JP3606153B2 - Creep force control device for vehicle automatic transmission - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a creep force control device for an automatic transmission for a vehicle that reduces the creep force by a torque converter when the automatic transmission stops in a travel range.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in a torque converter type automatic transmission provided in a vehicle such as an automobile, a low speed stage (for example, a first speed stage) is achieved when the shift range is stopped while the travel range (hereinafter referred to as D range) remains unchanged. In order to achieve this, a technique has been proposed in which the friction element (forward clutch) engaged to slip is controlled to approach the neutral state.
[0003]
Such control is generally called idle neutral control or creep force control, and is transmitted through a torque converter by executing such idle neutral control (hereinafter simply referred to as neutral control) while the vehicle is stopped. The engine torque can be reduced to reduce fuel consumption and idle vibration.
[0004]
The neutral control start conditions are set, for example, such that the vehicle speed is 0 km / h, the foot brake is being operated, the throttle opening is 0%, the predetermined time has elapsed since the first speed is achieved, etc. When the condition is satisfied, neutral control is started based on a command from the controller.
Further, when any one of the neutral control cancellation conditions such as the release of the foot brake operation, the operation of the accelerator pedal, or the vehicle speed exceeds a predetermined value is satisfied, the neutral control is canceled.
[0005]
[Problems to be solved by the invention]
By the way, during the neutral control as described above, the slip ratio in the torque converter, that is, the rate of change of the ratio (Nt / Ne) between the engine speed Ne and the turbine runner speed Nt is forwarded so as to become the target change rate. It is conceivable that the clutch engagement force is feedback-controlled, or the forward clutch engagement force is feedback-controlled so that the rate of change of the slip amount (Ne−Nt) in the torque converter becomes the target rate of change.
[0006]
In such a case, the engagement force of the forward clutch is generally duty controlled by hydraulic pressure. Specifically, a control valve that is turned on and off is provided on the line pressure supply path of the forward clutch, and the engagement force of the forward clutch is duty-controlled by appropriately setting the duty ratio of this control valve.
By the way, during neutral control, the line pressure may decrease due to an increase in the oil temperature, etc. If the engine speed fluctuates with the line pressure decreasing in this way, the line pressure or pilot pressure ( (Control pressure) may fluctuate, and the engaging force of the forward clutch may deviate greatly from the target value, and the turbine rotation speed may fluctuate.
[0007]
The present invention was devised in view of such problems, and is capable of executing stable neutral control (creep force control) even when sudden engine rotation fluctuations that cannot be corrected only by feedback control occur. An object of the present invention is to provide a creep force control device for an automatic transmission for a vehicle.
[0008]
[Means for Solving the Problems]
In the creep force control apparatus for an automatic transmission for a vehicle according to the present invention, when a predetermined condition is satisfied when the shift range of the automatic transmission is the travel range, the engagement force of the friction element that is engaged during travel is reduced. Reduces creep power. Then, the engagement force of the friction element is feedback-controlled by the feedback control means, and the automatic transmission is held in a state close to the neutral state.
[0009]
Here, after the predetermined condition is satisfied, a predetermined initial value is output from the initial value output means when feedback control is started. This initial value is a value serving as a reference for the engagement force of the friction element during the feedback control, and the feedback control is executed by the feedback control means based on the initial value. During execution of the feedback control, the learning means corrects the initial value based on a parameter value related to at least one of the oil temperature and the engine rotational speed, and the friction element based on the learned corrected initial value. The engagement force is feedback-controlled.
The learning means obtains the learning correction amount based on the deviation between the average value of the output values during the predetermined time and the value obtained at the end of the predetermined time and obtained from the engine speed and the oil temperature. .
[0010]
As a result, even if a sudden engine rotation fluctuation occurs, the initial value that is the basis for determining the engagement force of the friction element is learned and corrected, so that the engagement force of the friction element is accurately controlled and stable creep force control is performed. Can be executed.
According to a second aspect of the present invention, the initial value is set by the sum of the preset base value and the learning correction amount, and the learning correction is performed. The amount is calculated by the sum of the correction amount set from the map for correction of the learning correction amount set in advance according to the deviation and the learning correction amount at the previous calculation.
In the creep force control apparatus for an automatic transmission for a vehicle according to the third aspect of the present invention, the learning of the initial value is prohibited when the fluctuation range of the engine speed exceeds a predetermined value. Yes.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a creep force control apparatus for an automatic transmission for a vehicle according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing an overall configuration thereof.
As shown in FIG. 1, the automatic transmission 1 is mounted on a vehicle (not shown) in a state of being coupled to an engine 2. The output shaft 2a of the engine 2 is connected to a transmission mechanism 4 via a torque converter (fluid coupling) 3, and the transmission mechanism 4 is connected to driving wheels of a vehicle via a differential gear (not shown).
[0012]
The output shaft 2a of the engine 2 is connected to the pump impeller 3a of the torque converter 3. When the pump impeller 3a rotates with the rotation of the output shaft 2a, the turbine is connected via an ATF (automatic transmission fluid). The runner 3 b is driven to rotate, and the rotation is transmitted to the speed change mechanism 4.
[0013]
Although not described in detail, the speed change mechanism 4 includes a plurality of sets of planetary gear mechanisms and clutches and brakes that allow or restrict the operation of the components (sun gear, pinion gear, and ring gear). The engagement state of the clutch and the brake is appropriately switched by an ATF supplied from a hydraulic source (oil pump) to achieve a desired gear stage. Since the structure of the transmission mechanism 4 is generally known, the illustration of the configuration other than the forward clutch 7 is omitted.
[0014]
In such an automatic transmission 1, when the shift range is switched from the N range (non-traveling range) to the D range (traveling range), the speed change mechanism 4 is switched to the first speed stage in preparation for starting. At this time, the first speed is realized by further engaging the forward clutch 7 (friction element) with respect to the engagement state of various friction engagement elements in the N range.
[0015]
On the other hand, an A / T-ECU (automatic transmission control unit, hereinafter simply referred to as ECU) 11 is a storage device (ROM, RAM, BURAM, etc.) for storing an input / output device (not shown), a control program, a control map, and the like. ), A central processing unit (CPU), a timer counter, and the like, and various control signals are set based on information from various sensors, which will be described later, so that comprehensive control of the automatic transmission 1 is performed. It has become.
[0016]
On the input side of the ECU 11, an engine rotational speed sensor 12 for detecting the rotational speed Ne of the engine 2, a turbine rotational speed sensor 13 for detecting the rotational speed Nt of the turbine runner 3b (that is, the input rotational speed of the forward clutch 7), a vehicle A vehicle speed sensor 14 that detects the travel speed (vehicle speed) Vs of the vehicle, a brake pressure switch 20 that switches on and off based on the pressure of the brake oil, a throttle sensor 16 that detects a throttle opening θTH (= accelerator operation amount) of the engine 2, An oil temperature sensor 17 for detecting the oil temperature TOIL of the ATF, a shift position sensor 18 for detecting a shift position (for example, N range, D range, P range, R range, etc.) selected by the driver. It is connected. Instead of the brake pressure switch 20, a brake switch that is turned on when the brake pedal is depressed may be provided. When a drive-by-wire system that can electrically control the throttle opening is applied, an accelerator position sensor that detects the opening (depression amount) of the accelerator pedal may be added.
[0017]
Then, the ECU 11 sets a target shift stage from a shift map (not shown) using the throttle opening θTH detected by the throttle sensor 16 and the vehicle speed Vs detected by the vehicle speed sensor 14, and shifts to achieve this target shift stage. Shift control is executed by switching the engagement state of the engagement elements (clutch, brake, etc.) of the mechanism 4.
[0018]
Further, a large number of solenoid valves are connected to the output side of the ECU 11 for switching the hydraulic oil from the above oil pump to operate the clutch and brake engaging elements of the transmission mechanism 4. In FIG. 1, among such a large number of solenoid valves, only a solenoid valve (hereinafter simply referred to as a solenoid) 19 that switches the engagement state of the forward clutch 7 and only a pressure adjustment valve 21 that is adjusted by the solenoid 19 are shown. The other solenoid valves and pressure regulating valves are not shown.
[0019]
The operation of the solenoid 19 is duty-controlled by the ECU 11, and the supply state of the pilot pressure (control pressure) to the pressure adjusting valve 21 is adjusted according to the operation of the solenoid 19. . Specifically, when the pilot pressure is supplied to the pressure regulating valve 21 by the solenoid 19, the spool 21a of the pressure regulating valve 21 moves to the left side in the figure and the forward clutch 7 and the drain oil passage are in a direct communication state, and the forward pressure The hydraulic pressure is discharged from the clutch 7 and the engaging force of the forward clutch 7 is reduced. On the contrary, when the pilot pressure is discharged by the solenoid 19, the forward clutch 7 and the line pressure oil passage are in a direct communication state, and hydraulic pressure is supplied to the forward clutch 7 to increase the engagement force. Thus, by controlling the duty factor of the solenoid 19, the engagement force of the forward clutch 7 can be adjusted. In the present embodiment, the engagement force of the forward clutch 7 is set to increase as the duty ratio of the solenoid 19 increases.
[0020]
Next, the main part of the present invention will be described. FIG. 2 is a functional block diagram focusing on the function of the main part of the present invention. As shown in the figure, the ECU 11 includes an initial value output means 50, a learning means. 51 and feedback control means 52 are provided. Here, the feedback control means 52 is a means for feedback-controlling the engagement force of the forward clutch 7 so as to set the slip amount ΔN (= Ne−Nt) in the torque converter 3 to a target value when the neutral control is executed. Note that a slip amount change rate may be used as the target value.
[0021]
The initial value output means 50 outputs the duty ratio DS (initial value) of the solenoid 19 during the feedback control. The learning means 51 performs the oil temperature TOIL and the engine speed Ne during the feedback control. The initial value DS is learned and corrected every time. The detailed functions of these means 50 to 52 will be described later.
[0022]
Here, the neutral control (creep force control) will be briefly described. In this neutral control, when the vehicle running in the D range stops, the engagement force of the forward clutch 7 is reduced to control the state close to the neutral state. The neutral control (creep force control) is executed by slipping the forward clutch 7 as the friction engagement element.
[0023]
In this embodiment, the following conditions (1) to (3) are set as neutral control start conditions.
(1) The brake pressure switch 20 is turned on (the brake pressure is a predetermined value or more).
(2) The throttle sensor 16 detects that the accelerator is not operated (the throttle opening is equal to or less than a predetermined amount).
(3) The vehicle speed Vs detected by the vehicle speed sensor 14 is less than a predetermined value.
[0024]
When it is determined that all of the above conditions are satisfied (that is, when it is estimated that the vehicle has shifted from the running state to the almost stopped state), the neutral control is started. The case where all of the above conditions are satisfied is simply referred to as the start condition is satisfied below.
On the other hand, the neutral control cancellation condition is set as follows, and if any of them is satisfied, that is, if the driver's intention to start is estimated, it is determined that the cancellation condition is satisfied, and the ECU 11 performs neutral control. Is to be canceled.
(1) When the brake pressure switch 20 is turned off (the brake pressure is less than a predetermined value).
(2) When accelerator operation (throttle opening θth is equal to or greater than a predetermined value) is detected by the throttle sensor 16.
(3) When the traveling speed Vs detected by the vehicle speed sensor 14 exceeds a predetermined value.
[0025]
If at least one of the above three conditions is satisfied, the neutral control is released. The case where any one of the release conditions (1) to (3) is satisfied is simply referred to as the release condition is satisfied.
Next, a basic operation during neutral control will be described with reference to FIGS.
[0026]
[Inrush control for neutral control]
At the start (inrush) of neutral control, first, an operation to reduce the engagement pressure of the forward clutch 7 and release it to a predetermined slip amount (hereinafter, mainly referred to as a preliminary operation) is performed, and slip determination (preliminary operation completion determination) is performed. Is carried out as follows.
When the neutral control start condition is satisfied, the duty ratio D of the solenoid 19 for the forward clutch 7 is calculated according to the following equation (1).
[0027]
D = DN−DNS (1)
Here, DN is a duty factor set so that the engaged forward clutch 7 starts to slide after a predetermined time, and DNS is a duty factor (gradient term) for decreasing D with a constant time gradient. DN is calculated according to the following equation.
DN = DN0 + DNL (2)
Here, DN0 is the DN base value, DNL is the DN learning correction value, and these values DN0 and DNL are mapped according to the engine speed Ne and the ATF oil temperature T0IL. It is read from the address corresponding to the engine speed Ne at the time and the ATF oil temperature T0IL and used.
[0028]
Further, the learning process of the learning correction amount DNL is performed to optimize the DN so as to reduce the torque fluctuation when the forward clutch 7 in the engaged state shifts to the neutral control. In brief, the target time Ttg is set as an ideal value that can be realized in advance for the required time T for preliminary operation (the time required from the establishment of the neutral control start condition to the slip determination) (for example, 1 sec), and the target time Ttg is set. On the other hand, when the actual required time T is long (T> Ttg), the learning correction amount DNL is decreased. Conversely, when the required time T is short (T <Ttg), the learning correction amount DNL is increased.
[0029]
The obtained learning correction amount DNL is stored for each address corresponding to the engine rotational speed Ne and the ATF oil temperature TOIL as described above, and is used for the subsequent calculation of the immediately preceding slip value DN. . Note that the learning correction amount DNL may be included in DN, and the entire DN may be stored at the address.
By repeating this process, the DN calculated from the equation (2) is converged and maintained at the optimum duty ratio, so that the response at the start of control and the uncomfortable feeling of torque fluctuation are prevented.
[0030]
From this equation (2), as shown in FIG. 3 (b), immediately after the neutral control start condition is satisfied, the duty ratio D of the solenoid 9 decreases from 100% to DN in a stepwise manner [FIG. 3 (b). Point a], and then gradually decreases according to the gradient term DNS. As a result, the pilot pressure supply amount acting on the spool 21a of the pressure control valve 21 is increased, the hydraulic pressure in the forward clutch 7 is drastically drained, and the engagement pressure is lowered as shown in FIG. To do.
[0031]
Accordingly, as shown in FIG. 3A, the turbine runner 3b that has been stopped and held by the engagement of the forward clutch 7 is gradually released, and the turbine rotational speed Nt starts to increase. When the turbine rotation speed Nt reaches the slip determination value Nt0 (for example, 50 rpm), the ECU 11 determines that the forward clutch 7 has been operated to the vicinity of the predetermined slip amount (slip determination). Thereafter, until the release condition is satisfied, steady control by feedback control using the slip amount ΔN (= Ne−Nt) of the torque converter 3 as a preset target value (referred to as N control in FIG. 3). Is executed.
[0032]
(Steady control)
In the steady control, as an initial value for starting the feedback control, a value (initial value) DS 1 obtained by adding a predetermined value ΔDSB (for example, 2% of the duty factor D) to the last duty factor D gradually decreased by the preliminary operation is an initial value Output from the output means 50 [point b in FIG. 3B].
[0033]
From this point onward, the initial value DS is successively learned and output by the learning means 51 for each calculation control period when the engine is in a “stable operating state” to be described later even during steady control. ing. Therefore, it can be said that the initial value DS is a reference value for the duty ratio during steady-state control. The initial value (reference value) is expressed by the following equation (3).
[0034]
DS = DS0 + DSL (3)
DS0 is a preset base value, and DSL is a learning correction amount.
Hereinafter, a specific learning method of the initial value DS will be described. First, when it is determined that the vehicle is in a “stable operating state” continuously for a predetermined time tG (sec) during steady control, the predetermined time Difference ΔDS (= DSAVE−DSEND) between the average value DSAVE of DS output at tG (sec) and the initial value output at the end of tG (sec) and calculated from the engine speed and oil temperature Ask for.
[0035]
The “stable operation state” refers to a case where the following conditions are satisfied, for example.
-Engine speed fluctuation is within a predetermined value (+/- 50rpm).
The difference between the actual torque converter slip rotation speed and the target torque converter slip rotation speed is within a predetermined value (+/− 50 rpm).
[0036]
-Engine rotation speed is within a predetermined range (500-1300 rpm).
-The oil temperature is within a predetermined range (-15 to 120 ° C).
Then, ΔDSL is read from a map of learning correction amount correction ΔDSL set in advance according to the positive / negative magnitude of ΔDS, and based on this, a new learning correction amount DSLNEW is calculated by the following equation.
[0037]
DSLNEW = DSLOLD + ΔDSL (DSLOLD: learning correction amount at the previous calculation)
Then, a new initial value DSNNEW is calculated according to the following equation in accordance with the DSLNEW.
DSNEW = DSOLD + DSLNEW (DSOLD: initial value at the previous calculation)
The updated initial value DS is sequentially stored and stored for each address corresponding to the engine speed and the oil temperature as a map value.
[0038]
By using the initial value DS and the feedback correction value DFB that have been learned and updated as described above, the duty ratio DC for finally driving the solenoid 19 is output from the feedback control means 52. The duty factor DC is expressed by the following equation (4).
DC = DS + DFB (4)
Thereafter, this feedback control is repeated until the neutral control release condition is satisfied, the steady control is continued, and the slip amount ΔN is maintained in the vicinity of the target value.
[0039]
Note that in the feedback control immediately after shipment from the factory, since the learning value DSL = 0, DS = DS0 is used.
In the feedback control, the next duty ratio is determined based on how the control target (the slip amount of the torque converter in the present embodiment) changes as a result of outputting a certain duty ratio. That is, immediately before the feedback start, the feedback control itself is not performed, and there is no change in the control target by the feedback control. Therefore, the feedback correction value DFB cannot be set immediately after the feedback control starts (there is no control result based on the previous feedback). . For this reason, one cycle (or several cycles) immediately after the start determination is output as DC = DS.
[0040]
If DC1 is a duty ratio that is output only in the first period, it can be expressed as DC1 = DS, and the output duty ratio in the second and subsequent periods can be expressed as follows.
DC2 = DC1 + DFB1 = DS + DFB1
DC3 = DC2 + DFB2 = DS + DFB1 + DFB2
…
DCn = DCn−1 + DFBn−1 = DS + ΣDFBi (5)
Further, during the above-described stable operation state, the DS map itself is sequentially learned and updated, and the difference is subtracted from the equation (5) for each control period to determine the final output duty ratio.
[0041]
That is, using the learned and updated DS map, the DS corresponding to the engine speed and oil temperature in the current control cycle (DSn), and the DS corresponding to the engine speed and oil temperature in the previous control cycle. (DSa) is read. Since the difference described above is expressed as (DSn−DSa), the expression (5) can be expressed by the following expression (6).
[0042]
DCn = DCn−1 + DFBn−1 = DS + ΣDFbi− (DSn−DSa) (6)
Here, even if the engine rotational speed varies, if the variation range is small, the learning of DS is continued, but the correction amount by the (DSn-DSa) term is very small (including zero).
[0043]
On the other hand, since the learned value becomes unstable when the fluctuation range of the engine rotation speed becomes large, when the fluctuation range of the engine rotation speed exceeds a predetermined value (large fluctuation detection), learning of the initial value DS thereafter is prohibited. It has become. When learning is prohibited, DSn and DSa are read using the DS map (learned) immediately before the learning is prohibited. At this time, since the fluctuation range of the engine rotation speed is large, the correction amount by the (DSn−DSa) term is large.
[0044]
From the above, since the initial value DS is corrected by the engine rotation fluctuation amount based on the latest learned and updated DS map and the feedback correction value is continued as before, the fluctuation amount is reduced by the feedback correction value DFB as before. There is no need to compensate. For this reason, it is possible to follow the rotation fluctuation without diverging the feedback control.
[0045]
Further, when the rotational fluctuation becomes large, learning of DS is prohibited, so that the initial value DS can be stabilized.
Furthermore, since the initial value DS is a value that can make the operating state close to the target value from the beginning, and is a value that is sequentially updated to the optimal value by learning and stored in the map, only the feedback control can be performed by adding the DS fluctuation. Compared with the case, the effect that the control can be stabilized can be obtained.
[Neutral control release control]
When the above-described predetermined release condition is satisfied [point c in FIG. 3B], the forward clutch 7 is controlled toward the engagement side by gradually increasing the duty factor D of the solenoid 19, and the turbine rotational speed is increased. Nt is decreased. Then, synchronization determination is performed based on information from the engine rotation speed sensor 12 and the turbine rotation speed sensor 13, and it is determined that the rotation speed Nt of the turbine runner 3b substantially matches (synchronizes) with the engine rotation speed Ne. [Point d in FIG. 3 (b)] and the duty factor of the solenoid 19 is set to 100% after a predetermined time (te) has elapsed [point e in FIG. 3 (b)].
[0046]
Since the creep force control apparatus for an automatic transmission for a vehicle according to an embodiment of the present invention is configured as described above, the control characteristics when the present invention is applied are shown in FIGS. 4 (a) to 4 (c). It becomes like this. 4 (d) to 4 (f) are diagrams showing control characteristics when the present invention is not applied. Hereinafter, FIGS. 4 (a) to 4 (c) and FIGS. 4 (d) to (f). And will be described.
[0047]
First, the control characteristics when the present invention is not applied will be described. As shown in FIG. 4D, even when the engine speed Ne fluctuates, the duty ratio DS, which is the basis of feedback control, is constant. It is held [see FIG. 4 (e)]. Therefore, as shown in FIG. 4 (f), the line pressure and the forward clutch pressure (the engagement pressure of the forward clutch 7) fluctuate, and accordingly, as shown in FIG. The speed Nt will also fluctuate greatly. In such a state, the control diverges without being corrected only by the feedback control.
[0048]
On the other hand, when the present invention is applied, the duty factor DS (initial value) is changed by the learning means 51 of the initial value output means 50 when the engine speed Ne fluctuates as shown in FIG. [FIG. 4B]. As a result, as shown in FIG. 4C, even if the line pressure fluctuates, the forward clutch pressure and the turbine rotational speed Nt can be kept substantially constant, and stable control can be executed. .
[0049]
As described above, according to the creep force control device for an automatic transmission for a vehicle of the present invention, even when the line pressure fluctuates due to engine rotation fluctuation or oil temperature rise during neutral control (during steady control), feedback is performed. Control divergence can be prevented and stable control can be executed.
The creep force control device for an automatic transmission for a vehicle according to the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, in the above description, the initial value (duty factor DS) is learned and stored for each engine speed Ne and ATF oil temperature TOIL, but without using a map, the engine speed Ne and ATF oil temperature TOIL are stored. As a parameter, a correction value may be obtained by calculation, or learning may be performed by other methods.
[0050]
In the above-described embodiment, the initial value is learned and stored using both the engine speed Ne and the ATF oil temperature TOIL. Of the engine speed Ne and the ATF oil temperature TOIL, , Parameter values related to at least one of them may be used. The parameter value related to the engine rotational speed Ne may be, for example, the rotational speed of the pump impeller 3a, and the parameter value related to the ATF oil temperature TOIL may be, for example, the ATF viscosity or the engine water temperature.
[0051]
Further, the present invention can be widely applied to an automatic transmission that transmits engine driving force via a fluid clutch (torque converter), and also widely applied to an automatic transmission such as a belt-type continuously variable transmission. Can do. In the case of a belt-type continuously variable transmission, it can be used as a friction element for switching forward and backward.
[0052]
【The invention's effect】
As described above in detail, according to the creep force control device for an automatic transmission for a vehicle of the present invention, the initial value that is the basis for determining the engagement force of the friction element is maintained even if a sudden engine rotation fluctuation occurs. Since learning is performed, the divergence of feedback control can be prevented, and there is an advantage that stable creep force control can be executed.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing an overall configuration of a creep force control apparatus for an automatic transmission for a vehicle according to an embodiment of the present invention.
FIG. 2 is a functional block diagram focusing on the main functions of a creep force control device for a vehicle automatic transmission according to an embodiment of the present invention.
FIGS. 3A to 3C are time charts for explaining the operation of a creep force control device for an automatic transmission for a vehicle according to an embodiment of the present invention.
FIG. 4 is a diagram for explaining the characteristics of a creep force control device for an automatic transmission for a vehicle according to an embodiment of the present invention, as compared with a case where the present invention is not applied; ) Is a diagram showing characteristics when the present invention is applied, and (d) to (f) are diagrams showing characteristics when the present invention is not applied.
[Explanation of symbols]
1 Automatic transmission
2 Engine
7 Forward clutch (friction element)
11 ECU
50 Initial value output means
51 Means of learning
52 Feedback control means

Claims (3)

An automatic transmission for a vehicle configured to reduce the engagement force of a friction element that is engaged during traveling to reduce the creep force when a predetermined condition is satisfied when the shift range of the automatic transmission is the traveling range. In the creep force control device of
An initial value output means for outputting a predetermined initial value as an engagement force of the friction engagement element after the predetermined condition is satisfied;
Feedback control means for starting feedback control on the engagement force of the friction engagement element based on the predetermined initial value;
Learning means for learning and correcting the predetermined initial value during execution of the feedback control based on at least a parameter value related to one of oil temperature and engine speed ;
The learning means calculates a learning correction amount based on a deviation between an average value of the output values at a predetermined time and an output value at the end of the predetermined time, which is obtained from the engine speed and the oil temperature. A creep force control device for an automatic transmission for a vehicle, characterized in that it is obtained. The initial value is set by the sum of a preset base value and the learning correction amount,
The learning correction amount is calculated by the sum of the correction amount set from the correction amount correction amount map set in advance according to the deviation and the learning correction amount at the previous calculation.
The creep force control apparatus for an automatic transmission for a vehicle according to claim 1. It is set so that learning of the initial value is prohibited when the fluctuation range of the engine rotation speed exceeds a predetermined value.
The creep force control apparatus for an automatic transmission for a vehicle according to claim 1 or 2, characterized by the above.

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