Vehicle control device

Abstract

To suppress an engine performance from deteriorating in starting the engine.SOLUTION: In starting an engine, in a given progress step during a transition of switching to engaging a clutch, a clutch control part calculates instruction value information of a starting instruction value for the given progress step and transmits the instruction value information to an engine control part so that the engine control part, upon receiving the starting instruction value for the given progress step, outputs a start-time driving instruction value for the given progress step on the basis of the instruction value information, instead of outputting the starting instruction value. Therefore, even if there is variation in communication when transmitting a starting instruction value from the clutch control part to the engine control part, the start-time driving instruction value for the given progress step is made to be easily reproduced to be a starting instruction value, making it possible to suppress the deterioration of control performance in switching the clutch to an engaged state. Thus, it is possible to suppress an engine start performance from deteriorating in starting the engine.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a control device for a vehicle having a clutch provided between an engine and a drive wheel. [Background technology]

[0002] There is a well-known vehicle control device that includes an engine, a clutch provided in a power transmission path between the engine and driving wheels, and a hydraulic control circuit that supplies a regulated hydraulic pressure used to switch the control state of the clutch. For example, there is a vehicle control device described in Patent Document 1. Patent Document 1 discloses that the control device includes an engine electronic control unit that controls the operation of the engine, and a hybrid electronic control unit that controls a clutch switching means that switches the control state of the clutch when an engine start request is input, thereby switching the clutch to an engaged state, and that the hybrid electronic control unit is connected to the engine electronic control unit via a communication port. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5835345 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when various information is exchanged between a plurality of electronic control units, there is a risk that the control performance of the vehicle may deteriorate due to communication variations such as variations in transmission and reception timing, etc. For example, when starting the engine, the control performance of switching the clutch to an engaged state may deteriorate due to communication variations, which may result in a delay in starting the engine or a shock, thereby deteriorating the engine starting performance.

[0005] The present invention has been made against the background of the above circumstances, and an object of the present invention is to provide a vehicle control device that can suppress deterioration of engine starting performance when starting the engine. [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; a clutch provided in a power transmission path between the engine and a drive wheel; and a hydraulic control circuit that supplies a regulated hydraulic pressure used to switch a control state of the clutch, (b) a clutch control unit that calculates a start command value for regulating the hydraulic pressure so as to switch the control state of the clutch from a released state to an engaged state when the engine is started; and (c) a start-time drive command value that outputs a start-time drive command value for driving the hydraulic control circuit based on the start command value transmitted from the clutch control unit when the engine is started, and that is linked to the switching of the clutch to the engaged state. and an engine control unit that controls the engine so that the engine starts operating by calculating a command value for starting the engine when the engine is started. (d) the clutch control unit calculates command value information including a magnitude and an output time of a start command value at a predetermined stage of progress during a transition of switching the clutch to an engaged state at the start of the engine, and transmits the command value information to the engine control unit. (e) when the engine control unit receives a start command value at the predetermined stage of progress at the start of the engine, it outputs a start-time drive command value at the predetermined stage of progress based on the command value information in place of the start command value. Effect of the Invention

[0007] According to the first aspect of the present invention, when starting the engine, at a predetermined stage during the transition of the clutch to the engaged state, the clutch control unit calculates command value information for the start command value at the predetermined stage and transmits the command value information to the engine control unit. When the engine control unit receives the start command value at the predetermined stage, the start drive command value at the predetermined stage is output based on the command value information instead of the start command value. Therefore, even if there is a communication variability when transmitting the start command value from the clutch control unit to the engine control unit, the start drive command value at the predetermined stage is easily reproducible, and deterioration of the control performance for switching the clutch to the engaged state is suppressed. Therefore, deterioration of the engine start performance can be suppressed when starting the engine. [Brief description 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 a control system for various controls in the vehicle. [Diagram 2] FIG. 4 is a diagram showing an example of a time chart when engine start control is executed; [Diagram 3] FIG. 2 is a diagram illustrating an example of an engine control unit and a clutch control unit which constitute a part of the electronic control device. [Figure 4] 11 is a diagram showing an example of the present embodiment of a K0 drive current value based on a K0 command current value transmitted in a CAN communication system. FIG. [Diagram 5] 1 is a flowchart illustrating a main part of the control operation of the electronic control device, particularly a clutch control unit (CLT_ECU), and is a flowchart illustrating the control operation for suppressing deterioration of engine starting performance when starting the engine. [Figure 6] This is a flowchart explaining the main control operations of the electronic control device, particularly the engine control unit (ENG_ECU), and is a flowchart explaining the control operations for suppressing deterioration of engine starting performance when starting the engine, and is executed together with the flowchart of Figure 5. [Figure 7] FIG. 11 is a diagram showing an example of a comparative example of a K0 drive current value based on a K0 command current value transmitted in a CAN communication system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. EXAMPLES

[0010] Fig. 1 is a diagram for explaining the schematic configuration of a vehicle 10 to which the present invention is applied, and is also a diagram for explaining the main parts of the control functions and control system 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.

[0011] The engine 12 is a known internal combustion engine such as a gasoline engine, a diesel engine, etc. An engine control device 50 including a throttle actuator, a fuel injection device, an ignition device, etc., provided in the vehicle 10 is controlled by an electronic control device 90 described later, whereby an engine torque Te, which is an output torque of the engine 12, is controlled.

[0012] The electric motor MG is a rotating electric machine having a function as a motor that generates mechanical power from electric power and a function as a generator that generates electric power from mechanical power, and is a so-called motor generator. 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 electric motor MG controls the MG torque Tm, which is the output torque of the electric motor MG, by controlling the inverter 52 by an electronic control device 90 described later. For example, when the rotation direction of the electric motor MG is a positive rotation that is the same as the rotation direction when the engine 12 is in operation, the MG torque Tm is a power torque at the positive torque on the acceleration side, and a regenerative torque at the negative torque on the deceleration side. Specifically, the electric motor MG generates power by the electric power supplied from the battery 54. The electric motor MG also generates electric power by the power of the engine 12 or the driven force input from the drive wheels 14 side. The battery 54 is charged with the electric power generated by the electric motor MG. The term "electric power" also means electric energy unless otherwise specified. The term "motive power" also means driving force, torque, and force unless otherwise specified.

[0013] The power transmission device 16 includes a K0 clutch 20, a torque converter 22, an automatic transmission 24, and the like, in a case 18 that 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 a 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 a 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 that 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.

[0014] The electric motor MG is connected to the electric motor connecting shaft 36 in the case 18 so as to be capable of transmitting power. That is, the electric motor MG is connected to a power transmission path between the engine 12 and the drive wheels 14, in particular, to a 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 capable of transmitting power without passing through the K0 clutch 20.

[0015] The torque converter 22 includes a pump wheel 22a connected to the motor connecting shaft 36, and a turbine wheel 22b connected to a transmission input shaft 38 that is an input rotating member of the automatic transmission 24. The torque converter 22 is a fluid type power transmission device that transmits power from the power source SP from the motor connecting shaft 36 to the transmission input shaft 38 via fluid. The torque converter 22 includes an LU clutch 40 as a direct clutch that connects the pump wheel 22a and the turbine wheel 22b, that is, that connects the motor connecting shaft 36 and the transmission input shaft 38. The LU clutch 40 is a known lock-up clutch.

[0016] The LU clutch 40 switches between operating states, i.e., control states, by changing the LU torque Tlu, which is the torque capacity of the LU clutch 40, by the LU oil pressure PRlu, which is a regulated oil pressure supplied from a hydraulic control circuit 56 provided in the vehicle 10. The control states of the LU clutch 40 include a release state in which the LU clutch 40 is completely released, a slip state in which the LU clutch 40 is engaged with slipping, and an engagement state in which the LU clutch 40 is completely engaged. By setting the LU clutch 40 to the release state, the torque converter 22 is set to a torque converter state in which a torque amplification effect is obtained. Also, by setting the LU clutch 40 to the engagement state, the torque converter 22 is set to a lock-up state in which the pump impeller 22a and the turbine impeller 22b are rotated together.

[0017] The automatic transmission 24 is a known planetary gear type automatic transmission including, for example, one or more planetary gear devices (not shown) and a plurality of engagement devices CB. The engagement devices CB are, for example, known hydraulic friction engagement devices. The engagement devices CB have their respective torque capacities, or CB torque Tcb, changed by the CB hydraulic pressure PRcb, or regulated hydraulic pressure, supplied from a hydraulic control circuit 56, thereby switching the control state, such as an engaged state or a released state.

[0018] The automatic transmission 24 is a stepped transmission in which one of a plurality of gear stages (also called gear stages) with different speed ratios (also called 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 gear stages formed according to the accelerator operation of the driver (=operator) and the vehicle speed V by an electronic control device 90 described later. 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 the same value as 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 by 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 constituted by, for example, 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 torque capacity of the K0 clutch 20, which is a K0 torque Tk0, by the K0 hydraulic pressure PRk0, which is a regulated hydraulic pressure supplied from the hydraulic control circuit 56.

[0020] In the vehicle 10, when the K0 clutch 20 is in an engaged state, the engine 12 and the torque converter 22 are connected to each other so as to transmit power. On the other hand, when the K0 clutch 20 is in a disengaged state, power transmission between the engine 12 and the torque converter 22 is interrupted. Since 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 driving 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. Moreover, the power output from the electric motor MG is transmitted from the electric motor connecting shaft 36 to the driving 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, regardless of the control state of the K0 clutch 20.

[0022] The vehicle 10 includes the MOP 58, which is a mechanical oil pump, the EOP 60, which is an electric oil pump, and a pump motor 62. The MOP 58 is connected to the pump impeller 22a, and is rotated 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 rotating the EOP 60. The EOP 60 is rotated 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 the LU hydraulic pressure PRlu, the CB hydraulic pressure PRcb, the K0 hydraulic pressure PRk0, and the like, 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 including 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, and the like, and the CPU executes various controls of the vehicle 10 by performing signal processing according to a program previously stored in the ROM while utilizing the temporary storage function of the RAM. The electronic control device 90 includes computers for engine control, electric motor control, clutch control, and the like as necessary.

[0024] The electronic control device 90 is supplied with various signals based on detection values ​​by various sensors provided in the vehicle 10 (e.g., engine rotation speed sensor 70, turbine rotation speed sensor 72, output rotation speed sensor 74, MG rotation speed sensor 76, accelerator opening sensor 78, throttle valve opening sensor 80, brake switch 82, battery sensor 84, oil temperature sensor 86, etc.) (e.g., engine rotation speed Ne, which is the rotation speed of the engine 12, turbine rotation speed Nt, which is the same value as the AT input rotation speed Ni, AT output rotation speed No corresponding to the vehicle speed V, MG rotation speed Nm, which is the rotation speed of the electric motor MG, accelerator opening θacc, which is the amount of accelerator operation by the driver indicating the magnitude of the driver's acceleration operation, throttle valve opening θth, which is the opening of the electronic throttle valve, brake-on signal Bon, which is a signal indicating a state in which the brake pedal for operating the wheel brakes is being operated by the driver, battery temperature THbat, battery charge / discharge current Ibat, and battery voltage Vbat of the battery 54, and hydraulic oil temperature THoil, which is the temperature of the hydraulic oil 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 Sbc 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 (e.g., the engine control device 50, the inverter 52, the hydraulic control circuit 56, the pump motor 62, etc.) provided in the vehicle 10.

[0026] Each hydraulic control command signal S will be described by taking the K0 hydraulic control command signal Sk0 as an example. The electronic control device 90 calculates a K0 hydraulic command value Spk0, which is a hydraulic command value for supplying the regulated K0 hydraulic pressure PRk0 from the hydraulic control circuit 56. The electronic control device 90 converts the K0 hydraulic command value Spk0 into a K0 command current value Sik0 for driving the 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 hydraulic control command signal Sk0 is a K0 drive current value Sik0d for an SLk0 linear driver 92a3 (see FIG. 3 described later) provided in the electronic control device 90 to drive the K0 solenoid SLk0 based on the K0 command current value Sik0. The SLk0 linear driver 92a3 is a drive circuit for driving the K0 solenoid SLk0.

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

[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 by the engine 12 and the electric motor MG using these control functions.

[0029] The power source control unit 92 calculates a driving demand DEM from 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-wise determined and stored in advance, that is, a predetermined relationship. The driving demand DEM is, for example, a required driving torque Trdem at the driving wheels 14. In other words, the required driving torque Trdem [Nm] is the required driving power Prdem [W] at the vehicle speed V at that time. The driving demand DEM can also be a required driving force Frdem [N] at the driving wheels 14, a required AT output torque at the transmission output shaft 26, or the like. In calculating the driving demand DEM, an AT output rotation speed No, or the like, can 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 consideration the transmission loss, the auxiliary load, the gear ratio γat of the automatic transmission 24, etc. Note that in controls other than those for controlling the output of the vehicle 10, such as the driving torque Tr, the driving demand amount DEM can simply be, for example, the accelerator opening θacc or the throttle valve opening θth.

[0030] When the required drive torque Trdem can be satisfied only by the output of the electric motor MG, the power source control unit 92 sets the drive mode for driving the vehicle 10 to the BEV drive mode. The BEV drive mode is a motor drive mode that allows motor driving (=BEV driving) in which the vehicle runs using only the electric motor MG as the power source SP when the K0 clutch 20 is in the released state. 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 sets the drive mode to the engine drive mode, i.e., the HEV drive mode. The HEV drive mode is a hybrid drive mode that allows engine driving (=HEV driving) in which the vehicle runs using at least the engine 12 as the power source SP when the K0 clutch 20 is in the engaged state. On the other hand, even when the required drive torque Trdem can be satisfied only by the output of the electric motor MG, the power source control unit 92 establishes the HEV drive mode when the battery 54 needs to be charged or when the engine 12 or the like needs to be warmed up.

[0031] The power source control unit 92 determines whether or not there is an engine start request to switch the control state of the engine 12 from a stopped state to an operating state. For example, in the BEV drive mode, the power source control unit 92 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 only by the output of the electric motor MG, whether or not there is a need to warm up the engine 12, or whether or not there is a need to charge the battery 54, etc.

[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 calculates a K0 command current value Sik0 for controlling 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 side. That is, the clutch control unit 94 calculates a starting K0 command current value Sik0 as a starting command value for adjusting the K0 hydraulic pressure PRk0 so as to switch the control state of the K0 clutch 20 from the released state to the engaged state when starting the engine 12. The cranking torque Tcr is a 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, the engine control unit 92a outputs a K0 drive current value Sik0d at start as a start drive command value for driving the hydraulic control circuit 56, i.e., the K0 solenoid SLk0, based on the start K0 command current value Sik0 transmitted from the clutch control unit 94 when starting the engine 12. The electric motor control unit 92b outputs an MG control command signal Sm to the inverter 52 to cause the electric motor MG to output a cranking torque Tcr in accordance with the switching of the K0 clutch 20 to the engaged state. That is, the electric motor control unit 92b outputs an MG control command signal Sm to the inverter 52 to control the electric motor MG to output the cranking torque Tcr, i.e., to increase the MG torque Tm by the cranking torque Tcr, when starting the engine 12. Moreover, the engine control unit 92a outputs an engine control command signal Se to the engine control device 50 for starting fuel supply, engine ignition, and the like in conjunction with cranking of the engine 12. That is, when starting the engine 12, the engine control unit 92a outputs an engine control command signal Se to the engine control device 50 for controlling the engine 12 so that the engine 12 starts operating in conjunction with switching the K0 clutch 20 to an engaged state, that is, in conjunction with cranking of the engine 12. The engine control unit 92a outputs an engine control command signal Se to the engine control device 50 for outputting an engine torque Te so that the engine 12 reaches a stable state of independent rotation due to the explosion of the engine 12 after the initial explosion when ignition of the engine 12 is started, that is, a state in which the engine 12 reaches a complete explosion state.

[0034] When cranking the engine 12, a reaction torque occurs due to the 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 during engine start. Therefore, the MG torque Tm that is increased toward the cranking torque Tcr when starting the engine 12 is an MG torque Tm for canceling this reaction torque, and is an MG torque Tm for compensating for this reaction torque, that is, an MG torque Tm for reaction compensation. The cranking torque Tcr is the K0 torque Tk0 required for cranking the engine 12, and is the MG torque Tm required for cranking 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 determined in advance based on, for example, the specifications of the engine 12, the starting method of the engine 12, and the like.

[0035] After the initial explosion of the engine 12, the electric motor control unit 92b outputs an MG control command signal Sm to the inverter 52 to stop the output of the cranking torque Tcr by the electric motor MG, and ends the cranking of the engine 12. After the cranking of the engine 12 is ended, the clutch control unit 94 outputs a K0 command current value Sik0 for waiting for the switching of the K0 clutch 20 to the engaged state so that the K0 torque Tk0 is lowered below the cranking torque Tcr and maintained at a predetermined torque Tk0f. The predetermined torque Tk0f is a predetermined K0 torque Tk0 smaller than the cranking torque Tcr so as not to become a disturbance to the complete explosion of the engine 12 after the end of cranking. Not becoming a disturbance to the complete explosion of the engine 12 means not hindering the independent rotation of the engine 12 after the initial explosion of the engine 12. From another point of view, when the engine rotation speed Ne is increased by the self-rotating rotation of the engine 12 after ignition, if the K0 clutch 20 has a K0 torque Tk0 equivalent to the cranking torque Tcr, for example, the starting shock may increase due to the influence of the inertia of the electric motor MG downstream of the K0 clutch 20. The predetermined torque Tk0f is a predetermined K0 torque Tk0 smaller than the cranking torque Tcr for reducing the starting shock when the engine rotation speed Ne is increased by the self-rotating rotation of the engine 12 after the cranking of the engine 12 is completed. The clutch control unit 94 outputs a K0 command current value Sik0 for controlling the K0 clutch 20 toward the engaged state so that a synchronization K0 torque Tk0syc for synchronizing the input rotation speed and the output rotation speed of the K0 clutch 20 is obtained after the complete explosion of the engine 12. The input rotation speed of the K0 clutch 20 is the rotation speed of the engine connecting shaft 34 and is equal to the engine rotation speed Ne. The output rotation speed of the K0 clutch 20 is the rotation speed of the electric motor connecting shaft 36, and is equal to the MG rotation speed Nm. In other words, synchronizing the input rotation speed and output rotation speed of the K0 clutch 20 is equivalent to synchronizing the engine rotation speed Ne and the MG rotation speed Nm.

[0036] The power source control unit 92 determines whether there is an engine stop request, which is a request to stop the engine 12 by switching the control state of the engine 12 from a driving state to a stopped state. For example, the power source control unit 92 determines whether there is an engine stop request based on whether, in the HEV drive mode, the required drive torque Trdem is within a range that can be covered only by the output of the electric motor MG, warming up of the engine 12 and the like is not required, charging of the battery 54 is not required, and so on.

[0037] When the power source control unit 92 determines that there is an engine stop request, it outputs an engine control command signal Se to the engine control device 50 to gradually reduce the engine torque Te. After that, the power source control unit 92 outputs an engine control command signal Se to the engine control device 50 to execute a fuel cut to stop the supply of fuel to the engine 12 after the clutch control unit 94 switches the K0 clutch 20 to the released state.

[0038] The clutch control unit 94 judges whether or not the automatic transmission 24 should be shifted by 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 to execute shift control of the automatic transmission 24 as necessary. The shift map is a predetermined relationship having a shift line for judging whether or not the automatic transmission 24 should be shifted on a two-dimensional coordinate system having, for example, vehicle speed V and required driving torque Trdem as variables. In the shift map, the AT output rotation speed No may be used instead of the vehicle speed V, and the required driving force Frdem, accelerator opening θacc, throttle valve opening θth, etc. may be used instead of the required driving torque Trdem.

[0039] FIG. 2 is a diagram showing an example of a time chart when the start control of the engine 12 is executed. In FIG. 2, time t1 indicates a time when the start control of the engine 12 is started by determining that there is an engine start request accompanying the driver's further depression of the accelerator pedal during, for example, BEV driving. After the start control of the engine 12 is started, packing control of the K0 clutch 20, i.e., K0 packing control, is executed (see time t1-time t2). The K0 packing control is a control that makes the pack clearance of the friction plates of the K0 clutch 20 a packed state. In the K0 packing control, first, in order to improve the initial responsiveness of the K0 hydraulic pressure PRk0, a quick apply (=QA) that temporarily outputs a high K0 drive current value Sik0d is executed (see part a), and then, in order to complete the packing of the K0 clutch 20, a constant pressure standby for packing is executed (see part b). In the dashed line during constant pressure standby for packing, a K0 drive current value Sik0d is output to set the K0 clutch 20 to a constant pack pressure PRk0pk, which is the K0 hydraulic pressure PRk0 for maintaining the K0 clutch 20 in a packing completion state. In the solid line during constant pressure standby for packing, a K0 drive current value Sik0d is output to set the total K0 hydraulic pressure PRk0, which is the pack pressure PRk0pk plus the K0 hydraulic pressure PRk0 equivalent to the cranking torque Tcr. The K0 drive current value Sik0d shown in the dashed line and the K0 drive current value Sik0d shown in the solid line are different in the period of K0 packing control, but for convenience, they are shown to be the same length in FIG. 2. After the K0 packing control is completed, cranking is performed by the K0 clutch 20 that transmits the cranking torque Tcr to the engine 12 side, i.e., K0 cranking, in order to crank the engine 12 (see time t2-t3). The K0 driving current value Sik0d during K0 cranking is the K0 driving current value Sik0d for achieving the total K0 oil pressure PRk0 obtained by adding the K0 oil pressure PRk0 equivalent to the cranking torque Tcr to the pack pressure PRk0pk, and is the K0 driving current value Sik0d that adjusts the K0 oil pressure PRk0 so that the K0 clutch 20 transmits the cranking torque Tcr.During K0 cranking, the MG torque Tm having a magnitude equivalent to the cranking torque Tcr, i.e., the MG torque Tm for reaction force compensation, is output from the electric motor MG. During K0 cranking, when the engine rotation speed Ne is increased, engine ignition and the like are started and the engine 12 is caused to explode for the first time.

[0040] After the end of K0 cranking, in order to wait for the K0 clutch 20 to be switched to the engaged state, a constant pressure standby after cranking is executed (see time t3-t4), in which the K0 torque Tk0 is lowered below the cranking torque Tcr and maintained at a predetermined torque Tk0f. The K0 drive current value Sik0d during the constant pressure standby after cranking is, for example, the same as or greater than the value that maintains the K0 clutch 20 in the packing completion state, and is the K0 drive current value Sik0d for realizing the K0 torque Tk0 that does not disturb the complete explosion of the engine 12, and is the K0 drive current value Sik0d for adjusting the K0 hydraulic pressure PRk0 so that the K0 torque Tk0 is lowered below the cranking torque Tcr and temporarily maintained at the predetermined torque Tk0f. During the execution of the constant pressure standby after cranking, the engine rotation speed Ne is increased not by the K0 torque Tk0 but solely by the combustion torque of the engine 12. In this embodiment, in order to improve the initial response of the K0 hydraulic pressure PRk0 prior to the execution of the constant pressure standby after cranking, a quick drain (=QD) is executed to temporarily output a low K0 drive current value Sik0d (see part c). When the engine 12 reaches a stable state of self-sustaining rotation due to the explosion during the execution of the constant pressure standby after cranking, that is, when the engine 12 reaches a state of complete explosion, a rotation synchronization control between the engine 12 and the electric motor MG, that is, a synchronization control by the K0 clutch 20 that synchronizes the engine rotation speed Ne and the MG rotation speed Nm, that is, a K0 synchronization control, is executed (see t4 and after). The complete explosion of the engine 12 is determined, for example, when a complete explosion notification is output from the engine control unit 92a. The complete explosion notification of the engine 12 is output by the engine control unit 92a, for example, when the elapsed time from the time when the engine rotation speed Ne reaches a predetermined complete explosion rotation speed of the engine 12 exceeds a predetermined complete explosion notification waiting time. This complete explosion notification waiting time is predetermined, for example, taking into consideration the exhaust gas requirements of the engine 12. After synchronization of the input rotational speed and the output rotational speed of the K0 clutch 20, i.e., K0 synchronization, is completed, that is, after switching of the K0 clutch 20 to the engaged state, i.e., K0 engagement, is completed, K0 full engagement control is executed to transition the K0 clutch 20 to a fully engaged state.After the K0 clutch 20 is brought into the fully engaged state by the K0 full engagement control, the start control of the engine 12 is completed (see time t5), and the fully engaged state of the K0 clutch 20 is maintained (see time t5 and after).

[0041] FIG. 3 is a diagram showing an example of an engine control unit 92a and a clutch control unit 94 which constitute a part of the electronic control unit 90. In FIG. 3, the electronic control unit 90 includes an engine control computer ENG_ECU which functions as the engine control unit 92a, and a clutch control computer CLT_ECU which functions as the clutch control unit 94. The engine control unit 92a includes a start / stop determination unit 92a1, a K0 release permission determination unit 92a2, an SLk0 linear driver 92a3, and the like, and controls the engine 12, for example, in the start control and stop control of the engine 12 described above. The clutch control unit 94 includes a K0 control phase determination unit 94a, a required K0 oil pressure calculation unit 94b, a required SLk0 current calculation unit 94c, and the like, and controls the K0 clutch 20, for example, in the start control and stop control of the engine 12 described above. The K0 control phase is a plurality of progress stages divided according to the control state of the K0 clutch 20 which is switched during the start process and stop process of the engine 12. 2, the K0 control phase is defined as, for example, a QA phase, a constant pressure standby phase for packing, a K0 cranking phase, a QD phase, a constant pressure standby phase after cranking, a K0 synchronization phase, a K0 full engagement phase, etc. The required K0 oil pressure is the K0 oil pressure command value Spk0 for each K0 control phase. The required SLk0 current is the K0 command current value Sik0 for each K0 control phase.

[0042] Various signals are transmitted between the engine control unit 92a and the clutch control unit 94 via a predetermined communication system, for example, a CAN (Controller Area Network) communication system. The K0 command current value Sik0 transmitted from the clutch control unit 94 to the engine control unit 92a is output from the SLk0 linear driver 92a3 to the K0 solenoid SLk0 of the hydraulic control circuit 56 as a K0 drive current value Sik0d.

[0043] FIG. 7 is a diagram showing an example of a comparative example of the K0 drive current value Sik0d based on the K0 command current value Sik0 transmitted by the CAN communication system. In FIG. 7, time t1b indicates the time when the engine control unit 92a (ENG_ECU) determines that there is an engine start request. The engine start request transmitted from the engine control unit 92a at time t1b is received by the clutch control unit 94 (CLT_ECU) at time t2b after the CAN communication delay A. Signals transmitted through the CAN communication system have a communication delay due to the transmission period. The CAN communication delay A is caused solely by this communication delay. After receiving the engine start request, the clutch control unit 94 outputs the K0 command current value Sik0 in the QA phase (see time t2b-t4b), and then outputs the K0 command current value Sik0 in the packing constant pressure standby phase (see time t4b and after). The K0 command current value Sik0 is transmitted to the engine control unit 92a, and the engine control unit 92a outputs a K0 drive current value Sik0d based on the K0 command current value Sik0. In the K0 drive current value Sik0d, the start of the QA phase is set to time t3b, which is a CAN communication delay B time from time t2b, and the end of the QA phase is set to time t5b, which is a CAN communication delay C time from time t4b. The CAN communication delay B includes a transmission delay due to, for example, overlapping transmission timing, and is therefore set to be longer than the CAN communication delay A. On the other hand, the CAN communication delay C is a communication delay mainly due to the transmission cycle, and is therefore set to be equal to the CAN communication delay A. Therefore, as shown in FIG. 7, the shape of the current value in the QA phase that is equivalent to the K0 command current value Sik0 calculated by the clutch control unit 94 may not be realized by the K0 drive current value Sik0d due to variations in the CAN communication delay. In this case, the performance of QA is not sufficiently ensured, and there is a risk that, for example, a delay in engine start occurs due to a pack clogging delay, and engine start performance deteriorates. Alternatively, although not shown, there are cases in which the shape of the current value in the QD phase that is equivalent to the K0 command current value Sik0 calculated by the clutch control unit 94 cannot be realized by the K0 drive current value Sik0d due to variations in CAN communication delays.If this happens, the performance of the QD will not be sufficiently ensured, and for example, a shock may occur due to fluctuations in the rotation of the electric motor MG caused by deviations in the MG torque Tm for reaction force compensation due to variations in the degree to which the K0 oil pressure PRk0 is drained, which may result in a deterioration in engine starting performance.

[0044] Therefore, in a predetermined progress stage, i.e., a K0 control phase, the clutch control unit 94 calculates information on the shape of the current value read ahead in the predetermined K0 control phase, separately from the K0 command current value Sik0, and transmits the information on the shape of the read ahead current value together with the K0 command current value Sik0 to the engine control unit 92a. The predetermined K0 control phase is, for example, a K0 control phase that is determined in advance as a K0 control phase in which the engine starting performance may be deteriorated if the K0 drive current value Sik0d is made difficult to ensure the reproducibility of the K0 command current value Sik0 due to the variation in CAN communication delay, and is, for example, a QA phase or a QD phase. The information on the shape of the read ahead current value is, for example, command value information Icmd including the magnitude and output time of the K0 command current value Sik0 for starting in the predetermined K0 control phase. In addition, in order to execute the next K0 control phase after the end of the predetermined K0 control phase, the command value information Icmd may include, for example, the magnitude of the K0 command current value Sik0 for starting in the K0 control phase next to the predetermined K0 control phase. In this way, when the engine 12 is started, in a predetermined K0 control phase during the transition of switching the K0 clutch 20 to the engaged state, the clutch control unit 94 calculates command value information Icmd for the predetermined K0 control phase and transmits the command value information Icmd to the engine control unit 92a.

[0045] In a predetermined K0 control phase, the engine control unit 92a outputs the K0 driving current value Sik0d at the time of starting based on the K0 command current value Sik0 for starting based on the command value information Icmd. That is, in a predetermined K0 control phase, the engine control unit 92a sets the magnitude of the K0 driving current value Sik0d at the time of starting to the magnitude of the K0 command current value Sik0 for starting in the predetermined K0 control phase included in the command value information Icmd, and outputs the magnitude of the K0 command current value Sik0 for starting in the predetermined K0 control phase included in the command value information Icmd for the output time of the K0 command current value Sik0 for starting in the predetermined K0 control phase included in the command value information Icmd. After the end of the predetermined K0 control phase, the engine control unit 92a sets the magnitude of the K0 driving current value Sik0d at the time of starting to the magnitude of the K0 command current value Sik0 for starting in the K0 control phase next to the predetermined K0 control phase included in the command value information Icmd. In this way, when the engine control unit 92a receives the starting K0 command current value Sik0 in a specified K0 control phase at the start of the engine 12, it outputs the K0 drive current value Sik0d at the time of startup in the specified K0 control phase based on the command value information Icmd transmitted from the clutch control unit 94, instead of the starting K0 command current value Sik0.

[0046] FIG. 4 is a diagram showing an example of the present embodiment of the K0 drive current value Sik0d based on the K0 command current value Sik0 transmitted by the CAN communication system. In FIG. 4, time t1c indicates the time when the engine control unit 92a (ENG_ECU) determines that there is an engine start request. The engine start request transmitted from the engine control unit 92a at time t1c is received by the clutch control unit 94 (CLT_ECU) at time t2c after the CAN communication delay Ac. The CAN communication delay Ac is mainly due to the communication delay due to the transmission cycle of the CAN communication system. After receiving the engine start request, the clutch control unit 94 outputs the K0 command current value Sik0 in the QA phase (see time t2c-t4c), and then outputs the K0 command current value Sik0 in the packing constant pressure standby phase (see time t4c and after). In addition, the clutch control unit 94 calculates command value information Icmd and outputs the command value information Icmd (time t2c). The command value information Icmd includes, for example, a look-ahead current value 1, which is the magnitude of the K0 command current value Sik0 for starting in the QA phase, a look-ahead current time, which is the output time of the K0 command current value Sik0 for starting in the QA phase, and a look-ahead current value 2, which is the magnitude of the K0 command current value Sik0 for starting in the constant pressure waiting phase for packing. The command value information Icmd transmitted from the clutch control unit 94 together with the K0 command current value Sik0 at time t2c is received by the engine control unit 92a at time t3c after a CAN communication delay Bc time. In a comparative example shown by a broken line, for the K0 drive current value Sik0d, the start of the QA phase is set to time t3c after a CAN communication delay Bc time from time t2c, and the end of the QA phase is set to time t5c after a CAN communication delay Cc time from time t4c. The CAN communication delay Bc is longer than the CAN communication delay Ac because it includes a transmission delay due to, for example, overlapping transmission timing, while the CAN communication delay Cc is a communication delay due solely to the transmission cycle and is therefore equivalent in time to the CAN communication delay Ac. Therefore, in the comparative example, the shape of the current value in the QA phase that is desired to be realized, which is equivalent to the K0 command current value Sik0 calculated by the clutch control unit 94, is difficult to realize with the K0 drive current value Sik0d due to variations in the CAN communication delay.In contrast, in the present embodiment shown by the solid line, in the QA phase, the K0 driving current value Sik0d is output based on the command value information Icmd instead of the K0 command current value Sik0. Specifically, in the K0 driving current value Sik0d, the QA phase starts at time t3c with the magnitude of the look-ahead current value 1, and continues until time t6c after the look-ahead current time has elapsed. In the K0 driving current value Sik0d, following the QA phase that ends at time t6c, the packing constant pressure standby phase starts with the magnitude of the look-ahead current value 2 (see time t6c and after). As a result, in this embodiment, the shape of the current value in the QA phase that is to be realized, which is equivalent to the K0 command current value Sik0 calculated by the clutch control unit 94, is easily realized by the K0 driving current value Sik0d even if there is a variation in the CAN communication delay. Therefore, the performance of the QA is easily ensured, and deterioration of the engine starting performance is suppressed.

[0047] In this embodiment, outputting the K0 drive current value Sik0d at startup based on the command value information Icmd in place of the K0 command current value Sik0 for startup in a certain K0 control phase is expressed as "takeover".

[0048] FIG. 5 is a flowchart illustrating the main control operations of the electronic control device 90, which are for suppressing deterioration of engine starting performance when starting the engine 12, and which are executed, for example, repeatedly.

[0049] In FIG. 5, each step of the flow chart corresponds to a function of the clutch control unit 94 (CLT_ECU). In step (hereinafter, step will be omitted) S10a, it is determined whether or not the start control of the engine 12 is being executed. If the determination in S10a is positive, it is determined in S20a whether or not the current K0 control phase is a K0 control phase in which takeover is performed, that is, a predetermined K0 control phase. If the determination in S20a is positive, hydraulic shape information required for takeover is calculated in S30a. The hydraulic shape information required for takeover is, for example, the K0 hydraulic command value Spk0 in the current predetermined K0 control phase, the duration of the K0 hydraulic command value Spk0, and the K0 hydraulic command value Spk0 in the next K0 control phase of the current predetermined K0 control phase. If the determination in S10a is negative, or if the determination in S20a is negative, all hydraulic shape information required for takeover is set to an invalid value in S40a. Following S30a or S40a, in S50a, takeover current shape information is calculated by hydraulic-current conversion, and the takeover current shape information is transmitted to the engine control unit 92a (ENG_ECU). The takeover current shape information is, for example, the K0 command current value Sik0 in the current predetermined K0 control phase, i.e., the look-ahead current value 1, the duration of the K0 command current value Sik0, i.e., the look-ahead current time, and the K0 command current value Sik0 in the next K0 control phase of the current predetermined K0 control phase, i.e., the look-ahead current value 2, which are obtained by converting each value of the hydraulic shape information required for takeover. In this embodiment, the look-ahead current value 1 may be referred to as the take-ahead command current value 1, the look-ahead current time may be referred to as the take-ahead command current time, and the look-ahead current value 2 may be referred to as the take-ahead command current value 2. Note that, when all the hydraulic shape information required for take-over is set to an invalid value, all the take-over current shape information is also set to an invalid value.

[0050] FIG. 6 is a flowchart illustrating the main control operations of the electronic control device 90, and is a flowchart illustrating the control operations for suppressing deterioration of engine starting performance when starting the engine 12, and is repeatedly executed together with the flowchart of FIG. 5, for example.

[0051] In FIG. 6, each step of the flowchart corresponds to a function of the engine control unit 92a (ENG_ECU). In S10b, it is determined whether there is a takeover request with a higher priority than the takeover request from the clutch control unit 94, such as a fail-safe (=F / S). The takeover request from the clutch control unit 94 is transmitted together with, for example, takeover current shape information. If the determination in S10b is positive, it is determined in S20b whether the takeover execution determination is established. This takeover execution determination is, for example, a condition that the current K0 control phase is a K0 control phase in which takeover is executed, and all values ​​of the takeover current shape information are valid values. If the determination in S20b is positive, it is determined in S30b whether the takeover execution precondition is established. This takeover execution precondition is, for example, a condition that the hybrid system is started, that is, a state in which the vehicle can run if the accelerator is turned on, and the K0 control phase is not a phase in which the K0 clutch 20 is released or a backup phase in which the K0 clutch 20 is forcibly engaged. If the determination in S30b is positive, then in S40b, it is determined whether or not the takeover execution end condition is satisfied. The takeover execution end condition is, for example, a condition in which the takeover time, which is the elapsed time from the start of the takeover execution, is equal to or greater than the takeover instruction current time, or the takeover time is equal to or greater than the backup timer. The backup timer is, for example, a threshold value that is determined in advance as the time when the takeover needs to be forcibly ended due to the influence of variations or errors in CAN communication. If the determination in S40b is negative, then in S50b, the takeover instruction current value 1 from the clutch control unit 94 is output as the K0 drive current value Sik0d. If the determination in S40b is positive, then in S60b, it is determined whether or not the request SLk0 current other than the K0 control phase in which the takeover is executed, i.e., the K0 instruction current value Sik0, is transmitted from the clutch control unit 94. If the determination in S60b is negative, the takeover command current value 2 from the clutch control unit 94 is output as the K0 drive current value Sik0d in S70b.If the judgment in S10b above is negative, or if the judgment in S20b above is negative, or if the judgment in S30b above is negative, or if the judgment in S60b above is positive, in S80b, a value based on the K0 command current value Sik0, which is the normal command current value from the clutch control unit 94 (CLT_ECU), is output as the K0 driving current value Sik0d.

[0052] As described above, according to this embodiment, when starting the engine 12, in a predetermined K0 control phase during the transition of switching the K0 clutch 20 to the engaged state, the clutch control unit 94 calculates command value information Icmd for the predetermined K0 control phase and transmits the command value information Icmd to the engine control unit 92a. When the engine control unit 92a receives the K0 command current value Sik0 for starting in the predetermined K0 control phase, the K0 drive current value Sik0d at startup in the predetermined K0 control phase is output based on the command value information Icmd instead of the K0 command current value Sik0 for starting. Therefore, even if there is communication variation in the transmission of the K0 command current value Sik0 for starting from the clutch control unit 94 to the engine control unit 92a, the K0 drive current value Sik0d at startup in the predetermined K0 control phase is easily ensured to be reproducible to the K0 command current value Sik0 for starting, and deterioration of the control performance for switching the K0 clutch 20 to the engaged state is suppressed. Therefore, when starting the engine 12, deterioration of the engine starting performance can be suppressed.

[0053] Although the embodiment of the present invention has been described in detail above with reference to the drawings, the present invention can be applied to other embodiments.

[0054] For example, in the above embodiment, the starting K0 command current value Sik0 is exemplified as the starting command value, but the present invention is not limited to this. The starting command value may be, for example, a starting K0 hydraulic command value Spk0, a K0 command voltage value, etc. Also, the starting drive command value may be a starting hydraulic command value, a K0 drive voltage value, etc.

[0055] In addition, in the above embodiment, a planetary gear type automatic transmission is exemplified as the automatic transmission 24, but the present invention is not limited to this. The automatic transmission 24 may be a synchronous mesh type parallel two-shaft automatic transmission including a known DCT (Dual Clutch Transmission). In short, the present invention can be applied to any vehicle that includes an engine and a clutch provided between the engine and the drive wheels.

[0056] In the above 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 that does not amplify torque, such as a fluid coupling, 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.

[0057] It should be noted that the above is merely one embodiment, and the present invention can be embodied in various modified and improved forms based on the knowledge of those skilled in the art. [Explanation of symbols]

[0058] 10: Vehicle 12: Engine 14: Drive wheel 20:K0 clutch (clutch) 56: Hydraulic control circuit 90: Electronic control device (control device) 92a: Engine control unit 94: Clutch control unit

Claims

[Claim 1] A control device for a vehicle including an engine, a clutch provided in a power transmission path between the engine and a drive wheel, and a hydraulic control circuit that supplies a regulated hydraulic pressure used to switch a control state of the clutch, a clutch control unit that calculates a start command value for adjusting the hydraulic pressure so as to switch a control state of the clutch from a released state to an engaged state when starting the engine; an engine control unit that outputs a start-up drive command value for driving the hydraulic control circuit based on the start command value transmitted from the clutch control unit when starting the engine, and controls the engine so that the engine starts operating in conjunction with switching of the clutch to an engaged state; Contains the clutch control unit, when starting the engine, at a predetermined stage during a transition of switching the clutch to an engaged state, calculates command value information including a magnitude and an output time of a start command value at the predetermined stage, and transmits the command value information to the engine control unit, a start-up command value for the predetermined stage of progression when the engine control unit receives the start-up command value for the predetermined stage of progression at the time of starting the engine, the start-up command value being replaced by a start-up drive command value for the predetermined stage of progression based on the command value information.

Images