JPH09254752A - Brake controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent increase/reduction of braking force against intention of a driver by increasing a braking force only when an operation quantity of a brake operating member is increase if an actual speed reduction lowers a target speed reduction and reducing a braking force only when the operation quantity of the brake operating member is reduced if the actual speed reduction exceeds the target speed reduction. SOLUTION: In a controller 100, a braking force is increased by means of an accumulator 70 only when an operation quantity of a brake pedal 10 serving as a brake operating member to be detected by means of a pedal pressing force detector 114 is increased if an actual speed reduction lowers a target speed reduction. If the actual speed reduction exceeds the target speed reduction, the braking force is reduced by means of the accumulator 70 only when the brake pedal 10 operation quantity detected by means of the pressing force detector 114 is reduced. In this way, braking force reduction/increase against intention of a driver can be prevented.

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 decelerating and stopping a vehicle.

[0002]

2. Description of the Related Art Brake control devices for decelerating and stopping a vehicle include those disclosed in Japanese Patent Application Laid-Open No. 5-39008 or Japanese Patent Application Laid-Open No. 5-39014. These brake control devices include a brake operation member, an operation amount detection unit that detects an operation amount of the brake operation member, a wheel rotation suppression unit that has a brake that suppresses rotation of a wheel by a braking force, and an actual vehicle The deceleration detecting means for detecting the deceleration and the wheel rotation suppressing means are arranged so that the target deceleration determined based on the detection result of the operation amount detecting means and the actual deceleration detected by the deceleration detecting means match. It has a control means for controlling, and the braking force is increased or decreased when the actual deceleration of the vehicle deviates from the target deceleration by a predetermined value or more.

[0003]

However, if the braking force is increased or decreased when the actual deceleration of the vehicle deviates from the target deceleration by a predetermined value or more as described above, as long as this condition is satisfied, For example, the braking force may be increased or decreased even if the driver tries to maintain the braking force at that time and the operation amount of the brake operating member is kept constant. There was a problem in terms of operability. Therefore, an object of the present invention is to provide a brake control device capable of improving the operability by preventing the braking force from increasing or decreasing contrary to the driver's will.

[0004]

To achieve the above object, the invention according to claim 1 is a brake operating member, and an operation amount detecting means for detecting an operation amount of the brake operating member,
Wheel rotation restraining means having a brake that restrains wheel rotation with a braking force, deceleration detecting means for detecting the actual deceleration of the vehicle, target deceleration determined based on the detection result of the operation amount detecting means, and In a brake control device having a control means for controlling the wheel rotation restraining means so that the actual deceleration detected by the deceleration detecting means matches, the control means is configured such that the actual deceleration is the target. If the deceleration is below the deceleration, the braking force by the wheel rotation suppressing means is increased only when the operation amount of the brake operating member detected by the operation amount detecting means is increased, and the actual deceleration is When the target deceleration is exceeded, the braking by the wheel rotation suppressing means is performed only when the operation amount of the brake operating member detected by the operation amount detecting means decreases. It is characterized by reduced. As a result, when the actual deceleration is lower than the target deceleration, only when the operation amount of the brake operating member increases, that is, when the driver operates the brake operating member to increase the braking force. Only when the braking force is increased and the actual deceleration exceeds the target deceleration, only when the operation amount of the brake operating member decreases, that is, the driver tries to reduce the braking force. The braking force is reduced only when the operating member is operated.

Further, in the invention described in claim 2, the control means brakes according to an increasing speed of the operation amount calculated from the operation amount of the brake operation member detected by the operation amount detecting means. It is characterized in that the force is increased and the braking force is reduced in accordance with the decreasing speed of the operation amount calculated from the operation amount of the brake operation member detected by the operation amount detecting means. As a result, the braking force is increased in accordance with the increasing speed of the operation amount of the brake operating member, that is, the speed at which the driver intends to increase the braking force. The braking force will be reduced according to the decreasing speed, that is, the speed at which the driver is trying to reduce the braking force.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of the present invention will be described in detail below with reference to FIGS. In FIG. 2, 10 is a brake pedal as a brake operating member. The brake pedal 10 is connected to the master cylinder 12, and a hydraulic pressure corresponding to the depression force of the brake pedal 10 is generated in each of the two pressurizing chambers of the master cylinder 12. One pressurizing chamber of the master cylinder 12 is connected to front wheel cylinders 26, 28 of brakes provided on the left and right front wheels 22, 24 by liquid passages 14, 16 and branch passages 18, 20, respectively. The pressurizing chamber includes the liquid passages 30, 32 and the branch passages 34, 36.
Are connected to rear wheel cylinders 42, 44 of brakes provided on the left and right rear wheels 38, 40, respectively. Reference numeral 46 is a proportioning valve provided in the liquid passage 32 for the rear wheels 38, 40.

Electromagnetic directional control valves 50, 52, 54, 56 are provided in the branch passages 18, 20, 34, 36, respectively, and hydraulic pressure control valves 58, 60, 62, 64 are connected thereto. The solenoids of the electromagnetic directional control valves 50 to 56 are always demagnetized and in the original position shown in the figure, and the wheel cylinders 26, 28, 42, 44 are communicated with the hydraulic control valves 58 to 64, but the solenoids are excited. If so, the wheel cylinders 26, 28, 42,
44 is communicated with the master cylinder 12.

The hydraulic pressure control valves 58 to 64 are connected to an accumulator 70 and a reservoir 72 by liquid passages 74 and 76, respectively, and the accumulator 70 has a reservoir 7 therein.
The second liquid is pumped by the pump 80 and stored in a certain range. The hydraulic pressure control valves 58 to 64 control the hydraulic pressure of the accumulator 70 to a height required to suppress the rotation of the wheels by controlling the exciting current of the solenoid, and supply the hydraulic pressure to the wheel cylinders 26, 28, 42, 44. Then, the brake operates based on the hydraulic pressure, and the rotation of the wheels is suppressed by the operating force of the brake. In the first embodiment,
Wheel cylinders 26, 28, 42, 44, brakes (not shown) operated by these, and pump 8
0, the accumulator 70, the hydraulic pressure control valves 58 to 64, etc. constitute wheel rotation suppressing means.

Between the liquid passages 14 and 16 connecting the master cylinder 12 and the front wheel cylinders 26 and 28, and between the master cylinder 12 and the wheel cylinder 4.
Electromagnetic directional control valves 84 and 86 are provided between the liquid passages 30 and 32 connecting the valves 2 and 44, respectively, and the stroke simulators 88 and 90 are connected thereto. The stroke simulators 88, 90 store the brake fluid discharged from the master cylinder 12 to allow the brake pedal 10 to be depressed, and apply a reaction force corresponding to the depression stroke to the brake pedal 10. In the state where the rotation of the wheels is suppressed based on the hydraulic pressure controlled by the hydraulic pressure control valves 58 to 64, the electromagnetic directional control valve 84,
The solenoid of 86 is demagnetized so that the master cylinder 12 is communicated with the stroke simulators 88, 90, and the driver feels as if the wheel cylinders 26, 28, 42, 44.
It is designed to give a feeling of operation as if it were connected to.

This brake control device is controlled by a control device (control means) 100. Control device 100 is CP
U102, ROM104, RAM106, input unit 10
8 includes an output unit 110 and a bus. Control device 1
The input section 108 of 00 includes a brake switch 112 for detecting depression of the brake pedal 10 and a brake pedal 1
A pedaling force detecting device 114 as an operation amount detecting means for detecting a stepping force of 0, a hydraulic pressure sensor 116 for detecting the hydraulic pressure of the accumulator 70, wheel cylinders 26, 28, 42,
Hydraulic pressure sensors 118, 120, 12 for detecting the hydraulic pressure of 44
2,124, left and right front wheels 22,24 and rear wheels 38,4
Wheel speed sensors 126, 12 for detecting each rotation speed of 0
8, 130, 132 and vehicle height sensors 134, 136, 138, 140 for detecting the height of the vehicle body on each wheel are connected.

The output section 110 has hydraulic pressure control valves 58 to 64.
And electromagnetic directional control valves 50, 52, 54, 56, 84,
86 is connected. In addition, in the ROM 104, FIG.
A map for defining the relationship between the pedaling force of the brake pedal 10 and the target deceleration G _r shown in the graph and a wheel rotation suppression routine shown in the flowchart in FIG. 1 are stored. Hereinafter, suppression of wheel rotation will be described based on this flowchart.

The braking by the brake control device is usually performed based on the hydraulic pressure controlled by the hydraulic pressure control valves 58 to 64, and the electromagnetic directional control valves 50 to 56, 8 are used.
4,86 are always demagnetized and wheel cylinders 26,2
8, 42 and 44 are communicated with hydraulic pressure control valves 58 to 64, and the master cylinder 12 is connected to the stroke simulator 8
8,90. Then, at the same time when the ignition switch is turned on, a main routine (not shown) is executed, the friction coefficient μ of the friction material of the brake is set to the basic value μ _B in the initial setting, and the RAM 10 is set.
6 is stored in the friction coefficient storage area. The basic value μ _B is a value determined by design or an actual measurement value of a dry friction material at room temperature.

When the brake pedal 10 is depressed, first, step S1 (hereinafter abbreviated as S1) is executed to read the depression force P _E of the brake pedal 10, the wheel speed and the vehicle height, and then at S2, Stepping force P _E
The change speed P _E 'which is the differential value thereof is calculated from the wheel speed sensors 126, 128, 13 in S3.
The actual deceleration G of the vehicle is calculated based on the wheel speed detected at 0,132.

As a calculation method of S3, a predetermined time interval (100 ms to 500) of the maximum value of the wheel speed detected by the four wheel speed sensors 126, 128, 130, 132 is used.
ms, preferably 200 ms to 300 ms) is divided by the time interval to obtain the actual deceleration G, or every predetermined speed change (1 km / h to 5 km / h, preferably about 3 km / h) In addition, there is a method of obtaining the actual deceleration G by a value obtained by dividing it by the time between them, and further a method of obtaining the actual deceleration G by the so-called simulated vehicle body speed inclination used in the antilock brake system or the traction control system. Adopted.

Subsequently, the target deceleration G _r is calculated in S4. The target deceleration G _r is calculated from the map that defines the relationship between the depression force of the brake pedal 10 and the target deceleration G _r . Next, S5 to S10 are executed,
In order to match the target deceleration G _r and the actual deceleration G, the friction coefficient μ of the friction material is set in order to set the braking hydraulic pressure of the wheel cylinder.

The friction coefficient μ is the target deceleration G _r of the actual deceleration G.
It is set according to the ratio to. In S5, it is determined whether or not the actual deceleration G is 95% or less of the target deceleration G _r. If it is 95% or less, the determination result in S5 is YE.
Becomes S, it is determined whether the depression force of the brake pedal 10 is in the increasing state at S7, for example, the depression force change rate P _E 'beta is predetermined (β> 0) to P _E' It is performed depending on whether or not ≧ β. And P _E '
If ≧ β and the depression force of the brake pedal 10 is in the increasing state, the determination in S7 is YES and S10 is executed. In S10, μ = (1-K × P _E ′) μ so that the change of the friction coefficient μ is proportional to the changing speed P _E ′.
And the friction coefficient μ stored in the friction coefficient storage area is replaced. Here, K in this equation is a positive proportional constant, P _E 'is a differential value of the pedaling force P _E of the brake pedal 10, that is, a changing speed, and the pedaling force P _E of the brake pedal 10 increases. Therefore, P _E 'is positive, and the friction coefficient μ obtained from the above equation is smaller than the original value. On the other hand, if the depression force of the brake pedal 10 is not in the increasing state in S7, the determination in S7 is NO and S9 is executed, and the friction coefficient μ is determined to the same value as before.

When the actual deceleration G is larger than 95% of the target deceleration G _r in S5, S6 is executed,
It is determined whether the actual deceleration G is 105% or more of the target deceleration G _r . If it is 105% or more of the target deceleration G _r , the determination in S6 is YES, and in S8 it is determined whether or not the depression force of the brake pedal 10 is in a reduced state, for example, the change speed P _E 'of the depression force. Is determined depending on whether or not P _E '≦ −β with respect to a predetermined β (β> 0). Then, if P _E '≦ −β and the depression force of the brake pedal 10 is in a reduced state, the determination in S8 is Y.
It becomes ES and S10 is executed. In S10, the friction coefficient μ is determined to be μ = (1−K × P _E ′) μ and is replaced with the friction coefficient μ stored in the friction coefficient storage area until then. Where the brake pedal 1
Since the stepping force P _{E of} 0 is decreasing, P _E 'is negative and the friction coefficient μ obtained from the above equation is larger than the original value. On the other hand, if the stepping force of the brake pedal 10 is not in the reduced state in S8, the determination in S8 is NO
9 is executed, and the friction coefficient μ is determined to be the same value as before.

As a result, the actual deceleration G becomes the target deceleration G.
_While it is 95% or less of _r , the wheel rotation suppression routine 1 is executed only when the depression force of the brake pedal 10 increases.
The friction coefficient μ is reduced according to the increasing speed of the stepping force of the brake pedal 10 for each execution cycle, and the stepping force of the brake pedal 10 decreases while the actual deceleration G is 105% or more of the target deceleration G _r. The friction coefficient μ is increased according to the decreasing speed of the stepping force of the brake pedal 10 for each execution cycle of the wheel rotation suppression routine, and is 95%.
And 105% will not be changed.

Next, in S11, the left and right front wheels 22,
The wheel loads of 24 and the rear wheels 38, 40 are determined.
The magnitude of each load on the four wheels varies depending on the structure of the vehicle and the movement of the load from the rear to the front of the vehicle that occurs during braking, and rotation of the wheels cannot be suppressed so that the four wheels simultaneously lock with the same braking force. The wheel load is determined so that an appropriate braking force can be obtained for each wheel. The load F _FL of the left front wheel 22 is determined according to the following equation. F _FL = W _FL + ｛(H · G _X ) / 2L− (H · R _F · G _Y )
/ T｝ -M, where W _FL : weight of the vehicle applied to the left front wheel 22 in a stopped state H: height of the center of gravity of the vehicle G _X : longitudinal acceleration L: wheel base _RF : distribution of roll rigidity of the front wheels G _Y : lateral acceleration T ： Tread M ： Mass of vehicle

[0020] During braking, the moment of magnitude multiplied by the mass M of the height H and the vehicle center of gravity of the vehicle longitudinal acceleration _{G X (M · H · G} X) occurs, the moment applied from the ground to the front wheels Since it balances the reaction force F with the moment (F ・ L) obtained by multiplying the wheel base L, F = (M ・ H ・
G _X ) / L, and the reaction force F is equal to the left and right front wheels 2
2 and 24, the load on the left front wheel 22 is increased by (M · H · G _X ) / 2L.

Further, when the vehicle turns, a load movement occurs in the left-right direction of the vehicle. At the time of turning the vehicle, a moment (M · H · G _Y ) of a magnitude obtained by multiplying the lateral acceleration G _Y by the height H of the center of gravity is generated, and the moment (the reaction force F applied to the left front and rear wheels from the ground) is applied to the tread T ( F ・ T)
= (M · H · G _Y ) / T. This force F is shared between the front wheels and the rear wheels according to the magnitude of the roll rigidity distribution R _F , R _R. Roll stiffness distribution is the distribution ratio between the front and rear wheels of the restoring moment transmitted from the suspension to the sprung mass when the vehicle turns around the longitudinal axis.
A value obtained by multiplying the roll stiffness distribution R _F of _{(M · H · G Y)} / T to the front wheels 22, 24 is a variation of the load of the left front wheel 22 with the turning. If the lateral acceleration G _Y at the time of turning left is expressed as a positive value, in the case of the left front wheel 22, the load decreases due to the load movement at the time of turning left of the vehicle.
R _F · G _r ) / Τ is subtracted, G _Y becomes a negative value when turning right, and the load increases.

The load F _{FR on} the right front wheel 24 is calculated by the following equation. _{F FR = W FR + {(} H · G X) / 2L + (H · R F · G Y)
/ T｝ · M where W _FR = vehicle weight applied to the right front wheel 24 in a stopped state In the case of the right front wheel 24, when the vehicle makes a left turn, the load increases due to lateral load movement, and by adding this, the load F _FR is determined, the value of G _Y is negative when the right turning, the load is reduced.

Further, the loads F _RL and F _{RR on} the left rear wheel 38 and the right rear wheel 40 are obtained by the following equations. F _RL = W _RL -｛(H · G _X ) / 2L + (H · R _R · G _Y )
/ T｝ · MF _RR = W _RR -｛(H ・ G _X ) / 2L- (H ・ R _R・ G _Y )
/ T} · M However, W _RL: vehicle weight according to the left rear wheel 38 in a stopped state R _R: roll stiffness distribution W _RR of the rear wheel: longitudinal accompanying vehicle weight brake according to the right rear wheel 40 in a stopped state Since the load on the rear wheels decreases due to the load movement, (M ・ H ・ G _X ) / 2L is drawn. The moving load in the left-right direction is determined by multiplying the allocation ratio R _R of the roll stiffness of the rear wheels _{(M · H · G Y)} / T, pull when the value of the left rear wheel 38, right In the case of the rear wheel 40, it is added.

When the loads of the left and right front wheels 22, 24 and the rear wheels 38, 40 are obtained in this way, S12 is executed and the wheels of the respective wheels are adjusted so that the braking force corresponding to the magnitude of the load is obtained. The braking fluid pressures P _FL , P _FR , PR _L , P _RR supplied to the cylinders 26, 28, 42, 44 are calculated by the following equations. P _FL = (F _FL · G _r ) / (μ · b _F ) P _FR = (F _FR · G _r ) / (μ · b _F ) P _RL = (F _RL · G _r ) / (μ · b _R ) P _RR = (F _RR · G _r ) / (μ · b _R ), where b _F is the front wheel braking factor, b _R is the rear wheel braking factor, and b _F and b _R are respectively expressed by the following equations. To be done. b _F = 2 · A _F · (r / R) b _R = 2 · A _R · (r / R) where A _F : Piston cross-sectional area of left and right front wheels 22, 24 A _R : Left and right rear wheels 38, Piston area of 40 brakes r: Effective radius of disk rotor R: Effective radius of tire

Therefore, the actual deceleration G is equal to the target deceleration G _r.
Of 95% or less, the friction coefficient μ becomes equal to the brake pedal 1 only when the depression force of the brake pedal 10 increases.
The braking fluid pressure P is reduced in accordance with the increasing speed of the stepping force of 0, and the braking fluid pressure P corresponding to the same target deceleration G _r, that is, the braking hydraulic pressure P is corresponding to the friction coefficient μ, that is, the increasing speed of the pedaling force of the brake pedal 10. The obtained braking force will be increased. In this case, since the amount of wheel rotation suppression is insufficient, the braking fluid pressure P is determined to be high, and the amount of wheel rotation suppression is made large. Further, when the actual deceleration G is 105% or more of the target deceleration G _r , the friction coefficient μ increases in accordance with the decreasing speed of the pedaling force of the brake pedal 10 only when the pedaling force of the brake pedal 10 decreases. The friction coefficient μ, that is, the brake pedal 1
The target deceleration G _r
The braking fluid pressure P corresponding thereto, that is, the braking force obtained by the braking fluid pressure P is reduced. In this case, since the wheel rotation is excessively suppressed, the friction coefficient is increased, the braking hydraulic pressure P for the same target deceleration G _r is determined to be low, and the wheel rotation suppression amount is reduced.

Then, in S12, the magnitudes of the exciting currents of the solenoids of the hydraulic pressure control valves 58 to 64 are controlled so that the calculated braking hydraulic pressure is supplied to the wheel cylinders 26, 28, 42 and 44. . Liquid pressure sensor 118-12
Wheel cylinders 26, 28, 4 detected by
The hydraulic pressures supplied to 2, 44 and the set braking hydraulic pressure P are compared, and the current is feedback-controlled so that the braking hydraulic pressure P is obtained.

As described above, in order to obtain the target deceleration G _r corresponding to the depression force of the brake pedal 10, the height of the braking fluid pressure P is changed depending on the ratio of the actual deceleration G to the target deceleration G _r . While the actual deceleration G is 95% or less of the target deceleration G _r , the friction coefficient μ is reduced by an amount corresponding to the increasing speed of the depression force of the brake pedal 10 every time S10 is executed, and the braking fluid pressure P Is increased, and S1 is maintained while the actual deceleration G is 105% or more of the target deceleration Gr.
Every time 0 is executed, the friction coefficient μ is increased by an amount corresponding to the decreasing speed of the depression force of the brake pedal 10, and the braking hydraulic pressure P is decreased. When the actual deceleration G is greater than 95% and less than 105% of the target deceleration G _r , the friction coefficient μ is maintained at a constant value, and the actual deceleration G does not exactly match the target deceleration G _r. However, the braking fluid pressure P is kept constant within this range.

From the above, the actual deceleration G becomes the target deceleration G _r.
Is below 95% of the target deceleration G _r , only when the depression force of the brake pedal 10 increases in the determination of S7, that is, the driver tries to increase the braking force. Only when the brake pedal 10 is depressed, the friction coefficient μ is decreased and the braking force is increased in S10 to S12, and the actual deceleration G is the target deceleration G _r which is 105% or more of the target deceleration G _r. If the depression force of the brake pedal 10 decreases in the determination of S8, that is, only when the driver releases the depression of the brake pedal 10 in order to reduce the braking force, In S10 to S12, the friction coefficient μ is increased and the braking force is decreased. Therefore, operability can be improved by preventing the braking force from increasing or decreasing contrary to the driver's will.

Further, in S10, a speed proportional to the increasing speed according to the increasing speed of the depressing force of the brake pedal 10, that is, the speed at which the driver intends to increase the braking force. Thus, the friction coefficient μ can be decreased to increase the braking force, and the braking force can be increased according to the decreasing speed of the depression force of the brake pedal 10, that is, the speed at which the driver intends to decrease the braking force. Thus, it is possible to increase the friction coefficient μ and reduce the braking force at a speed proportional to the decreasing speed. Therefore, by changing the increasing speed and the decreasing speed of the braking force according to the stepping force based on the driver's will, the braking force can be generated more in accordance with the driver's will.

As is apparent from the above description, in the first embodiment, the wheel speed sensors 126, 128, 1 are used.
Reference numerals 30 and 132 constitute deceleration detecting means, and the control device 10
Of 0, the part of the ROM 104 that stores S1 to S12 and the part of the CPU 102 and the RAM 106 that executes these steps correspond to the control means.

In the above description, the brake pedal 1
The increase / decrease of the stepping force of 0 is determined by the change rate P _E ′ of the stepping force and a predetermined value β or −β that is set in advance.
It was performed by comparing with S1 and S2 described above, but S100 to S106 shown in FIG.
~ S106 may be performed based on. That is, in S100 after S1, the brake pedal 10 read in S1
The pedaling force P _E of _{No. 2} is compared with the maximum value P _{Epeak of the pedaling} force that has been stored so far by the replacement in S102 described below. Then, if it is determined in _step S100 that P _E > P _Epeak, it is determined in step S101 that the stepping force of the brake pedal 10 is in an increasing state and stored, and in step S102, the stepping force P _E at this time is set to the maximum value. _Remember as P _Epeak . As a result, when S7 is executed later, in S7, S1
When 01 is stored and the stepping force is stored as an increased state, YE
The determination of S is performed, and otherwise, the determination of NO is performed. Here, P _Epeak is reset to P _Epea k = 0 at the time when the ignition switch is turned on and when the depression force of the brake pedal 10 becomes 0, and the maximum value is detected between resets. Every time, the maximum value is sequentially replaced in S102.

On the other hand, if it is determined in S100 that the stepping force P _E is not greater than the maximum value P _Epeak , S
At 103, the stepping force P _E is set to a predetermined value α from the maximum value P _Epeak of the stepping force stored so far.
Compare (α> 0) with the subtracted value. Then, if it is determined in S103 that P _E <(P _Epeak −α), it is determined in S104 that the depression force of the brake pedal 10 is in a reduced state and stored, and in S105, the depression force P _E
The value obtained by adding the predetermined value α to is stored as the maximum value P _Epeak . As a result, when S8 is executed later, S
In S8, if it is stored in S104 that the depression force is in a reduced state, YES is determined, and if not, NO is determined.

Further, in S103, P _E <(P _Epeak −
If it is determined not to be α), it is determined in S106 that the depression force of the brake pedal 10 is in the holding state, and the result is stored. As a result, when S7 or S8 is executed later, the determination is NO in any of these determinations.

The second embodiment of the present invention will be described below with reference to FIGS. 5 and 6, focusing on the differences from the first embodiment. In the second embodiment, the hydraulic pressure control valves 58, 6 shown in FIG. 2 capable of modulating the brake hydraulic pressure for each wheel.
Booster 1 whose output can be modulated instead of 0, 62, 64
The point of using 60 is the main difference. That is, the second
As shown in FIG. 6, the brake control device according to the embodiment of the present invention is interposed between the brake pedal 10 and the master cylinder 12, and presses the brake pedal 10 into two pressurizing chambers of the master cylinder 12, respectively. The booster 160 that generates a hydraulic pressure corresponding to the force while assisting the depression force of the brake pedal 10 is provided.
Is adapted to modulate the hydraulic pressure generated from the master cylinder 12 by modulating the output thereof with the signal from the control device 100 as described above (for this booster 160, see JP-A-60-134067). Bulletin,
Japanese Utility Model Publication No. 60-134068 and Japanese Utility Model Publication 60-1.
34069).

One pressurizing chamber of the master cylinder 12 has a front wheel cylinder 26 and a right rear wheel 40 (FIG. 6) of a brake provided on the left front wheel 22 (not shown in FIG. 6).
Is connected to a rear wheel cylinder 44 of a brake provided on the front wheel cylinder 28 of the brake provided on the right front wheel 24 (not shown in FIG. 6). Left rear wheel 38 (Fig. 6
(Not shown) are connected to a rear wheel cylinder 42 of a brake provided in the vehicle. Proportioning valves 46 are provided in the liquid passages for the rear wheels 38 and 40, respectively. Note that reference numeral 162 indicates the master cylinder 1
The hydraulic pressure from 2 to the wheel cylinders 26, 28, 42, 44 is cut off as necessary while blocking the hydraulic pressure.
ABS that reduces and increases the hydraulic pressure of 8, 42 and 44
Actuator. Further, similarly to the third embodiment, the pedal effort detecting device 114 as the operation amount detecting means for detecting the pedal effort of the brake pedal 10, the left and right front wheels 22,
Wheel speed sensors 126, 128, 130, 132 (not shown in FIG. 6) for detecting the respective rotational speeds of the 24 and the rear wheels 38, 40 are provided. Incidentally, in the second embodiment, the wheel cylinders 26, 28, 42,
44, a brake (not shown) that is actuated by each of these, the booster 160, and the like constitute wheel rotation suppressing means.

The brake control device of the second embodiment is
Since the point that the booster 160 is used is mainly different from the first embodiment, in the wheel rotation suppression routine stored in the control device 100, the target deceleration G _r and the actual deceleration G are compared. The output of the booster 160 is changed according to the ratio to control the braking hydraulic pressure supplied to the wheel cylinders 26, 28, 42, 44.
The determination of the wheel load of 1 and the feedback control of the braking fluid pressure of S12 are abolished, whereby S1 is replaced by S1.
S201 in which the reading of the vehicle height is deleted is executed. Here, in the second embodiment, the control unit as a map is the reference output characteristic previously initialized of the corresponding booster 160 in one-to-one to each stepping force of the target deceleration G _r i.e. the brake pedal 10 100
Is stored in

In S5 of the wheel rotation suppression routine, it is determined whether or not the actual deceleration G is 95% or less of the target deceleration G _r . If 95% or less, the determination result in S5 is Y.
It becomes ES, and it is judged in S7 whether or not the stepping force of the brake pedal 10 is in an increasing state. For example, when the changing rate P _E 'of the stepping force is β for a predetermined β (β> 0),
It is performed depending on whether _E '≧ β. And P _E '≧ β
If the depression force of the brake pedal 10 is increasing, the determination in S7 is YES and S210 is executed. In S210, the coefficient value of the actual output characteristic with respect to the reference output characteristic of the booster 160 is changed by (100 × K × P _E ')% with respect to the value immediately before it. Here, K in this expression is a positive proportional constant, and P
_E 'is a differential value i.e. the rate of change of the depression force P _E of the brake pedal 10, the depression force of the brake pedal 10 P _E
Is increased, P _E 'is positive, and as a result, the actual output characteristic of the booster 160 obtained from the above equation is (100 × K × P _E ')% with respect to the output characteristic immediately before.
The booster 160 is controlled to be increased.

The output characteristic of the booster 160 is the output characteristic of the booster 160 with respect to the input, and is executed when the actual deceleration G is 95% or less of the target deceleration G _r. In S210, the outputs corresponding to the inputs from the brake pedal 10 on a one-to-one basis (outputs obtained for the same input) are all increased by (100 × K × P _E ')% with respect to the immediately preceding output. So that the output characteristics are changed as a whole
00 controls the booster 160. On the other hand, S7
If the depressing force of the brake pedal 10 is not in the increasing state, the determination in S7 is NO and S209 is executed, and the actual output characteristic of the booster 160 is maintained in the state up to that point.

When the actual deceleration G is greater than 95% of the target deceleration G _r , S6 is executed to determine whether the actual deceleration G is 105% or more of the target deceleration G _r. .
If 105% or more of the target deceleration G _r , the determination in S6 is Y.
As a result of ES, S8 is executed, and it is determined whether or not the pedaling force of the brake pedal 10 is in a reduced state. For example, when the pedaling force change speed P _E 'is β for a predetermined β (β> 0), It is performed depending on whether or not _E '≦ −β. And
If P _E '≦ −β and the depression force of the brake pedal 10 is in a reduced state, the determination in S8 is YES and S21.
0 is executed. In this S210, booster 1
The coefficient value of the actual output characteristic with respect to the reference output characteristic of 60 is changed by (100 × K × P _E ')% with respect to the value immediately before it. Here, K in this equation is a positive proportional constant, and P _E 'is the depression force P _{E of the} brake pedal 10.
Is the differential value of, that is, the changing speed, and is the brake pedal 10
Since the stepping force P _E of P _E is decreasing, P _E 'is negative, and as a result, the actual output characteristic of the booster 160 obtained from the above equation is (100 ×
The booster 160 is controlled so that K × P _E ')% is reduced.

The actual deceleration G is the target deceleration G.
_In S210 which is executed when _r is 105% or more, all the outputs (outputs obtained with respect to the same input) corresponding to each input from the brake pedal 10 in one-to-one relation The control device 100 controls the booster 160 so as to change the output characteristic as a whole so as to be decreased by 100 × K × P _E ')%. On the other hand, if the depression force of the brake pedal 10 is not in the reduced state in S8, the determination in S8 is NO and S209 is executed, and the actual output characteristic of the booster 160 is maintained in the state until then.

As a result, the actual deceleration G becomes the target deceleration G.
_While it is 95% or less of _r , the wheel rotation suppression routine 1 is executed only when the depression force of the brake pedal 10 increases.
The output characteristic of the booster 160 is increased by (100 × K × P _E ')% in accordance with the increasing speed of the stepping force for each execution cycle, so that a larger braking hydraulic pressure is applied to the wheel cylinder for the same stepping force of the brake pedal 10. 26, 28, 4
2 and 44, the output characteristics correspond to the speed of decrease of the pedaling force only when the pedaling force of the brake pedal 10 decreases while it is 105% or more (100
× K × P _E ')%, so that a smaller braking fluid pressure is transmitted to the wheel cylinders 26, 28, 42, 44 for the same depression force of the brake pedal 10, and 95% and 105%. Between the wheel cylinders 26, 28, 42 and 44, so that the same braking hydraulic pressure is transmitted to the wheel cylinders 26, 28, 42 and 44 for the same depression force of the brake pedal 10.

When the depression force of the brake pedal 10 becomes zero, the control device 100 initializes the output characteristic of the booster 160 to the reference output characteristic. As described above, in the second embodiment, not only the same effects as in the first embodiment are exhibited, but also the vehicle height sensor is unnecessary, so that the cost can be reduced.

The third embodiment of the present invention will be described below with reference to FIG. 7, focusing on the differences from the second embodiment. The control contents of the third embodiment are partially different from those of the second embodiment. In the third embodiment, the reference deceleration G _r, that is, the output characteristic of the reference braking hydraulic pressure that corresponds to each depression force of the brake pedal 10 on a one-to-one basis is preset in advance as a map of the control device 100.
Further, the output characteristics of the booster 160 corresponding to each braking hydraulic pressure on a one-to-one basis are preset in advance and stored in the control device 100 as a map.

Then, following S209 and S210, S3
In 12, the hydraulic pressure obtained from the output characteristic of the braking hydraulic pressure corresponding to the actual output characteristic of the booster determined in S209 and S210 is the wheel cylinders 26, 28, 42,
Booster 160 is controlled to be supplied to 44.
The hydraulic pressure supplied to the wheel cylinders 26, 28, 42, 44 detected by the hydraulic pressure sensors 118 to 124;
In order to generate this hydraulic pressure, the target deceleration G _r, that is, the hydraulic pressure on the output characteristic of the braking hydraulic pressure set according to the depression force of the brake pedal 10 is compared so that the set hydraulic pressure is obtained. The booster 160 is feedback-controlled. The above-described third embodiment can also exhibit the same effects as those of the second embodiment.

The control contents of the third embodiment are the same as those of the hydraulic control valves 58, 60, 62 of the first embodiment.
It is also possible to apply to a brake control device having 64. In this case, the booster 160 of the third embodiment
The portion for controlling the pressure may be replaced with the control of the hydraulic pressure control valves 58, 60, 62, 64. Here, in each of the above-described embodiments, the case where the depression force of the brake pedal 10 is detected as the operation amount of the brake pedal 10 has been described as an example, but the depression amount of the brake pedal 10 may be detected. In this case, as shown in FIG.
The relationship between the target deceleration and the depression amount of is to be set in advance as a map. In addition, instead of detecting the actual deceleration from the wheel speed, it is possible to use a deceleration sensor that directly detects the deceleration of the vehicle. In this case, the deceleration sensor needs to correct the inclination angle of the vehicle. Therefore, a sensor for performing this correction will be provided.

[0046]

As described above in detail, according to the invention of claim 1, when the actual deceleration is lower than the target deceleration, only when the operation amount of the brake operating member increases. That is, only when the driver operates the brake operating member to increase the braking force, the braking force is increased, and when the actual deceleration exceeds the target deceleration, the operation amount of the brake operating member is increased. Is reduced only when the driver operates the brake operating member to reduce the braking force. Therefore, operability can be improved by preventing the braking force from increasing or decreasing contrary to the driver's will.

Further, according to the second aspect of the invention, the brake is applied according to the increasing speed of the operation amount of the brake operating member, that is, the speed at which the driver intends to increase the braking force. The force is increased, and the braking force is reduced according to the decreasing speed of the operation amount of the brake operating member, that is, the speed at which the driver intends to decrease the braking force. Therefore, by changing the increasing speed and the decreasing speed of the braking force according to the driver's intention, the braking force can be generated more in accordance with the driver's intention.

[Brief description of drawings]

FIG. 1 is a flowchart showing a wheel rotation suppression routine stored in a control device according to a first embodiment of a brake control device of the present invention.

FIG. 2 is a configuration diagram of a first embodiment of a brake control device of the present invention.

FIG. 3 is a graph showing the relationship between the depressing force of the brake pedal stored in the control device of the first embodiment of the brake control device of the present invention and the target deceleration.

FIG. 4 is a flowchart showing a partially modified example of a wheel rotation suppression routine stored in the control device according to the first embodiment of the brake control device of the present invention.

FIG. 5 is a flowchart showing a wheel rotation suppression routine stored in the control device of the second embodiment of the brake control device of the present invention.

FIG. 6 is a configuration diagram of a second embodiment of a brake control device of the present invention.

FIG. 7 is a flowchart showing a wheel rotation suppression routine stored in the control device of the third embodiment of the brake control device of the present invention.

FIG. 8 is a graph showing the relationship between the amount of depression of the brake pedal and the target deceleration applicable to the brake control device of the present invention.

[Explanation of symbols]

10 Brake Pedal (Brake Operation Member) 26, 28 Front Wheel Cylinder (Wheel Rotation Suppressing Means) 42, 44 Rear Wheel Cylinder (Wheel Rotation Suppressing Means) 58, 60, 62, 64 Hydraulic Pressure Control Valve (Wheel Rotation Suppressing Means) 70 Accumulator (wheel rotation suppressing means) 80 Pump (wheel rotation suppressing means) 100 Control device (control means) 114 Pedal force detection device (manipulation amount detection means) 126, 128, 130, 132 Wheel speed sensor (deceleration detection means) 160 Booster (Wheel rotation suppressing means)

Claims (2)

[Claims] 1. A brake operating member, operation amount detecting means for detecting an operation amount of the brake operating member, wheel rotation suppressing means having a brake for suppressing rotation of wheels by a braking force, and deceleration of an actual vehicle. Deceleration detecting means for detecting the wheel rotation suppressing means so that the target deceleration determined based on the detection result of the operation amount detecting means and the actual deceleration detected by the deceleration detecting means match. In the brake control device having a control means for controlling, the control means operates the brake operation member detected by the operation amount detection means when the actual deceleration is lower than the target deceleration. The braking force by the wheel rotation suppressing means is increased only when the amount increases, and when the actual deceleration exceeds the target deceleration,
A brake control device, wherein the braking force by the wheel rotation suppressing means is reduced only when the operation amount of the brake operating member detected by the operation amount detecting means decreases. 2. The control means increases the braking force according to the increasing speed of the operation amount calculated from the operation amount of the brake operation member detected by the operation amount detecting means, and the operation amount detecting means. The brake control device according to claim 1, wherein the braking force is reduced in accordance with a rate of decrease of the operation amount calculated from the operation amount of the brake operation member detected in step 3.