JPH06255468A - Brake control device - Google Patents

Abstract

PURPOSE:To prevent rear lift-up, and thereby enhance vehicle stability in a brake control device including an ABS. CONSTITUTION:The device is made up of wheel speed sensors 11, 12, 13 and 14 disposed for ABS control at right and left front wheels, and right and left rear wheels for detecting each wheel speed, a G sensor 15 detecting the deceleration of a car body, an actuator 30 which boosts, holds and decompresses the hydraulic pressure of wheel cylinders(W/C) 21, 22, 23 and 24 disposed at the right and left front wheels, and the right and left rear wheels respectively based on hydraulic pressure from a master cylinder(M/C) 20, and of a computer 40. A condition liable to cause rear lift-up is judged by the computer 40 before and during ABS control for the right and left front wheels and the right and left rear wheels of a vehicle. The execution of brake control making use of an ABS based on the aforesaid judgement can enhance running stability without impairing braking force.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake control device capable of preventing rear lift-up of a vehicle.

[0002]

2. Description of the Related Art In recent years, based on a demand for further improvement in vehicle safety, for example, ABS control, which secures the steerability of the vehicle without impairing the braking force at the time of sudden braking, is also becoming popular mainly in passenger cars. Along with this, it is being installed in commercial vehicles.

[0003]

By the way, the center of gravity of the commercial vehicle, in particular, the 1BOX type vehicle is high, and the load distribution between the front and the rear largely changes depending on the loaded amount. In such a vehicle, during sudden braking on a high μ road surface such as dry asphalt, the wheel (axle) load on the rear side is lost due to the load movement to the front side, and rear lift-up (a phenomenon in which the rear side is lifted by the load movement) occurs. (See Figure 11). In the current ABS control, the slip state of each wheel is detected to control the brake fluid pressure of each wheel, and it is impossible to prevent the rear lift-up as described above. Immediately after sudden braking, the change in load movement with time is particularly large, and the degree of rear lift-up increases. When this rear lift up happens,
In the worst case, only two wheels, the left and right front wheels, are in contact with the ground, and the vehicle stability is significantly impaired due to steering of the steering wheel and variations in the road surface friction coefficient μ.

The present invention has been made to solve the above problems, and an object thereof is to prevent rear lift-up and improve vehicle stability in a brake control device having an ABS. Is.

[0005]

The first feature of the configuration of the invention for solving the above-mentioned problems is, as shown in the concept of FIG. 7, that of the two left and right front wheels and at least the left and right rear wheels. ABS control means G0 capable of increasing / decreasing the braking force of each of the four wheels based on the output signal from the wheel speed detecting means G01 for detecting the wheel speed of one wheel and the vehicle body speed.
In the brake control device having 2, a vehicle body deceleration detecting means G03 for detecting a vehicle body deceleration, and a high G braking determination for determining high G braking when the vehicle body deceleration after starting braking exceeds a predetermined value set in advance Means G04, and sudden braking determination means G05 for determining sudden braking when the temporal change amount of the vehicle body deceleration after the start of braking exceeds a preset predetermined value
When both of the determinations by the high G braking determination means and the sudden braking determination means are established, the actuator output determination means for gradually increasing the braking force on the front wheels.
It is equipped with G06.

In addition to the first feature, the second feature is that
The actuator output determining means, when the sudden braking determining means determines that the braking is sudden, holds the braking force for the front wheel once and then gradually increases the braking force.

A third feature is that the vehicle speed is based on an output signal from a wheel speed detecting means for detecting the wheel speed of each of the two left and right front wheels and at least one of the left and right rear wheels of the vehicle. AB that can increase or decrease the braking force of each of the four wheels
In a brake control device having an S control means, a vehicle body deceleration detecting means for detecting a vehicle body deceleration and a high G when the vehicle body deceleration after the start of braking exceeds a predetermined value set in advance.
High G braking determination means for determining braking, rear leading slip determination means for determining rear leading slip when the wheel speed of the rear wheels exceeds a predetermined amount and the downward slip amount is large before the front wheels, and the high When both determinations by the G braking determination means and the rear leading slip determination means are established, at least one of the actuator output determination means for gently reducing the braking force on the front wheel is provided.

In addition to the third feature, the fourth feature is
The actuator output determination means gradually increases the braking force on at least one of the front wheels when the vehicle body deceleration at the time when the braking force control is started becomes smaller by a predetermined value set in advance.

The fifth feature is that, in addition to the third and fourth features, the actuator output determination means is used when the time for gently reducing the braking force of at least one of the front wheels exceeds a predetermined value. That is, the braking force on the front wheels is gradually increased.

The sixth feature is that, in addition to the third, fourth and fifth features, the actuator output determining means determines that at least one of the front wheels is under ABS control and high G braking is performed. In addition, when the pressure reduction time of the rear wheels exceeds a predetermined value, the braking force on the front wheels is reduced.

The seventh feature is that, in addition to the third, fourth, fifth and sixth features, the actuator output determination means is configured to control the left and right sides when at least one of the front wheels is under ABS control. The braking force for the front wheels is increased or decreased based on the vehicle body deceleration immediately before the two front wheels are ABS-controlled.

The eighth characteristic is, in addition to the seventh characteristic,
The actuator output determination means uses a preset predetermined value when at least one of the front wheels is under ABS control and the vehicle body deceleration immediately before the two left and right front wheels are ABS controlled is not stored. To increase or decrease the braking force applied to the front wheels.

[0013]

[Action]

[Operation of First Characteristic] According to the above means, the vehicle body deceleration after the start of the braking of the vehicle exceeds the predetermined value, and the high G braking is performed.
Similarly, when the amount of change over time in the vehicle body deceleration exceeds a predetermined value and it is determined that the vehicle is in sudden braking, the braking force on the front wheels is gradually increased. That is, when such a condition is satisfied, it is possible to prevent the braking force of the front wheels from rising sharply, so that the rear lift-up is prevented.

[Operation of the Second Characteristic] According to the above means, when only the sudden braking judgment is established in both judgments in the operation of the first characteristic, the braking force for the front wheels is once held and then gently. Will be increased. In this case, the braking force of the front wheels is allowed to hold for the rear wheels once, so that the rear lift-up can be prevented more smoothly.

[Operation of Third Characteristic] According to the above means, the vehicle body deceleration after the start of the braking of the vehicle exceeds the predetermined value and the high G braking is performed, and the wheel speed of the rear wheels is higher than that of the front wheels. When it is determined that the value is less than the predetermined value, the braking force on at least one of the front wheels is gently reduced. That is, when such a condition is satisfied, the wheel load of the rear wheels is small and the rear is slipping, so the braking force of the front wheels is reduced and rear lift-up is prevented.

[Operation of Fourth Characteristic] According to the above-mentioned means, in addition to the operation of the third characteristic, at least one of the following is obtained when the vehicle body deceleration at the time when the braking force control is started is reduced by a predetermined value. The braking force on the front wheels is gradually increased. In this case, the braking force of the front wheels is gently increased to suppress the decreasing tendency of the vehicle body deceleration so that the brakes are activated.

[Operation of Fifth Characteristic] According to the above means, in addition to the operation of the third or fourth characteristic, the time during which the braking force of at least one front wheel is gently reduced exceeds a predetermined value. Then, the braking force on the front wheels is gradually increased. In this case, the braking force of the front wheels tends to increase after a predetermined time so that the braking distance is not reduced for a long time and the braking distance is not extended.

[Operation of Sixth Characteristic] According to the above means, in addition to the operation of the third, fourth or fifth characteristic, at least one front wheel is under ABS control and high G braking is performed. When the depressurization time of the rear wheels exceeds a predetermined value, the braking force on the front wheels is reduced. In this case, even if the rear wheels are further decompressed, the rear slip tendency is not eliminated, so it is determined that there is a rear lift-up tendency, and the braking force of the front wheels is reduced to eliminate the rear lift-up tendency. It will be executed.

"Operation of the seventh characteristic" According to the above means, in addition to the operation of the third, fourth, fifth or sixth characteristic,
When at least one front wheel is under ABS control,
The braking force on the front wheels is increased or decreased based on the vehicle body deceleration immediately before the two left and right front wheels are ABS controlled. That is, the processing for eliminating the rear lift-up tendency is executed by increasing / decreasing the ABS control braking force of the front wheels by the vehicle body deceleration that determines the rear lift-up tendency of the two right and left front wheels immediately before the ABS control. is there.

[Operation of Eighth Characteristic] According to the above means, in addition to the operation of the seventh characteristic, at least one front wheel is under ABS control and immediately before the two left and right front wheels are ABS controlled. Since the vehicle body deceleration is not stored, the braking force for the front wheel is increased or decreased by using a predetermined value. In this case, since the two left and right front wheels have no stored value of the vehicle body deceleration that determines the rear lift-up tendency immediately before the ABS control, the braking force of the ABS control of the front wheels is increased or decreased by using a predetermined value. The process for eliminating the tendency of rear lift-up is executed.

[0021]

EXAMPLES The present invention will be described below based on specific examples. FIG. 1 is an overall configuration diagram showing a brake control device according to the present invention. The present invention is a brake control device for preventing a rear lift-up of a vehicle by using ABS, and a wheel speed sensor arranged on each of the left and right front wheels and the left and right rear wheels to detect the wheel speed for ABS control. 11, 12,
13 and 14, G sensor 15 which is a vehicle body deceleration detecting means for detecting vehicle body deceleration, and wheels arranged on each of the left and right front wheels and the left and right rear wheels based on hydraulic pressure from a master cylinder (M / C) 20. Cylinder (W / C) 21, 22, 23, 2
Actuator 30 for increasing / holding / depressurizing the hydraulic pressure of 4
And a computer 40.

Next, the flowcharts of FIGS. 2, 3, 4 and 5 showing the processing procedure of the CPU used in the computer 40 constituting the apparatus of this embodiment, and an actual control example based on the processing results thereof. Will be described with reference to the time chart of FIG. Here, FIG. 2 is a main routine of the present brake control device, and FIGS. 3, 4 and 5 are flowcharts showing subroutines. Further, in FIG. 6, the front slip reference and the rear slip reference are A for convenience.
It is the same as the BS decompression standard. This process is started when an ignition switch (not shown) is turned on. Further, this processing is sequentially executed for each wheel of FL (left front wheel), FR (right front wheel), RL (left rear wheel), RR (right front wheel), for example, in the order of FL → FR → RL → RR. To be done.

First, in step 200 of FIG. 2, various flags and various counters to be described later are initialized as initialization. Next, in step 202, the wheel acceleration is calculated by the wheel speed V _W of the controlled object and its differential calculation based on the input signals from the wheel speed sensors 11, 12, 13, 14. Next, in step 204, the vehicle body deceleration V _{G in the} front-rear direction is calculated based on the input signal from the G sensor 15. Next, move to step 206,
Wheel speed calculated in step 202 and step 2
Based on the deceleration calculated in 04, the pseudo vehicle body speed V _SO
Is calculated. Then, in step 208, step 2 is performed as high G braking determination processing for achieving the high G braking determination means.
When the vehicle body deceleration V _G based on the calculation result of 04 is V _G ≧ G _H , it is determined to be high G braking.

Next, in step 210, each wheel of the actuator is controlled so as not to lock each wheel FL to RR to be controlled based on the wheel speed and acceleration of each wheel FL to RR calculated in step 202. Set the control mode (increase / hold / decrease) of the switching valve corresponding to. Since this setting is a well-known process in ABS control, detailed description is omitted here. In addition, the above step 210
The control mode of the switching valve that is set in the processing step is only numerical data in the computer, and the switching valve in the actuator is not driven yet. Further, in the processing step of the above step 210, during normal traveling in which the stop switch due to the depression of the brake pedal (not shown) is not operating, the control mode of the switching valve in the actuator is all set to the pressure increasing mode.

Next, the routine proceeds to step 212, where it is judged if the control object is the rear wheels (RL, RR). In step 212, if the control target is the rear wheel, the process proceeds to step 214, and the rear leading slip determination processing for achieving the rear leading slip determination means is executed. Step two
At 14, the pseudo vehicle body speed V calculated at step 206
_SO and the difference between the wheel velocity V _W calculated in step 202 is not less than the predetermined value KV _SR below a front slip determination flag FSFL, if it is not FSFR is set, the rear preceding slip determination flag FSR is set. When these conditions are not satisfied, the rear leading slip determination flag FSR is reset. Further, when the rear wheel is depressurized during ABS control, the depressurization time counter ΔTRR is incremented and reset except when depressurizing. Next step 2
After shifting to step 16, select low control (a left / right independent control of the front wheels and a left / right simultaneous control according to which one of the rear wheels easily slips one wheel), which is a well-known process as the rear actuator output determination process, is executed. Then, the process proceeds to step 226.

If the object to be controlled is the front wheels (FL, FR) in step 212, the process proceeds to step 218. In step 218, as the front slip determination processing, the pseudo vehicle body speed V _SO calculated in step 206 is calculated.
If the difference between the wheel speed V _W calculated in step 202 and the wheel speed V _W is equal to or greater than the predetermined value KV _SF and the control target is the left front wheel, the front slip determination flag FSFL is set, and if the right front wheel is set, the front slip determination flag FSFR is set. , Predetermined value K
If V _SF or less, each front slip determination flag is reset.

Next, the routine proceeds to step 220, where the sudden braking determining process for achieving the sudden braking determining means is executed by the subroutine shown in FIG. Step 300
Then, the vehicle body deceleration V _G calculated in step 204 described above.
Is less than the threshold value G _F1 , the routine proceeds to step 302, where the sudden braking determination counter ΔT _BF is cleared and the sudden braking determination flag FKB is reset. On the other hand, in step 300, when the inequality sign of V _G ≧ G _F1 is satisfied, the process proceeds to step 304, and the sudden braking determination counter ΔT _BF is incremented. Next, in step 306, if the vehicle body deceleration V _G calculated in step 204 is equal to or greater than the threshold value G _{F2, the process} proceeds to step 308 and the sudden braking determination counter ΔT _BF is equal to or less than the predetermined value CT _BF . If so, in step 310 the sudden braking determination flag FK
B is set.

Next, returning to step 222 of FIG. 2, the rear lift-up tendency presence / absence determination processing is executed by the subroutine shown in FIG. In this process, first, if the high G braking determination flag FHGB is reset in step 400, the process proceeds to step 402, and the rear lift-up tendency flag FLUP1 is reset. Then, in step 404, GST that is the rear lift-up start G
Is cleared, and in step 406, the rear lift-up control time counter T _SM is cleared. Next Step 40
8, the rear lift-up tendency flag FLUP2
Is reset.

If the high G braking determination flag FHGB is set in step 400 described above, step 410
Then, it is determined whether or not the front left wheel ABS control flag FABSFL is set, and whether or not the right front wheel ABS control flag FABSFR is set at step 412. That is, it is determined whether or not the two left and right front wheels are under ABS control. If even one of the left and right front wheels is under ABS control, the routine proceeds to step 414, where the rear lift-up tendency flags FLUP1, FLUP2 are set to 1 Once reset, the process proceeds to step 416. Here, the left and right front wheels are AB
If it is before the S control, the routine proceeds to step 418 after the determination of step 412, and by the processing of step 214 of FIG. 2, if it is in the high G control state and the rear leading slip state, the rear leading slip determination flag FSR. Is set, and the process proceeds to step 420.

On the other hand, if even one of the left and right front wheels is under ABS control, the slip of the front wheel is under ABS control, and even if the rear leading slip determination flag FSR is set, it is the rear leading slip at this point. It cannot be determined whether or not. Therefore, if even one of the left and right front wheels is under ABS control, "If the rear wheel slips, the rear wheel also ABS.
When the control is started and the rear lift-up tendency is exhibited, the wheel deceleration of the rear wheels exceeds the predetermined value and falls below the predetermined value due to the load loss, and the rear decompression state is reached, and the rear decompression time until it returns to the predetermined value is long. That is, the reason why the rear depressurization time is long is that it is difficult to be influenced by the road surface which tends to rotate the rear wheels due to the tendency of the rear lift up, so that the recovery of the wheel acceleration is delayed.
Therefore, if it is determined at step 416 that the rear wheel pressure reduction counter ΔTRR indicating the rear pressure reduction time exceeds the predetermined value CTR, the routine proceeds to step 420. If the inequality sign is not satisfied in step 416, the process proceeds to step 404 described above.

At step 420, it is judged if the rear lift-up control time counter T _SM is greater than or equal to a predetermined value CT _SM . This determination is the time guard of the rear lift-up prevention control, and if the inequality sign is satisfied, step 422 is executed.
Move to. Then, in step 422, the rear lift-up tendency flag FLUP2 is reset, and FLUP
1 is set. If the inequality sign is not satisfied in step 420, the process proceeds to step 424. In step 424, if GST which is the rear lift-up start G is cleared, the process proceeds to step 426, and the above GS is executed.
The current vehicle body deceleration V _G is set to T. On the other hand, if GST is set in step 424,
Step 426 is skipped, and the process proceeds to step 428. In step 428, it is determined whether or not the vehicle body deceleration V _G is greater than or equal to a value obtained by subtracting the predetermined value KGD from GST which is the rear lift-up start G. In step 428,
If the inequality sign is not satisfied, the process proceeds to step 422 as the vehicle body deceleration guard and the same process is executed. On the other hand, if the inequality sign is satisfied in step 428, the process proceeds to step 430, and the rear lift-up tendency flag FL is set.
UP1 and FLUP2 are set, and in step 432, the rear lift-up control time counter T _SM is incremented.

Next, returning to step 224 in FIG. 2, the front actuator output determination processing is executed by the subroutine shown in FIG. In this process, first, in step 500, the left front wheel ABS control in-progress flag FABSFL.
Whether or not is set, in step 502, the right front wheel A
It is determined whether the BS control flag FABSFR is set. That is, it is determined whether at least one of the left and right front wheels is under ABS control. If the determination in step 500 or step 502 is YES, step 504 is performed. If the determinations in both steps are NO, step 51 is performed.
Move to 2 respectively. Then, in step 504,
The counter ΔT _UP for ending the rear lift-up countermeasure control is cleared, and the routine _proceeds to step 506. At step 506, the rear lift-up tendency flag FLUP2
If it is set, the process proceeds to step 508, and the pulse reduction mode is selected (control corresponding to the selected mode is the period t ₃ to
_{t 4, t 6 ~t 7)} . In the pulse reduction mode, the switching valve in the actuator is gradually switched between the holding output and the pressure reducing output to gradually reduce the oil pressure of the wheel cylinder. Here, if the rear lift-up tendency flag FLUP2 is reset at step 506, the routine proceeds to step 510, and the conventional ABS control mode selected at step 210 of FIG. 2 is selected (corresponding to this selected mode. As the control to perform, the period t ₅ in FIG.
_{~t 6, t 8 ~t 9)} .

At step 512, the state of the rear lift-up tendency flag FLUP1 is judged. If it is set, step 514 is carried out, and if it is reset, step 5 is carried out.
Move to 24. In step 514, if the rear lift-up tendency flag FLUP2 is set, if it is set, the routine proceeds to step 508 described above, and the pulse reduction mode is selected. On the other hand, in step 514, when the rear lift-up tendency flag FLUP2 is in the reset state, the process proceeds to step 522 through steps 516 to 520, which will be described later, and the pulse increasing mode is selected (the control corresponding to the selected mode is , Period t _{4 to} t ₅ in FIG.
t ₇ ~t _8). Contrary to the above-described pulse decrease mode, the pulse increase mode is to gradually change the switching valve in the actuator between the holding output and the pressure increasing output to gradually increase the oil pressure of the wheel cylinder. Here, in step 516, the counter ΔT _UP for ending the rear lift-up countermeasure control is incremented, and step 51
If the counter ΔT _UP is _{equal to} or greater than the specified time CT _UP in step 8, the rear lift-up tendency flag F is determined in step 520.
LUP1 is reset and the rear lift-up countermeasure control is ended.

If the determination at step 512 is NO, the routine proceeds to step 524, where the sudden braking determination flag FKB is set.
Is reset, the process proceeds to step 526.
At step 526, the sudden braking control output counter ΔT
After clearing the counter ΔT _UP for ending the _KB and the rear lift-up countermeasure control, the routine proceeds to step 528, where the pressure increasing mode is selected (the control corresponding to this selected mode is the period in FIG. 6). t _{0 to} t _1, t ₉
~ Until the stop switch is turned off by pressing down the brake pedal). If the sudden braking determination flag FKB is set in step 524 described above, step 5
The flow shifts to 30, and the sudden braking control output counter ΔT _KB is incremented. Then, the process proceeds to step 532, and the sudden braking control output counter ΔT _KB is set to the predetermined value CT _KB.
It is determined whether or not the above. If the inequality sign is not satisfied in step 532, the process proceeds to step 522 described above,
Pulse increase mode is selected (as a control corresponding to the selected mode, the period t ₂ ~t ₃ in FIG. 6).
On the other hand, in step 532, when the inequality sign is satisfied, the process proceeds to step 534, and the holding mode is selected (the control corresponding to this selected mode is the period t _{1 to} t ₂ in FIG. 6).

Here, the reason why the hold mode in step 534 described above is necessary will be described below. When drivers perform a sudden braking operation like a spike, a phenomenon occurs in which the wheel cylinder hydraulic pressure of each wheel rises sharply and the vehicle body deceleration changes greatly. However, the output of the G sensor that detects the vehicle deceleration is filtered, and a response delay occurs. Therefore, the output value of the vehicle body deceleration corresponding to the oil pressure condition of the front wheels may not be obtained,
Since the subsequent control may be hindered, the braking force is not increased until the current actual vehicle deceleration is known in the holding mode. If there is no such problem, the above steps 530, 532 and 534 can be omitted.

After the front actuator output determination process of FIG. 5 described above, the process returns to step 226 of FIG. 2, and the output to the actuator is executed based on the results of the output determination processes of steps 216 and 224 described above. To finish. In this way, rear lift-up can be prevented in the high G braking state immediately after sudden braking, and vehicle stability can be secured and improved.

As the vehicle body deceleration calculation in step 204 of FIG. 2 described above, the wheel speed sensors 11, 12, 1 are used without using the output of the G sensor 15 shown in FIG.
The differential value of the pseudo vehicle body speed calculated in step 206 based on the output signals from 3 and 14 may be used. In this case, the G sensor 15 in FIG. 1 becomes unnecessary.

Further, the subroutine shown in FIG. 3 which is the sudden braking determination processing in step 220 of FIG. 2 may detect a large amount of change in the vehicle deceleration with time. In that case, the flow chart is as shown in FIG. That is, when the time ΔT _BF (abrupt brake determination counter) from the detection of the signal STP by the operation of the stop switch by pressing the brake pedal (not shown) to the predetermined vehicle body deceleration G _F3 is less than or equal to the predetermined value CT _BF , The brake determination flag FKB may be set.

As shown in the flow chart of FIG. 9, the subroutine for the sudden braking determination process is such that the time ΔT _BF (abrupt braking determination counter) is the predetermined value CT when the temporal change amount of the vehicle deceleration exceeds the predetermined value DGS. _BF or higher, and
The sudden braking determination flag FKB may be set when the current vehicle body deceleration V _G becomes G _F4 or more.

In the rear leading slip determination processing in step 214 of FIG. 2, the rear wheels are AB before the left and right front wheels.
When the S control is started, the rear leading slip determination flag FSR may be set and reset at the time when at least one of the left and right front wheels starts the ABS control. This is because starting ABS control is equivalent to slipping the wheel.

Further, the subroutine corresponding to the above-mentioned FIG. 4, which is the rear lift-up tendency presence / absence determination processing in step 222 of FIG. 2, may be a flow chart as shown in FIG. In this process, if at least one of the left and right front wheels is under ABS control, the GST that is the rear lift-up start G before the ABS control of the two left and right front wheels is stored as GSTM in step 1030 of FIG. In advance, using that value, steps 1020 and 10
The presence or absence of the tendency for rear lift up may be determined at 32.
If there is no stored value GSTM, step 10
If it is determined in step 16, the process proceeds to step 1018, and the preset value KGS may be set as the GSTM.

[0042]

As described above, the present invention determines the conditions that can be the rear lift-up state before and during the ABS control of the left and right front wheels and the left and right rear wheels of the vehicle, and the braking force of each wheel is determined based on the determination. By executing the brake control using the ABS capable of increasing and decreasing, the traveling stability can be improved without impairing the braking force.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing a brake control device according to a specific embodiment of the present invention.

FIG. 2 is a flow chart showing a processing procedure in a main routine of a CPU used in a computer constituting the apparatus of the embodiment.

FIG. 3 is a flowchart showing a processing procedure in a sudden braking determination processing which is a subroutine of a CPU used in a computer constituting the apparatus of the embodiment.

FIG. 4 is a flowchart showing a processing procedure in a rear lift-up tendency presence / absence determination processing which is a subroutine of a CPU used in a computer configuring the apparatus of the embodiment.

FIG. 5 is a flowchart showing a processing procedure in a front actuator output determination processing which is a subroutine of a CPU used in a computer configuring the apparatus of the embodiment.

FIG. 6 is a time chart showing an actual control example of the apparatus of the embodiment.

FIG. 7 is a block diagram showing the concept of the present invention.

8 is a flowchart showing a second embodiment of the sudden braking determination process of FIG.

9 is a flowchart showing a third embodiment of the sudden braking determination process of FIG.

FIG. 10 is a flow chart showing another embodiment of the rear lift-up tendency presence / absence determination processing of FIG.

FIG. 11 is a time chart illustrating a rear lift-up phenomenon in conventional brake control.

[Explanation of symbols]

 11, 12, 13, 14 ... Wheel speed sensor 15 ... G sensor 20 ... Master cylinder (M / C) 21, 22, 23, 24 ... Wheel cylinder (W / C) 30 ... Actuator 40 ... Computer

Claims (8)

[Claims] 1. The wheel 4 based on an output signal from a wheel speed detecting means for detecting the wheel speed of each of the two left and right front wheels and at least one of the left and right rear wheels of the vehicle and the vehicle speed.
ABS (Antilock Brak) that can increase or decrease the braking force of each wheel
e System) In a brake control device having a control means, a vehicle body deceleration detection means for detecting a vehicle body deceleration, and a high G braking determined when the vehicle body deceleration after the start of braking exceeds a predetermined value set in advance. G braking judgment means, sudden braking judgment means for judging sudden braking when the temporal change amount of the vehicle body deceleration after the start of braking exceeds a preset predetermined value, the high G braking judgment means and the sudden braking A brake control device comprising: an actuator output determination means for gradually increasing the braking force applied to the front wheel when both determinations by the determination means are established. 2. The actuator output determination means, when the sudden braking determination means determines a rapid braking, temporarily holds the braking force for the front wheel and then gradually increases the braking force. Brake control device. 3. The vehicle wheel 4 based on an output signal from a vehicle wheel speed detecting means for detecting the vehicle wheel speed of two wheels of the left and right front wheels and at least one of the left and right rear wheels of the vehicle.
In a brake control device having ABS control means capable of increasing / decreasing the braking force of each wheel, a vehicle body deceleration detecting means for detecting a vehicle body deceleration, and the vehicle body deceleration after the start of braking exceeds a predetermined value set in advance. High G braking determining means for determining high G braking; rear leading slip determining means for determining rear leading slip when the wheel speed of the rear wheels exceeds a predetermined amount and the downward slip amount is large before the front wheels. A brake control device comprising: an actuator output determination unit that gently reduces the braking force on at least one of the front wheels when both determinations by the high G braking determination unit and the rear leading slip determination unit are established. 4. The actuator output determination means gently increases the braking force for at least one of the front wheels when the deceleration of the vehicle body when the braking force control is started is reduced by a predetermined value. The brake control device according to claim 3, wherein 5. The actuator output determination means gradually increases the braking force applied to the front wheels when a time period during which the braking force of at least one of the front wheels is gently decreased exceeds a predetermined value. The brake control device according to claim 3 or claim 4. 6. The actuator output determination means, when at least one of the front wheels is under ABS control, it is determined to be high G braking, and when the pressure reduction time of the rear wheels exceeds a predetermined value, the braking force for the front wheels is determined. The brake control device according to claim 3, 4 or 5, wherein 7. The actuator output determination means, when at least one of the front wheels is under ABS control, applies a braking force to the front wheel based on the vehicle body deceleration immediately before the two left and right front wheels are ABS controlled. The brake control device according to claim 3, claim 4, claim 5, or claim 6, wherein the brake control device is configured to increase or decrease. 8. The actuator output determination means is preset when at least one of the front wheels is under ABS control and the vehicle body deceleration immediately before the two left and right front wheels are ABS controlled is not stored. The brake control device according to claim 7, wherein the braking force applied to the front wheel is increased or decreased by using the predetermined value.