Vehicle control device

Abstract

To suppress shift shock, in executing gear shift of a transmission and start of an engine at the same time.SOLUTION: In starting an engine during transition of gear-shift of a transmission, when a predetermined inertia phase start period overlaps with time of starting cranking, the starting of cranking is delayed up to time at which the inertia phase start period ends; or when a predetermined inertia phase completion period overlaps with the time of starting cranking, the starting of cranking is delayed up to time at which the predetermined inertia phase completion period ends; or when the predetermined inertia phase start period overlaps with a synchronization completion time point of a clutch, the starting of cranking is delayed so that the synchronization completion time point comes after the predetermined inertia phase start period ends; or when the predetermined inertia phase completion period overlaps with the synchronization completion time point, the starting of cranking is delayed so that the synchronization completion time point comes after the predetermined inertia phase completion period ends, which can avoid or suppress a situation where shift shock easily occurs.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a control device for a vehicle that includes a clutch provided between an engine and an electric motor, and a transmission that transmits power from a power source including the engine and the electric motor. [Background technology]

[0002] A control device for a vehicle including an engine, an electric motor connected to a power transmission path between the engine and drive wheels so as to transmit power, a clutch provided in the power transmission path between the engine and the electric motor, and a transmission provided in the power transmission path between the electric motor and the drive wheels is well known. For example, Patent Document 1 discloses a control device for a vehicle drive device. Patent Document 1 discloses that when a request is made to simultaneously execute engine start control and transmission shift control, one of the start control and the shift control is executed with priority, and after the one control is completed, the other control is executed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-36847 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when starting control and gear shift control are executed sequentially, the generation of the target drive torque is delayed compared to when both are executed in parallel, which may result in a deterioration in drivability. Therefore, when considering drivability, it is preferable to execute starting control and gear shift control in parallel. However, when executing both controls in parallel, if they are executed independently without coordination, there is a possibility of shift shock occurring due to fluctuations in the input torque of the transmission caused by a discrepancy between the torque capacity of the clutch during starting control and the cranking torque from the electric motor, or fluctuations in the inertia of the input rotating member of the transmission caused by the engine being connected to the power transmission path on the transmission side upon clutch engagement. While executing starting control and gear shift control in sequential order is sufficient to suppress shift shock, it is preferable to execute both controls in parallel to suppress shift shock in order to prevent a deterioration in drivability.

[0005] The present invention was made against the background of the above circumstances, and its purpose is to provide a vehicle control device that can suppress shift shock when shifting the transmission and starting the engine at the same time. [Means for solving the problem]

[0006] The gist of a first aspect of the present invention is a control device for a vehicle including: (a) an engine; an electric motor connected to a power transmission path between the engine and drive wheels so as to be able to transmit power; a clutch provided in the power transmission path between the engine and the electric motor; and a transmission provided in the power transmission path between the electric motor and the drive wheels, (b) an engine control unit that controls the engine so as to start operation when it is determined that there is a request to start the engine; and (c) a cranking torque required for cranking to increase the rotational speed of the engine when starting the engine, and a transmission that controls the cranking torque required for cranking to increase the rotational speed of the engine when starting the engine. (d) a clutch control unit that controls the clutch to switch the control state of the clutch from a released state to an engaged state so as to complete synchronization between the input rotation speed and the output rotation speed of the latch; (d) an electric motor control unit that controls the electric motor so that the electric motor outputs the cranking torque in conjunction with the cranking; and (e) a transmission control unit that determines a gear shift of the transmission using a predetermined relationship and controls the transmission to establish a gear ratio according to the result of the gear shift determination, and (f) the clutch control unit determines a start point of an inertia phase during the gear shift transition of the transmission when the engine is started during the gear shift transition of the transmission. In contrast, gear shift shock is likely to occur from a predetermined time before to a predetermined time after the shift. When a predetermined inertia phase start period and the start of cranking overlap, the start of cranking is delayed until after the predetermined inertia phase start period, and , at the end of the inertia phase In contrast, gear shift shock is likely to occur from a predetermined time before to a predetermined time after the shift. When the predetermined inertia phase end period and the start of the cranking overlap, the start of the cranking is delayed until after the predetermined inertia phase end period, and When the predetermined inertia phase start period and the synchronization completion time of the clutch overlap, the start of the cranking is delayed so that the synchronization completion time comes after the predetermined inertia phase start period, and If the predetermined inertia phase end period and the synchronization completion time point overlap, the start of cranking is delayed so that the synchronization completion time point comes after the predetermined inertia phase end period. [Effects of the Invention]

[0007] According to the first aspect of the present invention, when starting the engine during a gear shift transition of the transmission, if the predetermined inertia phase start period and the start of cranking overlap, the start of cranking is delayed until after the predetermined inertia phase start period, and If the predetermined inertia phase end period and the start of cranking overlap, the start of cranking is delayed until after the predetermined inertia phase end period, and If the predetermined inertia phase start period and the clutch synchronization completion time overlap, the start of cranking is delayed so that the synchronization completion time occurs after the predetermined inertia phase start period. and If the predetermined inertia phase end period and the synchronization completion time overlap, the start of cranking is delayed so that the synchronization completion time occurs after the predetermined inertia phase end period, thereby avoiding or suppressing situations where gear shift shock is likely to occur. Therefore, gear shift shock can be suppressed when the transmission shift and engine start are executed at the same time. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram illustrating a schematic configuration of a vehicle to which the present invention is applied, and is also a diagram illustrating main parts of control functions and control systems for various controls in the vehicle. [Figure 2] FIG. 4 is a diagram showing an example of a time chart when engine start control is executed. [Figure 3] FIG. 10 is a diagram illustrating an example of a cranking start delay request. [Figure 4] 1 is a flowchart illustrating the main control operations of an electronic control device, and is a flowchart illustrating the control operations for suppressing shift shock when shifting an automatic transmission and starting an engine are performed simultaneously. DETAILED DESCRIPTION OF THE INVENTION

[0009] In an embodiment of the present invention, the gear ratio of the transmission is "rotational speed of the input rotating member / rotational speed of the output rotating member." The high-side gear ratio of the transmission is the gear ratio on the high vehicle speed side where the gear ratio is small. The low-side gear ratio of the transmission is the gear ratio on the low vehicle speed side where the gear ratio is large. For example, the lowest-side gear ratio is the gear ratio on the lowest vehicle speed side where the gear ratio is the largest.

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. [Example]

[0011] Fig. 1 is a diagram illustrating the schematic configuration of a vehicle 10 to which the present invention is applied, and also illustrates the main parts of the control functions and control systems for various controls in the vehicle 10. In Fig. 1, the vehicle 10 is a hybrid vehicle equipped with an engine 12 and an electric motor MG that function as a power source SP. The vehicle 10 also has drive wheels 14 and a power transmission device 16 provided in a power transmission path between the engine 12 and the drive wheels 14.

[0012] The engine 12 is a known internal combustion engine such as a gasoline engine, a diesel engine, etc. An electronic control device 90 (described later) controls an engine control device 50 including a throttle actuator, a fuel injection device, an ignition device, etc., provided in the vehicle 10, thereby controlling the engine torque Te, which is the output torque of the engine 12.

[0013] The electric motor MG is a rotating electric machine, a so-called motor generator, that functions as a motor that generates mechanical power from electric power and as a generator that generates electric power from mechanical power. The electric motor MG is connected to a battery 54 provided in the vehicle 10 via an inverter 52 provided in the vehicle 10. The battery 54 is an electricity storage device that supplies and receives electric power to the electric motor MG. The inverter 52 is controlled by an electronic control device 90 (described later), thereby controlling the MG torque Tm, which is the output torque of the electric motor MG. For example, when the rotation direction of the electric motor MG is forward, which is the same as the rotation direction when the engine 12 is operating, the MG torque Tm is a power torque when the positive torque is on the acceleration side, and a regenerative torque when the negative torque is on the deceleration side. The electric power also refers to electric energy unless otherwise specified. The power also refers to driving force, torque, and force unless otherwise specified.

[0014] The power transmission device 16 includes a K0 clutch 20, a torque converter 22, an automatic transmission 24, and the like, housed within a case 18, which is a non-rotating member attached to the vehicle body. The K0 clutch 20 is a clutch provided between the engine 12 and the electric motor MG in a power transmission path between the engine 12 and the drive wheels 14. The torque converter 22 is connected to the engine 12 via the K0 clutch 20. The automatic transmission 24 is connected to the torque converter 22 and is interposed in the power transmission path between the torque converter 22 and the drive wheels 14. The automatic transmission 24 is a transmission provided between the electric motor MG and the drive wheels 14 in the power transmission path between the engine 12 and the drive wheels 14. The power transmission device 16 also includes a propeller shaft 28 connected to a transmission output shaft 26, which is an output rotating member of the automatic transmission 24, a differential gear 30 connected to the propeller shaft 28, a pair of drive shafts 32 connected to the differential gear 30, and the like. The power transmission device 16 also includes an engine connecting shaft 34 that connects the engine 12 and the K0 clutch 20, an electric motor connecting shaft 36 that connects the K0 clutch 20 and the torque converter 22, and the like.

[0015] The electric motor MG is connected to the electric motor connecting shaft 36 in the case 18 so as to be able to transmit power. In other words, the electric motor MG is connected to the power transmission path between the engine 12 and the drive wheels 14, particularly to the power transmission path between the K0 clutch 20 and the torque converter 22. In other words, the electric motor MG is connected to the torque converter 22 and the automatic transmission 24 so as to be able to transmit power without passing through the K0 clutch 20.

[0016] The torque converter 22 includes a pump wheel 22a connected to the electric motor connecting shaft 36, and a turbine wheel 22b connected to a transmission input shaft 38, which is an input rotating member of the automatic transmission 24. The torque converter 22 is a fluid transmission device that transmits power from the power source SP from the electric motor connecting shaft 36 to the transmission input shaft 38 via fluid. The torque converter 22 includes an LU clutch 40 as a direct-coupled clutch that connects the pump wheel 22a and the turbine wheel 22b, i.e., that connects the electric motor connecting shaft 36 and the transmission input shaft 38. The LU clutch 40 is a known lock-up clutch.

[0017] The automatic transmission 24 is a known planetary gear automatic transmission that includes, for example, one or more planetary gear devices (not shown) and an engagement device CB. The engagement device CB includes, for example, a plurality of hydraulic engagement devices, such as known friction engagement devices. Each engagement device CB has its torque capacity, or CB torque Tcb, changed by a CB hydraulic pressure PRcb, which is a regulated hydraulic pressure supplied from a hydraulic control circuit 56 provided in the vehicle 10, thereby switching between operating states, i.e., control states, such as an engaged state, a slip state, and a disengaged state.

[0018] The automatic transmission 24 is a stepped transmission in which one of a plurality of gear stages (also referred to as gear stages) with different speed ratios (also referred to as gear ratios) γat (=AT input rotation speed Ni / AT output rotation speed No) is formed by engaging one of the engagement devices CB. The automatic transmission 24 switches between the formed gear stages by an electronic control device 90 (described later) switching the control state of the engagement devices CB involved in the shifting of the automatic transmission 24 in accordance with the accelerator operation of the driver (=operator), the vehicle speed V, etc. In other words, in the shift control of the automatic transmission 24, a shift is performed, for example, by switching the engagement of the engagement devices involved in the shift, that is, a so-called clutch-to-clutch shift is performed in which a shift is performed by disengaging a release-side engagement device and engaging an engagement-side engagement device. The disengagement-side engagement device is an engagement device that, among the engagement devices involved in the shift, was in an engaged state before the automatic transmission 24 was shifted, and is an engagement device that is controlled from an engaged state to a disengaged state during a shift transition of the automatic transmission 24. The engagement-side engagement device is an engagement device that, among the engagement devices involved in the shift, was in a disengaged state before the automatic transmission 24 was shifted, and is an engagement device that is controlled from a disengaged state to an engaged state during a shift transition of the automatic transmission 24. The AT input rotation speed Ni is the rotation speed of the transmission input shaft 38, and is the input rotation speed of the automatic transmission 24. The AT input rotation speed Ni is equivalent to the turbine rotation speed Nt, which is the output rotation speed of the torque converter 22. The AT input rotation speed Ni can be expressed in terms of the turbine rotation speed Nt. The AT output rotation speed No is the rotation speed of the transmission output shaft 26, and is the output rotation speed of the automatic transmission 24.

[0019] The K0 clutch 20 is a hydraulic friction engagement device configured, for example, with a multi-plate or single-plate clutch. The K0 clutch 20 switches between control states such as an engaged state, a slip state, and a released state by changing the K0 torque Tk0, which is the torque capacity of the K0 clutch 20, using the K0 oil pressure PRk0, which is the adjusted oil pressure supplied from the hydraulic control circuit 56.

[0020] In the vehicle 10, when the K0 clutch 20 is engaged, the engine 12 and the torque converter 22 are connected to each other so that power can be transmitted between them. On the other hand, when the K0 clutch 20 is disengaged, power transmission between the engine 12 and the torque converter 22 is interrupted. Because the electric motor MG is connected to the torque converter 22, the K0 clutch 20 functions as a clutch that connects and disconnects the engine 12 from the electric motor MG.

[0021] In the power transmission device 16, when the K0 clutch 20 is engaged, the power output from the engine 12 is transmitted from the engine connecting shaft 34 to the drive wheels 14 via the K0 clutch 20, the electric motor connecting shaft 36, the torque converter 22, the automatic transmission 24, the propeller shaft 28, the differential gear 30, the drive shaft 32, etc. in this order. Furthermore, regardless of the control state of the K0 clutch 20, the power output from the electric motor MG is transmitted from the electric motor connecting shaft 36 to the drive wheels 14 via the torque converter 22, the automatic transmission 24, the propeller shaft 28, the differential gear 30, the drive shaft 32, etc. in this order.

[0022] The vehicle 10 is equipped with a MOP 58 which is a mechanical oil pump, an EOP 60 which is an electric oil pump, a pump motor 62, etc. The MOP 58 is connected to the pump impeller 22a and is driven to rotate by a power source SP to discharge hydraulic oil OIL used in the power transmission device 16. The pump motor 62 is a motor dedicated to the EOP 60 for driving the EOP 60 to rotate. The EOP 60 is driven to rotate by the pump motor 62 to discharge hydraulic oil OIL. The hydraulic oil OIL discharged by the MOP 58 and the EOP 60 is supplied to a hydraulic control circuit 56. The hydraulic control circuit 56 supplies a CB hydraulic pressure PRcb, a K0 hydraulic pressure PRk0, etc., which are adjusted based on the hydraulic oil OIL discharged by the MOP 58 and / or the EOP 60.

[0023] The vehicle 10 further includes an electronic control device 90 that includes a control device for the vehicle 10. The electronic control device 90 includes a so-called microcomputer equipped with, for example, a CPU, RAM, ROM, an input / output interface, etc., and the CPU executes various controls of the vehicle 10 by performing signal processing in accordance with programs stored in the ROM in advance while utilizing the temporary storage function of the RAM. The electronic control device 90 includes computers for engine control, electric motor control, clutch control, transmission control, etc. as necessary.

[0024] The electronic control device 90 is supplied with various signals based on detection values ​​from various sensors provided on the vehicle 10 (for example, an engine rotation speed sensor 70, a turbine rotation speed sensor 72, an output rotation speed sensor 74, an MG rotation speed sensor 76, an accelerator opening sensor 78, a throttle valve opening sensor 80, a brake switch 82, a battery sensor 84, an oil temperature sensor 86, etc.) (for example, an engine rotation speed Ne which is the rotation speed of the engine 12, a turbine rotation speed Nt which is the same value as the AT input rotation speed Ni, an AT output rotation speed No corresponding to the vehicle speed V, an MG rotation speed Nm which is the rotation speed of the electric motor MG, an accelerator opening θacc which is the amount of accelerator operation by the driver which indicates the magnitude of the driver's acceleration operation, a throttle valve opening θth which is the opening of the electronic throttle valve, a brake-on signal Bon which is a signal indicating the state in which the brake pedal for operating the wheel brakes is being operated by the driver, a battery temperature THbat, a battery charge / discharge current Ibat, a battery voltage Vbat of the battery 54, and a hydraulic oil temperature THoil which is the temperature of the hydraulic oil in the hydraulic control circuit 56).

[0025] The electronic control device 90 outputs various command signals (e.g., an engine control command signal Se for controlling the engine 12, an MG control command signal Sm for controlling the electric motor MG, a CB hydraulic control command signal Scb for controlling the engagement device CB, a K0 hydraulic control command signal Sk0 for controlling the K0 clutch 20, an LU hydraulic control command signal Slu for controlling the LU clutch 40, an EOP control command signal Seop for controlling the EOP 60, etc.) to each device provided in the vehicle 10 (e.g., the engine control device 50, the inverter 52, the hydraulic control circuit 56, the pump motor 62, etc.).

[0026] Each hydraulic control command signal S will be described using the K0 hydraulic control command signal Sk0 as an example. The electronic control unit 90 calculates a K0 clutch command pressure Spk0, which is a command pressure for the K0 clutch 20 to supply the adjusted K0 hydraulic pressure PRk0 from the hydraulic control circuit 56, as a command value for the K0 hydraulic pressure PRk0. The command pressure is a target hydraulic pressure commanded by the electronic control unit 90 for the hydraulic oil OIL supplied to the engagement device, and the actual hydraulic pressure, which is the actual hydraulic pressure supplied to the engagement device, changes depending on this command pressure. The electronic control unit 90 converts the K0 clutch command pressure Spk0 into a K0 command current value Sik0 for driving a K0 solenoid SLk0 provided in the hydraulic control circuit 56. The K0 solenoid SLk0 is a solenoid valve for the K0 clutch 20 that outputs the K0 hydraulic pressure PRk0. The K0 command current value Sik0 is a command current for a solenoid driver, which is a drive circuit provided in the electronic control unit 90 that drives the K0 solenoid SLk0. The K0 hydraulic control command signal Sk0 is a drive current or drive voltage for the solenoid driver to drive the K0 solenoid SLk0 based on the K0 command current value Sik0. In other words, the K0 clutch command pressure Spk0 is converted into the K0 hydraulic control command signal Sk0 and output to the hydraulic control circuit 56. In this embodiment, for convenience, the K0 clutch command pressure Spk0 and the K0 hydraulic control command signal Sk0 are treated as the same.

[0027] The electronic control unit 90 includes a power source control means, i.e., a power source control section 92, a clutch control means, i.e., a clutch control section 94, and a transmission control means, i.e., a transmission control section 96, in order to realize various controls in the vehicle 10.

[0028] The power source control unit 92 includes a function as engine control means, i.e., engine control unit 92a, that controls the operation of the engine 12, and a function as electric motor control means, i.e., electric motor control unit 92b, that controls the operation of the electric motor MG via the inverter 52, and is a hybrid control means, i.e., a hybrid control unit, that performs hybrid drive control using the engine 12 and the electric motor MG using these control functions.

[0029] The power source control unit 92 calculates the amount of driving demanded by the driver for the vehicle 10, for example, by applying the accelerator opening θacc and the vehicle speed V to a driving demand map. The driving demand map is a relationship that is experimentally or design-based and stored in advance, i.e., a predetermined relationship. The driving demand is, for example, the required driving torque Trdem at the drive wheels 14. In other words, the required driving torque Trdem [Nm] is the required driving power Prdem [W] at the current vehicle speed V. The driving demand may also be the required driving force Frdem [N] at the drive wheels 14 or the required AT output torque at the transmission output shaft 26. In calculating the driving demand, the AT output rotation speed No may be used instead of the vehicle speed V. The power source control unit 92 outputs an engine control command signal Se for controlling the engine 12 and an MG control command signal Sm for controlling the electric motor MG so as to realize the required driving power Prdem, taking into account transmission loss, auxiliary load, the gear ratio γat of the automatic transmission 24, etc.

[0030] When the required drive torque Trdem can be satisfied by the output of the electric motor MG alone, the power source control unit 92 establishes the motor drive mode, i.e., the BEV drive mode, as the drive mode for driving the vehicle 10. The BEV drive mode is an electric drive mode that enables motor driving, i.e., electric driving (=BEV driving), in which the vehicle runs using only the electric motor MG as the power source SP with the K0 clutch 20 disengaged and the engine 12 stopped. On the other hand, when the required drive torque Trdem cannot be satisfied without using at least the output of the engine 12, the power source control unit 92 establishes the engine drive mode, i.e., the HEV drive mode, as the drive mode. The HEV drive mode is a hybrid drive mode that enables engine driving, i.e., hybrid driving (=HEV driving), in which the vehicle runs using at least the engine 12 as the power source SP with the K0 clutch 20 engaged. On the other hand, even if the required drive torque Trdem can be met by the output of the electric motor MG alone, the power source control unit 92 establishes the HEV drive mode as the drive mode when it is necessary to charge the battery 54 or when it is necessary to warm up the engine 12, etc.

[0031] The power source control unit 92, particularly the engine control unit 92a, determines whether or not there is an engine start request, which is a request to start the engine 12 and switch the control state of the engine 12 from a stopped state to an operating state. For example, particularly the engine control unit 92a determines whether or not there is an engine start request based on whether or not the required drive torque Trdem has increased beyond a range that can be covered by the output of the electric motor MG alone during the BEV drive mode, whether or not the engine 12 and the like need to be warmed up, or whether or not the battery 54 needs to be charged.

[0032] When the power source control unit 92 determines that there is an engine start request, the clutch control unit 94 controls the K0 clutch 20 to execute start control of the engine 12. For example, the clutch control unit 94 outputs a K0 hydraulic control command signal Sk0 to the hydraulic control circuit 56 to control the K0 clutch 20 from a released state toward an engaged state so as to obtain a K0 torque Tk0 for transmitting the cranking torque Tcr to the engine 12. The cranking torque Tcr is a predetermined torque required for cranking the engine 12 to increase the engine rotation speed Ne.

[0033] When the power source control unit 92 determines that there is an engine start request, it controls the engine 12 and the electric motor MG to execute start control of the engine 12. For example, when starting the engine 12, the electric motor control unit 92b outputs an MG control command signal Sm to the inverter 52 in response to switching of the K0 clutch 20 to the engaged state, i.e., in conjunction with cranking of the engine 12 by the K0 clutch 20, so that the electric motor MG outputs a cranking torque Tcr. In this way, the electric motor control unit 92b controls the electric motor MG in conjunction with cranking by the K0 clutch 20, so that the electric motor MG outputs the cranking torque Tcr transmitted via the K0 clutch 20, i.e., so that the MG torque Tm is increased by the cranking torque Tcr. Furthermore, when starting the engine 12, the engine control unit 92a outputs an engine control command signal Se to the engine control device 50 in conjunction with cranking of the engine 12, so that the engine control unit 92a starts fuel supply, engine ignition, and the like. In this way, when it is determined that there is an engine start request, the engine control unit 92a controls the engine 12 so that the engine 12 starts operating.

[0034] When cranking the engine 12, a reaction torque is generated due to engagement of the K0 clutch 20. During BEV driving, this reaction torque causes a drop in the drive torque Tr due to the inertia of the engine 12 and other components during engine start. Therefore, the MG torque Tm that is increased toward the cranking torque Tcr when starting the engine 12 is the MG torque Tm that cancels out this reaction torque and compensates for this reaction torque, i.e., the MG torque Tm for reaction compensation. The cranking torque Tcr is the K0 torque Tk0 required to crank the engine 12, and is the MG torque Tm required to crank the engine 12 that flows from the electric motor MG side to the engine 12 side via the K0 clutch 20. The cranking torque Tcr is, for example, a constant torque that is predetermined based on, for example, the specifications of the engine 12, the starting method of the engine 12, etc.

[0035] FIG. 2 is a diagram showing an example of a time chart when start control of the engine 12, i.e., engine start control, is executed. In FIG. 2, time t1a indicates the time when engine start control is started, for example, when the driver further depresses the accelerator pedal during BEV driving, and it is determined that there is an engine start request. After the engine start control is started, packing control of the K0 clutch 20, i.e., K0 packing control, is executed (see time t1a-t2a). The packing control is a control that brings the friction engagement device into a packing-completed state, i.e., a packing-completed state, in which pack clearances in the friction plates of the friction engagement device are closed. The packing-completed state of the friction engagement device is a state in which the friction engagement device begins to have torque capacity if the hydraulic pressure supplied to the friction engagement device is increased from the packing-completed state. In the K0 packing control, first, a quick apply is executed to temporarily output a high K0 clutch command pressure Spk0 to improve the initial response of the K0 oil pressure PRk0 (see section a). Next, a constant pressure standby for packing is executed to wait at a constant pressure to complete packing of the K0 clutch 20 (see section b). The K0 clutch command pressure Spk0 shown by the dashed line is the K0 oil pressure PRk0 required to maintain the K0 clutch 20 in a packing-completed state. The K0 clutch command pressure Spk0 shown by the solid line is the total K0 oil pressure PRk0, which is the K0 oil pressure PRk0 required to maintain the packing-completed state plus the K0 oil pressure PRk0 corresponding to the cranking torque Tcr. The K0 clutch command pressure Spk0 shown by the dashed line and the K0 clutch command pressure Spk0 shown by the solid line actually have different K0 packing control periods, but for convenience, they are shown as the same length in FIG. 2. After the K0 packing control is completed, in order to crank the engine 12, cranking is performed by the K0 clutch 20 transmitting the cranking torque Tcr to the engine 12, i.e., K0 cranking is performed (see time t2a-t3a). During K0 cranking, when the engine rotation speed Ne is increased, engine ignition and the like are started, causing the engine 12 to first explode. As a result, the engine rotation speed Ne is increased by the combustion torque of the engine 12.

[0036] When the self-sustaining rotation due to the combustion of the engine 12 becomes stable, that is, when the engine 12 reaches a state of complete combustion, rotation synchronization control between the engine 12 and the electric motor MG, that is, synchronization control by the K0 clutch 20 to synchronize the engine rotation speed Ne and the MG rotation speed Nm, i.e., K0 synchronization control, is executed (see time points t3a to t4a). The engine rotation speed Ne is the rotation speed of the engine connecting shaft 34 and is equal to the input rotation speed of the K0 clutch 20. The MG rotation speed Nm is the rotation speed of the electric motor connecting shaft 36 and is equal to the output rotation speed of the K0 clutch 20. In other words, synchronizing the engine rotation speed Ne and the MG rotation speed Nm is the same as synchronizing the input rotation speed and output rotation speed of the K0 clutch 20. After the synchronization of the input rotation speed and the output rotation speed of the K0 clutch 20, i.e., K0 synchronization, is completed, that is, after the K0 clutch 20 is switched to the engaged state, i.e., K0 engagement is completed, K0 full engagement control is executed to maintain the fully engaged state of the K0 clutch 20 (see time t4a and thereafter), and then engine start control is completed (see time t5a). Note that in this embodiment, a start type is adopted in which the engine rotation speed Ne is increased by the self-rotation of the engine 12, but a start type may also be adopted in which the K0 clutch command pressure Spk0 is output to increase the engine rotation speed Ne until it is synchronized with the MG rotation speed Nm by executing K0 cranking or K0 synchronization control, and ignition of the engine 12 is started after the engine rotation speed Ne has been increased to near K0 synchronization or up to K0 synchronization.

[0037] Referring to FIG. 2, when starting the engine 12, the clutch control unit 94 controls the K0 clutch 20 to switch the control state of the K0 clutch 20 from the released state to the engaged state so as to transmit the cranking torque Tcr and complete K0 synchronization.

[0038] The transmission control unit 96 determines whether to shift the automatic transmission 24 using, for example, a shift map, which is a predetermined relationship, and outputs a CB hydraulic control command signal Sbc to the hydraulic control circuit 56 as needed to control the shift of the automatic transmission 24. That is, the transmission control unit 96 determines the gear of the automatic transmission 24 to be established using, for example, the shift map, and outputs a CB hydraulic control command signal Sbc to the hydraulic control circuit 56 to control the control state of the engagement devices CB so that the determined gear is established. In the shift control of the automatic transmission 24, the transmission control unit 96 shifts the automatic transmission 24 by, for example, switching a disengagement-side engagement device of the engagement devices CB to a disengaged state and switching an engagement-side engagement device of the engagement devices CB to an engaged state. In this way, the transmission control unit 96 determines whether to shift the automatic transmission 24 using a predetermined relationship and controls the automatic transmission 24 to establish a gear ratio γat corresponding to the result of the shift determination. The shift map is a predetermined relationship having shift lines on a two-dimensional coordinate system with vehicle speed V and required drive torque Trdem as variables, for example, to determine shifts in the automatic transmission 24. In the shift map, the AT output rotation speed No may be used instead of the vehicle speed V, and the required drive force Frdem, accelerator opening θacc, throttle valve opening θth, etc. may be used instead of the required drive torque Trdem.

[0039] The progression stages, or phases, of the shifting of the automatic transmission 24 will be described using an upshift as an example. When the transmission control unit 96 determines that the automatic transmission 24 is to upshift, the transmission control unit 96 outputs a CB hydraulic control command signal Scb to the hydraulic control circuit 56 to initiate the upshift. This signal sets the upshift phase to a preparation phase, i.e., a preparation phase in which the disengagement engagement device waits at a torque capacity capable of handling the input torque Tin to the automatic transmission 24 and the on-coming engagement device is in a packing-completed state. The preparation phase is clutch preparation control that prepares the disengagement engagement device to be switched to a released state and the on-coming engagement device to have torque capacity. The transmission control unit 96 determines whether the preparation phase is complete based on whether a predetermined preparation time has elapsed since the start of the preparation phase. This predetermined preparation time is, for example, a predetermined time for the on-coming engagement device to be in a packing-completed state. When the transmission control unit 96 determines that the preparation phase is complete, it outputs a CB hydraulic control command signal Sbc to the hydraulic control circuit 56 to gradually decrease the torque capacity of the disengagement engagement device and gradually increase the torque capacity of the engagement engagement device, thereby starting the torque phase. In the case of an upshift, this torque phase is the phase in which the engagement engagement device brings out its torque capacity, causing a change in the output torque of the automatic transmission 24. When the turbine rotation speed Nt (= AT input rotation speed Ni) is reduced toward the post-upshift synchronous rotation speed (= No × γat after upshift) during the upshift transition, the upshift phase transitions from the torque phase to the inertia phase. During the inertia phase, the transmission control unit 96 outputs a CB hydraulic control command signal Sbc to the hydraulic control circuit 56 to change the turbine rotation speed Nt at a predetermined decreasing gradient, taking into account, for example, the shift time and shift shock. The transmission control unit 96 determines whether the upshift is complete based on whether the turbine rotation speed Nt matches the post-upshift synchronous rotation speed.When the transmission control unit 96 determines that the upshift has ended, it outputs a CB hydraulic pressure control command signal Scb to the hydraulic control circuit 56 to set the CB hydraulic pressure PRcb of the disengaging engagement device to zero and to set the CB hydraulic pressure PRcb of the engaging side engagement device to the CB hydraulic pressure PRcb that maintains the engaging side engagement device in a fully engaged state, thereby completing a series of gear change controls related to the upshift.

[0040] Incidentally, there are cases where the start control of the engine 12 and the shift control of the automatic transmission 24 are executed at the same time. In this case, a shift shock may occur due to fluctuations in the input torque Tin to the automatic transmission 24. Factors that cause fluctuations in the input torque Tin include, for example, a difference in the rise timing between the K0 torque Tk0 and the reaction force compensation MG torque Tm at the start of K0 cranking, i.e., when the K0 clutch 20 is engaged, and a torque step between the K0 torque Tk0 and the engine torque Te at the completion of synchronization of the K0 clutch 20, i.e., at the K0 synchronization point or immediately after the K0 synchronization point.

[0041] Therefore, when engine start control and gear shift control are executed in an overlapping manner, the electronic control unit 90 avoids an overlap between the start of K0 cranking or the K0 synchronization point in the engine start control and the shift inertia phase start period or the shift inertia phase end period during the shift control transition, i.e., a K0 lap, in order to suppress gear shift shock. If a K0 lap occurs when engine start control and gear shift control are executed in an overlapping manner, the electronic control unit 90 delays the start of engine start control to avoid the K0 lap. That is, the start of K0 cranking is delayed during the shift inertia phase start period. The start of K0 cranking is also delayed during the shift inertia phase end period. The start of K0 cranking is also delayed during the shift inertia phase start period based on a cranking prediction period to prevent overlap with the K0 synchronization point. The start of K0 cranking is also delayed during the shift inertia phase end period based on a cranking prediction period to prevent overlap with the K0 synchronization point. The shift inertia phase start period is, for example, the start point of the inertia phase during a shift transition of the automatic transmission 24 and a predetermined inertia phase start period near that start point. The shift inertia phase end period is, for example, the end point of the inertia phase during a shift transition of the automatic transmission 24 and a predetermined inertia phase end period near that end point. The predicted cranking period is, for example, an estimated value of the cranking period from the start point of K0 cranking to the K0 synchronization point.

[0042] When starting the engine 12 during a shift transition of the automatic transmission 24, if the shift inertia phase start period and the start of K0 cranking overlap, the clutch control unit 94 delays the start of K0 cranking until after the shift inertia phase start period, and if the shift inertia phase end period and the start of K0 cranking overlap, the clutch control unit 94 delays the start of K0 cranking until after the shift inertia phase end period, and if the shift inertia phase start period and the K0 synchronization point overlap, the clutch control unit 94 delays the start of K0 cranking so that the K0 synchronization point comes after the shift inertia phase start period, and if the shift inertia phase end period and the K0 synchronization point overlap, the clutch control unit 94 delays the start of K0 cranking so that the K0 synchronization point comes after the shift inertia phase end period.

[0043] Specifically, the transmission control unit 96 determines whether or not shift control of the automatic transmission 24 is being executed. If it determines that shift control of the automatic transmission 24 is being executed, the transmission control unit 96 calculates a shift inertia phase start period and a shift inertia phase end period.

[0044] The end of the torque phase, i.e., the start of the inertia phase, can be predicted as the point when the total time of a predetermined preparatory time required for the preparatory phase and a predetermined target torque phase time required for the torque phase has elapsed from the start of shift control. As shown in FIG. 3, the shift inertia phase start period is defined as the period from a point (see time t3b) a predetermined constant A before the start of the inertia phase (see time t4b) to a point (see time t5b) a predetermined constant B after the start of the inertia phase. Constants A and B are predetermined constants for determining the period before and after the start of the inertia phase, during which shift shock is likely to occur. The transmission control unit 96 calculates the shift inertia phase start period based on, for example, the predetermined preparatory time, the target torque phase time, constants A, and constants B.

[0045] The point at which a predetermined target inertia phase time required for the inertia phase has elapsed from the start of the inertia phase can be predicted as the synchronization point of the gear shift, i.e., the end of the inertia phase. As shown in FIG. 3, the period from a point (see time t7b) a predetermined constant C before the end of the inertia phase (see time t9b) to a point (see time t10b) a predetermined constant D after the end of the inertia phase is defined as the gear shift inertia phase end period. Constants C and D are predetermined constants for determining the period before and after the end of the inertia phase, during which gear shift shock is likely to occur. The transmission control unit 96 calculates the gear shift inertia phase end period based on, for example, the target inertia phase time, constants C, and constants D.

[0046] When the power source control unit 92 determines that an engine start request has been made, the clutch control unit 94 determines whether the start of K0 cranking will be within the shift inertia phase start period calculated by the transmission control unit 96. When the clutch control unit 94 determines that the start of K0 cranking will be within the shift inertia phase start period, it outputs a cranking start delay request based on the start of cranking, as shown in FIG. 3 (see time t3b-t5b). In other words, the cranking start delay request is output during the shift inertia phase start period. When the power source control unit 92 determines that an engine start request has been made, the clutch control unit 94 also determines whether the start of K0 cranking will be within the shift inertia phase end period calculated by the transmission control unit 96. When the clutch control unit 94 determines that the start of K0 cranking will be within the shift inertia phase end period, it outputs a cranking start delay request based on the start of cranking, as shown in FIG. 3 (see time t7b-t10b). That is, the cranking start delay request is output during the end period of the shift inertia phase.

[0047] The clutch control unit 94 calculates an expected cranking period when the power source control unit 92 determines that an engine start request has been made. The clutch control unit 94 calculates the expected cranking period based on, for example, the start type of the engine 12, the increase gradient of the engine rotation speed Ne depending on differences in the K0 clutch command pressure Spk0 in the K0 packing control (see the solid and dashed lines in FIG. 2), the change state of the MG rotation speed Nm depending on changes in the vehicle speed V, and the differential rotation speed (=Nm-Ne) of the K0 clutch 20 (see the expected cranking period in FIG. 3).

[0048] The clutch control unit 94 determines whether the point after the cranking prediction period from the start of K0 cranking falls within the shift inertia phase start period calculated by the transmission control unit 96. That is, the clutch control unit 94 determines whether the K0 synchronization point falls within the shift inertia phase start period. If the clutch control unit 94 determines that the point after the cranking prediction period falls within the shift inertia phase start period, it outputs a cranking start delay request based on the cranking prediction period, i.e., based on the K0 synchronization prediction, as shown in FIG. 3 (see time t1b-time t2b). That is, the cranking start delay request is output during (shift inertia phase start period-cranking prediction period). The clutch control unit 94 also determines whether the point after the cranking prediction period from the start of K0 cranking falls within the shift inertia phase end period calculated by the transmission control unit 96. That is, the clutch control unit 94 determines whether the K0 synchronization point falls within the shift inertia phase end period. When the clutch control unit 94 determines that the point after the cranking predicted period falls within the shift inertia phase end period, it outputs a cranking start delay request based on the cranking predicted period (see time t6b-time t8b), as shown in Fig. 3. That is, the cranking start delay request is output during (the shift inertia phase end period-the cranking predicted period).

[0049] Based on the cranking start delay request based on the cranking start and the cranking start delay request based on the predicted cranking period, the clutch control unit 94 sets the period during which at least one of the cranking start delay requests is output as the cranking start delay request final output (see cranking start delay request final output in Figure 3).

[0050] When starting the engine 12, if the start of K0 cranking is within the period for which the cranking start delay request final output is set, the clutch control unit 94 delays the start of K0 cranking until after that period has ended. For example, if the start of K0 cranking is within the period (time t1b-time t2b) in Figure 3, the clutch control unit 94 delays the start of K0 cranking until time t2b, and starts K0 cranking at time t2b when the cranking start delay request final output is stopped. On the other hand, if the start of K0 cranking is before time t1b in Figure 3, for example, the clutch control unit 94 starts K0 cranking immediately at that time.

[0051] FIG. 4 is a flowchart explaining the main control operations of the electronic control unit 90, which is a flowchart explaining the control operations for suppressing shift shock when shifting the automatic transmission 24 and starting the engine 12 are executed simultaneously, for example, while the vehicle is running in a BEV mode.

[0052] 4, first, in step S10 (hereinafter, the term "step" will be omitted) corresponding to the function of the transmission control unit 96, it is determined whether or not shift control of the automatic transmission 24 is being executed. If the determination in S10 is affirmative, a shift inertia phase start period and a shift inertia phase end period are calculated in S20, corresponding to the function of the transmission control unit 96. Next, in S30, corresponding to the function of the power source control unit 92, it is determined whether or not an engine start request has been made. If the determination in S30 is affirmative, it is determined in S40, corresponding to the function of the clutch control unit 94, whether the start of K0 cranking will be within the shift inertia phase start period or the shift inertia phase end period. If the determination in S40 is negative, it is determined in S50, corresponding to the function of the clutch control unit 94, whether or not the point after the cranking prediction period from the start of K0 cranking is expected to be within the shift inertia phase start period or the shift inertia phase end period. If the determination in S40 above is positive, or if the determination in S50 above is positive, a delay in K0 cranking is requested, that is, a cranking start delay request is output, in S60, which corresponds to the function of the clutch control unit 94. If the determination in S10 above is negative, or if the determination in S30 above is negative, or if the determination in S50 above is negative, then a delay in K0 cranking is not requested, that is, the cranking start delay request is stopped, in S70, which corresponds to the function of the clutch control unit 94.

[0053] As described above, according to this embodiment, when starting the engine 12 during a shift transition of the automatic transmission 24, if the shift inertia phase start period and the start of K0 cranking overlap, the start of K0 cranking is delayed until after the shift inertia phase start period. Also, if the shift inertia phase end period and the start of K0 cranking overlap, the start of K0 cranking is delayed until after the shift inertia phase end period. Also, if the shift inertia phase start period and the K0 synchronization point overlap, the start of K0 cranking is delayed so that the K0 synchronization point occurs after the shift inertia phase start period. Also, if the shift inertia phase end period and the K0 synchronization point overlap, the start of K0 cranking is delayed so that the K0 synchronization point occurs after the shift inertia phase end period. Therefore, situations in which shift shock is likely to occur are avoided or suppressed. Therefore, shift shock can be suppressed when shifting the automatic transmission 24 and starting the engine 12 are performed simultaneously.

[0054] Although the embodiments of the present invention have been described in detail above with reference to the drawings, the present invention can also be applied to other embodiments.

[0055] For example, in the above-described embodiment, the shift inertia phase start period and / or the shift inertia phase end period may be calculated using a different method. For example, the end point of the shift inertia phase start period (see time t5b in FIG. 3) when determining whether the start of K0 cranking falls within the shift inertia phase start period may be set to a time a predetermined constant E after the actual start of the inertia phase, because the start of K0 cranking after the start of the inertia phase is the target. The constant E is, for example, a predetermined constant for determining the period after the start of the actual inertia phase during which shift shock is likely to occur. The actual start of the inertia phase is, for example, the time when it is determined that the turbine rotation speed Nt has changed by more than a predetermined threshold value for determining that the inertia phase has started, relative to the synchronous rotation speed before the shift (= No × γat before the shift).

[0056] In the above-described embodiment, the period for delaying the start of K0 cranking in one start control may be set to within a predetermined delay time in consideration of a decrease in drivability.

[0057] In addition, in the above-described embodiment, a planetary gear automatic transmission is exemplified as the automatic transmission 24, but the present invention is not limited to this. For example, the automatic transmission 24 may be a synchronous mesh parallel two-shaft automatic transmission including a known DCT (Dual Clutch Transmission), a known belt-type continuously variable transmission, or the like. In short, the present invention can be applied to any vehicle equipped with a power source including an engine and an electric motor, a clutch provided between the engine and the electric motor, and a transmission that transmits power from the power source to the drive wheels.

[0058] In the above-described embodiment, the torque converter 22 is used as the fluid transmission device, but the present invention is not limited to this. For example, instead of the torque converter 22, another fluid transmission device, such as a fluid coupling that does not have a torque amplifying effect, may be used as the fluid transmission device. Alternatively, the fluid transmission device does not necessarily have to be provided, and may be replaced with, for example, a starting clutch.

[0059] It should be noted that the above is merely one embodiment, and the present invention can be embodied in various forms with various modifications and improvements based on the knowledge of those skilled in the art. [Explanation of symbols]

[0060] 10: Vehicle 12: Engine 14: Drive wheel 20:K0 clutch (clutch) 24: Automatic transmission (transmission) 90: Electronic control device (control device) 92a: Engine control unit 92b: Motor control unit 94: Clutch control unit 96: Transmission control unit MG: Electric motor

Claims

[Claim 1] A control device for a vehicle including an engine, an electric motor connected to a power transmission path between the engine and drive wheels so as to be able to transmit power, a clutch provided in the power transmission path between the engine and the electric motor, and a transmission provided in the power transmission path between the electric motor and the drive wheels, an engine control unit that controls the engine so that the engine starts operating when it is determined that there is a request to start the engine; a clutch control unit that controls the clutch to switch a control state of the clutch from a released state to an engaged state so as to transmit a cranking torque required for cranking to increase the rotational speed of the engine when starting the engine and to complete synchronization between the input rotational speed and the output rotational speed of the clutch; an electric motor control unit that controls the electric motor so that the electric motor outputs the cranking torque in conjunction with the cranking; a transmission control unit that determines whether the transmission should be shifted using a predetermined relationship and controls the transmission to establish a gear ratio according to the result of the shift determination; It contains the clutch control unit, when starting the engine during a shift transition of the transmission, if a start of cranking overlaps with a predetermined inertia phase start period, during which a shift shock is likely to occur from a predetermined time before to a predetermined time after a start of an inertia phase during the shift transition, delays the start of cranking until after the predetermined inertia phase start period; and if a predetermined inertia phase end period, during which a shift shock is likely to occur from a predetermined time before to a predetermined time after the end of the inertia phase, delays the start of cranking until after the predetermined inertia phase end period; and if the predetermined inertia phase start period and a synchronization completion time of the clutch overlap, delays the start of cranking so that the synchronization completion time is after the predetermined inertia phase start period; and if the predetermined inertia phase end period and the synchronization completion time overlap, delays the start of cranking so that the synchronization completion time is after the predetermined inertia phase end period.

Images