JPH06144195A - Anti-lock control device for vehicle - Google Patents

Abstract

PURPOSE:To quickly converge the wheel speed to the target wheel speed and improve the responsiveness in the anti-lock control device of a vehicle controlling the action of an actuator to reduce the braking force when a wheel tends to be locked at the time of braking. CONSTITUTION:The control region is judged by a control region judging means 46 based on the comparison between the judging reference wheel speed based on the target wheel speed and the wheel speed. In the region where the wheel speed exceeds the judging reference wheel speed, the output of the first control quantity arithmetic means 47 determining the action control quantity of an actuator via the PID calculation based on the deviation between the wheel speed and the target wheel speed is used as the action control quantity. In the region where the wheel speed is below the judging reference wheel speed, the output of the second control quantity arithmetic means 49 determining the action control quantity of the actuator based on the acceleration/deceleration of the wheel is used as the action control quantity. Outputs of both control quantity arithmetic means 47, 49 are switched by a switching means 50.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises an actuator capable of adjusting the braking force of a wheel brake and, when the wheel is about to lock during braking, controls the operation of the actuator to reduce the braking force of a vehicle. TECHNICAL FIELD The present invention relates to a control device, and more particularly to a vehicle antilock control device for controlling a braking force of a wheel brake based on a comparison result of a wheel speed and a target wheel speed set by adding a predetermined slip ratio to a vehicle speed. .

[0002]

2. Description of the Related Art Conventionally, such an antilock control device is
For example, it is already known from JP-A-1-202566.

[0003]

By the way, in the above-mentioned conventional device, the braking force is adjusted by controlling the operation of the actuator based on the comparison result of the wheel speed and the target wheel speed during the antilock control. However, when the deviation between the wheel speed and the target wheel speed becomes large,
It takes a relatively long time for the wheel speed to converge to the target wheel speed, which causes a problem in responsiveness.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an anti-lock control device for a vehicle in which the wheel speed is quickly converged to the target wheel speed to improve the responsiveness. .

[0005]

In order to achieve the above object, the device of the present invention comprises a wheel speed detector for detecting a wheel speed, a vehicle speed detecting means for detecting a vehicle speed, and a predetermined slip for the vehicle speed. Based on the deviation between the wheel speed and the target wheel speed, target wheel speed setting means for setting the target wheel speed in consideration of the ratio, acceleration / deceleration calculating means for differentiating the wheel speed to obtain wheel acceleration / deceleration. First control amount calculation means for executing a PID calculation and determining an operation control amount of the actuator based on the PID calculation result, and second control amount calculation means for determining an operation control amount of the actuator based on wheel acceleration / deceleration. A control area determination means for determining a control area based on a comparison between a determination reference wheel speed set based on the target wheel speed and the wheel speed, and a wheel speed determined by the control area determination means. When it is determined that is a region that exceeds the determination reference wheel speed, a state in which the operation control amount is output from the first control amount calculation means, and when it is determined that the wheel speed is a region that is equal to or less than the determination reference wheel speed. And switching means for switching the state of outputting the operation control amount from the second control amount calculation means, and drive means for operating the actuator in accordance with the operation control amount from the switching means.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

1 to 16 show one embodiment of the present invention, FIG. 1 is a diagram showing a braking system of a vehicle, FIG. 2 is a diagram showing a configuration of a braking hydraulic circuit, and FIG. 3 is a control unit. 4 is a block diagram showing the set value of the braking pressure request value, FIG. 5 is a block diagram showing the structure of the left front wheel control unit, FIG. 6 is a diagram showing the set value of the target wheel speed, and FIG. 8 is a diagram showing a reference braking pressure setting map, FIG. 8 is a diagram showing a friction coefficient region determination map, FIG. 9 is a diagram for explaining a friction coefficient region determination procedure when antilock control is continued, and FIG. 10 is a control region determination. FIG. 11 is a diagram for explaining conditions, FIG. 11 is a diagram showing setting correction values according to wheel acceleration / deceleration, FIG. 12 is a flowchart showing a part of a main routine of antilock control processing, and FIG.
3 is a flowchart showing the remaining part of the main routine of the antilock control process, FIG. 14 is a flowchart showing a part of a subroutine for friction coefficient region determination and gain constant setting, and FIG. 15 is for friction coefficient region determination and gain constant setting. 16 is a flowchart showing the remaining part of the subroutine, and FIG. 16 is a flowchart showing the processing procedure at the end of the antilock control.

First, referring to FIG. 1, an engine and a transmission are shown.
The power from the power unit 11 including
Left, right front wheel W_FL, W_FRTransmitted to these front wheels W_FL，
W_FRThe wheel brake B_FL, B_FRAre installed respectively
And wheel speed detector 12 _FL, 12_FRWith each
Set up. The left and right rear wheels W that are driven wheels_RL, W_RRTo
Is the wheel brake B_RL, B_RRWhen each is installed
Muni wheel speed detector 12_RL, 12_RRAre attached respectively
It Thus, each wheel brake B_FL, B_FR, B_RL, B_RR
A braking hydraulic pressure is applied from the braking hydraulic pressure circuit 16 to the.

In FIG. 2, the braking fluid pressure circuit 16 has a left front
Wheel brake B_FLWith an actuator that can adjust the braking force of
Modulator 17_FLAnd right front wheel brake B_FRControl
Modulator as an actuator whose power can be adjusted
17_FRAnd the left rear wheel brake B _RLThe braking force of
Modulator 17 as a actuator_RLAnd the right rear wheel
Rake B_RRAs an actuator that can adjust the braking force of
Modulator 17_RRAnd each modulator 17_FL, 17
_FR, 17_RL, 17_RRAnd a hydraulic pressure source 18 common to

The hydraulic pressure source 18 includes a hydraulic pump 20 for pumping hydraulic oil from a hydraulic fluid tank 19, an accumulator 21 connected to the hydraulic pump 20, and a pressure for controlling the operation of the hydraulic pump 20. And a switch 22.

Each modulator 17 _FL , 17 _FR , 17 _RL ,
The 17 _RRs are arranged in parallel to each other in a common housing 25, and their modulators 17 _FL , 1
Since 7 _FR , 17 _RL , and 17 _RR have basically the same configuration, only the modulator 17 _FL will be described below in detail, and detailed description of the modulators 17 _FR , 17 _RL , and 17 _RR will be omitted.

In the housing 25, an input port 26 connected to the hydraulic pressure source 18, a release port 27 communicating with the hydraulic fluid tank 19, and brakes B _FL , B _FR , B _RL and B _RR are individually connected. 4 output ports 28 _FL , 28
_FR , 28 _RL , and 28 _RR are provided.

The modulator 17 _FL includes a spool 29 slidably fitted in the housing 25, and the spool 29.
And a linear solenoid 23 _FL attached to the housing 25 so as to push the linear solenoid 23 in the axial direction.
The drive rod 31 of the _FL is coaxially contacted with one end of the spool 29, and an output chamber 30 is formed in the housing 25 so as to face the other end surface of the spool 29. Moreover, the output chamber 30 communicates with the output port 28 _FL , and the return spring 32 that biases the spool 29 toward the linear solenoid 23 _FL is housed in the output chamber 30. Therefore, the spool 29
Comes into constant contact with the drive rod 31 due to the spring force of the return spring 32, and the spool 29 and the linear solenoid 23 _FL are interlocked and connected.

The housing 25 is provided with a cylinder hole 33 into which the spool 29 is slidably fitted, and an inner surface of the cylinder hole 33 communicates with an annular groove 34 communicating with the input port 26 and a release port 27. The annular groove 35 is provided at a position spaced apart in the axial direction. Also spool 2
The outer surface of 9 is provided with an annular recess 36 that is in constant communication with the output chamber 30. Thus, the spool 29 is in a state where the annular recess 36 is in communication with the annular groove 34 and the input port 26 is in communication with the output chamber 30, that is, the output port 28 _FL , and the annular recess 36 is in communication with the annular groove 35. The state in which 30 and the release port 27 are communicated is changed according to the axial position change due to the magnitude relationship between the thrust of the linear solenoid 23 _FL acting on one axial end and the hydraulic pressure of the output chamber 30 acting on the other axial end. It is something to switch.

By the way, the linear solenoid 23 _FL generates a thrust force according to its input electric quantity, and the hydraulic pressure of the output chamber 30, that is, the hydraulic pressure applied from the output port 28 _FL to the left front wheel brake B _FL is Linear solenoid 23 _FL
It is possible to arbitrarily control by controlling the energizing power amount of.

Another modulator 17_FR, 17_RL, 17_RR
Also for the modulator 17 _FLAs well as linear
Solenoid 23_FR, 23_RL, 23_RRControl the energizing power of
By doing the wheel brake B_FR, B_RL, B_RRAct on
It is possible to control the liquid pressure.

Again referring to FIG. 1, the antilock control is implemented.
The control unit 10 for operating the wheel speed detector
12_FL, 12_FR, 12_RL, 12_RR, And brake pedal
Detects the pedaling force acting on the dull 14, that is, the braking operation force
Braking operation force detector 13 is connected, anti-lock
In controlling, those detectors 12_FL, 12_FR, 1
Two_RL, 12_RR, 13 according to the detected value
17_FL, 17_FR, 17 _RL, 17_RRLinear Soleno at
Id 23_FL, 23_FR, 23_RL, 23_RRPower consumption of
It is controlled by the control unit 10.
The configuration of the unit 10 will be described.

In FIG. 3, the control unit 10 for executing anti-lock control has a braking pressure request value P _TF for the front wheels and a braking pressure request value P _{TR for the} rear wheels according to the detection value of the braking operation force detector 13. And the front left wheel speed V detected by the front left wheel speed detector 12 _FL.
WFL , right front wheel speed V _WFR detected by right front wheel wheel speed detector 12 _FR , left rear wheel speed V _WRL detected by left rear wheel wheel speed detector 12 _RL , right rear wheel wheel speed detector 12 _RR
The left front wheel control unit for individually controlling the operation of the linear solenoids 23 _FL , 23 _FR based on the left rear wheel speed V _WRR detected by the above and the front wheel braking pressure request value P _TF set by the request value setting means 38. 39 _FL and right front wheel control section 39 _FR ,
A left rear wheel control unit 39 _RL that individually controls the operation of the linear solenoids 23 _RL , 23 _RR based on the wheel speeds V _WFL , V _WFR , V _WRL , V _WRR and the braking pressure required value P _TR of the rear wheels. And a right rear wheel control unit 39 _RR .

As shown in FIG. 4, the required value determining means 38 presets the required braking pressure value P _{TF for} the front wheels and the required braking pressure value P _{TR for the} rear wheels in accordance with the braking operation force. The braking pressure required value P _{TR of the} rear wheels is set lower than the braking pressure required value P _TF of the front wheels at a certain braking operation force or more.

Left front wheel control unit 39 _FL , right front wheel control unit 3
The configurations of the 9 _FR , the left rear wheel control unit 39 _RL, and the right rear wheel control unit 39 _RR are basically the same, and hereinafter, the left front wheel control unit 39 _FL.
The configuration of will be described.

In FIG. 5, the left front wheel control unit 39_FLIs each
Wheel speed V_WFL, V_WFR, V_WRL, V_WRRBased on car
Body speed V_VBody speed detecting means 40 for detecting the
Degree V _VTarget wheel speed V by adding a predetermined slip ratio to_R
Target wheel speed setting means 41 for setting
_WFLAcceleration / deceleration calculation to differentiate the wheel to obtain the wheel acceleration / deceleration α
Means 42 and the braking pressure at the start of the antilock control of the wheels.
The wheel acceleration / deceleration as an index representing the locking tendency
The reference braking pressure P is corrected according to α._BRReference braking pressure
Friction between the setting means 43 and the road surface at the start of antilock control
A first friction coefficient region determining means 44 for determining a coefficient region,
Judgment of the friction coefficient area of the road surface during anti-lock control
Second friction coefficient region determining means 45, and the target wheel speed
V_RAnd left front wheel speed V_FLDetermine the control area based on
Control area determining means 46 and left front wheel speed V_WFL, Standard system
Dynamic pressure P_BR, First and second friction coefficient region determination means 44,
45 determination result and target wheel speed V_RBased on
Control amount P_Y1The first control amount calculation means 47 that determines the
.Correction value setting procedure for setting correction value D based on deceleration α
It is obtained by the step 48, the correction value D, and the first control amount calculation means 47.
Actuated control amount P _Y1And the determination of the control area determination means 46
Actuation control amount P according to the fixed result_Y2Second control amount calculation that determines
Means 49 and first and second controlled variable calculating means 47, 49
The operation control amount P obtained by_Y1, P_Y2Control one side
The control amount P is selected according to the determination result of the region determination means 46.
_YOutput from the switching means 50, and from the switching means 50
Control amount P_YAnd the required value P from the required value setting means 38
_TFLow-select hand to select whichever is lower
The step 51 and the control amount obtained by the row select means 51
Based on the linear solenoid 23_FLDriving hand that activates
And step 52.

The vehicle speed detecting means 40, the left front wheel speed detector 12 and the wheel speed V _{WF L} detected by the _FL, the wheel speed V _WFL ~V detected by the wheel speed detectors 12 _FL to 12 _FR
The highest value of _WRR is estimated as the vehicle body speed V _V by using the highest value of the outermost wheel speed during turning as a target wheel and the speed obtained by performing the turning correction to reduce the difference between the left front wheel speed V _WFL and the target wheel. Even if the target wheel has a tendency to lock and the wheel speed V _WFL of the target wheel, that is, the left front wheel, tends to decrease, it is based on the wheel rotation speeds of the wheels other than the target wheel that are in the non-locking tendency and the turning correction is performed. By using the speed that has been applied as the estimated vehicle body speed V _V , it is possible to improve the vehicle body speed estimation accuracy during antilock control.

In the target wheel speed setting means 41, the vehicle speed
Vehicle speed V obtained by the detection means 40 _VPredetermined slip on
By adding the rate, as shown in FIG.
Speed V_RIs set. In addition, the acceleration / deceleration calculation means 42
Is the left front wheel speed detector 12_FLWheel speed V obtained in_WFL
By differentiating, the wheel acceleration / deceleration α is obtained.

The reference braking pressure setting means 43 determines the reference braking pressure P _BR by correcting the braking pressure at the start of the antilock control according to the wheel acceleration / deceleration α at that time.
The output signal of the drive means 52 is a signal representative of the wheel acceleration / deceleration α obtained by the deceleration calculation means 42 and the braking pressure at the start of the antilock control.
Entered in. Thus, as shown in FIG. 7, the reference braking pressure P _BR corresponding to the plurality of braking pressures P _{A1 to} P _A6 is preset according to the wheel acceleration / deceleration α, and the reference braking pressure setting means 43 is provided. Outputs the reference braking pressure P _BR at the start of the antilock control.

The first friction coefficient determining means 44 determines which of a plurality of friction coefficient regions is set in advance according to the reference braking pressure P _BR at the start of the antilock control. As shown in, the μ1 region, which is a low friction coefficient region when P _BR ≦ P _B1 , the μ2 region which is a medium friction coefficient region when P _B1 <P _BR ≦ P _B2 , and P _B2 <P _BR . The μ3 region, which is the high friction coefficient region at that time, is preset, and the result of determining which of μ1, μ2, and μ3 regions is in accordance with the reference braking pressure P _BR is from the first friction coefficient determining means 44. Is output.

The second friction coefficient determining means 45 determines the friction coefficient area of the road surface on which the antilock control is continued based on the determination result of the first friction coefficient determining means 44, the vehicle body speed V _V and the left front wheel speed V _WFL. is intended, the coefficient of friction determination speed V _M that defines on the basis of the vehicle speed V _V based on the time exceeds the wheel speeds V _WFL, can change the coefficient of friction region definite during anti-lock control is started. Thus, the friction coefficient determination speed V _M can be calculated from the vehicle body speed V _V by (10 k
m / h) is subtracted, and V _WFL is set.
＞ V _M Start time counting and V _M ≧ V _WFL
Stop time counting with.

In determining the friction coefficient region by the time count, three determination count values T _M1 , T _M2 , T
_{When M3} (T _M1 <T _M2 <T _M3 ) is set and the time count value T is less than T _M1 (T <T _M1 ), it is determined that the friction coefficient region is lower. That is, when it is in the μ2 region, it is set as the μ1 region, when it is in the μ3 region, it is set as the μ2 region, and when it is in the μ1 region, it is held as it is.

When the time count value T is T _M1 or more and less than T _M2 (T _M1 ≤T <T _M2 ), the friction coefficient region is held as it is. That is, the μ1 region, μ2 region, and μ3 region are held as they are.

When the time count value T is T _M2 or more and T _M3
When it is less than (T _M2 ≦ T <T _M3 ), it is determined to be in a higher friction coefficient region. That is, when it is in the μ1 area, it is in the μ2 area, and when it is in the μ2 area, it is μ
There are three regions, and when the μ3 region is reached, it is held as it is.

Further, the time count value T is T _M3 or more (T _M3
When ≦ T), it is determined to be in the high friction coefficient region. That is, it is determined to be in the μ3 region.

For example, as shown in FIG. 9, the wheel speed V_WFL
When time t changes₁, T₃, T₇At each time
Time counting starts and time t₂, T₆, T₁₁
The time count ends with
T is T_M1Count end time t that is less than₂Then lower
It is determined that the friction coefficient is in the friction coefficient region, and the time count T is T _M1
Time t which is above_Four, T₈The friction coefficient region is retained
And the time count T is T _M2Time t which is above_Five, T₉so
Is determined to be in the higher friction coefficient region and
To T is T_M3Time t which is above_TenThen, in the high friction coefficient region
Will be determined.

The control area determining means 46 determines the control area based on the target wheel speed V _R obtained by the target wheel speed setting means 41 and the left front wheel speed V _FL obtained by the left front wheel speed detector 12 _FL. And as shown in FIG.
The first and second determination reference wheel speeds V _C1 and V _C2 are preset. Thus, the first judgment reference wheel speed V _C1 is a value obtained by subtracting (5 km / h) from the target wheel speed V _R , and the second judgment reference wheel speed V _C2 is _calculated from the target wheel speed V _R. For example, it is a value obtained by subtracting (10 km / h). Then, by comparing the left front wheel speed V _FL with the first and second determination reference wheel speeds V _C1 , V _C2 , the following three control regions a, b, c are set.

Control region a; V _WFL > V _C1 control region b; V _C1 ≧ V _WFL > V _C2 control region c; V _WFL <V _C2 Such control regions a, b, c are left front wheel speed V _WFL Is set in accordance with the degree of deviation from the target wheel speed V _R , the control region a is a region relatively close to the target wheel speed V _R , and the control region b is relatively far from the target wheel speed V _R. The region and the control region c are set as regions further apart from the target wheel speed V _R.

The first control amount calculation means 47 is based on the judgment results by the first and second friction coefficient region judgment means 44 and 45, the left front wheel speed V _WFL and the target wheel speed V _R.
A PID calculation circuit 54 for calculating the D calculation amount P _PID and a subtraction circuit 55 for subtracting the PID control amount P _PID from the reference braking pressure P _BR to obtain the operation control amount P _Y1 .

In the PID calculation circuit 54, the PID control amount P
_{The PID} is calculated based on the following formula (1).

P _{PID (k)} = K _P × P _(k) + K _I × I _(k) + K _D × D _(k) (1) where P _(k) = V _{WFL (k)} −V _{R (k)} I _(k) = P _(k) -I _(k-1) D _(k) = P _(k) -P _(k-1) . The subscript _(k) indicates the current value, the subscript _(k-1) indicates the previous value, and K _P , K _I , and K _D are gain constants determined by the friction coefficient region as shown in Table 1.
Moreover, when the control area determination means 46 determines that the control area is other than the control area a, that is, b, c, P _(k) ,
When D _(k) is cleared, PI in the next control area a
I _(k) is held in preparation for D control.

[0037]

[Table 1]

In the subtraction circuit 55, {P _Y1 = P _{BR (k)} -P
_{PID (k)} } is executed, and the operation control amount P _Y1 is input from the subtraction circuit 55 to the switching means 50.

In the correction value setting means 48, according to the wheel acceleration / deceleration α obtained by the acceleration / deceleration calculation means 42, as shown in FIG.
A correction value D set in advance is set as indicated by.

In the second control amount calculation means 49, the control area b
Alternatively, it is determined that the control area is the control area c.
Is determined, the following calculation is executed according to those control areas b and c.

Control region b; P _Y2 = P ₁₀ -D _{I (k)} Control region c; P _Y2 = P ₂₀ -D _{I (k)} where P ₁₀ is when shifting from control region a to control region b Is a final control amount in the control region a, and P ₂₀ is a final control amount in the control region b when the control region b is shifted to the control region c. D _{I (k)} is D _{I (k)} = D _(k) + D
_{I (k-1),} which is the integrated value of the correction value D. Further, D _{I (k)} is cleared when a transition between the control areas b and c occurs.

The operation control amount P _Y2 obtained by the second control amount calculation means 49 is input to the switching means 50 together with the operation control amount P _Y1 obtained by the first control amount calculation means 47.
Switching means 50, when the determination result of the control area determination section 46 there is shown a control region a select operation control quantity P _Y1 from the first control amount calculation means 47 as the operation control quantity P _Y, the control region When the determination result of the determination means 46 indicates the control region b or c, the operation control amount P _Y2 from the second control amount calculation means 49 is selected as the operation control amount P _Y.

The row selecting means 51 includes a switching means 50.
The control amount P _Y from the request value setting means 38 and the request value P _TF from the request value setting means 38 are input.
The lower one of P _Y and P _TF is selectively selected and given to the drive means 52, which drives the linear solenoid 2 based on the control amount obtained by the row select means 51.
3 Activate _FL .

The linear solenoid 23 _FL actuated by the driving means 52 exerts a thrust corresponding to the input electric quantity to make the braking pressure correspond to the input electric quantity. Therefore, the output of the driving means 52 The signal corresponds to the braking pressure.

Next, the operation of this embodiment will be described.
Then, in the control area determination means 46, the target wheel speed V_RBased on
First and second determination reference wheel speeds V set based on
_C1, V _C2And the front left wheel W that is the target wheel_FLWheel speed V_WFLWhen
The control area is determined by comparing_WFLIs the eye
Standard wheel speed V_RControl region a, which is relatively close to
_WFLIs the target wheel speed V_RControl area b relatively away from
And the target wheel speed V_RControl area c further away from
Is determined, and in the control area a, the first control amount
Operation control amount P based on PID calculation in the calculation means 47_Y1To
Control is performed, and wheel control is performed in control area b or c.
Obtained by the second controlled variable computing means 49 based on the deceleration α
Operation control amount P_Y2Control is executed. Therefore
Wheel speed V _WFLAnd target wheel speed V_RLarge deviation between
When it becomes low, operation control based on wheel acceleration / deceleration α
Quantity P_Y2Since the control by the
Degree V _WFLIs the target wheel speed V_RPromptly converge to
Therefore, the responsiveness can be improved.

Moreover, the wheel speed V _WFL is equal to the target wheel speed V _R.
In the control region b and the control region c which are relatively separated from each other, the reference value is changed from P ₁₀ to P ₂₀ when the control region b is shifted to the control region c.
So that the convergence to the target wheel speed V _R is more early.

Further, since the PID control is performed by using the reference braking pressure P _BR obtained by correcting the braking pressure at the start of the antilock control with the wheel acceleration / deceleration α as the reference value, the antilock control depends on how the brake pedal 14 is depressed. It is possible to prevent the reference pressure at the time from fluctuating and improve the accuracy of the antilock control. Moreover, the modulator 17 for adjusting the braking pressure
_{FL to} 17 _RR are electric actuators that make the braking pressure correspond to the input electric quantity, and the braking pressure at the start of the antilock control is obtained from the output of the driving means 52, so that the braking pressure can be detected. No sensor is required, which can contribute to a reduction in the number of parts.

By the way, while the antilock control is being executed, the vehicle
Also consider that the driver should relax the pedal effort of the brake pedal 14.
However, at that time, the row select means 51
The required value P according to the operation amount of the brake pedal 14._TFAh
Ruiha P_TRAnd the operation control amount P _YWhichever is lower is selected
Therefore, even if the anti-lock control is being
The same braking pressure can be obtained.

Furthermore, when the antilock control is started, the gain constants K _P , K _I , and K _D in the PID calculation are determined based on the judgment result of the first friction coefficient judgment means 44, and when the antilock control is continued, the second constants are set. The gain constants K _P , K _I and K are calculated based on the judgment result of the friction coefficient judging means 45.
_{Since D} is determined, it is possible to perform a control calculation that copes with a change in the friction coefficient of the road surface. Moreover, the friction coefficient determination speed V
_M is set based on the vehicle body speed V _V , and the first and second friction coefficient determining means 44, 45 change the frictional force between the wheel and the road surface in accordance with the change of the vehicle body speed V _V. The friction coefficient is determined in consideration of the above. Therefore, it is possible to prevent the increase of the braking distance and the increase of the locking tendency, and it is possible to perform the antilock control with improved accuracy in consideration of the change of the frictional force between the wheel and the road surface.

The antilock control process may be executed by a computer program, and the control process procedure for the left front wheel in that case will be described with reference to FIGS. 12 to 16.

First, in FIG. 12, in a first step S1, it is determined whether or not the flag F _ABS is "1". This flag F _ABS indicates whether the antilock control is started or is continuing, "1" indicates that the antilock control is continuing, and "0" is when the antilock control is started. It means that. Then F _{AB S}
When ≠ 1, each data is initialized in the second step S2, and then the reference braking pressure P _BR is set in the third step S3 according to the above-mentioned FIG. 7. When it is determined that F _ABS = 1 in the first step S1, the fourth step S4 bypassing the second and third steps S2 and S3.
Then, the previous P term and I term in the PID calculation are saved.

In the fifth step S5, the target wheel speed V _R is set according to the above-mentioned FIG. 6, and in the sixth step S6,
The required braking pressure values P _TF and P _TR are set according to FIG. In the subsequent seventh step S7, it is determined whether or not the wheel speed, for example, the left front wheel speed V _WFL exceeds the first determination reference wheel speed V _C1 , that is, whether or not it is in the control region a. When V _WFL > V _C1 , it is determined that the control area is a and the routine proceeds to the fifteenth step S15 in FIG.

When it is determined in the seventh step S7 that V _{WFL ≤V C1} , the process proceeds to an eighth step S8. In this eighth step S8, the wheel speed, for example the left front wheel speed V
It is determined whether _WFL exceeds the second determination reference wheel speed V _C2 , that is, whether it is in the control region b. Then V
_{When WFL} > V _C2 , it is determined that it is the control region b, and the process proceeds to a ninth step S9. In this ninth step S9, the integrated value D _I of the correction value D in the control region c is cleared, and the tenth
In step S10, the correction value D is retrieved according to the above-mentioned FIG. 11, and in the next eleventh step S11, the current integral correction value is set to D.
After calculation by _{I (k)} = D _(k) + DI _{( k-1)} , the process proceeds to the 18th step S18 of FIG.

When it is determined in the eighth step S8 that V _{WFL ≤V C2,} it is determined that the control region is c, and the process proceeds to a twelfth step S12. In the twelfth step S12, the integrated value D of the correction value D in the control region b is determined. Clear _I , 13th
In step S13, the correction value D is searched for in accordance with the above-described FIG. 11, and in the following fourteenth step S14, the current integral correction value is set to D.
After calculating _{I (k)} = D _(k) + D _{I (k-1)} , the process proceeds to the 21st step S21 of FIG.

In FIG. 13, in the fifteenth step S15 when it is in the control region a, the friction coefficient region of the road surface is determined according to the subroutine shown in FIGS. 14 and 15, and the gain constant K in the PID calculation is based on the determination result. Set _P , K _I and K _D. In FIG.
In the first step N1, determines whether the F _ABS = 1, when there was a F _ABS = 0, i.e. at the time of anti-lock control is started to set the coefficient of friction region by reference braking pressure P _BR at the second step N2 .

In the third step N3, it is judged whether or not it is in the low friction coefficient region, that is, in the μ1 region. When it is in the μ1 region, the gain constants K _P , K _I and K _D in the PID calculation are determined in the fourth step N4. Set according to Table 1.

When it is determined in the third step N3 that it is not in the μ1 region, it is determined in the fifth step N5 whether it is in the medium friction coefficient region, that is, in the μ2 region, and when it is in the μ2 region, the gain constant K is determined in the sixth step N6. _{When P} , K _I , and K _D are set according to the above-mentioned Table 1 and it is determined in the fifth step N5 that they are not in the μ2 region, it is determined that they are in the high friction coefficient region, that is, the μ3 region, and in the seventh step N7, the gain constant K Set _P , K _I and K _D according to Table 1 above.

If it is determined in the first step N1 that F _ABS = 1, that is, if it is determined that the antilock control is continuing, then in the eighth step N8, the left front wheel speed V _WFL.
Is greater than the friction coefficient determination speed V _M (V _WFL > V _M ). When V _WFL > V _M , the ninth step N9 is performed. When V _WFL ≦ V _M , the eighteenth step in FIG. The process proceeds to step N18.

In the ninth step N9, the time count value T
Is incremented by 1, and it is determined in the next tenth step N10 whether the time count value T is larger than the count determination value T _M3 . If T> T _M3 , the 11th step N11 is set in the μ3 region. Determine if there is. When it is determined in the 11th step N11 that the area is not the μ3 area, that is, when the area is in the μ2 area, the μ3 area is set in the 12th step N12, and the process proceeds to the third step N3.
When it is determined in the eleventh step N11 that it is in the μ3 region, the twelfth step N12 is bypassed and the third step N3 is executed.
Proceed to.

In the tenth step N10, T≤T_M3Determined as
If so, the process proceeds to the 13th step N13, and the 13th step
In step N13, the flag F_MIs "1"
To judge. Therefore, this flag F_MIs the time count value
T is the count judgment value T_M2It indicates whether or not
T> T_M2When F_M= 1, T ≤ T_M2When F _M
= 0.

When F _M = 1 in the 13th step N13, the process proceeds to the third step N3, and when F _M = 0, it is determined in the 14th step N14 whether T> T _M2 and T> T _M2. If T _M2 , the 15th step N
15, and if T ≦ T _M2 , the third step N
Go to 3. In the fifteenth step N15, it is determined whether or not it is in the μ3 region, and when it is not in the μ3 region, that is, μ
After changing the the μ2 to change and μ2 the μ1 at the 16 step N16 .mu.3 when was in 1 region or μ2 region, the flag F _M 17th step N17 to "1", the flow proceeds to the third step N3. The fifteenth step N1
If it is determined in step 5 that the current position is in the μ3 region, the fifteenth step N15 is bypassed and the process proceeds to the seventeenth step N17.

In FIG. 15, in the 18th step N18, it is judged whether or not the time count value T is "0",
If it is "0", the third step N3 (Fig. 14)
If T ≠ 0, the nineteenth step N19
Proceed to. In the 19th step N19, the time count value T
Is less than the count judgment value T _M1 and T
If <T _M1 , it is determined in a twentieth step N20 whether or not it is in the μ1 region. If it is not in the μ1 region, that is, if it is in the μ2 region or the μ3 region, μ2 is changed to μ1 in the 21st step N21, or μ3 is changed to μ2 and the process proceeds to the 22nd step N22 to proceed to the 20th step. When it is determined in step N20 that it is in the μ1 region, the process bypasses the 21st step N21 and proceeds to the 22nd step N22.

In the 22nd step N22, the time count value T is cleared, the flag F _{M is set} to "0" in the 23rd step N23, and then the process proceeds to the third step N3.

When it is determined in the 19th step N19 that T ≧ T _M1 , the time count value T is cleared in the 24th step N24, and then the process proceeds to the third step N3.

Thus, in this subroutine,
The time when the front left wheel speed V _WFL exceeds the friction coefficient judgment speed V _M is counted, and μ1 and μ are counted according to the count value.
It is determined which of the 2 and μ3 regions the region is in, the regions are changed, and the gain constants K _P , K _I and K _D in the PID calculation are set for each friction coefficient region.

Referring again to FIG. 13, the sixteenth step S1
6, the gain constant K determined in the fifteenth step S15
_The PID calculation is executed using _P , K _I and K _D , and the operation control amount P _Y1 (= P _BR −P _PID ) is calculated in the 17th step S17, and the process proceeds to the 24th step S24.

When the control area is b, the eighteenth step
In step S18, the operation control amount P_Y2(= P _Ten-D_I) Operation
Execute the operation control amount P in the 19th step S19._Y2Say
Then, in the 20th step S20, the P term of the PID calculation
And item I are cleared and the process proceeds to the 24th step S24.

Further, in the 21st step S21 in the case of the control region c, the operation control amount P _Y2 (= P ₂₀ −D _I ) is calculated, and after the operation control amount P _Y2 is saved in the 22nd step S22, In the 23rd step S23, the P and I terms of the PID calculation are cleared and the process proceeds to the 24th step S24.

In the 24th step S24, the operation control amount P
_Y , that is, P _Y1 when in the control region a and P _Y2 when in the control region b or c, is the required value P of the braking pressure.
It is judged whether it is less than _TF (P _Y <P _TF ), and P _Y <
If P _TF , P _Y is selected in the 25th step S25, and if P _Y ≧ P _TF , P _TF is selected in the 26th step S26, and then the operation control amount is saved in 27th step S27. The processing procedure of the cycle ends.

By the way, it is desirable that the braking pressure does not suddenly return to the depression amount of the brake pedal 14 at the end of the antilock control. In order to do so,
The processing procedure as shown in FIG. 16 is preset.

In FIG. 16, in the first step M1
Is the required value P of the braking pressure according to FIG._TFSet the
In 2 steps M2, the operation control amount P_YAnd the braking pressure request
Value P _TFAbsolute value of deviation | P_Y-P_TF| Is a constant value ΔP_O
It is determined whether or not to exceed. Ie brake pedal
Braking pressure required value P determined by the manipulated variable of 14_TFOperation control amount P
_YCheck whether the deviation from exceeds a predetermined value.
Judgment with M2, and as a result, | P_Y-P_TF│ ＞ ΔP_O
If so, the process proceeds to the third step M3.

[0072] In the third step M3 determines whether it is _{P Y <P TF, P Y} <P TF in which the operation control quantity P _Y in the fourth step M4 when (P _Y + constant value Δ
P _Y ), and when P _Y ≧ P _TF , the operation control amount P _{Y is set} to (P _Y −ΔP _Y ) in the fifth step M5.

In the second step M2, | P _Y -P _TF |
If it is determined that ≦ ΔP ₀ , the sixth step M6
The operation control amount P _Y is defined as P _Y = P _TF .

In this way, at the end of the antilock control, the braking pressure can be gradually returned according to the operation amount of the brake pedal 14.

Although the embodiments of the present invention have been described in detail above, 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 claims. It is possible to do.

[0076]

As described above, the device according to the present invention includes the wheel speed detector for detecting the wheel speed, the vehicle speed detecting means for detecting the vehicle speed, and the target wheel by adding a predetermined slip ratio to the vehicle speed. Target wheel speed setting means for setting speed, and wheel acceleration / deceleration for differentiating the wheel speed.
The deceleration calculation means, the first control amount calculation means for executing the PID calculation based on the deviation between the wheel speed and the target wheel speed, and determining the operation control amount of the actuator based on the PID calculation result, and the wheel acceleration / deceleration. Second control amount calculation means for determining the operation control amount of the actuator based on
In a region where the wheel speed exceeds the determination reference wheel speed in the control region determination means for determining the control region based on the comparison of the determination reference wheel speed and the wheel speed set based on the target wheel speed. When it is determined that there is a state in which the operation control amount is output from the first control amount calculation means, and when it is determined that the wheel speed is in a region equal to or lower than the determination reference wheel speed, the second control amount calculation means outputs Since the switching means for switching the state of outputting the operation control amount and the drive means for activating the actuator in accordance with the operation control amount from the switching means are provided, the comparison between the reference wheel speed and the wheel speed based on the target wheel speed is performed. With this, the deviation of the wheel speed from the target wheel speed is determined, and when the deviation becomes large, the actuation control amount calculated based on the wheel acceleration / deceleration is used to activate the wheel. By allowed to operate the mediator,
The wheel speed can be quickly converged to the target wheel speed, and the responsiveness can be improved.

[Brief description of drawings]

FIG. 1 is a diagram showing a braking system of a vehicle.

FIG. 2 is a diagram showing a configuration of a braking hydraulic circuit.

FIG. 3 is a block diagram showing a configuration of a control unit.

FIG. 4 is a diagram showing a set value of a required braking pressure value.

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

FIG. 6 is a diagram showing a set value of a target wheel speed.

FIG. 7 is a view showing a reference braking pressure setting map.

FIG. 8 is a diagram showing a friction coefficient region determination map.

FIG. 9 is a diagram for explaining a friction coefficient region determination procedure when antilock control is continued.

FIG. 10 is a diagram for explaining control region determination conditions.

FIG. 11 is a diagram showing setting correction values according to wheel acceleration / deceleration.

FIG. 12 is a flowchart showing a part of a main routine of antilock control processing.

FIG. 13 is a flowchart showing the rest of the main routine of the antilock control process.

FIG. 14 is a flowchart showing a part of a subroutine for determining a friction coefficient region and setting a gain constant.

FIG. 15 is a flowchart showing a remaining part of a subroutine for determining a friction coefficient region and setting a gain constant.

FIG. 16 is a flowchart showing a processing procedure at the end of antilock control.

[Explanation of symbols]

12 _FL , 12 _FR , 12 _RL , 12 _RR ... wheel speed detector 17 _FL , 17 _FR , 17 _RL , 17 _RR ... modulator as actuator 40 ... vehicle speed detecting means 41 ... target wheel speed setting means 42 ...... Acceleration / deceleration calculation means 46 ...... Control area determination means 47 ...... First control amount calculation means 49 ...... Second control amount calculation means 50 ...... Switching means 52 ...... Driving means B _FL , B _FR , B _RL , B _RR ... Wheel brake W _FL , W _FR , W _RL , W _RR ... Wheel

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] December 25, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction content]

The hydraulic pressure source 18 is operated from the hydraulic fluid tank 19.
A hydraulic pump 20 for pumping the liquid, an accumulator 21 connected to the hydraulic pump 20, and a pressure switch 22 for controlling the operation of the hydraulic pump 20 are provided.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0019

[Correction method] Change

[Correction content]

[0019] In demand value setting means 38, which as shown in Figure 4, the brake pressure demand value P _TR of braking pressure demand value P _TF and the rear wheel of the front wheels in response to the brake operation force is set in advance , The required braking pressure value P _TR for the rear wheels is set lower than the required braking pressure value P _TF for the front wheels above a certain braking operation force.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0064

[Correction method] Change

[Correction content]

When it is determined in the 19th step N19 that T ≧ T _M1 , the time counting is performed in the 22nd step N22.
The counter value T is cleared and the flag F is set in the 23rd step N23.
_{The M is set} to "0", and the process proceeds to the third step N3.

[Procedure amendment 4]

[Document name to be corrected] Drawing

[Correction target item name] Figure 15

[Correction method] Change

[Correction content]

FIG. 15

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Wataru Saito 1-4-1 Chuo, Wako-shi, Saitama, Ltd. Honda R & D Co., Ltd.

Claims (1)

[Claims] 1. Wheel brakes (B _FL , B _FR , B _RL ,
An actuator (17 _FL , which can adjust the braking force of B _RR )
17 _FR , 17 _RL , 17 _RR ), and when the wheels (W _FL , W _FR , W _RL , W _RR ) are likely to lock during braking, the actuator (17 _FL , 17 _FR , 17 _RL , 1)
(7 _RR ) to control the braking force to reduce the braking force of the vehicle, the wheel speed detector (12 _FL , 12 _FR , 12 _RL , 12 _RR ) for detecting the wheel speed and the vehicle speed are detected. Body speed detecting means (40), target wheel speed setting means (41) for setting a target wheel speed by adding a predetermined slip ratio to the vehicle speed, and wheel acceleration / deceleration for differentiating the wheel speed. Acceleration / deceleration calculation means (42)
And PID based on the deviation between the wheel speed and the target wheel speed
Based on the wheel acceleration / deceleration, the first control amount calculation means (47) for executing the calculation and determining the operation control amount of the actuators (17 _FL , 17 _FR , 17 _RL , 17 _RR ) based on the PID calculation result. Actuator (17 _FL , 17 _FL
FR , 17 _RL , 17 _RR ) second control amount calculating means (49) for determining the operation control amount of _FR , 17 _RL , 17 _RR ), and a control region based on the comparison of the judgment reference wheel speed and the wheel speed set based on the target wheel speed. Control area determining means (46) for determining, and operation from the first control amount calculating means (47) when the control area determining means (46) determines that the wheel speed exceeds the determination reference wheel speed. Switching means (50) for switching the state in which the control amount is output and the state in which the operation control amount is output from the second control amount calculation means (49) when it is determined that the wheel speed is in a region equal to or lower than the determination reference wheel speed. )
And an actuation means (52) for actuating the actuators (17 _FL , 17 _FR , 17 _RL , 17 _RR ) according to the actuation control amount from the switching means (50). Control device.