JPH07137624A - Antiskid control device - Google Patents

Abstract

PURPOSE:To secure a braking distance even while traveling on a bad road by furnishing a comparison means to compare a wheel accelerating and decelerating speed detection value and a specified value with each other and a time measuring means capable of measuring time in accordance with the compared value and judging traveling on the bad road by way of comparing the measured time with specified time. CONSTITUTION:Amplitude is monitored by comparing a detected value of a wheel accelerating and decelerating speed detection means with a set value of wheel acceleration and deceleration by a comparison means. In the meantime, a time measurement means monitors a cycle by way of measuring time in which a wheel accelerating and decelrating speed detection value does not exceed a specified value in the case when the wheel accelerating and decelerating speed detection value comes to be amplitude exceeding the specified value in accordance with the compared value. A bad road judgement means provided on an actuator control means judges it as bad road traveling in the case when amplitude of wheel accelerating and decelerating speed monitored by the comparison means exceeds the specified value of amplitude at the time of traveling on a bad road and a cycle of wheel accelerating and decelerating speed monitored by the time measurement means is shorter than a cycle generated, for example, by bad road traveling. In this case, of braking force is restrained and increase of a braking distance is lowered.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention controls the fluid pressure of a braking cylinder disposed on each wheel during braking to prevent the wheels from being locked, and particularly when braking on a rough road. The present invention relates to an anti-skid control device with improved performance.

[0002]

2. Description of the Related Art As an anti-skid control device for preventing wheel lock during braking of a vehicle, there is, for example, the one described in Japanese Patent Application Laid-Open No. 3-246158 previously proposed by the present applicant. With this anti-skid controller,
The wheel speed of each wheel of the vehicle is detected by a wheel speed sensor etc.,
On the other hand, the front-rear direction ground speed (vehicle speed) of the vehicle is detected by a vehicle speed sensor or the like, or is calculated from the wheel speed detection value, the vehicle front-rear direction acceleration detection value, etc., and the deviation between the two becomes, for example, a predetermined slip ratio or less. The target value of the wheel speed is set as follows. That is, the target value of the wheel speed is a value that enables the braking distance to be shortened while the grip force is sufficiently exerted without the wheel being locked. On the other hand, for example, when the wheel acceleration / deceleration is calculated by differentiating the wheel speed detection value, and the wheel speed detection value is within the target value of the wheel speed and the wheel acceleration / deceleration is larger than a predetermined value, When the negative acceleration of the wheel, that is, the deceleration is too small, the braking force of the wheel is increased, the wheel speed detection value is smaller than the target value of the wheel speed, and the wheel acceleration / deceleration is smaller than a predetermined value. In order to reduce the braking force of the wheel because the negative acceleration of the wheel, that is, the deceleration is too large, it is possible to increase or decrease the fluid pressure to the braking cylinder by the fluid pressure provided on each wheel. By performing the adjustment control by using such an actuator, it is possible to shorten the braking distance while satisfying the target value of the wheel speed, that is, preventing the wheel from locking.

From the essential purpose of the anti-skid control device, a predetermined threshold value for reducing the braking force of the wheel is relatively small on the positive acceleration side with respect to the wheel acceleration / deceleration. Since the slip ratio that is set to a value and at the same time enhances the braking effect while exhibiting a sufficient grip force as a tire characteristic is about 10 to 20%, another threshold value for reducing the braking force of the wheel is also provided. The target value of the wheel speed that becomes is a high value that is relatively close to the vehicle speed. Therefore, in the area exceeding the predetermined slip ratio,
The braking force is mainly controlled to decrease. And
In the anti-skid control device, the braking pressure (fluid pressure) related to the braking force control is obtained by searching a stored control map.

[0004]

By the way, the traveling road surface of a vehicle is various, and there is also a road surface which is generally referred to as a bad road and which has many irregularities and swells. Even in such a bad road, the road surface has a relatively large coefficient of friction and unevenness (including fine undulations).
There are many rough roads, such as the so-called Belgian Road, and wavy roads with small undulations.
On a bad road of such a property, so-called pulsation is likely to occur, in which the wheel speed greatly increases and the cycle becomes short as the wheel bounces and rebounds. Further, under such a circumstance, the wheel acceleration / deceleration, which is a differential value of the wheel speed, also has a large amplitude and its cycle becomes short.

When the amplitude of the wheel speed becomes large and the cycle becomes short in this way, the antiskid control device described above
The wheel speed detection value easily falls below the target value of the wheel speed, and the detected value or calculated value of the wheel acceleration / deceleration of a large wheel acceleration / deceleration is a threshold value for decreasing the braking force. Since it easily falls below the predetermined value on the acceleration side, in the braking pressure control, the braking pressure always tends to be reduced and the braking force is substantially reduced, which may result in a longer braking distance.

The present invention has been developed in view of these problems, and as described above, the large amplitude and short cycle of the wheel speed generated during traveling on a rough road are monitored by the pulsation of the wheel acceleration / deceleration, and When a large amplitude and a short cycle of wheel acceleration / deceleration are detected, for example, the braking distance can be secured even when driving on a rough road by forcibly stopping the reduction of the braking force or reducing the reduction gain. The present invention aims to provide a new anti-skid control device.

[0007]

The antiskid control device according to claim 1 of the present invention, as shown in the basic configuration diagram of FIG. 1a, supplies pressure to a braking cylinder provided on each wheel of a vehicle. An actuator that can be adjusted in accordance with a predetermined command signal, a vehicle speed detection unit that detects the front-rear direction ground speed of the vehicle, a wheel speed detection unit that detects the wheel speed of each wheel, and a wheel acceleration / deceleration of each wheel. Anti-skid control including wheel acceleration / deceleration detecting means for detecting, and actuator control means for outputting to the actuator the command signal having a value corresponding to a running state and a braking state of the vehicle based on detection values of the respective detecting means. In the device, comparing means for comparing the wheel acceleration / deceleration detection value from the wheel acceleration / deceleration detection means with a predetermined value, and when time can be measured according to the comparison value of the comparison means. Measuring means, and the actuator control means is provided with bad road judging means for judging traveling on a bad road by comparing a time measured by the time measuring means with a predetermined time. Is.

In the anti-skid control device according to claim 2 of the present invention, as shown in the basic configuration diagram of FIG. 1b, the supply pressure to the braking cylinders provided on each wheel of the vehicle is converted into a predetermined command signal. Actuators that can be adjusted accordingly, vehicle speed detecting means for detecting the front-rear direction ground speed of the vehicle, wheel speed detecting means for detecting the wheel speed of each wheel, and wheel acceleration / deceleration detection for detecting the wheel acceleration / deceleration of each wheel. Means and an actuator control means for outputting to the actuator the command signal having a value corresponding to the running state and the braking state of the vehicle based on the detection value of each of the detection means, the wheel adjustment First comparing means for comparing the wheel acceleration / deceleration detected value from the speed detecting means with a first predetermined value, and a time capable of measuring time according to the comparison value of the first comparing means. Measuring means and second comparing means for comparing the wheel acceleration / deceleration detection value from the wheel acceleration / deceleration detecting means with a second predetermined value, and the actuator control means measures the time by the time measuring means. It is characterized in that a bad road judging means for judging traveling on a bad road based on the time and the comparison value of the second comparing means is provided.

In the anti-skid control device according to a third aspect of the present invention, the first predetermined comparison means compares the wheel acceleration / deceleration detection value detected by the wheel acceleration / deceleration detection means with the first comparison means. The relationship between the value and the second predetermined value compared by the second comparing means is characterized in that the second predetermined value is smaller than the first predetermined value.

[0010]

In the anti-skid control device according to the first aspect of the present invention, as shown in the basic configuration diagram of FIG. 1a, the wheel speed of each wheel of the vehicle is detected by the wheel speed detecting means through a wheel speed sensor or the like. On the other hand, the ground speed (vehicle speed) in the front-rear direction of the vehicle is calculated and detected by the vehicle speed detecting means, for example, based on the wheel speed detection value detected by the wheel speed detecting means, and the actuator control means However, the deviation between the wheel speed detection value detected by the wheel speed detection means and the vehicle speed detection value detected by the vehicle speed detection means is set to, for example, a predetermined slip ratio or less so that the wheel does not lock and the grip force is sufficient. The target value of the wheel speed is set so that the braking distance can be shortened while exhibiting the above. On the other hand, the wheel acceleration / deceleration detection means calculates and detects the wheel acceleration / deceleration by, for example, differentiating the wheel speed detection value, and the actuator control means determines that the wheel speed detection value is the target value of the wheel speed. Within the range, the wheel acceleration / deceleration detection value detected by the wheel acceleration / deceleration detection means is larger than a predetermined value set to a relatively small value for the negative acceleration of the wheel, that is, the deceleration. Increases the braking force of the wheel, the wheel speed detection value is smaller than the target value of the wheel speed, and the wheel acceleration / deceleration corresponds to the predetermined negative acceleration of the wheel, that is, the deceleration. A command signal for reducing the braking force when it is smaller than the individual predetermined value set to a value larger than the value so that the wheel speed of the wheel exerts the maximum braking force within the target value of the wheel speed. To the actuator And the actuator satisfies the target value of the wheel speed by controlling the increase / decrease of the fluid pressure to the braking cylinder due to the fluid pressure provided on each wheel in response to this command signal. That is, while preventing the wheels from locking,
It is possible to shorten the braking distance. By the way, the comparison means compares the wheel acceleration / deceleration detection value of the wheel acceleration / deceleration detection means with a predetermined value which is set so that a large amplitude of the wheel acceleration / deceleration generated in traveling on a rough road, for example, is compared. Monitor the wheel acceleration / deceleration amplitude. On the other hand, when the wheel acceleration / deceleration detection value detected by the wheel acceleration / deceleration detection means has a large amplitude exceeding a predetermined value based on the comparison value of the comparison means, the time measurement means The period in which the acceleration / deceleration detection value does not exceed a predetermined value is measured to monitor the cycle of the wheel acceleration / deceleration. Then, the rough road determination means provided in the actuator control means has a predetermined value set such that the amplitude of the wheel acceleration / deceleration monitored by the comparison means exceeds a large amplitude generated in traveling on the rough road, for example. If the cycle of the wheel acceleration / deceleration that is exceeded and monitored by the time measuring means is shorter than, for example, a short cycle that occurs during traveling on a rough road, it is determined that the vehicle is traveling on a rough road. Therefore, when the rough road traveling determination means determines that the vehicle is traveling on a rough road, the actuator control means forcibly cancels the pressure reduction adjustment control of the fluid pressure to the braking cylinder by the actuator, for example. Alternatively, the control gain related to the pressure reducing adjustment control is reduced to forcibly suppress the reduction of the braking force of the wheel by the braking cylinder, thereby reducing the increase of the braking distance during traveling on a rough road. Can be deterred.

In the anti-skid control device according to the second aspect of the present invention, as shown in the basic configuration diagram of FIG. 1b, the wheel speed detecting means for detecting the wheel speed of each wheel of the vehicle through, for example, a wheel speed sensor or the like. On the other hand, the ground speed (vehicle speed) in the front-rear direction of the vehicle is calculated and detected by the vehicle speed detecting means, for example, based on the wheel speed detection value detected by the wheel speed detecting means, and the actuator control means However, the deviation between the wheel speed detection value detected by the wheel speed detection means and the vehicle speed detection value detected by the vehicle speed detection means is set to, for example, a predetermined slip ratio or less so that the wheel does not lock and the grip force is sufficient. The target value of the wheel speed is set so that the braking distance can be shortened while exhibiting the above. On the other hand, the wheel acceleration / deceleration detection means calculates and detects the wheel acceleration / deceleration by, for example, differentiating the wheel speed detection value, and the actuator control means determines that the wheel speed detection value is the target value of the wheel speed. If the wheel acceleration / deceleration detection value detected by the wheel acceleration / deceleration detection means is larger than the predetermined value set to a relatively small value for the negative acceleration of the wheel, that is, the deceleration within the range of The braking force of the wheel is increased, the detected value of the wheel speed is smaller than the target value of the wheel speed, and the wheel acceleration / deceleration is less than the predetermined value with respect to a preset negative acceleration of the wheel, that is, deceleration. When it is smaller than the individual predetermined value set to a large value, the braking force is reduced, and a command signal for causing the wheel speed of the wheel to exert the maximum braking force within the target value of the wheel speed is output by the actuator. Output towards , The actuator is a fluid pressure to the brake cylinder by the fluid pressure or the like provided in each wheel in response to the command signal, by increasing vacuum adjustment control, to meet the target value of the wheel speed,
That is, it is possible to shorten the braking distance while preventing the wheels from locking. By the way, the first comparison means compares the wheel acceleration / deceleration detection value of the wheel acceleration / deceleration detection means with a first predetermined value which is set so that a large amplitude of the wheel acceleration / deceleration generated in traveling on a rough road, for example, is exceeded. By comparison, the amplitude of the wheel acceleration / deceleration is monitored. When the wheel acceleration / deceleration detection value detected by the wheel acceleration / deceleration detection means has a large amplitude exceeding a predetermined value based on the comparison value of the first comparison means, for example, The period during which the wheel acceleration / deceleration detection value does not exceed a predetermined value is measured to monitor the cycle of the wheel acceleration / deceleration. On the other hand, the second comparing means sets the first predetermined value which is set so that the detected value of the wheel acceleration / deceleration of the wheel acceleration / deceleration detection means exceeds a large amplitude of the wheel acceleration / deceleration generated in traveling on a rough road, for example. And an individual second predetermined value are compared to monitor the amplitude of the wheel acceleration / deceleration. Here, for example, when the second predetermined value is set to a value smaller than the first predetermined value, as in the anti-skid control device according to claim 3 of the present invention, the setting deviations of both predetermined values are set to the above-mentioned values. Whether or not the true amplitude of the wheel acceleration / deceleration detection value exceeds the set deviation between the two predetermined values, that is, the amplitude is bad, by making the amplitude of the wheel acceleration / deceleration that is generated due to traveling on a rough road slightly smaller. It is possible to monitor whether or not the judgment is sufficient for road judgment. Then, the rough road determination means included in the actuator control means is set so that the amplitude of the wheel acceleration / deceleration monitored by the first comparison means exceeds, for example, the upper limit value of the large amplitude generated in the rough road traveling. It is judged that the cycle of the wheel acceleration / deceleration monitored by the time measuring means is shorter than the fast cycle that occurs during traveling on a rough road, and is monitored by the second comparing means. If the amplitude of the wheel acceleration / deceleration exceeds a second predetermined value set to exceed the lower limit of the large amplitude generated in traveling on a rough road, it is determined that the vehicle is traveling on a rough road. To do. Therefore, when the rough road running determination means determines that the vehicle is running on a rough road, the actuator control means forcibly cancels the pressure reduction adjustment control of the fluid pressure to the braking cylinder by the actuator, for example. Alternatively, the control gain related to the pressure reduction is reduced to forcibly suppress the reduction of the braking force of the wheel by the braking cylinder, thereby reducing or suppressing the increase of the braking distance during traveling on a rough road. be able to.

[0012]

Embodiments of the present invention will now be described with reference to the drawings.
To do. FIG. 2 shows the anti-skidding according to claim 1 of the present invention.
1 shows a first embodiment of a control device. In the figure, 1F
L and 1FR are left and right front wheels, and 1RL and 1RR are left and right rear wheels.
Then, the rear wheels 1RL and 1RR rotate from the engine EG.
The driving force is transmission T, propeller shaft PS and diff.
Each wheel 1FL ~
Each wheel has a wheel cylinder as a braking cylinder.
2FL to 2RR are provided, and front wheels 1FL and 1FR are further provided.
The sine wave signal S corresponding to these wheel rotation speeds_iFL, S
_iFRIf the wheel speed sensors 3FL and 3FR that output
The average of the rear wheels 1RL and 1RR on the propeller shaft PS
Sine wave signal S according to rotation speed_iRWheel speed sensor that outputs
3R is attached to each wheel speed sensor 3FL to 3R.
Are connected to wheel speed calculation circuits 15FL to 15R.
By so-called 3-channel anti-skid control car
It forms the wheel speed detection means.

Master cylinder pressures of two systems are individually supplied to the front wheel side wheel cylinders 2FL and 2FR via the front wheel side actuators 6FL and 6FR according to the depression of the brake pedal 4, and the rear wheel side wheel cylinders are also supplied. Two
The master cylinder pressure from the master cylinder 5 is supplied to RL and 2RR via a common rear wheel side actuator 6R.

As shown in FIG. 3, each of the actuators 6FL to 6R has an electromagnetic inflow valve 8 interposed between a hydraulic pipe 7 connected to the master cylinder 5 and the wheel cylinders 2FL to 2RR, and an electromagnetic inflow valve 8 for this electromagnetic inflow. A series circuit of an electromagnetic outflow valve 9, a hydraulic pump 10, and a check valve 11 connected in parallel with the inflow valve 8 and an accumulator 12 connected to a hydraulic pipe between the outflow valve 9 and the hydraulic pump 10 are provided.

The electromagnetic inflow valve 8, the electromagnetic outflow valve 9 and the hydraulic pump 10 of each of the actuators 6FL to 6R have hydraulic pressure control signals EV, AV and MR from the controller CR.
Controlled by. Each actuator 6 by the hydraulic pressure control signals EV, AV and MR from the controller CR
The wheel cylinder pressure control of FL to 6R will be briefly described later.

On the other hand, the longitudinal acceleration of the vehicle is applied to the vehicle.
A longitudinal acceleration sensor 13 for detecting is provided. this
The longitudinal acceleration sensor 13 does not apply acceleration to the vehicle.
Voltage becomes zero when the
Longitudinal acceleration detection value X that becomes a positive voltage proportional to this_GOut
Force The controller CR is a wheel speed sensor 3FL.
~ Wheel speed sine wave signal S from 3R_iFL~ S_iRIs entered
Based on these and the turning radii of the wheels 1FL to 1RR,
Wheel peripheral speed (wheel speed) Vw_FL~ Vw_RThe car that calculates
The wheel speed calculation circuits 15FL to 15R and the wheel speed calculation circuits
Wheel speed Vw of roads 15FL to 15R_FL~ Vw_ROut of
Higher wheel speed (select high wheel speed) Vw_HSelect
Select high switch 16 and this select high switch
Select high wheel speed Vw selected in H16 _HAnd before and after
The longitudinal acceleration detection value X of the speed sensor 13_GAnd are entered
Based on these, the pseudo vehicle speed V_iPseudo vehicle speed to calculate
Output from the generator 17 and this pseudo vehicle speed generator 17
Pseudo vehicle speed V_iAnd the wheel speed Vw_FL, Vw_FRAnd V
w_RBased on and, anti-skid control during braking is performed.
And a braking pressure control device 18
Control signals output from the drive circuits 22a to 22c.
And then supplied to the actuators 6FL to 6R.

As the pseudo vehicle speed generator 17, for example, one described in Japanese Patent Application Laid-Open No. 3-246158 previously proposed by the present applicant can be applied. The braking pressure control device 18 basically has wheel speeds Vw _FL , Vw _FR and Vw.
Each wheel 1FL to 1RR based on _R and the pseudo vehicle speed V _i
The actuators 6FL to 6R for controlling the supply pressure to the wheel cylinders 2FL to 2RR provided in the above are controlled. For example, as shown in FIG. 2, the input interface circuit 25a having the A / D conversion function and the D / A conversion function are provided. Output interface 25d having an arithmetic processing unit 25b
And a microcomputer 25 having at least a storage device 25c, and at least the wheel speed at which the deviation between the pseudo vehicle speed V _i and the wheel speeds Vw _FL , Vw _FR and Vw _R is equal to or less than a predetermined slip ratio (for example, 15%). The target value is calculated and set, and the wheel speeds Vw _FL , Vw _FR and Vw are set.
Wheel acceleration and deceleration from the differential value of the _R V'w _FL, V'w _FR and V'w _R
(These are also referred to as V'w _j ) are calculated to determine whether or not the wheel acceleration / deceleration V'w _FL , V'w _FR and V'w _R exceed a predetermined value, and the wheel speed Vw _FL , Depending on whether Vw _FR and Vw _R are within the range of the target value, the supply pressure to the wheel cylinders 2FL to 2RR is increased rapidly as shown in FIG. 4, a holding mode, a decompression mode and a slow increase. Braking pressure control is appropriately selected in the pressure mode. Here, in order to facilitate understanding, this control is usually defined as anti-skid control.

As the specific arithmetic processing in the microcomputer 25 for the normal anti-skid control, for example, the arithmetic processing described in Japanese Patent Laid-Open No. 3-246158 previously proposed by the applicant of the present application may be diverted. It is possible to perform the operation by appropriately selecting the rapid pressure increase mode, the holding mode, the pressure decrease mode and the slow pressure increase mode shown in FIG. Here, the selection of the pressure increase / decrease mode will be briefly described with reference to FIG. 4. The slip ratio S _j calculated from the wheel speed detection value Vw _j and the pseudo vehicle speed V _i is a predetermined value S ₀ set in advance. (For example, 15% above), and the wheel acceleration / deceleration V'w _j is between a preset negative acceleration / deceleration threshold α and positive acceleration / deceleration threshold β, that is, α <V'w _j <β.
Actuator 6F during non-braking and initial braking
In order to set the pressure of L to 6R to the rapid pressure increase mode in which the pressure is in accordance with the pressure of the master cylinder 5, the actuator 6
The control signals EV and AV for the FL to 6R are both set to the logical value "0" to control the inflow valve 8 of the actuators 6FL to 6R to the open state and the outflow valve 9 to the closed state.

Then, the braking state is established, and the wheel speed detection value V
w _j gradually decreases, and accordingly the wheel acceleration / deceleration V'w _j
Decreases in the negative direction as shown by the curve in FIG. 4, and when this wheel acceleration / deceleration V'w _j exceeds the negative acceleration / deceleration threshold α,
In order to set the high-pressure side holding mode for holding the internal pressure of the wheel cylinders 2FL to 2RR at a constant value, the actuator 6
The inflow valve 8 of the FL to 6R is controlled to be in the closed state and the outflow valve 9 is controlled to be in the closed state to maintain the internal pressure of the wheel cylinders 2FL to 2RR at the pressure immediately before that.

Even in this holding mode on the high pressure side, the wheels are
As shown in the curve of FIG. 4, the braking force acts on the
Wheel acceleration / deceleration V'w_jSlips with decreasing
Rate S _jIncreases, and the slip ratio S_jIs the predetermined value S₀
And wheel acceleration / deceleration V'w_jIs a positive acceleration / deceleration threshold β
When the value is maintained below the
No. MR is output to output the hydraulic pressure of actuators 6FL to 6R.
The pump 10 is activated. Because of this, the actuator
The pressure reduction mode is to gradually reduce the pressure of 6FL to 6R.
To close the inflow valve 8 of the actuators 6FL to 6R,
With the outflow valve 9 open, the wheel cylinders 2FL to 2R
The pressure held at R is used as the outflow valve 9, hydraulic pump 10 and
Back to the master cylinder 5 side via the check valve 11 and
The internal pressure of the cylinders 2FL to 2RR is reduced.

In this depressurization mode, the braking force on the wheels is alleviated, but the detected wheel speed value Vw _j is maintained in the decreasing state for a while, so that the wheel acceleration / deceleration V'w as shown by the curve in FIG. _j further decreases in the negative direction and the slip ratio S _j continues to increase, but thereafter, the decrease ratio of the wheel speed detection value Vw _j decreases and shifts to the acceleration state. In response to this, when the wheel acceleration / deceleration V'w _j increases in the positive direction and the wheel acceleration / deceleration V'w _j becomes equal to or greater than the positive acceleration / deceleration threshold β, the low pressure side that holds the pressure of the actuators 6FL to 6R on the low pressure side. In order to shift to the holding mode of the control signal EV, the control signal EV is set to the logical value "1" and the control signal AV is set in the same manner as the holding mode of the high voltage side.
Is controlled to a logical value "0", and the wheel cylinders 2FL to 2FL
The internal pressure of RR is maintained at the pressure immediately before that.

Even in this low pressure side holding mode, since the braking force acts on the wheels, the detected wheel speed value V
The increasing rate of w _j gradually decreases, and when the wheel acceleration / deceleration V′w _j becomes less than the positive acceleration / deceleration threshold β, the hydraulic fluid from the master cylinder 5 is intermittently fed to the wheel cylinders 2FL to 2RR.
And the internal pressure of the wheel cylinders 2FL to 2RR is increased stepwise to enter the slow pressure increasing mode, so that the control signals EV for the actuators 6FL to 6R are changed to the logical value "0" and the logical value "1". By repeating the control at a predetermined interval and setting the control signal AV to a logical value "0", the inflow valves 8 of the actuators 6FL to 6R are opened and closed at predetermined intervals, and the outflow valve 9 is closed, whereby the wheel cylinders 2FL to 2FL.
The internal pressure of 2RR is gradually increased in steps.

In this slow pressure increasing mode, the pressure increase of the wheel cylinders 2FL to 2RR becomes slow, so that the braking force on the wheels 1FL to 1RR gradually increases, and the wheels 1FL to 1RR gradually increase.
FL to 1RR are decelerated and the wheel speed detection value Vw _j also decreases. After that, when the wheel acceleration / deceleration V'w _j becomes less than the negative acceleration / deceleration threshold value α, the high pressure side holding mode is set, and when the slip rate S _j becomes the set slip rate S ₀ or more, the depressurization mode is set. After that, low pressure holding mode,
The slow pressure increasing mode, the high pressure maintaining mode, and the pressure reducing mode are repeated, and the antiskid effect can be exhibited.

When the vehicle speed decreases to some extent, the slip ratio S _j may recover to less than the set slip ratio S ₀ in the pressure reducing mode. At this time, the mode shifts to the slow pressure increasing mode and then to the high pressure side. After shifting to the holding mode of No. 2, the mode is shifted to the slow pressure increasing mode. Also,
When the vehicle reaches a speed that is close to a stop condition and other conditions that satisfy the control termination conditions are met, the normal anti-skid control is terminated after the rapid pressure increase mode is set.

Further, in the present embodiment, the microcomputer 25 determines whether or not the vehicle is traveling on a rough road represented by the Belgian road or a corrugated road, When it is determined that the vehicle is traveling on a rough road, the normal anti-skid control is stopped, and the supply pressure to the wheel cylinders 2FL to 2RR is returned to the supply pressure from the master cylinder 5 as quickly as possible. Performs rough road control.

Now, the basic principle of the microcomputer 25 for determining a bad road traveling will be described. FIG. 5 shows the changes over time in the vehicle speed during braking, the wheel speed, and the negative acceleration (deceleration) of the vehicle body, which have been subjected to the normal anti-skid control. Note that the wheel speeds indicate the front left wheel speed, the front right wheel speed, and the rear wheel speed, and are shifted in the vertical axis direction to facilitate understanding, but in reality, at least the values before and after braking are equal. It is almost the same. Further, in the figure, during traveling on a rough road, the normal anti-skid control is performed while traveling on a rough road such as the Belgian road and the corrugated road.

As mentioned above, with normal anti-skid control
Is the wheel according to the slip ratio obtained from the deviation from the vehicle speed.
Since the target speed value is set, the range of this target wheel speed value is set.
Avoids wheel lock while exerting maximum braking force in the area
To do. Here, as shown in FIG. 5,
Is a fluctuation frequency f = about 10 to 15 Hz, and a fluctuation amplitude A = 1
It can be seen that pulsation of about 5 km / h occurs. So
Then, when pulsation occurs in the wheel speed in this way, the normal
In the anti-skid control, the wheel speed detection value Vw _jBefore
Range of target value of wheel speed (V_i~ 0.85V_i) Below
Easy, and at the same time the wheel acceleration / deceleration V'w_jAlso to pulsate,
Since it is easy to fall below the positive acceleration / deceleration threshold β, as a result,
The pressure reducing mode is often selected as the braking pressure mode, and the braking force is
Vehicle body deceleration as a whole is reduced as shown in the figure.
Then, the vehicle speed becomes larger than the target vehicle speed, and the braking distance
Will be a problem.

A criterion for determining such a bad road traveling is that the variation amount (amplitude) of the wheel speed is large and the variation period is relatively short at the same time. Therefore, in the present embodiment, attention is paid to the acceleration / deceleration of the wheel that pulsates 90 ° in phase with respect to the pulsation of the wheel speed, and the maximum value of the pulsating wheel acceleration / deceleration having a large amplitude exceeds a predetermined value, and after that, The time when the pulsating wheel acceleration / deceleration is lower than the predetermined value is measured, and if the measurement time is shorter than the predetermined time, the fluctuation cycle of the pulsation of the acceleration / deceleration is relatively short as long as it can be determined to be traveling on a rough road. It is determined that the vehicle is running on a rough road.

Next, the rough road determination calculation process executed by the microcomputer 25 of the braking pressure control circuit 18 in order to realize the basic principle of this embodiment will be described with reference to FIG. This rough road determination calculation process is the same as the ΔT (for example, 5
msec.) is executed as a timer interrupt process every
Is a rough road determination control flag, which indicates that the vehicle is traveling on a rough road in the set state of F = 1 and is not traveling on a rough road in the reset state of F = 0, and N is a counter value and N = 0. Since it is possible to sequentially increment from the reset state to the maximum value state of N = N _MAX , the elapsed time t from the start of the increment of the count value is represented by the product of the counter value N and the predetermined time ΔT. It is assumed that the time t is the maximum value state N = N _MAX of the counter value and the predetermined time t ₀ has elapsed. If this predetermined time t ₀ is set to a time equal to or slightly shorter than the cycle of the wheel acceleration / deceleration V′w _j generated during traveling on the rough road, the elapsed time t calculated by substitution with the counter value N is predetermined. When it is equal to or shorter than the time t ₀ , it can be determined that the vehicle is traveling on a bad road.
The rough road determination control flag F and the counter value N are updated and stored in the storage device 25c of the microcomputer 25 every time this arithmetic processing is performed.

That is, when the arithmetic processing of FIG. 6 is started, first, at step S1, each wheel speed arithmetic circuit 15j (j = FL,
The current wheel speed detection value Vw _j output from FR, R) is read. Next, the process proceeds to step S2, and the storage device 2
The latest counter value N stored in 5c is read.

Next, in step S3, the wheel acceleration / deceleration V'w _j is calculated from the wheel speed detection value Vw _j read in step S1 by appropriate differential calculation processing such as high-pass filter processing. Next, the process proceeds to step S4, and the wheel acceleration / deceleration V'w _j calculated in step S3.
Is smaller than a predetermined value V'w ₀ set in advance to such an extent that the wheel acceleration / deceleration having a large amplitude generated during traveling on a rough road exceeds the predetermined value, and the wheel acceleration / deceleration V'w _j is the predetermined value V '. If it is smaller than w _{0, the process} proceeds to step S5, and if not, the process proceeds to step S6.

In step S5, in step S2
It is determined whether or not the counter value N read in is less than the maximum value state N _{MAX of} the counter value. If the counter value N is less than the maximum value state N _{MAX of the} counter value, the process proceeds to step S7, Otherwise, step S8
Move to. In the step S7, the counter value N
Is incremented by "1" to update and store it in the storage device 25c and then return to the main program.

In step S8, the rough road determination control flag F is reset to "0", updated and stored in the storage device 25c, and then the main program is restored. on the other hand,
In the step S6, it is judged whether or not the counter value N read in the step S2 is "0". If the counter value N is "0", the main program is restored, and if not, the counter value N is "0". Moves to step S9.

In step 9, the counter value N read in step S2 is the maximum value N of the counter values.
It is determined whether or not it is equal to or more than _MAX , and if the counter value N is equal to or more than the maximum value N _{MAX of the} counter value, step S
If not, the process proceeds to step S11. In the step S11, the rough road determination control flag F is set to "1", the storage device 25c is updated and stored, and then the process proceeds to the step S10.

In step S10, the counter value N is reset to "0", updated and stored in the storage device 25c, and then the main program is restored. In the microcomputer 25, the normal anti-skid control or the rough road traveling control is selectively controlled according to the state of the rough road determination control flag F as a result of the rough road determination calculation processing as described above. Is carried out according to the flowchart shown in FIG.

This rough road determination calculation process is executed as a timer interrupt process for each ΔT (for example, 5 msec.) Which is the same as the calculation process of the normal anti-skid control for a predetermined time.
In step S20, it is determined whether or not the rough road determination control flag F is "0". If the rough road determination control flag F is not "0", the process proceeds to step S21. If not, the process proceeds to step S22. Transition.

In step S21, it is determined that the rough road determination control flag F is not set to "1", that is, the vehicle is not traveling on a rough road, and the normal anti-skid control command is issued to return to the main program. On the other hand, in step S22, it is determined that the rough road determination control flag F is set to "1", that is, the vehicle is traveling on a rough road, and each of the actuators 6FL to 6R is instructed by the preceding normal anti-skid control command. Is operating, and if each of the actuators 6FL to 6R is operating, the process proceeds to step S23, and if not, the process proceeds to step S24.

In step S23, as a result of the actuators 6FL to 6R operating according to the preceding normal anti-skid control command, the braking pressure to the wheel cylinders 2FL to 2RR changing from the master cylinder pressure is set to the normal pressure. A command to return to the master cylinder pressure is issued in the rapid increase / decrease mode similar to the anti-skid control (that is, synonymous with the actuator opening mode), and the main program is returned.

On the other hand, in step S24, as a result of the fact that the actuators 6FL to 6R have not been actuated yet, the braking pressure to the wheel cylinders 2FL to 2RR is judged to be equal to the master cylinder pressure, and this master cylinder pressure is determined. A holding (that is, synonymous with prohibiting depressurization) command is issued to return to the main program. When it is determined by the control logic shown in FIG. 7 that the vehicle is not traveling on a rough road, the wheels are not locked by the normal anti-skid control and the braking force is exerted within a range of a sufficient tire grip force. The braking distance can be shortened. Further, when it is judged that the vehicle is traveling on a rough road, the pressure reduction mode by the normal anti-skid control, that is, the reduction of the braking force is forcibly suppressed, thereby preventing or suppressing the extension of the braking distance. be able to.

Next, the operation of the rough road determination control shown in FIG. 6 will be described with reference to the time chart shown in FIG. In this time chart, during the normal braking control, the vehicle entered the rough road near time t ₀ shown in the figure, and also exited the rough road near time t ₇ . Further, the wheel acceleration / deceleration V'w _j shown in the figure particularly indicates the left front wheel acceleration / deceleration V'w _FL , and the target wheel acceleration / deceleration V'w ^* which is the target value of this wheel acceleration / deceleration V'w _j ^.
Is a differential value of the lower limit value (0.85V _i ) of the target value of the wheel speed used in the normal anti-skid control, and the predetermined value V′w ₀ used in the arithmetic processing of FIG. 6 is the normal anti-skid It is set to a value equal to or near the positive acceleration / deceleration threshold β used in control. Further, the counter value N and the rough road determination control flag F in the figure are synonymous with those used in the arithmetic processing of FIG. Although the counter value incremented in the figure actually increases stepwise, it is shown here to increase linearly as a simple ramp function for easier understanding. Further, in the normal state where the rough road determination is not made, step S5 of FIG.
After the counter value increment from step S7 to step S7 is repeated, the rough road determination control flag F is reset to "0" while the process proceeds from step S5 to step S8, and the counter value N is maintained at the maximum value N _MAX. There is.

First, time t₀Then, the operation processing step of FIG.
Wheel speed detection value Vw read in step S1_jFrom step
Wheel acceleration / deceleration V'w in S3_j(J = FL) is calculated, and
Time t₀Wheel acceleration / deceleration V'w_jBut step
Predetermined value V'w at step S4₀It is judged that it is above, as a result
In step S6, the counter value N is the maximum value N_MAXMaintained in
Then, the process proceeds to steps S9 and S11,
The counter value N is reset to "0" in this step S11.
To be done. And pulsating wheel acceleration / deceleration V'w_jSoon
It begins to decrease beyond its maximum value, but at the next time t₁Until
The predetermined value V'w ₀, And thus, during the
The process proceeds from step S4 to step S6.
In 6, the counter value N remains “0”,
The flow of returning directly to the main program is repeated.
Will be returned. During this time, the rough road determination control flag F is set to "0".
It has been reset.

Next, at the time t ₁ , since the wheel acceleration / deceleration V'w _j that continues to decrease calculated in step S3 of the calculation process of FIG. 6 becomes smaller than the predetermined value V'w ₀ , the steps S4 to S4 are performed. The process moves to S5. Since the counter value N is still "0" at this point, the process proceeds from step S5 to step S7 to increment the counter value N and then returns to the main program. After that, the pulsating wheel acceleration / deceleration V′w _j begins to increase beyond its minimum value from the decreasing direction, but until the next time t ₂ , the wheel acceleration / deceleration V′w _j is the predetermined value V ′. Since it does not exceed w ₀ , the calculation process of FIG.
Then, the flow of returning to the main program through steps S5 and S7 is repeated, and as a result, the counter value N is incremented and incremented every predetermined time ΔT in which the arithmetic processing is performed.

Next, at the time t ₂ , since the continuously increasing wheel acceleration / deceleration V'w _j calculated in step S3 of the calculation process of FIG. 6 exceeds the predetermined value V'w ₀ , the step S3 is executed.
However, since the counter value N read in step S2 is not "0" by repeating the increment, the process proceeds to step S9. However, the counter value N has not yet reached its maximum value N _MAX, and therefore the process proceeds to step S11. In this step S11, the wheel acceleration / deceleration V'w _j exhibits a large amplitude so as to exceed the predetermined value V'w ₀ at the time t ₀ , and further, the elapsed time t (from the time t ₁ to the time t _{2 is} t ( = N · Δ
Since T) is shorter than a predetermined elapsed time t ₀ (= N _MAX · ΔT) corresponding to a short cycle of wheel acceleration / deceleration that occurs during traveling on a rough road, it is determined that the vehicle is traveling on a rough road, and As a result, the rough road running flag F is set to "1" and then the process proceeds to step S10, the counter value N is reset to "0" and the process returns to the main program. And
The pulsating wheel acceleration / deceleration V'w _j eventually begins to decrease beyond its maximum value, but the predetermined value V'w ₀ is reduced until the next time t _3.
Therefore, during that time, the process proceeds from step S4 to step S6, but since the counter value N remains "0" in this step S6, the flow of returning to the main program as it is is repeated.
During this time, the rough road determination control flag F remains set to "1".

Next, at time t ₃ , since the wheel acceleration / deceleration V'w _j that continues to decrease calculated in step S3 of the arithmetic processing of FIG. 6 becomes smaller than the predetermined value V'w ₀ , steps S4 to S4 In step S5, the counter value N, which is still "0", is transferred from step S5 to step S7, incremented, and then returned to the main program. Then, the pulsating wheel acceleration / deceleration V′w _j begins to increase beyond the minimum value from the decreasing direction, but until the next time t ₄ , the wheel acceleration / deceleration V′w _j is the predetermined value V ′. not exceed w _0, from step S4 by the arithmetic processing of FIG. 6 for the repeated flow of the process returns to the main program via step S5, S7, the result, at every predetermined time ΔT in which the arithmetic processing is performed The counter value N is incremented and increased. During this time, since the step S8 of resetting the rough road determination control flag F has never been performed, the rough road determination control flag F remains set to "1".

Next, the time t_FourThen, in the calculation processing of FIG.
Wheel acceleration / deceleration that continues to increase calculated in step S3
V'w_jIs the predetermined value V'w₀Exceeds and increments again
Since the counter value N repeated is not "0",
Moves from step S4 through step S6 to step S9
To do. However, this counter value N is still the maximum value N
_MAXHas not been reached, and therefore step S11 is entered.
Then, similarly to the above, the rough road determination control flag F is set to "1".
Continue to set, then move to step S10
After resetting the counter value N to "0", the main program
Return to Mu. And pulsating wheel acceleration / deceleration V'w_jIs
Eventually, the maximum value is exceeded and begins to decrease, but at the next time t
_FiveUp to the predetermined value V'w₀Is exceeded, so during that time,
The process moves from step S4 to step S6.
In step S6, the counter value N remains "0".
In order to return to the main program,
The flow is repeated. During this time, the rough road determination control flag F
Remains set to "1".

Next, at time t ₅ , since the wheel acceleration / deceleration V'w _j, which continues to decrease and is calculated in step S3 of the arithmetic processing of FIG. 6, becomes smaller than the predetermined value V'w ₀ , steps S4 to S4 are executed. In step S5, the counter value N, which is still "0", is transferred from step S5 to step S7, incremented, and then returned to the main program. Then, the pulsating wheel acceleration / deceleration V'w _j begins to increase beyond the minimum value from the decreasing direction, but until the next time t ₆ , the wheel acceleration / deceleration V'w _j is the predetermined value V '. not exceed w _0, from step S4 by the arithmetic processing of FIG. 6 for the repeated flow of the process returns to the main program via step S5, S7, the result, at every predetermined time ΔT in which the arithmetic processing is performed The counter value N is incremented and continues to increase. In the meantime, the rough road determination control flag F is reset in step S8.
Since it never shifts to, the rough road judgment control flag F remains set to "1".

Next, the time t₆Then, in the calculation processing of FIG.
Wheel acceleration / deceleration that continues to increase calculated in step S3
V'w_jIs the predetermined value V'w₀Exceeds and increments again
Since the counter value N repeated is not "0",
Moves from step S4 through step S6 to step S9
To do. However, this counter value N is still the maximum value N
_MAXHas not been reached, and therefore step S11 is entered.
Then, in the same manner as above, the rough road running flag F is set to "1".
Continue, then move to step S10
Reset the data value N to "0" and then enter the main program.
Return. And pulsating wheel acceleration / deceleration V'w_jHayaga
It begins to decrease beyond its maximum value, but at the next time t₇Well
And the predetermined value V'w₀And therefore during that time,
The process moves from step S4 to step S6.
At step S6, the counter value N remains "0".
In order to return to the main program,
Is repeated. During this time, the rough road determination control flag F is
It remains set to "1".

Next, at time t ₇ , since the continuously decreasing wheel acceleration / deceleration V'w _j calculated in step S3 of the arithmetic processing of FIG. 6 becomes smaller than the predetermined value V'w ₀ , steps S4 to S4 are executed. In step S5, the counter value N, which is still "0", is transferred from step S5 to step S7, incremented, and then returned to the main program. Then, the pulsating wheel acceleration / deceleration V′w _j begins to increase beyond its minimum value from the decreasing direction, but until the next time t ₉ , the wheel acceleration / deceleration V′w _j is the predetermined value V ′. Since it does not exceed w ₀ , the flow of returning to the main program through steps S4 to S5 and S7 in the arithmetic processing of FIG. 6 is repeated at least until time t ₈ described later, and as a result, The counter value N is incremented and continues to increase every predetermined time ΔT in which the arithmetic processing is performed. During this time, since the step S8 of resetting the rough road determination control flag F has never been performed, the rough road determination control flag F remains set to "1".

However, at the time t₇End the rough road
The calculated vehicle is calculated in step S3 of the calculation process of FIG.
Wheel acceleration / deceleration V'w_jIs the time t₇Since then
Become Therefore, the time t₇The calculation processing of Fig. 6 is actually
It is incremented and increased every predetermined time ΔT
The counter value N to be continued will eventually become the time t₈At that maximum
Value N_MAXMaintained at. Here, the operation processing step of FIG.
In S4, wheel acceleration / deceleration V'w_jIs the predetermined value V'w₀To
Since it has not exceeded, the process moves to step S5, and this step
In step S5, the counter value N is the maximum value N_MAXTo be
Go to step S8. In this step S8, the time
t₇From time t₈Elapsed time t (= N · ΔT)
Corresponds to the short cycle of wheel acceleration / deceleration that occurs when driving on rough roads.
Elapsed predetermined time t to hit₀(= N_MAX・ ΔT)
Since it is longer than this, it is judged that the vehicle is not on a bad road
As a result, the rough road determination control flag F is reset to “0”.
After setting, return to the main program. And
This time t₈From the time t ₉Until the wheel acceleration / deceleration
V'w_jIs the predetermined value V'w₀Not exceed, and cow
Input value N is the maximum value N_MAX6 to be maintained at
The calculation process of step S4 through steps S5 and S8
Repeat the flow of returning to the main program by
During this period, the rough road determination control flag F is continuously reset to "0".
It

[0050] Then the at time t _9, the step for the wheel acceleration V'w _j keeps increasing calculated in step S3 of the calculation process of Fig. 6 is exceeding the predetermined value V'w ₀ S4
From step S6 to step S6, since the counter value N, which is maintained at the maximum value N _MAX by repeating the increment, is not “0”,
In step S11, the counter value N is reset to "0" and then the process returns to the main program. Then, the pulsating wheel acceleration / deceleration V'w _j eventually begins to decrease beyond its maximum value, but it exceeds the predetermined value V'w ₀ until the next time t ₁₀ , so during that time, the steps from step S4 to step S4 are performed. Go to S6, but this step S
In 6, the counter value N remains “0”,
The flow of returning to the main program as it is is repeated. During this period, the step S11 has never been performed, so the rough road determination control flag F remains reset to "0".

Next, at time t ₁₀ , since the wheel acceleration / deceleration V'w _j, which continues to decrease and is calculated in step S3 of the calculation process of FIG. 6, becomes smaller than the predetermined value V'w ₀ , steps S4 to S4 are performed. In step S5, the counter value N, which is still "0", is transferred from step S5 to step S7, incremented, and then returned to the main program. Then, the pulsating wheel acceleration / deceleration V'w _j starts to increase beyond the minimum value from the decreasing direction, but in a vehicle that has finished traveling on a rough road, the wheel acceleration / deceleration V'w _j is then the predetermined value. Since V′w ₀ is not exceeded, therefore, at least until time t ₁₁ described later, the above-mentioned FIG.
The flow of returning to the main program from step S4 through steps S5 and S7 is repeated in the calculation process of 1. As a result, the counter value N is incremented and continues to increase every predetermined time ΔT in which the calculation process is performed.
During this period, the rough road traveling control flag F is still reset to "0".

Next, at the time t ₁₁ , the counter value N that keeps increasing reaches its maximum value N _MAX , so that the arithmetic processing of FIG. The road determination control flag F is continuously reset to "0" to return to the main program. After that, this flow is repeated and the bad road determination control flag F is continuously reset to "0".

As described above, according to the arithmetic processing of FIG. 6, the time t ₂ shortly after the time t ₀ when the rough road is started is started.
In bad road determination control flag F is set to "1", continues to be set to the bad road determination control flag F is "1" from the time t ₇ the completion of the rough road until shortly time t ₈ the time to be reset at t _8, can substantially accurately determine the rough road running of the vehicle in which the bad road determination control flag F is set to "1", during the rough road running judgment, FIG. 7 By the calculation processing of the above, the supply pressure to the wheel cylinders 2FL to 2RR of each wheel 1FL to 1RR is made to be the master cylinder pressure, and the pressure reduction control of each wheel cylinder pressure is substantially prohibited by this, so that the reduction of the braking force is suppressed. As a result, it is possible to suppress a decrease in the deceleration of the vehicle and suppress an increase in the braking distance.

Here, step S4 in the control logic shown in FIG. 6 corresponds to the comparing means of the anti-skid control device according to claim 1 of the present invention, and steps S4, S5 and S7 are the time measuring means. And steps S4, S5, S8 and steps S9, S11 correspond to rough road traveling determination means. Next, a second embodiment of the antiskid control device according to claims 2 and 3 of the present invention will be described with reference to FIGS. 9 and 10.

The concrete structure of the vehicle for constructing the anti-skid control device of this embodiment is shown in FIG. 2 of the first embodiment.
And similar or nearly similar to those shown in FIG. The contents of the normal anti-skid control executed by the microcomputer 25 of the controller CR are the same as or substantially the same as those in the first embodiment. The specific wheel cylinder pressure control is the series shown in FIG. It is similar or almost the same as the braking pressure control. Further, the arithmetic processing executed by the microcomputer 25 to stop the normal anti-skid control and shift to the bad road traveling control when the vehicle is judged to be traveling on the rough road is similar to or substantially the same as the arithmetic processing shown in FIG. When it is determined that the vehicle is traveling on a bad road such as the Belgian road or the corrugated road, the normal anti-skid control is stopped and the wheel cylinders 2FL to 2RR are driven. The supply pressure is returned to the supply pressure from the master cylinder 5 as quickly as possible.

In the present embodiment, only the arithmetic processing specifically performed by the microcomputer 25 for determining the rough road running is different. Now, the basic principle of the microcomputer 25 in the present embodiment for determining a bad road traveling will be described. In the first embodiment, the wheel acceleration / deceleration V'w _j is compared with one predetermined value V'w _0, and the fluctuating maximum value of the wheel acceleration / deceleration V'w _j exceeds the predetermined value V'w ₀ . Whether or not the variable wheel acceleration / deceleration V'w _j is below this predetermined value V'w ₀ is monitored by measuring its amplitude, and the wheel acceleration / deceleration fluctuates at this measured elapsed time t. The period of velocity V'w _j was monitored. Therefore, the deviation between the median value of the average amplitude of wheel acceleration / deceleration that occurs during traveling on a road surface that is not on a rough road and the median value of the average amplitude of wheel acceleration / deceleration that occurs during traveling on a rough road is small. In other words, the median amplitude as the average value of the wheel acceleration / deceleration that changes periodically does not change much between the two, and the wheel acceleration / deceleration that occurs during traveling on a road surface that is not a bad road is The fluctuation of the wheel acceleration / deceleration that occurs in the case where the amplitude is simply amplified and the frequency is increased, by appropriately setting one predetermined value in the first embodiment, it is possible to sufficiently drive on a rough road. Can be determined.

However, the deviation between the median of the average amplitudes of the wheel acceleration / deceleration generated during traveling on a road surface which is not a rough road and the median of the average amplitudes of the wheel acceleration / deceleration occurring during traveling on a rough road. Is large, that is, when the median value of the amplitude as the average value of the wheel acceleration / deceleration that changes periodically changes greatly between the two, only comparison with one predetermined value of the first embodiment is performed. Then, there is a possibility that traveling on a bad road cannot be accurately determined. Specifically, when driving on a rough road, the amplitude of wheel acceleration / deceleration is
Although it is larger than that when driving on a road surface that is not a bad road, for example, when the maximum value of the fluctuating wheel acceleration / deceleration of both wheels does not change much and only the minimum value changes significantly, the above-mentioned predetermined value Is set to a value such that the maximum value of the variable wheel acceleration / deceleration that occurs during traveling on a rough road exceeds the predetermined value, the wheel acceleration / deceleration during traveling on the rough road does not exceed this predetermined value. In the opposite case, the above predetermined value is
Even if the minimum value of the fluctuating wheel acceleration / deceleration generated during traveling on a rough road is set to a value lower than the minimum value, the wheel acceleration / deceleration during traveling on a rough road does not fall below this predetermined value. Therefore, in such a case, since the trigger for starting the measurement of the elapsed time does not occur, it becomes difficult to accurately determine the traveling on the rough road.

Therefore, in the present embodiment, two predetermined values to be compared with the wheel acceleration / deceleration are used, and each of them is set as, for example, an upper limit threshold value and a lower limit threshold value of the wheel acceleration / deceleration that fluctuate, whereby a deviation between the two threshold values is obtained. Then, the true amplitude of the wheel acceleration / deceleration is monitored, and, for example, from the time when the decreasing wheel acceleration / deceleration V'w _j falls below the first predetermined value V'w ₀₁ which is the upper limit threshold as in the first embodiment. Although the elapsed time t until the time when the next wheel acceleration / deceleration V'w _j exceeds the first predetermined value V'w ₀₁ is measured, this elapsed time t is the wheel acceleration / deceleration that occurs in the rough road traveling. Is shorter than a predetermined time t ₀ corresponding to the fluctuation period of the pulsation of the first rough road determination condition, and the wheel acceleration / deceleration V′w _j that decreases at the same time is the second predetermined value V′w set as the lower threshold. is set _{by 02} drops below and increases the wheel acceleration V'w _j First rough road judgment control flag F is reset when it exceeds the first predetermined value V'w _01
By setting ₁ as the second rough road determination condition and setting the second rough road determination control flag F ₂ that indicates the true rough road traveling determination only when both rough road determination conditions are met, the above problems are avoided. try to.

Next, in order to realize the basic principle of the present embodiment, a rough road determination calculation process executed by the microcomputer 25 of the braking pressure control circuit 18 will be described with reference to FIG. This rough road determination calculation process is the same as the ΔT (for example, 5
msec.) is executed as a timer interrupt process every
Reference numeral ₁ is a first rough road determination control flag indicating the one rough road determination condition. The first rough road running condition is satisfied in the set state of F ₁ = 1 and the first rough road determination condition is in the reset state of F ₁ = 0. It indicates that the traveling condition is not satisfied, and N is a counter value, which can be sequentially incremented from the reset state of N = 0 to the maximum value state of N = N _MAX . the elapsed time t is expressed by the product of the said counter value N and the predetermined time [Delta] t, the maximum state N = N _{MA X} predetermined time t of the counter value this elapsed time t
_It is assumed that ₀ has passed. If this predetermined time t ₀ is set to a time equal to or slightly shorter than the cycle of the wheel acceleration / deceleration V′w _j generated during traveling on the rough road, the elapsed time t calculated by substitution with the counter value N is predetermined. When it is equal to or shorter than the time t ₀ , it can be determined that the vehicle is traveling on a bad road. That is, the fact that the measured elapsed time t is equal to or shorter than the predetermined time t ₀ indicates that the second rough road traveling condition is satisfied. Then, F ₂ is a second rough road judgment control flag, it the condition count value N of the first rough road decision control flag F ₁ is set and in the increment is less than the maximum value N _MAX, F ₂ = 1 indicates that the vehicle is traveling on a rough road, and F ₂ = 0 indicates that the vehicle is not traveling on a rough road. The first and second rough road determination control flags F ₁ and F ₂ and the counter value N are stored in the microcomputer 25 every time this arithmetic processing is performed.
Is updated and stored in the storage device 25c.

That is, when the arithmetic processing of FIG. 9 is started, first, at step S21, each wheel speed arithmetic circuit 15j (j = F).
L, FR, R) present wheel speed detection value Vw output from
Read _j . Next, in step S22, the latest counter value N stored in the storage device 25c is read.

Next, in step S23, the wheel acceleration / deceleration V'w _j is calculated from the wheel speed detection value Vw _j read in step S21 by an appropriate differential calculation process such as a high pass filter process. At the next step S24, the wheel acceleration V'w _j calculated in the step S23 is the pre set so that the maximum value of the wheel acceleration and deceleration of large amplitude that occurs in bad road exceeds the It is determined whether or not it is smaller than the first predetermined value V'w _{01, and} if the wheel acceleration / deceleration V'w _j is smaller than the first predetermined value V'w _{01, the} process proceeds to step S25, and if not, the step is performed. S2
Go to 6.

In the step S25, the step S
Wheel acceleration / deceleration V'w calculated in 23 _jBut on a rough road
The minimum value of the generated wheel acceleration / deceleration of large amplitude falls below
The second predetermined value V'w previously set to₀₂Greater than or not
Whether the wheel acceleration / deceleration V'w_jIs the second predetermined value V'w
₀₂If it is larger, the process proceeds to step S27, so
If not, the process proceeds to step S28.

In the step S28, the first rough road running control flag F ₁ is set to "1" and the step S28 is executed.
Move to 27. In step S27, it is determined whether the counter value N read in step S22 is smaller than the maximum value N _{MAX of} the counter values, and the counter value N
Is smaller than the maximum value N _{MAX of the} counter value, the process proceeds to step S29, and if not, step S29.
Move to 30.

In step S29, the counter value N is incremented by "1", updated and stored in the storage device 25c, and then the main program is restored. In the step S30, the second rough road judgment control flag F ₂ is reset to “0”, and then the process proceeds to step S31 to reset the first rough road judgment control flag F ₁ to “0” to perform both controls. The set states of the flags F ₁ and F ₂ are updated and stored in the storage device 25c, and then the main program is restored.

On the other hand, in step S26, it is determined whether or not the counter value N read in step S22 is "0", and if the counter value N is "0", the process returns to the main program. If not, the process proceeds to step S32. In the step 32, it is judged whether or not the counter value N read in the step S22 is equal to or more than the maximum value N _{MAX of} the counter value, and the counter value N
Is greater than or equal to the maximum value N _{MAX of the} counter value, the process proceeds to step S33, and if not, step S33.
Move to 34.

In step S34, it is determined whether or not the first rough road judgment control flag F ₁ is in a reset state of "0", and the first rough road judgment control flag F ₁ is reset in "0". If it is in the state, the process proceeds to step S33, and if not, the process proceeds to step S35. In step S35, the second rough road determination control flag F
₂ is set to "1", the storage device 25c is updated and stored, and then the process proceeds to step S33.

In step S33, the first rough road judgment control flag F ₁ is set to "1", and the storage device 2
After updating and storing in 5c, the process proceeds to step S36. In step S36, the counter value N is reset to "0", updated and stored in the storage device 25c, and then the main program is restored. Further, in the microcomputer 25, according to the state of the second rough road judgment control flag F ₂ as a result of the rough road judgment calculation processing as described above,
Specifically, in a state where the second rough road determination control flag F ₂ is reset to “0”, the normal anti-skid control is executed, and the second rough road determination control flag F ₂ is set to “1”. In this state, the selection control for executing the rough road traveling control is executed according to the flowchart shown in FIG.
The operation is similar or almost the same as that described in the first embodiment.

Next, the operation of the rough road determination control shown in FIG. 9 will be described with reference to the time chart shown in FIG. In this time chart, during normal braking control, a bad road is approached in the vicinity of time t ₂₅ shown in the figure and the same time t ₃₄
I left the bad road in the vicinity of and then entered the bad road again near time t ₃₈ . In addition, the wheel acceleration / deceleration V'w _j shown in FIG.
Indicates the left front wheel acceleration / deceleration V'w _FL , and the target wheel acceleration / deceleration V'w ^*, which is the target value of the wheel acceleration / deceleration V'w _j , is the lower limit of the target value of the wheel speed used in the normal anti-skid control. Is a differential value of the value (0.85V _i ), and is the first predetermined value V′w ₀₁ used in the arithmetic processing of FIG. 9 equal to the positive acceleration / deceleration threshold β used in the normal anti-skid control? The value is set to a value in the vicinity of the second predetermined value V'w.
₀₂ is set to a value equal to or near the negative acceleration / deceleration threshold β used in the above-mentioned normal anti-skid control. Also,
The counter value N and the first and second rough road determination control flags F ₁ and F ₂ in the figure are synonymous with those used in the arithmetic processing of FIG. In addition, although the counter value N incremented in the figure actually increases stepwise, it is shown here to increase linearly as a simple ramp function for easier understanding. Further, under normal anti-skid control in which the rough road is not determined, step S in FIG.
After the counter value increment from 27 to step S29 is repeated, from step S27 to step S3
While shifting to 0 and S31, both the first and second rough road determination control flags F ₁ and F ₂ are reset to "0", and the counter value N is maintained at the maximum value N _MAX .

First, time t₂₀And the vehicle is not a bad road
Is traveling on the surface, and in step S21 of the arithmetic processing of FIG.
Read wheel speed detection value Vw_jFrom step S23 to car
Wheel acceleration / deceleration V'w_j(J = FL) is calculated, and this time t₂₀
Wheel acceleration / deceleration V'w_jIs step S24
And the first predetermined value V'w₀₁It is judged that it is above, and as a result
In step S26, the counter value N is the maximum value N_MAXMaintained in
Since it has been done, the process proceeds to steps S32 and S33.
Then, in step S33, the first control flag F ₁To
Continues to reset to "0", then in step S34
Reset the input value N to "0". And the pulsating car
Wheel acceleration / deceleration V'w_jEventually, it begins to decrease beyond its maximum value
But next time t_{twenty one}Up to the first predetermined value V'w₀₁Over
Therefore, in the meantime, from step S24,
However, in step S26,
Since the counter value N remains “0”,
The flow of returning to in-program is repeated
It During this time, the first and second rough road determination control flag F₁, F₂
Both remain reset to "0".

Next, the time t_{twenty one}Then, in the calculation processing of FIG.
Wheel acceleration / deceleration that continues to decrease calculated in step S23
V'w_jIs the first predetermined value V'w₀₁To be smaller,
The process moves from step S24 to step S25. See you
At the time of, the wheel acceleration / deceleration V'w _jIs the second predetermined value V'w₀₂
Since it is larger, the process proceeds to step S27 and this
Since the counter value N is still "0" at this point, step
Go to S29 to increment the counter value N
Then return to the main program. And pulsates
Wheel acceleration / deceleration V'w_jEventually the local minimum will be reduced
Begins to increase, but the vehicle has not yet entered the bad road
Next time t_{twenty two}Until the wheel acceleration / deceleration V'w
_jIs the second predetermined value V'w₀₂May fall below the first predetermined
Value V'w₀₁The performance of FIG.
In the calculation process, steps S24 to S25, S27,
Flow of returning to the main program via S29
Repeatedly, as a result, at a predetermined time when the arithmetic processing is performed
The counter value N is incremented and increased for each interval ΔT.
It During this period, the first rough road determination control flag F₁To
The second bad road determination is also made in step S28 where “1” is set.
Control flag F₂Is set to "1" in step S35
Since there is no transition, both bad road determination control flag F₁，
F₂Both are continuously reset to "0".

[0071] Then at the time t _22, since the wheel acceleration V'w _j keeps increasing calculated in step S23 in the arithmetic processing of Fig. 9 which exceeds the first predetermined value V'w _01, in step S26 However, the counter value N read in step S22 by repeating the increment here is "0".
Therefore, the process proceeds to step S32. However,
The counter value N has not yet reached its maximum value N _MAX , and therefore the process proceeds to step S34, but the first rough road determination control flag F ₁ is still reset to "0", so the step In S33, the first rough road determination control flag F ₁ is continuously reset to “0”,
Then, the process proceeds to step S36, and the counter value N is "0".
To the main program after updating and storing them in the storage device 25c. Then, the pulsating wheel acceleration / deceleration V'w _j eventually starts to decrease beyond its maximum value, but exceeds the first predetermined value V'w ₀₁ until the next time t _23. Therefore, during that period, the step S24 is performed. The process proceeds from step S26 to step S26. In step S26, since the counter value N remains "0", the flow of returning to the main program is repeated. During this time, the first and second rough road determination control flags F ₁ , F
Both ₂ are still reset to "0".

Next, at the time t ₂₃ , the continuously decreasing acceleration / deceleration V′w _j calculated in step S23 of the arithmetic processing of FIG. 9 becomes smaller than the first predetermined value V′w ₀₁ .
The process proceeds from step S24 to step S25, and since the wheel acceleration / deceleration V'w _j is larger than the second predetermined value V'w ₀₂ , the process then proceeds to step S27. Since the counter value N is still "0", step S29. And the counter value N is incremented before returning to the main program. Then, the pulsating wheel acceleration / deceleration V′w _j starts increasing from the decreasing direction over its minimum value, but since the vehicle has not yet entered the rough road, until the next time t ₂₄ , the wheel concerned. The acceleration / deceleration V′w _j does not fall below the second predetermined value V′w ₀₂ or above the first predetermined value V′w _01, and therefore, in the calculation processing of FIG. 9, steps S24 to S25, The flow of returning to the main program through S27 and S29 is repeated, and as a result, the counter value N is incremented and incremented every predetermined time ΔT in which the arithmetic processing is performed. Also, during this period,
Both the second rough road determination control flags F ₁ and F ₂ are continuously reset to “0”.

Next, at time t ₂₄ , the continuously increasing wheel acceleration / deceleration V'w _j calculated in step S23 of the arithmetic processing of FIG. 9 exceeds the first predetermined value V'w _01, and the process proceeds to step S26. However, since the counter value N obtained by repeating the increment is not "0", the process proceeds to step S32.
Since the counter value N has not reached the maximum value N _MAX yet, the process proceeds to step S34, and the first rough road determination control flag F ₁ is still reset to "0", so the process proceeds to step S33. Then, the first rough road determination control flag F ₁ is continuously reset to “0”, then the process proceeds to step S36, the counter value N is reset to “0”, and these are updated and stored in the storage device 25c. To return to the main program. Then, the pulsating wheel acceleration / deceleration V'w _j eventually starts to decrease beyond its maximum value, but exceeds the first predetermined value V'w ₀₁ until the next time t ₂₅ , during which time from step S24. Step S26
However, since the counter value N remains "0" in step S26, the flow for returning to the main program is repeated. During this time, the first and second rough road determination control flags F ₁ and F ₂ are both “0”.
Remains reset to.

Next, at the time t ₂₅ , the continuously decreasing wheel acceleration / deceleration V'w _j calculated in step S23 of the calculation process of FIG. 9 becomes smaller than the first predetermined value V'w ₀₁ .
The process proceeds from step S24 to step S25, and since the wheel acceleration / deceleration V'w _j is larger than the second predetermined value V'w ₀₂ , the process then proceeds to step S27. Since the counter value N is still "0", step S29. And the counter value N is incremented before returning to the main program. Then, the wheel acceleration / deceleration V′w _j that continues to decrease until the next time t ₂₆ described later is the second predetermined value V′w.
It does not fall below ₀₂ or above the first predetermined value V′w _01, and therefore, in the calculation processing of FIG.
Then, the flow of returning to the main program through steps S25, S27, S29 is repeated. As a result,
The counter value N is set every predetermined time ΔT in which the arithmetic processing is performed.
Is incremented and increased. Further, during this period, both the first and second rough road determination control flags F ₁ and F ₂ are continuously reset to “0”.

However, since the vehicle has entered the rough road at the time t ₂₅ , the amplitude of the wheel acceleration / deceleration V′w _j becomes large, and as a result, the decreasing wheel acceleration / deceleration V′w _j becomes the time t.
_{At 26,} it fell below the second predetermined value V′w ₀₂ . Accordingly, at this time t ₂₆ , the continuously decreasing wheel acceleration / deceleration V′w _j calculated in step S23 of the calculation process of FIG. 9 becomes smaller than the first predetermined value V′w ₀₁ , and therefore steps S24 to S24 are performed. Since the wheel acceleration / deceleration V'w _j is smaller than the second predetermined value V'w _{02 in} S25, the process proceeds to S28, in which the first rough road determination control flag F ₁ is set to "1". Then, the process proceeds to step S27. Then, at this point, the counter value N that has been continuously incremented is still smaller than the maximum value N _{MAX, so that the process} proceeds to step S29 to increment the counter value N and then returns to the main program. Then, the pulsating wheel acceleration / deceleration V'w _j
After a while, it starts increasing from the decreasing direction over its minimum value, but until the next time t ₂₇ , the wheel acceleration / deceleration V′w _j continues to fall below the second predetermined value V′w _02. From step S24, S25 to step S28, the first
The rough road determination control flag F ₁ is continuously set to “1”, and the flow of returning from the step S27 to the step S29 and returning to the main program is repeated. Is incremented and increased. During this period, the control flag F ₂ is continuously reset to "0" because the process does not proceed to step S35 where the second rough road determination control flag F ₂ is set to "1".

Next, at the time t ₂₇ , since the continuously increasing wheel acceleration / deceleration V′w _j calculated in step S23 of the arithmetic processing of FIG. 9 exceeds the second predetermined value V′w ₀₂ , the step S24 is executed. Through step S25 to step S27
The counter value N is still the maximum value N at this point.
_Since it is smaller than _{MAX, the} routine proceeds to step S29, where the counter value N is incremented, and then the next time t _28.
Until then, since the wheel acceleration / deceleration V'w _j does not exceed the first predetermined value V'w ₀₁ , steps S24 to S25, S27, S29 in the calculation process of FIG. 9 are performed.
After that, the flow of returning to the main program is repeated, and as a result, the predetermined processing time ΔT
The counter value N is incremented and increased each time. Further, during this period, the first rough road determination control flag F ₁ is continuously set to “1”, and the second rough road determination control flag F ₂ is continuously reset to “0”.

Next, at the time t ₂₈ , since the continuously increasing wheel acceleration / deceleration V'w _j calculated in step S23 of the arithmetic processing of FIG. 9 exceeds the first predetermined value V'w ₀₁ , the process proceeds to step S26. Since the counter value N which has been shifted and incremented is not "0", the process proceeds to step S32, and since the counter value N has not yet reached its maximum value N _MAX , the process proceeds to step S34. 1
Since the rough road determination control flag F ₁ is set to "1", the process proceeds to step S35. In this step S35, the wheel acceleration / deceleration V'w _j exceeds the first predetermined value V'w ₀₁ at the time t ₂₅ and falls below the second predetermined value V'w ₀₂ at the time t ₂₆ to determine the rough road traveling. It is recognized from the fact that the first rough road determination control flag F ₁ is set to "1" that a sufficiently large amplitude is generated, and the elapsed time t from the time t ₂₅ to the time t ₂₈ is recognized. Since (= N · ΔT) is shorter than a predetermined elapsed time t ₀ (= N _MAX · ΔT) corresponding to a short cycle of the wheel acceleration / deceleration that occurs during traveling on the rough road, the two rough road traveling determination conditions described above are satisfied. It is determined that the vehicle is satisfied, and it is determined that the vehicle is traveling on a rough road. As a result, the second rough road determination control flag F ₂ is set to "1", and then the process proceeds to step S33 to determine the first rough road. The control flag F ₁ is reset to “0”, then the process proceeds to step S36 and the counter The value N is reset to "0", these are updated and stored in the storage device 25c, and then the main program is restored. Then, the pulsating wheel acceleration / deceleration V′w _j eventually starts to decrease beyond its maximum value, but exceeds the first predetermined value V′w ₀₁ until the next time t ₂₉ , and during that period from step S24. The process proceeds to step S26, but since the counter value N remains "0" in step S26, the flow of returning to the main program as it is is repeated. During this time, the first rough road determination control flag F ₁ is “0” and the second rough road determination control flag F ₂ is “1”.
Remains set to.

Next, at the time t ₂₉ , the continuously decreasing wheel acceleration / deceleration V'w _j calculated in step S23 of the arithmetic processing of FIG. 9 becomes smaller than the first predetermined value V'w ₀₁ ,
The process proceeds from step S24 to step S25, and since the wheel acceleration / deceleration V'w _j is larger than the second predetermined value V'w ₀₂ , the process then proceeds to step S27. Since the counter value N is still "0", step S29. And the counter value N is incremented before returning to the main program. The wheel acceleration / deceleration V′w _j , which continues to decrease until the next time t ₃₀ described later, is the second predetermined value V′w.
It does not fall below ₀₂ or above the first predetermined value V′w _01, and therefore, in the calculation processing of FIG.
Then, the above flow of returning to the main program through steps S25, S27, S29 is repeated, and as a result, the counter value N is incremented and incremented every predetermined time ΔT in which the arithmetic processing is performed. During this period, the first rough road determination control flag F ₁ remains set to “0” and the second rough road determination control flag F ₂ remains set to “1”.

Next, at the time t ₃₀ , _the decreasing wheel acceleration / deceleration V'w _j falls below the second predetermined value V'w _02, and as a result, in the arithmetic processing of FIG.
25, the process proceeds to step S28, and the first rough road determination control flag F ₁ is set to "1", and then step S2.
Move to 7. At this point, the counter value N that has been continuously incremented from the time t ₂₉ is still the maximum value N.
_{Since it is} smaller than _{MAX, the process} proceeds to step S29 to increment the counter value N and then returns to the main program. Then, the pulsating wheel acceleration / deceleration V′w _j begins to increase beyond the minimum value from the decreasing direction, but until the next time t ₃₁ , the wheel acceleration / deceleration V′w _j is the second predetermined value. In order to keep below V'w ₀₂ , the above step S
24, from S25 to S28, the first rough road determination control flag F ₁ is continuously set to “1”, and the flow of returning from S27 to S29 to the main program is repeated. The counter value is incremented and increased every predetermined time ΔT in which the arithmetic processing is performed. During this period, the control flag F ₂ is continuously set to "1" because the process does not proceed to step S30 of resetting the second rough road determination control flag F ₂ to "0".

Next, at the time t ₃₁ , since the continuously increasing wheel acceleration / deceleration V'w _j calculated in step S23 of the arithmetic processing of FIG. 9 exceeds the second predetermined value V'w ₀₂ , the step S24 is executed. Through step S25 to step S27
The counter value N is still the maximum value N at this point.
_Since it is smaller than _{MAX, the process} proceeds to step S29, the counter value N is incremented, and then the next time t _32.
Until then, since the wheel acceleration / deceleration V'w _j does not exceed the first predetermined value V'w ₀₁ , steps S24 to S25, S27, S29 in the calculation process of FIG. 9 are performed.
After that, the flow of returning to the main program is repeated, and as a result, the predetermined processing time ΔT
The counter value N is incremented and increased each time. During this period, the first and second rough road determination control flags F ₁ , F ₂
Both continue to be set to "1".

Next, at the time t₃₂Then, in the calculation processing of FIG.
Wheel acceleration / deceleration that continues to increase calculated in step S23
V'w_jIs the first predetermined value V'w₀₁In order to cross the
Go to step S26 and repeat incrementing to the maximum value.
N_MAXStep S according to the counter value N that has not reached
The process proceeds from step 32 to step S34, and at this time the first bad road judgment
Constant control flag F₁Is set to “1”,
Up S35 and the second rough road determination control flag F₂To
Continue to set to "1", then move to step S33
1st rough road judgment control flag F₁Is reset to “0”,
Then, the process proceeds to step S36, and the counter value N is "0".
Reset them to the storage device 25c and update them.
Then return to the main program. And pulsates
Wheel acceleration / deceleration V'w_jEventually decreases beyond its maximum value
But at the next time t₃₃Up to the first predetermined value V'w₀₁To
It is higher than the above, and during
The process proceeds to step S26, but in this step S26, the
The counter value N remains “0”, so
The flow of returning to the program is repeated.
During this time, the first rough road determination control flag F₁Is "0", the second
Bad road judgment control flag F ₂Remains set to "1"
is there.

Next, at the time t₃₃Then, in the calculation processing of FIG.
Wheel acceleration / deceleration that continues to decrease calculated in step S23
V'w_jIs the first predetermined value V'w₀₁To be smaller,
Shift from step S24 to step S25
Speed V'w_jIs the second predetermined value V'w₀₂Next to be larger
Then, the process proceeds to step S27, and the counter value N is still
Since it is "0", the process proceeds to step S29 and the counter value
After incrementing N, return to the main program.
Return, next time t described later₃₄Until then, repeat this flow
As a result of returning, as a result, the predetermined time during which the arithmetic processing is performed
The counter value N is incremented and increased for each ΔT.
It During this period, the first rough road determination control flag F ₁Is
The second rough road determination control flag F is set to "0".₂Is set to "1"
It is still on.

Next, at the time t₃₄so_,Wheels decrease
Speed V'w_jIs the second predetermined value V'w₀₂Below that
As a result, in the arithmetic processing of FIG.
After 25, the process proceeds to step S28, and the first rough road determination is made.
Control flag F₁Is set to "1" and then step S2
Move to 7. Then, at this point, the time t₂₉From
The counter value N that continues to be incremented is still the maximum value N
_MAXSince it is smaller, the process proceeds to step S29 and the counter
After incrementing the value N, enter the main program
Return. And pulsating wheel acceleration / deceleration V'w_jHayaga
Then begins to increase beyond the minimum value from the decreasing direction, but
The next time t, which will be described later at least₃₅Until the wheel is adjusted
Speed V'w_jIs the second predetermined value V'w₀₂To keep below
From step S24, S25 to step S28
Transition to the first rough road determination control flag F ₁Set to "1"
Continue, and through steps S27 to S29
Repeat the flow of returning to the main program,
As a result, the calculation is performed at every predetermined time ΔT in which the arithmetic processing is performed.
The counter value is incremented and increased. During this time,
2 Bad road judgment control flag F₂To reset to 0
Control flag F since there is no transition to step S30
₂Keeps being set to "1".

Next, at the time t ₃₅ , the continuously increasing wheel acceleration / deceleration V′w _j calculated in step S23 of the calculation process of FIG. 9 exceeds the second predetermined value V′w _02, and therefore the step S24 is performed. Through step S25 to step S27
The counter value N is still the maximum value N at this point.
Since less than _MAX proceeds to step S29 to increment the counter value N, then, until the next time t ₃₆ at least below, the wheel acceleration V'w _j
Does not exceed the first predetermined value V′w ₀₁ , the steps S24 to S2 in the calculation process of FIG.
The flow of returning to the main program through 5, S27 and S29 is repeated, and as a result, the counter value N is incremented and incremented every predetermined time ΔT in which the arithmetic processing is performed. Further, during this period, both the first and second rough road determination control flags F ₁ and F ₂ are continuously set to "1".

However, at the time t₃₄And once out of the bad road
For a vehicle that has run out, the calculation is performed in step S23 of the calculation process of FIG.
Wheel acceleration / deceleration V'w_jIs the time t₃₄Since
It will be long afterwards. Therefore, the time t₃₃To the calculation process of FIG. 9
Is incremented and incremented every predetermined time ΔT
The counter value N that continues to be added eventually becomes the time t₃₆And that
Maximum value N_MAXMaintained at. Here, in the calculation process of FIG.
In step S24, the wheel acceleration / deceleration V'w_jIs the first predetermined
Value V'w₀₁Since it is smaller, the process proceeds to step S25
Wheel acceleration / deceleration V'w_jIs the second predetermined value V'w₀₂Greater than
To move to step S27,
And the counter value N is the maximum value N_MAXTo be step S
Move to 30. In this step S30, the time t
₃₃From time t₃₆Until the elapsed time t (= N · ΔT)
Corresponds to the short cycle of wheel acceleration / deceleration that occurs when driving on rough roads
Predetermined elapsed time t₀(= N_MAX・ ΔT) or the same
Since it is longer than, it is judged that the vehicle is not driving on a bad road,
As a result, the second evil indicating that the vehicle is traveling on the rough road
Road determination control flag F₂Is reset to “0” and then
The first rough road determination control flag F which is the rough road traveling determination condition
₁Also resets to "0" and then returns to the main program
To do. And this time t₃₆From the time t ₃₇For up to
, Wheel acceleration / deceleration V'w_jIs the first predetermined value V'w₀₁Less than
The counter value N is the maximum value N_MAXMaintained in
Therefore, in the calculation processing of FIG.
Main program after going through S25, S27, S30 and S31
The flow to return to Gram is repeated,
2 Bad road judgment control flag F₁, F₂Both reset to “0”
Continue to be treated.

Next, at the time t ₃₇ , the continuously decreasing wheel acceleration / deceleration V'w _j calculated in step S23 of the arithmetic processing of FIG. 9 becomes smaller than the first predetermined value V'w ₀₁ ,
The process proceeds from step S24 to step S25, and since the wheel acceleration / deceleration V'w _j is larger than the second predetermined value V'w ₀₂ , the process then proceeds to step S27. Since the counter value N is still "0", step S29. And the counter value N is incremented before returning to the main program. Then, the wheel acceleration / deceleration V′w _j that continues to decrease until the next time t ₃₉ described later is the second predetermined value V′w.
It does not fall below ₀₂ or above the first predetermined value V′w _01, and therefore, in the calculation processing of FIG.
Then, the flow of returning to the main program through steps S25, S27, S29 is repeated. As a result,
The counter value N is set every predetermined time ΔT in which the arithmetic processing is performed.
Is incremented and increased. Further, during this period, both the first and second rough road determination control flags F ₁ and F ₂ are continuously reset to “0”.

However, at time t ₃₈ , the vehicle again entered the rough road, so that the amplitude of the wheel acceleration / deceleration V'w _j becomes large and the fluctuation cycle thereof becomes short. Therefore, at this time t ₃₉ , the continuously decreasing wheel acceleration / deceleration V′w _j calculated in step S23 of the calculation process of FIG. 9 becomes smaller than the first predetermined value V′w ₀₁ , and therefore steps S24 to S24 are performed. Since the wheel acceleration / deceleration V'w _j is smaller than the second predetermined value V'w _{02 in} S25, the process proceeds to S28, in which the first rough road determination control flag F ₁ is set to "1". After that, the process proceeds to step S27, and at this time, the counter value N that has been continuously incremented is still the maximum value N _MAX.
Since it is smaller, the process proceeds to step S29 and the counter value N
After incrementing, return to the main program. Then, the pulsating wheel acceleration / deceleration V′w _j starts to increase beyond its minimum value from the decreasing direction, but until the next time t ₄₀ , the wheel acceleration / deceleration V′w _j is the second predetermined value. In order to keep below V'w ₀₂ , the above step S2
4, the flow from S25 to step S28 is continued to set the first rough road determination control flag F ₁ to “1”, and the flow from step S27 to step S29 to return to the main program is repeated. The counter value is incremented and increased every predetermined time ΔT in which the arithmetic processing is performed. During this period, the control flag F ₂ is continuously reset to "0" because the process does not proceed to step S35 where the second rough road determination control flag F ₂ is set to "1".

Next, at the time t ₄₀ , since the continuously increasing wheel acceleration / deceleration V'w _j calculated in step S23 of the calculation process of FIG. 9 exceeds the second predetermined value V'w ₀₂ , the step S24 is executed. Through step S25 to step S27
The counter value N is still the maximum value N at this point.
_Since it is smaller than _{MAX, the} routine proceeds to step S29, where the counter value N is incremented, and then the next time t _41.
Until then, since the wheel acceleration / deceleration V'w _j does not exceed the first predetermined value V'w ₀₁ , steps S24 to S25, S27, S29 in the calculation process of FIG. 9 are performed.
After that, the flow of returning to the main program is repeated, and as a result, the predetermined processing time ΔT
The counter value N is incremented and increased each time. Further, during this period, the first rough road determination control flag F ₁ is continuously set to “1”, and the second rough road determination control flag F ₂ is continuously reset to “0”.

Next, at the time t₄₁Then, in the calculation processing of FIG.
Wheel acceleration / deceleration that continues to increase calculated in step S23
V'w_jIs the first predetermined value V'w₀₁In order to cross the
A counter that repeats increments after moving to step S26.
Since the data value N is not "0", the process proceeds to step S32.
However, this counter value N is still the maximum value N_MAXHas reached
If not, the process proceeds to step S34, but at this time, the first
Bad road judgment control flag F₁Is set to "1"
Then, the process proceeds to step S35. In this step S35
Is the time t₂₈The same two evils as above
The vehicle runs on a bad road as if it satisfies the road running determination condition.
It is judged that it is in the middle, and as a result, the second rough road judgment control frame
Rag F₂Is set to "1" and then the process proceeds to step S33.
1st rough road judgment control flag F₁Reset to "0"
Then, the process proceeds to step S36 and the counter value N is
Reset them to "0" and update them to the storage device 25c.
After making a new memory, return to the main program. And
Pulsating wheel acceleration / deceleration V'w_jEventually beyond that maximum
Begins to decrease, but at the next time t₄₂Up to the first predetermined value
V'w ₀₁, And during that time, in the step S24
From step S26 to step S26, but in step S26
Since the counter value N remains "0",
The flow of returning to the main program as it is repeated
To be done. During this time, the first rough road determination control flag F₁Is "0"
The second rough road determination control flag F₂Is set to "1"
It remains.

Next, at time t ₄₂ , since the wheel acceleration / deceleration V′w _j that continues to decrease and is calculated in step S23 of the arithmetic processing of FIG. 9 becomes smaller than the first predetermined value V′w ₀₁ ,
The process proceeds from step S24 to step S25, and since the wheel acceleration / deceleration V'w _j is larger than the second predetermined value V'w ₀₂ , the process then proceeds to step S27. Since the counter value N is still "0", step S29. To the main program after the counter value N is incremented to return to the main program, and the wheel acceleration / deceleration V′w _j continues to decrease until the next time t ₄₃ described later is the second predetermined value V′w. _Since it does not fall below _{02 or} exceeds the first predetermined value V′w ₀₁ , the above flow is repeated, and as a result, the counter value N is incremented and increased at every predetermined time ΔT in which the arithmetic processing is performed. During this period, the first rough road determination control flag F ₁ is “0” and the second rough road determination control flag F ₂ is “1”.
Remains set to.

Next, at the time t ₄₃ , _the decreasing wheel acceleration / deceleration V'w _j falls below the second predetermined value V'w _02, and as a result, in the arithmetic processing of FIG.
25, the process proceeds to step S28, and the first rough road determination control flag F ₁ is set to "1", and then step S2.
Move to 7. At this point, the counter value N that has been continuously incremented from the time t ₂₉ is still the maximum value N.
_{Since it is} smaller than _{MAX, the process} proceeds to step S29 to increment the counter value N and then returns to the main program. Then, the pulsating wheel acceleration / deceleration V′w _j begins to increase beyond the minimum value from the decreasing direction, but until the next time t ₄₄ , the wheel acceleration / deceleration V′w _j is the second predetermined value. In order to keep below V'w ₀₂ , the above step S
24, from S25 to S28, the first rough road determination control flag F ₁ is continuously set to “1”, and the flow of returning from S27 to S29 to the main program is repeated. The counter value is incremented and increased every predetermined time ΔT in which the arithmetic processing is performed. During this period, the control flag F ₂ is continuously set to "1" because the process does not proceed to step S30 of resetting the second rough road determination control flag F ₂ to "0".

Next, at the time t ₄₄ , since the continuously increasing wheel acceleration / deceleration V′w _j calculated in step S23 of the arithmetic processing of FIG. 9 exceeds the second predetermined value V′w ₀₂ , the step S24 is executed. Through step S25 to step S27
The counter value N is still the maximum value N at this point.
_Since it is smaller than _{MAX, the} routine proceeds to step S29, where the counter value N is incremented, and thereafter, until the next time (not shown) in which the wheel acceleration / deceleration V'w _j exceeds the first predetermined value V'w _01. , Step S in the arithmetic processing of FIG.
The flow of returning from 24 to steps S25, S27, S29 and returning to the main program is repeated, and as a result, the counter value N is incremented and increased at every predetermined time ΔT in which the arithmetic processing is performed. Also, during this time,
Both the first and second rough road determination control flags F ₁ and F ₂ are “1”
Continues to be set.

As described above, according to the arithmetic processing of FIG.
For example, the time t when the vehicle starts traveling on a rough road _{twenty five}Just after
Tick t₂₈2nd rough road control flag F₂Is set to "1"
And the time t when driving on a rough road is completed₃₄Time t
₃₅Until this second rough road running control flag F₂Is set to “1”
This time t₃₅Is reset by
Time t when traveling on a rough road again₃₈Time t₄₁
2nd rough road control flag F₂Is set to "1"
Therefore, the second rough road traveling control flag F₂Is set to “1”
It is possible to accurately judge the bad road driving of the vehicle by being
During this rough road traveling judgment, the calculation processing of FIG.
Wheel cylinders 2FL to 2RR with wheels 1FL to 1RR
The supply pressure to the master cylinder pressure is
Since the pressure reduction control of the wheel cylinder pressure is virtually prohibited
It suppresses the decrease in braking force, resulting in a decrease in vehicle deceleration.
It is possible to suppress the braking distance from being lengthened.

Here, step S24 in the control logic shown in FIG. 6 corresponds to the first comparing means of the anti-skid control device according to claim 2 of the present invention, and steps S24, S27 and S29 are the same as the following. It corresponds to measuring means, step S25 corresponds to second comparing means, and steps S24, S25, S28 and steps S32, S3.
4, S35 corresponds to a rough road traveling determination means.

In the above-mentioned embodiment, only the case of the three-channel anti-skid control device in which the wheel speed on the rear wheel side is detected by the common wheel speed sensor has been described in detail, but not limited to this, the left and right wheel on the rear wheel side. With respect to the above, it is also possible to develop a so-called four-channel anti-skid control device in which a wheel speed sensor is individually provided and corresponding actuators are provided for the left and right wheel cylinders.

In the above embodiment, the case where the select high wheel speed is selected as the wheel speed selection value has been described. However, the select high wheel speed is selected during the anti-skid control and the lowest select speed is selected during the non-anti-skid control. The low wheel speed may be selected. The anti-skid control device of the present invention is not limited to the rear-wheel drive vehicle,
It can also be applied to front-wheel drive vehicles and four-wheel drive vehicles.

Further, although the case where the microcomputer is applied as the braking pressure control device 18 has been described in the above embodiment, the invention is not limited to this, and electronic circuits such as a comparison circuit, an arithmetic circuit and a logic circuit are combined. It can also be configured.

[0098]

As described above, according to the anti-skid control device of the present invention, the pulsation of the wheel speed generated during traveling on a rough road is compared with a predetermined value of the amplitude of the wheel acceleration / deceleration. The wheel acceleration / deceleration is greater than a predetermined amplitude and the cycle is shorter than the predetermined cycle, while the cycle is converted by the elapsed time from the predetermined value comparison result and compared with the predetermined time. Since it is possible to determine that the vehicle is traveling on a rough road, it is possible to forcibly suppress the decrease in the braking force of each wheel when this rough road traveling is determined and shorten the braking distance in a stable state of the vehicle. it can.

Further, in the anti-skid control device according to the second or third aspect of the present invention, the minimum / maximum value of the amplitude of the wheel acceleration / deceleration is monitored by two predetermined values to determine the true value of the wheel acceleration / deceleration. Since the amplitude can be monitored, it is possible to more accurately determine the rough road traveling.

[Brief description of drawings]

FIG. 1 is a basic configuration diagram showing a schematic configuration of an anti-skid control device of the present invention.

FIG. 2 is a block diagram showing an example of an anti-skid control device of the present invention.

3 is a configuration diagram showing an example of an actuator used in the anti-skid control device of FIG. 2. FIG.

FIG. 4 is an explanatory diagram showing a control map of the braking pressure control circuit shown in FIG.

FIG. 5 is a time chart for explaining wheel speeds, vehicle speeds, and vehicle body decelerations that occur under normal anti-skid control during traveling on a rough road.

FIG. 6 is a flowchart showing a first embodiment of rough road traveling determination of the present invention executed by the anti-skid control device of FIG.

7 is a flowchart showing an example of selection control between rough road running control and normal anti-skid control executed by the anti-skid control device of FIG.

FIG. 8 is a time chart for explaining the operation of the calculation processing of the rough road traveling determination of FIG.

9 is a flowchart showing a second embodiment of the rough road traveling determination of the present invention executed by the anti-skid control device of FIG.

FIG. 10 is a time chart for explaining the operation of the calculation processing for rough road traveling determination in FIG.

[Explanation of symbols]

 1FL to 1RR are wheels 2FL to 2RR are wheel cylinders 3FL to 3R are wheel speed sensors 4 are brake pedals 5 are master cylinders 6FL to 6R are actuators 7 Pipes 8 are inflow valves 9 Outflow valves 10 are hydraulic pumps 11 are non-returns Valve 12 is an accumulator 13 is a longitudinal acceleration sensor 15FL to 15R is a wheel speed calculation circuit 16 is a select high switch 17 is a pseudo vehicle speed calculation circuit 18 is a braking pressure control circuit CR is a controller

Claims (3)

[Claims] 1. An actuator capable of adjusting a supply pressure to a braking cylinder provided on each wheel of a vehicle in accordance with a predetermined command signal, a vehicle speed detecting means for detecting a front-rear direction ground speed of the vehicle, and Wheel speed detection means for detecting the wheel speed of the wheels, wheel acceleration / deceleration detection means for detecting the wheel acceleration / deceleration of each wheel, and a value corresponding to the running state and braking state of the vehicle based on the detection values of the detection means. In the anti-skid control device including an actuator control unit that outputs the command signal to the actuator, a comparison unit that compares a wheel acceleration / deceleration detection value from the wheel acceleration / deceleration detection unit with a predetermined value, and the comparison unit. And a time measuring unit capable of measuring time according to the comparison value of the An anti-skid control device comprising a rough road judging means for judging traveling on a rough road. 2. An actuator capable of adjusting a supply pressure to a braking cylinder provided on each wheel of a vehicle according to a predetermined command signal, a vehicle speed detecting means for detecting a front-rear direction ground speed of the vehicle, and Wheel speed detection means for detecting the wheel speed of the wheels, wheel acceleration / deceleration detection means for detecting the wheel acceleration / deceleration of each wheel, and a value corresponding to the running state and braking state of the vehicle based on the detection values of the detection means. In the anti-skid control device including the actuator control means for outputting the command signal to the actuator, first comparison means for comparing the wheel acceleration / deceleration detection value from the wheel acceleration / deceleration detection means with a first predetermined value. A time measuring means capable of measuring time according to the comparison value of the first comparing means; a wheel acceleration / deceleration detection value from the wheel acceleration / deceleration detecting means;
And a second comparison means for comparing the predetermined value of the second comparison means with the actuator control means. An anti-skid control device characterized by comprising rough road determining means. 3. A wheel acceleration / deceleration detection value detected by the wheel acceleration / deceleration detection means, a first predetermined value compared by the first comparison means, and a second comparison value compared by the second comparison means. The anti-skid control device according to claim 2, wherein the second predetermined value is smaller than the first predetermined value in the relationship with the predetermined value.