JP6648357B2 - Control device for automatic transmission - Google Patents

Description

  The present invention relates to a control device for an automatic transmission.

  2. Description of the Related Art Conventionally, it is known to reduce the torque of an engine when improving shift shock during an upshift. However, there is a lower limit value at which the engine torque cannot be further reduced (hereinafter referred to as a torque lower limit value), so that a necessary torque reduction amount may not be secured in some cases. Then, it becomes difficult to advance the shift. Therefore, in the technology described in Patent Literature 1, by increasing and correcting the engagement capacity in the inertia phase of the engagement element that is engaged in the shift speed after the shift by the insufficient torque down amount, the shift shock is caused while the shift is advanced. Has improved.

JP 2004-314842 A

  However, if the engagement capacity in the inertia phase is corrected to be increased, the vehicle acceleration during the inertia phase increases, so that the acceleration change when the vehicle acceleration decreases at the end of the inertia phase increases, which may give a driver a sense of incongruity. .

  SUMMARY OF THE INVENTION The present invention has been made in view of the above problem, and an object of the present invention is to provide a control device for an automatic transmission that can suppress discomfort given to a driver during an upshift.

In order to achieve the above object, in the control device for an automatic transmission according to the present invention , the control device is arranged between a power source and a driving wheel, and is released by releasing a first fastening element and fastening a second fastening element. In the control device of the automatic transmission that shifts, when an upshift is requested, during the inertia phase, a request is made to decrease the torque of the power source by a first predetermined amount, and the second fastening element is required. Requesting a torque increase by adding a third predetermined amount to the torque of the power source at the end of the inertia phase, and adding a third predetermined amount to the torque of the power source at the end of the inertia phase. estimating the difference between the vehicle acceleration, and when the difference is the fourth predetermined amount or less, you and inhibits a request for the torque-up.

  Therefore, it is possible to suppress a change in acceleration at the end of the inertia phase while securing the shift speed, and it is possible to suppress a feeling of discomfort given to the driver during an upshift.

1 is a schematic diagram illustrating a system configuration of an automatic transmission according to a first embodiment. FIG. 5 is a common speed diagram illustrating a change state of a rotating element when the automatic transmission according to the first embodiment upshifts. 5 is a flowchart illustrating an upshift process according to the first embodiment. FIG. 3 is a characteristic diagram illustrating a relationship between an engine speed and an engine torque according to the first embodiment. 6 is a time chart illustrating an upshift process according to the first embodiment. 5 is a performance priority determination map according to the first embodiment. 5 is a performance requirement realization control map showing the contents executed by the performance requirement realization control of the first embodiment.

  FIG. 1 is a schematic diagram illustrating a system configuration of the automatic transmission according to the first embodiment. The engine 1 controls the engine torque Te by an accelerator pedal operated by a driver or a throttle valve that opens and closes according to a control command, and outputs a driving force. The driving force of the engine 1 is input to an input shaft Input of the automatic transmission 2. The automatic transmission 2 is provided between a plurality of coaxially arranged input shafts Input and output shafts Output by a plurality of planetary gear sets constituting a rotating element (not shown) and hydraulic pressure output from a control valve 23 for controlling hydraulic pressure. A plurality of fastening elements to be activated. The automatic transmission 2 switches a power transmission path by a combination of engagement and release of a plurality of engagement elements to realize a desired gear. In the first embodiment, for the sake of explanation, a fastening element that achieves a certain low speed stage is a first fastening element CL1, and a fastening element that achieves a certain high speed stage is a second fastening element CL2. The case where the driving force is transmitted from the input shaft Input to the output shaft Output via the first rotating member M1 is the low speed stage, and the case where the driving force is transmitted from the input shaft Input to the output shaft Output via the second rotating member M2 is the high speed stage. And Upshifting from the low gear to the high gear is achieved by releasing the first fastening element CL1 and fastening the second fastening element CL2.

  An engine controller (hereinafter, referred to as an ECU) 10 controls the throttle valve of the engine 1 in response to accelerator pedal opening information of an APO sensor 22 for detecting a driver's accelerator pedal operation amount or a request from another controller. Controls the opening TVO, fuel injection amount, etc. Thus, the engine torque Te output from the engine 1 is controlled. An automatic transmission controller (hereinafter, referred to as ATCU) 20 determines a target shift speed based on accelerator pedal opening information and vehicle speed, and outputs a hydraulic pressure command for generating a fastening torque to a necessary fastening element. . As a result, the gear is controlled to a gear corresponding to the traveling state.

  In the vehicle provided with the automatic transmission according to the first embodiment, the shift lever 21 operated by the driver is provided with a D range, and a drive range (hereinafter, referred to as a D range) requesting an automatic shift and a driver are provided. And a manual range (hereinafter, referred to as an M range) for shifting gears according to the gear shifting intention. In the M range, an upshift request switch, a downshift request switch, and a neutral position for maintaining the current gear position are provided. When the driver operates the upshift from the neutral position, the upshift request switch is turned on and an upshift request is output.When the driver operates the downshift from the neutral position, the downshift request switch is turned off. And a downshift request is output.

  FIG. 2 is a common speed diagram showing a change state of a rotating element when the automatic transmission according to the first embodiment upshifts. In FIG. 2, the relationship among the input shaft rotation speed (the same rotation speed as the engine rotation speed Ne), the output shaft rotation speed, the first rotation member rotation speed, and the second rotation member rotation speed is shown in order from the left. A straight line connecting the rotation speeds is called a rigid lever. In the case of the automatic transmission 2, the vehicle speed hardly changes because the speed is changed instantaneously. Accordingly, the rigid lever rotates around the output shaft rotation speed. At the low speed stage, the first fastening element CL1 is fastened, so that the rigid lever has an output shaft speed of VSP1 and an engine speed Ne of Ne1. When an upshift is performed from this state, the first fastening element CL1 is released and the second fastening element CL2 is fastened. At this time, since the output shaft rotation speed hardly changes, the rigid lever rotates clockwise around VSP1 in FIG. 2, and the engine rotation speed Ne becomes Ne2 (<Ne1).

  At this time, if the engine 1 is outputting a positive torque, the engine speed Ne cannot be reduced quickly, and it is difficult to secure a shift speed. Therefore, during the inertia phase in which the upshift is started and the gear ratio actually changes, the engine 1 is requested to reduce the torque (hereinafter, referred to as a required torque reduction amount Tdown), thereby achieving a quick shift.

  However, the engine 1 has a torque lower limit value Tmin that cannot be further reduced. Therefore, if the required torque down amount Tdown cannot be all reduced, it becomes difficult to advance the inertia phase. Therefore, the engagement torque Tcl of the second engagement element CL2 is increased based on the difference between the current engine torque Te and the torque lower limit Tmin and the required torque reduction amount Tdwon. As a result, the rigid lever can be pulled up to the second fastening element CL2 side, and the inertia phase can proceed even if the engine torque Te does not decrease (see time t2 to t3 in FIG. 5).

  At this time, during the inertia phase, since the rigid lever is rotated by the fastening torque Tcl of the second fastening element CL2, the engine speed Ne is forcibly reduced. Then, since the amount of increase in the fastening torque of the second fastening element CL2 and the inertia torque generated when the engine speed Ne is reduced are output from the output shaft Opput, the vehicle acceleration G during the inertia phase increases. Thereafter, when the inertia phase ends, the inertia torque disappears, so that the vehicle acceleration G becomes the acceleration after the normal upshift (see the dotted line after time t3 in FIG. 5). Then, a step between the vehicle acceleration during the inertia phase (hereinafter referred to as “Gip”) and the vehicle acceleration after the inertia phase (hereinafter referred to as “Gend”) becomes large, and there is a possibility that the driver may feel uncomfortable. . Therefore, in the first embodiment, when the level difference between Gip and Gend is large, a predetermined torque Tup is added to the engine torque Te after the inertia phase is completed, so that the level difference between Gip and Gend is reduced.

(Upshift processing)
FIG. 3 is a flowchart illustrating the upshift processing according to the first embodiment.
In step S1, performance priority determination processing is performed. Details of the performance priority determination processing will be described later.
In step S2, a shift target value is calculated. The shift target value is the engagement torque Tcl of the second engagement element CL2, which is a reference when performing a normal shift, and the required torque down amount Tdown during the inertia phase.

In step S3, a torque lower limit value Tmin, which is a minimum engine torque that can be handled by the engine speed Ne during the inertia phase, and a reference engagement torque Tcl of the second engagement element CL2 during the inertia phase are calculated.
In step S4, it is determined whether or not the required torque down amount Tdown is larger than the allowable torque down value Tdownmax. If it is larger, the process proceeds to step S6, and if smaller than Tdwonmax, the process proceeds to step S5. Here, the allowable torque down value Tdownmax is a difference between the basic engine torque Te and Tmin calculated from the engine speed Ne and the accelerator pedal opening. Therefore, when Tdown> Tdownmax, the required torque down amount cannot be satisfied, and when Tdown ≦ Tdownmax, the required torque down amount can be satisfied.
In step S5, since the required torque reduction amount Tdown during the inertia phase can be satisfied, the upshift is started while requesting the required torque reduction amount Tdown from the ECU 10 to the ECU 10. Further, a later-described shift start flag F1 is reset to 0.

In step S6, a correction torque α to be added to the reference engagement torque Tcl of the second engagement element CL2 during the inertia phase is calculated based on the difference between Tdown and Tdownmax. When the difference between Tdown and Tdownmax is large, α is increased, and when the difference is small, α is decreased.
In step S7, the vehicle acceleration G during the inertia phase and the vehicle acceleration G after the end of the inertia phase are estimated and calculated based on α, and the difference ΔG1 is estimated and calculated.
In step S8, it is determined whether or not ΔG1 is equal to or smaller than a predetermined value ΔGx. If ΔG1 is equal to or smaller than ΔGx, the process proceeds to step S9. Here, the predetermined value ΔGx is an acceleration change amount threshold value that is considered to give a sense of incongruity to the driver.A change in acceleration larger than ΔGx is likely to cause discomfort to the driver. Does not give a sense of incongruity.

In step S9, even if the correction torque α is added during the inertia phase, since the change in acceleration at the end of the inertia phase is small, the torque is reduced to Tdownmax, and α is added to the engagement torque Tcl of the second engagement element CL2. Upshift by value. Further, a later-described shift start flag F1 is reset to 0.
In step S10, the engine torque addition amount Tup after the end of the inertia phase is calculated. The engine torque addition amount Tup is an engine torque that can eliminate the difference between ΔG1 and ΔGx. It is sufficient that ΔG1 is equal to or less than ΔGx as a result of adding Tup.

In step S11, it is determined whether or not Tup is equal to or smaller than Tup_max. If Tup is equal to or smaller than Tup_max, the process proceeds to step S12; otherwise, the process proceeds to step S13. Tup_max is a limit value for increasing the engine torque.
FIG. 4 is a characteristic diagram illustrating a relationship between the engine speed and the engine torque according to the first embodiment. A plurality of lines in FIG. 4 indicate characteristics set according to the throttle valve opening TVO. The engine speed before the start of the inertia phase is Ne_before, and the engine speed at the end of the inertia phase is Ne_after. As shown in FIG. 4, when the engine torque is P1_before in Ne_before and the engine speed Ne becomes Ne_after due to the end of the inertia phase, the highest torque becomes P1_after_max even if the throttle valve opening TVO is controlled. At this time, even if P1_after is requested by Tup, it is not feasible. That is, Tup_max is defined by the difference between the basic engine torque Te and P1_after_max. Therefore, if Tup ≦ Tup_max, all of Tup can be satisfied, and the process proceeds to step S12. On the other hand, if Tup> Tup_max, all the Tups cannot be satisfied, so the process proceeds to step S13.

In step S12, the torque is reduced to Tdownmax, α is added to the reference engagement torque Tcl of the second engagement element CL2 to perform an upshift, and Tup is added to the engine torque Te at the end of the inertia phase. Further, a later-described shift start flag F1 is reset to 0. This suppresses a change in acceleration due to an upshift.
In step S13, the shift start flag F1 is set to 1, and the process returns to the performance priority determination process in step S1 to determine the performance priority again.

FIG. 5 is a time chart illustrating the upshift processing of the first embodiment.
At time t1, when an upshift request is output, the engagement pressure of first engagement element CL1 is reduced to a level that does not cause slip, and precharging of second engagement element CL2 is started. When the precharge is completed and the second fastening element CL2 is ready to generate a certain fastening torque, the fastening pressure of the first fastening element CL1 is further reduced, and the first fastening element CL1 is released.
At the time t2, when the inertia phase starts, the required torque down amount Tdown is performed, and the fastening torque of the second fastening element CL2 is increased. At this time, since Tdowm cannot be satisfied by Tmin, α is added to the fastening torque Tcl of the second fastening element CL2 to increase the fastening torque of the second fastening element CL2. The engagement pressure Pup that generates the engagement torque obtained by adding α is higher than the engagement pressure Pnor that generates the reference engagement torque Tcl in FIG. Thus, even when a sufficient amount of torque reduction cannot be secured, the inertia phase can be advanced.
At time t3, when the engine speed Ne decreases to the inertia phase end speed, the torque reduction ends, and the second fastening element CL2 further increases the fastening pressure toward complete engagement. At this time, Tup is added to the basic engine torque Te as the engine torque. Accordingly, the vehicle acceleration G is also a Gend that is raised by ΔG (Tup) from the Gend before Tup is added, and a change in vehicle acceleration during the inertia phase can be suppressed, and a sense of discomfort given to the driver is suppressed. it can. At time t4, when the increase in the engine torque Te is completed, the second engagement element CL2 increases the engagement pressure and shifts to complete engagement.

(About performance priority judgment processing)
Next, the performance priority determination processing will be described. FIG. 6 is a performance priority determination map according to the first embodiment. The vehicle according to the first embodiment has a D range and an M range. Further, it has a mode switch for setting an operation mode, and has three modes of a sports mode, a normal mode, and an eco mode (comfort mode). In the sport mode, the responsiveness is more important than the suppression of the shift shock. In the normal mode, the balance between the suppression of the shift shock and the responsiveness is emphasized. In the eco mode, the suppression of the shift shock is more important than the responsiveness. When the accelerator pedal opening is larger than APO1 (sixth predetermined value), since the intention of acceleration is strong, responsiveness is emphasized, and the accelerator pedal opening is smaller than APO1 and APO2 (<APO1: the seventh predetermined value). When the accelerator pedal opening is smaller than APO2, the emphasis is placed on suppressing shift shocks because the intention of acceleration is weak and acceleration fluctuations are likely to be worrisome. In the vehicle of the first embodiment, based on the relationship between the performance based on the range position, the performance based on the driving mode, and the performance based on the accelerator pedal opening, responsive importance control (hereinafter referred to as Rescon) and balance. Three performance requirement realization controls such as priority control (hereinafter referred to as Balcon) and shock suppression priority control (hereinafter referred to as Shockcon) are appropriately selected.

(Response-oriented control)
FIG. 7 is a performance requirement realization control map showing the contents executed by the performance requirement realization control of the first embodiment. In FIG. 7, A1 can realize all Tdown, A2 can realize all Tup, B1 can partially realize Tdown, B2 can partially realize Tup, C1 can not realize Tdown at all , C2 represent the case where Tup cannot be realized at all. Hereinafter, these combinations are described as (A1 / A2) or (B1 / C2).

In the case of (A1 / A2) In this case, the addition of α and the Tup are not performed in all the performance request realization controls. This is because if Tdown is all satisfied during the upshift, the shift speed can be secured.

(B1 / A2) In this case, Tdown only partially satisfies and Tup satisfies all. Therefore, in Rescon and Balcon, α is added based on the difference between Tdown and Tdownmax, and the inertia phase proceeds. Further, Tup is performed according to ΔG1. Thereby, the shift shock is suppressed as much as possible. In Shockcon, α that is equal to or smaller than ΔGx (hereinafter referred to as α1) is added, and Tup is performed in accordance with ΔG1 due to α1. As a result, although the progress of the inertia phase is slowed down, the shift shock is suppressed by suppressing ΔG1.

In the case of (B1 / B2) In this case, both Tdown and Tup only partially satisfy. Therefore, in Rescon, α is added, and Tup is performed as much as possible. Due to insufficient Tup, shift shock cannot be sufficiently suppressed, but the shift speed is secured. In Balcon and Shockcon, α1 that is equal to or smaller than ΔGx is added, and Tup is performed according to ΔG1 due to α1. As a result, although the progress of the inertia phase is slowed down, the shift shock is suppressed by suppressing ΔG1.

In the case of (B1 / C2) In this case, Tdown only partially satisfies, and Tup cannot satisfy at all. Therefore, in Rescon, α is added, and Tup is not performed. Thus, the shift shock cannot be suppressed, but the shift speed is secured. At Balcon, α1 is added, and Tup is not performed. Thereby, the shift shock is suppressed while increasing the shift speed. In Shockcon, α and α1 are not added and Tup is not performed. Therefore, although the shift speed cannot be secured, the occurrence of the shift shock itself is suppressed.

In the case of (C1 / C2) In this case, both Tdown and Tup cannot be satisfied at all. Therefore, in Rescon, α is added, and Tup is not performed. Thus, the shift shock cannot be suppressed, but the shift speed is secured. At Balcon, α1 is added, and Tup is not performed. Thereby, the shift shock is suppressed while increasing the shift speed. In Shockcon, α and α1 are not added and Tup is not performed. Therefore, although the shift speed cannot be secured, the occurrence of the shift shock itself is suppressed.

  In this way, in accordance with the driver's request, a combination of performance requirement realization control is set, and the process first proceeds to step S2 and later with a combination of (A1 / A2), and if No is determined in step S11, By changing the combination to (B1 / A2), (B1 / B2), (B1 / C2), or (C1 / C2), it is possible to realize an upshift according to the driving state or the driver's request.

As described above, the first embodiment has the following advantages.
(1) Arranged between the engine 1 (power source) and the drive wheels 3 to fasten the first fastening element CL1 (release the first fastening element and fasten the second fastening element CL2 (second fastening element)) In an automatic transmission control device that upshifts by
When an upshift is requested, during the inertia phase, a request is made to decrease the torque of the engine 1 by Tdownmax (a first predetermined amount), and the engagement torque of the second engagement element CL2 is set to α (second A predetermined amount) is added, and at the end of the inertia phase, a request for increasing the torque by adding Tup (third predetermined amount) to the torque of the engine 1 is requested.
Therefore, it is possible to suppress a change in acceleration at the end of the inertia phase while securing a shift speed, and it is possible to suppress a feeling of discomfort given to the driver during an upshift.

(2) If it is estimated that Tup cannot be added before the start of the inertia phase, α is set to α1 (decreased).
That is, by suppressing an increase in vehicle acceleration during the inertia phase, a change in vehicle acceleration at the end of the inertia phase can be suppressed.

(3) The difference ΔG1 between the vehicle acceleration during the inertia phase and the vehicle acceleration at the end of the inertia phase is estimated. If ΔG1 is equal to or smaller than ΔGx (a fourth predetermined amount), the request for increasing the torque is prohibited.
Therefore, when the vehicle acceleration fluctuation is small, unnecessary fuel increase can be suppressed to improve fuel efficiency.

(4) When a torque down request to lower the torque of the engine 1 by Tdown (fifth predetermined amount) larger than Tdownmax is possible, α and Tup are reduced. Specifically, α is set to 0, Tup is set to 0, and no torque increase request is made.
That is, when all of Tdown can be satisfied, the inertia phase can be advanced without increasing the fastening torque of the second fastening element CL2. In this case, an increase in vehicle acceleration during the inertia phase caused by adding α to the second fastening element CL2 can be avoided, and ΔG1 is small, so that there is no need to issue a torque increase request. Thereby, fuel efficiency can be improved.

(5) having an accelerator pedal opening sensor 22 for detecting the accelerator pedal opening;
If it is estimated that the accelerator pedal opening is equal to or more than APO1 (sixth predetermined value) and that Tup cannot be added, it is prohibited to reduce α.
That is, if Tup cannot be added, ΔG1 at the end of the inertia phase will increase, and α should be reduced. However, since the driver depresses the accelerator pedal greatly and has a strong intention to accelerate, responsiveness is required. Therefore, at this time, the shift response can be ensured by adding α to secure the shift speed.

(6) having an accelerator pedal opening sensor 22 for detecting an accelerator pedal opening;
If the accelerator pedal opening is less than APO2 (sixth predetermined value) and it is estimated that Tup cannot be added, the addition of α and Tup is prohibited.
That is, when the accelerator pedal opening is small, the driver's intention to accelerate is weak, and the ride comfort should be emphasized. Therefore, at this time, by prohibiting the addition of α and Tup, ΔG1 can be reduced even if the shift time takes, and the uncomfortable feeling given to the driver can be suppressed.

  As described above, the present invention has been described based on the embodiments based on the embodiments. However, the present invention is not limited to the above configuration, and other changes may be made. In the first embodiment, the automatic transmission including the engine 1 is described as an example. However, the present invention may be applied to a hybrid vehicle including an electric motor as a power source or an electric vehicle including only an electric motor. In the first embodiment, for the sake of explanation, an example in which one upshift is achieved by releasing one fastening element and fastening one fastening element has been described. However, the upshift is performed by a combination of a plurality of fastening elements. The present invention can be similarly applied to an automatic transmission that performs the same.

DESCRIPTION OF SYMBOLS 1 Engine 2 Automatic transmission 3 Drive wheel 10 Engine controller 20 Automatic transmission controller 21 Shift lever 22 APO sensor
Input Input axis
Output Output shaft
CL1 First fastening element CL1
CL2 Second fastening element CL2

Claims (5)

In the control device of the automatic transmission, which is arranged between the power source and the drive wheels, releases the first fastening element, and upshifts by fastening the second fastening element,
When an upshift is requested, during the inertia phase, a request is made to decrease the torque of the power source by a first predetermined amount, and a second predetermined amount is set to the fastening torque of the second fastening element. At the end of the inertia phase, request a torque increase to add a third predetermined amount to the torque of the power source , estimate the difference between the vehicle acceleration during the inertia phase and the vehicle acceleration at the end of the inertia phase, The control device for an automatic transmission , wherein when the difference is equal to or less than a fourth predetermined amount, the request for increasing the torque is prohibited . The control device for an automatic transmission according to claim 1,
When it is estimated before the start of the inertia phase that the third predetermined amount cannot be added, the second predetermined amount is reduced as compared with a case where the third predetermined amount can be added. Machine control device. The control device for an automatic transmission according to claim 1 or 2 ,
When a torque-down request to reduce the torque of the power source by a fifth predetermined amount larger than the first predetermined amount is possible, the torque of the power source is reduced by a first predetermined amount, A control device for an automatic transmission, wherein the predetermined amount and the third predetermined amount are reduced. The control device for an automatic transmission according to claim 2,
Has an accelerator pedal opening sensor that detects the accelerator pedal opening,
When it is estimated that the accelerator pedal opening is equal to or more than a sixth predetermined value, and the third predetermined amount cannot be added, the second predetermined amount is compared with the case where the third predetermined amount can be added. A control device for an automatic transmission, wherein a reduction in a predetermined amount is prohibited. The control device for an automatic transmission according to claim 2,
Has an accelerator pedal opening sensor that detects the accelerator pedal opening,
When the accelerator pedal opening is less than the seventh predetermined value and it is estimated that the third predetermined amount cannot be added, the addition of the second predetermined amount and the third predetermined amount is prohibited. A control device for an automatic transmission, comprising:

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