JPH10227354A - Gear shift control device for automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make possible compensation so as to control the working hydraulic pressure of a friction element to be an equal value against an equal command value by correcting a predetermined command value and a working hydraulic pressure characteristic so that required working hydraulic pressure and a command value to an actuator correspond to each other. SOLUTION: Required working hydraulic pressure PA corresponding to the transmitting torque of joint side friction element at starting inertia phase is obtained, and the operation characteristic of an actuator is corrected so that the required working hydraulic pressure PA at starting the inertia phase and the command value to a duty solenoid (duty D) at starting the inertia phase corresponding to each other. Consequently, even if the operation characteristic of the actuator generates dispersion or changes, the required working hydraulic pressure of the friction element on the joint side and the command value of the actuator correspond to each other, as a result, even if the operation characteristic of the actuator generates dispersion or changes, there is no possibility that the joint capacity of the friction element becomes excessively large or excessively small during the torque phase.

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 the working fluid pressure of a friction element during the shifting, the working fluid pressure characteristic varies with a command value. The present invention relates to a shift control device capable of correcting a change in the characteristics or changing the characteristics to maintain a predetermined shift performance.

[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. In the following, the friction element to be switched from the engaged state to the released state during the shift is referred to as a release-side friction element, the hydraulic fluid pressure thereof is referred to as a release-side hydraulic pressure, and the friction element to be switched from the released state to the engaged state is engaged. The hydraulic fluid pressure of the side friction element is referred to as an engagement hydraulic fluid pressure.

[0003] When raising or lowering the hydraulic fluid pressure related to the friction element, it is conceivable that this is performed by an actuator that responds to a command value from a controller. In this case, an inherent fluid illustrated by a solid line in FIG. In general, the control for increasing and decreasing the hydraulic fluid pressure is performed based on the operating characteristics as follows.

In other words, 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.
As shown in FIG. 7, the information is obtained by a search or the like from the actuator operation characteristics indicated by the solid line and output to the actuator.

[0005]

By the way, the operating characteristics of the friction element do not have a large variation toward the left and are not affected by the temperature change. However, the relationship between the duty D, which is the command value of the actuator, and the hydraulic fluid pressure is determined. The operating characteristics shown are
For example, as shown by a one-dot chain line in FIG. 9, there is a large variation between products, the variation varies with temperature, and also varies with time.

A case where the actuator operating characteristics are different from each other as shown by a dashed line in FIG. 9 will be described. For the same command duty D, the torque that can be transmitted by the friction element is like _T02 . Will be bigger,
The fastening capacity of the friction element becomes excessive. Of course, if the actuator operation characteristics differ in the direction opposite to the one-dot chain line in FIG. 9, the fastening capacity of the friction element becomes too small.

[0007] When the operating characteristics of the actuator vary or change as described above, the fastening capacity of the friction element becomes excessively large or small during the torque phase. Here, if the engagement capacity of the friction element becomes excessive during the torque phase, the torque pull-in at the end of the torque phase, that is, at the start of the inertia phase, becomes large, which is disadvantageous in terms of a shift shock. On the other hand, if the engagement capacity of the friction element becomes too small during the torque phase, the torque phase time becomes long, and the feeling of pull-in is greatly felt, which causes a problem of giving the driver an uncomfortable feeling.

According to the present invention, there is provided an automatic transmission capable of realizing compensation for controlling the hydraulic fluid pressure of the friction element to the same value for the same command value even if the operating characteristics of the actuator vary or change. It is an object of the present invention to propose a shift control device for a machine.

[0009]

For this purpose, claim 1 is provided.
The gear shift control device according to the first aspect of the present invention is configured to release a friction element selected from the plurality of friction elements by lowering hydraulic fluid pressure by an actuator responding to a command value from a controller, or to release the friction element from the controller. The shift is performed by engaging the hydraulic fluid by increasing the hydraulic fluid pressure by the actuator that responds to the command value, and the controller determines the command value to the actuator based on the predetermined command value and hydraulic fluid pressure characteristic of the actuator, and requests the friction element. In the automatic transmission, which is determined in association with the required hydraulic fluid pressure corresponding to the engagement capacity, the required hydraulic fluid pressure corresponding to the required engagement capacity of the friction element at the start of the inertia phase during the gear shift is obtained. Required hydraulic fluid pressure at the start of the phase and the actuator at the start of the inertia phase. It is characterized in that the command value is configured to correct the command value, the hydraulic fluid pressure characteristics of the scheduled to be associated with each other.

According to a second aspect of the present invention, in the transmission control apparatus according to the second aspect of the present invention, the predetermined command value / hydraulic fluid pressure characteristic is corrected at the time of shifting during power-on traveling. It is characterized by having comprised.

According to a third aspect of the present invention, there is provided the transmission control apparatus according to the first or second aspect, wherein the required engagement capacity of the friction element is controlled by the input / output rotation of the torque converter in a stage preceding the automatic transmission. It is characterized in that it is configured to calculate using the torque sharing ratio of the friction element based on the transmission input torque obtained from the difference.

A shift control according to a fourth aspect of the present invention.
The device according to any one 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 characterized by having comprised so that it might be.

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

[0014]

According to the automatic transmission, a friction element selected from a plurality of friction elements can be released by a decrease in hydraulic fluid pressure by an actuator responding to a command value from a controller, or can be released from a command value from the controller. The shift is performed by engaging the hydraulic fluid by increasing the hydraulic fluid pressure by a corresponding actuator.

Here, the controller determines a command value to the actuator based on a predetermined command value / hydraulic pressure characteristic specific to the actuator and in association with a required hydraulic pressure corresponding to a required engagement capacity of the friction element.

According to the first aspect of the present invention, the required working fluid pressure corresponding to the required engagement capacity of the friction element at the start of the inertia phase during the shift is determined, and the required working fluid pressure at the start of the inertia phase and the inertia phase are determined. The predetermined command value / hydraulic pressure characteristic is corrected so that the command value to the actuator at the time of start is associated with each other.

Therefore, even if the operating characteristics of the actuator vary or change, the required hydraulic pressure at the start of the inertia phase and the command value to the actuator at the start of the inertia phase must be associated with each other. As a result, compensation can be realized such that the hydraulic fluid pressure of the friction element becomes the same value for the same command value. Therefore, even if the operating characteristics of the actuator vary or change, the engagement capacity of the friction element does not become excessively large or small during the torque phase, so that at the end of the torque phase, that is, at the start of the inertia phase. It is possible to solve the problems that the pull-in of the torque at the time is large and the torque phase time is long.

In the second invention, the predetermined command value
Since the correction relating to the hydraulic fluid pressure characteristic is performed at the time of gear shifting during power-on traveling, the required engagement capacity of the friction element at the start of the inertia phase can be accurately determined, and the required hydraulic fluid pressure corresponding to this can be obtained. It is possible to obtain it accurately, and the operation and effect of the first invention can be made remarkable.

According to a third aspect of the present invention, the required engagement capacity of the friction element is determined by using a torque sharing ratio of the friction element based on a transmission input torque obtained from an input / output rotation difference of a torque converter in a preceding stage of the automatic transmission. , The required engagement capacity of the friction element can be easily obtained, and the operation and effect of the first invention can be further enhanced.

In the fourth invention, the predetermined command value
Hydraulic pressure characteristics quantize command value and hydraulic pressure respectively
If the maps are associated with each other,
Before and after the command hydraulic pressure P at the start of the phase
Hydraulic pressure value P on the map₁, P_TwoCommand operation between
At the beginning of the inertia phase,
Required hydraulic pressure P_AOn the map before and after
Working fluid pressure value P_Three, P_FourRequired hydraulic pressure P between_Aof
Internal division ratio b and activation at the start of inertia phase
Map before and after the command value D to the heater
Upper command value D₁, D_TwoAnd the inertia on the map
Required hydraulic pressure P at start of phase_AActuator corresponding to
Command value D_AOn the map before and after
Command value D_Three, D _FourAnd the command value and operation
Correct the hydraulic pressure characteristics.

In the fourth aspect of the present invention, even when the predetermined command value / working fluid pressure characteristic is a map in which the command value and the working fluid pressure are respectively quantized and associated with each other,
The same functions and effects as in the first to third inventions can be achieved.

In the fifth invention, the command values D ₃ and D ₄ are respectively set 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) · D ₃ ] to correct and update the expected command value / hydraulic fluid pressure characteristic, so that the expected command value / hydraulic fluid characteristic quantifies the command value and the hydraulic fluid pressure, respectively. In the case of maps that have been converted and associated with each other, it is possible to easily correct the characteristic map by using mathematical expressions.

[0023]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1A shows a shift control device for an automatic transmission according to an embodiment of the present invention, and FIG. 1B is a fastening logic table of friction elements in the automatic transmission. In FIG. 1A, 1 is an engine, 2 is a torque converter, 3 is an automatic transmission, and engine rotation is transmitted to an input shaft 4 of the automatic transmission via the torque converter 2.

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, row one way clutch L / OWC, and reverse clutch R / C.
(B) is fastened by being fastened as indicated by a circle.
It is assumed that the reverse gear can be selected from the first to fourth speeds.
The low reverse brake LR / B (Ｌ)
Indicates that the engine is to be engaged at the first speed when the engine brake is required.

Further, in order to execute the selective operation (engagement) of the friction element, the control valve 8 of the automatic transmission 3 is controlled.
Includes 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. A duty solenoid 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 these to realize the engagement logic shown in FIG. Transient control is performed individually.

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 the input 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 I do.

The controller 14 executes the control programs shown in FIGS. 2 to 7 based on the above-mentioned input information, and controls the automatic transmission 3 in the following manner. Figure 2 is a main routine, first in step 21 reads the throttle opening TVO and the output shaft speed N _o, further calculates the vehicle speed VSP from the output shaft speed N _o.

In the next step 22, a shift determination is made as follows. That is, based on the vehicle speed VSP and the throttle opening TVO, a shift speed suitable for the current driving state is determined from a shift pattern that is not shown, and the preferred shift speed thus determined and the current selected shift speed are determined. If this is the case, the control is naturally terminated without any speed change. If the currently selected shift speed is different from the preferred shift speed, the control proceeds to step 23 to issue a shift command, in which operating hydraulic pressure is supplied to the corresponding friction element in order to realize shifting to the preferred shift speed. To control the duty of the corresponding duty solenoids 9 to 13

In the present embodiment, among the shifts, a shift performed by changing a friction element, that is, a friction element is released by lowering the hydraulic fluid pressure by a corresponding duty solenoid, and another friction element is released. Upshifts during power-on travel, in which power is transmitted from the engine to the wheel side by depressing the accelerator pedal, are performed in a fixed cycle. The release-side friction element hydraulic fluid pressure _Po and the engagement-side friction element hydraulic fluid as shown in the time chart of FIG. 8 are provided in accordance with the control program of FIGS. It shall be executed by the aging of the pressure P _C.

FIG. 3 shows the control relating to the first stage performed during the time t ₁ from the instant of the shift command in FIG.
1, a flag f indicating the start of the first stage
Setting ₁ to 1 causes step 32 to advance control to steps 33-37. Meanwhile, a loop comprising the steps 33 to 37, since the flag f ₁ is reset to 0 in step 37, in which only one is executed.

The loop of steps 33 to 36 will be described.
In step 33, the timer t is reset to 0
Enables measurement of elapsed time from the start of the first stage
You. Further, the control time t of the first stage₁And FIG.
Control time related to the second stage corresponding to the allowance time illustrated
t_TwoAs well as the loss straw of the friction element on the fastening side.
Precharge command pressure P to quickly complete_b
Read. Here, the control time t of the first stage
₁Is the precharge command pressure P_bUnder the friction element
Is the time it takes to complete the loss stroke of
It is determined in advance for each transmission operating oil temperature T. Second step
Control time t related to_TwoIs the hydraulic fluid of the release side friction element
Pressure P_oTo reduce the first stage control time
t₁Try to complete the decline in a short time like
And the release side hydraulic pressure P_oDrops too quickly and control ends.
1st stay
Control time t ₁To prevent undershoot added to
The interval is set in advance.

In step 34, the engine speed (torque converter input speed) _Ne and the transmission input shaft speed (output speed of the torque converter T / C) _Ni and the characteristic diagram of the torque converter T / C. From this, the turbine torque of the torque converter T / C (transmission input torque) T _t
Is calculated as follows. That is, first, determine the speed ratio N _i / N _e of the torque converter T / C, this and from the characteristic diagram of the torque converter T / C, determine the torque ratio and torque coefficient, these torque ratio and torque coefficient Multiplied by the turbine torque (transmission input torque)
Calculate _Tt .

[0033] At step 35, the above turbine torque (transmission input torque) T _t of the hydraulic P required for the fastening barely state the release side frictional element under ₀₀ (see FIG. 8), the undershoot Wachi P _a of the hydraulic α for prevention
Ask for.

In the next step 36, the control time sum t ₁ + t ₂ = t _{a for the} stage and the stage is obtained from the shift command.
Just after elapse, the release-side hydraulic pressure Po is _adjusted to the above _Pa
Ramp slope Δ of release hydraulic pressure P _o for reducing pressure
To calculate the P _1. In the next step 37,
Resetting the flag f ₁ as described above.

Thereafter, the reset of the flag f ₁ causes the step 32 to advance the control to the steps 38 to 40. At step 38, the timer t is incremented by an operation cycle Δt of the control program, and an elapsed time from the start of the first stage is measured. Next step 3
In 9, Step 3 the disengagement side hydraulic fluid pressure command value P _o
[Delta] P ₁ at a time reduces the 6, to pre-charge command pressure P _b in the engagement side hydraulic fluid pressure command value P _C Step 33. Such hydraulic pressure control is continued until it is determined in step 40 that the timer t indicates that the first stage control time t ₁ has elapsed.

It should be noted that ΔP₁Released release
Side hydraulic pressure command value P_o, And precharge command pressure P_b
Engagement side hydraulic pressure command value P set to_CIn realizing
Is the expected command value of the corresponding duty solenoid.
(Duty)-Hydraulic fluid pressure characteristics as illustrated in FIG.
Command value (duty) is D₁, D_Two, D_Three...
And the working fluid pressure is also P₁, P_Two, P_Three···of
Quantized as D ₁And P₁And D
_TwoAnd P_TwoAnd D_ThreeAnd P_ThreeIs associated with
Memory as a saved map, and
Release-side working fluid pressure command value P determined as described above_oAnd conclusion
Side hydraulic pressure command value P_CDuty corresponding to each
It is determined by search and well-known linear interpolation,
By instructing the corresponding duty solenoid,
Release hydraulic pressure command value P_oAnd engagement side hydraulic pressure command value
P_CShall be achieved.

Therefore, as shown in FIG.
One stage control time t₁Medium, release side hydraulic pressure command value P_o
Is ΔP₁Is reduced by the ramp gradient of
Value P _CIs the precharge command pressure P_bIs kept at the fastening side
In theory, the loss stroke of the friction element is controlled at the first stage.
Interval t₁Can be completed instantly.

When it is determined in step 40 that the timer t has reached the lapse of the first stage control time t ₁ ,
Control proceeds to step 42 to start the second stage. Control of the second stage is intended such shown in FIG. 4, at step 51, by setting the flag f ₂ indicating the start of the second stage to 1, step 52 advances the control to step 53 to 55 To do.
By the way, the loop including these steps 53 to 55 is as follows.
Since the flag f ₂ is reset to 0 in step 55, in which only one is executed.

To explain the loop of steps 53 to 55, in step 53, the timer t is reset to 0 so that the elapsed time from the start of the second stage can be measured. Furthermore, read the return spring equivalent pressure P _d in the loss stroke at the end of control time t ₂ and the engagement side frictional element according to the second stage. Here, the control time t ₂ of the second stage is a margin time to be added to the first stage control time t ₁ for preventing undershoot in step 33 as described above, and the return spring equivalent pressure _Pd is the friction element is the value of the engagement side hydraulic pressure P _C required for the loss stroke end state.

In step 54, it reads the reduced lamp gradient [Delta] P ₁ of the disengagement side hydraulic fluid pressure P _o calculated in step 36, step 55, the flag f as described above
Reset ₂

[0041] Thereafter, the step 52 by the reset flag f ₂ is the control proceeds to step 56-58. In step 56, the timer t is incremented by an operation cycle Δt of the control program, and the elapsed time from the start of the second stage is measured. Next Step 5
In 7, Step 5 the release-side hydraulic fluid pressure command value P _o
4 [Delta] P ₁ at a time reduces the to the engagement side hydraulic fluid pressure command value P _C to the return spring equivalent pressure P _d at the step 53. Such hydraulic fluid pressure control a timer t in Step 58 is continued until it is determined that led to indicate the passage of the second stage control time t _2.

[0042] Incidentally, the above also when Such a [Delta] P ₁ by one drop is allowed the disengagement side hydraulic fluid pressure command value P _o, and the return spring equivalent pressure P engagement side hydraulic fluid is set to _d pressure command value for realizing the P _C If likewise, the map relating to the actuator operating characteristics, determined by the search and the well-known linear interpolation duty corresponding respectively to disengagement side hydraulic fluid pressure command value P _o and the engagement side hydraulic fluid pressure command value P _C, corresponding to these by commanding the duty solenoid, disengagement side hydraulic fluid pressure command value P _o and the engagement side hydraulic fluid pressure command value P
_C shall be achieved.

[0043] Accordingly, as shown in FIG. 8, the second in stage control time t ₂ from the end instant of the first stage, the disengagement side hydraulic fluid pressure command value P _o [Delta] P ₁ subsequent to the first stage
Is reduced in ramp slope, just the end instant of the second stage, becomes the above-mentioned P _a pressure, also the engagement side hydraulic fluid pressure command value P _C is maintained at a return spring equivalent pressure P _d, the engagement side friction element The loss stroke end state is maintained.

When it is determined in step 58 that the timer t has reached the lapse of the second stage control time t ₂ ,
Control proceeds to step 59 to start the third stage. The control of the third stage, those such shown in FIG. 5, in step 61, by setting the flag f ₃ indicating the start of the third stage to 1, step 62 advances the control to step 63-64 To do.
By the way, the loop including these steps 63 to 64 is
Since the flag f ₃ is reset to 0 in step 64, in which only one is executed.

To explain the loop of steps 63 to 64, in step 63, the timer t is reset to 0 so that the elapsed time from the start of the third stage can be measured. Further, the control time t ₃ of the third stage is read,
The control time t _3, even if the actual increase in the engagement side hydraulic pressure P _C by the precharge of the first stage is the most delayed, the instantaneous as engagement side frictional element is reliably terminate the loss stroke Is determined in advance.

In step 63, the release-side hydraulic pressure finger is further
Price P_oIs the third stage control time t _ThreeInside, the third stay
Value P at the beginning of the session_aReduced by the margin pressure α
And the required hydraulic pressure P₀₀Release actuation to
Ramp gradient ΔP of hydraulic pressure_TwoIs calculated, and step 53
Spring equivalent pressure P of the engagement-side friction element at
_dRead.

In step 64, the flag is set as described above.
f_ThreeIs reset, and thereafter, step 62
The control proceeds to steps 65 to 67. In step 65
Is the control program by incrementing the timer t.
Advances the ram operation cycle Δt and opens the third stage.
Measure the elapsed time from the beginning. In the next step 66
The release hydraulic pressure command value P_oIn step 63
ΔP_TwoThe engagement side hydraulic fluid pressure command value P_CThe
Return spring equivalent pressure P at step 63_dNasu
You. Such hydraulic pressure control is performed by the timer t in step 67.
Is the third stage control time t _ThreeIs determined to have shown the progress of
Continue until another.

[0048] Incidentally, the above also when Such a [Delta] P ₂ at a time reduction is not the disengagement side hydraulic fluid pressure command value P _o, and the return spring equivalent pressure P engagement side hydraulic fluid is set to _d pressure command value for realizing the P _C Similarly to the above, from the map relating to the actuator operation characteristics, these release side hydraulic pressure command values P
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, by commanding them to the corresponding duty solenoid, disengagement side hydraulic fluid pressure command value P _o and engagement side We shall achieve hydraulic fluid pressure command value P _C.

[0049] Accordingly, as shown in FIG. 8, in the third stage control time t ₃ from the end instant of the second stage, the release-side hydraulic fluid pressure command value P _o is α at a ramp of [Delta] P ₂ from P _a value
It is reduced by fastening required pressure P _00, and the just ended instantaneous third stage, release side frictional element is reduced fastening force to the marginal condition fastening. The engagement side hydraulic fluid pressure command value P _C while kept at a return spring equivalent pressure P _d, to hold the engagement side frictional element to the loss stroke end state. By controlling the hydraulic pressure of these friction elements, the torque phase can be started immediately at the end of the third stage.

When it is determined in step 67 that the timer t has reached the lapse of the third stage control time t ₃ ,
Control proceeds to step 68 to start the fourth stage. Control of the fourth stage, those such shown in FIG. 6, in step 71, by setting the flag f ₄ indicating the start of the fourth stage 1, step 72 advances the control to step 73 to 75 To do.
By the way, a loop including these steps 73 to 75 is as follows.
Since the flag f ₄ is reset to 0 in step 75, in which only one is executed.

To explain the loop of steps 73 to 75, in step 73, the timer t is reset to 0 so that the elapsed time (torque phase time) from the start of the fourth stage can be measured. Further, the control time t ₄ of the fourth stage is read, and the control time t ₄ is set to the fourth time even when the torque phase cannot be ended for some reason.
After t ₄ hours has elapsed from the start of the stage, forcibly terminate the torque phase, was set in order to start the inertia phase, it is assumed that predetermined as the time for a so-called fail-safe.

[0052] Further in step 73, reads the lamp gradient [Delta] P _C is increased change ratio of the fourth stage of the engagement side hydraulic fluid pressure command value P _C, the ramp slope [Delta] P
_C is appropriately corrected by learning control so that the torque phase time becomes a suitable time as described later. In step 73, a set gear ratio g for judging the end of the torque phase and therefore the start of the inertia phase is further determined.
_{Read rtrg} . As shown in FIG. 8, the set gear ratio _grtrg is set to a gear ratio slightly shifted from the pre-shift gear ratio to the post-shift gear ratio, and is determined in advance for each type of shift.

In Step 74, in the torque phase, control constants used upon calculated by the disengagement side hydraulic fluid pressure command value P _o to as described later, i.e. proportional control constant K _p,
Read the integral control constant K _i, and the differential control constants K _d, respectively. Here, the proportional control constant _Kp and the derivative control constant _Kd are set to predetermined fixed values.
_i is appropriately corrected by learning control so that the torque phase time becomes a suitable time as described later.

[0054] At step 75 resets the flag f ₄ as described above, thereby the subsequent, step 72 advances the control to step 76-81. In step 76, the timer t is incremented by an operation cycle Δt of the control program, and an elapsed time from the start of the fourth stage, that is, a torque phase time is measured.

In step 77, the input shaft rotation speed of the transmission
N_iAnd output shaft speed N_oIs read, and step 78
Then, these input shaft rotation speed N_i, N_oTo the actual gear ratio
Effective gear ratio g_rG_r= N_i/ N_oIt is calculated by: Soshi
In the next step 79, the gear ratio g_rAnd one time ago
g_r1And g two times before_r2And the gear before shifting as shown in FIG.
Target gear ratio g set slightly higher than ratio _r0And from
Gear ratio g during lux phase_rIs the target gear ratio g_r0Keep
Required hydraulic fluid pressure command value P_oOne operation cycle of
Operation amount per unit ΔP_g(Positive indicates increase, negative indicates decrease)
Is calculated by the following PID calculation. ΔP_g= K_p(G_r-G_r1) + K_i(G_r0-G_r) + K_d(G_r-2g_r1+ G_r2) ... (1)

In the next step 80, the release-side working fluid pressure command value P _o is increased or decreased by ΔP _g by adding ΔP _g in step 79, and the engagement side working fluid pressure command value P
_C is increased by the ramp gradient ΔP _C in step 73. In the hydraulic pressure control, the gear ratio g
_r is judged to have decreased to g _RTRG in step 73, the inertia phase start instant of Figure 8, or a timer t in Step 82, the course of the torque phase kill time t ₄ when set to a fail-safe as described above It continues until it is judged that it has come to indicate.

Note that ΔP_gRelease increased or decreased
Side hydraulic pressure command value P_o, And ΔP _CSo as to rise
Set engagement side hydraulic pressure command value P_CWhen realizing
Is the map related to the actuator operation characteristics described above?
From the release hydraulic pressure command value P_oAnd fastening side operation
Hydraulic pressure command value P_CSearch for the duty corresponding to each
And the well-known linear interpolation
To the release side hydraulic fluid finger
Price P_oAnd the engagement side hydraulic pressure command value P_CAlso achieve
And

[0058] Accordingly, as shown in FIG. 8, in the torque phase from the end instant of the third stage to the inertia phase is started, the engagement side hydraulic fluid pressure command value P _C is [Delta] P _C
And on the other hand, the release side hydraulic pressure command value P
_o From P ₀₀ value is reduced to the feedback control under to keep the gear ratio g _r a target gear ratio g _r0, and the torque phase in the changeover of the engagement side frictional element and the release side frictional element according to control these hydraulic completion , The inertia phase is started.

[0059] When determining the completion of the torque phase in step 81, in step 83, the lamp gradient [Delta] P _C and the integral control constant K _i of the engagement side hydraulic fluid pressure and learning control so that as the torque phase time is preferred Thereafter, in step 84, the stage is started. In addition, if it is determined that the timer t has measured the time t ₄ in step 82 because the torque phase does not end at any time, the learning control described above becomes inaccurate.
Step 83 is skipped, and the stage in step 84 is started.

The stage in step 84 is shown in FIG.
As described above, the inertia
At the beginning of the phase, the act
Responded to changes in the characteristics of the map related to
Make corrections and release during the inertia phase
Side hydraulic pressure command value P_oAnd the engagement side hydraulic pressure command value P _C
Is performed.

First, the former characteristic map correction operation will be described. Prior to this, the principle of the correction operation will be described.
The instantaneous value of the engagement side hydraulic fluid pressure command value P _C in the inertia phase start instant of FIG. 8, are those such as indicated by P in the actuator operation characteristic map of FIG. 9, thus the command value to the actuator 15 (duty) is FIG. 9
Despite those such shown in D in, was occurring actually start of the inertia phase (gear ratio g _r
Is reduced to the inertia phase start determination gear ratio _grtrg .) The actual value of the engagement side hydraulic fluid is P _{A in} FIGS. 8 and 9.
Explaining the case shown in FIG. 9, the front and back values of quantized P and D on the map of FIG. 9 are P ₁ and P ₂ and D ₁ and D ₂ respectively, and the front and back values of P _A is P _3, P _4, further longitudinal value of the duty D _a corresponding to the P _a is D _3, D _4.

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.

To explain the characteristic map correction operation of FIG.
First, at step 91, the search from the operating characteristic map of the actuator of Figure 9, the longitudinal value P _1, P ₂ and D _1, D ₂ of the hydraulic fluid pressure command value P and the duty D of the engagement side frictional element in the inertia phase start instant I do.

Next, at step 92, the duty D corresponding to the working fluid pressure command value P is
5 to control the engagement-side friction element command pressure _Pc to P at the start of the inertia phase.

In the next step 93, P ₁ , P ₂
Internal ratio of P between _{(P-P 1) / (} P 2 -P 1) =
a, and in step 94, step 34 of FIG.
Using the turbine torque (transmission input torque) _Tt at the start of the inertia phase and the torque sharing ratio of the engagement-side friction element as 1 in the same manner as in the above, the transmission torque of the engagement-side friction element is determined. Of the required engagement capacity of
Determining an operating pressure P _A of the engagement side friction element for generating the request torque capacity. The hydraulic fluid pressure P _A is the pressure for causing the occurrence of the start of the actual inertia phase by the gear ratio g _r is reduced to the inertia phase start determination gear ratio g _RTRG 8, definitive beginning of the inertia phase It represents the actual pressure of the engagement-side friction element.

In the next step 95, the actual hydraulic pressure P _A of the engagement-side friction element at the moment of the start of the inertia phase is obtained from the operation characteristic map of the actuator shown in FIG.
And duty D before and after values of _A P ₃ corresponding thereto, P
₄ and D _3, it searches the D _4, step 96, the internal division ratio of P _3, the actual value hydraulic fluid pressure between _{P 4 P A P A (P} A -P 3) / (P 4 -P 3 ) = B is calculated.

Further, in step 97, the above (6)
The corrected values of D ₃ and D ₄ are obtained by the calculations of the equations (7),
D ₃ and D ₄ in the map are updated to the correction values calculated by these calculations. Therefore, in the next shift, until the start of the inertia phase in FIG. 8, the command value (duty) to the duty solenoid for the required hydraulic fluid pressure value of the engagement-side friction element is set based on the corrected D ₃ and D _4. ) Is obtained by search and linear interpolation.

[0070] Thus, according to this embodiment, obtains the required hydraulic fluid pressure P _A corresponding to the transmission torque of the engagement side frictional element at the start of the inertia phase, the request hydraulic pressure P _A at the time of the inertia phase start Since the operation characteristics of the actuator are corrected so that the command value (duty D) to the duty solenoid at the start of the inertia phase is associated with each other, even if the operation characteristics of the actuator fluctuate or change, the connection is always performed. The required hydraulic pressure of the side friction element and the command value to the actuator are associated with each other. As a result, even if the actuator operating characteristics vary or change, the engagement capacity of the friction element during the torque phase is changed. At the end of the torque phase without becoming too large or too small. It is possible to solve the problems that the pull-in of the torque at the start of the inertia phase is large and the torque phase time is long.

Further, since the correction relating to the actuator operating characteristics is performed during the upshift during power-on traveling, the transmission torque of the engagement-side friction element at the start of the inertia phase, and therefore, the required engagement capacity can be accurately obtained. Therefore, the required hydraulic pressure of the engagement-side friction element can be accurately obtained, and the operation characteristics of the actuator can be corrected more accurately.

Further, in the present embodiment, the transmission torque of the engagement-side friction element is determined based on the transmission input torque obtained from the input / output rotation difference of the torque converter T / C at the preceding stage of the automatic transmission. Friction element Since the calculation is performed using the torque sharing ratio of the friction element, the required engagement capacity of the engagement-side friction element, that is, the required hydraulic fluid pressure can be easily obtained, and the actuator operating characteristics can be easily corrected. Can be.

[0073] Finally, in step 98 in FIG. 7, known control of inertia phase disengagement side hydraulic fluid pressure command value required in the corresponding stage to a period P _o and the engagement side hydraulic fluid pressure command value P _C in FIG. 8 I do. In particular the control contents were not shown, simultaneously with the start of the inertia phase, the release-side hydraulic fluid pressure command value P _o to 0, the engagement side hydraulic fluid pressure command value P _C, the gear ratio during the inertia phase g Feedback control is performed so that _r smoothly changes from _grtrg toward the post-shift gear ratio. The control as shown in FIG. 8, the gear ratio g _r is terminates at shift completion detecting reaching the post-shift gear ratio, once raised to the original pressure of the engagement side hydraulic fluid pressure command value P _C at the shift end detection.

[Brief description of the drawings]

FIG. 1A is an overall system diagram showing a shift control device of an automatic transmission according to an embodiment of the present invention, and FIG. 1B is a diagram showing engagement logic of a friction element and a selected shift speed in the automatic transmission. FIG.

FIG. 2 is a flowchart showing a main routine of a shift determination program to be executed by a controller in the embodiment.

FIG. 3 is a flowchart showing a first stage subroutine relating to a shift control to be executed when a shift command is issued in the shift determination.

FIG. 4 is a flowchart showing a second stage subroutine related to the speed change control.

FIG. 5 is a flowchart showing a third stage subroutine related to the speed change control.

FIG. 6 is a flowchart showing a subroutine of a fourth stage related to the shift control.

FIG. 7 is a flowchart showing a subroutine of a fifth stage relating to the shift control.

FIG. 8 is an operation time chart showing changes over time of an engagement side hydraulic pressure command value and a release side hydraulic pressure command value by the same shift control.

FIG. 9 is a diagram showing a relationship between an engagement side hydraulic pressure command value, a duty command value to an actuator, and a transmission torque of a friction element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine 2 Torque converter 3 Automatic transmission 4 Transmission input shaft 5 Transmission output shaft 6 Front planetary gear set 7 Rear planetary gear set 8 Control valve 9 Duty solenoid (actuator) 10 Duty solenoid (actuator) 11 Duty solenoid (actuator) 12 Duty Solenoid (actuator) 13 Duty solenoid (actuator) 14 Controller 16 Throttle opening sensor 17 Engine rotation sensor 18 Input rotation sensor 19 Output rotation sensor 20 Oil temperature sensor

Claims (5)

[Claims] A friction element selected from a plurality of friction elements is released due to a decrease in hydraulic fluid pressure by an actuator responsive to a command value from a controller, or actuated by an actuator responsive to a command value from the controller. The gear is shifted by increasing the hydraulic pressure to perform a shift, and the controller converts a command value to the actuator into a required hydraulic fluid corresponding to 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 pressure, a required working fluid pressure corresponding to a required engagement capacity of the friction element at the start of the inertia phase during the shift is obtained, and the required working fluid pressure at the start of the inertia phase is obtained. And the command value to the actuator at the start of the inertia phase are associated with each other. A shift control device for an automatic transmission, wherein the predetermined command value / hydraulic fluid pressure characteristic is corrected so as to be able to be operated. 2. The method according to claim 1, wherein the predetermined command value
A shift control device for an automatic transmission, wherein a correction relating to a hydraulic fluid pressure characteristic is performed at the time of shifting during power-on traveling. 3. The torque sharing of a friction element according to claim 1, wherein the required engagement capacity of the friction element is determined based on a transmission input torque obtained from an input / output rotation difference of a torque converter in a preceding stage of the automatic transmission. A shift control device for an automatic transmission, wherein the shift control device is configured to calculate using a ratio. 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.