JP2015140880A - Gear change control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gear change control device which can properly decide three control operation amounts by using a gear change model even if there are the three control operation amounts with respect to two gear change target values, and can suppress a gear change shock.SOLUTION: A gear change control device comprises an automatic transmission having a plurality of engagement devices for transmitting torque between an input shaft and an output shaft, and a control part. The control part sets output shaft torque and an input shaft rotation change amount as gear change target values, sets three values of input shaft torque, a torque capacity of the engagement device at a release side, and a torque capacity of the engagement device at an engagement side as control operation amounts, and calculates the control operation amounts on the basis of a gear change model while setting a share rate of torque which is possessed by the engagement devices at the release side and the engagement side at a gear change as a constriction condition. When a progress degree of a torque phase is not lower than a prescribed ratio, the control part stops an increase of the share rate xhi of the torque of the engagement device at the engagement side, sets the share rate as a prescribed value x1, and lowers the output torque of a drive force source according to a difference between the share rate xt of the torque corresponding to the progress degree of the engagement device at the engagement side and the prescribed value x1.

Description

  The present invention relates to a transmission control device.

  Conventionally, there is a shift control device. For example, Patent Literature 1 discloses an input shaft that receives a driving force from a driving engine, an output shaft that transmits driving force to wheels, and a plurality of engagements that set power transmission characteristics between the input shaft and the output shaft. And a control means for controlling the release and engagement of the engagement element at the time of shifting. The control means is a target in which the rotation speed of the input shaft defines a change in the rotation speed of the input shaft in inertia phase control. An automatic transmission technique is disclosed in which the hydraulic pressure of an engagement element on the engagement side is changed based on a shift model of an automatic transmission so as to follow a target rotational speed set based on a pattern.

JP 2000-97325 A

  The technique of the above-mentioned patent document 1 executes a shift by operating one control object for one shift target value or by operating two control objects for two shift target values. . By the way, the shift target value is set with two values, and the control operation amount is set to the torque on the rotating member on the input shaft side, the torque capacity of the engagement device on the engagement side at the time of shifting, and the release side at the time of shifting. The gear model is used by setting the torque sharing rate of the transmission torque that is set by three values of the torque capacity of the engagement device and is set by the engagement device on the engagement side and the engagement device on the release side when shifting. Thus, a technology for executing a shift of an automatic transmission can be considered. According to this technology, even if there are three control operation amounts for two shift target values, the three control operation amounts are appropriately set using a shift model. Can be determined.

  Here, due to variations in the engagement devices, the inertia phase starts before the transmission torque is completely transferred from the engagement device on the release side to the engagement device on the engagement side, and a shift shock may occur. There is.

  The object of the present invention is to appropriately determine the three control operation amounts using the shift model even if there are three control operation amounts for the two shift target values, and to suppress the shift shock. It is an object of the present invention to provide a speed change control device capable of

  The speed change control device of the present invention includes an input shaft to which power from a driving force source is input, an output shaft that outputs power to the drive wheels, and a plurality of torque transmissions between the input shaft and the output shaft. An automatic transmission that shifts by switching between engagement and disengagement of the engagement device, and the automatic transmission based on a shift model that determines a control operation amount for realizing a shift target value. A control unit that controls the two values of the output shaft torque and the input shaft rotation change amount as the shift target value, the input shaft torque, the torque capacity of the engagement device on the disengagement side, and the engagement. The three values of the torque capacity of the engagement device on the engagement side are set as the control operation amount, and the ratio of the torques that the engagement device on the engagement side and the engagement device on the release side handle at the time of shifting is set as a constraint condition. The control operation amount is calculated based on the shift model. The control unit stops the increase of the torque sharing ratio of the engagement device on the engagement side to a predetermined value when the degree of progress of the torque phase is greater than or equal to a predetermined ratio during shifting, and The output torque of the driving force source is reduced according to the difference between the torque sharing rate according to the degree of progress of the engagement device on the side and the predetermined value.

  The transmission control device according to the present invention includes an input shaft to which power from a driving force source is input, an output shaft that outputs power to the drive wheels, and a plurality of units that transmit torque between the input shaft and the output shaft. And a control for controlling the automatic transmission based on a shift model for determining a control operation amount for realizing a shift target value. A section.

  The control unit uses two values of the output shaft torque and the input shaft rotation change amount as a shift target value, and includes three values of the input shaft torque, the torque capacity of the disengagement side engagement device, and the torque capacity of the engagement side engagement device. The control operation amount is calculated based on the shift model, with the value as the control operation amount, and with the torque sharing ratio of the engagement device and the disengagement engagement device at the time of shifting as a constraint. In addition, when the degree of progress of the torque phase is greater than or equal to a predetermined ratio during the shift, the control unit stops increasing the torque sharing rate of the engagement device on the engagement side to a predetermined value, and The output torque of the driving force source is reduced according to the difference between the torque sharing rate according to the degree of progress of the engagement device and a predetermined value. According to the shift control device of the present invention, even if there are three control operation amounts for two shift target values, the three control operation amounts can be appropriately determined using the shift model, and There is an effect that the shock can be suppressed.

FIG. 1 is a schematic configuration diagram of a vehicle according to an embodiment. FIG. 2 is a schematic configuration diagram of the automatic transmission according to the embodiment. FIG. 3 is a diagram illustrating an operation engagement table of the automatic transmission according to the embodiment. FIG. 4 is a block diagram of the shift control apparatus according to the embodiment. FIG. 5 is a flowchart illustrating an example of shift control according to the embodiment. FIG. 6 is a time chart according to an example of the shift control. FIG. 7 is a flowchart of the shift control related to the power-on up shift according to the embodiment. FIG. 8 is a time chart of the shift control related to the power-on up shift according to the embodiment.

  Hereinafter, a shift control device according to an embodiment of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by this embodiment. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same.

[Embodiment]
The embodiment will be described with reference to FIGS. 1 to 8. The present embodiment relates to a shift control device. 1 is a schematic configuration diagram of a vehicle according to an embodiment of the present invention, FIG. 2 is a schematic configuration diagram of an automatic transmission according to the embodiment, and FIG. 3 is an operation engagement table of the automatic transmission according to the embodiment. FIG. 4 is a block diagram of the shift control device according to the embodiment, FIG. 5 is a flowchart illustrating an example of the shift control according to the embodiment, FIG. 6 is a time chart according to an example of the shift control, and FIG. FIG. 8 is a time chart of the shift control related to the power-on-up shift according to the embodiment.

  As shown in FIG. 1, the vehicle 10 includes an engine 12, a torque converter 14, drive wheels 26, and a transmission control device 1. The shift control device 1 according to the present embodiment includes an automatic transmission 18 and a control unit 70. The engine 12 is an example of a driving force source, and converts the combustion energy of the fuel into a rotational motion and outputs it. The engine 12 is connected to the input shaft 16 of the automatic transmission 18 via the torque converter 14. An output shaft 20 of the automatic transmission 18 is connected to left and right drive wheels 26 via a differential gear 22 and left and right drive shafts 24.

  The torque converter 14 transmits torque by fluid transmission between a pump impeller connected to the engine 12 and a turbine runner connected to the input shaft 16 of the automatic transmission 18. The torque converter 14 further has a lockup clutch.

  The automatic transmission 18 includes one or a plurality of planetary gear devices disposed in a transmission case as a non-rotating member attached to the vehicle body, and a plurality of engagement devices. The automatic transmission 18 is a planetary gear type stepped automatic transmission in which a plurality of gear stages are alternatively realized by an engagement device. The automatic transmission 18 performs clutch-to-clutch shift by re-holding a plurality of engagement devices, that is, by releasing the engagement device on the release side and engaging the engagement device on the engagement side. Each of the plurality of engaging devices transmits torque between the input shaft 16 and the output shaft 20. The engagement device of the present embodiment is a hydraulic friction engagement device, for example, a wet multi-plate clutch.

  Engagement and release of the engagement device of the automatic transmission 18 is controlled by a hydraulic control circuit 28. The automatic transmission 18 shifts by switching between engagement and disengagement of the engagement device. The hydraulic control circuit 28 has a pressure regulating valve such as a solenoid valve that controls the hydraulic pressure supplied to each engagement device. The hydraulic control circuit 28 has a function of controlling the torque capacity of each engagement device, that is, the engagement force to an arbitrary value by controlling the supply pressure by adjusting the opening of the pressure regulating valve.

  As shown in FIG. 2, in addition to the input shaft 16 and the output shaft 20, the automatic transmission 18 includes a first planetary gear device 37, a second planetary gear device 9, an intermediate shaft 8, a first clutch C1, and a second clutch. C2, the third clutch C3, the fourth clutch C4, the first brake B1, the second brake B2, the one-way clutch F1, and the like. The automatic transmission 18 has clutches C1, C2, C3, C4 and brakes B1, B2 as a plurality of engagement devices. The input shaft 16 receives power from the engine 12. The output shaft 20 outputs power to the drive wheels 26.

  The first planetary gear device 37 is a double pinion type, and includes a first ring gear 38, an inner pinion gear 39 a, an outer pinion gear 39 b, a first sun gear 41, and a first carrier 40. The inner pinion gear 39a meshes with the first sun gear 41 and the outer pinion gear 39b. The outer pinion gear 39b meshes with the inner pinion gear 39a and the first ring gear 38. The first carrier 40 rotatably supports a plurality of gear pairs composed of pinion gears 39a and 39b.

  The second planetary gear mechanism 9 is a composite planetary that combines a double pinion type component and a single pinion type component. The double pinion type component includes a second ring gear 30, a second sun gear 31, a short pinion gear 33 a, a long pinion gear 33 b, and a second carrier 34. Short pinion gear 33a meshes with second sun gear 31 and long pinion gear 33b. The long pinion gear 33 b meshes with the short pinion gear 33 a and the second ring gear 30. The single pinion type component includes a third sun gear 32, a long pinion gear 33 b, and a second ring gear 30. The third sun gear 32 is disposed adjacent to the second sun gear 31 on the same axis. Long pinion gear 33 b meshes with third sun gear 32 and second ring gear 30. The second carrier 34 rotatably supports a plurality of gear pairs composed of a short pinion gear 33a and a long pinion gear 33b.

  The intermediate shaft 8 is connected to the input shaft 16 and rotates integrally with the input shaft 16. The first sun gear 41, the third sun gear 32, and the second sun gear 31 are disposed on the radially outer side with respect to the intermediate shaft 8, and are supported so as to be relatively rotatable with respect to the intermediate shaft 8. The first carrier 40 is connected to the intermediate shaft 8 and rotates integrally with the intermediate shaft 8. The first sun gear 41 is fixed to the vehicle body side, for example, a transmission case, and cannot rotate. Therefore, in the first planetary gear device 37, the first sun gear 41 functions as a reaction force receiver, and transmits power between the first carrier 40 and the first ring gear 38.

  The first clutch C <b> 1 connects or disconnects the first ring gear 38 and the second sun gear 31. The second clutch C2 connects or disconnects the intermediate shaft 8 and the second carrier 34. The third clutch C3 connects or disconnects the first ring gear 38 and the third sun gear 32. The fourth clutch C4 connects or disconnects the first carrier 40 and the third sun gear 32. The first brake B1 regulates the rotation of the third sun gear 32 by being engaged. The second brake B2 restricts the rotation of the second carrier 34 by engaging. The one-way clutch F1 allows the second carrier 34 to rotate forward and restricts reverse rotation. Here, the positive rotation direction is the same as the rotation direction of the input shaft 16.

  The second ring gear 30 is connected to the counter drive gear 35. The counter drive gear 35 is disposed on the radially outer side with respect to the intermediate shaft 8 and is supported so as to be rotatable relative to the intermediate shaft 8. The counter drive gear 35 is also the output shaft 20 of the automatic transmission 18. The counter drive gear 35 meshes with the counter driven gear 36. The counter driven gear 36 is connected to the drive pinion gear 42. The drive pinion gear 42 meshes with the ring gear 43 of the differential gear 22.

  The automatic transmission 18 of the present embodiment can selectively establish eight gear stages from the first forward speed to the eighth forward speed. As shown in FIG. 3, at the first gear (1st), the first clutch C1 is engaged. Accordingly, the rotation and torque of the engine 12 transmitted from the input shaft 16 to the first carrier 40 are transmitted from the first ring gear 38 to the second sun gear 31 via the first clutch C1. The one-way clutch F1 is engaged to restrict the rotation of the second carrier 34. Accordingly, the second carrier 34 functions as a reaction force receiver, and rotation and torque can be transmitted from the second sun gear 31 to the second ring gear 30. The rotation and torque transmitted from the second sun gear 31 to the second ring gear 30 are output from the counter drive gear 35 and transmitted to the drive wheels 26 via the counter driven gear 36, the drive pinion gear 42 and the ring gear 43.

  In the second speed gear stage (2nd), as shown in FIG. 3, the first clutch C1 and the first brake B1 are engaged. When the first brake B1 is engaged, the rotation of the third sun gear 32 is restricted. Thereby, the third sun gear 32 functions as a reaction force receiver, and rotation and torque can be transmitted from the second sun gear 31 to the second ring gear 30.

  In the third gear (3rd), the first clutch C1 and the third clutch C3 are engaged. By engaging the third clutch C3, the first ring gear 38 and the third sun gear 32 are connected. That is, the rotation and torque output from the first ring gear 38 are input to the second sun gear 31 via the first clutch C1, and are also input to the third sun gear 32 via the third clutch C3. Output from the ring gear 30.

  In the fourth gear (4th), the first clutch C1 and the fourth clutch C4 are engaged. When the fourth clutch C4 is engaged, the first carrier 40 and the third sun gear 32 are connected. That is, the rotation and torque output from the first planetary gear unit 37 are input to the second sun gear 31 via the first clutch C1, and are input to the third sun gear 32 via the fourth clutch C4. Output from the second ring gear 30.

  In the fifth gear (5th), the first clutch C1 and the second clutch C2 are engaged. The intermediate shaft 8 and the second carrier 34 are connected by the engagement of the second clutch C2. Therefore, the rotation and torque transmitted from the engine 12 to the input shaft 16 are input to the second sun gear 31 via the first planetary gear unit 37 and the first clutch C1, and via the second clutch C2. It is input to the second carrier 34 and output from the second ring gear 30.

  At the sixth speed (6th), the second clutch C2 and the fourth clutch C4 are engaged. Therefore, the rotation and torque transmitted from the engine 12 to the input shaft 16 are input to the third sun gear 32 via the first planetary gear unit 37 and the fourth clutch C4, and via the second clutch C2. It is input to the second carrier 34 and output from the second ring gear 30.

  In the seventh gear (7th), the second clutch C2 and the third clutch C3 are engaged. Therefore, the rotation and torque transmitted from the engine 12 to the input shaft 16 are input to the third sun gear 32 via the first planetary gear unit 37 and the third clutch C3, and via the second clutch C2. It is input to the second carrier 34 and output from the second ring gear 30.

  At the eighth speed (8th), the second clutch C2 and the first brake B1 are engaged. When the first brake B1 is engaged, the third sun gear 32 functions as a reaction force receiver. Therefore, the rotation and torque input from the intermediate shaft 8 to the second carrier 34 via the second clutch C <b> 2 are output from the second ring gear 30.

  In the present embodiment, among the engagement devices that are re-gripped at the time of shifting, an engagement device that is involved in the establishment of the low gear stage side is referred to as a low gear stage engagement apparatus, and the engagement device that is involved in the establishment of the high gear stage side. Is referred to as a high gear stage engaging device. For example, when an upshift is performed from the second speed gear stage to the third speed gear stage, the first brake B1 is used as the low gear stage engaging device, and the third clutch C3 is used as the high gear stage engaging device. A replacement is made.

  In the present embodiment, among the engagement devices that are re-gripped at the time of a shift, the engagement device that is released at the shift is referred to as a release-side engagement device, and the engagement device that is engaged at the shift is engaged. Is referred to as an engagement device on the engagement side. For example, when an upshift is performed from the second gear to the third gear, the first brake B1 is the disengagement side engagement device, and the third clutch C3 is the engagement side engagement device. .

  Returning to FIG. 1, the control unit 70 controls each unit of the vehicle 10. The control unit 70 of the present embodiment is an electronic control unit that includes a computer. An engine speed sensor 50, a turbine speed sensor 52, and an output shaft speed sensor 54 are connected to the control unit 70. The engine speed sensor 50 detects the engine speed ωe. The turbine rotation speed sensor 52 detects a turbine rotation speed ωt that is the rotation speed of the turbine runner of the torque converter 14. The turbine rotational speed ωt is also the input shaft rotational speed ωi that is the rotational speed of the input shaft 16. The output shaft rotational speed sensor 54 detects an output shaft rotational speed ωo that is the rotational speed of the output shaft 20. The vehicle speed V of the vehicle 10 is calculated from the output shaft speed ωo.

  An accelerator opening sensor 56, a throttle opening sensor 58, and a shift sensor 60 are connected to the control unit 70. The accelerator opening sensor 56 detects the accelerator opening Acc. The throttle opening sensor 58 detects the opening θth of the throttle valve of the engine 12. The shift sensor 60 detects a shift operation SH for the shift lever and the paddle switch.

  As shown in FIG. 4, the control unit 70 includes an engine output control unit 72, a shift control unit 74, and a control operation amount calculation unit 76. The control operation amount calculation unit 76 includes a torque sharing rate calculation unit 78 and a shift target value calculation unit 80.

  The engine output control unit 72 outputs a command value related to the throttle control, fuel injection control, ignition control, and the like of the engine 12 based on the required engine torque. Further, the engine output control unit 72 calculates a required driving force Fdem for the vehicle 10. The required driving force Fdem is calculated based on, for example, the accelerator opening Acc and the vehicle speed V. The engine output control unit 72 calculates a torque value that can generate the required driving force Fdem as the required engine torque Tedem based on the current gear ratio of the automatic transmission 18, the torque ratio t of the torque converter 14, and the like. The torque ratio t is calculated based on, for example, the relationship between the speed ratio (= turbine rotational speed ωt / pump rotational speed ωp (engine rotational speed ωe)), torque ratio t, efficiency, and capacity coefficient.

  The shift control unit 74 executes shift control of the automatic transmission 18. The shift control unit 74 makes a shift determination based on a relationship (shift map or shift diagram) stored in advance with the vehicle speed V and the accelerator opening Acc as variables. If the shift control unit 74 determines that the shift of the automatic transmission 18 should be executed, the shift control unit 74 executes the shift of the automatic transmission 18 and switches from the gear stage before the shift to the gear stage after the shift. The shift control unit 74 outputs to the hydraulic control circuit 28 a hydraulic command signal Sp that engages or releases the engagement device involved in the shift so as to switch the gear stage of the automatic transmission 18 to the target gear stage. The hydraulic pressure command signal Sp includes a hydraulic pressure command value for the hydraulic pressure supplied to the engagement device on the release side and a hydraulic pressure command value for the hydraulic pressure supplied to the engagement device on the engagement side.

  As the shift control, for example, the torque capacity (or hydraulic pressure command of each engagement device at the time of the shift is determined based on a control map determined by the adaptation while evaluating whether the shift shock, the shift time, etc. are appropriate. There is a method of determining the value) and executing the shift of the automatic transmission 18. In the method using such a control map, which shift pattern is a power-on upshift, power-off upshift, power-on downshift, and power-off downshift, and between which gear positions It is necessary to create a different control map for each. Therefore, the more gear stages of the automatic transmission 18 are, the more labor is required for the adaptation work.

  The control unit 70 of the present embodiment executes a shift of the automatic transmission 18 using a shift model that determines a control operation amount for realizing a shift target value, instead of using the above-described control map as the shift control. . The shift target value is a target value of an element that determines a change mode to be realized at the time of shifting, for example, a target value of a shift time and a driving force. The control operation amount is a required value of an element to be operated with respect to the control target, for example, a required value of engine torque and clutch torque.

Hereinafter, the shift control of the automatic transmission 18 using the shift model will be described. The equation of motion during the shift of the automatic transmission 18 is expressed by the following [Equation 1] and [Equation 2].

  The above [Equation 1] and [Equation 2] are derived from the equations of motion of the mutually connected rotating elements constituting the automatic transmission 18 and the relational expression in the planetary gear device constituting the automatic transmission 18. The equation of motion for each rotating element is the torque represented by the product of the inertia in each rotating element and the rate of change in rotational speed with time, the three planetary gear units (sun gear, carrier, ring gear), and the engagement device. It is the equation of motion defined by the torque acting on the members involved in each rotating element among the members on both sides. In addition, the relational expression in the planetary gear device is obtained by using the gear ratio of the planetary gear device (the number of teeth of the sun gear / the number of teeth of the ring gear) and the relationship between the torque in the three members of the planetary gear device and the rate of change in rotational speed with time. Are the relational expressions respectively defining the relations.

  In [Equation 1] and [Equation 2], dωt / dt is the time derivative (time change rate) of the turbine rotational speed ωt, and the angular acceleration of the input shaft 16 as the speed change amount of the rotating member on the input shaft 16 side. (Hereinafter simply referred to as “input shaft angular acceleration”). In the drawings and mathematical formulas, the rate of time change is indicated by a dot on the character. dωo / dt is the time change rate of the output shaft rotational speed ωo and represents the output shaft angular acceleration. The turbine torque Tt is torque on the input shaft 16 as an example of torque on the rotating member on the input shaft 16 side. The turbine torque Tt is also an input shaft torque Ti that is an input torque of the automatic transmission 18. The turbine torque Tt is equivalent to the engine torque Te (= Tt / t) when the torque ratio t of the torque converter 14 is taken into consideration.

  The output shaft torque To is an example of torque on the rotating member on the output shaft 20 side, and is torque on the output shaft 20. The low gear stage side clutch torque Tclow is a release side clutch torque at the time of upshift and an engagement side clutch torque at the time of downshift. The high gear stage side clutch torque Tchi is an engagement side clutch torque at the time of upshift and a release side clutch torque at the time of downshift. Coefficients a1, a2, b1, b2, c1, c2, d1, and d2 in [Equation 1] and [Equation 2] are constants, and are determined by design from the inertia in each rotating element and the gear ratio of the planetary gear device. It is a coefficient. The values of the coefficients a1, a2, b1, b2, c1, c2, d1, and d2 are different for each shift pattern.

  [Equation 1] and [Equation 2] are gear train motion equations of the automatic transmission 18 in which the relationship between the shift target value and the control operation amount is formulated. The shift target value can represent the shift time and the target value of the driving force and can be handled on the gear train motion equation. In the present embodiment, the input shaft angular acceleration dωt / dt is used as an example of a physical quantity representing the shift time. Further, the output shaft torque To is used as an example of a physical quantity representing the driving force. That is, the control unit 70 uses the two values of the output shaft torque To and the input shaft rotation change amount (input shaft angular acceleration dωt / dt) as the shift target value.

  In the present embodiment, the control operation amount for establishing the shift target value is set to three values: turbine torque Tt (the engine torque Te is also agreed), low gear stage side clutch torque Tclow, and high gear stage side clutch torque Tchi. That is, the control unit 70 uses the three values of the input shaft torque Ti, the torque capacity of the disengagement-side engagement device, and the torque capacity of the engagement-side engagement device as the control operation amount. In this case, since the equation of motion is the above two equations [Equation 1] and [Equation 2], there are three control operation amounts. Therefore, the control operation amount that establishes two shift target values is uniquely solved. I can't. Therefore, a study was made to add a constraint condition to the equations of motion of the above [Equation 1] and [Equation 2] to uniquely solve the control operation amount.

  Here, what is difficult in the shift control of the automatic transmission 18 is to control torque transfer (that is, shift progress) between the disengagement side engagement device and the engagement side engagement device. On the other hand, when any one of the control operation amounts is set to a predetermined value in order to determine the three control operation amounts, there are an infinite number of methods such as setting a predetermined value according to each shift pattern. With regard to this predetermined value, for example, if only one of the release side clutch torque and the engagement side clutch torque is set as a restraint condition, tie-ups or blow-ups are likely to occur during a shift, or during a shift There is a possibility that the controllability of the control that causes a tie-up or a blow-up will be lowered. Further, if the engine torque change mode is a constraint condition, it may not be possible to execute engine torque down control that temporarily changes the engine torque during the inertia phase.

Therefore, in this embodiment, the engagement device on the disengagement side is suitable as a restraint condition that can express and control the transfer of torque during the shift, and can deal with any shift pattern. And the torque sharing rate of the transmission torque that is handled by the engagement device on the engagement side. By using the torque sharing rate as a constraint, it is possible to incorporate torque transfer during gear shifting into the equation of motion and uniquely solve the control operation amount. The torque sharing ratio is the total transmission torque (total transmission torque) that must be handled by the disengagement side engagement device and the engagement side engagement device when the automatic transmission 18 is shifted, for example, torque on the input shaft 16. Is the ratio of the transmission torque shared by the two engaging devices with respect to the total transmission torque on the input shaft. In the present embodiment, the torque sharing rate of the low gear stage engaging device is “xlow”, and the torque sharing rate of the high gear stage engaging device is “xhi”. During the shift, each torque sharing rate changes in time series to reflect the torque transfer. Assuming that the value of the torque sharing rate xlow of the low gear stage engaging device at a certain moment is x (for example, 0 ≦ x ≦ 1), each torque sharing rate is expressed by the following equations (1) and (2).
xlow = x (1)
xhi = 1-x (2)

  The relational expression between the low gear stage side clutch torque Tclow and the high gear stage side clutch torque Tchi is the values of the clutch torques Tclow and Tchi converted to the torque on the input shaft 16 and the torque sharing ratio values “x” and “1− x ". Then, a relational expression for calculating the control operation amount is obtained from the relational expressions of the above [Equation 1], [Equation 2] and the low gear stage side clutch torque Tclow and the high gear stage side clutch torque Tchi converted to the torque on the input shaft 16. Derived. From the derived relational expression, turbine torque Tt, low gear stage side clutch torque Tclow, and high gear stage side clutch torque Tchi are calculated.

  The turbine torque Tt is represented by a relational expression using torque sharing ratio values “x”, “1-x”, input shaft angular acceleration dωt / dt, output shaft torque To, and the like. Similarly, the low gear stage side clutch torque Tclow is represented by a relational expression using a torque sharing ratio value “x”, input shaft angular acceleration dωt / dt, output shaft torque To, and the like. The high gear stage side clutch torque Tchi is represented by a relational expression using a torque sharing ratio value “1-x”, input shaft angular acceleration dωt / dt, output shaft torque To, and the like. In other words, the speed change model of the present embodiment includes the equation of motion ([Expression 1], [Expression 2]) of the automatic transmission 18 including the shift target value and the control operation amount, and the relationship (Expression (1) ) And equation (2)), the control operation amount is calculated based on the shift target value. As described above, in the present embodiment, the shift of the automatic transmission 18 is executed using the shift model by adding the constraint condition set by the torque sharing ratio x to the above [Expression 1] and [Expression 2]. .

  The control operation amount calculation unit 76 shown in FIG. 4 calculates the control operation amount based on the shift target value using the shift model while the automatic transmission 18 is shifting. Specifically, the control operation amount calculation unit 76 includes a torque sharing rate calculation unit 78 and a shift target value calculation unit 80. The torque sharing rate calculation unit 78 stores, for example, a shift progress map that defines a mode for changing the torque sharing rate x. The shift progress map shows the correspondence between the elapsed time during the shift and the torque sharing rate x to be realized. The elapsed time during the shift is an elapsed time from the start of the shift control, an elapsed time after calculating the previous torque sharing ratio x, or the like. The torque sharing rate calculation unit 78 calculates the current target torque sharing rate x based on the elapsed time and the shift progress map.

  From the calculated torque sharing rate x and the above formulas (1) and (2), the torque sharing rate calculation unit 78 calculates the torque sharing rate xlow of the low gear stage engaging device and the torque sharing rate xhi of the high gear stage engaging device. calculate. The shift progress map is preferably determined in advance for each shift pattern or for each shift stage. The initial value of the torque sharing ratio x is preferably 1 for an upshift and 0 for a downshift.

  The shift target value calculation unit 80 stores an input shaft angular acceleration change map. The input shaft angular acceleration change map is a map that defines a mode of changing the input shaft angular acceleration dωt / dt. The input shaft angular acceleration change map is determined in advance so that the turbine rotational speed ωt can be changed during the inertia phase while simultaneously suppressing the shift shock and shortening the shift time. The shift target value calculation unit 80 calculates the target value of the input shaft angular acceleration dωt / dt during the inertia phase based on the elapsed time during the shift and the input shaft angular acceleration change map. The elapsed time is, for example, the elapsed time from the start of the inertia phase, the elapsed time after calculating the target value of the previous input shaft angular acceleration dωt / dt, or the like. The shift target value calculation unit 80 calculates the target value of the input shaft angular acceleration dωt / dt based on the change in the turbine speed ωt except during the inertia phase.

  The shift target value calculation unit 80 stores an output shaft torque change map. The output shaft torque change map is a map that defines a mode in which the output shaft torque To is changed. The shift target value calculation unit 80 calculates the target value of the output shaft torque To based on the required driving force Fdem calculated by the engine output control unit 72 and the elapsed time from the start of the shift control. Note that the input shaft angular acceleration change map and the output shaft torque change map are determined in advance for each shift pattern or between shift stages, for example.

  The control operation amount calculation unit 76 calculates the torque sharing rate (x, xlow, xhi) of the engagement device calculated by the torque sharing rate calculation unit 78 and the shift target value calculation unit 80 from the relational expression for calculating the control operation amount. Based on the respective shift target values (target values of the input shaft angular acceleration dωt / dt and the output shaft torque To) calculated by the above, the turbine torque Tt, the low gear stage side clutch torque Tclow, and the high gear stage side clutch torque as the control operation amount Each required value of Tchi is calculated.

  When the shift control unit 74 determines that the automatic transmission 18 is shifting, the engine output control unit 72 can obtain the required value of the turbine torque Tt calculated by the control operation amount calculation unit 76. The engine output control command signal Se is output. When the shift control unit 74 determines that the shift of the automatic transmission 18 is to be executed, the low gear stage side clutch torque Tclow calculated by the control operation amount calculation unit 76 and the control operation amount calculation unit 76 so that the target gear stage is achieved. A hydraulic pressure command signal Sp for obtaining each required value of the high gear stage side clutch torque Tchi is output to the hydraulic pressure control circuit 28.

  Next, an example of shift control based on the shift model of the present embodiment will be described with reference to FIGS. FIG. 6 shows an operation during power-on upshift. FIG. 6 shows (a) turbine speed, (b) target value of input shaft angular acceleration, (c) target value of output shaft torque To, (d) required value of engine torque Te, (e) clutch torque. The required value and (f) the torque sharing rate of the engagement device are shown.

  The control flow shown in FIG. 5 is repeatedly executed at predetermined intervals. In step S10, the shift control unit 74 determines whether a shift is being performed. As a result of the determination in step S10, if it is determined that the gear is being changed (step S10-Y), the process proceeds to step S20. If not (step S10-N), the control flow ends. In FIG. 6, it is determined that a shift is being performed between time t1 and time t3.

  In step S20, the torque sharing rate calculation unit 78 calculates the torque sharing rates (x, xlow, xhi) of the engaging device. The torque sharing ratio calculation unit 78 calculates the torque sharing ratio based on, for example, an elapsed time from the start of shifting and a shift progress map. When step S20 is executed, the process proceeds to step S30.

  In step S30, the shift target value calculation unit 80 calculates a shift target value. The shift target value calculation unit 80 calculates the target value of the input shaft angular acceleration dωt / dt based on, for example, the input shaft angular acceleration change map and the change in the turbine speed ωt. The shift target value calculation unit 80 calculates the target value of the output shaft torque To based on the output shaft torque change map, for example. When step S30 is executed, the process proceeds to step S40.

  In step S <b> 40, the control operation amount calculator 76 calculates the control operation amount. The control operation amount calculator 76 calculates the engine torque Te based on the torque sharing ratio value calculated in step S20, the shift target value calculated in step S30, and the relational expression for calculating the control operation amount described above. A required value, a required value of the low gear stage side clutch torque Tclow, and a required value of the high gear stage side clutch torque Tchi are calculated. When step S40 is executed, the process proceeds to step S50.

  In step S 50, torque control of the power source by the engine output control unit 72 and control of the engagement device by the shift control unit 74 are executed. The engine output control unit 72 generates and outputs an engine output control command signal Se so as to realize the required value of the engine torque Te calculated in step S40. Further, the shift control unit 74 generates and outputs a hydraulic pressure command signal Sp to realize the low gear stage side clutch torque Tclow and the high gear stage side clutch torque Tchi calculated in step S40. When step S50 is executed, the control flow ends.

  During the shift of the automatic transmission 18, the output shaft torque To may be suddenly changed by the inertia torque in the inertia phase. On the other hand, as shown in FIG. 6, the target value of the output shaft torque To during the inertia phase is determined so as to feel as if no inertia torque has occurred. The required value of the engine torque Te is determined so as to realize this target value. That is, in the inertia phase, engine torque down control is executed to cancel the inertia torque. As described above, in this embodiment, the engine 12 is incorporated in the equation of motion as a control target without destroying the entire shift model control.

  Here, there is a possibility that the start timing of the inertia phase is shifted from the target timing due to variations in the engagement devices. For example, in the power-on upshift, it is preferable that the inertia phase starts after the engagement device on the engagement side has completely taken over the torque. In other words, it is preferable that the inertia phase starts after the torque is completely transferred from the disengagement-side engagement device to the engagement-side engagement device. However, due to variations in the engagement devices, there is a possibility that the inertia phase starts before the engagement device on the engagement side takes over the torque completely. In this case, there is a problem that a shock occurs at the start of the inertia phase.

  In addition, it has been studied to start the inertia phase by torque down control for reducing the output torque of the power source. For example, in the torque phase, it is conceivable to start the inertia phase by lowering the value of the engine torque Te to a value smaller than the torque that realizes the required driving force. At this time, if the torque is reduced before the torque phase is sufficiently advanced, a part of the progression of the torque phase is performed due to the torque reduction, and a drawing shock may occur. Further, if the amount of torque reduction is larger than an appropriate value, the output shaft torque may be reduced more than necessary, and a drawing shock may occur in the inertia phase.

  As will be described below, the control unit 70 of the present embodiment stops increasing the torque sharing rate of the engagement device on the engagement side when the degree of progress of the torque phase is greater than or equal to a predetermined ratio during gear shifting. The output torque of the driving force source is reduced according to the difference between the predetermined value and the torque sharing ratio of the engagement device on the engagement side corresponding to the degree of progress of the torque phase. Thereby, according to the transmission control apparatus 1 which concerns on this embodiment, a transmission shock can be suppressed.

  With reference to FIGS. 7 and 8, the shift control of the present embodiment will be described. The time chart of FIG. 8 relates to the power-on upshift. FIG. 8 shows (a) the target gear stage, (b) the target value of the driving force, (c) the turbine speed ωt, (d) the required value of the clutch torque, and (e) the torque sharing rate of the engaging device. It is shown.

  At time t11, the shift determination of the power-on upshift is made, and the target gear stage is changed to the high speed side gear stage. The control unit 70 decreases the hydraulic pressure with respect to the low gear stage engagement device that is the disengagement side engagement device, and increases the hydraulic pressure with respect to the high gear stage engagement device that is the engagement side engagement device. When the packing of the engaging device is completed at time t13, the torque sharing rate calculation unit 78 changes the torque sharing rate of the engaging device according to the elapsed time.

  Based on the torque sharing ratios xhi and xlow calculated by the torque sharing ratio calculating section 78, the control operation amount calculating section 76 calculates the required value of the clutch torque of each engagement device. As the torque sharing ratio xhi of the high gear stage engaging device increases as the torque phase progresses, the high gear stage side clutch torque Tchi increases. Further, the low gear stage side clutch torque Tclow decreases as the torque sharing rate xlow of the low gear stage engaging device decreases as the torque phase progresses. Note that the torque sharing ratio and the required value of the clutch torque may be moved forward according to the dead time of the torque of the engaging device. For example, the torque sharing rate may start to change at time t12 by moving forward by the dead time of the actuator of the engagement device.

  At time t15, the degree of progress of the torque phase increases to a predetermined ratio, and the torque sharing ratio xhi of the high gear stage engaging device becomes a predetermined value x1. When the degree of progress of the torque phase is equal to or greater than a predetermined ratio, the control operation amount calculation unit 76 of the present embodiment calculates the torque sharing rate of the engagement device on the engagement side (here, the torque sharing rate xhi of the high gear stage engagement device). ) Is stopped to a predetermined value x1. As a result, the required value of the high gear stage side clutch torque Tchi stops increasing at the predetermined torque T1 corresponding to the predetermined value x1. Thereby, it is suppressed that the inertia phase is started before the engagement device on the engagement side completely takes over the torque due to variations in the engagement devices. The predetermined ratio is determined so that the inertia phase does not start even if the clutch torque varies, for example.

  When the torque sharing ratio xhi of the high gear stage engaging device is set to the predetermined value x1, the control operation amount calculation unit 76 of the present embodiment advances the torque phase by reducing the input shaft torque Ti. The control operation amount calculation unit 76 reduces the input shaft torque Ti (engine torque Te) according to the difference between the torque sharing ratio xt of the engagement device on the engagement side according to the degree of progress of the torque phase and the predetermined value x1. . In FIG. 8, the progress degree of the torque phase becomes a predetermined ratio at time t15. As a result, the control operation amount calculation unit 76 stops increasing the torque sharing rate xhi of the high gear stage engaging device after time t15 and maintains the value of the torque sharing rate xhi of the high gear stage engaging device at the predetermined value x1. . Note that the clutch torque Tcx indicated by a broken line is a torque capacity (hereinafter simply referred to as “corresponding torque capacity Tcx”) corresponding to the torque sharing ratio xt of the high gear stage engaging device corresponding to the degree of progress of the torque phase.

  The shift target value calculation unit 80 uses the clutch torque calculation target driving force Fc as means for stopping the torque sharing ratio xhi of the high gear stage engaging device in the course of the torque phase. The clutch torque calculation target driving force Fc is a driving force used when calculating the torque sharing ratio of the engaging device and the clutch torque. The clutch torque calculation target driving force Fc is the same value as the requested driving force Fdem from time t11 when shift determination is made to time t15 when the degree of progress of the torque phase becomes a predetermined ratio. The shift target value calculation unit 80 sets the value of the clutch torque calculation target driving force Fc to the value Fc1 at time t15 from time t15 to time t16 when the torque phase is completed. That is, during the period from time t15 to time t16, the torque sharing ratio and the required value of the clutch torque are calculated based on the driving force value Fc1. In the present embodiment, the torque sharing ratio xhi and the high gear stage side clutch torque Tchi of the high gear stage engaging device from time t15 to time t16 are calculated based on the driving force value Fc1.

  The control operation amount calculation unit 76 executes torque-down control for reducing the engine torque Te so as to cancel the deviation between the clutch torque calculation target driving force Fc and the required driving force Fdem. The control operation amount calculation unit 76 calculates the control operation amount by substituting the clutch torque calculation target driving force Fc into the equation of motion of the shift model from time t15 to time t16, and the engine torque obtained as a result thereof. Torque down correction is performed for Te (which agrees with the turbine torque Tt). This correction amount is calculated based on the difference between the clutch torque calculation target driving force Fc and the required driving force Fdem. This suppresses the actual output shaft torque To from deviating from the driver's required torque. After time t15, instead of increasing the high gear side clutch torque Tchi, the torque phase advances due to a decrease in engine torque Te.

  The torque phase ends at time t16. When the torque phase ends, the control operation amount calculation unit 76 starts the inertia phase by torque reduction. The control operation amount calculation unit 76 matches the clutch torque calculation target driving force Fc after time t16 with the required driving force Fdem. Further, the control operation amount calculation unit 76 starts torque-down control of the engine torque Te after time t16. The control operation amount calculation unit 76 performs, for example, feedforward control that calculates a target value of the input shaft torque Ti based on a target value change speed α of the turbine speed ωt. The control operation amount calculator 76 calculates the driving force decrease amount ΔF so as to realize the above-described change speed α, and determines the torque reduction amount of the engine torque Te so as to realize the decrease amount ΔF. Thereby, torque-down control of the engine torque Te is performed, and the inertia phase is started. Note that the clutch torque calculation target driving force Fc decreases, so that the high gear stage side clutch torque Tchi increases at time t16, and the engagement device on the engagement side is completely engaged. When the inertia phase ends, the shift control is completed at time t17.

  The details of the shift control will be described with reference to the flowchart of FIG. The control flow shown in FIG. 7 is repeatedly executed at predetermined intervals, for example. In step S100, the shift control unit 74 determines whether a power-on upshift is being performed. The shift control unit 74 makes an affirmative determination in step S <b> 100 when, for example, an upshift is determined based on a shift map or a shift line in a state where accelerator-on is detected, and a shift is being performed. As a result of the determination in step S100, when it is determined that the power-on upshift is being performed (step S100-Y), the process proceeds to step S110. Otherwise (step S100-N), the control flow ends.

  In step S110, the shift control unit 74 determines whether a condition for permitting inertia phase start control by torque reduction is satisfied. For example, when the torque phase is completed, the shift control unit 74 makes an affirmative determination in step S110. As a result of the determination in step S110, if the condition for permitting the inertia phase start control by torque reduction is satisfied (step S110-Y), the process proceeds to step S120, and if not (step S110-N), the process proceeds to step S120. The process proceeds to S160.

  In step S120, the shift control unit 74 determines whether the inertia phase has started. The shift control unit 74 determines, for example, whether the inertia phase has started based on the transition of the turbine speed ωt. As a result of the determination in step S120, if it is determined that the inertia phase has started (step S120-Y), the process proceeds to step S170, and if not (step S120-N), the process proceeds to step S130.

  In step S130, the shift control unit 74 determines whether the progress of the torque phase is equal to or greater than a predetermined rate. For example, when the torque sharing rate xhi of the high gear engagement device calculated by the torque sharing rate calculating unit 78 is equal to or greater than a predetermined value, the shift control unit 74 makes an affirmative determination in step S140. The predetermined ratio can be 90%, for example. In this case, the predetermined value x1 regarding the torque sharing ratio xhi of the high gear stage engaging device shown in FIG. 8 is 0.9. As a result of the determination in step S130, if it is determined that the progress of the torque phase is greater than or equal to the predetermined ratio (step S130-Y), the process proceeds to step S140, and if not (step S130-N), the process proceeds to step S150. .

  In step S <b> 140, the torque reduction amount is calculated by the control operation amount calculation unit 76. The control operation amount calculator 76 calculates the torque reduction amount of the engine torque Te based on the difference between the clutch torque calculation target driving force Fc and the required driving force Fdem. The control operation amount calculation unit 76 corrects the torque-down amount based on the difference in the driving force with respect to the required value of the engine torque Te calculated using the target driving force Fc for calculating the clutch torque, so that the engine An output control command signal Se is generated. When step S140 is executed, this control flow ends.

  In step S150, the control operation amount calculation unit 76 prohibits torque reduction. When step S150 is executed, the control flow ends.

  When an affirmative determination is made in step S110 and the process proceeds to step S160, in step S160, the shift control unit 74 determines whether or not the inertia phase has started. As a result of the determination in step S160, if it is determined that the inertia phase has started (step S160-Y), the process proceeds to step S170. If not (step S160-N), the process proceeds to step S180.

  In step S <b> 170, the control operation amount calculation unit 76 calculates the torque down amount during the inertia phase according to the equation of motion. In the inertia phase, the required driving force Fdem is substituted into the equation of motion of the transmission model, and the control operation amount is calculated. In step S170, the control operation amount calculation unit 76 calculates a torque down amount corresponding to the driving force decrease amount ΔF. The control operation amount calculator 76 corrects the torque reduction amount calculated in step S170 with respect to the required value of the engine torque Te based on the equation of motion, and generates the engine output control command signal Se. When step S170 is executed, the process proceeds to step S190.

  In step S180, the control operation amount calculation unit 76 prohibits torque reduction. When step S180 is executed, the process proceeds to step S190.

  In step S190, the shift control unit 74 determines whether or not the inertia phase is in the final stage. The shift control unit 74 performs the determination in step S190 based on, for example, the turbine speed ωt. As a result of the determination in step S190, if it is determined that the inertia phase is the final stage (step S190-Y), the process proceeds to step S200, and if not (step S190-N), the control flow ends.

  In step S200, the control unit 70 performs a torque down control end process. The shift target value calculation unit 80 gradually increases the clutch torque calculation target driving force Fc toward the required driving force Fdem, and finally matches the required driving force Fdem. Thereby, the torque-down control in the inertia phase ends. When step S200 is executed, the control flow ends.

  As described above, the shift control device 1 of the present embodiment stops the increase in the torque capacity of the engagement device on the engagement side and decreases the input shaft torque Ti when the degree of progress of the torque phase reaches a predetermined ratio or more. To advance the torque phase. Thereby, even if there is variation in the engagement devices, the torque phase can be completed while suppressing the inertia phase from starting at an earlier timing than expected. According to the transmission control device 1 of the present embodiment, the output shaft torque To can be designed even when the torque of the input shaft torque Ti is reduced during the torque phase.

  In FIG. 8, the increase in the torque sharing ratio xhi of the high gear engagement device is stopped by substituting the clutch torque calculation target driving force Fc into the equation of motion. The torque sharing ratio xhi of the mating engagement device may be stopped. That is, the control unit 70 calculates the control operation amount by substituting the required driving force Fdem into the equation of motion, and when the degree of progress of the torque phase exceeds a predetermined ratio, the engine torque Te corresponding to the driver request decreases. Even if it does, you may make it stop the raise of the torque sharing rate xhi of the engagement apparatus of an engagement side. If it does in this way, the clutch torque Tchi of the engagement device on the engagement side stops increasing at the time (time t15) when the progression of the torque phase due to the torque reduction of the engine 12 is started. Further, since the required driving force Fdem is used when calculating the engine torque Te (input shaft torque Ti) based on the equation of motion, the engine torque Te decreases based on the target progress rate of the torque phase. Therefore, even if the torque down correction is not executed, the engine torque Te is reduced and the torque phase is advanced.

  It should be noted that the change request for the input shaft torque Ti may be put forward by the dead time of the throttle valve actuator. For example, the degree of progress of the torque phase becomes a predetermined ratio at time t15, but the torque request (start command for torque down control) may be advanced and started at time t14.

  The contents disclosed in the above embodiments can be executed in appropriate combination.

DESCRIPTION OF SYMBOLS 1 Shift control apparatus 10 Vehicle 12 Engine 16 Input shaft 18 Automatic transmission 20 Output shaft 26 Drive wheel 70 Control part C1, C2, C3, C3 Clutch (engagement device)
B1, B2 Brake (engagement device)
dωt / dt Input shaft angular acceleration (input shaft rotation change)
Tclow Low gear stage side clutch torque Tchi High gear stage side clutch torque Ti Input shaft torque To Output shaft torque x1 Predetermined value xlow Torque sharing rate of low gear stage engaging device xhi Torque sharing rate of high gear stage engaging device ωt Turbine speed

Claims (1)

An input shaft to which power from a driving force source is input, an output shaft that outputs power to the drive wheels, and a plurality of engagement devices that transmit torque between the input shaft and the output shaft; An automatic transmission that shifts by switching between engagement and release of the engagement device;
A control unit for controlling the automatic transmission based on a shift model for determining a control operation amount for realizing a shift target value;
With
The controller is
Two values of the output shaft torque and the input shaft rotation change amount are set as the shift target value, and the input shaft torque, the torque capacity of the engagement device on the release side, and the torque capacity of the engagement device on the engagement side The control operation amount is calculated on the basis of the shift model, with the torque sharing ratio of the engagement device on the engagement side and the engagement device on the release side as a constraint condition at the time of shifting,
When the degree of progress of the torque phase is greater than or equal to a predetermined ratio during the shift, the control unit stops increasing the torque sharing rate of the engagement device on the engagement side to a predetermined value, and The speed change control device, wherein the output torque of the driving force source is reduced in accordance with a difference between the torque sharing rate according to the degree of progress of the engagement device and the predetermined value.

Images