JP2000337493A - Input torque estimating device for automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the torque converter input obtained from a rotary sensor from being abnormal even when the output of the rotary sensor is abnormal to prevent the abnormality in loss torque obtained by subtracting the torque converter input from the engine torque. SOLUTION: In the determination of a torque converter input torque Te from an engine in S9 during the non-locking-up state, Te is controlled to be not over Timax (Ne) when a value min τ×Ne2, Timax (Ne)} of smaller one of a value obtained by multiplying a squared value Ne2 of the engine revolution speed by a capacity coefficient τ, and a maximum value Timax (Ne) of torque generated in engine corresponding to the engine revolution speed Ne on an engine performance diagram, is regarded as Te. In S9, the transmission input torque Ti is determined by multiplying Te by a torque ratio (t) in S3. In S10, the engine loss torque Tf as a smaller value min (Ti-Te), 0} of a value obtained by substracting Te from the torque generated by torque Ti determined in S4 and 0, is controlled to be not a negative value. In S11, Tf is updated as a learned value. During the locking-up, Te is determined on the basis of Ti-Tf, to be regarded as the transmission input torque (turbine torque) Tt.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for estimating an input torque of an automatic transmission, and more particularly to an input torque of an automatic transmission useful when a torque converter is in a lockup state in which input and output elements are directly connected. The present invention relates to an estimation device.

[0002]

2. Description of the Related Art Many automatic transmissions are configured so that engine rotation is input via a torque converter. Further, the torque converter has an input-side pump impeller, which is an input element, and an output, in terms of transmission efficiency. A device provided with a lock-up mechanism for directly connecting a turbine runner on the transmission input shaft side, which is an element, as appropriate, is widely used. Then, the automatic transmission switches the gear position by selectively engaging the friction elements such as a plurality of hydraulically actuated clutches and hydraulically actuated brakes, but in order to reduce the shock during the gear shift, The torque input to the automatic transmission from the torque converter, that is, the output torque (turbine torque) of the torta converter, is detected, and the operating oil pressure of the friction element is supplied directly or to the operation of the friction element according to the turbine torque. It is desired to control the line pressure of automatic transmissions.

However, since the torque converter and the automatic transmission have a very close layout and are housed in a substantially integral housing, the turbine torque is substantially between the torque converter and the automatic transmission. Arranging a torque sensor for detection is extremely difficult in terms of layout. Therefore, various methods for estimating the turbine torque from other parameters have been devised. For example,
In the technique proposed by the applicant of the present invention in Japanese Patent Application Laid-Open No. 1-116363, since the fuel injection pulse width of the engine is substantially proportional to the engine generated torque, a table look-up is performed based on the fuel injection pulse width and the engine speed. The engine generated torque determined by the up-up method is used as turbine torque (transmission input torque), and the line pressure is determined accordingly.

[0004] However, in the above-described method, the accuracy of turbine torque estimation cannot be increased because the torque loss due to the friction of the engine and the load on the engine driving auxiliary equipment is not taken into account. Even if the loss torque is determined experimentally in advance and this is reflected in the values in the data table, the loss torque that actually occurs has considerable variation, so it is inevitable that an error will occur, In fact, it was not possible to achieve the desired shift shock reduction effect.

On the other hand, the applicant of the present application has previously described Japanese Patent Application Laid-Open No. 5-2968.
No. 86, the speed ratio e (=
(Torque converter output speed / input speed)
Torque ratio t and torque based on the performance diagram
And the engine speed N_eTo
First, the torque converter input torque T_eTo T_e=
(Τ × N_e ^Two), Then enter the torque converter
Force torque T_eMultiplied by the torque ratio t from the turbine runner
Converter output torque (transmission input torque) T
_t= T × T_e= T × τ × N_e ^TwoAnd calculate the torque
If the converter is locked up, the above relationship
Non-lock-up of the torque converter
Torque T of the engine during_iAnd the above torque converter
Force torque T_eThe difference between the engine and the loss torque for each operating condition
T _fAnd lock the torque converter
Transmission input torque T during_tWith the engine generated torque T_i
From the engine loss torque for each operating condition stored above
K T_fHas already been proposed
is there. In this case, the torque converter is not locked
The turbine torque (transmission input torque)
H) T_tCan be estimated, and the torque converter
During the backup state, the turbine torque T_tEstimation
There is an effect that the operation is not impossible.

[0006]

SUMMARY OF THE INVENTION The above-mentioned proposed technology
Still make sure that there are problems described below.
Was. That is, the speed ratio e of the torque converter is obtained.
The output speed of the torque converter (turbine rotation
Number) N_tAnd input speed (engine speed) N_eKnow
It is necessary to have a sensor to detect these rotation speeds.
Become. Therefore, noise may enter these sensors.
Calculate the corresponding rotation speed from the detection signal
Sometimes an error is included, so the above-described operation T_e= Τ × N_e ^Two
Converter input torque T obtained by_eIs original
There is a concern that the value may be too large to exist. This place
The loss torque T of the engine_fNegative that does not exist
Value, which is far away from the true value
Even if the value is incorrect, it is memorized as it is and the next lock
Torque (transmission input torque) T at start-up
_tOf the turbine torque (transmission input torque)
Luke) T_tAutomatic transmission control based on
You.

According to a first aspect of the present invention, there is provided an input torque estimating apparatus for an automatic transmission in which the above-mentioned problem does not occur by limiting the value of the torque converter input torque calculated as described above. The purpose is to propose.

According to a second aspect of the present invention, when the calculated value of the input torque of the torque converter is limited as in the first aspect of the invention, the calculation data of the engine generated torque necessary for obtaining the loss torque is used. It is an object of the present invention to propose an input torque estimating apparatus for an automatic transmission, which can determine the limit value and can thereby achieve the operation and effect of the first invention without requiring new data for the limit value. And

According to a third aspect of the present invention, when the calculated value of the torque converter input torque is limited as in the first invention, the calculated value of the engine-generated torque necessary for obtaining the loss torque is set to the limit value. Accordingly, it is an object of the present invention to propose an input torque estimation device for an automatic transmission that can achieve the operation and effect of the first invention without requiring new data for a limit value.

According to a fourth aspect of the present invention, not only the torque converter input torque calculation value is limited, but also the loss torque of the stored engine is limited, so that the above-mentioned problem can be more reliably solved. It is an object of the present invention to propose an input torque estimation device for an automatic transmission.

According to a fifth aspect of the present invention, an input torque estimating apparatus for an automatic transmission is proposed which is capable of determining the limit value most easily when limiting the loss torque of the engine to be stored. The purpose is to do.

According to a sixth aspect of the present invention, in the intermediate state between the non-lockup state and the lockup state of the torque converter, where the calculation of the engine loss torque and the estimation of the transmission input torque are not possible, It is an object of the present invention to propose an input torque estimating apparatus for an automatic transmission, which can avoid the calculation and storage of the engine loss torque and the estimation of the transmission input torque according to the fifth invention.

[0013]

SUMMARY OF THE INVENTION For these purposes, the first
An input torque estimating device for an automatic transmission according to the present invention is used in an automatic transmission in which engine power is input via a torque converter capable of locking up a torque converter input / output element, and detects relative rotation between the torque converter input / output elements. During non-lockup without restriction, the difference between the generated torque of the engine and the torque converter input torque calculated from the torque capacity coefficient of the torque converter and the engine speed is stored as the engine loss torque for each operating condition, and the torque converter input torque is stored. When obtaining the input torque from the torque converter to the automatic transmission during lock-up in which the relative rotation between the output elements is set to 0, the lock loss is obtained by subtracting the loss torque of the engine for each of the stored operating conditions from the torque generated by the engine. Estimation of input torque of automatic transmission that calculates transmission input torque at up In location and is characterized by being configured to set an upper limit to the torque converter input torque calculated from the torque capacity coefficient and the engine speed.

According to a second aspect of the present invention, the input torque estimating apparatus for an automatic transmission according to the first aspect, wherein an upper limit of the calculated torque converter input torque is set to a maximum value of the generated torque of the engine according to the engine speed. It is characterized by having done.

According to a third aspect of the present invention, there is provided an input torque estimating apparatus for an automatic transmission according to the first aspect, wherein an upper limit of the calculated torque converter input torque is set to a generated torque of the engine. is there.

According to a fourth aspect of the present invention, there is provided an input torque estimating apparatus for an automatic transmission according to any one of the first to third aspects, wherein the lower limit is set for the stored engine torque loss. It is.

According to a fifth aspect of the present invention, in the input torque estimating apparatus for an automatic transmission according to the fourth aspect, the lower limit of the stored engine torque loss is set to zero.

According to a sixth aspect of the present invention, there is provided an input torque estimating apparatus for an automatic transmission according to any one of the first to fifth aspects, wherein the torque converter is in an intermediate state between the non-lockup state and the lockup state. The calculation and storage of the engine loss torque and the estimation of the transmission input torque are prohibited.

[0019]

According to the first aspect of the invention, even when the torque converter is locked up, the input torque to the automatic transmission can be estimated from the torque converter in consideration of the loss torque of the engine. During lock-up, the difference between the generated torque of the engine and the torque converter input torque calculated from the torque capacity coefficient of the torque converter and the engine speed is stored as the loss torque of the engine for each operating condition. When obtaining the input torque from the torque converter to the automatic transmission during the up-up, the lock-up transmission input torque is obtained by subtracting the engine loss torque for each of the stored operating conditions from the engine generated torque. Therefore, the transmission input torque can be estimated even during lock-up while taking into account the loss torque of the engine.

In the first invention, the upper limit is set for the torque converter input torque calculated from the torque capacity coefficient and the engine speed, as described above. Therefore, the torque converter input / output speed required for the torque capacity coefficient is set. The above-described torque converter input torque calculation value is not affected even if noise is mixed in the detection sensor of the engine and the detection sensor of the engine rotation speed, or an error is included when calculating the corresponding rotation speed from the sensor detection signal. Then, there is no danger of a large value that does not exist, and the loss torque of the engine obtained from the torque converter input torque calculation value as described above does not become a negative value that should not exist. Therefore, even if the noise is mixed or the calculation error is present, the loss torque of the engine is not stored as an erroneous value that is far from the true value, and is not reduced below the value limited by the above. . As a result, the input torque of the transmission obtained by subtracting the loss torque of the engine from the torque generated by the engine at the next lock-up is significantly different from the true value, and the control of the automatic transmission based on this is inaccurate. Can be solved.

In the second invention, when setting the upper limit to the torque converter input torque calculation value as in the first invention, the upper limit is set to the maximum value of the generated torque of the engine according to the engine speed. The upper limit value can be determined by using the calculated data of the engine-generated torque required when obtaining the torque, so that the operation and effect of the first invention can be achieved at low cost without requiring new data for the upper limit value. Can be achieved.

In the third invention, when the upper limit is set for the torque converter input torque calculation value as in the first invention, the upper limit is used as the generated torque of the engine. The calculated value of the torque is determined as the upper limit value as it is, so that the operation and effect of the first invention can be achieved at low cost without requiring new data for the upper limit value.

In the fourth invention, not only is the torque converter input torque calculated value limited as in the first invention to the third invention, but also a lower limit is set for the stored engine loss torque. The above-mentioned conventional problem solving can also be achieved by the provision of (1), and the problem solving can be further ensured.

In the fifth invention, since the lower limit of the stored engine torque loss is set to 0, the lower limit can be set most easily, and the operation and effect of the fourth invention can be achieved at low cost. Can be.

In the sixth invention, the calculation and storage of the engine loss torque and the estimation of the transmission input torque are prohibited while the torque converter is in an intermediate state between the non-lockup state and the lockup state. In the intermediate state between the non-lockup state and the lockup state of the torque converter where the calculation of the engine loss torque and the estimation of the transmission input torque cannot be performed, the calculation and storage of the engine loss torque according to the first invention to the fifth invention, the transmission It is possible to avoid the fact that the input torque is estimated and these torque values become different from the actual values.

[0026]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a power train of a vehicle having an automatic transmission equipped with an input torque estimating apparatus according to an embodiment of the present invention in a transmission system together with a control system thereof. In the figure, reference numeral 11 denotes an electronically controlled fuel injection type internal combustion engine, 12 denotes a torque converter which is drivingly coupled to a crankshaft 13 which is an output shaft of the internal combustion engine 11, and 14 denotes a rotation from the internal combustion engine 11 via the torque converter 12. This is an automatic transmission to be input, and the automatic transmission 14 is constituted by a well-known planetary gear transmission mechanism. The output shaft 15 of the automatic transmission 14 is connected via a differential gear 16 to the axle of the drive wheels 17.

The torta converter 12 comprises a pump impeller 12a as an input element, a turbine runner 12b as an output element, and a lock-up clutch 19 capable of appropriately locking up the input and output elements of the torque converter. By fastening 19, the torque converter 12 can be changed from a converter state in which the input / output elements are not directly connected to a lockup state in which the input / output elements are directly connected. The torta converter 12 couples the pump impeller 12 a to the output shaft 13 of the internal combustion engine 11, connects the turbine 12 b to the input shaft 18 of the automatic transmission 14, and inserts the turbine 12 b between the internal combustion engine 11 and the automatic transmission 14. Can be transmitted to the automatic transmission 14 in the converter state or the lock-up state.

In the transmission system of the vehicle having the above configuration,
The internal combustion engine 11 controls the fuel injection amount, the ignition timing, and the like comprehensively by an engine controller 20. The automatic transmission 14 controls the shift speed (shift) and the lock-up clutch 19 by the transmission controller 21, and further controls the lock-up clutch 19. Control the line pressure, which is the operating pressure, individually.
The automatic transmission 14 has a control valve 22,
The line pressure control, the lock-up control, and the shift control are executed by electronically controlling the line pressure solenoid 23, the lock-up solenoid 24, and the shift solenoids 25 and 26 inserted therein by the transmission controller 21. And Here, it is assumed that the selected shift speed of the automatic transmission 14 is determined by a combination of ON and OFF of the shift solenoids 25 and 26, as is well known in particular regarding the shift control.

For the above control, both controllers 20,
It is assumed that the following information is input to each of the keys 21. First, the engine controller 20 receives a signal from an engine water temperature sensor 31 for detecting a cooling water temperature Temp of the engine 11 and a signal from an intake air amount sensor 32 such as a hot-wire air flow meter for measuring the intake air amount Q of the engine 11. When,
A signal from a throttle opening sensor 33 for detecting a throttle opening TVO of the engine 11, a signal from a transmission output rotation sensor 34 for detecting an output rotation speed N _O of the automatic transmission 14, and a rotation speed N of the engine 11. detection a signal from an engine rotation sensor 35 for detecting the _e, ON the compressor air conditioner, a signal SWac from the air conditioner switch 36 to OFF, the rotation speed N _t of the turbine runner 12b which is the output rotation of the torque converter 12 And a signal from the turbine rotation sensor 38 to be executed.

On the other hand, the transmission controller 21 receives a signal from the throttle opening sensor 33, a signal from the transmission output rotation sensor 34, a signal from the engine rotation sensor 35, and a current acting as a load on the alternator. I
inputting a signal from the alternator current sensor 37 for detecting the magnitude of the agc, the signal from the line pressure sensor 39 for detecting the line pressure P _L of the automatic transmission 14. It is assumed that necessary signals are exchanged between the engine controller 20 and the transmission controller 21.

The details will consist lost torque T _f is a number of factors of the engine 11 in question in the present invention as described later in actuality, in the present embodiment, the loss T _c by air-conditioner compressor and an electrical load T _a of the alternator, the friction (including Bonpin gross) and T _fr, and be focused on four of the oil pump friction T _OP. Here, air conditioning compressor losses T _c can be considered a function of the SWac and the engine speed N _e, similarly electric load T _a function of the current IAGC, friction T _fr is the water temperature Temp and the engine speed N _e
The oil pump friction _TOP is the line pressure P
It can be considered as a function of _L and the engine rotational speed N _e. Thus the entire torque loss T _f is, SWac, N _e, Iag
The loss torque Tf can be represented by five-dimensional parameters of c, Temp, and P _{L. In} the present embodiment, as an example, the loss torque Tf is learned using this five-dimensional parameter array.

Next, the operation of the above embodiment will be described in detail with reference to the flowcharts of FIG. The flowchart of FIG.
It shows a flow of an output torque estimation process repeatedly executed every msec. Here, calculation of the turbine torque _Tt and learning of the loss torque _Tf are mainly performed. First, the engine speed N _e in step S1, and the turbine speed N _t, a transmission output speed N _O, and signal SWac the air conditioner switch 36, an alternator current Iag
read and c, and the engine coolant temperature Temp, and a line pressure P _L.

[0033] In step S2, determine the gear ratio gr of the automatic transmission 14 by the operation of the gr = N _t / N _O, and the speed ratio e of the torque converter 12 is obtained by calculation of _e = N _t / N e. In step S3, the torque ratio t of the torque converter 12 is searched from the speed ratio e based on a map corresponding to the performance diagram of the torque converter 12 illustrated in FIG.

Next, in step S4, the engine generated torque T _i that should be generated by the internal combustion engine 11 is estimated as follows using a map corresponding to the engine performance diagram shown in FIG. 8 or FIG. FIG. 8 shows the engine intake air amount Q and the engine speed N.
FIG. 9 illustrates a performance diagram of the engine with e as a parameter, FIG. 9 illustrates a performance diagram of the engine with the throttle opening TVO and the engine speed Ne as parameters, and a map corresponding to FIG. Intake air amount Q and engine speed N
When the engine generated torque _Ti is searched from e and the map corresponding to FIG. 9 is used, the engine generated torque _Ti is searched from the throttle opening TVO and the engine speed Ne. Note that other, since the amount of air actually sucked into the cylinder by such intake pipe pressure and the engine speed N _e downstream of the throttle valve is shown, it is also possible to estimate the generated torque T _i based on these.

In the next step S5, it is determined whether it is the first time immediately after the start of the flowchart of FIG. 2, and only in the first time, in step S6, the initial value of the loss torque _Tf is obtained as described later. Set based on the learning value. Specifically, as the learning value of the loss torque T _f is the aforementioned, SWac as a loss load conditions, N _e, IAGC, Temp,
Since it is stored with a 5-dimensional parameter array of P _L, air conditioning ON at that time, it reads out the learning value corresponding to a loss load conditions OFF etc. from the learning memory, set as the initial value of the loss torque T _f I do.

Except for the first time, step S6 advances the control to step S7, and the following control is performed. First, step S7
In FIG. 1, whether the lock-up clutch 19 of the torque converter 12 is engaged (lock-up = L / U) or released (non-lock-up = converter = C / V) based on a signal directed to the lock-up solenoid 24 in FIG. State or intermediate slip between them (S / L)
It is determined whether it is in the state.

If it is in the non-lockup state, step S8
7, the torque capacity coefficient τ of the torque converter 12 is calculated from the speed ratio e in step S2 based on a map corresponding to the performance diagram of the torque converter 12 illustrated in FIG.
Search for. Then, in step S9, it obtains the actual input torque T _e from the engine 11 to the torque converter 12, this time the input torque T _e is multiplied by the torque capacity coefficient τ to the square value N _e ² known as the engine speed calculation value obtained Te (τ × N _e ²⁾ and, 8 or on the diagram engine performance line shown in FIG. 9 the maximum value T _imax of the engine generated torque T _i corresponding to the current engine speed N _e (N _e of), and torque converter input torque T _e by selecting the smaller value ^{_{min {τ × N e 2,}} T imax (N e)}.

Thus, the torque converter input torque T _e
By determining the following, the following effects can be obtained. That is, the output rotational speed of the required torque converter search for the required speed ratio e in the process of obtaining the torque converter input torque T _e (turbine speed) N _t and the input rotational speed (engine speed) is detected N _e the sensor 38, 35 is often noise is mixed, and because the error is also included when calculating the number of revolutions from the corresponding detection signal, a torque converter input torque obtained by the calculation T _e = τ × N _e ² of the T _e and there is a fear that a large value such as does not exist if the original. Then, as described above, T _e = min ｛τ × N
If _e ^2, the T _imax (N _e)} to obtain a torque converter input torque T _e, torque converter input torque T _e even if the above noise and calculation error according to the engine speed N _e Maximum value T of engine generated torque T _i
imax (N _e) without exceeding, it is possible to dispel fear that a large value so as not to exist if the torque converter input torque T _e originally.

In step S9, further, as described above,
Torque converter input torque T _eAt step S3
Multiply by the obtained torque ratio t to obtain the transmission input torque.
Luc converter output torque (turbine torque) T_tSeeking
This is referred to as the control of the transmission described later with reference to FIGS.
To serve. Next, in step S10, the engine 11
Loss torque from friction and engine driven accessories
T_fIs obtained by the following. At this time, the engine loss torque T_f
Is the engine generated torque T determined in step S4._iFrom to
Actual input torque T to converter 12_eSubtract
The usual value (T_i-T_e), 0 and
The smaller of min ｛(T_i-T_e), Select 0｝
Related loss torque T_fAnd

By determining the engine loss torque _Tf as described above, the following effects can be obtained. In other words, so that no if the torque converter input torque T _e is inherent in such noise mixing into the sensor 38, 35 when determining the torque converter input torque T _e to be determined as the prior to obtaining the engine torque loss T _f If the value becomes too large, the loss torque _Tf may become a negative value that does not exist originally, but as described above, _Tf = min ｛(T _i −
If the engine loss torque _Tf is obtained from T _e ), 0 °, there is no fear that the engine loss torque _Tf becomes a negative value smaller than 0, which is not originally present, even if the above-mentioned noise or the like is present. be able to.

In step S11, the engine loss torque _Tf obtained as described above is converted to the load loss condition SWa
_{c, N e, Iagc, Temp} , updated as a learning value for the five-dimensional parameter array of P _L, the loss torque T _f
To learn. Therefore, while the operation is continued in the non-lockup state, the learning value of the loss torque _Tf assigned to various loss load conditions is updated successively. Then, in step S12, the flag FLAG is reset to 0 to indicate that the lock-up clutch 19 is not in the slip state.

On the other hand, at step S7, lock-up (L /
U), it is determined in step S13 that the loss torque T corresponding to the loss load condition at that time is determined.
Set _f based on the learning value. That is, a learning value corresponding to the loss load condition is read from the learning memory having the five-dimensional parameter array, and is set as the loss torque _Tf . Next, in step S14, the torque converter input torque _Te is obtained by an operation (T _i −T _f ) by subtracting the loss torque T _f from the engine generated torque T _i. intact T _e, the transmission input torque become torque converter output torque (turbine torque) T _t, which are subjected to the control of the transmission to be described later with reference to FIGS. In step S15, the flag FLAG is set to 0 to indicate that the lock-up clutch 19 is not in the slip state.
Reset to.

If it is determined in step S7 that the lock-up clutch 19 is in an intermediate slip (S / L) state between the engaged state and the released state, step S1 is performed.
In step 6, the flag F
Set LAG to 1. Here, by ending the control as it is, steps S8 to S15
And the calculation and learning of the engine loss torque _Tf and the estimation of the transmission input torque (turbine torque) _Tt performed in these steps are prohibited.

Next, control of the automatic transmission 14 using the turbine torque (transmission input torque) _Tt obtained as described above in steps S9 and S14 will be described with reference to FIGS. The flowchart of FIG. 3 shows the control of the clutch engagement hydraulic pressure at the time of shifting of the automatic transmission 14, and the control signal of the clutch engagement hydraulic pressure _PcL determined here is output, for example, every 10 ms by the routine shown in FIG. I do.

In step S20 of FIG. 3, the timing and mode of the shift are determined from the throttle opening TVO and the transmission output rotational speed N _O (vehicle speed) based on a predetermined shift pattern, and the shift is determined to be executed here. Only step S2
The control of the clutch engagement hydraulic pressure _PcL after 1 will be performed. In step S21, the lock-up clutch 1 is determined based on whether the flag FLAG determined in FIG.
9 is an intermediate slip between the engaged state and the released state (S
/ L) state is determined, and slip (S / L) is determined.
If not, the transmission input torque T _t obtained from FIG.
Is useful, the clutch engagement hydraulic pressure _PcL is controlled as follows.

First, in step S22, it is determined whether or not the shift control routine is to be executed for the first time. If it is the first time, in step S23, a timer TM for counting the number of times of execution of the shift control routine is reset and added. Thus, the final target gear ratio grm and the optimal shift time tmr of the shift are determined. Where the final target gear ratio gr
_m is determined to be the same value as the gear ratio of the third speed when the shift determination in step S20 is a shift command from the second speed to the third speed, and the optimum shift time tmr is determined by the type of the shift and the FIG. 10 shows an example of the time of 2 → 3 shift according to the operating state including the rotation speed of the engine 11 and the engine cooling water temperature.
Determined as shown in

In the next step S24, the transmission output torque T _O1 immediately before the shift is changed to the turbine torque T _t , the turbine torque T _t , the gear ratio gr before the shift, and the transmission output speed N
_From the differential value N _O dt (acceleration of the vehicle) of _O and the inertia I _{O of the} drive system, T _O1 = T _t × gr + N _O dt × I
Calculated by _O. In the next step S25, an initial value relating to the target input rotation change rate N _t dt of the transmission input shaft 18 is set as shown in FIG. 10B from a predetermined data table in which the output torque immediately before the shift T _O1 is used as a parameter. Set to. Next, in step S26, this N
By dividing the initial value of _t dt by the optimum shift time tmr, a ratio N _t step of N _t dt to be changed per unit time is obtained as shown in FIG.

After the second time, step S22 controls the control.
Proceed to step S27, where the timer TM is advanced
The elapsed time from the start of the gear change (hereinafter, for convenience,
The same sign TM is used). And
In step S28, the above-mentioned elapsed time TM is set to the optimum shift
It is determined whether or not time tmr has been reached, and in step S29
The gear ratio gr is equal to the final target gear ratio gr. _mReached or not
Is determined. The elapsed time TM is equal to the optimal shift time tmr.
Gear ratio gr until the final target gear ratio gr
_mIn the shift transition period until
Proceed to S30 to S32 and set the clutch engagement hydraulic pressure as follows.
P_cLControl.

In step S30, the above-described FIG.
Transmission input torque T determined as follows: _tAnd related to this
Coefficient I determined by rotational inertia and gear ratio gr₁
, And the value obtained last time in the subsequent step S32.
Target input rotation change rate N_tdt and its related rotary inertia
Coefficient I determined by gear ratio and gear ratio gr_TwoMultiplication with
Value, and also the transmission output speed N_ODerivative N of_Odt (car
Acceleration) and the rotational inertia and gear
Coefficient I determined by gear ratio gr_ThreeAnd the product of
Required clutch engagement force T_cL(= T_t× I₁+ N_tdt × I_Two
+ N_Odt × I _Three) Is calculated. This request clutch engagement
Force T_cLIs the target input rotation change rate N_tdt is step S3
2, the constant determined in step S26
Ratio N_tInput rotation change because it is subtracted in step
FIG. 10B shows the target input rotation change rate N_tas dt
As shown, the initial value is reduced to 0 by multiplying the optimal shift time tmr
It expresses the clutch engagement force as follows.

Next, at step S31, the required clutch engagement hydraulic pressure P _cL for achieving the required clutch engagement force T _cL is obtained by dividing the required clutch engagement force T _cL by a predetermined clutch coefficient k _cL , as shown in FIG. ) Is calculated as shown by the broken line, and this is output to the line pressure solenoid 23 of FIG. Here, the actual clutch engagement hydraulic pressure _PcL1 is shown in FIG.
As shown by the solid line in (c), the required clutch engagement hydraulic pressure P _cL
Of course with a slight time delay.

Further, in step S32, the target input rotation change rate N _t dt is calculated from the initial value determined in step S25 to the change rate N per unit time obtained in step S26.
Subtract _t steps. This target input rotation change rate N _t
dt is as shown in FIG. 10 (b), is varied to reach just 0 between the optimum shift time tmr from an initial value determined in step S25, subjected to the calculation of the required clutch engagement force T _cL of the next step S30 Is done. Therefore, should the clutch engagement hydraulic pressure P _cL at step S31 in order to achieve this required clutch engagement force T _cL is the rotation rate of change of transmission input shaft 18 FIG 10 (b) to indicate the target input revolution change rate N _t
dt.

According to the above control shown in FIG.
Output torque T_OIs the torque value T just before shifting_O1Since
Target input rotation change rate N_tGiven the initial value of dt,
Target input rotation change rate N_tdt is the optimal shift time tmr
Constant rate N, which is just 0 at times_tchanges in steps
Clutch engagement hydraulic pressure P_cLIs controlled,
Machine output torque T_OIs the optimal shift as shown in FIG.
The torque value T before shifting starts over the time tmr_O1Shift from
End point torque value T_O2To connect smoothly to
Therefore, it is possible to reduce the shift shock. Soshi
In this embodiment, in particular, the transmission input torque (torque)
-Bin torque) T _tDuring non-lockup and lockup
Can be accurately estimated in both cases.
Force rotation change rate N_tso that the initial value of dt is given properly
And reduce shift shocks with high-precision hydraulic control
It can be something.

In step S28, it is determined that the elapsed time TM from the shift command has become the optimum shift time tmr, or in step S29, the gear ratio gr is set to the final target gear ratio gr _m.
Is reached after the shift is completed, the maximum value _PcL of the clutch engagement hydraulic pressure _PcL is determined in step S33.
_max is instructed to the line pressure solenoid 23 in FIG. 1 to completely engage the clutch.

By the way, in step S16 of FIG.
When the LAG is set to 1, that is, when the lock-up clutch 19 is in an intermediate slip state between the engaged state and the released state, step S21 in FIG. Since the process is ended, the shift control based on the transmission input torque (turbine torque) _Tt is not performed, and the shift control according to the throttle opening TVO is performed instead in step S34. Therefore, when the lock-up clutch 19 is in the slip state, the transmission input torque (turbine torque) T _t.
The inconvenience that the shift control based on this is continued despite the fact that the estimation is not performed can be eliminated.

Transmission input torque (turbine torque)
The control of the transmission according to _Tt and the flag FLAG is not limited to the above-described transient control of the clutch engagement pressure during the shift, and the following line pressure control as shown in FIG. 5 is also possible. In step S41, it is checked whether or not the flag FLAG is 1. If not, the lockup clutch 19 is in the engaged state or the released state, and the transmission input torque (turbine torque) _Tt is estimated according to FIG. Therefore, in step S42, line pressure control is performed based on the transmission input torque (turbine torque) _Tt . However, if the flag FLAG is 1, the lockup clutch 19 is in an intermediate slip state between the engaged state and the released state, and the transmission input torque (turbine torque) _Tt cannot be estimated from FIG. From step S
At 43, line pressure control is performed based on the throttle opening TVO instead of the transmission input torque (turbine torque) _Tt .

[0056] Figure 6 shows another embodiment of the present invention, in this embodiment unlike in the case of engine 11 at step S9 in FIG. 2 upon obtaining the actual input torque T _e of the torque converter 12, Calculated value obtained by multiplying the square value _Ne ² of the engine speed by the torque capacity coefficient τ (τ × N _e ² )
And the engine generated torque T _i obtained in step S4,
And selects the smaller value ^{_{min {τ × N e 2,}} T i} and torque converter input torque T _e by. Such a following action and effect to determine the torque converter input torque T _e obtained frequently paid. That is, the torque converter input torque T _e output speed of the required torque converter search for the required speed ratio e in the process of obtaining the (turbine speed)
N _t and the input rotational speed (engine speed) the sensor 38, 35 for detecting the N _e is often noise is mixed,
Since the error is also included when calculating the number of revolutions from the corresponding detection signals, fear that the calculation T _e = τ × N _e torque converter input torque T _e as determined by ² becomes a large value that does not exist would otherwise There is. Thus As indicated above _{T e = min {τ × N} e 2, T it} by if to determine the torque converter input torque T _e, the above noise and the torque converter as an arithmetic error was input torque T _e but without exceeding the engine generated torque T _i obtained in step S4, it is possible to dispel the concern that the torque converter input torque T _e becomes a large value that does not exist would otherwise.

[Brief description of the drawings]

FIG. 1 is a system diagram showing a power train of a vehicle including an automatic transmission including an input torque estimating apparatus according to an embodiment of the present invention, together with a control system thereof.

FIG. 2 is a flowchart showing a transmission input torque estimation program according to the embodiment.

FIG. 3 is a flowchart showing a program of clutch engagement pressure control during shifting as an example of control of the automatic transmission according to the embodiment.

FIG. 4 is a flowchart showing an output program of the clutch engagement pressure control signal.

FIG. 5 is a flowchart showing a line pressure control program as an example of control of the automatic transmission according to the embodiment.

FIG. 6 is a flowchart showing a transmission input torque estimation program similar to FIG. 2, showing another embodiment of the present invention.

FIG. 7 is a performance diagram of a torque converter shown as a change characteristic of a torque ratio and a torque capacity coefficient with respect to a speed ratio of the torque converter.

FIG. 8 is a diagram exemplifying a performance diagram of an engine used for obtaining a generated torque of the engine.

FIG. 9 is a diagram exemplifying a performance diagram of another type of engine used when obtaining the generated torque of the engine;

FIGS. 10A and 10B are operation time charts of the clutch engagement pressure control during shifting shown in FIGS. 3 and 4, wherein FIG. 10A is a change time chart of a transmission output torque, and FIG. 10B is a change time of a target input rotation change rate. The chart (c) is a change time chart of the clutch engagement pressure.

[Explanation of symbols]

 11 Engine 12 Torque converter 14 Automatic transmission 16 Differential gear 17 Drive wheel 18 Transmission input shaft 20 Engine controller 21 Transmission controller 22 Control valve 23 Line pressure solenoid 24 Lock-up solenoid 25 Shift solenoid 26 Shift solenoid 31 Engine water temperature sensor 32 Suction Air flow sensor 33 Throttle opening sensor 34 Transmission output rotation sensor 35 Engine rotation sensor 36 Air conditioner switch 37 Alternator current sensor 38 Turbine rotation sensor 39 Line pressure sensor

Claims (6)

[Claims] The present invention is used in an automatic transmission in which engine power is input via a torque converter capable of locking up between a torque converter input / output element and during non-lockup in which the relative rotation between the torque converter input / output element is not limited. The difference between the generated torque of the engine and the torque converter input torque calculated from the torque capacity coefficient of the torque converter and the engine speed is stored as the loss torque of the engine for each operating condition, and the relative rotation between the torque converter input and output elements is stored. When obtaining the input torque from the torque converter to the automatic transmission during the lock-up to 0, the lock-up transmission input torque is obtained by subtracting the loss torque of the engine for each of the stored operating conditions from the generated torque of the engine. In the input torque estimating device for an automatic transmission, the torque capacity And the input torque estimating device for an automatic transmission which is characterized by being configured to set an upper limit to the torque converter input torque calculated from the engine speed. 2. The input torque of an automatic transmission according to claim 1, wherein an upper limit of the calculated torque converter input torque is set to a maximum value of an engine generated torque corresponding to an engine speed. Estimation device. 3. The input torque estimating device for an automatic transmission according to claim 1, wherein an upper limit of the calculated torque converter input torque is set to a generated torque of the engine. 4. The input torque estimating device for an automatic transmission according to claim 1, wherein a lower limit is set for the stored engine torque loss. 5. The input torque estimating device for an automatic transmission according to claim 4, wherein a lower limit of the stored engine loss torque is set to 0. 6. The transmission according to claim 1, wherein the torque converter is calculated and stored while the torque converter is in an intermediate state between the non-lockup state and the lockup state. An input torque estimating device for an automatic transmission, wherein input torque estimating is prohibited.