JPH0699803A - Anti-skid controller - Google Patents

Abstract

PURPOSE:To provide an anti-skid controller for enabling stable vehicle running by accurately carrying out prevention of entering an ABS mode, or judgment whether the ABS mode is entered or not in a temporary slip condition caused by relatively abrupt brake operation by a driver due to red traffic light and the like or by steering in the middle of brake operation. CONSTITUTION:Abrupt change of a vehicle carried out by a driver can be detected, and steps 20, 21 are proceeded only when the status is detected. When it is judged that a slip rate (sr) of front wheels is no less than a predetermined slip rate threshold (sl) at the step 20, or when a front wheel speed reduction rate (a) is no less than a predetermined wheel speed reduction rate threshold A2, at a step 21, an ABS mode is entered.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ABS (anti-skid brake system), and in particular, an anti-skid that enables stable vehicle running by accurately determining whether or not to enter the ABS mode. Regarding the control device.

[0002]

2. Description of the Related Art An antiskid control device for preventing wheels from locking during vehicle braking has been known. This anti-skid control device is used when the vehicle speed is lower than a predetermined value with respect to the simulated speed (vehicle body speed) estimated from the wheel speed when the vehicle is braked by depressing the brake pedal, or when the wheel deceleration is a predetermined value If it becomes larger than this, it is determined that slip has occurred and ABS mode (anti-skid brake mode) is set.
The brake pressure supplied to the wheel is reduced in the BS mode. In many cases, whether or not such slip has occurred is determined for each wheel, and the ABS mode is also set for each wheel.

[0003]

By the way, in the above-described anti-skid control device, the ABS mode may be entered because the braking force is a little too large at the time of temporary stop at the red signal. The behavior of the vehicle may become unstable due to a reduction in pressure that extends the stopping distance of the vehicle and a sudden change in the slip ratio in the steering state. The state at this time will be described with reference to FIG. In this figure, the vertical axis indicates the vehicle and wheel speed (peripheral speed), and the horizontal axis indicates time. First, at the time of the code (a), when the driver is steering while performing the brake operation, the speed decreases and the yaw rate becomes a predetermined value as shown by the code (b), and when this state further progresses, As indicated by the symbol (c), the wheel speed of the outer front wheel is below a predetermined value with respect to the simulated speed (vehicle body speed) indicated by the one-dot chain line,
As a result, the outer wheels behave in a manner similar to the slip state.

When such a behavior occurs in the outer wheel, the outer wheel is set to the ABS mode so that the brake pressure of the outer wheel is reduced (see reference numeral (d)), and such an anti-skid is performed. By performing the above, there is a problem that the speed of the outer front wheel is increased and the cornering force is increased to show an oversteer tendency, that is, the vehicle behavior is deteriorated (symbol (e)).
reference).

The present invention has been made in view of the above circumstances, and is a temporary slip that occurs when a driver performs a relatively rapid braking operation due to a red signal or the like, or when steering is performed during braking operation. It is an object of the present invention to provide an anti-skid control device that prevents the ABS mode from being entered in a state, that is, accurately determines whether or not to enter the ABS mode and enables stable vehicle traveling.

[0006]

In order to achieve the above object, in the first aspect of the invention, a master cylinder for generating a brake pressure by a stepping force of a brake pedal, and a brake pressure generated by the master cylinder are applied to respective wheels. Wheel cylinders that respectively generate a braking force, front wheel hydraulic pressure control means that at least increases or decreases the brake pressure supplied from the master cylinder to the wheel cylinders of the front wheels, and front wheels that detect the speed of the front wheels. A wheel speed sensor, a panic condition detecting means for detecting a sudden change made by the driver to the vehicle, and a brake pressure to the front wheel hydraulic pressure control means based on a detection value of the front wheel speed sensor. The controller has a controller for setting an anti-skid brake mode for decompressing and increasing pressure for the front wheels. In the case of the trolley, if the panic condition detecting means does not detect the panic condition, the anti-skid brake mode for the front wheels is not set.

According to the second aspect of the invention, the brake pressure supplied from the master cylinder to the rear wheel cylinder is
At least the rear wheel hydraulic pressure control means for increasing or decreasing the pressure, and a rear wheel wheel speed sensor for detecting the speed of the rear wheel are further provided, and the controller is configured to detect the rear wheel speed based on the detected value of the rear wheel speed sensor. The anti-skid brake mode for reducing the brake pressure is set to the wheel hydraulic pressure control means for the rear wheels, and the panic condition detecting means sets the anti-skid brake mode for the rear wheels to the panic condition. I try to regard it as.

In the third invention, whether the wheel deceleration calculated from the wheel speed of the front wheels exceeds a wheel deceleration threshold value set to a degree larger than a slip degree judgment reference value for entering the antiskid brake mode. By determining whether or not the driver has provided a panic condition detecting means for detecting a sudden change made by the driver in the vehicle.

In the fourth aspect of the present invention, whether or not the slip ratio calculated from the wheel speed of the front wheels exceeds a slip ratio threshold value set to a degree larger than a slip degree judgment reference value for entering the anti-skid brake mode. By determining, the panic state detecting means for detecting the abrupt change made by the driver to the vehicle is provided.

According to the fifth aspect of the present invention, it is determined by the driver whether or not the steering angle of the steering wheel detected by the steering angle sensor exceeds a preset steering angle threshold value. A panic condition detecting means for detecting a sudden change is provided.

According to the sixth aspect of the invention, the driver is caused to perform the operation on the vehicle by determining whether the lateral acceleration of the vehicle body detected by the lateral acceleration sensor exceeds a preset lateral acceleration threshold value. A panic condition detecting means for detecting a sudden change is provided.

[0012]

According to the anti-skid control device of the first aspect of the invention, only when the panic condition detecting means detects the abrupt change made by the driver to the vehicle, the anti-skid brake mode for the front wheels is set. The controller is made to control the setting.
That is, when the driver performs a relatively rapid braking operation due to a red signal or the like and the steering is performed during the braking operation, the front wheels may fall into a temporary slip state, but the controller of the present invention detects the panic state. By means of the means, it is possible to judge whether the slip state of the front wheels is temporary, or whether it is preferable not to enter the ABS control, and further, when it is judged that this slip state of the front wheels is temporary. In addition, the front wheels are prevented from entering the anti-skid brake mode mode. As a result, the anti-skid control device of the present invention can prevent unnecessary anti-skid control of the front wheels, and thereby prevent the vehicle from becoming unstable.

In the second to sixth aspects of the invention, the judgment of the panic state in which the driver performs a sudden braking operation or abrupt steering is
Whether the rear wheels have entered the anti-skid brake mode mode, whether the wheel deceleration of the front wheels has exceeded the wheel deceleration threshold value set to a level greater than the slip level judgment reference value, and the slip ratio of the front wheels is Whether or not the slip ratio threshold value set to a value greater than the slip level judgment reference value has been exceeded, whether the steering angle of the steering wheel has exceeded the steering angle threshold value, or the lateral acceleration of the vehicle body is the lateral acceleration threshold value. The judgment is made based on whether or not the value exceeds. That is, it is possible to determine the panic state in which the driver performs a sudden braking operation or abrupt steering in various cases.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction of an antiskid control device shown as an embodiment of the present invention will be described below with reference to FIGS. First, the overall configuration of the antiskid control device will be described with reference to FIGS. 1 and 2. Reference numeral 1 is a master cylinder, and this master cylinder 1 generates a brake fluid pressure by the depression force of the brake pedal 2. The hydraulic pressure generated in the master cylinder 1 is supplied to the wheel cylinders 4 and 5 of the left and right front wheels via the modulator 3, and is also supplied to the left and right rear wheel brakes via the hydraulic pressure control valves 6 and 7. It is supplied to the wheel cylinders 8 and 9.

The modulator 3 is a master cylinder 1
To the wheel cylinders 4, 5, 8 and 9 respectively, and has a function of restricting an increase in the brake hydraulic pressure or recovering the hydraulic pressure by a control signal provided from the controller 10. ing. The details of the modulator 3 will be described later. Further, wheel speed sensors S1 to S4 for detecting the peripheral speed of the respective wheels are provided respectively, and the wheel speed data obtained from these wheel speed sensors S1 to S4 are supplied to the controller 10. It Then, the controller 10 calculates whether or not the wheel is slipping based on the wheel speed data and the degree of the slip, and based on the calculation result, a predetermined anti-skid control is performed on the modulator 3. I'm trying to run it.

Further, the controller 10 is provided with a steering angle detection sensor 30, a lateral acceleration sensor 31, a yaw rate detection sensor 32, and a pedaling force sensor 33, and the detection data of these sensors 30 to 33 are supplied to the controller 10. It is like this. The steering angle detection sensor 30 detects the steering angle (st) when the steering wheel is operated, and outputs a positive value when the steering wheel rotates in one direction and outputs a negative value when the steering wheel rotates in the other direction. Output. The lateral acceleration sensor 31 is a sensor for detecting lateral (width) acceleration (g-lat) of the vehicle. In the present embodiment, it suffices to detect whether or not the lateral acceleration of the vehicle has become equal to or higher than a certain value. Therefore, instead of the lateral acceleration sensor 31, the lateral acceleration of the vehicle becomes equal to or more than a certain value. A lateral acceleration switch for detecting whether or not it may be used. In this case, only step 9 described later is executed, and step 10 is not executed (described later).

The yaw rate detection sensor 32 is a sensor for detecting the yaw rate (y) of the vehicle, and outputs a positive value when it rotates in one direction and a negative value when it rotates in the other direction. The pedal force sensor 33 is a sensor that detects the pedal force (pe) of the brake pedal 2, but the pedal force sensor 33 may be replaced with a master cylinder pressure sensor that detects the pressure applied to the master cylinder 1. And
In this case, step 13 and step 14 described later
Should be changed as follows. That is, step 1
In step 3, it is judged whether or not the master cylinder pressure (pmc) detected by the master cylinder pressure sensor is larger than a preset master cylinder pressure threshold value (PMC1). Master cylinder boost speed (pm) calculated from cylinder pressure (pmc)
c ') is larger than a preset master cylinder pressure rising speed threshold value (DPMC1). Further, the pedal force sensor 33 is not limited to this, and may be replaced with a master cylinder pressure switch that detects whether or not a pressure above a certain value is applied to the master cylinder 1. In addition,
In this case, only step 13 is executed, and step 14
Do not run.

Next, referring to FIG. 2, each modulator 3
The specific configuration of will be described. Reference numerals 11 to 14 denote switching valves that can be switched to either open or closed positions.
Through 14, the piping systems from the master cylinder 1 to the wheel cylinders 4, 5, 8 and 9 are opened and closed, respectively. Further, the switching valves 11 to 14 are provided with check valves 15 to 18, respectively.
When the valve 14 is in the "closed" state, the flow of the liquid in the direction toward the master cylinder 1 is permitted. Further, switching valves 19 to 22 are connected to positions in parallel with the switching valves 11 to 14, and the switching valves 19 to 22 are connected.
Is operated to open and close so as to release the hydraulic oil in the wheel cylinders 4,5, 8 and 9 to the reservoirs 23 and 24, respectively, by the control signal supplied from the controller 10. The reference numerals 25 and 26 denote pumps driven by the motor 27,
The pumps 25 and 26 are driven by a control signal supplied from the controller 10 so as to recover the hydraulic pressure in the piping system that has dropped during the anti-skid control.

With the above-mentioned structure, the modulator 3 is provided in each piping system from the master cylinder 1 to the wheel cylinders 4, 5, 8 and 9.
(A) When the switching valves 11 to 14 are "open", the switching valves 19 to 22
Pressure increasing mode in which is closed, (b) Switching valves 11 to 1
4 is set to "closed" and the switching valves 19 to 22 are set to "open", and (c) both switching valves 11 to 14 and 19 to 22 are set to "holding mode". , Wheel cylinders 4, 5, 8, 9 and master cylinder 1
It is adapted to control the flow of liquid in the conduit between and.

In the modulator 3 thus constructed, the pressure increasing mode is set when the driver depresses the brake pedal 2 to apply the brake, whereby the wheel cylinders 4, 5, 8 ... Although the hydraulic oil is supplied to 9 to increase the brake pressure,
At this time, when the wheel slips, the controller 10 performs the anti-skid control and moves the modulator 3 from the pressure increasing mode to, for example, the pressure reducing mode based on the signals supplied from the wheel speed sensors S1 to S4. mode,
It is set to hold mode.

In the above structure, the wheel speed sensors S1 and S2 for detecting the wheel speed of the front wheels constitute a "front wheel wheel speed sensor", and the wheel speed sensors S3 and S4 for detecting the wheel speed of the rear wheels "rear wheel". A wheel / wheel speed sensor "is configured. Further, in the modulator 3, the switching valves 11, 19 and the check valve 15, which control the wheel cylinder 4 of the FR,
And a switching valve 12 for controlling the wheel cylinder 5 of the FL,
20 and the check valve 16 constitute "front wheel hydraulic pressure control means", while the switching valves 13 and 21 and the check valve 17 that control the wheel cylinder 8 of the RR and the switching valve that control the wheel cylinder 9 of the RL. The “rear wheel hydraulic pressure control means” is configured by the check valves 14, 22 and the check valve 18.

Here, the control of the brake hydraulic pressure after the brake operation will be described step by step with reference to the flow charts of FIGS. 3 and 4.

The wheel deceleration a and the slip ratio sr used as various determination data in the following description are calculated based on the wheel speed data output from the wheel speed sensors S (S1 to S4) as described above. It is something. The wheel deceleration a, the slip ratio sr, the steering angle (st) detected by the steering angle detection sensor 30, and the lateral acceleration (g-la) of the vehicle detected by the lateral acceleration sensor 31 (g-la
t), the yaw rate (y) of the vehicle detected by the yaw rate detection sensor 32, and the pedaling force (pe) of the brake pedal 2 detected by the pedaling force sensor 33. The wheel deceleration threshold values (A1 to A3) are respectively compared. However, A3>A2>A1> 0),
Slip rate threshold value (s1, s2, where S2>S1>
0), steering angle threshold value (st1), steering angle change speed threshold value (DST1), lateral acceleration threshold value (G1), lateral acceleration change speed threshold value (DG1), yaw rate threshold value (Y1) , The yaw rate change speed threshold value (DY1), the pedal depression force threshold value (PE1), the pedal depression force change speed threshold value (DPE1), and the control contents shown in the following flowchart (see FIG. 3) are the same as those of the controller 10 described above. Are stored in advance in.

The flowcharts of FIGS. 3 and 4 are sequentially processed for each wheel at predetermined timings when the vehicle is traveling, for example. Necessary data (wheel deceleration, etc.) is also calculated and stored at each predetermined timing, and is read when necessary in the steps of the flowchart. Further, various variables (STABLE, ABS) are initialized (STABLE = 1, ABS = 1, other variables are 0) when the engine of the vehicle is turned on, for example. Select low control or the like may be used to control the front two wheels or the rear two wheels in the same manner. In this case, hydraulic pressure control means common to the front two wheels or the rear two wheels (two solenoid valves for two wheel cylinders in this embodiment) can be used.

<< Step 1 >> If "STABLE = 0", proceed to step 30. If "STABLE = 1", proceed to step 1 ("STABLE" indicates whether or not the wheels are in a slip state. Recognize.) <Step 30> It is determined whether or not the wheel deceleration a calculated based on the wheel speed data output from the wheel speed sensor S (S1 to S4) is equal to or more than a preset set value, and the setting is performed. When the value is equal to or more than the value (when the wheel deceleration is large), it is determined that the slip increase tendency is present, and the routine proceeds to step 31, and when it is smaller than the set value, it is determined that the slip increase tendency is not present and the routine proceeds to step 32. . In this step 30, the slip ratio sr may be read and it may be determined whether or not the slip increase tendency is present depending on whether or not the slip ratio sr is equal to or greater than a predetermined value. << Step 31 >> The pressure reducing mode is set for the modulator 3.

<< Step 32 >> For example, the slip ratio sr
Is equal to or less than a predetermined value and whether the wheel deceleration a is “a> 0” determines whether or not the slip is recovered. If YES, the process proceeds to step 33, and if NO, step 34. Proceed to. << Step 33 >> Assuming that the vehicle is in a stable state, "ST
Set "ABLE" to "1". << Step 34 >> The holding mode is set for the modulator 3. << Step 35 >> The modulator 3 is set to a pulse pressure increasing mode in which the brake pressure is increased stepwise by operating the solenoid valves 11 to 14 intermittently.

<< Step 2 >> On the other hand, in Step 1, "ST
It is determined whether or not the ABS mode has already been set for the wheel determined to have “ABLE = 1”, and the ABS is set to the wheel.
When it is determined that the mode is not set to "0", the process proceeds to the next step 3, and when it is determined that the ABS mode is set to "1", the process proceeds to step 20. The flag indicating the ABS mode is set in step 22 described later and is released in step 19 described later. << Step 3 >> It is judged whether or not the processing wheel belongs to the front wheel, and it is judged that the wheel belongs to the front wheel. YES
In the case of, the process proceeds to the next step 4, and in the case of NO which is determined to belong to the rear wheel, the process proceeds to step 20.

The following Step 4 and Step 5
Step 14 shows, for example, a panic condition detecting step of detecting a sudden braking, a sudden steering, and a sudden change in the vehicle condition caused by the driver's vehicle. <Step 4> When the wheel performing the process belongs to the front wheels, it is determined whether or not the ABS mode is set for at least one of the rear wheels, and it is determined that the ABS mode is not set is NO. And proceed to the next step 5,
In the case of YES where it is determined that the ABS mode is set, the process proceeds to the next step 20.

<< Step 5 >> For any of the front wheels,
It is determined whether the wheel deceleration a calculated based on the wheel speed data output from the wheel speed sensor S (S1, S2) is equal to or more than a preset wheel deceleration threshold value A3, and N
If it is O (that is, the degree of slip is small), proceed to step 6, and if it is YES (that is, the degree of slip is large), proceed to step 20. << Step 6 >> The slip ratio sr calculated based on the wheel speed data output from the wheel speed sensor S (S1, S2) for any of the front wheels is equal to or greater than the preset slip ratio threshold value s2. If NO (that is, the degree of slip is small), proceed to step 7,
If YES (that is, the degree of slip is large), the process proceeds to step 20.

<< Step 7 >> It is judged whether or not the absolute value of the steering angle (st) detected by the steering angle detection sensor 30 is larger than a preset steering angle threshold value (st1). To step 8, and if YES, to step 20. << Step 8 >> Steering angle change speed (st ') calculated from the change in the steering angle (st) detected by the steering angle detection sensor 30
It is determined whether the absolute value of is larger than a preset steering angle change speed threshold value (DST1). If NO, the process proceeds to step 9, and if YES, the process proceeds to step 20.

<< Step 9 >> Whether the absolute value of the lateral acceleration (g-lat) of the vehicle detected by the lateral acceleration sensor 31 is larger than a preset lateral acceleration threshold value (G1) or not. If NO, go to step 10,
If YES, the process proceeds to step 20. << Step 10 >> Lateral acceleration change speed (g-la) calculated from the acceleration (g-lat) detected by the lateral acceleration sensor 31.
The absolute value of t ') is the lateral acceleration change speed threshold (DG1)
It is judged whether or not it is larger, and if NO, step 11
If YES, then go to step 20.

<< Step 11 >> Yaw rate detection sensor 3
It is determined whether or not the absolute value of the vehicle yaw rate (y) detected in 2 is larger than a preset yaw rate threshold value (Y1). If NO, the process proceeds to step 12, and
If yes, go to step 20. << Step 12 >> It is judged whether or not the absolute value of the change speed (y ') of the yaw rate (y) of the vehicle detected by the yaw rate detection sensor 32 is larger than the yaw rate change speed threshold value (DY1). If yes, go to step 13; if yes, go to step 20.

<< Step 13 >> It is judged whether or not the pedaling force (pe) of the brake pedal 2 detected by the pedaling force sensor 33 is larger than a preset pedal pedaling force threshold value (PE1). Proceed to step 14, and if YES, proceed to step 20. << Step 14 >> It is judged whether the changing speed (PE ') of the pedaling force (pe) of the brake pedal 2 detected by the pedaling force sensor 33 is larger than the pedaling force changing speed threshold value (DPE1). If yes, go to step 15, and if yes, go to step 20.

<< Step 15 >> Step 4 to Step 1
At 4, sudden braking, sudden steering, these sudden braking,
If no abrupt change in vehicle condition due to a sudden steering is detected, it is further determined in step 15 whether the wheel deceleration a is equal to or more than the wheel deceleration threshold A1. If the result of this determination is NO that the wheel deceleration a is smaller than the wheel deceleration threshold A1, step 16
And the wheel deceleration a is the wheel deceleration threshold A1.
If YES, which is determined to be larger, the process proceeds to step 34. << Step 16 >> It is determined whether or not the ABS mode is set. If NO, the process proceeds to step 17, and if YES, the process proceeds to step 18. << Step 17 >> After increasing the normal brake pressure (a state in which the master cylinder and the wheel brake are simply connected), that is, after setting the pressure increase mode, the present flow chart ends one cycle.

<Step 18> It is judged whether or not the pulse pressure increase is continued for a predetermined time or longer. If NO is judged, the operation proceeds to step 35, and if YES is judged, the operation proceeds to step 19. . << Step 19 >> It is judged that the vehicle is already in a stable state that does not require anti-skid, and the ABS mode setting is canceled (ABS = 0 is set), and then the routine proceeds to step 17.

<< Step 20 >> Wheel speed sensor S (S1-
It is determined whether the slip ratio sr calculated based on the wheel speed data output from S4) is greater than or equal to the slip ratio threshold s1 (slip degree determination reference value), and NO (the degree of slip is small). ), Proceed to step 21, and
If YES (the degree of slip is large), the process proceeds to step 22. << Step 21 >> Wheel deceleration a calculated based on the wheel speed data output from the wheel speed sensor S (S1 to S4)
Is greater than or equal to a preset wheel deceleration threshold A2 (that is, greater than or equal to the slip degree determination reference value), and NO (small degree of slip: that is, less than or equal to the slip degree determination reference value). In the case of, the process proceeds to step 15, and in the case of YES (the degree of slip is large: that is, the slip degree determination reference value or more), the process proceeds to step 22.

<< Step 22 >> ABS = 0 indicating the anti-skid control state is set, and "STABL indicating the vehicle state is set.
"E" is set to "0", which is an unstable or slip state. In the above flowchart, step 4 is a determination corresponding to "claim 2", and step 5
Is a determination corresponding to "claim 3", step 6 is a determination corresponding to "claim 4", step 7 is a determination corresponding to "claim 5", and step 9 is "claim 6". It is a judgment corresponding to.

Next, a specific example of "front wheel control" when a panic condition occurs will be described using the above flow chart. (1) Control example when the front wheels exhibit a sudden deceleration or an increase in slip ratio. After sequentially passing through Step 1 to Step 4, in Step 5, the wheel deceleration a of the front wheel being processed
Is greater than or equal to a preset wheel deceleration threshold A3, or in step 6, the slip ratio sr of the front wheel is equal to or greater than the preset slip ratio threshold s.
Judge whether it is 2 or more. That is, in these steps 5 and 6, it is judged whether or not a panic condition has occurred, and in steps 20 and 21, the front wheel is set to A.
It is determined whether or not to set the BS mode. In this case, if step 5 or step 6 is YES,
If YES in step 20 or step 21, ABS = 1 is set in step 22 to enter the ABS mode, and in step 31, the depressurization mode is set.

(2) An example of control of the front wheels when the ABS mode is set for the rear wheels. After step 1 to step 3 are sequentially passed, step 4
When it is determined that the rear wheels are in the ABS mode, the process proceeds to steps 20 and 21, and this step 20
At 21, it is determined whether the front wheels have a slip condition. In step 20, it is judged whether or not the slip ratio sr of the front wheel is equal to or more than a preset slip ratio threshold value s1, and in step 21, the wheel deceleration a of the front wheel a.
Is greater than or equal to a preset wheel deceleration threshold value A2, and as a result, in Steps 20 and 21, it is determined that the front wheel has a slip state after YES in Step 4. (YES in step 20 or 21)
First, it is determined that the slip state is not temporary, and the brake pressure of the front wheels is reduced in step 31. On the other hand, when it is determined that the slip state is small in steps 20 and 21 (NO in steps 20 and 21), it is determined that the front wheels are not in the slip state and the process proceeds to step 15 and below to increase the brake pressure. Alternatively, set to hold.

(3) Steering angle detection sensor 30, lateral acceleration sensor 31, yaw rate detection sensor 32, pedal force sensor 33
An example of control of the front wheels when a panic condition is detected by. After step 1 to step 6 are sequentially passed, step 7
If the panic condition of the vehicle is detected in ~ 14,
Proceed to steps 20 and 21. In step 20, it is judged whether or not the slip ratio sr of the front wheel is equal to or more than a preset slip ratio threshold value s1, and in step 21, the wheel deceleration a of the front wheel a.
Is greater than or equal to a preset wheel deceleration threshold A2. Then, if it is determined in Steps 20 and 21 that the front wheel has a slip state (YES in Step 20 or 21) after the YES in any of Steps 7 to 14, the slip state is temporary. If not, the brake pressure of the front wheels is reduced in step 31. On the other hand, this step 20
When it is determined that the slip state is small in 21 (NO in steps 20 and 21), the process proceeds to step 15 and below, and the brake pressure is set to increase or hold.

As described in detail above, according to the anti-skid control device of this embodiment, it is possible to detect the abrupt change made by the driver in the vehicle in steps 4 to 14. If such a detection is made, the process proceeds to steps 20 and 21. By this ABS
ABS mode can only be entered when control is required. Then, in step 20, the wheel speed sensor S
When it is determined that the slip ratio sr of the front wheels obtained from the detected values of S1 and S2 is less than or equal to the preset slip ratio threshold value s1, in step 21, it is obtained from the detected values of the wheel speed sensors S1 and S2. The wheel deceleration a of the front wheel is
If it is equal to or less than the preset wheel deceleration threshold value A2, it is determined that the front wheels are not in the slip state and the process proceeds to step 15. That is, according to the anti-skid control device shown in the present embodiment, steps 4 to 14
Since the front wheels can enter the ABS mode only when passing through the vehicle, no decompression of the wheel cylinders of the front wheels is performed in other cases, thereby preventing unnecessary anti-skid control of the front wheels. It is possible to hold the brake pressure as shown in (f) in FIG. 6 (B), to show (to) in FIG. 6 (A), and to (h) in FIG. 6 (C).
As shown by, the effect of preventing the vehicle from becoming unstable can be obtained.

In this embodiment, the modulator 3 is of a type capable of holding the brake pressure, but the modulator 40 is not limited to this type, and the modulator 40 shown in FIG. May be. That is, the brake fluid sent from the master cylinder 41 is transferred to the switching valve 4
1-44 direct to the wheel cylinders 4, 5, 8, 9 (pressure increase, slow pressure increase), or the pump 45 discharges brake fluid from the wheel cylinders 4, 5, 8, 9 (pressure reduction). A modulator 40 that cannot be used may be used. In FIG. 5, reference numeral 46 is a reservoir, and reference numerals 47 and 48 are check valves.

[0043]

As described in detail above, according to the anti-skid control device of the first invention, the panic condition detecting means can detect the abrupt change made by the driver to the vehicle only. , The controller is made to control to set the anti-skid brake mode for the front wheels. That is, when the driver performs a relatively rapid braking operation due to a red signal or the like and the steering is performed during the braking operation, the front wheels may fall into a temporary slip state, but the controller of the present invention detects the panic state. By means of the means, it is possible to judge whether the slip state of the front wheels is temporary, or whether it is preferable not to enter the ABS control, and further, when it is judged that this slip state of the front wheels is temporary. In addition, the front wheels are prevented from entering the anti-skid brake mode mode. As a result, in the anti-skid control device of the present invention, it is possible to prevent unnecessary anti-skid control of the front wheels, and thereby an effect of preventing the vehicle from becoming unstable can be obtained.

In the second to sixth inventions, the rear wheels enter the anti-skid brake mode mode by judging the panic condition, which indicates whether or not the driver has performed a relatively rapid braking operation and steering, based on a red signal or the like. Whether or not the wheel deceleration of the front wheels exceeds a wheel deceleration threshold value set to a degree larger than the slip degree determination reference value, the slip ratio of the front wheels is greater than the slip degree determination reference value. Determined by whether the slip ratio threshold set to a large degree is exceeded, whether the steering angle of the steering wheel exceeds the steering angle threshold, or whether the lateral acceleration of the vehicle body exceeds the lateral acceleration threshold I decided to do it. That is, the effect of being able to determine the panic state indicating whether or not the driver has performed a relatively rapid braking operation and steering in various cases is obtained.

[Brief description of drawings]

FIG. 1 is a piping diagram showing a brake fluid pressure system for supplying hydraulic oil to a wheel cylinder of a brake.

FIG. 2 is a piping diagram showing a specific configuration of a modulator 3 shown in FIG.

FIG. 3 is a flow chart according to the present invention for controlling a modulator.

FIG. 4 is a flow chart according to the present invention for controlling a modulator.

5 is a piping diagram showing another specific configuration of the modulator 3 shown in FIG.

6A is a graph showing a relationship between a vehicle body speed and outer front wheel speeds; FIG. 6B is a graph showing brake pressures of outer front wheels;
(C) A graph showing the yaw rate of the vehicle body.

[Explanation of symbols]

 3 Modulator (Front / Rear Wheel Hydraulic Pressure Control Means) 4 Wheel Cylinder 5 Wheel Cylinder 8 Wheel Cylinder 9 Wheel Cylinder 10 Controller (Panic State Detecting Means) S1 ・ S2 Wheel Speed Sensor (Front Wheel Wheel Speed Sensor) S3 ・ S4 Wheel Speed Sensor (Rear wheel speed sensor) 40 modulator (front wheel / rear wheel hydraulic pressure control means)

Claims (6)

[Claims] 1. A master cylinder for generating a brake pressure by a stepping force of a brake pedal, a wheel cylinder for generating a brake force for each wheel by a brake pressure generated by the master cylinder, and a front wheel from the master cylinder. Front wheel hydraulic pressure control means for at least increasing or reducing the brake pressure supplied to the wheel cylinders, a front wheel speed sensor for detecting the speed of the front wheels, and a rapid change made by the driver to the vehicle. And a controller for setting an antiskid brake mode for the front wheels to reduce or increase the brake pressure to the front wheel hydraulic pressure control means based on the detection value of the front wheel speed sensor. In the controller, the panic condition detecting means detects a panic condition. The anti-skid control device is characterized in that the anti-skid brake mode for the front wheels is not set when the vehicle is not released. 2. A rear wheel hydraulic pressure control means for at least increasing or decreasing the brake pressure supplied from the master cylinder to the wheel cylinders of the rear wheels, and a rear wheel wheel speed sensor for detecting the speed of the rear wheels. Further, the controller causes the rear wheel hydraulic pressure control means to set an antiskid brake mode for reducing the brake pressure for the rear wheels based on the detection value of the rear wheel wheel speed sensor, and the panic state The anti-skid control device according to claim 1, wherein the detection means considers that the anti-skid brake mode is set for the rear wheel when the rear wheel is set. 3. The wheel deceleration threshold value set in the panic condition detecting means such that the wheel deceleration calculated from the wheel speed of the front wheels is set to be larger than a slip degree determination reference value for entering the anti-skid brake mode. The anti-skid control device according to claim 1, wherein a rapid change made by the driver with respect to the vehicle is detected by determining whether or not the value exceeds the limit. 4. The panic condition detecting means, wherein the slip ratio calculated from the wheel speed of the front wheels exceeds a slip ratio threshold value set to a level larger than a slip level determination reference value for entering an anti-skid brake mode. The anti-skid control device according to claim 1, wherein a rapid change made by the driver with respect to the vehicle is detected by determining whether or not the vehicle. 5. The panic condition detecting means determines whether or not the steering angle of the steering wheel detected by the steering angle sensor exceeds a preset steering angle threshold value so that the driver can operate the vehicle with respect to the vehicle. The anti-skid control device according to claim 1, wherein a rapid change caused by the above is detected. 6. The panic condition detecting means determines whether or not the lateral acceleration of the vehicle body detected by the lateral acceleration sensor exceeds a preset lateral acceleration threshold value, whereby the driver is The anti-skid control device according to claim 1, wherein a rapid change caused by the above is detected.