JP2011094665A - Control device of automatic transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress shift shock caused by speed difference between an engine speed and a turbine speed when a down-shift is performed in a vehicle during deceleration while performing power-on running on a climbing road. <P>SOLUTION: When an ECU 100 determines that the down-shift is requested in a power-on state (step ST1: YES), and further determines that the acceleration of the vehicle is less than reference acceleration (step ST2: YES), it corrects timing of starting release operation of a release-side frictional engagement element to a delay side according to the acceleration of the vehicle and difference rotation frequency between the engine rotation frequency and the turbine rotation frequency, and also corrects a reduction ratio of sweep-down indicating hydraulic pressure of the release-side frictional engagement element to become smaller (steps ST3, ST4). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a control device for an automatic transmission mounted on a vehicle. More particularly, the present invention relates to a control device for an automatic transmission that suppresses a shift shock that occurs when a power-on downshift is performed while decelerating while traveling on an uphill road.

  Patent Documents 1 to 4 disclose techniques for correcting the hydraulic pressure supplied to the frictional engagement elements during power-on downshifts in order to suppress shift shocks.

JP-A-11-108168 JP 2008-51299 A JP 2007-263206 A JP 2005-337410 A

  When the vehicle decelerates while driving on an uphill road, the engine speed is higher than the turbine speed and the differential rotation is more likely to occur than when the vehicle is power-on on a flat road. When the downshift is performed in a state where the differential rotational speed between the engine rotational speed and the turbine rotational speed is large, when the engagement of the friction engagement element on the release side is released, the turbine rotational speed is increased according to the differential rotational speed. Numbers are likely to rise rapidly. For this reason, the shift time is shortened and a shift shock may occur.

  Since the automatic transmission control device disclosed in Patent Documents 1 to 4 does not correct the hydraulic pressure supplied to the friction engagement element in consideration of the shift shock generated due to the differential rotation. In the automatic transmission control devices disclosed in Patent Documents 1 to 4, it is difficult to suppress the shift shock generated due to the differential rotation.

  The present invention was devised in view of the above problems, and provides an automatic transmission control device that suppresses a shift shock that occurs when a vehicle decelerates while driving on an uphill road while performing a power-on downshift. For the purpose.

  As means for solving the above-described problems, the control device for an automatic transmission according to the present invention is configured as follows.

  That is, the control device for an automatic transmission according to the present invention is premised on the control of the hydraulic pressure supplied to the friction engagement element of the automatic transmission mounted on the vehicle, and whether or not there is a request for a power-on downshift. A power-on downshift determining means for determining the vehicle, an acceleration detecting means for detecting longitudinal acceleration of the vehicle, a differential speed detecting means for detecting a differential speed between the engine speed and the turbine speed, and the power-on-down When the shift determination means determines that there is a request for a power-on downshift, if the longitudinal acceleration of the vehicle detected by the acceleration detection means is less than a reference acceleration, the longitudinal acceleration of the vehicle and the differential rotational speed detection means detect Delay control means for correcting the start timing of the release operation of the release side frictional engagement element to the delay side in accordance with the differential rotational speed to be provided.

  According to the control apparatus for an automatic transmission having such a configuration, when the vehicle is decelerating while traveling on an uphill road and the power-on downshift is performed, if the longitudinal acceleration of the vehicle is less than the reference acceleration, The start timing of the release operation is delayed. As a result, the time required for the turbine rotation speed to increase easily (when the friction engagement elements are switched, the torque capacity of any of the friction engagement elements on the release side and the engagement side is reduced) is short. As a result, the rapid increase in the turbine rotational speed caused by the differential rotation between the engine rotational speed and the turbine rotational speed is suppressed. As a result, the shift shock is suppressed.

  Further, the control device for an automatic transmission according to the present invention is based on the premise that the hydraulic pressure supplied to the friction engagement element of the automatic transmission mounted on the vehicle is premised, and whether or not there is a request for a power-on downshift. A power-on downshift determining means for determining the vehicle, an acceleration detecting means for detecting longitudinal acceleration of the vehicle, a differential speed detecting means for detecting a differential speed between the engine speed and the turbine speed, and the power-on-down When the shift determination means determines that there is a request for a power-on downshift, if the longitudinal acceleration of the vehicle detected by the acceleration detection means is less than a reference acceleration, the longitudinal acceleration of the vehicle and the differential rotational speed detection means detect Sweep control means for correcting the reduction rate of the sweep-down command hydraulic pressure of the disengagement side frictional engagement element to be small in accordance with the differential rotational speed.

  According to the control device for an automatic transmission having such a configuration, when the vehicle decelerates while traveling on an uphill road and the power-on downshift is performed, if the vehicle acceleration is less than the reference acceleration, the sweep of the disengagement side frictional engagement element is performed. The reduction rate of the down instruction hydraulic pressure is corrected so as to decrease, and the release operation of the disengagement side frictional engagement element is delayed, so that the rapid increase of the turbine speed due to the differential rotation between the engine speed and the turbine speed is suppressed. The Thereby, the shift shock is suppressed.

  According to the automatic transmission control device of the present invention, when the vehicle decelerates while traveling on an uphill road and performs a power-on downshift, a shift shock generated due to a differential rotation between the engine speed and the turbine speed. Is suppressed.

It is a schematic block diagram which shows an example of the vehicle carrying the control apparatus of the automatic transmission of this invention. It is an operation | movement table | surface of the automatic transmission shown in FIG. It is a block diagram which shows the structure of control systems, such as ECU. It is a perspective view which shows the structure of the shift lever part of a shift apparatus. It is a figure which shows the shift map used for shift control. It is a flowchart which shows the procedure of the hydraulic control at the time of a power-on downshift. It is a timing chart which shows the specific example by the hydraulic control at the time of a power-off downshift.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic configuration diagram illustrating an example of a vehicle equipped with a control device for an automatic transmission according to an embodiment of the present invention. The vehicle includes an engine 1, a torque converter 2, an automatic transmission 3, a hydraulic control circuit 300 (see FIG. 3), an ECU 100, and the like.

-Engine-
A crankshaft 11 that is an output shaft of the engine 1 is connected to an input shaft of the torque converter 2. The rotational speed of the crankshaft 11 (engine rotational speed) is detected by an engine rotational speed sensor 201.

  The amount of air taken into the engine 1 is adjusted by an electronically controlled throttle valve 12. The opening of the throttle valve 12 (throttle opening) is detected by a throttle opening sensor 202.

  The throttle opening of the throttle valve 12 is driven and controlled by the ECU 100. Specifically, the optimum intake air amount (target intake air amount) according to the operating state of the engine 1 such as the engine speed detected by the engine speed sensor 201 and the accelerator pedal depression amount (accelerator opening) of the driver. Is controlled so that the throttle opening of the throttle valve 12 is obtained.

-Torque converter-
The torque converter 2 includes a pump impeller 21 on the input shaft side, a turbine runner 22 on the output shaft side, a stator 23 that exhibits a torque amplification function, and a one-way clutch 24, and is provided between the pump impeller 21 and the turbine runner 22. The power is transmitted through the fluid.

  The torque converter 2 is provided with a lockup clutch 25 that directly connects the input side and the output side. By engaging the lockup clutch 25, the pump impeller 21 and the turbine runner 22 rotate integrally. To do. The turbine speed Nt of the torque converter 2 is detected by the turbine speed sensor 203. Engagement / release of the lockup clutch 25 of the torque converter 2 is controlled by the hydraulic control circuit 300 and the ECU 100.

-Automatic transmission-
For example, as shown in FIG. 1, the automatic transmission 3 includes a double pinion type first planetary gear unit 31, a single pinion type second planetary gear unit 32, and a single pinion type third planetary gear unit 33. It is a gear type transmission.

  The sun gear S1 of the first planetary gear unit 31 is selectively coupled to the input shaft 30 via the clutch C3. The sun gear S1 is selectively coupled to the housing via the one-way clutch F2 and the brake B3, and is prevented from rotating in the reverse direction (the direction opposite to the rotation of the input shaft 30). The carrier CA1 of the first planetary gear unit 31 is selectively connected to the housing via the brake B1, and is always prevented from rotating in the reverse direction by the one-way clutch F1 provided in parallel with the brake B1. The ring gear R1 of the first planetary gear device 31 is integrally connected to the ring gear R2 of the second planetary gear device 32, and is selectively connected to the housing via the brake B2.

  The sun gear S2 of the second planetary gear device 32 is integrally connected to the sun gear S3 of the third planetary gear device 33, and is selectively connected to the input shaft 30 via the clutch C4. The sun gear S2 is selectively connected to the input shaft 30 via the one-way clutch F0 and the clutch C1, and is prevented from rotating in the opposite direction relative to the input shaft 30.

  The carrier CA2 of the second planetary gear device 32 is integrally connected to the ring gear R3 of the third planetary gear device 33, is selectively connected to the input shaft 30 via the clutch C2, and via the brake B4. And selectively coupled to the housing. The carrier CA2 is always prevented from rotating in the reverse direction by the one-way clutch F3 provided in parallel with the brake B4. The carrier CA3 of the third planetary gear device 33 is integrally connected to the output shaft 34. The rotational speed of the output shaft 34 is detected by the output shaft rotational speed sensor 204.

  In the automatic transmission 3 described above, the clutches C1 to C4, the brakes B1 to B4, the one-way clutches F0 to F3, and the like, which are friction engagement elements, are engaged or disengaged in a predetermined state, so that the gear stage (shift stage) Is set. Engagement / release of the clutches C1 to C4 and the brakes B1 to B4 is controlled by a hydraulic control circuit 300 (see FIG. 3).

  The hydraulic control circuit 300 is provided with a linear solenoid valve, an on / off solenoid valve, and the like. The clutches C1 to C4 and the brake of the automatic transmission 3 are switched by switching the hydraulic circuit by controlling excitation / de-excitation of these solenoid valves. The engagement / release of B1 to B4 can be controlled. Excitation / non-excitation of the linear solenoid valve and the on / off solenoid valve of the hydraulic control circuit 300 is controlled by a solenoid control signal (instructed hydraulic signal) from the ECU 100.

  The operation table of FIG. 2 shows the engaged / released states of the clutches C1 to C4, the brakes B1 to B4, and the one-way clutches F0 to F3 of the automatic transmission 3 described above. In the operation table of FIG. 2, “◯” represents “engaged”, and “blank” represents “released”. Further, “を” represents “engagement during engine braking”, and “Δ” represents “engagement not related to power transmission”.

  As shown in FIG. 2, for example, at the first speed (1st) used when the vehicle starts, the clutch C1 and the one-way clutches F0 and F3 are engaged. For example, when downshifting from 6th speed (6th) to 5th speed (5th), the brake B2 is released and the clutch C2 is engaged at the same time.

  On the other hand, a shift device 4 shown in FIG. 4 is arranged in the vicinity of the driver's seat of the vehicle. The shift device 4 is provided with a shift lever 41 that can be displaced. The shift device 4 has a reverse (R) position, a neutral (N) position, a drive (D) position, and a sequential (S) position, and the driver displaces the shift lever 41 to a desired shift position. It is possible. The shift positions of the reverse (R) position, neutral (N) position, drive (D) position, and sequential (S) position (including the following “+” position and “−” position) are represented by the shift position sensor 206 ( (See FIG. 3).

  Hereinafter, the situation in which these shift positions are selected and the operation mode of the automatic transmission 3 at that time will be described for each shift position (“N position”, “R position”, “D position”, “S position”). .

  The “N position” is a position selected when the connection between the input shaft 30 and the output shaft 34 of the automatic transmission 3 is disconnected. When the shift lever 41 is operated to the “N position”, the automatic transmission 3 clutches C1 to C4, brakes B1 to B4, and one-way clutches F0 to F3 are all released (see FIG. 2).

  The “R position” is a position selected when the vehicle is moved backward, and when the shift lever 41 is operated to the R position, the automatic transmission 3 is switched to the reverse gear.

  The “D position” is a position selected when the vehicle moves forward. When the shift lever 41 is operated to the D position, a plurality of forward gears of the automatic transmission 3 are selected according to the driving state of the vehicle. The speed of the stage (sixth forward speed) is automatically controlled.

  The “S position” is a position (manual shift position) that is selected when the driver manually performs a shift operation of a plurality of forward gears (sixth forward speed). And a “+” position is provided. The “+” position is a position where the shift lever 41 is operated during a manual upshift, and the “−” position is a position where the shift lever 41 is operated during a manual downshift. When the shift lever 41 is in the S position and the shift lever 41 is operated to the “+” position or the “−” position with the S position as a neutral position, the forward gear of the automatic transmission 3 is increased or decreased. Is done. Specifically, the gear stage is increased by one stage for each operation to the “+” position (for example, 1st → 2nd →... → 6th). On the other hand, the gear stage is lowered by one stage for each operation to the “−” position (for example, 6th → 5th →... → 1st).

-ECU-
As shown in FIG. 3, the ECU 100 includes a CPU 101, a ROM 102, a RAM 103, a backup RAM 104, and the like.

  The ROM 102 stores various programs including a program for executing a shift control for setting the gear stage of the automatic transmission 3 in accordance with the vehicle running state, in addition to the control related to the basic driving of the vehicle. . Specific contents of this shift control will be described later.

  The CPU 101 executes arithmetic processing based on various control programs and maps stored in the ROM 102. The RAM 103 is a memory that temporarily stores calculation results of the CPU 101, data input from each sensor, and the like. The backup RAM 104 is a non-volatile memory that stores data to be saved when the engine 1 is stopped. is there.

  The CPU 101, ROM 102, RAM 103 and backup RAM 104 are connected to each other via a bus 106 and to an interface 105.

  An interface 105 of the ECU 100 includes an engine speed sensor 201, a throttle opening sensor 202, a turbine speed sensor 203, an output shaft speed sensor 204, an accelerator opening sensor 205 that detects an accelerator pedal opening, and a shift position sensor 206. A brake pedal sensor 207, an in-vehicle acceleration sensor 208 for detecting longitudinal acceleration of the vehicle, and the like are connected, and signals from these sensors are input to the ECU 100.

  The ECU 100 executes various controls of the engine 1 including the opening control of the throttle valve 12 of the engine 1 based on the output signals of the various sensors described above.

  The ECU 100 outputs a lockup clutch control signal to the torque converter 2. Based on the lockup clutch control signal, the engagement pressure of the lockup clutch 25 is controlled. The ECU 100 also outputs a solenoid control signal (hydraulic command signal) to the hydraulic control circuit 300 of the automatic transmission 3. Based on this solenoid control signal, the linear solenoid valve, the on-off solenoid valve, etc. of the hydraulic control circuit 300 are controlled, and the clutches C1 to C4 and the brake B1 are configured so as to constitute a predetermined transmission gear stage (first speed to sixth speed). -B4, one-way clutches F0-F3, etc. are engaged or released in a predetermined state.

  Further, the ECU 100 executes the following “shift control” and “power-on downshift control”.

-Shift control-
First, the shift map (shift diagram) will be described with reference to FIG. The shift map shown in FIG. 5 is a map in which a vehicle speed and a throttle opening are used as parameters, and a plurality of areas for obtaining an appropriate gear stage are set according to the vehicle speed and the accelerator opening. Is stored within. Each region of the shift map is partitioned by a plurality of shift lines (gear stage switching lines).

  In the shift map shown in FIG. 5, the upshift line (shift line) is indicated by a solid line, and the downshift line (shift line) is indicated by a broken line. Also, each switching direction of upshifting and downshifting is shown using numerals and arrows in the figure.

  Next, the basic operation of the shift control will be described.

  The ECU 100 calculates the vehicle speed from the output signal of the output shaft rotational speed sensor 204, calculates the throttle opening from the output signal of the throttle opening sensor 202, and based on the vehicle speed and the throttle opening, the shift map of FIG. The target gear stage is calculated with reference to the above, and the target gear stage is compared with the current gear stage to determine whether or not a speed change operation is necessary.

  As a result of the determination, when there is no need for shifting (when the target gear stage and the current gear stage are the same and the gear stage is set appropriately), a solenoid control signal (hydraulic command signal for maintaining the current gear stage) ) To the hydraulic control circuit 300 of the automatic transmission 3.

  On the other hand, when the target gear stage and the current gear stage are different, shift control is performed. For example, when the driving state of the vehicle changes from the state where the gear stage of the automatic transmission 3 is running at the “5-speed” state, for example, the point A changes to the point B shown in FIG. Since the change occurs across the shift line [5 → 4], the target gear stage calculated from the shift map is “fourth speed”, and the solenoid control signal (hydraulic command signal) for setting the fourth gear stage is automatically shifted. Output to the hydraulic control circuit 300 of the machine 3 to perform a shift (5 → 4 downshift) from the fifth gear to the fourth gear.

-Power-on downshift control-
Hereinafter, the power-on downshift control executed by the ECU 100 will be described based on the flowchart of FIG. 6.

  First, in step ST1, it is determined whether or not there is a power-on downshift request, that is, a downshift request (for example, a shift request from “second speed” to “first speed”) in the power-on state. If an affirmative determination is made here, the process proceeds to step ST2, and if a negative determination is made, this routine is temporarily terminated.

  The determination as to whether or not the vehicle is in the power-on state is made with reference to a known power-on / off determination map (not shown) using the vehicle speed and the throttle opening as parameters. This power on / off determination map is stored in the ROM 102 of the ECU 100. Further, the downshift request is caused to change over a shift down shift line, for example, [2 → 1], and the ECU 100 determines that the downshift is necessary by comparing the target gear stage with the current gear stage. And done.

  In step ST2, it is determined whether the longitudinal acceleration of the vehicle calculated based on the output signal of the in-vehicle acceleration sensor 208 is less than the reference acceleration. If the determination is affirmative, the process proceeds to step ST3. If the determination is negative, the process proceeds to step ST6.

  The reference acceleration is set in advance for each shift stage with the acceleration when the vehicle is traveling forward on a flat road with zero gradient as parameters of the accelerator opening and the engine speed, and is mapped to the ROM 102 of the ECU 100 (not shown). As shown). Such a reference acceleration can be obtained by experiments and calculations.

  In step ST3, a differential rotational speed between the engine rotational speed and the turbine rotational speed is calculated. Then, with reference to a correction map (not shown) stored in advance in the ROM 102 of the ECU 100 using the calculated differential rotational speed and acceleration in the traveling direction of the vehicle as parameters, the disengagement side frictional engagement of the automatic transmission 3 is performed. A correction value for the delay time of the start timing of the element release operation is calculated. Further, the command hydraulic pressure (torque capacity) of the disengagement side frictional engagement element of the automatic transmission 3 is reduced with reference to the correction map using the calculated differential rotational speed and acceleration in the traveling direction of the vehicle as parameters ( A correction value for the rate of decrease of the sweep-down command oil pressure (rate of decrease with respect to time) in the release sweep control to be gradually decreased) is calculated.

  In the correction map, the correction value is set so that the delay time of the start timing of the release operation of the release side frictional engagement element becomes longer as the differential rotation speed and the vehicle deceleration are larger. Further, the correction value is set so that the decrease rate of the sweep-down command oil pressure in the release sweep control becomes smaller (gradually) as the differential rotational speed and the vehicle deceleration are larger. It should be noted that the release side frictional engagement element is released so that the shift time, the inclination of the inertia phase of the turbine rotation speed, and the like are approximately the same as in the case of a power-on downshift while the vehicle is traveling on a flat road. The correction value of the delay time of the operation start timing and the correction value of the decrease rate of the sweep down instruction oil pressure are obtained by experiments and calculations.

  As described above, it is necessary to set a slight delay time for the control of the hydraulic pressure supplied to the engagement side frictional engagement element as the instruction hydraulic pressure to the release side frictional engagement element is corrected. There is a case. This delay time is also obtained by experiments and calculations so that the shift shock is reduced.

  In step ST4, the correction value calculated in step ST3 is applied. The start timing of the release operation of the release side frictional engagement element is delayed as compared with the case where the normal hydraulic pressure control described in step ST6 to be described later is executed, and the sweepdown instruction of the release side frictional engagement element is given. The hydraulic control of the disengagement side frictional engagement element is executed so that the rate of decrease of the hydraulic pressure becomes small.

  As a result, even when the differential rotational speed between the engine rotational speed and the turbine rotational speed increases when performing a power-on downshift while traveling on an uphill road, the turbine rotational speed rapidly increases (inertia phase) according to the differential rotational speed. (A steep slope) is suppressed, and a shift can be performed in an appropriate shift time, and a shift shock is also suppressed. That is, when the start timing of the release operation of the release side frictional engagement element is delayed, the turbine rotational speed is likely to increase (when the frictional engagement element is switched, either the release side or the engagement side The time during which the torque capacity of the friction engagement element is also reduced) is shortened, so that a rapid increase in the turbine speed is suppressed. In addition, a rapid increase in the turbine rotational speed is also suppressed by a decrease in the release operation of the release side frictional engagement element due to a decrease in the decrease rate of the sweep-down instruction hydraulic pressure of the release side frictional engagement element.

  When it is determined in step ST5 that the shift has been completed, this routine is once terminated. The determination of the end of the shift is made by, for example, multiplying the output shaft rotational speed detected by the output shaft rotational speed sensor 204 by the low speed side (after downshift) gear ratio and the turbine detected by the turbine rotational speed sensor 203. This is performed by determining whether or not the difference from the rotational speed is within a predetermined range.

In step ST6, hydraulic control of the disengagement side frictional engagement element at the time of normal power-on downshift is executed. That is, the delay process of the release timing of the release operation of the release side frictional engagement element and the correction of the decrease rate of the sweep down instruction oil pressure are not performed. Thereafter, the process proceeds to step ST5.
-Specific example of control during power-on downshift-
An example of specific hydraulic control by the above automatic transmission control device will be described based on the time chart of FIG. The time chart of FIG. 7 shows a case where a downshift is performed from “second speed” to “first speed” when the vehicle is decelerating while driving on an uphill road. In FIG. 7, the elapsed time is shown on the horizontal axis. In addition, the vertical axis represents the vehicle speed, the shift instruction state, the instruction hydraulic pressure to the release side clutch (brake), the turbine rotational speed, and the longitudinal acceleration of the vehicle. The broken line shown in FIG. 7 shows a case where hydraulic control of the disengagement side clutch (brake) during normal power-on downshift (hereinafter also referred to as “normal hydraulic control”) is executed.

  When downshifting from the second speed to the first speed, the brake B3 serves as a disengagement side frictional engagement element. This is because in the automatic transmission 3, "second speed" is formed when the clutch C1 and the brake B3 are engaged, and "first speed" is formed when the clutch C1 is engaged.

  At time T (0), when the vehicle is decelerating while driving on an uphill road, if there is a downshift instruction from “2nd speed” to “1st speed” (ST1: YES), the vehicle Is less than the reference acceleration (ST2: YES), the brake B3 (release side frictional engagement element) is released according to the difference between the engine speed and the turbine speed and the deceleration of the vehicle. The correction value of the delay time of the operation start timing and the correction value of the decrease rate of the sweep-down command oil pressure in the subsequent release sweep control of the brake B3 are calculated (ST3).

  Then, compared with the case where “normal hydraulic control” is executed (see the broken line in FIG. 7), the release operation of the brake B3 is delayed and started from time T (1), and thereafter time T ( The decrease rate of the sweep-down command oil pressure of the brake B3 from 1) to time T (4) is also smaller (slowly) than when “normal oil pressure control” is executed (see the broken line in FIG. 7). Become).

  As a result, the shift time from time T (0) to time T (3) is longer than the shift time (time T (0) to time T (2)) when “normal hydraulic control” is executed. Further, the inclination of the inertia phase of the turbine rotation speed also becomes gentle (appropriate inclination), and the shift shock (the fluctuation of the acceleration in the longitudinal direction of the vehicle) is suppressed.

  As described above, according to the power-on downshift control according to the present embodiment, when the power-on downshift is performed while decelerating while traveling on an uphill road, according to the differential rotational speed and the vehicle deceleration described above. Since the start timing of the release operation of the release side frictional engagement element is delayed, and the rate of decrease in the sweep down instruction oil pressure of the release side frictional engagement element is reduced, the shift shock caused by the differential rotation is suppressed. .

  The present invention is, for example, an automatic transmission mounted on an automobile, and can be applied to a control device for an automatic transmission that performs clutch-to-clutch shift.

3 Automatic transmission 100 ECU
201 Engine speed sensor 203 Turbine speed sensor 208 Acceleration sensor B3 Brake (release side frictional engagement element)
300 Hydraulic control circuit

Claims (2)

A control device for an automatic transmission that controls hydraulic pressure supplied to a friction engagement element of an automatic transmission mounted on a vehicle,
Power-on downshift determining means for determining whether there is a request for power-on downshift;
Acceleration detecting means for detecting longitudinal acceleration of the vehicle;
Differential speed detection means for detecting a differential speed between the engine speed and the turbine speed;
If the longitudinal acceleration of the vehicle detected by the acceleration detection means is less than a reference acceleration when the power-on downshift determination means determines that there is a request for a power-on downshift, the longitudinal acceleration of the vehicle and the differential rotational speed Delay control means for correcting the start timing of the release operation of the release side frictional engagement element to the delay side according to the differential rotation speed detected by the detection means;
A control device for an automatic transmission, comprising: A control device for an automatic transmission that controls hydraulic pressure supplied to a friction engagement element of an automatic transmission mounted on a vehicle,
Power-on downshift determining means for determining whether there is a request for power-on downshift;
Acceleration detecting means for detecting longitudinal acceleration of the vehicle;
Differential speed detection means for detecting a differential speed between the engine speed and the turbine speed;
If the longitudinal acceleration of the vehicle detected by the acceleration detection means is less than a reference acceleration when the power-on downshift determination means determines that there is a request for a power-on downshift, the longitudinal acceleration of the vehicle and the differential rotational speed Sweep control means for correcting the reduction rate of the sweep-down instruction hydraulic pressure of the disengagement side frictional engagement element to be small according to the differential rotational speed detected by the detection means;
A control device for an automatic transmission, comprising:

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