JP2000283280A - Controller for automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To judge non-slipping of a drive wheel with high precision, and to release increase suppression control of differential rotation of a differential gear with satisfactory response property and at proper timing without giving a sense of incongruity to a driver. SOLUTION: In a control unit 1 in which output signals of a brake switch 2, a turbine sensor 3, an inhibitor switch 4, an engine rotation sensor 5, and a throttle sensor 7 are input, a value indicating that differential rotation of a differential gear between right and left drive wheels is due to slipping of the drive wheels is detected. An increase in differential rotation of the differential gear is suppressed based on the results of detection of slipping. Moreover, if it is judged that the drive wheels cause non-slipping, the suppression of increase of differential rotation of the differential gear is released. As for the judgement of whether the drive wheels cause non-slipping or not, acceleration of the drive wheels is calculated based on changes of the number of revolutions of a turbine of a torque converter, and it is judged that the drive wheels cause non-slipping when the acceleration is smaller than a predetermined value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an automatic transmission, and more particularly, to a control device for an automatic transmission for performing control for suppressing an increase in differential rotation of a differential gear due to idling of a drive wheel. The present invention relates to a control device for an automatic transmission capable of determining that a drive wheel is not idling without detecting a wheel speed in order to cancel the suppression control, and belongs to a technical field of electronic control of an automobile.

[0002]

2. Description of the Related Art Generally, an automatic transmission mounted on an automobile sets a target shift speed in accordance with a shift map set in advance using a vehicle speed and a throttle opening as parameters.
A plurality of friction elements such as clutches and brakes are selectively engaged and released so as to realize the shift speed, and the power transmission path of the transmission gear mechanism is automatically switched. Conventionally, such control of the automatic transmission basically transmits the engine output efficiently in consideration of the running characteristics of the vehicle, the fuel efficiency, and the like, thereby improving the fuel efficiency and the drivability. .

[0003] One of such controls is as follows.
There is a technique disclosed in JP-A-9-210190. This is to avoid the problem of damage to the differential gear which can occur when one of the driving wheels slips on a snowy road or the like and the vehicle is stuck. In other words, in the above case, the rotation of the differential case is completely converted into the rotation of the idle driving wheel without the rotation of the grounded driving wheel rising, so that the idle wheel is rotated. Rotation greatly increases. At this time,
If the accelerator pedal is still depressed, a shift-up shift based on the shift map occurs, and the differential rotation further increases, causing burn-in of the pinion gear and eventually damages the differential gear. In this case, the technique disclosed in the above-mentioned publication focuses on the fact that the rotation inertia is small when the driving wheel is idling, and the rotation rises earlier than when the driving wheel is not idling, so that the 1-2 shift-up shift occurs earlier. In such a case, the target shift speed is fixed to a low shift speed such as the second speed, for example, and control is performed to prevent further rotation of the differential case or increase in differential rotation.

[0004]

However, if the gear is fixed to the second speed or the like in order to suppress the increase in the differential rotation of the differential gear, the vehicle then escapes from a snowy road or the like. When the driver starts running normally, the driver will feel uncomfortable that the driver will not shift unless the second speed fixation is immediately released. In addition, for example, there are unpaved gravel roads on both sides of the paved road, and when the vehicle is started from the unpaved gravel road, the drive wheels may run while slipping before moving the vehicle to the paved road. If the second speed fixed control is activated at this time, the vehicle does not shift to the second speed or higher immediately after starting, and it is necessary to release the vehicle immediately.

The above publication discloses that the second speed is fixed when the vehicle stops, when the range is switched to the L range, when a predetermined time has elapsed, or when the difference between the right and left wheel speeds becomes small. It is disclosed to cancel. However, in order to check the difference between the left and right wheel speeds, it is necessary to provide a wheel speed sensor for each wheel, which leads to an increase in cost, which is not preferable. In other release conditions, the second speed is fixed immediately after normal running. Cannot be released.

Accordingly, the present invention provides a method for accurately determining non-idling of a drive wheel without using a wheel speed sensor or the like and using a device included in an existing basic control system of an automatic transmission to drive the vehicle. It is an object of the present invention to cancel the control for suppressing the increase in the differential rotation of the differential gear at an appropriate timing with good responsiveness without giving an uncomfortable feeling to the user. Hereinafter, the present invention will be described in detail including other problems.

[0007]

That is, in order to solve the above-mentioned problems, the invention described in claim 1 of the present application claims that the differential rotation of the differential gear between the left and right drive wheels is performed by the idle rotation of the drive wheels. A control device for an automatic transmission, comprising: an idling detection unit that detects a value indicating that the rotation speed is determined by the driving unit; and a suppression unit that suppresses an increase in differential rotation of a differential gear based on a detection result of the detection unit. ,
Judgment means for judging that the drive wheel is not idling, and suppression cancellation for canceling suppression of increase in differential rotation of the differential gear by the suppression means when the judgment means judges that the drive wheel is not idling. Means for detecting the rotational speed of the turbine of the torque converter, and drive wheel acceleration calculation for calculating the acceleration of the drive wheel from a change in the turbine speed detected by the detecting means. Means are provided, and the determining means determines that the drive wheel is not idling when the acceleration calculated by the calculating means is smaller than a predetermined value.

According to the present invention, when it is determined that the driving wheel is not idling, the suppression of the increase in the differential rotation of the differential gear is released. When the acceleration is smaller than the predetermined value, it is determined that the driving wheel is not idling. Inertia and non-idling greatly differ in inertial mass, and even when the same driving force is applied, the acceleration during non-idling is significantly smaller than that during idling. Therefore, it is possible to accurately separate idle and non-idling by such a difference in acceleration. In order to obtain the acceleration, a turbine speed normally used as a parameter in normal shift control is used, so that a wheel speed sensor or the like is not required. And since such a turbine speed is always sensed, it is possible to always determine whether it is idling or non-idling, and immediately after the non-idling, the increase suppression control of the differential rotation is released. Become.

Next, a second aspect of the present invention is the invention according to the first aspect, wherein a stepped state detecting means for detecting a stepped state of an accelerator pedal, and a driving force for driving wheels based on an output torque of the torque converter. Driving force calculating means for calculating the driving force, wherein when the detecting means detects that the accelerator pedal is depressed, the driving force calculated by the calculating means is larger than a predetermined value, and When the acceleration calculated by the wheel acceleration calculation means is smaller than a predetermined value, it is determined that the driving wheel is not idling.

According to the present invention, when the accelerator pedal is depressed and the driving force is supplied from the engine to the driving wheel, the acceleration of the driving wheel is increased when the driving force has a substantially large value. Since the non-idling of the drive wheel is determined by being small, the determination accuracy is ensured.

According to a third aspect of the present invention, in the second aspect of the invention, the determining means determines that the state in which the driving force calculated by the driving force calculating means is larger than a predetermined value is longer than a predetermined time. It is characterized in that it is determined that the driving wheel is not idling when the acceleration is continued and the acceleration calculated by the driving wheel acceleration calculating means is smaller than a predetermined value.

According to the present invention, the non-idling of the drive wheel is determined after further adding another condition that the driving force having a substantially large value continues for a predetermined time or more, so that the determination accuracy is determined. Is further secured.

Next, according to a fourth aspect of the present invention, in the third aspect of the present invention, the time changing means for shortening the predetermined time for determination as the driving force calculated by the driving force calculating means increases. It is characterized by being provided.

According to the present invention, the higher the driving force, the faster the speed rises, so that the predetermined time for determining whether the acceleration is smaller than the predetermined value can be shortened,
Accordingly, as a result, the determination of the non-idling of the drive wheels is ended early.

Next, according to a fifth aspect of the present invention, in the first aspect of the present invention, there is provided a depressed state detecting means for detecting a depressed state of the accelerator pedal, and the determining means comprises:
When the deceleration of the drive wheel after the detection means detects that the accelerator pedal is released is smaller than a predetermined value, it is determined that the drive wheel is not idling.

According to the present invention, when the accelerator pedal is depressed and the vehicle decelerates while coasting due to the inertia of the vehicle, the deceleration is smaller than the predetermined value, so that it is determined that the drive wheels are not idling. . That is, when the turbine rotational speed, in other words, the rotational speed of the drive wheels or the speed of the vehicle does not decrease, the non-idling of the drive wheels is determined. As described above, the inertial mass is largely different between the idling state and the non-idling state, and the deceleration when the driving force is not supplied is significantly smaller in the non-idling state than in the idling state. Therefore, the idling and the non-idling can also be accurately distinguished by the difference in the deceleration when the accelerator is off. Such a deceleration can also be calculated from the turbine speed, so that a wheel speed sensor or the like is not required, and it is possible to always determine whether the vehicle is idling or non-idling.

Hereinafter, the present invention will be described in more detail through embodiments of the present invention.

[0018]

FIG. 1 is a block diagram showing a configuration of a control device for an automatic transmission according to the present embodiment. The control device firstly prevents the differential gear from being prevented from being damaged due to the idling of the drive wheels by the differential gear differential rotation suppressing means, and when the non-idling determining means determines that the driving wheel is not idling, The suppression control is immediately released by the suppression release means so that the driver does not feel uncomfortable due to the suppression control being continued even after the non-idling operation.

FIG. 2 is a system configuration diagram of the control device for the automatic transmission according to the present embodiment. This control device has a control unit 1 for controlling an automatic transmission. The control unit 1 includes a brake switch 2 that is turned on when a brake pedal is depressed, a turbine sensor 3 that detects a rotation speed of a turbine of a torque converter, an inhibitor switch 4 that detects a range selection position by a driver, and an engine switch. An air flow sensor 5 for detecting an air flow rate of an intake system, an engine rotation sensor 6 for detecting an output speed of an engine, a throttle sensor 7 for detecting an opening degree of a throttle valve of an intake system of the engine, and an accelerator pedal is not depressed. Various signals from the idle switch 8 which are turned on at the time are input.

The control unit 1 includes a CPU 10 for controlling a shift, a ROM 11 for storing fixed parameters and a control program typified by a shift map, and a RAM 12 for temporarily storing variable parameters and as a work area of the CPU 10. . The CPU 10 performs calculations based on the input signals from the sensors and the switches 2 to 8 and outputs a control signal to the shift solenoid 9 as a result of the calculations to achieve a shift-up shift or a shift-down shift.

Next, an example of a specific operation of the control for suppressing the increase in the differential rotation of the differential gear and the control for releasing the differential rotation performed by the control unit 1 will be described with reference to a flowchart. Among them, the flowchart shown in FIG. 3 shows that the idling flag 1 (fs
1) represents a control program for setting 1 to 1 and fixing the gear (G) to the second speed. The flow charts shown in FIGS. 6 and 7 show that the idling flag 1 (fs1) is set to 1 and the idling flag is still determined when it is determined that the driving wheels are idling when the gear position (G) is fixed to the second speed. 2 (fs2) is set to 1, the control program for fixing the gear position (G) to the first speed, and thereafter, the control program for resetting only the idling flag 2 (fs2) to 0, and the idling flag 1 (fs1 ) And 2 (fs2) are both reset to 0. FIG.
The flowchart shown in FIG.
A control program for resetting only (fs1) to 0;
The control program resets both the idling flags 1 (fs1) and 2 (fs2) to 0.

First, in step S1 of FIG. 3, various signals such as the current vehicle speed (V), gear stage (G), and turbine speed (Nt) are read, and drive is performed based on a change in turbine speed (Nt). The wheel acceleration (acc) is calculated. In step S2, the vehicle speed (V) is lower than the predetermined vehicle speed (V1) stored in the ROM 11 in advance, and the gear (G) is 1
It is determined whether or not the turbine speed (Nt) is lower than a predetermined turbine speed (Nt1) stored in the ROM 11 in advance. If this condition is not met,
It can be determined that the gear is not the first gear but the second gear or higher, and the process proceeds to step S10 described later. On the other hand, if this condition is satisfied, it can be determined that the vehicle is in the first speed, and the process proceeds to the next step S3.

In step S3, the first counter (CNT)
a) is reset to 0. In step S4, the gear position (G) is the first speed, and the turbine speed (Nt) is a predetermined turbine speed (Nt) stored in the ROM 11 in advance.
t2) is determined (for example, Nt2)
Is set to 0, and if the turbine speed Nt is not 0, it is determined that the vehicle has started.) If this condition is not satisfied, step S
Return to 3 and repeat the loop. On the other hand, if this condition is satisfied, the process proceeds to step S5, where the first counter (CNT)
Start counting in a).

In step S6, when the 1-2 shift-up shift command is output, a routine is executed to detect and store the count value (CNTa) and the throttle opening (TVO1) at that time. That is, the control unit 1 performs control to set the target shift speed by applying the vehicle speed and the throttle opening to the shift map irrespective of this control, and the second shift speed is set by the shift speed setting control. When the 1-2 shift-up shift command is output, the routine of step S6 is executed.

In step S7, a predetermined value (CNT1) corresponding to the count value (CNTa) is obtained from the throttle opening (TVO1) at the time of output of the 1-2 shift-up shift command using a characteristic map as shown in FIG. Ask for. Next, at step S8, the count value (CNTa) at the time of output of the 1-2 shift-up shift command is set to the predetermined value (CNTa).
It is determined whether it is smaller than 1). That is, idling of the drive wheels is determined by detecting whether or not the 1-2 shift-up shift has occurred within a short period of time that cannot occur in normal running. If this condition is not satisfied, it is determined that the vehicle is traveling normally and the routine returns. If it is satisfied, it is determined that the driving wheels are idling, and the idling flag 1 (fs1) is set to 1 in step S9. At the same time, the gear (G) is fixed to the present second speed. As a result, an increase in the differential rotation of the differential gear is suppressed, and problems such as seizure of the pinion gear and damage to the differential gear are avoided.

In step S2, not the first speed but the second speed
If it is determined that the speed is higher than the high speed, step S
Proceeding to 10, the acceleration (acc) of the drive wheel is set to a predetermined value (K
It is determined whether it is larger than 1). That is, the acceleration (acc) of the drive wheel when the shift speed is 2nd, 3rd, 4th, etc.
Is large, it is determined that the drive wheel is idling. As shown in FIG. 5, the inertial mass is largely different between the idle state and the non-idle state. Even when the same driving force is applied, the acceleration (acc) is significantly larger in the idle state than in the non-idle state. Therefore, due to such a difference in acceleration, slip and non-slip can be accurately separated from each other as shown by reference numerals (a) and (a) in the figure.

As a result, if this condition is satisfied, the routine proceeds to step S9, where the idling flag 1 (fs
1) is set to 1, and the gear (G) is fixed to the second speed. As a result, for example, 3-2 downshifting,
Alternatively, a case where a 4-3-2 downshift occurs may occur. As described above, the turbine speed (Nt) normally used as a parameter in the normal shift control is used to determine the acceleration (acc) of the drive wheel, so that a wheel speed sensor or the like is not required. Then, since such a turbine speed (Nt) is constantly sensed, it is possible to always determine whether the motor is idling or non-idling, and immediately set the idling flag 1 (fs1) to 1 when idling occurs. You can do it.

Next, in the flowcharts shown in FIGS. 6 and 7, first, in step S11, various signals such as the current turbine speed (Nt) are read, and the drive wheels are determined based on the change in the turbine speed (Nt). Acceleration (ac
c) is calculated, and the turbine torque (Tt), that is, the output torque of the torque converter is calculated from the throttle opening and the like. This turbine torque (Tt) is calculated from the throttle opening, the engine output torque obtained from the engine speed, the intake air amount, and the like, and the torque converter torque ratio obtained from the engine speed and the turbine speed. Is done. Further, a driving force (F) applied to the driving wheels or the vehicle is calculated from the turbine torque (Tt), the gear position of the automatic transmission, the final gear ratio of the differential gear, and the like.

In step S12, the idling flag 1 (fs
It is determined whether 1) is set to 1 or not, and YES
In step S13, the second to fourth counters (CNTb, CNTc, CNTd) used later are set to 0 in step S13.
Reset to. Then, in step S14, it is determined whether or not the acceleration (acc) of the drive wheel is greater than a predetermined value (K2).
To start counting the second counter (CNTb), and in step S16 the count value (CN)
When Tb) has exceeded the predetermined value (CNT2), the process proceeds to step S17, where the idling flag 2 (fs2) is set to 1 and the gear position (G) is fixed to the first speed. In other words, if the state of further acceleration continues beyond the predetermined time (CNT2) in the state where the gear is fixed at the second speed, it is determined that the vehicle is still idling and the rotational speed of the differential gear is further reduced. Shift down to first gear.
Also in this case, as shown in FIG. 5 described above, the inertial mass is largely different between the idling state and the non-idling state. acc) is significantly increased. Therefore, due to such a difference in acceleration, idling and non-idling can be accurately distinguished from each other as shown by reference numerals (a) and (a) in the figure, and the idling flag 2 (fs
2) can be set to 1.

Next, in step S18, after the counting of the third counter (CNTc) is started, in step S1
At S9, it is determined whether or not the turbine torque (Tt) is larger than a predetermined value (Tt1). As a result, when a turbine torque of a certain magnitude is output, step S20 is performed.
Then, the counting of the fourth counter (CNTd) is started.
Then, when the count value (CNTd) of the fourth counter is larger than the predetermined value (CNT3) in step S21, the idling flag 2 (fs2) is reset to 0 in step S22. That is, when a certain amount of turbine torque is continuously output for a predetermined time (CNT3) or more, it can be determined that the driving wheels are not idling and that the vehicle is in contact with the ground and performing normal grip traveling. .

On the other hand, if NO in step S19, the process proceeds to step S23, and if it is determined that the accelerator pedal has not been depressed and the vehicle is fully closed, the process proceeds to step S23.
At 24, the turbine speed (Nt3) at the time when the accelerator is turned off is read. Then, step S2
When the count value (CNTc) of the third counter has elapsed for a predetermined time or more at 5, the turbine speed (Nt4) at that time point is read at step S26. The difference between these two turbine speeds (Nt3-N
If (t4) is smaller than the predetermined value (ΔN), the process proceeds to step S22, where the idling flag 2 (fs2) is also determined.
Is reset to 0. That is, if the deceleration of the vehicle within a predetermined time after the accelerator is turned off is small and the decrease in the vehicle speed is small, it can be determined that the drive wheels are not idling, that they are in contact with the ground, and that they are running with normal grip. is there.

That is, when the accelerator pedal is released and the vehicle is coasting due to the inertia of the vehicle, the drive wheels are not idling when the deceleration (Nt3-Nt4) is smaller than a predetermined value (ΔN). Can be determined. In other words, when the turbine rotational speed (Nt), that is, the rotational speed of the drive wheels or the speed of the vehicle does not readily decrease, the non-idling of the drive wheels is determined. Also in this case, as shown in FIG. 5 described above, the inertial mass is largely different between the idling time and the non-idling state, and the deceleration when the supply of the driving force is stopped is smaller than that in the idling state in the non-idling state. It becomes significantly smaller. Therefore, the idling and the non-idling can also be accurately distinguished by the difference in the deceleration when the accelerator is off. Then, such a deceleration can be calculated from the existing turbine speed (Nt), and as a result,
No wheel speed sensor or the like is required, and it is possible to always determine whether the vehicle is idling or non-idling.

If NO in step S23,
The process proceeds to step S28, and if it is determined that the brake pedal is depressed, the process proceeds to step S29 to reset both the idling flags 1 and 2 (fs1, fs2) to 0. In other words, when the brake is on when fully closed,
The idling determination is immediately released.

Next, in the flowcharts shown in FIGS. 8 to 10, first, in step S31, various signals such as the current turbine speed (Nt) are read, and the turbine torque is determined from the throttle opening and the like in the same manner as described above. (Tt) is calculated, and idling flag 1 (fs1) is set to 1
, That is, the elapsed time from the time when the first idling determination is performed. In step S32, the fifth to eighth counters (CNT) used later
e, CNTf, CNTg, CNTh) are reset to 0, respectively.

Then, in step S33, the idling flag 1
(Fs1) is set to 1 and step S3
If the idling flag 2 (fs2) is reset to 0 at 4, it is determined at step S35 whether the turbine torque (Tt) is greater than a predetermined value (α). as a result,
If it is larger, the process proceeds to step S36, and the count of the fifth counter (CNTe) is started, while if not larger, the process proceeds to step S40, where the turbine torque (Tt) becomes larger than the predetermined value (β). It is determined whether it is larger. As a result, when it is larger, the process proceeds to step S41, and the count of the sixth counter (CNTf) is started, while when it is not larger, the process proceeds to step S44, where the turbine torque (Tt) is set to a predetermined value ( γ) is determined. As a result, if it is larger, the process proceeds to step S45, and the counting of the seventh counter (CNTg) is started, while if not larger, the process returns.

Here, the predetermined values (α), (β),
(Γ) is a value set to decrease in this order. That is, when the turbine torque (Tt) is large, the process proceeds to step S36 and the subsequent steps, and the turbine torque (Tt)
If t) is moderately large, the routine proceeds to step S41 and below, and if the turbine torque (Tt) is small, the routine proceeds to step S45 and below. In any case, in steps S37, S42, and S46, the value of each counter (C
NTe), (CNTf), and (CNTg) are predetermined values (CN
T5), (CNT6), and (CNT7), when they become larger than (CNT7), in steps S38, S43, and S47,
Once again, the turbine torque (Tt) becomes the predetermined value (α),
It is determined whether or not it is larger than (β) and (γ). If it is larger, the process proceeds to step S39, where the idling flag 1 (fs1) is reset to 0. That is, in each case, the turbine torque (Tt) of each magnitude is set to the predetermined time (CNT).
5) When (CNT6), (CNT7) or more are continuously output, it can be determined that the drive wheels are not idling, that they are in contact with the ground, and that they are running with normal grip.

Here, the predetermined time (CNT)
5), (CNT6) and (CNT7) are values set to be longer in this order. That is, when the turbine torque (Tt) is large, the idling flag 1 (fs1) is reset to 0 if the state continues for a short time, and when the turbine torque (Tt) is moderately large,
The idling flag 1 (fs1) is reset to 0 when the state continues for a moderately long time, and if the turbine torque (Tt) is small, the idling flag must be maintained for the longest time. 1 (fs1) is not reset to 0.

As described above, since different judgment routines are executed according to the magnitude of the turbine torque (Tt) or the driving force (F), the accuracy of the judgment is improved, and the turbine torque (Tt) or the driving force (F) is improved. Is larger, the non-idling can be determined in a shorter time, and as a result, the determination of the non-idling of the drive wheels can be ended earlier.

If NO in step S34, that is, if both the idling flags 1 and 2 (fs1, fs2) are set to 1, the process proceeds to step S48, where the accelerator pedal is depressed. If it is determined that the brake pedal is fully closed and the brake pedal is depressed, the process directly proceeds to step S56, and both the idling flags 1 and 2 (fs1, fs2) are reset to 0. That is, in the same manner as described above, the idling determination is immediately released when the brake is turned on with the vehicle fully closed.

On the other hand, if the accelerator pedal is depressed or the brake pedal is not depressed, the process proceeds to step S49, where it is determined whether or not the vehicle is fully closed. When neither the pedal nor the brake pedal is depressed, the process proceeds to step S50. On the other hand, when it is not fully closed, that is, when only the accelerator pedal is depressed, the process returns as it is. In step S50, the eighth
The counting of the counter (CNTh) is started, and in step S51, the current turbine speed (Nt5) is read. Then, the elapsed time (tim) from the time when the idling determination is first performed in step S52 is a predetermined value (K).
If 3) is exceeded and the count value (CNTh) of the counter exceeds the predetermined value (CNT8) in step S53, the turbine speed (Nt6) at that point is read in step S54, and , At step S55, the difference between these two turbine speeds (N
When (t5−Nt6) is smaller than the predetermined value (ΔN),
Proceeding to step S56, the idling flags 1 and 2 (fs
1, fs2) are both reset to 0. In other words, if the deceleration of the vehicle within a predetermined time after the accelerator is turned off is small and the decrease in the vehicle speed is small, it is determined that the driving wheels are not idling, that the vehicle is on the ground and that the vehicle is traveling with a normal grip. You can.

Next, a modified example of the reset condition of the idling flag 2 (fs2) will be described with reference to the flowcharts shown in FIGS. First, steps S61 to S67
Until the above, it substantially corresponds to steps S11 to S17 shown in FIG. That is, after the idling flag 2 (fs2) is set to 1 in step S67 and the gear position (G) is fixed to the first speed, step S6 is performed.
Proceeding to 8, the driving force (F) transmitted to the driving wheels is calculated from the turbine torque (Tt). As described above, the driving force (F) is calculated based on the turbine torque (Tt), the gear position (G) of the automatic transmission, the final gear ratio of the differential gear, the tire diameter of the wheels, and the like. Is calculated.

Next, at step S69, the calculated driving force (F) is stored in a map set in advance as shown in FIG.
And reads a predetermined value (acc1) for the drive wheel acceleration (acc). Then, in step S70,
The drive wheel acceleration (acc) is equal to the predetermined value (acc)
It is determined whether it is smaller than 1). As a result, when this condition is satisfied, in step S71, the idling flag 2
(Fs2) is reset to 0.

That is, the acceleration (acc) of the drive wheel calculated from the change in the turbine speed (Nt) is equal to the predetermined value (acc).
If it is smaller than 1), it is determined that the drive wheel is not idling. As shown in FIG. 5 described above, the inertial mass is largely different between the idling state and the non-idling state, and the acceleration (a) is larger in the non-idling state than in the idling state even when the same driving force is applied.
cc) is significantly reduced. Therefore, due to such a difference in acceleration, slip and non-slip can be accurately separated from each other as shown by reference numerals (a) and (a) in the figure. Since the acceleration (acc) is obtained using the turbine speed (Nt) normally used as a parameter in the normal shift control, a wheel speed sensor or the like is not required. And such a turbine rotation speed (Nt)
Is sensed at all times, and consequently, it is always possible to determine whether the vehicle is idling or non-idling, and the idle flag 2 (fs2) can be immediately reset to 0 when the vehicle becomes non-idling.

It is needless to say that the determination based on the fact that the acceleration (acc) is smaller than the predetermined value (acc1) may be used as a condition for resetting the other idling flag 1 (fs1). By resetting not only the slip flag 2 (fs2) but also the slip flag 1 (fs1), the control for suppressing the increase in the differential rotation is immediately released.

In this case, when the depression of the accelerator pedal is detected, the driving force (F) calculated from the throttle opening or the turbine torque (Tt) is larger than a predetermined value and the turbine rotation speed is increased. When the acceleration (acc) calculated from the number (Nt) is smaller than a predetermined value, it may be determined that the drive wheel is not idling. At the time of acceleration when the accelerator pedal is depressed and the driving force is supplied from the engine to the driving wheels, when the driving force (F) has a substantially large value, the acceleration (acc) of the driving wheels is small. Since the non-idling of the driving wheel is determined, the determination accuracy is ensured.

Further, in this case, when the driving force (F) is larger than the predetermined value for a predetermined time or more and the acceleration (acc) is smaller than the predetermined value, the driving wheel is not idling. May be determined. The non-idling of the drive wheel is determined after another condition that the driving force (F) of a substantially large value continues for a predetermined time or more is further added, so that the determination accuracy is further ensured. Will be.

In this case, the predetermined time for determination may be shortened as the driving force (F) increases. The larger the driving force (F), the faster the speed rises, so that the predetermined time for determining whether the acceleration (acc) is smaller than a predetermined value can be shortened, and as a result, the driving The determination of non-slip of the wheel ends early.

[0048]

As described above in detail with reference to specific examples, according to the present invention, it is possible to use a device included in an existing basic automatic transmission control system without providing a wheel speed sensor or the like. In addition, the non-idling of the drive wheels can be accurately determined, and the control for suppressing the increase in the differential rotation of the differential gear can be canceled at an appropriate timing with good responsiveness without giving the driver an uncomfortable feeling. INDUSTRIAL APPLICABILITY The present invention is preferably applicable to automobiles equipped with an automatic transmission in which powertrain electronic control is performed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a control device for an automatic transmission according to the present embodiment.

FIG. 2 is a system configuration diagram of a control device of the automatic transmission.

FIG. 3 is a flowchart showing a control operation performed by a control unit in the control device for the automatic transmission.

FIG. 4 is a characteristic diagram used in the control operation.

FIG. 5 is also a characteristic diagram.

FIG. 6 is a first half of a flowchart showing another control operation performed by the control unit.

FIG. 7 is the latter half part.

FIG. 8 is a part of a flowchart showing still another control operation performed by the control unit.

FIG. 9 shows the intermediate portion.

FIG. 10 is also an intermediate portion.

FIG. 11 is a first half of a flowchart showing still another control operation performed by the control unit.

FIG. 12 is the latter half part.

[Explanation of symbols]

 Reference Signs List 1 control unit 2 brake switch 3 turbine sensor 6 engine rotation sensor 7 throttle sensor 8 idle switch

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme Court II (Reference) F16H 59:48 (72) Inventor Kazuo Oyama 3-1, Fuchu-cho, Shinchu, Aki-gun, Hiroshima Prefecture Mazda Co., Ltd. (72) Invention Person Toshio Futo 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima F-term in Mazda Co., Ltd. (Reference) 3J052 AA09 AA17 BB02 BB16 GC13 GC23 GC44 GC51 HA01 LA01

Claims (5)

[Claims] 1. An idling detecting means for detecting a value indicating that the differential rotation of a differential gear between left and right driving wheels is caused by idling of a driving wheel, and a difference between the differential gear based on a detection result of the detecting means. A control device for an automatic transmission, comprising: a suppression unit that suppresses an increase in dynamic rotation;
Judgment means for judging that the drive wheel is not idling, and suppression cancellation for canceling suppression of increase in differential rotation of the differential gear by the suppression means when the judgment means judges that the drive wheel is not idling. Means for detecting the rotational speed of the turbine of the torque converter, and drive wheel acceleration calculation for calculating the acceleration of the drive wheel from a change in the turbine speed detected by the detecting means. Control means for the automatic transmission, wherein the determination means determines that the drive wheel is not idling when the acceleration calculated by the calculation means is smaller than a predetermined value. 2. The vehicle according to claim 1, further comprising: a stepped state detecting unit that detects a stepped state of an accelerator pedal; and a driving force calculating unit that calculates a driving force of a driving wheel from an output torque of a torque converter. When the depression of the accelerator pedal is detected, when the driving force calculated by the calculating means is larger than a predetermined value and when the acceleration calculated by the driving wheel acceleration calculating means is smaller than the predetermined value, the driving wheel is driven. 2. The method according to claim 1, wherein it is determined that the vehicle is not slipping.
3. The control device for an automatic transmission according to claim 1. 3. The determining means determines that the driving force calculated by the driving force calculating means is greater than a predetermined value for a predetermined time or more, and the acceleration calculated by the driving wheel acceleration calculating means is smaller than the predetermined value. The control device for an automatic transmission according to claim 2, wherein it is determined that the drive wheel is not idle at all times. 4. The control of the automatic transmission according to claim 3, further comprising time changing means for shortening the predetermined time for determination as the driving force calculated by the driving force calculating means is larger. apparatus. 5. A depressed state detecting means for detecting a depressed state of an accelerator pedal, wherein the judging means determines that the deceleration of the drive wheel after the detection of the depressed release of the accelerator pedal is smaller than a predetermined value. The control device for an automatic transmission according to claim 1, wherein it is determined that the driving wheel is not idling when the driving wheel is small.