JP2736392B2 - Vehicle wheel force detection device, vehicle anti-lock brake device, and vehicle traction control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention relates to a vehicle wheel force detection device that outputs a signal approximately corresponding to a road surface friction coefficient, an anti-lock brake device that prevents locking of a wheel during braking of a vehicle, and an excessive slip of a wheel during acceleration of a vehicle. The present invention relates to a traction control device for preventing traction.

2. Description of the Related Art

Conventionally, as a brake torque detecting device,
Japanese Patent Application Laid-Open No. 27049 or Japanese Patent Application Laid-Open No. 62-75142 is known. In the former disk brake mechanism, a brake torque acting on a brake pad (a member that generates braking friction between the brake disk and the brake disk) is transmitted to a lever, and the torsional deformation of the lever shaft is magnetostricted. It is measured by a sensor. The latter is provided with a load cell (means for measuring a load), and measures a brake torque by transmitting a brake torque acting on a brake pad to the load cell via a lever. All of these have the disadvantage that the structure of the device is complicated. Conventional antilock brake systems (ABS) installed in automobiles generally control braking so that a slip ratio falls within a certain range based on a vehicle speed and a wheel speed. (For example, Japanese Patent Publication No. 59-3058)
No. 5, JP-A-60-61354, etc.). However, the relationship between the road friction coefficient and the slip ratio is
It can change depending on the road conditions,
In the above conventional method, the braking force may not be maximum depending on the road surface condition, and in that case, the minimum braking distance cannot be obtained. Further, since the vehicle speed is merely an estimated value from the wheel speed, there is a problem in accuracy in controlling the slip ratio. In order to accurately grasp the vehicle speed, complicated devices such as a ground speed sensor (for example, see JP-A-63-64861) and a vehicle-body deceleration sensor (for example, see JP-A-63-170157) are required. And Further, in the device disclosed in JP-A-63-25169,
The torque (diamond torque) caused by the road surface frictional force acting on the wheels is calculated from the wheel angular acceleration and the brake fluid pressure, and the start of the decrease in the tire torque during the increase in the brake fluid pressure is immediately before the wheel lock. It is used as one of the materials for judging the state. However, in this device, the tire torque is calculated indirectly from the wheel angular acceleration and the brake fluid pressure, and the calculated values are calculated due to the existence of uncertain constants such as the wheel inertia rate and the braking efficiency of the brake. Has a problem with accuracy. In addition, conventional traction control devices (TC
S), like the conventional anti-lock brake system (ABS), is based on the detection signal of the wheel speed sensor, based on the wheel acceleration (the rate of change in the peripheral speed of the wheel over time) and the slip ratio (the degree of wheel slip) , Which is defined as a complement to 1 of the ratio of the vehicle speed, ie, the ratio of the vehicle speed to the wheel speed (wheel rotation speed), and is expressed as S. The control of the wheel acceleration is performed so as to prevent the slip.
That is, the current TCS is a means for detecting a road surface frictional force (a frictional force acting between a road surface and a wheel and denoted by E) or a road surface friction coefficient (a friction coefficient between a road surface and a wheel). , Which is denoted by μ). Therefore, it is not easy for the current TCS to control the wheel acceleration so that the road surface friction force or the road surface friction coefficient is at an optimum value near the maximum value, and the acceleration time (the time when the vehicle is accelerated to a predetermined speed) ) Does not become the shortest. The present invention provides a wheel acting force detecting device, an anti-lock brake device,
Another object of the present invention is to provide a traction control device.

[Means for Solving the Problems]

In order to solve the above problems, the present invention employs the following technical means. That is, the vehicle wheel acting force detection device provided by the first aspect of the present invention is arranged such that two devices are provided on one side so as to face each other in the front-rear direction with respect to the center line near the axle or the axle of the vehicle. A total of four strain gauges are set to axes perpendicular to the central axis when viewed in the front-rear direction, in a plane in which the two strain gauges on each side are substantially parallel to the central axis and extend in a substantially vertical direction. First detecting means arranged so as to intersect symmetrically with respect to each other, and a bridge circuit including each strain gauge configured to output a signal proportional to only a vertical load acting on the axle; Two strain gauges, two on each side, a total of four strain gauges, and two strain gauges on each side are positioned with respect to the center axis so as to be opposed in the vertical direction with the center line near the axle or the axle neighborhood. In a plane that is substantially parallel and extends in a substantially horizontal direction Are arranged so as to intersect symmetrically with respect to an axis perpendicular to the central axis when viewed in the up-down direction, and output a signal proportional to only the shaft torque acting on the axle to the bridge circuit including each strain gauge. And a signal approximately corresponding to the road surface friction coefficient is output by using the output signal of the first detection device and the output signal of the second detection device. It is characterized by having been constituted so that. The vehicle wheel acting force detection device provided by the second aspect of the present invention is configured such that two devices are provided on one side such that they are opposed to each other in the front-rear direction across a center line near the axle of the vehicle or the axle. A total of four strain gauges are set to axes perpendicular to the central axis when viewed in the front-rear direction, in a plane in which the two strain gauges on each side are substantially parallel to the central axis and extend in a substantially vertical direction. First detecting means arranged so as to intersect symmetrically with respect to each other, and a bridge circuit including each strain gauge configured to output a signal proportional to only a vertical load acting on the axle; and a brake caliper. A third detecting means configured to output a signal proportional to the shaft torque caused by the brake torque by a strain gauge disposed at an appropriate portion of the support member and a bridge circuit including the strain gauge; An output signal by the first detecting means,
It is characterized in that it is configured to output a signal approximately corresponding to the road surface friction coefficient using the detection signal from the third detection means. Further, a traction control device for a vehicle provided by the third aspect of the present invention includes a wheel acting force detection device, an accelerator pedal depression force sensor, and a pedal force sensor provided by the first or second aspect of the present invention. ,
A control device for a brake fluid pressure generating device and a throttle valve driving device for the engine, wherein the control device controls the output of the wheel force detection device as the opening of the throttle valve of the engine increases during acceleration of the vehicle. While the value increases, the opening of the throttle valve is increased. When the rate of increase of the output value for some or all of the driving wheels falls below a predetermined set value including a negative number, the opening of the throttle valve is increased. At least one of attenuating or closing the vehicle, and applying braking to some or all of the drive wheels, and after the output value has attenuated below a set value, the opening is increased again, and When braking is applied to the wheels, release or attenuate them, and repeat the above operation to open the throttle valve of the engine or the drive wheels. It is characterized in that so as to control at least one of the dynamic. Further, an anti-lock brake device for a vehicle provided by the fourth aspect of the present invention includes a wheel acting force detecting device provided by the first or second aspect of the present invention, and a brake fluid pressure generating device. And a control device of
The control device increases the brake fluid pressure while the output value of the wheel acting force detecting device increases with the increase of the brake fluid pressure during braking while the vehicle is traveling. It is characterized in that the brake fluid pressure is relaxed or released when the pressure becomes below, and the brake fluid pressure is increased again after the output value attenuates below the set value, so that the above operation is repeated.

[Action]

In the wheel acting force detecting device according to the first aspect of the present invention, the first detecting means arranges a total of four strain gauges as described above and configures a bridge circuit including each strain gauge. By devising, while outputting a signal proportional to only the vertical load acting on the axle,
The detection means outputs a signal proportional to only the shaft torque acting on the axle by arranging a total of four strain gauges as described above and devising a configuration of a bridge circuit including each strain gauge, A predetermined arithmetic circuit outputs a signal approximately corresponding to the road surface friction coefficient by using the output signal from the first detection unit and the output signal from the second detection unit. In the wheel acting force detecting device according to the second aspect of the present invention, the first detecting means arranges a total of four strain gauges as described above and configures a bridge circuit including each strain gauge. By devising, while outputting a signal proportional to only the vertical load acting on the axle,
Detecting means for detecting the acting force acting on the brake caliper support member, thereby outputting a signal proportional to the shaft torque caused by the brake torque. The predetermined calculating means outputs the output signal from the first detecting means. And a signal approximately corresponding to the road surface friction coefficient using the output signal from the third detection means. In the traction control device for a vehicle according to the third aspect of the present invention, when the vehicle accelerates, the output from the wheel acting force detection device according to the first aspect or the second aspect, that is, approximately the road surface friction coefficient. At least one of the opening degree of the throttle valve of the engine or the braking of the drive wheels is controlled so that the rising speed of the output value corresponding to the predetermined value falls within a predetermined range including a negative number. In the antilock brake device for a vehicle according to the fourth aspect of the present invention, the output of the wheel acting force detection device according to the first aspect or the second aspect, that is, the coefficient of road surface friction, is approximated during braking of the vehicle. The brake fluid pressure is controlled so that the corresponding output value increasing speed falls within a predetermined set range.

[Explanation of the embodiment]

Hereinafter, specific examples of the present invention will be described with reference to the drawings.
Will be described. The embodiment described below is particularly suitable for automatic
This is an example of application to cars, but cars other than cars
The present invention can be similarly applied to both.
You. The following embodiment is a preferred embodiment.
Therefore, the scope of the present invention is not limited to such an embodiment.
Not. The wheel force detection device according to the first aspect of the present invention is based on
Essentially, it is arranged in a predetermined manner near the axle or near the axle
Only for a total of four strain gauges and vertical loads acting on the axle
Include the above strain gauge to output a proportional signal
First detecting means comprising a bridge circuit configured;
A total of four, arranged as specified near the axle or axle
The strain gauge and the signal proportional to only the shaft torque acting on the axle
No. which is configured to include the above strain gauge so as to output the signal
And an output signal of the first detecting means.
And the output signal of the second detecting means,
Is configured to output a signal that recently corresponds to the friction coefficient.
It is a thing. 1 to 4 show the first detecting means and
5 shows an example of the arrangement of strain gauges of the second detection means. In FIGS. 1, 2 and 3, the arrow 31 indicates a wheel.
34 indicates the vertical direction, 32 indicates the traveling direction, and 33 indicates the axle direction.
You. In FIG. 1, reference numeral 36 denotes an axle shaft of a rear wheel 34.
The housing 35 elastically supports the axle housing on the vehicle body 28
FIG. In this example,
Rear spring 35 in the axle housing 34
Eight strain gauges 11 to 14,2 are provided on the surface between
1 to 24 are attached. Of these, the numerals 11 to 14 are
The strain gauge for constituting the first detecting means is denoted by reference numeral 21.
24 to 24 are strain gauges for constituting the second detecting means.
Are respectively shown. The strain gauges 11 to 14 align the center line of the axle housing 36.
Two pieces on one side so that they face each other
A total of four are orthogonal to the central axis when viewed in the front-rear direction
And symmetrically intersect at 45 °
Are located. The strain gauges 11 to 14 are
In the example, the surface of the cylindrical arsle housing is
So that each two strain gauges
Are substantially parallel to the central axis and extend in a substantially vertical direction.
Will be located in the plane where The strain gauges 21 to 24 are provided inside the axle housing 36.
Be opposed to each other in the vertical direction with the core wire
, The total of four is the central axis when viewed in the vertical direction.
Intersect at 45 ° with respect to the axis perpendicular to
It is arranged to. Similarly, these strain gauges 21 to 24
Further, each of the two strain gauges is substantially parallel to the central axis.
And is located in a plane extending in a substantially horizontal direction. The four strain gauges 11 to 14 and 21 to 24 are shown in FIG.
In the bridge circuit in the
A stage and second detection means are configured. Axle housing due to vertical load on wheels 34
36 has a curved central axis on the vertical plane containing the central axis.
Bending deformation occurs. At the same time, axle housing 36
Cross section perpendicular to the central axis, equal to the vertical load
Shear force is applied vertically. Proportional to this shear force
Therefore, a shear strain is generated in the axle housing 36. Distortion
Of the first strain measuring means consisting of a set of pages 11, 12, 13, 14
The shear circuit detects this shear strain. If the bending change
As each strain gauge receives compression or expansion depending on the shape
Also, as described above, a bridge circuit is configured as shown in FIG.
Therefore, the effect of the bending deformation is offset. sand
That is, the voltage output of the amplifier 15 has a vertical load applied to the wheels.
Only proportional to the circumference of the rear spring 35 due to the vertical load.
The effect of the moment does not appear. The axle housing
36 has a bending deformation in which the central axis bends on the water surface including the central axis.
Shape is added. At the same time, wheel brake torque is generated
The axle housing 36
Kink deformation occurs. Furthermore, in the axle housing 36
In a section perpendicular to the axle, a thread equal in size to the road friction
A shear force is applied in the horizontal direction. Set of strain gauges 21, 22, 23, 24
The bridge circuit of the second measuring means consisting of
That is, torsional deformation due to brake torque is detected. However
And a bridge circuit is configured as shown in FIG.
The effects of the above bending deformation and shear strain are offset. did
Therefore, the voltage output of the amplifier 25 is
It is proportional only to the kitten. In addition, bending deformation of the axle housing due to vertical load
Shape and shear strain consist of a set of strain gauges 21-24
Does not affect the output voltage of the bridge circuit, and reduces road friction
Bending deformation, shear strain, and torsional deformation
The output voltage of the bridge circuit consisting of a set of strain gauges 11-14
Has no effect. Side force applied to wheel 34 (wheel
Axle housing 36
Compression or tensile strain in the direction of the central axis
These strains are bridge circuits consisting of a set of strain gauges 11 to 14.
Output voltage, also consists of another set of strain gauges 21-24
It does not affect the output voltage of the bridge circuit. Furthermore, the axle housing 36 is made of steel with high thermal conductivity.
Considering that the strain gauges 11 and 14 are
Temperature difference between the strain gauges and the strain gauges 21 to 24 is small.
Even if there is a change, the effect on the output voltage of each amplifier 15, 25 is small.
Please. That is, the vertical load and brake torque
The effect of temperature changes on outgoing prices is small. Axle housing
36 is partially surface-treated with copper material, and eight strain gauges are
The temperature difference between gauges can be further reduced by attaching
And therefore the effect of temperature changes
Can be done. The vertical load and brake torque applied to the rear wheels 34
Spring acting on the axle housing 36
The moment around 35 is the vertical load or brake torque
Ground contact point on the tire surface even if the
It changes with axial movement. Therefore, these models
Vertical load and brake torque without detecting
It is desirable to detect itself. In this embodiment,
The wheel acting force detecting device meets this demand. As shown in FIG. 4, the wheel action force detection according to this embodiment is performed.
Output device, the vertical load obtained as the output of the amplifier 15
Proportional voltage signal and car obtained as output of amplifier 25
And a voltage signal proportional to the brake torque of the wheel.
It is input to the arithmetic circuit 26. This arithmetic circuit 26
Calculate the quotient of brake torque and vertical load to calculate road friction
An electric signal approximately corresponding to the coefficient μ is output. FIGS. 5 and 6 show the front wheel 27 near the axle.
The example of attaching strain gauges
The case of the “strut type” will be exemplified. In addition,
Arrow 31 is the vertical direction of the wheel, 17 is the traveling direction, 18 is the axle direction
Are respectively shown. Arrow 16 is parallel to arrow 18
This shows an example in which the direction of the arrow is placed on the wheel.
Support member 69 that transmits force applied to wheel 27 to strut 68
Strain gauges 11 to 14 on the sides
Paste each. Strain gauges 11 to 14 are 45 for vertical direction 31
In a direction at an angle of か つ, and a pair of 11 and 12 and 13 and 14
And the symmetrical position on both sides of the support member 69
Affixed to Similarly, the strain gauges 21 to 24 are
At an angle of 45 ° to the
Pairs 23 and 24 are positioned symmetrically on the upper and lower surfaces of the support member 69.
It is affixed as follows. These strain gauges 11-14 and 21-
The 24 sets each have a bridge circuit as shown in FIG.
Configure and connect to amplifiers 15,25. Each amplifier 15, 25
Vertical load acting on each wheel 27 and braking of the wheels
It outputs an electric signal proportional to the torque. In addition, these
The electric signal is input to the arithmetic circuit 26, and the above-mentioned rear wheel 34
As in the case, the electric power approximately corresponds to the road friction coefficient μ
A signal is output from the arithmetic circuit 26. Also in this embodiment, the side force applied to the wheels
Affects the detected values of vertical load and wheel brake torque.
Does not affect. In addition, the vertical load detects the brake torque.
It does not affect the value, and vice versa. further,
The effect of temperature changes is also small. Part of the surface of the support member 69 is made of copper
If the material is treated with a material and a strain gauge is attached to the surface,
Can be further reduced. Rear wheels 34
As in the case, the vertical load on the wheels 27
Not only shear strain but also bending deformation is applied to the material 69. Further
When the brake of the wheel 27 is activated,
Not only lux, but also shear strain and bending deformation occur.
However, the strain gauge sets 11-14 and 21-24
Of the bridge circuit output voltage
These deformations and distortions of have no effect. Therefore,
Amplifiers 15 and 25 are used to apply vertical load and
Outputs a voltage signal proportional to only the torque. The wheel acting force detecting device according to the second aspect of the present invention is
Essentially, it is arranged in a predetermined manner near the axle or near the axle
Only for a total of four strain gauges and vertical loads acting on the axle
Include the above strain gauge to output a proportional signal
A first detecting means including a bridge circuit having a configuration;
The strain gauge and the rake caliper
The bridge circuit including the strain gauge
Output a signal proportional to the shaft torque caused by the torque
And the third detection means, wherein the first detection means
And an output signal from the third detecting means.
Signal and the signal approximately corresponding to the road surface friction coefficient
It is configured to output. That is, this
The wheel acting force detection device according to the second aspect is the first aspect.
The second detecting means in the wheel acting force detecting device according to
It is replaced with the third detection means exemplified below.
You. 7 to 9 show examples of the configuration of the third detecting means.
You. Both FIGS. 7 and 8
Supports the caliper that holds the pad for braking the disc 50.
Attach strain gauges 21 to 24 to appropriate parts of caliper support member 52
It is attached. These strain gauges 21 to 24 are shown in FIG.
Configure a bridge circuit as shown in
It is. In the example shown in FIG.
On the side of the arm-shaped part as close as possible to
Gauges are attached at four locations. Gauge direction is axle
The direction perpendicular to the central axis of is preferable. In this set of gauges,
The bending strain of the arm-shaped part in the material 52 was measured.
You. In the example shown in FIG.
A strain gauge as a cross gauge is attached to the front of the part
Have been. In this gauge set, the arm-shaped part
Is measured. In each case, amplification
25 outputs a signal proportional to the wheel brake torque.
Is done. In the present invention, the axle or the vicinity of the axle
The components are axle housing, knuckle, brake
It is a member including a disk. Axle housing,
Suspension mechanism (machine where the body flexibly supports the wheels
), Which supports the drive axle via rotary bearings
Mechanism that covers the drive axle at the same time
A car is also a part of the suspension mechanism, and a car
A mechanical unit integrated with the bearing that rotatably supports the wheel
It includes all of the minutes. When accelerating the vehicle, the wheel
The vehicle does not get enough acceleration due to
May be stable. To prevent this
Control the slip of the wheels, and improve the driving force and stability of the vehicle
Traction control (TCS)
You. In a third aspect of the present invention, the first aspect is provided.
Or the output from the wheel force detection device according to the second aspect
The road surface friction coefficient represented by the force signal
Open the throttle valve or drive the engine
Cars that control at least one of the braking of moving wheels
Both traction control devices are provided. FIGS. 10 to 14 show the traction according to the present invention.
3 shows an embodiment of a control device. Figure 10 shows this
Block diagram of the overall configuration of the traction control device
An example is shown below. In this embodiment, the wheel acting force detecting device 10
1, which approximately corresponds to the road friction coefficient.
Output the signal which has already been described in the present application.
Wheel force detection according to the first or second aspect of Ming
A device is used. The output of this wheel acting force detection device 101
Signal and the signal from the accelerator pedal depression force sensor 102 are controlled.
Input to the control device 103. In the control device 103, these signals
Of the throttle valve of the engine,
The brake fluid pressure is controlled by the throttle valve driving device 107,
In addition, an instruction is given to the brake fluid pressure generating device 104. Control device 1
03 is the microprocessor, memory, and I / O
It is composed of electronic circuits including
It operates according to the program written in the memory. An example of the operation of the control device 103 is shown in FIG. 11 to FIG.
The description will be given according to the flowchart. The value of the detection signal by the acting force detection device 101 is
It changes in the opposite direction when it starts. Sign of braking is positive
The sign at the time of acceleration is negative. When the pedaling force of the Alcel pedal exceeds the set value, this
The traction control unit starts operating and normal
Transition from high-speed operation to traction control operation.
Step 1110 of the main routine shown in FIG.
This indicates the start of the action control operation. continue
In step 1111, the detection obtained by the detection device 101 is performed.
Output value μ, and in step 1112, the value of μ
Store in the variable labeled t-1. Then this value
Is stored in the variable labeled μp in step 1113
I do. Next, in step 1115, the opening of the throttle valve is
After the increase, μ is detected in step 1116. Step
In step 1117, the variable labeled μt is
Is stored. Next, go to step 1118
Is compared with a predetermined reference value μc.
Is done. If this difference μt−μt−1 is smaller than μc,
Proceed to step 1119, and if equal or greater,
Proceed to the acceleration mitigation routine. In step 1119, the variable μ
The value stored in t is stored in a variable
The stored value of -1 is updated. Then, the process proceeds to step 11
Return to 13. In the acceleration mitigation routine 1123, as shown in FIG.
First, in step 1142, reduce the opening of the throttle valve.
And increase the brake fluid pressure. Then in step 1143
After detecting μ, this detection is added to the variable μt-1 in step 1144.
Store the output value. Next, the routine proceeds to step 1146, where μt−1
Is compared with α · μp. Coefficient α ranges from zero to one
Is a constant preset in advance to an appropriate constant value. Strange
If a few μt−1 is larger, proceed to step 1149
End acceleration relaxation routine 1123 and re-accelerate in step 1124
Proceed to routine. Whether the variable μt-1 is smaller
If it is, the process returns to step 1142. In the reacceleration routine 1124 following the acceleration relaxation routine 1123
Performs the processing shown in FIG. First, in step 1162
Increase the throttle valve opening and brake fluid pressure
To release. Then, in step 1163, μ is detected, and
This is stored in a variable μt in step 1164. Then step 11
At 65, the variable μt is compared with the variable μt-1. Variable μt
If the value is smaller, the process proceeds to step 1166 to set the variable μt−1.
Stores the value of variable μt and updates the stored value of variable μt-1
You. Then, proceed to step 1171 to end the re-acceleration routine.
Then, the process returns to step 1113 of the main routine. Steps
If the variable μt is larger or equal in 1165,
Proceeds to step 1167, and sets the variable μ
Update to the value of t-1. The control unit 103 performs the above processing, thereby
The example traction control device operates as follows:
Make. When the traction control device starts operating, the car
Of the detection value μ substantially obtained by the wheel action force detection device
While the descent speed is below the specified reference value, the throttle valve
The opening of the valve is increased. Based on the falling speed of the detection value μ
If it is higher than the value, the throttle valve opening will decrease
At the same time as increasing the brake fluid pressure. At this time,
The value of the detection value μ immediately before the change is stored. This memory
Variable is μp. The detection value μ is determined by α
When the percentage rises to, for example, 50%, the throttle
Turn the valve opening to increase and at the same time brake fluid pressure
To release. Hereinafter, the above operation is repeated. At any point in the flowchart,
Also, when the accelerator pedal depression force falls below a predetermined reference value,
The interrupt routine shown in Fig. 14 is executed and the traction
Control operation ends and the accelerator pedal is
Restores the function of the xel pedal. Comparison at step 1165 in the reacceleration routine 1124
Is given by μt− against a predetermined appropriate negative reference value μc2.
Replace with contents to compare whether μt-1 <μc2
Traction control operation more effectively
It can be carried out. In this case, during the acceleration mitigation routine 1123
Steps 1143 through 1146 and 1149 of the re-acceleration routine
The time between steps 1160 and 1163 in 1124, and
Steps 1163 to 1165, 1167, and 11 in the acceleration routine 1124
Of the time to go around the loop returning to 1163 via 62,
At step 11 in the main routine
Loop from 16 to 1118, 1119, 1113 and back to 1116
Assuming that the time to perform is Δt1, the reference value μc2 is μc2 / Δt2 <
It is preferable to set an appropriate value such as μc / Δt1. Ma
In the main routine shown in FIG.
The re-acceleration routine described above may be inserted after 12. Stay
The flow returning from step 1119 to step 1113 is unchanged.
You. In this case, from step 1111, the inserted re-acceleration
Time to step 1163 in routine 1124 and insertion
Steps 1163 to 1165 in the reacceleration routine 1124
After passing through 1167, 1162 and returning to 1163,
Of the inserted reacceleration
The reference value μc2 in the routine 1124 is defined as μc2 / Δt2 <μc / Δt1.
It is good to set to an appropriate value as follows. In the flowchart shown in FIG.
Equipped with a key pedal depression force sensor, and outputs the output signal of this sensor.
May also be input to the control device 103. The controller 103
While the action control device is operating,
In the routine, the brake fluid pressure
It will not be less than the magnitude corresponding to the output signal of the force sensor
It is preferable to control as follows. In conventional traction control systems,
Control the opening of the gin throttle valve and
There is known one that controls a brake independently of left and right. This
The key to these controls is very fast response
Is required. Traction according to the present invention
The control device outputs the output corresponding to the road friction coefficient μ.
Equipped with a wheel acting force detection device
Of the road surface friction coefficient μ
Output in real time, and based on this,
Gin throttle valve opening or drive wheel brake
It controls the rake, or both.
For this purpose, the conventional wheel speed is detected and the slip ratio is calculated.
Traction control device
And is extremely excellent, and draws out the maximum driving force with high accuracy
Responsiveness, differential lock effect, etc.
Can be realized. According to a fourth aspect of the present invention, there is provided the first aspect.
Or output from a wheel force detection device according to the second aspect
The road surface friction coefficient μ that the signal
The brake fluid pressure is controlled to
A tilok brake device (ABS) is provided. 15 to 19 show the antilock according to the present invention.
3 shows an embodiment of a brake device. Figure 15 shows this
An example of a block diagram of the overall configuration of the tilock brake device
Show. In this embodiment, a wheel acting force detecting device 12 is provided.
This is a signal that approximately corresponds to the road friction coefficient.
To be output.
The wheel acting force detecting device according to the side or the second side of the
Can be. The control device 3 controls the brake pedal force and the wheel operation described above.
Detection corresponding to road surface friction coefficient obtained by utility detection device 12
Control the brake fluid pressure with reference to the value μ and the detected value of the vehicle speed.
You. Brake pedal depression force sensor 2, brake fluid pressure generation
The raw device 4 and the brake device 5 use a known technique.
You. The control device 3 includes a microprocessor, a memory, and
It is composed of electronic circuits including input / output interfaces,
Operate according to the program written in the memory
You. An example of the operation of the control device 3 is shown in FIG. 16 to FIG.
The description will be given according to the flowchart. When the brake pedal pressure exceeds the set value, this anti-lock
The braking device starts operating and the brake is operating normally.
Then, it shifts to the anti-lock brake operation. Shown in Figure 16
Step 110 of the main routine
This indicates the start of the key operation. Then, in step 111,
The detection value μ obtained by the detection device is detected, and step 11
In step 2, the value of μ is converted to a variable labeled μt-1.
Remember. Subsequently, this value is expressed as μp in step 113.
Store it in a labeled variable. Next, at step 115
After increasing the pressure of the rake liquid, μ is detected in step 116.
You. In step 117, step into the variable labeled μt.
The detected value of μ at step 116 is stored. Then go to step 118
Going forward, the difference μt−μt− between the two stored values μt and μt−1
1 is compared with a predetermined reference value μc. Difference μt-μt-
If 1 is larger than μc, proceed to step 119,
If it is smaller, go to the brake fluid decompression routine in step 123.
move on. In step 119, the value stored in the variable μt is changed.
Stored in several μt−1 and the stored value of μt−1 is updated
It is. Subsequently, the process returns to step 113. In the brake fluid decompression routine 123, as shown in FIG.
First, in step 142, the brake fluid pressure is released or
Reduce pressure to a certain low level. Then, in step 143,
After the detection, the detected value is stored in a variable μt−1 in step 144.
Is stored. Next, the routine proceeds to step 146, where μt−1 is
Compare with α · μp. Coefficient α in the range of 0 to 1
This is a constant preset to an appropriate constant value. Variable μt-1
If it is smaller, go to step 149 and
The decompression routine 123 ends, and the brake
Proceed to pressure routine. Whether the variable μt-1 is larger, etc.
If so, the process returns to step 142. Brake fluid re-pressurization following brake fluid pressure reduction routine 123
In the routine 124, the processing shown in FIG. 18 is performed. First,
In step 162, the pressure of the brake fluid is increased. Then step 1
Detects μ at 63 and stores it in variable μt at step 164
I do. Next, in step 165, the variable μt is replaced with the variable μt-1.
Compare. If the variable μt is larger, step 166
To store the value of the variable μt in the variable μt−1,
Update the stored value of t-1. Then, proceed to step 171.
To end the brake fluid re-pressurization routine and
The process returns to step 113. In step 165, the variable μt
If is smaller or equal, proceed to step 167.
Then, the value of the variable μt−1 is changed to the value of μt in the same manner as in step 166.
Update. Then, the process returns to step 162. The present embodiment is performed by the control device 3 performing the above processing.
The anti-lock brake device according to
You. When the antilock brake device starts operating, it is detected
The rising speed of the detection value μ obtained by the device is a predetermined reference value.
During this period, increase the brake fluid pressure. Detection value
When the speed of μ rises below the reference value, the brake fluid pressure
Relieve or open. At this time, the detection just before it starts to decrease
The value μ is stored. This stored variable is μp
is there. A predetermined ratio where the detection value μ is determined by α, for example,
When the pressure drops to 50%, the brake fluid pressure is increased again.
Make Hereinafter, the above operation is repeated. The vehicle speed detector 6 in FIG. 15 is displayed on the front of the driver's seat.
Conventional equipment for doing so can be utilized. This car
The speed is calculated, for example, by using the output of the rotational speed sensor of the transmission drive shaft.
Obtained by electrical processing. Drive shaft rotation speed and display car
There is usually a time delay between speed and speed. This time delay
May be used as it is. is there
Otherwise, the rotation speed sensor of the transmission drive shaft
Add a signal processing system that outputs a vehicle speed signal with a delay
This causes a time delay in the output of the vehicle speed signal,
This may be input to the control device 3 as vehicle speed data. System
The control device 3 determines that the vehicle speed is lower than a certain value (for example, several kilometers per hour).
If it goes down, depress the brake pedal with more than the specified pedaling force.
However, the anti-lock brake operation changes from the normal brake operation.
There is no transition to work. During anti-lock brake operation
If the vehicle speed falls below a certain value, the control device 3
At any point in the flowchart shown in Figures 16 to 18
However, immediately execute the interrupt routine shown in FIG.
Ends anti-lock brake operation and normal brake operation
The brake hydraulic device is controlled to return to. Vehicle speed is enough
If it is low, the need for antilock brake operation is low, and
There is no need at all when driving. Considering this point,
In the example, the anti-lock brake operation is performed at a certain speed or lower.
Do not let. The vehicle speed data to be referenced is based on the rotation speed of the drive shaft.
Drive wheel during braking
Responds to sudden decrease in drive shaft rotation speed due to
Absent. For this reason, normal brake operation by operating the brake pedal
Immediately before entering anti-lock brake operation from
Danger that the system will not shift to antilock brake operation.
Ruggedness is reduced. Also, during anti-lock brake operation
When the lock occurs, the anti-lock brake operation is
The danger of being released and returning to normal braking is eliminated
You. As described above, the control device 3
Even in the stage, the anti-lock brake release command
Immediately, the interrupt routine of FIG.
Terminate the tilock brake operation and perform normal brake operation.
Return to Generation of antilock brake release command
(1) The brake pedal pressure falls below a predetermined reference value.
(2) Release the brake pedal force and
(3) Engine key when you start to depress
Can be adopted when the user cuts the sword. Of these, (2) and
In cases (3) and (4), the driver is unable to operate due to an accident.
The vehicle automatically stops with ideal braking and characteristics.
It is possible to stop. In step 165 of the brake fluid re-pressurization routine 124,
The content of the comparison to the appropriate positive reference value μc2.
To compare whether μt-μt-1> μc2
If you replace the anti-lock brake more effectively
Control can be performed. In this case, brake fluid pressure reduction
After steps 143 to 146 and 149 in routine 123, brake
Steps 160 to 163 in the liquid repressurization routine 124
And step 1 in the brake fluid repressurization routine 124.
The larger of the time to go around the loop returning to 63 is Δ
t2, steps 116 to 118, 11 in the main routine
Let Δt1 be the time to go around the loop returning to 116 via 9, 113
Then, the reference value μc2 becomes μc2 / Δt2> μc / Δt1.
It is better to set an appropriate value. Also, the menu shown in FIG.
In the in-routine, after step 112,
It is advisable to insert a re-pressurization routine for the liquid. Step 119
The flow from step to step 113 remains unchanged. This place
The re-pressurization loop inserted from step 111
Time until step 163 in chin 124 and inserted
Steps 163 to 16 in the brake fluid repressurization routine 124
With the time to go around the loop returning to 163 via 5, 167, 162
Of which, the larger one is Δt2,
The reference value μc2 in the pressurization loop 124 is defined as μc2 / Δt2> μc / Δt1
It is good to set to an appropriate value such that

【The invention's effect】

As can be understood from the above description, according to the wheel acting force detection device of the present invention, it is possible to accurately and in real time detect an output value corresponding to the road surface friction coefficient μ with a simple configuration. . According to the traction control device according to the present invention for controlling the opening degree of the throttle valve and the like so that the road surface friction coefficient corresponding value output in real time by the wheel acting force detection device falls within a predetermined condition range, Regardless of the situation, the acceleration time can be reduced as much as possible. Further, according to the anti-block brake device according to the present invention for controlling the brake fluid pressure such that the road surface friction coefficient corresponding value output in real time by the wheel acting force detection device falls within a predetermined condition range, Regardless, the braking distance can be reduced as much as possible.

[Brief description of the drawings]

FIG. 1 is a front view showing an example of mounting a strain gauge for constituting a wheel acting force detecting device according to the present invention. FIG. 2 is an enlarged front view of an example of mounting the strain gauge shown in FIG. FIG. 3 is an enlarged plan view of an example of mounting the strain gauge shown in FIG. FIG. 4 is a configuration diagram of a bridge circuit for configuring the wheel acting force detection device according to the present invention. FIG. 5 is a front view showing another mounting example of the strain gauge for constituting the wheel acting force detecting device according to the present invention. FIG. 6 is an enlarged perspective view of an example of mounting the strain gauge shown in FIG. FIG. 7 is an explanatory view of another example of the brake torque detecting means for constituting the wheel acting force detecting device according to the present invention. FIG. 8 is an explanatory view of still another example of the brake torque detecting means for constituting the wheel acting force detecting device according to the present invention. FIG. 9 is a block diagram of a bridge circuit using a strain gauge in the detecting means shown in FIG. 7 or FIG. FIG. 10 is a block diagram of an example of a traction control device for a vehicle according to the present invention. FIG. 11 is a flowchart showing an operation main routine of the control device shown in FIG. FIG. 12 is a flowchart showing details of the acceleration mitigation routine in FIG. FIG. 13 is a flowchart showing the details of the re-acceleration routine in FIG. FIG. 14 is a flowchart showing an interrupt process for the main routine process of FIG. FIG. 15 is a block diagram of an example of the antilock brake device for a vehicle according to the present invention. FIG. 16 is a flowchart showing an operation main routine of the control device shown in FIG. FIG. 17 is a flowchart showing details of a brake fluid pressure reducing routine in FIG. FIG. 18 is a flowchart showing details of the brake fluid re-pressurization routine in FIG. FIG. 19 is a flowchart showing an interrupt process for the main routine process of FIG. 11, 12, 13, 14 ... strain gauges (for first detecting means) 15 ... amplifiers 21, 22, 23, 24 ... strain gauges (for second and third detecting means) 25 ... amplifier 26 …… Calculation circuit 27 …… wheel 3,103 …… control device 12,101 …… wheel acting force detection device

Continuation of the front page (56) References JP-A-59-50806 (JP, A) JP-A-51-69680 (JP, A) JP-A-62-3137 (JP, A) JP-A-63-96530 (JP) JP-A-47-27072 (JP, A) JP-A-60-173432 (JP, A) JP-A-56-148957 (JP, U)

Claims (4)

(57) [Claims] 1. A total of four strain gauges, two on each side, and two strain gauges on each side so as to face each other in the front-rear direction across a center line near the axle or the axle of the vehicle. Are arranged so as to intersect symmetrically with respect to an axis perpendicular to the central axis when viewed in the front-rear direction in a plane extending substantially parallel to and substantially perpendicular to the central axis. A first detecting means configured to output a signal proportional to only the vertical load acting on the axle, and a bridge circuit including the bridge circuit vertically facing the center line near or near the axle of the vehicle. A total of four strain gauges, two on each side, and two strain gauges on each side are viewed in the vertical direction in a plane substantially parallel to the central axis and extending in a substantially horizontal direction. Symmetrical with respect to the axis perpendicular to the central axis Second detection means arranged so as to intersect and configured to output a signal proportional to only the shaft torque acting on the axle, and a bridge circuit including each strain gauge;
Using the output signal of the first detection means and the output signal of the second detection means, to output a signal approximately corresponding to the road surface friction coefficient, Vehicle wheel force detection device. 2. A total of four strain gauges, two on each side, and two strain gauges on each side so as to face each other in the front-rear direction with a center line near the axle or the axle of the vehicle interposed therebetween. Are arranged so as to intersect symmetrically with respect to an axis perpendicular to the central axis when viewed in the front-rear direction in a plane extending substantially parallel to and substantially perpendicular to the central axis. Detecting means configured to output a signal proportional to only a vertical load acting on an axle, a strain gauge disposed at an appropriate portion of a brake caliper support member, and a bridge including the strain gauge A third detection unit configured to output a signal proportional to the shaft torque caused by the brake torque by a circuit; and an output signal from the first detection unit and an output from the third detection unit. With No., characterized by being configured to output approximately the corresponding signal to the road surface friction coefficient, the wheel action force detection apparatus for a vehicle. 3. The control system according to claim 1, further comprising: a wheel operating force detecting device according to claim 1; an accelerator pedal depression force sensor; and a control device for a brake fluid pressure generating device and a throttle valve driving device for an engine. The device increases the opening of the throttle valve while the output center axis of the wheel acting force detecting device increases with an increase in the opening of the throttle valve of the engine when the vehicle is accelerating. When the rising speed of the output value for some or all wheels falls below a predetermined value including a negative number, the opening is attenuated or closed, or braking is performed on some or all of the drive wheels. If the output is attenuated below the set value, the opening is increased again, and if braking is applied to the drive wheels, Les performs open or attenuation adjusted, characterized by being adapted to control at least one of the braking or more iterations to engine throttle valve opening operation or driving wheels, the traction control apparatus for a vehicle. 4. A brake fluid pressure detecting device according to claim 1 or 2, further comprising a control device for a brake fluid pressure generating device, wherein said control device controls the brake fluid pressure during braking of the vehicle. The brake fluid pressure is increased while the output value of the wheel acting force detection device increases with the rise of the brake fluid pressure, and the brake fluid pressure is relaxed or released when the output value increasing speed is equal to or less than the set speed, After the output value has attenuated below a set value, the brake fluid pressure is increased again, and the above operation is repeated.