JP2006097791A - Control device for automatic transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device for an automatic transmission for stabilizing shifting quality by learning and controlling the irregularity of engagement to be absorbed during footing release and upshifting. <P>SOLUTION: After determining shift transmission with footing release and upshifting, initial hydraulic pressure is reduced in the next shift transmission when the rotating speed change rate of an input shaft is smaller than a preset value at synchronous determination, the initial hydraulic pressure is increased in the next shift transmission when the rotating speed change rate of the input shaft is a positive value, and the initial hydraulic pressure is corrected to be increased in the next shift transmission when the rotating speed of the input shaft does not fall in a preset range of a synchronous rotating speed or higher. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a control device for an automatic transmission used in an automobile or the like, and more particularly to a learning function in hydraulic control of a coupling-side friction element.

In an automatic transmission for an automobile (A / T), a transmission mechanism using a planetary gear is generally used. By engaging (or coupling) or releasing a hydraulic friction element such as a hydraulic wet multi-plate clutch, a sun gear, a planetary carrier, etc. Are connected or fixed to obtain a desired gear position.
A torque converter, which is a fluid coupling, is interposed between the engine (internal combustion engine) and the speed change mechanism. This torque converter is composed of an input-side pump and an output-side turbine. The engine torque is increased and transmitted to the speed change mechanism at the time of starting, etc. It is designed to absorb shocks.

  In recent automatic transmission transmission mechanisms, the ECU (electronic control unit) performs duty drive control of a solenoid valve for hydraulic control, thereby releasing and coupling a hydraulic friction engagement element (hereinafter simply referred to as a friction element). The number of electronically controlled devices that perform the above is increasing. In such an automatic transmission, generally, the shift control is performed based on a shift map using the throttle opening and the vehicle speed as parameters. That is, a shift command is output at the time when the driving state becomes the downshift timing or the upshift timing on the shift map, and the operating hydraulic pressure supplied to the coupling side friction element or the release side friction element according to this shift command is output. The discharged hydraulic pressure is controlled so that the gears are changed.

In this shift control, the initial value of the operating hydraulic pressure supplied to the coupling side friction element, that is, the starting supply hydraulic pressure is set according to the turbine torque (T _T ) obtained from the engine torque, and during the shift, the duty drive is performed. The duty ratio of the solenoid valve to be controlled is feedback controlled to an optimum value, and the hydraulic pressure is optimized so that the speed change can be achieved quickly.

  In this feedback control, a target turbine rotational speed change rate is obtained based on a predetermined shift time set in advance and an expected turbine rotational speed difference, and the actual turbine rotational speed change rate obtained by actual measurement is the target turbine rotational speed. The hydraulic pressure is increased or decreased so as to approach the rate of change. As a result, a good speed change is achieved without the coupling-side and release-side friction elements being coupled or released simultaneously.

  Of such shift control, upshift (on-upshift) by depressing the accelerator, downshift (kickdownshift) by depressing the accelerator, downshift before stopping, and shift by shifting operation of the driver (engage shift) are shifted. A learning function has been established in order to stabilize the quality, and optimal shift control is executed even if there is a difference between individual transmissions.

Further, for example, Patent Document 1 discloses a technique related to shift control at the time of upshift (lift foot (LF) upshift or footshift) by releasing the accelerator of the driver.
JP 2002-39346 A

  However, since the learning function is not provided in the shift control at the time of LF upshift conventionally, the variation of the vehicle and the transmission itself cannot be absorbed, and the engagement is performed before the coupling friction element is synchronized. In other words, there is a problem that a so-called sticking out feeling is caused, or conversely, even if synchronization is passed, a delay in the engagement of the coupling side friction element (response delay) occurs, resulting in a feeling of braking in the vehicle.

Moreover, although the learning method based on the undershoot is disclosed in Patent Document 1, the technique disclosed in Patent Document 1 is not a system for detecting an initial synchronization point, but a re-starting process after the initial synchronization point. Since the control is based on the synchronization point, there is a problem that the response of the LF upshift decreases.
The present invention was devised in view of such a problem, and provides an automatic transmission control device that absorbs variation in engagement during LF upshift by learning control and obtains stable shift quality. The purpose is to provide.

  According to a first aspect of the present invention, there is provided a control apparatus for an automatic transmission according to a first aspect of the present invention, based on shift determination means for determining an upshift when the throttle opening is equal to or less than a predetermined opening, An input shaft rotational speed estimating means for calculating a synchronous rotational speed of the subsequent input shaft and an input shaft rotational speed at the time of synchronous determination higher than the synchronous rotational speed of the input shaft by a predetermined rotational speed; Release-side friction element control means for reducing the hydraulic pressure of the friction element on the side, and after the shift determination, the hydraulic pressure of the friction element on the coupling side is increased at a predetermined gradient from the initial hydraulic pressure having no capacity, and the hydraulic pressure is increased after reaching the synchronous rotation. An initial hydraulic pressure learning for correcting the initial hydraulic pressure of the friction element on the coupling side based on a previous shift result in a control unit of an automatic transmission including a coupling-side friction element control unit that raises and completes coupling With control means, The initial hydraulic pressure learning control means includes a first determination means for determining whether or not the rate of change of the input shaft rotational speed at the time of synchronization determination is smaller than a predetermined value, and the input shaft rotational speed change after a predetermined period has elapsed after the synchronization determination. A second determining means for determining whether the rate has increased or whether the input shaft rotational speed change rate is a positive value; and after the synchronization determination, the input shaft rotational speed is determined by the input shaft rotational speed estimating means. And a third determination means for determining whether the input shaft change rate is within a predetermined range equal to or higher than the synchronous rotational speed of the input shaft after the shift calculated by the step, and the first determination means causes the input shaft change rate to be less than a predetermined value. A first learning correction means for correcting the initial hydraulic pressure so that the initial hydraulic pressure at the next shift is reduced when it is determined to be small; and a rate of change of the input shaft rotational speed after a predetermined period of time has elapsed after the synchronization determination by the second determination means. Increased or the When it is determined that the rate of change in the rotational speed of the power shaft is a positive value, a second learning correction unit that corrects the initial hydraulic pressure so that the initial hydraulic pressure at the next shift increases, and the input shaft by the third determination unit If it is determined that the rotational speed is not within the predetermined range equal to or higher than the synchronous rotational speed of the input shaft after the shift calculated by the input shaft rotational speed estimating means, the initial hydraulic pressure at the next shift is increased. It has the 3rd learning correction | amendment means which correct | amends an initial hydraulic pressure, It is characterized by the above-mentioned.

When the input shaft rotational speed change rate is negative, the direction in which the change rate changes is close to zero, and the direction away from zero is the decrease direction.
A control device for an automatic transmission according to a second aspect of the present invention is the control device for an automatic transmission according to the first aspect, wherein the correction amount (γ) for the initial hydraulic pressure by the second learning correction means is set to the first 3 It is characterized in that it is set to a value larger than the correction amount (β) for the initial hydraulic pressure by the learning correction means.

  According to a third aspect of the present invention, there is provided a control device for an automatic transmission according to the present invention, comprising a high-speed side friction element and a low-speed side friction element for establishing a high-speed side shift stage and a low-speed side shift stage, respectively. In a shift control device for an automatic transmission in which the high-speed friction element is engaged after the disengagement and the upshift from the low-speed gear to the high-speed gear is performed, the speed is increased by releasing the accelerator pedal. An initial hydraulic pressure learning control unit that corrects the initial hydraulic pressure of the high-speed side friction element based on the previous shift result when the shift is executed, and the initial hydraulic pressure learning control unit determines synchronization of the upshift When the change rate of the input shaft rotation speed of the transmission at the time is determined to be smaller than a predetermined value, the initial hydraulic pressure is corrected so that the initial hydraulic pressure at the next shift is reduced. It is.

  According to a fourth aspect of the present invention, there is provided a control device for an automatic transmission according to the present invention, comprising a high-speed side friction element and a low-speed side friction element for establishing a high-speed side shift stage and a low-speed side shift stage, respectively. In a shift control device for an automatic transmission in which the high-speed friction element is engaged after the disengagement and the upshift from the low-speed gear to the high-speed gear is performed, the speed is increased by releasing the accelerator pedal. An initial hydraulic pressure learning control unit that corrects the initial hydraulic pressure of the high-speed side friction element based on the previous shift result when the shift is executed, and the initial hydraulic pressure learning control unit determines synchronization of the upshift When it is determined that the change rate of the input shaft rotation speed of the transmission has increased or the change rate of the input shaft rotation speed is a positive value after a predetermined period has elapsed, the initial hydraulic pressure at the next shift increases. To do It is characterized by correcting the period hydraulic.

  According to a fifth aspect of the present invention, there is provided a control device for an automatic transmission according to the present invention comprising a high speed side friction element and a low speed side friction element for establishing a high speed side shift stage and a low speed side shift stage, respectively. In a shift control device for an automatic transmission in which the high-speed friction element is engaged after the disengagement and the upshift from the low-speed gear to the high-speed gear is performed, the speed is increased by releasing the accelerator pedal. An initial hydraulic pressure learning control unit that corrects the initial hydraulic pressure of the high-speed side friction element based on the previous shift result when the shift is executed, and the initial hydraulic pressure learning control unit determines synchronization of the upshift Thereafter, when it is determined that the rotational speed of the input shaft of the transmission is not within a predetermined range, the initial hydraulic pressure is corrected so that the initial hydraulic pressure at the next shift is increased.

  A control device for an automatic transmission according to a sixth aspect of the present invention is the control device for an automatic transmission according to the fifth aspect, wherein the predetermined range is at least equal to or greater than the synchronous rotational speed of the input shaft after the speed change. The rotation speed is set.

  According to the automatic transmission control apparatus of the present invention, when the absolute value of the input shaft change rate is higher than the target value before the synchronization determination point by the first determination unit and the first learning correction unit, that is, the initial hydraulic pressure is high. Therefore, if the coupling friction element has a capacity before the synchronization determination, correction is performed so that the initial hydraulic pressure at the next shift is reduced. No longer has capacity. Therefore, it is possible to prevent the occurrence of a shift shock due to the coupling of the friction elements before the initial hydraulic pressure is too high to reach the synchronous rotational speed.

  By the second determination means and the second learning correction means, the input shaft change rate has increased (the input rotation shaft change rate has changed in the positive direction) or the actual input shaft rotation change has passed since a predetermined period has been exceeded from the synchronous rotation speed. If the ratio turns to a positive value, that is, if the initial hydraulic pressure is low and the actual hydraulic pressure does not increase even if the synchronous hydraulic pressure is judged and the hydraulic pressure increase instruction is issued, it is determined that there is a complete synchronization delay. Thus, correction is performed such that the initial hydraulic pressure at the next shift is increased, so that a shift shock due to coupling delay can be prevented.

  On the other hand, even if the input rotation axis change rate changes in the plus direction, the input shaft rotation speed continues to decrease unless the input shaft rotation speed change rate becomes a positive value. Therefore, even if the change rate of the input shaft rotational speed change rate changes to a positive value within a predetermined period, if the response of the hydraulic pressure has deteriorated due to variations, the input shaft rotational speed is There is a risk of lower than the shaft rotation speed. Therefore, even if it is determined by the second determination means that the rate of change of the input shaft rotation speed change rate has changed in the positive direction, the third determination means does not exceed the synchronous rotation speed calculated by the input shaft rotation speed estimation means. If it is determined that it is not within the predetermined range, the third learning correction means corrects the initial hydraulic pressure so that the initial hydraulic pressure at the next shift is increased, thereby preventing undershoot due to responsiveness deterioration. Shift shock due to undershoot is prevented.

And by providing the said 1st-3rd learning correction | amendment means, after a learning convergence, while an undershoot does not generate | occur | produce, a synchronous time period can be shortened by raising oil_pressure | hydraulic in step shape after a synchronous determination.
Further, the correction amount (γ) for the initial hydraulic pressure by the second learning correction unit is set to a value larger than the correction amount (β) for the initial hydraulic pressure by the third learning correction unit, so that an LF upshift (step-off) is performed. When there is a complete synchronization delay at the time of upshift), it is corrected with a large correction amount. On the other hand, the initial hydraulic pressure is maintained at an appropriate hydraulic pressure, but undershoot occurs due to low response of the hydraulic pressure. Since correction is performed with a small correction amount, excessive correction is not performed, so that the convergence of learning control can be accelerated.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 14 show a control device for an automatic transmission for automobiles as an embodiment of the present invention.
FIG. 1 is a diagram showing a schematic configuration of a passenger car power plant to which a control device according to the present invention is applied. As shown in FIG. 1, an automatic transmission 2 is connected to the rear end of an engine 1, The driving force of the engine (internal combustion engine) 1 is transmitted to driving wheels (not shown) via the automatic transmission 2. The automatic transmission 2 includes a torque converter 3, a transmission body 4, and a hydraulic controller 5, and is driven and controlled by an automatic transmission control ECU (electronic control unit; control means) 6 installed in the passenger compartment or the like. The The transmission main body 4 incorporates a plurality of sets of planetary gears and friction elements such as a hydraulic clutch and a hydraulic brake. In addition to the integrally formed hydraulic circuit, the hydraulic controller 5 houses a plurality of solenoid valves that are duty-driven by the ECU 6 (only the second solenoid valve 71 is illustrated in FIG. 4 described later). . This solenoid valve is provided for each of a plurality of friction elements described later.

Further, the automatic transmission 2 is equipped with a switching lever (not shown) for switching the driving mode. When the driver operates the switching lever, the parking range, the traveling range (for example, the first gear to the fourth gear) Speed range), neutral range, reverse range, etc. can be manually selected. This travel range has two shift modes, an automatic shift mode and a manual shift mode (manual shift mode). When the automatic shift mode is selected, the shift (shift stage switching) is performed at the engine speed (for example, torque). When the manual shift mode is selected, it is automatically performed according to a preset shift map based on the turbine rotation speed N _T of the turbine 30 of the converter 3 and the engine load (for example, the throttle opening θ _TH ). The shift stage is fixed to the selected shift stage regardless of the shift map, or is automatically performed according to the shift map limited to the selected shift stage region.

The ECU 6 includes an input / output device (not shown), a storage device (non-volatile RAM, ROM, etc.) incorporating a large number of control programs, a central processing unit (CPU), a timer counter, and the like. An _NT sensor 7 for detecting the turbine rotational speed _NT of the turbine 30 of the converter 3, a vehicle speed sensor 8 for detecting the vehicle speed V, a throttle sensor 9 for detecting an opening θ _{TH of a} throttle valve (not shown), and an intake air amount of the engine 1 air flow sensor 9a for detecting, such as N _E sensor 39 of electromagnetic pickup for detecting the engine rotational speed N _E from the rotation of the ring gear 38 of the flywheel is connected to. On the other hand, a plurality of solenoid valves housed in the hydraulic controller 5 are connected to the output side. In addition to these sensors, the ECU 6 is connected to various sensors and switches such as an inhibitor switch for detecting the shift position of the shift range and an idle switch for detecting the closed state of the throttle valve.

  The torque converter 3 includes a fluid coupling including a housing 37, a casing 34, a pump 31, a stator 32, a turbine 30, and the like. The pump 31 is connected to the engine drive shaft 36 via the casing 34. The stator 32 is connected to a housing 37 via a one-way clutch 33, and the turbine 30 is connected to an input shaft (turbine shaft) 11 of the transmission main body 4 serving as an output shaft. Further, in the torque converter 3, a wet single-plate type damper clutch (lock-up clutch) 35 is interposed between the casing 34 and the turbine 30, and the drive shaft 36 and the turbine shaft are engaged by the engagement of the damper clutch 35. 11 can be directly connected. The damper clutch 35 is driven by hydraulic oil supplied from a damper clutch hydraulic control circuit 40 in the hydraulic controller 5 through oil passages 65 and 66.

  The damper clutch control valve 41 that forms the center of the damper clutch hydraulic control circuit 40 includes a spool valve 43 that controls the hydraulic pressure supplied to the damper clutch 35, a left end chamber 44 and a right end chamber 45 that are positioned at both ends of the spool valve 43, and both chambers. Oil passages 46 and 47 for introducing pilot pressure to 44 and 45, a spring 48 for urging the spool valve 43 in the right direction in the drawing, a normally closed damper clutch solenoid valve 42, and the like. The oil passage 46 to the left end chamber 44 side is connected to the solenoid valve 42 via the branch oil passage 49. When the solenoid valve 42 is in a closed state (that is, in the OFF position), the left end chamber 44, the right end chamber 45, As a result, the spool valve 43 biased by the spring 48 moves to the right in the drawing. When the solenoid valve 42 is in the open state (that is, the ON position), the pilot pressure in the left end chamber 44 is released, and the spool valve 43 is moved to the left in the figure by being biased by the pilot pressure on the right end chamber 45 side. Move to. In addition, orifices 46a and 49a are formed in the oil passage 46 and the branch oil passage 49, respectively, and a rapid fluctuation of the pilot pressure is prevented.

  When the spool valve 43 moves to the right, torque converter lubricating oil pressure (release pressure) is supplied between the casing 34 and the damper clutch 35 via the oil passage 65, and at the same time, hydraulic oil is supplied from the casing 34 via the oil passage 66. Is discharged, the damper clutch 35 is released (non-directly connected), and the rotation of the drive shaft 36 is transmitted to the turbine shaft 11 by rotating the turbine 30 with the discharge pressure of the pump 31. On the other hand, when the spool valve 43 moves to the left, the hydraulic oil between the casing 34 and the damper clutch 35 is discharged through the oil passage 65, and at the same time, the control valve 41 is adjusted into the casing 34 through the oil passage 66. The applied pressure based on the pressure is supplied, the damper clutch 35 is engaged (completely directly coupled), and the rotation of the drive shaft 36 is directly transmitted to the turbine shaft 11.

  Thus, the connection / disconnection of the damper clutch 35 is determined by the position of the spool valve 43, that is, the pressure difference between the pilot pressures supplied to the left end chamber 44 and the right end chamber 45, and this pressure difference drives the solenoid valve 42 with duty. Is controlled. For example, when the ECU 6 drives the solenoid valve 42 at a duty ratio of 100%, the pilot pressure in the left end chamber 44 is almost completely discharged through the branch oil passage 49 and the solenoid valve 42, and the spool valve 43 moves to the left end. The damper clutch 35 is in a completely directly connected state by the action of the apply pressure described above. Further, when the solenoid valve 42 is driven at a duty ratio of 0% (that is, when it is not driven at all), the pilot pressure in the left end chamber 44 and the right end chamber 45 is balanced, so that it is urged by the spring 48 and spool 43 Moves to the right end, and the damper clutch 35 is brought into a non-directly connected state by the action of the release pressure described above. And if it drives with a predetermined | prescribed duty factor (for example, 25-35%), a low apply pressure state can be created and the damper clutch 35 will be in a half-clutch state. Note that the line pressure adjusted by a regulator valve, which will be described later, is used as the input pressure of the release pressure and the apply pressure that are the output pressure of the control valve 41.

Normally, the ECU 6 controls the drive of the damper clutch 35 based on the map shown in FIG. 2 except when the shift control is being performed. In this map, the horizontal axis is the turbine rotational speed _NT , and the vertical axis is the throttle opening θ _TH . As shown in FIG. 2, when the turbine rotational speed _NT is relatively high and the throttle opening θ _TH is larger than the power online L _PO , most of the region is a completely directly connected region, and the damper clutch 35 Is completely directly controlled. That is, as described above, the apply pressure is supplied from the control valve 41 into the casing 34, while the release pressure is discharged from between the damper clutch 35 and the casing 34, and the damper clutch 35 is coupled. On the power online _LPO , the engine rotational speed _NE and the turbine rotational speed _NT theoretically coincide, and neither acceleration nor deceleration is performed. However, in actuality, it may be slightly accelerated or decelerated due to variations in engine output.

Further, in a power-off state where the throttle opening θ _TH is smaller than the power online L _PO , all of the direct-deceleration speed reduction regions are in the region where the turbine rotational speed _NT is slightly higher than the idle rotational speed (1200 rpm in the present embodiment). Become. In the deceleration direct coupling region, the minimum required apply pressure is supplied to the damper clutch 35 and a half clutch state is established, and the engine 1 and the transmission main body 4 are directly coupled via the damper clutch 35 with a predetermined slip amount. The damper clutch 35 is quickly released during sudden braking or the like, and engine stall can be avoided. In addition, since the fuel supply can be stopped while maintaining the rotation of the engine 1 at the time of the direct deceleration connection, the fuel efficiency is greatly improved.

  FIG. 3 is a schematic diagram showing a gear train in the automatic transmission main body 4 that can achieve four forward speeds and one reverse speed. As shown in FIG. 3, a turbine shaft 11 is connected to the turbine 30, and the sun gear of the first planetary gear 12 as well as the first and second planetary gears 12 and 13 as the speed change mechanism 10 is connected to the turbine shaft 11. 14 is connected to the turbine shaft 11, the second clutch 17 is connected to the pinion carrier 16 of the second planetary gear 13, and the third clutch is connected to the turbine shaft 11 of the sun gear 18 of the second planetary gear 13. 19 is held. In addition, the internal gear 21 of the first planetary gear 12 is fixed to the casing 20 of the transmission body 4, and the first brake 22 that is a reaction force element and the sun gear 18 of the second planetary gear 13 are fixed, and the reaction force element A second brake 23 is attached. The rotation of the turbine shaft 11 is transmitted to the countershaft 28 via the pinion carrier 24 of the first planetary gear 12, the drive gear 26 connected to the pinion carrier 24 and the driven gear 27, and further transmitted to the differential carrier 29.

The internal gear 21 of the first planetary gear 12 and the pinion carrier 16 of the second planetary gear 13, the pinion carrier 24 of the first planetary gear 12 and the internal gear 25 of the second planetary gear 13 are coupled together, and they are integrally formed. Rotate.
FIG. 4 shows a part of a hydraulic control circuit for the friction element, and the hydraulic circuit includes a solenoid valve for controlling the supply and discharge of the hydraulic pressure to the friction element, for example, the second clutch 17, for example, the second solenoid valve 71. . The second solenoid valve 71 is a normally closed two-position switching valve, and has ports 71a, 71b, 71c at three locations.

  A first oil passage 60 extending to an oil pump 69 that pumps hydraulic oil from an oil pan 68 is connected to the first port 71a, and a pressure regulating valve (regulator valve) 70 is interposed in the first oil passage 60. The hydraulic pressure (line pressure) adjusted to a predetermined pressure is supplied to the solenoid valve, the control valve 41 described above, and the like. A second oil passage 61 extending to the second clutch 17 is connected to the second port 71b, and a third oil passage 62 for discharging hydraulic oil to the oil pan 68 is connected to the third port 71c. An accumulator 73 is interposed in the second oil passage 61.

  The second solenoid valve 71 is electrically connected to the ECU 6, and duty control is executed by a drive signal from the ECU 6. When the solenoid 71e is de-energized, the valve element 71f is pressed by the return spring 71g to cut off the communication between the first port 71a and the second port 71b, and the second port 71b and the third port. 71c is made to communicate. On the other hand, when the solenoid 71e is energized, the valve body 71f is lifted against the return spring 71g to connect the first port 71a and the second port 71b, and to connect the second port 71b and the third port 71b. The communication with the port 71c is blocked.

  When the duty ratio supplied from the ECU 6 to the solenoid valve, for example, the second solenoid valve 71 is 100%, the hydraulic pressure supplied to the friction element, for example, the second clutch 17, is the line pressure adjusted by the pressure adjusting valve 70. It becomes. On the other hand, as the duty ratio decreases, the hydraulic pressure supplied to the second clutch 17 decreases. When the duty ratio is 0%, the valve body 71f is connected to the first port 71a and the second port 71b by the return spring 71g. The second port 71b and the third port 71c are communicated with each other, and the hydraulic oil is discharged from the second clutch 17.

  FIG. 5 is a detailed cross-sectional view of the second clutch 17. As shown in FIG. 5, the second clutch 17 includes a large number of friction engagement plates 50. The friction engagement plates 50 include a clutch plate 50 a that rotates integrally with the turbine shaft 11 and a clutch disk 50 b that rotates integrally with the pinion carrier 16. When the second clutch 17 is engaged, the hydraulic oil hydraulically controlled by the second solenoid valve 71 is supplied from the first oil passage 61 to the second clutch 17 through the port 51, and the piston 52 moves forward to move to each The clutch plate 50a and the clutch disk 50b of the friction engagement plate 50 are coupled. On the other hand, at the time of release, the piston 52 is pushed back by the return spring 53, so that the hydraulic oil is discharged through the port 51, the first oil passage 61, the second solenoid valve 71, and the second oil passage 62, and the clutch plate 50a The frictional engagement with the clutch disk 50b is released.

  A sufficient clearance (backlash) is provided between the clutch plate 50a of the second clutch 17 and the clutch disk 50b so that a drag phenomenon does not occur at the time of release so that the second clutch 17 is completely released. . Therefore, at the time of coupling, before the clutch plate 50a and the clutch disk 50b enter the coupled state, first, a so-called backlash operation for reducing the invalid stroke is performed by setting the clearance (backlash) to substantially zero. The

Note that the first clutch 15, the second brake 23, and the like have substantially the same configuration as that of the second clutch 17, and a description thereof will be omitted.
In the automatic transmission 2 having the transmission main body 4 having the above-described configuration, the vehicle speed V detected by the vehicle speed sensor 7 as described above when the switch lever is selected to be in the automatic shift mode of the travel range and travels. The friction elements such as the first to third clutches 15, 17, 19 and the first to second brakes 22, 23 are set in accordance with the throttle opening θ _TH detected by the throttle sensor 8. Duty drive control is performed by a solenoid valve, and each gear stage is automatically established by a combination of coupling or releasing as shown in Table 1. The circles in Table 1 indicate the coupling of each clutch or each brake.

At the time of shifting, a drive signal set at a predetermined duty ratio is supplied to each solenoid valve of the hydraulic controller 5 with a predetermined output pattern, and optimal shift control with good shift feeling is executed.
By the way, in the situation where the driver takes his / her foot off the accelerator pedal, that is, in the upshift switching (lift foot (LF) upshift) in the coasting state, the friction element on the high speed side is released after the engagement of the friction element on the low speed side is released. By engaging, an upshift from the low speed side gear stage to the high speed side gear stage is executed.

Then, the ECU 6 has a shift determining means 301 for determining an upshift (LF upshift) in which the throttle opening is equal to or less than a predetermined opening and is substantially zero in order to learn such hydraulic control during LF upshift. Based on the turbine rotational speed (input shaft rotational speed) _NT at the time of the LF upshift determination, the turbine rotational speed (synchronous rotational speed) _NTJ after the shift and a predetermined rotational speed than the synchronous rotational speed _NTJ The input shaft rotation speed estimation means 302 for calculating the turbine rotation speed at the time of high synchronization determination, the release side friction element control means 303 for lowering the hydraulic pressure of the release side friction element after the shift determination of the LF upshift, and the shift After the determination, the hydraulic pressure of the friction element on the coupling side is increased from the initial hydraulic pressure having no capacity with a predetermined gradient, and after reaching the synchronous rotation, the hydraulic pressure is increased to complete the coupling. An element control unit 304, the initial hydraulic pressure of the friction elements of the binding side, and a initial oil pressure learning control unit 305 performs correction based on the previous shift result.

Further, as shown in the figure, the initial hydraulic pressure learning control means 305 is provided with first to third determination means 101 to 103 and first to third learning correction means. The detailed functions of these means will be described later.
FIGS. 7 to 9 are flowcharts showing the upshift transmission control executed by the ECU 6 during such LF upshift, and FIG. 10 shows the turbine rotation based on the release side control and the coupling side control of these flowcharts. The speed N _T , the supply signal duty ratio D _R to the solenoid valve of the release side friction element, the supply signal duty ratio D _C to the solenoid valve of the connection side friction element, and the hydraulic pressure supplied to the release and connection side friction elements FIG. 7 is a graph showing changes over time, and LF upshift control will be described below with reference to FIGS.

  As is apparent from Table 1, the high-speed side friction element at the time of upshift (coupling side friction element) indicates that the second brake 23 is set to 2 for the 1-2 upshift from the first gear to the second gear. The second clutch 17 is shown for the 2-3 upshift from the third gear to the third gear, and the second brake 23 is shown for the 3-4 upshift from the third gear to the fourth gear. The release side friction element) indicates the first brake 22 for the 1-2 upshift, the second brake 23 for the 2-3 upshift, and the first clutch 15 for the 3-4 upshift.

FIG. 7 shows an LF upshift control routine which is the main control at the time of LF upshift from the second gear (first gear) to the third gear (second gear), for example. An upshift will be described as an example.
First, in step S14, to implement the release side control for controlling the duty ratio D _R of the disengagement side frictional element. This disengagement side control, as shown in FIG. 10, switching the duty ratio D _R to 0% from 100% with control start command, performs the hydraulic pressure released from the second brake 23.

Then, the process proceeds to step S16, to implement the linked side control for controlling the duty ratio D _R of the coupling side of the friction element. Hereinafter, control of the coupling side friction element in step S16 (subroutine of step S16) will be described with reference to FIG.
In this coupling side control, when a shift command (SS) is output from the ECU 6 at the shift control start time (SS time) as shown in FIG. 10, first, as shown in FIG. and in order to pack the clearance (backlash) between the clutch discs 50b, performs the play elimination operation by a predetermined play elimination time t _F, as described above. The play reduction operation, since it is intended to eliminate the ineffective stroke of the second clutch 17, the duty ratio D _C so that operation becomes fastest, as shown in FIG. 10 (c) is set to 100% The second clutch 17 is supplied with hydraulic oil having a line pressure. As a result, the hydraulic pressure on the coupling side gradually increases as shown in the hydraulic diagram of FIG. 10D (see the curve of the coupling element). The play elimination time t _F is intended to be corrected by learning, after a lapse of play elimination time t _F, then performs Step S42.

In step S42, it performs a calculation of the turbine torque T _T to be transmitted from the engine 1 to the turbine 30 (output torque detection). By obtaining the turbine torque T _T, it is possible to set the hydraulic pressure to be supplied to the second clutch 17 of the coupling side after play elimination time t _F has elapsed. In operation of the turbine torque T _T, a subroutine shown in the flowchart of FIG.

In step S90 of FIG. 9, first, the current A / N (intake amount per intake stroke) is read. This A / N is calculated based on input information from the airflow sensor 9a. Then, at the next step S92, it reads based current turbine speed N _T and the engine rotational speed N _E to the N _T sensor 7 and N _E sensor 39 input information taken respectively.
In step S94, calculates the engine torque T _E by the engine 1 is output from the current A / N read in step S90. This engine torque _TE is expressed as a function of A / N as shown by the following equation (A1).

T _E = f (A / N) (A1)
Here, A / N is used to obtain the engine torque T _E , but instead of A / N, the throttle opening θ _TH detected by the throttle sensor 9 and the engine rotational speed N _E are used. , it may be obtained engine torque T _E on the basis of these values.

In the next step S96, it calculates the slip ratio e from the following equation (A2) from the read current of the turbine speed N _T and the engine speed N _E at step S92.
e = N _T / N _E (A2)
In the next step S98, a torque ratio t between the engine torque T _E and the turbine torque T _T is calculated from the following equation (A3) based on the slip ratio e.

t = f (e) (A3)
Finally, in step S100, the turbine torque T _T is calculated from the following equation (A4) based on the torque ratio t and the engine torque T _E.
T _T = t × T _E (A4)
After determining the turbine torque T _T in the manner described above, then the process proceeds to step S50 in FIG. 8.

In step S50, a reference duty ratio D _A2 is set. The reference duty ratio D _A2 is set based on a map (not shown) indicating the relationship between the turbine torque T _T and the reference duty ratio D _A2 , which is determined by experiments or the like and stored in advance in the ECU 6.
When the reference duty ratio D _A2 is set according to this map, the process proceeds to step S51, where the rotational speed difference between the turbine rotational speed _NT at the start of the shift and the synchronous rotational speed _NTJ of the turbine at the third speed stage after the shift. _A duty factor correction amount ΔDA is set based on (N _T −N _TJ ). This duty factor correction amount ΔD _A is set based on a map as shown by a solid line or a two-dot chain line in FIG.

As shown by the solid line or two-dot chain line in FIG. 6, the duty factor correction amount [Delta] D _A, the rotational speed difference (N _T -N _TJ) large in area is small, the rotational speed difference (N _T -N _TJ) is a predetermined value When N _X or more, the rotation speed difference (N _T −N _TJ ) is set so as to become smaller. In general, the higher the vehicle speed, that is, the greater the rotational speed difference (N _T −N _TJ ), the longer it takes to connect the friction elements. Conversely, the vehicle speed is low and the rotational speed difference ( This is because the smaller N _T −N _TJ ), the shorter the time required for coupling the friction elements.

Further, the correction amount [Delta] D _A, as described below, but are additive correction to the reference duty ratio D _A2, the setting of the reference duty ratio D _A2, the correction amount [Delta] D _A is always to take a value of 0 or more It is set (see the solid line in FIG. 6) or set to take a negative value (see the two-dot chain line in FIG. 6).
After setting the correction amount [Delta] D _A, then the process proceeds to step S52.

In step S52, the duty ratio D _U1 is calculated from the following equation (B1) based on the reference duty ratio D _A2 , the duty ratio learning value D _AL and the correction amount ΔD _A. The initial value of the duty ratio D _U1 (value at the IF point shown in FIG. 10) is particularly referred to as an initial engagement hydraulic pressure (initial hydraulic pressure) D _A.
D _U1 = D _A2 + D _AL + ΔD _A + D _AS (B1)
Here, the duty ratio learning value _DAL is a value for correcting the reference duty ratio D _A2 at the start of the feedback control to an appropriate value, and is set and corrected by learning based on the previous shift result, as will be described later.

Further, D _AS is a duty gradient term is a term that increases the duty ratio with a gradient of dD _{A. DAS} has an initial value of 0 (% / s), and is set based on the elapsed time from completion of backlash filling.
The next step S62 after a step of performing the shift control of the coupling side engaging element, first, in step S62, setting the duty ratio D _C of the binding side again to the duty ratio D _U1.

Then, in step S66, the setting a target turbine speed change rate dN _T. In the present embodiment, the target turbine rotational speed change rate dN _T is set to a constant value irrespective of the vehicle speed V. This is because in LF upshift transmission control, the turbine rotation speed change rate depends on the engine rotation speed change rate, and this engine speed change rate is not normally reduced by the clutch capacity unlike the upshift. This is because it is a natural decrease due to the fact that the opening degree is substantially zero. Thus, no problem arises even if a constant value is used regardless of the vehicle speed.

Target turbine speed change rate dN _T in the LF up-shift is determined by experiment, and is stored as a map in the ECU 6.
Thus, here, reads the target turbine rotational speed change rate dN _T at LF upshift from this map. In the upshift, the target turbine rotational speed change rate dN _T is indicated by a negative value.

The next step S68 is a step for determining whether or not the shift is nearing the end, and the difference (N _T −N _TJ ) between the turbine rotational speed _NT and the synchronous rotational speed _NTJ at the third speed after the shift. There or less than a predetermined value .DELTA.N _C is determined. If the decision result is No in (negative) is still shift can determined not to reach the end, in this case, the process returns to step S42 again, the duty ratio D _C, re-sets the duty ratio D _U1 that fixes To do. This reset of D _U1 is made when the determination result in Step S68 is No (No), and the difference (N _T −N _TJ ) between the turbine rotation speed N _T and the synchronous rotation speed N _TJ at the third speed after the shift is obtained. it is repeatedly performed as long as the predetermined value .DELTA.N _C greater than.

When the LF upshift is in progress, the engine rotational speed Ne and the turbine rotational speed _NT are substantially constant, so that the turbine torque T _T is constant. Therefore, the corrected duty ratio D _U1 is substantially corrected based on the elapsed time from the completion of backlash without changing the terms D _AL and D _A2 and only the duty gradient term D _AS. It means to become a thing.

The speed change proceeds, the determination result in step S68 is Yes (positive), and the difference (N _T −N _TJ ) between the turbine rotational speed _NT and the turbine rotational speed _NTJ at the third speed after the speed change is a predetermined value ΔN _C. If it becomes below, it can be determined that the shift is nearing the end, and in this case, the process proceeds to step S80. The time point when the difference (N _T −N _TJ ) between the turbine rotation speed N _T and the turbine rotation speed N _TJ at the third gear stage after the shift becomes equal to or less than a predetermined value ΔN _DE is the synchronization determination point or synchronization determination point. This point is defined as the FF time point as shown in FIG.

In step S80, the coupling-side duty factor D _C is set to the duty factor D _E over a predetermined time t _E1 . This duty factor D _E is a duty factor appropriately higher than the feedback control duty factor D _U1 .
When the predetermined time t _E1 has elapsed, the process proceeds to step S82, and the subsequent predetermined time t _E2 increases the coupling-side duty factor D _C with a predetermined gradient κ as shown in the following equation (C2).

D _C = D _E + κ · tt (B2)
Note that tt represents an elapsed time with a base point that is a predetermined time t _E1 after the FF time.
Further, after a lapse of the predetermined time t _E2, finally the duty ratio D _C to 100% in step S84.

In this way, just before the end of shifting, the coupling-side duty factor D _C is set to a duty factor D _E that is appropriately higher than the feedback control duty factor D _U1 for a predetermined time t _E1 (step S80). the duty ratio D _C of the binding side was increased at a predetermined gradient κ in (step S82) after the duty ratio D _C to 100% (step S84) so generated when the duty ratio D _C at 100% Shift shock can be reduced.

When the shift end time (SF time) is reached, the second clutch 17 is completely engaged, and a series of 2-3 upshifts ends.
When the coupling side control is executed, the process returns to the LF upshift control routine of FIG. 7, and step S17 is executed. In step S17, it is determined whether or not the upshift has been completed (whether or not the turbine rotational speed _NT has reached the synchronous rotational speed _NTJ at the third gear). If the determination result is No (No) and the upshift has not yet ended, the release side control and the coupling side control are continued. On the other hand, if the determination result is Yes (positive) and it is determined that the upshift has ended, the process proceeds to step S18.

Steps S18 to S24 are steps for performing various kinds of learning, that is, learning of the backlashing time t _F , the hydraulic pressure release time t _R, and the duty factor learning value D _AL . Among these, the learning of the backlashing time t _F and the hydraulic pressure release time t _R can be performed by a known technique.
Next, describing the details of the learning control of the duty ratio learning value D _AL as part of the invention, as described above, in the control apparatus for an automatic transmission according to the present embodiment, the frictional member of the binding side in ECU6 An initial hydraulic pressure learning control unit 305 is provided for correcting the initial hydraulic pressure based on the previous shift result.

As shown in FIG. 11, the initial hydraulic pressure learning control unit 305 includes a determination unit 100 and an initial hydraulic pressure learning control unit 200, and the determination unit 100 includes a turbine rotation speed change rate at the time of synchronous rotation determination. (input shaft change rate) dN _T is first judging means 101 judges whether or not greater than a predetermined value, after the synchronization determination, whether the input shaft change rate dN _T after the predetermined time period T has passed is increased, or The second determination means 102 for determining whether or not the input shaft change rate dN _T > 0, and the input shaft rotational speed _NT after the synchronization determination is equal to or higher than the input shaft rotational speed (synchronous rotational speed) _NTJ after the shift. and a third determination unit 103 determines whether within a predetermined range .DELTA.N _F.

The initial oil pressure learning control means 200, the first judging means 101, when the input shaft change rate dN _T is determined to be greater than the predetermined value, the initial oil pressure so that the initial oil pressure in the next shifting time is decreased α % first learning correction means 201 for correcting by simply reducing, by the second judging means 202, the input shaft change rate dN _T is increased (i.e., when the change rate is negative, the current input shaft change rate dN _{T (n)} > when the previous input shaft change rate dN _{T (n−1)} is satisfied, in other words, when the change rate of the input shaft change rate dN _T > 0), or the input shaft change rate dN _T > When it is determined that the initial hydraulic pressure at the next shift is increased, the second learning correction unit 202 corrects the initial hydraulic pressure by + γ% so that the initial hydraulic pressure increases at the next shift, and the third determination unit 103 performs input. The shaft rotation speed _NT is When the input shaft rotational speed estimating means 302 does not fall within the predetermined range equal to or higher than the input shaft rotational speed _NTJ after the shift, the initial hydraulic pressure is increased by + β% so that the initial hydraulic pressure at the next shift is increased. And third learning correction means 103 for correcting the initial hydraulic pressure.

When the input shaft rotational speed change rate is negative, the direction in which the change rate changes is close to zero, and the direction away from zero is the decrease direction.
Next, the learning control of the duty ratio learning value D _AL as a subroutine of Step S22 of FIG. 7 will be described with reference to the flowchart shown in FIG. 12. First, in step S201, it is determined based on information from the shift determination means 301 whether or not an LF upshift has been established. If the LF upshift has not been established, the process proceeds to step S208, and in particular, the duty ratio learning value _DAL is returned without performing learning correction.

On the other hand, if it is determined in step S201 that the LF upshift has been established, the process proceeds to step S202, where the actual turbine rotational speed change rate (actual dN _T ) is the target turbine rotational speed before the synchronization determination point (FF point). The first determination means 101 determines whether or not the speed change rate (target dN _T ) is smaller than a value obtained by multiplying a predetermined coefficient k (for example, k = 1.1). Here, since the actual dN _T and the target dN _T are both negative values, the step S202 determines whether or not | actual dN _T |> | target dN _T | × k is established. It can also be said.

If | actual dN _T |> | target dN _T | × k, the process proceeds to step S203, and the first learning correction unit 201 reduces the duty factor learned value D _AL by a predetermined amount (α%).
That is, as shown in FIG. 14, when the turbine rotation speed _NT is rapidly decreased when the turbine rotation speed is decreasing toward the synchronization point (FF point), the hydraulic control of the coupling side friction element is performed. Can be considered to be due to the piston stroke of the coupling-side friction element being completed too early. Therefore, in this case, the initial engagement hydraulic pressure (initial hydraulic pressure) at the next shift is set on the condition that the actual turbine rotational speed change rate (actual dN _T ) is lower than the threshold value or the target value (= target dN _T × k). ) In order to reduce D _A , the duty ratio learning value D _AL is reduced by a predetermined amount (α%) to suppress a shock at the next shift control.

Thus, when the input shaft change rate dN _T in synchronization judgment temae is lower than the target value (if the absolute value of the input shaft change rate is higher than the target value), i.e. synchronization determination for initial oil pressure is high temae If the coupling side friction element has a capacity, the correction will be made so that the initial hydraulic pressure at the next shift will decrease, so the coupling side friction element must have the capacity before synchronization. Therefore, it is possible to prevent a shift shock caused by the frictional elements joining before the hydraulic pressure is too high to reach the synchronous rotational speed.

On the other hand, if | actual dN _T |> | target dN _T | × k is not established in step S202, the process proceeds to step S204, and the second determination means 102 causes the synchronization determination point (FF point) to elapse after a predetermined time T. in the case where the turbine rotational speed change rate dN _T is determined increases, or a turbine rotational speed change rate dN _T positive and proceeds to step S205, the process proceeds to step S206 otherwise.
Then, if the procedure advances to Step S205, an initial engagement pressure D _A to increase the duty ratio learning value D _AL is increased corrected by a predetermined amount (gamma%) in the next transmission time of the second learning correction means 202 .

That is, as shown in FIG. 15, such a shift-up but the duty ratio of the synchronization determination simultaneously with binding side frictional element is increased in steps until the hydraulic pressure corresponding to the input torque, or require initial engagement hydraulic D _A If it is too low, the piston stroke of the friction element is not completed at the time of the synchronization determination, and the engagement (beginning of capacity) is greatly delayed, resulting in an undershoot.

Therefore, in this case, after the predetermined time T from the synchronization determination point, the turbine speed change rate dN _T is increased (i.e., degree of decrease was smaller in the turbine speed change rate dN _T) or turbine speed change rate dN _T is positive when it is detected (i.e., the turbine rotational speed was increased) that, with each other to as to increase correct the duty ratio learning value D _AL predetermined amount (gamma%) only.

That is, to the initial engagement hydraulic D _A is low, does not increase the actual oil pressure out the oil pressure of up indication to determine the synchronous rotation, or when such insufficient, determines that the full synchronization delay Thus, by performing correction so that the initial engagement hydraulic pressure at the next shift is increased, it is possible to prevent a shift shock due to a coupling delay at the next and subsequent LF upshifts.
On the other hand, when the process proceeds from step S204 to step S206, the third determination means 103 causes the turbine shaft rotation speed _NT to be calculated by the input shaft rotation speed estimation means 302 by the third determination means 103. It is determined whether or not it is within the predetermined range ΔN _F (see FIGS. 13 and 14) equal to or greater than _TJ . If it is determined that it is not within the predetermined range ΔN _F , the process proceeds to step S207. Then, the process proceeds to step S208. The predetermined range .DELTA.N _F, in the present embodiment, .DELTA.N _DE are applied as a basis for synchronization determination point described above. That is, ΔN _F = ΔN _DE .

Then, if the procedure advances to Step S207, an initial engagement pressure D _A to increase the duty ratio learning value D _AL is increased corrected by a predetermined amount (beta%) in the next transmission time of the third learning correction means 303 . The correction amount β corrected by learning by the third learning correction unit 303 is set to a value smaller than the correction amount γ corrected by learning by the second learning correction unit 302.
Here, the turbine rotary shaft change rate dN _T rate of change also changes to a positive value, as long as the input shaft rotation speed change rate does not become positive value, the input shaft rotational speed continues to decrease. Therefore, even if the change rate of the turbine shaft rotation speed change rate changes in the positive direction within the predetermined period T, if the hydraulic response is deteriorated due to variations or the like, the turbine shaft rotation speed _NT is rotated synchronously. The speed may be lower than _NTJ . Therefore, even if it is determined by the second determination means that the change rate of the turbine shaft rotation speed change rate has changed in the positive direction, the third determination means 103 and the third learning correction means 203 cause the input shaft rotation speed estimation means to If the calculated synchronous rotational speed N _TJ above that does not fall within a predetermined range .DELTA.N _F, by correcting the initial hydraulic pressure as an initial pressure D _a in the next shifting time increases, under due hyporesponsiveness Shooting is prevented and shift shock due to undershooting is prevented.

Further, when the process proceeds to step S208, that is, when the LF upshift is not established or when the LF upshift is established, | actual dN _T |> | target dN _T | × k is not established ( (See Step S202) and the turbine rotational speed change rate dN _T is increased or neither of the turbine rotational speed change rates dN _T > 0 is satisfied (see Step S204), and the turbine shaft rotational speed _NT is If you are seated in synchronous rotational speed in the N _TJ or more predetermined range .DELTA.N _F (see step S207), and then returns without performing any correction.

In this case, the initial engagement hydraulic D _A is supplied without excess or deficiency, as shown in FIG. 13, since the overshoot is also when the engagement is complete without also not occur undershoot, when the control period Return while holding the duty factor learning value _DAL at.
When the learning of the duty factor learning value _DAL is completed by the first to third learning correction _units , a series of 2-3 upshift control is terminated.

With the configuration as described above, according to the transmission control apparatus of one embodiment of the present invention, when the hydraulic control of the coupling side friction element of the LF upshift is overshooting, the duty factor learning value D _AL Is reduced by a predetermined amount (α%), the shock at the next shift control can be suppressed.
Further, when the hydraulic control of the coupling side engaging element of such LF upshift undershoot feeling is after the predetermined time T from the synchronization determination point, the turbine speed change rate dN _T of the rate of change is positive, or turbine When the rotational speed variation rate dN _T detects positive, it is determined that the full synchronization delay by increasing corrects the duty ratio learning value D _AL predetermined amount (gamma%) only binds delay the next time after the LF upshift Therefore, it is possible to reliably prevent a shift shock due to.

  Further, since the correction amount γ for the initial hydraulic pressure by the second learning correction unit 202 is set to a value larger than the correction amount β for the initial hydraulic pressure by the third learning correction unit 103, a complete synchronization delay is caused during the LF upshift. Is corrected with a large correction amount.On the other hand, the initial hydraulic pressure is maintained at an appropriate hydraulic pressure, but when an undershoot occurs due to low hydraulic response, correction is performed with a relatively small correction amount. Since the excessive correction is not performed, the convergence of the learning control can be accelerated.

Further, the "turbine speed change rate dN _T is increased, or the turbine speed change rate dN _T positive" even that condition even if not true, the turbine shaft speed N _T is synchronous rotational speed N _TJ if not fall within the above predetermined range .DELTA.N _F, those not synchronized delayed enough described above, it is determined that the synchronization is somewhat delayed slightly, where the duty ratio learning value D _AL is smaller than the γ Since only a fixed amount (β%) is corrected, it is possible to prevent a reduction in hydraulic response due to individual differences or variations in the transmission itself, and to prevent a shift shock due to undershoot.

Therefore, the variation in engagement during the LF upshift is absorbed by the learning control, and it is possible to prevent a protruding feeling, a brake feeling, etc. during the LF upshift, and to always obtain a stable shift quality.
Further, set in terms of the correction friction element binding side, i.e. by the duty factor correction amount ΔD corresponding duty ratio D _C of the supplied hydraulic pressure to the rotational speed difference (N _T -N _TJ) to the second clutch 17 Therefore, the timing for engaging the second friction element can be set to an optimum value according to the rotational speed difference (N _T −N _TJ ), that is, the vehicle speed.

In other words, in the case of upshift switching (lift foot upshift) when the output torque is equal to or less than a predetermined value, the turbine-side rotational speed difference (N _T −N _TJ ) before and after the shift depends on the vehicle speed. Differently, the optimum timing for engaging the friction element is also different according to the rotational speed difference (N _T −N _TJ ).
In contrast, in the present apparatus, the supply oil pressure setting means so sets the duty ratio D _C in terms of the correction process by the duty factor correction amount [Delta] D, the timing of engaging the second friction element, according to the vehicle speed It can be set to an optimum value, such as a drive system shock when the engagement timing of the second friction element is too early, a drive system shock when the engagement timing of the second friction element is too late, and a vehicle protruding feeling. Occurrence can be suppressed.

Although the embodiments of the present invention have been described above, the present invention is not limited to such embodiments, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above-described embodiment, the 2-3 upshift transmission control is exemplified, but the above-described transmission control is executed similarly for the 1-2 upshift, the 3-4 upshift, and the like.
In the above embodiment, the automatic transmission 2 that can achieve four forward speeds has been described. However, the above-described controls can be similarly applied to any automatic transmission that has at least two forward speeds. It is.

Further, the correction amount (α, β, γ) of the above-described duty factor learning value _DAL may be appropriately set according to the characteristics and specifications of the transmission and the engine, and is not limited to any numerical value. Further, in the present embodiment the predetermined range .DELTA.N _F used in the third judging means 103 has been set equal to .DELTA.N _DE, which may be a larger value may be set to a value smaller than. Note that when the predetermined range ΔN _F = ΔN _DE is set, the predetermined range is equivalent to a range that can be regarded as synchronized, and thus it can be said that it is preferable in terms of control.

1 is a schematic configuration diagram of a power plant and a hydraulic control circuit of a torque converter to which an automatic transmission control device according to an embodiment of the present invention is applied. It is the map which showed the control area of the damper clutch. It is a schematic block diagram of the gear train in the transmission main body of FIG. FIG. 4 is a schematic configuration diagram of a hydraulic control circuit for a friction element of the gear train of FIG. 3. FIG. 4 is a cross-sectional view showing a clutch or a brake that is a friction element of the gear train of FIG. 3. It is a figure (map) explaining the characteristic of the correction | amendment term of the starting supply hydraulic pressure supplied to the 2nd friction element in one Embodiment of this invention. It is a flowchart which shows the lift foot upshift control routine which ECU (electronic control unit) of FIG. 1 performs. It is a flowchart which shows the subroutine of the coupling | bonding side control shown in FIG. It is a flowchart showing a subroutine of the turbine torque T _T calculation shown in FIG. Is a diagram showing turbine speed N _T, the duty ratio D _R of the release side solenoid valve, the temporal variation of the hydraulic pressure supplied to the respective friction elements of the duty ratio D _C and the release side to the binding side of the coupling-side solenoid valve . It is a schematic diagram which shows the principal part structure in one Embodiment of this invention. It is a flowchart which shows the subroutine of the duty factor learning value _DAL shown in FIG. It is a time chart when engagement of the friction element on the coupling side is normally performed. It is a time chart when engagement of the friction element on the coupling side has overshooted. It is a time chart when engagement of the friction element on the coupling side undershoots.

Explanation of symbols

1 Engine 2 Automatic transmission 3 Torque converter (fluid coupling)
4 Transmission body 5 Hydraulic controller 6 ECU (electronic control unit)
7 _NT sensor 8 Vehicle speed sensor 9 Throttle sensor 9a Air flow sensor 10 Transmission mechanism 11 Turbine shaft 15 First clutch (friction element)
17 Second clutch (friction element)
19 Third clutch (friction element)
22 First brake (friction element)
23 Second brake (friction element)
30 Turbine 35 Damper clutch (lock-up clutch)
Reference Signs List 41 damper clutch control valve 42 damper clutch solenoid valve 101-103 first to third determination means 201-203 first to third learning correction means 301 shift determination means 302 input shaft rotational speed estimation means 303 release side friction element control means 304 Coupling side friction element control means 305 Initial oil pressure learning control means

Claims (6)

Shift determination means for determining an upshift when the throttle opening is equal to or less than a predetermined opening;
Based on the input shaft rotation speed at the time of shift determination, the synchronous rotation speed of the input shaft after the shift and the input shaft rotation speed at the time of synchronization determination higher than the synchronization rotation speed of the input shaft by a predetermined rotation speed are calculated. Input shaft rotational speed estimation means;
A release-side friction element control means for reducing the oil pressure of the release-side friction element after the shift determination;
And a coupling-side friction element control means for increasing the hydraulic pressure of the friction element on the coupling side from the initial hydraulic pressure having no capacity after the shift determination with a predetermined gradient, and increasing the hydraulic pressure after reaching the synchronous rotation to complete the coupling. In the control means of the automatic transmission,
Initial hydraulic pressure learning control means for correcting the initial hydraulic pressure of the coupling-side friction element based on the previous shift result;
The initial hydraulic pressure learning control means includes
First determination means for determining whether or not the rate of change of the input shaft rotation speed at the time of synchronization determination is smaller than a predetermined value;
Second determination means for determining whether the input shaft rotation speed change rate has increased after a predetermined period of time has elapsed after the synchronization determination, or whether the input shaft rotation speed change rate is a positive value;
Third determination means for determining whether the input shaft rotation speed is within a predetermined range equal to or greater than the synchronous rotation speed of the input shaft after the shift calculated by the input shaft rotation speed estimation means after the synchronization determination. When,
First learning correction means for correcting the initial hydraulic pressure so that the initial hydraulic pressure at the next shift is lowered when the first determination means determines that the input shaft change rate is smaller than a predetermined value;
If it is determined by the second determination means that the input shaft rotational speed change rate has increased after a lapse of a predetermined period after the synchronization determination or the input shaft rotational speed change rate is a positive value, Second learning correction means for correcting the initial hydraulic pressure so that the hydraulic pressure increases;
If it is determined by the third determination means that the input shaft rotation speed is not within the predetermined range equal to or greater than the synchronous rotation speed of the input shaft after the shift calculated by the input shaft rotation speed estimation means, A control device for an automatic transmission, comprising: third learning correction means for correcting the initial hydraulic pressure so that the initial hydraulic pressure at the time increases. 2. The control device for an automatic transmission according to claim 1, wherein the correction amount for the initial hydraulic pressure by the second learning correction means is set to a value larger than the correction amount for the initial hydraulic pressure by the third learning correction means. . A high-speed side friction element and a low-speed side friction element for establishing a high-speed side shift stage and a low-speed side shift stage, respectively;
In a shift control device for an automatic transmission in which the high speed side friction element is engaged after the low speed side friction element is disengaged, and an upshift from the low speed side gear stage to the high speed side gear stage is executed.
An initial hydraulic pressure learning control means for correcting the initial hydraulic pressure of the friction element on the high speed side based on a previous shift result when an upshift is executed by releasing the accelerator pedal;
The initial hydraulic pressure learning control means
When determining that the change rate of the input shaft rotational speed of the transmission at the time of the upshift synchronization determination is smaller than a predetermined value, the initial hydraulic pressure is corrected so that the initial hydraulic pressure at the next shift is reduced. A control device for an automatic transmission. A high-speed side friction element and a low-speed side friction element for establishing a high-speed side shift stage and a low-speed side shift stage, respectively;
In a shift control device for an automatic transmission in which the high speed side friction element is engaged after the low speed side friction element is disengaged, and an upshift from the low speed side gear stage to the high speed side gear stage is executed.
An initial hydraulic pressure learning control means for correcting the initial hydraulic pressure of the friction element on the high speed side based on a previous shift result when an upshift is executed by releasing the accelerator pedal;
The initial hydraulic pressure learning control means
When it is determined that the change rate of the input shaft rotation speed of the transmission has increased after a predetermined period has elapsed after the synchronization determination of the upshift or the change rate of the input shaft rotation speed is a positive value, A control device for an automatic transmission, wherein the initial hydraulic pressure is corrected so that the initial hydraulic pressure increases in the automatic transmission. A high-speed side friction element and a low-speed side friction element for establishing a high-speed side shift stage and a low-speed side shift stage, respectively;
In a shift control device for an automatic transmission in which the high speed side friction element is engaged after the low speed side friction element is disengaged, and an upshift from the low speed side gear stage to the high speed side gear stage is executed.
An initial hydraulic pressure learning control means for correcting the initial hydraulic pressure of the friction element on the high speed side based on a previous shift result when an upshift is executed by releasing the accelerator pedal;
The initial hydraulic pressure learning control means
After determining the synchronization of the upshift, if it is determined that the rotation speed of the input shaft of the transmission is not within a predetermined range, the initial hydraulic pressure is corrected so that the initial hydraulic pressure at the next shift is increased. Automatic transmission control device. 6. The control apparatus for an automatic transmission according to claim 5, wherein the predetermined range is set to a rotational speed at least equal to or greater than the synchronous rotational speed of the input shaft after the shift.

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