JPH0674065A - Acceleration slip control device for vehicle - Google Patents

Abstract

PURPOSE:To realize stable running of a vehicle by executing acceleration slip control in consideration of an element related to the drive transmission system of a vehicle, such as a torque converter and an automatic transmission. CONSTITUTION:An input shaft 17 and an output shaft 19 are fixed to the pump impeller 16 and the turbine runner 18, respectively, of a torque converter 15 and the shafts 17 and 19 are coupled to the engine 1 side and the automatic transmission 21 side. Rear wheels (drive wheels) 26 and 27 are coupled to the automatic transmission 21 through a differential gear 23. An acceleration slip control circuit 35 executes control of the opening of a subthrottle valve 6 and executes control of the number of revolutions of the engine 1 through cut of fuel. Further, the acceleration slip control circuit 35 provides the target number of revolutions of an engine through control of the number of revolutions based on a deviation between the number of revolutions on the input side (the number of revolutions of an engine) and the number of revolutions on the output side (the number of revolutions of a turbine) of the torque converter 15 and the speed change step of the automatic transmission 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle acceleration slip control device applied to a vehicle equipped with an engine, a torque converter and an automatic transmission.

[0002]

2. Description of the Related Art Conventionally, as an acceleration slip control device for a vehicle, for example, JP-A-1-280530 and JP-A-2-176136 have been disclosed.

Among these, in the acceleration slip control device disclosed in Japanese Unexamined Patent Publication No. 1-208530, when an acceleration slip occurs, opening / closing control of a throttle valve having poor response and output torque reduction control having good response are performed in parallel. To be done. Then, in this control device, the output torque reduction control such as the ignition timing control and the fuel cut control is performed only during the period in which the acceleration slip cannot be suppressed by the opening / closing control of the throttle valve immediately after the occurrence of the acceleration slip.

Further, in the acceleration slip control device disclosed in Japanese Patent Laid-Open No. 2-176136, when an acceleration slip occurs on the drive wheels during acceleration, fuel cut control is performed and the fuel cut control is performed according to the slip ratio at that time. The engine speed is set. Further, in this control device, the higher the slip ratio, the higher the engine speed at the end of fuel cut.

[0005]

However, in the control device disclosed in JP-A-1-208530, the execution time of the output torque reduction control due to fuel cut or the like is set to a constant value, and the friction coefficient of the road surface is reduced. Due to differences and the like, such control within a certain period of time did not always provide a sufficient effect. That is, when the control time is too short with respect to the appropriate control time, the effect of the output torque reduction control is small, and when the control time is too long, the output torque becomes too small and the engine may be stalled.

On the other hand, in the control device disclosed in Japanese Unexamined Patent Publication No. 2-176136, the acceleration slip control is executed using only the slip ratio generated on the wheels as a parameter.
Considering the influence of elements of the drive transmission system, such as the torque converter and the automatic transmission, on the acceleration slip control, a sufficient effect could not be expected.

That is, in the case of a vehicle equipped with an automatic transmission,
If the shift speed is automatically changed during acceleration, the speed of the vehicle may change significantly, and the drivability of the vehicle may become unstable. That is, during acceleration, for example, if the gear stage is changed to a larger gear stage, the gear ratio with respect to the gear stage becomes small.
As shown in, the rotation speed transmitted to the drive wheel side is high. FIG. 14 is a characteristic diagram showing the engine speed for keeping the slip ratio of the drive wheels constant at each shift speed according to the vehicle speed. Therefore, in the above-described conventional control device in which the target engine speed is set regardless of the gear position, a shift shock occurs or a large acceleration slip occurs during gear shifting of the automatic transmission, resulting in stable vehicle running. There was a problem that was damaged.

Further, in the torque converter, when the input rotation speed from the engine is transmitted to the output rotation speed to the drive wheels, slip occurs in the torque converter. At this time, in the above-described conventional control device, the target engine speed is set regardless of the slip in the torque converter, so when the target engine speed is output to the drive wheels, only the slip amount is output. It will be a lowered value. As a result, there arises a problem that the control accuracy based on the target engine speed decreases.

The present invention has been made in view of the above problems, and an object of the present invention is to consider acceleration slip control in consideration of elements related to a vehicle drive transmission system such as a torque converter and an automatic transmission. The object of the present invention is to provide an acceleration slip control device for a vehicle, which can realize stable vehicle travel by implementing the above.

[0010]

In order to achieve the above object, a vehicle acceleration slip control device according to the present invention is drivingly connected to an automatic transmission having an output shaft of an engine having a plurality of gear ratios via a torque converter. In addition, the automatic transmission is drivingly connected to the drive wheels of the vehicle, and the opening of the throttle valve is controlled to eliminate the deviation between the target vehicle body speed of the vehicle and the drive wheel speed, and the target engine speed is If the deviation between the engine speed and the actual engine speed is more than a predetermined value, in order to eliminate the deviation, the output slip of the engine is controlled by the fuel cut or ignition timing. The input side speed of the torque converter is the engine speed of,
Deviation from the output side speed of the torque converter, and
The gist is that the target engine speed is generated based on the shift speed of the automatic transmission.

Further, the target engine rotational speed increases as the deviation between the input rotational speed and the output rotational speed of the torque converter increases or the gear ratio corresponding to the shift speed of the automatic transmission increases. , It is desirable to set it to be large.

[0012]

According to the above construction, the opening degree of the throttle valve is controlled so as to eliminate the deviation between the target vehicle body speed of the vehicle and the driving wheel speed, and the deviation between the target engine speed and the actual engine speed is achieved. Is greater than or equal to a predetermined value, the output torque of the engine is controlled by fuel cut or ignition timing in order to eliminate the deviation. As a result, in the region where the deviation between the target engine speed and the actual engine speed is smaller than the predetermined value, only the throttle valve opening control is performed. If the deviation is equal to or larger than the predetermined value, the output torque control is performed together with the throttle valve opening control. Therefore, when the deviation is large, the output torque control with good responsiveness acts to supplement the opening control of the throttle valve with poor responsiveness to ensure the control responsiveness, and when the deviation is small, the output torque control is performed by the throttle valve. The stability of the control is ensured without interfering with the valve opening control.

Further, in the present invention, particularly, the target engine speed of the output torque control of the engine is the deviation between the input speed of the torque converter and the output speed of the torque converter, which is the speed of the engine, and It is generated based on the gear ratio of the automatic transmission. Specifically, the target engine rotation speed is set to increase as the deviation between the input rotation speed and the output rotation speed of the torque converter increases or the gear ratio corresponding to the shift stage of the automatic transmission increases. Is set.

As a result, even if the drive wheel speed on the output side becomes smaller than the target engine speed on the input side by the amount of slip occurrence in the torque converter, the slip amount is corrected. Even if the automatic transmission shifts during the acceleration slip control and the ratio of the speed of the driving wheels to the engine speed changes, the target engine speed is set according to the speed ratio, and Gear shift shock and acceleration slip are less likely to occur.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing a configuration of a rear-wheel drive vehicle including the acceleration slip control device of the embodiment. The vehicle in this embodiment is equipped with a 6-cylinder engine, and has a torque converter and an automatic transmission.
It is a so-called A / T (automatic transmission) vehicle. In the engine 1, the intake pipe 2 is provided with a main throttle valve 4 which is opened / closed in association with the depression operation of the accelerator pedal 3. A throttle opening sensor 5 is connected to the main throttle valve 4, and the opening of the main throttle valve 4 is detected by the throttle opening sensor 5. Further, a sub-slut valve 6 is arranged in the intake pipe 2 upstream of the main throttle valve 4, and the sub-slut valve 6 is opened and closed by driving a drive motor 7. Further, an injector 8 is arranged on the most downstream side of the intake pipe 2.

A piston 10 is reciprocally arranged in a cylinder block 9 of the engine 1, and a spark plug 12 is arranged in a combustion chamber 11 defined by the cylinder block 9 and the piston 10. The ignition timing of the spark plug 12 is determined by the high voltage generation timing from the ignition device 13. An engine speed sensor 14 for detecting the engine speed is arranged on a crankshaft (not shown).

On the other hand, in the drive transmission system of the engine 1,
A pump impeller 16 and a turbine runner 18 are arranged in the torque converter 15 so as to be integrally rotatable via a working fluid. An input shaft 17 is fixedly connected to the pump impeller 16, and an output shaft 19 is fixedly connected to the turbine runner 18. The input shaft 17 is connected to the output rotation shaft (crank shaft) of the engine 1 and inputs the rotation of the engine 1 to the output shaft 19
Outputs rotation to the automatic transmission 21 described later. Further, a turbine rotation speed sensor 20 for detecting the rotation speed of the turbine runner 18 is arranged near the output shaft 19. In this embodiment, the turbine speed detected by the turbine speed sensor 20 is the torque converter 15.
And the engine speed detected by the engine speed sensor 14 corresponds to the input speed of the torque converter 15.

The automatic transmission 21 connected to the output shaft 19 of the torque converter 15 is composed of a planetary gear (not shown) and a multi-plate clutch (not shown), and a command signal from the transmission control circuit 37. The gear position is changed based on. The automatic transmission 21 according to the present embodiment has a parking stage, a neutral stage, a drive stage (1st to 4th gears),
It has a reverse stage.

A differential gear 23 (differential device) is connected to a propulsion shaft 22 extending from the automatic transmission 21,
Left and right rear wheels (drive wheels) 26, 27 are connected to the differential gear 23 via a drive shaft 25. A left rear wheel rotation speed sensor 28 is attached to the left rear wheel 26, and a right rear wheel rotation speed sensor 29 is attached to the right rear wheel 27. A left front wheel rotation speed sensor 32 and a right front wheel rotation speed sensor 33 are attached to the left and right front wheels (driven wheels) 31, respectively.

Further, the acceleration slip control device in this embodiment is provided with an acceleration slip control circuit 35, an engine control circuit 36 and a transmission control circuit 37. Among them, the acceleration slip control circuit 35 is configured as a logical operation circuit mainly including a CPU 35a, a ROM 35b, a RAM 35c, a backup RAM 35d, etc., as shown in FIG. The input port 35f, the output port 35g, and the D / A converter 35 are provided via the common bus 35e.
It is connected to h and inputs and outputs with the outside.

Although not shown, the engine control circuit 3
6, the transmission control circuit 37 and the transmission control circuit 37 are logical operation circuits mainly composed of a CPU, a ROM, a RAM, a backup RAM and the like like the acceleration slip control circuit 35.

The turbine rotation speed sensor 20 is connected to the transmission control circuit 37, and the detected value by the turbine rotation speed sensor 20 is the transmission control circuit 3.
The waveform is shaped in 7 and input to the acceleration slip control circuit 35. The transmission control circuit 37 also controls the automatic transmission 2 based on the driving state of the vehicle such as driving wheel speed and throttle opening.
In order to automatically switch the first gear, the automatic transmission 21
The shift signal is output to.

The acceleration slip control circuit 35 includes the left and right rear wheel rotation speed sensors 28 and 29 and the left and right front wheel rotation speed sensors 3.
2 and 33 are connected, and the detection signal from each rotation speed sensor is input to the CPU 35a via the waveform shaping circuit 35i and the input port 35f. Further, the engine speed sensor 14 and the throttle opening sensor 5 are connected to the acceleration slip control circuit 35, and a detection signal from each sensor is input. The acceleration slip control circuit 35 then detects the rear wheels 26, 27 based on the detection signals from these sensors.
The slip state of is detected.

Further, the acceleration slip control circuit 35 includes
A drive motor 7 for driving the sub-throttle valve is connected, and the CPU 35a outputs a control signal to the drive circuit 35j via an output port 35g based on a control result described later. That is, the CPU 35a executes drive control of the drive motor 7, that is, opening / closing control of the sub-throttle valve 6.

In addition, the acceleration slip control circuit 35 includes
The engine control circuit 36 is connected to the CPU 35a.
Outputs an engine speed control signal (voltage signal) to the engine control circuit 36 via the D / A converter 35h based on the control result described later. And the engine control circuit 3
6 cuts the fuel injected from the injector 8 to the engine 1 based on the output voltage, and executes the rotation speed control of the engine 1 as the output torque control.

As described above, in this embodiment, as the acceleration slip control, the opening / closing control of the sub-throttle valve 6 and the rotational speed control of the engine 1 are executed.
In addition, the engine control circuit 36 receives detection signals from various sensors that detect the operating state of the engine 1, and according to the detection results, a high voltage generation timing from the ignition device 13 to the ignition plug 12, that is, an ignition timing. To control.

Next, the acceleration slip control operation of the acceleration slip control device of this embodiment will be described. First, the opening / closing control of the sub-throttle valve 6 will be described below.

3 and 4 show an acceleration slip control circuit 3
6 is a flowchart showing the opening / closing control of the sub-throttle valve 6 executed by the CPU 35a in 5 every predetermined time,
FIG. 3 shows a control amount calculation routine for the sub throttle valve 6, and FIG. 4 shows a driving routine for the sub throttle valve 6.

In the opening / closing control routine of the sub-throttle valve 6 shown in FIG. 3, first, the CPU 35a executes step 10
Left and right rear wheel and left and right front wheel rotation speed sensors 28, 2
The detection signals from 9, 32, and 33 are input, and the vehicle speed VF is input.
And the drive wheel speed VR are calculated. The vehicle body speed VF is the average value of the output values VFL and VFR of the left and right front wheel rotation speed sensors 32 and 33, or the left and right front wheel rotation speed sensors 32 and 3 thereof.
Of the output values VFL and VFR of 3 to the larger value of the front wheel 30,
It is a value calculated by multiplying the perimeter of 31. Further, the driving wheel speed VR is a larger value of the output values VRL, VRR of the left and right rear wheel rotation speed sensors 28, or the smaller output value when the differential gear 23 has a differential limiting device (LSD). Is a value calculated by multiplying by the perimeter of the rear wheels 26, 27.

Next, in step 101, the CPU 35a
From the vehicle body speed VF calculated in step 100, the control reference speed VS as the target vehicle body speed of the opening / closing control is calculated using the following mathematical expression 1.

[0031]

## EQU1 ## VS = VF · a where a is a constant of 1 or more. This control reference speed V
S is a rear wheel 2 which is a driving wheel in the acceleration slip control.
Since the target speed is 6, 27, the constant a is 1.12 to 1.12 so that the driving force on the road surface of that value becomes the largest.
A value of around 1.20 is selected. The control reference speed VS may be calculated by the following mathematical formula 2 instead of the mathematical formula 1.

[0032]

## EQU00002 ## VS = VF + b where b is a positive constant.

Next, in step 102, the CPU 35a causes the open / close control execution flag FS to be reset (FS).
= 0) is determined. Here, the opening / closing control execution flag FS is set (FS = 1) when the opening / closing control of the sub-throttle valve 6 is started, and it is determined in step 102 whether the opening / closing control of the sub-throttle valve 6 is currently executed. Is determined. When the open / close control execution flag FS is reset and it is determined that the open / close control is not executed, the CPU 35a proceeds to the subsequent step 103.

In step 103, the CPU 35a determines whether or not the conditions for executing the acceleration slip control are satisfied. Specifically, in step 103, it is judged if the main throttle valve 4 is not in the fully closed state and the drive wheel speed VR is equal to or higher than the control reference speed VS. And CP
If the control execution condition is not satisfied in step 103, the U35a temporarily terminates the process, and if the control execution condition is satisfied, the process proceeds to step 104.

In step 104, the CPU 35a determines whether or not a predetermined time (for example, 8 msec.) Has elapsed after the establishment of step 103. If the predetermined time has not elapsed, the CPU 35a ends the process. By the processing of step 104, even if a momentary rotational change of the rear wheels 28, 29 due to unevenness of the road surface or the like occurs, the rotational change is not erroneously determined as an acceleration slip.

Then, when step 104 is satisfied,
The CPU 35a goes to the following step 105 and sets the opening / closing control execution flag FS (FS = 1). Then C
The PU 35a proceeds to step 106 and detects the engine speed NE detected by the engine speed sensor 14.
And the throttle opening θ, the correction coefficient K is interpolated from the two-dimensional map shown in FIG.

In calculating the correction coefficient K,
The opening degree of the main throttle valve 4 (hereinafter referred to as the main throttle opening degree) θM is the opening degree of the sub-throttle valve 6 (hereinafter referred to as the sub-throttle opening degree θS) when the opening / closing control is started.
In the case of the following, the main throttle opening θM detected by the throttle opening sensor 5 is used as the throttle opening θ. If the sub-throttle opening θS becomes smaller than the main throttle opening θM after the opening / closing control is started, the sub-throttle opening θS becomes the throttle opening θS.
Used as. That is, the smaller one of the main throttle opening θM and the sub throttle opening θS is used as the throttle opening θ. Here, the sub throttle opening θS is calculated based on the driving amount of the sub throttle valve 6 by the driving process described later.

Next, the CPU 35a calculates the control amount .theta.S1 of the sub-throttle valve 6 by the following formula 3 in step 107.

[0039]

## EQU00003 ## .theta.S1 = K.multidot. (. Alpha..DELTA.V + .beta..multidot..DELTA.V1) The control amount .theta.S1 represents the change amount of the sub throttle opening .theta.S per unit time, that is, the drive motor 7 for driving the sub throttle valve. It is the target rotation speed. or,
In Equation 3, α is a proportional gain, β is a differential gain, and ΔV is a control reference speed VS that is the target speed of the driving wheels.
And the speed difference between the drive wheel speed VR and the drive wheel speed VR (= VS-VR), ΔV
1 is a time differential value of the speed difference ΔV. The opening / closing control of the sub-throttle valve 6 is executed so that the drive wheel speed VR approaches the control reference speed VS by the control amount θS1.

Here, FIG. 5 was used to obtain the correction coefficient K in step 106. In this figure, the correction coefficient K increases as the engine speed NE increases and the throttle opening θ increases. Is set to.
This is because, as shown in FIG. 6, the output torque with respect to the throttle opening θ responds with good sensitivity at a low throttle opening (the inclination of the output torque characteristic at each engine speed NE in FIG. 6 is large), and the medium throttle This is because the degree of increase becomes slower from the opening to the high throttle opening (the inclination of the output torque characteristic in FIG. 6 is small). That is, the larger the engine speed NE and the larger the throttle opening θ,
The correction coefficient K is set to a large value, and the control amount θS1 calculated by the equation 3 also increases. As a result, it is possible to prevent the control responsiveness of the sub-throttle valve 6 from being lowered.

After the control amount θS1 of the sub-throttle valve 6 is set in this way, the CPU 35a once ends the processing. On the other hand, if it is determined in step 102 that the opening / closing control execution flag FS is in the set state (FS = 1), that is, if the opening / closing control of the sub-throttle valve 6 has already been executed, the CPU 35a starts from step 102. Go to step 108. Then, the CPU 35a determines in step 108 whether or not the valve opening determination flag FA is set. This valve opening determination flag F
A is set when the sub-throttle opening θS becomes equal to or less than the main throttle opening θM after the opening / closing control is started by the drive routine of FIG.
If the valve opening determination flag FA is not set in step 108, the process proceeds to step 106.

If the valve opening determination flag FA is set, that is, if the sub-throttle opening θS has once become less than or equal to the main throttle opening θM after the start of control, the routine proceeds to step 109. Then, it is determined whether or not the sub throttle opening θS becomes larger than the main throttle opening θM. Then, if θ S ≦ θ M, the process proceeds to step 106 again, and the control amount calculation process of the sub-throttle valve 6 is executed as described above. Further, if θS> θM, it is determined that the acceleration slip does not occur on the drive wheels anymore, and the flags FS and FA are reset (FS, FA = 0) in step 110 and step 111, and then the processing is performed. It ends once.

Next, in the driving routine for the sub-throttle valve 6 shown in FIG.
Now, the opening / closing control execution flag FS is set (FS = 1)
It is determined whether or not it has been done. Then, if the opening / closing control execution flag FS is set, the routine proceeds to step 201, where it is judged whether or not the sub-throttle opening θS is less than or equal to the main throttle opening θM.

If step 201 is not established,
That is, if θS> θM, the process proceeds to step 202, the drive motor 7 is driven to close the sub-throttle valve 6 rapidly, and then the process is terminated. On the other hand, step 20
When 1 is satisfied, that is, when θS ≦ θM, the routine proceeds to step 203, where the valve opening determination flag FA is set (FA = 1), and then the routine proceeds to step 204. C
The PU 35a sets the sub throttle valve 6 according to the control amount θS1 set in the routine of FIG. 3 in step 204.
After driving the drive motor 7 to open and close, the process is temporarily terminated.

On the other hand, when it is determined in step 200 that the opening / closing control execution flag FS is in the reset state (FS = 0), the CPU 35a proceeds to step 205 and determines whether the sub throttle valve 6 is in the fully open state. To judge. In this judgment, the sub-throttle opening θS is the maximum value θ
It depends on whether or not it is above SMAX. Then, the sub throttle valve 6 is not in the fully open state, and θS <
If θSMAX, the CPU 35a drives the drive motor 7 to rapidly open the sub-throttle valve 6 in step 206, and then ends the process once.

If the sub-throttle valve 6 is in the fully open state (θS ≧ θSMAX), the CPU 35a stops the drive motor 7 to stop the driving of the sub-throttle valve 6 in step 207, and then once the process is completed. Stop.

As described above, in the opening / closing control of the sub-throttle valve 6, the drive wheel speed VR and the control reference speed VS are set.
The acceleration slip of the drive wheels is detected based on the above (step 103 in FIG. 3), and opening / closing control of the sub-throttle valve 6 is started. Then, the sub throttle opening θS is controlled based on the deviation between the drive wheel speed VR and the control reference speed VS (step 107 in FIG. 3), and when the sub throttle opening θS exceeds the main throttle opening θM, the vehicle is opened. Is determined to be in an operating state in which it is not necessary to execute the acceleration slip control, and the opening / closing control of the sub-throttle valve 6 is ended (step 110 in FIG. 3).

Next, engine speed control by fuel cut will be described with reference to FIGS. The flowcharts of FIGS. 7 to 9 represent a routine executed by the CPU 35a in the acceleration slip control circuit 35 at predetermined time intervals as in the processes of FIGS. 7 and 8 show a routine for outputting the rotation speed control signal of the engine 1 to the engine control circuit 36, and FIG. 9 shows a routine for processing the shift signal from the transmission control circuit 37. There is.

7, in step 300, the CPU 35a first determines from the control reference speed VS calculated in step 101 of FIG. 3 and the gear ratio GR corresponding to the gear stage of the automatic transmission 21 as follows. The target rotation speed (hereinafter, referred to as the target torque converter rotation speed) NCT of the torque converter 15 is calculated by using the equation (4).

[0050]

## EQU00004 ## NCT = GR.VS The speed change ratio GR is set based on the speed change signal input from the transmission control circuit 37, and also includes a coefficient for converting the speed into the number of revolutions.

Then, the CPU 35a proceeds to step 301.
At 304, it is determined whether or not the drive wheel speed VR of the vehicle in the initial stage of acceleration converges within a predetermined range and various conditions for executing the engine speed control are satisfied. Steps 301 to 30
4, the CPU 35a will execute the step 30.
1, the open / close control execution flag FS is set (FS =
It is determined whether or not 1). In step 302, it is determined whether or not the average speed {= (VRL + VRR) / 2} of the left and right rear wheels 26, 27 is greater than the vehicle body speed VF. In step 303, it is determined whether the drive wheel speed VR is smaller than the control reference speed VS. Further, in step 304, the engine speed N detected by the engine speed sensor 14
It is determined whether E is equal to or higher than the turbine rotation speed NC detected by the turbine rotation speed sensor 20, that is, whether a positive torque is transmitted from the engine 1 to the torque converter 15.

If all the determination processes in steps 301 to 304 are satisfied, the CPU 35a proceeds to step 305 and shifts flag XSFT described later is executed.
Is in the reset state (XSFT = 0). If the shifting flag XSFT is "0", that is, if the automatic transmission 21 is not shifting, the CPU 35a proceeds to step 306. In step 306, the CPU 35a determines from the engine speed NE and the turbine speed NC that
The slip rotation speed NSC of the torque converter 15 is calculated using the following mathematical expression 5.

[0053]

## EQU5 ## NSC = NE-NC In the following step 307, the CPU 35a sets the target engine speed calculation flag XFB (XFB = 1). Then, if the target engine speed calculation flag XFB is in the set state (XFB = 1), the target engine speed NT is calculated by Equation 6 described later, and the reset state (X
If FB = 0), the target engine speed NT is calculated in the map of FIG. 10 described later.

Then, in the next step 308, the CPU
35a is the target torque converter rotational speed NCT calculated in step 300 and the slip rotational speed NS calculated in step 306
From C and C, the target engine speed NT is calculated using Equation 6.

[0055]

[Equation 6] NT = NCT + NSC As described above, when steps 301 to 304 are satisfied and the automatic transmission 21 is not in the middle of shifting (XSFT =
0), the slip rotation speed NSC is determined in step 306.
Is calculated and the previous value is updated.

On the other hand, if any of the determination processes of steps 301 to 305 is not established, the CPU 35a immediately proceeds to step 309, and the target engine speed calculation flag XFB is currently set (XFB = 1). It is determined whether or not there is. When the target engine speed calculation flag XFB is set ((XFB = 1)), the process proceeds to step 308 described above, and the target engine speed NT is calculated from the equation (6).

If the target engine speed calculation flag XFB is in the reset state (XFB = 0) in step 309, the CPU 35a proceeds to step 310 and sets a preset value, for example, the target from the map of FIG. The engine speed NT is calculated. In FIG. 10, the target engine speed NT corresponding to the target torque converter speed NCT is set, and the characteristic line L of FIG. 10 shows the characteristics when the road surface friction coefficient is 0.4. is there. At this time, the target engine speed NT calculated by the characteristic line L (the target speed on the input side of the torque converter 15)
Is always a value obtained by adding the expected amount of slip in the torque converter 15 to the target torque converter speed NCT (target speed on the output side). The characteristics shown in FIG. 10 may be obtained by detecting a parameter based on the friction coefficient of the road surface as disclosed in Japanese Patent Laid-Open No. 19622/1990, and adding a correction according to the parameter.

After that, the CPU 35a proceeds to step 3 in FIG.
After the processing of 08 or 310, the process proceeds to step 311 of FIG. 8 and the output conditions of the engine speed control signal are determined in steps 311 to 313. For details, see step 311.
Then, the engine speed NE is a predetermined speed (in the present embodiment,
(1000 rpm) or higher is determined. This process is for preventing control execution in the low rotation speed region to prevent engine stall. In step 312, it is determined whether or not the gear stage of the automatic transmission 21 is the neutral gear or the parking gear. This process is for preventing control execution at the neutral stage or the parking stage. In step 313, it is determined whether or not the opening / closing control execution flag FS is set (FS = 1).

When all the steps 311 to 313 are established, the CPU 35a proceeds to step 314 and determines whether or not the shifting flag XSFT is in the reset state (XSFT = 0). If the shifting flag XSFT has been reset, the CPU 35a proceeds to step 315.
Then, the fuel cut cylinder number TR as the engine speed control value is calculated from the characteristic line LA (shown by the solid line) of FIG. That is, if the automatic transmission 21 is not shifting, CP
The U 35 a sets the fuel cut cylinder number TR to any of “0” to “6” according to the deviation (= NE−NT) between the engine speed NE and the target engine speed NT.

If it is determined in step 314 that the shifting flag XSFT is set (XSFT = 1), the CPU 35a proceeds to step 316 and moves from the characteristic line LB (shown by the broken line) in FIG. 11 to the fuel cut cylinder. Calculate the number TR. That is, the CPU 35a sets the fuel cut cylinder number TR to any of "0" to "2" according to the deviation (= NE-NT) while the automatic transmission 21 is in the middle of shifting.
Then, the signal of the fuel cut cylinder number TR thus set is output from the acceleration slip control circuit 35 to the engine control circuit 36, and the engine control circuit 36 executes the fuel cut based on the TR signal.

In FIG. 11, the maximum number of cylinders for fuel cut of the characteristic line LB is limited to "2" by limiting the control amount with respect to the engine speed at the time of shifting to prevent the occurrence of rattling of the engine 1. This is because Further, in FIG. 11, if the deviation (= NE-NT) between the engine speed NE and the target engine speed NT is smaller than the predetermined value NA, the fuel cut cylinder number TR becomes "0", and the engine 1
The rotation speed control is not performed.

On the other hand, if any of steps 311 to 313 is not established, the CPU 35a proceeds to step 317 to reset the target engine speed calculation flag XFB (XFB = 0). Then, the CPU 35a sets the fuel cut cylinder number TR to "0" in the following step 318, and ends this routine. That is, steps 311 to 311
When the process shifts from 13 to steps 317 and 318, it is determined that the engine speed control is not necessary, and the fuel cut cylinder number TR is set to "0".

Next, the processing routine of the shift signal of FIG. 9 will be described. In FIG. 9, the CPU 35a first determines in step 401 whether or not the shift-in-progress flag XSFT is currently in the set state (XSFT = 1). And
If XSFT = 0 and the automatic transmission 21 is not in the speed change state, the CPU 35a proceeds to step 402 and stores the shift value stored value SHM of the automatic transmission 21 at the time of the previous processing.
Then, it is determined whether or not the input value SHI of the shift stage input from the transmission control circuit 37 this time is the same. And
If they are the same (SHM = SHI), the CPU 35a
Assuming that the gear shift has not been performed, the routine proceeds to step 409, the gear ratio GR is calculated from the stored value SHM of the gear stage using the characteristic example of FIG. 12, and this routine is ended.
In FIG. 12, the gear ratio GR corresponding to each gear is set, and the gear ratio GR becomes smaller as the gear becomes larger.

On the other hand, if they are not the same in step 402 (SHM ≠ SHI), the CPU 35a proceeds to step 40.
3, and after step 402 is not established, a predetermined time (0.
It is determined whether or not 2 seconds) has elapsed. At this time, 0.2 seconds is a delay time from when the transmission control circuit 37 outputs the shift signal to when the shift is started in the automatic transmission 21,
The value may be changed depending on the driving conditions and the vehicle model. Then, when 0.2 seconds has elapsed, the CPU 35a proceeds to step 4
04, the input value SHI is stored as the stored value SHM, and the process proceeds to step 405.

The CPU 35a sets the in-shift flag XSFT in step 405, and proceeds to step 406. In step 406, the CPU 35a calculates the slip rotation speed NSC of the torque converter 15 using the following formula 7.

[0066]

## EQU00007 ## NSCi = 1.8.NSCi-1 However, the subscript i in the equation 7 indicates the current value, and the subscript i-1 indicates the previous value.

By this step 406, XSFT = 1
In this case, the slip rotation speed NSC calculated in step 306 of FIG. 7 described above is updated. The coefficient “1.8” in Expression 7 is expected to increase the slip amount of the torque converter 15 at the time of shifting, and may be changed depending on the running condition.

On the other hand, in step 401, the shifting flag XS
If FT is set (XSFT = 1), then C
The PU 35a proceeds to step 407, and the automatic transmission 21
The presence or absence of slip inside is determined. That is, slip occurs between the gears in the automatic transmission 21 via the working fluid during the shift operation of the shift stage. Therefore, the CPU 35a determines the presence / absence of slip in the automatic transmission 21 by the following formula 8.

[0069]

[Equation 8]

According to this equation 8, the turbine speed NC
And the average value of the left and right rear wheels 26, 27 {= (VRL + VRR) /
The absolute value of the deviation from the value obtained by multiplying 2} by the gear ratio GR is 50r.
It is determined whether it is pm or more. In other words, the expression 8 determines whether or not the deviation between the rotation speed on the input side and the rotation speed on the output side of the automatic transmission 21 is 50 rpm or less. Then, if Equation 8 is established, the CPU
35a determines that the automatic transmission 21 is still in the shifting operation and that the automatic transmission 21 is slipping, and proceeds to step 409. The CPU 35a is
As described above in step 409, the gear ratio GR is calculated, and the routine ends.

On the other hand, when the shifting operation of the automatic transmission 21 ends, the slip in the automatic transmission 21 subsides, and the equation 8 is not satisfied. Then, the CPU 35a carries out step 4
In 08, the shifting flag XSFT is reset (XSFT =
0), and similarly to the above, after calculating the gear ratio GR, the routine ends.

FIG. 13 is a time chart showing the control operation of this embodiment. In FIG. 13, the occurrence of acceleration slip is detected at the timing of t1, and the opening / closing control execution flag FS is set (FS = 1). Further, at the timing of t3, the target engine speed calculation flag XFB is set (XF
B = 1) and the in-shift flag XSFT is set (XSFT = 1) at the timing of t4 to t5.

Explaining in order below, first, at the timing of t1, the drive wheel speed VR is temporarily set to the control reference speed VS,
It sharply increases with respect to the vehicle body speed VF and becomes equal to or lower than the control reference speed VS at the timing of t3.

Before the timing t3, the target engine speed calculation flag XFB is in the reset state, so the target engine speed NT is calculated according to the target torque converter speed NCT using the map of FIG. It When the target engine speed calculation flag XFB is set at the timing of t3, the target engine speed NT
Is calculated by adding the target torque converter rotational speed NCT and the slip rotational speed NSC (Equation 6).

Further, after the timing of t1 to t4 and the timing of t5, the shifting flag XSFT is reset, so that it corresponds to the deviation (= NE-NT) between the engine speed NE and the target engine speed NT. The number of fuel cut cylinders TR is set. At this time, the number of fuel cut cylinders T
R is calculated by the characteristic line LA of FIG. And t
At the timing of 1 to t2, the number of fuel cut cylinders TR becomes smaller as the deviation (= NE-NT) decreases, and
When the deviation (= NE-NT) becomes smaller than the predetermined value NA in FIG. 11 at the timing of, TR = 0. After the timing of t2 to t4 and the timing of t5 when TR = 0, the rotation speed control of the engine 1 by the fuel cut is not executed, but only the opening / closing control of the sub-throttle valve 6 is executed.

On the other hand, at the timing of t4, for example, 1
When the shift speed is increased in the order of speed → second speed, second speed → third speed, the gear ratio GR becomes smaller (see FIG. 12), and the set values of the target torque converter speed NCT and the target engine speed NT become smaller. Therefore, at the timing of t4, the deviation between the engine speed NE and the target engine speed NT becomes large again. Then, the number of fuel cut cylinders TR is set by the characteristic line LB of FIG. 11 at the timing of t4 to t5 when the in-shift flag XSFT is in the set state (XSFT = 1). As described above, in the vehicle acceleration slip control device of the present embodiment, in order to eliminate the deviation between the target vehicle body speed (control reference speed VS) and the drive wheel speed VR of the vehicle,
The opening degree control of the sub-throttle valve 6 is performed. or,
If the deviation between the target engine speed NT and the actual engine speed NE is equal to or greater than the predetermined value NA, the engine speed control of the engine 1 is performed by the fuel cut in order to eliminate the deviation. As a result, in the region where the deviation between the target engine speed NT and the actual engine speed NE is smaller than the predetermined value NA, only the opening control of the sub throttle valve 6 is performed. If the deviation is equal to or more than the predetermined value NA, the opening speed control of the sub-throttle valve 6 and the rotation speed control of the engine 1 are performed. Therefore, when the deviation is large, the rotational speed control of the engine 1 having a good responsiveness acts to supplement the opening control of the sub-throttle valve 6 having a poor responsiveness, and the responsiveness of the control is secured. When the deviation is small, the engine speed control of the engine 1 does not interfere with the opening control of the sub-throttle valve 6, and the control stability is ensured.

Further, in the present embodiment, the target engine speed NT particularly for the engine speed control of the engine 1 is the input side speed of the torque converter 15 (engine speed NE) and the output speed of the torque converter 15 (turbine). Deviation from the rotational speed NC), that is, the slip speed NSC, and the automatic transmission 2
It is generated based on the gear ratio GR of 1. More specifically, the target engine rotational speed NT is set to increase as the slip rotational speed NSC increases or the gear ratio GR corresponding to the gear stage of the automatic transmission 21 increases.

As a result, even if the output rotation speed on the drive wheel side becomes smaller than the input rotation speed on the engine 1 side by the amount of slip occurrence in the torque converter 15, the slip amount is corrected. Even if the automatic transmission 21 shifts during acceleration and the ratio of the speed of the drive wheels to the engine speed changes, the target engine speed NT is set according to the gear ratio, and the gear shift shock at the time of gear shifting is set. Or acceleration slip is less likely to occur.

Further, in the conventional control device, the control is performed for a certain period of time, but in the control device of the present embodiment, the engine output reduction control is performed by the engine speed control, so that the control without risk of engine stalling can be performed. It will be possible.

As described above, in the control device of this embodiment, unlike the conventional control device in which only the slip ratio of the wheels is used as a parameter, the parameters of the drive transmission system such as the torque converter 15 and the automatic transmission 21 are different. By using, it is possible to enhance control accuracy and realize stable vehicle traveling.

It should be noted that the present invention is not limited to the above-described embodiment, and for example, as the engine speed control (output torque control) of the engine 1, the ignition timing retarding method may be used instead of the fuel cut method. For example, the present invention can be embodied by being arbitrarily modified within a range not departing from the spirit of the invention.

[0082]

According to the present invention, stable vehicle running can be realized by performing the acceleration slip control in consideration of the elements related to the vehicle drive transmission system, such as the torque converter and the automatic transmission. Exerts an excellent effect.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram illustrating a configuration of a rear-wheel drive vehicle including an acceleration slip control device according to an embodiment.

FIG. 2 is a block diagram showing a configuration of an acceleration slip control circuit.

FIG. 3 is a flowchart showing opening / closing control of a sub-throttle valve.

FIG. 4 is a flowchart of the same.

FIG. 5 is a map for setting a correction coefficient K used to determine the control amount of the sub throttle valve.

FIG. 6 is a diagram showing a relationship between a throttle opening and an output torque of an engine.

FIG. 7 is a flowchart showing a routine for outputting an engine speed control signal.

FIG. 8 is a flowchart following FIG.

FIG. 9 is a flowchart showing a routine for processing a shift signal.

FIG. 10 is a characteristic diagram for calculating a target engine speed.

FIG. 11 is a diagram for calculating the number of fuel cut cylinders.

FIG. 12 is a diagram for calculating a gear ratio.

FIG. 13 is a time chart.

FIG. 14 is a characteristic diagram showing an engine speed at each gear according to a vehicle speed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Engine 4 ... Main throttle valve 6 ... Sub throttle valve 14 ... Engine speed sensor 15 ... Torque converter 20 ... Turbine speed sensor 21 ... Automatic transmission 26, 27 ... Rear wheel as drive wheel 30, 31 ... Driven wheel Front wheel 35 as ... Acceleration slip control circuit 36 ... Engine control circuit 37 ... Transmission control circuit

Claims (2)

[Claims] 1. An output shaft of an engine is drivingly connected to an automatic transmission through a torque converter, the automatic transmission is drivingly connected to driving wheels of a vehicle, and a target vehicle body speed and driving wheel speed of the vehicle. In order to eliminate the deviation between the target engine speed and the actual engine speed in order to eliminate the deviation, if the deviation between the target engine speed and the actual engine speed is a predetermined value or more, fuel cut or ignition timing, etc. In the vehicle acceleration slip control device configured to control the output torque of the engine according to the above, in the deviation between the input side rotation speed of the torque converter that is the actual engine rotation speed and the output side rotation speed of the torque converter, and , Based on the shift speed of the automatic transmission,
An acceleration slip control device for a vehicle, wherein the target engine speed is generated. 2. The target engine speed increases as the deviation between the input speed and the output speed of the torque converter increases, or the gear ratio corresponding to the shift speed of the automatic transmission increases. The acceleration slip control device for a vehicle according to claim 1, wherein the acceleration slip control device is set to be large.