HYDRAULIC PRESSURE CALCULATION DEVICE

Abstract

Hydraulic pressure calculation device (Z) for application to a gear shift system (90, 30) with a transmission (30) designed to switch between a connected state and a disconnected state of a friction engagement element (C1, C2, B1, B2) depending on a hydraulic pressure from a hydraulic circuit (67), and a hydraulic control unit designed to control the hydraulic circuit (67), wherein the hydraulic pressure calculation device (Z) comprises: a memory (95); and a processor, wherein: the memory (95) stores parts of mapping data (D) of several phases obtained by subdividing a time interval from a switching start between the connected state and the disconnected state of the friction engagement element (C1, C2, B1, B2) to a switching end between the connected state and the disconnected state of the friction engagement element (C1, C2, B1, B2), wherein each of the parts of mapping data (D) defines a mapping; the processor is designed to output, as an output variable (y), an estimated hydraulic pressure variable, which is a variable that provides an estimate of an actual hydraulic pressure (PWc) applied to the friction engagement element (C1, C2, B1, B2) by the hydraulic circuit (67); The diagram includes, as one of several input variables (x(1) - x(5)), a target hydraulic pressure variable (PZc), which is a variable that specifies a target hydraulic pressure (PZ) calculated by the hydraulic control unit as a target value of the hydraulic pressure with which the friction engagement element (C1, C2, B1, B2) is acted upon by the hydraulic circuit (67); and The processor is designed to: a determination process to determine values ​​of the input variables (x(1) - x(5)), a selection process for selecting, from the parts of mapping data (D) of the phases, a part of the mapping data (D) that are assigned to a phase in which the values ​​of the input variables (x(1) - x(5)) are determined, and a calculation process to calculate a value of the output variable (y) by inputting the values ​​of the input variables (x(1) - x(5)) determined in the determination process into the mapping of the mapping data selected in the selection process (D) to execute.

Description

[0001] The present invention relates to a hydraulic pressure calculation device.

[0002] A vehicle disclosed in the unexamined Japanese patent publication JP 2019-157 896 A comprises an automatic transmission and a control unit. The automatic transmission includes several friction elements. A hydraulic circuit switches the individual friction elements between a connected and a disconnected state depending on a hydraulic pressure. The control unit calculates a target hydraulic pressure to be applied to the friction element. The control unit regulates the hydraulic pressure in the hydraulic circuit based on the calculated target hydraulic pressure.

[0003] The control unit calculates a time constant that represents the delay between the actual hydraulic pressure and the set hydraulic pressure. Based on this time constant, the control unit calculates an estimated hydraulic pressure, which is an approximation of the actual hydraulic pressure. The estimated hydraulic pressure reflects this delay in the response to the set hydraulic pressure.

[0004] For a better understanding of the present invention, reference is also made to DE 198 54 624 A1, in which “a device and a method for controlling an automatic transmission” are described.

[0005] The delay in the response of the actual hydraulic pressure to the target hydraulic pressure is not always constant during the switching process between the connected and disconnected states of the friction engagement element. Therefore, it is possible that the estimated hydraulic pressure cannot be calculated accurately if only the response delay is considered, as described in JP 2019-157 896 A.

[0006] A hydraulic pressure calculation device according to one aspect of the present invention is applied to a gearshift system with a transmission designed to switch between a connected and a disconnected state of a friction engagement element depending on a hydraulic pressure from a hydraulic circuit. The hydraulic pressure calculation device comprises a memory and a processor. The memory stores portions of mapping data from several phases, which are obtained by subdividing a time interval from the start of a switch between the connected and disconnected states of the friction engagement element to the end of a switch. Each portion of mapping data defines a mapping.The processor is designed to output an estimated hydraulic pressure variable as its output variable. This variable represents an estimated value of the actual hydraulic pressure applied to the friction engagement element by the hydraulic circuit. The diagram includes, as one or more input variables, a target hydraulic pressure variable. This variable represents a target hydraulic pressure calculated by the hydraulic control unit as the setpoint for the hydraulic pressure applied to the friction engagement element by the hydraulic circuit.The processor is designed to perform a determination process to determine the values ​​of the input variables, a selection process to select the portions of mapping data of the phases, a portion of the mapping data that are assigned to a phase in which the values ​​of the input variables are determined, and a calculation process to calculate a value of the output variable by inputting the values ​​of the input variables determined in the determination process into the mapping of the mapping data selected in the selection process.

[0007] According to the configuration described above, the mappings assigned to the individual phases are used. Therefore, the difference can be reflected in the output variable even if the relationship between the target hydraulic pressure and the actual hydraulic pressure differs between the phases.

[0008] In the aspect described above, the memory for the phases can store portions of connection mapping data, which are mapping data to be used when the friction engagement element is switched to the connected state, and portions of disconnection mapping data, which are mapping data to be used when the friction engagement element is switched to the disconnected state. The processor can be designed such that, in a case where the input variables are determined in the detection process when the friction engagement element is switched to the connected state, it selects from the portions of connection mapping data of the phases that corresponds to a phase in which the input variables are determined, during the selection process.The processor can be designed such that, when the input variables are determined in the determination process, when the friction engagement element is switched to the separated state, it selects from the parts of separation mapping data of the phases a part of the separation mapping data that is assigned to a phase in which the input variables are determined, in the selection process.

[0009] In the configuration described above, dedicated mappings are used for the case where the friction engagement element is switched to the connected state and for the case where the friction engagement element is switched to the disconnected state. Therefore, even if the way the hydraulic pressure changes differs between switching to the connected state and switching to the disconnected state, accurate output variables suitable for both cases can be obtained.

[0010] In the aspect described above, an accelerator pedal actuation amount variable, which is a variable indicating the amount of pressure applied to the accelerator pedal of a vehicle in which the transmission is installed, can be included as one of the input variables. By including the accelerator pedal actuation amount variable as one of the input variables, as in the configuration described above, the output variable can be derived based on the torque applied to the transmission.

[0011] In the aspect described above, a gear shift variable, which is a variable indicating a change in gear stage before and after shifting, can be included as one of the input variables. According to the configuration described above, an accurate output variable can be obtained even if the deviation of the actual hydraulic pressure from the target hydraulic pressure varies depending on the change in gear stage.

[0012] In the aspect described above, an oil temperature variable, which indicates the temperature of the oil in the hydraulic circuit, can be included as one of the input variables. According to the configuration described above, the output variable can be derived based on the oil temperature, which can influence the actual hydraulic pressure.

[0013] In the aspect described above, an input shaft variable, which is a variable indicating the rotational speed of an input shaft of the gearbox or a change in the rotational speed of the input shaft, can be included as one of the input variables. The rotational speed of the input shaft and the change in the rotational speed of the input shaft can serve as an index of a temporal stage within the same phase. According to the configuration described above, a finer stage than the subdivision range of each phase can be reflected in the output variable.

[0014] Features, advantages and technical and industrial significance of exemplary embodiments of the invention are described below with reference to the accompanying drawings, in which the same signs denote the same elements and wherein: Fig. 1 is a schematic structure diagram of a vehicle; Fig. 2 is an explanatory drawing showing the relationships between gear stages of an automatic transmission and friction engagement elements; Fig. 3 is a time diagram showing an example of the progression of a gear shift control; Fig. 4 is a flowchart showing a processing procedure of a connection hydraulic pressure calculation process; and Fig. Figure 5 is a schematic diagram showing a modified example of a hydraulic pressure calculation device.

[0015] The following describes a hydraulic pressure calculation device of one embodiment with reference to the drawings. First, a schematic structure of a vehicle is described. As it is in Fig. As shown in Figure 1, a vehicle 100 comprises an internal combustion engine 10, a power distribution device 20, an automatic transmission 30, drive wheels 69, a hydraulic device 65, a first motor generator 61 and a second motor generator 62.

[0016] The power distribution device 20 is coupled to a crankshaft 11, which is an output shaft of the internal combustion engine 10. The power distribution device 20 is a planetary gear mechanism with a sun gear S, a ring gear R, and a carrier C. The crankshaft 11 is coupled to the carrier C of the power distribution device 20. A rotating shaft 61A of the first motor-generator 61 is coupled to the sun gear S. A rotating shaft 62A of the second motor-generator 62 is coupled to a ring gear shaft RA, which is an output shaft of the ring gear R. An input shaft 41 of the automatic transmission 30 is also coupled to the ring gear shaft RA. The right and left drive gears 69 are coupled via a differential (not shown) to an output shaft 42 of the automatic transmission 30.

[0017] When the internal combustion engine 10 is operated and torque is transmitted from the crankshaft 11 to the carrier C of the power distribution device 20, the torque is divided into a torque on the sun gear side S and a torque on the ring gear side R. When the first motor-generator 61 operates as a motor and torque is transmitted to the sun gear S of the power distribution device 20, the torque is divided into a torque on the carrier C side and a torque on the ring gear side R.

[0018] When the second motor-generator 62 operates as a motor and transmits torque to the hollow gear shaft RA, the torque is transmitted to the automatic transmission 30. When torque is transmitted from the drive wheels 69 via the hollow gear shaft RA to the second motor-generator 62, the second motor-generator 62 functions as a generator. Thus, regenerative braking can be generated in the vehicle 100.

[0019] The automatic transmission 30 comprises a first planetary gear mechanism 30A, a second planetary gear mechanism 30B, a first clutch C1, a second clutch C2, a first brake B1, a second brake B2 and a one-way clutch F1.

[0020] The first planetary gear mechanism 30A comprises a sun gear 31, a ring gear 32, pinions 33, and a carrier 34. The ring gear 32 is coupled to the sun gear 31 via the pinions 33. The pinions 33 are supported on the carrier 34.

[0021] The sun gear 31 is coupled to the first brake B1. The first brake B1 is switched between a connected and a disconnected state depending on the pressure (hereinafter referred to as "hydraulic pressure") of the oil supplied to the first brake B1. Specifically, the first brake B1 switches from the disconnected state to the connected state when the hydraulic pressure acting on the first brake B1 increases. In the connected state of the first brake B1, the rotation of the sun gear 31 is braked.

[0022] The one-way coupling F1 is coupled to the support 34. The one-way coupling F1 restricts the rotation of the support 34 in one direction and allows its rotation in the other. That is, the one-way coupling F1 is switched to a restricted state to limit the rotation of the support 34, or to a permissible state to allow or enable its rotation. The support 34 is coupled to the second brake B2. Similar to the first brake B1, the second brake B2 is switched to a connected or disconnected state depending on the hydraulic pressure applied to it. In the connected state of the second brake B2, the rotation of the support 34 is braked.

[0023] The second planetary gear mechanism 30B comprises a sun gear 36, a ring gear 37, pinions 38, and a carrier 39. The ring gear 37 is coupled to the sun gear 36 via the pinions 38. The pinions 38 are supported on the carrier 39. The output shaft 42 is coupled to the carrier 39.

[0024] In the planetary gear mechanism constructed as described above, the carrier 34 of the first planetary gear mechanism 30A is coupled to the ring gear 37 of the second planetary gear mechanism 30B. The ring gear 32 of the first planetary gear mechanism 30A is coupled to the carrier 39 of the second planetary gear mechanism 30B.

[0025] The sun gear 36 of the second planetary gear mechanism 30B is coupled to the input shaft 41 via the first clutch C1. The first clutch C1 is switched between a connected and a disconnected state depending on the hydraulic pressure applied to it. Specifically, the first clutch C1 switches from the disconnected state to the connected state when the hydraulic pressure applied to it increases. In the connected state of the first clutch C1, the sun gear 36 of the second planetary gear mechanism 30B rotates together with the input shaft 41.

[0026] The carrier 34 of the first planetary gear mechanism 30A is coupled to the input shaft 41 via the second clutch C2. Corresponding to the first clutch C1, the second clutch C2 is switched to a connected or disconnected state depending on the hydraulic pressure applied to it. When the second clutch C2 is connected, the carrier 34 of the first planetary gear mechanism 30A rotates together with the input shaft 41. In this embodiment, the first clutch C1, the second clutch C2, the first brake B1, and the second brake B2 are friction elements.

[0027] As it is in Fig. As shown in Figure 2, the gear stages of the automatic transmission 30 are shifted based on combinations of the engaged or disengaged states of the first clutch C1, the second clutch C2, the first brake B1, and the second brake B2, and a combination of the restricted or permissible state of the one-way clutch F1. The automatic transmission 30 allows a total of five gear stages, of which four gear stages, "first gear" to "fourth gear," are for forward driving and one gear stage, "R," is for reverse driving.

[0028] In Fig. 2 represents a symbol “◯” indicating the engaged state of the friction element, such as the first clutch C1, and the restricted state of the one-way clutch F1. A symbol “(◯)” represents the engaged or disengaged state of the second brake B2. An empty field represents the disengaged state of the friction element, such as the first clutch C1, and the permissible state of the one-way clutch F1. For example, if the gear stage of automatic transmission 30 is second gear, the first clutch C1 and the first brake B1 are engaged, the second clutch C2 and the second brake B2 are disengaged, and the one-way clutch F1 allows rotation.

[0029] As it is in Fig. As shown in Figure 1, the hydraulic unit 65 is installed in the vehicle 100. The hydraulic unit 65 comprises an oil pump 66, a hydraulic circuit 67, and an oil reservoir 68. The oil reservoir 68 stores oil that is to be supplied to the automatic transmission 30. The oil pump 66 is a so-called mechanical oil pump, designed to operate by absorbing torque from the crankshaft 11. The oil pump 66 supplies the oil stored in the oil reservoir 68 to the hydraulic circuit 67. The hydraulic circuit 67 includes solenoid valves 63 for the individual friction elements. By controlling the solenoid valves 63, hydraulic pressures are set that actuate the first clutch C1, the second clutch C2, the first brake B1, and the second brake B2.

[0030] A first rotation angle sensor 52, a second rotation angle sensor 54, an oil temperature sensor 56, a vehicle speed sensor 58, an accelerator position sensor 59, and an acceleration sensor 64 are installed in the vehicle 100. An accelerator pedal 60 is also installed in the vehicle 100. The first rotation angle sensor 52 detects a first rotation angle Sm1, which is a rotation angle of the rotating shaft 61A of the first motor generator 61. The second rotation angle sensor 54 detects a second rotation angle Sm2, which is a rotation angle of the rotating shaft 62A of the second motor generator 62. The oil temperature sensor 56 detects an oil temperature of the oil in the hydraulic circuit 67. The vehicle speed sensor 58 detects a vehicle speed SPD, which is a driving speed of the vehicle 100. The accelerator position sensor 59 detects an accelerator actuation amount ACCP, which is an actuation amount of the accelerator pedal 60 actuated by a driver.The acceleration sensor 64 detects a longitudinal acceleration W of the vehicle 100.

[0031] The following describes a control configuration for vehicle 100. First, a basic configuration and basic control of a control unit are described. Vehicle 100 includes a control unit 90. A signal indicating the first rotation angle Sm1 is supplied to control unit 90 by the first rotation angle sensor 52. A signal indicating the second rotation angle Sm2 is supplied to control unit 90 by the second rotation angle sensor 54. A signal indicating the oil temperature Toil is supplied to control unit 90 by the oil temperature sensor 56. A signal indicating the vehicle speed SPD is supplied to control unit 90 by the vehicle speed sensor 58. A signal indicating the accelerator pedal actuation amount ACCP is supplied to control unit 90 by the accelerator pedal sensor 59.

[0032] The control unit 90 can be designed as one or more processors to execute various processes based on computer programs (software). The control unit 90 can also be constructed as one or more dedicated hardware circuits, such as an application-specific integrated circuit (ASIC), designed to execute at least some of the various processes, or as a circuit containing a combination of these hardware circuits. The processor comprises a central processing unit (CPU) 91 and memory with random-access memory (RAM) and read-only memory (ROM) 93. The memory stores program code or instructions to cause the CPU 91 to execute processes. The memory, that is, a computer-readable medium, includes any available medium accessible to a general-purpose or dedicated computer.The control unit 90 includes a memory 95, which is an electrically rewritable, non-volatile memory. The CPU 91, the ROM 93, and the memory 95 can communicate with each other via an internal bus 98.

[0033] For example, the CPU 91 controls the internal combustion engine 10, the first motor-generator 61, and the second motor-generator 62 by executing various programs stored in ROM 93. Specifically, based on the accelerator pedal actuation amount ACCP and the vehicle speed SPD, the CPU 91 calculates a requested vehicle power output, which is the power required for the vehicle to travel at 100 km / h. The CPU 91 determines a torque distribution for the internal combustion engine 10, the first motor-generator 61, and the second motor-generator 62 based on the requested vehicle power output. The CPU 91 controls the power output of the internal combustion engine 10 and the power operation and regeneration of the first motor-generator 61 and the second motor-generator 62 based on the torque distribution of the internal combustion engine 10, the first motor-generator 61, and the second motor-generator 62.

[0034] The following describes a control system for shifting the automatic transmission 30. The CPU 91 controls the automatic transmission 30 by executing a program stored in ROM 93. Specifically, the CPU 91 calculates a target gear stage SFT of the automatic transmission 30 based on the vehicle speed SPD and the requested vehicle power. If the final target gear stage SFT differs from a previously calculated target gear stage SFT, the CPU 91 executes the gear shift control to change the gear stage. In the gear shift control, the CPU 91 switches the connected or disconnected states of target friction elements. For example, if the gear stage is second gear before the gear shift operation, the first clutch C1 and the first brake B1 are connected, the second clutch C2 and the second brake B2 are disconnected, and the one-way clutch F1 allows rotation as described in Fig. Figure 2 shows that when the target transmission stage SFT is shifted from second gear to third gear, the CPU, via the gearshift control, switches the first brake B1 to the disengaged state and the second clutch C2 to the engaged state. This shifts the transmission stage into third gear.

[0035] In the gearshift control, the CPU 91 switches the engaged and disengaged states of the friction engagement element by regulating the hydraulic pressure applied to the friction engagement element by the hydraulic circuit 67. At this point, the CPU 91 calculates a target hydraulic pressure PZ, which is a setpoint for the hydraulic pressure applied to each individual friction engagement element by the hydraulic circuit 67. In this embodiment, target hydraulic pressures PZ are calculated individually for the first clutch C1, the second clutch C2, the first brake B1, and the second brake B2. Once the target hydraulic pressures PZ are calculated, the CPU 91 outputs a control signal G to the hydraulic device 65 based on the target hydraulic pressures PZ, as described in Fig. Figure 1 shows that, in response to the control signal G, the solenoid valves 63 of the hydraulic circuit 67 operate to adjust the hydraulic pressures to which the respective friction engagement elements are to be subjected.

[0036] In the gearshift control, the CPU 91 changes the individual target hydraulic pressures PZ over time as follows. The switching between the connected and disconnected states of the friction engagement element, along with the corresponding change in the target hydraulic pressure PZ, is described below. A friction engagement element that is switched from the connected to the disconnected state by the gearshift control is referred to as a "disconnected-side friction engagement element." A friction engagement element that is switched from the disconnected to the connected state by the gearshift control is referred to as a "connected-side friction engagement element."For example, when the target gear stage SFT is switched from second gear to third gear in the gear shift control, the first brake B1 is the "separation-side friction engagement element" and the second clutch C2 is the "connection-side friction engagement element".

[0037] As described in section (a) and section (d) in Fig. As shown in Figure 3, the CPU reduces 91 when the gear shift control is started in response to a shift of the target gear stage SFT (see “t1” in Figure 3). Fig. 3) The CPU 91 steeply increases the target hydraulic pressure PZf for the separating-side friction engagement element from a separating-side holding hydraulic pressure Hf. Subsequently, the CPU 91 maintains the target hydraulic pressure PZf constant for a period of time and then gradually reduces it. The separating-side holding hydraulic pressure Hf is the hydraulic pressure necessary to keep the separating-side friction engagement element in the connected state.

[0038] As described in section (c) in Fig. As shown in section 3, the CPU increases by 91 when the gear shift control is started (see “t1” in Fig. 3) temporarily sets the target hydraulic pressure PZc for the connection-side friction engagement element to "0". The CPU 91 then reduces the target hydraulic pressure to a standby pressure and waits for a predetermined time period. The standby pressure is the hydraulic pressure immediately before the connection-side friction engagement element has a torque capacity that can transmit torque. During the predetermined time period, the distance between the friction elements of the connection-side friction engagement element decreases. At an end point of the predetermined time period (see "t3" in Fig. 3) the friction element on the connection side is in a so-called packing filling state immediately before the friction elements of the friction element on the connection side come into contact.

[0039] After the predetermined time period has elapsed, the CPU 91 gradually increases the target hydraulic pressure PZc for the connection-side friction engagement element. As described in section (c) and section (d) in Fig. As shown in Figure 3, the CPU 91 begins to increase the setpoint hydraulic pressure PZc for the connection-side friction element while simultaneously decreasing the setpoint hydraulic pressure PZf for the disconnect-side friction element. As the setpoint hydraulic pressure PZc for the connection-side friction element increases by the CPU 91, the connection-side friction element begins to absorb torque, and the torque transmitted by the connection-side friction element gradually increases. As the setpoint hydraulic pressure PZf for the disconnect-side friction element decreases by the CPU 91, the torque transmitted by the disconnect-side friction element decreases. In this way, the friction elements that transmit the torque are switched.If the target hydraulic pressure PZc for the connection-side friction engagement element has increased to a certain degree, the CPU 91 sets the target hydraulic pressure PZf for the separation-side friction engagement element to “0” (see “t4” in . Fig. 3) Along with this operation, the friction engagement element on the separating side is disconnected. The time period during which the friction engagement elements, which transmit the torque, are switched corresponds to a so-called torque phase.

[0040] The CPU 91 continues to increase the target hydraulic pressure PZc for the coupling-side friction engagement element. Along with this operation, the rotational speed NA of the input shaft 41 of the automatic transmission 30 changes towards a rotational speed NA2, which corresponds to a gear stage after gear shifting, as described in section (b) in Fig. 3 is shown. When the speed NA of the input shaft 41 reaches the speed NA2, which corresponds to the gear stage after the gear change, and thus the gear change process is completed (see “t6” in Fig. 3) The CPU 91 steeply increases the target hydraulic pressure PZc for the connecting-side friction engagement element to a connecting-side holding hydraulic pressure Lc. Simultaneously, the connecting-side friction engagement element is engaged. The connecting-side holding hydraulic pressure Lc is the hydraulic pressure necessary to hold the connecting-side friction engagement element in the engaged state. The time it takes for the rotational speed NA of the input shaft 41 to change towards the rotational speed NA2, which corresponds to the gear stage after gear shifting, is known as the inertia phase.

[0041] The CPU 91 terminates the gear shift control through the sequence of processes described above. As described above, in the gear shift control, the point at which the switching of the connected and disconnected states of the friction elements begins is the point at which the target hydraulic pressure PZf for the disconnecting friction element steeply decreases from the disconnecting-side holding hydraulic pressure Hf. The point at which the switching process of the connected and disconnected states of the friction elements ends is the point at which the target hydraulic pressure PZc for the connecting-side friction element steeply increases to the connecting-side holding hydraulic pressure Lc.

[0042] In the process sequence described above, the CPU 91 calculates the target hydraulic pressures PZ for the coupling-side friction engagement element and the disengaging-side friction engagement element based on the accelerator actuation amount ACCP, the oil temperature Toil, and a gear shift type variable ΔVsft. Based on these parameters, the CPU 91 calculates the values ​​of the target hydraulic pressures PZ to be kept constant and the rates of change of the target hydraulic pressures PZ to be gradually altered. The gear shift type variable ΔVsft identifies the type of gear stage change before and after the gear stage shift. For example, the gear shift type variable ΔVsft indicates the gear shift from first gear to second gear or the gear shift from second gear to first gear.The gear shift type variable ΔVsft is defined as a positive integer to identify the type of gear shift operation for the transmission stage. For example, the gear shift type variable ΔVsft is "1" for the gear shift from first gear to second gear and "2" for the gear shift from second gear to first gear. The gear shift type variable ΔVsft distinguishes a power-ON gear shift in a state where the accelerator pedal 60 is depressed and a power-OFF gear shift in a state where the accelerator pedal 60 is not depressed. When the CPU 91 executes the gear shift control, it calculates the gear shift type variable ΔVsft based on the target gear stages SFT before and after the shift operation at a stage where the gear shift control is initiated, and uses the gear shift type variable ΔVsft to calculate the target hydraulic pressures PZ.

[0043] The following describes a process for identifying phases within an execution period of the gear shift control. During the execution of the gear shift control, the CPU 91 performs a phase identification process to identify multiple phases by dividing the execution period of the gear shift control. The CPU 91 uses a phase identification result obtained through the phase identification process to calculate an estimated hydraulic pressure PE, as described below. In this embodiment, the CPU 91 identifies five phases.

[0044] As it is in Fig. As shown in Figure 3, a first phase Q1 is a time interval from time t1, when the gearshift control is initiated in response to the shifting of the target gear stage SFT, until time t2, when the torque phase is initiated. The CPU 91 determines that the first phase Q1 is initiated when the phase identification process is started along with the initiation of the gearshift control. In this embodiment, longitudinal acceleration is used to determine the start of the torque phase. When the torque phase is initiated, the torque transmitted by the disengagement-side friction engagement element decreases. Along with this decrease, the longitudinal acceleration W changes. The CPU 91 determines that the torque phase is initiated when the absolute value of the rate of change of the longitudinal acceleration W per unit time is greater than a predetermined specified rate of change after the initiation of the gearshift control.

[0045] A second phase, Q2, is a time interval from time t2, when the torque phase is started, until time t3, when the packing of the connection-side friction engagement element is complete. In the gearshift control, the length of this time interval, from the start of the gearshift control until the completion of the packing, is predetermined. The CPU 91 determines that the packing is complete when the predetermined time interval has elapsed since the start of the gearshift control.

[0046] A third phase Q3 is a time interval from time t3, when the packing filling is complete, until time t4, when the inertia phase is started. In this embodiment, the CPU 91 determines that the inertia phase is started when an absolute value of the difference between the rotational speed NA of the input shaft 41 of the automatic transmission 30 and a rotational speed NA1 of the input shaft 41, which is determined based on a transmission stage before the gear shift operation and a rotational speed NB of the output shaft 42, is equal to or greater than a predetermined determining reference value after the completion of the packing filling.The speed NA1, determined on the basis of the transmission stage before the gear shift and the speed NB of the output shaft 42, is the speed of the input shaft 41 assuming that the transmission stage before the gear shift continues, and is obtained by multiplying a gear ratio corresponding to the transmission stage before the gear shift by the speed NB of the output shaft 42. The CPU 91 calculates the speed NA of the input shaft 41 and the speed NB of the output shaft 42 of the automatic transmission 30 in the background. Specifically, the CPU 91 calculates a second speed, which is the speed of the rotating shaft 62A of the second motor generator 62, based on a signal input from the second rotation angle sensor 54. The CPU 91 processes this second speed as the speed NA of the input shaft 41. The CPU 91 calculates the speed NB of the output shaft 42 based on a signal input from the vehicle speed sensor 58.

[0047] A fourth phase, Q4, is a time interval from time t4, when the inertial phase begins, until time t5, when the change in the rotational speed NA of the input shaft 41 is stable. Specifically, the fourth phase, Q4, is a transition period from when the rotational speed NA of the input shaft 41 begins to change in the direction of the rotational speed NA2, corresponding to the gear stage after gear shifting, until when the rotational speed NA continues to change with a constant gradient. The CPU 91 determines that the change in the rotational speed NA of the input shaft 41 is stable when the rate of change of the rotational speed NA of the input shaft 41 per unit time after the start of the inertial phase can be considered essentially constant.

[0048] A fifth phase, Q5, is a time interval from time t5, when the change in speed of the input shaft 41 is stable, until time t6, when the gear shifting operation is complete. The CPU 91 determines that the gear shifting operation is complete when the speed NA of the input shaft 41 equals the speed NA2 corresponding to the gear stage after the gear shift, once the change in speed NA of the input shaft 41 has stabilized. The speed NA2 corresponding to the gear stage after the gear shift is obtained by multiplying a gear ratio corresponding to the gear stage after the gear shift by the speed NB of the output shaft 42.

[0049] The CPU 91 identifies the phases within the execution time of the gearshift control through the phase identification process under the determination conditions described above. Once the phases are identified, the CPU 91 calculates a phase variable Vpase. The phase variable Vpase is used to identify a phase within the execution time of the gearshift control. In this embodiment, the phase variable is defined as a positive integer to identify each phase. For example, the phase variable is Q1 "1" in the first phase and Q2 "2" in the second phase. The control unit 90, together with the automatic transmission 30, forms a gearshift system.

[0050] The following describes a control configuration related to the calculation of an estimated value PE of an actual hydraulic pressure (hereinafter referred to as "estimated hydraulic pressure") applied to the friction engagement element by the hydraulic circuit 67. As described in Fig. As shown in Figure 1, memory 95 stores mapping data D for defining a mapping that uses various input variables as inputs and outputs one output variable. In this embodiment, the input variables include a setpoint hydraulic pressure variable, which indicates the setpoint hydraulic pressure. The input variables include an accelerator actuation amount variable, which indicates the accelerator actuation amount ACCP. The input variables include a gear shift variable, which indicates a change in gear stage before and after switching the engaged and disengaged states of the friction engagement element. The input variables include an oil temperature variable, which indicates the oil temperature Toil. The input variables include an input shaft variable, which indicates the rotational speed NA of the input shaft 41 of the automatic transmission 30. The output variable is an estimated hydraulic pressure variable, which indicates the estimated hydraulic pressure PE.

[0051] Memory 95 stores connection mapping data Dc, which are mapping data D to be used when the friction engagement element is switched to the connected state. That is, the connection mapping data Dc are mapping data D that are assigned to the connection-side friction engagement element. Memory 95 stores portions of connection mapping data Dc for the five phases. Memory 95 stores the five portions of connection mapping data Dc for each phase for each of the four friction engagement elements. That is, memory 95 of this embodiment stores a total of 20 portions of connection mapping data Dc.

[0052] Memory 95 stores separation mapping data Df, which are mapping data D to be used when the friction engagement element is switched to the separated state. That is, the separation mapping data Df are mapping data D assigned to the separation-side friction engagement element. Memory 95 stores portions of separation mapping data Df for each of the five phases. Memory 95 stores the five portions of separation mapping data Df for each of the four friction engagement elements. That is, memory 95 of this embodiment stores a total of 20 portions of separation mapping data Df.

[0053] The CPU 91 can execute a connection hydraulic pressure calculation process to calculate an estimated hydraulic pressure PEc when the friction engagement element is switched to the connected state. The CPU 91 implements processes in the connection hydraulic pressure calculation process by executing a program stored in ROM 93. In this embodiment, the CPU 91 and ROM 93 form a single processor.

[0054] In the connection hydraulic pressure calculation process, the CPU 91 executes a determination process, a selection process, and a calculation process. In the determination process, the CPU 91 determines various input variables related to switching the connection-side friction engagement element into the connected state, such as the target hydraulic pressure PZc for the connection-side friction engagement element. In the selection process, the CPU 91 selects connection mapping data Dc from the portions of connection mapping data Dc of the individual phases stored in memory 95, which are then associated with a phase in which the various input variables are determined. In the calculation process, the CPU 91 calculates a value of the output variable by inputting values ​​of the input variables determined in the determination process into a mapping of the connection mapping data Dc selected in the selection process.

[0055] The CPU 91 can execute a separation hydraulic pressure calculation process to calculate an estimated hydraulic pressure PEf when the friction engagement element is switched to the separated state. The CPU 91 implements processes in the separation hydraulic pressure calculation process by executing a program stored in ROM 93.

[0056] In the separation hydraulic pressure calculation process, the CPU 91, similar to the connection hydraulic pressure calculation process, executes a determination process, a selection process, and a calculation process. In the determination process, the CPU 91 determines various input variables related to switching the separation-side friction engagement element into the separated state, such as the target hydraulic pressure PZf for the separation-side friction engagement element. In the selection process, the CPU 91 selects separation mapping data Df from the portions of separation mapping data Df of the individual phases stored in memory 95. These data are then associated with a phase in which the various input variables are determined.In the calculation process, the CPU 91 calculates a value of the output variable by inputting values ​​of the input variables, which are determined in the determination process, into a mapping of the separation mapping data Df selected in the selection process.

[0057] The processes involved in calculating the hydraulic pressure of the connection are described in detail below. During the execution of the gear shift control, the CPU 91 repeatedly performs the hydraulic pressure calculation process. As described in Fig. As shown in Figure 4, when the connection hydraulic pressure calculation process is started, the CPU 91 executes a process from step S10. In step S10, the CPU 91 determines various variables that are necessary in the processes of step S20 and the subsequent steps. In particular, the CPU 91 determines the phase variable Vpase, the target hydraulic pressure PZc for the connection-side friction engagement element, the accelerator actuation amount ACCP, the gear shift type variable ΔVsft, the oil temperature Toil, and an input shaft difference NM.

[0058] For the phase variable Vpase, the CPU 91 determines the last value calculated in the phase identification process. For the target hydraulic pressure PZc, the CPU 91 determines the last value calculated in the gear shift control. The target hydraulic pressure PZc is the target hydraulic pressure variable. For the accelerator actuation amount ACCP, the CPU 91 determines the last value entered into the control unit 90 by the accelerator sensor 59. The accelerator actuation amount ACCP is the accelerator actuation amount variable. For the gear shift type variable ΔVsft, the CPU 91 determines the last value calculated in the gear shift control. The gear shift type variable ΔVsft is the gear shift variable. For the oil temperature Toil, the CPU 91 determines the last value entered into the control unit 90 by the oil temperature sensor 56. The oil temperature Toil is the oil temperature variable.

[0059] The input shaft difference NM is an absolute value representing the difference between the instantaneous speed NA of input shaft 41 and the speed NA2 of input shaft 41 corresponding to the gear stage after gear shifting. When the CPU 91 determines the input shaft difference NM, it calculates the last value of the speed NA of input shaft 41 (calculated in the background), the last value of the speed NB of output shaft 42, and the last target gear stage SFT. The CPU 91 calculates an absolute value representing the difference between the speed NA of input shaft 41 and a value obtained by multiplying a gear ratio corresponding to the target gear stage SFT by the speed NB of output shaft 42. The CPU 91 determines the resulting value as the input shaft difference NM.Therefore, the input shaft difference NM indicates the magnitude of the instantaneous rotational speed NA of input shaft 41 relative to the rotational speed NA2 of input shaft 41, which corresponds to the gear stage after gear shifting. That is, the input shaft difference NM is the input shaft variable.

[0060] Once the values ​​of the various variables have been determined as described above, CPU 91 continues the process with step S20. The process of step S10 is the determination process. In step S20, CPU 91 selects connection mapping data Dc for use in calculating the estimated hydraulic pressure PEc based on the phase variable Vpase. Memory 95 stores a map for each friction engagement element that relates the phase variable Vpase to the connection mapping data Dc. Referencing this map, CPU 91 selects, from the portions of connection mapping data Dc of each phase stored in memory 95, the connection mapping data Dc of the friction engagement element that is a target for calculating the estimated hydraulic pressure PEc in the phase corresponding to the phase variable Vpase. Once the connection mapping data Dc is selected, CPU 91 continues the process with step S30.The process of step S20 is the selection process.

[0061] In step S30, the CPU 91 sets the values ​​of the various variables determined in step S10 for input variables x(1) to x(5), which are to be entered into a diagram as a process prior to the calculation of the estimated hydraulic pressure Pec. Specifically, the CPU 91 sets the target hydraulic pressure PZc for the connection-side friction engagement element for input variable x(1). The CPU 91 sets the accelerator actuation amount ACCP for input variable x(2). The CPU 91 sets the gear shift type variable ΔVsft for input variable x(3). The CPU 91 sets the oil temperature Toil for input variable x(4). The CPU 91 sets the input shaft difference NM for input variable x(5). The CPU 91 then continues the process with step S40.

[0062] In step S40, the CPU 91 calculates an output variable y by inserting the input variables x(1) to x(5) into the mapping defined by the connection mapping data Dc, which is selected in step S20. The output variable y is the estimated hydraulic pressure Pec relative to the connection-side friction engagement element.

[0063] The diagram is constructed as a fully connected, forward-facing neural network with an intermediate layer. The neural network comprises an input coefficient wFjk (j = 0 to n, k = 0 to 5) and an activation function h(x). The activation function h(x) is an input nonlinear map that nonlinearly transforms outputs from an input linear map. The input linear map is a linear map defined by the input coefficient wFjk. In this embodiment, a hyperbolic tangent, or hyperbolic tangent, "tanh(x)" is described by way of example as the activation function h(x). The neural network further comprises an output coefficient wSj (j = 0 to n) and an activation function f(x). The activation function f(x) is an output nonlinear map that nonlinearly transforms outputs from an output linear map.The output-side linear map is a linear map defined by the output-side coefficient wSj. In this embodiment, a hyperbolic tangent "tanh(x)" is described as the activation function f(x). The value n represents a dimension of the intermediate layer. An input-side coefficient wFj0 ​​is a bias parameter and serves as a coefficient of an input variable x(0). The input variable x(0) is defined as "1". An output-side coefficient wS0 is also a bias parameter.

[0064] The figure is a model that is trained before installation in the vehicle 100 using a power transmission device comprising the internal combustion engine 10, the power distribution device 20, the automatic transmission 30, the hydraulic unit 65, the first motor-generator 61, and the second motor-generator 62, which are installed in the vehicle 100. During training, training and teaching data are acquired beforehand. That is, the training and teaching data are generated by attaching the power transmission device to a roller dynamometer and simulating the vehicle's operation. During the generation of the training and teaching data, the gear shift control is executed, with the state of the power transmission device being adjusted differently. The state of the power transmission device is determined by a combination of the gear shift type variable ΔVsft, the accelerator actuation amount ACCP, and the oil temperature Toil.This means that the gear shift control is executed while situations are simulated, derived from various combinations of these parameter values, and actual hydraulic pressures in each situation are determined as training data. The actual hydraulic pressure can be determined by attaching a hydraulic pressure sensor to the hydraulic circuit 67 and recording a value detected by the sensor. Simultaneously with the determination of the actual hydraulic pressures, the values ​​of various variables, serving as input variables for the diagram, are determined as training data. At this stage, the values ​​of the various variables are determined similarly to the process in step S10.In this way, the training and teaching data components are determined under the individual conditions of the power transmission device, and the actuator is trained using combinations of the training and teaching data associated with those conditions. That is, input and output variables are set for the various conditions of the power transmission device such that the difference between a value output by the actuator after inputting the training data and the teaching data (the actual hydraulic pressure) is equal to or less than a predetermined value. Training is complete when the difference is equal to or less than the predetermined value. The actuator is trained for a period corresponding to the actuator's duration.

[0065] When the estimated hydraulic pressure PEc is calculated as the output variable y in step S40, CPU 91 temporarily terminates the sequence of processes in the hydraulic pressure calculation process. Afterwards, CPU 91 re-executes the process from step S10, provided that the gear shift control is being executed. The process in step S40 is the calculation process.

[0066] Similar to the connection hydraulic pressure calculation process, the CPU 91 repeatedly executes the separation hydraulic pressure calculation process during the execution of the gear shift control. The separation hydraulic pressure calculation process is essentially the same as the connection hydraulic pressure calculation process; therefore, a detailed description is omitted. The separation hydraulic pressure calculation process differs from the connection hydraulic pressure calculation process in the following points: In the determination process, the CPU 91 calculates the target hydraulic pressure PZf for the separation-side friction engagement element instead of the target hydraulic pressure PZc for the connection-side friction engagement element.In the selection process, CPU 91 selects separation mapping data Df in conjunction with a phase of the gearshift control from the portions of separation mapping data Df of the individual phases stored in memory 95, instead of the portions of connection mapping data Dc. In the calculation process, CPU 91 calculates the estimated hydraulic pressure Pef with respect to the separation-side friction engagement element as the output variable y using a mapping defined by the separation mapping data Df, instead of the connection mapping data Dc.

[0067] The effect of this embodiment is described below. During the execution of the gear shift control, the CPU 91 calculates the estimated hydraulic pressure PEc relative to the connection-side friction engagement element using the connection mapping data Dc. At this point, the CPU 91 selects the connection mapping data Dc that are associated with a phase of the gear shift control and calculates the estimated hydraulic pressure PEc by inputting various input variables into the selected connection mapping data Dc.

[0068] During the execution of the gear shift control, the CPU 91 calculates the estimated hydraulic pressure PEf relative to the friction engagement element on the separation side using the separation mapping data Df. At this point, the CPU 91 selects the separation mapping data Df that are assigned to any phase of the gear shift control and calculates the estimated hydraulic pressure PEf by inputting various input variables into the selected separation mapping data Df.

[0069] The effects and consequences of this embodiment are described below. (1) As indicated by a long-short-short dashed line PWc in section (c) in Fig. As shown in Figure 3, the actual hydraulic pressure applied to the friction engagement element on the connection side lags behind the target hydraulic pressure PZc or changes smoothly or slowly compared to a steep or sudden change in the target hydraulic pressure PZc. This is indicated by a long-short-short dashed line PWf in section (d) in Fig. As shown in Figure 3, the actual hydraulic pressure applied to the friction element on the separating side also changes with a deviation from the target hydraulic pressure PZf. In order to calculate the estimated hydraulic pressure PE accurately in light of these circumstances, the relationship between the target hydraulic pressure PZ and the actual hydraulic pressure must be appropriately considered when calculating the estimated hydraulic pressure PE.

[0070] To reflect the relationship between the target hydraulic pressure PZ and the actual hydraulic pressure when calculating the estimated hydraulic pressure PE, it is conceivable to derive a relational expression representing this relationship and to use it for calculating PE. However, the characteristics of the change in the target hydraulic pressure PZ differ in each phase of the gear shift control. Consequently, the relationship between the target hydraulic pressure PZ and the actual hydraulic pressure also differs for each phase. Therefore, it is difficult to derive a relational expression applicable to all phases within the execution time of the gear shift control. Alternatively, it is conceivable to derive relational expressions for the individual phases of the gear shift control.In this case, however, it is necessary to derive relational expressions suitable for each individual phase by repeatedly analyzing the relationship between the target hydraulic pressure PZ and the actual hydraulic pressure. This requires considerable time and effort.

[0071] If, as in the configuration described above, the estimated hydraulic pressure PE is calculated using the diagram, the relationship between the target hydraulic pressure PZ and the actual hydraulic pressure can be reflected in the calculation of the estimated hydraulic pressure PE without the time and effort of deriving a complex relational expression, provided suitable training and instruction data can be prepared. In the configuration described above, the diagrams assigned to each phase are used. Therefore, relationships between the target hydraulic pressure PZ and the actual hydraulic pressure, appropriate for each phase, can be considered when calculating the estimated hydraulic pressure PE. When the estimated hydraulic pressure PE is calculated using the diagram, the accuracy of the estimated hydraulic pressure PE can be ensured, provided some training and instruction data can be prepared.In the configuration described above, not only the target hydraulic pressure PZ, but also several variables are used as input variables. Therefore, the estimated hydraulic pressure PE can be calculated by considering the relationships between the variables and the actual hydraulic pressure. Thus, the estimated hydraulic pressure PE can be calculated with high accuracy.

[0072] (2) The characteristics of the temporal change during the execution period of the gear shift control differ between the target hydraulic pressure PZc for the coupling-side friction engagement element and the target hydraulic pressure PZf for the disconnect-side friction engagement element. Therefore, the relationship between the target hydraulic pressure PZ and the actual hydraulic pressure differs between the coupling-side and disconnect-side friction engagement elements. By using the diagrams assigned to the coupling-side and disconnect-side friction engagement elements, as in the configuration described above, the respective estimated hydraulic pressures PE can be calculated exactly.

[0073] (3) The torque acting on the automatic transmission 30 varies depending on the accelerator pedal actuation amount ACCP. Consequently, the way in which the target hydraulic pressure PZ changes varies, such as an increase rate PZc for the coupling-side friction element or a decrease rate PZf for the disengagement-side friction element during the torque phase, depending on the accelerator pedal actuation amount ACCP. Because the way in which the target hydraulic pressure PZ changes varies, the relationship between the target hydraulic pressure PZ and the actual hydraulic pressure also varies.By including the accelerator actuation amount ACCP as one of the input variables of the diagram, as in the configuration described above, the estimated hydraulic pressure PE can be calculated taking into account the relationship between the target hydraulic pressure PZ and the actual hydraulic pressure, based not only on the magnitude of the target hydraulic pressure PZ, but also on the way in which the target hydraulic pressure PZ changes.

[0074] (4) Similar to the accelerator actuation amount ACCP in section (3), the way in which the target hydraulic pressure PZ changes varies depending on the type of change in the gear stage. For example, the way in which the target hydraulic pressure PZ changes may differ between a case where the gear stage is changed from first gear to second gear and a case where the gear stage is changed from third gear to second gear, although both cases are the same in that the first brake B1 is engaged. By including the gear shift type variable ΔVsft as one of the input variables, as in the configuration described above, the estimated hydraulic pressure PE can be calculated based on the way in which the target hydraulic pressure PZ changes, taking into account the relationship between the target hydraulic pressure PZ and the actual hydraulic pressure.

[0075] (5) When the oil temperature (Toil) is low, it is difficult to increase the actual hydraulic pressure due to the low viscosity of the oil. By including the oil temperature (Toil) as one of the input variables, as in the configuration described above, the estimated hydraulic pressure (PE) can be calculated based on the oil temperature (Toil), taking into account the characteristics of the actual hydraulic pressure.

[0076] (6) The input shaft difference NM is the absolute value of the difference between the instantaneous rotational speed NA of input shaft 41 and the rotational speed NA2 of input shaft 41 corresponding to the gear stage after gear shifting. In the first phase Q1 to the third phase Q3 before the inertia phase, the input shaft difference NM is essentially constant. In the fourth phase Q4 and the fifth phase Q5, which correspond to the inertia phase, the input shaft difference NM decreases as the time phase of the gear shift control progresses. Therefore, the input shaft difference NM in the fourth phase Q4 and the fifth phase Q5 can serve as an index of the time stage in the same phase. By including the input shaft difference NM as one of the input variables, as in the configuration described above, the estimated hydraulic pressure PE can be calculated taking into account the time stage in the same phase.Thus, the estimated hydraulic pressure PE can be calculated taking into account the relationship between the target hydraulic pressure PZ and the actual hydraulic pressure at a finer stage than the subdivision range of the individual phases.

[0077] This embodiment can be modified as follows. This embodiment and the following modified examples can be combined without creating technical contradictions. Part of the connection hydraulic pressure calculation process can be performed by a computer outside the vehicle. For example, a server, as described in Fig. As shown in Figure 5, the server 600 is located outside the vehicle 100. The server 600 can perform the selection and calculation processes within the hydraulic pressure calculation process. In this case, the server 600 can be configured as one or more processors, each configured to execute different processes based on computer programs (software). The server 600 can also be configured as one or more hardware circuits, such as an application-specific integrated circuit (ASIC), designed to execute at least some of the different processes, or as a circuit comprising a combination of these hardware circuits. The processor includes a CPU 602 and memory comprising a RAM and a ROM 604. The memory stores program code or instructions to cause the CPU 602 to execute processes.The memory, that is, a computer-readable medium, comprises any available medium accessible to a general-purpose computer or a dedicated computer. The server 600 includes a memory 606, which is an electrically rewritable, non-volatile memory. The memory 606 stores the portions of connection mapping data Dc of each phase as described in the embodiment above. The server 600 includes a communication device 610 for connecting to the environment of the server 600 via an external communication network 700. The CPU 602, the ROM 604, the memory 606, and the communication device 610 can communicate with each other via an internal bus 608.

[0078] When the server 600 performs the selection and calculation processes in the hydraulic pressure calculation process, the vehicle 100's control unit 90 includes a communication device 99 for communicating with the environment of the control unit 90 via the external communication network 700. The configuration of the control unit 90 is the same as in the embodiment described above, except for the inclusion of the communication device 99. Therefore, a detailed description of the control unit 90 is omitted. Fig. 5 are parts with the same functions as those in Fig. 1 by the same reference symbols as those in Fig. 1 is designated. The control unit 90, together with the server 600, forms a hydraulic pressure calculation device Z.

[0079] When the server 600 executes the selection and calculation processes in the connection hydraulic pressure calculation process, the control unit 90 of the vehicle 100, in the embodiment described above, first executes the determination process of step S10. If various variables are determined by the process of step S10, the control unit 90 sends the values ​​of the determined variables to the server 600. When the values ​​of the various variables are received, the CPU 602 of the server 600 calculates the estimated hydraulic pressure PEc with respect to the connection-side friction engagement element by executing the processes of steps S20, S30, and S40 in the embodiment. The CPU 602 of the server 600 executes the processes of steps S20, S30, and S40 by running a program stored in ROM 604.

[0080] If the control unit 90 of the vehicle 100 and the server 600 execute the connection hydraulic pressure calculation process as in the modified example, the CPU 91 and the ROM 93 of the control unit 90 of the vehicle 100 and the CPU 602 and the ROM 604 of the server 600 form the processor.

[0081] All processes in the connection hydraulic pressure calculation process can be executed by the computer outside of the vehicle 100. For example, if, as in the modified example described above, the server 600 is located outside of the vehicle 100, the control unit 90 of the vehicle 100 sends sensing signals from various sensors attached to the vehicle 100 to the server 600. The control unit 90 of the vehicle 100 also sends other variables for use in the connection hydraulic pressure calculation process, such as the phase variable Vpase and the gear shift type variable ΔVsft, to the server 600. The CPU 602 of the server 600 determines values ​​of the various variables by executing a process corresponding to that of step S10 in the embodiment described above. Similar to the modified example, the CPU 602 of the server 600 then executes processes corresponding to those of steps S20, S30, and S40.In this configuration, the server 600 performs the investigation process, the selection process, and the calculation process.

[0082] Part or all of the separation hydraulic pressure calculation process can be performed by the Server 600. In this case, the Server 600's memory 606 can store the portions of separation mapping data Df from each phase of the gear shift control.

[0083] In the embodiment described above, both the connection hydraulic pressure calculation process and the separation hydraulic pressure calculation process are executed. However, it is also possible to execute only one of these calculation processes and omit the other. In this case, memory 95 does not need to store the portions of mapping data D for use in the omitted process.

[0084] In the embodiment described above, the estimated hydraulic pressure PE can be calculated using the same mapping data D when the friction engagement element is switched to the connected state and when the friction engagement element is switched to the disconnected state. It is assumed that the connected and disconnected states are similar with respect to behavior such as the delay of the actual hydraulic pressure from the target hydraulic pressure PZ in each phase of the gear shift control execution time. Provided that the portions of mapping data D are prepared for the individual phases, a certain level of accuracy with respect to the estimated hydraulic pressure PE can be expected even when the same mapping data D is used for switching to the connected state and switching to the disconnected state.

[0085] The method for determining the phases in the execution time of the gearshift control is not limited to the example of the embodiment described above. Any determination method can be used, as long as the beginning and end of each phase can be determined appropriately. The method for subdividing the phases in the execution time of the gearshift control is also not limited to the example of the embodiment. For example, the phases can be subdivided into three stages: one stage before the torque phase, one stage during the torque phase, and one stage during the inertia phase. If the method for subdividing the phases is modified from the method of the embodiment, the memory can store 95 parts of mapping data D of the modified phases.

[0086] The method for subdividing the phases when calculating the estimated hydraulic pressure PEc with respect to the connection-side friction engagement element may differ from the method for subdividing the phases when calculating the estimated hydraulic pressure PEf with respect to the separation-side friction engagement element.

[0087] The accelerator actuation amount ACCP to be determined in step S10 is not limited to the last value at the time of execution of the process in step S10. For example, a maximum value of the accelerator actuation amount ACCP can be determined over a time interval from the execution of step S10 at a previous time to the execution of step S10 at a later time. Instead of determining the instantaneous value, an average value of the accelerator actuation amounts ACCP over a predetermined time interval can be determined. The same applies to the oil temperature Toil.

[0088] The variable to be used as the target hydraulic pressure variable is not limited to the example of the embodiment described above. For example, the target hydraulic pressure variable can be a value obtained by multiplying the target hydraulic pressure PZ by a correction coefficient suitable for accurately calculating the estimated hydraulic pressure PE. The target hydraulic pressure variable can be any variable, including the target hydraulic pressure itself.

[0089] The variable to be used as the accelerator actuation amount variable is not limited to the example of the embodiment described above. For example, the accelerator actuation amount variable can be a value that specifies one or more levels of the accelerator actuation amount ACCP. The accelerator actuation amount variable can be any variable, including the accelerator actuation amount ACCP.

[0090] The variable to be used as the gear shift variable is not limited to the example of the embodiment described above. For example, the gear shift variable can be a positive or a negative value that distinguishes the target gear stage SFT after shifting between a higher and a lower gear stage. The gear shift variable can be any variable that indicates the change in gear stage before and after the friction engagement element shifts.

[0091] The variable to be used as the oil temperature variable is not limited to the example of the embodiment described above. For example, the oil temperature variable could be a value indicating one or more levels of the oil temperature. The oil temperature variable can be any variable that indicates the oil temperature.

[0092] The variable to be used as the input wave variable is not limited to the example of the embodiment described above. The input wave variable can be a variable that indicates a change in the input wave 41. For example, the input wave variable can be a rate of change of the rotational speed NA of the input wave 41 per unit time. Depending on how phases are subdivided, the rate of change of the rotational speed NA of the input wave 41 can also be the index of the time stage within the same phase. The input wave variable can be any variable that indicates the rotational speed NA of the input wave 41 or the change in the rotational speed NA of the input wave.

[0093] The type of input variable is not limited to the examples of the embodiment described above. The input variables can be any other variables instead of, or in addition to, those described in the embodiment. The number of input variables can be reduced compared to the number in the embodiment. It is only necessary that the number of input variables be at least two and that one of these at least two input variables be the target hydraulic pressure variable.

[0094] The accelerator actuation amount variable, the gear shift variable, the oil temperature variable, and the input shaft variable are not necessary as input variables. Even without these variables, the estimated hydraulic pressure PE can be calculated with a certain level of accuracy, as long as at least two variables containing the target hydraulic pressure variable are used as input variables.

[0095] The input variable can be a different variable than the one described in the embodiment above. For example, the input variable can be a variable indicating the degree of deterioration of the hydraulic circuit 67 over time. In particular, the variable indicating the degree of deterioration of the hydraulic circuit 67 over time can be the total distance traveled by the vehicle 100. The response of the actual hydraulic pressure to the target hydraulic pressure PZ can change depending on the degree of deterioration of the hydraulic circuit 67 over time. By using the variable indicating the degree of deterioration of the hydraulic circuit 67 over time as one of the input variables, the estimated hydraulic pressure PE can be calculated taking into account the degree of deterioration of the hydraulic circuit 67 over time.

[0096] The variable to be used as the estimating hydraulic pressure variable is not limited to the example of the embodiment described above. For example, the estimating hydraulic pressure variable can be a value obtained by converting the hydraulic pressure into an oil flow rate. The estimating hydraulic pressure variable can be any variable that specifies the estimated hydraulic pressure PE.

[0097] The configuration of the diagram is not limited to the embodiment described above. For example, the neural network can have two or more intermediate layers. For instance, the neural network can be a recurrent neural network. In this case, previous values ​​of the input variables are reflected when the value of the output variable is recalculated. Therefore, the recurrent neural network is suitable for calculating the estimated hydraulic pressure PE, reflecting previous records.

[0098] The method for determining the training data and the teaching data to be used for training the figure is not limited to the example of the embodiment described above. For example, the training data and the teaching data can be determined in such a way that a vehicle with the same specifications as vehicle 100 actually drives.

[0099] The structure of vehicle 100 is not limited to the embodiment described above. For example, it is possible that only the internal combustion engine 10 is installed as the drive source of vehicle 100. The automatic transmission can be a continuously variable transmission.

[0100] The change in the target hydraulic pressure PZ over time in the gearshift control is not limited to the example of the embodiment described above. The target hydraulic pressure PZ can change over time in any way, as long as the connected and disconnected states of the friction engagement element can be switched appropriately.

Claims

Hydraulic pressure calculation device (Z) for application to a gear shift system (90, 30) with a transmission (30) designed to switch between a connected state and a disconnected state of a friction engagement element (C1, C2, B1, B2) depending on a hydraulic pressure from a hydraulic circuit (67), and a hydraulic control unit designed to control the hydraulic circuit (67), wherein the hydraulic pressure calculation device (Z) comprises: an accumulator (95); and a processor, wherein: the memory (95) stores parts of mapping data (D) of several phases obtained by subdividing a time interval from a switching start between the connected state and the disconnected state of the friction engagement element (C1, C2, B1, B2) to a switching end between the connected state and the disconnected state of the friction engagement element (C1, C2, B1, B2), wherein each of the parts of mapping data (D) defines a mapping;the processor is designed to output, as an output variable (y), an estimated hydraulic pressure variable, which is a variable that indicates an estimated value of an actual hydraulic pressure (PWc) applied to the friction engagement element (C1, C2, B1, B2) by the hydraulic circuit (67); the figure includes, as one of several input variables (x(1) - x(5)), a target hydraulic pressure variable (PZc), which is a variable that indicates a target hydraulic pressure (PZ) calculated by the hydraulic control unit as a target value of the hydraulic pressure applied to the friction engagement element (C1, C2, B1, B2) by the hydraulic circuit (67);and the processor is designed to: a determination process to determine values ​​of the input variables (x(1) - x(5)), a selection process to select, from the portions of mapping data (D) of the phases, a portion of the mapping data (D) that are assigned to a phase in which the values ​​of the input variables (x(1) - x(5)) are determined, and a computation process to calculate a value of the output variable (y) by inputting the values ​​of the input variables (x(1) - x(5)) determined in the determination process into the mapping of the mapping data (D) selected in the selection process. Hydraulic pressure calculation device (Z) according to claim 1, wherein: the memory (95) stores, for the phases, portions of connection mapping data (Dc), which are mapping data (D) to be used when the friction engagement element (C1, C2, B1, B2) is switched to the connected state, and portions of separation mapping data (Df), which are mapping data (D) to be used when the friction engagement element (C1, C2, B1, B2) is switched to the separated state; the processor is designed to, when the input variables (x(1) - x(5)) are determined in the determination process when the friction engagement element (C1, C2, B1, B2) is switched to the connected state, from the portions of connection mapping data (Dc) of the phases, a portion of the connection mapping data (Dc) that is assigned to a phase in which the input variables (x(1) - x(5)) are determined to be selected in the selection process;and the processor is designed to select, when the input variables (x) are determined in the determination process, when the friction engagement element (C1, C2, B1, B2) is switched to the separated state, from the parts of separation mapping data (Df) of the phases, a part of the separation mapping data (Df) that is associated with a phase in which the input variables (x(1) - x(5)) are determined, in the selection process. Hydraulic pressure calculation device (Z) according to claim 1 or 2, wherein an accelerator actuation amount variable (ACCP), which is a variable that specifies an actuation amount of an accelerator pedal (60) of a vehicle (100) in which the transmission (30) is installed, is included as one of the input variables (x(1) - x(5)). Hydraulic pressure calculation device (Z) according to one of claims 1 to 3, wherein a gear shift variable (ΔVsft), which is a variable indicating a change of a gear stage before and after switching between the connected state and the disconnected state of the friction engagement element (C1, C2, B1, B2), is included as one of the input variables (x(1) - x(5)). Hydraulic pressure calculation device (Z) according to one of claims 1 to 4, wherein an oil temperature variable, which is a variable that indicates a temperature (Toil) of oil in the hydraulic circuit (67), is included as one of the input variables (x(1) - x(5)). Hydraulic pressure calculation device (Z) according to one of claims 1 to 5, wherein an input shaft variable, which is a variable that indicates a rotational speed of an input shaft (41) of the transmission (30) or a change in the rotational speed of the input shaft (41), is included as one of the input variables (x(1) - x(5)).

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