JPH106969A - Anti-lock brake control device for vehicles - Google Patents

Abstract

(57) Abstract: An anti-lock brake control should be started based on a wheel speed obtained by a wheel speed detecting means and an estimated vehicle speed obtained by a vehicle speed estimating means based on the wheel speed. Is determined by the control start determining means, and the control mode determining means sets the brake fluid pressure control mode based on the wheel speed and the estimated vehicle speed during the antilock brake control. In the device, a stable braking force can be exerted regardless of the level of the road surface friction coefficient, and a smooth transition to antilock brake control is enabled. Kind Code: A1 A control is performed until a predetermined time elapses after the control start determining means determines that antilock brake control should be started or until wheel acceleration obtained by the wheel acceleration detecting means exceeds a predetermined value. The mode is maintained at the reduced pressure mode.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wheel speed detecting means for detecting a wheel speed, a vehicle speed estimating means for estimating a vehicle speed based on the wheel speed obtained by the wheel speed detecting means, Control start determining means for determining whether antilock brake control should be started based on the wheel speed obtained by the detecting means and the estimated vehicle speed obtained by the vehicle speed estimating means, and antilock brake control Brake fluid pressure based on the wheel speed obtained by the wheel speed detecting means and the estimated vehicle speed obtained by the vehicle speed estimating means in response to the control start determining means determining that the control should be started. Control mode determining means for controlling the operation of the brake fluid pressure adjusting means according to the brake fluid pressure control mode. On Kkubureki control device.

[0002]

2. Description of the Related Art It has been already known, for example, from JP-A-3-16866 or the like that a condition that the anti-lock brake control is started when the slip ratio exceeds a start determination threshold value.

[0003]

By the way, the threshold value for judging the start of the slip ratio, which determines the start of the antilock brake control, is sufficient to prevent excessive antilock brake control and decelerate the vehicle body at the beginning of the antilock brake control. Is generally set to be larger than the target slip ratio during execution of the antilock brake control, and the antilock brake control on a road surface having a low friction coefficient is likely to be delayed. Therefore, as disclosed in JP-A-63-265758, the pressure-reducing mode is maintained until a predetermined time elapses after the start of the antilock brake control, thereby achieving a smooth transition to the antilock brake control. However, due to the relatively weak brake input of the vehicle driver, it is not possible to cope with a case where the wheel speed increases before the predetermined time has elapsed, and the braking distance is increased. .

[0004] The present invention has been made in view of such circumstances, and has made it possible to exhibit a stable braking force irrespective of the level of the road surface friction coefficient, and to enable a smooth transition to antilock brake control. An object of the present invention is to provide an anti-lock brake control device for a vehicle.

[0005]

In order to achieve the above object, the present invention provides a wheel speed detecting means for detecting a wheel speed, and an estimation of a vehicle body speed based on the wheel speed obtained by the wheel speed detecting means. Determining whether anti-lock brake control should be started based on the vehicle speed estimating means to be performed, the wheel speed obtained by the wheel speed detecting means, and the estimated vehicle speed obtained by the vehicle speed estimating means. Control start determining means, and a wheel speed obtained by the wheel speed detecting means and a vehicle speed obtained by the vehicle body speed estimating means in response to the control start determining means determining that antilock brake control should be started. A control mode for setting the brake fluid pressure control mode based on the estimated vehicle speed and controlling the operation of the brake fluid pressure adjusting means according to the brake fluid pressure control mode The vehicle anti-lock brake control device comprising: a wheel acceleration detection means for detecting wheel acceleration based on the wheel speed obtained by the wheel speed detection means, the control mode determination means, the control start determination means in the control start determination means The control mode is configured to be maintained in the decompression mode until a predetermined time elapses after it is determined that the antilock brake control should be started or until the wheel acceleration obtained by the wheel acceleration detection means exceeds a predetermined value. It is characterized by being performed.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below based on one embodiment of the present invention shown in the accompanying drawings.

FIGS. 1 to 10 show an embodiment in which the present invention is applied to a motorcycle. FIG. 1 is an overall configuration diagram of a motorcycle braking device, and FIG. 2 is a block diagram showing a configuration of a control unit. FIGS. 3 and 4 are flowcharts showing a vehicle speed estimation procedure, FIG. 4 is a diagram for explaining a calculation process of an estimated vehicle speed based on wheel speeds, FIG. 5 is a block diagram showing a configuration of a front wheel control unit, and FIG. FIG. 7 is a flowchart showing a processing procedure in the mode determining means, FIG. 7 is a view showing a map for determining a control mode, and FIG. 8 is a diagram showing changes in actual vehicle speed, wheel speed and brake pressure when forced pressure reduction is performed at the start of antilock control. FIG. 9 is a timing chart at the time of anti-lock brake control on a road surface with a high friction coefficient, and FIG. 10 is an anti-lock brake control on a road surface with a low friction coefficient. Is a timing chart at the time of brake control.

First, in FIG. 1, a master cylinder 2 for outputting a hydraulic pressure in accordance with an operation of a brake lever 1 and a pair of left and right front wheel brakes B _F1 and B _F1 mounted on a front wheel of a motorcycle.
Between the B _F2, both the front wheel brake B _F1, the brake fluid pressure of the B _F2 adjustable brake fluid pressure adjusting means 3 _F are provided. The adjustment between the master cylinder 5 for outputting a hydraulic pressure corresponding to the operation of the brake pedal 4, between the rear wheel brake B _R, which is attached to a rear wheel of a motorcycle, the hydraulic pressure of the rear wheel brake B _R A possible brake fluid pressure adjusting means _3R is provided.

The brake fluid pressure adjusting means _3F includes a reservoir 6
And _F, both the front wheel brake B _F1, B _F2 and the normally and open solenoid valve 7 _F provided between the master cylinder 2, reservoir 6 _F and both the front wheel brake B _F1, the normally closed solenoid valve is provided between the B _F2 8 and _F, both the front wheel brake B _F1, and a check valve 9 _F brake fluid from the B _F2 side to the master cylinder 2 side are connected in parallel to tolerable normally open solenoid valve 7 _F that flows, the suction port through the suction valve 10 _F and a pump 11 _F return discharge ports is connected to the reservoir 6 _F is connected to the master cylinder 2 through the discharge valve 12 _F.

Further the brake fluid pressure adjusting means 3 _R, the reservoir 6 _R, normally open electromagnetic valve 7 _R, the normally closed electromagnetic valves 8 _R, check valve 9 _R, suction valve 10 _R, the return pump 11 _R and a discharge valve comprise 12 _R, configured similarly to the brake fluid pressure adjusting means 3 _F.

[0011] Moreover the pump 11 _F returns the brake fluid pressure adjusting means 3 _F, and the return pump 11 _R of the brake fluid pressure adjusting means 3 _R are driven by a common motor 13.

Brake fluid pressure adjusting means 3_FNormally open type in
Solenoid valve 7_FAnd normally closed solenoid valve 8_FAnd brake fluid pressure control
Adjusting means 3_RNormally open solenoid valve 7_RAnd normally closed electromagnetic
Valve 8 _RAnd the motor 13 are controlled by the control unit 14.
Is controlled. The control unit 14 is fixed to the front wheels.
Pulsar gear 15_FIs fixedly arranged facing the side of
Front wheel speed sensor 16_F, Pulsar fixed to the rear wheel
-Gear 15_RRear wheel car fixedly arranged facing the side of the car
Wheel speed sensor 16_RBrake switch for front wheel brake
17_FAnd rear wheel brake switch 17_ROutput signal
Are respectively input, and the control unit 14
Sensor 16_F, 16_RAnd switch 17_F, 17
_RThe normally-open solenoid valve 7 according to the output of_F, 7_R, Normally closed
Solenoid valve 8 _F, 8_RAnd the operation of the motor 13 is controlled.

[0013] In the control unit 14, will be described with reference to FIG. 2 the structure of a portion related to the anti-lock brake control, the control unit 14, front wheel corresponds to the brake fluid pressure adjusting means 3 _F for the front wheels Speed calculation means 20 _F , front wheel acceleration / deceleration calculation means 21 _F for front wheel as wheel acceleration calculation means, vehicle speed calculation means 22 for front wheels
Provided with a _F and the front wheel side control unit 23 _F, the rear-wheel brake fluid pressure adjusting means 3 wheel rear wheel corresponds to the _R speed calculating means 20 _R, wheel wheel acceleration and reduction after the wheel acceleration calculating means A speed calculating means 21 _R , a rear wheel body speed calculating means 22 _R and a rear wheel side control section 23 _R are provided, and the reference vehicle body as a vehicle body speed estimating means common to both brake fluid pressure adjusting means 3 _F and 3 _R. Speed setting means 24 is provided.

Thus, the front wheel side control unit 23_FThe system defined in
The control amount is the front wheel solenoid driving means 25._FIs entered in
Front wheel solenoid drive means 25_FFor the front wheels
Fluid pressure adjusting means 3_FNormally open solenoid valve 7_Fand
Normally closed solenoid valve 8_FIs driven to open and close, and the rear wheel side control unit 2
3_RIs controlled by the rear wheel solenoid driving means 2
5_RAnd the rear wheel solenoid driving means 25_R
Means for adjusting brake fluid pressure for rear wheels 3_RNormally open in
Type solenoid valve 7_RAnd normally closed solenoid valve 8_RIs driven to open and close,
Further, both brake fluid pressure adjusting means 3_F, 3_RCommon mode
Data 13 for executing anti-lock brake control.
The control amount is the front wheel side and rear wheel side control unit 23 _F, 23_RFrom
In response to the motor driving means 26, the motor
It is operated by the driving means 26.

The wheel speed calculating means 20 _F for the front wheels is for calculating a front wheel speed in response to an output signal of the front wheel speed sensor 16 _F, front wheel speed detecting means with a wheel speed sensor 16 _F for the front wheel Construct 19 _F. The rear wheel speed calculating means 20 _R is for calculating a rear wheel speed in response to an output signal of the rear-wheel wheel speed sensor 16 _R, the wheel for the rear wheel together with the wheel speed sensors 16 _R for rear wheel The speed detecting means _19R is constituted.

By the way, both wheel acceleration / deceleration calculating means 21
_F , 21 _R , both vehicle body speed calculating means 22 _F , 22 _R , and front wheel side and rear wheel side control units 23 _F , 23 _R have the same functions, respectively. Speed calculation means 21 _F , front wheel body speed calculation means 2
2 _F, only describes the front-wheel side control unit 23 _F, the description thereof is omitted for the rear wheel wheel acceleration or deceleration calculating means 21 _R, the rear wheel vehicle speed calculating means 22 _R and the rear wheel side control part 23 _R .

The front wheel acceleration / deceleration calculating means _21F includes:
It is intended to obtain a pressure or deceleration of the front wheel by differentiating the front wheel speed obtained in front wheel speed calculating means 20 _F in front wheel speed detecting means 19 _F.

The vehicle speed calculating section 22 _F is for the front wheels, front wheel speed detected by the front wheel speed detecting means 19 _F, and the front wheel acceleration or deceleration calculated by the front wheel acceleration or deceleration calculating means 21 _F An estimated vehicle speed for the front wheels is calculated based on the estimated vehicle speed based on the processing procedure shown in FIG.

[0019] In step S1 of FIG. 3, reads the front wheel speed detecting means 19 _F at the detected wheel speed VW and calculated in front wheel acceleration or deceleration calculating means 21 _F front wheel acceleration or deceleration dVW, In step S2, the flag F
Is determined to be "0", and when F = 0, the estimated vehicle speed VR is set to the front wheel speed VW in step S3, and the flag F is set to "1" in step S4. Steps S1 to S4 are processing steps at the start of the calculation of the estimated vehicle body speed. In the next calculation processing cycle, F =
Since it is 1, the process proceeds from step S2 to step S5.

In step S5, the current wheel speed VW
When it is determined whether or not (n) is equal to or less than the previous estimated vehicle speed VR (n-1), that is, whether the front wheel speed is in a constant speed or deceleration process, Proceeding to step S6, it is determined whether or not dVW ≦ α1, that is, the deceleration of the front wheel speed is equal to the set deceleration α1.
(For example, -1 G) or more. Thus, when VW (n) ≦ VR (n−1), that is, when it can be determined that the front wheel speed is in a constant speed or in a deceleration process, the process proceeds to step S6, and the flag Fα2 is set to “0”. In step S7, it is determined whether or not Fα1 = 1. This flag Fα1 becomes “1” when the acceleration / deceleration is set to the set deceleration α1 in the deceleration process. Since Fα1 = 0 in the first processing cycle, the process proceeds from step S7 to step S8.

In step S8, it is determined whether or not dVW ≦ α1, that is, whether or not the deceleration of the front wheel speed is equal to or greater than the set deceleration α1. If dVW ≦ α1, the acceleration / deceleration α is set to the set deceleration α1 in step S9, the flag Fα1 is set to “1” in step S10, and the process proceeds to step S11.

In step S11, the estimated vehicle speed VR is calculated, and the previous estimated vehicle speed is calculated as VR (n
-1), and the time of the arithmetic processing cycle is ΔT (for example, 3
m), the current estimated vehicle speed VR (n) is calculated as VR (n) = VR (n−1) + α · ΔT.

When it is determined in step S8 that dVW> α1, the acceleration / deceleration α is set to the front wheel acceleration / deceleration dVW in step S12, and the process proceeds to step S11. Further, in step S7, Fα1 When it is determined that = 1, the process proceeds from step S7 to step S11. That is, in the deceleration process of the front wheel speed, when the front wheel acceleration / deceleration dVW becomes equal to or more than the set deceleration α1, the set deceleration α1 is set in the subsequent deceleration process.
It is assumed that the vehicle speed is decreasing at
Is calculated.

When it is determined in step S5 that VW (n)> VR (n-1), that is, when it is determined that the front wheel speed is in the process of increasing the speed, steps S5 to S13 are performed.
After setting the flag Fα1 = 0 in step S13, it is determined in step S14 whether the flag Fα2 = 1. This flag Fα2 becomes “1” when the acceleration / deceleration is set to the set acceleration α2 in the speed increasing process.
Since Fα2 = 0 in the first processing cycle of the speed increasing process, the process proceeds from step S14 to step S1.
In step S15, it is determined whether dVW ≧ α2, that is, the acceleration of the front wheel speed is equal to the set acceleration α.
It is determined whether it is two or more. If dVW ≧ α2, the acceleration / deceleration α is set to the set acceleration α2 in step S16, and after setting the flag Fα2 = 1 in step S17, the process proceeds to step S11. If dVW <α2, the acceleration / deceleration α is set to the front wheel acceleration / deceleration dVW in step S18, and the process proceeds to step S11. If it is determined that Fα2 = 1 in step S14, the process proceeds to step S11. become.
That is, in the process of increasing the front wheel speed, the front wheel acceleration / deceleration d
When VW becomes equal to or greater than the set acceleration α2,
In the subsequent speed increasing process, the estimated vehicle speed VR is calculated assuming that the vehicle speed is increasing at the set acceleration α2.

Such a front wheel body speed calculating means 22 _F
According to the above calculation, the estimated vehicle speed is as shown in FIG. 4. In the process of decelerating the front wheel speed, the estimated vehicle speed VR using the deceleration of the front wheel speed is set so that the deceleration does not exceed the set deceleration α1. In the process of increasing the front wheel speed, the estimated vehicle speed VR using the acceleration of the front wheel speed is calculated so that the acceleration does not exceed the set acceleration α2.

The set acceleration α2 is, for example, +1 G
However, it may be set to a larger value during the antilock brake control, or may be changed according to the vehicle body deceleration.

The reference vehicle speed setting means 24, based on the wheel estimated vehicle speed after calculating front wheel estimated vehicle speed calculated by the vehicle speed calculating means 22 _F for the front wheels, and the vehicle speed calculating means 22 _R for the rear wheels , front and rear wheels is for setting the estimated vehicle speed as a reference for determining the slip rate of, for example, front-wheel estimated vehicle speed calculated by the vehicle speed calculating means 22 _F for the front wheels, and rear wheel vehicle speed calculating means 22 sets high select value of the wheel estimated vehicle speed after calculated in _R as the estimated vehicle speed criterion.

The front-wheel side control unit 23 _F is the front wheel speed detected by the front wheel speed detecting means 19 _F, the front wheel acceleration or deceleration obtained in front wheel acceleration or deceleration calculating means 21 _F, and the reference vehicle body The brake fluid pressure control amounts of the front wheel brakes B _F1 and B _F2 are determined based on the estimated vehicle speed obtained by the speed setting means 24, and are configured as shown in FIG.

In FIG. 5, the front wheel control unit _23F includes a slip ratio calculating unit 28 and a target slip ratio calculating unit 29.
And a deviation calculation unit 30, a control start determination unit 31, a friction coefficient determination unit 32, a PID calculation unit 33, and a control mode determination unit 34.

The slip rate calculating means 28, the detected wheel speed front wheel speed detecting means 19 _F, and based on the estimated vehicle speed obtained by the reference vehicle body speed setting means 24 calculates the front wheel slip ratio Things. That is, the slip ratio is SR, the estimated vehicle speed is VR, and the front wheel speed is V
When W is set, the slip ratio SR is calculated by the slip ratio calculator 28 as SR = (VR−VW) / VR.

In the target slip rate setting means 29, based on the estimated vehicle speed obtained by the reference vehicle speed setting means 24, a target slip rate when traveling at the estimated vehicle speed is set as a target slip rate SRobj. .

The deviation calculating means 30 calculates a deviation ΔS (= SRobj-SR) between the target slip rate SRobj set by the target slip rate setting means 29 and the slip rate SR calculated by the slip rate calculating means 28. You.

The control start judging means 31 determines whether the slip rate calculated by the slip rate calculating means 28 exceeds a start judgment threshold value determined as a function of the estimated vehicle speed obtained by the reference vehicle speed setting means 24. It is determined that the antilock brake control should be started, and the function may be changed according to the level of the road surface friction coefficient, or may be changed depending on whether the road is rough or not. .

[0034] The friction coefficient judging means 32, the estimated vehicle speed obtained by the reference vehicle body speed setting means 24, and has a front wheel speed obtained in front wheel speed detecting means 19 _F is inputted, the coefficient of friction determination The means 32 determines the friction coefficient of the road surface by comparing the vehicle deceleration calculated based on the estimated vehicle speed and the front wheel speed with a preset value.

In the PID calculation means 33, the deviation calculation means 3
The following PID calculation is performed based on the deviation ΔS obtained at 0, and the PID calculation value Kpid as the calculation result is
It is obtained by the ID calculation means 33.

Kpid = Kp × ΔS + Ki × ΣΔS + Kd
× ｛ΔS (n−3) −ΔS (n)｝ That is, the PID calculating means 33 performs a proportional operation of multiplying the deviation ΔS by a gain constant Kp, an integral operation of multiplying the product sum of the deviation ΔSＳΔS by a gain constant Ki, The deviation ΔS (n−3) before the time (for example, three times before) and the current deviation ΔS
A differential operation of multiplying the difference of (n) by a gain constant Kd and an addition operation of those operation values are performed.

The control mode determining means 34, the wheel acceleration or deceleration obtained in front wheel acceleration or deceleration calculating means 21 _F,
The judgment result of the control start judgment means 31 and the friction coefficient judgment means 3
2 and the output of the PID calculating means 33 are input, and the control mode determining means 34 determines the control mode based on the input data in a procedure as shown in FIG.

In FIG. 6, in step S101, it is determined whether or not the anti-lock brake control is being performed. If the anti-lock brake control is being performed, the process proceeds to step S102. It is determined whether it is determined that the brake control should be started. When the antilock brake control should not be started, the timer is cleared in step S103.

When it is determined in step S101 that the anti-lock brake control is being executed, or when it is confirmed in step S102 that the anti-lock brake control should be started by the control start determining means 31, In step S104, the control mode is determined.

In deciding this control mode, PI
The PID operation value Kpid input from the D operation means 33 is compared with threshold values K ₁ and K ₂ on a preset map, and the map is set as shown in FIG. In this map, the areas of the pressure reduction mode, the holding mode, and the pressure increase mode determined by the threshold values K ₁ and K _{2 that} change according to the estimated vehicle speed obtained by the reference vehicle speed setting means 24 are determined by the road surface determined by the friction coefficient determination means 32. Are prepared in accordance with the friction coefficient determination result. Further, the threshold values K ₁ and K ₂ are changed depending on whether the wheel speed is decelerating or accelerating. When the wheel speed is decelerating, as shown by the broken line in FIG. ₁ , K
_{While 2} is set, when the wheel is accelerating, K ₁ and K ₂ are set as shown by the solid lines in FIG. That is, the threshold values K ₁ and K ₂ are set slightly larger when the wheel speed is decelerating than when the wheel speed is accelerating.

[0041] Based on this map, when the Kpid ≦ K ₁ pressure reduction mode is selected, when the K ₁ <Kpid ≦ K ₂ holding mode is selected, the pressure increase mode is selected when more of K ₂ <Kpid Will be. In Thus to pressure reduction mode, the brake fluid pressure adjusting means 3 _F, normally closed solenoid valve 8 _F is the valve opening control with a predetermined duty with closed normally open electromagnetic valve 7 _F, in the holding mode the normally open type solenoid valve 7 _F and the normally closed solenoid valve 8 _F is closed together, yet the pressure increasing mode normally open electromagnetic valve 7 _F valve opening control with a predetermined duty with closed normally closed solenoid valve 8 _F Is done.

In step S105 after the control mode is set in step S104, the timer is incremented by "1", and in the next step S106, it is determined whether or not the count value T of the timer has become equal to or longer than a predetermined time T1. I do.
When T ≧ T1, the process proceeds from step S106 to S107, and the control mode determined in step S104 is output.

If it is determined in step S106 that T <T1, the process proceeds from step S106 to step S1.
Proceeds to 08, setting the acceleration α of the wheel acceleration or deceleration dVW obtained in front wheel acceleration or deceleration calculating means 21 _F predetermined
Then, if dVW ≦ α3, the control mode is forcibly set to the pressure reduction mode in step S109, and the pressure reduction mode is output in step S107.

On the other hand, when it is determined in step S106 that dVW> α3, the count value of the timer is forcibly set to T1 in step S110, and step S107 is performed.
Will go on.

According to the control mode determining means 34, the predetermined time T1 from the start of the antilock brake control
Is maintained until the wheel acceleration does not exceed the set acceleration α3. If the wheel acceleration exceeds the set acceleration α3 before the predetermined time T1 elapses, the decompression mode is forcibly performed at that time. The maintenance of the decompression mode ends.

Next, the operation of this embodiment will be described. When the antilock brake control is started based on the change in the wheel speed as shown by the solid line in FIG. 8A, the control mode is changed to the solid line in FIG. As a result, the pressure reduction mode is forcibly set as shown in FIG. 8, and the brake pressure changes as shown by the solid line in FIG. On the other hand, as shown by the broken line in FIG. 8B, the wheel speed and the brake pressure of the conventional one in which the control mode is the holding mode at the start of the antilock brake control are the broken line in FIGS. 8A and 8C. It will change as shown by. Thus, as apparent from FIG. 8A, the braking distance of the present invention can be shorter than that of the conventional one.

When the anti-lock brake control is performed when the friction coefficient of the road surface is relatively high, the wheel speed is set to the value shown in FIG.
(A), the wheel acceleration / deceleration changes as shown in FIG. 9 (b), the control mode changes as shown in FIG. 9 (c), and the count value of the timer changes as shown in FIG. 9 (d). The control mode is forcibly set to the depressurization mode in accordance with the above. However, the timing at which the wheel acceleration / deceleration exceeds the set acceleration α3 is relatively early based on the relatively high friction coefficient of the traveling road surface. pressure decreasing mode at the time t ₁ before the predetermined time T1 from when the brake control start has elapsed is completed.

During antilock brake control when the coefficient of friction of the road surface is relatively low, the wheel speed is set to the value shown in FIG.
(A), the wheel acceleration / deceleration changes as shown in FIG. 10 (b), the control mode changes as shown in FIG. 10 (c), and the count value of the timer changes as shown in FIG. 10 (d). The control mode is forcibly set to the depressurizing mode in accordance with the condition, but the timing at which the wheel acceleration / deceleration exceeds the set acceleration α3 is relatively late based on the relatively low coefficient of friction of the traveling road surface. vacuum mode from the start of control at time t ₂ when the predetermined time T1 has elapsed is completed.

That is, when the friction coefficient of the road surface is relatively high, the decompression mode is terminated when the wheel acceleration / deceleration exceeds the set acceleration α3 in consideration of the relatively quick recovery of the wheel speed. When the friction coefficient is relatively low, the pressure reduction mode ends when a predetermined time T1 has elapsed from the start of the anti-lock brake control in consideration of the relatively slow recovery of the wheel speed. Regardless of the height of the vehicle, a stable braking force can be exhibited.

Although the embodiments of the present invention have been described in detail, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the appended claims. It is possible to do.

For example, the present invention is applicable not only to motorcycles but also to four-wheel passenger vehicles.

[0052]

As described above, according to the present invention, the value obtained by the control start determining means until the predetermined time elapses after the antilock brake control is determined to be started, or by the wheel acceleration detecting means. Until the wheel acceleration exceeds a predetermined value, the control mode is maintained in the depressurizing mode, so that stable braking force can be exerted regardless of the level of road surface friction coefficient, and a smooth transition to antilock brake control Becomes possible.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a brake device of a motorcycle.

FIG. 2 is a block diagram illustrating a configuration of a control unit.

FIG. 3 is a flowchart illustrating a vehicle speed estimation procedure.

FIG. 4 is a diagram for explaining a calculation process of an estimated vehicle body speed based on a wheel speed.

FIG. 5 is a block diagram illustrating a configuration of a front wheel control unit.

FIG. 6 is a flowchart showing a processing procedure in a control mode determining means.

FIG. 7 is a diagram showing a map for determining a control mode.

FIG. 8 is a diagram illustrating a case where changes in the actual vehicle speed, wheel speed, and brake pressure are not corrected when forced pressure reduction is performed at the start of antilock control.

FIG. 9 is a timing chart at the time of antilock brake control on a road surface having a high friction coefficient.

FIG. 10 is a timing chart at the time of antilock brake control on a road surface having a low friction coefficient.

[Explanation of symbols]

3 _F, 3 _R ... brake fluid pressure adjusting means 19 _F, 19 _R ... wheel speed detecting means 21 _F, 21 _R ... wheel acceleration wheel acceleration or deceleration calculating means 24 ... as an arithmetic means Reference vehicle speed setting means as vehicle speed estimating means 31 Control start determining means 34 Control mode determining means

Claims (1)

[Claims] 1. A wheel speed detecting means for detecting a wheel speed (19 _F, 19 _R), the wheel speed detecting means (19 _F,
A vehicle body speed estimating means (24) for estimating the vehicle speed based on the wheel speed obtained in 19 _R), the wheel speed detecting means (19 _F, 19 _R) obtained in the wheel speed and the vehicle speed estimating means Control start determining means (31) for determining whether or not antilock brake control should be started based on the estimated vehicle speed obtained in (24); and determining that antilock brake control should be started. The wheel speed obtained by the wheel speed detecting means ( _19F , _19R ) and the estimated vehicle speed obtained by the vehicle speed estimating means (24) in response to the determination by the control start determining means (31). Bei brake fluid brake fluid pressure adjusting means in accordance with the control mode of the pressure (3 _F, 3 _R) control mode determining means for controlling the operation of the (34) sets the control mode of the brake fluid pressure based That the anti-lock brake control apparatus for a vehicle, comprising a wheel acceleration detecting means (21 _F, 21 _R) for detecting a wheel acceleration based on the wheel speed obtained by the wheel speed detection means (19 _F, 19 _R), the control The mode determining means (34) determines whether the anti-lock brake control should be started by the control start determining means (31) until a predetermined time has elapsed, or the wheel acceleration detecting means (21 _F , 21 _R ). An anti-lock brake control device for a vehicle, characterized in that the control mode is maintained in the pressure reduction mode until the wheel acceleration obtained in (1) exceeds a predetermined value.