JP3036398B2 - Vehicle control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicular braking system for assisting sudden braking.

[0002]

2. Description of the Related Art At present, as a braking force assisting method, a braking device (brake system) for a vehicle is often provided with a booster (master back, hydro master, etc.) for assisting a driver to depress a brake pedal. ing. This booster uses a negative pressure or the like generated in an intake manifold of an engine to operate a power piston having a fixed area to assist a braking force.

[0003] As a braking force assisting method at the time of emergency sudden braking, for example, there is a method disclosed in JP-A-5-42862. This is because when the brake is depressed while the distance between the vehicle and the vehicle in front is less than a predetermined amount or the relative speed is more than a predetermined amount, a strong brake is activated at an early stage of the brake operation and the brake characteristics change to the safe side. It is to let. Further, in addition to the one disclosed in this publication, there is one disclosed in Japanese Utility Model Laid-Open No. 1-157070. This is to determine whether the braking is normal braking or emergency braking based on the lateral acceleration of the vehicle, and in the case of emergency braking, prevent execution of the swingback prevention control. Is to be stopped.

[0004]

However, in the apparatus disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 5-42862,
Unless the brake pedal is operated with a predetermined depression force, assist by negative pressure is not started, and the output (brake pressure) obtained through this booster is set uniformly to the input that depresses the brake pedal. It has been done. Therefore, a woman or an elderly person who tends to have a weak brake pedal operating force does not immediately increase the brake pressure even when the brake pedal is depressed, and it takes some time before braking is started. In particular, when it is desired to stop the vehicle urgently, there is a problem that the braking performance cannot be fully utilized.

Similarly, in the vehicle disclosed in Japanese Utility Model Laid-Open Publication No. 1-157070, the braking force is determined based on the turning strength (lateral acceleration) of the vehicle generated when the brake pedal is depressed by a predetermined amount. The brake performance cannot be fully utilized during emergency braking by women and the elderly.

[0006] In order to solve the above-mentioned problems, the present applicant has already applied for a vehicle braking device as Japanese Patent Application No. 6-123515 (filed on June 6, 1994).
This application determines whether the vehicle is in normal braking or emergency braking based on the brake pedal switch, the hydraulic pressure of the brake master cylinder, the maximum gradient of this hydraulic pressure and the brake pedaling force,
It assists the brake operation force.

[0007] The vehicle braking device of this application can safely assist a brake operation force even in a driver who has a weak brake operation force, such as a woman or an elderly person, at the time of an emergency stop of the vehicle to stop the vehicle safely. it can. However, in the vehicle braking device of this application, the reference time of the pressure and the pressure gradient of the brake master cylinder is measured by connecting and disconnecting a switch of a brake pedal. There is a case where a driver performs a double brake operation in which the driver depresses a brake pedal to decelerate the vehicle, then slightly returns the brake pedal, and immediately again depresses the brake pedal to stop braking the vehicle.
The operation of the brake and the operation of the switch of the brake pedal do not completely coincide with each other, and the switch of the brake pedal is in the on state or continues during the double braking described above. Therefore, the control is started before resetting, and the actual brake assisting force may be larger than the necessary brake assisting force, and a stable braking operation of the vehicle may not be obtained.

In the vehicle braking device of the above-mentioned application, normal braking and emergency braking are determined based on the brake pedaling force and the magnitude of the pressure gradient of the master cylinder. Even if there is, the brake operation force can be surely assisted. By the way, when driving a vehicle, the driving state (brake operation state) differs in an urban area, a mountainous road, a congested road, and the like. Further, this driving state differs depending on whether the vehicle is traveling normally, sports, or hard. Therefore, as in the aforementioned application,
If the judgment of the normal braking and the emergency braking is made based on the magnitude of the pressure gradient of the master cylinder, it becomes difficult to distinguish between the driving condition of the elderly and the driving condition such as sports driving or hard driving.

FIG. 27 is a graph showing the maximum gradient of the master cylinder at the time of sudden braking in different driving operation states.
As can be seen from this graph, for example, the time required from the start of depressing the brake to the maximum gradient of the master cylinder is one.
00ms or more, and the maximum gradient of the master cylinder is 30M
When the speed is less than Pa / s, it is determined that the braking is urgent, and when the brake operation force is assisted, the maximum gradient is 10 to 30M.
Elderly people in the range of Pa / s are excluded, and the braking force cannot be assisted. Therefore, if the lower limit of the maximum pressure gradient is set to 10 MPa / s, there is a problem that sports running or hard running will be performed this time, and the brake operating force will fall within the range that is unnecessary.

[0010] The present invention is intended to solve such a problem. Even a driver having a weak braking force, such as a woman or an elderly person, utilizes the braking performance during emergency braking to ensure the safety of the vehicle. It is another object of the present invention to provide a vehicle braking device with improved running stability.

[0011]

According to a first aspect of the present invention, there is provided a vehicle braking device for operating a driver, the operating member being operated by a driver, and the operating force of the operating member being converted into a fluid pressure. A booster having a master cylinder that applies a braking force according to the operating force to the wheels, a braking force increasing unit that increases the output of the booster regardless of the operating force of the operating member, and a braking operation by the operating member. Normal braking or braking condition determining means for determining whether it is emergency braking, and when the braking operation is determined to be normal braking by the braking condition determining means, While a braking force according to the operating force is applied to the wheels by the booster, if it is determined that the braking is an emergency braking, the braking force increasing means applies the braking force regardless of the operating force of the operating member. Control means for increasing the output of the booster by increasing means to apply a larger braking force to the wheels than at the time of normal braking, wherein the braking condition determining means includes an output of the master cylinder as an output of the master cylinder. A pressure detecting means for detecting the fluid pressure, wherein a pressure gradient of the detected pressure detected by the pressure detecting means becomes equal to or more than a first predetermined value which is equal to or greater than a predetermined first predetermined value, and the detected pressure is not more than a first predetermined time. The first detection pressure which is smaller than the average value by adding the set value to the detection pressure after the second predetermined time from the time point
The condition is satisfied, and thereafter, the second predetermined time
The pressure gradient after a third predetermined time exceeds the first regulation.
When a second condition that is greater than or equal to a second specified value that is larger than the value is satisfied, it is determined that the emergency braking is performed by a driver having a weak force for operating the operation member.

Further, in the vehicle braking device according to a second aspect of the present invention, when the first condition is established, the braking condition determining means measures a time when the pressure gradient becomes zero or a negative value. When the time is equal to or longer than a fourth predetermined time, it is determined that the braking is normal, and the establishment of the first condition is released.

[0013] In a third aspect of the present invention, the second predetermined value is variable in accordance with a vehicle driving operation state.

According to a fourth aspect of the present invention, there is provided a vehicle braking device comprising: a vehicle speed detecting means for detecting a vehicle speed; a steering wheel angle detecting means for detecting a steering wheel angle; an accelerator opening sensor for detecting an accelerator opening; The vehicle speed is calculated using a running time ratio and an average speed derived based on the vehicle speed detected by the vehicle speed detecting means, and an average lateral acceleration derived based on the vehicle speed and the steering wheel angle detected by the steering wheel angle detecting means. First estimating means for estimating a road traffic situation to be placed; a frequency analysis value of an accelerator opening derived based on the accelerator opening detected by the accelerator opening sensor; and a vehicle speed detected by the vehicle speed detecting means. A frequency analysis value, a frequency analysis value of longitudinal acceleration derived from the vehicle speed, and a frequency analysis value of lateral acceleration derived based on the vehicle speed and the steering wheel angle. Second estimating means for estimating a driver's intended driving orientation using the road traffic situation estimated by the first estimating means; and the second regulation based on the driving orientation estimated by the second estimating means. And a second specified value setting means for setting a value.

According to a fifth aspect of the present invention, the second estimating means obtains a frequency distribution for each parameter of the accelerator opening, the vehicle speed, the longitudinal acceleration, and the lateral acceleration. The driving direction is estimated based on a weighted sum of an average value and a variance value of each parameter derived from the frequency distribution and a road traffic condition estimated by the first estimating means. .

[0016]

Therefore, according to the first aspect of the present invention, the braking state determining means is provided for the first predetermined time before the time when the pressure gradient of the detected pressure detected by the pressure detecting means becomes equal to or greater than the preset first specified value. The first condition in which the detected pressure after the second predetermined time is smaller than the value obtained by adding the set value to the average value of the detected pressures up to the first condition is satisfied, and then the second condition is set from the time.
The pressure gradient after the third predetermined time beyond the fixed time is the first specified value
When a second condition that is greater than or equal to a second predetermined value that is greater than or equal to is satisfied, it is determined that the driver has a weak force to operate the operating member, and the braking force is increased by the braking force increasing means. However, the output of the booster, that is, the braking force is increased, and a greater braking force is applied to the wheels than during normal braking.

According to the second aspect of the present invention, when the first condition is satisfied, the braking condition determining means measures the time when the pressure gradient becomes zero or a negative value, and this time is the fourth predetermined time. When it becomes the above, it is determined that the braking is normal and the first braking is performed.
By canceling the satisfaction of the condition, normal braking and emergency braking can be accurately determined.

According to the third aspect of the present invention, since the second specified value is variable in accordance with the vehicle driving operation state, the operating force of a woman, an elderly person, or the like can be used for normal running, sports running, and hard running. Braking by a weak driver can be distinguished.

Further, in the invention according to claim 4, the second estimating means includes a frequency analysis value of the accelerator opening, a frequency analysis value of the vehicle speed, a frequency analysis value of the longitudinal acceleration, a frequency analysis value of the lateral acceleration, and the first estimation means. The driving direction intended by the driver is estimated by using the road traffic situation estimated by the above, and the second specified value setting means sets the second specified value based on the driving direction estimated by the second estimating means. With the setting, the influence of the road traffic condition on the vehicle driving state is reflected, so that the driving operation state of the driver can be appropriately estimated and the normal braking and the emergency braking can be accurately distinguished.

Further, in the invention according to claim 5, the second estimating means obtains a frequency distribution for each parameter of the accelerator opening, the vehicle speed, the longitudinal acceleration, and the lateral acceleration, and calculates an average of the parameters derived from the frequency distribution. Driving direction is estimated based on the weighted sum of the value, the variance value, and the road traffic situation estimated by the first estimating means. Is estimated based on the degree of crispness, for example, and the vehicle can be stably braked.

[0021]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a schematic diagram showing a vehicle braking device according to a first embodiment of the present invention, FIG. 2 is a schematic diagram showing an operation state of the vehicle braking device of the present embodiment, and FIG. 3 is a vehicle braking device of the present embodiment. FIG. 4 is a flowchart showing the operation of the vehicle braking system, FIG. 5 is a graph showing the hydraulic pressure gradient with respect to elapsed time, FIG. 6 is a hydraulic pressure and pressure gradient with respect to elapsed time, and a brake lamp. 3 shows a graph showing a relationship with a switch.

In a tandem type master back (negative pressure booster) applied to the vehicle braking system of the present embodiment, as shown in FIG. 3, a booster shell 1a of a master back 1 for operating a brake master cylinder 50 has a rear shell. The rear shell half 1b is sealed by a half 1b, and is supported by a vehicle body (not shown). The inside of the booster shell 1a is partitioned into a front shell chamber 2 and a rear shell chamber 3 by a partition plate 1c. The front shell chamber 2 has a front piston 4 accommodated therein so as to be able to reciprocate back and forth, and a front diaphragm 6 bound to the rear surface and sandwiched between the booster shell 1a and the partition plate 1c. The rear shell chamber 3 is divided into a front negative pressure chamber 2a and a rear front atmospheric pressure 2b, and a rear piston 5 is housed in the front shell 2 so as to be able to reciprocate back and forth. The rear diaphragm 7 sandwiched between the shell 1a and the rear shell half 1b defines a front rear negative pressure chamber 3a and a rear rear atmospheric chamber 3b.

A valve cylinder 8 is fixed to the center of the rear piston 5, and this valve cylinder 8 is slidably supported at the center of the partition plate 1c, and extends rearward of the rear shell half 1b. At 9, it is slidably supported. further,
Since the distal end of the valve cylinder 8 is fixed to the center of the front piston 4, the sliding of the valve cylinder 8 causes the front piston 4 to move.
The rear piston 5 and the rear piston 5 operate synchronously.

A reinforcing plate 17 is adhered to the inner surface of the front negative pressure chamber 2a of the booster shell 1a.
A tube connection joint 17a is provided so as to project toward the front negative pressure chamber 2a. One end of a front tube 18 is connected to the tube connection joint 17a, and one end of the front tube 18 is connected to the front piston 4 so as to be able to bend or expand and contract and prevent the tube from deforming eccentrically to the center axis. Is connected to a tube connection joint 4a provided to protrude toward the front negative pressure chamber 2a. Thereby, the front air chamber 2b is connected to the later-described atmospheric pressure introduction solenoid valve or the like (FIG. 1 or FIG. 2) through the front tube 18 and the air introduction pipe 20 attached to the booster shell 1a.
The exhaust valve 41 and the intake valve 42) communicate with each other.

The partition plate 1c and the rear piston 5 are also provided with tube connection joints 1d and 5a so as to protrude toward the rear negative pressure chamber 3a, and these tube connection joints 1d and 5a are bent or expanded and contracted. They are connected to each other by a rear tube 19 which is free and can prevent deformation in the direction of the center axis of the tubes. Thereby, the rear atmosphere chamber 3b is connected to the rear tube 19.
And communicates with the front atmosphere chamber 2b through
Furthermore, it communicates with a later-described electromagnetic valve for introducing atmospheric pressure through the front tube 18.

The front negative pressure chamber 2a is connected to a negative pressure source (not shown) (for example, inside the intake manifold of the engine) via a negative pressure introducing pipe 10, and the first negative pressure chamber 2a of the valve cylinder 8 is connected to the first negative pressure chamber 2a.
The port 11 communicates with the rear negative pressure chamber 3a.
Further, the front negative pressure chamber 2a is connected to the third port 14 of the valve cylinder 8,
The control valve 13 can communicate with the rear atmosphere chamber 3b. The rear air chamber 3b and the front air chamber 2b communicate with each other via the rear tube 19 as described above, and also communicate with each other via the second port 12 of the valve cylinder 8 as described above. The communication of the chamber 3b is alternately switched to the front negative pressure chamber 2a on the negative pressure side via the third port 14 of the valve cylinder 8 and the rear atmospheric chamber 15 on the atmospheric pressure side by switching the control valve 13. It has become.

An input punch 22 connected to a brake pedal (operating member) 21 and the control valve 13 controlled by the input punch 22 are provided in the valve cylinder 8. A valve piston 24 is slid on the cylinder 23a. The front end of the input punch 22 is swingably connected to the rear end of the valve piston 24. An annular first valve seat 25 is formed at the rear end of the valve cylinder center 8a, and an annular second valve seat 26 is also formed at the rear end of the valve piston 24 surrounded by the first valve seat 25. I have. A valve body 27 cooperating with the first valve seat 25 and the second valve seat 26 is provided in the valve cylinder 8. The valve body 27 is made of, for example, rubber and can be expanded and contracted. The rear end of the valve body 27 is held in close contact with the inner peripheral surface of the valve cylinder 8, and the first valve seat 25 and the second valve A valve section 28 is provided to face the seat 26. Thereby, the negative pressure valve 13a is constituted by the first valve seat 25 and the valve portion 28, and the atmospheric valve 13b is constituted by the second valve seat 26 and the valve portion 28, so that the control valve 13 is formed. .

Normally, the valve portion 28 is not in contact with the first valve seat 25 by a return spring 30 which is held on the inner peripheral surface of the valve cylinder 8 and urges the input punch 22 to the return side, ie, the negative pressure valve 1
3a is kept open, while the valve 28
Between the valve seat 28 and the input punch 22,
The valve spring 29 urges the second valve seat 26 toward the second valve seat 26, thereby closing the atmosphere valve 13b. Therefore, when the brake pedal 21 is not operated, the negative pressure valve 13a is opened, and the front atmosphere chamber 2b and the rear atmosphere chamber 3b are in the same pressure as the front negative pressure chamber 2a.

When the brake pedal 21 is depressed and the input punch 22 advances, the valve portion 28 also advances together with the valve spring 29, and the valve portion 28 abuts against the valve seat 25. Thereby, the negative pressure valve 13
is closed, and the communication between the third port 14 of the valve cylinder 8, the front air chamber 2b, and the rear air chamber 3b is cut off. If the input punch 22 is further advanced even after the negative pressure valve 13a is closed, the valve spring 29 starts to contract together with the valve body 27, and only the valve piston 24 continues to advance. As a result, the second valve seat 26 is separated from the valve portion 28, the atmosphere valve 13b is opened, and the atmosphere flows into the front atmosphere chamber 2b and the rear atmosphere chamber 3b from the rear atmosphere chamber 15.

A rubber elastic piston 3 having a rear end face facing the valve piston 24 is provided at the center of the front surface of the valve cylinder center 8a.
1 are joined, and an output punch 32 is loosely fitted so as to be in contact with the front surface of the elastic piston 31. The front end of the output punch 32 is connected to a piston (not shown) of the brake master cylinder 50. Accordingly, when the input punch 22 is advanced, the valve piston 24 hits the elastic piston 31. When the input piston 22 is further advanced, the pressing force of the input punch 22 exceeds the elastic limit of the elastic piston 31 and the input punch 22 is pushed. The force will be transmitted directly to the output punch 32.

A stopper plate 33 is provided around the central constricted portion 24a of the valve piston 24 so as to have a predetermined play in the front-rear direction of the valve piston 24. When the input punch 22 is pressed, the stopper plate 33
The valve cylinder 8 is advanced together with the advance of the valve 4. On the other hand, the atmosphere is supplied to the front atmosphere chamber 2b and the rear atmosphere chamber 3b by opening the atmosphere valve 13b, and a pressure difference is generated between the front negative pressure chamber 2a and the negative pressure of the rear negative pressure chamber 3a. When the front piston 4 and the rear piston 5 are urged forward, the output punch 32 can be advanced through the valve piston 24.

Between the central portion 8a of the valve cylinder and the booster shell 1a, a valve cylinder return spring 34 for applying a retreat force to the front and rear pistons 4, 5 is contracted, and the front negative pressure is reduced. When there is no pressure difference between the chamber 2a and the front atmosphere chamber 2b and between the rear negative pressure chamber 3a and the rear atmosphere chamber 3b, the front and rear pistons 4 and 5 always retreat together with the valve cylinder 8. Will be located at

In the vehicle braking system of the present embodiment to which the master bag 1 constructed as described above is applied, as shown in FIG.
1 is connected, negative pressure source (inside the intake manifold)
It is connected to the. An air path A2 branches off from the air path A1, and the air path A2 is connected to an exhaust valve 41 which is a normally closed solenoid valve. Further, the exhaust valve 41 is connected to the air path A3, and one end thereof is connected to an intake valve 42 which is a normally closed solenoid valve. An airway A4 branches off from the airway A3, and the airway A4 is connected to the atmosphere introduction pipe 20 of the master bag 1 described above.

From the tandem type brake master cylinder 50 connected to the front part of the master back 1, oil passages P1a,
P1b extends and is finally connected to a wheel cylinder (not shown) (for example, reference numerals 71 to 74 in FIG. 7 or FIG. 8 described later). These oil passages P1a, P1b
Of the oil pressure sensors 45a, 45
5b are respectively connected.

On the brake pedal 21 connected to the input punch 22 of the master back 1, a brake SW (brake lamp SW, etc.) 46 and an operating force detecting means are mounted as operation detecting means so as to detect the operation of the brake pedal 21. Is provided. The stepping force sensor 47 is, for example, a stepping pressure sensor such as a foot pedal type variable resistor, and is fixed to substantially the center of the surface of the brake pedal 21 on the driver side so as to be surely stepped on.

On the input side of the electronic control unit ECU 40 mounted on the vehicle, the above-described hydraulic sensor 45 is provided.
a, 45b, a brake SW 46, and the like are connected. On the other hand, the solenoids of the exhaust valve 41 and the intake valve 42 of the rapid braking assist system are connected to the output side.

Hereinafter, the operation of the vehicle braking device of the present embodiment configured as described above will be described.

As shown in FIG. 4, in step S100, whether the sudden braking is a situation in which the system of the vehicle braking device is desired to be activated (a situation in which a driver with a weak pedaling force such as a woman or an elderly person performs a sudden braking). The discrimination material for judging whether or not the data is read is read into the storage device. Here, the elapsed time t from when the brake SW 46 detects the pedal operation, the oil pressure sensor 45a connected to the output side of the brake master cylinder 50,
The hydraulic pressure PM detected by 45b and the value of the pressure gradient d (PM) / dt of this hydraulic pressure are read. Reading of these values is performed at every routine execution cycle (for example, 5 ms).

Next, the process proceeds to step S101, and after step S101, it is determined whether or not the driver with a weak pedaling force has performed the sudden braking. That is, first, in step S101, if the brake lamp SW, which is the determination material read in step S100, is ON, the process proceeds to step S102, where the master cylinder (M / M
C) determining whether the pressure gradient d (PM) / dt is equal to or greater than the first predetermined value XdPM _A, step S if so
Move to 103. Then, in step S103, step from that point to the average value PMa first as the predetermined time t ₁ of 0.1 second earlier M / C pressure and memory S1
Move to 04. In this embodiment, the first specified value X
dPM _A is set to 10 MPa / s.

[0041] Then, in step S104, based on the graph expressed by 5, the time (the area master cylinder (M / C) pressure gradient d (PM) / dt is equal to or greater than the first predetermined value XdPM _A in step S102 M / C pressure PM of 0.1 seconds after a) as the second predetermined time t ₂ is set value PM to the memory value PM _S that the memory in step S103
_It is determined whether the value is equal to or less than the value obtained by adding _K. In the present embodiment, the first predetermined value XdPM _A was 10 MPa / s, the set value PM _K is a 2.5 MPa. If it is determined in step S104 that the read M / C pressure is equal to or less than the memory value PM _S + the set value PM _K , the process proceeds to step S104.
The process proceeds to 105 (the first condition is satisfied).

In this step S105, when the M / C pressure gradient d (PM) / dt is 0 or negative, the set time t
It is determined whether it is within ₀ (50 ms in this embodiment). That is, as shown in FIG. 6, when the driver depresses the brake pedal to brake the vehicle, the brake lamp S
W changes from OFF to ON, the master cylinder M / C pressure PM gradually increases, and the M / C pressure gradient d (PM) / dt
Also rises. Then, M / C pressure gradient d (PM) / dt is the first predetermined value at time t _a XdPM _A = 10MPa / s
Traversal, the maximum value d (PM) / dt max at time t _b. When the driver holds will depress the brake pedal, M / C pressure PM at time t _c is the maximum value PMmax next, M / C pressure gradient d (PM) / dt is 0
MPa / s. Thereafter, when the driver returns the brake pedal, the M / C pressure PM decreases, and the M / C pressure gradient d (PM) / dt also decreases and becomes negative. And time t
_At the time point _d , the M / C pressure becomes 0 MPa, and the M / C pressure gradient d (PM) / dt becomes 0 MPa / s. At this time, if the driver depresses the brake pedal again without fully returning, the brake lamp SW remains ON, and the M / C pressure PM and the M / C pressure gradient d (PM) / dt rise. Go.

In such an operating state, in step S105 described above, the elapsed time (t _c -t _d ) when the M / C pressure gradient d (PM) / dt becomes zero or negative is measured, and the elapsed time is measured. If the time is less than the fourth predetermined time t ₄ = 50 ms, the process proceeds to step S106, and if not, the process is reset. Therefore, in the case of a double brake operation such as the above-described driving state, a malfunction of the control is prevented by resetting each detection value.

Then, in step S106, M /
C pressure gradient d (PM) / dt is the elapsed time t a at the second predetermined value XdPM _B or determines whether a third predetermined time t ₃ or more. That is, the M / C pressure gradient d (PM) / dt is shown in FIG.
It is intended to determine whether the region B shown in the second predetermined value XdPM _B in this example is 30 MPa / s, the third predetermined time t ₃ is set to 100 ms. Then, in this step S106, the M / C pressure gradient d (PM) /
If dt is 30 MPa or more and the elapsed time t is 100 ms or more, the flow shifts to step S107 (the second condition is satisfied).

In step S107, it is determined whether or not the M / C pressure PM is equal to or higher than a first reference value PM _S1 (in this embodiment, PM _S1 = 1.6 MPa / s) due to file safety.
If so, it is determined that sudden braking has been performed, and the process proceeds to step S108 to operate the system of the vehicle braking device.

It should be noted that, in the above-described flowchart of the system of the vehicle braking system of the present embodiment, the first reference value P
M _S1 , a first specified value XdPM _A , a second specified value XdPM _B ,
The set value PM _K , the first predetermined time t ₁ , the second predetermined time t ₂ ,
The values of the third predetermined time t ₃ , the fourth predetermined time t _{4, and the} like are based on experimental data obtained by a driver having a low brake pedal depression force, such as a woman or an elderly person. Although but not elevated, directed to a situation such that the degree rapidly increases that can be regarded as the brake pressure is subjected to sudden braking if elapses between a predetermined time. If the situation to be targeted changes, these thresholds are changed accordingly.

If NO is determined in each of the above-described steps S101 to S107, as shown in FIG. 1, the intake valve 42 is turned off and the rapid braking assist system is not operated, that is, the normal operation of the master back 1 In this state, the atmosphere valve 13b is open. At this time, since the intake valve 42 is already closed, the atmosphere flows into the front atmosphere chamber 2b and the rear atmosphere chamber 3b from the rear atmosphere chamber 15 by opening the atmosphere valve 13b (indicated by an arrow). ), Atmosphere chamber 2
The front piston 4 and the rear piston 5 are pushed toward the negative pressure chambers 2a and 3a by the pressure difference between the front and rear negative pressure chambers 2a and 3a, and the braking force is normally assisted. .

When the brake pedal 21 is not operated or immediately after the brake pedal 21 is operated, the negative pressure valve 13a is opened and the atmospheric valve 13b is closed as described above. Therefore, in this case, as described above, the atmospheric chambers 2b and 3b are maintained at the same pressure as the negative pressure chambers 2a and 3a, and there is no pressure difference between them. The front piston 4 and the rear piston 5 return the valve cylinder to the valve cylinder. The spring 34 is retracted to the retreat limit.

On the other hand, if all of the determinations in steps S101 to S107 are YES, and the sudden braking assist system is activated, as shown in FIG.
Is urged to open the valve, and the atmosphere is forcibly sucked into the front atmosphere chamber 2b through the atmosphere introduction pipe 20 and the tube 18 and further into the rear atmosphere chamber 3b through the tube 19 (arrow). ). As a result, a pressure difference is suddenly generated between the front negative pressure chamber 2a and the front atmospheric chamber 2b and between the rear negative pressure chamber 3a and the rear atmospheric chamber 3b.
The rear piston 5 and the rear piston 5 are both urged toward the negative pressure side, that is, the front side where braking is performed, and forcibly assist the braking force. At this time, when the atmosphere valve 13b is open as shown in the figure, the atmosphere also flows from the rear atmosphere chamber 15 (indicated by an arrow), and the braking force is further assisted.

The exhaust valve 4 is opened simultaneously with the opening of the intake valve 42.
1, a part of the atmosphere flowing from the intake valve 42 is released to the negative pressure source side, whereby the atmosphere chamber 2b,
It is possible to fine-tune the pressure acting on 3b. By the way, this forced supply of air is
Immediately after the step 1 is depressed, that is, while the negative pressure valve 13a is opened, it is determined that the rapid braking state is established, and when the atmospheric valve 42 is opened, the atmospheric chambers 2b and 3b are connected via the negative pressure valve 13a. Since it is in communication with the negative pressure side, the pressure acting on the atmosphere chambers 2b and 3b is lower than the atmospheric pressure. However, in the rapid braking state, the period during which the negative pressure valve 13a is open is a very short time, and the negative pressure valve 13a is closed instantaneously, and the communication between the atmosphere chambers 2b, 3b and the negative pressure side is cut off. Power assistance will be well implemented.

As described above, the intake valve 42 is opened and the atmosphere is forcibly supplied to the atmosphere chambers 2b and 3b.
Sufficient braking force can be obtained even when a driver with weak pedaling force such as a woman or an elderly person performs sudden braking. Here, the pressure acting on the atmosphere chambers 2b, 3b is set to the atmospheric pressure, but the intake valve 42 is connected to an air compressor or the like, and when the intake valve 42 is opened, the pressure higher than the atmospheric pressure is applied to the atmosphere chambers 2b, 3b.
b, so that the assistance of the braking force may be further enhanced.

Further, as boosters, negative pressure chambers 2a, 2b
To the atmosphere chambers 2b and 3b at atmospheric pressure (positive pressure)
A negative pressure booster like the master bag 1 is used, but the negative pressure chambers 2a and 2
A positive pressure booster is used in which the part b corresponds to the atmosphere chamber and the parts of the atmosphere chambers 2b and 3b correspond to the positive pressure chamber. The positive pressure may be applied to assist the braking force.

Next, as another embodiment, a case where the above-described rapid braking assist system control is applied to another sudden braking assist system (brake hydraulic system) will be described. FIG. 7 shows a schematic configuration of a vehicle braking device according to a second embodiment of the present invention, and FIG. 8 schematically shows an operation state of the vehicle braking device of the present embodiment.

As shown in FIG. 7, output ports provided at two positions of a tandem type brake master cylinder 50 provided at a front portion of a normal master back 1 'are connected to oil passages P1a and P1b, respectively. It is connected. Oil pressure sensors 45a, 45b are provided in these oil passages P1a, P1b.

The oil passages P1a and P1b are branched, and the oil passage P1a is connected to the oil passages P2a, P3a and P4a and the oil passage P1b.
Is divided into oil passages P2b, P3b and P4b. Oil passage P2
a, P2b are switching valves 63a, 63 which are normally open solenoid valves.
b is interposed, and the oil passages P3a and P3b
Pressure valves 65a and 65b that open the hydraulic pressures a and P2b as pilot pressures are provided. Also, the oil passages P4a,
Check valves 66a and 66b are interposed in P4b.

Then, the oil passages P2a, P3a, P4a and the oil passages P2b, P3b, P4b merge into the oil passage P5.
ABSI 70a and ABSII 70b, which are valve units connected to a and P5b, respectively, and constituting an ABS system.
Are connected to each of the wheel cylinders 71 to 74 via the. ABSI 70a is connected to wheel cylinder FL71 and wheel cylinder RR72, while ABSII 70b is connected to wheel cylinder FR73 and wheel cylinder RL74. The ABSI 70a and the ABSII 70b, which are the valve units constituting the ABS system, are as follows.
This is a conventionally known system, and the description is omitted here.

On the other hand, the oil storage cylinders 51a and 51b provided in the tandem type brake master cylinder 50 are connected to the oil passage P6.
Are connected to the reserve tank 52 via the oil passages P7a and P7b. Pumps 61a and 61b operated by the drive motor 60 are interposed in the oil passages P7a and P7b, and check valves 62a and 62b are provided downstream thereof. These oil passages P7a, P7b are connected to check valves 62a, 62b.
At the downstream of b, it joins the above-mentioned oil passages P5a and P5b.

The input side of the ECU 40 includes, in addition to the oil pressure sensors 45a and 45b, the brake SW 46, and the ABSI 7 in the same manner as described in the first embodiment.
0a, sensors necessary for the operation of the ABSII 70b are connected, and on the output side, the switching valve 63 of the sudden braking assist system is provided.
a, 63b, ABSI 70a, AB
The solenoid of each solenoid valve (not shown) of the SII 70b is connected.

The operation of the rapid braking assist system of the vehicle brake system according to the present embodiment having the above-described structure will be described below.
Note that, also in the present embodiment, the sudden braking assist system control executes the routine of FIG. 4 described in the first embodiment, but in step S108, the switching valve 63a,
63b and the motor 60 are turned on, and the switching valves 63a, 6
3b and the step of turning off the motor 60.

A sudden braking assist system control routine is executed, and according to the determinations in steps S101 to S107, the brake is not operated without operating the brake pedal 21 or the system is not operated at the time when the braking is started. If it is determined that the braking is normal,
In step S108, the switching valves 63a and 63b and the motor 60 are turned off, and the sudden braking assist system is not operated without being operated.

In this case, as shown in the non-operating state of FIG. 7, the drive signals of the ECU 40 are not supplied to the switching valves 63a and 63b and both are opened, and the hydraulic pressure from the output port of the brake master cylinder 50 is released. Are ABSI 70a and A
Each wheel cylinder 71, 7 directly via BSII 70b
2, 73, 74. Also,
Since no drive signal is supplied to the motor 60, the pump 6
Both 1a and 61b are in a stopped state in which they do not operate.

At this time, the switching valve 63 in the opened state is
When the oil pressure in the oil passages P2a and P2b reaches a predetermined pilot pressure set in advance, the pressure valve 6
5a and 65b are opened, and the oil passages P3a and P3b are connected to the oil passage P.
Used as a flow path together with 2a and P2b, the flow rate increases, and the braking force increases. The high pressure oil passage P5 supplied from the brake master cylinder 50
The oils a and P5b are prevented from flowing back to the reserve tank 52 by the action of the check valves 62a and 62b.

On the other hand, if it is determined in the steps S101 to S107 of the sudden braking assist system control routine that it is necessary to assist the braking force, the process proceeds to a step S108.
The switching valves 63a and 63b and the motor 60 are turned on
Then, the operation of the sudden braking assist system is started.

In this case, as shown in FIG. 8, the switching valves 63a and 63b are closed by the supply of the drive signal, and the motor 60 rotates to turn the pumps 61a and 61a.
61b is activated, and each wheel cylinder 7
1, 72, 73, 74 include ABSI 70a and AB
The discharge pressure of the pumps 61a and 61b is supplied via the SII 70b. The discharge pressures of the pumps 61a and 61b are set in advance to a pressure necessary and sufficient to perform sudden braking, so that even a driver such as a woman or an elderly person with a weak brake pedaling force has a sufficient control. Power will be obtained.

At this point, the oil passages P1a and P1a
Although the oil pressure of b is lower than the oil pressures of the oil passages P5a and P5b, the brake pedal 21 is more strongly depressed after the operation of the auxiliary system, and the oil pressure of the oil passages P1a and P1b is reduced to the discharge pressure of the pumps 61a and 61b. Defeat, oilway P5
a, after the oil pressure becomes higher than P5b, the oil is
ABSI 70a and ABSII7 through 6a, 66b
0b side.

Incidentally, ABSI 70a and ABSII
70b, when a predetermined state is detected, a predetermined drive signal is supplied from the ECU 40 to operate.
As a result, the effect of the sudden braking assist system can be further enhanced. However, since the operation of the ABS system is conventionally known, the description is omitted here.

The sensors for detecting the sudden braking state are not limited to the oil pressure sensor and the brake switch used in the above-described embodiment. For example, a scanning laser radar or a wheel mounted on the front end of the vehicle may be used. A speed sensor, a steering angle sensor attached to the steering unit, or the like may be used. Further, the sudden braking assistance system of the first embodiment is provided with the same ABS system (ABS I 70) as that of the second embodiment.
a and ABSII 70b) may be applied, whereby the braking performance can be further improved.

In each of the above-described embodiments, when discriminating between normal braking and emergency braking, the M / C pressure gradient d (P
M) / dt and a second specified value XdMP _B (30 MPa / s). The second specified value XdMP _B was a constant value based on experimental data. Is also good.

FIG. 9 is a flowchart showing the operation of the vehicle control device according to the third embodiment of the present invention. FIG. 10 is a graph showing the relationship between the specified value of the M / C pressure gradient and the crispness.
1, a concept representing a road traffic condition grasping procedure in a method for estimating a vehicle driving state applied to the vehicle braking device of the present embodiment;
FIG. 12 is a conceptual diagram showing a procedure for grasping a driving operation state, FIG. 13 is a schematic block diagram showing a controller and a sensor for implementing a method for estimating a vehicle driving operation state, and FIG. 14 is a flowchart of a driving time ratio calculation routine executed by the controller. FIG. 15 is a flowchart showing an average speed calculation routine executed by the controller. FIG. 16 is a flowchart showing an average lateral acceleration calculation routine executed by the controller. FIG. 17 shows membership functions for defining a fuzzy set related to the travel time ratio. FIG. 18 is a graph showing a membership function for defining a fuzzy set with respect to the average speed, FIG. 19 is a graph showing an example of calculating the degree of adaptation of the actual travel time ratio to the travel time ratio fuzzy set, and FIG. Of the actual average speed for the set Graph showing a calculation example of Godo, 2
1 is a graph illustrating an average lateral acceleration / mountain road degree map,
FIG. 21 is a flowchart of a frequency analysis routine executed by the controller. FIG. 23 is a graph showing an array constituting a population of input data as a frequency analysis target.
FIG. 25 is a conceptual diagram showing processing elements forming a neural network, FIG. 25 is a conceptual diagram of a neural network formed by processing elements, and FIG. 26 is a flowchart showing a crispness calculation routine executed by a controller.

First, a description will be given of a method of estimating a vehicle driving operation state applied to the vehicle braking device of the present embodiment. In the estimation method according to the present embodiment, a vehicle driving operation state by a driver is estimated based on a road traffic condition obtained based on a vehicle driving state parameter and a physical quantity representing the vehicle driving state.

More specifically, as shown in FIG. 11, the vehicle running state parameter
The average speed, the running time ratio (the ratio of the running time to the total time including the vehicle running time and the running stop time), and the average lateral acceleration are obtained. Then, by means of fuzzy inference based on these vehicle running state parameters, the degree of urban area, the degree of congested road, and the degree of mountain road are detected as parameters representing road traffic conditions.

On the other hand, as shown in FIG. 12, a physical quantity representing a vehicle driving state, such as an accelerator opening, a vehicle speed and a steering wheel angle, is detected, and a longitudinal acceleration is calculated from the vehicle speed, and a lateral acceleration is calculated from the vehicle speed and the steering wheel angle. Required by Then, the frequency distribution of each of the vehicle speed, the accelerator opening, the longitudinal acceleration, and the lateral acceleration as the vehicle driving parameters is obtained by the frequency analysis. Next, an average value and a variance of each frequency distribution are obtained as parameters characterizing the frequency distribution.

Further, parameters representing road traffic conditions (city level, congested road level, and mountain road level) and parameters (average value and variance) characterizing the frequency distribution of each vehicle driving parameter are input to the neural network. Is done. In the neural network, a weighted sum of these parameters is obtained, and thereby an output parameter representing a vehicle driving operation state of the driver, for example, a degree of crispness in the vehicle driving operation of the driver is obtained.

A vehicle to which the estimation method according to the present embodiment is applied is equipped with a controller 80 as shown in FIG. Although not shown, the controller 80
Includes a processor having a fuzzy inference function and a neural network function, a memory, and an input / output circuit, and the memory stores various control programs and various data. The controller 80 is connected to a vehicle speed sensor 81, a steering wheel angle sensor 82, and a throttle opening sensor 83. The processor of the controller 80 receives the vehicle speed signal, the steering wheel angle signal, and the throttle opening signal from the sensors 81, 82, and 83, sequentially executes various routines described later, and estimates the driver's crispness. I have.

Running Time Ratio Calculation Routine For example, after the engine is started, while the vehicle is in a driving state (including a running state and a running stopped state), the processor of the controller 80 executes the running time ratio calculation routine shown in FIG. It is repeatedly executed in a cycle of 2 seconds.

In each calculation routine execution cycle, the processor inputs the vehicle speed signal vel from the vehicle speed sensor 81 representing the actual vehicle speed, and determines whether or not the vehicle speed vel exceeds a predetermined vehicle speed (for example, 10 km / h). (Step S1). If the result of this determination is affirmative, the count value of a running time counter (not shown) built in the controller 80
"1" is added to rtime (step S2). on the other hand,
If the determination result in step S1 is negative, "1" is added to the count value "stime" of the traveling stop time counter (not shown) (step S3).

Step S4 following step S2 or S3
Then, it is determined whether or not the sum of the running time counter value rtime and the running stop time counter value stime is equal to “200”. If the determination result is negative, the running time counter value rtime is set to this value and the running stop time counter value st.
The value obtained by dividing by the sum with ime is multiplied by the value “100” to calculate the running time ratio ratio (%) (step S
5).

On the other hand, if the determination in step S4 is affirmative, a value equal to the product of the running time counter value rtime and the value "0.95" is reset in the running time counter, and
A value equal to the product of the running stop time counter value "stime" and the value "0.95" is reset to the running stop time counter (step S6), and then the running time ratio ratio is calculated in step S5.

That is, from the time the engine is started, the value of the vehicle becomes “2”.
The counter values are reset at the point of time when driving is performed for 400 seconds corresponding to "00", and thereafter, the counter values are reset every 10 seconds. This allows
Even if a counter having a relatively small capacity is used, it is possible to calculate the running time ratio reflecting the vehicle driving situation before the present time.

Average Speed Calculation Routine The processor of the controller 80 repeatedly executes the average speed calculation routine shown in FIG. In each routine execution cycle, the processor reads the vehicle speed data vx from the vehicle speed sensor 81,
The vehicle speed vx is added to each of the stored values vxsum i (i = 1 to 5) of the five cumulative speed registers built in the controller 80 (step S11). Next, the processor
It is determined whether or not the value of f 1m is “1” indicating the average speed calculation timing (step S12). This flag f 1m
Takes a value “1” in one-minute cycles. If the result of the determination in step S12 is negative, the processing in the current cycle ends.

If one minute elapses from the start of this routine and the determination result in step S12 becomes positive, the index jj
Is added to the value "1" to update the index jj, and the updated index
The accumulated speed register value vxsum jj corresponding to jj is changed to “15
Calculate the average speed vxave by dividing by 0 ”
vxsum jj is reset to “0” (step S1
3). Then, it is determined whether or not the updated index jj is "5" (step S14). If the determination result is negative, the process in the current cycle is ended.

Thereafter, the index jj is updated every one minute, and the progressive speed register value corresponding to the updated index jj is updated.
The average speed vxave is obtained from vxsum jj. And
The index jj is reset to "0" every five minutes (step S15). As described above, the actual vehicle speed vx is added to each of the five cumulative speed register values vxsum i every two seconds, and the corresponding one of the five cumulative speed registers is detected 150 times (5 minutes). Based on the stored value vxsum jj representing the total vehicle speed, the average speed vxave is 1
Calculated every minute.

Average Lateral Acceleration Calculation Routine The processor of the controller 80 repeatedly executes the average lateral acceleration calculation routine shown in FIG. 16 at a cycle of, for example, 2 seconds. In each routine execution cycle, the processor of the controller 80 includes a vehicle speed sensor 81 representing a vehicle speed vx.
And the output signal from the steering wheel angle sensor 82 representing the steering wheel angle steera, and referring to a map (not shown), a predetermined steering wheel angle gygain which is expressed as a function of the vehicle speed vx and gives a lateral acceleration of 1 (G). Is calculated based on the vehicle speed vx. Next, the processor calculates the lateral acceleration gy by dividing the steering wheel angle steera by the predetermined steering wheel angle gygain, and calculates the stored values gysumi (i = 1 to 5) of the five cumulative lateral acceleration registers incorporated in the controller 80. The lateral acceleration gy is added to each of them (step S21). Next, the processor determines whether or not the value of the flag f8s is “1” indicating the average lateral acceleration calculation timing (step S2).
2). This flag f8s takes a value "1" in an 8-second cycle. If the result of the determination in step S22 is negative, the processing in the current cycle ends.

When eight seconds have elapsed since the start of this routine and the determination result in step S22 becomes positive, the index jj
Is added to the value "1" to update the index jj, and the updated index
The cumulative lateral acceleration register value gysum jj corresponding to jj
By dividing by zero, the average lateral acceleration gyave is calculated, and this register value gysum jj is reset to “0” (step S2).
3). Then, it is determined whether or not the updated index jj is "5" (step S24), and if the result of this determination is negative, the processing in this cycle is ended.

Thereafter, the index jj is updated every eight seconds, and the average lateral acceleration gyave is obtained from the accumulated lateral acceleration register value gysum jj corresponding to the updated index jj.
Then, the index jj is reset to “0” every time 40 seconds elapse (step S25). As described above, the calculated lateral acceleration gy is added to each of the five cumulative lateral acceleration register values gysum i every two seconds, and the corresponding one of the five cumulative lateral acceleration registers, 20 times (40 seconds) The average lateral acceleration gyave is calculated every 8 seconds, based on the stored value gysum jj representing the total lateral acceleration calculated over the period.

[0086] The city area degree, congestion road degree and mountain road degree calculation
In the present embodiment, a city driving mode as a vehicle driving mode related to the vehicle driving operation state estimation by the driver,
The traffic congestion road running mode and the mountain road driving mode are set as the discrimination targets, and the city area degree, the traffic congestion road degree, and the mountain road degree are discriminated.

The degree of urban area and the degree of congested road are determined by fuzzy inference. In connection with this fuzzy inference, a membership function (FIGS. 17 and 18) representing a fuzzy subset in the whole space (set of cars) for the travel time ratio and the average speed, and nine fuzzy rules shown in the following table It is set in advance and stored in the memory of the controller 15.

[0088]

[Table 1] The fuzzy rule settings shown in the table above are based on the fact that the average speed is low and the travel time ratio is medium when traveling in urban areas, and the average speed is low and the travel time ratio is low when traveling on congested roads. It is.

In FIG. 17, each of the symbols S, M and B is
It is a label indicating a fuzzy set in a set of tables relating to a travel time ratio. The membership function defining the fuzzy set S has a fitness of “1” when the running time ratio is between 0% and 20%, and the running time ratio is between 20% and 4%.
The degree of conformity is determined to decrease from "1" to "0" as it increases to 0%. The membership function defining the fuzzy set M has a running time ratio of 20%.
The degree of conformity increases from “0” to “1” as the distance increases from 40% to 40%, and the degree of conformity is “1” when the running time ratio is between 40% and 65%, and the running time ratio is 65%.
The fitness is defined to decrease from "1" to "0" as the percentage increases from% to 85%. Then, the membership function defining the fuzzy set B shows that the fitness increases from “0” to “1” as the running time ratio increases from 65% to 85%, and the running time ratio increases to 85%.
In the above, the conformity is determined to be “1”.

Referring to FIG. 18, the membership function defining the fuzzy set S in the platform set with respect to the average speed is such that the fitness is “1” when the average speed is between 0 km / h and 10 km / h, and the average speed is “1”. Is determined so that the fitness decreases from “1” to “0” as the speed increases from 10 km / h to 20 km / h. The membership function that defines the fuzzy set M has an average speed of 10 km / h to 20 km / h.
The fitness level increases from "0" to "1" as the speed increases to km / h, and the fitness level is "1" between 20 km / h and 40 km / h, and the average speed is 40 km / h. From 60
The fitness is determined to decrease from “1” to “0” as the speed increases to km / h. The membership function defining the fuzzy set B has an average speed of 40
The degree of conformity is “0” as it increases from km / h to 60 km / h
From "1" to "1", and the fitness is determined to be "1" when the average speed is 60 km / h or more.

The processor of the controller 80 is shown in FIG.
And the combination of the running time ratio (%) and the average speed (km / h) obtained by the calculation routine shown in FIG.
The degree of adaptation adapt i for each of the ninth rules is obtained, and then the city area degree and the congestion road degree are calculated according to the following formulas. Urban area level city = Σ (adap i × r city i) ÷ adapt i (i = 1-9) Traffic jam degree jam = Σ (adap i × r jam i) ÷ adapt i (i = 1-9) The processor determines the fitness of the actual travel time ratio to one of the fuzzy sets S, M, and B corresponding to the ith rule among the travel time ratios, and then determines the fitness of the fuzzy sets S, M, and B for the average speed. i
The fitness of the actual average speed for one corresponding to the rule is determined. Then, the smaller one of the two degrees of fitness is referred to as the i-th
The adaptability of the combination of the actual running time ratio and the actual average speed with respect to the rule is defined as adapti.

Referring to the first rule, as shown in FIGS. 19 and 20, when the actual traveling time ratio is 30% and the actual average speed is 10 km / h, the driving time ratio fuzzy set S "0.5" is obtained as the fitness of the actual running time ratio 30%, and "1" is obtained as the fitness of the actual average speed 10 km / h with respect to the average speed fuzzy set S. Therefore, the adaptability adapt1 to the first rule of the combination of the actual traveling time ratio of 30% and the actual average speed of 10 km / h is "0.5".

Next, the processor of the controller 80
The average lateral acceleration stored in the memory of the controller 80
With reference to the mountain road map, the mountain road is calculated based on the average lateral acceleration obtained in the routine of FIG. As illustrated in FIG. 21, in this map, the mountain road degree becomes “0” when the average lateral acceleration is between 0 G and about 0.1 G, and the average lateral acceleration increases from about 0.1 G to 0.4 G. The mountain road degree increases from “0” to “100” as the distance from the vehicle increases, and the mountain road degree is set to “100” when the average lateral acceleration is 0.4 G or more. This map setting is based on the fact that the lateral acceleration integral value increases when traveling on a mountain road.

The processor of the frequency analysis routine controller 80 determines the vehicle speed, longitudinal acceleration,
The frequency analysis for each of the lateral acceleration and the accelerator opening is executed at a cycle of, for example, 200 milliseconds, and the average value and the variance of each physical quantity are obtained. FIG. 22 shows a frequency analysis routine for the vehicle speed. A frequency analysis routine (not shown) other than the vehicle speed has the same configuration as this routine.

The vehicle speed as the frequency analysis target parameter is
It is represented by an output signal from the vehicle speed sensor 26, and its input range is set to, for example, 0 to 100 km / h. The accelerator opening tps (%) is calculated by the throttle opening sensor 104
Is calculated according to the following equation based on the output signal of
Its input range is 0-100%. tps = (tdata−tpsoff) ÷ (tpson−tpsoff) × 10
Here, the symbol tdata represents the current throttle opening sensor output, and the symbols tpsoff and tpson represent the throttle opening sensor output in the accelerator off state and the accelerator fully opened state, respectively.

Further, the processor of the controller 80
The output of the vehicle speed sensor 81 is sampled at a cycle of, for example, 100 milliseconds, and the longitudinal acceleration gx (unit G) is calculated according to the following equation. The input range of longitudinal acceleration is, for example, 0-0.3G
It is. gx = (vx−vx0) × 10 ÷ (3.6 × 9.8) Here, the symbol vx represents the current vehicle speed (km / h), and vx0 is 1
Indicates the vehicle speed (km / h) 00 milliseconds ago.

Further, an output signal from the vehicle speed sensor 81 representing the vehicle speed vx and the steering wheel angle sensor 8 representing the steering wheel angle steera
2, a predetermined steering wheel angle gygain which is expressed as a function of the vehicle speed vx and gives a lateral acceleration of 1 (G) is obtained based on the vehicle speed vx with reference to a map (not shown). Next, as shown in the following equation, the processor calculates the lateral acceleration gy (G) by dividing the steering wheel angle steera by the predetermined steering wheel angle gygain. The input range of the lateral acceleration is, for example, 0 to 0.5G.

Gy = steera ÷ gygain Referring to FIG. 22, the processor of the controller 80 divides a vehicle speed signal vel as a frequency analysis target parameter (input data) into 10 equal parts within an input range of 0 to 100 km / h ( INT (vel / 10)) is added with "1" to obtain a value dat (step S31), and it is determined whether or not this value dat is greater than "10" (step S32). If the determination result is affirmative, the value dat is reset to "10" in step S33, and the process shifts to step S34. On the other hand, if the decision result in the step S32 is negative, the process immediately shifts from the step S32 to the step S34. In step S34, as shown in FIG. 23, the corresponding one element number hist dat among the ten arrays (the number of elements of the maximum value side array is 0 in FIG. 13) constituting the population of the input data.
Is added to "1".

In the next step S35, first to first
The sum num of the number of elements in the 0 array is obtained, and the sum sum of the product of the number of elements obtained for each array (the i-th array) and the value “i−1” is obtained. The processor sums the product su
The value obtained by dividing m by the total sum num of the elements is further divided by the value "10" to obtain an average value ave of the input data (here, the vehicle speed) (step S36).

Next, the processor determines that the average value ave is "10".
"0" (step S37).
If the determination result is affirmative, the average value is determined in step S38.
ave is reset to “100”, and the routine goes to Step S39. On the other hand, if the decision result in the step S37 is negative, the process immediately shifts from the step S37 to the step S39.
That is, the average value ave of the input data is limited to a value up to “100”.

In step S39, the average value ave is changed to “1”.
0 is subtracted from the value “i−1” ((i−
1)-(ave / 10)) and the number of array elements hist i
Is obtained for each array, and then the sum of the products sum2
Is calculated. Next, the processor further divides a value obtained by dividing the sum sum2 by the sum num of the number of elements by a value “5”. The variance var of the input data is calculated (step S40). Then, it is determined whether or not the variance var of the input data is greater than "100" (step S41). If the determination result is affirmative, the variance var is set to "10" in step S42.
After resetting to “0”, the process proceeds to step S43. If the determination result in step S41 is negative, step S41 is performed.
The process immediately shifts from step S43 to step S43. That is, the variance var of the input data is limited to the value “100”.

In step S43, it is determined whether or not the sum num of the number of elements is greater than "256". If the result of the determination is negative, the process in the current cycle is terminated, while if the result of the determination is positive. For example, the number of elements hist i of each of the first to tenth arrays is reset to a value obtained by multiplying it by the value “15/16” (step S44), and the processing in the current cycle ends. That is, the number of elements num of the population is "256"
Is exceeded, the number of elements in each array is reduced by a factor of "15/16". Thereafter, the processing of FIG. 22 is repeated, and the average value and variance of the vehicle speed vel as input data are periodically obtained.

Accelerator opening, which is other input data,
The average value and variance of each of the longitudinal acceleration and the lateral acceleration are obtained in the same manner. The average value and the variance of each input data increase as the driving method of the driver becomes crisp. However, the average value of the vehicle speed is greatly affected by the road traffic conditions.

Driving operation state calculation routine The processor of the controller 80 obtains the driving operation state of the driver by using the neural network function. In the present embodiment, in addition to the average value and the variance of the vehicle speed, the accelerator opening, the longitudinal acceleration, and the lateral acceleration obtained by the above-described frequency analysis, the urban area degree, the congestion degree, and the mountain road obtained by the fuzzy inference described above. The degree is input to the neural network, and thereby the degree of crispness as a driving operation state by the driver is obtained.

Conceptually, a neural network is
The processing element (PE) shown in FIG.
As shown in FIG. 25 , each PE is intricately entangled with each other, and each PE receives a total sum of multiple inputs x [i] multiplied by respective weights w [j] [i]. Then, in each PE, the sum is converted by a certain transfer function f, and an output y [i] is sent from each PE.

Referring to FIGS. 24 and 25,
The neural network used in this embodiment is an input layer 2
01 and an output layer 203 with one hidden layer 202 interposed, the input layer 201 is composed of 11 PEs,
The hidden layer 202 is composed of six PEs, and the output layer 203 is 1
Consists of two PEs. And the transfer function f of PE is f
(x) = x. The weight wji at the connection between the PEs is determined through a learning process. Note that an input 204 called a bias is additionally set in the neural network of this embodiment.

In this embodiment, the function of the neural network described above is achieved by the controller 80. In order to achieve this neural network function, the processor of the controller 80 determines the average and variance of the vehicle speed, the accelerator opening, the longitudinal acceleration and the lateral acceleration, the city area degree, the congestion road degree and the mountain road degree (all of the output range). 26 is periodically executed using the crispness calculation routine shown in FIG. 26 as input data of “0” to “100”.

In the routine shown in FIG. 26, the processor of the controller 80 subtracts "100" from the product of the input data ddi and "2" to obtain 11 input data dd i (i
= 1 to 11) from "0 to 100" to "-100"
１００100 ”, thereby obtaining input data dini after range conversion (step S51). Next, the processor obtains a total sum drive of the product of the input data din i obtained for each range-converted input data din i and the weight coefficient nmap i + 1, and also obtains the same product for the bias (nmap 1 * 100). And the product (nmap 1 * 100) related to the bias is added to the sum drive related to the input data to determine the output drive representing the degree of crispness (step S).
52).

Then, the crispness output drive is set to “100”.
“100” is added to the value obtained by dividing by “00”, and the addition result is divided by “2” to change the range of the crispness output to “−1”.
"000000 to 100000" is converted to "0 to 100" (step S53), whereby the calculation of the crispness in the -calculation cycle ends.

As described above, the output drive representing the degree of crispness as the vehicle driving operation state by the driver is obtained. According to the test running results, the estimated value of the driver's crispness represented by the output drive was in good agreement with the crispness evaluated and reported by the driver himself. This is based on the evaluation of the driving operation state of the driver, which is difficult to evaluate with physical quantities such as vehicle speed, based on the average and variance of physical quantities that characterize the frequency distribution of various physical quantities, and taking into account road traffic conditions. It is understood that it depends.

Hereinafter, a description will be given of a rapid braking assist system of the vehicle braking apparatus according to the present embodiment to which the above-described vehicle driving characteristic control method is applied.

The present embodiment is intended to control the vehicle driving characteristics to those suitable for the vehicle driving operation state (crispness) estimated by the above-described estimation method. Are the same as those described above, and a description of the device configuration and the like will be omitted.
Further, in the present embodiment, as shown in FIG. 9, in the flowchart, the control in step S207 is different from step S107 (see FIG. 4) in the first embodiment described above, and the other steps S100 to S105 S10
7 and S108 are the same, and a description thereof will be omitted.

In the vehicle braking system of the present embodiment, the second specified value XdMP _{B of the} master cylinder M / C pressure gradient d (PM) / dt used for discriminating between normal braking and emergency braking. Is set in accordance with the crispness obtained by the above-described method of estimating the vehicle driving operation state. As can be seen from the graph shown in FIG. 10, the M / C pressure gradient d (PM) with respect to the estimated crispness
When / dt is in the region C, it is determined that braking is urgent.

That is, as shown in the flowchart of FIG. 9, when the M / C pressure gradient is equal to or greater than the specified value and the elapsed time is equal to or greater than 100 ms in step S206, the process proceeds to step S207 to operate the system. Let it. In this case, when the vehicle is running in sports or running hard, the driver's crispness is high. For example, when the crispness is "70", the specified value is 30 MPa / s. on the other hand,
When the vehicle is driven by a woman or the elderly, the driver's crispness is low. For example, when the crispness is "30", the specified value is 10 MPa / s.

[0115]

As described above in detail with reference to the embodiments, according to the vehicle braking apparatus of the first aspect, the braking condition judging means makes the pressure gradient of the detected pressure detected by the pressure detecting means smaller. The detected pressure after the second predetermined time from the time is smaller than the value obtained by adding the set value to the average value of the detected pressure from the time when the predetermined value becomes equal to or more than the predetermined first predetermined value to the first predetermined time before 1 condition is satisfied, and thereafter,
The pressure gradient after the third predetermined time exceeding the second predetermined time is the first
When a second condition that is equal to or greater than a second specified value that is larger than the specified value is satisfied, it is determined that emergency braking is performed by a driver having a weak force for operating the operating member, and the operating force of the operating member is determined by the braking force increasing unit. Irrespective of the output of the booster, that is, the braking force is increased, and a greater braking force is applied to the wheels than during normal braking. Even in the case of emergency braking, the braking performance can be fully utilized, and the traveling safety and traveling stability of the vehicle can be improved.

According to the second aspect of the present invention, when the first condition is satisfied, the braking condition determining means measures the time when the pressure gradient becomes zero or a negative value. When the time is equal to or longer than the fourth predetermined time, it is determined that normal braking is performed, and the establishment of the first condition is released. Therefore, normal braking and emergency braking can be determined,
The braking force can be assisted only during sudden braking.

According to the vehicle braking device of the third aspect of the present invention, since the second specified value is varied in accordance with the vehicle driving operation state, the woman or the elderly can perform normal driving, sports driving, and hard driving. For example, it is possible to distinguish braking by a driver having a weak operating force.

Further, according to the vehicle braking device of the fourth aspect, the frequency analysis value of the accelerator opening, the frequency analysis value of the vehicle speed, the frequency analysis value of the longitudinal acceleration, the frequency analysis value of the lateral acceleration, and the first estimating means are provided. The driving direction intended by the driver is estimated by using the road traffic situation estimated by the above, and the second specified value setting means sets the second specified value based on the driving direction estimated by the second estimating means. Since the setting is performed, the influence of the road traffic condition on the vehicle driving state is reflected, and the driving operation state of the driver can be appropriately estimated, and the normal braking and the emergency braking can be accurately determined.

Further, according to the vehicle braking device of the fifth aspect , the second estimating means obtains a frequency distribution for each parameter of the accelerator opening, the vehicle speed, the longitudinal acceleration, and the lateral acceleration, and derives from the frequency distribution. The driving direction is estimated based on the weighted sum of the average value and the variance value of each parameter and the road traffic condition estimated by the first estimating means. The driving operation state of the person, for example, by estimating the degree of crispness,
The vehicle can be braked stably.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating a vehicle braking device according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram illustrating an operation state of the vehicle braking device according to the embodiment.

FIG. 3 is a sectional view of a master back applied to the vehicle braking device of the embodiment.

FIG. 4 is a flowchart showing the operation of the vehicle braking device.

FIG. 5 is a graph showing an M / C pressure gradient with respect to elapsed time.

FIG. 6 is a graph showing a relationship among an M / C pressure, an M / C pressure gradient, and a brake lamp switch with respect to an elapsed time.

FIG. 7 is a schematic configuration diagram of a vehicle braking device according to a second embodiment of the present invention.

FIG. 8 is a schematic diagram illustrating an operation state of the vehicle braking device according to the present embodiment.

FIG. 9 is a flowchart illustrating an operation of the vehicle braking device according to the third embodiment of the present invention.

FIG. 10 is a graph showing a relationship between MC pressure gradient and crispness.

FIG. 11 is a conceptual diagram showing a road traffic condition grasping procedure in a method for estimating a vehicle driving operation state applied to a vehicle braking device according to a third embodiment of the present invention.

FIG. 12 is a conceptual diagram showing a driving operation state grasping procedure.

FIG. 13 is a schematic block diagram showing a controller and a sensor for implementing a method for estimating a vehicle driving operation state.

FIG. 14 is a flowchart of a running time ratio calculation routine executed by the controller.

FIG. 15 is a flowchart showing an average speed calculation routine executed by the controller.

FIG. 16 is a flowchart of an average lateral acceleration calculation routine executed by the controller.

FIG. 17 is a graph showing a membership function that defines a fuzzy set for a travel time ratio.

FIG. 18 is a graph showing a membership function defining a fuzzy set for average speed.

FIG. 19 is a graph showing a calculation example of the degree of adaptation of the actual traveling time ratio to the traveling time ratio fuzzy set.

FIG. 20 is a graph showing a calculation example of the degree of fitness of the actual average speed with respect to the average speed fuzzy set.

FIG. 21 is a graph illustrating an average lateral acceleration and a mountain road degree map;

FIG. 22 is a flowchart of a frequency analysis routine executed by the controller.

FIG. 23 is a graph showing an array constituting a population of input data as a frequency analysis target.

FIG. 24 is a conceptual diagram showing processing elements constituting a neural network.

FIG. 25 is a conceptual diagram of a neural network constituted by processing elements.

FIG. 26 is a flowchart illustrating a crispness calculation routine executed by the controller.

FIG. 27 is a graph showing the master cylinder maximum gradient at the time of sudden braking in different driving operation states.

[Explanation of symbols]

 Reference Signs List 1 master back 2a front negative pressure chamber 2b front atmospheric chamber 3a rear negative pressure chamber 3b rear atmospheric chamber 4 front piston 5 rear piston 11 first port 12 second port 13 control valve 13a negative pressure valve 13b atmospheric valve 14 third Port 18 Front tube 19 Rear tube 20 Atmosphere introduction pipe 21 Brake pedal 40 Electronic control unit (ECU) 41 Exhaust valve 42 Intake valve 45a Oil pressure sensor (pressure detection means) 45b Oil pressure sensor (pressure detection means) 46 Brake SW (operation detection) Means) 50 brake master cylinder 60 drive motor 61a pump 61b pump 63a switching valve 63b switching valve 80 controller 81 vehicle speed sensor 82 handle angle sensor 83 throttle opening sensor

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-268560 (JP, A) JP-A-4-121260 (JP, A) JP-A-7-17390 (JP, A) JP-A-7- 17391 (JP, a) JP flat 7-156786 (JP, a) patent 2727161 (JP, B2) patent 2727162 (JP, B2) patent 2727165 (JP, B2) (58 ) investigated the field (Int.Cl. ⁷ , DB name) B60T 8/00 B60T 13/52

Claims (5)

(57) [Claims] 1. A booster having an operating member operated by a driver, a master cylinder for converting an operating force of the operating member into a fluid pressure and applying a braking force according to the operating force to wheels, and the booster. Braking force increasing means for increasing the output of the operating member irrespective of the operating force of the operating member; braking situation determining means for determining whether the braking operation by the operating member is normal braking or emergency braking; When the braking condition determining means determines that the braking operation is normal braking, the braking force according to the operating force of the operating member is applied to the wheels by the booster, while the braking is performed in an emergency braking manner. When it is determined that the braking force is greater than the normal braking time, the braking force increasing means increases the output of the booster regardless of the operating force of the operating member. A control device for applying power to the wheels, wherein the braking condition determining device has a pressure detecting device that detects a fluid pressure as an output of the master cylinder, and the braking condition determining device detects the fluid pressure. A second predetermined time from the time when the set value is added to the average value of the detected pressures from the time when the pressure gradient of the detected pressure becomes equal to or more than the first predetermined value set beforehand to the first predetermined time. The first condition where the later detected pressure is small is satisfied, and thereafter,
After a third predetermined time exceeding the second predetermined time from the time point
Is greater than the first prescribed value.
A vehicle braking device, wherein when a second condition that is equal to or greater than a value is satisfied, it is determined that the braking is urgent by a driver having a weak force to operate the operation member. 2. The vehicle braking device according to claim 1, wherein the braking condition determination unit measures a time when the pressure gradient becomes zero or a negative value when the first condition is established, A vehicle braking device, characterized in that when the time is equal to or longer than a fourth predetermined time, normal braking is determined and the first condition is not satisfied. 3. The vehicle braking device according to claim 1, wherein the second specified value is variable according to a vehicle driving operation state. 4. The vehicle braking device according to claim 1, wherein a vehicle speed detecting means for detecting a vehicle speed, a steering wheel angle detecting means for detecting a steering wheel angle, an accelerator opening sensor for detecting an accelerator opening, and the vehicle speed. The vehicle is placed using a running time ratio and an average speed derived based on the vehicle speed detected by the detecting means, and an average lateral acceleration derived based on the vehicle speed and the steering wheel angle detected by the steering wheel angle detecting means. First estimating means for estimating road traffic conditions, a frequency analysis value of an accelerator opening derived based on the accelerator opening detected by the accelerator opening sensor, and a frequency analysis of a vehicle speed detected by the vehicle speed detecting means Value and the frequency analysis value of the longitudinal acceleration derived from the vehicle speed, and the frequency analysis value of the lateral acceleration derived based on the vehicle speed and the steering wheel angle, and A second estimating means for estimating a driving intention intended by the driver using the road traffic situation estimated by the first estimating means; and the second regulation based on the driving orientation estimated by the second estimating means. A vehicle braking device comprising: a second specified value setting means for setting a value. 5. The braking apparatus for a vehicle according to claim 4, wherein the second estimating means obtains a frequency distribution for each of the accelerator opening, the vehicle speed, the longitudinal acceleration, and the lateral acceleration, and calculates the frequency distribution. A vehicle braking device, wherein the driving direction is estimated based on a weighted sum of an average value and a variance value of each parameter derived from a distribution and a road traffic condition estimated by the first estimating means.