JPH02102861A - Antiskid controller - Google Patents

Abstract

PURPOSE:To actualize compatibility of braking efficiency and running stability by judging a frictional stage between a wheel and road surface, and performing control over a high-select approach on a normal uniform road, while during sudden turning and on a low frictional road or the like, preferentially controlling brake pressure of the wheel at a side being considered to be yet more important. CONSTITUTION:In this controller, there are provided with a braking force adjusting means M1 controlling braking force between a first wheel and a second wheel, both wheel speed detecting means M2, M3 detecting each wheel speed, a running state calculating means M4 calculating a vehicle running state on the basis of the detected wheel speed, and a frictional state judging means M5 judging a frictional state between the wheels and a road surface on the basis of the calculated running state. In addition, there are provided with a weighting factor output means M6, which selects a weighting factor to be used at a weighting mean on the basis of the judged result here at, and a weighting means wheel speed calculating means M7 for finding a weighting mean wheel speed on the basis of each wheel speed and the weighting factor. Then, the braking force adjusting means M1 is controlled according to the weighting mean wheel speed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an anti-skid control device that prevents wheel locking during wheel braking, and more particularly to one that controls two different wheels using a common pressure.

[Prior Art] Various anti-skid control devices with simplified structures have been proposed. For example, JP-A-52-1
As stated in Publication No. 13093, in order to separate the front wheel side and rear wheel side brake systems and control the different brake pressures of the left and right wheels with a common pressure control device, wheels with a large slip ratio, to put it simply, are used. Low selection (hereinafter referred to as low selection), which performs brake control only on wheels with a relatively low rotational speed, and brake control only on wheels with a small slip ratio, in other words, wheels with a relatively high rotational speed. It is known that the high selection (hereinafter referred to as "high selection") performed is switched between the front wheels and the rear wheels so that they are opposite to each other. However, with this device, control is switched between high select and low select, so the non-selected wheel of the one controlled by high select becomes locked, which may cause uneven tire wear or vehicle movement depending on the road surface. Stability, especially steering performance, may deteriorate, and in those controlled by low select,
There was a problem that braking performance deteriorated. Therefore, in order to solve this problem, as stated in Japanese Patent Application No. 63-83370, the wheel speeds of the first and second wheels controlled by a common brake pressure, the vehicle body speed, and the difference in both wheel speeds were developed. A system has been proposed in which a weighted average wheel speed is determined from a weighting coefficient based on the driving state, and brake force control is executed in accordance with this weighted average wheel speed.

[Problems to be Solved by the Invention] However, in these conventional devices, the weighting coefficients are continuously switched depending on the driving conditions such as the vehicle speed and the speed difference between both wheels, so the braking efficiency and the braking efficiency are not adjusted according to the driving conditions. Both driving stability and driving stability are achieved. However, depending on the road surface condition, for example, when driving on a cross road where the left and right wheels have different coefficients of friction, or when driving on a low friction road, the non-selected wheel of the one controlled by the aforementioned high select may lock. This resulted in a decrease in vehicle running stability, and in the case of low select control, braking performance decreased, resulting in an insufficient balance between braking efficiency and running stability.

Therefore, the present invention aims to solve the above problems,
An object of the present invention is to provide an anti-skid control device that achieves both braking efficiency and running stability in response to running conditions and road surface conditions.

[Means for Solving the Problems] In order to achieve the above object, the present invention has the following configuration as a means for solving the problems. That is, as illustrated in FIG. 1, a single brake force adjustment means M1 that commonly controls the brake force of a first wheel and a second wheel different from the first wheel; The first step is to detect the wheel speed of each of the wheels. Second wheel speed detection means M2. M3, and the first. Second wheel speed detection means M2. a driving state calculating means M4 for calculating the vehicle driving state based on the wheel speed detected by the driving state calculating means M3; and a friction means for determining the friction state between the wheels and the road surface based on the driving state calculated by the driving state calculating means M4. a state determining means M5; and a weighting coefficient output means M6 for selecting and outputting a weighting coefficient for use in the weighted average from a plurality of predetermined weighting coefficients based on the determination result of the friction state determining means M5; Said 1st. Weighted average wheel speed calculation means M7 for calculating a weighted average wheel speed based on the second wheel speed and the weighting coefficient; and outputting a control signal to the brake force adjustment means M1 to control the brake pressure according to the weighted average wheel speed. This is the configuration of an anti-skid control device characterized by comprising: a control means M8;

[Function] The anti-skid control device having the above configuration has the following features. Second wheel speed detection means M2. M3 detects the wheel speeds of the first wheel and the second wheel, the running state calculating means M4 calculates the vehicle running state based on the wheel speeds, and the friction state determining means M5 detects the wheel speeds of the first wheel and the second wheel based on the running state. The friction state with the road surface is determined, the weighting coefficient output means M6 selects and outputs a weighting coefficient based on the determination result, and the weighted average wheel speed calculation means M7 selects and outputs the weighting coefficient based on the determination result. A weighted average wheel speed is determined based on the second wheel speed and the weighting coefficient, and the control means M8 outputs a control signal to control the brake pressure according to the weighted average wheel speed.
The brake force adjustment means M1 executes brake force control according to the weighted average wheel speed. Therefore, braking force control is executed depending on the driving condition and the road surface condition to achieve both braking efficiency and driving stability.

[Example code] Embodiments of the present invention will be described in detail below based on the drawings.

FIG. 2 is a schematic diagram of an anti-skid control device applied to a rear wheel drive vehicle, which is an embodiment of the present invention.

1 to 4 represent each wheel of the vehicle; 1 is the right front wheel, 2 is the left front wheel, 3 is the right rear wheel, and 4 is the left rear wheel. Reference numerals 5 to 7 designate vehicle speed sensors corresponding to wheel speed detection means M2 and M3, respectively, and are electromagnetic pickup type or photoelectric conversion type vehicle speed sensors for detecting the rotational speed of each wheel 1 to 4. The right front axle vehicle speed sensor 5 is installed near the right front wheel 1.
generates a signal according to the rotation of the The left front axle vehicle speed sensor 6 is attached near the left front wheel 2 and generates a signal in accordance with the rotation of the left front wheel 2. On the other hand, the rear wheel speed sensor 7 is attached to a propeller shaft 8 that transmits power to the right rear wheel 3 and the left rear wheel 4, which are drive wheels, and the propeller shaft 8 corresponds to the average rotation speed of the right rear wheel 3 and the left rear wheel 4. A signal is generated in accordance with the rotation of the shaft 8. These signals are treated as wheel speed signals.

Moreover, 9 to 12 are hydraulic brake devices, respectively, and the hydraulic brake device 9 is installed on the right front wheel 1, and the hydraulic brake device 10 is installed on the right front wheel 1.
is provided on the left front wheel 2, the hydraulic brake device 11 is provided on the right rear wheel 3, and the hydraulic brake device 12 is provided on the left rear wheel 4. These hydraulic brake devices 9 to 12 operate to apply braking force to the wheels 1 to 4 in response to hydraulic pressure from a hydraulic cylinder 15 that generates brake hydraulic pressure in response to depression of the brake pedal 13. . The hydraulic pressure from the hydraulic cylinder 15 is maintained at an appropriate pressure reduction level by two actuators 17 and 19 controlled by an electronic control circuit 16, which will be described later, so as to achieve anti-skid for each wheel and obtain high braking force◆ It is configured to be pressurized. Among the actuators 17.19, 17 is a front wheel actuator that commonly corresponds to the hydraulic brake device 9°10 of the front wheels 1.2;
Reference numeral 19 denotes a rear wheel actuator corresponding to the recuperation brake devices 11 and 12 of the rear wheels 3 and 4.

20.22 is a hydraulic pressure pipe for guiding the adjusted hydraulic pressure from the actuator 17.19 to the hydraulic brake devices 9 to 12; 9. A hydraulic pipe line 22 is provided between the rear wheel actuator 19 and the rear wheels 3 and 4.
represents a hydraulic conduit provided between the hydraulic brake device 11 and the hydraulic brake device 11.12 of the vehicle. In this embodiment, the first. The second wheel is the right front wheel 1
゜Corresponds to the left front wheel 2, and adjusted hydraulic pressure is supplied from the actuator 17 to the hydraulic brake devices 9 and 10 via the hydraulic pressure pipe 20, and the first. The second wheels are configured to be controlled by a common braking force. The hydraulic brake devices 9 and 10, the hydraulic pipe line 20, the actuator 17, and the hydraulic cylinder 15 constitute a brake force adjusting means M1. Also, the right front wheel 1. Speed sensors 5 and 6 that detect the respective wheel speeds of the left front wheel 2 are the first. Second wheel speed detection means M2. Configure M3. As described above, in the first embodiment, the present invention is applied to the right front wheel 1. This is applied to the left front wheel 2, and the following description will focus on the front wheel side.

As shown in FIG. 3, the electronic control circuit 16 is operated by being supplied with power from a battery 27, and receives various human power signals related to the braking state of the vehicle, such as speed signals from vehicle speed sensors 5 to 7, Signals from the stop switch 28 that detects the braking operation of the brake pedal 13 are manually input, and based on these signals, various control devices, in this case actuators 17 and 19 that control the brake fluid pressure, are sent. The control signal is configured to output a control signal.

Next, the configuration of this electronic control circuit 16 will be explained in detail.

In the electronic control circuit 16, 30 to 32 in the figure
are waveform shaping amplifier circuits, and the waveform shaping amplifier circuit 30 converts the signal from the vehicle speed sensor 5 into a microcomputer 35.
The other waveform shaping amplifier circuits 31 and 32 are configured to produce similar pulse signals, respectively. 33 is a buffer circuit electrically connected to the stop switch 28, 34 is a power supply circuit for supplying the power supply voltage supplied by the battery 27 as a constant voltage to the entire device when the ignition switch 27a is turned on, and 35 is a well-known CP ( J35a, ROM35b, RAM
35c, I10 circuit 35d, etc. 36 and 3 are drive circuits that output according to control signals from the microcomputer 35, respectively. Of these, 36 is a front wheel actuator drive circuit for driving the electromagnetic solenoid of the front wheel actuator 17; This is a rear wheel actuator drive circuit for driving the electromagnetic solenoid of the rear wheel actuator 19.

Next, the processing and operation of the anti-skid control device configured as described above will be explained.

When the ignition switch 27a is turned on, a constant voltage from the power supply circuit 34 is applied to the microcomputer 35, etc., and the CPU 35a of the microcomputer 35 starts executing arithmetic processing according to a program preset in the ROM 35b.

Next, the control executed by the electronic control circuit 16 will be explained based on the flowchart shown in FIG.

First, initialization processing such as memory clearing and flag reset is executed (step 100). Next, a process of reading the detection signals of each sensor and switch described above is performed (step 200). Based on this read wheel speed signal, the wheel speed VIJFL, VIJ of each wheel is determined.
FR+ VuRR and wheel acceleration DVwFt, DVu
Driving state calculation means M4 that calculates pρ* DVwau
Processing is performed as follows (step 300). continue,
Right front wheel 1. Friction state determination processing is performed as the friction state determination means M5 for determining which of the left front wheels 2 should be weighted and controlled preferentially (step 400).

Next, weighting coefficient output means M6 selects and outputs a weighting coefficient K based on the result of this friction state determination process.
Processing is performed as follows (step 500). Processing is performed as a weighted average wheel speed calculation means M7 that calculates a weighted average wheel speed VFn and a weighted average wheel acceleration DVi1pn, which will be described later, using this weighting coefficient K (step 600). Subsequently, this weighted average wheel speed V, IFn, weighted average wheel acceleration DVwpn
A process of setting the operation mode of the actuator 17, 19 is performed (step 700). After outputting a switching control signal to the electromagnetic solenoid of the actuator 17 to achieve this set operation mode (step 800)
, the process returns to step 200.

Note that the processing in steps 700 and 800 works as control means M8. Thereafter, the anti-skinned control process repeats steps 200 to 800 at predetermined intervals.

Next, details of the arithmetic processing in step 300 will be explained based on the flowchart of FIG.

First, each wheel speed Vwpt + Vwrt+, Vwup t is determined by signals from each wheel speed sensor 5 to 7.
- Calculate (step 31O). Next, the determined wheel speed VwFL, VIJFR+VwpR'
e Differentiation, T each wheel acceleration DVupt, DVup
p, DVIJRR is calculated (step 320
). Next, the maximum value of each wheel speed V41FL + Vwpp + V4JRp obtained in the process of step 310 is set as the vehicle body speed V! l [V mouth ← MA X (VwFL
.

VwFR + VwaR)
)” 330). Then, the left wheel speed VupL and right wheel speed VLJLρ of the right front wheel 1 and the left front wheel 2 are compared in magnitude, and the wheel speed on the low speed side is determined as the low speed wheel speed VwpLo [V
iJEt.

← Find it as MIN(VmiFL, VwpR). Also, the wheel acceleration on the low speed side is the low speed wheel acceleration DV
Find it as liLO (Ste Tsubu 340). continue,
Similarly, the right front wheel 1. Comparing the left wheel speed VwFL and right wheel speed VIJFR of the left front wheel 2, the wheel speed on the high speed side is determined as the high speed wheel speed VIJFI [VWI-H+←MAX
(VwpL, VurR). In addition, the wheel acceleration on the high-speed side is called the high-speed wheel acceleration DVIJFHI.
(step 350).

Next, details of the friction state determination process of the step knob 400 will be explained with reference to the flowchart of FIG.

First, the first flag F is set by the process described later.
1.It is determined whether 11ER is Hani 1 (St.
Whelk 402). If it is determined that the shift is not 1, the drive signal to the actuator 17 becomes a pressure reduction output state by a process not shown, and the drive signal becomes 1 until the next time it switches to a pressure increase output state, and otherwise the value is set to 1. Depressurizing flag Fl: I[, , which is set to 0.

It is determined whether or not the value is 1 (step 404)6
If it is determined that the value is 1, that is, the brake pressure is in a reduced pressure output state, it is determined whether the high speed wheel speed VwpH+ is equal to or higher than the high speed reference speed KVwH determined based on the wheel speed (step 406). When the high-speed wheel speed VIJIHI is equal to or higher than the high-speed reference speed I (V, A), or when the high-speed wheel speed VIAr:H+ is smaller than the high-speed reference speed KVu+q, the flag Fl-
IDROI) to the value 1 (step 408
), it is determined whether this flag FHDROI) is the value 1 (step 410). Flag F, 4uRop
is not the value 1, that is, high wheel speed Vu+:1.
When l+ is equal to or higher than the high-speed reference speed KVug, the high-speed wheel speed Vur1. The speed difference ΔVwp between I+ and the low-speed wheel speed VwrLO is calculated, and the process is performed to sequentially integrate the speed difference ΔVwp each time this routine is repeatedly executed (step 412
). While integrating the speed difference △Vwp, the counter CTD
Execute the process of counting and subtracting the first shift of I:L (
Step 414).

Next, it is determined whether the low speed wheel speed Vu'LO is smaller than the low speed reference speed KVIJL determined based on the wheel speed (step 416).The low speed wheel speed VwE(
When o is smaller than the low reference speed KVIiL, the first
Set the value l to the flag FHIER (Step 4)
18).

On the other hand, the low speed wheel speed VurLo is the low speed reference speed KV-5.
If this is the case, it is determined whether one count of the counter CTDEL is smaller than a predetermined reference value KToεL1 (msec) (step 420). When the value of the counter CTDEL is smaller than the reference (1K T DEL +), that is, when the predetermined time has not elapsed, it is determined whether the integrated value of the speed difference △Vwr resulting from the process of step 412 is equal to or greater than the predetermined reference speed f1MKVwo[1. (step 422). Then, when the speed difference ΔVμ is integrated (the speed difference is equal to or higher than the reference speed KVLJ[lEL), the process of step 418 is executed and the first flag Fw+
Set cpE Kobani 1. Furthermore, when the integrated value of the speed difference ΔVu'' is less than the reference speed value KVuoEt, the process returns to the main routine.

On the other hand, the flag FHDpop is set by the process of step 410.
is determined to have a value of 1, that is, the high wheel speed VIJF
When l-11 is less than the high-speed reference speed KVIJ)1, a second flag FLOER, which will be described later, is set to the value 1 (step 424).

If the value 1 is set to the first flag F141[:R in the process of step 41, or if the value 1 is set to the second flag FLOER in the process of step 410, or if the value 1 is set to the second flag FLOER in the process of step 420, the counter CT[ l
When it is determined that the value of EL is greater than or equal to the reference value KTocLt and a predetermined time has elapsed, the integrated value of the speed difference ΔVup is cleared (step 426).

Then, the first shift of the counter CTDI:L is cleared (step 428), and the process returns to the main routine.

On the other hand, if it is determined that the decompression flag FqtLm is not 1 in the process of step 404, the flag F)I
DROP is cleared (step 430), and a second flag FLocp, which will be described later, is cleared (step 4).
32), execute the processing from step 412 onwards.

By executing the above-described process, as shown in FIG. 9(a), after the drive signal of the actuator 17 becomes the reduced pressure output state (step 404), it is determined that the high speed wheel speed vupold is equal to or higher than the high speed reference speed KVwH ( Ste Tsubu 40G),
and low wheel speed Vupt.

is smaller than the low-speed reference speed KVIA (step 416), the first flag PHIER is set to (direct 1) (step 418). , two criteria KVIJH by threshold method.

Judgment is made using KVIJL, and if the difference in drop is large, the road surface friction coefficient lL of each of right front wheel 1 and left front wheel 2 is determined.
It is determined that the difference is large, and the first flag FHIEII+ is set to 1.
Set straight 1.

Alternatively, as shown in FIG. 9(b), depending on the integration method, the integrated value of the speed difference ΔVwF between the right front wheel 1 and the left front wheel 2 will be changed from the reduced pressure output state (step 404) until a predetermined time elapses ( Steps 414 and 420), and when the reference speed (I r < V woEL 9 is exceeded (Step 422), the first flag F14+εR is set to 1
Se soto. This allows gentle braking on road surfaces where the front right wheel 1 and the front left wheel 2 have slightly different road friction coefficients μ, which cannot be detected by the threshold method, and on road surfaces where the front right wheel 1 and the front left wheel 2 have different road friction coefficients U. The first flag F1.11
[Set 1 shift 1 to R.

That is, the first flag FHIER is set to (i1) when the friction conditions between the right front wheel 1 and the left front wheel 2 and the road surface are different between the left and right wheels 1 and 2 as described above.

In addition, the second flag F LOER is set to the high wheel speed V as shown in FIG. 10(a).
When MFI41 is the high-speed reference speed KV, which is less than 1.4 (step 406.408.410), the friction state between the right front wheel 1 and the left front wheel 2 and the road surface is such that both axles 1°2 are running on a low friction road. This is the case in the middle.

On the other hand, as a result of the process in step 402, the first flag F
If it is determined that HIII:R is set to a value of 1, it is determined whether a flag FLDROP set by a process described later is a value of 1 (step 434). If it is determined that the flag (FLDROI) is not 1, the low wheel speed V. It is determined whether PLO is smaller than a predetermined first reference speed KVwo+ (step 436). When it is determined that the low speed wheel speed Vw'to is smaller than the first reference speed KVwo+, the flag FLDROP is set to the value 1 (step 438).

When this flag FLDρ0ρ is set to (In 1),
Alternatively, the low wheel speed V is determined by the process in step 436.
If wpLo is equal to or higher than the first reference speed KVuo+, this routine is repeatedly executed without setting the value 1 to the flag FLDROP or after setting the value 1 to the flag FLLDROP. It is determined that the flag FLohop is 1 through the processing, and the low speed wheel speed Vupto is set to the first reference speed KVwo.
If the second reference speed KViio2, which is higher than
2).

When the speed difference ΔVwp is smaller than the reference value KVnEL2, the slope of the counter CTD[:L is equal to the predetermined reference value KT.
It is determined whether or not it is greater than or equal to oεL2 (msec) (step 444). When the f axis of the counter CTDEL is smaller than the reference (the axis KToεL2), the counter Cyo
tt is counted up (step 446), and the process returns to the main routine.

By repeatedly executing this routine, it is determined that the flag FLDρop has a value of 1 in the process of step 434,
That is, the low wheel speed VIJ "Lo is the first reference speed KVwn
+ If, after the low speed wheel speed VIJFLo is determined to be equal to or higher than the second reference speed KVIJD2 by the processing in step 440, or the slope of the counter CTDI:L reaches the reference value KTDl by the processing in step 440.
: If it is determined that it is L2 or more and a predetermined time has elapsed, the first flag PHIεR is cleared (step 448). Then, by clearing the value of the flag (FLDROI) (step 450), or by processing in step 442, the speed difference △Vl, IF is set to the reference value KVl.
] If it is determined that the value is EL2 or higher, the counter CTDE
The first shift of L is cleared (step 452). Then return to the main routine.

That is, by repeatedly executing this routine, as shown in FIG. 9(c), the low speed wheel speed VurLo reaches the first reference speed K.
After becoming smaller than Vi+o+ (step 436
), when it is determined that the second reference speed KVwo2 or higher is reached (step 440), the value of the first flag Fw+qp is set to 0 (step 448). This is the first flag F+
, n "When q is 1 (controlled by high select), the wheel speeds Vw of the front right wheel 1 and the front left wheel 2 are
pR* VwEL falls, the drive signal of the actuator 17 becomes a reduced pressure output state, and the hydraulic brake device 9,
10 is in a state where the pressure level is slightly lowered. and,
It is determined whether or not the wheel speed of the car vaIIll (the side that has fallen significantly) on the low-friction road side has recovered and is on the rise. When there is a tendency to increase, it is determined that the friction between the right front wheel 1 and the left front wheel 2 and the road surface is such that the difference in the friction coefficient B between the left and right axles 1.2 is small, and the first flag F141Eρ is cleared. do.

Or, it is determined that the difference in grip force between the road surface and both wheels has become smaller due to a sharp turn on a high-friction road, and the first flag F+-+ is set.
Clear +cρ.

Alternatively, as shown in FIG. 9(d), the speed difference ΔV
When wF continues for a predetermined period of time or more, it reaches the reference value ((V DEL
Even when it is smaller than 2 (Ste Tsubu 442. 444.
446), and similarly sets the value of the first flag P-- HIER to 0 (step 44B). If this cannot be determined by the process described above, for example, if gentle braking is performed and the drop in wheel speed is small, this process is executed to clear the value of the first flag FH11mR.

On the other hand, as shown in FIG. 10(b), the decompression flag F
After Ri-Lm becomes (direct 1), that is, after the actuator drive signal becomes a pressure reduction output state, it becomes a pressure increase output state and the pressure reduction flag FRELr+ becomes 0 (step 404). 2 Flag F LOIl-R value is 0
(Step 432).

Next, the above-mentioned weighting coefficient output processing (step 50
0) will be explained in detail with reference to the flowchart in FIG.

First, it is determined whether the first flag FHIερ has a value of 1 (step 510). When the first flag F81εR is Asahi 1, the left and right front wheels 1. 2 and the road surface, the front right wheel 1 and the front left wheel 2 are on a cross road where there is a difference in the coefficient of road friction H, or the front right wheel 1 and the front left wheel 2 are turning sharply, and the road surface is affected by the difference in wheel behavior between the front right wheel 1 and the front left wheel 2. It is determined that there is a difference in the friction state with
.

On the other hand, when the first flag FH1[R is not 1,
It is determined whether or not the second flag FLO["R has a value of 1 (step 530). When the first flag F old ε9 has a value of 0 and the second flag FLOεp has a value of 1, the left and right front wheels 1. It is determined that the vehicle is traveling on a low-friction road where the friction between the road surface and the road surface is small, and the weighting coefficient ■( is set to a predetermined maximum (
KML (0.5 in this embodiment) (step 54)
0).

Also, the first flag FH1i and the second flag F. When both ERs have an inclination of 0, it is determined that the friction state between the left and right front wheels 1.2 and the road surface is such that both axles 1.2 are running on a normal road surface, and a weighting coefficient of 1 ( The intermediate value [(MH (in this embodiment, 0°15)) is set (step 550). When the processing of any one of steps 520, 550, and 540 is completed, the process returns to the main routine.

Note that this intermediate value KMH does not have to be a fixed value,
It may be variable as shown in FIG. 12 depending on the vehicle speed VB. For example, if the vehicle speed VFI is 30 m/
Below h, emphasis is placed on braking efficiency at low speeds, and intermediate fff
i K M H is set to 0.1, and the vehicle speed V is set to 30 r
n / h) ;) When the speed is less than 70 km/h, the intermediate (i K M) 1 = 0.0025 Vo + 0.025
When the vehicle speed V9 is +n/hn/lower than 70, the intermediate value KMH is set to 0.000 to ensure uniform energization, prevent one-wheel locking on the road, and prevent uneven tire wear. It may be set to 2.

Moreover, the intermediate value KMH of the weighting coefficient is the vehicle body speed V9
Instead, as shown in FIG. 13, the low wheel speed Vwl=Lo and the high wheel speed V1−1 may be varied depending on which speed difference ΔVw. When the speed difference ΔVu is small, the intermediate value KMH is made small and the speed difference ΔVI
By slightly increasing the intermediate fi K M H as I increases, if the speed difference △V- is small and the left and right road surface friction coefficients and the loads on the left and right front wheels 1.2 are slightly different, it is close to high selection. control and obtain good braking efficiency. In addition, if the speed difference △Vw is somewhat large, control is performed using a weighted average wheel speed Vwpn, which will be described later, which reflects the wheel speed on the low speed side.
This prevents one-wheel locking and also prevents an unnecessary drop in braking efficiency as seen in low selection.

Next, the process of step 600 described above will be explained in detail.
weighted average wheel speed Vwp from pto, high speed wheel speed VWFI-11, and high speed wheel acceleration DVupH+. , weighted average wheel acceleration DV and H are calculated using the following formula.

Vwp+1 =KXVwrLo+ (IK)
Vw “w+D Vwpn =KX D VwFLo
+ (1-K) D Vwpw, weighting coefficient K
When driving on a cross road or the like where KEY is the minimum value (0 in this example), the weighted average wheel speed Vurr+ is determined by the high speed wheel speed Vur1, ll and the weighted average wheel acceleration DV, Jl:1. I is the high-speed wheel acceleration D of that wheel
High select control is performed to set VwFH+. Further, the weighting coefficient K is the maximum value I (ML (in this embodiment, 0.
5) When traveling on a low friction road etc., the weighted average wheel speed VwEr is the average speed and weighted average wheel acceleration DV upH of the low speed wheel speed Vi + pLo and the high speed wheel speed F 1-11, and the weighted average wheel acceleration DV upH is the low speed wheel acceleration DVu
An average value control is performed in which the average acceleration is set to ``to'' and the high-speed wheel acceleration DVwpx + which average acceleration.Furthermore, when driving on a normal uniform road surface where the weighting coefficient K is an intermediate value KMH (0.15 in this example). Sometimes, the weighted average wheel speed V\IFr'l is a speed closer to the high-speed wheel speed Vwpst, and the weighted average wheel acceleration DVIJFH is an acceleration closer to the high-speed wheel acceleration D Vurn+ of that wheel. Control toward high selection is performed.

Next, details of the operation mode setting process executed in the process of step 700 will be explained with reference to the flowchart of FIG.

First, it is determined whether the weighted average wheel speed VwFn is less than a reference speed KV determined based on the vehicle speed Ve (step 705).

When the weighted average wheel speed Vwr is less than the reference speed KV, a control flag F indicating that anti-skid/rotation control is in progress is set.
Set B to clay 1 (step 710).

Next, it is determined whether the weighted average wheel acceleration DVuF)1 is less than the acceleration reference KG determined based on the vehicle speed (9) (step 715). If the weighted average wheel acceleration D VwFH is less than the acceleration reference KG, hysteresis P is set to the acceleration reference KG (KG=KC;+P
) (Ste Tsubu 720).

After that, the decompression mode is set (step 725),
Return to main routine.

On the other hand, if it is determined in the process of step 715 that the weighted average wheel acceleration D VwFH is not less than the acceleration reference KG, the hysteresis P is reset -C (step 730), the holding mode is set (step 735),
Return to main routine.

Furthermore, in the process of step 705, the average speed V
When it is determined that wFr+ is not less than the reference speed KV, it is determined whether the flag FB during control f31 is 1 (step 745). If the under-control flag FB has a value of 1, it is assumed that the anti-skid control fan is in effect, and after resetting the hysteresis P (step 750), it is determined whether or not the edge area mode has been in effect for a predetermined period of time or longer ( Step 755
). If it is determined that the device is not in edge mode for a certain period of time,
The edge area mode setting is performed (step 760). This edge region mode is an operation pattern consisting of a short pressure increase and subsequent holding, which is repeated a predetermined number of times n.

Therefore, as shown in FIG. 11, the first flag F) 11E
After determining the value of R and switching the value of the first flag FHIER from 0 to 1, a predetermined time Td (30
0 +n5ec), the pressure increase time is increased with respect to the holding time of the edge area mode, the operation pattern period is shortened, and the number of repetitions n is increased, so that the pressure increase gradient of the wheel cylinder oil pressure is made relatively Enlarge. the result,
On a so-called straddling road where the left and right road surface friction coefficients μ are different, first, the wheel speed on the low-friction road side is controlled by looking at the drop in wheel speed V to 0, and the oil pressure that was kept low on the low-friction road is switched (first (Switching the head of flag FHIER from 0 to 1)
At the same time, the oil pressure can quickly rise to a level suitable for high-friction roads, resulting in good braking efficiency.

On the other hand, in the process of step 705, the average speed Vwp
It is determined that n is not less than the reference speed I (V, and
If it is determined in the process of the knob 745 that the control flag FB is not 1, the pressure increase mode is set (step 765
) a Also, in the processing of step 745, it is determined that the control flag FB is 1, and step 7
If it is determined in the process of step 55 that the mode is in the edge area mode for a certain period of time or more, the under control flag FB is reset (step 770), and then the pressure increase mode is set (step 765).
. After completing the processing in steps 725, 735, 760, and 765, the process returns to the main routine.

Next, in the processing of the step tube 700, the solenoid valve switching control signal is applied to the actuator 1 according to the processing of the pressure reduction mode setting, holding mode setting, edge area mode setting, and pressure increase mode setting.
7 to control the brake pressure.

As mentioned above, the anti-skid control device of this embodiment has the following features:
Determine the friction state between the right front wheel 1 and left front wheel 2 and the road surface,
When driving on a normal level road, the control is set closer to the high select (weighting factor rliK = K M Hl, e.g. 0.15), and when driving on a cross road etc., the control is set closer to the high select (weighting factor RK = K H5, e.g. 0) control, and while driving on a low-friction road, the average value (weighting coefficient = KML,
For example, the control is set to 0.5), and the control is executed to switch roughly in three ways.

Therefore, by executing control closer to the high select on a normal level road, it is possible to obtain good braking efficiency while avoiding the single front wheel bulge seen in the simple high select control. In addition, in road conditions where it is difficult to achieve both braking efficiency and driving stability such as steering performance (straddling roads, sharp turns, low-friction roads, etc.), by determining this, Select control is executed to emphasize braking efficiency, and on low-friction roads, average value control is executed to emphasize driving stability such as steering performance. In this way, by prioritizing and controlling the brake pressure of the wheel that is considered more important, it is possible to achieve both good braking efficiency and driving stability, such as steering performance, depending on various road conditions and driving conditions. can.

In the anti-skid control of the embodiment described above, the brake pressure was controlled by comparing the weighted average wheel speeds, but the slip rate of each wheel is calculated individually, and the weighted average is calculated for these slip rates. Processing may be performed to control the brake pressure according to this weighted average slip ratio. In addition, the actuator that controls the brake pressure is 3
Various types of valves such as position valves and two-position valves can be used.

In addition, in the embodiment described above, the wheel speed of the rear wheels 3 and 4 is
The front wheels 1.2 are configured to be detected by independent sensors, and three wheel speed sensors are used, so the overall configuration is simple. Appropriate running stability and best braking efficiency can be obtained. Note that wheel speed sensors are also provided for each of the rear two wheels, and as described above, the friction state between the left and right rear wheels and the road surface is determined, and the weighting coefficient K and weighted average speed are calculated to perform brake control. good.

Furthermore, in the first embodiment described above, the front left and right wheels are controlled by a common brake fluid pressure and applied to a brake device that is separated into front and rear wheels. It is also applicable to a cross-piped brake system controlled by brake fluid pressure.

In this second embodiment, as shown in FIG. a, 7
b is a rear wheel speed sensor, 20 is an actuator that commonly controls the brake pressure of the right front wheel and left rear wheel system, and 21 is a left front wheel.
This is an actuator that commonly controls the brake pressure for the right rear wheel system. In this case, the front right wheel 1 and the rear left wheel 4 correspond to the first wheel and the second wheel, respectively, thereby configuring the device of the first embodiment described above. Also, the left front wheel 2
and the right rear wheel 3 may be configured separately from the device of the first embodiment described above, which corresponds to the first wheel and the second wheel, respectively. By replacing the above-mentioned calculation formula with the following calculation formula, it can be implemented without major changes.

Vwqn = KXMAX (Vl, IFA, Vw
pA)+(1-K)XMIN(Vwpg,
VIJRA ) D Vwgm = K XMAX (D
Vwra, D VIJRA ) + (I
K) XM r N (DVl, JrA
, DVupo) Vwan=KXMT N
(Vwpi+, VwRe)+ (1-[<
) XMAX (Vwpe, V
uRe ) DVIJ811 = Kxx I N (
D VIJF9, D Vi<pp )+ (1-
K) X[VIAX (DVwFe, DVwhe
) Here, Vwpq is the speed of the larger front wheel, V
upe is the speed of the smaller front wheel, Vwpa is the rear wheel speed of the same system as the front wheel, V whe is the rear wheel speed of the same system as the front wheel, V uAn and DVIAqn are the weighted average wheels of the same system as the front wheel. velocity and acceleration, V
ui+n and DVw9m are the weighted average wheel speed and acceleration of the same system as the wheel.

As described above, the present invention is not equally limited to these embodiments, and may be implemented in various forms without departing from the gist of the present invention.

[Effects of the Invention] As detailed above, the anti-skid control device of the present invention determines the friction state between the wheels and the road surface, and based on the determination result, on a normal level road, the anti-skid control device By performing this control, it is possible to obtain good braking efficiency while avoiding single front wheel locking that occurs with simple high select control. In addition, in road conditions where it is difficult to achieve both braking efficiency and driving stability such as steering performance (straddling roads, sharp turns, low-friction roads, etc.), by distinguishing between these conditions, braking efficiency can be improved. We place emphasis on driving stability such as steering performance on low-friction roads, and prioritize and control the brake pressure of the wheels that are considered more important, thereby ensuring optimal control according to various road conditions and driving conditions. This has the effect of achieving both braking efficiency and driving stability such as steering performance.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an anti-skid control device illustrating the basic configuration of the present invention, FIG. 2 is a schematic configuration diagram of an anti-skid control device as an embodiment of the present invention, and FIG. 3 is a block diagram of an anti-skid control device as an example of the present invention. FIG. 4 is a block diagram showing the configuration of the electrical system, FIG. 4 is a flowchart showing the main processing procedure of this embodiment, and FIG.
The figure is a flowchart showing the processing procedure for determining the wheel speed and wheel acceleration of this embodiment, FIG. 6 is a flowchart showing the processing procedure for determining the friction state of this embodiment, and FIG. Flowchart showing the processing procedure for outputting, FIG. 8 is a flowchart showing the processing procedure for setting the operation mode of this embodiment, and FIG. 9 shows the judgment condition of the first flag used when judging the friction state of this embodiment. FIG. 1O is an explanatory diagram explaining the determination condition of the second flag used in determining the friction state of this embodiment. FIG. 11 is an explanatory diagram explaining the wheel speed and actuator operation of this embodiment. 12 is a map showing the relationship between the vehicle speed and the weighting coefficient as another example, and FIG. 13 is a map showing the relationship between the speed difference and the weighting coefficient l( as another example).
FIG. 14 is a schematic configuration diagram of the second embodiment. 1, 2. 3. 4... Wheels 5, 6. 7. 7a, 7b--Vehicle speed sensor 9
．． 10.11.12...Brake device 16...Electronic control circuit 17.19.20.21...Actuator Fig. 2 Agent: Patent attorney Tsutomu Sadachi (and 2 others) Fig. 3 76, Fig. Figure 10 (a) (b) FstLMo-"-1- Ftoln (,-1-1 Figure 11 Figure 9 (a) (C) HIER m--1- (d) Figure 12 Figure 13 Diagram → Traction speed ~ W → Speed difference

Claims (1)

[Scope of Claims] A single braking force adjusting means that commonly controls the braking force of a first wheel and a second wheel different from the first wheel, and each of the first wheel and the second wheel. first and second wheel speed detection means for detecting speed; running state calculation means for calculating a vehicle running state based on the wheel speeds detected by the first and second wheel speed detection means; and the running state calculation. friction state determining means for determining the friction state between the wheels and the road surface based on the running state calculated by the means; and a plurality of weighting coefficients for use in a weighted average based on the determination result of the friction state determining means. weighting coefficient output means that selects and outputs a weighting coefficient from predetermined weighting coefficients; weighted average wheel speed calculation means that calculates a weighted average wheel speed based on the first and second wheel speeds and the weighting coefficient; and the weighting coefficient. An anti-skid control device comprising: control means for outputting a control signal to the brake force adjustment means to control brake pressure according to average wheel speed.