JPH01269655A - Control for antiskid controller - Google Patents

Abstract

PURPOSE:To properly prevent the wheel lock and shorten the brake distance by independently controlling the front wheel brake pressure on an ordinary road surface and selectively controlling the rear wheel brake pressure into low value and controlling said pressure in the reverse direction on a split road surface. CONSTITUTION:The control signals of the wheel speed detectors 28a, 28b, 29a and 29b installed onto the front/rear and right/left wheels are inputted into the logic circuits 35a, 35b, 36a and 36b through the cycle conversion circuits 33a, 33b, 34a and 34b in a control unit 31, and compared with a pseudo car body speed signal, and a slip signal and acceleration/deceleration signals are generated. On an ordinary road surface, the front wheel brake pressure is controlled independently, and the rear wheel brake pressure is selection-low- controlled. Further, when a detector 42 detects a split road surface having each different frictional coefficient on the right and left road surfaces, the selectors 38a, 38b, 39a and 39b are selected, and the front wheel brake pressure is selection-low-controlled, and the rear wheel brake pressure is controlled independently.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an example of a control method for an anti-skid control device for a vehicle, and particularly to a control method for an anti-skid control device installed in a light truck or the like.

[Conventional technology]

In recent years, the installation of anti-skid control devices on passenger cars has become widespread, and by controlling the brake pressure during braking, this prevents the wheels from locking and maintains steering performance and directional stability of the vehicle body. Moreover, it is designed to achieve the optimum braking distance.

Generally, this device controls the brake pressure of both front wheels completely independently, and integrates the brake pressure of both rear wheels.
A-control method is adopted.

It is also desirable for vehicles such as light trucks to be equipped with anti-skid control devices for safety reasons.

[Problem to be solved by the invention 1-2] By the way, vehicles such as daytime trucks (generally) are of #I' construction in which the king pin offset (scrapping radius) of the suspension is positive and large. Therefore, when the brakes are applied while driving on a so-called split road surface where the braking friction coefficients are significantly different between the left and right road surfaces, the yaw torque acting around the center becomes larger than in a passenger car, causing a large swing toward the high-friction road surface. For this reason, the driver corrects the steering wheel in the opposite direction, but the vehicle rotates toward the high μ side at any faster speed. That is, this type of vehicle has a property that the yaw moment is larger than that of a passenger car, and combined with the fact that the center of gravity is high, in the worst case, it may overturn.

Therefore, if the above-mentioned anti-skid control device that independently controls the front wheels is applied to this coffin vehicle, the yaw moment will increase even more on split road surfaces, which is dangerous. In other words, because the front wheels are independently controlled, the brake pressure on the front wheels on the high μ side that locks or does not have a tendency to lock is high, and the brake pressure on the front wheels on the low friction road side that locks or has a tendency to lock is controlled low. A brake pressure difference occurs between the front wheels,
The yaw moment of the vehicle toward the frictional road surface side increases, and the installation of the anti-skid control exterior cover using the above-mentioned control method has the disadvantage that it has the opposite effect in terms of the directional stability of the vehicle.

On the other hand, for example, in Japanese Patent Application Laid-open No. 112093/1983,
The logic circuit of each axle can be selectively switched from select low control to select high control or from select high control to select low control, and the logic circuit of one axle can be switched simultaneously with the logic circuit of the other axle. On the other hand, there are descriptions of devices that can be switched.

However, in this case, one wheel of the axle on the select high control side inevitably locks on a split road surface, resulting in a loss of directional stability of the vehicle. This locking of the wheels reduces the braking force and increases the braking distance.

Furthermore, JP-A-54-90720 discloses that in anti-skid control, switching from independent control to select-low control or vice versa, and immediately after switching from select-low control to independent control, Non-low channel (high μ
It is disclosed that the gradient of pressure rise on the side) is suppressed.

However, the switching is performed depending on the conditions of the load, the pulling shaft, etc., and the switching is not performed by detecting a split road surface.

Therefore, although the yaw moment could be suppressed to some extent, the danger could not be completely avoided.

The present invention has been made in view of the above-mentioned problems of the prior art, and even in vehicles where the yaw moment becomes extremely large when braking on a split road surface due to the unique structure of the vehicle, the present invention reliably suppresses the yaw moment as much as possible and improves the steering performance of the vehicle. It is an object of the present invention to provide a control method for an anti-skid control device that ensures directional stability and shortens braking distance.

[Means to solve the problem]

The problem mentioned above is that the braking friction coefficients of the left and right road surfaces are different in the control method of the anti-skid control device, in which the brake pressure of both wheels on one axle is controlled independently, and the brake pressure of both wheels of the other axle is selectively low controlled. A split road surface detection device is provided to detect this, and normally the brake pressure of both front wheels of the front axle is controlled independently.The brake pressure of both the rear wheels of the rear axle is also selectively low controlled, and the split road surface detection device detects the The problem is solved by a control method for an anti-skid control device, characterized in that the brake pressures of the two front wheels can be switched to select low control under predetermined conditions, and the brake pressures of the two rear wheels can be switched to independent control, depending on the output. Ru.

[For production]

When detecting a split road surface, the brake pressure of one front wheel is selectively low controlled under predetermined conditions.The brake pressure difference between both front wheels is reduced to suppress the yaw moment.
Additionally, braking force is ensured by independently controlling the brake pressure on both rear wheels.

〔Example〕

Hereinafter, an anti-skid control device that performs a control method according to an embodiment of the present invention will be described with reference to the drawings.

First, the piping and wiring system of the entire apparatus of this embodiment will be explained with reference to FIG.

In Fig. 1, a mask cylinder (1) is connected to a pedal (2), and one of the hydraulic pressure generating chambers is connected to a pipe (3), a 3-position electromagnetic switching valve (4a) (4b), a pipe (5a) ( 5b) to the wheel cylinders (12a) and (7b) of the right rear wheel (tia) and the left front wheel (6b).

The other hydraulic pressure generation chamber of the mask cylinder (1) is connected to the pipe (G).
3-position solenoid switching valve (4c) (4d), pipe line (5c) (
5d) to the right front wheel (6a) and the left rear wheel (xtb).
) are connected to the wheel cylinders (7a) (12b). The outlet of the switching valve (saX4b) (4c) (4d) is connected to the reservoir (25a) (
25b). Reservoir (25a) (25b)
is a piston (27a) (27) slidably fitted into the main body.
b) and weak springs (26a) (26b), the reservoir chamber is connected to the suction port of the hydraulic pump can. The hydraulic pump (1) is shown schematically, but as is known, it has a main body ci! that slidably accommodates a piston! u, reverse valves (23a) (23b) (24a) of the electric motor that reciprocates this piston.
) (24b), the outlet of which is pipe (3) oB
Connected to I. In addition, dampers (8) are installed in pipes (3) and (4).
a) (8b) is connected and is used to absorb the pulse pressure of the hydraulic pump...

Wheel speed trial gains (28a) (28t)) (29a) (
29b) is provided. Cholera detector to wheel (6a)
A pulse signal with a frequency proportional to the rotational speed of (6b)01a)(llb) is obtained, and the control unit 01
) is added as input. control unino) c
311 is a control signal 83%sb, Se, which will be explained in detail later.
Xsa generates motor drive signal Qo. Control signal Sa
N 8b N Se -, Sd is a 3-position solenoid switching valve (
4a) (4b) (4e) (4d) Solenoid (30a
) (30b) (30e) (30d). The 3-position solenoid switching valves (4a) (4b) (4e) (4d) are connected to their solenoids (30a) (30b) (30c) (30d).
Control signals Sa X8b , Se , Sd supplied to
It is configured to take one of three positions A, B, or C depending on the magnitude of the current. That is, when the current of the control signals SaXSb, Se, and Sd is 0, the first position Δ is taken as the brake applied position. In this position, the master cylinder (1) side and the wheel cylinder side are in communication. Control signal Sa, 5bX
The currents in Sc and Sa are at low levels (hereinafter, for convenience, the symbol "-"
''), that is, when a brake hold signal is generated, the second
Take position B.

In this position, there is a gap between the mask cylinder (1) side and the wheel cylinder side, and between the wheel cylinder side and the reservoir (2
5a) and the (25b) side are cut off. Furthermore, when the currents of the control signals 8a, 5b
takes the third digit &C as the brake release position. In this position, the mask cylinder (1) side and the wheel cylinder side are cut off, but the wheel cylinder side and the reservoir (25a) (25b) side are placed in a communication state, and the wheel cylinder side is in a state of communication. The brake pressure fluid is connected to the reservoir (2sa) (z5b) through the pipes (60a) (60b).
1 and is discharged. Control signals Sa, XSb, respectively
, i Se % Sd, which is generated when any one of them becomes ``l'', is supplied to the electric motor C2', 51C as a hydraulic pump driving means.

Next, the control unit 3υ will be explained with reference to FIGS. 2 and 3.

Each sensor (28a) (28b) (29a) (29b)
f7) Output is each frequency speed conversion circuit (33a)
(33b) (34a) (34t3). child\
In this case, a digital or analog wheel speed signal is formed, and this is sent to the next stage logic circuits (35a), (35b), and (36).
a) Supplied to (36h). Logic circuit (35a) (3
5b) (36a) (36b) Known CD YoK 1m for each car An approximate vehicle speed signal is formed based on the speed signal, which is compared with the wheel speed signal to generate a slip signal, - 1-1. It has a circuit configuration that differentiates the knee wheel speed signal and compares this differential value with a predetermined deceleration/acceleration to generate a deceleration signal and an acceleration signal, but these slip signals, Deceleration signal, acceleration 1 (depending on the occurrence and disappearance of the signal, logical combination of these 'F%W) Signal A, VVRSALV VLlA
VHR-AVHLi*u 7-1. '-key hold 4
No. 71 EVVR, EVVL, EVHR, EVHL will be formed. These signals are transmitted through the current control circuit/amplifier (40a) (40h) (4i
a) (41b) or the approximate select C-control circuit (37a) and select C-control circuit (37a) whose details are shown in FIG.
:cyb). The control circuit (37b) uses the known select low control to generate a brake pressure release signal N to q (-ma/+, , which is common to the left and right rear wheels) to form a brake holding signal EVI.The control circuit (37a) ) (37b) or logic circuit (35a) (35b) (36a) (36b)
Cr) Each output is a current control circuit/amplifier (40a) (4
0b) (41a) (41b), where a current of a predetermined strength, that is, a "-" level is generated by the brake hold signal, and a level "1" current is generated by the brake release signal. . These are the control signals 8a and 8a shown in FIG.
Sb, 5eXSd as switching valve (4a) ~ (4d
) are supplied to the solitary maid parts (30a) to (30d). That is, the level of each of these signals is 1i
It consists of n level Shingetsu.

Each movable contact m of the switch (38a) (38b) (39a) (39b) is normally connected to the illustrated fixed contact side. In other words, the movable contact of the front wheel side switch (38a) (3813)? 7! are connected to the fixed contacts on the amplifier (40a) (40b) side, and the switch (39a) (39
The movable contact m in b) is connected to the fixed contact on the select C-control circuit (37b) side. -7, these switching devices (38a) (38b) (39a) (39b)
-/) The output terminal of the road surface detection device @147J is connected.
It's tzzling. Logic circuits (35a) (35b) (36a) (
36b) i4 Above-mentioned Q brake release signal xvv: 3Δ
VVL・・・・・・・・・Brake force holding signal EV
In addition to VR, EVVL, etc., when the brake release signal AViXAVVL...... is generated for the first time, these are added to the off delay timer, and from then on, these outputs are used as anti-brake release signals. High level during skid control @l
” AVZVR, entering VZVL...
* are also generated, but these signals are supplied to the split road surface detection device 143.

In the split road surface detection device, K is configured with a circuit represented by the following logical formula.

That is, when the split road surface detection device is activated and the front and rear wheels on one side are both under anti-skid control, and the front and rear wheels on the other side are not under anti-skid control, an output signal "B" is generated.This output signal Each switch (38a) (38b) (39a) (39b) is configured to be switched from the fixed contact shown in the figure to the fixed contact on the opposite side by "l#".When the output signal becomes "O", the switch (38a) (38b) (39a) (39b) is switched from the fixed contact shown in the figure to the fixed contact on the opposite side. It is possible to switch to the position.

Note that in FIG. 2, the electric line K(1) shown is composed of two electric wires. Therefore, there are two switches (38a), (38b), (39a), and (39b) each, for a total of eight switches.

Next, details of the approximate select low control circuit (37a) will be explained with reference to FIG.

The front wheel brake holding signals EvVR and EVVL are directly supplied to the current control circuit and amplifier (40a) (40b).

In addition, the brake release signal inputs VVR and AVVL are respectively one input terminal of the OR gate (61a) (61b), one input terminal of the AND/GO gate (63a) (63b), and the input terminal of the ON delay timer (62a) (62b). supplied to The output terminals of the on-delay timers (62a) (62b) are connected to the negative input terminal of an AND gate (63aX63b). The output terminals of (63a) and (63b) are connected to the other input terminals of OR gates (61a) and (61b), and the output terminals of these gates (6ia) and (61b) are connected to the current control circuit and amplifier (40a). (40b)
K-connected. Current control circuit and amplifier (40a) (40
In b), as mentioned above, a current of a predetermined strength, that is, a level of "↓" is caused by EVVR and BVVL to reach level 11#.
A current is generated from AVVR and input VVL.

These are supplied to amplifiers (40a) (40b) so as to form the control signals 8c, 8b shown in FIG. These are supplied to the solenoid sections (30c) (30b) of the control valve in FIG. That is, the control signal 5bXSC is made up of a signal at the level "@" corresponding to the signals EVVR and gvvL and a signal at the level "1" corresponding to the signal AVVR and input vvL.

The first embodiment of the present invention is constructed as described above, and its operation will be explained next.

Now, suppose that a vehicle equipped with the device of the embodiment is running on a road surface (sp IJ-1), and the right side is a low side (low friction road surface).If a brake holding signal EVVR is generated at a certain time on the right front wheel (6a). , since the switch (38a) is still in the position shown in the figure, this is supplied to the amplifier (40a), and a current at the level of "±" is generated, causing the control signal Sc to change to the switch valve (40a).
C) is supplied to the solenoid section (30c). From this K, the switching valve (4C) is switched to the B position, and the hydraulic pressure in the wheel cylinder (7a) is maintained constant. On the other hand, when the signal BVHR is generated at the right rear wheel (ila), since the switch (39a) is in the position shown in the figure, this signal is supplied to the select low control circuit (37b), which generates the signal EVH. The control signal 5aXSd of the "-" level current is supplied to the amplifiers (41a) (4tb) and is applied to the switching valve (
It is supplied to the solenoid section (3oaXsod) of 4a) and (4d). That is, the switching valves (4a) (4d) are also switched through eight positions, and the brake fluid pressures of the wheel cylinders (12a) (12b) of the right and left rear wheels (rta) (ttb) are maintained constant.

Next, when the brake release signal AVVR is generated at the right front wheel (6a), since the switch (38a) is still in the position shown, this becomes the control signal Sc at the level of "l#" via the amplifier (40a). This is supplied to the solenoid section (30c) of the switching valve (4c), which switches to the C position and reduces the brake fluid pressure of the front wheels (6a).

On the other hand, when the brake release signal AVHR is also generated at the right rear wheel (lta), the first term terror of the above logical formula AVZVR, AVZHR, AVZVL, AVZHL 1
4 "l'" split road surface detection device (42
The output of J is ""l#, which is the output of each switch (38a)
(38b) (39a%39b) K supplied, 'iiJ
The moving contact is switched from the water position to the other fixed contact side. Therefore, the front wheel side signal Pi is supplied to the approximate select a-control circuit (37a), and the rear wheel side signal is directly supplied to the amplifiers (41a) (41b). That is, the front wheels (6a) (6b) are switched to Vi approximate select [-low control, and the rear wheels (IIA) (ILB) are switched to independent control.

Follower signals A, VH, and R are multiplied by an amplifier (41a) K
rooster m is supplied, and the switching valve (4
It is supplied to the solenoid section (30a) in a). Then, the switching valve (4a) is switched to the C position, and the right side stop wheel (i
The brakes of ra) are released.

After that, the previous f'm signals AVVR, , EVVR, AVV
L, EVVL i4 approximate select low control circuit (
37a) K supplied, ffl 4m (7) Signal A
VI(R, EVHR, EVHL, A-VHL i-j
: ii, the brake fluid pressure of each wheel is controlled by being supplied to the boosters (41a) and (41b), but the brake fluid pressure of the front wheels (6
If the brake release signal AVVR is still generated 17 at a), the current is supplied to the control circuit/multiplier (40a) through the brake release signal (61a).On the other hand, It is also supplied to one input terminal of the AND gate (f; 3a), and the output of the on-delay timer (62a) is 10'' from when this signal is input 1- until the set delay time has elapsed, so the output of the ON delay timer (62a) is 10''. The output of (63a) becomes l#,
This output is supplied to a current control circuit/amplifier (40b) via an orgut (6th).

Therefore, the solenoid part (30
e) (3ob) is excited with a stronger current and switched to the C position, reducing the brake fluid pressure of both front wheels (6a) (6b).

When the set delay time of the on-delay timer (62b) has elapsed, the signal AVVR is still generated.
The output of 63a) becomes "0", and the flow of excitation to the solenoid part (30b) of the switching valve (4b) becomes "0", switching to the 8-position, and the braking force of the left wheel 011 (6h) is again Note that when the signal Δ-VVR disappears (~) before the set delay time of the on-delay timer (62b) elapses, the solenoid part (30b) of the switching valve (4b) (4e)
) (30e) is simultaneously de-energized and switched to the on position, and the fl-1 front wheels (6a) and (6b) are turned off.
At the same time, it begins to rise.

That's all Noyo 5 K I, Te'iM AVVR, EVVR,
A, VVL, EVVLaha tv Ia8- AV
HR, EVHR, EVHL,, AVHJ, K!
The pull/pull hydraulic pressure of the 68 wheels is controlled,
Both front wheels (6a x 6b) Regarding K, as mentioned above, the switching valve (4b) (4
Since the solenoid parts (30b) (30c) in e) are controlled, the brake pressure difference between the front wheels (6a) and (6b) is small, and the yaw moment that conventionally occurs is reduced to a large IJ.
The driving stability of the vehicle is guaranteed. Also, the rear wheel (
Since tta) and ttb are independently controlled, it is possible to shorten the braking distance and prevent all wheels from slipping.

FIGS. 4 and 5 show a computer unit carrying out the method according to the second embodiment of the present invention.
The piping system will be the same as shown in Figure 1. In addition, in Fig. 4, ? corresponds to Fig. 2. For each part, the same code is given.
~, these descriptions will be omitted.

That is, Hontora Example O Control Yonit C311'
In this case, the switch (39a) (39b) is installed on the rear wheel side.
) and the current control circuit/amplifier (4ta) (4ti) are provided with brake pressure gradual increase circuits (5xa) (5th).

The details of this are shown in FIG. 5, and the logic circuit (36a) (3
6b) Color i Rarel (No. AVHR, BVH lump EVH
L, &VHJ, A, V7. H.R.

AVZHL is supplied. Logic circuit (36a) (36b
), the brake release signals AVHR and AvHL are supplied to the off delay timer, and this output is A, VZHR% AVZ.
HL, but these are AND gates (45a) (45
b) and is supplied to both constant input terminals of Antogame Mlη. The above-mentioned off-delay timer -〇delay time should be long enough to maintain the output after the brake release signal &Vi(R, AVHL is generated for the first time.In other words, the delay time The next signal Δ−VHR,
A. VHL will occur.

The output terminals of the AND gates (45a) (45b) are supplied with the flip terminal 8VC.

This Q output terminal (zu7 pulse 2^ transmitter (49a) (49
b) and this output terminal is
a) Connected to the negative input terminal of (50b). Also, the brake holding signal EVHRIBVHL td, t7
'y' -) (50a) (50b) CD Other (D
Supplied to the input terminal. The above signal input VZHR, AVZ
HL is further supplied to one input terminal of (48a) (48b), and the output terminal of the AND gate (4η is connected to the other input terminal.These goo) (48
a) (48b) output terminal is a flip 70 tube (46a
) (46b).

The output terminals of the above-mentioned OR gates (50a) (isOb) are connected to the current control circuit/amplifier (4ta) (also shown in FIG. 4).
4tb). These K are further supplied with brake release signals AVHR, VHL.

The second embodiment of the present invention is constructed as described above, and its operation will be explained next.

Now, when the split road surface detection device 143 detects that the road surface is a split road, the front wheels (6a) (6b)
Approximate select low control is performed as described above, and when a brake release signal or hold signal for the front wheel on the low side occurs, the select low control signal AVVXEV
V is formed, and the solenoid parts (3Ub) (3Uc) of the switching valve (4bX4c) are equally controlled by these,
The yaw moment of the vehicle can be suppressed as described above, but according to this embodiment, by further providing the brake force gradual rise circuits (5La) (51b) for the rear wheels,
Furthermore, the yaw moment of the vehicle can be reduced. In other words, the Kaneishi side is the low side and the brake release signal & VH
R occurs first, and at this time, the brake release signal AV is sent from the pressure side rear wheel (ztb), which is the high side (high friction road surface).
Assume that HL has not occurred.

The signal input VHR is fed to the off-delay timer, and this output signal &VZHR is 11", which is
(45a) and (45b), the output of the AND gate (45a) is not @l'', but the input to one input terminal of the AND gate (45b) is
l#, and since the signal AVHL has not yet been generated at the other negative input terminal, this output becomes "l#".
#, and the input to the set terminal S of the flip-flop (46b) becomes +alat. When the control is not performed, that is, when the signal AVZHR and the input V ZHL are both @0#, the AND gate (4η output is 11") has both constant input terminals.
The flip-flop (46a and 46b) was reset through the OR gates (48a and 48b), but due to the generation of the signal AVZHR), the output of the OR gate (48b) is
It becomes 0#.

Therefore, the Q output of the flip 70 knob (46b) is “l”
As a result, the pulse oscillator (49b) is driven to generate a pulse output, which is supplied to the current control circuit/amplifier (4th) via the OR gate (50b). As described above, the solenoid part (3Oa) of the switching valve (4a) of the right rear wheel (ita) is switched to the C position by the control signal AVHR, and the brake of the right rear wheel (ha) is released, but the left rear wheel (tib ) for brakes, use a pulse transmitter (
49b), the signals l1all, "ll', "
0""Beep.......repeat. In other words, the switching valve (
The current level to the solenoid part (3υd) of 4d) is “υ
'', ``3'', ``0'', ``left''...The brake pressure repeats rising, holding constant, rising, and holding constant. In other words, it is raised stepwise. In other words, the brake pressure had previously risen rapidly, but due to this staircase rise, it now rises slowly, causing the hydraulic pressure to rise gradually.

As described above, in both rear wheels (1ta) (ixb), the brake pressure difference between the right rear wheel (lta) and the left rear wheel (tib) can be further reduced in the case of the first embodiment. The yaw moment for the vehicle can be further reduced, further improving the running stability of the vehicle.

Note that when the signal AVHR is generated, the output AVZHR of the off-delay timer maintains 1 bit, so that the output of the AND gate (45a) maintains ``0#'', and the input to the set terminal S of the flip-flop becomes ``'' It remains at 0#, and the pulse generator (49a) does not operate.

On the other hand, when the brake release signal input VHL occurs, the solenoid (3Ud) of the switching valve (4d) of the left rear wheel (ltb)
is also switched to the C position, and the brake of the left rear wheel (xtb) is also released. Then, the output VZHL of the off-delay timer (44b) also becomes "L", and this similarly continues during anti-skid control, so the output is "L" (45b).
The output becomes “0” and it goes awry again) (48b)
'fI: The flip-flop (46b) is reset via.

For this reason, the pulse transmitter (49b)? -1 Stop operation.

Therefore, the output of the off-delay timer is "1" during anti-skid control, so the off-gate (48a) ( 48b) to keep both flip-flops (46a) (46b) in a reset state. For this reason, from now on, one side of the valve 1/~gi loosening signal AV
A special case where HR crossing A, VH, L occurs, even if the brake release signal AVHL or A, VHR on the other side does not occur, the brake force is gradually increased without causing the initial control. The above-mentioned action is performed only during the cycle. Therefore, the braking distance # can be shortened while further reducing the yaw moment.

FIG. 6 shows a first modification σα of the approximate select low control circuit (37a) in the first or second embodiment of the present invention.
VVL fi, / 7'r h (65b) (65
a) and D ; t 7 gates (69a) (69b) first input terminals and other side OAK) (69b) (69
a) is connected to the second input terminal of a). Oraku) (6
9a) (69b) output terminal is 3, current control circuit (38
a) Connected to (38b).

tit, 7' v-ki release signal AVVR, AVVL u
, /7 gates (6sb) (6sa) and one input terminal of the OR gate (7Ua) (7t)b) are connected, and are respectively connected to the low-side discrimination circuit συ.

This discrimination circuit σV has a signal AVVL as a signal AV VR.
When the signal is generated after , "B" is generated, and in the opposite case, the output "fI" becomes "0".

Alternatively, instead of this (Ft No. A, VVL is the signal &
If V VR↓ occurs first and 7 occurs, pressure may be set to "1", and vice versa, it may be set to "0".

This output is "-" of the AND gates (68a) (68b).
The output terminals of the pulse generators (67a) (67b) are connected to the other input terminals of the antgelts (68a) (68b).

The output terminals of the AND gates (66a) (66b) are connected to the input terminals of the pulse oscillators (67a) (67b).
Input terminal K td-1 signal AVZVLAVZVRf &
Wachi, (IA, VVL, AVVRe (illustration-) f
j-1 whose output is supplied to the on-delay timer. In addition, the other input terminal is
5a) (65b) are connected. This Noah
(65x) Ku4N HVVL and rJ A
, VV, T, Kaku J&, and Noah Gate (6sb
) fc is supplied with signals EVVR and AVVR. The output terminals θ2 of the AND gates (68a) (68b) are connected to the third input terminals of the above-mentioned OR gates (69a) (69h). In addition, the G L/-G loosening signal AVVR,A
V'VL i-J:, Has#s estrus organ (72h) (72
a) (D is supplied to the input terminal 1, this output terminal is
It is connected to the other input terminal of the OR gate (70a) (711b).

The first and second embodiments of the present invention (the approximate control circuits described above are implemented as described above, but next, there are a number of exceptions regarding this function).

Also in this case, it is assumed that the right side of the road surface is the low side. )
Then, when the brake holding signal @ EVVR is generated from the right front wheel (6a) at a time δ after switching the switch (3sa bar: +5b) (39a) (3q), this is off (69a). is supplied to the flow control circuit/intensifier (40a) through the flow control circuit/intensifier (40a).'?As a result, the solenoid section (3Uc) of the switching valve (4C) is switched to the B position, and the right front wheel (6a) The braking force of the front right wheel (6a) is held constant at a certain time.
- When the tension loosening signal AVVR is generated, this signal is supplied to the current control circuit (38a) via the current control circuit (70a) and switches the switching valve (4c) to the C position. As a result, the braking force on the right front wheel (6a) f/) is reduced. On the other hand, the brake release signals A and V VR are supplied to the pulse generator (72h), and this output is supplied to the OR gate (7ub), so this output is also "L".
Then, K is supplied to the other current control circuit/amplifier (40b). From the pulse transmitter (72b), predetermined signals are output from the pulse generator (72b).
- In this high 1 novel, the pulse is generated in the current control circuit/amplifier (4ob), and the l/bell ""i" is input to the solenoid part (3ob) of the switching valve (4d). Apply a signal to switch this switching valve 1!:C position. Decrease the pulse duration time t/-. Then, until the missing pulse, the current control circuit/amplifier (Jo
The free flow from b) is inside and the switching valve (4b)
fI:j: Switch to B position, h-ru.

Thereafter, by switching alternately as 1i1B, , C, B, C..., the left front wheel (6b)
) Brake force (荊) will be reduced step by step.

When the signals AVVR and BVVR disappear, the braking force of the right front wheel (6a) increases again, but at this time, the output of the Noagu (65b) becomes @l" υ, while the signal AVZVR is already "l"K Therefore, the output of Ando Goo (66b) is 111. Therefore, the pulse generator (67b) is driven. Also, since the braking friction coefficient of the right road surface is currently lower, the low side The output of the discrimination circuit συ is @0#, and the AND gate (6
8b) becomes conductive in response to the output of the pulse generator (67b). That is, the pulse output of the OR gate (69b) is supplied to the current control circuit/amplifier (4Ub). As a result, the solenoid part (aob) of the switching valve (4b) changes to 0'', ``λ'', ``0'', ``earth''...
The level of gold will be increased slowly in a stepwise manner repeatedly.

Then, when the brake holding signals EVVR, BVVL are generated from the right front wheel (6a) or the left front wheel (6b),
Anti-skid control is performed by repeating the above-described actions.

It is clear that this modification example also performs approximate select low control as described above, and has the same effects as the above embodiment.

FIG. 7 shows a second modification of the approximate select low control circuit (37a) in the first or second embodiment of the present invention. (6a) (6b) Brake force holding signal EVVR
.

EVVL ff, off /l -t (74a) (74b
) O and F) are supplied to the input terminals, and the output terminals are supplied to the current control circuit and amplifier (40a) (40b). In addition, the brake release signal inputs VVR and AVVL are supplied to the current control circuit and amplifier (40a) (40b), and are also connected to the input terminals of the off delay timers (75a) (75b), and are connected to the output terminals of the off-delay timers (75a) (75b). are connected to the set terminals SK of the 7-rip flops (76b) (76a), and to the reset terminals R of the 7-rip flops (76a) (76b) on the other side.

Also, the Q of these flip-flops (76a) (76b)
The output terminal is connected to the other input terminal of the above-mentioned OR gates (74a) (74b).
The output terminal of 4b) is the current control circuit/amplifier (40a) (
40b).

This modified example is configured as described above, and its operation will be explained next. Assuming that the right side of the road surface is the low side and the switch (38a) (38b) is switched, when the brake hold signal EVVR is generated from the front Jim (6a) on the right side, this is the
(74a) is supplied to the current control circuit and amplifier (40a), and the solenoid part (30c) of the switching valve (4c) is switched to the B position to maintain a constant braking force on the right front wheel (6a). do. Next, when the brake release signal AVVR is generated from this front wheel (6a), it is also supplied to the current control circuit and amplifier (40a), and the solenoid part (30c) of the switching valve (4C) is excited at level @l#. Been,
The switching valve (4C) can be switched to the C position. This results in
The braking force of the right front wheel (6a) is reduced. On the other hand, this brake release signal AVVR is supplied to the off delay timer (75a), and its output becomes l#.
This is supplied to the set terminal S of one 7-rip 70 tube (76b), and this Q output becomes "L" and is supplied to the OR gate (74b). Therefore, by supplying the current to the current control circuit/amplifier (40b) via the OR gate (74b), the solenoid section (30b) of the switching valve (4b) is controlled by the current at the level of 0. switch to position B. Therefore, the braking force on the left front wheel (6b) is kept constant.

And the brake release signal AVVR for the right front wheel (6a)
disappears, the brake force on the right front wheel (6a) is increased again, but the output of the off delay timer (75a) is
During anti-skid control, this is supplied to the set terminal S sum of the other 7-lip valve A tube (76b), and the Q output is still "I", so it is too low (76b).
4b), and the solenoid part (30b) of the switching valve (4b) is also controlled at the level 11#, so that the braking force of the left front wheel (6b) is kept constant. Then, when the brake release signal AVVL is generated on the high-side front wheel (6b), this signal is transmitted to the flip 70 knob (76b) via the off delay timer (75b).
), the output of the Q output terminal becomes "0".

Therefore, the output of the OR gate (74b) becomes "θ', and the brake release signals A and VVL generated at this time
The brake is lowered from K.

Does this modification also have the same effect as the above embodiment? Since it is clear that this is the case, the explanation thereof will be omitted.

FIG. 8 shows a third modification example □□□ of the approximate selenium a-control circuit (37a) in the first or second embodiment of the present invention, but it is different from the modification example in FIG. Delay timer (75a) (75b) and 7-lip 7CI knob (76a)
) (76b) on delay tie? -(78a)(
78b) The only difference is that f is provided, but when the right side of the road surface is on the low side, the brake release signal & VVR is generated first from the right front wheel (6a), and this causes the brake release signal & VVR to be generated from the right front wheel (6a). The braking force is relaxed, but in this modification, the braking force of the high-side front wheel (6b) is not immediately held constant, but is delayed by the on-delay timer (78a). After the elapse of time, the upper output becomes "l", and the flip 70 knob (
The output is supplied to the set terminal S of 76b), and the Q output is “
1'', and the output of the high side front wheel (6b) is held constant.

In this modification, the working tool in the second modification is a-
Instead of holding the brake release signal of the front wheel (6b) on the high side at a constant level immediately after the brake release signal is output to the side front wheel (6a), However, until then, the braking force is increased, so in the modification shown in FIG. 8, the braking force can be more fully supplemented. The other effects are exactly the same.

Although the embodiments of the present invention have been described above, the present invention is of course not limited to these, and various modifications can be made based on the technical idea of the present invention.

For example, in the first embodiment, the on-delay timer (62a) (6
Although the delay time in 2b) was set constant and the pressure reduction time of the high-side front wheel was set constant, the on-delay timer may be made variable and may be changed depending on the magnitude of deceleration, for example.

In addition, in the first modification, the brake pressure of the high-side front wheels was reduced in a pulsed manner throughout the pressure reduction period of the low-side front wheels, but the brake pressure was reduced only during a part of the pressure reduction period of the a-side front wheels. The brake pressure on the side front wheels may be reduced in a pulsed manner.

Further, in the third modification, the pressure is increased continuously until a predetermined period of time has elapsed after the start of pressure reduction of the Roseide side front wheels, but the pressure may be increased in a pulsed manner.

Further, in the above embodiment, the front wheels are subjected to select low control under each predetermined condition, but the front wheels may be selectively low controlled under the following predetermined conditions.

In other words, when the first depressurization signal is generated at the front wheel with a lower braking friction coefficient (low side), the brake pressure of the front wheel with a higher braking friction coefficient (high side) is held constant.
After the pressure reduction signal disappears, the brake pressure of both front widths may be controlled in accordance with the rotational state of the front wheel with the lower braking friction coefficient.

Alternatively, the brake pressure of the front wheel with the higher braking friction coefficient is continued to be increased until a first predetermined time period elapses after the first pressure reduction signal is generated in the front wheel with the lower braking friction coefficient 7, After the first predetermined time elapses, the brake pressure of the front wheel with the higher braking friction coefficient is held constant until a second predetermined time elapses or until the pressure reduction signal disappears, and thereafter the braking friction coefficient may be 1 or more so that the brake pressures of both front widths are controlled in accordance with the rotational state of the front wheel with the lower one.

In addition, in the above embodiment, an approximate vehicle speed signal is generated for each wheel in order to form the IJ knob signal, but instead, an approximate vehicle speed signal is generated for each wheel on the diagonal line.
That is, it may be formed by combining the right front wheel and the left rear wheel, the left front wheel and the right rear wheel, or it may be formed from the highest wheel among all the wheels.

Furthermore, although the X piping has been described in the above embodiments, the present invention is also applicable to brake piping types that separate the front and rear wheels.

In addition, in the second embodiment described above, the brake force is increased in steps to gradually increase the brake, but by providing a variable throttle, for example, the above conditions can be satisfied in the first control cycle. In this case, the throttle passage may be made smaller to allow for gradual upward movement. Furthermore, the increasing gradient of the brake pressure of the rear wheel on the high friction road surface side may be made smaller than normal not only in the first control cycle but also in several or all subsequent control cycles.

Further, the logical expression for detecting a split road surface may be the following instead of the one described above.

ffxbchi, AVZVR, AVZHR4VZVL +
AVZVL, AVZHL, AVZVR=tCr)
Toki and Luka, Aruiha AVZVR, AVZHR, A
VZHL +AAVZVL, AVZHL, AVZ
It is also possible to set HR=1. Alternatively, it may be a logical combination of other signals.

Alternatively, a splat road surface may be detected by detecting lateral acceleration using an accelerometer or by detecting a rolling moment using a yaw sensor.

In addition, in the above embodiment, the road surface detection device IA
Z (D Do N Ill a 'e AVZVR-
AVZHR-AvZVL, AVZHL+ AVZVL,
AVZHL, AVZVR, AVZHR= 1 (7)
It is assumed that the road surface is a split road surface, and when this logical formula becomes 0, the switches (38a) (38b) (39a) (39
The system switches to the original position b), but instead, if the time difference between successive brake release signals for both rear wheels becomes less than a certain value, it is determined that the road surface has exited split mode and the switch is switched. The device may be switched back to its original position. Alternatively, it may be determined that the road surface is a split road when the time difference between the brake release signals for both rear wheels exceeds a certain value.

Furthermore, in the second embodiment, the circuit shown in Fig. 5 is used to slowly increase the brake pressure on the rear wheel on the high side.
Other known circuit configurations may also be used.

〔Effect of the invention〕

As described above, according to the control method of the anti-skid control device according to the present invention, the brake pressures of both front elms are controlled independently on a normal road surface, and both rear wheels are controlled in select low. Furthermore, when a split road surface is detected, both front wheels are controlled in select low under predetermined conditions, and the brake pressure of both rear wheels is controlled independently, so none of the wheels lock up and the difference in brake fluid pressure between the front wheels is controlled. It is possible to suppress the occurrence of yaw moment in the vehicle as much as possible, and the brake pressure of both rear wheels can be increased to the maximum until each reaches the lock pressure, so the braking distance can be shortened. .

[Brief explanation of the drawing]

Fig. 1 is a piping system diagram of a vehicle anti-skid control device according to a first embodiment of the present invention, Fig. 2 is a circuit diagram showing details of the control and unit in Fig.
FIG. 4 is a circuit diagram showing the details of the approximate select low control circuit in FIG. Circuit diagram showing details of brake pressure gradual increase circuit, No. 6
8 are circuit diagrams showing modifications of the approximate select low control circuit in the first and second embodiments of the present invention, respectively. In the figure,

Claims (9)

[Claims] (1) The braking friction coefficients of the left and right road surfaces are different in the control method of the anti-skid control device, in which the brake pressure of both wheels on one axle is controlled independently, and the brake pressure of both wheels of the other axle is selectively low controlled. Normally, the brake pressure of both front wheels of the front axle is independently controlled, and the brake pressure of both rear wheels of the rear axle is selectively low controlled. A control method for an anti-skid control device, characterized in that the brake pressures of the two front wheels can be switched to select low control under predetermined conditions, and the brake pressures of the two rear wheels can be switched to independent control according to an output. (2) When the brake pressure of both rear wheels is switched to independent control based on the output from the split road surface detection device, a brake pressure release signal is generated for the rear wheel with the lower braking friction coefficient, and the braking friction coefficient If a brake pressure release signal is not generated for the rear wheel with a higher braking friction coefficient, at least during the first control cycle, the increase gradient of the brake pressure of the rear wheel with a higher braking friction coefficient is set to be higher than normal. 2. The control method for an anti-skid control device according to claim 1, wherein the anti-skid control device is made small. (3) The anti-skid control device according to claim 1 or 2, wherein the predetermined condition is such that the depressurization time of the front wheel with a higher braking friction coefficient is shorter than that of the front wheel with a lower braking friction coefficient. Control method. (4) During the pressure reduction period and/or pressure increase period of the front wheel with the lower braking friction coefficient under the predetermined conditions, the braking friction coefficient increases the pressure reduction gradient and/or pressure increase gradient of the front wheel with the higher braking friction coefficient. 3. The control method for an anti-skid control device according to claim 1, wherein the pressure reduction gradient and/or pressure increase gradient of the lower front wheel are made smaller. (5) The predetermined conditions are such that the depressurization time of the front wheel with the higher braking friction coefficient is shorter than that of the front wheel with the lower braking friction coefficient, and the depressurization gradient of the higher braking friction coefficient is set so that the braking friction coefficient is 3. The control method for an anti-skid control device according to claim 1, wherein the anti-skid control device is made smaller than the lower one. (6) Under the above predetermined conditions, the braking friction coefficient is maintained between the time when the first decompression signal is generated on the front wheel with the lower braking friction coefficient and the time when the first decompression signal is generated on the front wheel with the higher braking friction coefficient. 3. A control method for an anti-skid control system according to claim 1, wherein the brake pressure of the higher front wheel is maintained constant. (7) Under the above predetermined conditions, the brake pressure of the front wheel with a higher braking friction coefficient is continued to increase until a predetermined time period elapses after the first pressure reduction signal is generated on the front wheel with a lower braking friction coefficient. 2. The brake pressure of the front wheel with the higher braking friction coefficient is maintained constant until the first pressure reduction signal is generated in the front wheel with the higher braking friction coefficient after the predetermined time has elapsed. 2. The control method in the anti-skid control device according to item 2. (8) When the first depressurization signal is generated on the front wheel with the lower braking friction coefficient under the predetermined conditions, the brake pressure of the front wheel with the higher braking friction coefficient is held constant, and after the depressurization signal disappears, the brake pressure is maintained constant. 3. The control method for an anti-skid control device according to claim 1, wherein the brake pressures of both front wheels are controlled in accordance with the rotational state of the front wheel having a lower coefficient of dynamic friction. (9) Under the predetermined conditions, the brake pressure of the front wheel with the higher braking friction coefficient is increased until the first predetermined time period elapses after the first pressure reduction signal is generated on the front wheel with the lower braking friction coefficient. After the first predetermined time has elapsed, the brake pressure of the front wheel with the higher braking friction coefficient is maintained constant until the second predetermined time has elapsed or the pressure reduction signal disappears; 3. The control method for an anti-skid control device according to claim 1, wherein thereafter, the brake pressures of both front wheels are controlled in accordance with the rotational state of the front wheel having a lower braking friction coefficient.