JP3250480B2 - Transmission control device for automatic transmission - Google Patents

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, and more particularly to an actuator for controlling a hydraulic pressure of a friction element during downshifting by changing a friction element during power-on traveling. The present invention relates to a shift control device which is capable of maintaining a predetermined shift performance even if the hydraulic fluid characteristic has a variation with respect to a value or a change in the characteristic.

[0002]

2. Description of the Related Art An automatic transmission is provided with a gear transmission system by selectively engaging a plurality of clutches, brakes, and other speed-changing friction elements by increasing hydraulic fluid pressure or releasing them by decreasing hydraulic fluid pressure. Is determined by determining the power transmission path (gear stage) of the vehicle and switching the friction element that operates. Therefore, in an automatic transmission, a downshift that is performed by changing the friction element in the engaged state by simultaneously releasing the friction element in the engaged state by lowering the hydraulic fluid pressure and engaging the friction element in the released state by increasing the hydraulic fluid pressure is performed. Exists.

[0003] In the following description, the friction element to be switched from the engaged state to the released state during the gear shift is referred to as a release-side friction element, the hydraulic fluid thereof is referred to as a release-side hydraulic pressure, and the friction to be switched from the released state to the engaged state. The element is referred to as a fastening-side friction element, and its hydraulic pressure is referred to as a fastening-side hydraulic pressure.

[0004] In particular, when the downshift is performed while the accelerator pedal is being depressed, that is, during power-on traveling, the shift shock is likely to be large, so that the switching of the friction element is performed under a fine control. Must be done in

Therefore, conventionally, for example, Japanese Patent Application Laid-Open No. 5-33244.
As described in No. 0 publication. During downshifting during power-on traveling, feedback control is performed on the hydraulic fluid pressure of the disengagement-side friction element so that the input shaft rotation change rate becomes a target value, and the input shaft rotation speed does not hunt the initial pressure at the start of feedback control. It has been proposed to perform learning control.

[0006]

Regardless of the countermeasures taken, the controller increases the control of the hydraulic fluid pressure related to the engagement-side friction element and the control of the reduction of the hydraulic fluid pressure related to the release-side friction element. It is common sense to do this with an actuator that responds to the command value of
In general, the hydraulic fluid pressure is increased or decreased as described below based on the inherent operation characteristics exemplified by the solid line in FIG.

That is, the transmission torque of the friction element is T
_Assuming that it is as shown by ₀₁ , the command hydraulic pressure P for generating the required engagement capacity is determined from the operating characteristics of the friction element, and the corresponding duty D is calculated as shown in FIG.
In FIG. 4, a search and linear interpolation are performed based on the actuator operation characteristics indicated by the solid line, and the obtained values are output to the actuator.

The operating characteristics of the friction element do not have a large variation toward the left and are not significantly affected by a temperature change. However, the operating characteristics indicating the relationship between the duty D, which is the command value of the actuator, and the hydraulic fluid pressure are as follows. For example, FIG.
As shown by a one-dot chain line, there is a large variation among products, the variation varies with temperature, and also varies with time.

FIG. 24 shows the operation characteristics of the actuator.
When explained when it becomes different as indicated by the one-dot chain line, even for the same command duty D, transmissible torque of the friction element is assumed large as T _02, the engagement capacity of the friction element Too much. Of course, when the actuator operation characteristics are different in the direction opposite to the one-dot chain line in FIG. 21, the fastening capacity of the friction element becomes too small.

In this case, even if a countermeasure as exemplified in the above-mentioned document is taken, since the essential hydraulic fluid pressure does not reach the target value, the intended shift control cannot be achieved.

When the operating characteristics of the actuator vary or change as described above, when the engagement force on the engagement side is excessive, the engagement capacity after the shift is completed before synchronizing with the gear ratio after the shift is completed, and the output shaft torque is increased. After the shift is completed, the gear is synchronized with the gear ratio after the shift is completed, and when the fastening force on the fastening side is too small, idling occurs and not only is the durability of the friction fastening element disadvantageous, but also the torque fluctuates at full fastening. It cannot be forbidden to give the driver a sense of discomfort.

According to the first aspect of the present invention, even if the operating characteristics of the actuator relating to the engagement-side friction element to be engaged vary or change during downshifting during power-on traveling, the friction element can be used. It is an object of the present invention to propose a shift control device for an automatic transmission, which is capable of realizing compensation such that the hydraulic fluid pressure does not become excessive.

According to a second aspect of the present invention, even if the operating characteristics of the actuator relating to the engagement-side friction element to be engaged vary or change during downshifting during power-on traveling, the friction element can be used. It is an object of the present invention to propose a shift control device for an automatic transmission, which is capable of realizing compensation so that the hydraulic fluid pressure does not become too small.

According to a third aspect of the present invention, the hydraulic fluid pressure of the friction element does not become excessive even if the operating characteristics of the actuator related to the engagement-side friction element vary or change. It is an object of the present invention to propose a shift control device for an automatic transmission, which is capable of realizing compensation and also realizing compensation that does not become too small.

A fourth aspect of the present invention is to embody the first to third aspects of the invention when controlling the hydraulic pressure of the engagement-side friction element to a constant shelf pressure during the torque phase. And

A fifth aspect of the present invention is directed to a modification of the actuator operating characteristic according to the fourth aspect of the present invention.

According to a sixth aspect of the present invention, in the case where the command value / working fluid pressure characteristic relating to the actuator is a map in which the command value and the working fluid pressure are quantized and associated with each other, It is intended to embody the fourth invention or the fifth invention.

A seventh object of the present invention is to enable the correction of the command value / hydraulic fluid pressure characteristic in the sixth invention to be simplified by using a mathematical expression.

[0019]

SUMMARY OF THE INVENTION To achieve the above object, a shift control device for an automatic transmission according to a first aspect of the present invention controls a friction element in an engaged state by reducing hydraulic fluid pressure by an actuator responsive to a command value from a controller. Simultaneously with the release, the friction element in the released state is engaged by increasing the hydraulic fluid pressure by the actuator responding to the command value from the controller, thereby performing a downshift, and the controller sends the command value to each of the actuators. In an automatic transmission, which is determined based on a predetermined command value and a working fluid pressure characteristic specific to an actuator based on a required working fluid pressure corresponding to a required engagement capacity of a friction element, under power-on traveling, During the downshifting, the torque phase opening at which the gear ratio represented by the transmission input / output rotation ratio first matches the gear ratio after shifting is performed. Thereafter, when the time during which the gear ratio exceeds the set gear ratio is longer than a predetermined time, the hydraulic fluid pressure of the engagement-side friction element to be engaged increases with respect to the same command value from the controller to the actuator. Thus, the predetermined command value / hydraulic fluid pressure characteristic is modified.

The shift control device for an automatic transmission according to the second invention releases the friction element in the engaged state by lowering the hydraulic fluid pressure by an actuator responsive to a command value from the controller, and simultaneously releases the friction element in the released state. The shift is performed by increasing the hydraulic fluid pressure by an actuator that responds to the command value from the controller to perform a downshift, and the controller converts the command value to each actuator into a predetermined command value and hydraulic fluid specific to the actuator. In the automatic transmission, which is determined based on the pressure characteristics in association with the required hydraulic pressure corresponding to the required engagement capacity of the friction element, the input / output of the transmission After the start of the torque phase in which the gear ratio represented by the rotation ratio first matches the gear ratio after shifting, the gear ratio exceeds the set gear ratio If the time period is shorter than the scheduled time, the predetermined command value / operating fluid pressure characteristic is set so that the working fluid pressure of the engagement-side friction element to be fastened is lower than the same command value from the controller to the actuator. Is modified.

A shift control device for an automatic transmission according to a third aspect of the present invention releases a friction element in an engaged state by lowering hydraulic fluid pressure by an actuator responsive to a command value from a controller, and simultaneously releases the friction element in a released state. The shift is performed by increasing the hydraulic fluid pressure by an actuator that responds to the command value from the controller to perform a downshift, and the controller converts the command value to each actuator into a predetermined command value and hydraulic fluid specific to the actuator. In the automatic transmission, which is determined based on the pressure characteristics in association with the required hydraulic pressure corresponding to the required engagement capacity of the friction element, the input / output of the transmission After the start of the torque phase in which the gear ratio represented by the rotation ratio first matches the gear ratio after shifting, the gear ratio exceeds the set gear ratio If the time period is longer than the scheduled time, the predetermined command value / operating fluid pressure characteristic is set so that the hydraulic fluid pressure of the engagement-side friction element to be engaged becomes higher with respect to the same command value from the controller to the actuator. After the start of the torque phase in which the gear ratio represented by the transmission input / output rotation ratio first coincides with the post-shift gear ratio during the downshifting under power-on traveling, the gear ratio is set. If the time during which the gear ratio is exceeded is shorter than the scheduled time, the predetermined command value is set so that the hydraulic pressure of the engagement-side friction element to be fastened is lower than the same command value from the controller to the actuator. -The hydraulic fluid pressure characteristics are modified.

According to a fourth aspect of the present invention, there is provided the transmission control apparatus for an automatic transmission according to any one of the first to third aspects, wherein the hydraulic fluid pressure of the engagement-side friction element is controlled to a constant shelf pressure during a torque phase. The predetermined command value / hydraulic fluid pressure characteristic is modified so that the shelf pressure becomes a corrected shelf pressure obtained by adding or subtracting a predetermined amount from the same command value to the actuator. .

According to a fifth aspect of the present invention, in the transmission control apparatus for an automatic transmission according to the fourth aspect, the predetermined amount to be added to the shelf pressure is:
The larger the time during which the gear ratio exceeds the set gear ratio is longer than the scheduled time, the larger the ratio.

A shift control device for an automatic transmission according to a sixth invention.
Is the fourth invention or the fifth invention, wherein
The command value and hydraulic pressure characteristics correspond to the command value and hydraulic pressure, respectively.
If the map is quantized and associated with each other,
On the map before and after the shelf pressure P before correction
Dynamic fluid pressure value P₁, P _TwoRatio a of shelf pressure P before correction between
And the corrected shelf pressure P_ABetween before and after
Hydraulic pressure P on the tap_Three, P_FourShelf pressure after correction P between
_AAnd the torque ratio for the pre-correction shelf pressure P
Command value D to the actuator during
Command value D on the map before and after₁, D_TwoAnd the
Shelf pressure P after correction on top_ATo the actuator corresponding to
Command value D_ACommand values on the map before and after
D_Three, D_FourAnd the command value and hydraulic pressure characteristics
It is configured to correct the gender.

According to a seventh aspect of the present invention, in the shift control device for an automatic transmission according to the sixth aspect, the command values D ₃ and D ₄ are respectively set as follows: D ₃ = [1 / (1-b)] [(1-a ) ・ D ₁ + a ・ D
_2- b · D ₄ ] D ₄ = (1 / b) [(1-a) · D ₁ + a · D _2- (1
-B) .D ₃ ] to correct the scheduled command value / hydraulic fluid pressure characteristic.

[0026]

According to the first aspect of the present invention, the automatic transmission releases the friction element in the engaged state by lowering the hydraulic fluid pressure by the actuator responsive to the command value from the controller, and simultaneously releases the friction element in the released state. Downshifting is performed by engaging with an increase in hydraulic fluid pressure by an actuator that responds to a command value from the controller.

Here, the controller determines a command value for each actuator in accordance with a required command hydraulic capacity corresponding to a required engagement capacity of the friction element based on a predetermined command value and hydraulic fluid characteristic specific to the actuator.

During the above-mentioned downshift under power-on traveling, after the start of the torque phase in which the gear ratio represented by the transmission input / output rotation ratio first matches the post-shift gear ratio, the gear ratio If the time during which the gear ratio exceeds the set gear ratio is longer than the scheduled time, the hydraulic fluid pressure of the engagement-side friction element to be engaged is too low for the request, and the state in which the transmission input rotation greatly exceeds the synchronous rotation may occur. Since the operation time is relatively long, the hydraulic fluid pressure of the engagement-side friction element is increased with respect to the same command value from the controller to the actuator.
That is, under the same conditions, the predetermined command value / working fluid pressure characteristic is corrected so that an actuator command value for increasing the working fluid pressure of the engagement side friction element is issued next time.

Therefore, the command value / hydraulic pressure characteristic of the actuator relating to the engagement-side friction element can be corrected so that the hydraulic pressure of the engagement-side friction element does not become too small. In addition, it is possible to avoid such a problem that the hydraulic fluid pressure of the engagement-side friction element becomes too small to perform predetermined shift control.

In the second invention, during the above-mentioned downshift under power-on traveling, after the start of the torque phase in which the gear ratio represented by the transmission input / output rotation ratio first matches the post-shift gear ratio. If the time during which the gear ratio exceeds the set gear ratio is shorter than the scheduled time, the working fluid pressure of the engagement-side friction element is too high with respect to the value required for the shift shock, so that the engagement-side friction element The hydraulic fluid pressure becomes lower for the same command value from the controller to the actuator, that is, the actuator command value that lowers the hydraulic fluid pressure of the engagement side friction element next time under the same conditions is issued. Correct the predetermined command value / working fluid pressure characteristic.

Therefore, the command value / hydraulic pressure characteristic of the actuator relating to the engagement-side friction element can be corrected so that the hydraulic pressure of the engagement-side friction element does not become excessive, and even when the characteristic changes. In addition, it is possible to avoid such an adverse effect that the hydraulic pressure of the engagement-side friction element becomes excessively large and the shift shock increases.

In the third aspect of the present invention, during the above-mentioned downshift under power-on traveling, after the start of a torque phase in which the gear ratio first matches the post-shift gear ratio, the gear ratio exceeds the set gear ratio. If the time is longer than the scheduled time, the hydraulic fluid pressure of the engagement-side friction element is corrected with respect to the same command value from the controller to the actuator, so that the scheduled command value / hydraulic fluid pressure characteristic is corrected, Conversely, during the above downshift under power-on traveling, after the start of the torque phase in which the gear ratio first matches the post-shift gear ratio, the time during which the gear ratio exceeds the set gear ratio is the scheduled time. If it is shorter than the predetermined value, the predetermined command value / working fluid pressure characteristic is corrected so that the working fluid pressure of the engagement-side friction element becomes lower with respect to the same command value from the controller to the actuator.

Therefore, the third aspect of the invention is capable of correcting the hydraulic fluid pressure of the engagement-side friction element so as not to become too small even if the command value / hydraulic fluid pressure characteristic of the actuator relating to the engagement-side friction element changes. It is possible to realize both the operation and effect of the first invention and the operation and effect of the second invention that the hydraulic fluid pressure of the engagement-side friction element can be corrected so as not to be excessive.

A fourth aspect of the present invention is to control the hydraulic pressure of the engagement-side friction element to a constant shelf pressure during the torque phase at the time of the downshift under power-on traveling. The predetermined command value so that the corrected shelf pressure obtained by adding or subtracting a predetermined amount from the same command value to
Correct the hydraulic pressure characteristics. Therefore, the fourth invention can embody the first to third inventions in an automatic transmission in which the torque phase of the downshift is advanced by shelf pressure control.

In the fifth invention, the predetermined amount to be added to the shelf pressure in the fourth invention is increased as the time during which the gear ratio exceeds the set gear ratio is longer than the scheduled time. According to the fact that the pressure is insufficient, the correction of the actuator operating characteristics can be performed more reliably.

In a sixth aspect of the present invention, the predetermined command value and hydraulic pressure
The characteristics quantize the command value and the hydraulic pressure respectively, and
In the case where the map is associated with
Hydraulic fluid pressure values on the map before and after the shelf pressure P
P₁, P _TwoInternal ratio a of the shelf pressure P before correction between
Shelf pressure P after correction_AOn the map before and after
Hydraulic fluid pressure value P_Three, P_FourShelf pressure after correction P between_AInside of
During the torque phase for the ratio b and the shelf pressure P before correction
Before and after the command value D to the actuator
Command value D on the map₁, D_TwoAnd on the map
Shelf pressure after correction P_ACommand value D to the actuator corresponding to
_ACommand values D on the map before and after_Three, D
_FourTo correct the expected command value and hydraulic pressure characteristics
Therefore, the command value and hydraulic pressure characteristics are
Even in certain cases, the fourth and fifth inventions are implemented
Corresponding effects can be achieved.

According to a seventh aspect of the present invention, the command values D ₃ and D ₄ in the sixth aspect of the invention are calculated as follows: D ₃ = [1 / (1-b)] [(1-a) · D ₁ + a · D
_2- b · D ₄ ] D ₄ = (1 / b) [(1-a) · D ₁ + a · D _2- (1
-B) By correcting and updating according to D ₃ ], the predetermined command value / hydraulic pressure characteristic is corrected, so that the command value / hydraulic pressure characteristic of the actuator can be simply corrected by a mathematical formula. Can be.

[0038]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a control system of an automatic transmission provided with a shift control device according to one embodiment of the present invention, wherein 1 is an engine, 2 is a torque converter, 3 is an automatic transmission, and the engine rotation is a torque converter 2 Through the input shaft 4 of the automatic transmission.

The automatic transmission 3 is basically the same as that described in "RE4R01A Automatic Transmission Maintenance Manual" (A261C07) issued by Nissan Motor Co., Ltd. , 5 are provided with a front planetary gear set 6 and a rear planetary gear set 7 mounted thereon. The forward clutch F / C and the high clutch H are used as friction elements.
/ C, band brake B / B, low reverse brake L
R / B, a low one-way clutch L / OWC, and a reverse clutch R / C, and selectively engaging these as indicated by a circle in FIG.
The speed and the reverse gear can be selected. (○) regarding the low reverse brake LR / B indicates the first
Indicates that the engine is to be engaged when needed at high speed.

In order to execute the selective operation (engagement) of the friction element, the control valve 8 of the automatic transmission 3 is operated.
Include a duty solenoid 9 for a forward clutch F / C, a duty solenoid 10 for a high clutch H / C, a duty solenoid 11 for a band brake B / B, a duty solenoid 12 for a low reverse brake LR / B, and a river. The duty logic 13 for the scratch R / C is provided, and the duty of the operating oil pressure of the corresponding friction element is individually controlled by the duty solenoid 13 to realize the engagement logic shown in FIG. Transient control.

The duty control of the solenoids 9 to 13 is performed by a controller 14, which receives a signal from a throttle opening sensor 16 for detecting a throttle opening TVO of the engine 1 and an engine speed N.
_e , a signal from the engine rotation sensor 17 for detecting _e , and an input rotation speed N _i from the torque converter 2 to the automatic transmission 3.
A signal from an input rotation sensor 18 for detecting a signal from the output rotation sensor 19 for detecting a transmission output speed N _o, and a signal from an oil temperature sensor 20 for detecting a transmission working oil temperature T _OIL input.

In this embodiment, the band brake B / B in the engaged state is released by lowering the hydraulic pressure, and the forward clutch F / C in the released state is engaged by increasing the hydraulic pressure. The concept of the present invention is applied to the downshift from the fourth speed to the third speed to be performed.
For this reason, in particular, the hydraulic fluid pressure control portion of the forward clutch F / C and the band brake B / B extracted from FIG. 1 and shown in FIGS. 3 and 4, respectively, will be described in detail below.

FIG. 3 shows the hydraulic fluid pressure control circuit of the forward clutch F / C, which is the engagement-side friction element to be changed from the released state to the engaged state during the downshift from the fourth speed to the third speed. , A pressure regulating valve 22 is provided in an operating pressure circuit 21 of the forward clutch F / C.
The line pressure P _L is used as the base pressure, and the operating oil pressure P _c of the forward clutch F / C according to the increase of the control pressure in the chamber 22a.
From 0.

The control pressure in the chamber 22a of the pressure regulating valve 22 is determined by the corresponding solenoid 9.
The solenoid 9, the constant pilot pressure P _p that created the line pressure P _L under reduced pressure and source pressure, and supplies a control pressure according to the driving duty of the solenoid 9 in the chamber 22a.

FIG. 4 shows a hydraulic fluid pressure control circuit of the band brake B / B, which is a disengagement-side friction element to be changed from the engaged state to the disengaged state during the downshift from the fourth speed to the third speed. , A pressure control valve 24 is provided in the operating pressure circuit 23 of the band brake B / B. The pressure control valve 24 uses the line pressure P _L as a base pressure, and controls the band brake B / B in response to an increase in the control pressure in the chamber 24a. It is assumed that the working fluid pressure _Po is increased from zero.

The control in the pressure regulating valve 24 in chamber 24a pressure, what determines by the solenoid 11 corresponding, the solenoid 11, the original pressure constant pilot pressure P _p that created the line pressure P _L in vacuo The control pressure according to the drive duty of the solenoid 11 is supplied to the chamber 24a.

The controller 14 in FIG. 1 executes the control program shown in FIG. 5 based on the above input information,
Particularly, the downshift from the fourth speed to the third speed is performed according to the time chart of FIG. FIG.
In step 31, the engine throttle opening TVO detected by the sensor 16, since the transmission output speed N _o detected by the sensor 19 (vehicle speed), based on the shift map will also to the driving conditions The desired preferred gear is searched for, and if the currently selected gear is the same as this preferred gear, there is no need for gear shifting, so control is terminated as it is, and if the current selected gear is different from this preferred gear, Step 3
In step 2, the shift to the preferred gear is performed.

The shift in step 32 is a downshift from the fourth speed to the third speed during power-on traveling in which power is transmitted from the engine to the wheels by depressing the accelerator pedal. 21. First, FIG. 6 shows the processing in the first stage in FIG. 23. In step 41 of FIG. 23, it is determined whether or not the 4 → 3 downshift command has been issued and this is the first time. If it is the first time, in step 42, control data used in the first stage is set.

The control data set in step 42 is as shown in FIG.
The precharge pressure _Ppr to be applied to the engagement-side friction element (forward clutch F / C) in the first stage, the first-stage control time t ₁ (see FIG. 23), and the release-side friction that continuously decreases after the first stage Ramp control time t for operating pressure P _o of element (band brake B / B)
₂ (see FIG. 23).

Here, the control time t of the first stage
₁ is the time required for completing the loss stroke of the engagement-side friction element under the precharge command pressure _Ppr , and is set in advance, for example, for each transmission operating oil temperature T _OIL . Also, a time t ₂ for lowering the operating oil pressure _Po of the release-side friction element at the same gradient as the first stage after the first stage.
Is, when reducing an operating pressure P _o of the disengagement side frictional element, when an attempt to complete the short time in the reduction, such as the first stage control time t _1, rapid decrease in the release-side hydraulic pressure P _o too, since causing undershoot at the control end, predetermined as the time for preventing undershoot to be added to the first stage control time t _1.

[0051] Then, in step 52, calculates the transmission input torque T _i. At the time of this calculation, as shown in FIG. 8, first, in step 61, the engine speed _Ne (torque converter input speed) and the transmission input shaft speed (output speed of the torque converter) _{Ni are used} to calculate the torque converter speed. The speed ratio e (e = N _i / N _e ) is obtained,
Next, at step 62, the torque ratio t and the torque capacity coefficient τ of the torque converter are obtained from the speed ratio e based on the performance diagram of the torque converter.
Using these, the turbine torque (transmission input torque) T _i is calculated by the calculation of T _i = τ · t · _Ne ² .

[0052] In step 53 of FIG. 7, the release-side friction element under the input torque T _i (band brake B
/ B), as shown in FIG. 9, the required hydraulic pressure P _omin (see FIG. 23) for _{keeping the} oil pressure just before slipping.

(Equation 1) However, alpha: torque sharing rate of the band brake B / B A: pressure-receiving area of the disengagement side hydraulic pressure P _o R: brake drum radius e: base of natural logarithm mu: friction coefficient of the brake band theta: the wrap angle of the brake band calculate.

[0053] In step 54 of FIG. 7, was added disengagement side hydraulic pressure P _o from the line pressure P _L corresponding value, the fluid pressure d for the undershoot preventing disengagement side required oil pressure P _Omin as shown in FIG. 23 required to reduce to a pressure value _(P omin + d), the first ramp gradient Δ of the disengagement side hydraulic pressure P _o
P _o1 and [Delta] P _o1 = - is calculated by _{[P L} (P omin + d)] _{/ (t 1 + t 2)} ··· (1).

In step 43 of FIG. 6, based on the data set as described above in step 42, the control of the engagement side operating oil pressure _Pc and the release side operating oil pressure _Po in the first stage is performed as follows. Do. In other words, as shown in FIG. 23, the engagement side operating oil pressure _Pc is commanded to the solenoid 9 to be the precharge pressure _Ppr, and the loss stroke of the engagement side friction element (forward clutch F / C) is quickly increased. be completed, the disengagement side hydraulic pressure P _o is this, instructs the solenoid 11 to is shown in Figure 23 reduces by one first ramp gradient [Delta] P _o1.

In order to realize the engagement side hydraulic pressure command value P _C set to the precharge instruction pressure P _pr and the release side hydraulic pressure command value P _o reduced by ΔP _o1 , The command values (duty) and working fluid pressure characteristics of the solenoid actuators 9 and 11 to be operated are determined by changing the command values (duty) to D ₁ , D ₂ , and D as illustrated in FIG.
₃ quantized to as the ..., hydraulic fluid pressure is also P _1, P _2,
Quantized as P ₃ ..., D ₁ and P ₁ are associated with each other, D ₂ and P ₂ are associated with each other, and D ₃ and P ₃ are associated with each other and stored as a map. The release-side hydraulic pressure command value P determined as described above from the map
Each determined by the search and the well-known linear interpolation corresponding duty to _o and engagement side hydraulic fluid pressure command value P _C, these by commanding the solenoid actuator 9 and 11, above the disengagement side hydraulic fluid pressure command value P _o and we shall achieve engagement side hydraulic fluid pressure command value P _C.

The processing in step 43 is the same as that in step 44
The timer TM incremented by t
, Until it is determined that the first stage control time t ₁ has been reached, and as shown in FIG. 23, during the first stage control time t ₁ from the 4 → 3 downshift command,
Disengagement side hydraulic fluid pressure command value P _o is reduced by a ramp of [Delta] P _o1, the engagement side hydraulic fluid pressure command value P _C is maintained to the precharge command pressure P _pr, theoretically the loss stroke of the engagement side frictional element , At the end of the first stage control time t ₁ .

During this time, at step 45, the release-side operating oil pressure P
_o time to determine that it has reduced to the required pressure P _Omin holds the required oil pressure P _Omin the disengagement side hydraulic pressure P _o in step 46, that the disengagement side hydraulic pressure P _o lower than required oil pressure P _Omin Not to be. If it is determined in step 47 that the timer TM indicates the first stage control time t ₁ , the timer TM is reset to 0 in step 48 so that the timer TM can be used for subsequent use. The control proceeds to the second stage in FIG.

[0058] Control of the second stage is intended such shown in FIG. 10, the timer TM is Δt increments incremented in step 71 after the transition to the second stage, as shown in a second stage control time t ₃ at Step 86 In steps 72 to 85, until it is determined that
The following shift control is performed as shown in FIG.

In step 72, go to the second stage
Selected only when it is determined that this is the first time after the transition
In step 73, data used for control in the second stage is used.
The data is set as shown in FIG. First, at step 91
Of the engagement-side friction element (forward clutch F / C)
Return spring equivalent pressure P_crtn, When controlling the second stage
Interval t_Three(See FIG. 23), the friction element on the fastening side (forward
Operating oil pressure P of latch F / C)_cThe return spring phase
This pressure P_crtnReturn spring equivalent pressure to keep
Control time t_Four, Already mentioned above, but after precharge
Operating oil pressure P_oOf the first ramp control time t
_Two, The operating oil pressure P for the release-side friction element_oFirst
Ramp gradient ΔP_o1, Set a gentler gradient than this
Release hydraulic pressure P_oRamp slope ΔP of_o2,
First reference gear for determining start of inertia phase
Ratio g _r1, A larger second reference gear ratio g_r2Read
No.

In step 92 of FIG. 11, the transmission input torque Ti at the time of entering the second stage is calculated in the same manner as described above with reference to FIG. 8, and in the next step 93, the transmission input torque T _i is calculated as described above with reference to FIG. in the same manner as under the transmission input torque T _i, disengagement side frictional element (the band brake B
/ B) is calculated so as to maintain the _minimum required hydraulic pressure P _omin for maintaining the state just before slipping.

Based on the control data set as described above, the shift control for the second stage is executed as follows after step 74 in FIG. Step 74
In to 76, until it is determined that the timer TM in step 74 becomes as shown the course of the return spring equivalent pressure control time t ₄ from the transition to the second stage, the working oil pressure of the engagement side frictional element at step 75 The solenoid TM is instructed to set P _c to the return spring equivalent pressure P _crtn , and in step 74, the timer TM _{sets the} return spring equivalent pressure control time t ₄ from the shift to the second stage.
After it is determined that the time has elapsed, step 7
The working oil pressure P _c of the engagement side frictional element directs the solenoid solenoid 9 to be increased at the first ramp gradient [Delta] P _c1 as shown in FIG. 23 at 6.

In steps 77 to 79, steps from step 77 in which the timer TM determines that the first ramp control time t ₂ for the release-side friction element has elapsed since the shift to the second stage are determined. At 78, the operating pressure P _o of the disengagement side frictional element is commanded to the solenoid 11 to decrease at the first ramp gradient ΔP _o1 , and at step 77, the timer TM is switched from the transition to the second stage to the first ramp control for the disengagement side friction element. after determining that began to show the passage of time t _2, the second ramp gradient Δ a working oil pressure P _o of the disengagement side frictional element at step 79, as shown in FIG. 23
A command is issued to the solenoid 11 to lower it at _Po2 .

[0063] Also in the case to realize a hydraulic pressure command value P _c and P _o of such engagement side frictional element, as in the previously described per step 43 of FIG. 6, the map relating to the operating characteristics of the corresponding solenoid actuator 9,11 obtains the duty corresponding to these working oil pressure command value P _c and P _o by the search and the linear interpolation, and realizes the hydraulic pressure command value P _c and P _o by commanding them to the solenoid actuator 9,11 .

In the meantime, at step 80, the release side operating oil pressure P
_o is, when determined that the reduction to the required oil pressure P _Omin corresponding to the transmission input torque T _i in the transition moment to the second stage determined in Figure 11, the required release-side hydraulic pressure P _o in step 81 It held to the hydraulic P _{om in,} so as not to lower than necessary oil pressure P _Omin disengagement side working oil pressure P _o.

In step 82 of FIG. 10, FIG.
The transmission input / output rotation speed N _i, N_oDetermined from
Gear ratio g_r= N_i/ N_oIs the first reference gear ratio g_r1Greater than
The inertia phase starts depending on whether
It is determined whether or not it has just been performed. Start of inertia phase
Immediately after that, in step 83 which is selected only once, the process shown in FIG.
Step 43 and steps 75, 76, 78,
At 79, the command value (duty) to the solenoids 9 and 11 is
Commands to solenoids 9 and 11 used for determination
Value and friction element operating pressure P_c, P_oShows the relationship with
Command value / Hydraulic pressure characteristic map (actuator operation characteristics
G) is modified as follows.

The modification is as shown in FIGS. 13 to 15. First, in step 101 of FIG. 13, the required hydraulic pressure _Pot of the disengagement-side friction element (band brake B / B) at the start of the inertia phase is calculated. . The process when, first in the same manner as in FIG. 8, obtains a transmission input torque T _i at the start of the inertia phase,
Then in the same manner as in FIG. 9, according the input torque T _i
Is calculated as the hydraulic pressure required to keep the disengagement-side friction element (band brake B / B) in a state immediately before not slipping. .

In the next step 102, the
Release friction element (band
Actual command pressure P of brake B / B)_oAnd the above-mentioned required oil
Pressure P _otIs compared with. Start the inertia phase
Required fastening hydraulic pressure P_otRelease side actual command pressure P_o
When it is determined that the
B / B) actual command pressure P_oBut the oil actually generated
Pressure P_otThe map has shifted so that it is higher than
Therefore, in step 103, the release-side friction element
(Band brake B / B) command pressure P_oIs solenoid 1
Release side activator so that it becomes lower for the same command value to 1.
Modify the operation characteristic map of the router.

The modification of the release side characteristic map is shown in FIG.
This is clearly stated, but prior to its explanation,
The principle of the correction operation will be described below. Inertia of FIG.
Release-side working fluid pressure command value P at the moment when the pressure phase starts_o
The instantaneous value of is on the actuator operation characteristic map of FIG.
, And therefore the actuator 1
The command value (duty) to 1 is also shown in FIG.
Despite this, the inertia is actually
The start of the gear phase (gear ratio g_rThe inertia
Phase start judgment gear ratio g_r1Released side)
The actual value of the hydraulic pressure is indicated by P in FIGS._A(here
Is the required hydraulic pressure P on the release side._ot)
A description will be given of a certain case.
The values before and after the quantized P and D are P₁, P _TwoYou
And D₁, D_TwoAnd P_ABefore and after is P_Three, P_Four
And P_ADuty D corresponding to_ABefore and after
D_Three, D_FourIt is.

Here, the internal division ratio of P between P ₁ and P ₂ (P−P ₁ ) / (P ₂ −P ₁ ) is a, and the internal division ratio of P _A between P ₃ and P ₄ ( P _A -P ₃ ) / (P ₄ -P ₃ )
Is b, P, D, P _A , and D _A are respectively represented by the following equations. P = (1-a) P 1 + a · P 2 ···· (2) D = (1-a) D 1 + a · D 2 ···· (3) P A = (1-b) P 3 _{+ b · P 4 ··· (4} ) D A = (1-b) D 3 + b · D 4 ··· (5)

[0070] In the above phenomenon, since the fact hydraulic fluid pressure with respect to the command value D at the start of the inertia phase is outputted P _A, this command value D and the hydraulic pressure P _A is associated if you modify a map of the actuator operating characteristics as, you will be able to utilize the relationship of the next shift control when D and P _a, it is understood that it is possible to realize the shift control as aimed.

[0071] In order to be able to use the relationship between D and P _A is the song, D ₃ which is used when calculating the P _A, D
₄ needs to be modified. Meanwhile in the value of D _A is D _{is, (1-a) D 1} + a · D 2 = (1-b) D 3
+ B · D ₄ must be satisfied, and from this equation, the corrected values of D ₃ and D ₄ are D ₃ = [1 / (1-b)] [(1-a) · D ₁ + a · D ₂ −b · D ₄ ] (6) D ₄ = (1 / b) [(1−a) · D ₁ + a · D ₂ − (1−b) · D ₃ ] (7) ), And D ₃ and D ₄ are updated to the correction values calculated by these calculations. However, D ₄ and D _{3 on} the right side of the above two equations are respectively map values before updating.

A description will be given of the operation of modifying the characteristic map shown in FIG. 14 based on the above principle. First, in step 111, the operation characteristic map of the actuator shown in FIG.
The hydraulic fluid command value P of the disengagement side friction element and the values P ₁ , P before and after the duty D at the moment of the start of the inertia phase.
₂ and D ₁ and D ₂ are searched.

Next, at step 112, the duty D corresponding to the working fluid pressure command value P is output to the actuator 11, and control is performed to set the command pressure _Pc of the release-side friction element at the start of the inertia phase to P.

In the next step 113, P ₁ , P
Internal ratio of P between _{2 (P-P 1) /} (P 2 -P 1)
In step 114, the transmission input torque T _i at the start of the inertia phase and the torque sharing ratio of the disengagement-side friction element, which are obtained in the same manner as in FIG. , The required engagement capacity of the element is estimated, and the working fluid pressure P _A of the disengagement-side friction element for generating the required engagement capacity (here, the required engagement hydraulic pressure P _ot on the release side) is determined. . This request hydraulic pressure P _A is the pressure for actually rise to the start of the inertia phase by the gear ratio g _r is reduced to the inertia phase start determination gear ratio g _r1 as shown in FIG. 23, at the start of the inertia phase It represents the actual pressure of the release-side friction element.

[0075] In the next step 115, the operation characteristic map of the actuator of Figure 24, before and after values P ₃ of the duty D _A corresponding to the hydraulic pressure actual value P _A and its engagement side frictional element in the inertia phase start instant , P ₄ and D ₃ , D ₄ , and step 116
Now, the actual hydraulic pressure value P _A between P ₃ and P ₄
Is calculated as (P _A -P ₃ ) / (P ₄ -P ₃ ) = b.

Further, in step 117, the above (6)
Equation (7) gives D_Three, D _FourFind the corrected value of
D in the map_Three, D_FourIs calculated by these calculations
Update to the corrected value. Therefore, when shifting from next time
The modified D_Three, D_FourBased on the release side friction element
To the actuator 11 for the required hydraulic fluid pressure value
Value (duty) is found by search and linear interpolation
The Rukoto.

Thus, according to the present embodiment, the required engagement hydraulic pressure P _A (P _ot ) corresponding to the transmission torque of the disengagement-side friction element at the start of the inertia phase is obtained, and under the same torque condition, the required engagement hydraulic pressure P _A (P _ot ) is determined. as the hydraulic P _a is command pressure, and the command pressure, since the command value to the actuator 11 and the (duty D) to modify the operating characteristics of the actuator to be associated with each other, the operation characteristics of the actuator variation Whatever happens or changes,
The required hydraulic fluid pressure of the disengagement-side friction element and the command value to the actuator are associated with each other. As a result, the command pressure P and the actually generated required hydraulic pressure P _A (P _ot )
Can be always realized. This because, even when the actuator operation characteristics change or cause variations may be hydraulic pressure P _o of the disengagement side frictional element is not to be or become excessively small, constantly reliably achieve shift quality as intended.

In step 102 of FIG.
The release-side friction element (band
Rake B / B) actual command pressure P_oAnd the required hydraulic pressure P
_otStart of inertia phase based on size comparison
Required hydraulic pressure P_otRelease side actual command pressure P_oIs small
If it is determined that the
Switch F / C) is too large and the release-side friction element
(Brake B / B) operating oil pressure P _oWhere is low
Since the inertia phase was started at
Command pressure P of connection side friction element (forward clutch F / C)
_cIs lower than the actual hydraulic pressure.
Since the gap of the tip has occurred,
, The engagement side friction element (forward clutch F / C)
Command pressure P_cIs high for the same command value to solenoid 9
Operating characteristics map of the fastening actuator so that
Fix it.

The modification of the engagement-side actuator characteristic map is as clearly shown in FIG.
1, the engagement-side friction element (forward clutch F /
Since the operating oil pressure _{Pc of} C) is too high at the start of the inertia phase, the engagement side return spring equivalent pressure P _crtn at the start of the inertia phase is
The amount is reduced by a predetermined amount ΔP _crtn determined in consideration of convergence conditions and the like. Next, at step 122, the engagement side return spring equivalent pressure P at the start of the inertia phase is set.
Correction operation of the characteristic map of the fastening actuator for _crtn . Map of modifications in this case also, a fastening side return spring equivalent pressure before P is corrected and also except that the engagement-side return spring equivalent pressure after corrected P _A, the same as described above while referring to FIG. 14, this As a result, the operating characteristic map of the engagement-side actuator is modified so that the operating oil pressure command value _Pc of the engagement-side friction element (forward clutch F / C) becomes higher with respect to the same command value to the solenoid 9, and the engagement-side actuator is modified. Even if the operating characteristics of the actuator vary or change, the operating oil pressure _Pc of the engagement-side friction element does not become excessive, and the intended shift quality can always be reliably achieved.

[0080] In step 84 of FIG. 10, after the gear ratio g _r calculated as 12 is judged to be the second reference gear ratio g _r2 above, in step 85, smoothly varying during the inertia phase After calculating the instantaneous target gear ratio _gr0 and performing the calculation,
Alternatively, after it is determined in step 86 that the second stage control time t ₃ has elapsed since the timer TM entered the second stage, the timer TM is reset to 0 in step 87.
, And the control advances to the next third stage in a step 88.

The third stage is as shown in FIG. 16. In step 131, the timer TM is incremented to measure the elapsed time since entering the third stage. In step 133, which is selected only once in step 132 after entering the third stage, as shown in FIG. 17, the control data used in the stage, that is, the release-side friction element (band brake B /
B) The proportional control constant K _p , the integral control constant _Ki , and the differential control constant K _d used when performing the feedback (PID) control of the operating oil pressure P _o, and the operating oil pressure of the engagement-side friction element (forward clutch F / C). A first ramp gradient ΔP _c1 and a second ramp gradient ΔP _c2 used when increasing P _c is controlled.
And a third reference gear ratio _gr3 and a fourth reference gear ratio _gr4 . Here the fourth reference gear ratio g _r4 particularly, to the post-shift gear ratio (third speed gear ratio) the same value, with the time when the gear ratio g _r has reached the fourth reference gear ratio g _r4, transmission input rotation the number N _i is synchronized instantaneously matching the rotational speed to be reached after the shift, it can be regarded as a torque-phase start instant in other words.

[0082] In step 134 and 135 in FIG. 16, the gear ratio g _r as shown in FIG. 23 the third reference gear ratio g
until reaching _r3, it instructs the solenoid 9 to increase the engagement side hydraulic pressure P _c in the first ramp gradient [Delta] P _c1, in step 136 and 137, also has a gear ratio g _r as shown in FIG. 23 first 4 until it reaches the reference gear ratio g _r4, it commands the solenoid 9 to increase the engagement side hydraulic pressure P _c in the second ramp gradient [Delta] P _c2.

In the third stage, the fastening side
Operating oil pressure P_cRelease side operating oil pressure P_o,
In step 138, the current gear ratio g_rThe previous gi
Ya ratio g_r-1Gear ratio g before 2 times_r-2, And target gear ratio
g_r0And the control constant K _p, K_i, K_dWith P_o= P_o+ K_p(G_r-G_r-1) + K_i(G_r0-G_r) + K_d(G_r-2g_r-1+ G_r-2) (8), and this is commanded to the solenoid 11. that's all
Release side working oil pressure P_oFeedback control
If it is, the operating hydraulic pressure P on the fastening side_cTogether with the lifting control of the gear
Ratio g_rIs the target gear ratio g_r0Can be shocked
It is possible to execute the gear shift control as small as desired.

[0084] Then, the gear ratio g _r is determined torque-phase start instant after to have reached the fourth reference gear ratio g _r4, that is the synchronous speed transmission input rotational speed N _i should reached after shifting in step 136 After the synchronizing instant that coincides with, control proceeds to the fourth stage in step 139.

The fourth stage is as shown in FIG.
In step 141, the timer TM is incremented.
The stage after entering the fourth stage
Measure the time. Only once since entering stage 4
Step 143 selected by step 142
In addition, as shown in FIG.
Data, that is, the release-side friction element (band brake B /
B) Working hydraulic pressure P_oFeedback (PID) control
Proportional control constant K used when_p, Integral control constant K_i,
And differential control constant K_dAnd the fastening-side friction element (forward
Operating oil pressure P of clutch F / C)_cWhen controlling the rise
Third ramp gradient ΔP_c3And first shelf pressure P_FourAnd the said
Reference gear ratio g for synchronization determination_r4Set slightly higher than
The fifth reference gear ratio g _r5And the return value of the release hydraulic pressure
Lower limit pressure P which is the pulling equivalent pressure_ortnAnd.

[0086] In step 144-146 of FIG. 18, but increases the engagement side hydraulic pressure P _c as shown in FIG. 23 in the third ramp gradient [Delta] P _c3, engagement side working oil pressure P _c is the first shelf pressure P ₄ instructs the solenoid 9 to hold to the first shelf pressure P ₄ was reached. And step 14
By the processing shown in FIG. 20 in 7 integrates the gear ratio deviation Delta] g _r between the gear ratio g _r a fifth reference gear ratio g _r5 in the fourth stage (in torque phase) time.

[0087] In step 161 of FIG. 20 calculates the gear ratio deviation Delta] g _r between the gear ratio g _r a fifth reference gear ratio g _r5, then in step 162, sequentially adds the gear ratio deviation Delta] g _r by (Σg _r) is the integral value of the gear ratio deviation Delta] g _r in the fourth stage (in torque phase) ∫ (g _r -g _r5) seeking dt.

The fastening by steps 144 to 146 in FIG.
Connection hydraulic pressure P_c, The release side operating oil pressure P_o,
At step 148, the current gear ratio g_rThe previous gi
Ya ratio g_r-1Gear ratio g before 2 times_r-2, And target gear ratio
g_r0And the control constant K _p, K_i, K_dWith P_o= P_o+ K_p(G_r-G_r-1) + K_i(G_r0-G_r) + K_d(G_r-2g_r-1+ G_r-2) (9) is calculated, and this is commanded to the solenoid 11. Heel
Release side working oil pressure P_oGear by feedback control of
Ratio g_rIs the target gear ratio g_r0Can be brought to

[0089] However, in step 149, after the release-side hydraulic pressure P _o which is Such feedback control is determined to have dropped to the return spring equivalent pressure P _Ortn, in step 150, the release-side hydraulic pressure P _o of the return spring The pressure is maintained at the equivalent pressure _Portn so that it does not drop below this.

The above control is performed by the timer 151 in step 151.
M continues until it is determined that the fourth stage control time t ₅ has elapsed. Immediately after the instant of the determination, in step 152, the engagement-side friction element (forward clutch F /
The operation characteristic map of the actuator relating to C) is corrected, and then, in step 153, the fifth stage is started.

Modifying the fastening-side actuator characteristic map
The positive is as clearly shown in FIG.
In FIG. 1, based on the map corresponding to FIG.
Gear ratio deviation Δg_rOf the integral ∫ (g_r-G_r5) From dt, the first
Shelf pressure P_FourIs searched for the correction amount ΔP. Where the gear ratio deviation
Integral value ∫ (g_r-G_r5) Dt is the gear ratio g_rIs the set gear ratio
g _r523 indicates the length of time that exceeds
The gear ratio changes as indicated by the two-dot chain line.
Is the first shelf pressure P_FourIs too low and the engine blows
Transmission input rotation speed N_iThat the rise in
The engagement-side actuator characteristic map indicates the engagement-side hydraulic pressure.
P_cShift that lowers the
Conversely, conversely, the gear ratio deviation integrated value ∫ (g_r-G
_r5) The small dt means that the first shelf pressure P_FourIs too high
As shown by the chain line in FIG.
That a change (shift shock) has occurred,
The side actuator characteristic map shows the engagement side working oil pressure P_cRequired
That there is a gap that makes
means.

Therefore, in FIG. 22, the gear ratio deviation
Integral value ∫ (g_r-G_r5) Dt is the first set value∫₁Less than
In the case, the first shelf pressure P_FourIs set to a negative constant value.
2 Set value∫_TwoIf greater, the first shelf pressure P_FourCorrection amount Δ
P is the gear ratio deviation integrated value ∫ (g _r-G_r5) As dt increases
To make it bigger.

In step 172 of FIG. 21, the first
The shelf pressure P ₄ is calculated by adding the correction amount ΔP to the correction amount ΔP
In step 173, the deviation of the engagement-side actuator characteristic map is corrected using the increased / decreased first shelf pressure after correction and the first shelf pressure before correction. But is the same as previously described for each engagement side actuator characteristic map of the correction is also 14 in this case, but in which a first shelf pressure before P is corrected in FIG. 14, also, the P _A is the modified Of course, it is one shelf pressure. First shelf pressure P applied to the engagement-side friction element (forward clutch F / C) during the next torque phase
₄ , the operating characteristic map of the engagement-side actuator is modified so that the modified first shelf pressure is obtained under the same torque condition, and the operational characteristics of the engagement-side actuator vary or change. Also, by repeatedly modifying the map, the operating oil pressure P of the engagement-side friction element
_c does not become too large or too small, and the intended shift quality can always be reliably achieved.

As described above, at step 153 in FIG.
5th stage is not showing control program
However, as shown in FIG.
Roller release hydraulic pressure P_oIs set to 0, and the engagement side hydraulic pressure P
_cIs the first shelf pressure P_FourMultiplied by the safety factor (about 1.2)
Second shelf pressure P_FiveBut the fifth stage control time t ₆
Line pressure P when_LTo the same highest value as
The shift is ended.

[0095] In the embodiment having the above structure, during 4 → 3 downshift under power-on drive shown in FIG. 23, the first gear ratio g _r is the post-shifting gear ratio g _r4 after matching the start of the torque phase, the gear ratio deviation integrated value ∫ (g _r -g _r5) dt is the second set value ∫ ₂ (see FIG. 22) is greater than, i.e., the gear ratio g _r is a predetermined gear ratio g _r5 If the excess time is longer than the scheduled time, the engagement-side friction element (forward clutch F / C) during the torque phase
The first shelf pressure P ₄ is provide with too low to request, since the state of the transmission input rotation is greatly exceeds the rotational synchronization is relatively long-lasting, the engagement side frictional element (the forward clutch F / C ) is first shelf pressure P ₄ of, to be higher for the same command value to the actuator from the controller, i.e., the next under the same conditions actuator command value so as to raise the first shelf pressure P ₄ The command value / working fluid pressure characteristic map of the engagement-side actuator is corrected by the processing of FIG. 21 so that the command value-working fluid pressure characteristic map of the engagement-side actuator is generated. Can be corrected so as not to be too small, and even when the characteristic is changed, it is possible to avoid the adverse effect that the working fluid pressure of the engagement-side friction element becomes too small to perform predetermined shift control. Door can be.

When the characteristic map of the engagement-side actuator for increasing the first shelf pressure P ₄ is corrected, the increase ΔP is changed to the gear ratio deviation integral value ∫ (g, as shown in FIG. _r -g _r5) because dt is the increasing extent greater than the second set value ∫ _2, the gear ratio deviation integrated value ∫ (g _r -g _r5) first shelf as dt is greater than the second set value ∫ ₂ and consistent with the fact that pressure P ₄ is insufficient large, it is possible to modify the map of the engagement side actuator operating characteristics more reliably.

[0097] Conversely, during 4 → 3 downshift under power-on drive shown in FIG. 23, torque phase after the start of the gear ratio g _r coincides with the first gear after the gear ratio g _r4, gear ratio deviation integrated value ∫ (g _r -g _r5) dt is the second set value ∫
₁ (see FIG. 22) is smaller than, that is, the gear ratio g _r
If is the time exceeds the predetermined gear ratio g _r5 is shorter than the scheduled time, the first shelf pressure P ₄ given to the engagement side frictional element (the forward clutch F / C) in the torque phase is too high to request, since the resulting sudden change of transmission output shaft torque (dashed line in FIG. 23), the first shelf pressure P ₄ of the engagement side frictional element (the forward clutch F / C) is, for the same command value to the actuator from the controller as the lower Te, i.e., the next time under the same conditions as the actuator command value is issued so as to lower the first shelf pressure P _4, the command value, the hydraulic fluid pressure characteristic map of the fastening-side actuator 21
Therefore, the command value / working fluid pressure characteristic map of the engagement-side actuator can be modified so that the working fluid pressure of the engagement-side friction element does not become excessive. In addition, it is possible to avoid a problem that the hydraulic fluid pressure of the engagement-side friction element becomes excessively large and the predetermined shift control cannot be performed.

[Brief description of the drawings]

FIG. 1 is a control system diagram of an automatic transmission including a shift control device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between engagement logic of a friction element and a selected shift speed in the automatic transmission.

FIG. 3 is a circuit diagram showing a working pressure control circuit of a forward clutch that becomes an engagement-side friction element when downshifting from the fourth speed to the third speed in the automatic transmission.

FIG. 4 is a circuit diagram showing an operating pressure control circuit of a band brake serving as a disengagement-side friction element when downshifting from the fourth speed to the third speed in the automatic transmission.

FIG. 5 is a flowchart showing a main routine of a shift determination program to be executed by a controller in the embodiment.

FIG. 6 is a flowchart illustrating a subroutine relating to a first stage of shift control to be executed when a 4 → 3 downshift shift command is issued in the shift determination.

FIG. 7 is a flowchart showing a control data setting routine used in the first stage.

FIG. 8 is a flowchart showing a subroutine for calculating a transmission input torque among control data used in the first stage.

FIG. 9 is a flowchart showing a subroutine for calculating a release-side engagement required oil pressure among control data used in the first stage.

FIG. 10 is a flowchart showing a subroutine relating to a second stage of shift control to be executed when the 4 → 3 downshift shift command is issued.

FIG. 11 is a flowchart showing a control data setting routine used in the second stage.

FIG. 12 is a flowchart showing a subroutine for calculating a gear ratio among control data used in the second stage.

FIG. 13 is a flowchart showing a program for correcting an actuator operation characteristic map to be executed in the second stage.

FIG. 14 is a flowchart showing a correction program related to an operation characteristic map of the release-side actuator.

FIG. 15 is a flowchart showing a correction program related to the operation characteristic map of the engagement-side actuator.

FIG. 16 is a flowchart showing a subroutine relating to a third stage of shift control to be executed when the 4 → 3 downshift shift command is issued.

FIG. 17 is a flowchart showing a control data setting routine used in the third stage.

FIG. 18 is a flowchart showing a subroutine relating to a fourth stage of shift control to be executed when the 4 → 3 downshift shift command is issued.

FIG. 19 is a flowchart showing a control data setting routine used in the fourth stage.

FIG. 20 is a flowchart showing a gear ratio deviation integral calculation process performed in the fourth stage.

FIG. 21 is a flowchart showing a program for correcting an engagement-side actuator operation characteristic map to be executed in a fourth stage.

FIG. 22 is a characteristic diagram showing a first shelf pressure correction amount change characteristic of an engagement-side friction element corrected by the correction program.

FIG. 23 is an operation time chart of the 4 → 3 downshift control shown in FIGS. 6 to 21;

FIG. 24 is a diagram showing a relationship between a hydraulic fluid command value of a friction element, a duty command value to an actuator, and a friction element transmission torque.

[Explanation of symbols]

 1 Engine 2 Torque converter 3 Automatic transmission 4 Input shaft 5 Output shaft 6 Front planetary gear set 7 Rear planetary gear set 8 Control valve 9 Duty solenoid 10 Duty solenoid 11 Duty solenoid 12 Duty solenoid 13 Duty solenoid 14 Controller 16 Throttle opening sensor 17 Engine Rotation sensor 18 Input rotation sensor 19 Output rotation sensor 20 Oil temperature sensor 22 Pressure regulator 24 Pressure regulator F / C Forward clutch (engagement side friction element) B / B Band brake (release side friction element) H / C High clutch LR / B Low reverse brake R / C reverse clutch

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-332440 (JP, A) JP-A-7-259981 (JP, A) JP-A 1-261560 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) F16H 61/00-61/24

Claims (7)

(57) [Claims] An actuator responsive to a command value from a controller, while releasing a friction element in a fastened state by lowering hydraulic fluid pressure by an actuator responsive to a command value from a controller. A downshift is performed by engaging the hydraulic fluid by increasing the hydraulic fluid pressure, and the controller converts the command value to each of the actuators into a required engagement capacity of the friction element based on a predetermined command value and hydraulic fluid pressure characteristic specific to the actuator. In the automatic transmission, which is determined in association with the required hydraulic pressure corresponding to the following, during the downshifting under power-on traveling, the gear ratio represented by the transmission input / output rotation ratio is After the start of the torque phase that first matches the gear ratio, if the time during which the gear ratio exceeds the set gear ratio is longer than the scheduled time, The predetermined command value / working fluid pressure characteristic is modified so that the working fluid pressure of the engagement-side friction element to be connected is higher for the same command value from the controller to the actuator. Transmission control device for automatic transmission. 2. An actuator responsive to a command value from the controller, while releasing the friction element in the engaged state by lowering hydraulic fluid pressure by an actuator responsive to a command value from the controller. A downshift is performed by engaging the hydraulic fluid by increasing the hydraulic fluid pressure, and the controller converts the command value to each of the actuators into a required engagement capacity of the friction element based on a predetermined command value and hydraulic fluid pressure characteristic specific to the actuator. In the automatic transmission, which is determined in association with the required hydraulic pressure corresponding to the following, during the downshifting under power-on traveling, the gear ratio represented by the transmission input / output rotation ratio is After the start of the torque phase that first matches the gear ratio, if the time during which the gear ratio exceeds the set gear ratio is shorter than the scheduled time, The predetermined command value / working fluid pressure characteristic is modified so that the working fluid pressure of the engagement-side friction element to be connected becomes lower with respect to the same command value from the controller to the actuator. Transmission control device for automatic transmission. 3. An actuator responsive to a command value from the controller, while releasing the friction element in the engaged state by lowering the hydraulic fluid pressure by an actuator responsive to a command value from the controller. A downshift is performed by engaging the hydraulic fluid by increasing the hydraulic fluid pressure, and the controller converts the command value to each of the actuators into a required engagement capacity of the friction element based on a predetermined command value and hydraulic fluid pressure characteristic specific to the actuator. In the automatic transmission, which is determined in association with the required hydraulic pressure corresponding to the following, during the downshifting under power-on traveling, the gear ratio represented by the transmission input / output rotation ratio is After the start of the torque phase that first matches the gear ratio, if the time during which the gear ratio exceeds the set gear ratio is longer than the scheduled time, The predetermined command value / working fluid pressure characteristic is corrected so that the working fluid pressure of the engagement-side friction element to be connected becomes higher with respect to the same command value from the controller to the actuator. After the start of the torque phase in which the gear ratio represented by the transmission input / output rotation ratio first matches the post-shift gear ratio during the downshift, the time during which the gear ratio exceeds the set gear ratio is longer than the scheduled time. Also, when the operating fluid pressure of the engagement-side friction element to be engaged is lower than the same command value from the controller to the actuator, the predetermined command value / operating fluid pressure characteristic is modified. A shift control device for an automatic transmission, comprising: 4. The control device according to claim 1, wherein the hydraulic pressure of the engagement-side friction element is controlled to a constant shelf pressure during the torque phase, and the shelf pressure is set to the same command value to the actuator. A shift control device for an automatic transmission, wherein the predetermined command value / working fluid pressure characteristic is corrected so as to obtain a corrected shelf pressure obtained by adding or subtracting a predetermined amount from the command value. 5. The automatic transmission according to claim 4, wherein the predetermined amount to be added to the shelf pressure is increased as the time during which the gear ratio exceeds the set gear ratio is longer than a scheduled time. Transmission control device. 6. The schedule according to claim 4, wherein
The command value and hydraulic pressure characteristics correspond to the command value and hydraulic pressure, respectively.
When the maps are quantized and corresponded to each other, the map before and after the shelf pressure P before the correction
Working fluid pressure value P₁, P _TwoOf the shelf pressure P before correction between
Ratio a and the corrected shelf pressure P_AMap before and after
Upper working fluid pressure value P_Three, P_FourShelf pressure after correction P between_Aof
During the torque phase for the internal pressure ratio b and the shelf pressure P before correction,
Machining before and after the command value D to the actuator
Command value D₁, D_TwoAnd the corrected shelf pressure P on the map_AActuator corresponding to
Command value D_AOn the map before and after
Command value D_Three, D_FourIs used to correct the predetermined command value / hydraulic pressure characteristic.
A shift control device for an automatic transmission. 7. The method according to claim 6, wherein the command values D ₃ , D
₄ as D ₃ = [1 / (1-b)] [(1-a) · D ₁ + a · D
_2- b · D ₄ ] D ₄ = (1 / b) [(1-a) · D ₁ + a · D _2- (1
-B) - by updating to modify the D _3], shift control apparatus for an automatic transmission which is characterized by being configured so as to correct the command value, the hydraulic fluid pressure characteristics of the event.