JPH02136361A - Antiskid controller - Google Patents

Abstract

PURPOSE:To calculate antiskid control at a high speed by providing two processing means provided for each pair of wheels at diagonal positions and outputting control request signals and transferring the control request signal determined by each processing means to the other processing means for processing. CONSTITUTION:Oil pressures to be fed to wheel cylinders on wheels are controlled via selector valves 6a-6b so that the friction brake forces between wheels at diagonal positions and the road face have increasing slip ratios in the first and second processing means 4a and 4b based on outputs of wheel speed sensors 2a-2d of the wheels at diagonal positions, i.e., the right front wheel and the left rear wheel, the left front wheel and the right rear wheel. In this case, the first and second processing means 4a and 4b receive control request signals sent from the other processing means 4b and 4a, they are compared with the control request signals determined by the processing means 4a and 4b based on the preset precedence, and the control request signal with high precedence is sent as the control signal.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an anti-skid control device that prevents the wheels of an automobile from becoming locked when the brake pedal is depressed.

2. Description of the Related Art In a typical conventional anti-skid control device, an anti-skid control device is provided on each wheel in order to prevent the wheel rotational speed (hereinafter referred to as "wheel speed") from becoming zero due to depression of the brake pedal. The hydraulic pressure supplied to the hydraulic braking means for braking the wheel speed is controlled, and the slip rate of the wheels is controlled so that the frictional braking force between the wheels and the road surface is maximized. Here, if the traveling speed of the automobile is VS and the wheel speed is VW, the slip rate S is defined by the first equation.

In order to shorten the braking distance required to stop the vehicle by depressing the brake pedal, the speed of each wheel must be controlled independently so that the slip rate S for each wheel becomes the value that produces the highest braking force. This is desirable. However, even on so-called split 1 roads, where the friction coefficients of the left and right wheels with respect to the road surface are significantly different, if anti-skid control is performed independently on the left and right wheels, a yaw moment force (in the direction of travel of the vehicle) generated in each wheel is generated. rotational force in the direction perpendicular to the
becomes large, impairing the driving stability of the vehicle.

Therefore, in order to improve the running stability of a car, the so-called SELEC system is used to supply the same hydraulic pressure to the hydraulic braking means that brakes the left and right rear wheels. -Low control is being performed. This select low control ensures that the yaw moment force generated on the left and right rear wheels is almost the same, maintaining driving stability.

Problems to be Solved by the Invention As described above, in the conventional anti-skid control device, select low control is performed on the rear wheels in order to improve the running stability of the vehicle on the road. However, in order to perform anti-skid control calculations at high speed, in an anti-skid control device, control calculations for the left and right rear wheels are performed by different processing means.
Since it is necessary to output the same control signal to each hydraulic braking means of the rear wheels, it is necessary to mutually transfer the wheel speed take, which is the basis for calculating the control signal in each processing means. These wheel speeds are set to minimize the number of signal lines.
This is transferred as a serial signal, and since it is necessary to transfer this wheel speed to each hydraulic braking means every control cycle, a problem arises in that the control cycle becomes long.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an anti-skid control device that can perform select low control without delaying the control cycle even in an anti-skid control device that independently controls left and right rear wheels. It is in.

Means for Solving the Problems The present invention responds to wheel speed signals from wheel speed sensors provided on the front right wheel and rear left wheel of an automobile, and controls the friction between the front right wheel and rear left wheel and the road surface. a first processing means that controls hydraulic pressure supplied to the hydraulic control means provided on the right front wheel and the left rear wheel so as to achieve a slip ratio that increases power, and a wheel speed sensor provided on the left front wheel and the right rear wheel. In response to each wheel speed signal from In the anti-skid control device, the first and second processing means each receive a control request signal sent from the other processing means with one processing means, and perform each processing. The control request signal determined by the means and the received control request signal are compared based on a predetermined priority order, and a control request signal with a higher priority is selected as a control signal and sent to the hydraulic braking means. This is a unique anti-skid control device.

Further, in the present invention, the priority level is set to the highest priority level for the pressure reduction control request signal.

Function In the present invention, the front right wheel and the rear left wheel of the automobile include:
A wheel speed sensor is provided to detect the rotational speed of the wheels, and hydraulic braking means are provided to hydraulically control the rotational speed of the long wheels. The first processing means is configured to supply hydraulic pressure to the hydraulic braking means based on each wheel speed signal outputted from the wheel speed sensor so that a slip ratio is achieved that increases the frictional braking force between each wheel and the road surface. Control. Further, the front left wheel and the rear right wheel are provided with a wheel speed sensor and a hydraulic braking means for controlling the rotational speed of the wheels. The second processing means is configured to supply hydraulic pressure to the hydraulic braking means based on the wheel speed signals from each of the wheel speed sensors so that the slip ratio increases the frictional braking force between each of the wheels and the road surface. Control.

The first processing means generates a control request signal to output a hydraulic braking means l\ installed on the right front wheel and the left rear wheel, based on wheel speed signals from wheel speed sensors installed on the right front wheel and left rear wheel. At the same time as creating the control request signal, the control request signal is sent to the second processing means.

Further, the second processing means similarly creates a control request signal based on each wheel speed signal from the wheel speed sensors provided on the front left wheel and the rear right wheel, and sends it to the first processing means l\. The first processing means and the second processing means have predetermined priorities for the control request signals, and the control request signal created by one processing means and the control request signal sent from the other processing means. and, based on a set of priorities, a control request signal with a higher priority is selected as the control signal,
Sent to hydraulic braking means.

Further, in the present invention, among the various control request signals, the pressure reduction control request signal is set to have the highest priority.

Embodiment FIG. 1 is a block diagram of an anti-skid control device which is an embodiment of the present invention. The anti-skid control circuit 1 is provided, for example, in a vehicle interior or a rear trunk. Wheel speed sensors 2a to 2d are provided for each wheel and are sensors for detecting wheel speed. For example, the wheel speed sensors 2a to 2d have a detection plate made of a ferromagnetic material on which protrusions and a large number of notches spaced at equal intervals in the circumferential direction are fixed to the wheel shaft, and a detection plate made of a ferromagnetic material is fixed to the wheel shaft, and a detection plate is formed near the circumference of the detection plate. A signal having a frequency proportional to the wheel speed is outputted by a provided electromagnetic pickup, for example. Wheel speed sensor 2a-2
The wheel speed signal detected by d is sent to the waveform shaping circuit 3a.
Processing circuit 4a realized by a microcomputer or the like after waveform shaping into a pulse signal by ~3d
, 4b.

The switch 2e is, for example, a brake switch that sends out a signal indicating that the brake pedal has been depressed, and the output signal of the switch 2e is given to a level conversion circuit 3e, so that the signal level is adjusted to a voltage that is compatible with the anti-skid control circuit 1. converted to level. The output of the level conversion circuit 3e is sent to processing circuits 4a and 4b.

The processing circuit 4a calculates the respective wheel speeds based on the wheel speed signals from the wheel speed sensor 2a provided on the right front wheel and the wheel speed sensor 2b provided on the left rear wheel, and then calculates the wheel speed of the larger wheel. The speed is transferred to the processing circuit 4b via the signal line 511.

Similarly, the processing circuit 4b calculates the respective wheel speeds based on the wheel speed signals from the wheel speed sensor 2c provided on the left front wheel and the wheel speed sensor 2d provided on the right rear wheel, and then selects the larger one. The wheel speed is transferred to the processing circuit 4a via the signal line sf2.

The processing circuits 4a, 41:1 estimate, for example, the larger of these wheel speeds as the vehicle body speed from the transferred wheel speeds and the wheel speeds calculated within each processing circuit.

An anti-skid control calculation is performed based on this vehicle speed and each wheel speed, and a control request signal is created, which is a pressure reduction control request signal, a holding control request signal, a pressure increase control request signal, or a pulse pressure increase control request signal. This control request signal is transmitted from the processing circuit 4a to the processing circuit 4 via the signal line s13.
b and from the processing circuit 4b to the processing circuit 4a via the signal line s14. Each processing circuit 4a4b receives a control request signal with a higher priority as a control signal according to a predetermined priority from the control request signal calculated within each processing circuit and the transferred control request signal, and outputs a control request signal with a higher priority as a control signal, and is controlled.

Processing circuits 4a, 4. After the control signal output from b is power amplified by the solenoid drive circuits 5a to 5d,
It is applied to the solenoid coils provided in the switching valves 6a to 6d. Processing circuit 4a.

The solenoid relay drive signal sent from solenoid relay drive circuit 4b is given to AND circuit 7, and its output is power amplified by solenoid relay drive circuit 8, and then given to one relay coil 9a of the solenoid relay. When the contact 9b becomes conductive, the battery voltage of the battery 11 is applied to the other end of the solenoid coil incorporated in the switching valves 6a to 6d via the contact 9b and the connection point 10.

The waveform shaping circuits 3a, 3b and the processing circuit 4a constitute a first processing means together with the solenoid drive circuits 5a, 51:+, and similarly the waveform shaping circuits 3c, 3d and the processing circuit 4 constitute a first processing means.
b constitutes a second processing means together with the solenoid drive circuit 5 (, 5d).

A motor]-2a is a motor for driving a hydraulic pump, and when the motor relay 13 is turned on, electric power is supplied from the battery]1 to generate control hydraulic pressure. Processing circuit 4a
, 4b are given to an OR circuit 14, and when either of the motor drive signals from the processing circuits 4a, 4b becomes high level, the motor relay drive circuit 15 is turned on and the motor relay 13 is turned on. The lamp drive signal from the processing circuit 4a or 4b is sent to the lamp drive circuit]6
When the alarm lamp 17 is given, the alarm lamp 17 lights up.

The warning lamp 17 lights up when some kind of abnormality occurs in the anti-skid control device to alert the driver.

A positive electrode of the battery 11 is connected to a power supply circuit 19 via a power switch 18 . The power supply circuit 19 converts the battery voltage into a desired voltage, and then supplies the converted voltage to each circuit. Further, the negative electrode of the battery 11 is connected to the vehicle body, so that so-called body grounding is performed.

FIG. 2 is a block diagram for explaining a hydraulic path of an anti-skid control device according to an embodiment of the present invention. Hydraulic pressure generated in the mask cylinder 21 by pressing the brake pedal 20 is applied to the wheel cylinders 22a to 22d via the switching valves 6a to 6d, and
Decrease the rotation speed of 23d. In addition, the switching valves 68 to 6d
and wheel cylinders 22a to 22d each constitute hydraulic braking means.

During anti-skid control, the braking oil pressure generated by driving the motor 12a is applied to the P valve 24b.

24d. When the pressure increase control signal is sent from the anti-skid control circuit 1 to the switching valve 6a, the hydraulic pressure source 1
The braking oil pressure generated in step 2 is supplied to the wheel cylinder 22a via pipes 25a and 26a. Further, when the pressure reduction control signal is sent to the switching valve 6a, the wheel cylinder 2
The oil pressure in the wheel cylinder 22a is returned to the reservoir tank 28 via the pipes 26a and 27, and reduces the oil pressure in the wheel cylinder 22a. Further, when the holding control signal is sent to the switching valve 6a, all of the pipes 25a, 26a, and 27 are shut off, and the oil pressure in the wheel cylinder 22a is maintained constant. The above switching also applies to the switching valves 6b to 6 (1).

The P valves 24b and 24d are connected to the rear wheel cylinder 2.
This valve is for restricting the slope of the braking oil pressure supplied to 2b and 22d rising from a predetermined value or higher.

FIG. 3 is a functional block diagram for explaining the selection of control request signals in the processing circuits 4a and 4b. In order to perform selective low control on the left rear wheel 23b and the right rear wheel 23d, which are anti-skid controlled by separate processing circuits, the processing circuits 4a and 4b output the control signal immediately before outputting the control signal to the hydraulic braking means. Hereinafter referred to as the "control request signal." ) is necessary to know. By comparing the control request signal determined by each processing circuit with the control request signal transferred from the other processing circuit, and outputting a control request signal with a higher priority as a control signal according to a predetermined priority order, the processing circuit 4a , 4b can perform select low control on the left rear wheel 23b and the right rear wheel 23d. A more detailed explanation will be given below based on FIG. 3.

The wheel speed signal output from the wheel speed sensor 2b is waveform-shaped by the waveform shaping circuit 3b and then input to the control request signal determining means 4al. Control request signal determining means 4a
In order to avoid locking of the left rear wheel 231], l is the control with the highest slip rate S determined by the first equation from the wheel speed of the left rear wheel 23b and the predetermined vehicle speed. In order to exert power, a pressure reduction control request signal, a holding control request signal, a pressure increase control request signal, or a pulse pressure increase control request signal is determined for the hydraulic braking means 22b. Here, the "pressure reduction control request signal" is a signal for reducing the hydraulic pressure supplied to the hydraulic braking means 221 during the period during which this signal is output, and the "holding control request signal" is a signal during the period during which this signal is output. It is a signal that keeps the oil pressure constant, and the "pressure increase control request signal" is a signal that increases the oil pressure during the period when this signal is output, and the "pulse pressure increase control request signal" is a signal that increases the pressure This signal is a combination of the pressure increase signal and the hold signal, and increases the oil pressure only during the period when the pressure increase signal is output, and after that, the oil pressure is held constant by the hold signal. The control request signal determining means 4al determines the various control request signals described above, sends them to the control signal selecting means 4a2, and also sends them to the control signal selecting means 4I:+ 2 /\ of the processing circuit 41].
It is sent out via signal line sp3.

The control request signal determining means 4bl of the processing circuit 4I-J performs the same processing as the control request signal determining means 4al, and generates a control request signal based on the wheel speed signal of the right rear wheel 23d output from the wheel speed sensor 2d. determined, the control signal selection means 4
1] 2 and the control signal selection means 4a2.
It is also sent to the signal line sN4.

Signal line sN 3. The type of control request signal transferred over sn4 is coded and sent as a 2-bit identification signal, for example, as shown in Table 1, in order to shorten the transfer time.

Table 1 The control signal selection means 4a2 and 4b2 select a control request signal with a higher priority as a control signal according to a predetermined priority order from among the control request signals determined by the control request signal determination means 4al and 4bl, and cylinder 2
In order to hydraulically control 2b and 22d, a solenoid drive circuit 5
Output to b, 5d. As the above-mentioned priority order, for example, the priority order shown in Table 2 is adopted.

(The following is a blank space) Table 2 FIG. 4 is a timing chart showing typical output states of control signals with respect to changes in wheel speed.

In FIG. 4, line p1 is a line that shows changes in vehicle speed, and line 12 is a line that does not show changes in wheel speed. When the vehicle speed and wheel speed shown in FIG. 4 (1) change, the processing circuit determines the control request signal shown in FIG. 4 (2).

That is, when the wheel speed begins to rapidly decrease at time t], the processing circuit outputs a pressure reduction control signal to reduce the hydraulic pressure to the hydraulic braking means in order to avoid the wheels from becoming locked. . When the wheel speed stops decreasing and begins to show signs of recovery at time t2, a holding control signal is output to temporarily maintain the oil pressure constant. Thereafter, when the wheel speed sufficiently recovers, a pressure increase control signal is output at time 3 to increase the braking force on the road surface. Further thereafter, when time t4 is reached, a pulse pressure increase control signal is output in order to maintain the frictional braking force with the highest wheel slip rate S. However, when the wheel speed begins to rapidly decrease again at time t5, the pressure reduction control signal is outputted again in order to avoid the wheel lock state as described above. Hereinafter, time t6. t7
At t8, a holding control signal, a pressure increase control signal, and a pulse pressure increase control signal are outputted as described above, and the slip ratio S of the wheels is controlled to maintain the highest frictional braking force against the road surface.

FIG. 5 is a timing chart illustrating changes in the wheel speeds of the left and right rear wheels and the output state of the control signal. Figure 5 (
In 1), a line 13 shows a change in vehicle speed, a line p4 shows a change in wheel speed of the left rear wheel 23b, and a line 15 shows a change in wheel speed of the right rear wheel 23d. In this way, each processing circuit 4a, 4b attempts to output a control signal in response to a change in wheel speed, as shown in FIG.

That is, as shown in FIG. 5 (2>, (3)), in the control request signal determining means 4al and 4bl,
-) line ff4. Not shown on line p5, in response to changes in wheel speed, a pressure reduction control request signal, a holding control request signal,
A pressure increase control request signal or a pulse pressure increase control request signal is determined. Once such a control request signal is determined, the aforementioned control signal selection means 4a2.4b2 selects the control signal according to the priority order shown in Table 2.

That is, as shown in FIG. 5(4), at time 1.11, the control request signal determining means 4a1 determines the pressure reduction control request signal, and then outputs the pulse pressure increase determined by the control request signal determining means 4bl. The control request signal is compared, and the pressure reduction control signal is selected as the control signal. Also, time t
12, the control request signal determining means 4al similarly determines the holding control request signal;
Since the pressure reduction control request signal has been determined in L)1, the control signal selection means 4a2.41:+2 selects the pressure reduction control signal. As described above, each control request signal determining means 4al
, 4bl, the control request signal with a higher priority is selected as a control signal and output.

Next, the determination of a control request signal and the selection of a control signal in the processing circuits 4a, 41:) will be described below with reference to the flowcharts of FIGS. 6 and 7.

FIG. 6 is a circuit diagram flowchart of anti-skid control in which control request signals in processing circuits 4a and 4b are determined. In addition, in order to simplify the explanation below, the left rear wheel 23
The control for 7) will be explained, but the control for the right rear wheel 23d is completely similar.

When the anti-skid control starts in the processing circuit 4a, it is first determined in step S1 whether or not the anti-skid control is currently being executed, and if the anti-skid control is currently being executed, there is no need to judge whether to start the anti-skid control. Therefore, the process advances to step S4. In step S1, if anti-skid control is not performed, step S2
Then, it is determined whether the conditions for starting anti-skid control are satisfied. The anti-skid control start conditions include, for example, when the wheels are locked, or when the wheel speed becomes lower than a predetermined rotation speed, and when the wheel deceleration (
It is determined whether the negative wheel acceleration (negative wheel acceleration) is greater than a predetermined deceleration. If the conditions for starting anti-skid control are satisfied, step 33
/\, and a pressure reduction flag for causing the wheel cylinder to perform a pressure reduction operation is set in a predetermined memory area of the processing circuit 4a.

In step s2, if it is determined that the conditions for starting anti-skid control are not met, the process proceeds to step s14, in which the hydraulic pressure generated in the mask cylinder by depression of the brake pedal is directly transmitted to the wheel cylinder. The switching valve 6a is set to the pressure increasing position.

In step S4, the condition for ending the anti-skid control is determined. For example, when the foot is released from the brake pedal or when the vehicle speed becomes 5 krn/h or less, the anti-skid control is canceled. Step S4
If the conditions for ending the undesired skid control are not satisfied, the process proceeds to step s5, where a flag for controlling the increase/decrease of the oil pressure of the wheel cylinder is determined.

When the anti-skid control starts, since the pressure reduction flag is set in step S3, the process proceeds to step s6, and the conditions for ending the pressure reduction control are determined. In step s6, when the pressure reduction control termination condition is met, that is, the wheel acceleration exceeds a predetermined acceleration and the wheel speed begins to show signs of recovery, the process proceeds to step 37 /\. step s7
Then, a holding flag is set to keep the oil pressure of the wheel cylinder 22b constant. Once the retention flag is set, the process advances to step S8, where retention termination conditions are determined.

In step s8, when the wheel acceleration exceeds the predetermined acceleration and falls below the predetermined acceleration, the holding end condition is satisfied. When the holding end condition is satisfied, the process proceeds to step s9, where a pressure increase flag for increasing the oil pressure of the wheel cylinder 22b is set. When the pressure increase flag is set in step S9, the process proceeds to step slo'\ and the pressure increase end condition is determined. In step slo, the pressure increase end condition,
For example, when the oil pressure recovers to a predetermined value, the process proceeds to step S1, where a pulse pressure increase flag is set to gradually increase the oil pressure in the wheel cylinder 221). Then, in step s12, when the pulse pressure increase end condition, for example, the wheel speed satisfies the pulse pressure increase end condition,
Proceeding to step s13, a pressure reduction flag is set.

When the flag determined by each control request signal shown in FIG. 6 is set, the control signal selection process shown in the flowchart of FIG. 7 is performed. Flowcharts 1 to 7 in FIG. 7 show the processing in the control signal selection means 4a2, and the processing in the control signal selection means 4b2 is also similar. step n 1
It is determined whether the control request signal determined by the control request signal determining means 4al- is a pressure reduction control request signal.

Further, step n2 is the control request signal determining means 41]1
It is determined whether the control request signal determined in is a pressure reduction control request signal. Step r+l, r1
2, if it is determined that the pressure reduction control request signal has been determined, the process proceeds to step n3, and the control signal selection means 4a2 outputs the pressure reduction control signal.

If it is determined in both step rrl and step r12 that the pressure reduction control request signal has not been determined, the process proceeds to step r+4.

Thereafter, similar processing is performed, steps r+4, r
If it is determined in any step r5 that the holding control request signal has been determined, the process proceeds to step rr6, where the holding control signal is selected and output.

If it is determined that the holding control request signal has not been determined in either step r14 or step n5, the process proceeds to step r+7'\.

Furthermore, step n7. If it is determined in any step n8 that the pressure increase control request signal has been determined, the process proceeds to step n9, where the pressure increase control signal is selected and output. If it is not determined in either step n7 or step n8 that the pressure increase control request signal has been determined, the process proceeds to step rr10.

If it is determined in either step n10 or rr11 that the pulse pressure increase control request signal has been determined, the process proceeds to step n1.2'\ where the pulse pressure increase control signal is selected and output. . step n 1
If it is determined that the pulse pressure increase control request signal has not been determined in either step r113' or step n11, the process proceeds to step r113'\. Step [113 is when the control signal is not output, and the switching valve 6a is used to directly transmit the hydraulic pressure generated in the mask cylinder 21 by pressing the brake pedal 20 to the wheel cylinder 22a\22d. ~6d is set to the pressure increase position.

As described above, according to this embodiment, since the control request signal determined by the calculation in the processing circuits 4a4b is transferred to the other processing circuit using a 2-bit coded identification signal, both processing circuits The control state of the other processing circuit can be recognized. In this embodiment, the priority order for selecting control signals is shown in Table 2.
It is not limited to this order, but other orders or
Other forms of control signals, for example, control request signals such as pulse decompression control request signals, may be added and priorities may be set.

Further, the control request signal is transferred through a separate signal line s/3 as shown in FIG. s1!4, but these signal lines are not used and the signal line sl! 1. Control request signals may be mutually transferred using sN2.

According to the present invention, the control request signals determined in the first processing means and the second processing means are respectively transferred to the other processing means, so that the undesired control calculation can be performed at high speed. Therefore, the time required to output a control signal in response to a change in wheel speed can be shortened, and the responsiveness of control can be improved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an anti-skid control device according to an embodiment of the present invention, FIG. 2 is a block diagram for explaining the hydraulic path of the anti-skid control device according to the present invention, and FIG. 3 is a processing circuit 4. a, a functional block diagram for explaining the selection of control signals at 41:+, Fig. 4 is a timing chart showing typical control signal output states in response to changes in wheel speed, and Fig. 5 A timing chart for explaining changes in wheel speed and output states of control signals, FIG. 6 is a circuit diagram of anti-skid control in which control request signals are generated in the processing circuits 4a and 4b, and FIG. 7 is a flowchart of anti-skid control. 3 is a flowchart for explaining selection of control signals. 1.-Anti-skid control circuit, 2a-2 CI wheel speed sensor, 3 f14-3 d.-Waveform shaping circuit, 4
a4b ・Processing circuit, 5a to 5d...Solenoid drive circuit, 6a to 6d...Switching valve, 9 Solenoid relay 11
,...Battery, 12...Motor, 13...Motor relay, 15...Motor relay drive circuit, one...
Power supply circuit, 21... Master cylinder, 22 a to 22 (
1 Boil Jirinda Agent Patent Attorney Keiichi

Claims (2)

[Claims] (1) In response to each wheel speed signal from the wheel speed sensors installed on the right front wheel and left rear wheel of the automobile, the slip ratio increases the frictional braking force between the right front wheel and left rear wheel and the road surface. a first processing means for respectively controlling the hydraulic pressure supplied to the hydraulic control means provided on the front right wheel and the rear left wheel; and a first processing means responsive to each wheel speed signal from a wheel speed sensor provided on the front left wheel and the rear right wheel. and a second process of controlling the hydraulic pressure supplied to the hydraulic braking means provided on the front left wheel and the rear right wheel so that the frictional braking force between the left front wheel and the right rear wheel and the road surface increases, respectively. In the anti-skid control device, the first and second processing means each receive a control request signal sent from the other processing means with one of the processing means, and receive the control request signal determined in each processing means. and the received control request signal based on a predetermined priority order, and selects a control request signal with a higher priority as a control signal and sends it to the hydraulic braking means. (2) The anti-skid control device according to claim 1, wherein the priority is set such that a pressure reduction control request signal is set highest.