JP3320843B2 - Brake control device - Google Patents

Abstract

PURPOSE:To obtain optimum brake characteristics according to the tendency related to the stepping operation for a brake pedal and the reaction speed for avoiding danger, by installing a control means for controlling an assisting force varying means on the basis of the assistance quantity determined by an assistance quantity determining means. CONSTITUTION:A control unit 20 detects the deceleration pattern in brake application on the basis of the signal supplied from a vehicle speed sensor 42, and learns brake stepping force on the basis of the deceleration pattern, and determines the boost factor (assistance quantity) of a subbooster 4 on the basis of the result of the learning. The target pressure value in an air chamber 14 for obtaining the boost factor is set, and the duty ratio of the control signal outputted into the control valves 16 and 17 is calculated from the target pressure value, and the control valves 16 and 17 are duty-controlled so that the pressure value in the air chamber 14 becomes close to the target pressure value. Further, in the control, the feedback control utilizing the output of a pressure sensor 43 is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake control device for a vehicle.

[0002]

2. Description of the Related Art A general automobile is provided with an assisting means such as a booster (booster) for assisting a braking force generated by a depression operation of a brake pedal.

[0003] For example, Japanese Patent Application Laid-Open No. Sho 61-10236
In the vehicle braking device disclosed in Japanese Unexamined Patent Publication No. 1 (1993), by changing the assist force based on the load applied to the wheels, the braking force generated corresponding to the depression amount of the brake pedal is changed.

[0004]

However, when the driver performs the stepping operation of the brake padal, the mode of the stepping operation of the brake padal is variously varied depending on the individual behavior of the driver or the reaction speed of avoiding danger. With regard to the depressing operation of the driver, a driver having a peculiar habit and a driver having a slow reaction speed of danger avoidance may not be able to perform an appropriate brake operation.

Therefore, even if the amount of depression of the brake pedal is the same, the magnitude of the generated braking force varies depending on the running state of the vehicle, the habit of the driver depressing the brake padal, and the reaction speed of avoiding danger. Is preferably changed to

In view of the above-mentioned circumstances, an object of the present invention is to provide a brake control device capable of obtaining optimum braking characteristics in accordance with the habit of a driver's depressing operation of a brake padal and the reaction speed of danger avoidance. I do.

[0007]

As shown in FIG. 1, a brake control apparatus according to a first aspect of the present invention includes an assist means for assisting a braking force generated by a driver's depressing operation of a brake pedal; An assist force varying means capable of changing the generated assist force, a first detecting means for detecting a vehicle speed, a second detecting means for detecting a distance between the host vehicle and an obstacle, and an accelerator pedal for braking. Pedal depressing time measuring means for measuring the depressing time to the brake pedal, vehicle speed and obstacle distance detected by the first and second detecting means during braking, and pedal measured by the measuring means Driving characteristic learning means for learning the driving characteristics of the driver based on the step change time, and a driving characteristic learned by the learning means. And an assist amount determination means for determining a cyst volume and is characterized by comprising a control means for controlling the assisting force variation means based on the assist amount determined by said assist amount determination means.

The learning of the driving characteristics of the driver by the learning means is based on a ratio of a standard pedal change time preset from the vehicle speed and the obstacle distance to a pedal change time measured by the measuring means. Done.

The learning of the driving characteristics of the driver determines the habit of the driver with respect to the depression operation of the brake pedal.

[0010] Further, the learning speed of the driver's drivability is determined by learning the driving characteristics of the driver.

[0011] The driver's habit is determined based on a map showing the relationship between the vehicle speed and the obstacle distance.

[0012] In this case, the assisting force is increased for a driver having a habit of shortening the inter-vehicle distance.

[0013] The assisting force is increased for a driver whose reaction speed for avoiding danger to an obstacle is slow.

According to a second aspect of the present invention, there is provided a brake control device comprising:
A brake pedal force learning unit for learning a brake pedal depression force is provided, and the assist amount is determined based on the learning of the brake depression force by the learning unit.

One embodiment of the brake control device according to the second invention is, as shown in FIG. 11, an assist means for assisting a braking force generated by a driver's depressing operation of a brake pedal, and Assist force variable means for changing the generated assist force, deceleration pattern detection means for detecting a deceleration pattern of the vehicle body during a brake operation, and brake depression force learning for learning a brake pedal depression force based on detection of the deceleration pattern by the detection means Means, assist amount determining means for determining an assist amount based on learning of the brake pedal force by the learning means, and control means for controlling the assist force varying means based on the assist amount determined by the assist amount determining means. It is characterized by becoming.

As shown in FIG. 21, another embodiment of the brake control apparatus according to the second aspect of the present invention is an assist means for assisting a braking force generated by a driver's depressing operation of a brake pedal. An assist force varying means capable of changing the generated assist force;
Obstacle distance detecting means for detecting the distance between the host vehicle and the obstacle, pedal depressing time measuring means for measuring the depressing time from the accelerator pedal to the brake pedal during braking, and the obstacle distance detecting means Brake pedal learning means for learning a brake pedal depression force based on the obstacle distance detected by the above and the pedal depression time measured by the pedal depression time measurement means, and an assist amount based on the learning of the brake depression force by the learning means. And assist means for controlling the assist force varying means based on the assist amount determined by the assist amount determining means.

In this case, when the obstacle distance detected by the obstacle distance detecting means and the pedal change time measured by the pedal change time measuring means are relatively short, the learning of the brake pedal depressing force is performed. Is made.

A brake control device according to a third aspect of the present invention includes:
A plurality of assist means for assisting a braking force generated by a driver's depressing operation of a brake pedal are connected in tandem and interposed between the brake pedal and the master cylinder, and at least one of the plurality of assist means is provided. The assist force generated from the assist means is
It is characterized by being changed by controlling the negative pressure and the atmospheric pressure applied to the at least one assist means.

[0019]

According to the first aspect of the present invention, the driving characteristics of the driver are learned based on the vehicle speed during braking, the obstacle distance (for example, the inter-vehicle distance), and the pedal change time. Since the assisting force of the assisting means is determined based on the assisting means, there is an effect that a reliable braking force can always be obtained irrespective of the driver's habit of depressing the brake pedal and the reaction speed of avoiding danger.

According to the second aspect of the present invention, the brake pedal force of the driver is learned based on the deceleration pattern at the time of braking, or based on the obstacle distance and the pedal stepping time, and the assist means is provided based on the learning. Since the assisting force is determined by the driving force, there is an effect that a reliable braking force can always be obtained regardless of the individual differences in the driver's braking force.

Further, according to the third invention, a plurality of assist means for assisting the braking force are connected in tandem and interposed between the brake pedal and the master cylinder. Since the assist force generated from the at least one assist means is configured to be changed by controlling the negative pressure and the atmospheric pressure applied to the at least one assist means, the assist force can be easily controlled. , A large assist force can be obtained.

[0022]

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

FIG. 2 is an overall system diagram showing an embodiment of the brake control device according to the first invention shown in the block diagram of FIG.

In FIG. 2, 1 is a brake pedal, 2 is a master cylinder, and a main booster 3 and a sub-booster 4 connected in tandem are provided as assist means between the brake pedal 1 and the master cylinder 2. Have been.

The main booster 3 is provided with a diaphragm 7 provided in a shell 6 in a state where the main booster 3 is urged leftward in the figure by a return spring 5, and a diaphragm chamber 8 partitioned by the diaphragm 7 has a diaphragm 7. The vacuum pressure in the intake manifold of the engine or the vacuum pressure from the vacuum pump is supplied through the check valve 9.

Similarly, the sub-booster 4 includes a diaphragm 12 provided in a shell 11 in a state where the sub-booster 4 is urged leftward in the figure by a return spring 10. The diaphragm 12 is partitioned by the diaphragm 12. An air chamber 14 is connected to the chamber 13.

Vacuum pressure is supplied to the air chamber 14 via a check valve 15 and a control valve (vacuum valve) 16 and atmospheric pressure is supplied via a control valve 17 (atmospheric pressure valve). It has become. The control valves 16 and 17 are duty solenoid valves.
The opening of 7 is duty-controlled by a control unit 20 composed of a microcomputer, whereby the assisting force by the sub-booster 4 is changed as described later.

The brake pedal 1 and the piston 21 of the master cylinder 2 are connected by a rod 22 extending through the center of the diaphragms 7 and 12 of the main booster 3 and the sub-booster 4. The central portions of the diaphragms 7 and 12 are engaged.

Therefore, when the pressure in the diaphragm chambers 8 and 13 becomes negative, the center portions of the diaphragms 7 and 12 are displaced to the right in FIG. 2 against the urging forces of the return springs 7 and 10, respectively. An assist force corresponding to the pedaling force of the pedal 1 is applied to the rod 22. In this case, the pedaling force of the brake pedal 1 is applied to the piston 21 of the master cylinder 2 in a manner in which the assisting force of the main booster 3 and the assisting force of the sub-booster 4 are multiplied, and the assisting force of the sub-booster 4 is reduced. It is configured such that the overall assist force is changed by changing the assist force.

Reference numeral 25 denotes a hydraulic disc brake device.
A disk 27 that rotates with wheels 26 and a caliper 2
8 is provided. Caliper 28 is brake pad 29
The brake pad 29 is pressed against the disc 27 with a force corresponding to the magnitude of the brake fluid pressure supplied to the cylinder 30 from the master cylinder 2 through the oil passage 31 from the master cylinder 2, and a wheel 26 is provided. Braking force is generated.

The illustrated disc brake device 25 is for a front wheel, and brake fluid pressure for a rear wheel brake device (not shown) is supplied from an oil passage 31 via a proportioning valve 32.

The control unit 20 includes a brake switch signal Bsw from a brake switch 41 which is turned on when the brake pedal 1 is depressed, a vehicle speed sensor 42 for detecting a vehicle speed V, and a pressure in the air chamber 14. ON when the accelerator pedal 44 is depressed and the chamber pressure signal from the pressure sensor 43 for detecting Pc
And an inter-vehicle distance sensor 47 that detects an inter-vehicle distance L that detects the inter-vehicle distance between the preceding vehicle and the host vehicle, and the control unit 20 outputs the control signal. Control signals are output to the valves 16 and 17.

The control unit 20 learns the driving characteristics of the driver based on the signals from the switches 41 and 45 and the sensors 42 and 47, and based on the learning, the boost magnification (assist amount) in the sub booster 4. Is determined, a target pressure value in the air chamber 14 for obtaining the boost magnification is set, and a duty ratio of a control signal to be output to the control valves 16 and 17 is calculated from the target pressure value. The duty of the control valves 16 (vacuum valve) and 17 (atmospheric pressure valve) is controlled so that the pressure value in the chamber approaches the target pressure value. At the time of this control, feedback control using the output of the pressure sensor 43 is performed.

Next, the contents of the control routine executed by the control unit 20 will be described with reference to the flowcharts shown in FIG. In the following description, S indicates a step.

FIG. 3 shows the general flow. First, in S1, the entire system is initialized. In S2, the output signals from the switches or the sensors are read as input data. Learning, boost magnification decision in S4 and S5
And outputs the control signal. The learning of the driving characteristics is not executed until the data of 10 times after the start is collected,
Until then, the previous learning value is used.

FIG. 4 shows the contents of the system initialization in S1. First, the memory values of the first and second variables DK ₁ and DK ₂ representing the driving characteristics of the driver are read, and each variable is read. Reset. The above memory values are saved in the memory when the power is turned off. Resetting variables inter-vehicle distance L ₀ when the accelerator off (Asw = 0), the inter-vehicle distance L ₁ when the brake is on (BSW = 1), the vehicle speed V ₀ which when the accelerator off (Asw = 0), the brake from the accelerator-off Pedal depression time until turning on Δ
T, 10 operating characteristic variables DK ₁ (1) to DK each
₁ (10), a DK ₂ (1) to Dk ₂ average calculation data and sample number n of (10) (n = 1 to 10).

FIGS. 4 and 5 show the contents of the data input routine in S2 of FIG. That is, in S11, the accelerator switch signal Asw and the brake switch signal Bs
w and the chamber pressure Pc are read, and the count value of the pedal depression time ΔT is reset in S12 of FIG.

Next, an accelerator operation determination is made in S13.
Until it is determined that the accelerator is off (Asw = 0) at (S
13, NO), returning to S12, accelerator off (Asw =
When it is determined to be (0) (S13, YES), in S14, the inter-vehicle distance L ₀ and the vehicle speed V ₀ when the accelerator is off are read, and the counting of the pedal depressing time ΔT is started. Next, a brake operation determination is made in S15, and until the brake is turned on (Bsw = 1) (S15, NO),
In step 16, the accelerator operation is determined, and the accelerator is turned off (Asw
= 0) (S16, YES), the brake operation determination is repeated in S15. And brake on (Bsw
= When it becomes 1) (S15, YES), reads inter-vehicle distance L ₁ proceeds to S17, the pedal depression replacement time ΔT
And the number of samples is counted.

FIGS. 6 and 7 show S3 and S4 of FIG.
One aspect of each routine of the learning routine of the driving characteristics and the routine of determining the boost ratio is described. In this case, the first driving characteristic variable DK ₁ representing the driving characteristic of the driver is represented by the ratio of the inter-vehicle distance L ₀ to the vehicle speed V ₀ when the accelerator is off (Asw = 0), and the second driving characteristic variable DK ₂
Represented by the product of the inter-vehicle distance L ₁ and the pedal depression replacement time ΔT when the brake is on (Bsw = 1).

That is, first in step S21 of FIG.
₁ (n) = L ₀ / V ₀ , DK ₂ = L ₁ · ΔT,
In the next S22, the number of samples n is checked. Number of samples n = 1
During the period from to 9 (S22, NO), the learning of the driving characteristics is not executed, and the previous learning value is used.

When the number of samples n reaches ten (S2
2, YES), and at S23, each of the ten driving characteristic variables D
The average value of K ₁ and DK ₂ is obtained, and the driving characteristics of the driver are learned. Then, in the next S24, sorting for the next learning is performed.

FIG. 7 shows the contents of the boost magnification determination routine in S4 of FIG. The control unit 20
The in memory, as shown in S25 in FIG. 7, the map for calculating the target boost magnification TGK from learning value of the operating characteristic variables DK _1, DK ₂ obtained in S23 in FIG. 6 is stored, this Target boost magnification TGK using map
Is required. The learning values of the driving characteristic variables DK ₁ and DK ₂ reflect the habits and individual differences of the driver, and the driver tends to reduce the inter-vehicle distance L despite the high vehicle speed V. by characteristic variables DK ₁ becomes smaller, the target boost magnification TGK is increased, the assist force is increased. Also, slow reaction with respect to the obstacle, for drivers tend to pedal depression replacement time ΔT is longer, by the operating characteristic variables DK ₂ increases, the target boost magnification TGK is increased, the assist force is increased .

FIGS. 8 and 9 show S3 and S4 of FIG.
4 shows other aspects of the routine for learning the driving characteristics and the routine for determining the boost magnification in FIG. In this case, the first operating characteristic variables DK ₁ representing the operational characteristics of the driver, the accelerator is off in an emergency (Asw = 0) inter-vehicle distance L ₀ is short state with respect to the vehicle speed V ₀ which time, i.e. in an emergency represented by the ratio of the inter-vehicle distance L ₀ with respect to the vehicle speed V _0, the second operating characteristic variables DK ₂ is a standard pedal depression replacement time T
It is expressed as the ratio of the pedal depression time ΔT to _ST .

That is, first, in S31 of FIG. 8, DK ₁
(N) = L ₀ / V ₀ , DK ₂ = ΔT / T _ST is calculated.
The standard pedal depressing time T _ST is calculated from a previous map of vehicle speed V ₀ and inter-vehicle distance L ₀ as shown in the figure. Then, in the next S32, the number n of samples is checked. While the number of samples n = 1 to 9 (S32, NO), learning of the driving characteristics is not performed, and the previous learning value is used.

When the number of samples n reaches 10 (S3
2, YES), in S33, the current running state, as shown, a large vehicle speed V _0, to determine whether the inter-vehicle distance L ₀ is in the short urgent area, unless an emergency area (S33,
NO), 1 is subtracted from the sample number n in S34, and the data at this time is not integrated.

On the other hand, if it is an emergency area (S33, YE
S), and proceed to S35, where each of the ten operation characteristic variables DK ₁ ,
An average value of DK _2, thereby learning the driving characteristics of the driver. Then, in the next S36, sorting for the next learning is performed.

FIG. 9 shows the contents of the boost magnification determination routine in this case. In the memory of the control unit 20, as shown in S37 of FIG. 9, S3 of FIG.
Map for calculating a target boost magnification TGK from learning value of the operating characteristic variables DK ₂ obtained in 5 is stored, the target boost magnification TGK is calculated using this map. In this case, although the an emergency area, when the pedal depression replacement time ΔT is longer than the standard pedal depression replacement time T _ST, by the operating characteristic variables DK ₂ increases, the target boost magnification TGK increases, Assist power is increased.

Finally, the contents of the output process in S5 of FIG. 3 will be described with reference to the flowchart of FIG.

First, in S41, a target chamber pressure TGP corresponding to the target magnification TGK is read from a map showing the relationship between the target magnification TGK and the target chamber pressure TGP.

Next, at step S42, the actual chamber pressure Pc is subtracted from the target chamber pressure TGP to obtain a difference ΔP. Then, a dead zone with threshold values of the positive and negative predetermined values α and −α is set, and in S43 and S44, ΔP> α, ΔP <−α, or −α <ΔP <α. Is determined.

First, when it is determined in S43 that ΔP> α (S43, YES), the negative pressure in the vacuum chamber 14 is too high, so the control valve 1 in S45.
6 (vacuum valve) is closed and a decision is made to introduce only atmospheric pressure into the chamber 14. Then, in S46, ΔP of the control signal to the control valve 17 (atmospheric pressure valve)
Is read out from the map in accordance with step S47.
A control signal having this duty ratio is output to the control valve 17 (atmospheric pressure valve),
A control signal for closing the control valve 16 (vacuum valve), that is, a control signal for setting the duty ratio to 0%, is output to the control valve 16 (vacuum valve).

On the other hand, when it is determined in S43 and S44 that ΔP <−α (S43, NO, S44, YE
S) Since the negative pressure in the vacuum chamber 14 is too low, the control valve 17 (atmospheric pressure valve) is closed in S48, and it is determined that only the vacuum pressure is introduced into the chamber 14. Then, in S49, the duty ratio corresponding to ΔP of the control signal for the control valve 16 (vacuum valve) is read from the map, and in S47, the control signal having this duty ratio is output to the control valve 16 (vacuum valve). At the same time, a control signal for setting the duty ratio to 0% is output to the control valve 17 (atmospheric pressure valve).

Further, at steps S43 and S44, -α <ΔP <α
Is determined (S43, NO, S44, N
O) Since it means that the pressure Pc in the vacuum chamber 14 is within the target range, it is determined that both the control valves 16 and 17 are closed in S50 and S51, and in S47.
Then, a control signal for setting the duty ratio to 0% is output to the control valves 16 and 17, and both the control valves 16 and 17 are closed to maintain the pressure in the chamber 14.

The above is the description of the structure and operation of the first embodiment of the present invention. According to this embodiment, the driving characteristics of the driver are learned based on the vehicle speed, the following distance, and the pedal change time. However, since the assisting force of the sub-booster 4 is changed based on the learning result, a reliable and appropriate braking force is always obtained regardless of the driver's habits regarding the operation of the brake pedal and the slow response speed of avoiding danger. Can be obtained.

FIG. 12 is an overall system diagram showing a brake control device according to one embodiment of the second invention shown in the block diagram of FIG.

FIG. 12 has the same configuration as that of FIG. 2 except that the accelerator switch 45 and the inter-vehicle distance sensor 47 are omitted from the configuration of FIG. Although omitted, the control unit 20 receives a vehicle speed signal from a vehicle speed sensor 42, a brake switch signal from a brake switch 41, and a chamber pressure signal from a pressure sensor 43 that detects the pressure in the air chamber 14. At the same time, a control signal is output from the control unit 20 to the control valves 16 and 17.

The control unit 20 detects a deceleration pattern during braking based on the signal from the vehicle speed sensor 42, learns the brake pedal force based on the deceleration pattern, and boosts the sub-booster 4 based on the learning result. A magnification (assist amount) is determined, a target pressure value in the air chamber 14 for obtaining the boost magnification is set, and a duty ratio of a control signal to be output to the control valves 16 and 17 is calculated from the target pressure value. Then, the control valves 16 (vacuum valve) and 17 (atmospheric pressure valve) are duty-controlled so that the pressure value in the air chamber 14 approaches the target pressure value. In this control, feedback control using the output of the pressure sensor 43 is performed.

Next, the contents of the control routine executed by the control unit 20 will be described with reference to the flowcharts shown in FIG.

First, in S61 of FIG. 13, various memories and constants are initialized, and in S62, the vehicle speed V, the brake switch signal Bsw and the chamber pressure Pc are read. Next, the vehicle body deceleration G during braking is calculated in S63, and in S64,
Assuming that the vehicle speed V at the start of the brake operation is 100%, the vehicle speed V
The data of the deceleration G is taken until the value becomes 0%.
Then, the vehicle speed position G _MAX % at which the maximum value G _MAX of the deceleration G occurs during one deceleration is calculated in S65. In this case, the curve indicated by the solid line in FIG. 13 G _MAX% = 40
%, And the curve shown by the dashed line is G _MAX % <40%
And the curve shown by the dashed line is G _MAX %> 40.
%. With this G _MAX % value, it is possible to detect when the driver strongly presses the brake pedal.

In the next S66, the G _MAX % value G in the past five times
Updates the M ₁ ~GM _5, calculates the average value GP of the past five G _MAX% value in S67. As described above, the learning of the driver's brake pressing force is performed by calculating the average value GP. Then, in S68, GP = 40
% Is good, GP> 40% and GP <40% are bad.

The memory of the control unit 20 stores the last five G times as shown in S69 of FIG.
A map for obtaining the boost factor K from the average value GP of the _MAX % value and the level of the vehicle speed is stored, and the boost factor K is read from this map. As is clear from the above map, when GP = 40%, the value of the boost magnification K is kept at a constant value 1.5 from the start of the brake operation until the vehicle stops, but when GP> 40%, the boost ratio K is increased. The value of the magnification K changes from 1.0 to 2.0 as the vehicle speed decreases.
And when GP <40%, the boost magnification K
Decreases from 2.0 to 1.0 as the vehicle speed decreases, whereby the individual differences in the driver's braking force and the habit of depressing the brake pedal 1 are corrected to a standard value. Become.

Next, at S70, the brake switch signal B
Whether or not sw is 1, that is, the brake pedal 1
It is determined whether or not is stepped on. If Bsw = 0 (S70, NO), in S71, the boost magnification determination routine ends with the map value K in S69 as the target magnification TGK, but when Bsw = 1. (S70, YES), the map value is not changed this time so that the driver does not feel uncomfortable.

Finally, based on the target magnification TGK,
A routine for outputting a control signal to the control valves 16 and 17 is executed in accordance with the flowchart of FIG. 15, and the flowchart of FIG. 15 shows the contents of the map of S41 'for calculating the target chamber pressure TGP from the target magnification TGK in FIG. Except that it is slightly different from that used in S41,
Since this is the same as FIG. 10, duplicate description will be omitted.

As is apparent from the above description, according to the present embodiment, the brake pedal force is learned indirectly by learning the driving characteristics of the driver based on the vehicle deceleration pattern during braking, and based on the learning result, Since the assisting force of the sub-booster 4 is changed, it is possible to correct the strength of the brake pressing force due to individual differences of the driver and the habit of the driver appearing in the stepping manner, and obtain a reliable braking force.

The flowcharts of FIGS. 16 to 20 correspond to FIG.
1 shows another embodiment in which the device shown in FIG. 1 learns the brake depression force from the deceleration pattern of the vehicle body during braking, and changes the assist force by the sub-booster 4 based on the learning result.

First, in S81 of FIG. 16, the system is initialized. That is, while reading the memory value of the variable DK representing the driving characteristics of the driver,
Reset each variable. The above memory values are saved in the memory when the power is turned off. The variable to be reset is the vehicle speed V
(ΔTb) and the brake operation time ΔTb.

FIGS. 16 and 17 show the contents of the data input routine. That is, the brake switch signal Bsw and the chamber pressure Pc are read in S82, and the count value of the brake operation time ΔTb is reset in S83 of FIG. Next, in S84, the brake switch signal B
It is determined whether or not sw has become 1, and when Bsw = 1 (S84, YES), the process proceeds to S85, and the vehicle speed V (ΔTb) at that time is read. In the next S86, the vehicle speed V
It is determined whether or not (ΔTb) has become zero. If not (S86, YES), the vehicle speed V (ΔTb) is determined in S87.
The period ΔT is added to the brake operation time ΔTb for each sampling period of b), and the brake operation time ΔTb is counted. Then, Bsw = 1 (S84, YE
S) and while the vehicle speed V (ΔTb) does not become zero, (S
86, YES), the flow of S84 to S87 is repeated, and when the vehicle speed V (ΔTb) becomes zero (S86, N)
O), proceeding to S88, ending the counting of the brake operation time ΔTb. Next, in S89, it is determined whether or not the brake operation time ΔTb is 3 seconds or more. If ΔTb is 3 seconds or more (S89, YES), the process proceeds to S90 in FIG.
If Tb is less than 3 seconds (S89, NO), the flow returns to S83 to reset the count value of ΔTb.

At S90 in FIG. 18, the deceleration G ₀ for one second at the beginning of deceleration, the deceleration G _M for one second at the intermediate point of ΔTb, and the deceleration G _E for one second immediately before the stop are calculated. I do. In FIG. 19, ΔG is a threshold value for determining a difference in deceleration, and D ₁ , D ₂ , Dg, and Dt are pattern coefficients. The greater the value of the pattern coefficient, the more dangerous the danger is, and the more rapid deceleration just before the stop, the more dangerous the deceleration is determined (Dg = D ₁ + 3 × D ₂ ). And
The driving characteristic variable DK of the driver is calculated by the equation DK = K ₁ (Dt +
Dg) + K ₂ · DK However, K ₁ + K ₂ =
1.0, K ₁ <K ₂ .

After the driving characteristic variable DK is obtained as described above, the target boost factor TGK is read from the map shown in S92 of FIG. 20, and this target boost factor TGK is read.
, A control signal output routine similar to that of FIG. 10 may be executed.

Also in this embodiment, the braking force is learned indirectly by learning the driving characteristics of the driver based on the vehicle deceleration pattern during braking, and the assist force by the sub-booster 4 is changed based on the learning result. Therefore, it is possible to correct a driver's individual difference appearing in how to depress the brake pedal 1 and obtain a reliable braking force.

FIG. 22 is an overall system diagram showing an embodiment of the brake control device shown in the block diagram of FIG. 21 of the second invention.

In FIG. 22, a brake depression force sensor 46 for detecting the depression force of the brake pedal 1 is added to the configuration of FIG.

The flow charts of FIGS. 23 to 25 show that the inter-vehicle distance L at the start of braking and the time ΔT for changing over the pedal from the accelerator pedal 44 to the brake pedal 1 are each shorter than a predetermined value. This shows an embodiment in which learning is performed and the assisting force of the sub booster 4 is changed based on the learning result.

First, in S101 of FIG. 23, the system is initialized. That is, the memory value of the variable DK representing the driving characteristics of the driver is read, and each variable is reset. The above memory values are saved in the memory when the power is turned off. The variables to be reset are the brake operation time ΔTb and the average brake depression force AVFb.

FIGS. 23 and 24 show the contents of the data input routine. That is, in S102, the accelerator switch signal Asw, the brake switch signal Bsw, and the chamber pressure Pc are read, and the count value of the pedal depression time ΔT is reset in S103 of FIG.
Next, when it is determined in S104 that the accelerator switch signal Asw has become 0 (S104, YES), S1
At step 05, the inter-vehicle distance L is read, and the counting of the pedal depressing time ΔT is started. Until the brake switch signal Bsw becomes 1 in S106, it is confirmed in S107 that the accelerator switch signal Asw is maintained at 0 (S107, YES), and the brake switch signal Bsw becomes 1. (S10
6, YES), and the count of the pedal depressing time ΔT is terminated in S108.

Next, it is determined at S109 whether or not the area is a learning area. As shown in the drawing, this learning area is set in advance under the condition that the inter-vehicle distance L at the start of braking and the time ΔT for changing over the pedal from the accelerator pedal 44 to the brake pedal 1 are each shorter than a predetermined value. Keep it. If it is the learning area (S109, YES), S1
At 10, the counting of the brake operation time ΔTb is started.
In the next step S111, the brake depression force Fb is read, and in step S11.
In step 2, the value of the brake depression force Fb is added. next,
In S113, it is determined whether or not the brake switch signal Bsw has become 0, and when Bsw = 0, (S113,
NO), the counting of the brake operation time ΔTb ends (S114).

Next, at step S115 in FIG.
Is divided by the brake operation time ΔTb to calculate an average brake depression force AVFb, and learning of the driving characteristics is executed in the next S116. In S116, the average brake depression force AVF
b, and reads the coefficient Db from the driving characteristic variable D of the driver.
K is obtained from the equation DK = K ₁ · Db + K ₂ · DK. However, K ₁ + K ₂ = 1.0 and K ₁ <K ₂ .

After the driving characteristic variable DK is obtained as described above, the target boost factor TGK is read from the map shown in S92 of FIG. 20, and this target boost factor TGK is read.
, A control signal output routine similar to that of FIG. 10 may be executed.

In this embodiment, the learning of the brake pedal force Fb is limited to a preset learning region based on the following distance L at the start of braking and the time ΔT for changing the pedal from the accelerator pedal 44 to the brake pedal 1. As a result, it is possible to obtain a reliable braking force according to the degree of danger that appears in how to depress the brake pedal 1 during braking.

When learning the brake depression force, the brake depression force may be detected from the seat pressure applied to the driver seat when the driver depresses the brake pedal during braking, for example. In a vehicle configured to operate a parking brake by a foot-operated pedal, it is also possible to estimate a brake depression force from a depression force of a parking brake pedal in a vehicle stationary state.

Further, prior to changing the assist force according to the driving characteristics of the driver, the friction coefficient μ
Or the assisting force may be changed in advance according to the load.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a brake control device according to a first invention;

FIG. 2 is an overall system diagram showing a specific example of a brake control device according to the first invention.

FIG. 3 is a flowchart showing a main routine of a control example of the brake control device according to the first invention;

FIG. 4 is a flowchart showing a part of the contents of steps S1 and S2 in FIG. 3;

FIG. 5 is a flowchart showing the rest of the contents of step S2 in FIG. 3;

FIG. 6 is a flowchart showing an example of the contents of step S3 in FIG. 3;

FIG. 7 is a flowchart showing the contents of step S4 in FIG. 3 following FIG. 6;

FIG. 8 is a flowchart showing another example of the content of step S3 in FIG. 3;

FIG. 9 is a flowchart showing the contents of step S4 in FIG. 3 following FIG. 8;

FIG. 10 is a flowchart showing the contents of step S5 in FIG. 3;

FIG. 11 shows a brake control device according to a second invention.
FIG. 2 is a block diagram illustrating a configuration of an embodiment.

12 is an overall system diagram showing a specific example of the brake control device of FIG. 11;

FIG. 13 is a flowchart showing the contents of a driving characteristic learning routine executed by the control unit of FIG. 12;

FIG. 14 is a flowchart showing the contents of a boost magnification determination routine;

FIG. 15 is a flowchart showing the contents of the control signal output routine.

16 is a flowchart showing a part of the contents of a system initialization routine and a data input routine executed by the control unit of FIG. 12;

FIG. 17 is a flowchart showing the contents of a data input routine following FIG. 16;

FIG. 18 is a flowchart showing the contents of a deceleration calculation routine following FIG. 17;

FIG. 19 is a flowchart showing the contents of a driving characteristic learning routine following FIG. 18;

FIG. 20 is a flowchart showing the contents of a boost magnification determination routine following FIG. 19;

FIG. 21 is a block diagram showing the configuration of another embodiment of the brake control device according to the second invention.

FIG. 22 is an overall system diagram showing a specific example of the brake control device of FIG. 21;

23 is a flowchart showing a part of the contents of a system initialization routine and a data input routine executed by the control unit of FIG. 22;

FIG. 24 is a flowchart showing the contents of a data input routine following FIG. 23;

FIG. 25 is a flowchart showing the contents of a driving characteristic learning routine following FIG. 24;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Brake pedal 2 Master cylinder 3 Main booster 4 Sub booster 7,12 Diaphragm 8,13 Diaphragm room 9,15 Check valve 14 Air chamber 16 Control valve (vacuum valve) 17 Control valve (atmospheric pressure valve) 20 Control unit 25 Disc brake Device 41 Brake switch 42 Vehicle speed sensor 43 Pressure sensor 44 Accelerator pedal 45 Accelerator switch 46 Brake depression force sensor 47 Inter-vehicle distance sensor

──────────────────────────────────────────────────続 き Continuing on the front page (72) Akira Iwamoto, Inventor 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Inside Mazda Co., Ltd. (72) Inventor Masao Murata 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Matsu (72) Inventor Tamio Hirasawa 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Corporation (72) Inventor Yukiya Tanaka 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda (56) References JP-A-7-17380 (JP, A) JP-A-4-118344 (JP, A) JP-A-5-294218 (JP, A) JP-A-5-155272 (JP, A) JP-A-6-199155 (JP, A) JP-A-59-18053 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60T 8/58 B60T 13/66

Claims (11)

(57) [Claims] 1. An assisting means for assisting a braking force generated by a driver's depressing operation of a brake pedal, an assisting force variable means for changing an assisting force generated from the assisting means, and a first detection for detecting a vehicle speed Means, second detecting means for detecting the distance between the host vehicle and the obstacle, pedal changing time measuring means for measuring the changing time from the accelerator pedal to the brake pedal during braking, and Driving characteristic learning means for learning the driving characteristic of the driver based on the vehicle speed and obstacle distance detected by the first and second detection means, and the pedaling time measured by the measurement means; An assist amount determining means for determining an assist amount based on the driving characteristics learned by the means; Control device for a brake, wherein the control means for controlling the assisting force variation means based on the determined assist amount, to become equipped with. 2. The method according to claim 1, wherein the learning of the driving characteristics of the driver by the learning means is performed by a ratio of a standard pedal depressing time set in advance based on a vehicle speed and an obstacle distance to a pedal depressing time measured by the measuring means. The brake control device according to claim 1, wherein the control is performed based on: 3. By learning the driving characteristics of the driver,
The brake control device according to claim 2, wherein a habit regarding a driver's operation of depressing a brake pedal is determined. 4. By learning the driving characteristics of the driver,
3. The brake control device according to claim 2, wherein a reaction speed of danger avoidance of the driver is determined. 5. The brake control device according to claim 3, wherein the driver's behavior is determined based on a map indicating a relationship between a vehicle speed and an obstacle distance. 6. The brake control device according to claim 3, wherein the assist force is increased for a driver having a habit of shortening the inter-vehicle distance. 7. The brake control device according to claim 3, wherein the assist force is increased for a driver who tends to delay the response to an obstacle. 8. An assisting means for assisting a braking force generated by a driver's depressing operation of a brake pedal, an assisting force variable means for changing an assisting force generated from the assisting means, and a brake depressing force for learning a brake pedal depressing force. Learning means; assist amount determining means for determining an assist amount based on learning of brake depression force by the learning means; control means for controlling the assist force varying means based on the assist amount determined by the assist amount determining means; A brake control device comprising: 9. A vehicle comprising a deceleration pattern detecting means for detecting a deceleration pattern of a vehicle body at the time of a brake operation, wherein the learning of the brake pedal depression force is performed based on the deceleration pattern detected by the deceleration pattern detection means. The brake control device according to claim 8, wherein 10. An obstacle distance detecting means for detecting a distance between the host vehicle and an obstacle, and a pedal depressing time measuring means for measuring a depressing time from an accelerator pedal to the brake pedal during braking. The learning of the brake pedal depression force is performed when the obstacle distance detected by the obstacle distance detection unit and the pedal depression time measured by the pedal depression time measurement unit are relatively short. 9. The brake control device according to claim 8, wherein: 11. A plurality of assist means for assisting a braking force generated by a driver depressing a brake pedal are connected in tandem and interposed between the brake pedal and the master cylinder. A brake control device wherein an assist force generated from at least one of the assist means is changed by controlling a negative pressure and an atmospheric pressure applied to the at least one assist means.