JPH10227355A - Transmission control device for automatic transmission - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To enable a correction of a characteristic map to make a command pressure coincide with a required engagement pressure of a friction element at the start of an inertia phase during a step-down downshift even when an operation characteristic changes. . In A 111, the map value P ₁ sandwiching the release element command pressure P and the duty D at the start of the inertia phase of the downshifting with the gas pedal depressed, P ₂ and D _1, D ₂
And the internal division ratio a of the command pressure P is calculated at 113. 114
In, calculates a required hydraulic pressure P _A from the release element transmission torque at the start of the inertia phase, at 115, demand pressure P _A and the map value P ₃ sandwiching the duty D _A corresponding thereto, P ₄ and D _3, Search for D _4, demand pressure P at 116
Calculate the internal division ratio b of _A. In 117, D ₃ = [1 / (1-
b)] [(1-a) · D ₁ + a · D ₂ −b · D ₄ ] and D ₄ =
Correction of D ₃ and D ₄ is performed by (1 / b) [(1−a) · D ₁ + a · D ₂ − (1−b) · D ₃ ].

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 for 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 control for increasing or decreasing the hydraulic fluid pressure is performed on the basis of the specific operation characteristic exemplified by the solid line in FIG. 21 as follows.

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. 1, a search and linear interpolation are performed based on the actuator operation characteristics indicated by the solid line, and output to the actuator.

By the way, the operating characteristics indicating the relationship between the duty D, which is the command value of the actuator, and the hydraulic pressure have large variations among products as shown by a dashed line in FIG. It changes, and it changes with aging.

FIG. 21 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.

If the operating characteristics of the actuator vary or change as described above, the fastening capacity of the friction element may become too large or too small during the torque phase.
If the engagement capacity of the engagement-side friction element becomes excessive during the torque phase, the calorific value of the engagement-side friction element increases, and the output torque at the start of the inertia phase becomes smaller than necessary. If the engagement capacity of the friction element becomes too small, the inertia phase changes quickly without starting the engagement of the engagement side friction element, and the driver cannot properly engage the engagement side friction element at the time of low-speed gear synchronization, causing the driver to feel a sense of idling. To give.

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 disengagement-side friction element to be disengaged during downshifting during power-on running vary or change, the friction element can be disengaged. 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. Compensation can be realized, and compensation can be realized such that the hydraulic fluid pressure of the friction element does not become too small even if the operating characteristics of the actuator related to the release-side friction element vary or change. An object of the present invention is to propose a shift control device for an automatic transmission.

According to a fourth aspect of the present invention, in the case where the command value and the working fluid pressure characteristic relating to the actuator are maps in which the command value and the working fluid pressure are respectively quantized and associated with each other, An object of the present invention is to embody the first to third inventions.

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

[0017]

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 downshift, the release side to be released corresponding to the transmission input torque at the start of the inertia phase When the command hydraulic fluid pressure of the release-side friction element is smaller than the required hydraulic fluid pressure of the friction element, the hydraulic fluid pressure of the engagement-side friction element to be fastened is higher for the same command value from the controller to the actuator. So that
It is configured to correct the predetermined command value / working fluid pressure characteristic.

A shift control device for an automatic transmission according to a second 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, during the downshifting under power-on traveling, at the start of the inertia phase Solution for the required hydraulic pressure of the release-side friction element to be released corresponding to the transmission input torque at If the command hydraulic fluid pressure of the side friction element is large, the predetermined command value / hydraulic pressure characteristic is changed so that the hydraulic fluid pressure of the release-side friction element becomes lower with respect to the same command value from the controller to the actuator. It is configured to be 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, during the downshifting under power-on traveling, at the start of the inertia phase Solution for the required hydraulic pressure of the release-side friction element to be released corresponding to the transmission input torque at When the command hydraulic fluid pressure of the side friction element is small, the predetermined command value / hydraulic fluid is set so that the hydraulic fluid pressure of the engagement-side friction element to be fastened becomes higher with respect to the same command value from the controller to the actuator. The pressure characteristic is corrected to release the required hydraulic fluid pressure of the release-side friction element to be released corresponding to the transmission input torque at the start of the inertia phase during the downshift under power-on traveling. If the command hydraulic fluid pressure of the side friction element is large, the predetermined command value / hydraulic pressure characteristic is changed so that the hydraulic fluid pressure of the release-side friction element becomes lower with respect to the same command value from the controller to the actuator. It is configured to be modified.

A shift control device for an automatic transmission according to a fourth invention.
Refers to any of the first to third inventions,
The command value and working fluid pressure characteristics to be described are the command value and working fluid pressure.
Is a map in which each is quantized and associated with each other.
If the command hydraulic pressure P at the start of the inertia phase is
Hydraulic fluid pressure value P on the map before and after sandwiching₁, P
_TwoBetween the internal working ratio a of the command hydraulic pressure P and the inertia
Required hydraulic pressure P at the start of Sha phase_AAcross
Hydraulic fluid pressure value P on the map before and after that_Three, P_FourBetween
Required hydraulic pressure P_AAnd the inertia ratio b
The command value D to the actuator at the start of the phase
Command value D on the map before and after sandwiching₁, D
_TwoAt the start of the inertia phase on the map
Hydraulic pressure P_ACommand value D to the actuator corresponding to_A
Command values D on the map before and after_Three, D _Four
To correct the predetermined command value / hydraulic fluid pressure characteristic.
It is configured so that:

According to a fifth aspect of the present invention, in the transmission control apparatus for an automatic transmission according to the fourth 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.

[0022]

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 to each actuator based on a predetermined command value and working fluid pressure characteristic specific to the actuator, in association with a required working fluid pressure corresponding to a required engagement capacity of the friction element.

During the above-mentioned downshift under power-on traveling, a command for the release-side friction element in response to a required hydraulic pressure of the release-side friction element corresponding to the transmission input torque at the start of the inertia phase. If the hydraulic fluid pressure is low, the inertia phase is started at a location where the engagement hydraulic capacity of the engagement-side friction element is too large and the hydraulic fluid pressure of the release-side friction element is low. From the above-mentioned predetermined command value so that it becomes higher for the same command value to the actuator, that is, under the same torque condition, an actuator command value that decreases the engagement side working fluid pressure is output next time. Correct the hydraulic pressure characteristics. Therefore, the command value / hydraulic fluid pressure characteristic of the actuator related to the engagement-side friction element can be corrected so that the hydraulic fluid pressure of the engagement-side friction element does not become excessive, and the hydraulic fluid pressure of the engagement-side friction element becomes lower. It is possible to eliminate the adverse effect that the transmission becomes excessively large and the predetermined shift control cannot be performed.

In the second aspect of the invention, during the above-mentioned downshift under power-on traveling, the required hydraulic fluid pressure of the disengagement-side friction element corresponding to the transmission input torque at the start of the inertia phase with respect to the disengagement side is determined. When the command hydraulic fluid pressure of the friction element is large, the hydraulic fluid pressure of the release friction element is too low for the demand. The command value / working fluid pressure characteristic is corrected so that the actuator command value for increasing the release-side working fluid pressure is output next time under the same torque condition so that the release-side working fluid pressure is increased.

Therefore, even if the operating characteristics of the actuator relating to the release-side friction element vary or change, the hydraulic fluid pressure of the friction element does not become too small with respect to the command value to the actuator. Thus, it is possible to eliminate the adverse effect that predetermined shift control cannot be performed.

In the third aspect of the invention, during the above-mentioned downshift under power-on traveling, the release hydraulic pressure required by the release-side friction element corresponding to the transmission input torque at the start of the inertia phase with respect to the release hydraulic pressure is determined. If the command hydraulic fluid pressure of the friction element is small, correct the planned command value / hydraulic pressure characteristics so that the hydraulic fluid pressure of the engagement-side friction element becomes higher for the same command value from the controller to the actuator. If the command hydraulic pressure of the release-side friction element is larger than the required hydraulic pressure of the release-side friction element, the hydraulic pressure of the release-side friction element becomes lower with respect to the same command value from the controller to the actuator. Correct the expected command value and working fluid pressure characteristics so that

Thus, according to the third aspect of the invention, the effect of the first aspect of the invention, that is, the effect of eliminating the adverse effect that the hydraulic fluid pressure on the engagement-side friction element becomes excessive and the predetermined shift control cannot be performed. The effect of the second aspect of the invention, that is, a change in the command value / hydraulic fluid pressure characteristic of the actuator related to the release-side friction element causes the hydraulic fluid pressure of the release-side friction element to become too low, and the predetermined shift control is not performed. It is possible to achieve both the effect of eliminating the adverse effect such as the inability to perform.

In the fourth invention, the predetermined command value
Hydraulic pressure characteristics quantize command value and hydraulic pressure respectively
In the case of maps that correspond to each other,
Before and after the command hydraulic pressure P at the start of the
Hydraulic pressure value P on the map after₁, P_TwoIn between
Internal ratio a of command hydraulic pressure P and start of inertia phase
Required hydraulic pressure P at the time_ABefore and after
Hydraulic fluid pressure value P on map_Three, P_FourRequired hydraulic fluid between
Pressure P_AAt the beginning of the inertia phase
Before and after the command value D to the actuator
Command value D on the map₁, D_TwoAnd Ina on the map above
Required hydraulic fluid pressure P at the start of the inertia phase_AA corresponding to
Command value D to actuator_ABefore and after
Command value D on map_Three, D _FourUsing the finger of the above plan
Actuator pressure and hydraulic fluid characteristics
Command value and working fluid pressure characteristics related to the
A map in which the hydraulic pressure is quantized and associated with each other
In the case of, the first to third inventions are specifically described.
And the corresponding effects can be achieved.

In the fifth invention, the above-mentioned command values D ₃ and D ₄ in the fourth invention are respectively represented by 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.

[0031]

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 controlled.
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 the 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 fluid pressure, and the forward clutch F / C in the released state is engaged by increasing the hydraulic fluid 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 a hydraulic pressure control circuit of the forward clutch F / C, which is an engagement-side friction element to be changed from the released state to the engaged state in 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 pressure in the chamber 24a of the pressure regulating valve 24 is determined by the corresponding solenoid 11, and the solenoid 11 applies a constant pilot pressure P _p generated by reducing the line pressure P _L to the original pressure. 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. 19. First, FIG. 6 shows the processing in the first stage in FIG. 20, and in step 41 in FIG. 20, 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. 20), 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. 20).

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.

Next, at step 52, the transmission input torque T _i is calculated. At the time of this calculation, first, as shown in FIG.
seeking _e (torque converter input rotational speed) and the transmission input shaft rotational speed (output rotational speed of the torque converter) speed ratio of the torque converter from _{N i e (e = N i} / N e), then in step 62, the From the speed ratio e, a torque ratio t and a torque capacity coefficient τ of the torque converter are obtained based on the performance diagram of the torque converter.
Using these, the turbine torque (transmission input torque) T
_i is calculated by an operation of T _i = τ · t · _Ne ² .

[0045] In step 53 of FIG. 7, the release-side friction element under the input torque T _i (band brake B
As shown in FIG. 9, the required hydraulic pressure P _omin (see FIG. 20) on the release side for keeping / B) in a state just before slipping does not _occur, as shown in FIG.

(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: Drum radius e: base of natural logarithm mu: friction coefficient of the brake band theta: the wrap angle of the brake band calculate.

[0046] In step 54 of FIG. 7, was added from the disengagement side hydraulic pressure P _o of 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. 20 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 working oil pressure _Pc and the release side working oil pressure _Po in the first stage is performed as follows. Do. That is, as shown in FIG. 20, the engagement side operating oil pressure _Pc is instructed to the precharge pressure _Ppr to the solenoid 9 to quickly reduce the loss stroke of the engagement side friction element (forward clutch F / C). be completed, the disengagement side hydraulic pressure P _o is this, instructs the solenoid 11 to is shown in Figure 20 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 command 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
20 until it is determined that the first stage control time t ₁ has been reached. Therefore, as shown in FIG. 20, 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.

The 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, the process proceeds to the second stage.
Step selected when it is determined to be the first time after
In step 73, data used for control in the second stage is
Set as shown in FIG. First, in step 91,
Retardation of engagement side friction element (forward clutch F / C)
Spring equivalent pressure P_crtn, The second stage control time t_Three
(See FIG. 20), engagement-side friction element (forward clutch
F / C) operating oil pressure P_cIs the return spring equivalent pressure P
_crtnDuring return spring equivalent pressure control to keep
Interval t_Four, Already described above but released after precharge
Side friction element operating oil pressure P_oOf the first ramp control time t_Two,same
The release-side friction element operating oil pressure P_oNo. 1 ramp
Gradient ΔP_o1, Release side set at a gentler slope than this
Friction element operating oil pressure P_oRamp slope ΔP of_o2, Inner
First reference gear ratio for determining the start of the shear phase
g _r1, A larger second reference gear ratio g_r2Read.

In step 92 of FIG. 11, the transmission input torque T _i 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 from 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. 20 at 6.

[0055] In step 77-79, until it is determined that the timer TM in step 77 becomes as shown the course of releasing the first for friction element lamp control time t ₂ from the transition to the second stage, step 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 it is determined that the time t ₂ has elapsed, in step 79, the operating oil pressure P _o of the disengagement-side friction element is changed to the second ramp gradient Δ as shown in FIG.
A command is issued to the solenoid 11 to lower it at _Po2 .

[0056] 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 .

During this time, at step 80, the release hydraulic 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 correction 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 hydraulic pressure P actually generated_otRelease actual command
Pressure P_oWhen it is determined that the
Operating brake command value P for brakes B / B)_oBut actually
Generated hydraulic pressure P_otMap displacement that is higher than
Has occurred, in step 103, the solution
Operating pressure P of release-side friction element (band brake B / B)_oBut
In order to be lower for the same command value to the solenoid 11,
Modify the operation characteristic map of the release-side actuator.

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. 20 inertia
Release-side working fluid pressure command value P at the moment when the pressure phase starts_o
Is on the actuator operation characteristic map in 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 (P−P ₁ ) / (P ₂ −P ₁ ) between P ₁ and P ₂ is defined as 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)

[0063] 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.

[0064] 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.

The operation of modifying the characteristic map shown in FIG. 14 based on the above principle will be described. 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 causing the occurrence of the start of the actual inertia phase reduce the gear ratio g _r to inertia phase start determination gear ratio g _r1 as shown in FIG. 20, at the start of the inertia phase It represents the actual pressure of the release-side friction element.

[0068] In the next step 115, the operation characteristic map of the actuator of Figure 21, 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, since the command value to the command pressure and 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 occurs variation Even if it changes, the required hydraulic pressure of the disengagement-side friction element and the command value to the actuator are always associated with each other. As a result, the command pressure P and the actually required engagement hydraulic pressure P _A ( P _ot ) can always be compensated. 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 comparison of size
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
Hydraulic oil for engagement side friction element (forward clutch F / C)
Pressure P_cIs lower than the actual hydraulic pressure
Since a map shift has occurred, step 104
At the engagement side friction element (forward clutch F /
C) Command pressure P_cFor the same command value to solenoid 9
Operating characteristic map of the fastening actuator so that
Modify the loop.

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 . Also map of correction in this case, an engagement side return spring equivalent pressure before P is corrected, except P _A is engagement-side return spring equivalent pressure after correction, the same as described above for each 14, thereby fastening The operating characteristic map of the engagement-side actuator is modified so that the operating oil pressure of the side friction element (forward clutch F / C) increases with respect to the same command value to the solenoid 9, and the operating characteristics of the engagement-side actuator vary. Does occur, 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.

[0073] In step 84 of FIG. 10, after the gear ratio g _r calculated in as in FIG. 12 is judged to be the second reference gear ratio g _r2 above, in step 85, time series during the inertia phase It calculates a target gear ratio g _r0 momentary smoothly varying, after the calculation, or represents passage from the timer TM is contained in the second stage of the second stage control time t ₃ at step 86 After determining that the timer TM
Is reset to 0, 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 it can be regarded as the number N _i is matched synchronization instant rotational speed to be reached after the shift.

[0075] In step 134 and 135 in FIG. 16, the gear ratio g _r as shown in FIG. 20 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. 20 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) is calculated, 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.

[0077] The synchronization gear ratio g _r in step 136 after it is determined to have reached the fourth reference gear ratio g _r4, i.e. the transmission input rotational speed N _i matches the synchronous speed to be reached after the shift After the instant, control proceeds to the fourth stage in step 139.

The fourth stage is as shown in FIG. 18. In step 141, the timer TM is incremented to measure the elapsed time since entering the fourth stage. In step 143 selected once by step 142 after entering the fourth stage, as shown in FIG. 19, 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). The third ramp gradient ΔP _c3 and the limit pressure P ₄ used for controlling the rise of P _c , and the lower limit pressure P which is the return spring equivalent pressure of the release side working oil pressure
_ortn is set.

[0079] In step 144-146 of FIG. 18, but increases the engagement side hydraulic pressure P _c as shown in FIG. 20 in the third ramp gradient [Delta] P _c3, engagement side working oil pressure P _c is reach the limit pressure P ₄ It instructs the solenoid 9 to hold where the to the limit pressure P _4. Then, during the control of the engagement-side operating oil pressure _Pc , the release-side operating oil pressure _{Po is changed} to the step 1
In 47, this time of the gear ratio g _r, 1 times before the gear ratio g
_r-1, the two previous gear ratio g _r-2, and the target gear ratio g _r0 used, further control constant K _p, K _i, P using the _{K d 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), and outputs this to the solenoid 11 to perform the release side operation. the gear ratio g _r so that housing 1000. the target gear ratio g _r0 by the feedback control of the hydraulic P _o.

[0080] However, in step 148, 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 149, the return spring of the disengagement side hydraulic pressure P _o The pressure is maintained at the equivalent pressure _Portn so that it does not drop below this.

The above control is performed at step 150 when the timer T
Continued until it is determined that M began to indicate the passage of a fourth stage control time t _5, steps thereafter controls 151
To start the fifth stage.

The fifth stage shows a control program.
No, but entered the stage as shown in FIG.
Release side working oil pressure P_oTo 0, hydraulic fluid on the fastening side
Pressure P _cIs the limiting pressure P_FourMultiplied by the safety factor (about 1.2)
Determined shelf pressure P_FiveBut the fifth stage control time t₆But
Line pressure P when elapsed_LRise to the same maximum value as
Quit speed.

[0083] In the embodiment having the above structure, the inertia phase start instant the gear ratio g _r has reached the first reference gear ratio g _r1 shown in FIG. 20, the solenoid 9,1
Command value to 1 (duty), the friction elements hydraulic pressure P _c, the command value-actuating hydraulic pressure characteristic map showing respectively relationship between P _o (actuator operating characteristics), modifies the as follows. That calculates the release side clutching required oil pressure P _ot necessary to keep the state just before not slip disengagement side frictional element (the band brake B / B) under a transmission input torque T _i at the start the inertia phase when it is determined that the release-side actual command pressure P _o is larger than the fastening required oil pressure P _ot that actually is occurring the start of the inertia phase, the command pressure P _o of the disengagement side frictional element (the band brake B / B) Since the map is shifted so as to be higher than the actually required required hydraulic pressure _Pot , the command pressure _{Po of} the release-side friction element (band brake B / B) is the same as that applied to the solenoid 11. The operating characteristic map of the release-side actuator is corrected so as to be lower than the command value. This therefore, that the release-side actuator operating characteristics also vary or occur variations, without working oil pressure P _o of the disengagement side frictional element may become too small, constantly reliably achieve shift quality as intended it can.

Conversely, when it is determined that the release-side actual command pressure _Po is smaller than the required engagement hydraulic pressure _Pot that actually caused the start of the inertia phase, the engagement-side friction element (forward clutch F / C) The inertia phase was started when the operating oil pressure P _{o of} the disengagement-side friction element (band brake B / B) was low because the engagement capacity of the engagement side was too large, that is, the command oil pressure of the engagement-side friction element (forward clutch F / C) Since the map is shifted such that P _c becomes lower than the actually generated oil pressure, the command oil pressure P _{c of} the engagement-side friction element (forward clutch F / C) is set to the same command to the solenoid 9. The operation characteristic map of the engagement-side actuator is corrected so as to be higher than the value. Therefore, even if the operating characteristics of the engagement-side actuator vary or change, the operating oil pressure _Pc of the engagement-side friction element does not become excessive, and the intended shift quality is always reliably achieved. Can be.

[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 an operation time chart of the 4 → 3 downshift control according to FIGS. 6 to 19;

FIG. 21 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

Claims (5)

[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. The automatic transmission, which is determined in association with the required hydraulic pressure corresponding to the above, comprises: during the downshifting under power-on traveling, the release corresponding to the transmission input torque at the start of the inertia phase. If the commanded hydraulic pressure of the release-side friction element is smaller than the required hydraulic pressure of the release-side friction element to be
The hydraulic fluid pressure of the engagement-side friction element to be tightened is configured to be modified with respect to the same command value from the controller to the actuator so as to correct the predetermined command value / hydraulic fluid pressure characteristic. 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. The automatic transmission, which is determined in association with the required hydraulic pressure corresponding to the above, comprises: during the downshifting under power-on traveling, the release corresponding to the transmission input torque at the start of the inertia phase. If the commanded hydraulic pressure of the release-side friction element is larger than the required hydraulic pressure of the release-side friction element to be
The hydraulic fluid pressure of the release-side friction element is lower with respect to the same command value from the controller to the actuator,
A shift control device for an automatic transmission, wherein the scheduled command value / operating fluid pressure characteristic is modified. 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. The automatic transmission, which is determined in association with the required hydraulic pressure corresponding to the above, comprises: during the downshifting under power-on traveling, the release corresponding to the transmission input torque at the start of the inertia phase. If the commanded hydraulic pressure of the release-side friction element is smaller than the required hydraulic pressure of the release-side friction element to be
The predetermined command value / working fluid pressure characteristic is corrected so that the working fluid pressure of the engagement-side friction element to be fastened becomes higher with respect to the same command value from the controller to the actuator. During the downshift, the command hydraulic fluid pressure of the release-side friction element is larger than the required hydraulic pressure of the release-side friction element to be released, which corresponds to the transmission input torque at the start of the inertia phase.
The hydraulic fluid pressure of the release-side friction element is lower with respect to the same command value from the controller to the actuator,
A shift control device for an automatic transmission, wherein the scheduled command value / operating fluid pressure characteristic is modified. 4. The method according to claim 1, wherein:
The expected command value and working fluid pressure characteristics are
A map in which the hydraulic pressure is quantized and associated with each other
In some cases, the command hydraulic pressure P at the start of the inertia phase
And hydraulic fluid pressure value P on the map before and after₁, P_Twowhile
And the required hydraulic pressure P at the start of the inertia phase.
_AHydraulic pressure values on the map before and after
P_Three, P_FourRequired hydraulic pressure P between_AAnd the actuator at the start of the inertia phase
Commands on the map before and after the command value D
Value D₁, D_TwoAnd the required hydraulic fluid at the start of the inertia phase on the map
Pressure P_ACommand value D to the actuator corresponding to_AAcross
And the command value D on the map before and after_Three, D _FourAnd for
And is configured to correct the predetermined command value / hydraulic fluid pressure characteristic.
A shift control device for an automatic transmission. 5. The method according to claim 4, 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.