JPH068102B2 - Anti-skidding control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention generates a pseudo vehicle body speed based on the detected wheel speed at that time when a predetermined wheel deceleration is reached. The present invention relates to an improvement of an anti-skid control device that performs a pressure reduction control of a brake hydraulic pressure when a slip ratio determined by a vehicle speed and a detected wheel speed reaches a preset set value.

[Conventional technology]

As shown in FIG. 11, the friction coefficient μ between the wheel and the road surface of the vehicle generally becomes maximum μ (max) at a predetermined slip ratio λ _o (15%), at which time the braking efficiency of the vehicle becomes maximum. .

Therefore, in normal anti-skid control, when the vehicle is being braked, the slip ratio λ of the wheels is always the slip ratio λ.
_The braking fluid pressure is controlled to be increased, reduced, or maintained so that the value becomes a value near _o .

As a result, the stopping distance at the time of braking can be shortened and steering stability can be ensured.

By the way, in the actual anti-skid controller,
The slip ratio λ is obtained by detecting the vehicle body speed V _c and the wheel speed V _w from the relationship of λ = 1−V _w / V _c , but the vehicle body speed V _c during braking is directly detected. Since it is technically difficult to do so, the present inventors propose to create a pseudo vehicle body speed (hereinafter referred to as a pseudo vehicle speed V _i ) based on the detected wheel speed during braking.

Conventionally, in this type of anti-skid controller, for example, braking control as shown in FIG. 12 has been performed (for example, Japanese Patent Publication No. 53-13751 and Japanese Patent Publication No. 50-24185).

This is because when the wheel speed V _w decreases during braking and the wheel deceleration increases to reach a predetermined value b ₁ , the pseudo vehicle speed V decreases from the detected wheel speed V _b at that time with a predetermined inclination.
generate _i .

The gradient of the pseudo vehicle speed V _i may be a fixed value so as to be an experimental value, for example, 0.4 G, which is obtained by experimentally obtaining a general deceleration tendency during sudden braking. It may be sequentially variable based on the decreasing tendency of a plurality of detected wheel speeds each time the wheel deceleration b ₁ is reached.

Then, when the detected wheel speed V _w falls below the target wheel speed V _wo corresponding to the slip ratio λ ₀ λ ₀ = 1-V _wo / V _i = 15% at which the braking efficiency becomes maximum, the braking fluid pressure P is reduced. The control is performed so that the wheel speed V _w does not excessively decrease from the target wheel speed V _wo .

In this example, further provided so as to control the brake hydraulic pressure based on wheel acceleration, until the detected wheel speed V _w drops below the target wheel speed V _wo, the wheel deceleration is a predetermined value b
_The pressure increase control is performed in the range of ₁ (deceleration) to a ₁ (acceleration), and the holding control is performed until the wheel deceleration reaches b ₁ , and when the wheel acceleration is a predetermined value a ₁ or more, the braking fluid pressure is increased. Holding control is performed (note that V in FIG. 12 is
_c is the true vehicle speed).

In such an anti-skid control device, when the wheel deceleration reaches the predetermined value b ₁ , the pseudo vehicle speed V _i is generated based on the detected wheel speed V _b at that time, and the wheel speed V _w is generated.
Is reached at a target wheel speed V _wo that is 85% of the pseudo vehicle speed V _i (that is, every time the slip ratio λ reaches a predetermined value λ ₀ ) until the wheel acceleration reaches a predetermined value a _1. Since the hydraulic pressure is controlled to be reduced, the wheel speed V _w does not excessively decrease from the target wheel speed V _wo, and efficient braking that prevents wheel lock is possible.

[Problems to be Solved by the Invention]

However, for example, when the vehicle approaches a high μ road surface having a large friction coefficient μ during braking, the wheel speed V _w temporarily becomes higher than the actual vehicle body speed V _c due to the pressure reduction control of the braking hydraulic pressure.

For this reason, this high level wheel speed V _w is reduced by subsequent brake fluid pressure increase control and the like, and the wheel deceleration is the predetermined value b ₁
The pseudo vehicle speed V _i generated when the vehicle speed reaches V is also at a high level as a whole because the detected wheel speed V _b at that time has a large value.

Therefore, the target wheel speed V _wo is also at a high level,
Nevertheless desired to further reduce the original wheel speed V _w, since below the relatively large wheel speed V _w at a the target wheel speed V _wo be, brake fluid pressure is the pressure reduction control, the stopping distance of the vehicle It was longer than the target stop distance.

In addition, the same situation occurs when a wheel spin occurs when the vehicle starts, and there is a risk that braking will not be applied even if the brake pedal is depressed immediately after the vehicle starts due to the pressure reduction control.

The present invention has been made in view of the above, and when the wheel speed sharply increases due to the pressure reduction control of the braking fluid pressure on the high μ road surface, etc., due to the high level pseudo vehicle body speed that occurs immediately after that. An object of the present invention is to provide an anti-skid control device in which the braking fluid pressure is controlled to be reduced under a relatively large wheel speed condition and the stop distance is prevented from being extended.

[Means for Solving the Problems]

In the present invention, when the predetermined wheel deceleration b ₁ is reached, the pseudo vehicle body speed V is calculated based on the detected wheel speed V _w at that time.
_i is generated, and the detected wheel speed V _w is lower than the target wheel speed V _wo obtained from the pseudo vehicle body speed V _i ,
A means (3) for detecting an acceleration a _w of a wheel after pressure reduction control in an anti-skid control device adapted to perform pressure reduction control of braking hydraulic pressure.
When, the predetermined predetermined time after the detection of the predetermined wheel acceleration a ₂ were characterized by comprising a means (61) for reducing a predetermined amount the target wheel speed V _wo.

[Action]

By thus configured, upon detecting a predetermined wheel acceleration a ₂ to means (3) is predetermined per unit (61) a predetermined time (between t ₄ ~t _10), forcing the target wheel speed V _wo In order to reduce the brake fluid pressure by a predetermined amount, the braking hydraulic pressure is reduced in a relatively large wheel speed state due to the high-level pseudo vehicle speed V _i generated immediately after that even if the wheel speed rapidly increases. It becomes possible to effectively prevent the stop distance from being extended due to the control.

〔Example〕

 Embodiments will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the basic configuration of an anti-skid control device according to the present invention. That is, basically, this anti-skid control device (anti-skid control circuit 100)
Is the wheel 10 output from the wheel speed sensor 1 during braking.
2 from the master cylinder 101 of the braking hydraulic system to the wheel cylinder 1 on the basis of the detection signal of the frequency proportional to the rotation speed.
Inflow valve 14 (hereinafter, EV valve 14
Switch control, and the outflow valve 1 provided in the preceding stage of the reservoir tank 104 and the pump 17 in the hydraulic pressure recovery path from the wheel cylinder 103 to the reservoir tank 104 and the pump 17 for recovering the hydraulic pressure to the master cylinder 101.
5 (hereinafter referred to as AV valve 15) switching control. The wheel cylinder 103 is driven by the switching signal of the EV valve 17 (hereinafter referred to as EV signal) and the switching signal of the AV valve 15 (hereinafter referred to as AV signal).
The hydraulic pressure of, that is, the braking hydraulic pressure is controlled as shown in the following table.

Here, the specific configuration of the anti-skid control circuit 100 is as shown in FIG. In the figure, a wheel speed detection circuit 3 for calculating a wheel speed V _w based on an output signal from a two-wheel speed sensor 1 and a wheel speed detection circuit 3, for example, differentiates the detected wheel speed signal from the wheel speed detection circuit 2 to accelerate the wheel acceleration. And an acceleration / deceleration detection circuit for detecting deceleration (negative acceleration). Reference numeral 4 is a pseudo vehicle speed generation circuit that generates a pseudo vehicle speed V _i (pseudo vehicle speed) necessary for detecting the slip ratio λ, and reference numeral 5 is a reference deceleration b ₁ that is the deceleration detected by the acceleration / deceleration detection circuit 3. It is a comparison circuit that outputs an H level signal (hereinafter referred to as b ₁ signal) when the above is reached, and the pseudo vehicle speed generation circuit 4 receives the b ₁ signal from the comparison circuit 5 every time it is input.
For example, the pseudo vehicle speed V _{i which} is a speed straight line having a predetermined constant slope from the detected wheel speed value output from the wheel speed detection circuit 2 at that time, or the detected wheel speed when the b ₁ signal was input last time and the current time The pseudo vehicle speed V _i, which is a speed straight line connecting the detected wheel speed of _{No. 1,} is output. Reference numeral 6 denotes a target wheel speed generation circuit. The target wheel speed generation circuit 6 has a structure as shown in FIG. 3, for example, as will be described later, and basically, the pseudo vehicle speed V _i from the pseudo vehicle speed generation circuit 4 is changed. braking efficiency based is to output a slip ratio _{λ 0 λ 0 = 1- (V} wo / V i) target wheel speed V _wo as a control target corresponding to the maximized.

7 inputs the target wheel speed V _wo from the target wheel speed generation circuit 6 and the detected wheel speed V _w from the wheel speed detection circuit 2, and when the detected wheel speed V _w is below the target wheel speed V _wo , H A comparison circuit that outputs a level signal (hereinafter referred to as a slip signal), and 8 outputs an H level signal (hereinafter referred to as an a ₁ signal) when the acceleration detected by the acceleration / deceleration detection circuit 3 becomes equal to or higher than the reference acceleration a _1. Similarly to the comparison circuit 5, the reference deceleration b is the detected deceleration from the acceleration / deceleration detection circuit 3.
It is a comparison circuit that outputs an H level signal (b ₁ signal) when it becomes ₁ or more. Then, the AND signal (AV signal) by the AND gate 10 of the inverted signal of the a ₁ signal from the comparison circuit 8 and the slip signal from the comparison circuit 7 is output by the driver 13
Input to the AV valve 15 via the AND circuit, and the a ₁ signal from the comparison circuit 8, the b ₁ signal from the comparison circuit 9 and the AND gate 1
The OR signal (EV signal) from the OR gate 11 and the output signal from 0 are input to the EV valve via the driver 12.

Reference numeral 16 is a re-trigger that outputs an H level signal (hereinafter referred to as an MR signal) for a predetermined time (for example, about 2 seconds) every time an output signal (AV signal) from the AND gate 10 is input, which is activated at the rising edge thereof. It is a bull timer, and the MR signal from the retriggerable timer 16 activates the hydraulic pressure recovery pump 17, while the pseudo vehicle speed generating circuit 4 is further controlled by the MR signal. (When the MR signal is at the H level, the original pseudo vehicle speed V _i is generated).

Here, the target wheel speed generation circuit 6 is, for example, as shown in FIG. In the figure, 60 is 0.85 as the pseudo vehicle speed value V _i sequentially output from the pseudo vehicle speed generation circuit 4.
0.85 × V _i as the target wheel speed V _wo output from the multiplication circuit 60 corresponds to the slip ratio λ ₀ (= 15%) which is regarded as the maximum braking efficiency. is there. Reference numeral 61 denotes a multiplication circuit for multiplying the pseudo vehicle speed value V _i by 0.60. 0.60 × V _i as the target wheel speed V _wo output from the multiplication circuit 61 is the slip ratio λ = 40.
It corresponds to%.

_Reference numeral 62 denotes the output of the target wheel speed _Vwo for the comparison circuit 7 in FIG.
The selector switch 63 switches the output to 1. The wheel acceleration α _w output from the acceleration / deceleration detection circuit 3 is compared with a predetermined reference value a ₂ , for example, a value corresponding to 10 G, and the wheel acceleration α _w is the reference value. A comparator circuit that outputs an H-level signal when it becomes a ₂ or more, and 64 is a timer that outputs an H-level signal for a predetermined time (about 100 ms) after the output from the comparator circuit 63 falls from H level to L level. The changeover switch 62 is controlled by the output signal Q from the timer 64, and switches to the multiplication circuit 60 side when the output signal Q is L level and to the multiplication circuit 61 side when the output signal Q is H level. It has become.

Next, the operation of this device will be described.

When the driver depresses the brake pedal to increase the braking hydraulic pressure (the hydraulic pressure in the wheel cylinder 103), the wheel speed decreases and the wheel speed speed (negative acceleration) increases accordingly. Here, the wheel deceleration is further increased to a predetermined value b ₁
When is reached, and output _{b 1} signal from the comparator circuit 9, the _{b 1} signal via the OR gate 11 (EV signal) by E
The V-valve 14 is activated and the braking hydraulic pressure is maintained at that time.
At this time, when the wheel deceleration reaches the predetermined value b ₁ ,
The pseudo vehicle speed generation circuit 4 outputs the pseudo vehicle speed V _i having a predetermined inclination from the detected wheel speed at that time, and at the same time, the changeover switch 62 in the target wheel speed generation circuit 6
Since it is held in the multiplication circuit 60, the target wheel speed V _wo corresponding to the slip ratio λ ₀ is output from the target wheel speed generation circuit 6.
(= 0.85 × V _i ) are sequentially output.

Then, when the wheel speed further decreases due to the holding of the brake hydraulic pressure at a high hydraulic pressure as described above and falls below the target wheel speed V _wo , a slip signal is output from the comparison circuit 7 and passed through the AND gate 10. The AV signal 15 is operated by the slip signal (AV signal), and the operational state of the EV valve 14 is maintained by the slip signal (EV signal) via the OR gate 11, and the braking hydraulic pressure is reduced.

When the braking fluid pressure is reduced in this way, the wheel speed and the wheel acceleration are restored accordingly, and the wheel acceleration is reduced to the predetermined value a.
Upon reaching the _{1, a 1} signal output from the comparator circuit 8, while the operation of the EV valve 14 is further sustained by the _{a 1} signal via the OR gate 11 (EV signal), the AND gate 10 by the _{a 1} signal Since the prohibition state is established, the AV valve 15 returns to the initial state, and the braking hydraulic pressure is maintained. If the braking hydraulic pressure is maintained even though the hydraulic pressure is relatively low in this way, it starts to decrease again when the wheel speed exceeds the target wheel speed (the slip signal disappears at this point) to some extent. The wheel acceleration also decreases from the value equal to or greater than the predetermined value a ₁ . Here, when the wheel acceleration falls below a predetermined value a ₁ , the a ₁ signal from the comparison circuit 8 falls, and the outputs from the comparison circuits 7 and 9 at that time are L level. As a result, the EV signal and the AV signal become L level, and the braking fluid pressure is increased again. Then, the wheel speed and the wheel acceleration further decrease, and thereafter, the same control of the brake hydraulic pressure as described above is sequentially repeated.

That is, the switching control of the braking hydraulic pressure during the braking is performed according to the control mode determined based on the wheel acceleration / deceleration α _w and the slip ratio λ (actually V _w / V _i ) as shown in FIG. .

In the process of controlling the brake hydraulic pressure as described above, for example, as shown in FIG. 5, the wheel speed V _w reaches the target wheel speed V _wo (= 0.85 × V _i ) at time t _1. When the braking hydraulic pressure P is controlled to be reduced and then the wheel acceleration reaches a ₁ at time t ₂ and the braking hydraulic pressure P is maintained at a relatively low hydraulic pressure, the wheel speed is increased due to a high μ road surface or the like. When the wheel acceleration rapidly rises and reaches a predetermined constant reference value a ₂ (time t ₃ ), the output of the comparison circuit 63 becomes H level.

Then, after the wheel acceleration reaches the peak and then decreases and falls below the reference value a ₂ at time t ₄ , the output signal from the comparison circuit 63 falls to the L level, and accordingly the timer 64.
Output Q becomes H level, and the changeover switch 62 is switched to the multiplication circuit 61 side. Then, the target wheel speed V
_wo is 0.60 × V _i output from the multiplication circuit 61. After that, the wheel acceleration further decreases and falls below the predetermined value a ₁ , the braking fluid pressure P is controlled to increase, the wheel speed V _w reaches a peak, and then starts to decrease again, and the wheel deceleration is predetermined at time t ₅ . When the value b ₁ is reached, a new pseudo wheel speed V _i is generated and the braking hydraulic pressure P is maintained.

Then, after the wheel deceleration reaches its peak due to the holding of the braking hydraulic pressure P and then recovers, the wheel speed V _w continues to decrease, and the time t _{6 when the} wheel speed V _w reaches 0.85 × V _i. Then (conventionally here is the pressure reduction control), since the output Q of the timer 64 holds the H level, the output of the target wheel speed generation circuit 6 holds 0.60 × V _i and the comparison circuit 7 The slip signal is not output, and the braking fluid pressure P maintains the holding fluid pressure.

By maintaining this hydraulic pressure, the wheel deceleration is reduced to a predetermined value b at time t _7.
When it returns to ₁ , the braking fluid pressure is controlled to be increased, the wheel speed V _w is further decreased, the wheel deceleration is also decreased to reach the predetermined value b ₁ again, and a new pseudo vehicle speed V _i is generated and braking is performed. The hydraulic pressure P is maintained at a relatively high hydraulic pressure.

Here, at time t ₉ when the wheel speed further decreases and reaches 0.85 × V _i , the output Q from the target wheel speed generation circuit 6 is maintained because the output Q of the timer 64 is maintained at the H level as described above. Holds 0.60 × V _i , and the braking hydraulic pressure P continues to be held at the relatively high hydraulic pressure. Thereafter, when at time t ₁₀ the wheel speed V _w is decreased further reaches 0.60 × V _i, and outputs the slip signal from the comparison circuit 7, the brake fluid pressure P
Is depressurized at this point.

According to the present embodiment as described above, the wheel acceleration is, for example, 10
The target wheel speed V _wo is set from 85% to 60% with respect to the pseudo vehicle speed V _i only for a predetermined time from the time when the vehicle returns after exceeding G.
Since you switched percent, it is possible to inhibit the pressure reduction control in the large state of relatively wheel speed value due to the pseudo vehicle speed V _i of high level generated after the wheel speed is rapidly increased.

FIG. 6 is a block diagram showing another configuration of the target wheel speed generation circuit 6, and in this example, only the target wheel speed V _wo for the pseudo vehicle speed V _i generated when the wheel speed V _w rises sharply, The set value is changed.

In the figure, reference numerals 60 and 61 denote multiplication circuits for multiplying the pseudo vehicle speed V _i by 0.85 and 0.60, respectively, similarly to those shown in FIG. 3, and the output signals of these multiplication circuits 60 and 61 are Input is made to the comparison circuit 7 via a changeover switch 62 'for changing over each output. Reference numeral 63 also designates a comparator circuit which outputs an H level signal when the wheel acceleration exceeds a predetermined value corresponding to, for example, 10 G, and 64 'designates an output of the comparator circuit 63 from H level to L level, as shown in FIG. A timer that outputs an H level signal for a predetermined time (shorter than the time set by the timer 64 shown in FIG. 3) after falling to the level, and 65 outputs an H level signal when the wheel deceleration exceeds a predetermined value b ₁ Comparing circuit, 6
Reference numeral 6 is an RS flip-flop (hereinafter, simply referred to as FF), and this FF 66 is set at the rising edge of the AND signal by the AND gate G ₁ between the output from the timer 64 ′ and the output from the comparison circuit 65, while the tire 64 is set. It is arranged to be reset at the rising edge of the AND signal by the AND gate G ₂ of the output inversion signal from ′ and the output from the comparison circuit 65.

Then, the changeover switch 62 'controls the output Q of the FF.
When the output Q is at the L level, it is on the side of the multiplication circuit 60, and when the output Q is at the H level, the multiplication circuit 61
It is designed to switch to the side.

In such an embodiment, in FIG. 5, after at time t ₄ the output Q of the timer 64 'becomes H level, the time t ₅ in FF66 to b ₁ signal is output is set, its output Q ( The switch 62 'that is switched depending on the H level) is switched to the multiplication circuit 61 side.

Then, the target wheel speed V _wo becomes V _wo = 0.60 × V _{i with} respect to the pseudo vehicle speed V _i generated at the time t ₅ , and the same switching control of the braking hydraulic pressure as in the above-described embodiment is performed.

After that, when the wheel deceleration reaches the predetermined value b ₁ at time t ₈ and a new pseudo vehicle speed V _i is further generated, the output Q of the timer 64 ′ is already at the L level at that time, and the b ₁ is concerned.
The FF 66 is reset by the signal, and the changeover switch 62 'is switched to the multiplication circuit 60 side.

Therefore, after time t ₈ , the target wheel speed V _wo becomes V _wo = 0.85 × V _i with respect to the pseudo vehicle speed V ₁ , and normal braking control is performed. For example, at time t ₉ , Speed V
_{When w} falls below the target wheel speed difference V _wo (= 0.85 × V _i ), the brake fluid pressure is reduced.

Also in this embodiment, the depressurization control in the state where the wheel speed value is relatively large, which is caused by the high-level pseudo vehicle speed V _i generated immediately after the wheel speed rapidly increases, is almost the same as that in the above embodiment. Can be banned.

The setting value changing of the slip ratio lambda, i.e. the pseudo vehicle speed V _i setting change of the target wheel speed V _wo respect, the above pseudo vehicle speed V _i
In addition to changing the multiplication value to, for example, as shown in FIG. 7, a predetermined value (for example, 5 km / h) is subtracted from the normal target wheel speed V _wo (= 0.85 × V _i ) by the subtraction circuit 67. You may do it.

Further, the predetermined value to be subtracted can be made variable based on the wheel acceleration as shown in FIG. 8, for example.

Here, the configuration of the target wheel speed generation circuit 6 shown in FIG. 8 will be briefly described. When the wheel acceleration α _w becomes equal to or greater than a predetermined value a ₃ that is, for example, 5 G, the comparison circuit 63 becomes H level,
A predetermined time timer 64 from the fall of the comparison circuit 63
The H level signal is output from the.

Then, the output of the comparison circuit 63 and the output Q from the timer 64
When the OR signal by the OR gate G ₃ is at the H level, the peak hold circuit 69 causes the peak value α of the wheel acceleration during that period (the period when the output of the OR gate G ₃ becomes the H level) as shown in FIG. _w (max) is detected, and the peak value α _w (max) data detected by the peak hold circuit 69 is subtracted by the subtraction value determining circuit 70.
From the normal target wheel speed V _wo (= 0.85 × V _i ) according to the relationship between the peak value α _w (max) and the subtraction value δ as shown in FIG. , Subtraction circuit 6
The subtraction value δ to be reduced is determined by 8.

According to the target wheel speed generation circuit 6 shown in FIG. 8, the larger the degree of increase in wheel speed (the degree of increase in wheel acceleration), the smaller the value of the target wheel speed V _wo that is output, and the more the braking is performed. The timing at which the hydraulic pressure is reduced is delayed, and the wheel speed can be reduced faster.

Even in the example shown in FIG. 3 or 6, it is possible to make the multiplication value variable based on the wheel acceleration.

〔The invention's effect〕

As described above, according to the present invention, when the predetermined wheel deceleration is reached, the pseudo vehicle body speed is generated based on the detected wheel speed at that time, and the detected wheel speed is the pseudo vehicle body speed. In the anti-skid control device configured to perform the pressure reduction control of the braking hydraulic pressure when the target wheel speed obtained from is decreased, the predetermined time after the means (3) detects the predetermined constant wheel acceleration, Since the target wheel speed is decreased by the predetermined amount by the means (61), even if the wheel speed sharply rises, the control based on the high-level pseudo vehicle body speed that occurs immediately after the wheel speed causes a comparatively small amount. It is possible to prevent the brake fluid pressure from being controlled to be reduced in a state where the wheel speed value is large, and it is possible to prevent the stop distance of the vehicle from unnecessarily increasing.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of a braking hydraulic system in an anti-skid control device according to the present invention, FIG. 2 is a block diagram showing a basic configuration of an example of an anti-skid control device according to the present invention, and FIG. A block diagram showing an example of a concrete configuration of the target wheel speed generating circuit in FIG. 2, FIG. 4 is an explanatory diagram showing a braking fluid pressure control mode by the device shown in FIG. 2, and FIG. FIG. 3 and a timing chart showing the operating state of the device shown in FIG. 6 described later, FIGS. 6 to 8 are block diagrams showing other specific configurations of the target wheel speed generation circuit in FIG. 2, FIG. 9 is an explanatory view showing a subtraction value determination pattern in the subtraction value determination circuit in FIG. 8, FIG. 10 is an explanatory view showing the operation of the peak hold circuit in FIG. 8, and FIG. 11 is friction between wheels and a road surface. Coefficient μ and slip ratio λ Graph showing the relationship FIG. 12 the wheel speed during braking by conventional anti-skid control device, the brake fluid pressure is an explanatory diagram showing a state of the wheel acceleration and deceleration. 1 ... Wheel speed sensor 2 ... Wheel speed detection circuit 3 ... Wheel acceleration / deceleration detection circuit 4 ... Pseudo vehicle speed generation circuit 5, 7, 8, 9 ... Comparison circuit 12, 13 ... Driver 14 ... Inflow valve (EV valve) 15 ... Outflow Valve (AV valve) 16 ... Retriggerable timer 17 ... Pump 60 ... Multiplier circuit (× 0.85) 61 ... Multiplier circuit (× 0.60) 62, 62 '... Changeover switch 63 ... Comparison circuit 64, 64' ... Timer 65 ... Comparison circuit 66 ... RS flip-flop (FF)

Claims (1)

[Claims] 1. When a predetermined wheel deceleration b ₁ is reached, a pseudo vehicle body speed V _i is generated based on the detected wheel speed V _w at that time, and the detected wheel speed V _w is the pseudo wheel speed V _w. the one where there was falls below the target wheel speed V _wo obtained from vehicle speed V _i, the anti-skid control apparatus that performs decompression control of the brake fluid pressure, means for detecting an acceleration a _w of the wheel after pressure reduction control (3)
When, the predetermined predetermined time after the detection of the predetermined wheel acceleration a ₂ has means for reducing a predetermined amount the target wheel speed V _wo (6
1) An anti-skid control device comprising: