JPS60213557A - Antiskid controller - Google Patents

Abstract

PURPOSE:To control a wheel revolving speed in a proper manner according to a running state, by selecting a reference value in accordance with a difference between a car speed and the wheel revolving speed calculated on the basis of the wheel revolving speed, while comparing this reference value with a wheel adjustable speed, and judging of whether a variation in braking hydraulic pressure is required or not. CONSTITUTION:A microprocessor 13 calculates a car's estimated speed on the basis of wheel revolving speed S1-S3. And, when a speed differential between this estimated speed and the wheel revolving speed is large enough, it roughly refers to an adjustable speed differential, and that whether bfaking hydraulic control is required or not is judged with the speed differential as a main subject. When the speed differential is extremely large, the adjustable speed differential is left out of consideration whereby the braking hydraulic pressure is decompressed. In proportion as the speed differential becomes smaller, a reference value allocated to this speed differential is selected and the adjustable speed is minutely contrasted whereby that whether braking hydraulic pressure is required or not is judged.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention provides anti-skid control that reduces the brake fluid pressure in the wheel brake cylinder when the wheels of a vehicle are about to lock when braking to prevent skidding due to wheel locking. Regarding equipment.

[Prior art]

Various configurations are already known as anti-skid devices for vehicles, but brake fluid pressure fluctuations in the wheel cylinder when the anti-skid device is activated are not transmitted to the brake mask cylinder, so the brake pedal operation feeling is good. For example, there are those disclosed in JP-A-58-450 and JP-A-58-26658.

In these devices, a pressure control valve device is inserted between the wheel cylinder and the mask cylinder in order to adjust the brake fluid pressure in the wheel cylinder independently of the fluid pressure generated in the brake mask cylinder. The pressure control valve device includes a piston that moves in one direction due to brake fluid pressure, and a valve member that blocks a flow path of brake pressure from a mask cylinder to a wheel cylinder. Power hydraulic pressure generated by the pump and applied through the solenoid valve acts on the piston to oppose the brake hydraulic pressure, and this power hydraulic pressure causes the piston to move in the other direction against the brake hydraulic pressure. to open the valve member.

In such conventional devices, power hydraulic pressure is constantly applied to the piston of the pressure control valve device to hold the valve member in the open position in opposition to brake hydraulic pressure during braking, and this power hydraulic pressure is The output of the pump is stored in an accumulator, or the output of the pump is opened via a throttle valve responsive to brake fluid pressure and obtained at the stage before the throttle valve.

Also, to prevent the piston of the pressure control valve device from moving by the brake fluid pressure and opening the valve member when the power fluid pressure is lost, thereby preventing the wheel cylinder fluid pressure from decreasing.

A bypass valve device is inserted between the wheel cylinder and the pressure control valve device to directly apply brake pressure from the mask cylinder to the wheel cylinder when power hydraulic pressure is lacking (Japanese Patent Laid-Open No. 58-26658).

Conventionally, 1 (both skids are highly recognized as driving under special road conditions, and therefore conventional anti-skid control is relatively rough control from the perspective of automatic safety control in special conditions. Ta.

However, as vehicles are used more frequently these days, and people drive under various road conditions as if they were in good condition, anti-skid control becomes less necessary. When executed, it is desirable that anti-skid control be performed more stably, and a more appropriate and stable anti-skid control device is desired.

In addition, in anti-skid control using the above-mentioned conventional device or other conventional devices, the brake pedal is depressed.
If a predetermined condition is met after the brake fluid pressure is established, the brake fluid pressure is increased or decreased. However, if the state parameter referred to in anti-skid control is near the boundary value that distinguishes between pressure increase and pressure decrease, When the pressure decreases or vice versa, there are many alternating repetitions of short-cycle increases and decreases,
This will cause the vehicle to vibrate and give the driver a sense of abnormality, and will also increase the consumption of power hydraulic pressure, increasing the burden on the power hydraulic pressure source. After applying the brakes, such vibrations occur near the pressure increase and pressure decrease boundary values of several state parameters, so such vibrations occur irregularly or almost regularly while the vehicle speed gradually decreases after the brake pedal is depressed. This may cause severe vibrations.

8-Also, even if this anti-skin 1~ control is activated when the vehicle speed is low or low, it has virtually no effect, and the condition judgment for anti-skid control becomes uncertain, making anti-skid control unstable. In some cases, the braking distance may be extended, which can be dangerous.

Furthermore, if anti-skid control is performed above a predetermined vehicle speed as a boundary and anti-skid control is turned off below it, when anti-skid control is started at a vehicle speed higher than the boundary value, When this is released, the feeling of driving the vehicle will be greatly different and there is a risk that driving will become unstable.

Therefore, stability of anti-skid control in the low speed range is desired.

On the other hand, in the conventional device described above, the brake pressure to the wheel cylinder is reduced by constantly operating the pump to maintain the power pressure at a constant high value, or by releasing the power pressure from the pressure control valve device through the solenoid valve. For example, as disclosed in Japanese Patent Application No. 57-078630, when applying and releasing power pressure to a solenoid valve frequently in order to achieve accurate and smooth control, power pressure is consumed rapidly and the power pressure source device There were problems such as requiring a large mechanism and large power to maintain a constant power pressure at a high capacity, such as increasing the capacity of the pump or speeding up the pump drive.

Therefore, the present applicant operates the electric motor that drives the pump of the power pressure source device only during braking and detects that the rotational state of the wheel is close to the state in which the solenoid valve is operated for the first time. An anti-skid control device was provided which releases pressure fluid from a power pressure source into a reservoir after an electric motor is stopped (Japanese Patent Application No. 58-212831). According to this, when comparing the time when the brakes are applied and the time when the brakes are not applied during the entire driving time of the vehicle, the time when the brakes are not applied is much longer, and when the brakes are not applied, the electric power is The motor is not running and therefore no power hydraulic pressure is generated. Furthermore, even when the brakes are applied, the electric motor is not activated unless the wheels are likely to lock up. Therefore, the time during which power hydraulic pressure is generated is significantly shorter than that of the conventional system. When the brake is not applied, no power hydraulic pressure is generated, so when the brake is applied, the pressure control valve device communicates the wheel cylinder and the mask cylinder. Therefore, brake fluid pressure acts from the mask cylinder to the wheel cylinder from the beginning when the brake is applied.

As a result of the above, the mechanism of the power source device can be made smaller without impairing the action of the brake, and its power is small, and the power consumption is also small. It is desired to further reduce power consumption.

[Purpose of the invention]

A first object of the present invention is to make the unskid control more appropriate and stable depending on the driving condition of the vehicle.

A second object of the present invention is to prevent the alternating repetition of short-term increases and decreases, such as when the pressure increases and then immediately decreases, or vice versa, thereby reducing vehicle vibration and driver damage. The aim is to prevent abnormal sensations.

11- The third object of the present invention is to improve the stability of anti-skid control in a low speed range and to improve the stability of single vehicle operation.

A fourth object of the present invention is to safely and efficiently operate a pump drive electric motor of a power hydraulic pressure source device that provides power hydraulic pressure to a pressure control valve device and a bypass valve device; The aim is to reduce the power capacity required of the electric motor and to allow the use of smaller electric motors.

[Structure of the invention]

In normal anti-skid control, the estimated vehicle speed is calculated from the rotational speed of the axle, and if the difference between the estimated vehicle speed and the rotational speed is large, the brake fluid pressure is released, or if the deceleration of the axle is large, the brake fluid pressure is released. I'm combing it. However, in any case, the friction coefficient of the road and the vehicle speed during braking are related, so in the former case, brake fluid pressure control is delayed relative to the behavior of the axle speed during braking, and in the latter case, the deceleration is large. Therefore, if the brake fluid pressure is lowered, the acceleration will become very large in the low speed range, and accordingly the brake fluid pressure will be increased, resulting in wheel lock.

Therefore, in the present invention, the increase or decrease of brake fluid pressure is controlled using parameters such as the difference between the estimated vehicle speed and the rotational speed of the wheels and the acceleration/deceleration of the wheels, but the anti-skid control is made more stable and suitable for the driving conditions. Therefore, a control means that determines whether or not it is necessary to increase or decrease the brake fluid pressure and performs the control: calculates the estimated speed Vs of the vehicle based on the rotational speed Va of the axle, and adjusts the rotational speed Va while the brake is depressed. Speed Dv and ΔV
With s = Vs - Va as a parameter, a reference value is selected according to the value of ΔVs, and the acceleration/deceleration Dv is compared with the reference value to determine whether the brake fluid pressure needs to be increased or decreased.

In other words, the first parameter for determining whether or not brake fluid pressure needs to be increased or decreased is the speed difference ΔVs, and when the speed difference is large, the acceleration/deceleration Dv is roughly referred to and the brake fluid pressure is increased or decreased mainly based on the speed difference ΔVs. Determine whether it is necessary, and if it is extremely large, ignore the acceleration/deceleration Dv and reduce the brake fluid pressure to restore the wheel speed. As the speed difference becomes smaller, select the reference value assigned to each value of ΔVs and reduce the acceleration/deceleration Dv. A detailed comparison is made to determine whether brake fluid pressure needs to be increased or decreased.

According to this, in a region where the deviation ΔVs = Vs − Va of the wheel speed Va from the estimated speed (reference vehicle speed) V+ is large [axle slip (slip) or high vehicle speed]: the acceleration/deceleration of the axle fluctuates quickly and greatly. If you control the brake fluid pressure according to the following, it is easy to cause axle lock when the pressure is increased after the pressure is decreased.In addition, the increase and decrease in pressure become frequent, which tends to cause vibration, which tends to make anti-skid control unstable.
Priority is given to this acceleration/deceleration, and the increase or decrease of brake fluid pressure is determined based on ΔVs, which fluctuates slowly in this region and provides a stable value, so stable anti-skid control that does not cause axle lock or excessive or low pressure can be achieved. It is done.

Also, the wheel speed Va with respect to the estimated speed (reference vehicle speed) Vs
In the region where the deviation ΔVs = Vs - Va is small [low wheel slip or low vehicle speed]: ΔVs itself is small, so the judgment based on it is unstable, and the axle is likely to lock when the pressure is increased after the pressure reduction, and if the pressure increase is delayed. Problems such as the braking becoming difficult to apply and the braking distance becoming long tend to occur, but since this ΔVs is given priority and the acceleration/deceleration is finely controlled based on stable acceleration/deceleration values, such problems do not occur.

In a preferred embodiment of the present invention, when ΔVs is extremely high, for example, exceeds (1/2)·Vs, that is, when it can be considered that a large slip (slip) is occurring, the pressure is immediately reduced. In other words, the brake fluid pressure is reduced substantially without reference to the acceleration/deceleration of the axle.

In addition, after giving an instruction to set the brake fluid pressure control valve device to a pressure increasing state or a pressure reducing state, the pressure is increased to a different value regarding the acceleration/deceleration Dv, which is one parameter, in the pressure increasing state and the pressure reducing state. The boundary value for determining whether to increase or decrease the brake fluid pressure, that is, the reference value, is used to determine whether or not the brake fluid pressure needs to be increased or decreased.

According to this, the acceleration/deceleration boundary values for determining the necessity of increasing or decreasing pressure are different when the pressure is being reduced and when the pressure is being increased, so a so-called hysteresis is provided. This prevents the alternating repetition of short cycles of increase and decrease of pressure, such as increase and vice versa, thereby eliminating vehicle vibrations and the driver's sense of abnormality.

In a preferred embodiment of the invention, the control means further comprises:

The estimated speed of the vehicle is calculated from the rotational speed, and when the brake is depressed, it is determined whether the brake fluid pressure needs to be increased or decreased based on the estimated speed9 rotational speed and the acceleration/deceleration of the rotational speed, and when the estimated vehicle speed is at a predetermined level. 1 (for example, 20 km/h) or more, an instruction is given to the valve device operating means to set the brake fluid pressure control valve device to a pressure increase or a pressure decrease state based on the judgment result, and once this instruction is given, the brake is depressed. While this continues, the estimated vehicle speed is set to a second value (for example, 8KIL) that is smaller than the first value.
/h) Based on the determination result, an instruction is given to the valve device operating means to set the brake fluid pressure control valve device to a pressure increasing state or a pressure decreasing state until the brake fluid pressure control valve device is set to the pressure increasing or decreasing state.

According to this, anti-skid control is not started when the vehicle speed is lower than the first value (the upper limit low speed at which anti-skid control is effective), and when anti-skid control is started when the vehicle speed is higher than the first value, the anti-skid control is started. A second value lower than the value of 1 (
Anti-skid control continues until the very low speed when anti-skid control is no longer required (-16=), which increases the stability of vehicle operation at low speeds and significantly lengthens braking distance. Things will go away. In particular, when anti-skid control is entered at a speed higher than the first value, the reliability of the initial conditions and judgment is high;
Moreover, once anti-skid control is entered, it follows the changes in the situation brought about by anti-skid control and advances control according to the situation change, so even if the value falls below the first value, anti-skid control remains highly stable. The anti-skid control, which has a high degree of stability, is also terminated at the second value, which is no longer necessary. The braking sensation given to the driver is stable and drivability is improved.

Furthermore, in a preferred embodiment of the present invention, the brake fluid pressure control valve device includes a brake fluid pressure port h that receives brake fluid pressure from a brake mask cylinder, and control output ports 1 to 1 that provide brake fluid pressure to the wheel cylinders. A valve member that opens and closes between the control input port, power hydraulic boat, output boat and control input port 1.

a spring means for forcing the valve member in a closed direction;

a bypass valve device comprising a piston that receives pressure from a power hydraulic boat in the direction of driving the valve member open; and a brake hydraulic pressure port that receives brake hydraulic pressure from the brake mask cylinder, and a hydraulic pressure that communicates with the control input port. Control room, power hydraulic ports.

A valve member for opening and closing between the hydraulic pressure control chamber and the brake hydraulic port, a spring means for forcing the valve member in a closing direction, and
When the valve member receives pressure from the power hydraulic port in the direction to drive it open, moving in that direction reduces the volume of the hydraulic control chamber, and moving in the opposite direction increases the volume of the hydraulic control chamber, causing the power hydraulic port to open. A piston that receives pressure from a hydraulic control chamber in a direction that opposes the pressure.

A hydraulic control valve device comprising: an electric motor, a liquid pressurizing pump driven by the electric motor, an accumulator receiving the discharge pressure of the liquid pressurizing pump, and detecting the accumulator pressure. a power hydraulic pressure source that applies an accumulator pressure to the power hydraulic port of the bypass valve device; and a power hydraulic pressure source of the accumulator pressure output port and drain pressure boat of the power hydraulic pressure source and the hydraulic pressure control valve device. an electromagnetic switching valve device which is inserted between the ports and selectively connects the power hydraulic pressure bow 1- of the hydraulic pressure control valve device to the accumulator pressure output port and the drain pressure port in response to energization; The electromagnetic switching valve device operates at least in a pressure increasing state in which the power hydraulic port of the hydraulic pressure control valve device is connected to the accumulator pressure output capo-1-, in a hold state in which the power hydraulic pressure port is closed, and in accordance with the current value. The power hydraulic port is connected to a drain pressure port, and the control means controls energization and deenergization of the electric motor according to the accumulator pressure, and the control means controls energization and deenergization of the electric motor according to the accumulator pressure. While the electric motor is not energized, the value is counted up at a predetermined up rate, and when the count value reaches the predetermined value, the electric motor is de-energized; the brake is depressed. Based on the estimated speed 9 rotation speed and acceleration/deceleration of the rotation speed, it is determined whether or not to increase, hold, and decrease the brake fluid pressure, and the states of the electromagnetic switching valve device are controlled in chronological order. The rate of increase in brake fluid pressure to the wheel cylinder is determined by the combination of the duration of the pressure state and the duration of the hold state, and the brake fluid pressure to the wheel cylinder is determined by the combination of the duration of the depressurization state and the hold state. The decompression rate shall be determined;

According to this, the accumulated pressure in the accumulator is maintained at a predetermined value when anti-skid control is not performed. When anti-skid control is not performed, almost no accumulator pressure is consumed, so the electric motor is not energized and power consumption is low. Since it is sufficient to accumulate pressure in the accumulator during non-control times with a pump and electric motor having a smaller capacity than the capacity that provides the amount of hydraulic pressure required during anti-skid control, small-sized pumps and electric motors can be used.

Even if a small pump and electric motor are used, a numerical value is counted up when the electric motor is energized, and counted down while the electric motor is not energized to obtain an estimated motor temperature value, and when this value reaches a predetermined value, the electric motor is activated. Since the current is turned off, overheating of the electric motor is prevented, and abnormalities such as burnout of the motor due to long-term energization are avoided. Even if the electric motor is stopped as mentioned above in order to prevent such abnormalities, there is still pressure buildup in the accumulator, and in the worst case, there is a bypass valve device that directly supplies brake fluid pressure from the mask cylinder to the wheel cylinder. Since it is equipped with the brake function, the braking action is not impaired.

Compared to the conventional case where the brake fluid pressure to the wheel cylinders is controlled by a combination of only pressure increase and pressure decrease (power fluid pressure consumption) (alternating switching between power pressure application and power pressure release to the reservoir). Since no power pressure is consumed during hold, the brake fluid pressure is controlled in the manner of increasing the pressure and holding it, and decreasing the pressure and holding it, thereby significantly reducing the consumption of para-hydraulic pressure. This reduction allows for further downsizing of the pump and electric motor. As well,
Pressure increase speed can be adjusted by combining pressure increase for a predetermined time and holding time of any length and repeating the same, and similarly, pressure increase speed can be adjusted by combining pressure reduction for a predetermined time and hold time of arbitrary length and repeating the same. This enables more accurate and smooth anti-skid control.

Other objects and features of the invention will become apparent from the following description of embodiments with reference to the drawings.

〔Example〕

FIG. 1a shows a system configuration of an embodiment of the present invention.

In this embodiment, the front right axle FR and the front left wheel FL are each independently anti-skid controlled, and the rear right wheel RR
And the rear left wheel RL is collectively subjected to anti-skid control. So, the front right axle FR.

Speed sensors 10, 11 and 12 are provided to detect the rotational speeds of the front right axle FL and the rear wheels RR, R1.

All of these sensors consist of a magnetic gear connected to an axle or a transmission output shaft, a permanent magnet core fixed opposite to the gear, and a permanent magnet core wound around the core that generates a frequency corresponding to the rotation of the gear. It consists of an electric coil that generates voltage. The generated voltages 81 to S of these sensors 10 to 12
3 is applied to the electronic control unit 14.

When the brake pedal l is depressed, the brake operation detection switch n5t1, which is open when the brake pedal is not depressed, is closed. A status signal indicating whether the switch BSu is open or closed is provided to the electronic control unit 14.

Brake fluid pressure is applied from the brake mask cylinder 2 to the brake fluid pressure ports t-(3a) of the brake fluid pressure control valve units 3, 4, and 5. Brake fluid pressure control valve units! The hydraulic pressures of the control ratios Kapo-1 to (3b) of ~3, 4, and 5 are respectively the brake wheel cylinder 7 of the front right axle F-R, the brake wheel cylinder 6 of the front left wheel F1,
It is also applied to the brake wheel cylinders 8 of the rear axles RR and RL.

The output pressure of the power hydraulic pressure source device PPS, that is, the accumulated pressure of the accumulator 17, is applied to the power hydraulic boats (3d) of the bypass valve devices of the brake hydraulic pressure control valve units 3.4 and 5. Power hydraulic boat (3k) of hydraulic control valve device for brake hydraulic control valve units h3, 4 and 5
The pressures from the output ports 1 to 1 of the electromagnetic switching valve devices 501.1.5QL2 and 501.3 are applied, respectively.

The brake fluid pressure control valve units 3, 4 and 5 are
− All have the same configuration. FIG. 1b shows the configuration of the control valve unit 3. The control valve unit 3 includes a bypass valve device (3a
~3h) and a hydraulic control valve device 1 (3i~3k).

The bus pass control valve device communicates with the brake hydraulic boat 3a and includes a coil storage space that stores a compression coil spring 3f, and a control output port 3b that communicates with this space and a valve actuation that stores a ball valve (valve member) 3e. Room.

An operator operating space that communicates with this chamber and the control input port 3c and through which an operator integrated with the piston 3h passes, and the piston 3
It has a piston operating space which accommodates h and communicates with the power hydraulic pressure bow)-3d.

The hydraulic control valve device includes a valve operating chamber that communicates with the brake hydraulic pressure port 31 and houses a compression coil spring 3m and a ball valve 3Q, a control chamber that communicates with the input port 3c, and an integrated operator passing through the piston 3n. It has a hydraulic pressure control chamber 3j+ and a piston operating space that houses a screw I-n 3n and communicates with the power hydraulic boat 3k.

When a predetermined power hydraulic pressure is applied to the boat 3d (
During normal operation), the piston 3h moves to the right from the state shown in the figure, the ball valve 3e moves to the right against the force of the spring 3f, and the control output port 3b communicates with the control input port 3C. are doing. In addition, when anti-skid control is not substantially performed (the state where the electromagnetic switching valve 5OLI is in the first state (de-energized) and shown in Fig. 1a), the boat 3k
Power hydraulic pressure is applied to the piston 3n, the piston 3n has moved to the right from the state shown in FIG. A wheel cylinder 6 communicates with the mask cylinder 2 through a path of input port h3c - working chamber 3g - control output boat 3b - wheel cylinder 6.

When skid prevention control is not being performed, brake fluid pressure is applied to the wheel cylinder 6 through this route even when the brake is depressed and the brake fluid rises. Even in this state,
As will be described later, it is monitored whether or not there is a possibility that a skid will occur. Briefly speaking, if the possibility of skidding is high, the electromagnetic switching valve 501.1 is energized to reduce the pressure in a predetermined energization pattern. At the time of depressurization energization, drain pressure is applied to the output port 1 of the electromagnetic switching valve 501.1, that is, the power hydraulic pressure port 3k of the hydraulic pressure control valve device, and the piston 3n moves to the left, thereby causing the ball valve 3Q to open. Brake hydraulic port 3
1 and the hydraulic pressure control chamber 3j, the volume of the hydraulic pressure control chamber 3j increases, its pressure decreases, and this is transmitted to the wheel cylinder 6 through the control input port 3c-control output port 3b, and the wheel cylinder 6 The brake fluid pressure decreases and the braking force weakens.

When the output power hydraulic pressure of the power hydraulic pressure source device PPS decreases (in an abnormal state), the piston 3h of the bypass valve device moves to the left, and the ball valve 3e moves to the left, as shown in FIG. 1b. In this way, the control output port 3b and the control input port 3c are cut off, and the brake hydraulic pressure port 3a and the control output port 3b are communicated (bypass). In this state, brake fluid pressure from the mask cylinder 2 is directly applied to the wheel cylinder 6.

Brake fluid pressure control valve units 4 and 5 have exactly the same configuration as unit 3, and also include electromagnetic on-off valves 5OL2゜5OL.
3 has exactly the same configuration as 5OLl. Therefore, the application of brake fluid pressure to wheel cylinder 7 and the application of brake fluid pressure to wheel cylinders 8 and 9 are similar to the application of brake fluid pressure to wheel cylinder 6 described above.

However, control such as reducing, increasing, and holding the brake fluid pressure to the wheel cylinders by anti-skid control is limited to the wheel cylinder 7 of the front right axle FR, the wheel cylinder 6 of the front left wheel FL, and the brake fluid pressure of the rear axles RR and RL. The three wheel cylinders 8 and 9 are each operated independently.

Referring again to FIG. 1a. The power hydraulic pressure source device pps is
Reservoir R5V, pump 16. The main components are an accumulator 17 and an electric motor 15, and this device PPS
The power hydraulic port (3d) of the bypass valve of units 3 to 5 and the electromagnetic switching valve device 5QLI to 5 are connected to the output port 17o of the unit 3 to 5.
The high pressure input port 1lin of the OL3 is connected, and the low pressure ports and out of the electromagnetic switching valve device SOI and 1 to 5 OL3 are connected to the drain port 17d of the device PPS.

When the hydraulic pressure of the accumulator 17 is lower than a predetermined pressure, the pressure detection switch ps is opened and a high level signal is given to the electronic control unit 14, and when it is high, a low level L signal is given to the electronic control unit 14 when it is closed.

Briefly, when switch PS is open (low pressure), electronic control unit 14 energizes motor energizing relay RLY to energize motor 15 to drive pump 16, and when switch PS
When closed (high voltage), relay RLY is deenergized and motor 1
5 and stops the pump 16. In addition, in order to prevent the motor from turning on and off in short cycles, the pressure detection switch PS changes from open (low pressure) to closed (
Even after switching to high pressure), the motor 15 is kept energized for 3 seconds, and the motor 15 is stopped at a pressure higher than the pressure at which the switch PS is closed.

The electromagnetic switching valve devices 5QLI to 5OL3 are capable of linearly controlling the position of the flow path switching piston or plunger using the energizing current value. pressure connection), at the maximum energized current value Imax, connect the low pressure port Lout to the output port (3k) (reduced pressure connection), and at the intermediate value between de-energized and Imax, connect the output capo-1-(3k) to the high hydraulic input port 1lin, 28- is for blocking (holding) any of the low pressure ports Lout.

Since the positions of the flow path switching plungers of the electromagnetic switching valve devices 501.1 to 5OL3 are linear in accordance with the energizing current value, in the anti-skid control described later, 5OLI.

The control of 5QL2 is such that in the first state (pressure increase connection), the current value is set to 0/8 with respect to Imax, and in the second state (hold)
In the third state (reduced pressure connection), the current value is set to 278 with respect to Imax, and in the third state (reduced pressure connection), the current value is set to 7/8 with respect to Imax.

The control of 5OL3 is such that in the first state (pressure increase connection), the current value is set to 0/4 with respect to Imax, and in the second state (hold)
For In+ax, the current value is set to 1/4, and for the third state (reduced pressure connection), the current value is set to 3/4 for In+ax.
It is set at 4.

The reason why 8 is used as the denominator in the control of 5OLI and 5QL2 is that 3 bits are allocated to the energizing current value designation code of 5QLI and 501.2. The numerator indicates a value (decimal number) expressed by 3-bit data. The reason why 4 is used as the denominator in the control of 5OL3 is that 2 bits are assigned to the energizing current value designation code of sO+ and a. The molecule is 2
Indicates a value expressed in bit data (decimal number).

The microprocessor 13 of the electronic control unit 14 outputs a code specifying such a current value, and in the electronic control unit 14, the code is converted into an analog signal by an A/D converter, and the analog signal is converted to an analog signal by a linear amplifier. The signal is amplified and the electromagnetic switching valve devices 5OLI-5OL3 are energized at a level corresponding to the analog signal level.

A power supply voltage is applied to the linear amplifier as a power voltage through a main relay MRv.

When main relay MRV is open, the output of the linear amplifier is zero (de-energized) despite the output code of microprocessor 3.

The microprocessor 13 of the electronic control unit 14 has interrupt ports 51 to S3, and executes an interrupt every time a pulse obtained by shaping the vehicle speed detection voltage arrives, and determines whether the incoming pulse is up or down and the time has elapsed. Create basic data for calculating wheel speed. In addition to interrupts, calculation of wheel speed.

Creation of anti-skid control basic data, energization control, temperature estimation and protection control of the compressor motor 15.

It performs continuous long-term pressure reduction monitoring, protection control, anti-skid control (energization control of electromagnetic switching valves SQL I to 5OL3), etc.

The energization pattern of 501.1 to 5OL3 during anti-skid control is shown in FIG. Referring to Fig. 2, before the start of control, the electromagnetic switching valve system [501, 1 to 5OL3 is not energized (20/8 output energization is the same as in the pressure increase state, 0/
4 output energization).

At this time, for example, when unit 3 (FIG. 1b) is illuminated, mask cylinder 2 - brake hydraulic boat 31 -
The wheel cylinder 6 communicates with the mask cylinder 2 through the path of hydraulic pressure control chamber 3j - control input port 3c - working chamber 3g - control output port 3b - wheel cylinder 6, and a normal brake hydraulic pressure loop (no anti-skid control) is established. loop) is formed, and the pistons 3h and 3n are located at the rightmost possible end.

The pressure increase energization pattern in the state where anti-skid control is entered is the energization pattern shown in the second column of Fig. 2, and SO+
, t and 501.2, as shown in the left column 31-, 0/8 energization for 24m5ec (same as non-energization: pressure increase) to speed up the transition to the hold state for the second 6m5ec. 3/8 energization (pass-through type in the hold direction)
and 278 energization (hold) for the next 42m5ec
One unit is 72IIlsec.

The continuous pressure increase in the third column is caused by continuous de-energization. The sot, t, and 5QL20 hold energization patterns, as shown in the left column of the fourth column, are 2/8 energization continuation, and the duration is indefinite, and is based on the result of status reading and calculation in anti-skid control, which will be described later. is determined depending on the circumstances.

The depressurization energization pattern of 5OLI and 5QL2 is 778 energization (depressurization) for 48m5ec as shown in the left column of the 5th column.
and 2/8 energization (hold) for the next 72m5ec as one unit.

The 611th continuous pressure reduction is brought about by 778 continuous energizations.

The energization patterns for pressure increase, hold, depressurization, etc. of 5OL3 are the same as those described above, but in response to the difference in brake characteristics between the front and rear wheels, the number of bits of the energization instruction code is also different. The pattern is slightly different. Please refer to the right column of FIG. 2 for the energization pattern of 5OL3.

Desired pressure increase patterns and pressure decrease patterns can be obtained by various combinations of the above-described energization patterns.

For example, one unit of pressure increase pattern (72 msec or 5
4m5ec) is repeated continuously, Ll shown in Figure 3 is obtained.
The pressure increase is brought about at a fast rate, such as 11 C,.

A short hold period following a unit pressure increase pattern will result in a slightly slower rate of pressure increase, as in UPIll in Figure 3, and even a slightly longer hold period following a unit pressure increase pattern. A hold period results in a slow rate of pressure increase, such as 1IPl+2 in FIG.

Similarly, in the case of pressure reduction, by adding a hold period to one unit of pressure reduction and varying the length of this hold period, a pressure reduction pattern with a desired falling rate can be obtained. The concept of setting the pressure increase and decrease speeds is as described in the following two series, but in this example, the hold time (see 241! and 541J in Fig. 2) is constant, and the time of pressure increase and decrease energization is changed. Depending on the situation, the length can be changed to a longer or shorter length to obtain the desired pressure increase or decrease speed.

Note that even when executing a single unit pressure increase or decrease pattern, or even when in the hold state, if it is determined that it is necessary to shift to another control mode by reading the status, calculating, etc., that pattern will be executed at that time. is stopped and the next required pattern is executed.

When the brake pedal 1 is depressed and the switch B51N is closed, anti-skid control is started under the condition classification shown in FIG. 4a. In Fig. 4a, the area marked as pressure increase hold means that the pressure increase setting state (0/8 energization: no anti-skid control) is held as is (2/8 energization), and there is a thick downward slope to the left. The area indicated by the line is the area where the brake pressure is assumed to be insufficient and the pressure is continuously increased (pressure increase before control starts: see FIG. 2).

After the anti-skid control (pressure increase hold) is entered in the area division shown in FIG. 4a, various control modes are entered in the condition division shown in FIG. 4b (pressure increase or pressure increase hold state). In Fig. 4b, the thick downward sloping line indicates the condition area where continuous decompression occurs, the thin downward sloping line indicates the area where pressure decreases, the thin downward sloping line to the left indicates the area where pressure increases, and the thick downward sloping line indicates the condition area where pressure continues to decrease. Areas proceeding to continuous pressure increase are shown, and white indicates areas proceeding to hold.

When proceeding to depressurization or depressurization hold, the process proceeds to various control modes according to the condition classification shown in FIG. 4c. The inclined lines etc. in FIG. 40 indicate areas similar to those in FIG. 4b.

The area in which the next step is to proceed after pressure reduction or pressure reduction hold (Fig. 4c) is shifted to the upper right than the area to which the next step is to be carried out during pressure increase or amplification hold (Fig. 4b). This is to provide hysteresis to prevent frequent control switching between the two.

Next, an overview of the anti-skid control by the microprocessor 13 will be explained with reference to FIG. 5. The microprocessor 13 estimates and calculates the reference vehicle speed Vs' from the axle speeds (51 to 53). The reference vehicle speed Vs' is the higher of the average wheel speed of the front wheels and the axle speed of the rear wheels.

When the brake pedal l is not depressed, the control reference vehicle speed Vs is made to match the reference vehicle speed Vs'. Also, when the reference vehicle speed Vs' decreases, control 35-- sets the higher of the calculated value obtained by reducing the reference vehicle speed Vs by a deceleration of 1.3G and the reference vehicle speed Vs' as the control reference vehicle speed Vs, and sets the control reference vehicle speed Vs to 1.3G. When the time for which the value calculated by deceleration is set as the control reference vehicle speed Vs reaches 96m5ec, the speed is 0.15G
Of the calculated value reduced by the deceleration of and the reference vehicle speed Vg',
The higher one is set as the control reference vehicle speed Vs.

Therefore, based on the acceleration/deceleration Dv of each wheel and the deviation ΔVs between the wheel speed and the control reference vehicle speed Vs, either Fig. 4b (when the current control is in the pressure increase mode or pressure increase hold mode) or Fig. 4c Pressure increase, pressure decrease, and hold control is performed under the condition categories shown in the figure (when the current control is in the pressure reduction mode or pressure reduction hold mode).

As shown in Figures 4b and 4c, the deviation ΔVs is Δ
When v2=ΔVs/2 or more (when the deviation ΔVs of the wheel speed Va from the control reference vehicle speed Vs is large and the two wheels are largely idling), the pressure is continuously reduced regardless of the wheel acceleration/deceleration Dv. In other words, priority is given to determining the next control mode based on the deviation ΔVs, and the brake pressure is lowered at high speed.

=36- Control unit 7 (a) When the vehicle speed becomes 8 Km/hJ, all-wheel anti-skid control is not necessary, so SO[,1~
Cut off the electricity to SO1 and SO3. If the speed is 8KIII/h or more but less than I (1Km/h), anti-skid control of the front axle is not required, and in order to ensure the directional stability of the vehicle, power to 5OLI and 5QL2 is cut off and the front Stop anti-skid control for only the axis.

So that the hydraulic pressure of the accumulator 17 is equal to or higher than a predetermined pressure,
When the pressure is low, the motor 15 is energized when the switch PS is opened, and when the pressure is high, the motor 1 is energized when the switch PS is opened.
5 is considered to be a stop, but when the motor is in operation, the estimated motor temperature is counted up in a predetermined pattern described later, and counted down while the motor is stopped, and when the estimated motor temperature reaches a predetermined high value, the motor is stopped. do. Thereafter, the motor temperature is counted down to a predetermined value, and when the estimated motor temperature value reaches a predetermined low value, the motor is energized if the motor needs to be energized.

The anti-skid control described above is performed only when the axle speeds Va of both front wheels FR and FL exceed 20 km/h. This is done because changing the brake pressure using anti-skid control at low speeds has no particular effect and may even increase the braking distance, which can be dangerous. When anti-skid control is entered at an axle speed exceeding 20 km/h, anti-skid control is stopped for both front and rear wheels when the control reference vehicle speed is less than 8 m/h (estimated at axle speed of 5 km/h), as described above. 10km/h
Stopping anti-skid control for only the front wheels at speeds below 20 km/h (estimated axle speed of 7 km/h) is because the situation judgment for anti-skid control at speeds above 20 m/h is accurate and the subsequent misjudgment. This means that the anti-skid control is safer, and once the anti-skid control has started, it is better to continue it until the car comes to a stop, resulting in a smoother driving stability and brake feel. by. For example, if the anti-skid control stops at 201 (m/h).

This causes the car to respond differently to driving operations, making it difficult to drive.

The reason why the speed at which anti-skid control is stopped for the front and rear axles is set to 10 m/h and 8 km/h, respectively, and the vehicle speed is slightly higher for the front wheels, is to improve the directional stability of the actual driving. When anti-skid control is activated and the car decelerates, the brake force on the rear axle is first increased, and then the brake force on the front wheels is increased. Does not cause swings.

If anti-skid control is performed as it is during acceleration slipping, such as when the accelerator is depressed and the brake is depressed, there is a risk that pressure reduction control will be applied and no braking will occur. In the anti-skid control described therein, the microprocessor 13 controls the rear wheels (vehicles driven by an engine+l
The presence or absence of acceleration slip is determined by comparing the wheel speeds of the vehicle and the front wheels (wheels not driven by the engine), and anti-skid control is not performed when acceleration slip occurs.

In addition, in the anti-skid control described above, the microprocessor 13 monitors the duration of the pressure reduction mode, and when the duration of the pressure reduction mode is long (brake fluid pressure on a road with a low friction coefficient μ (hereinafter referred to as a low μ road)), the microprocessor 13 monitors the duration of the pressure reduction mode. In this case, the speed of pressure increase to restore brake pressure is slowed down by 39- and waits for the axle speed to return. This is to avoid early locking, which is likely to occur if the pressure increase rate is high on a low μ road.

In the anti-skid control described above, if the duration of the decompression mode exceeds a predetermined time, the microprocessor 13 refers to the axle speed Va and determines whether the axle speed is restored (increased).
When this happens, it is not considered abnormal and the depressurization mode scheduled for control continues. If the axle speed Va has not recovered, it is determined that there is an abnormality and the depressurization mode is stopped after a predetermined period of time.

In the above-mentioned anti-skid control, the repetition cycle of pressure increase and decrease in the anti-skid control is set to the unsprung level so that the vibration of the braking force due to repeated increases and decreases in the brake fluid pressure does not synchronize or resonate with the unsprung vibration of the vehicle. It is made to be larger than the period of vibration.

Next, details of the control by the microprocessor 13 will be explained with reference to flowchart 1 shown in the drawings.

When the power is turned on, the microprocessor I3
Execute the main routine shown in the figure, and then cancel the 40-interrupt mask. Note that this microprocessor 13 has three interrupt ports 1-51 to S3, among which ports S1 and 53 can set whether or not to execute an interrupt by interrupt mask control. is a port that cannot be masked, and when the power is turned on and a signal change that starts an interrupt to (t3) appears on this port,
Execute interrupt processing.

First, the interrupt processing operation in the boat S1 will be explained with reference to FIG. 6a. In a state where the interrupt mask of port S1 is released, the signal Sl (speed pulse obtained by binarizing the voltage generated by the speed sensor 10 of the front old axle FR) changes from high level j11 to low level 1. Boat S
1 flip-flop is set to cell 1~, and the interrupt processing shown in FIG. 6a is executed. That is, first, the flip-flop is reset to wait for the next signal change (from I+ to 1.) Step 1: Only the numbers are written below. The numbers in parentheses below indicate the step numbers), then the pulse number counter N'&I counts up 2), then the value T, which is the value obtained by subtracting the previous time T1 from the current time To, -T, that is, the elapsed time since the previous time. Compare the time with 6m5ec (3
).

If the elapsed time is less than 6 m5ec, the process returns to the step before entering the current interrupt. If the elapsed time is 6m5eC or more, the elapsed time r, -Tt is stored in the time interval register T4), the current time is updated in the previous time register T15), and the pulse number counter N' is stored.
Store the value N' in the pulse number register N6),
A pulse number counter N' is initialized (7). Then, the FR6 msec end flag indicating that 611 ISeC or more time has elapsed since the previous time is set to Sera IL (8), and the process returns to the step before the interrupt.

It should be noted that inside the microprocessor 13, if the clock pulse is constantly counted and 6m5ec is counted, 6I
Set the flag OCF indicating that nsec has passed and return to the initial state (
When the internal counter with a cycle of 6 tnsec returns to the count time 0 and counts up again, and the clock pulse is constantly counted l-L 64 msec, the result is 64 m.
The flag TOF indicating the passage of 5ec is set to the initial state (
There is an internal counter with a cycle of 64m5ec that returns to count time 0) and counts up again, and the current time To
is obtained from the 1-value of the ' counter in this 64 m5 ec cycle.

Therefore T. -11 can be negative, but if it is negative then T (1+ 64111sec -T I to T.

-T1.

Due to the interrupt control described above, when the FR6msec end flag is set to 1, the number of pulses that arrived at the boat S1 during the time (6 seconds or more) stored in the time interval register T is the number of pulses in the pulse number register N. The previous time register T1 stores the time at which pulse counting was newly started.

The rotational speed (wheel speed) of the front wheel FR is obtained by multiplying N/T by a constant, and the wheel speed can be calculated from the contents of register T and N. The speed of the car 111 is determined by referring to the flag in the main routine (Fig. 7b) to be described later.
It is calculated when the ec end flag is set to 1-. - The interrupt processing in the interrupt port 1-53 (FIG. 6c) is exactly the same as the interrupt processing in the port S1 (FIG. 6a), so a description thereof will be omitted.

43- The interrupt processing of the interrupt boat S2 is shown in FIG. 6b.

In this interrupt processing, first, the presence or absence of the initialization end flag is checked, and if it is not present, the process returns to the main routine. If there,
Step 16 is performed which is exactly the same as steps 2-8 of FIG. 6a. As a result: this interrupt processing will not be executed if initialization has not been completed.゛Through the interrupt processing explained above, data for axle speed calculation is sent to registers T and N at a cycle of 6IIlsec or more.
The memory will be updated. Note that the interrupt is executed on the condition that there is a change in the speed detection pulse (51 to S3), so the interrupt is not executed when the vehicle is stopped, and when the axle speed is extremely low and the speed detection pulse period When is 64m5ec or more, registers T and N
Speed calculations based on data are completely unreliable.・Therefore, the vehicle speed sensors 10, 11 and 12 are designed to generate voltage oscillations with a period longer than 30+n5ec (less than 50m5ec) at the planned minimum speed of the vehicle.As a result, when the vehicle is running at this minimum speed, When there is 6r
When the nsec end flag is activated, the data in the time interval register 1 indicates a value shorter than 3sec, longer < 50m5ec. In the control flow described later (steps 147 to 158 in FIG. 10a), data T in register T is stored. -Refer to T1, the length is longer than 30m5ec (, '50m5ec
When the value is shorter than , it is the minimum speed, so to set the detected axle speed to O, set register N to 0 (clear register N). Note that this minimum speed is not necessarily the minimum speed. Although this does not correspond to the vehicle speed of 0, there is no problem in calculating and controlling the vehicle speed by setting this minimum speed to 0 in terms of anti-skid control. As described later, the lowest axle speed that can be controlled by the control is 7.7 km/h or around it, so the wheel speed (minimum speed) for setting register N to 0 is about 5 m/'h or less. That's fine.

7a and 7b show the control main routine of the microprocessor 13.

To explain this main routine, the microprocessor 13 executes steps 17 to 24 when the power is turned on.
Initialize with .

During this initialization, various registers, timers, and counters.

Clear the flags, etc., set the input port to the signal waiting state, send the waiting signal to the output ports 1~, turn on the main relay MRV, cancel the interrupt mask of ports SL and 53, and initialize. Set the conversion end flag to Cera I, and set the current time (
64 msec internal counter count value) is set in register T1, and time interval register T is set as follows:
The calculated speed value N/T (actually, the value obtained by multiplying it by a constant) is set to a value of 32 m5ec, which is considered to be substantially 0.

This initialization enables interrupt processing operations of the interrupt ports 51 to S3.

Next, the microprocessor 13 refers to the presence or absence of the flag OCF indicating that the 6m5ec internal counter has overcounted (25), and if so, subroutine OCFMAi (
Anti-skid control: Not only actual brake pressure control, but also status reading, calculation,
It also includes control such as status determination. Details are shown in Figures 10a to 11c. )(26) and if you exit this or if there is no OCF, proceed to step 27 and get 64m5
Flag TOF indicating ec internal counter count over
Refers to the presence or absence of.

If TOF is present, subroutine TOFMAi (motor energization control) is executed.

Details are shown in Figures 9a and 9b. ) (28>, and when it exits or there is no TOF, the warning flag is set by referring to the presence or absence of a warning flag (a flag that is set when an abnormality is determined: described later) (29). If there is no "electromagnetic switching valve device 501.
Referring to the energization status of each of 1 to 5OL3, if the depressurization energization is not performed, the count register 501.1 on counter, 5QL2 on counter, and SOI, 3 on counter for monitoring the depressurization energization time of 5OLI, 5OL2, and 5OL3. Clear each one (35). SQl, 1
, Sol,2, 501.3 is under reduced pressure energization, the count value is referred to as 31, 32, . ), if the duration is longer than 5 seconds, the decrease in brake fluid pressure continues for a long time, so in step 33a, the wheel acceleration/deceleration mouth ν is
is compared with a predetermined value -0.2G. If it is greater than -0.2G, the wheel speed Va has recovered due to depressurization (deceleration has stopped) and can be considered normal, so proceed to step 36. However, if the mouth V is less than 10.2G, the depressurization is long and the wheel speed is abnormally slow to return.In order to avoid no-brake, it is necessary to set the abnormality flag VRNFLG33), turn off the main relay MRV, and turn off the electromagnetic switching valve device SQL,1.
.

All of 5QL2 and 5OL3 are de-energized (pressure increased), motor relay RL'V is turned off, and energization of motor 15 is stopped (34).

When there is a warning flag (29), when the on counter is cleared (35), or when the main relay MRY
and when motor relay RLV is turned off (34),
The input of the port BS (whether the brake pedal is pressed 1 or not) is read (36), and the read state is compared with the memory contents of the BS register (37). Note that immediately after turning on the power, this B
The initial state (brake pedal 1 not depressed) is set in the S register by the above-mentioned initialization.

If the comparison results do not match, this means that the brake pressure control 1 has changed from no depression to depression, or vice versa. Therefore, the BS change counter will be increased by 1 count.
8), check whether the count value is 5 or more (39)
, 5 or more, the process proceeds to the next step 42, passes through the subsequent control steps, and then returns to the Stella 48-P 36737. In this way, if you check the discrepancy 5 times, the count value will be 5 (after referencing it 5 times,
Since the state was the same all five times), the state read in step 40 should be updated to the BS register, the new state of the brake pedal l should be memorized), and the BS change counter should be cleared for the next reading judgment. 41), next step 4
Proceed to step 2. If the same reading is not obtained five times after detecting a discrepancy, it is assumed that the brake has not been depressed or released sufficiently or that the switch is simply chattering, and the process proceeds to steps 37 to 41.
5 Clear the counter, and do not change the contents of the BS register to the read state. By reading the state and updating the memory in this manner, only when the brake pedal 1 changes from not being depressed to definitely being depressed or vice versa, the changed state is stored in the 85 register.

The next steps 42, 43, 44 and 45 are the same as the previously described steps 25, 26, 27 and 28, respectively, and therefore will not be described here.

After passing through step 45 and proceeding to steps 46 and 47, the contents of the priority counter are referred to, and if the contents of the priority counter is 1, the process goes to step 48 in Figure 7b, and if it is 2, the process goes to step 51 in Figure 7b. , and if it is neither 1 nor 2, the process proceeds to step 54 in FIG. 7C. steps 46 to 66
Up to this point, the axle speed is calculated based on the speed pulse count value N and time interval T obtained by the interrupt processing (FIGS. 6a to 6c).

Note that when the 6m5ec end flag is not set to 1~ in the interrupt processing, the speed calculation data is not ready, so the wheel speed is calculated only when the 6m5ec end flag is set.

Assuming that the axle speeds of the front cloth wheel FR, front left axle FL, and both rear wheels are all calculated, the calculation takes a relatively long time, and there is a control delay, especially the anti-skid control OCFMAj and Since there is a risk that the motor energization control TOFMAi, which is executed every time the 64IIISeC internal counter times out, will be delayed, in the calculation of the wheel speed after step 46, when the wheel speed has entered - times, it will be the maximum (that is, the 6m5eC end flag is set). ) - Only the speed of the wheels is calculated.

In this, the old car'I! F Rr front axle F1. If the calculation class for the wheel speeds of the two rear wheels is fixed, the probability of entering the calculation will be different for each wheel.

Therefore, by using the priority counter (register) and going through the same speed calculation flow (steps 46 to 64), step 64
The priority counter is incremented by 1, and as soon as it exceeds a predetermined count value, it is initialized (l is set). However, when the priority counter is 1, step 4
Proceeding to step 8, the presence or absence of the FL6msec, 4% flag is checked, and if it is found, the process proceeds to calculation of the speed of FL (front passenger axle), and upon completion of this, the priority counter is incremented by one count (64). If there is no Fl, 6m5ec end flag, refer to the presence or absence of the rear 6m5ec end flag (49), and if there is, proceed to rear (rear wheel) speed calculation,
When this is completed, the priority counter is incremented by 1 (
64). If there is no rear 6m5ec end flag, refer to the FR6msec end flag (50), and if it is present, 5 is added to the FR (front right axle) speed calculation (57-63).
1- Advance, and when it is completed, the priority counter is incremented by 1 (64).

In this way, if the priority counter is 1 when entering steps 46 and 47, as described above, FL6msec
The process proceeds with reference to the end flag (48), reference to the rear 6m5ec end flag (49), and reference to the FR6msec end flag (50), so when the priority counter is 1, the calculation priority order is FL, rear, and FR. .

However, when the content of the priority counter is 2, the rear 6II
lsec end flag reference (51), FR6msec
Since the process proceeds with reference to the end flag (52) and reference to the FL6 msec end flag (53), when the priority counter is 2, the calculation priority order is rear, FR, and FL.

Also, when the priority counter is 3, the process proceeds with reference to the FR6msec end flag (54), reference to the FL'6m5ec end flag (55), and reference to the rear 6m5ec4% completion flag (56), so when the priority counter is 3,
The calculation priority order is FR, FL, and rear.

Due to the above priority shift, the speeds of each wheel are calculated in the same order. In any case, if the FL6mse52-C end flag is present, the process proceeds to subtraction of the speed of Fl, and the rear six
When the m5ec end flag is present, proceed to rear speed subtraction and F
If the R6 msec end flag is present, the process proceeds to steps 57 to 63, FR speed subtraction.

In the FR speed calculation, the 61Ilsec end flag set in the interrupt processing (Figure 6a) is cleared for the next data processing (57), and the data N of the pulse number counter N is stored in the accumulator register for the next calculation. Sera 1-do (58).

Next, in step 59, axle speed = AN/T multiplied by a constant A
Subroutine 01U1.XN. VIil).

In FIG. 8a, constant multiplication M l]1. The subroutine of VυV is shown. In this case, the number of pulses N is 70 (compared to 10), and if it does not exceed 10, leave N unchanged;
If it exceeds, it is larger than the maximum speed corresponding value, so the pulse number N is set to lO (71). Then, AXN is calculated (72). A is a constant. Next, store the AN value in memory 73) and step 74, which has the same content as steps 25 to 45.
77, returns to 1, and sets the time interval T to the accumulator register in step 60.

Next, in step 61, the AN/T division subroutine (Di
VVW).

FIG. 8b shows the subroutine DiVVu. In this case, calculate Vv = AN/T and calculate the calculated value Vw as FR
Memorize as axle speed 78.79), step 25
Steps 80 to 83, which are the same as steps 80 to 28, are executed, and the process returns to step 62, where Vty is set in the accumulator register. Next, in step 63, the average value (average W
(Execute the calculation subroutine DiGFj,L.

FIG. 8c shows the average value calculation subroutine DiGFiL. In this case, smoothed value va=(VW-2+ 2 Vw -i +Vw) /
4 (84), then the acceleration/deceleration Dv of the smoothed value Va.
Calculate = (Va - Va -1)/T (85)
. Note that V w -1 is the previous calculated value, VW-2 is the previous calculated value, and Va, -1 is the previous calculated value. In the following, Va will be referred to as wheel speed, and Dv will be referred to as acceleration/deceleration.

Next, update the Va to the Va-1 register in the memory (86),
Execute steps 87 to 90, which are the same as steps 25 to 28, return to the original step, and in step 64, increment the priority counter by 1 as described above.64)
Check whether the value is 4 or not (65), if it is not 4, leave it as is, and if it is 4, count
- Update the value to 1 (66), then calculate the average speed of FR and RL (front) (FR Va + FR Va)/2 and compare this with the rear speed Va (67).

If the average speed of the front 1- is larger than the rear speed, the average front vehicle speed is set to the reference vehicle speed Vs69),
When the average speed of the front is less than the speed of the rear,
The rear speed is adjusted to the reference vehicle speed Vs (68), and then the process returns to step 25, and the steps from step 25 described above are executed. Repeat this below.

In the control spin flow explained above, step 2
If the flag is set to O at each of 5, 42, 74, and 80.87,
If there is a CF, the next step is to execute the subroutine OCFMi that performs anti-skid control, and in step 27,
Temporarily flag TOF at each of 44, 76, 82, and 89.
If there is, the next step is to control one motor unit.
5- Run routine TOFMAi.

As explained above, OCF is set when the 6m5ec internal counter times out, and TOF is set when the 6m5ec internal counter times out.
IIlsec Set when the internal counter times out. As mentioned above, the presence or absence of these flags is referenced in many steps, and if there is one, the anti-skid control starts motor energization control accordingly, so the anti-skid control OCFMAi is effectively 6m5ec.
The motor energization control will be executed in 6 cycles.
It will be executed every 4m5ec.

First, the motor energization control TOFMAi is
This will be explained with reference to the flowchart shown in FIG.

Proceeding to motor energization control, the microprocessor 13:
First, the TOF flag is cleared and the presence or absence of a warning flag is referred to (91). This flag is set when an abnormality is detected, which will be described later.

If there is no warning flag, the flashing counter is cleared and motor relay RLY is turned on in step 106.

Proceeds to off reference, but if there is a warning flag, 56
- Refer to the presence or absence of the depressurization abnormality continuation flag il RN F L G in step 33 of Fig. 7a).93a)
, also refer to the sensor waking flag (!13
b).

If WRNFI and G are present, set the 3-time blink pattern data in the register (94), and if there is a sensor warning flag, set the 2-time blink pattern data in the register (93C), main relay MRV, motor relay R1.
, '/ and the electromagnetic switching valve devices 501.1 to 5QL3 are de-energized (95). In other words, the anti-skid control (brake fluid pressure control) is set to a state (abnormality safe state). Then, in steps 96 to 105, as the subsequent steps progress, the warning lamp set is turned on for 0.5 seconds, turned off for the next 0.5 seconds, and turned on for the next 0.5 seconds. Controls the blinking of the warning lamp till. After this blinking for 5 seconds, the light goes out. However, if vRN F +,,G is present even after 5 seconds, the blinking control will be performed in the same way as described above, so the result will be 111.
While the RNFLG is on, the warning lamp lights up every 5 seconds.
Flashes 3 times every second. This blinking will stop when uRNFLG is cleared. If there is a sensor warning flag, it will blink twice.

Motor relay RL'/
Please refer to on/off of 106: In addition, wRNFtG
is turned off in step 95), and when it is off (motor stopped), the contents of the estimated temperature register Tl11 are compared with 40 (estimated temperature 40°C), and if it exceeds 40 ( (Since the temperature difference with the surroundings is large and the temperature decreases quickly), the contents of the estimated temperature register Tm are updated to a value obtained by subtracting 3 from the current value (108).

When the content of the estimated temperature register Tm is 40 or less, it is compared with 20 (estimated temperature 20°C) (1.00
).

When the temperature is higher than 20, the contents of the estimated temperature register Tm are
Update to the value obtained by subtracting 2 from the current value (1'IO).

When the contents of the estimated temperature register Tm are 20 or less, a value obtained by subtracting 1 from the contents of the estimated temperature register Tm is updated to the estimated temperature register Tm (111).

If the updated memory value is smaller than O, the contents of the estimated temperature register are updated (cleared) to 0 (112, 113).

After updating in this way, the contents of the updated estimated temperature register Tm will be compared with 20 (114), and if it is smaller than 20, the estimated motor temperature will be over 80 and there is a risk of overheating, so if the motor relay is stopped, Clears the motor-on prohibition flag indicating prohibition IL of motor subdivision. ``This means that motor energization is prohibited at an estimated temperature value of 80, and this prohibition is canceled when the estimated temperature value becomes less than 20. The reason why a large hysteresis is provided for inhibiting and canceling motor energization in this manner is to take into consideration the stability of control and the braking feeling of the vehicle driver. If you try to cancel motor subdivision control inhibition at high temperatures,
In addition, there is a high possibility that the temperature will quickly rise to the prohibition temperature, and there will be many cycles of prohibition and cancellation, which will not only make automatic control unstable, but also cause the driver's braking sensation to change from time to time, causing trouble. This is because it becomes high.

Next, the process proceeds to step 124, where the warning flag is referenced. If the motor 59-tary relay RILY is on in step 106 described above, the motor is being energized, so compare the contents of the estimated temperature register Tm with 40 (116), and if it exceeds 40, the motor temperature will increase. Since the temperature is relatively high and the heat dissipation is large and the temperature rise rate is small, the estimated temperature register Tm is calculated by adding 2 to the contents of the estimated temperature register Tm.
,, Tm4 Yu update Yue: Nosu, (1□7). When the contents of the estimated temperature register Tm are less than 40, the contents of the estimated temperature register Tm are compared with 20 (118), 2
If the value exceeds 0, the value obtained by adding 3 to the contents of the estimated temperature register Tm is updated to memory in the estimated temperature register Tm (11
9). If the contents of the estimated temperature register Tm are 20 or less, a value obtained by adding 4 to the contents of the estimated temperature register T+n is updated and stored in the estimated temperature register Tm (120).

Next, set the updated value in the estimated temperature register Tm to 8.
Compared with 0, if it exceeds 80, the estimated temperature register T+
Update the contents of m to 80 (memory 122), motor 15
It is assumed that the motor is overheating, and in order to ensure the safety of the motor, a motor-on prohibition flag is set (12'3), and the presence or absence of a warning flag is checked in step 124.

60- If there is a warning flag in step 124, turn off motor relay R1, ■130), clear the extended 3-sec timer, and proceed to step 133, but if there is no warning flag, check whether or not there is a motor-on prohibition flag. With reference to (] 25), motor relay R1 as well as
, 130), clear the extended 3-sec timer, and proceed to step 133, but if there is no motor-on prohibition flag, read the open/closed state of the pressure switch PS and refer to whether it is a low pressure state or a high pressure state.126), low pressure If so, turn on motor relay RLY and proceed to step 132). If the voltage is high, motor relay RL is turned on.
(See OFF (127)), and if it is not ON (which is fine), proceed to step 133. If it is on, it should be turned off, but if the extension timer has not been set, it should be set. If the cell number is 1~, the extension timer is set to 1 (64m).
sec) Increment +28), check whether the value is -,L (3000/64 or more) for 3 seconds or more.129) If not, mark the sticker 33 to continue the rayon. move on. If the time has exceeded 3 seconds, the motor relay RL'/ is turned off (130) and the extension timer is cleared. In this way, the low pressure condition (switch P
The reason why the motor 15 is energized by the switch (S open) and continues to be energized for 3 seconds even after the pressure rises and the switch PS is closed is to provide hysteresis in motor energization and stopping. . If these 3 seconds are omitted, the motor 15 will be subdivided as soon as the pressure in the accumulator drops slightly, and then as soon as it rises slightly, the motor 15 will be stopped and the motor 15 will be turned on.

This is to prevent the number of off-times from becoming too large.

Proceeding to step 133, the microprocessor 13 refers to the code set as an output on the output port 5OL3 to determine whether or not the code indicates depressurization energization. And if it does not indicate reduced pressure energization, S Q L
Clear the 3-on counter (134) and step 137
Proceed to. If it indicates depressurization energization, refer to the presence or absence of the rear pressure down stop flag and check 1. :35)
, if so, the process proceeds to step 137. Without that,
Since the pressure is being energized (brake fluid pressure is being reduced), Sol,
3-on counter increased by 1 (64111sec
)L/te (13-6) Proceed to step 137.

Proceeding to step 137, the microprocessor 13 refers to the code set as an output in the output port 1-501, 1 to determine whether or not the code indicates energization under reduced pressure. And if it does not indicate reduced pressure energization, 501
□Clear the 1-on counter (138) Step 14
Go to 1. When it indicates reduced pressure energization, Fl
, check the presence or absence of the pressure stop flag (139), and if so, proceed to step January. If it is not there, the pressure is being energized (brake fluid pressure is being reduced), so the SQL + on counter is increased by 1 count (64 msec) L/te (
140) Step l Go back 1flim.

Proceeding to step 1, the microprocessor 13 refers to the code set in the output ports 1 to 5QL2 to determine whether or not the code indicates depressurization energization. If it does not indicate reduced pressure energization, the 5QL2 on counter is cleared (142), and the routine returns to the original routine from which motor energization control was entered (return). If it indicates depressurization energization, check the presence or absence of the FR pressure S1 hesop flag (113), and if there is J1=63-, the program returns to the original routine from which motor energization control was entered (return). If this is not the case, the 5QL2 ON counter is counted up by 1 (64 msec) (136) because the pressure is being energized (brake fluid pressure is being reduced), and the routine returns to the original routine from which motor energization control was entered (return).

By the motor energization control TOFMAi described above, the motor 15 is energized when the accumulator pressure becomes lower than a predetermined pressure, and the motor 15 is stopped 3 seconds after the accumulator pressure reaches the predetermined pressure. While the motor 15 is energized, the estimated motor temperature value is increased at a speed corresponding to the range to which the estimated value belongs, and when the motor 15 is stopped, it is decreased at a speed corresponding to the range to which the estimated value belongs.

When the estimated motor temperature value exceeds a predetermined value of 80, a motor on prohibition flag is set to stop the energization of the motor 15. After setting the flag, the estimated motor temperature value is set to 2.
When it becomes less than 0, the flag is cleared and motor energization is enabled. Further, when the brake fluid pressure is being reduced, among the on counters 5OLI to 5QL3 for monitoring the duration of pressure reduction, those corresponding to the electromagnetic switching valve devices SQL1 to 5OL3 that are being energized for pressure reduction are incremented by one.

64- In the above-mentioned main routine, the contents of these 5QLI to 5013 on counters are referred to.If the value is 2 for more than 5 seconds, the abnormality continues, so a flag indicating the continuation of the decompression abnormality is set. , set G. When this is set, the motor energization fli9 control controls the flashing of the warning lamp WL, and turns off all main relays MR, Y, motor relay RLY, and electromagnetic switching valve devices 5QL1 to 5OL3 to protect against abnormalities. shall be.

Next, the anti-skid control OCFMAi will be explained with reference to Figures 11 and 11c.

As mentioned above, the microprocessor 13 is substantially 611I
The process proceeds to anti-skid control OCFMAi at a period of sec.

Proceeding to this anti-skid control OCFMA i, 6
Flag OC indicating time over of m5ec internal counter
Clear F+45), reset the 6+n5ec internal counter146), memory the contents of the previous time register T1 assigned to the rear as explained in interrupt handling+47), reset the rear time interval T as explained in interrupt handling compared with 30 m5ec and 50 m5ec (148). When T is between them, the axle speed is 0
Assuming that
(clear). Then, the rear 6m5ec end flag is set (150). Similarly, for FR and FL, in steps 151 to 154 and 155 to 158, it is determined whether the axle speed is 0, and if it is 0, N is set to 0, and 6
Set the m5ec end flag to 1-.

Next, the microprocessor 13 registers the BS register (7a
Refer to the data in 15! (The state read by reading the change in brake switch BS in the figure is stored in memory). ]), that is 1. (without pressing the brake), the pressure increase mode counter is set to 3 and the pressure reduction counter is cleared.
Clear the flag (160). That is, the status register for anti-skid control when the brake pedal l is depressed (11) is initialized.

Next, the reference vehicle speed Vs (see steps 67 to 69 in FIG. 7b) is compared with the rear axle speed Va (161). When the rear axle speed is different from the rear axle speed Va, the reference speed Vs should be the average wheel speed of front wheel 1 minus the axle (the front wheel speed is higher than the rear axle speed), so the process proceeds to step 174, but the reference speed Vs is different from the rear axle speed Va. When the vehicle speed ■9 is equal to the rear axle speed Va, the rear axle speed is higher than the front axle speed (because there is a possibility of acceleration slip),
Compared to FR speed and 0.875Vs (Vs = rear Va) +62), if FR speed is smaller than 0.875Vs, the possibility of acceleration slip is even higher, so FL speed and f), 8
Compare with 75Vs (Vs=rear v, 1) (163).

If the FL speed is smaller than 0.875Vs, it is assumed that there is an acceleration slip and an acceleration slip flag is set (16
4). 1. If the R speed is 0.875Vs or more, or the Fl speed is 0.875Vs or more, it is assumed that there is no acceleration slip and the process proceeds to step 17+ to clear the acceleration slip flag.

In step +61 described above, the reference vehicle speed Vs (see steps 67 to 69 in Fig. 7b) is compared with the rear axle speed Va, and if it is different from the rear axle speed Va, the reference speed Vs is the average axle speed of the front wheels (front wheel Since the speed should be higher than the rear axle speed, the process proceeds to 6-foot step 174, where the reference speed Vs is compared with the average speed of the front wheels (174). Here, if the standard speed Vs and Freon 1 to average speed do not match,
Since acceleration slip judgment cannot be made (data is not yet complete), clear the acceleration slip flag (17)
. If they match (the average front speed is higher than the rear speed), compare the reference speed Vs with 30km/h (175
).

When the front speed is higher than the rear speed with the brakes off and the vehicle speed is over 30km/h, the rear speed and 0.75V
176), if the rear speed is 0.75Vs or more, at least one of the vehicle speed sensors 10 to 12 is abnormal and a sensor warning flag is set.
L (1,70) Clear acceleration slip flag (1
71).

If the rear speed is less than 0.75Vs, the FR speed is 1,
Compare 25Vs and 0.75Vs: 177.17
8) If the FR speed is greater than 1.25Vs or less than 0.75Vs, the vehicle speed sensor 10~
12 is abnormal, the sensor warning flag is cleared, and the acceleration slip flag is cleared (171).

-68=If the FR speed is in the range of 1.25Vs to 0.7'5Vs (7), it is considered to be normal and no acceleration slip has occurred, so the acceleration slip flag is cleared (171).

When the reference speed Vs' is less than 30 km/h (+
75), the reference speed vsL is set to 20 K m/I
Compare with I (179).

If the reference speed is less than 20 km/h, the acceleration slip flag is cleared ('171).

When the speed is 20Km/h or more, compare the rear speed, FR speed, and Fl speed with 5Km/h, and calculate 5Km/h.
If the speed is below Km/h, the condition that has progressed so far is to turn off the brakes, and if the front average speed is greater than the rear speed, it will be 20 km.
/h or more, and the heavy wheel speed is abnormally low compared to this, so at least one of the vehicle speed sensors 10 to 12 is abnormal and the sensor warning flag is set as h L (
170) Clear acceleration slip flag (171)
7 Now, if we determine that there is an acceleration slip and set the acceleration slip flag to +L (1.64), the FR speed, Fl, and speed will be compared to 20 Km/h (165, 166).
, the speed difference between FR and FL is small at speeds exceeding 20 km/h, so let's compare FR speed and FL speed: 167.1
68), if the difference between the two is too large, the vehicle speed sensors 10 to 12
170) Clear the acceleration slip flag (171).

If the difference between the two is small, it is assumed that the sensor is normal and the state determination is correct, and a control reference vehicle speed at the start of anti-skid control when the brake is on is set (169). This is done by setting the reference vehicle speed Vg in the control reference vehicle speed register. When the brakes are turned on, as shown in FIG. 5, control starts from the deceleration region summer, so as a preparation state for that period, a flag indicating deceleration region I is set and the rear control is started.

Clear the OCR (anti-skid required flag) of FL and FR, and clear the mode counter, control counter, high μ flag, slip counter, deceleration area counter, etc. (1
72). Note that the state in which the high μ flag is cleared is the state in which the low μ flag is set. That is, when the acceleration slip flag is set (164), the low μ flag is set (172). Next, the electromagnetic switching valve device 5QLI to 5OL3
Assuming that the current is not energized (173), this anti-skid control O
Return to the control step before entering CFMAi.

Enter anti-skid control OCFMaj, step 1
When BS=H in step 59 (brake depression), proceed to step 183 in Fig. 10b and refer to the presence or absence of the acceleration slip flag (183), otherwise, in step 188, the anti-skid control required flag OCR is set. Refer to the presence or absence of.

When there is an acceleration slip flag, the rear wheels are slipping, so the average wheel speed of the front FR and FL should be set to the reference vehicle speed Vg' (184), and this reference vehicle speed Vg
is compared with the rear axle speed (185). Rear speed is V+
If it is smaller than ', the acceleration slip state is no longer present, so clear the acceleration slip flag (187) and refer to the presence or absence of the anti-skid control required flag OCR (187).
8g).

If the rear speed is above vsl, there is a possibility that the vehicle is under acceleration slipping, but if the brake is on (BS = 11) it is 300
Please refer to whether or not more than m5ec has elapsed.
− The rear speed is the standard speed Vs' (front average speed)
Since there is a high possibility that the value is higher than that, the acceleration slip flag should be cleared (187), and the presence or absence of the anti-skid control required flag OCR is referred to (18g).

Now, in step 18B, check the anti-skid control required flag OC.
The presence or absence of R (one assigned to each of FL, FR, and rear) is checked, and if it does not exist, the process proceeds to the anti-skid necessity determination shown in FIG. 10c, and at least one OCR is detected. Step 1 of figure tob
Proceed to brake fluid pressure control below 89.

First, the determination of whether anti-skid control is necessary will be explained with reference to FIG. 10c. First, the pressure increase mode counter is set to 3 (228), and the control reference vehicle speed Vs is compared with 20 km/h (229).

Since there is no need to start anti-skid control when the control reference vehicle speed Vs is 20 Km/h or less, the process proceeds to step 169 in FIG. 10a to update the control reference vehicle speed Vg.

In this case, the reference vehicle speed Vg' at that time is updated and stored in the control reference vehicle speed register.

72- If the control reference vehicle speed Vs exceeds 20 km/h, it is necessary to perform anti-skid control (brake fluid pressure control) depending on the situation, so in steps 230 to 23] the control reference vehicle speed is set to the one during braking. Update to. That is, if the control reference vehicle speed is calculated and decelerated at a deceleration of 1.3G, the calculated value is compared with the actual reference vehicle speed Vg', and the higher one is set as the control reference vehicle speed Vs (this is the area shown in FIG. 5). ■). Next, in steps 233 to 238, it is determined in which of the antiskid control condition categories at the start of brake-on shown in FIG. 4a, and if the condition is in the region marked as pressure increase hold in FIG. Pressure increase hold mode flag FLUPH, FRUPII or RR at 244
Set UPll, anti-skid control required flag OC
Set R and proceed to front right wheel anti-skid control (FRCONT), front left axle anti-skid control (FLCONT), or rear axle anti-skid control (RRCONT) shown in FIG.

Note that when the pressure is in the continuous pressure increase region shown in FIG. 4a, the electromagnetic switching valve devices 5OLI-5OL3 are in the pressure increase (non-energized) state at this point, so there is nothing to do and the anti-skid control continues. Return to the control step before entering OCFMAi. Therefore, even if the brake is turned on, if the pressure is continuously increased as shown in FIG. is applied, the brake fluid pressure increases as the output fluid pressure of the mask cylinder 2 increases, the braking force increases, and eventually advances to the pressure increase hold region shown in FIG. 4a,
Therefore, through steps 233 to 244, the pressure increase hold mode flag FLUP11, 'FRUPH or ItRUP is set.
H is set, and the anti-skid control required flag OCR is set.

Now, the pressure increase hold flag FLOP)l, FRUP
Set I+ or RRUPH and set the anti-skid control required flag FLOCR, FROCR or RROCR to perform anti-skid control FLCONT, FRCON.
T or RRCONT, and then return to the control step before entering the anti-skid control OCFMAi) Also, if you proceed to the anti-skid control OCFMAi and execute control up to step 188, the anti-skid control is required at this point. Flag OCR is set (anti-skid control FLCONT more than once,
(FRC'ONT or RRCONT is being executed), the process proceeds from step 188 to step 189, and it is checked whether the deceleration region I is present. Deceleration region 1 (see Figure 5)
If the actual reference speed is greater than the calculated value, the actual reference speed is stored in the register as the control reference speed. Update memory 191)”, step 1
The process advances to 96 to clear the area 1 control counter. If the calculated speed is greater than the actual reference vehicle speed, the area 1 control counter is set to 1.
Count up (6msec) L/ (193), compare the contents of area I counter with 96m5ec (194)
).

If the content of the area I control counter is 9'6 m5ec or more, the area ■ control flag is set to calculate deceleration at a deceleration of 0.15G, and the area 1 control counter is cleared (195). Clear the control counter (196). If it is not 96m5ec or more, it is still 1.3
In order to perform deceleration calculation with G, the area control flag is not changed.

75- Next, in step 197, the electromagnetic switching valve devices 5QLI to SO
Please refer to the energization amount specification code for 1 and 3 197.199
．． 201), when the reduced pressure is energized (778 energized or 3/4 energized), the reduced pressure counter is counted up by 1 (
6msec) (, 198, 200, 202). When the reduced pressure is not energized, and when the reduced pressure increases the counter by 1 count because the reduced pressure is energized, the control reference vehicle speed is compared with 8 Km/h (203), 8 Kn+/h.
If it is less than 2'IO, the anti-skid control required flag "OeR" is cleared in order to end the anti-skid control of all wheels, the decompression stop flag is set, and the control counter is cleared (2'IO), and the electromagnetic switching valve device 5QLI ~SO'
All L3 are de-energized and anti-skid control OeF
Return to the control step before entering MAi (return)
.

When the control reference vehicle speed is 8 km/h or more, the control reference vehicle speed is compared with 10 km/h (204). If the control reference vehicle speed is less than 10 km/h, only the anti-skid control for the front wheels is terminated, so the anti-skid control required flag OCR for FR and FL is cleared, and the anti-skid control required flag OCR for FR and FL is
The depressurization stop flag of L is set to 7 times on the cell control counter (208). and electromagnetic switching valve device 501.1
and 5QL2 are de-energized, and the process proceeds to rear anti-skid control RRCONT on the condition that the rear anti-skid control required flag RROCR exists.

Now, step 189 is the deceleration area! If not (that is, in area ■), the deceleration calculation was performed at a deceleration of 0.1'4G. Compare the calculated value with the actual reference speed 2] 2) If the calculated value is greater than the actual reference speed, the control standard Set the calculated value to the speed (216), area ■Increase the control counter by 1 count (6 msec) L (217), refer to the presence or absence of the low μ flag (21B)) Without it, there will be little slippage, so turn on the brake 200 insec 219) If it has passed, braking must be working, so compare the control reference speed with 7.7 Km/h and if it is smaller than 7.7 Km/h, step 214 Proceed to 214) to set the area ■ control flag, clear the area ■ control flag (214), and clear the area ■ control counter (215). Then, the process returns to step 197.

When there is a low μ flag, 200m5 from the brake on
ec has not elapsed, or the control reference vehicle speed is 7.
When the speed is 7km/h or more, the brake is turned on
Referring to whether 00m5ec has elapsed (220
), if it has elapsed, set the low μ flag and clear the high μ flag (222), if it has not elapsed, skip this step 222 and refer to the elapsed time of area ■ from the contents of the area ■ control counter. (223, 224).

The elapsed time is 100, 200, 300, 450.・600
, 7, 50, 900 or 1200 m5ec, the presence or absence of the low μ flag is referred to (225), and when there is a low μ flag, the total axle speed Va is compared with the control reference speed, and it is determined whether all differences are within β. Also, if there is no low μ flag, check whether all the differences are greater than or equal to γ (226
, 227). If all values are within β or γ, the process proceeds to step 214, where the area control flag is set to area ■, and the area ■ control flag is cleared (215). The difference is β
If it is not within γ or not within γ, the process returns to step 197 without changing the area control flag. When the elapsed time is 1500 msec, the area is changed to ■.

For other elapsed times, the process advances to step 197 and waits for the elapsed time.

"Setting the control reference vehicle speed" in steps 189 to 227 described above is executed only when the OCR is set, and the elapsed time from the brake ON is executed.

Based on the correlation between the elapsed time of each region, the presence or absence of the low μ flag (presence or absence of slip), the reference vehicle speed Vs, and the calculation speed of the predetermined deceleration, the control reference vehicle speed in time series and the speed region I or
, is determined.

Therefore, in the case of region (2), that is, when the reference vehicle speed (estimated vehicle speed) is decreasing as shown in FIG. 5, it is determined in steps 190 to 195 whether the conditions for transition to region (2) are satisfied.

In region ■, that is, when the reference speed (estimated vehicle speed) Vs has recovered as shown in FIG.
12-227--In step 197, it is determined whether the conditions for returning to area I are satisfied.

Setting the control reference vehicle speed explained above (189 to 227)
During the anti-skid control, the control reference vehicle speed is set and updated, and the depressurization duration is counted during the depressurization.

1.0. Front left wheel F in steps 205 to 207 in figure b
R's 79- Anti-skid control (brake fluid pressure control) FRCON
T.

The anti-skid control (brake fluid pressure control) FLCONT for the front left wheel FL and the anti-skid control (brake fluid pressure control (RRCONT) for the rear wheel RR are virtually the same, and the front FR, FL and rear RR are constant values. The only difference is that

Therefore, the anti-skid control (brake fluid pressure control) flow is for the front left wheel F! , C0NT only in Figure 11a~
Shown in Figure 11c. Next, this anti-skid control FLC
Explain ONT.

When proceeding to FLCONT, the microprocessor 13 sets the control address of the electromagnetic switching valve device SQL 1 (245), increments the control counter by 1 (246), and calculates the FL wheel speed V relative to the control reference vehicle speed Vs.
The difference ΔVs = Vs − Va is calculated and it is determined whether ΔVs is less than 0 (whether the wheel speed Va is higher than the control reference vehicle speed Vg) (2.47). ΔVFI is from 0,
If it is small (wheel speed is higher than the control reference vehicle speed), check the presence or absence of the anti-skid control required flag OCR (FLOCR), and if it is not present, there is no need for anti-skid control (brake fluid pressure control). The electromagnetic switching valve device S01, l is de-energized (0/
! energization output), and the process proceeds to step 267, which will be described later.

If the control required flags Fl and OCR are present, refer to the presence or absence of the low μ flag (258), and if the low μ flag is not present, the acceleration/deceleration of the axle speed Dv (positive: >n speed, negative: deceleration) is compared with 12G. , (259), 12G Yorimo Dai 1? Ito, No. 4b
As shown in Figures and *Figure 4c, when ΔVs is less than 0 and acceleration/deceleration force exceeds 5129, the pressure is continuously increased regardless of the current brake fluid pressure control mode (anti-skid control is not required in this state). Normal brake: 501.
Since one continuous de-energization) is sufficient, the pressure increase mode counter is cleared 260) and the process proceeds to step 262, which will be described later.

When there is a low μ flag or acceleration/deceleration Dv is 12G
If the pressure is below, it is in the pressure increase region regardless of whether you refer to FIG.
Since it is necessary to control the energization pattern of the pressure increase (control mode) shown in the second column of the figure, it is determined whether or not the pressure increase mode has already been entered by referring to the flag (261).

If the pressure increase mode is not set, set the pressure increase mode flag FLUPS here (262), and set the electromagnetic switching valve device SQL1 to O/8 output energization (263:
(See the pattern in the left column of the second column in Figure 2).

Next, a pressure reduction stop flag is set (264), and a pressure increase mode counter is set (265). In this case, when the value of the pressure increase mode counter is O, it is set to 1,
If it is 1, set it to 2, and if it is 3, leave it as 3. When entering this control for the first time, the previous step 2
Since the pressure increase mode counter is set to 3 in step 28 (FIG. 10c), in this case, the content of the pressure increase mode counter is not changed in step 265.

Next, anti-skid control required flag OCR (FLOCR)
266) Clear the control counter 267) and proceed to the next control step 207 (return).

If the pressure increase mode is set, it means that the pressure increase mode has already been entered, so steps 261 to 26
Proceed to Step 8, refer to the elapsed time since entering the pressure increase mode (see 26B), and the elapsed time is 6niSec (set the pressure increase mode (262, 263), then start the next cycle (6 m).
sec), the content of the reduced pressure counter is referred to in steps 269 and 271,
If the content of the pressure reduction counter is 500m5ec or more, the slip is large and the brake fluid pressure has been reduced for a long time by then, so set the low μ flag.
Also, in order to reduce the pressure increase speed (shorten the 078 energization time in pressure increase mode), first set the control counter to 1.
Count up (add 6 msec elapsed) L (27
0), the value obtained by subtracting 48 isec from the contents of the vacuum pressure counter is updated and set in the vacuum pressure counter.

Next, count up another 2 (add 12 msec elapsed)
(273). The content of the reduced pressure counter is 500m5ec.
If it is less than 48m5ec, the low μ flag is set and the control counter is counted up by 2 (12m5ec).
ec progress) (273). Then, the value obtained by subtracting 48m5ec from the contents of the reduced pressure counter (remaining reduced pressure after deducting due to pressure increase) is updated to the reduced pressure counter (
274). 9) When the content of the reduced pressure counter is smaller than 48m5ec), the control counter is not counted up and the reduced pressure counter is cleared (272).
. In this case, at 83-, the increased pressure of 6 m+ec is offset from the reduced pressure by clearing the reduced pressure counter.

6m after setting the pressure increase (262, 263) by the above control counter □ count up process
When 5ec has passed, depending on the previous depressurization state (road friction coefficient), if it took 1 long to reach the depressurization state (low μ
), the low μ flag is set, and the elapsed time of pressure increase (0/8 energized: de-energized) is counted (control counter) longer than the actual elapsed time, and the pressure increase energization (07
8 Energization: Shorten the actual time (see the pattern in the left column of the second column in FIG. 2) (delay the rise due to pressure increase). In other words μ
Set the pressure increase time accordingly.

If it is not 6m5ec in step 268, refer to the elapsed time since entering the pressure increase mode in steps 275, 277, 279 and 282, and 24m5ec (4m5ec).
count), change the energization indication code of the electromagnetic switching valve device 5OLI to one that indicates the 378 energization level, and
If it is 0m5ec (5 counts), set the energization instruction code to 2.
/8 Changed to indicate the energization level, 72m5ec
or more (12 counts or more), steps 262-2
Proceed to step 67 and control the pressure increase mode again (left column of the second column in Figure 2) by resetting the pressure increase mode flag FLUPS and setting the energization instruction code to 078 energization level (non-energization). Reset.

When it is less than 72m5ec (12 counts), further Δ
Compare Vs with 0 (276), and if it is less than 0, proceed to the next step (207) (return), but if it is 0 or more, the pressure increase mode is set at this point, so in Figure 4b (pressure increase In order to determine the control mode to which the mode should be shifted, shown in
The process proceeds to determination of the next control mode in the pressure increase mode and pressure increase hold mode shown in FIG. 1b.

Note that the reason why the next control mode is not determined when ΔVs<O is that when ΔVs<0, the next control mode classification condition (Fig. 4c) in pressure reduction mode/pressure reduction hold mode and pressure increase mode/pressure increase hold mode Next control mode classification condition (
4b) are exactly the same, so steps 247~
259, the next control mode is judged and shifted when ΔV s < 0, and only when ΔV s ≧ 0, only in the pressure increase mode and pressure increase hold mode, as shown in FIG. 4b (pressure increase mode, pressure increase In order to determine the control mode to which the control mode should be shifted, shown in the condition classification (referenced in the hold mode), the process proceeds to determination of the next control mode in the pressure increase mode/pressure increase hold mode shown in FIG. 11b.

As a result of comparing ΔVs and O in step 247, ΔVs
If ≧0, compare ΔVs with 1/2Vs (reference vehicle speed)248), and if ΔVs is larger than that, the next control mode will be continuous pressure reduction regardless of the current control mode, so set the pressure reduction mode flag FLDPS. Set 249)
, set 5OLI to 778 energization 250), clear the pressure increase mode counter 251), and proceed to step 266.

If ΔVs is less than 1/2Vs (reference vehicle speed), compare Dv with 20G (252), and if Dv is greater than 20G (because the next control mode is continuous pressure increase), compare the reference speed Vs with 30Km/h. If Vs is large, the high μ flag is set, the low μ flag is cleared (254), the pressure increase mode counter is cleared (255), and the process proceeds to step 262. Vs
If it is smaller than 30KIn/h, the μ flag is left as is and the process proceeds to step 255.

If Dv is smaller than 20G, step 299 (11th
Proceed to Figure c).

When proceeding to the determination of the next control mode in the pressure increase mode/pressure increase hold mode shown in Fig. = Vs - Va to 8 m/
If ΔVs is lower than 249), set the pressure reduction mode flag FLDPS, set the electromagnetic switching valve device 5OLI to 7/8 energization (250), and clear the pressure increase mode counter. 251), step 266
Proceed to. If ΔVs is smaller than 8KIIl/h, refer to the contents of the pressure increase mode counter (280, 290), and if it is 1 (entering the first pressure increase mode after executing the pressure reduction mode more than once), Just like that! Since the pressure may be continued, the process returns (transition to step 207).

If the content of the pressure increase mode counter is 2 (entering the second pressure increase mode control after executing the pressure reduction mode more than once), 5OLI is energized (hold power is being applied after pressure increase 0/8 has been completed). :Refer to the left column of 29 in Figure 2).291), and if the current is being applied, the pressure will continue to increase (1
Return 87- to complete the cycle of boosting energization. If the current is not being applied, the required pressure increase has ended, so step 249 is performed to control the pressure reduction mode.
Proceed to. When the pressure increase mode counter is 3, it means that the pressure increase mode is being executed for the first time after the brake is turned on (this means that the pressure increase mode counter is 3 in step 228).
is set, and if the content is 3 in step 265, 3 is set.
(This is due to the fact that the pressure remains unchanged), and the next control determination is the depressurization mode (see Figure 4b), so step 2
Proceed to pressure reduction mode control below 49.

In this way, during pressure increase mode control for the first time after the brakes are turned on, the reason why the next control mode is determined to be pressure reduction mode and then immediately proceeds to pressure reduction mode control is to prevent excessive pressure increase (axle lock). be. After that, when the pressure reduction mode control is executed at least once (this clears the pressure increase mode counter), in the subsequent pressure increase, the pressure increase mode control must be repeated at least twice as described in 9 above for the pressure increase time. This is to lengthen the brake fluid pressure, and as a result, when there is a pressure reduction, the pressure reduction time will inevitably become longer, and the period of rise and fall of the brake fluid pressure will be lengthened. By increasing the length in this way, the vibration period of the braking force due to the vertical movement of the brake fluid pressure becomes significantly longer than the period of the vehicle's unsprung vibration, which prevents amplification of the unsprung vibration due to resonance, synchronization, etc. do not have. In other words, once the pressure is reached, the pressure increase mode is controlled (Figure 2, column 2, left column).
This is repeated twice in a row to prevent resonance with unsprung vibration.

Even in these two consecutive pressure increase mode controls, the brake fluid pressure has been lowered once by the previous pressure reduction, so there is no risk of the pressure being increased too much (axle locking).

Referring again to step 282 in Figure 11b. When the wheel acceleration/deceleration rlv is equal to or higher than 14G in step 282, Dv is compared with 12G (283). Dv is 12
If it is smaller than G, compare ΔVs with α292), and if it is larger than α, the next control mode is continuous pressure reduction or pressure reduction.In any case, the pressure reduction mode should be executed, so step 2
The process proceeds to step 88, and the process proceeds to pressure increase continuation or pressure reduction mode control in the same manner as the condition determination after step 288 described above.

When it is less than α, the next control mode is hold (currently pressure increase mode, pressure increase hold: hold after pressure increase, brake fluid pressure is held in the increased state), so step Set the flag to indicate pressure increase hold mode via 293.294) SOLI to 27
8 energization 295) Proceed to step 266. Note that when the process proceeds to step 293 after the next 6 m5 ec, the pressure increase hold mode has been set, so the process returns from step 293. That is, once the pressure increase hold mode is entered, the hold is continued until a condition other than the hold mode is reached with reference to the condition divisions in FIG. 4b.

Refer again to step 283. r) in step 283
When v is 12G or more, compare ΔVs with α (284), and if it is smaller than α, the next control mode will be pressure increase, so check whether the current is pressure increase mode or pressure increase hold mode (297 , 298), if it is the pressure increase mode, it returns as is, and if it is the pressure increase hold mode, it proceeds to step 262 to set the pressure increase mode.

If ΔVs is greater than or equal to α in step 284, ΔVs is compared with β (285). If ΔV's is smaller than β, Dv is compared with -1.3G to determine whether the hold mode or pressure increase mode should be selected (296). Dv
If the current mode is smaller than -1.3G, the hold mode (pressure increase hold mode) should be selected, so in step 293 and below, the current mode is referred to and if the current mode is the pressure increase mode, the pressure increase hold mode is selected. Please set 294), 5
Set 01.1 to 278 energization (295) and proceed to step 266. If the current mode is the pressure increase hold mode, no change is required and the process returns.

If Dv is -1.3G or more, it is necessary to set the pressure increase mode, and the current control mode is referred to, and if it is the pressure increase mode, it returns as is, and if it is the pressure increase hold mode, it goes to step 262. Proceed (297, 298).

Refer to step 285 again. At step 285 ΔV
If s is greater than β, compare ΔVs with γ286),
If ΔVs is larger than γ, the next control mode is the pressure reduction mode, so the process proceeds to step 288.

When ΔVs is less than γ, Dv is compared with 6G287)
, nv is 6G or less, the next control mode is the pressure reduction mode, and the process proceeds to step 288.

If Dv exceeds 6G, the next control mode is pressure increase mode 9.
1-, the process advances to step 297.

Determination of the next control mode in mode/decompression hold mode will be explained.

Referring to the current mode (309), if it is the decompression mode, the duration of the decompression mode is read from the contents of the decompression counter and compared to 120 m5ec (323).

If 1201 Ilsec or more have elapsed, it means that one cycle of pressure reduction control (left column of column 5 in FIG. 2) has been completed, so the process proceeds to step 245. When it is less than 120m5ec, compare the contents of the reduced pressure counter with 48m5ec (ld [energization time: left column of column 5 in Figure 2)3i4), 48m5ec.
When m5ec is present, 5OLI is energized at 278 times (hold)
325) L, proceed to step 313. 4
If it exceeds 8m5ec, proceed to step 313. In step 313, Dv is compared with -1.3G, and if Dv is less than -1.3G, Dv is reduced to -12 in step 327.
If Dv is greater than or equal to 112G, step 33
Go to 0. If Dv is smaller than 112G, the high μ flag is referenced, and if it is present, the process proceeds to step 328, and if not, the process proceeds to step 249.

-92= Now, if it is determined in step 309 that the mode is not in the vacuum hold mode, check whether the mode is in the vacuum hold mode (310), and if it is not in the vacuum hold mode (this is impossible), the process returns. When in decompression hold mode,
Refer to the contents of the control counter and compare it (-pressure honild time) with 150 m5ec (312), 15
If it is more than 0 Insec, it is assumed that the pressure reduction is insufficient and the process proceeds to step '249, where the pressure reduction mode is set. 150m
If it is less than 5ec, Dv is -1, 31 compared to 3G.
3) If Dv is -1.3G or less, it means pressure reduction or continuous pressure reduction, so proceed to step 327. If it exceeds -1.3G, ΔVs is compared with α (314). If ΔVs is smaller than α, the next control mode is the pressure increase mode, and the process proceeds to step 262 and subsequent pressure increase settings.

If CDvs is greater than or equal to α, compare r)v with -0.6G (315'), and if CDv is less than -0.6G, the next control mode is pressure reduction mode or continuous pressure reduction mode, so proceed to step 330. Set the decompression mode with . Dv is-
If it exceeds 0.6G, in step 316 ΔVs is
If ΔVs is smaller than β, the process proceeds to step 262 and subsequent steps to set the pressure increase mode. If ΔVsQ<β or more, Dv is compared with 0.6G in step 317, and Dv is determined to be 0.
．． If Dv is 66 or less, the process proceeds to step 330, but if Dv is 0
．． If it exceeds 6G, the Dv will be 31g compared to 6G),
If Dv exceeds 6G, compare ΔVs with γ329
), γ or more, the next control mode is the depressurization hold mode, so the process proceeds to step 320. If it is less than γ, the pressure is increased, and the process proceeds to step 262, where the pressure increase mode is set.

When Dv is 6G or less in step 318, Δ
Compare Vs with γ (319), and if it is greater than or equal to γ, the next control mode is the pressure reduction mode, and the process proceeds to step 330. γ
If it is less than that, it is in decompression hold mode, so step 3
As described above, the parameter classification for determining the next control mode is set as shown in FIGS. 4b and 4c, and in steps 248, 282 to 291 and 299. ~32
As shown in 2, first determine the acceleration/deceleration by ΔVs, then set the acceleration/deceleration reference value individually for each division of ΔVs, and if it is large, set a rough reference value according to ΔVs, and then set the reference value more roughly than the reference value. Rather, the determination is made based on ΔVs, and where ΔVs is small, a fine reference value is set, and the determination is made based on acceleration/deceleration Dν rather than ΔVs. This provides stable and appropriate anti-skid control. ΔVs
In the region >(1/2)·Vs, it is considered that the wheel slip is large and immediate pressure reduction is required, so the process proceeds to pressure reduction without referring to acceleration/deceleration Dv (24, 8-249).

In the region of ΔVs≧(1/2)・Vs, acceleration/deceleration D
The reference value of v is set to infinity.

In pressure increase mode or pressure increase hold mode, the next control mode is determined according to the flow shown in Fig. 11b based on the data in Fig. 4b, and in pressure reduction mode or pressure reduction hold mode, the next control mode is determined according to the flow shown in Fig. 1.1c based on the data in Fig. 4c. Steps 309-328
The next control mode is determined according to the flow in Figure 4b and Figure 4.
In figure c, the acceleration/deceleration G that differentiates between pressure reduction and hold, the acceleration/deceleration G that differentiates between hold and pressure increase, and the acceleration/deceleration G that differentiates between pressure increase and pressure reduction are 1. Since the acceleration is set to the low acceleration side in Fig. 4b and the high acceleration side in Fig. 4c, there is no frequent switching from increased pressure to reduced pressure or vice versa, which reduces vehicle vibration. In addition, a hold area (pressure reduction hold, pressure increase hall call) is inserted between the main pressure area and the pressure increase area, so that the pressure can be instantly changed from pressure increase to decrease, or vice versa. On the other hand, the probability of sudden changes in brake pressure control is low, making it less likely that vibrations will occur.
It also consumes less power hydraulic pressure. When brake pedal 1 is depressed, anti-skid control (brake fluid pressure control) is entered on the condition that the estimated vehicle speed is 20 km/h or higher, which is the first value, and anti-skid control is activated when it is less than 20 km/h. Do not fit.

This is step 1 when brake pedal 1 is depressed.
59 to step 183 and then step 18
After going through steps 4 to 187, the presence or absence of the anti-skid required flag OCR is checked in step 188, and if it is not present (anti-skid control has not yet entered), the process proceeds to step 228, and then proceeds to step 229, where the control standard vehicle speed is determined. is 2
If the speed does not exceed 0 Km/h, the process returns to step 169 and does not enter anti-skid control, and in step 20, it is determined whether or not anti-skid is necessary on the condition that the speed exceeds IIl/h96-.233-244) Anti-skid This is because the flag OCR indicating that it is important is set in step 240, 242 or 244, and the process proceeds to anti-skid control (brake fluid pressure control) 205, 206 or 207.

Once anti-skid control is entered, if brake pedal 1 is continuously depressed (anti-skid required flag OC
R is set), in step 203, the control standard vehicle speed is compared with 8 km/h (end speed regarding rear wheel anti-skid control: second value), and in steps 2!4, the control standard and vehicle speed are set. When the control standard vehicle speed reaches 10/Ha compared to 107K (end speed for front axle anti-skid control: second value), the flag OCR is cleared to end front wheel anti-skid control. The electromagnetic switching valve device 5OLI, SOI, 2 is de-energized, and when the control reference vehicle speed becomes less than 8 km/h, the flag OCR is cleared to end the anti-skid control of the front and rear wheels, and the electromagnetic switching valve device 1sOLl, Since 5QL2 and 5OL3 are de-energized, when anti-skid control (brake fluid pressure control) is further advanced at a speed of 20 km/h or more, the front wheels will continue to operate until the estimated speed becomes less than 10+n/h. Furthermore, anti-skid control for the rear wheels continues until the estimated speed becomes less than 8 km/h. Since this anti-skid control starts at speeds of 20 km/h or more, the state detection at the beginning of the control is accurate, and it continues continuously according to a predetermined logic, so it has high continuity and stability. , does not give the driver a sense of abnormality, and does not particularly lengthen the braking distance. Anti-skid control does not start when brake pedal 1 is depressed at a speed of 20 km/h or less, but since the speed is low, the possibility of wheel lock is low, and the driver's brake operation is sufficient to respond to the situation. At the same time, even if the axle locks up, the speed will be low, so anti-skid control will be applied only after 20 km.
Operational operability and stability are higher than when operating even at speeds of /h or less.

〔Effect of the invention〕

As explained above, in the present invention, the axle speed deviation ΔVs
and wheel acceleration/deceleration Dv are used as parameters for determining whether to increase or decrease the brake fluid pressure with priority that matches the vehicle's driving condition and is highly reliable, resulting in even greater stability and reliability of anti-skid control. is brought about.

In a preferred embodiment of the present invention, there is no short-cycle switching of brake fluid pressure from pressure increase to pressure decrease or from pressure decrease to pressure increase, so that vibration of the vehicle and abnormal feeling to the driver are not substantially caused. . Furthermore, the stability of anti-skid control in the low speed range is improved, and the stability of vehicle operation is also improved. Furthermore, the accumulated pressure in the accumulator is maintained at a predetermined value when anti-skid control is not performed. When anti-skid control is not performed, almost no accumulator pressure is consumed, so the electric motor is not energized and power consumption is low. Since it is sufficient to accumulate pressure in the accumulator during non-control times with a pump and electric motor having a smaller capacity than the capacity that provides the amount of hydraulic pressure required during anti-skid control, small-sized pumps and electric motors can be used.

Even if a small pump and electric motor are used, the temperature will be counted up when the motor is energized, and counted down when it is not energized to obtain the estimated motor temperature. Since the electric motor is de-energized, overheating of the electric motor is prevented, and abnormalities such as burnout of the motor due to the electric motor being energized for a long period of time are avoided. Even if the electric motor is stopped as described above to prevent such an abnormality, there will still be pressure accumulation in the accumulator, and in the worst case, there will be a bypass valve device that directly applies brake fluid pressure from the mask cylinder to the wheel cylinder. Therefore, the braking action is not impaired.

Also, compared to the conventional case where the brake fluid pressure to the wheel cylinders is controlled by a combination of only pressure increase and pressure decrease (power fluid pressure consumption) (alternating switching between power pressure application and power pressure release to the reservoir). Since no power pressure is consumed during hold, the brake fluid pressure can be controlled in the manner of increasing the pressure and holding it, and decreasing the pressure and holding it, thereby significantly reducing the consumption of power fluid pressure. This reduction allows for further downsizing of the pump and electric motor. 1o
o- In addition, the pressure increase rate can be adjusted by a combination of pressure increase for a predetermined time and a hold time of an arbitrary length and its repetition, and similarly, the combination of a pressure reduction for a predetermined time and a hold time of an arbitrary length and its repetition. The pressure increase speed can be adjusted repeatedly, enabling more accurate and smooth anti-skid control.

[Brief explanation of the drawing]

FIG. 1a is a block diagram showing the system configuration of an embodiment of the present invention, and FIG. 1b is a sectional view showing details of the configuration of the hydraulic pressure control valve unit 3 shown in FIG. 1a. FIG. 2 is a plan view showing the energization pattern in which the microprocessor 13 energizes the electromagnetic switching valve device 5OLI-501, 3 in the brake fluid pressure control of this embodiment, and FIG. 3 is a plan view showing the energization pattern obtained by combining various energization patterns. Figure 4a is a graph showing how the brake fluid pressure increases and decreases. Figure 4a is a graph showing the relationship between the vehicle running state and the control mode when anti-skid control is entered. Figure 4b is a graph showing the relationship between the vehicle running state and the control mode when anti-skid control is entered. A graph showing the next control mode to proceed to in light of the vehicle running state during anti-skid control, and FIG. This is a graph showing the mode, and FIG. 5 is a time chart showing the relationship among wheel speed, reference vehicle speed, control reference vehicle speed, wheel cylinder hydraulic pressure, etc. during anti-skid control. 6a, 6b and 6c are flowcharts showing the interrupt processing operation of the microprocessor 13;
FIGS. 8a and 7b are flowcharts showing the main control operation (main routine) related to anti-skid control of the microprocessor 13, FIGS. 8a, 8b and 8c are flowcharts showing the subroutine for calculating wheel speeds, and FIGS. 9a and 9b are flowcharts showing motor energization control (subroutine), and FIG. 10a is a flowchart showing motor energization control (subroutine). 10b and 10c are flowcharts showing anti-skid control (subroutine), FIG. 11a and 1
1b and 11c show anti-skid control (10th
It is a flowchart which shows the anti-skid control (electromagnetic switching valve device energization control: subroutine) which actually controls brake fluid pressure in FIG.a, FIG. 10b, and FIG. 10c). l: 2-brake mask cylinder for brake pedal 3.4
, 5: Hydraulic pressure control valve units 3a to 3h: Bypass valve devices 31 to 3n: Hydraulic pressure control valve devices 6.7, 8, 9 Ni Brake wheel cylinder 10.1
1, 12: Speed sensor 13: Microprocessor 1
4: Electronic control unit 15: Electric motor 16: Pump 1
7: Accumulator pps Nibrake hydraulic pressure source device R1, Y: Motor relay WRY: Main relay! i
lL: Warning lamp BSIII Brake operation detection switch PS: Pressure detection switch R5V: Reservoir' 48 Figure d"'Vs-'9'12B + 0.3 mh east 4b
Figure/Z Cocall 1 Cod Etc. 4JE Japan-Isshi-do-va: Wheel i vs: @ Elevation standard vehicle creation "Figure 4c' Figure 6a Figure 6b Figure F mouth ■ [I mouth ■ JP-A-Sho GO- 213557 (30) Perforation 60 figure [Naoko Tokukai Sho GO-213557 (31) East 98 figure [Shoagon]

Claims (11)

[Claims] (1) A brake fluid pressure control valve device inserted in the brake fluid pressure supply line from the brake mask cylinder to the brake wheel cylinder; Valve device operation means for controlling the state of the brake fluid pressure control valve device; Speed detection means for detecting; Brake depression detection means for detecting depression of the brake hydraulic pressure; and Monitoring the states of the speed detection means and the brake depression detection means, and calculates the estimated speed Vs of the vehicle based on the rotational speed Va. Then, when the brake is depressed, the acceleration/deceleration Dv of the rotational speed Va and ΔVs = Vs − Va are parameters, and Δ
A reference value is selected according to the value of Vs, and the acceleration/deceleration Dv is compared with the reference value to increase the brake fluid pressure. An anti-skid control device comprising: a control device that determines whether or not pressure reduction is necessary and, based on the determination result, gives an instruction to a valve device operating device to set a brake fluid pressure control valve device to a pressure increase or pressure decrease state. (2) The anti-skid control according to claim (1), wherein when ΔVs exceeds a high predetermined value, the control means issues an instruction to reduce the pressure without comparing the acceleration/deceleration with a reference value. Device. (3) The anti-skid control device according to claim (2), wherein the high predetermined value is a value obtained by multiplying the estimated speed Vs by a predetermined coefficient. (4) After giving an instruction to increase or decrease the brake fluid pressure, the control means controls the brake fluid pressure at least once in the increased pressure state and the reduced pressure state.
Different values for the two parameters are used as boundary values for determining whether to increase or decrease the pressure.
An anti-skid control device according to claim 1, which determines whether pressure reduction is necessary. (5) The anti-skid control device according to claim 4, wherein the at least one parameter is wheel acceleration/deceleration Dv, and the determination boundary value is a reference value. (6) The control means starts brake fluid pressure control that gives an instruction to increase or decrease the pressure based on the determination result when the estimated speed is equal to or higher than a predetermined first value, and once this vibration starts, the brake fluid pressure control is started. Then, while the brake is depressed, the brake fluid pressure control is continued until the estimated speed becomes equal to or less than a second value, which is smaller than the first value. Device. (7) The brake fluid pressure control valve device includes a brake fluid pressure port that receives brake fluid pressure from the brake mask cylinder;
Open between the control output port, control input port, power hydraulic boat, output port and control input port to give brake fluid pressure to the wheel cylinder. a bypass valve device comprising a valve member to be closed, spring means for forcing the valve member in a closing direction, and a piston receiving pressure from a power hydraulic port in a direction to drive the valve member open; A brake fluid pressure boat that receives brake fluid pressure, and a fluid pressure control chamber that communicates with the above control input port. A power hydraulic port, a valve member that opens and closes between the hydraulic control chamber and the brake hydraulic port, a spring means that forces the valve member in the closing direction, and a power hydraulic port that drives the valve member open. The volume of the hydraulic control chamber is reduced by moving in that direction, and the volume of the hydraulic control chamber is increased by moving in the opposite direction. a hydraulic control valve apparatus comprising a piston receiving a piston;
The valve device operating means includes: a power hydraulic pressure source that applies accumulator pressure to the power hydraulic port of the bypass valve device; an electromagnetic switching valve device that is inserted between the power hydraulic ports of the valve device and selectively connects the power hydraulic port of the hydraulic control valve device to the accumulator pressure output port and the drain pressure port in response to energization; An anti-skid control device according to claim (1). (8) The power hydraulic pressure source includes an electric motor, a liquid pressurizing pump driven by the electric motor, and an accumulator that receives the discharge pressure of the liquid pressurizing pump, and includes a power hydraulic pressure source for the bypass valve device. The anti-skid control device according to claim 7, wherein an accumulator pressure is applied to the port. (9) The power hydraulic pressure source includes a pressure detection means for detecting the accumulator pressure; the control means controls energization and deenergization of the electric motor according to the accumulator pressure, and maintains a predetermined increase rate during energization of the electric motor. Counts up a numerical value, counts down the numerical value at a predetermined down rate while the electric motor is not energized, and stops energizing the electric motor when the count value reaches a predetermined value; Anti-skid control device as described in section. (10) The electromagnetic switching valve device is in a pressure increasing state in which at least the power hydraulic port of the hydraulic pressure control valve device is connected to the accumulator pressure output port according to the current value. The multi-position switching solenoid valve device is in a hold state in which the power hydraulic pressure port is closed and in a depressurization state in which the power hydraulic pressure port is connected to a drain pressure boat; the control means is configured to control the estimated speed when the brake is depressed. 41 Based on the rotational speed and the acceleration/deceleration of the rotational speed, it is determined whether or not to increase, hold, and reduce the brake fluid pressure, and the above-mentioned state of the electromagnetic switching valve device is controlled in time series; The anti-skid control device according to range (8). (11) The control means determines the rate of increase in brake fluid pressure to the wheel cylinder based on a combination of the duration time of the pressure increase state and the duration time of the hold state, and determines the pressure increase rate of brake fluid pressure to the wheel cylinder based on the combination of the duration time of the pressure reduction state and the hold state. The anti-skid control device according to claim 10, which determines the rate of brake fluid pressure reduction.