JPS627954A - Acceleration slip control device for car - Google Patents

Abstract

PURPOSE:To suppress recurrence of acceleration slip by furnishing a target opening setting means which is to set the target opening of a throttle valve on an acceleration slip control means on the basis of the difference between the drivewheel speed and reference speed. CONSTITUTION:The reference speed for a drive wheel M2 is calculated M3 on the basis of the car running speed sensed by a speed sensor of an idling wheel. The revolving speed of drive wheel M3 is sensed M4 from a drive wheel speed sensor. Therefrom the acceleration slip is sensed, and it is suppressed by driving a throttle valve M7 in the direction of closing. When the throttle valve M7 is driven again in the direction of opening, the target degree of opening is set M9 on the basis of the difference between the drive wheel speed and reference speed. This ensures that the degree of opening of the throttle valve M7 is suppressed in accordance with the magnitude of slip, which will serve suppression of recurrence of acceleration slip.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention is a method for accelerating a vehicle that suppresses acceleration slip of driving wheels that occurs when the vehicle accelerates by controlling the opening and closing of a throttle valve provided in the intake system of an internal combustion engine. This invention relates to a slip control device.

[Prior Art] When a vehicle suddenly accelerates when starting or running, the drive wheels slip. When this phenomenon occurs, the drive wheels not only spin and shorten the life of the tires, but also cause damage to the relationship between the tires and the road surface. The lateral drag of the vehicle also decreases, causing various problems such as loss of maneuverability and deterioration of fuel efficiency.

Therefore, in recent years, various acceleration slip control devices have been developed to deal with this problem.
As described in Japanese Patent No. 167845, etc., when acceleration slip occurs, the throttle valve provided in the intake system of the internal combustion engine is driven in the opening direction to forcibly reduce the amount of intake air, thereby suppressing the output torque of the internal combustion engine. Some attempt to suppress the rotation of the drive wheels.

[Problems to be solved by the invention] This type of acceleration slip control device directly controls the intake air amount of the internal combustion engine to suppress the output torque. Acceleration slip can be effectively suppressed, but conventional systems rely on simple opening/closing control of the throttle valve, which closes the throttle valve when acceleration slip occurs and opens the throttle valve when acceleration slip does not occur. As a result, the rotation of the drive wheels decreases and increases.

There was a problem in that when the rapid slip was suppressed, the throttle valve was opened as it was, causing a large acceleration slip to occur again. In other words, in conventional control, once acceleration slip is suppressed, the throttle valve is opened to an opening degree corresponding to the amount of depression of the accelerator pedal by the driver.
A problem arises in that a large acceleration slip occurs again and it takes time to completely suppress the acceleration slip.

Therefore, the present invention closes the throttle valve when acceleration slip occurs and once the rotation of the drive wheels is suppressed, and then when driving the throttle valve in the opening direction, the amount of drive is limited according to the degree of acceleration slip, thereby accelerating. The purpose of this device is to provide an acceleration slip control device that suppresses the recurrence of slips and provides optimal acceleration performance, and has the following configuration.

[Means for Solving the Problems] That is, the configuration of the present invention as a means for solving the above problems, as shown in FIG. Reference speed calculation means M3 that calculates the reference speed of the driving wheels M2 based on the running speed of the vehicle detected by the speed detection means M1; and Drive wheel speed detection means M that detects the rotational speed of the driving wheels M2.
4, detecting acceleration slip of the driving wheel M2 using the rotational speed of the driving wheel M2 detected by the driving wheel speed detecting means M4 and the reference speed calculated by the reference speed calculating means M3 as parameters, and detecting the acceleration slip of the driving wheel M2; An acceleration slip control device for a vehicle, comprising: an acceleration slip suppression means M8 for controlling slip by opening/closing control of a throttle valve M7 provided in an intake system M6 of an internal combustion engine M5 of the vehicle; M8, when the throttle valve M7 is driven in the opening direction, its target opening is determined based on the reference speed calculated by the reference speed calculation means M3 and the drive wheel speed detected by the drive shaft speed detection means M4. The gist of the present invention is an acceleration slip control W device for a vehicle, which is characterized in that a target opening setting means M9 is provided for setting based on the difference, and is configured to suppress recurrence of acceleration slip.

Here, the vehicle speed detection means M1 detects the running speed of the vehicle, that is, the moving speed of the vehicle body, and for example,
This can be easily realized by providing a speed sensor on the idler wheel so as to detect the rotational speed of the idler wheel that is not driven by 5 as the vehicle body speed, or by providing a speed sensor on the vehicle body that utilizes the Doppler effect.

Furthermore, the reference speed determined by the reference speed calculation means M3 is as follows:
When the vehicle accelerates, the rotation speed of the driving wheel M2 is determined at the rotation speed at which the coefficient of surface friction between the tire and the road surface becomes the largest, that is, the slip ratio [
(vehicle speed - drive wheel rotation speed)/drive wheel speed] is -0,
This is to detect that acceleration slip has occurred in the driving wheel M2 when the rotation speed exceeds a rotation speed of 1 to -0.2, and by multiplying the vehicle body speed by 1.1 to 1.2. It can be easily calculated.

Next, the acceleration slip suppressing means M8 causes acceleration slip in the driving wheel when the rotational speed of the driving wheel M2 detected by the driving wheel speed detecting means M4, that is, the driving wheel speed exceeds the predetermined reference speed. It is detected that this has occurred, and the throttle valve M7 is
The output torque of the internal combustion engine is suppressed by the opening/closing control of the drive wheels, and the slippage of the driving wheels, that is, acceleration slip, is suppressed.In the present invention, by providing target opening degree setting means M9 in this acceleration slip control means M8, When driving the throttle valve M7 in the opening direction, its target opening degree is set according to the difference between the reference speed and the driving wheel speed.

[Operation] Therefore, when acceleration slip of the driving wheels is detected and the -H acceleration slip is suppressed by driving the throttle valve in the closing direction, when the throttle valve is subsequently driven in the opening direction,
The opening degree is changed to 11111@ according to the difference between the reference speed and the drive wheel speed (factor), that is, the degree of slip, and the acceleration slip can be quickly suppressed without causing a large acceleration slip again.

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

FIG. 2 is a schematic configuration diagram of this embodiment, in which the present invention is applied to a front engine rear drive (FR type) automobile equipped with a gasoline engine. In the figure, 1 is a four-cylinder fuel injection type engine, 2 is an intake pipe, 3 is an air flow meter, 4 is a fuel injection valve provided for each cylinder that injects fuel into the intake air, and 5 is a spark plug. (In the figure, the fuel injection valve 4 and spark plug 5 are only shown for one cylinder.) 6 is a distributor that supplies high voltage to the ignition plug, 7 is an engine speed sensor consisting of a gear and an electromagnetic pickup, 8 is a A main throttle valve that is driven via a link mechanism in response to depression of the accelerator pedal 9 to adjust the intake air amount; 10 is a sub-throttle valve that is provided upstream of the main throttle valve 8 and that adjusts the intake air amount during acceleration slip control. 11 is a DC motor that drives the auxiliary throttle valve; 12 is a main throttle sensor that detects the throttle opening of the main throttle valve 8;
Reference numeral 13 represents a sub-throttle sensor that detects the throttle opening of the sub-throttle valve 10. The throttle sensors 12 and 13 are connected to each of the throttle valves 8.
It outputs a detection signal according to the opening degree of 10.

On the other hand, 20.21 represents the left and right drive wheels, respectively, and the power of the engine 1 is transmitted to the transmission 22.21. The signal is transmitted via the propeller shaft 23 and the like. Further, 24.25 is a left and right drive wheel speed sensor that detects the rotational speed of the left and right drive wheels 20.21, respectively, 26°27 is a left and right idler wheel that rotates as the vehicle travels, and 28.29 are left and right idle wheel speed sensors, respectively. In addition, these sensors 24, 25, 28
゜29 consists of gears and an electromagnetic pickup.

Next, 30 is an electronic control circuit constructed using a microcomputer, and is constructed as shown in FIG. In FIG. 3, 31 inputs and calculates the data detected by the above-mentioned sensors according to the control program, and
A central processing unit (CPLI) performs processing to drive and control the motor 11, 32 is a read-only memory (ROM) in which data such as the control program and map is stored, and 33 is a ROM that stores data from each of the sensors and arithmetic control. A random access memory (RAM) in which data necessary for the operation is temporarily read and written; 34 is an input unit equipped with a waveform shaping circuit and a multiplexer that selectively outputs the output signals of each sensor to the CPU 31; 35 is a DC motor 11; An output section 36 includes a drive circuit that drives the CPU 31 . A path line 37 connects each element such as the ROM 32, the input section 34, and the output section 35 and serves as a path for various data, and 37 represents a power supply circuit that supplies power to each of the above sections.

In this electronic control circuit 30, the left drive wheel speed sensor 24
, right driving wheel speed sensor 25 and left idle wheel speed sensor 28
, receives various detection signals from the right idle wheel speed sensor 29, etc., and sends a drive signal to the DC motor 11, which adjusts the opening degree of the sub-throttle valve 10 so that optimum acceleration performance can be obtained without causing acceleration slip when the vehicle accelerates. In addition to executing acceleration slip control, which is the main process related to the present invention, such as outputting and suppressing engine output, it also performs control based on the operating state of the engine 1 detected by the air 70 meter 3, engine speed sensor 7, etc. Accordingly, well-known engine control for controlling fuel injection amount and ignition timing is also executed.

Hereinafter, the acceleration slip control executed by the electronic control circuit 30 will be explained in detail with reference to the flowcharts shown in FIGS. 4 and 5.

First of all, in FIG.
This represents an acceleration slip determination routine that calculates the pulse duty ratio of the drive signal, and by repeating this process at predetermined intervals, acceleration slip can be constantly monitored.

When the process is started, step 101 is first executed, and the speed sensors 24, 25, 28, 2 provided on each of the wheels are
9 and the detection signals from each throttle sensor 12 and 13 are read, and the average rotational speed Vr of the left and right driving wheels (hereinafter referred to as driving wheel speed) and the average rotational speed Vf of the left and right idle wheels are read.

(hereinafter referred to as idle wheel speed), main throttle open -11
Once θ1 and sub-throttle distance θ2 are calculated.

Next, in step 102, the idle wheel speed Vf determined above is
Based on the reference speed Vt for determining acceleration slip
is calculated using the following formula % formula %. This coefficient of 1.2 means that the rotation of the driving wheels is controlled so that maximum frictional force is generated between the tires of the driving wheels and the road surface during acceleration, and optimum acceleration is obtained, that is, the slip ratio is 120%. This is a value set for control.

When the reference speed Vt is calculated in step 102, the process moves to step 103 to determine whether or not the drive wheel speed Vr obtained in step 101 exceeds the reference speed Vt, that is, acceleration slip occurs in the drive wheels. determine whether or not. If Vr>vt, it is determined that an acceleration slip has occurred, and the process moves to the next step 104, where a flag F1 indicating execution of slip control is set.

Next, in step 105, during the execution of slip control, acceleration slip continues to occur, and even in the previous process, the closing direction of the sub-throttle valve in steps 108 to 111 (or step 112), which will be described later, is determined. It is determined whether a flag F2 indicating that drive control has been executed is set.

Then, if the flag F2 is in the reset state, the next step 1
06, the target opening degree θ of the sub-throttle valve 10 is determined.
2' -H Set the opening degree θ2 of the auxiliary throttle valve 10 obtained in step 101 above, and then proceed to the next step 10.
At step 7, flag F2 is set.

On the other hand, if it is determined in step 105 that the flag F2 is set, or if the flag F2 is set in step 107, the process moves to step 108,
Difference between driving wheel speed Vr and reference speed Vt (Vr - Vt
) as a parameter as shown in FIG. 6, the driving amount Δθ2 of the sub throttle valve 10 is calculated, and the process proceeds to step 109. Then, in step 109, the drive amount Δ is adjusted to the target opening θ2' of the sub-throttle valve 10.
The target opening degree θ2' is updated by adding θ2.

In this case, since Δθ2 obtained from map A is a negative value, the target opening degree 02' becomes small, but this represents that the sub-throttle valve 10 is driven in the closing direction.

Next, in step 110, the minimum limit opening degree θ2'1n of the auxiliary throttle valve 10 is calculated using a map B as shown in FIG. 7, which uses the idle wheel speed Vf as a parameter.

Then, the process moves to the next step 111, where the obtained minimum limit opening degree θ2'1n and the updated target opening degree 02' are combined.
Compare the size with. In this step 111, θ2′ is reduced to θ
2-m1n, step 11
2, the target opening degree θ2 of the sub-throttle valve 10 is determined.
' is rewritten to the value of the minimum limit opening θ2'1n,
゛Proceeds to step 113, and in step 111 θ2
If it is determined that '≧θ2'1n, the process directly proceeds to step 113.

Note that the minimum opening limit θ2 obtained in step 110 above
-1n is for limiting the amount of drive in the opening direction to prevent the auxiliary throttle valve 10 from closing too much and causing sudden engine braking when the auxiliary throttle valve 10 is driven in the closing direction. Thus, acceleration slip can be smoothly suppressed without causing surging, hunting, etc. in the vehicle.

Next, if it is determined in step 103 that Vr≦Vt, the process moves to step 114. Step 1
In step 14, it is determined whether the sub-throttle valve distance θ2 determined in step 101 is larger than the main throttle opening θ1, that is, whether the vehicle is accelerating.

When it is determined in step 114 that θ1 < θ2 that the vehicle is accelerating, the process moves to the next step 115, and the flag F
1 is in the set state, that is, whether -H acceleration slip has occurred and acceleration slip control is currently being executed. If the acceleration slip control is currently being executed and F1=1, the process moves to the next step 116, where it is determined whether or not the flag F2 is in the reset state.

If it is determined in this step 116 that the flag F2 is in the reset state, that is, in this routine up to now, steps 108 to 111 (or step 1
12), the drive control of the sub throttle valve 10 in the opening direction has been executed, and if this is the first time to execute the following drive control of the sub throttle valve 10 in the open direction, proceed to the next step 117. Then, as in step 106, the target opening degree 02' of the auxiliary throttle valve 10 is set to the value of the current auxiliary throttle distance θ2, and the process proceeds to the next step 118. Then, in step 118, the flag F2 is reset, and the process moves to the next step 119, where the value of the counter is incremented.

The value on this counter indicates how many times the sub throttle valve 10 is to be controlled in the opening direction after the start of the acceleration slip control.

Next, in step 120, the maximum value of the difference between the reference speed Vt and the drive wheel speed Vr in the current drive control in the opening direction of the auxiliary throttle valve 10, that is, the maximum speed deviation ΔV
k (however, the subscript represents the value of the above-mentioned caranta) is set in rOJ, and the process moves to the next step 121. Then, in step 121, it is determined whether the value on the counter is 1, that is, whether the opening control of the sub-throttle valve 10 currently being executed is the first opening control after the start of the acceleration slip control, and if K=1. If so, proceed to the next step 122, and set θ1/2 to the maximum limit opening θ1 (of the target opening θ2'. If ≠1 on the other hand, proceed to step 123. Then, in step 123, the previous The maximum speed deviation ΔV (k-o) is the parameter of the maximum speed deviation ΔV (k-o) that was previously used, based on the map C shown in FIG. A correction value Δθk of n is calculated, and the process moves to step 124.In step 124, the maximum limit opening degree θcb-t used last time is calculated.
)' and the correction value Δθk to determine the current maximum opening limit θ.
Totosu.

Next, if it is determined in step 116 that the flag F2 is set and drive control of the auxiliary throttle valve 10 in the opening direction is continuously being executed, or if step 122 or step 124 is executed. Then, the process moves to step 125, and in conjunction with the next step 126 and step 127, a process of calculating Vk to the maximum speed deviation is executed.

That is, in steps 125 to 127, the reference speed Vt obtained in step 101 and the driving wheel speed Vr are
The deviation Δ■ from
If ΔVk<Δ■, processing is executed to set the value of ΔVk to Δ■.

Next, in step 128, similarly to step 109,
Difference between driving wheel speed ■r and reference speed ■t (Vr - Vt
) is used as a parameter and the drive amount Δθ2 of the sub throttle valve 10 is calculated using the map A shown in FIG. 6, and the process proceeds to step 129.

Then, in step 129, similar to step 110,
Add the drive amount Δθ2 to the target opening 02', and set the target opening 02.
' is updated and the process moves to step 130.

In step 130, the filled target opening degree θ
2', the maximum opening limit value θ, and the smallest value MIN (02', 1θ1 for θ) are set as the target opening θ2' of the sub-throttle valve 10, and the process moves to step 113. do.

Note that the processing in step 130 limits the target opening θ2' to the maximum limit opening θ to prevent the target opening θ2' obtained in step 129 from becoming too large and causing a large acceleration slip again. There is no point in making the opening larger than the main throttle valve θ1, and if the sub-throttle opening θ2 exceeds the main throttle opening θ1, the response when acceleration slip occurs again will decrease, so the target opening This is to prevent θ2' from exceeding the main throttle opening θ1.

Next, in step 114, if it is determined that θ1≧θ2, the process moves to step 131 and the flag F1 is reset. Further, if it is determined in step 115 that the flag F1 is in the reset state, or if the flag F1 is reset in step 131, the process moves to step 132 and the flag F2 is reset. Then, in the next step 133, the value in the counter is cleared, and in the next step 134, the target opening degree θ2' of the sub throttle valve 10 is set to the main throttle opening degree θ1, and the process moves to step 113. As described above, the processes in steps 131 to 134 are executed when the vehicle is not accelerating, or even when accelerating, no acceleration slip has occurred and acceleration slip control is not being executed. In this case, the sub-throttle opening θ2 simply becomes the main throttle opening θ1, and the target opening is set to 0 so that the response when acceleration slip occurs is good.
2' is set to the main throttle opening degree θ1.

As described above, the sub-throttle valve 10 under each condition
Step 1 is executed after the target opening degree θ2- is set.
In step 13, the target opening degree θ2' and the above step 10 are determined.
Comparing with the sub-throttle opening degree θ2 obtained in 1.
The drive signal Vs (
duty ratio) and temporarily ends the processing of this routine. Incidentally, when setting this rotational speed, a map D as shown in FIG. 9 is used.

Next, FIG. 5 shows the rotational speed VS of the DC motor 11 and the target opening degree θ determined by the acceleration slip determination routine shown in FIG. 4 above.
2' and the sub-throttle opening degree θ2, the DC motor 11 is driven in the opening direction or the closing direction of the sub-throttle valve 10 to actually execute slip control.

This process is executed by interrupts at predetermined time intervals. When the process starts, first in step 201 the target opening degree is set to 02.
' and the sub-throttle opening degree θ2 to determine the driving direction of the sub-throttle valve 10. That is, 02′〈θ2
If so, it is determined that the sub-throttle valve 10 is to be driven in the closing direction, and the process proceeds to step 202, in which the DC motor 11 is driven by the drive signal Vl set in step 113.
1 to drive the sub throttle valve 10 in the opening direction.

On the other hand, if θ2'≧θ2, it is determined that the sub-throttle valve 10 is to be driven in the opening direction, and step 203
Then, the DC motor 11 is driven in the opening direction of the sub-throttle valve 10 using the drive signal Vs. At this time, 02
'=02 and the drive signal ■S may be "O", but in that case, the DC motor 11 will not be driven.

As explained above, in the acceleration slip control device of this embodiment, when it is determined that the driving wheel speed Vr exceeds the reference speed Vt and acceleration slip is occurring in the driving wheels, the target opening degree θ2 of the sub-throttle valve 10 is changed. , the idle wheel speed Vf, that is, the minimum limit opening degree θ2-m1 set according to the vehicle running speed.
n, and the drive wheel speed V' and reference speed Vt are limited for each process.
It will be gradually reduced according to the difference between the two. Therefore, as shown in FIG. 10, the sub-throttle opening degree θ2 does not decrease suddenly, but gradually decreases, so that a large engine brake does not occur and give the driver a sense of discomfort.

Also, once acceleration slip occurs and its control is started,
Even if the driving wheel speed Vr is lower than the reference speed Vt, the target opening degree θ2- of the auxiliary throttle valve 10 is set according to the difference between the driving wheel speed vr and the reference speed Vt, and the auxiliary throttle opening is maintained as shown in FIG. The degree θ2 will be gradually increased.

Therefore, stable acceleration performance can be obtained without causing a large acceleration slip to occur again due to the sub-throttle opening degree θ2 suddenly increasing after the acceleration slip is suppressed as in the conventional case.

Furthermore, even when the sub-throttle valve 10 is gradually opened as described above, the driving wheel speed V
When the deviation between r and the reference speed Vt becomes large, the driving amount of the sub-throttle valve 10 is set to be large in order to improve the responsiveness of the process, and the sub-throttle opening degree θ2 may increase too much. In this embodiment, the upper limit, that is, the maximum limit opening θk is set to the drive wheel speed Vr during the previous process.
Since it is set and limited according to the maximum speed deviation Δy(b-t) between the reference speed Vt and the reference speed Vt, recurrence of acceleration slip can be more completely suppressed.

In this embodiment, as mentioned above, the sub-throttle valve 10
When driving in the opening direction, while limiting the target opening degree 02' by the maximum limit opening degree θk, the driving wheel speed Vr and the reference speed V
It was configured to be set and controlled according to the deviation from t, but
Simply drive wheel speed Vr without using maximum opening limit θk
Recurrence of acceleration slip can be suppressed simply by setting the target opening degree θ2- according to the deviation between the reference speed Vt and the reference speed Vt, and gradually driving the sub-throttle valve 10 in the opening direction.

In addition, in this embodiment, the throttle valve installed in the intake system of the internal combustion engine is divided into two parts, one as a main throttle valve linked to the accelerator pedal, and the other as a sub-throttle valve driven by a DC motor to perform acceleration slip control. However, in the case of a vehicle that uses a so-called linkless throttle valve, which is not linked to the accelerator pedal, the system is configured to use a sub-throttle valve for acceleration slip control as described above. Acceleration slip control as described above can be performed by directly driving and controlling the linkless throttle valve. In this case, the process of detecting the opening of the main throttle valve and opening the sub-throttle valve according to the valve opening as described above becomes unnecessary, which further simplifies acceleration slip control. be able to.

[Effects of the Invention] As detailed above, in the acceleration slip control device for a vehicle of the present invention, when an acceleration slip occurs, the throttle valve is driven in the closing direction to suppress the rotation of the drive wheels, and then the throttle valve is driven in the opening direction. When driving, the target opening degree is set according to the deviation between the rotation speed of the drive wheels and the reference speed, so after acceleration slip is suppressed, large acceleration slip does not occur again, and acceleration Recurrence of slip can be effectively suppressed. Therefore, the time it takes to completely suppress acceleration slip can be shortened.
It becomes possible to obtain good acceleration performance.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of the present invention, FIGS. 2 to 10 show an embodiment of the present invention, FIG. 2 is a schematic configuration diagram thereof, and FIG. 3 is a block diagram showing an electronic control circuit. ,
FIG. 4 is a flowchart showing the control program of the acceleration slip determination routine of acceleration slip control executed by the electronic control circuit, FIG. 5 is a flowchart showing the control program of the slip control routine, and FIGS. 6 to 9 are respectively A diagram showing the contents of maps A to D used in the acceleration slip determination routine, and FIG. 10 is a time chart showing wheel speeds, throttle openings, and counter values that change due to acceleration slip control. 8... Main throttle valve 9... Accelerator pedal 10... Sub throttle valve 11... DC motor 12... Main throttle sensor 13... Sub throttle sensor 24... Left drive Wheel speed sensor 25...Right drive wheel speed sensor 30...Electronic control circuit

Claims (1)

[Scope of Claims] Vehicle speed detection means for detecting the running speed of the vehicle; reference speed calculation means for calculating a reference speed of the driving wheels based on the running speed of the vehicle detected by the vehicle speed detection means; and the driving wheels. a driving wheel speed detection means for detecting the rotational speed of the driving wheel; a rotational speed of the driving wheel detected by the driving wheel speed detection means;
and detecting acceleration slip of the driving wheels using the reference speed calculated by the reference speed calculation means as a parameter, and suppressing the acceleration slip by opening/closing control of a throttle valve provided in the intake system of the internal combustion engine of the vehicle. In the acceleration slip control device for a vehicle, the acceleration slip suppressing means calculates a target opening degree of the throttle valve when the throttle valve is driven in the opening direction. A vehicle characterized in that it is configured to include target opening setting means for setting based on the difference between a reference speed and a driving wheel speed detected by the driving wheel speed detecting means, and to suppress recurrence of acceleration slip. Acceleration slip control device.