JPS60209355A - Antiskid controller - Google Patents

Abstract

PURPOSE:To improve stabilization in car driving at low speed, by making a device perform antiskid control continuously to the extent of the second specified value being lower than the said value at a time when it does not start the antiskid control if a car speed is below the specified value but starts the antiskid control as it comes to more than the specified value. CONSTITUTION:A device bearing the above caption feeds a hydraulic fluid out of a master cylinder 2 to wheel cylinders 6-9 for front and rear wheels at both sides via each of hydraulic control valve units 3-5, while each of these units 3- 5 controls them by an electronic controller 14 on the basis of each output signal out of wheel speed sensors 10-12, and a brake operation detecting switch BSW. In this case, the controller 14 controls each of these units 3-5 on the basis of the judged results of whether the increase or decrease of is required or not if a estimated car speed to be calculated out of a wheel revolving speed is above the specified first value. And, during continuation of a brake operating state, a control command based on the said judged result is made to be given to each of these units 3-5 till the estimated car speed comes to less than the second value being smaller than the first value.

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 axle is about to lock when braking a vehicle to prevent skidding due to the axle locking. Regarding equipment.

[Prior art]

Various configurations are already known as anti-skid devices for vehicles, but since the brake fluid pressure fluctuations in the wheel cylinders when the anti-skid devices are activated are not transmitted to the brake mask cylinders, the brake pedal As something with a good feeling of operation,
For example, JP-A-58-450 and JP-A-58-2
There is one disclosed in Japanese Patent No. 6658.

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 based on 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.

In addition, in order to prevent the piston of the pressure control valve device from moving by the brake fluid pressure and opening the valve member and reducing the wheel cylinder fluid pressure when the power fluid pressure is lost, there is a space between the wheel cylinder and the pressure control valve device. A bypass valve device is inserted to directly apply brake pressure from the mask cylinder to the wheel cylinder in the event of power hydraulic pressure loss (Japanese Patent Laid-Open No. 58-2
6658).

In anti-skid control using these conventional devices or other conventional devices, the brake fluid pressure is increased or decreased when a predetermined condition is met after the brake fluid pressure lever is depressed. Even if the anti-skid control operates, it has virtually no effect, and the judgment of the conditions for the anti-skid control becomes uncertain, which may make the anti-skid control unstable or even extend the braking distance, which can be dangerous.

In addition, if anti-skid control is performed above a predetermined vehicle speed as a boundary, but anti-skid control is cut below it, if anti-skid control is started at a vehicle speed higher than the boundary value, it will be stopped at the boundary value. Once the system is released, the driving sensation of the vehicle will be significantly 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 driving the pump to maintain the power pressure at a constant high value, or by releasing the power pressure of the pressure control valve device through the solenoid valve. For example, as disclosed in Japanese Patent Application No. 57-078630, in order to perform anti-skid control accurately and smoothly, power pressure is applied to a solenoid valve.
If the release is done frequently, power pressure is consumed rapidly, and a large mechanism and large amount of power are required to maintain a constant power pressure at a high capacity, such as increasing the capacity of the power pressure source device or speeding up the pump drive. There were problems such as.

Therefore, the present applicant has developed an electric motor that drives the pump of the power pressure source device by detecting only when the vehicle is braking and when the rotating state of the seven wheels of the vehicle is close to the state in which the solenoid valve is operated for the first time. An anti-skid control device was provided which discharges pressure fluid from a power pressure source into a reservoir after the 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. Also, even when the brakes are applied, the electric motor is not activated unless the axle is 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, without impairing the action of the brake, the mechanism of the power source device becomes smaller, the power required is small, and the power consumption is also small. In particular, it is desirable to further reduce power consumption.

[Purpose of the invention]

A first object of the present invention is to improve the stability of anti-skid control in a low speed range, thereby increasing the stability of vehicle operation.

A second object of the present invention is to safely and highly 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 object is to reduce the power capacity required of the electric motor and to enable the use of small electric motors.

[Structure of the invention]

In order to achieve the above object, the present invention provides a brake fluid pressure control valve device inserted in a brake fluid pressure supply line from a brake mask cylinder to a brake wheel cylinder; a valve that controls the state of a brake fluid pressure control well device; Device operation means; Speed detection means for detecting the rotational speed of the axle; Brake depression detection means for detecting depression of the brake fluid pressure; Also, monitors the states of the speed detection means and the brake depression detection means and adjusts the brake fluid according to the situation. In an anti-skid control device, the anti-skid control device includes a control device that determines whether pressure needs to be increased or decreased and, based on the determination result, instructs the valve device operating device to set the brake fluid pressure control valve device to a pressure increasing or decreasing state: The control means calculates the estimated speed of the vehicle from the rotational speed, determines whether or not brake fluid pressure needs to be increased or decreased based on the estimated speed 2 rotational speed and the acceleration/deceleration of the rotational speed when the brake is depressed, and calculates the estimated vehicle speed. is a predetermined first value (for example, 20Km
/h) Based on the above determination results, 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, and once this instruction is given, the estimated vehicle speed will be changed while the brake is depressed. Based on the determination result, the brake fluid pressure control valve device is increased in pressure by the valve device operating means until it becomes less than or equal to a second value (for example, 8 km/h) that is smaller than the first value.

Instructions shall be given to set the vacuum condition.

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 (
Since anti-skid control continues after anti-skid control starts until extremely low speeds when anti-skid control is no longer required, the stability of vehicle operation at low speeds is increased and braking distances do not need to be particularly long. . In particular, when anti-skid control is entered at a speed higher than the first value, the reliability of the initial condition judgment is high, and once anti-skid control is entered, the situation changes by following the situation change brought about by anti-skid control. Since the control is advanced according to the first value, the stability of the anti-skid control is high even if the value falls below the first value, and the highly stable anti-skid control is terminated at the second value, which eliminates the need for the anti-skid control. The braking sensation given to the driver is stable and drivability is improved.

In a preferred embodiment of the present invention, brake fluid pressure control = 11 = The control valve device is a brake fluid pressure boat that receives brake fluid pressure from a brake mask cylinder, and a control output port that provides brake fluid pressure to a wheel cylinder.

a control input boat, a power hydraulic port, a valve member for opening and closing between the output port and the control input port, a spring means for forcing the valve member in the closing direction, and a power hydraulic pressure in the direction for driving the valve member open. a bypass valve device comprising: a piston receiving pressure from the port; and a brake hydraulic port receiving brake hydraulic pressure from a brake mask cylinder, a hydraulic control chamber communicating with the control input port, and a power hydraulic boat.

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 discharge pressure of the liquid pressurizing pump, and an accumulator pressure control valve device; A power hydraulic pressure source that provides an accumulator pressure to the power hydraulic port of the bypass valve device; and a power source for the accumulator pressure output port and drain pressure boat of the power hydraulic pressure source and the power of the hydraulic control valve device. an electromagnetic switching valve device that is inserted between the hydraulic ports and selectively connects the power hydraulic port of the hydraulic control valve device to the accumulator pressure output port and the drain pressure boat in response to energization;
This electromagnetic switching valve device has at least a pressure increase state in which the power hydraulic port of the hydraulic pressure control valve device is connected to the accumulator pressure output port, a hold state in which the power hydraulic pressure port is closed, and a hold state in which the power hydraulic pressure port is connected according to the current value. The hydraulic pressure port is connected to the drain pressure port, and the multi-position switching solenoid valve device is in a depressurized state, and the control means controls energization and deenergization of the electric motor according to the accumulator pressure, and maintains a predetermined state while the electric motor is energized. Counts up the numerical value at an up rate of , 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 the predetermined value; with the brake depressed, Estimated Speed 2 Based on the rotational speed and the acceleration/deceleration of the rotational speed, the necessity of increasing, holding, and decreasing the brake fluid pressure is determined, and the above-mentioned state of the electromagnetic switching valve device is controlled in time series; The combination of the duration and the duration of the hold state determines the rate of increase in brake fluid pressure to the wheel cylinder, and the combination of the duration of the depressurization state and the hold state determines the rate of decrease in brake fluid pressure to the wheel cylinder; shall be.

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 current being applied 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.

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 power fluid pressure consumption15-. This reduction allows for further downsizing of the pump and electric motor. In addition, the rate of pressure increase can be adjusted by combining and repeating pressure increase for a predetermined time and hold time for an arbitrary length, and similarly, the rate of pressure increase can be adjusted by combining pressure reduction for a predetermined time and hold time for an arbitrary length and repeating the same. Pressure speed can be adjusted, allowing 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 wheel FR and the front left axle FL are each independently anti-skid controlled, and the rear right axle RR
Anti-skid control is performed on the rear right axle RL and the rear right axle RL all at once. So, the front right wheel FR.

Speed sensors 10, 11 and 12 are provided to detect the rotation speeds of the front left axle FL and the rear wheels RR, RL. Both of these sensors are connected to the axle or transmission output shaft = 16
- It consists of a magnetic gear coupled to the gear, a permanent magnet core fixed opposite to the gear, and an electric coil wound around the core to generate a voltage at a frequency corresponding to the rotation of the gear. The generated voltage 81 of these sensors 10 to 12
~S3 is applied to the electronic control unit 14.

When the brake pedal 1 is depressed, the brake operation detection switch BSV, which is open when the brake pedal is not depressed, is closed. A status signal indicating whether the switch BSW 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 boats (3a) of the brake fluid pressure control valve units 3, 4, and 5. The hydraulic pressures of the control output ports (3b) of the brake hydraulic pressure control valve units 3, 4, and 5 are applied to the brake wheel cylinder 7 of the front right wheel FR, the brake wheel cylinder 6 of the front left wheel FL, and the rear axle RR, respectively. It is applied to the brake wheel cylinder 8 of the 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 ports (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 equipment for brake hydraulic control valve units 3, 4 and 5
Each of the solenoid switching valve devices 5OLI.

Pressure at the output ports of 5QL2 and 5OL3 is applied.

Brake fluid pressure control valve units 3, 4 and 5 all have the same configuration. FIG. 1b shows the configuration of the control valve unit 3. The control valve unit 3 includes bypass valve devices (3a to 3).
h) and hydraulic control valve devices (3i to 3k).

The bus pass control valve device includes a coil storage space that communicates with a brake hydraulic pressure port 3a and accommodates a compression coil spring 3f, and a control output port 3b that communicates with this space and a valve operation that accommodates 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 that houses the piston h and communicates with the power hydraulic port 3d.

The hydraulic control valve device includes a valve operating chamber that communicates with the brake hydraulic boat 3i and houses a compression coil spring 3[11 and a ball valve 3Q, and a valve operating chamber that communicates with the control input port 3C and has an operator integrated with the piston 3n. The hydraulic pressure control room 3j passes through.

It also has a piston operating space that accommodates the piston 3n and communicates with the power hydraulic port 3k.

When a predetermined power hydraulic pressure is applied to the bows 1-3d (normal condition), the piston 3h moves to the right from the illustrated state, and the ball valve 3e moves to the right against the force of the spring 3f. and the control output port 3b is the control input port 3.
It communicates with c. In addition, a state in which anti-skid control is not substantially performed (the electromagnetic switching valve 5OL1 is in the first state (
In the state (de-energized) shown in Fig. 1a), power hydraulic pressure is applied to the boat 3k, the piston 3n has moved to the right compared to the state in Fig. 1b, and the ball valve 3Q has moved to the right. , brake hydraulic ports 3a, 3i - pressure control chamber 33 - control input boat 3C - working chamber 3g - control output port 3b - mask cylinder 2 in the path of wheel cylinder 6
The wheel cylinder 6 is in communication with the wheel cylinder 6.

When skid prevention control is not being performed, brake fluid pressure is applied to the wheel cylinder 6 through this route 19- 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.Roughly speaking, if the possibility of skidding is high, the electromagnetic switching valve 5OLI is energized to reduce the pressure in a predetermined energization pattern. When energizing for reduced pressure, the solenoid switching valve 5
The output port of OLI, that is, the power hydraulic port 3k of the hydraulic pressure control valve device becomes the drain pressure, and the piston 3n moves to the left, thereby causing the ball valve 3Q to move between the brake hydraulic port 31 and the hydraulic control chamber 3J. and shut off the hydraulic control chamber 3.
The volume of j increases, its pressure decreases, and this reaches the wheel cylinder 6 through the control input ports 1 to 3c and the control output port 3b, and the brake fluid pressure of the wheel cylinder 6 decreases, weakening the braking force.

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, the 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 5QL2゜5OL.
3 has exactly the same configuration as 5OLI. 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, anti-skid control such as reducing, increasing, and holding the brake fluid pressure to the wheel cylinders is limited to wheel cylinder 7 of both axles FR, wheel cylinder 6 of the front left axle FL, and 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 nsv, 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 SQLI to 5 are connected to the output port 17o of the unit 3 to 5.
The high pressure input port Hin of OL3 is connected, and the electromagnetic switching valve device 5 is connected to the drain port 17d of the device PPS.
The low pressure ports Lout of OLI~Sol and 3 are connected.

When the hydraulic pressure of the accumulator 17 is lower than a predetermined pressure, the pressure detection switch ps is open 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 when it is closed.

Briefly, when the switch PS is open (low pressure), the electronic control unit 14 energizes the motor energizing relay RL'/ to energize the motor 15 to drive the pump 16, and the switch P
When S is closed (high pressure), relay RLY is deenergized to cut off power to motor 15 and stop pump 16. In addition, this is to prevent the motor from turning on and off in short cycles.

The pressure detection switch ps is opened by the motor energization control described later (
Even after switching from low pressure (low pressure) to close (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 5QL3 can linearly control the position of the flow path switching piston or plunger using the energizing current value, and connect the high hydraulic pressure input port Hin to the output capo-1-(3k) without energizing. output port (3k) to low voltage port 1~Lout at maximum current value Imax
At an intermediate value between de-energization and Imax, the output capo-1-(3k) is cut off (held) from both the high-wave press-in capo Hin and the low-pressure bow 1-Lout.

@Since the position of the flow path switching plunger of the magnetic switching valve devices 5OL1 to 5OL3 is 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 078 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 Sol, 3 is Imax in the first state (pressure increase connection)
The energizing current value is set to 0/4 for In+ax, the second state (hold) is 1/4 the energizing current value for Imax, and the third state (reduced pressure connection) is 3/4 for In+ax.
It is set at 4.

23- In addition, the reason why 8 is used as the denominator in the control of 5OLI and 5QL2 is that 3 is used in the energizing current value specification code of 5OLI and 5QL2.
This is because bits are assigned. The numerator indicates a value (decimal number) expressed by 3-bit data. 4 under control of 5OL3
is used as the denominator because 2 bits are assigned to the energizing current value designation code of 5OL3. The numerator indicates a value (decimal number) expressed as 2-bit data.

The microprocessor 13 of the electronic control unit 14 outputs a code specifying such a current value, the code is converted into an analog signal by an A/D converter in the electronic control unit 14, and the analog signal is converted to an analog signal by a linear amplifier. The signal is amplified and the electromagnetic switching valve devices 5QLI to 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 MR''/.

When main relay MRV is open, the output of the linear amplifier is zero (de-energized), regardless of the output code of microprocessor 13.

The microprocessor 13 of the electronic control unit 14 has a ratio of 2
4- Has integrated ports 81 to S3, and executes an interrupt every time a pulse obtained by shaping the wheel speed detection voltage arrives, counts up the arriving pulse and determines the elapsed time, and calculates the wheel speed. Create basic data. 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 5OLI to 5OL3), etc.

FIG. 2 shows the energization pattern of 5QLI to 5OL3 during anti-skid control. Referring to FIG. 2, before the start of control, the electromagnetic switching valve devices 5QLI to 5OL3 are not energized (same as the pressure increase state: 0/8 output energization, o/4 output energization).

At this time, for example, referring to unit 3 (FIG. 1b), mask cylinder 2 - brake hydraulic port 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 boat 3b - wheel cylinder 6, and the normal brake hydraulic pressure loop (without anti-skid control) 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 5OL
The pressure increase energization pattern of I and 5OL2 is shown in the left column, 078 energization for 24m5ec (same as non-energization: pressure increase)
378 energization (passing type in the hold direction) to speed up the transition to the hold state for the first 6III sec and 278 energization (hold) for the next 42 m5 sec, 7
One unit is 2IllSeC.

The continuous pressure increase in the third column is caused by continuous de-energization. As shown in the 49th left column, the hold energization pattern of 5OLI and 5OL2 is a continuation of 278 energizations, and the duration is indefinite, depending on the result of status reading and calculation in anti-skid control, which will be described later, that is, the occasional situation. Determined accordingly.

The depressurization energization pattern of 5OLI and 5QL2 is 778 energization (depressurization) for 48m5ec as shown in the left column of the 5th column.
The 2/8 energization (hold) for the next 72m5ec is 97- for one unit.

The 69th continuous pressure reduction is brought about by 778 continuous energizations.

The energization patterns of 5QL3, such as pressure increase, hold, and depressurization, are the same as those described above, but in response to the difference in brake characteristics between the front and rear wheels, and the difference in the number of bits of the energization instruction code. The pattern is slightly different. 5QL3
Please refer to the right column of FIG. 2 for the energization pattern.

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, the up shown in Fig. 3 is obtained.
As in c, the pressure increase is brought about at a fast rate.

A short hold period following a unit pressure increase pattern will result in a slightly slower rate of pressure increase as in the UP old case in Figure 3, and furthermore, a slight hold period following a unit pressure increase pattern will result in a slightly slower rate of pressure increase as in the UP old case in Figure 3. A long hold period will result in a slow rate of pressure build-up, such as UPI+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 above, but in this embodiment, the hold time (see columns 2 and 5 in Figure 2) is constant, and the times of pressure increase and decrease energization are varied depending on the situation. Depending on the situation, change the length to be longer or shorter 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 B51il 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 increased continuously (pressure increase before the start of control: see Figure 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 reason why the region to which the next step is to proceed during pressure reduction or pressure reduction hold (Fig. 4c) is shifted to the upper right than the region to which the next step is to be carried out during pressure increase or amplification hold (Fig. 4b) is due to the difference between pressure increase and pressure reduction. This is to provide hysteresis to prevent control switching.

Next, an overview of the anti-skid control by the microprocessor 13 will be explained with reference to FIG.
Estimating s' is calculated. The reference vehicle speed Vg' is the higher of the average wheel speed of the front wheels and the axle speed of the rear axle. When the brake pedal 1 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, the control reference vehicle speed Vs is set to 1.3.
The higher of the calculated value reduced by the deceleration of G and the reference vehicle speed Vg' is set as the control reference vehicle speed Vg, and the value calculated by deceleration at 1.3G is set as the control reference vehicle speed Vs.When the time reaches 96 m5ec, then The higher of the calculated value reduced by the deceleration of 0.15G and the reference vehicle speed Vg' is set as the control reference vehicle speed Vg.

Accordingly, based on the acceleration/deceleration Dv of each wheel and the deviation ΔVs between the axle 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 Vg is large: when the axle is largely idling), the pressure is continuously reduced regardless of the axle 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.

If the control reference vehicle speed is less than 8 km/h, anti-skid control of the gold wheel is not necessary, so 5QLI to 5OL3
Cut off the electricity. 8Km/h or more but 10Km/h
If it is less than h, anti-skid control of the front wheels is not necessary, and in order to ensure the directional stability of the vehicle, the 5OL
I, 5QL2 are de-energized and anti-skid control of only the front axle is stopped.

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 closed.
5 is considered to be a stop, but while the motor is energized, the estimated motor temperature value is counted up in a predetermined pattern described later, and while the motor is stopped, it is counted down, and when the estimated motor temperature value reaches a predetermined high value, the motor is stopped. Stop overnight. Thereafter, the estimated motor temperature value is counted down, and when the estimated motor temperature value reaches a predetermined low value, the motor is energized if the motor energization is required.

The anti-skid control described above is performed only when the wheel 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 wheel speed is 5 km/h), as described above. 10km/h
The reason why anti-skid control for only the front wheels is stopped at speeds below 20 km/h (estimated at 7 km/h in terms of axle speed) is that the situation judgment for anti-skid control at speeds above 20 km/h is accurate and there are fewer false judgments thereafter. Therefore, anti-skid control is highly safe, and once anti-skid control is activated, it is better to continue it until the car stops, which improves the driving stability of the car and provides a smoother feel when applying the brakes. by. For example, if the anti-skid control stops at 20 km/h, the car will react differently to driving operations at that point, making it difficult to drive.

The reason why the speed at which anti-skid control is stopped for the front and rear wheels is set to 10 km/h and 8 km/h, respectively, and the front wheels are set at a slightly higher vehicle speed, is to improve the directional stability of the actual driving. When anti-skid control is activated and the car decelerates, the brakes on the rear wheels are first applied harder, and then the front wheels are applied harder, which makes steering easier and prevents the car from swaying. .

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. Therefore, in the above-mentioned anti-skid control, the microprocessor 13 controls the rear wheels (wheels driven by the engine).
The axle speed of the front wheels (axles not driven by the engine) are compared to determine whether there is acceleration slippage, and anti-skid control is not performed when acceleration slippage occurs.

In addition, in the above-mentioned anti-skid control, the microprocessor 13 monitors the duration of the pressure reduction mode, and when the duration of the pressure reduction mode is long (braking 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. , slow down the speed of pressure increase to restore brake pressure and wait for wheel 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 wheel speed Va has not recovered, it is determined that there is an abnormality and the pressure reduction 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 control by the microprocessor 13 will be explained with reference to a flowchart shown in the drawings.

When the power is turned on, the microprocessor 13
Execute the main routine shown in the figure and cancel the interrupt mask there. Note that this microprocessor 13 has three interrupt ports 31 to S3, among which ports 51 and 8
Port S2 is a port where mask control is not possible, and the signal to this port changes to start an interrupt when the power is turned on. When appears, interrupt processing is executed.

First, the interrupt processing operation at port S1 will be explained with reference to FIG. 6a. When the signal SL (speed pulse obtained by binarizing the voltage generated by the speed sensor 10 of the front right wheel FR) falls from the high level ■ to the low level L while the interrupt mask of port S1 is released. The flip-flop of port S1 is set to execute the interrupt processing shown in FIG. 6a. That is, first, the flip-flop must be reset to wait for the next signal change (from 01 to L).Step 1: Hereinafter, only the numbers will be written. The numbers in parentheses below indicate the step numbers), then the pulse number counter N
' is counted up by 1 (2), and then compared with the value To-1, which is the value obtained by subtracting the previous time T1 from the current time T0, that is, the elapsed time from the previous time 6111 seconds (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 6 m5ec or more, the elapsed time ro-Ti 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),
Initialize the pulse number counter N' (7). And FR indicating that more than 6m5ec has passed since the last time.
Set the 6msec end flag (8) and return to the step before the interrupt.

In addition, if the clock pulse is constantly counted and 6m5ec is counted inside the microprocessor 13, 6+
Set the flag OCF indicating n5ec progress and initial state 3
6- Returning to (count time 0), the internal counter with a cycle of 6 m5 ec counts up again, and the clock pulse is constantly counted and 64 m5 ec is counted.
The flag TOF indicating the ec progress is set and the count returns to the initial state (count time 0) and the count is increased in the same manner64.
There is an internal counter with an m5ec cycle, and the current time To is obtained from the count value of this counter with a 64m5ec cycle.

Therefore, T, -TI may be negative, but in the case of negative, T o +64m5ec -T I is To - Ti
shall be.

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

The rotational speed (wheel speed) of the front wheel FR is multiplied by the N/T1m constant, and the wheel speed can be calculated from the contents of registers T and N. The wheel speed is determined by referring to the flag in the main routine (Fig. 7b) to be described later.
Calculated when the c end flag is set.

Since the interrupt processing in the interrupt boat S3 (FIG. 6C) is exactly the same as the interrupt processing in the boat S1 (FIG. 6a), the explanation will be omitted.

The interrupt processing of 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 is not executed unless initialization has been completed.

Through the interrupt processing described above, data for axle speed calculation is updated and stored in registers T and N at a cycle of 6 m5 ec or more. In addition, the speed detection pulse (S
Since the interrupt is executed on the condition that there is a change in t~S3), the interrupt is not executed when the vehicle is stopped, and when the axle speed is extremely low and the speed detection pulse period is 6.
When the speed is 4m5ec or more, the speed calculation value based on the data in registers T and N has no reliability. Therefore, the vehicle speed sensors 10, 11, and 12 are designed to generate voltage oscillations with a period of more than 30 m5 ec and less than 50 m5 ec at the planned minimum speed of the vehicle. As a result, when the vehicle is traveling at this minimum speed, if the 6m5ec end flag is set, the data in the time interval register T will be longer than 30m5ec < 50m5e
Indicates a value shorter than c. Control flow (10a) to be described later
In steps 147 to 158 in the figure, data T in register T is stored. - T1 and if it is longer than 30m5ec (50
When the value is shorter than m5ec, it is the lowest speed, so register N is set to set the detected axle speed data to 0.
Set 0 to (clear register N). Note that, although this minimum speed does not necessarily correspond to the vehicle speed of 0, there is no problem in calculating and controlling the vehicle with this minimum speed as 0 in terms of anti-skid control. As will be described later, the minimum axle speed referred to in the control is 7.7 m/h or around it, so the wheel speed (minimum speed) for setting the register N to 0 only needs to be about 5 km/h or less.

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

To explain this main routine, when the power is turned on, the microprocessor 13 performs initialization in steps 17-24.

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

Clear the flags, etc., set the input port to the signal waiting state, set the standby signal to the output port, turn on the main relay MRY, cancel the interrupt mask of boats S1 and 83, and complete the initialization. Set the flag and set the current time (64
msec internal counter count value) is set in register T1, and time interval register T is set to a value 32IIISeC at which the speed calculation value N/T (actually, the value obtained by multiplying it by a constant) is considered to be essentially 0. .

This initialization enables interrupt processing operations for the 1 interrupt ports 81 to S3.

Next, the microprocessor 13 refers to the presence or absence of a flag OCF indicating that the 6m5ec internal counter has overcounted (25), and if so, subroutine OCFMAi (4).
0- Anti-skid control: In the following, 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. ) (2g), 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). Without the electromagnetic cutting eradication device 5QLI~
Refer to the activation state of each 5OL3, and if the depressurization is not energized, clear the count registers 5QL1 on counter, 5QL2 on counter, and 5QL3 on counter for monitoring the decompression activation time of each of 5OLI, 5OL2, and 5OL3 (35 ). 5OLI, 5QL2
．． If any of the 5OL3 is energized to reduce pressure, refer to the count value (31.32), and if the duration is 5 seconds or more, the brake fluid pressure has continued to decrease for a long time, so the wheel adjustment is performed in step 33a. The speed Dv is compared with a predetermined value -0.2G. -If it is greater than 0.2G, the wheel speed V due to pressure reduction
Since a has recovered (deceleration has stopped) and can be considered normal, proceed to step 36, but if Dv is less than 10.2G, the decompression will take a long time and the return of the axle speed will be abnormally slow. , In order to avoid no-brake, the abnormality flag WRNFLG should be set.33) Main relay MR'
/ is turned off and the electromagnetic switching valve device 5OLI.

All of 5OL2 and 5OL3 are de-energized (pressure increased), motor relay RLV 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 RLY is turned off (34),
The input of the boat BS (whether or not one brake pedal is depressed) 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 l is not depressed) is set in the S register by the above-mentioned initialization.

If the comparison results do not match, it means that the brake pedal 1 has changed from not being depressed to being depressed, 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 steps 36-37. In this way, when I check the mismatch 5 times, the count value is 5 (I referenced it 5 times, and the state was the same all 5 times), so I updated the state read in step 4o to the BS register and set the brake. The new state of the petal l is memorized) and the BS change counter is cleared for the next reading decision (41), and the process proceeds to the next step 42. If the same reading is not obtained five times after detecting a discrepancy, it is assumed that the brake was not depressed or released sufficiently or that the switch was simply chattering, and the process proceeds from step 37 to step 41 to clear the BS counter. BS
The contents of the register are not changed to the state read. By reading the state and updating the memory in this manner, the changed state is stored in the BS register only when the brake pedal 1 changes from not being depressed to definitely being depressed 45- or vice versa.

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

Note that when the 6m5ecJ4 completion flag is not set in the interrupt process, the speed calculation data is not ready, so the wheel speed is calculated only when the 6m5ecJ4 completion flag is set.

If we calculate all the axle speeds of both axles FR, front left axle FL, and both rear wheels, the calculations will take a relatively long time, resulting in control delays, especially the anti-skid that is executed every time the 6m5ec internal counter times out. Control OCFM
Since there is a risk that the motor energization control TOFMAi, which is executed every time the Ai and 64m5ec internal counters time out, will be delayed, in the wheel speed calculations from step 46 onward,
When the vehicle enters the cycle twice, only the speed of the wheel is calculated at the maximum (that is, on the condition that the 6m5ec end flag is set).

In this case, if the calculations of the axle speeds of the two axles FR, the front left axle FL, and the two rear wheels are 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 when it exceeds a predetermined count value, it is initialized (set to 1). Therefore, when the priority counter is 1, step 48
Proceed to step 1 and refer to the presence or absence of the FL6msec end flag, and if it is found, proceed to calculate the FL (front left axle) speed, and when that is completed, increase the priority counter by 1 (64).
. If there is no FL6msec end flag, check whether there is a rear 6m5ec end flag (49), and if there is, proceed to calculate the rear (rear axle) speed, and when that is completed, increase the priority counter by one (64). rear 6
When there is no m5ec end flag, FR6mse
Refer to the end flag c (50), and when it is found, proceed to the speed calculation of the FR (front right axle) (57 to 63), and when that is completed, the priority counter is incremented by one (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 (4B), reference to the rear 6IIlsec 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 priority counter content is 2, the rear 6m5
The process proceeds with reference to the ec end flag (51), reference to the FR6msec end flag (52), and reference to the FL6msec end flag (53), so when the priority counter is 2, the calculation priority order is rear, FR, and FL. .

Also, when the priority counter is 3, the operations proceed as follows: reference to the FR6msec end flag (54), reference to the FL6msec end flag (55), and reference to the rear 6IIISeC end flag (56), so when the priority counter is 3, the operation priority order is The FR, FL, and rear are 1.

Due to the above priority shift, the speeds of each wheel are calculated in the same order. In any case, if there is a FL6msec end flag, it will proceed to FL speed calculation, and if there is a rear 6m5ec end flag, it will proceed to rear speed calculation, and if there is a rear 6msec end flag, it will proceed to rear speed calculation.
If the c end flag is present, the process proceeds to steps 57 to 63 for calculating the FR speed.

In the FR speed calculation, the 6m5ec end flag set in the interrupt processing (Figure 6a) is cleared for the next data processing57), and the data N of the pulse number counter N is
is set in the accumulator register for the next calculation (58).

Next, in step 59, constant multiplication A of wheel speed = AN/T
A subroutine (MυLVIN) for performing XN is executed.

FIG. 8a shows a subroutine for constant multiplication MULVn. In this case, the number of pulses N is 70 compared to 10)
, if it does not exceed 10, leave N unchanged; if it exceeds 47-, it is larger than the maximum speed corresponding value, so change the number of pulses N.
is set to 10 (71). Then, AXN is calculated (72). A is a constant. Next, store the AN value in memory.
3), Steps 74 to 45 have the same content as Steps 25 to 45
Step 77 is executed, the program returns to the original step, and step 60 is executed to set the time interval T to the accumulator register.

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

FIG. 8b shows the subroutine DiVVW. In this case, calculate Vw=AN/T and memorize the calculated value Vw as the FR wheel speed (78.79), Steps 25 to 2
Execute steps 80 to 83, which are the same as in step 8, return to the original state, and set Vw to the accumulator register in step 62.
Set. Next, in step 63, an average value (smoothed value) calculation subroutine DiGFiL is executed.

FIG. 8c shows the average value calculation subroutine DiGFiL. In this case, smoothed value Va=(Vw-2+2Vw-t+Vw)/4
84), and then calculate the acceleration/deceleration of the smoothed value Va 48-Dv=(Va-Va-1)/T(84).
5). Note that V W -1 is the previous calculated value, V W -
2 is the calculated value from the time before the previous one, and Va-1 is the calculated value from the previous time.

In the following, Va will be referred to as axle speed, and Dv will be referred to as acceleration/deceleration.

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

If the average front speed is greater than the rear speed, the front average vehicle speed should be set to the reference vehicle speed Vs69), and if the front average speed is less than the rear speed, the rear speed should be set to the reference vehicle speed Vg68) , then returns to step 25 again and executes the steps from step 25 described above. Repeat this below.

In the control main flow explained above, step 2
If the flag is O at each of 5, 42.14, 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 so, the subroutine TOFMAi for controlling motor energization is executed in the next step.

As explained above, OCF is set when the 6m5ec internal counter times out, and TOF is set when the 6m5ec internal counter times out.
Set when the m5ec internal counter times out. As mentioned above, the presence or absence of these flags is referenced in many steps, and if they are present, anti-skid control or motor energization control is started accordingly, so the anti-skid control OCFMAi is practically executed at a 6m5ec cycle. The motor energization control is essentially 64i.
It will be executed every sec.

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 RLV is turned on in step 106.

Proceeds to off reference, but if there is a warning flag, the seventh
Decompression abnormality continuation flag W set in step 33 in Figure a
The presence or absence of RNFLG is checked 93a), and the sensor waking flag is checked (93b).

If WRNFLG exists, set the 3-time flash pattern data in the register94), and if the sensor warning flag exists, set the 2-time flash pattern data in the register93c), main relay MRY, motor relay RLY, and electromagnetic switching valve device. 5QLI to 5OL3 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, the warning lamp WL is turned on for 0.5 seconds, turned off for the next 0.5 seconds, and turned on for the next 0.5 seconds as the subsequent steps progress. Performs 91 flashing control of the awning lamp WL. After this blinking for 5 seconds, the light goes out. However, if WRNFLG is still present after 5 seconds, the blinking control is performed in the same way as described above, so that while the resultant VRNFLG is present, the warning lamp blinks three times at a 1-second cycle every 5 seconds. This blinking will stop when vRNFLG is cleared. If there is a sensor warning flag, it will blink twice.

Both when this flashing control is not performed and when it is performed (during flashing control), the motor relay RLY
(Please refer to 71 on, off 106;
When G is set, it is turned off in step 95), and when it is off (motor stopped), the contents of the estimated temperature register Tm are compared with 40 (estimated temperature 40'C), and if it exceeds 40 ( (Because the temperature difference with the surrounding area is large and the temperature decreases quickly), the contents of the estimated temperature register Tl11 are updated to the value obtained by subtracting 3 from the current value (10g).
.

When the content of the estimated temperature register Tm is 40 or less, compare it with 20 (estimated temperature 20°C) (109)
.

When the temperature is higher than 20, the contents of the estimated temperature register T+n are updated to a value obtained by subtracting 2 from the current value (52-) (110).

When the contents of the estimated temperature register TII+ are 20 or less, the value obtained by subtracting 1 from the contents of the estimated temperature register Tl11 is updated to the estimated temperature register Tl11.111)
do.

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

When updated in this way, the contents of the updated estimated temperature register Tm are compared with 20 (114), and if it is smaller than 20, the motor temperature estimate is 80 or more and there is a risk of overheating, so if motor energization is stopped. Clears the motor-on prohibition flag that is set to prohibit motor energization.

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 the motor energization control prohibition at high temperature,
In addition, there is a high possibility that the temperature will quickly rise to the prohibited temperature, which will lead to repeated 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, potentially causing trouble. This is because it becomes expensive.

Next, the process proceeds to step 124, where the warning flag is referenced. If the motor relay RLV is on in step 106 described above, the motor is being energized, so the contents of the estimated temperature register Tm are compared with 40 (116), 4
If it exceeds 0, the motor temperature is relatively high, heat dissipation is large, and the temperature rise rate is small, so the estimated temperature register T
The value obtained by adding 2 to the contents of m is updated and stored in the estimated temperature register (117). The contents of the estimated temperature register Tm are 4.
If it is less than 0, the contents of the estimated temperature register Tl11 are compared with 20 (118), and if it exceeds 20, the value obtained by adding 3 to the contents of the estimated temperature register Tm is updated and stored in the estimated temperature register Tm (119). ). If the contents of the estimated temperature register T+++ are 20 or less, the value obtained by adding 4 to the contents of the estimated temperature register The is set as the estimated temperature register Tm.
The updated memory is stored (120).

Next, set the updated value in the estimated temperature register Tm to 8.
0, and if it exceeds 80, the estimated temperature register Tm
The contents of the memory are updated to 80 (122), and it is assumed that the motor 15 is overheating, and in order to ensure the safety of the motor,
The motor-on prohibition flag is set (123), and the presence or absence of the warning flag is checked in step 124.

If there is a warning flag in step 124.

Turn off motor relay RL'/130), extend for 3 seconds
Clear the ec timer and proceed to step 133, but if there is no warning flag, refer to the presence or absence of the motor on prohibition flag (125), turn off the motor relay RLY in the same way as if there is a warning flag (130), and set the 3-sec extension timer. is cleared and the process proceeds to step 133, but if there is no motor-on prohibition flag, the open/closed state of the pressure switch PS is read and whether it is a low pressure state or a high pressure state is checked (126), and if the pressure is low, the motor relay RLY is turned on (132). Proceed to step 133. If the voltage is high, motor relay RLY turns 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 is not set, set it. If set, the extension timer will be set to 1 (64ms
ec) Increment 12g) and check whether the value is 3 seconds or more (3000/64 or more) 129
) If no, Leon continues as is,
Proceed to step 133. If the time has exceeded 3 seconds, motor relay RLv is turned off (130) and the extension timer is cleared. The reason why the motor 15 is energized in a low pressure state (switch PS is open) and continues to be energized for 3 seconds even after the pressure rises and the switch PS is closed is due to hysteresis in motor energization and stopping. This is to have the following. This 3
When the second is set to zero, the motor 15 is energized as soon as the accumulator pressure drops slightly, and then as soon as it rises slightly, the motor 15 is stopped and the dryer 15 is 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 at its output port 5OL3 to determine whether or not the code indicates depressurization energization. If it does not indicate depressurization energization, the 5QL3 on counter is cleared (134) and the process proceeds to step 137. If it indicates depressurization energization, the presence or absence of the rear pressure down stop flag is checked (135), and if so, the process proceeds to step 137. If you do not stir, the 5OL3 ON counter will increase by 1 count (64mse) because the depressurization current is being applied (brake fluid pressure is being depressurized).
c) At Ll (136), proceed to step 137.

Proceeding to step 137, the microprocessor 13 refers to the code set as an output at its output port 5OLI to determine whether or not the code indicates depressurization energization. If it does not indicate reduced pressure energization, the 5QL1 on counter is cleared (138) and the process proceeds to step 141. If it indicates depressurization energization, check whether there is an FL press-fit stop flag (139), and if there is, the process advances to step 141. If it is not there, the 5QLI on counter will be set to 1 because the pressure is being energized (brake fluid pressure is being reduced).
The count is increased (64 msec) (140) and the process proceeds to step 141.

Proceeding to step 141, the microprocessor 13 refers to the code set as an output at its output port 5QL2 to determine whether the code indicates depressurization energization. If it does not indicate reduced pressure energization, the 5OL2 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, the presence or absence of the FR press-in stop flag is checked (143), and if there is, the routine returns to the original routine from which motor energization control was entered (return). If it is not there, the pressure is being energized (brake fluid pressure is being reduced), so it is 5QL.
2-on counter is counted up by 1 (64msec)
(136), and returns to the original routine from which motor energization control was entered.

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 exceeds a predetermined value of 80, a motor-on prohibition flag is set to stop the motor 15. After setting this flag, when the estimated motor temperature becomes less than 20, the flag is set. is cleared to enable motor energization. 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 5QLI to 5OL3 that are being energized for pressure reduction are counted up.

In the main routine mentioned above, the contents of these 5OLI to 5QL3 on counters are referred to, and if it is longer than 5 seconds, the abnormality continues, so flags WR and N are set to indicate abnormal decompression continues.
Set FLG. When this is set, the motor energization control controls the blinking of the warning lamp WL, and for abnormality protection, the main relay MRY, motor relay RLY, and electromagnetic switching valve device SQL 1-5OL3
are all turned off.

Next, the anti-skid control OCFMAi will be explained with reference to FIGS. 10a to 11c.

As mentioned above, the microprocessor 13 has a size of substantially 6 m5.
The process proceeds to anti-skid control OCFMAi at the ec cycle. Proceeding to this anti-skid control OCFMAi, 6 m5
Clear the flag OCF indicating time-over of the ec internal counter 145), reset the m5ec internal counter 146), and store the contents of the previous time register T1 allocated to the rear as explained in the interrupt processing 147.
), rear time interval T explained in interrupt processing
Compare with 30m5ec and 5°1Ilsec (1
48). If T is between them, the wheel speed is assumed to be 0, and the contents of the pulse number register N are set to 0 (clear) in order to simplify the subsequent wheel speed calculation (Fig. 7b). Then, the rear 6m5ec end flag is set (150). Similarly, for FR and FL, the axle speed O is determined in steps 151 to 154 and 155 to 158, and if it is 0, N is set to 0, and the speed is set to 6m5ec.
Set the end flag.

Next, the microprocessor 13 registers the BS register (7a
1.59)), and if it is L (brake not depressed), set 3 in the pressure increase mode counter, Clear the reduced pressure counter and clear the low μ flag (160), that is, initialize the status register for anti-skid control when brake pedal 1 is depressed (H).

Next, the reference vehicle speed Vg (see steps 67 to 69 in FIG. 7b) is compared with the rear wheel speed Va (161). If the rear axle speed is different from the rear axle speed Va, the reference speed Vs should be the average axle speed of the front wheels (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 is equal to the rear axle speed Va, since the rear axle speed is higher than the front wheel speed (because of the possibility of acceleration slip), F
Compared to R speed and 0.875Vq (Vs = rear Va), 162), if FR speed is smaller than 0.875Vs, the possibility of acceleration slip is even higher, so FL speed and 0.875
It is compared with Vs (Vs=rear Va) (163). If the FL speed is smaller than 0.875V5, it is assumed that there is an acceleration slip, and an acceleration slip flag is set (164).

FR speed is 0.875Vg or more or FL
If the speed is 0.875Vs or more, it is assumed that there is no acceleration slip, and the process proceeds to step 171, where the acceleration slip flag is reset.

In step 161 described above, the reference vehicle speed Vs (see steps 67 to 69 in FIG. 7b) is compared with the rear axle speed Va. If the reference vehicle speed Vs is different from the rear axle speed Va, the reference speed Vs is determined by the average axle speed of the front wheels (front wheel speed should be higher than the rear axle speed), so step 1
74, where the reference speed Vs is compared with the average speed of the front axle (1.74). Here, the reference speed Vs
If the and front average speed do not match, acceleration slip judgment cannot be made (data is not yet available), so
Clear the acceleration slip flag (171). If they match (the front average speed is higher than the rear speed), compare the reference speed Vs with 30 K n+ / 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
If the rear speed is 0.75 Vs or more, it is assumed that at least one of the vehicle speed sensors 10 to 12 is abnormal and a sensor warning flag is set.
L (170) Clear the acceleration slip flag (17
1).

If the rear speed is less than 0.75Vs, the FR speed is 1,
Compare 25Vs and 0.75Vg: 177.17
11) If the FR speed is greater than 1.25Vs or less than 0.75Vs, the vehicle speed sensor 10~
170) Clear the acceleration slip flag (171).

When the FR speed is in the range of 1.25Vs to 0.75Vs, it is considered normal and no acceleration slip has occurred, so the acceleration slip flag is cleared (171).
.

When the reference speed Vs' is less than 30+a/h (
175), the reference speed Vs' is compared with 20 Km/h (179).

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

20, when the speed is more than +n/h, the rear speed, FR
Speed and FL speed are each compared with 5Km/h, and 5
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 axle 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 to 63-170) The acceleration slip flag is cleared (
171).

Now, when it is determined that there is an acceleration slip and the acceleration slip flag is set (164), the FR speed and FL speed are respectively compared to 20 km/h (165, 166), 20
At speeds exceeding Km/h, the speed difference between FR and FL is small, so let's compare FR speed and FL speed167, 168)
If the difference between the two is too large, it is assumed that at least one of the vehicle speed sensors 10 to 12 is abnormal, and a sensor warning flag is set. 170) The acceleration slip flag is cleared (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, control starts from deceleration region I as shown in FIG.

Clear the OCR (anti-skid required flag) of FL and PR, and clear the mode counter, control counter, high μ flag, sulin 64-pu counter, deceleration area counter, etc. (172
). 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 (164).
172). Next, the electromagnetic switching valve devices 5QLI to 5OL3 are de-energized (173), and this anti-skid control OCF
Return to the control step before entering MAi
do.

Enter anti-skid control OCFMAi, step 1
59, when BS=8 (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 vS' (184), and this reference vehicle speed Vs
is compared with the rear wheel speed (185). Rear speed is Vs
“ 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 (1
88).

If the rear speed is Vs' or more, there is a possibility that the acceleration is slipping, but if the brake is on (BS = H) at 300m
Please refer to 186) to see if 5ec or more has elapsed.If it has elapsed, there is a high possibility that the rear speed is higher than the standard speed Vs' (front average speed) due to front wheel braking rather than acceleration slippage. Therefore, clear the acceleration slip flag (187), and set the anti-skid control flag O.
The presence or absence of CR is checked (188).

Now, in step 188, the anti-skid control necessary flag is set to OC.
The presence or absence of R (one assigned to each of FL, FR, and rear) is referred to, and if it does not exist, the process proceeds to the anti-skid necessity determination shown in Figure 10c, and at least one OCR is assigned. If so, the process advances to step 189 and subsequent brake fluid pressure control in FIG. 10b.

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 (22g), 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 Vs.

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

If the control reference vehicle speed Vg 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 231 the control reference vehicle speed is updated to the one during braking. . That is, if the control reference vehicle speed is calculated and decelerated by a deceleration of 1.3G, the calculated value is compared with the actual reference vehicle speed Vs, and the higher one is set as the control reference vehicle speed Vg (this is the area shown in Fig. 5). Next, in steps 233 to 238, it is determined which of the anti-skid control condition categories at the start of brake-on shown in FIG. Sometimes, the pressure increase hold mode flag FLUPH, FRUPH or RRU is set in steps 239-244.
P) Set l, anti-skid control required flag OCR
and set the front right axle anti-skid control (FRCONT) shown in Figure 10b as 6R.
, proceed to front left axle anti-skid control (FLCONT) or rear axle anti-skid control (RRCONT).

Note that when the pressure is in the continuous pressure increase region shown in FIG. 4a, the electromagnetic switching valve devices 5QLI to 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 FLUPH, FRUPH, or RRUPH is set, and the anti-skid control necessary flag OCR is set.

Now, set the pressure increase hold flag FLUPH, FRUPH or RRllPH, set the anti-skid control required flag FLOCR, FROCR or RROCR, and perform anti-skid control FLCONT, FRCONT or RR.
Proceed to CONT, then anti-skid control OCF
Return to the control step before entering MAi) Also proceed to anti-skid control OCFMAi and step 1
Assuming that control is executed up to 88, the anti-skid control required flag OCR is set at this point (anti-skid control FLCONT, FRCON
T or RRCONT), so step 1
The process proceeds from step 88 to step 189, and it is checked whether the deceleration area is in the deceleration region ■. In the deceleration region I (see Figure 5), 1.
Compare the value calculated by decelerating the control reference speed with 3G deceleration and the actual reference speed 190), and if the actual reference speed is larger than the calculated value, update the memory in the register with the actual reference vehicle speed as the control reference speed 191), Proceeding to step 196, the area ① control counter is cleared. If the calculated speed is greater than the actual reference vehicle speed, the area 1 control counter is incremented by 1 (
6msec) (193) and compares the contents of the area I counter with 96m5ec (194).

If the content of the area I control counter is 96 m5ec or more, the area ■ control flag is set to calculate deceleration at a deceleration of 0.15G, and the area I control counter is cleared (195). Clear (19
6). If it is not 96m5ec or more, the area control flag is not changed in order to calculate deceleration at 1.3G.

Next, in step 197, the electromagnetic switching valve devices 5QLI to 5O
Please refer to the energization amount specification code to L3 197.199,
201), when the reduced pressure is energized (7/8 energized or 3/4 energized), the reduced pressure counter is counted up by 1 (6
msec) (198, 200, 202). When depressurization is not energized, and when depressurization is energized and the decompression counter increases by one count, compare the control standard vehicle speed with 8 km/h (203), and if it is less than 8 km/h, anti-skid on all axles. To end the control, clear the anti-skid control required flag OCR, set the decompression stop flag, and clear the control counter.
0), all of the electromagnetic switching valve devices 5QLI to 5QL3 are de-energized, and the process returns to the control step before entering the anti-skid control OCFMAi (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 decompression stop flag of L is set and the control counter is cleared (20B). And electromagnetic switching valve device 5OLI and 5
QL2 is de-energized and the process proceeds to rear anti-skid control RRCON on the condition that the rear anti-skid control required flag RROCR exists.

Now, if it is determined in step 189 that the deceleration is not in the area I (in other words, it is in the area ■), the deceleration calculation was performed at a deceleration of 0.14G. If it is larger, set the calculated value to the control reference speed (216), area ■Control counter 1 count up (6 msec) (217), refer to the presence or absence of the low μ flag (21B) If it is not there, there will be less slip, so brake Check to see if 200m5ec has passed since turning on 219) If it has, the braking must be working, so compare the control reference speed with 7.7Km/h -71 = 7.7Km/h If it is smaller than , the process proceeds to step 214, where the area ■ control flag is set, the area ■ control flag is cleared (214), and the area ■ control counter is cleared (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,
When the value is 600, 750, 900 or 1200m5ec, the presence or absence of the low μ flag is checked (225), and the low μ
When there is a flag, all axle speeds Va are compared with the control reference speed and it is checked whether all the differences are within β, and when there is no low μ flag, it is checked whether all the differences are over γ (2
26, 227). If all values are within β or γ, the process proceeds to step 214, sets the area control flag to area I, and clears the area=72-① control flag (215). If the difference is not within β or within γ, the process returns to step 197 without changing the area control flag. Elapsed time is 15
When the time is 00111 sec, 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 of the elapsed time of each region, the presence or absence of the low μ flag (presence or absence of slip), the reference vehicle speed Vg, the calculation speed of the predetermined deceleration, etc., the time series control reference vehicle speed and the speed region I or ■
, is determined.

Therefore, in the case of region I, 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 when the pressure is being reduced, the duration of the pressure reduction is counted.

Anti-skid control (brake fluid pressure control) of the front old axle FR in steps 205 to 207 in Fig. 10b FRCON
T.

The anti-skid control (brake fluid pressure control) FLCONT of the front left axle FL and the anti-skid control (brake fluid pressure control (RRCONT) of 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 shown in FIGS. 11a to 11c only for FLCONT for the front left axle. Next, this anti-skid control FLCO
Explain NT.

When proceeding to FLCONT, the microprocessor 13 sets the control address of the electromagnetic switching valve device 5OLI to 2.
45), the control counter is counted up by one 246), and the FL axle speed Va relative to the control reference vehicle speed Vs is
Calculate the difference ΔVs = Vs − Va, and find that ΔVs is 0
(247) whether the axle speed Va is higher than the control reference vehicle speed Vs. ΔVs is smaller than 0 (
(the axle speed is higher than the control reference vehicle speed) and the presence or absence of the anti-skid control required flag OCR (FLOCR),
Without it, anti-skid control (brake fluid pressure control)
Since there is no need to energize the solenoid switching valve device 5OLI (0
/8 energization output), and the process proceeds to step 267, which will be described later.

If the control required flag FLOCR is present, refer to the presence or absence of the low μ flag (258), and if there is no low μ flag, compare the acceleration/deceleration Dv of the axle speed (acceleration for positive, deceleration for negative) with 12G259), 12G If ΔVs is less than 0 and the acceleration/deceleration is 12, as shown in FIGS. 4b and 4c,
When exceeding G, the pressure is continuously increased regardless of the current brake fluid pressure control mode (in this state, normal brakes that do not require anti-skid control = SOLI continuous de-energization)
), clear the pressure increase mode counter to 260.
), 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 it is below, it is in the pressure increase region regardless of whether you refer to Figure 4b or Figure 1/D-40, so the pressure increase mode (pressure increase (during control) shown in the second column of Figure Since it is necessary to control the energization pattern, it is determined whether or not this pressure increase mode has already entered by referring to the flag (2
61).

If the pressure increase mode is not set, set the pressure increase mode flag FLIIPS here (262), and set the electromagnetic switching valve device 5OLI to 0/8 output bias (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 0, the value of the pressure increase mode counter 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) =76- 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 (268), and the elapsed time is 6 m5ec (set the pressure increase mode (262, 263), then set the next cycle (6 ms).
ec) later entered OCFMAi], the content of the reduced pressure counter is referred to in steps 269 and 271, and if the content of the reduced pressure counter is 500 m5ec or more, the slip is large and the brake fluid has been used for a long time. Since the pressure is being reduced, the low μ flag is set, and in order to reduce the pressure increase speed (shorten the 078 energization time in pressure increase mode), first count up the control counter by 1 (6 msec). (Add progress) L (270
), the value obtained by subtracting 48+n5ec 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 or more, the low μ flag is set and the control counter is counted up by 2 (12ms
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 and set in the reduced pressure counter (2
74).

When the content of the reduced pressure counter is smaller than 48 m5ec, the control counter is not counted up and the reduced pressure counter is cleared (272). In this case, 6
By clearing the pressure reduction counter, the pressure increase of m5ec is offset from the pressure reduction.

By the above control counter count-up processing, the pressure increase is set (262, 263) and then 6m5
When ec has passed, depending on the previous depressurization state (road friction coefficient), if the depressurization state was long (low μ), the low μ flag is set, and the pressure is increased (078 energization:
Count the elapsed time (de-energized) longer than the actual elapsed time (control counter), and calculate the actual time of pressure increase energization (0/8 energized: refer to the pattern in the left column of the second column in Figure 2). Shorten (slow rise of pressure increase). In other words, the pressure increase time is set according to μ.

If it is not 611Isec in step 268, refer to the elapsed time since entering the pressure increase mode in steps 275, 277, 279 and 282, and if it is 24m5ec (4 counts), the energization instruction code of the electromagnetic switching valve device 5OLI is set to 378 energization. Change the level to something that indicates 30
If it is m5ec (5 counts), the energization instruction code is 27.
8 Change the energization level to one that indicates it, and if it is 72m5ec or more (12 counts or more), step 262 to 26
Proceed to step 7, reset the pressure increase mode flag FLUPS, set the energization instruction code to 0/8 energization level (non-energization), and control the pressure increase mode again (see 211 in Figure 2).
(left column).

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, pressure increase hole, and de mode shown in FIG. 1b.

Note that the reason why the next control mode is not determined when ΔV s < O is that when ΔV s < O, the next control mode classification conditions (Fig. 4C) in the pressure reduction mode/pressure reduction hold mode and the pressure increase mode/increase Next control mode classification conditions in pressure hold mode (
4b) are exactly the same, so steps 247-2
59, the next control mode is determined and shifted when ΔVs<O, and only when ΔVs≧0 is the pressure increase mode/pressure increase hold mode as described above, FIG. 4b (pressure increase mode,
In order to determine the control mode to which the control mode should be shifted as shown in the condition classification (referenced in the pressure increase hold mode), the process proceeds to determination of the next control mode in the pressure increase mode and 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)
, 5OLI is 778 energized, Sera 1 to 250), pressure increase mode counter is cleared 251), Step 266
Proceed to.

If ΔVs is less than 1/2Vs (reference vehicle speed), Dv
252), if Dv is larger than 20G (because the next control mode is continuous pressure increase), the reference speed vs.
is compared with 30 Km/h and 80-, and 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 is 30km/h
If it is smaller, leave the μ flag as is and proceed to step 255.
Proceed to.

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. 11b, the axle acceleration/deceleration Dv is compared with -4G (282). = Vs - Va to 8 + n
/h, and if ΔVs is greater than that, set the pressure reduction mode flag FLDPS 249), set the electromagnetic switching valve device 5OLI to 7/8 energization 250), clear the pressure increase mode counter 251), step Proceed to 266. If ΔVs is less than 8 Km/h, refer to the contents of the pressure increase mode counter (289.290), and if it is 1 (entering the first pressure increase mode after executing the pressure reduction mode more than once), Since the pressure increase may be continued as it is, the process returns (transition to step 207). If the content of the pressure increase mode counter is 2 (the second pressure increase mode control has been started after executing the pressure reduction mode more than once),
5 Check whether or not the OLI is energized (hold energized after completing pressure increase 0/8: refer to the left column of the second column in Figure 2).
If energization is in progress, the process returns to continue increasing the pressure (to complete one cycle of pressure increase energization). If the current is not being applied, it means that the required pressure increase has been completed, so the process proceeds to step 249 for pressure reduction mode control. When the content of 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 is caused by leaving it at 3), and the next control determination is depressurization mode (
(see FIG. 4b), the process proceeds to step 249 and subsequent steps for pressure reduction mode control.

In this way, in the pressure increase mode control for the first time after the brake is turned on, the reason why the next control mode is determined to be the pressure decrease mode and then immediately proceeds to the pressure decrease mode control is to prevent pressure increase too much (wheel 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 above. This is to make the brake fluid pressure longer, 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 increased, the pressure increase mode control (left column of the second column in FIG. 2) is repeated twice in succession 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 (wheel lock).

Referring again to step 282 in Figure 11b. When the axle acceleration/deceleration Dv is equal to or greater than 14 G in step 282, Dv is compared with 12 G (283). Dv is 12G
If it is smaller, ΔVs is compared with α (292), and if it is greater than or equal to α (83-), the next control mode is continuous depressurization or depressurization, and in any case, the depressurization mode should be executed, so proceed to step 288 and repeat the steps described above. In the same manner as the condition determination after step 288, the process proceeds to pressure increase continuation or pressure reduction mode control.

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 294) Set the flag to indicate pressure increase hold mode via 293.
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. Dv in step 283
If it is 12G or more, compare ΔVs with α284).If it is smaller than α, the next control mode will be pressure increase, so check whether the current pressure increase mode or pressure increase hold mode84- 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 ΔVs is smaller than β, Dv is compared with −1.3G in order to determine whether the hold mode or pressure increase mode should be selected (296). If Dv is smaller than -1.3G, the hold mode (pressure increase hold mode) should be selected, so in step 293 and subsequent steps, the current mode is referred to and if the current mode is the pressure increase mode, the pressure increase hold mode is selected. Set the mode 294), 5O
Set L1 to 278 energization (295), step 26
Proceed to step 6. 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)
, Dv 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 the pressure increase mode, so the process advances to step 297.

Next, the determination of the next control mode in the pressure reduction mode and pressure reduction hold mode from step 309 onward in FIG. 11c will be explained.

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

If 120m5ec or more has passed, one cycle of depressurization control (
This means that the left column of column 5 in Figure 2 has been completed.
Proceed to step 245. When the pressure is less than 120m5ec, the contents of the reduced pressure counter are changed to 48m5ec (reduced pressure energization time:
324), 48m5e
If c, set 5OLI to 278 energization (hold) (325) L. Proceed to step 313. 48IIl
If it exceeds sec, the process advances to step 313. In step 313, Dv is compared with -1 and 3G, and Dv is -1.
, 3G or less, Dv is compared with -12G in step 327, and if Dv is greater than -12G, the process proceeds to step 330. If Dv is less than 112G, refer to the high μ flag, and if it is present, proceed to step 328; otherwise, step 2
Proceed to step 49.

Now, if it is determined in step 309 that the mode is not the reduced pressure mode, it is checked whether the mode is the reduced pressure hold mode or not (310), and if it is not the reduced pressure hold mode (this is impossible), the process returns. When in decompression hold mode,
Refer to the contents of the control counter and compare it (decompression hold time) with 150+r+ec (312), 1
．． If it is 50 m5ec or more, it is considered that the pressure reduction is insufficient, and the process proceeds to step 249, where the pressure reduction mode is set. 150m5
If it is less than ec, Dv is -1, 313 compared to 3G.
), if Dv is -1.3G or less, the pressure is reduced or the pressure is continuously reduced, so the process proceeds to step 327. -1.3G is exceeded, Δ'Js 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 cellar 1-.

When ΔVs is greater than α, Dv becomes -0.3 compared to 6G.
15) If Dv is -0.6G or less, the next control mode is pressure reduction mode or continuous pressure reduction mode, so step 33
Go to 0 to set decompression mode. Dv is -0.6G
If it exceeds β, ΔVa is compared with β in step 316, and if ΔVs is smaller than β, the process proceeds to step 262 and subsequent steps to set the pressure increase mode. If 8Vs is equal to or greater than β, Dv is compared with 0.6G in step 317, and if Dv is less than 0.6G, the process proceeds to step 330, but if Dv exceeds 0.6G, Dv is compared with 6G. 31B), Dv is 6
If it exceeds G, compare 8 Vs with γ (329), and if it exceeds γ, the next control mode is the decompression hold mode, so the process goes 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
Proceed to set vacuum hold mode below 20.

88- As explained above, after brake pedal 1 is depressed, anti-skid control (brake fluid pressure control) is performed on the condition that the estimated vehicle speed is equal to or higher than the first value of 20 KIa/h.
Anti-skid control is not activated at speeds below 20 km/h.

This is step 1 when brake pedal 1 is depressed.
59 to step 183 and then step 18
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 to step 229, where the control reference vehicle speed is set. is 2
If the speed does not exceed 0 km/h, the process returns to step 169 and does not enter anti-skid control, but it is determined whether anti-skid is necessary on the condition that the speed exceeds 20 km/h (steps 233 to 244). A flag OCR indicating this is set in step 240, 242 or 244, and the anti-skid control (brake fluid pressure control) 20
5, 206 or 207.

Once anti-skid control is entered, if brake pedal 1 is continuously depressed (anti-skid required flag OC
R), in step 203 the control reference vehicle speed is compared with 8 Km/h (end speed for rear wheel anti-skid control: second value), and in step 204 the control reference vehicle speed is set to 10/Km ( When the control standard vehicle speed reaches 10/Km compared to the end speed (second value) for anti-skid control of the front wheels, the flag OCR is cleared to end the anti-skid control of the front axle, and the electromagnetic switching valve device 5
OLI and 5OL2 are de-energized and the control reference vehicle speed is 8km.
/h, the flag OCR is cleared and the electromagnetic switching valve devices 5OLI, 5QL2 and 5OL3 are de-energized in order to end anti-skid control for the front wheels and rear axle, so at speeds of 20km/h or more. When the anti-skid control (brake fluid pressure control) is further advanced, anti-skid control is continued for the front wheels until the estimated speed becomes less than 10 km/h, and for the rear axle until the estimated speed becomes less than 8 km/h. This anti-skid control is 20km/h
Since the above has been started, the state detection at the beginning of the control is accurate, and since it continues continuously according to a predetermined logic, it has high continuity and stability, so it does not give the driver a sense of abnormality. It also does not significantly increase 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 axle locking is low, and the driver's brake operation is sufficient to respond to the situation. In addition, even if the axle locks occur, the speed is low, so the operability and stability of driving are higher than when the anti-skid control is applied even at speeds of 20 km/h or less.

〔Effect of the invention〕

As explained above, according to the present invention, the stability of anti-skid control in a low speed range is improved, and the stability of vehicle operation is also improved.

In the preferred embodiment of the present invention described above, 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 current being applied 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). Therefore, 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 power fluid pressure consumption. This reduction allows for further downsizing of the pump and electric motor. In addition, the rate of pressure increase can be adjusted by combining and repeating pressure increase for a predetermined time and hold time for an arbitrary length, and similarly, the rate of pressure increase can be adjusted by combining pressure reduction for a predetermined time and hold time for an arbitrary length and repeating the same. Pressure speed can be adjusted, allowing more accurate and smooth anti-skid control.

[Brief explanation of drawings]

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 devices 5QLI to 5OL3 in the brake fluid pressure control of this embodiment, and FIG. 3 shows the brake fluid obtained by combining various energization patterns. A graph showing how the pressure increases and decreases; FIG. 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 next control mode to proceed to in light of vehicle running conditions when anti-skid control is being performed in pressure increase mode or pressure increase hold mode, and Figure 4c is a graph showing anti-skid control in pressure reduction mode or pressure reduction hold mode. Inside is a graph showing the next control mode in light of the vehicle running condition, 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. It is. 6a, 6b and 6c are flowcharts showing the interrupt processing operation of the microprocessor 13;
Figures 8a and 7b are flowcharts showing the main control operation (main routine) related to anti-skid control of the microprocessor 13; Figures 8a, 8b and 8c are flowcharts showing the subroutine for calculating axle speed; 9a and 9b are flowcharts showing motor energization control (subroutine), and FIG. 10a is a flowchart showing motor energization control (subroutine). 95- Figures 10b and 10c are flowcharts showing anti-skid control (subroutine), Figures 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). 1: 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 RLY: Motorary L/-MR'/l in-relay vL
: Warning lamp BSI+I Brake operation detection match PS: Pressure detection switch R5V : Reservoir 96- Fig. 6a Fig. 6b [I port] [I=ko JP-A-Sho GO-209355 (28) Helmet Fig. 60 [I] Special Kaisho GO-209355 (29) Fig. 8a Fig. 8b [-ma] "Cao Ying" Japanese Patent Kaisho GO-209355 (31) Fig. 8c [4 times] Part 9a "Kenzu"

Claims (6)

[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 operating means for controlling the state of the brake fluid pressure control valve device; Controlling the rotational speed of the axle. Speed detection means for detecting: a brake depression detection means i that detects the depression of the brake hydraulic pressure, and monitors the states of the speed detection means and the brake depression detection means, calculates the estimated speed of the vehicle from the rotational speed, and determines the brake depression state. Based on the estimated speed 2 rotational speed and the acceleration/deceleration of the rotational speed, it is determined whether the brake fluid pressure needs to be increased or decreased,
When the estimated vehicle speed is equal to or higher than a predetermined first value, 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 determination result, and once this instruction is given, the brake is depressed. While this continues, an instruction is given to the valve device operating means to set the brake fluid pressure control valve device to a pressure increasing or decreasing state based on the determination result until the estimated vehicle speed becomes equal to or less than a second value smaller than the first value. An anti-skid control device comprising control means 1. (2) The brake fluid pressure control valve device includes a brake fluid pressure boat 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 port that receives brake fluid pressure, and a fluid pressure control chamber that communicates with the 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. By moving in that direction, the volume of the hydraulic control chamber is reduced, and by moving in the opposite direction, the volume of the hydraulic control chamber is increased. 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; and an accumulator pressure output boat and a drain pressure boat of the power hydraulic pressure source and a hydraulic control valve device. an electromagnetic switching valve device that is inserted between the power hydraulic ports 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). (3) 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 the accumulator is connected to the power hydraulic port of the bypass valve device. The anti-skid control device according to claim 2, wherein the anti-skid control device applies pressure. (4) 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. A numerical value is counted up, and the numerical value is counted down at a predetermined down rate while the electric motor is not energized, and when the count value reaches a predetermined value, the energization of the electric motor is stopped; Claim (3) Anti-skid control device as described in section. (5) The electromagnetic switching valve device has at least a pressure increasing state in which the power hydraulic port of the hydraulic pressure control valve device is connected to the accumulator pressure output boat, a hold state in which the power hydraulic port is closed, and The control means is a multi-position switching solenoid valve device that connects the power hydraulic port to a drain pressure port and enters a reduced pressure state;
Based on the estimated speed 9 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 scope (3). (6) 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 the 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 5, which determines the rate of brake fluid pressure reduction.