JPH01269656A - Trouble judging device for vehicle and antiskid controller using said device - Google Patents

Abstract

PURPOSE:To prevent the erroneous operation due to trouble by judging that a hydraulic detection element is in trouble when the detected hydraulic value due to a hydraulic pressure detecting element for detecting the hydraulic pressure of a hydraulic type brake means differs from the value which is previously set in correspondence with a brake pedal steepping-on quantity. CONSTITUTION:When a brake pedal is stepped ON, a brake power is generated by supplying working oil pressure generated in a master cylinder 1 into each wheel cylinder 5 (5a-5d) through the electromagnetic control valve 4 (4a-4d) and pipes p5-p8. At this time, the hydraulic pressure in the wheel cylinder 5 is detected by each hydraulic sensor 11 (11a-11d), and the output is feedback- controlled into the antiskid control calculation. In this case, in a processing circuit 7 in which the electromagnetic control valve 4 is controlled, the value set in correspondence with the brake pedal stepping-on quantity which is detected by a stroke sensor 10 and the output of the hydraulic sensor 11 are compared, and when the both differ, it is judged that the hydraulic sensor 11 is in trouble.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a wheel braking device using a hydraulic pressure detection element, and more particularly to a failure determination device for a hydraulic pressure detection element used in a wheel braking device and a failure determination device thereof. This is suitably implemented in the anti-skid control device used.

BACKGROUND ART When a foot brake pedal (hereinafter referred to as a "brake pedal") is depressed, the oil pressure of a wheel cylinder provided in each wheel increases, and a braking operation is started for each wheel. When the brake pedal is momentarily strongly depressed while driving, a strong braking force is applied to each wheel by the hydraulic braking means, and the rotational speed of the wheels (hereinafter referred to as "wheel speed") decreases rapidly. is in a locked state, that is, the wheel speed is 0.
The state will be as follows. When the rotation of the wheels is locked, the ability to steer the vehicle using the steering wheel is lost, resulting in a dangerous situation. In particular, when the coefficient of friction between the wheels and the road surface is small, 1%, the rotation of the wheels is likely to be locked, and greater care is required when operating the brakes.

However, it is extremely difficult for the driver of the vehicle to adjust the amount of depression of the brake pedal in order to obtain the maximum ig1 power due to the relationship with the coefficient of friction with the road surface as described above.

Anti-skid control devices are installed in automobiles to alleviate the above-mentioned difficulties.
This device calculates the slip rate of the wheels from the vehicle speed (hereinafter referred to as "vehicle speed") and the wheel speed, and controls the oil pressure in the wheel cylinders so that the slip rate becomes a value that produces the maximum braking force. In this way, the anti-skid control device controls the oil pressure inside the wheel cylinder, so it detects the oil pressure value using the oil pressure detection element installed inside the wheel cylinder, and feeds it back to the anti-skid control calculation to achieve more accurate control. Achieves high anti-skid control. For example, the level of the coefficient of friction between the wheels and the road surface can be determined from the relationship between the slip ratio of the wheels and the oil pressure value, and by switching the control output based on that level, the braking force can be further increased. Further, by increasing or decreasing the wheel cylinder oil pressure based on the oil pressure value, it is possible to realize anti-skid control with improved responsiveness.

Problems to be Solved by the Invention As mentioned in item i above, in an anti-skid control device using a hydraulic pressure detection element, the hydraulic pressure value is one of the important parameters for anti-skid control calculation.

Therefore, if the value is abnormal, accurate anti-skid control cannot be expected, and a driver who operates the brakes while trusting that anti-skid control will be performed may find himself in a dangerous situation.

The purpose of the present invention is to solve two problems: detect a failure of a hydraulic pressure detection element, and
An object of the present invention is to provide an anti-skid control device that continues anti-skid control even when a malfunction is detected. A failure determination device for a braking system of an automobile that generates III friction braking force by a hydraulic braking means installed on a wheel, comprising: a hydraulic pressure detection element that detects the hydraulic pressure; and a hydraulic pressure detection element that detects depression I of a brake pedal. In response to the output from the depression amount detection means, the oil pressure detection element and the lower stage of depression amount detection, when the output of the oil pressure detection element differs from a preset value corresponding to the depression amount of the brake pedal, The failure determination device for a braking system of an automobile is characterized in that it includes means for determining that the oil pressure detection element is malfunctioning.

In addition, the present invention generates a frictional braking force by a hydraulic braking means provided on each wheel of an automobile by performing a depressing motion of the brake pedal, and increases the hydraulic pressure during frictional braking. An anti-skid control device that increases the coefficient of friction between the wheels and the road surface by increasing the pressure, reducing the pressure, or maintaining the pressure, includes a hydraulic pressure detection element that is installed on each wheel of an automobile and detects the hydraulic pressure, and a brake pedal depression. a depression amount detection means for detecting the amount of depression; means for determining that the oil pressure detection element is in a malfunction state when the value differs from the value determined by the oil pressure detection element; When the oil pressure detection element is determined to be abnormal, the anti-skid control is carried out using the anti-skid control. This is an anti-skid control device characterized by an anti-skid system (2) which performs anti-skid control using a detection element.

However, the present invention is still effective in controlling the depression of the brake pedal. 1 to generate frictional braking force by means of hydraulic braking means provided at each wheel of the automobile.
7. In an anti-skid control device that increases, decreases or maintains hydraulic pressure according to a control signal during friction braking to increase the narrowing coefficient between the wheels and the road surface, the anti-skid control device is provided for each wheel of an automobile and controls the hydraulic pressure respectively. an oil pressure detection element to detect; a depression amount detection means for detecting the amount of depression of the brake pedal; means for determining that the oil pressure detection element is malfunctioning when preset values are different from each other; At times, the output of the oil pressure detection element is used to execute the first anti-skid control 10, which performs undesired skid control, and when it is determined that the oil pressure detection element is abnormal, the output of the oil pressure detection element is 2. Anti-skid control means for performing anti-skid control without using a skid control program.

In the present invention, the first anti-skid system (the first anti-skid brake 17 damper) includes a step of storing the detected oil pressure detected by the oil pressure detection element when locking occurs during wheel braking, and the control signal causes the pressure to increase. The present invention is characterized in that it includes a step of creating a pressurization signal (creating a wholesale signal) so that the oil pressure is smaller by a predetermined percentage than the oil pressure stored in the storage means when representing what to do.

The present invention also provides an anti-skid system that increases, decreases, or maintains the hydraulic pressure of a hydraulic braking means provided in connection with the wheels of an automobile using a control signal to control the hydraulic pressure so as to increase the coefficient of friction between the wheels and the road surface. A failure detection device for a hydraulic pressure detecting element used in a control device includes: a hydraulic pressure detecting element that detects the hydraulic pressure; and a hydraulic pressure detecting element that increases, decreases, or maintains the hydraulic pressure according to the control signal in response to the control signal and the output of the hydraulic pressure detecting element. and means for determining that the oil pressure detection element is malfunctioning when the oil pressure detected by the oil pressure detection element is different from a value corresponding to the control signal. This is a failure detection device for a detection element.

Further, the present invention increases, decreases, or maintains the hydraulic pressure of a hydraulic braking means provided in connection with the wheels of an automobile using a control signal, thereby controlling the hydraulic pressure so as to increase the coefficient of friction between the wheels and the road surface. , an anti-skid control device that performs an anti-skid control operation for each wheel, comprising: an oil pressure detection element that is provided for each wheel of a vehicle and detects the oil pressure; When the oil pressure detected by the oil pressure detection element is different from a value corresponding to the control signal when the oil pressure should be increased, decreased or maintained according to the control signal, it is determined that the oil pressure detection element is malfunctioning. means, in response to the output of the failure determining means, when the oil pressure detection element is normal, performing anti-skid control using the output of the oil pressure detection element, and when it is determined that the oil pressure detection element is abnormal; The anti-skid control device is characterized in that it includes anti-skid control means that performs anti-skid control using a normal oil pressure detection element provided on the same side of the wheel as the oil pressure detection element in the abnormal state.

In addition, the present invention increases, decreases, or maintains the hydraulic pressure of a hydraulic braking means provided in connection with the wheels of an automobile using a control signal, thereby controlling the hydraulic pressure so as to increase the coefficient of friction between the wheels and the road surface. An anti-skid control device that performs an anti-skid control operation for each wheel includes: an oil pressure detection element that is provided for each wheel of a vehicle and detects the oil pressure; means for determining that the oil pressure detection element is malfunctioning when the oil pressure detected by the oil pressure detection element is different from a value corresponding to the control signal when the oil pressure should be increased, decreased or maintained; , in response to the output of the failure determining means, when the oil pressure detection element is normal, a first anti-skid control program is executed for performing anti-skid control using the output of the oil pressure detection element, and the oil pressure detection element is activated. and anti-skid control means for executing a second anti-skid control program that performs anti-skid control without using the output of the oil pressure detection element when it is determined that there is an abnormality. .

In addition, the present invention generates a frictional braking force by the hydraulic braking means provided on the wheel by the depression operation fv of the brake pedal, and in a state in which this frictional braking force is generated, a predetermined condition for controlling the anti-skid is met. In a failure determination device for an anti-skid control device, which increases, decreases, or maintains the hydraulic pressure of the hydraulic braking means in accordance with a control signal to control the hydraulic pressure so as to increase the coefficient of friction between the wheels and the road surface. an oil pressure detection element for detecting a brake pedal; a depression amount detection means for detecting an amount of depression of a brake pedal; and a pressure detection means for detecting a depression amount of a brake pedal; In response to the output from the detection element and the depression amount detection means, when the output of the oil pressure detection element is different from a predetermined value corresponding to the amount of depression of the brake pedal, the oil pressure detection element is malfunctioning. When the anti-skid control condition 1''F- is satisfied, the hydraulic pressure should be increased, decreased or maintained by the control signal in response to the output signal and the output of the oil pressure detection element. When the oil pressure detected by the oil pressure detection element is different from the value corresponding to the control (wholesale signal),
This failure determination device for an anti-skid control device is characterized in that it includes means for determining that the oil pressure detection element is malfunctioning.

Function: In the present invention, when anti-skid control is not performed, when the oil pressure detected by the oil pressure detection element is different from a preset value corresponding to the amount of pedal depression, the oil pressure detection element is activated. It is determined that there is a malfunction. In addition, during anti-skid control, the oil pressure detected by the oil pressure detection element should be increased, decreased, or maintained by the control signal, and even if the oil pressure detected by the oil pressure detection element is When the pressure is equal to that corresponding to the control signal, it is determined that the oil pressure detection element is malfunctioning.

Further, in the present invention, when the oil pressure detection element is determined to be normal, anti-skid control is performed using the output of the oil pressure detection element, and when it is determined that the oil pressure detection element is abnormal, Anti-skid control is performed using a normal oil pressure detection element provided on the same side of the wheel as the oil pressure detection element f in the abnormal state.

In the present invention, when the oil pressure detection element r is determined to be normal, the first anti-skid control program that performs anti-skid control using the output of the oil pressure detection element is executed, and the oil pressure is When it is determined that the detection element is abnormal, the first anti-skid control program for performing anti-skid control is executed without using the output of the oil pressure detection element. The anti-skid control program C1 memorizes the detected oil pressure detected by the oil pressure detection element when the wheels are locked, and control No. Regulations/
, performs pressurization control that results in a hydraulic pressure that is 41 times smaller.

Further, in the present invention, the anti-skid control 40' (
When the condition "f" is not established, it is determined that the oil pressure sensing element f is malfunctioning (7) when the output from the oil pressure sensing element differs from a preset value corresponding to the amount of depression of the butto-kibe pedal. In addition, when anti-skid control condition 11 is satisfied, when the output from the oil pressure detection element is different from the value corresponding to the control signal for suppressing the oil pressure of the hydraulic braking means, the oil pressure detection element malfunctions. judge that it is.

Embodiment No. 1164 is an embodiment (J) of the present invention.
FIG. 3 is a block diagram of an I/control unit 311. The oil pressure of the hydraulic oil in the master cylinder 1 can be adjusted by pressing the brake pedal 2 or by pumping the hydraulic oil flowing into the valve tank 8 through the lever 9'.
Oil pump motor 3 that supplies the master cylinder 1
It rises due to the drive of. Pipes P1 to p4 are provided between the master cylinder 1 and the electromagnetic control valves 4a to 4d, and the hydraulic oil in the master cylinder 1 is supplied to the electromagnetic control valves 48 to 4d via the pipes pl to p4. It will be done. Mako,
Electromagnetic control (31 valves 4a-4d and wheel cylinders 5a-
Pipes I)5 to p8 are provided between the master cylinder 1 and the wheel cylinder 5 installed in the hydraulic braking means through the electromagnetic control valves 4a to 4d I7.
= Increase the oil pressure within t~5d and brake the wheels 68~5d 11. Satkaru. Electromagnetic η no 1 (Sukei・ia −
/4 (l is 3f) A 7-position electromagnetic i1i'l i'l# valve is operated by a processing circuit 7 composed of an individual semiconductor or a microcomputer, etc., according to an 8(ri) control 11 signal.
(One of the three positions (pressure increase, hold, pressure decrease) is selected.

Solenoid control valve 4 in Fig. 1 = J] at pressure increase position 4
Table 17 shows that when a 1 is selected, the pipe p ] - and the pipe l) 5 are in a conductive state 1B, and when the holding position 4 a 2 is selected, the pipe p) 1 and the pipe p5 are cut off. When the decompression position 4a3 is selected, the pipe p
5 and tube 19 are in electrical continuity.

The solenoid control valve 4a is set to the pressure increasing position 4al by the processing circuit 7.
When controlled to the pressure reducing position 4a3, the hydraulic oil in the master cylinder 1 flows into the wheel cylinder 5EL'\ via the pipes Pi and p5, and when the pressure is controlled to the reduced pressure position 4a3, the hydraulic oil in the wheel cylinder 5a flows into the wheel cylinder 5EL'\ through the pipes Pi and p5. It is refluxed to the reservoir tank 8 via p5°p9. Note that the above-mentioned operation is performed by the electromagnetic control valve 4b.
The same goes for ~4d, and the subscripts 1, 2.3 of reference mark 4a
means a pressure increase position, a holding position, and a pressure reduction position, respectively, and the same applies to the electromagnetic control valves 46 to 4d.

tube p6. P valves 9b, 9 provided in the middle of p8
d is a wheel cylinder 5b provided on the left rear wheel 6b
and a wheel cylinder 5d provided on the right rear wheel 6d.
This pulp is used to limit the hydraulic pressure applied to the hydraulic oil so that it does not exceed a predetermined value.

A stroke sensor 10, which is attached to the brake pedal 2 and is realized by a linear potentiometer or the like that detects the position in a linear direction, is a means for detecting the amount of depression of the brake pedal 2, and the detected amount is fed to the processing circuit 7. It will be done.

The oil pressure sensors Lla to 11d installed in the wheel cylinders 5a to 5d are oil pressure detection elements realized by a strain gauge type or a semiconductor, and the detected pressure is given to the processing circuit 7.

The wheels 6a to 6d are provided with wheel speed sensors 12a to 12 (I) to detect the rotational speed of the wheels, and the detection signal is given to the processing circuit 7 as a wheel speed signal.As the wheel series sensors 12a to 12d, for example, A detection plate made of ferromagnetic material fixed to the wheel axle is provided with a large number of equally spaced notches and protrusions in the circumferential direction, and an electromagnetic pickup attached near the circumference of the detection plate detects a frequency proportional to the wheel speed. There is a sensor that detects the wheel speed signal.

The operation of the anti-skid control device configured as above will be briefly explained. When anti-skid control is not performed, the master cylinder 1 transfers the brake pressure generated by depressing the brake pedal 2 to the electromagnetic control valves 4a to 4d.
The electromagnetic control valves 4a to 4d are set at pressure increasing positions so that the brake pressure is applied to the wheel cylinder 5.

When the brake pedal 2 is strongly depressed while driving, the pressure inside the wheel cylinders 5a to 5d rises rapidly, causing the wheels 6a to
6 d starts slipping. The processing circuit 7 calculates the slip rate of each wheel (represented by the difference between the vehicle body speed and the wheel speed and the ratio of the vehicle body speed) and the wheel acceleration (the wheel detected last time) based on the signals from the wheel speed sensors 12a to 12d. When the slip rate and wheel deceleration (negative acceleration) exceed a predetermined value, , start anti-skid control. That is, the processing circuit 7 sets the electromagnetic control valves 4a to 4d to the pressure reducing position, and the wheel cylinder 5a
Reduce the oil pressure within ~5d and increase the wheel speed? Let it be. Then, control such as 0 or more is performed for each wheel to select and control the pressure increase position, holding position, or pressure reduction position so that the slip ratio of the wheel becomes the state with the highest braking force. It is controlled to generate high braking force.

Next, an example of anti-skid control using a hydraulic pressure sensor will be described with reference to a flowchart shown in FIG. The process shown in FIG. 2 is a flowchart that is executed at predetermined time intervals. In step m1, the slip rate level of the wheels is determined. Strictly speaking, the wheel slip rate is calculated from the vehicle speed and wheel speed.
In this example, the slip rate is 0% to 5%, 5% to
It is determined whether it belongs to any of the following ranges: 10%, 10% to 20%, and 20% to. In step n12, the level of wheel acceleration is determined.

Similarly to step m1, it is determined which of the predetermined wheel acceleration ranges the wheel acceleration level belongs to.

In step m3, it is determined whether anti-skid control start conditions are satisfied. For example, when it is determined that the wheel slip rate exceeds 10%, the wheel deceleration exceeds a predetermined value, and the brake pedal is depressed, anti-skid control is started. step m3
When the anti-skid control start conditions are satisfied in step 1, the flow advances to step roto-1, where the oil pressure in the wheel cylinder 524-5d at the start of the anti-skid control is detected and stored. The stored oil pressure is used as the basis for pressure increase control, which will be described later. The process proceeds from step rn4 to step 111 port 5, where a decompression operation is performed. This decompression moving item is
This is done by setting the electromagnetic control valves 4a and 4d to the pressure reducing position.

During the period in which the pressure reduction operation is being carried out, it is determined in step rn6 whether the pressure reduction end condition 1''1~ is satisfied or not. As soon as the pressure reduction termination condition is satisfied in step m6, the process proceeds from step ms to step ms, and the processing circuit 'i closes the solenoid control valve 4a.
4. A control signal is sent to the electromagnetic control valve 4 to switch the operating position of d from the pressure reduction value 5 to the holding position.

In step m7, it is determined whether the holding end condition is satisfied. That is, when the wheel speed starts to increase and the wheel acceleration exceeds a predetermined value, the holding motion 1F ends when Tll [11] occurs. The holding operation P moves from step 2 to step 9, and at step 10 the pressure increase operation starts.The pressure increase operation is performed by setting the solenoid control valve 4 to the pressure increase position It is done. Then, when the oil pressure detected by the oil pressure sensor 11 a-11 (l) reaches a predetermined value of 1/S (for example, 80% or 902≦) with respect to the oil pressure stored in the ST 911 port 4, the pressure increases. When the pressure increase state ends, the electromagnetic control valve 11 is switched to the holding position l.

When the pressure increasing state is completed in step m9, the process proceeds from step rn11 to step 111 and port 12, where a pulse pressure increasing operation is performed for a certain period of time. The pulse pressure increase operation is an operation in which the electromagnetic control valve = 1 a to 4 (l is an operation in which the holding position and the pressure increase position are alternately switched, and the pulse width of the control signal output from the processing circuit 7 corresponds to l, 2). Due to the pulse pressure increasing motion (Y), the oil pressure of the wheel cylinder 5 gradually increases, and the braking force of the wheel 6 gradually increases.

When the anti-skid control is completed, the electromagnetic control valves 4a to 4
d is set at a pressure increase position 1u so that the hydraulic pressure generated by depression of the brake pedal 2 is applied to the wheel cylinder.

Next, the failure detection means for the oil pressure sensor will be explained.

Hydraulic sensor f) Failure detection differs between anti-skid non-control (1 o'clock and anti-skid control), so each will be explained below.

When the Annas kit is not controlled, the oil pressure sensor t 1
If the detected oil pressure at a-11d exceeds the oil pressure range predetermined by the depression of the brake pedal 2, it is determined that the oil pressure sensor has failed. The third [, 'l is a graph for explaining the determination of whether the oil pressure sensor is normal/'W normal based on the relationship between Play A=Pedal 2 depression and the pressure inside the wheel cylinder. Line 1!1 shows the relationship between the normal oil pressure sensor's depression of the brake pedal 2 and the pressure inside the wheel cylinder. The amount of depression is detected by a stroke sensor 10 attached to the brake pedal 2. The line β2 is the limit line for determining normality/abnormality, and the line p3 is the lower limit line. However, line 1yitt is line β
The area between line 2 and line 13 is determined to be the Masahatagashira area.

FIG. 4 is a flowchart of a failure determination program for hydraulic pressure control when anti-skid control is not performed.

In step rl], the processing circuit 7 performs an anti-skid system! 31 and whether or not it is determined. In the non-operation mode, step r12/\ progresses, and the upper and lower limits of the normal oil value for the amount of depression from the stroke sensor IO are set as shown in the graph of FIG. step r
+3, it is determined whether the oil pressure detected by the oil pressure sensor]1 is within the normal range set in step r12.

If the value is not within the normal range, the process proceeds from step rI4 to step [15], where the failure of the oil pressure sensor is compensated for.

As a failure treatment for the oil pressure sensor, ), for example, failure 1-5.
The anti-skid control calculation is continued using the output of the same right or left oil pressure sensor as the oil pressure sensor that was used, or the anti-skid control calculation is performed without using the oil pressure sensor.

Figure 5 shows the failure of the oil pressure sensor ITi during anti-skid control.
Figure 2 is a flowchart of an embodiment of 'I'l+constant 10 grams. During anti-skid control, the oil pressure control n signal from the processing circuit 7 determines whether the oil pressure sensors lla to lid are normal or abnormal depending on whether the detected oil pressure of the oil pressure sensors 11a to 11 (1) changes according to the same logic as the control signal. to judge.

In step r1, it is determined whether the processing circuit 7 is performing anti-skid control.

If anti-skid control is being performed, step r2
Then, it is determined whether the processing circuit 7 is sending out the pressure increase control signal from the electromagnetic control valves 4a to 4d/\. If the pressure increase control signal is being sent, proceed to step r3'\;
The current oil pressure sensor output is read and stored. In step r4, the difference between the output value of the oil pressure sensor stored last time and the output value of the oil pressure sensor stored this time is calculated. In step r5, it is determined whether the result calculated in step r4 is positive. Since the pressure increase control signal is output from the processing circuit 7, the output value of the oil pressure sensor must be increasing, and if not, step r6'\
It is determined that the advance oil pressure sensor is malfunctioning. Further, the determination is made in the same manner when the control signal is for holding or reducing the pressure. The holding field r2 becomes <holding> and r5 becomes (ΔP-0)
Similarly, when the pressure reduction signal is output, r2 becomes (pressure reduction in progress) and r5 becomes (ΔPn<O).If the oil pressure sensor is malfunctioning, the fourth step (same as explained in 21st step rI5) processing is performed.

Next, anti-skid control when a failure of the oil pressure sensor is discovered will be explained. Oil pressure sensors 11a to 11 (
1 is a wheel cylinder 5a installed in each wheel.
- 5d, respectively, and the processing circuit 7 performs failure detection processing for each of the oil pressure sensors lla to 11d individually, and when an abnormal oil pressure sensor is discovered by the failure detection processing of the oil pressure sensors lla to lid. , other normal oil pressure sensors can be used to perform anti-skid control.

In anti-skid control, a hydraulic sensor can be used to determine the level of the coefficient of friction (μ) between the wheels and the road surface. For example, if the wheels start to lock when the oil pressure in the wheel cylinders is high, it can be determined that the road surface has a high μ road surface, and if the wheels start to lock when the oil pressure in the wheel cylinders is low, it can be determined that the road surface has a low μ road surface. It can be determined that Then, the friction coefficient level determined in this manner allows the anti-skid control to be performed more smoothly by varying the pressure increasing time of the pressure increase and the pulse pressure increase in the anti-skid control. Therefore, when it is determined that the oil pressure sensor is abnormal, the friction coefficient level is determined using the output of a normal oil pressure sensor installed on the same side of the wheel as the oil pressure sensor in the abnormal state. Anti-skid control of wheels with oil pressure sensors installed can be continued. For example, when the oil pressure sensor llc of the left front wheel 6C is out of order, the friction coefficient level can be determined using the output of the oil pressure sensor llb of the left rear wheel 6b, and anti-skid control of the left front wheel can be continued.

In this way, determining the level of the friction coefficient using the output of a normal oil pressure sensor installed on the wheel on the same side as the malfunctioning oil pressure sensor means that the wheel running on almost the same part of the road surface p! determined from the output of the oil pressure sensor that is set at f! This is because the friction coefficient level of the malfunctioning oil pressure sensor is considered to be the same as that of the damaged wheel.

The above failure detection process is performed when only one oil pressure sensor is out of order, but if multiple oil pressure sensors are out of order, anti-failure detection can be performed by switching to control that does not use the output signal of the oil pressure sensor, as explained below. Skid control can continue. That is, the processing circuit 7 includes hydraulic pressure sensors lla to lid.
The first anti-skid control program performs anti-skid control 311 using By doing so, the first or second anti-skid control program is executed.

By performing such processing, the anti-skid control device can continue anti-skid control regardless of whether or not there is a failure of the oil pressure sensor, and the
W properties can be realized.

FIG. 6 is a flowchart I for explaining anti-skid control when the oil pressure sensors 11a''-11d are not used, and in 7 steps s1, the processing circuit 7 determines whether to start anti-skid control or not. +l+.

When the brake pedal 2 is depressed and the wheel slip rate exceeds 10% and the wheel acceleration is lower than a predetermined wheel acceleration G, anti-skid control is started. When the anti-skid control is started, the process proceeds from step s2 to step s3A, and the wheel slip rate l novel, that is, the wheel slip rate is 0 to 10%, 10% to
It is determined which level it is included in: 20%, 20%'-1. The process then proceeds to step s4, where the wheel acceleration l novel is determined. The acceleration level of the wheel is determined by the difference between the wheel speed detected last time and the wheel speed detected this time, and the difference is the predetermined acceleration Gl r 62 + (33
The decision is made based on which area it belongs to.

When the determination of the wheel slip rate level and the determination of the wheel acceleration level are completed, the process proceeds to step s5, and the wheels 6a to 6d are
The friction coefficient level between h and the road surface is determined, and it is determined whether the road belongs to a high μ road or a low μ road. You can tell whether it is a high μ road or a low μ road by recovering the wheel speed from a state where the wheels are stuck or close to it (depending on the magnitude of the wheel acceleration when walking). A case where the acceleration is larger than a predetermined value is a high μ road, and a case where the acceleration is smaller is a low μ road. If you are cut off by 11 on a high μ road, step! .

6, the output control for the high μ road shown in FIG. The output is sent as a control signal to the electromagnetic control valve 4a.-/4 (l/\).

If it is determined in step S that the road has a low coefficient of friction between the wheels and the road surface, the process proceeds to step S8;
An output determined by the wheel slip rate and wheel acceleration is selected from a control map for low slip roads, which will be described later. When output j) is selected in step s8, the process proceeds to step s7, and the selected output is sent to the electromagnetic control valves 4a to 4d as a control f signal.

After the anti-skid control described above is performed, in step s2, the conditions for terminating the anti-skid control are met.
If it is determined that the anti-skid system is being strained, the process proceeds to step S9, where the anti-skid system is canceled and when the brake pedal 2 is depressed, the hydraulic pressure in the master turn cylinder is controlled via the electromagnetic control valve 4.:L-4d. wheel cylinder 5a
~5(l! The problem is when brake pedal 2 is released or when the vehicle speed is 5.
If k rn / H or less, t: is the case 9. Figure 7 shows the anti-skid control flowchart in Figure 6.
The control map shown in FIG. 7 is stored in the processing circuit 7, and is divided into 12 regions divided by wheel slip rate and wheel acceleration. It is being Here, the areas Fl 1 , R2
, R3, R6, and R7, "pulse pressure increase" refers to control that sets the pressure increase position for a time corresponding to the pulse width of the control signal sent from the processing circuit 7 to the solenoid control valve lft-/ld.
"Pressure increase" shown in regions R4 and R8 means that the solenoid control valve 4i is used to continuously increase the pressure in the wheel cylinders 5a to 5d.
This means that L to 4d are continuously set to the pressure increasing position. Region R] "Pulse pressure reduction" shown in O refers to the pulse corner time when the processing circuit 7 sends a pulse to the solenoid control valve 41 to -4 (l). good,
"Depressurization" not shown in areas R5 and R9 refers to the solenoid control valve 4Ji.
Continuously reduce the pressure by ~4d (setting J'' at position i)
Further, "holding" shown in areas F-11, R, and F-12 means a system in which the solenoid control valves 4a to 4d are set to the holding direction and the hydraulic pressure in the wheel cylinder is maintained.

Note that the control map for low μ roads differs from the control map for high μ roads shown in FIG. 7 in that only the "vano [spring pressure]" output in region R10 is changed to "rivi pressure" output. be. Although the other outputs are exactly the same as the high μ road control map, the reference constants of the control map such as wheel acceleration G1 may be changed.

As described above, if this example is followed, the oil pressure sensor is normal.
'Anomalies can be detected both when anti-skid control is not being controlled and when anti-skid control is being controlled, and anti-skid control continues even when a failure of the oil pressure sensor is discovered, ensuring safety. Therefore, it is possible to realize an anti-skid control device with high performance.

Effects of the Invention As described above, the anti-skid control device according to the present invention is equipped with a means for detecting failure of the oil pressure detection element, so that it is possible to prevent erroneous IY due to failure of the oil pressure detection element. Control malfunctions can be reliably prevented. Furthermore, the anti-skid control device according to the present invention is equipped with a program that performs anti-skid control without using the oil pressure detection element even in the case of a failure in the oil pressure detection element, so it can achieve extremely reliable anti-skid control. Can provide drawings.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an anti-skid control device that is an embodiment of the present invention, Fig. 2 is a flowchart for explaining anti-skid control when using a hydraulic sensor, and Fig. 3 is the amount of depression of the brake pedal. Graph to explain whether the pressure sensor is normal or abnormal based on the relationship between system 1 and wheel cylinder internal pressure. Figure 4 is a flowchart of the oil pressure sensor failure determination program when anti-skid control is not performed. Figure 5 is the anti-skid A flowchart of the oil pressure sensor failure determination program during control, Fig. 6 is a flowchart for explaining anti-skid control when no oil pressure sensor is used, and Fig. 7 is a flowchart of the anti-skid control flowchart used in the anti-skid control flowchart of Fig. 6. This is a control map for μ road. 1... Master cylinder, 2... Brake pedal,
3...Motor, 4a-4d...Solenoid control valve, 5a-
5d...Wheel cylinder, 6a-6d...Wheel,
7... Processing circuit, 10... Stroke sensor, lla
~11 (1...Oil pressure sensor, 12a-12d...Wheel speed sensor Agent Patent attorney Keiichi SaikyoFigure 4Figure 5Figure 7Vehicle assistance degree

Claims (8)

[Claims] (1) In a failure determination device for a braking system of an automobile, in which a frictional braking force is generated by hydraulic braking means provided on a wheel by depression of a brake pedal, an oil pressure detection element for detecting the oil pressure. and a depression amount detection means for detecting the depression amount of the brake pedal; and in response to outputs from the oil pressure detection element and the depression amount detection means, the output of the oil pressure detection element is set in advance in accordance with the depression amount of the brake pedal. A failure determination device for a braking system of an automobile, comprising means for determining that the oil pressure detection element is malfunctioning when the value differs from a set value. (2) By depressing the brake pedal, a frictional braking force is generated by the hydraulic braking means provided on each wheel of the automobile, and during frictional braking, the hydraulic pressure is increased, decreased, or maintained to drive the wheels. An anti-skid control device that increases the coefficient of friction between the brake pedal and the road surface, comprising: a hydraulic pressure detection element provided for each wheel of the vehicle to detect the hydraulic pressure, and a depression amount detection means to detect the depression amount of the brake pedal. , in response to the output from the oil pressure detection element and the depression amount detection means, when the output of the oil pressure detection element differs from a preset value corresponding to the depression amount of the brake pedal, the oil pressure detection element malfunctions. and a means for determining whether the hydraulic pressure detecting element is abnormal, responsive to the output of the failure determining means, performing anti-skid control using the output of the hydraulic pressure detecting element when the hydraulic pressure detecting element is normal; and an anti-skid control means for performing anti-skid control using a normal oil pressure detection element provided on the same side of the wheel as the oil pressure detection element in the abnormal state when it is determined that the oil pressure detection element is in an abnormal state. Skid control device. (3) By depressing the brake pedal, a frictional braking force is generated by the hydraulic braking means provided on each wheel of the automobile, and during friction braking, the hydraulic pressure is increased or decreased according to a control signal. Alternatively, in an anti-skid control device that maintains the friction coefficient between the wheels and the road surface to increase the coefficient of friction between the wheels and the road surface, an oil pressure detection element is provided for each wheel of the automobile and detects the oil pressure, and the amount of depression of the brake pedal is detected. a pedal depression amount detection means; and in response to outputs from the oil pressure detection element and the depression amount detection means, when the output of the oil pressure detection element differs from a preset value corresponding to the depression amount of the brake pedal, the oil pressure is increased. means for determining that the detection element is malfunctioning; and a first means for performing anti-skid control using the output of the oil pressure detection element in response to the output of the failure determination means and using the output of the oil pressure detection element when the oil pressure detection element is normal. an anti-skid control means that executes an anti-skid control program and executes a second anti-skid control program that performs anti-skid control without using the output of the oil pressure detection element when it is determined that the oil pressure detection element is abnormal; An anti-skid control device comprising: (4) The first anti-skid control program includes a step of storing the detected oil pressure detected by the oil pressure detection element when locking occurs during wheel braking, and the control signal indicates that the pressure should be increased. Claim 3, characterized in that it includes the step of creating a pressurization control signal for making the oil pressure smaller by a predetermined percentage than the oil pressure stored in the storage means when representing the oil pressure stored in the storage means. Anti-skid control device. (5) Anti-skid that increases, decreases, or maintains the hydraulic pressure of a hydraulic braking means provided in connection with the wheels of an automobile using a control signal to control the hydraulic pressure so as to increase the coefficient of friction between the wheels and the road surface. A failure detection device for a hydraulic pressure detecting element used in a control device includes: a hydraulic pressure detecting element that detects the hydraulic pressure; and a hydraulic pressure detecting element that increases, decreases, or increases the hydraulic pressure according to the control signal in response to the control signal and the output of the hydraulic pressure detecting element. and means for determining that the oil pressure detection element is malfunctioning when the oil pressure detected by the oil pressure detection element is different from a value corresponding to the control signal when the oil pressure detection element should be held. Features: Failure detection device for oil pressure detection elements. (6) The hydraulic pressure of the hydraulic braking means provided in connection with the wheels of the automobile is increased, decreased, or maintained using a control signal, and the hydraulic pressure is controlled so as to increase the coefficient of friction between the wheels and the road surface. , an anti-skid control device that performs an anti-skid control operation for each wheel, comprising: an oil pressure detection element that is provided for each wheel of a vehicle and detects the oil pressure; When the oil pressure detected by the oil pressure detection element is different from the value corresponding to the control signal when the oil pressure should be increased, decreased or maintained according to the control signal, the oil pressure detection element is malfunctioning. and a means for determining whether the oil pressure is abnormal, and in response to the output of the failure determination means, performs anti-skid control using the output of the oil pressure detection element when the oil pressure detection element is normal, and determines that the oil pressure detection element is abnormal. Anti-skid control characterized in that it includes an anti-skid control means that performs anti-skid control using a normal oil pressure detection element provided on the same side of the wheel as the oil pressure detection element in the abnormal state when it is determined that the oil pressure detection element is in an abnormal state. Device. (7) The hydraulic pressure of the hydraulic braking means provided in relation to the wheels of the automobile is increased, decreased or maintained using a control signal, and the hydraulic pressure is controlled so as to increase the coefficient of friction between the wheels and the road surface. An anti-skid control device that performs an anti-skid control operation for each wheel includes: a hydraulic pressure detection element that is provided for each wheel of a vehicle and detects the hydraulic pressure; When the oil pressure detected by the oil pressure detection element is different from the value corresponding to the control signal when the oil pressure should be increased, decreased or maintained by the oil pressure detection element, it is determined that the oil pressure detection element is malfunctioning. and a first anti-skid control program for performing anti-skid control using the output of the oil pressure detection element when the oil pressure detection element is normal in response to the output of the failure judgment means; Anti-skid control means for executing a second anti-skid control program that performs anti-skid control without using the output of the oil pressure detection element when it is determined that the oil pressure detection element is abnormal. Control device. (8) Conditions under which a frictional braking force is generated by the hydraulic braking means provided on the wheels by depression of the brake pedal, and predetermined anti-skid control is to be performed while this frictional braking force is being generated. In a failure determination device for an anti-skid control device, which increases, decreases, or maintains the hydraulic pressure of the hydraulic braking means in accordance with a control signal when the above is established, and controls the hydraulic pressure so that the coefficient of friction between the wheels and the road surface becomes large. an oil pressure detection element that detects the oil pressure; a depression amount detection means that detects the amount of depression of the brake pedal; and a detection means that detects the anti-skid control condition in response to the outputs of the oil pressure detection element and the depression amount detection means. Sometimes, in response to outputs from the oil pressure detection element and the depression amount detection means, when the output of the oil pressure detection element differs from a preset value corresponding to the depression amount of the brake pedal, the oil pressure detection element malfunctions. When the anti-skid control condition is satisfied, the oil pressure detection element responds to the control signal and the output of the oil pressure detection element, and when the oil pressure should be increased, decreased or maintained according to the control signal. A failure determination device for an anti-skid control device, comprising: means for determining that the oil pressure detection element is malfunctioning when the oil pressure detected by the oil pressure detection element is different from a value corresponding to the control signal. .