JP2000104821A - Speed change control device for automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To carry out a smooth speed change control not being affected to the dispersion of the characteristic of an automatic transmission, even when the oil temperature of ATF just after connecting to a battery is not raises sufficiently. SOLUTION: A learning correction means 2 learningly corrects the parameter value on a speed change as a rule when the oil temperature of an automatic transmission 10 is a prescribed value or more, but just after a battery connection judging means 4 judges that a battery is connected to the automatic transmission 10, the parameter value is corrected learningly, even when the oil temperature is less than a prescribed value. The learning correction means 2 does not learningly correct the parameter value in the temperature area in which the oil temperature is less than the prescribed value as a principle after the oil temperature becomes once a prescribed value or more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift control device for an automatic transmission suitable for use in an automobile, and more particularly to a shift control device for an automatic transmission having a learning correction function.

[0002]

2. Description of the Related Art Automatic transmissions provided in automobiles and the like are:
A predetermined shift stage is achieved by appropriately releasing and connecting a plurality of friction elements such as a hydraulic clutch and a hydraulic brake provided therein. For example, in the automatic transmission as shown in FIG. 4, when shifting from the second gear to the third gear in a so-called power-on state in which the accelerator is depressed, the connection of the UD (under drive) clutch 24 is kept unchanged. Release the connection of the 2nd (second) brake 22, which has been released, and release the released OD instead.
(Overdrive) The clutch 20 is connected.

At this time, if the release of the second brake 22 is too early, the engine loses the load and suddenly blows up. Conversely, if the engagement of the OD clutch 20 is too early, the automatic transmission enters an interlock state, and Shock will occur. Therefore, in order to perform a smooth shift, it is necessary to always control connection and release of each friction element at an appropriate timing.

[0004] Although friction elements such as hydraulic clutches and hydraulic brakes are manufactured with a predetermined accuracy, there are small variations within the accuracy. Although this variation in accuracy is slight, the timing of coupling and disengagement during shifting is very delicate, so even if shifting control is performed at the same timing, depending on such minute variation in accuracy, The above-described engine blow-up and shock may occur. Even if there is no variation at the beginning, variation may occur in accuracy due to aging according to the number of years of use.

Therefore, conventionally, in order to prevent deterioration of the shift feeling due to variations in the characteristics of each of these automatic transmissions, an automatic transmission having a function of learning and correcting a parameter value related to a shift during a shift control is conventionally provided. Control devices have been developed. For example, JP-A-7-239020
Japanese Patent Application Laid-Open Publication No. 2000-133,1992 discloses a technique for learning and correcting a time for eliminating backlash between plates and an invalid stroke of a piston of a friction element, a so-called play reduction time, and a hydraulic pressure release time for releasing hydraulic pressure from an engaged friction element. Japanese Patent Laying-Open No. 5-263912 discloses a technique related to learning correction of an initial duty ratio output to a solenoid when a friction element that has been in a released state is engaged. Further, Japanese Patent Application Laid-Open No. 8-254262 discloses a technique in which each parameter value related to a shift is set in a divided manner according to the engine speed and the oil temperature.

[0006]

In the conventional shift control device for an automatic transmission, one of the conditions for performing such learning correction of the parameter value is that the oil temperature of the ATF (automatic transmission oil) is controlled. The condition is that the temperature is equal to or higher than a predetermined temperature (for example, 50 ° C.). This is because when the oil temperature is lower than the predetermined temperature, the characteristics of the automatic transmission are not stable, and when learning correction is performed in such a low temperature range, the correction tends to greatly vary, and in a high temperature stable state. Is large, and the convergence value varies. Therefore, the learning correction is prohibited when the oil temperature is lower than the predetermined temperature, and the shift control is performed by the parameter value corrected and learned in a stable state at a high temperature.

[0007] However, the parameter values that have been learned and corrected are stored in storage means such as a RAM. However, if the battery is disconnected from the vehicle, the stored contents will be lost. Therefore, immediately after the battery is connected, the parameter value is in an unlearned state. Also, immediately after the line is cut off from the factory, the learning correction of the parameter value is not performed.

[0008] Even in such an unlearned state, when the operation is started when the oil temperature of the ATF has risen sufficiently and has reached a predetermined temperature or higher, the transmission control device immediately starts learning correction of the parameter value. Deterioration of the shift feeling due to variations in the characteristics of the individual automatic transmissions can be suppressed. However, when the operation is started in a state where the oil temperature is not sufficiently raised, the learning and correction of the parameter value are not performed until the oil temperature reaches a predetermined temperature or more. Sometimes, the engine may blow up or a shock may occur.

The present invention has been made in view of such a problem, and even when the oil temperature of the ATF immediately after the connection of the battery is not sufficiently increased, the ATF is not affected by the variation in the characteristics of the automatic transmission and has a smooth structure. An object of the present invention is to provide a shift control device for an automatic transmission, which can perform shift control.

[0010]

Therefore, in the transmission control apparatus for an automatic transmission according to the first aspect of the present invention, the learning correction means is provided, in principle, when the oil temperature of the automatic transmission is equal to or higher than a predetermined value. The parameter value related to the shift is learned and corrected. Immediately after the battery connection determination unit determines that the battery is connected, the parameter value is learned and corrected even if the oil temperature is lower than a predetermined value.

Further, in the shift control device for an automatic transmission according to the present invention, the learning correction means may, as a rule, after the oil temperature once exceeds the predetermined value, change the temperature of the oil temperature below the predetermined value. In the area, the parameter value is not learned and corrected.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 to 3 show a shift control device for an automatic transmission for a vehicle as one embodiment of the present invention, and FIG. 1 is a functional block diagram showing the configuration thereof. As shown in FIG. 1, the present shift control device includes a control unit 1, an input rotation speed sensor 12 for detecting a rotation speed _NT of a turbine shaft 25, and a rotation speed N _O of an output shaft 26.
, An oil temperature sensor 14 for detecting the temperature of ATF (oil for automatic transmission), a throttle position sensor 30 for detecting the throttle opening of the engine (not shown), and an air flow for detecting the intake air amount of the engine. Various sensors such as a sensor 31, a battery 32,
It is configured with a hydraulic circuit 11 of the automatic transmission 10,
By the control means 1, each of the sensors 12, 13, 14, 3
A desired gear position is determined based on detection signals from 0, 31 and the like, and a gear shift control for achieving the determined gear position via the hydraulic circuit 11 is performed.

The gear position of the automatic transmission 10 is determined by the automatic transmission 1
0, it is determined by the engagement relationship of frictional elements such as a planetary gear unit, a plurality of hydraulic clutches, and hydraulic brakes. However, FIG. OD (overdrive) clutch 20, Rev (reverse) clutch 21, 2nd (second) brake 22, LR (low reverse) brake 23, and UD (underdrive) clutch 24. The automatic transmission 10 has the same configuration as that of the conventional automatic transmission (see FIG. 4), and the reference numerals indicating the friction elements 20 to 24 correspond to FIG. Further, the turbine shaft 25, the output shaft 26, and the oil pump 27 also correspond to FIG.

Then, for example, the UD clutches 24, 2n
The d brake 22 is connected, and the OD clutch 20, Rev
When the clutch 21 and the LR brake 23 are released, 2
Gears are to be achieved. The shift from the second gear to the third gear is achieved by releasing the connected second brake 22 and connecting the OD clutch 20. These friction elements 2
The engagement state of 0 to 24 is controlled by the control means 1, and the shift speed is determined by the engagement relationship of these friction elements 20 to 24, and the timing of coupling and release is appropriately measured. Shift control is performed.

The friction elements 20 to 24 by the control means 1
Is controlled via the hydraulic circuit 11. That is, the hydraulic circuit 11 is provided with a plurality of solenoid valves (not shown), and by appropriately driving these solenoid valves, the ATF sent from the oil pump 27 is supplied to the friction elements 20 to 24. I have. In the control means 1, the throttle opening detected by the throttle position sensor 30 and
Based on the vehicle speed which is calculated to determine the gear position based on the rotational speed N _O of the output shaft 26 detected by the output rotation speed sensor 13, determined solenoid friction elements 20 to 24 corresponding to the shift to the gear stage The drive signal (duty ratio signal) is output to the valve. The ATF is adjusted to a predetermined oil pressure (line pressure) by a regulator valve (not shown), and the ATF adjusted to the line pressure is supplied to a hydraulic circuit 11 that operates the friction elements 20 to 24. It has become.

Here, the control contents of the shift control of the automatic transmission 1 by the present shift control device will be described in detail by taking an upshift from the second gear to the third gear as an example. FIG. 2 is a diagram showing the control timing, and FIG.
5, the rotational speed N _T of FIG.
(c) is the duty ratio of the solenoid (the OD clutch 20) on the coupling side.
(D) is the duty ratio of the solenoid that drives
The hydraulic pressures of the nd brake 22 (disengagement side element) and the OD clutch 20 (engagement side element) are shown.

When the control means 1 determines the shift from the second gear to the third gear based on the throttle opening and the vehicle speed, first,
The duty ratio of the solenoid of the OD clutch 20 is increased from 0% to 100% (time S
S). Each of the friction elements 20 to 24 has a clearance (play) between a clutch plate (or brake plate) and a clutch disk (or brake disk) (not shown). It is necessary to reduce the play, and in order to achieve a speed change in a short time, it is necessary to perform the play for reducing the play quickly. Therefore, when the control is started (time point SS), the duty ratio is set to 1
00% and the line pressure AT is applied to the OD clutch 20.
F is supplied.

The play elimination of OD clutch 20 by setting the duty ratio of 100% is carried out for a predetermined play elimination time t _F, after play elimination time t _F (point IF), the predetermined duty ratio It is designed to decrease to _DA1 . However, at this time IF, the play reduction is not actually completed, and the play reduction is actually completed after a lapse of the time t _C. The reason why the duty ratio is reduced to the predetermined duty ratio D _A1 before the completion of the backlash is that if the OD clutch 20 is engaged before the release of the second brake 22 is completed, an interlock state will occur, and hunting or shock will occur. Therefore, after the backlash is reduced to some extent, the applied hydraulic pressure is reduced to prevent sudden coupling.

On the other hand, on the second brake 22 side, the duty ratio of the solenoid is reduced from 100% to 0% from a predetermined time point RB. By setting the duty ratio to 0%, the hydraulic pressure applied to the second brake 22 gradually decreases from the line pressure,
Eventually, when the oil pressure drops to a predetermined oil pressure, the connection of the second brake 22 is released, and the vehicle starts to slide.

At this time, if the loosening of the OD clutch 20 is completed and the OD clutch 20 has started to be engaged,
The turbine rotational speed _{NT is determined} by the frictional resistance of the D clutch 20.
Abrupt changes in the temperature can be suppressed. However, 2nd
When the time point RB at which the hydraulic pressure of the brake 22 is released is earlier than the completion of the rattling of the OD clutch 20, that is, 2n
If the time t _R from the setting of the duty ratio of the solenoid of the d-brake 22 to 0% to the completion of the loosening of the OD clutch 20 is too long, the turbine shaft 25
Is not constrained by either the second brake 22 _{or the} OD clutch 20, and the rotational speed _NT rapidly increases. In FIG. 2A, N _TI and N _TJ are the synchronous rotation speeds of the turbine shaft 25 at the second speed and at the third speed, respectively.

Such a turbine rotation speed N_TSudden rise
Control to prevent the engine from rising
Means 1 includes a turbine rotation speed N_TAnd synchronous rotation at 2nd gear
Speed N _TISpeed difference (N_T-N_TI) To calculate this speed
Difference (N_T-N_TI) Is the predetermined value ΔN ₁(ΔN₁> 0)
Again, the solenoid of the second brake 22
Set the duty ratio to 100% and set the 2nd brake 22
To supply the line pressure ATF to the
BS). By resupplying the line pressure ATF, 2n
The d-brake 22 starts recoupling, and the second brake 22
The frictional resistance associated with the reconnection of the
5 is the rotation speed N_TIs to be reduced.

The speed difference (N _T -N _TI ) is equal to a predetermined value Δ
When it becomes smaller than N ₂ (0 <ΔN ₂ <ΔN ₁ ),
Again, the duty ratio of the solenoid of the second brake 22 is set to 0%, and the hydraulic pressure acting on the second brake 22 is released (time point BF). At this stage, if the loosening of the OD clutch 20 has been completed and the engagement has started, the engine does not blow up again and the turbine rotational speed _NT does not rapidly increase (the state shown in FIG. 2A). ).

However, the OD clutch 20 is still loose.
Is not completed and the connection has not started, 2nd block
With the release of the rake 22, the turbine rotational speed N_TIs steep again
Will rise. Therefore, the control means 1 determines the speed difference
(N_T-N_TI) Is the predetermined value ΔN ₁Until it does not exceed
That is, until the OD clutch 20 starts engaging,
The reconnection control of the second brake 22 described above is repeatedly performed.
It has become.

Then, even if the second brake 22 is released,
Speed difference (N_T-N_TI) Is the predetermined value ΔN ₁When it fits inside
Since the engagement of the D clutch 20 has been started, the
Rotation speed N_TWill gradually decrease. What
In this example, the dew of the solenoid of the OD clutch 20
The duty ratio to a predetermined duty ratio D_A1Increased at a given slope from
This is due to some reason
A battery to prevent shifting due to insufficient hydraulic pressure
Is set as backup control.

Then, the turbine rotation speed N_TAt 2nd gear
Synchronous rotation speed N_TIIs less than ΔN_BWhen it exceeds
(Time SB), the control means 1 controls the OD clutch 20
The duty ratio of the inductor is changed to a second predetermined duty ratio (initial
Duty ratio) D_A2Is set to. this
Initial duty ratio D_A2Is the first predetermined duty ratio D _A1
A predetermined value ΔD is greater than a value obtained by adding a predetermined gradient increase to_A
And the initial duty ratio D_A2Is decided
Then, the first predetermined duty ratio D_A1Also inevitably decided
It is supposed to be.

By the way, as the engagement of the OD clutch 20 progresses, the turbine rotation speed _NT gradually decreases, and when the engagement is completed, the synchronous rotation speed N _T at the third speed is established.
Becomes equal to _TJ, during which the rate of change of the turbine rotational speed N _T (decrease rate) dN _T is too the shift shock is large size, conversely, it can not be carried out promptly shift up too small. Therefore, the control unit 1, by correcting the duty ratio for each duty cycle based on a difference between a rotational speed change rate dN _T and the optimum value target change rate dN _i, turbine rotational speed N _T is the target rate of change dN Feedback control is performed so as to change with _i .

The rotation speed at the start of this feedback control
Change rate dN_TIs the OD class at the start of feedback control
Of the duty ratio of the solenoid of the switch 20, that is,
Initial duty ratio D_A2Is determined by the size of Accordingly
The initial duty ratio D _A2Is greater than optimal
And the rotation speed change rate dN at the start of the feedback control. _T
Is the target change rate dN_iHunting and strange
Increase the speed shock, etc. Conversely, if it is small, rotate
Speed change rate dN_TIs the target change rate dN_iSmaller than
Therefore, the completion of the upshift is delayed.

[0028] Thus, as the rotational speed variation rate dN _T at the feedback control start becomes equal to the target change rate dN _i, it is necessary to set the initial duty ratio D _A2.
The optimization of the initial duty ratio _DA2 , that is, the learning correction will be described later. In the feedback control, the speed difference between the turbine rotation speed _NT and the synchronous rotation speed _NTJ at the third speed is ΔN _F after a predetermined time set for optimizing the initial duty ratio _DA2 (time FB). (Time FF). And
After the feedback control ends, the duty ratio of the solenoid of the OD clutch 20 is increased by a predetermined value ΔD _E , and after a lapse of a predetermined time t _H , the duty ratio is increased to 100%. As a result, the turbine rotational speed N _T becomes completely equal to the synchronous rotational speed N _TJ at the third speed stage, and the hydraulic pressure acting on the OD clutch 20 becomes equal to the line pressure until the connection is completely completed. Upshifting from the second gear to the third gear is achieved.

In this transmission control device, 2
Upshifting from the first gear to the third gear is achieved, but the same applies to upshifting from the first gear to the second gear and from the third gear to the fourth gear. Yes,
When shifting up from the 1st gear to the 2nd gear, the LR brake 23 is on the release side and the 2nd brake 22 is on the coupling side, and when shifting up from the 3rd gear to the 4th gear, UD
The clutch 24 is on the release side, and the second brake 22 is on the coupling side.

Incidentally, as described above, the automatic transmission 10
In the speed change control, the backlash time t _{F, the} hydraulic pressure release time t _R , and the initial duty ratio D _A2 are important parameters, and the control characteristics are greatly influenced by the set values. In other words, taking the upshift from the second gear to the third gear as an example, if the setting of the play reduction time t _F is short, that is, the AT of the line pressure is applied to the OD clutch 20 on the coupling side.
If the time for supplying F is short, the engagement of the OD clutch 20 is delayed with respect to the release of the second brake 22, so that the engine blows up and it becomes necessary to perform the reconnection control of the release-side second brake 22. On the other hand, if the setting of the play reduction time t _F is long, the engagement of the OD clutch 20 precedes the release of the second brake 22, and there is a possibility that an interlock state may occur.

If the setting of the hydraulic release time t _R is short,
That is, the release of the second brake 22 may be delayed with respect to the engagement of the OD clutch 20 to cause an interlock state. Conversely, if the setting of the hydraulic release time t _R is long, the release of the second brake 22 Release is OD clutch 2
It would be too fast for a zero combination and the engine would blow up. That is, the hydraulic release time t _R
Is relative to the backlash time t _F , and the optimum value is determined by the relationship between the two.

Initial duty ratio D_A2Is, as mentioned above,
Rotation speed change rate dN at the start of feedback control_TShadow
And the rate of change of the rotation speed at the start of this feedback control.
dN _TAnd target change rate dN_iHaunch
Cause shifts and shift shocks, etc.
May cause delays. Also, a first predetermined duty ratio
D_A1Is the initial duty ratio D_A2Is a dependent value for
However, this predetermined duty ratio D_A1Is the play time t_F
With the time to complete the OD clutch 20
One of the parameters. That is, the play is started (time point S
Deute from S) to the end of recombination control (time point BF)
Is the stroke of the piston of the OD clutch 20
Corresponding to the predetermined duty ratio D_A1Big and small
The time to complete the play is shorter or longer
It becomes.

That is, the play-out time t_F,hydraulic
Release time t_R, Initial duty ratio D _A2Are independent of each other
Parameters, rather than the parameters
It is decided. However, this
Their value t_R, T_F, D_A2Is within the allowable range at the time of production.
Each individual unit of the automatic transmission 10 due to dimensional errors, aging, etc.
There is a variation in the optimal value between all automatic transmissions
It is difficult to determine an optimum value common to the ten. There
In this transmission control device, these values t_R, T_F, D_A2
Learning correction through the actual control of the optimal value of
The shift control can be performed.

Learning correction of these values t _R , t _F and D _A2 is performed by learning correction means 2 (FIG. 1) which is a functional element of the control means 1.
Ref.). The learning correction means 2 learns and corrects the optimum values for t _R , t _F , and D _A2 through the actual operation, and stores them in the storage means 3. A RAM is set in the storage means 3 for each shift mode and for each A / N (intake air amount / engine speed) zone. For example, when there are four A / N zones, the shift mode is 1 → 2, 2 →
3, 3 → 4, and 4 × 3 for each of t _R , t _F , and D _A2.
, And a total of 12 × 3 36 RAMs are set. Then, t _R ,
t _F and D _A2 are stored and updated.

Various known methods can be used as the learning correction method for these values t _R , t _F , and D _A2 , and the learning correction of the backlash time t _F and the hydraulic pressure release time t _R is described below. can be used a method as disclosed in JP-a-7-239020, as the learning correction of the initial duty ratio D _A2, using a method as disclosed in JP-a-5-263912 be able to.

For example, shifting up from the second gear to the third gear
To give a simple explanation, taking the example of
Rate D_A2In the learning correction, the learning correction means 2
-Bin rotation speed N_TSynchronous speed N in the second gear_TI
Speed difference (N_TI-N_T) Is the predetermined value ΔN_BGreater than
When a predetermined time has passed since the time when the sound became clear (time SB)
The average rotational speed change rate at [
From the duty control cycle to the time point FF (here, 9 cycles
Period), the average rotation speed change rate of the last five cycles] dN
_TAVEAnd the target change rate dN which is the optimum value_iAnd compare
Difference ΔN_i(ΔN _i= DN_i-DN_TAVE)
It has become.

The learning correction means 2 includes a change rate difference ΔN_iAnd supplement
Positive amount ΔD_AA map showing the relationship with
By referring to this map,
Rate D_A2(n) correction amount ΔD_Ato determine (n)
Has become. And the shift from the next gear to the third gear
Initial duty ratio D used for up_A2(n + 1) [D
_A2(n + 1) = D_A2(n) + ΔD_A2(n)).
ing. Calculated initial duty ratio D_A2(n + 1) is
Is stored and updated in a predetermined RAM of the storage means 3, and the next second gear
Used when shifting up to 3rd gear
ing.

Next, the learning correction of the backlash reduction time t _F will be described. First, the learning correction means 2 starts from the time when the duty ratio of the solenoid of the OD clutch 20 is set to 100% (time SS), and starts the second brake 22. The total sum of the duties up to the time point (time point BF) at which the reconnection control is completed is calculated, and the stroke amount S _CT (n) of the piston of the OD clutch 20 is converted from the calculated total sum of the duties.

This stroke amount S_CT(n) is the previous second gear
Learning correction is performed when shifting from the third gear to the third gear.
Playback time t_F(n)
This is the result of performing_FIs an automatic transmission 1
If it is an appropriate value according to the characteristic of 0, this stroke amount
S_CT(n) also converges to a certain appropriate value. Therefore, learning correction
Means 2 is the current stroke amount S_CT(n) and previous 2nd gear
Amount of Stroke S in Upshifting from Gear to Third Speed_CT
(n-1) and the difference ΔS_CT(n) [ΔS _CT(n) =
S_CT(n-1) -S_CT(n)] is calculated.

Then, referring to the map stored in advance,
Calculated stroke difference ΔS_CTPlayback time based on (n)
t_F(n) correction amount Δt_F(n) is determined and the next 2nd gear
When backlash used in upshifting from 1st to 3rd gear
Interval t_F(n + 1) [t_F(n + 1) = t_F(n) + Δt_F(n))
It is to be calculated. Calculated play time t _F
(n + 1) is stored and updated in a predetermined RAM of the storage means 3, and
Used when shifting up from the 2nd gear to the 3rd gear
It has become so.

Hydraulic release time t_RIn the learning correction of
The learning correction means 2 releases the hydraulic pressure of the second brake 22
From the time point RB, the reconnection system of the first 2nd brake 22
Time till the start of the control (BS) (actual release time) t_RC(n)
Measured and the previous actual release time t _RC(n-1)
Δt_RC(n) [Δt_RC(n) = t_RC(n) -t_RC(n-1)]
It comes out.

The learning correction means 2 includes an actual release time difference Δt _RC
A map indicating the relationship between the hydraulic pressure release time t _{R and} the correction amount Δt _R is stored in advance, and the correction amount Δt _R (n) of the current hydraulic release time t _R (n) is referred to by referring to this map.
Is to be determined. Then, the hydraulic pressure release time t _R (n + 1) [t _R (n + 1) = t _R (n) + Δt _R (n)] to be used in the next upshift from the second speed to the third speed is calculated. It has become. The calculated hydraulic release time t _R (n
+1) is stored and updated in a predetermined RAM of the storage means 3 and, based on the relationship with the backlash reduction time t _F (n + 1), the hydraulic pressure at the next shift from the second gear to the third gear is increased. Release start time R
B is determined.

At the time of the first shift control, these t
_F , t _R , and D _A2 are not subjected to learning correction, so that
Initial setting value t previously stored in learning correction means 2
_F (1), t _R (1), and D _A2 (1) are used. In learning correction of learning values of t _F and t _R ,
At the time of the first learning correction, the previous play reduction time t _F (n-1)
, Hydraulic pressure release time t _R (n-1) does not exist, so that the initial set values t _F (1) and t _R (1) are substituted.

The learning correction method for the play reduction time t _F , the oil pressure release time t _R , and the initial duty ratio DA _{2 in} the learning correction means 2 has been described above. However, the control means 1 controls the connection information of the battery 32 and the oil temperature sensor. ATF detected at 14
Based on the oil temperature T, it is determined whether or not to perform these learning corrections. This determination is made by the determination means (battery connection determination means) 4 which is a functional element of the control means 1.

There are the following two cases where the judging means 4 judges whether the learning correction means 2 permits the learning correction. First, as a first case, the oil temperature T of the ATF is equal to or higher than a _first predetermined temperature T ₁ (for example, T ₁ = 50 ° C.) (T ≧ T ₁ ). Conversely, oil temperature T
If is lower than the first predetermined temperature T ₁ of is that it does not allow the learning correction. This is the oil temperature T is a low temperature such as lower than the first predetermined temperature T _1, the automatic transmission 10
Characteristics are not stable, so if the learning correction is continued from a low temperature state, the difference between the learning correction value at a high temperature (stable state) and the convergence value of the learning correction value will vary, resulting in a smooth shift. This is because control is hindered.

In the second case, immediately after the connection of the battery 32, the oil temperature T of the ATF is equal to or higher than a _second predetermined temperature T ₂ (T ₂ <T ₁ , for example, T ₂ = 10 ° C.). It is to be. When the connection of the battery 32 is released, t _F , t _R , and D _A2 stored in the RAM of the storage means 3 are stored.
Immediately after the battery 32 is connected, it is not possible to perform the shift control using the learning correction value obtained by the learning correction in the high temperature stable state. Further, even when the new vehicle is shipped, if the vehicle is in the unlearned state immediately after the connection of the battery 32, the gear shift control using the learning correction value cannot be performed. However, even in such a case, it is necessary to perform a smooth shift control by preventing a sudden rise or shock of the engine.

Therefore, the determination means 4 allows the learning correction immediately after the battery 32 is connected, regardless of the above-described first case condition (T ≧ T ₁ ), and performs the shift control based on the learning correction value. It is possible. However,
When the oil temperature T is lower than the second predetermined temperature T ₂ is very unstable learning correction value, because the effect of active learning correction can not be obtained, still learning correction Such extremely low temperature Is not performed.

Also, even when the learning correction is started immediately after the battery 32 is connected, once the oil temperature T becomes equal to or higher than the first predetermined temperature T ₁ , the oil temperature T is reduced to the first predetermined temperature T 1.
When it becomes lower than _1, learning correction is not allowed. This is an extremely countermeasure in the second case when the shift control based on the learning correction value in the oil temperature stable state cannot be performed, and the oil temperature T rises and the automatic transmission 10 becomes stable. When this happens, the learning correction value is made to converge to an optimum value by following the conditions in the above-described first case, and smooth shift control is performed.

Since the shift control device for an automatic transmission according to one embodiment of the present invention is configured as described above, FIG.
According to the flow shown in FIG. 7, learning correction of the play reduction time t _F , the hydraulic pressure release time t _R , and the initial duty ratio D _A2 is performed. As shown in FIG. 3, the determining means 4 first determines whether or not the battery 32 has just been connected based on the battery connection flag F (step S10). The battery connection flag F indicates whether the battery 32 has been disconnected or the battery 3
As when 2 is broken, cleared (F = 0) when all power is turned off, since the battery 32 is connected and the oil temperature T of the ATF is the first predetermined temperature T ₁ set (F = 1).

When the battery connection flag F is 1, that is,
If the battery 32 has not been connected immediately, step S2
0, the oil temperature T of the ATF detected by the temperature sensor 14
Is higher than or equal to a _first predetermined temperature T1 (step S
20). When the detected oil temperature T is lower than the first predetermined temperature T ₁ , the determination means 4 does not allow the learning correction of the learning correction means 2, and t _F , t _R , and D _A2 indicate the previous speed change. The learning correction value at the time of the control is held, and the learning correction value at the time of the previous shift control is used at the next corresponding shift control.

When the oil temperature T is equal to or higher than the _first predetermined temperature T ₁ , the judging means 4 allows the learning correction of the learning correction means 2, and the learning correction means 2 outputs t _F , t _R , A learning correction of D _A2 is performed. Then, each learning correction value is stored and updated in a predetermined RAM of the storage means 3, and is used at the next corresponding shift control (step 30). On the other hand, either when the battery connection flag F is 0, i.e., when the battery 32 is immediately after connection, the process proceeds to step S40, the oil temperature T of the ATF detected by the temperature sensor 14 is the second predetermined temperature T ₂ higher It is determined whether or not it is (step S40). When the detected oil temperature T is lower than the second predetermined temperature T ₂ , the determining means 4 does not allow the learning correction means 2 to perform the learning correction, and the learning correction means 2 is stored in advance in the learning correction means 2 for the shift control. Initial setting values t _F0 , t _R0 , and D _A20 are used.

When the oil temperature T is equal to the second predetermined temperature T_TwoBecame more than
In this case, the determination means 4 further determines that the oil temperature T is equal to the first predetermined value.
Temperature T₁It is determined whether or not this is the case (step S50). this
When the oil temperature T is equal to the first predetermined temperature T₁Lower than
Proceeds to step S30, where t _F, T_R, D_A2Learning assistant
Do the right thing. Then, each learning correction value is stored in a predetermined
Of the first predetermined temperature T₁Less than
The next applicable shift control is performed using the learning correction value at low temperature.
Now (step 30).

When the oil temperature T has become equal to or higher than the first predetermined temperature T ₁ , the determining means 4 sets the battery connection flag F (F = 1) in step S60, and proceeds to step S30, where t _F, t _R, the learning correction of D _A2 is performed.
Then, stored and updated in a predetermined RAM storage means 3 each learning correction value, the next at the time of the relevant shift control, the learning correction value in the state where the first predetermined temperature above T ₁ of the automatic transmission 10 stable Is used (step 30).

[0054] By battery connection flag F is set (F = 1) at step S60, from the next control cycle, the oil temperature T is lower than the first predetermined temperature T _1, t
The learning correction of _F , t _R and D _A2 is prohibited (step S1).
0, S20). Thereby, t _F , t _R , and D _{A2 become} the first.
The results in the predetermined temperature above T ₁ of the automatic transmission 10 is only learning correction in a stable region, convergence to the optimal value is tomb.

As described above, according to the present shift control device, the AT
F is the first predetermined temperature T₁Even at low temperatures
Immediately after the battery 32 is connected, the oil temperature T becomes the second predetermined value.
Temperature T_TwoAs long as it is more than the play time t_F, When hydraulic pressure is released
Interval t_R, Initial duty ratio D _A2Make learning correction
, So that the battery 32
Even at low temperatures immediately after connection, the characteristics of the automatic transmission 10
Shift control can be performed based on the learning correction value,
Engine suddenly blows up,
Smooth shifting control possible by preventing shock
Becomes

[0056] Further, since once the oil temperature T of the ATF when it becomes the first predetermined temperature T ₁ above is adapted to prohibit the first learning correction in less than the predetermined temperature T _1, the automatic Learning correction can be performed only when the transmission 10 is in a stable state, and the learning correction value can be made to converge to an appropriate value, so that smoother shift control can be performed. It should be noted that the present invention is not limited to the above-described embodiment, and can be implemented with various modifications without departing from the spirit of the present invention. For example, in the above-described embodiment, the second predetermined temperature T ₂
Set, but the oil temperature T even just after the connection of the battery 32 is adapted to not perform the learning correction if the second predetermined temperature T ₂ or higher, for example, be used under the car is always warm climate etc. If that, without setting a predetermined temperature T ₂ of the second, oil temperature T if immediately after connection of the battery 32
The learning correction may be started irrespective of.

The values of the first predetermined temperature T ₁ and the second predetermined temperature T ₂ are not limited to the values of the present embodiment, but may be appropriately determined according to the characteristics of the automatic transmission 10 and the ATF. It can be set. Further, in the above-described embodiment, the case where the upshift is performed particularly as the shift control is described. However, the downshift, the shift from the N (neutral range) to the D (drive range), and the N to the R (reverse) are performed. Of course, it is also possible to apply to shifting to (range).

That is, the learning correction of the parameter value relating to the shift down or the like is basically permitted only when the oil temperature T is equal to or higher than the _first predetermined temperature T ₁ , and only when the battery 32 is connected, the first predetermined temperature T be less than _1, it is to allow long second predetermined temperature T ₂ or more. Then, once the oil temperature T is in when it becomes the first predetermined temperature T ₁ or more and to prohibit the learning correction in the first lower than the predetermined temperature T _1. As a result, as in the case of the upshift described above, it is possible to perform smooth shift control (shift down or the like) even at a low temperature immediately after the connection of the battery 32, such as at the time of factory shipment.

[0059]

As described above in detail, according to the shift control apparatus for an automatic transmission according to the present invention, the learning correction means determines that the battery connection determination means has connected the battery. Immediately after, even when the oil temperature is lower than the predetermined value, the parameter value related to the shift is learned and corrected, so that the shift control based on the parameter value learned and corrected according to the characteristics of the automatic transmission can be performed. Thus, it is possible to perform a smooth shift control by preventing a sudden blow-up or shock of the engine.

According to the shift control device for an automatic transmission according to the second aspect of the present invention, after the oil temperature once becomes higher than the predetermined value, the learning correction means may in principle make the oil temperature lower than the predetermined value. In the temperature range of, the parameter value is not learned and corrected, so that the parameter value can be learned and corrected only when the automatic transmission is stable.
The parameter value can be made to converge to an appropriate value, and smoother shift control can be performed.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing a configuration of a shift control device for an automatic transmission as one embodiment of the present invention.

FIGS. 2A and 2B are diagrams illustrating timings of shift control according to a shift control device of an automatic transmission according to an embodiment of the present invention, wherein FIG. 2A is a diagram illustrating a change over time of a rotation speed of a turbine shaft, and FIG. Is a diagram showing the control timing of the duty ratio of the solenoid on the release side, (c) is a diagram showing the control timing of the duty ratio of the solenoid on the connection side, and (d) is a graph showing the time change of the hydraulic pressure of the release side element and the hydraulic pressure of the connection side element. FIG.

FIG. 3 is a diagram illustrating a learning flow of a parameter value according to a shift control device of an automatic transmission as one embodiment of the present invention.

FIG. 4 is a skeleton diagram showing a configuration of a conventional automatic transmission.

[Explanation of symbols]

 Reference Signs List 1 control means 2 learning correction means 3 storage means 4 determination means (battery connection determination means) 10 automatic transmission 11 hydraulic circuit 14 oil temperature sensor 20 OD clutch 21 Rev clutch 22 2nd brake 23 LR brake 24 UD clutch 32 battery

Claims (2)

[Claims] When the oil temperature of an automatic transmission is equal to or higher than a predetermined value,
A shift control device for an automatic transmission having a learning correction means for learning and correcting a parameter value relating to a shift, comprising: a battery connection determining means for determining whether or not a battery is connected to the shift control device; Immediately after it is determined that the battery is connected, the learning correction means learns and corrects the parameter value even when the oil temperature is lower than the predetermined value. . 2. The method according to claim 1, wherein the learning correction means does not perform learning correction of the parameter value in a temperature range in which the oil temperature is lower than the predetermined value after the oil temperature once exceeds the predetermined value. The shift control device for an automatic transmission according to claim 1.