the left simultaneously. Eventually, when the control valve 30 comes into contact with the vacuum valve 32 and the conduction between the passage A and the passage B is cut off, the conduction between the constant pressure chambers 23a and 23b and the variable pressure chambers 24a and 24b is also cut off.
[0021]
When the air valve 29 advances further to the left, the air valve 29 and the control valve 30 are separated from each other, and the atmosphere flows through the passage B into the variable pressure chambers 24a and 24b. At this time, a pressure difference is generated between the variable pressure chambers 24a, 24b and the constant pressure chambers 23a, 23b, and the diaphragms 22a, 22b move to the left. The force generated at this time is transmitted to the booster piston rod 28 via the reaction disk 33, and this is the output of V / B2. As described above, when the brake pedal 1 is depressed, the diaphragms 22a and 22b move to the left in the drawing and the volumes of the constant pressure chambers 23a and 23b are reduced. Therefore, the negative pressure in the constant pressure chambers 23a and 23b is temporarily reduced. Decrease. In the present description, the pressure decrease is referred to as “negative pressure” with reference to the atmospheric pressure, and a decrease in the negative pressure means that the pressure approaches the atmospheric pressure.
[0022]
On the other hand, when the depression force of the brake pedal 1 decreases, the balance between the reaction disk 33 and the air valve 29 is lost, and the air valve 29 is pushed back to the right. The air valve 29 comes into contact with the control valve 30 and shuts off the variable pressure chambers 24a and 24b and the atmosphere, and simultaneously pushes back the control valve 30 to open the vacuum valve 32. For this reason, the passage A and the passage B are conducted, and the air in the variable pressure chambers 24a and 24b flows into the constant pressure chambers 23a and 23b, and the pressure difference between the two chambers is eliminated. The diaphragms 22a and 22b are returned to the non-operating position by the booster return spring 34. As described above, when the depression operation of the brake pedal 1 is released, the diaphragms 22a and 22b move to the right in the drawing, the volume of the constant pressure chambers 23a and 23b is increased, and the identification pressure chambers 23a and 23b are moved. Since the air flows in, the negative pressure in the constant pressure chambers 23a and 23b temporarily decreases.
[0023]
Further, in the case of V / B2 of this configuration, even when V / B2 is lost and both the constant pressure chambers 23a and 23b and the variable pressure chambers 24a and 24b become atmospheric pressure, M / C3 Can be operated to ensure the braking operation. That is, when the brake pedal 1 is depressed, the valve operating rod 27 pushes the air valve 29 and proceeds to the left in the figure, and comes into contact with the reaction disk 33. At this time, the booster piston rod 28 is pushed leftward against the urging force of the booster return spring 34, and the pedal depression force is transmitted to M / C3. In this case, a boosting action of V / B2 cannot be obtained, but a braking force corresponding to the pedal depression operation can be obtained.
[0024]
Next, operations and effects peculiar to the present embodiment will be described with reference to FIGS. Here, FIG. 3 is a flowchart showing a V / B abnormality determination routine executed by the ECU 40. Hereinafter, specific contents of the V / B2 abnormality determination will be described using the same flow.
[0025]
When the routine of FIG. 3 is started, the ECU 40 first inputs the intake negative pressure calculated based on the detection result of the intake pipe negative pressure sensor 16 in step 100. Further, in the subsequent step 101, the ECU 40 integrates the intake negative pressure from a state where the change of the intake negative pressure is small (accelerator off steady state), and estimates the M / C oil pressure at that time.
[0026]
Further, the ECU 40 calculates a deceleration (hereinafter referred to as an estimated deceleration) GM / C with respect to the estimated value of the M / C hydraulic pressure at step 102, and at the subsequent step 103, an actual vehicle deceleration (hereinafter referred to as an actual deceleration). Gx is calculated. Here, the estimated deceleration value GM / C in step 102 is calculated according to the M / C oil pressure at that time using the map of FIG. 4, and the actual deceleration Gx in step 103 is detected by a change in vehicle body speed or an acceleration sensor. Calculated from the results.
[0027]
Thereafter, in step 104, the ECU 40 determines whether V / B2 is normal (whether F = 0) based on the state of the abnormality determination flag F, and if an abnormality has occurred, that is, F If = 1, the process returns to step 100. If normal, that is, if F = 0, the process proceeds to step 105.
[0028]
Further, the ECU 40 determines whether or not the value (= GM / C−Gx) obtained by subtracting the actual deceleration Gx from the estimated deceleration GM / C of the vehicle body in step 105 is equal to or greater than a predetermined determination value ε during ABS control. Determine. That is, since the actual deceleration Gx decreases due to the pressure reducing action during the ABS control, the actual deceleration Gx is smaller than the estimated deceleration GM / C calculated from the estimated value of the M / C hydraulic pressure (GM / C> Gx ). Therefore, when “GM / C−Gx ≧ ε” is satisfied during ABS control (step 105 is YES), the estimated deceleration GM / C value (estimated value of M / C oil pressure) is correct and V This means that a negative pressure change of / B2 occurs. Further, when “GM / C−Gx <ε” is satisfied during the ABS control (NO in step 105), the value of the estimated deceleration GM / C (estimated value of the M / C oil pressure) is not correct, and is related to the brake operation. This means that no negative pressure change of V / B2 has occurred.
[0029]
Accordingly, if step 105 is YES, the ECU 40 proceeds to step 106 and resets the abnormality determination flag F to “0”, assuming that V / B2 is normal. Then, the ECU 40 permits the execution of the braking control in the subsequent step 107 and returns to the step 100. If step 105 is NO, the ECU 40 proceeds to step 108 and sets the abnormality determination flag F to “1”, assuming that V / B2 is abnormal. Then, the ECU 40 prohibits execution of the braking control in the subsequent step 109 and returns to the step 100.
[0030]
The above process will be described more specifically with reference to the timing charts of FIGS. 5A shows an operation when V / B2 is normal, and FIG. 5B shows an operation when an abnormality (such as negative pressure leakage due to a defect) occurs in V / B2.
[0031]
In FIG. 5A, the intake negative pressure temporarily changes at the start and end of the depression of the brake pedal 1 (time t1, t3), and the M / C oil pressure is estimated from the change in the intake negative pressure. At time t2 during the ABS control, the value obtained by subtracting the actual deceleration Gx from the estimated deceleration GM / C obtained from the estimated value of the M / C oil pressure (= GM / C−Gx) is equal to or greater than the determination value ε. And V / B2 is considered normal. Accordingly, step 105 in FIG. 3 is positively determined and the abnormality determination flag F is held at “0”. In this case, V / B2 assists the depressing operation of the brake pedal 1 and transmits the assist force to M / C3.
[0032]
On the other hand, in FIG. 5B, due to the lack of V / B2, there is almost no change in the intake negative pressure at the start and end of the brake pedal 1 (time t11, t13). / B2 cannot assist. In this case, the actual M / C oil pressure is a pressure corresponding to the pedal depression force by the driver, but the M / C oil pressure estimated from the intake negative pressure is a considerably smaller value (almost 0).
[0033]
As a result, the estimated deceleration GM / C becomes a small value even though the vehicle is actually decelerated. Therefore, at time t12 during the ABS control, the value obtained by subtracting the actual deceleration Gx from the estimated deceleration GM / C (= GM / C−Gx) does not exceed the judgment value ε, and V / B2 is abnormal. Is considered. At time t12, a negative determination is made at step 105 in FIG. 3 and an abnormality determination flag F is set to “1”.
[0034]
Thus, in the traction control device of this embodiment, the intake negative pressure introduced into V / B2 is detected, and the M / C oil pressure is estimated from the integrated value of the intake negative pressure (step 101 in FIG. 3). ). Further, Gx after actual deceleration of the vehicle is calculated, and an estimated deceleration GM / C of the vehicle is calculated based on the estimated value of the M / C hydraulic pressure (steps 102 and 103 in FIG. 3), and the estimated deceleration GM during ABS control is calculated. When the value obtained by subtracting the actual deceleration Gx from / C is less than the predetermined determination value ε, it is determined that a V / B abnormality (brake system abnormality) has occurred (step 105 in FIG. 3).
[0035]
That is, since the negative pressure level introduced into V / B2 changes during the brake operation, the M / C oil pressure can be detected accurately and simply by using this. Further, when an abnormality occurs in V / B2 and the intake negative pressure does not change despite the brake operation, the estimated deceleration GM / C of the vehicle obtained from the estimated value of the M / C oil pressure is the actual deceleration of the vehicle. It will not be suitable for Gx. Therefore, the abnormality of V / B2 can be easily detected by using the values of the estimated deceleration GM / C and the actual deceleration Gx.
[0036]
Further, in the present embodiment, since the intake pipe negative pressure sensor 16 provided in the intake pipe 14 of the engine 13 is configured to detect the negative pressure introduced into V / B2, another negative pressure sensor is provided. There is no need, and the configuration can be simplified.
[0037]
In the above embodiment, the abnormality determination is performed using the value of “GM / C−Gx” at the time of ABS control, but the estimated deceleration GM / C and the actual deceleration at the time of normal braking (at the time of non-ABS control). It is also possible to calculate the absolute value of the difference from Gx (= | GM / C−Gx |) and determine that an abnormality has occurred when the calculated value is equal to or greater than a predetermined value.
(Second embodiment)
Next, the vehicular braking control apparatus of the second embodiment will be described focusing on the differences from the first embodiment. In the first embodiment, the brake system abnormality detection process has been described by detecting the abnormality of V / B2 using the estimated value of the M / C hydraulic pressure. In the second embodiment, the brake system abnormality detection process is also described. The abnormality detection process of the brake sensor 17 using the estimated value of the M / C oil pressure will be described. FIG. 6 is a flowchart showing a sensor abnormality determination routine executed by the ECU 40.
[0038]
When the routine of FIG. 6 is started, the ECU 40 first inputs the intake negative pressure in step 200, and in the subsequent step 201 integrates the intake negative pressure to estimate the M / C oil pressure at that time. Further, the ECU 40 determines in step 202 whether or not the brake sensor 17 is normal. If an abnormality has occurred, the ECU 40 returns to step 200, and if normal, the process proceeds to step 203. In step 202, for example, an abnormal state is determined from a set state of an abnormality determination flag set at the time of abnormality determination.
[0039]
Thereafter, the ECU 40 determines in step 203 whether or not the amount of change in the estimated value of the M / C oil pressure is greater than a predetermined determination level. In this case, if the brake pedal 1 is not depressed, step 203 is negatively determined, and the ECU 40 returns to step 200. If there is a stepping operation, an affirmative determination is made in step 203 and the ECU 40 proceeds to step 204.
[0040]
Then, when the ECU 40 proceeds to step 204, it determines whether or not the detection signal of the brake sensor 17 has been switched on / off. In this case, if step 204 is affirmed, the ECU 40 regards that the pedal depression operation in step 203 is normally detected by the brake sensor 17 and determines that the sensor is normal in step 205. Thereafter, the ECU 40 permits the brake control in step 206 and returns to step 200.
[0041]
If the determination in step 204 is negative, the ECU 40 determines that the pedal depression operation in step 203 has not been detected by the brake sensor 17 and determines in step 207 that the sensor is abnormal. Thereafter, the ECU 40 prohibits the braking control at step 208 and returns to step 200.
[0042]
Thus, in the second embodiment, the abnormality of the brake sensor 17 can be easily detected by using the change amount of the estimated value of the M / C oil pressure. In the second embodiment, if the brake sensor 17 is not on when the estimated value of the M / C oil pressure is large, it can be determined that the sensor 17 is abnormal.
[0043]
In addition to the above embodiment, the present invention can be embodied in the following manner.
(1) In each of the above embodiments, the negative pressure introduced into V / B2 is obtained from the detection result of the intake pipe negative pressure sensor 16, but this may be changed. For example, a booster negative pressure sensor may be provided near the negative pressure port 25 of V / B2, and the booster negative pressure may be directly detected. In this case, a negative pressure sensor different from the intake pipe negative pressure sensor 16 is required, but if the detection result is used, the M / C hydraulic pressure can be accurately estimated as in the above embodiment.
[0044]
(2) In each of the above embodiments, the M / C oil pressure is estimated from the integral of the intake negative pressure introduced into V / B2, but the change rate of the intake negative pressure is calculated by differentiation, and the M / C oil pressure is calculated from the change rate. The C hydraulic pressure may be estimated.
[0045]
(3) In each of the above embodiments, the process of detecting the M / C oil pressure has been described as an example of detecting the brake pressure by the intake negative pressure introduced into V / B2, but the intake negative pressure of V / B2 is similarly used. It is also possible to detect the W / C oil pressure of each wheel as a brake pressure.
[0046]
(4) Although the brake control apparatus determines an abnormality in the brake system using the estimated value of the M / C oil pressure, this M / C oil pressure information can also be used for other processes in the brake control. For example, the M / C hydraulic pressure can be used as a vehicle deceleration request (braking request), and this request can be used as a condition for executing or terminating ABS control or TRC control.
[0047]
(5) In the above embodiment, the brake pressure detection device of the present invention is embodied in a brake control device having ABS control and TRC control. However, it can be embodied in a brake device that does not perform these controls. In this case, the brake pressure information can be used for other vehicle motion control.
[0048]
【The invention's effect】
According to the brake pressure detecting device of the first aspect, a new configuration can be used and a brake can be simply performed by utilizing the fact that the negative pressure level of the vacuum booster temporarily changes during the brake operation. The pressure can be detected.
[0049]
According to the brake pressure detecting device of the second aspect, it is not necessary to newly provide a negative pressure sensor, and the configuration can be simplified.
According to the brake system abnormality detection device of the third aspect, the abnormality of the booster can be detected easily and accurately from the negative pressure change of the vacuum booster.
[0050]
According to the brake system abnormality detection device of the fourth aspect, it is possible to easily and accurately detect the abnormality of the brake sensor from the negative pressure change of the vacuum booster.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a vehicle brake control device according to an embodiment.
FIG. 2 is a cross-sectional view showing a configuration of V / B.
FIG. 3 is a flowchart showing a V / B abnormality determination routine.
FIG. 4 is a diagram for calculating an estimated deceleration.
FIG. 5 is a timing chart for explaining the operation of the embodiment.
FIG. 6 is a flowchart showing a sensor abnormality determination routine.
[Explanation of symbols]
2 ... Vacuum booster (V / B), 3 ... Master cylinder (M / C), 10FL to 10RR ... Wheel cylinder (W / C), 13 ... Engine, 14 ... Intake pipe, 16 ... Negative pressure detection means Intake pipe negative pressure sensor, 17 ... brake sensor, 40 ... negative pressure detection means, brake pressure estimation means, actual deceleration detection means, estimated deceleration calculation means, booster abnormality detection means, electronic control device as sensor abnormality detection means ( ECU), FL ... left front wheel, FR ... right front wheel, RL ... left rear wheel, RR ... right rear wheel.

Claims (4)

The intake negative pressure of the engine is introduced, the brake operation force is boosted according to the difference between the intake negative pressure and the atmospheric pressure introduced according to the operation of the brake pedal, and when the brake pedal is operated, the intake negative pressure is increased. A vacuum booster having a variable pressure level, and used for a brake device for transmitting the brake pressure of a master cylinder operated through the booster to the wheel cylinder of each wheel;
Negative pressure detecting means for detecting intake negative pressure introduced into the vacuum booster;
A brake pressure detecting device comprising: a brake pressure estimating unit that estimates a brake pressure according to a change in intake negative pressure detected by the negative pressure detecting unit. The brake pressure detecting device according to claim 1, wherein the negative pressure detecting means is an intake pipe negative pressure sensor disposed in an intake pipe of an engine. A brake system abnormality detection device using the brake pressure detection device according to claim 1,
Actual deceleration detection means for detecting the actual deceleration of the vehicle;
An estimated deceleration calculating means for calculating an estimated deceleration of the vehicle based on the brake pressure estimated by the brake pressure estimating means;
A brake system abnormality detection device comprising booster abnormality detection means for determining that an abnormality has occurred in the vacuum booster when a difference between the actual deceleration and the estimated deceleration exceeds a predetermined value. A brake system abnormality detection device using the brake pressure detection device according to claim 1,
A brake sensor for detecting the presence or absence of a brake operation by the driver;
Sensor abnormality detecting means for determining that an abnormality has occurred in the brake sensor when the brake operation by the brake sensor is not detected even when the brake pressure estimated by the brake pressure estimating means reaches a predetermined value. Brake system abnormality detection device characterized by.

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