Vehicle control device

Abstract

To provide a control device which can reduce the sliding-down of a vehicle which occurs when a shift operation position is operated to a traveling position, in the vehicle comprising an electric motor and a mechanical transmission device having a prescribed engagement device.SOLUTION: When an AT output rotational speed No of an automatic transmission 24 having a correlation with a vehicle speed V reaches a prescribed rotational speed No1 or higher during garage control CTg, a garage control part 96a prohibits backlash control CTp, and raises a target rotational speed Nmf. Also, when the sliding-down of a vehicle 10 is detected, the garage control part prohibits the backlash control CTp, and quickly raises an MG rotational speed Nm of an electric motor MG to the target rotational speed Nmf or higher, to thereby generate creep torque Tcrp. Therefore, the sliding-down of the vehicle 10 can be quickly eliminated, and an incongruity imparted to a driver resulting from the sliding-down of the vehicle 10 can be suppressed.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a control device for a vehicle that uses at least an electric motor as a driving force source. [Background technology]

[0002] A vehicle is known that includes an electric motor and a mechanical transmission device provided in a power transmission path between the electric motor and drive wheels, the mechanical transmission device being provided with a predetermined engagement device that connects and disconnects the power transmission path between the electric motor and the drive wheels, and when the shift operation position of a shift operation device is operated to a drive position, the predetermined engagement device is switched to an engaged state, thereby transmitting the power of the electric motor to the drive wheels. Patent Document 1 describes an example of such a vehicle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-217914 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above vehicle, when the shift operation position is operated to the driving position, a garage control is proposed in which the predetermined engagement device is engaged and then the rotation speed of the electric motor is increased to a target rotation speed or higher to generate creep torque. In addition, during a transitional period in which the rotation speed of the electric motor is increased during garage control, the backlash formed between the gears constituting the mechanical transmission is eliminated, and there is a risk of a shock occurring due to the impact when the backlash is eliminated. In response to this, it is desirable to perform backlash elimination control that reduces the change gradient of the rotation speed of the electric motor to reduce the shock occurring when the backlash is eliminated. However, when the vehicle is located, for example, on an uphill lane and the shift operation position is switched, for example, from a non-driving position to a driving position, if the brake operation is released, it is considered that the vehicle will slide down during the switching transitional period. If the backlash elimination control is continued in such a case, the responsiveness of the vehicle will decrease, causing the vehicle to slide down more, which may cause the driver to feel uncomfortable.

[0005] The present invention has been made against the background of the above circumstances, and its object is to provide a control device that can reduce vehicle slippage that occurs when the shift operating position is operated to the driving position in a vehicle equipped with an electric motor and a mechanical transmission device equipped with a specified engagement device. [Means for solving the problem]

[0006] The gist of a first invention is a control device for a vehicle including: (a) an electric motor; and a mechanical transmission device provided in a power transmission path between the electric motor and driving wheels, the mechanical transmission device being provided with a predetermined engagement device that connects and disconnects power transmission in the power transmission path, and the predetermined engagement device being switched to an engaged state when a shift operation position of a shift operation device is operated to a drive position; and (b) a garage control device that, when the shift operation position is switched to the drive position from a state in which another operation position different from the drive position is selected, executes control to engage the predetermined engagement device, and then executes garage control to control the rotation speed of the electric motor to be equal to or higher than a target rotation speed, thereby generating a creep torque that causes a creep phenomenon. and (c) a backlash eliminating control unit that executes backlash eliminating control to temporarily make a gradient of change in the rotation speed of the electric motor gentler so that a shock generated when backlash formed on a power transmission path between the electric motor and the drive wheels is eliminated during a transitional period in which the garage control unit increases the rotation speed of the electric motor is reduced, (d) when a rotation speed correlated with a vehicle speed becomes equal to or higher than a predetermined rotation speed during execution of garage control, the garage control unit prohibits the backlash eliminating control and increases the rotation speed of the electric motor to equal to or higher than the target rotation speed, while (e) when torque is not input to the mechanical transmission device, the garage control unit executes rapid garage control to stepwise increase a command pressure of the predetermined engagement device. When the rapid garage control is not performed, the command pressure for the predetermined engagement device is gradually increased. The present invention is characterized by the above. Effect of the Invention

[0007] According to the first aspect of the present invention, when the rotation speed correlated with the vehicle speed becomes equal to or higher than a predetermined rotation speed during garage control, the backlash elimination control is prohibited and the rotation speed of the electric motor is increased to or higher than the target rotation speed, so that when a skid of the vehicle is detected based on a change in the rotation speed correlated with the vehicle speed, the backlash elimination control is prohibited and the rotation speed of the electric motor is quickly increased to or higher than the target rotation speed to generate creep torque. Therefore, the skid of the vehicle is quickly resolved and the discomfort felt by the driver due to the skid of the vehicle can be suppressed. In addition, when torque is not input to the mechanical transmission device, the garage control unit executes rapid garage control to increase the command pressure of the predetermined engagement device in a stepwise manner. Compared to the case where the rapid garage control that gradually increases the command pressure of a specific engagement device is not performed. By quickly engaging the predetermined engagement device, the responsiveness of the vehicle is improved. [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] This is a flowchart explaining the main control operations of the electronic control device, and is a flowchart explaining the control operations when the vehicle slide is detected after the start of the backlash elimination control executed after the garage operation. [Diagram 3] For example, this is a time chart showing the behavior when the driver performs an R→D operation in the R position of the automatic transmission in the BEV driving mode. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Preferably, when the accelerator opening becomes equal to or larger than a predetermined opening while the garage control is being executed, the garage control unit increases the rotation speed of the electric motor to equal to or larger than the target rotation speed without executing the backlash eliminating control. In this way, the responsiveness of the vehicle to the driver's acceleration request is improved, and the driver's desired acceleration can be realized.

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that in the following embodiments, the drawings are appropriately simplified or modified, and the dimensional ratios and shapes of the various parts are not necessarily drawn accurately. EXAMPLES

[0012] Fig. 1 is a diagram illustrating a 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 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, which are driving power sources for traveling. The vehicle 10 also has driving wheels 14, and a power transmission device 16 provided in a power transmission path between the engine 12 and the electric motor MG and the driving wheels 14.

[0013] 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.

[0014] 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 operating, the MG torque Tm is a power torque when it is a positive torque on the acceleration side, and is a regenerative torque when it is a negative torque on the deceleration side. The electric power is the same as electric energy unless otherwise specified. The power is the same as torque or force unless otherwise specified.

[0015] The power transmission device 16 includes a K0 clutch 20, a torque converter 22, an automatic transmission 24, and the like, housed in 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 torque converter 22 and the automatic transmission 24 each constitute a part of the power transmission path between the drive power source (engine 12, electric motor MG) 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, etc. The power transmission device 16 also includes an engine connecting shaft 34 which connects the engine 12 and the K0 clutch 20, an electric motor connecting shaft 36 which connects the K0 clutch 20 and the torque converter 22, etc. The power transmission device 16 corresponds to the mechanical transmission of the present invention.

[0016] 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. In other words, the electric motor MG is connected to a power transmission path between the K0 clutch 20 and the torque converter 22 so as to be capable of transmitting power. 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.

[0017] 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 driving force from each of the driving force sources (the engine 12, the electric motor MG) to the automatic transmission 24 via fluid. The torque converter 22 includes an LU clutch 40 that serves as a direct clutch that connects the pump wheel 22a and the turbine wheel 22b, that is, that connects the electric motor connecting shaft 36 and the transmission input shaft 38. The LU clutch 40 is a known lock-up clutch.

[0018] 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 the hydraulic control circuit 56, thereby switching between operating states, such as an engaged state and a released state, i.e., control states.

[0019] 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 the formed gear stages by switching the control state of the engagement devices CB involved in the shifting of the automatic transmission 24 in response to the accelerator operation of the driver (=operator) and the vehicle speed V by an electronic control device 90 described later. That is, in the shift control of the automatic transmission 24, a so-called clutch-to-clutch shift is performed in which the shift is performed by, for example, releasing the release-side engagement device and engaging the engagement-side engagement device. The release-side engagement device is an engagement device that was in an engaged state before the shifting of the automatic transmission 24 among the engagement devices involved in the shifting, and is an engagement device that is controlled from the engaged state to the released state during the shifting transition of the automatic transmission 24. The engagement side engagement device is an engagement device that is in a disengaged state before the automatic transmission 24 is shifted among the engagement devices involved in the shift, and is an engagement device that is controlled from the disengaged state to the engaged state during the 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 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.

[0020] 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 and a released state by changing the torque capacity of the K0 clutch 20, that is, the K0 torque Tk0, by the K0 oil pressure PRk0, that is, the regulated oil pressure supplied from the hydraulic control circuit 56.

[0021] 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.

[0022] 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.

[0023] The vehicle 10 further 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 and driven by a driving force source (the engine 12, the electric motor MG) to discharge hydraulic oil used in the power transmission device 16. The pump motor 62 is a motor dedicated to the EOP 60 for rotating and driving the EOP 60. The EOP 60 is rotated and driven by the pump motor 62 to discharge hydraulic oil. The hydraulic oil discharged by the MOP 58 and the EOP 60 is supplied to the hydraulic control circuit 56. The hydraulic control circuit 56 supplies the CB hydraulic pressure PRcb, the K0 hydraulic pressure PRk0, and the like, which are adjusted based on the hydraulic oil discharged by at least one of the MOP 58 and the EOP 60.

[0024] 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, hydraulic control, and the like as necessary.

[0025] The electronic control device 90 receives various signals based on detection values ​​from various sensors provided in the vehicle 10 (for example, an engine rotation speed sensor 70, a turbine rotation speed sensor 72, an output rotation speed sensor 74, a MG rotation speed sensor 76, an accelerator opening sensor 78, a throttle valve opening sensor 80, a brake pedal sensor 82, a battery sensor 84, an oil temperature sensor 86, a shift position sensor 88, 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 which corresponds to the vehicle speed V, an MG rotation speed Nm which is the rotation speed of the electric motor MG, a driver's The accelerator opening θacc, which is the amount of accelerator operation by the driver and indicates the magnitude of the acceleration operation; the throttle valve opening θth, which is the opening of the electronic throttle valve; the brake signal Bon, which is a signal indicating the state in which the brake pedal for activating the wheel brakes is being operated by the driver; the battery temperature THbat, the battery charge / discharge current Ibat, and the battery voltage Vbat of the battery 54; the hydraulic oil temperature THoil, which is the temperature of the hydraulic oil in the hydraulic control circuit 56; and the shift operation position (=shift operation position POSsh), which indicates the position to which the shift lever 64 of the shift operation device 63 provided on the vehicle 10 has been operated.

[0026] The shift lever 64 is a shift operation member that is operated by the driver to one of a plurality of shift operation positions POSsh. The shift operation position POSsh is a signal for selecting one of a plurality of shift ranges of the automatic transmission 24, and includes, for example, the P, R, N, and D positions.

[0027] The P position is a parking operation position for realizing a P range (=parking range) which is a parking range of the automatic transmission 24. The P range of the automatic transmission 24 is a non-driving range (power transmission cut-off range) of the automatic transmission 24 in which the automatic transmission 24 is in a neutral state and the rotation of the transmission output shaft 26 is mechanically prevented. The neutral state of the automatic transmission 24 is a state in which the automatic transmission 24 cannot transmit driving force, and is realized, for example, when all of the engagement devices CB are in a disengaged state and the power transmission in the automatic transmission 24 is cut off. The state in which the rotation of the transmission output shaft 26 is mechanically prevented is a parking lock state in which the transmission output shaft 26 is fixed so as not to rotate by a known parking lock mechanism provided in the vehicle 10.

[0028] The R position is a reverse drive operating position for realizing the R range, which is a reverse drive range of the automatic transmission 24. The R range of the automatic transmission 24 is a drive range (power transmission range) of the automatic transmission 24 that enables the vehicle 10 to drive in reverse.

[0029] The N position is a neutral operation position for realizing the N range, which is a power transmission cut-off range (=neutral range) of the automatic transmission 24. The N range of the automatic transmission 24 is a non-driving range (power transmission cut-off range) of the automatic transmission 24 in which the automatic transmission 24 is in a power transmission cut-off state (neutral state).

[0030] The D position is a forward driving operation position for achieving the D range, which is a forward driving range of the automatic transmission 24. The D range of the automatic transmission 24 is a driving range (power transmission range) of the automatic transmission 24 that enables the vehicle 10 to drive forward.

[0031] Among the shift operation positions POSsh, the P position and the N position are non-driving positions of the shift operation device 63 where the automatic transmission 24 cannot transmit driving force from each of the driving force sources (the engine 12, the electric motor MG). Among the shift operation positions POSsh, the R position and the D position are driving positions of the shift operation device 63 where the automatic transmission 24 can transmit driving force from each of the driving force sources.

[0032] 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.

[0033] The electronic control unit 90 includes a hybrid control means, or hybrid control unit 92 , a clutch control means, or clutch control unit 94 , and a gear shift control means, or gear shift control unit 96 in order to realize various controls in the vehicle 10 .

[0034] The hybrid 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 executes hybrid drive control by the engine 12 and the electric motor MG using these control functions. The hybrid control unit 92 also includes a backlash eliminating control unit 92c that serves as backlash eliminating control means that executes backlash eliminating control, which will be described later.

[0035] The hybrid control unit 92 calculates the driving demand amount of the vehicle 10 by the driver, for example, by applying the accelerator opening θacc and the vehicle speed V to a driving demand amount map. The driving demand amount map is a relationship that is experimentally or design-wise obtained and stored in advance, that is, a predetermined relationship. The driving demand amount 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 amount 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. Alternatively, the driving demand amount can simply be the accelerator opening θacc or the throttle valve opening θth. In calculating the driving demand amount, the AT output rotation speed No, or the like, can be used instead of the vehicle speed V.

[0036] The hybrid 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, the chargeable power Win and the dischargeable power Wout of the battery 54, etc. The engine control command signal Se is, for example, a command value for the engine power Pe, which is the power of the engine 12 that outputs the engine torque Te at the engine rotation speed Ne at that time. The MG control command signal Sm is, for example, a command value for the power consumption Wm of the electric motor MG that outputs the MG torque Tm at the MG rotation speed Nm at that time.

[0037] The chargeable power Win of the battery 54 is the maximum power that can be input, which specifies the limit on the input power of the battery 54, and indicates the input limit of the battery 54. The dischargeable power Wout of the battery 54 is the maximum power that can be output, which specifies the limit on the output power of the battery 54, and indicates the output limit of the battery 54. The chargeable power Win and dischargeable power Wout of the battery 54 are calculated by the electronic control device 90, for example, based on the battery temperature THbat and the state of charge value SOC [%] of the battery 54. The state of charge value SOC of the battery 54 is a value indicating the state of charge corresponding to the amount of charge of the battery 54, and is calculated by the electronic control device 90, for example, based on the battery charge / discharge current Ibat and the battery voltage Vbat.

[0038] When the required driving torque Trdem can be satisfied only by the output of the electric motor MG, the hybrid control unit 92 sets the driving mode to the motor driving (=BEV driving) mode. The BEV driving mode is a driving mode in which the vehicle can travel using the driving force from the electric motor MG with the operation of the engine 12 stopped. In the BEV driving mode, the hybrid control unit 92 performs BEV driving in which the vehicle travels using the driving force output only from the electric motor MG among the driving force sources (engine 12, electric motor MG) when the K0 clutch 20 is in the released state.

[0039] On the other hand, when the required drive torque Trdem cannot be satisfied without using at least the output of the engine 12, the hybrid control unit 92 sets the drive mode to the engine drive mode, i.e., the hybrid drive (=HEV drive) mode. In the HEV drive mode, the hybrid control unit 92 performs engine drive, i.e., HEV drive, in which the drive force is output from at least the engine 12 of the drive power sources (engine 12, electric motor MG) when the K0 clutch 20 is in an engaged state. On the other hand, even if the required drive torque Trdem can be satisfied only by the output of the electric motor MG, the hybrid control unit 92 establishes the HEV drive mode when the state of charge value SOC of the battery 54 is less than a predetermined engine start threshold value or when the engine 12 or the like needs to be warmed up. The engine start threshold value is a predetermined threshold value for determining that the state of charge value SOC is at a value at which the engine 12 needs to be forcibly started and the battery 54 needs to be charged.

[0040] The motor control unit 92b executes MG idling control, which is idling control of the motor MG, for example, when the engine 12 is stopped. The MG idling control is a control that controls the MG rotation speed Nm of the motor MG to be equal to or higher than a predetermined target rotation speed Nmf, and generates a creep torque Tcrp for generating a creep phenomenon in which the vehicle 10 moves slowly when the brake pedal is released even if the accelerator is in an off state. When the MG rotation speed Nm of the motor MG is controlled to be equal to or higher than the target rotation speed Nmf, the rotation is transmitted to the torque converter 22 and the torque is amplified. The amplified torque is transmitted to the drive wheels 14 as the creep torque Tcrp via the automatic transmission 24 and the like. The MG idling control by the motor control unit 92b is executed, for example, in the BEV driving mode, when the drive demand amount is equal to or lower than a predetermined zero determination threshold value that can be determined to be zero, and the shift operation position POSsh is in the D position or the R position, which is a driving position. The drive demand amount is equal to or smaller than the zero determination threshold value when, for example, the accelerator opening θacc is determined to be zero and the accelerator is off.

[0041] The clutch control unit 94 controls the K0 clutch 20 according to the driving mode during driving. For example, when it is determined that the driving mode is switched to the HEV driving mode during BEV driving, the clutch control unit 94 performs engagement control of the K0 clutch 20 so as to execute start control of the engine 12. For example, when it is determined that there is a request to start the engine 12 based on the driving state, the clutch control unit 94 outputs a K0 hydraulic control command signal Sk0 to the hydraulic control circuit 56 for controlling the K0 clutch 20 from a released state toward an engaged state so as to obtain a K0 torque Tk0 for transmitting a torque (i.e., a cranking torque Tcrn) required for cranking the engine 12, which is a torque for increasing the engine rotation speed Ne, to the engine 12 side.

[0042] The shift control unit 96 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. In the shift control of the automatic transmission 24, the shift control unit 96 shifts the automatic transmission 24 by, for example, switching the disengagement side engagement device to a disengaged state and switching the engagement side engagement device to an engaged state. 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, the vehicle speed V and the 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, the accelerator opening θacc, the throttle valve opening θth, or the like may be used instead of the required driving torque Trdem.

[0043] The gear shift control unit 96 includes a function as garage control means, i.e., a garage control unit 96a, which performs garage control CTg when a garage operation OPg is performed by the driver. The garage operation OPg is one of the operations of the shift lever 64 by the driver, and is, for example, a switching operation in which the shift operation position POSsh (shift operation position) of the shift operation device 63 is switched from a state in which another shift operation position POSsh (another operation position) different from one driving position (D position or R position) is selected to a state in which the one driving position is selected. When one driving position is set to the D position, the other shift operation position POSsh is, for example, the R position. In this case, the state in which one driving position is selected is a state in which the shift operation position POSsh is set to the D position. The state in which the other shift operation position POSsh is selected is a state in which the shift operation position POSsh is set to the R position. In other words, the garage operation OPg is, for example, an R → D operation. Or, the other shift operation position POSsh is, for example, a non-driving position, such as a P position or an N position. In this case, the state in which the non-driving position of the automatic transmission 24 is selected is a state in which the shift operation position POSsh is the P position or the N position. That is, the garage operation OPg is, for example, an N(P)→D operation. Note that a D→R operation, which is a switching operation from a state in which the D position is selected to a state in which the R position is selected, and an N(P)→R operation, which is a switching operation from a state in which the P position or the N position is selected to a state in which the R position is selected, are also types of garage operation OPg. Also, depending on the shift operation position POSsh of the shift lever 64, for example, an R→D operation or a D→R operation may go through the N position.

[0044] In the automatic transmission 24, for example, when the first engagement device CB1 and the third engagement device CB3 of the engagement devices CB are both engaged, a forward gear stage, for example, a first gear stage, is established and the automatic transmission 24 is in the D range. In addition, in the automatic transmission 24, for example, when the second engagement device CB2 and the third engagement device CB3 of the engagement devices CB are both engaged, a reverse gear stage is established and the automatic transmission 24 is in the R range.

[0045] When the driver performs an N(P) to D operation in the neutral range of the automatic transmission 24 with the first engagement device CB1 in the disengaged state, the garage control unit 96a performs garage control CTg to switch the first engagement device CB1 to the engaged state to establish a first gear stage, thereby placing the automatic transmission 24 in the D range.

[0046] Furthermore, when the driver performs an N(P)→R operation in the neutral range of the automatic transmission 24 with the second engagement device CB2 in the disengaged state, the garage control unit 96a performs garage control CTg to switch the second engagement device CB2 to the engaged state and establish a gear for reverse travel, thereby placing the automatic transmission 24 in the R range.

[0047] In addition, when the driver performs a D→R operation while the first gear stage is formed, the garage control unit 96a performs garage control CTg, for example, by switching the first engagement device CB1 to a disengaged state and switching the second engagement device CB2 to an engaged state to form a gear stage for reverse. As a result, the automatic transmission 24 is switched from the D range to the R range. In addition, when the driver performs a R→D operation while the first gear stage is formed, the garage control unit 96a performs garage control CTg, for example, by switching the second engagement device CB2 to a disengaged state and switching the first engagement device CB1 to an engaged state to form a gear stage for reverse. As a result, the automatic transmission 24 is switched from the R range to the D range.

[0048] The automatic transmission 24 is provided with a first engagement device CB1, and when the shift operation position POSsh is switched to the D position, which is the drive position, the first engagement device CB1 is brought into an engaged state, thereby switching to the D range, which is the forward drive range. The automatic transmission 24 is part of the power transmission device 16, and is part of a mechanical transmission device provided in the power transmission path between the engine 12 and the electric motor MG, and the drive wheels 14. The first engagement device CB1 of the engagement devices CB is a predetermined engagement device that connects and disconnects power transmission in the power transmission path between the engine 12 and the electric motor MG, and the drive wheels 14.

[0049] The R position, which is exemplified as another shift operation position POSsh (shift operation position) other than the D position of the automatic transmission 24, is a driving position that is formed by engaging the second engagement device CB2 provided in the automatic transmission 24. The second engagement device CB2 of the engagement devices CB is a predetermined engagement device that interrupts power transmission in a power transmission path between the engine 12 and the electric motor MG and the drive wheels 14.

[0050] Here, in order to suppress the engagement shock that occurs during the engagement transition period of a predetermined engagement device engaged in the garage control CTg, the garage control unit 96a outputs a CB hydraulic control command signal Sbc to the hydraulic control circuit 56 to execute a loose engagement command DRls for gradually increasing the command pressure of the predetermined engagement device to gently engage the predetermined engagement device. In other words, the garage control unit 96a executes the normal garage control CTgn for executing the loose engagement command DRls. The loose engagement command DRls is an engagement command for gently engaging the predetermined engagement device compared to a sudden engagement command DRhs, which will be described later.

[0051] Alternatively, in order to execute the garage control CTg more quickly than the normal garage control CTgn, the garage control unit 96a can execute a sudden engagement command DRhs, which increases the command pressure of a predetermined engagement device in a stepwise manner, instead of the loose engagement command DRls to quickly engage the predetermined engagement device. However, if the sudden engagement command DRhs is executed when torque is input to the automatic transmission 24, an engagement shock is likely to occur, or the predetermined engagement device may not be quickly engaged even if the sudden engagement command DRhs is executed. Therefore, it is desirable to execute the sudden engagement command DRhs when torque is not input to the automatic transmission 24. A state in which torque does not need to be input to the automatic transmission 24 is, for example, when the accelerator is off, and when the output of the creep torque Tcrp may be temporarily stopped. Also, when the output of the creep torque Tcrp may be temporarily stopped, it is in the BEV driving mode in consideration of responsiveness.

[0052] When a garage operation OPg is performed by the driver, the garage control unit 96a issues a sudden engagement command DRhs to engage a predetermined engagement device in a state in which the output of creep torque Tcrp is stopped, i.e., in a creep cut state, and then controls the MG rotation speed Nm to be equal to or higher than a target rotation speed Nmf, thereby executing a rapid garage control CTgq to generate a creep torque Tcrp that causes a creep phenomenon. The creep cut state is a state in which the output of creep torque Tcrp is prohibited and the MG rotation speed Nm is set to zero or approximately zero. The garage control unit 96a executes the rapid garage control CTgq when a garage operation OPg is performed by the driver in a BEV driving mode in which the operation of the engine 12 is stopped. Since the rapid engagement command DRhs is executed when the MG rotation speed Nm is zero or approximately zero, the garage control unit 96a drives the EOP 60 while the rapid garage control CTgq is being executed, and uses the hydraulic oil discharged from the EOP 60 as the source pressure to control the CB hydraulic pressure PRcb, which is the engagement hydraulic pressure of a specified engagement device.

[0053] Whether or not to execute the rapid garage control CTgq is determined based on whether or not each of the following predetermined conditions is satisfied: the BEV driving mode, the accelerator is off, the AT input rotation speed Ni, i.e., the turbine rotation speed Nt, is equal to or lower than a predetermined input rotation speed Nif, and the AT output rotation speed No is equal to or lower than a predetermined rotation speed Nof. Note that the predetermined input rotation speed Nif and the predetermined rotation speed Nof are both set to zero or close to zero.

[0054] In addition, when the rotation of the electric motor MG is transmitted to the automatic transmission 24 side during the transitional period in which the MG rotation speed Nm is increased during the rapid garage control CTgq, the backlash formed on the power transmission path between the engine 12 and the electric motor MG and the drive wheels 14 is eliminated (backlash elimination). The backlash corresponds to, for example, a gap in the rotational direction formed between various meshing gears provided in the automatic transmission 24 constituting the power transmission path between the engine 12 and the electric motor MG and the drive wheels 14. At this time, there is a risk of a shock being generated due to the impact of the gears colliding with each other when the backlash is eliminated. In order to suppress the shock caused by the backlash elimination, during the transitional period in which the MG rotation speed Nm is increased during the execution of the rapid garage control CTgq, the backlash elimination control unit 92c executes backlash elimination control CTp, which temporarily makes the change gradient of the MG rotation speed Nm during the increase transitional period of the MG rotation speed Nm gentle so that the shock generated when the backlash is eliminated is reduced.

[0055] When the quick garage control CTgq is started, the backlash elimination control unit 92c starts increasing the MG rotation speed Nm at a time when a predetermined time TMf has elapsed since the time when the sudden engagement command DRhs was output in the creep cut state, and increases the MG rotation speed Nm at a predetermined increasing gradient. When the MG rotation speed Nm reaches a predetermined holding rotation speed Nmk, the backlash elimination control unit 92c holds the MG rotation speed Nmk for a predetermined time TMk. The predetermined increasing gradient of the MG rotation speed Nm by the backlash elimination control CTp, the holding rotation speed Nmk at which the MG rotation speed Nm is temporarily held, and the predetermined time TMk for holding the MG rotation speed Nm at the holding rotation speed Nmk are determined in advance experimentally or by design, and are set to values ​​at which the shock caused by backlash elimination occurring during the rising transition period of the MG rotation speed Nm falls within an allowable range and the execution time of the backlash elimination control CTp is minimized. The predetermined time TMf is, for example, the time when it can be determined that the switching of the predetermined engaging device engaged in the garage control CTg to the engaged state has progressed, that is, the time when the torque capacity of the predetermined engaging device becomes the capacity capable of transmitting the MG torque Tm of the electric motor MG. In this way, by temporarily holding the MG rotation speed Nm at the holding rotation speed Nmk during the rising transition period of the MG rotation speed Nm, the gradient of change in the MG rotation speed Nm becomes gentle, and the impact caused by the collision of the gears when the backlash is eliminated is reduced, thereby reducing the shock. When the backlash elimination control CTp is completed, the electric motor control unit 92b increases the MG rotation speed Nm to the target rotation speed Nmf or higher to generate the creep torque Tcrp.

[0056] When the garage operation OPg is, for example, an R→D operation, it is necessary to switch the second engagement device CB2 to a released state. In addition, in the R position, the MG torque Tm for generating the creep torque Tcrp is input to the automatic transmission 24. When the garage operation OPg which is an R→D operation is performed by the driver, the garage control unit 96a outputs a CB hydraulic control command signal Sbc to the hydraulic control circuit 56 in order to perform a release command DRr for releasing the second engagement device CB2 by reducing the command pressure of the second engagement device CB2 before starting a rapid engagement command DRhs for the first engagement device CB1 (predetermined engagement device). Furthermore, when the garage operation OPg is performed by the driver in a state in which the MG torque Tm is being output from the electric motor MG, the garage control unit 96a executes the rapid garage control CTgq in a state in which the output of the MG torque Tm is temporarily stopped. That is, when MG torque Tm is being output from the electric motor MG at the start of rapid garage control CTgq, the garage control unit 96a outputs a command to the hybrid control unit 92 to stop the electric motor MG, thereby stopping the electric motor MG. Note that similar control is also executed when the garage operation OPg is a D→R operation. Although a detailed explanation will be omitted, when the garage operation OPg is a D→R operation, the first engagement device CB1 becomes the release side engagement device, and the second engagement device CB2 becomes the engagement side engagement device (i.e., the specified engagement device).

[0057] In addition, when the accelerator is operated during execution of the rapid garage control CTgq, the garage control unit 96a outputs an output command DRop to the motor control unit 92b to increase the MG rotation speed Nm without executing the backlash eliminating control CTp during the rising transition period of the MG rotation speed Nm of the electric motor MG. When the accelerator opening θacc becomes equal to or greater than a predetermined opening θacc1 during the rising transition period of the MG rotation speed Nm of the electric motor MG, the garage control unit 96a interrupts the backlash eliminating control CTp and outputs an output command DRop to increase the MG rotation speed Nm to the electric motor control unit 92b. Based on the output command DRop from the garage control unit 96a, the electric motor control unit 92b increases the MG rotation speed Nm to the target rotation speed Nmf or higher without executing the backlash eliminating control CTp, and generates the MG torque Tm from the electric motor MG according to the accelerator opening θacc. This allows the vehicle 10 to be accelerated quickly, and the driver's discomfort due to a delay in acceleration is suppressed. Here, the predetermined opening θacc1 is determined in advance experimentally or by design, and is set to a threshold value of the accelerator opening θacc at which the driver determines that he or she wants to prioritize rapid acceleration over shocks caused by backlash.

[0058] In addition, when the vehicle 10 starts to slide down due to, for example, the brake pedal being released during execution of the rapid garage control CTgq, it is necessary to quickly suppress the vehicle 10 from sliding down. On the other hand, if the electric motor MG is controlled to be equal to or higher than the target rotation speed Nmf through the clearance elimination control CTp, a delay occurs in the generation of the creep torque Tcrp, and the vehicle 10 may slide more significantly, causing the driver to feel uncomfortable. Therefore, when the garage control unit 96a detects that the vehicle 10 is sliding down during execution of the rapid garage control CTgq, it prohibits the clearance elimination control CTp and quickly increases the MG rotation speed Nm to the target rotation speed Nmf or higher. By prohibiting the clearance elimination control CTp, the creep torque Tcrp is quickly output from the drive wheels 14, and the vehicle 10 is prevented from sliding down.

[0059] When the quick garage control CTgq is started, the garage control unit 96a judges at any time whether the AT output rotation speed No, which is correlated with the vehicle speed V, becomes equal to or greater than a predetermined rotation speed No1 during the execution of the quick garage control CTgq. The predetermined rotation speed No1 is determined in advance experimentally or by design, and is set to a threshold value at which it can be determined that the vehicle 10 has slipped as perceived by the driver. When the AT output rotation speed No is less than the predetermined rotation speed No1 during the execution of the quick garage control CTgq, the garage control unit 96a permits the execution of the backlash eliminating control CTp. In other words, when the AT output rotation speed No is less than the predetermined rotation speed No1, the backlash eliminating control CTp is executed.

[0060] On the other hand, when the AT output rotation speed No becomes equal to or higher than the predetermined rotation speed No1 during execution of the quick garage control CTgq, the garage control unit 96a prohibits the backlash eliminating control CTp and outputs an output command DRop to the motor control unit 92b to increase the MG rotation speed Nm to the target rotation speed Nmf or higher at a predetermined increasing gradient that is set in advance. In response to this, the motor control unit 92b increases the MG rotation speed Nm to the target rotation speed Nmf or higher without executing the backlash eliminating control CTp, thereby generating a creep torque Tcrp. Note that the increasing gradient of the MG rotation speed Nm when the backlash eliminating control CTp is prohibited is previously determined experimentally or by design, and is set to a value that quickly eliminates the rolling down of the vehicle 10.

[0061] If the AT output rotation speed No becomes equal to or higher than the predetermined rotation speed No1 after the start of the rapid garage control CTgq and before the MG rotation speed Nm starts to increase, the garage control unit 96a increases the MG rotation speed Nm at a predetermined increasing gradient without executing the backlash-eliminating control CTp once a predetermined time TMf has elapsed since the sudden engagement command DRhs was output. In other words, when the rapid garage control CTgq increases the torque capacity of the predetermined engagement device to a level that allows it to transmit the torque input from the electric motor MG side, the garage control unit 96a increases the MG rotation speed Nm of the electric motor MG to equal to or higher than the target rotation speed Nmf without executing the backlash-eliminating control CTp.

[0062] Furthermore, when the AT output rotation speed No becomes equal to or greater than the predetermined rotation speed No1 after the backlash eliminating control CTp is started, the garage control unit 96a interrupts the backlash eliminating control CTp and raises the MG rotation speed Nm to equal to or greater than the target rotation speed Nmf at a predetermined rising gradient. In this way, when a skid of the vehicle 10 is detected based on the AT output rotation speed No becoming equal to or greater than the predetermined rotation speed No1 during execution of the rapid garage control CTgq, the backlash eliminating control CTp is prohibited and the MG rotation speed Nm is quickly controlled to equal to or greater than the target rotation speed Nmf. As a result, the creep torque Tcrp is quickly generated and the skid of the vehicle 10 is suppressed.

[0063] 2 is a flowchart for explaining the main part of the control operation of the electronic control device 90, and is a flowchart for explaining the control operation when a slide of the vehicle 10 is detected after the start of the backlash elimination control CTP executed after the garage operation OPg. This flowchart is executed when the backlash elimination control CTP is started after the garage operation OPg.

[0064] First, in step S10 (hereinafter, steps are omitted) corresponding to the control function of the backlash eliminating control unit 92c, the backlash eliminating control CTp is started. In S20 corresponding to the control function of the backlash eliminating control unit 92c, the backlash eliminating control CTp is continuously executed. In S30 corresponding to the control function of the garage control unit 96a, it is determined whether the AT output rotation speed No is equal to or greater than a predetermined rotation speed No1. If the determination in S30 is negative, it is determined in S40 corresponding to the control function of the garage control unit 96a whether the accelerator opening θacc is equal to or greater than a predetermined opening θacc1. If the determination in S40 is negative, it is determined in S50 corresponding to the control function of the backlash eliminating control unit 92c whether the backlash eliminating control CTp is completed. The completion of the backlash eliminating control CTp is determined, for example, based on whether the time during which the MG rotation speed Nm is held at the held rotation speed Nmk has reached a predetermined time TMk. If the determination in S50 is negative, the process returns to S20 and the backlash eliminating control CTp is continuously executed. If the determination in S50 is positive, the process proceeds to S60, where the backlash elimination control CTp is terminated and the MG rotation speed Nm is increased to or above the target rotation speed Nmf.

[0065] When the determination in S30 is positive and when the determination in S40 is positive, in S60 corresponding to the control function of the garage control unit 96a, the backlash elimination control CTp is interrupted and the MG rotation speed Nm is increased to the target rotation speed Nmf or higher. As a result, if the driver depresses the accelerator pedal or the vehicle 10 rolls over during the execution of the backlash elimination control CTp, the backlash elimination control CTp is interrupted and the MG rotation speed Nm is quickly increased to the target rotation speed Nmf or higher, so that the driving force (creep torque Tcrp) is quickly output from the vehicle 10. As a result, the vehicle 10 is quickly accelerated in response to the accelerator operation and the vehicle 10 is prevented from rolling over.

[0066] Fig. 3 is a time chart showing behavior when an R→D operation is performed by the driver with the automatic transmission 24 in the R position in the BEV driving mode. In Fig. 3, the horizontal axis shows elapsed time, and the vertical axis shows, from the top, the shift operation position POSsh, the brake signal Bon, the AT output rotation speed No, the MG rotation speed Nm, the amount of backlash Gap eliminated by the backlash eliminating control CTp, the CB2 hydraulic pressure PRcb2 (release side hydraulic pressure) of the second engagement device CB2 that is released in conjunction with the R→D operation, and the CB1 hydraulic pressure PRcb1 (engagement side hydraulic pressure) of the first engagement device CB1 that is engaged in conjunction with the R→D operation.

[0067] When an R→D operation is performed at time t1 shown in FIG. 3, garage control CTg is started, and shift control is executed to switch from R range to D range in the automatic transmission 24, that is, to release the second engagement device CB2 which is the release side engagement device, and to engage the first engagement device CB1 which is the engagement side engagement device. At time t1, release of the second engagement device CB2 which is the release side engagement device is started, and the CB2 oil pressure PRcb2 (indicated pressure) of the second engagement device CB2 shown by the solid line decreases to a predetermined value, and then decreases at a predetermined gradient, and then decreases to zero. In addition, the CB2 oil pressure PRcb2 (actual pressure) shown by the broken line decreases so as to follow the indicated pressure of the solid line. In addition, at time t1, the MG rotation speed Nm of the electric motor MG decreases toward zero, and a transition is made to a creep cut state in which the creep torque Tcrp is not output.

[0068] At time t2, the brake signal Bon is switched from on to off, allowing the vehicle 10 to move. Furthermore, the first engagement device CB1, which is the engagement side engagement device, begins to engage, and the CB1 oil pressure PRcb1 (command pressure) of the first engagement device CB1, shown by the solid line, increases in a stepped manner to a maximum value at which the first engagement device CB1 is in a fully engaged state. Furthermore, the CB1 oil pressure PRcb1 (actual pressure), shown by the dashed line, increases so as to follow the command pressure of the solid line. Between time t2 and time t3, the MG rotation speed Nm becomes zero, and a creep cut state is entered in which the creep torque Tcrp is not output.

[0069] At time t3, the backlash eliminating control CTp is started, the MG rotation speed Nm increases at a predetermined gradient, and when the MG rotation speed Nm reaches the holding rotation speed Nmk, it is temporarily held at the holding rotation speed Nmk. As the MG rotation speed Nm increases, the backlash amount Gap gradually decreases.

[0070] At time t4, the AT output rotation speed No is detected to be equal to or greater than the predetermined rotation speed No1, so that the backlash eliminating control CTp is interrupted, and the MG rotation speed Nm rises at a predetermined rising gradient. Here, the AT output rotation speed No shown in FIG. 3 is shown as an absolute value, and in fact, the AT output rotation speed No at time t4 is shown to be rotating in the reverse direction. That is, the vehicle 10 is sliding backward. In response to the vehicle 10 sliding backward, the MG rotation speed Nm is controlled to be quickly at or above the target rotation speed Nmf. As a result, the backlash is quickly eliminated, and the creep torque Tcrp is output from the drive wheels 14, so that the AT output rotation speed No shown by the solid line decreases toward zero, and the vehicle 10 is prevented from sliding backward. At time t5, the AT output rotation speed No becomes zero, and thereafter the AT output rotation speed No rotates forward, so that the AT output rotation speed No rises.

[0071] The AT output rotation speed No, the MG rotation speed Nm, and the backlash amount Gap shown by the broken lines after the time t4 indicate the behavior in the conventional control, that is, the behavior when the backlash eliminating control CTp is continued even when the AT output rotation speed No becomes equal to or exceeds the predetermined rotation speed No1. In the conventional control, the backlash eliminating control CTp is continued even after the time t4, so that the MG rotation speed Nm is maintained at the holding rotation speed Nmk. In relation to this, the reduction in the backlash amount Gap is slower than in this embodiment. In addition, the maximum value of the AT output rotation speed No is higher than in the embodiment shown by the solid line, and the vehicle 10 slides down significantly. Furthermore, the timing at which the vehicle 10 slides down is eliminated, that is, the timing at which the MG rotation speed Nm drops to zero, is also slower. In contrast, in this embodiment, the backlash eliminating control CTp is interrupted when the AT output rotation speed No becomes equal to or exceeds the predetermined rotation speed No1, thereby suppressing the vehicle 10 from sliding down.

[0072] As described above, according to this embodiment, when the AT output rotation speed No of the automatic transmission 24, which is correlated with the vehicle speed V, becomes equal to or higher than the predetermined rotation speed No1 during execution of the garage control CTg, the backlash eliminating control CTp is prohibited and the MG rotation speed Nm of the electric motor MG is increased to or higher than the target rotation speed Nmf, so that when a skid of the vehicle 10 is detected based on a change in the AT output rotation speed No, the backlash eliminating control CTp is prohibited and the MG rotation speed Nm of the electric motor MG is quickly increased to or higher than the target rotation speed Nmf to generate the creep torque Tcrp. Therefore, the skid of the vehicle 10 is quickly resolved, and the discomfort felt by the driver due to the skid of the vehicle 10 can be suppressed.

[0073] 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.

[0074] For example, in the above-mentioned embodiment, the control after the start of the backlash eliminating control CTp was described in the flowchart of FIG. 2 and the time chart of FIG. 3, but the present invention can be applied even before the start of the backlash eliminating control CTp. When the AT output rotation speed No becomes equal to or higher than the predetermined rotation speed No1 before the start of the backlash eliminating control CTp, the MG rotation speed Nm is reduced to zero, and the engagement of the first engagement device CB1 and the release of the second engagement device CB2 are executed, as in the conventional control, until the backlash eliminating control CTp is started. Next, when the MG rotation speed Nm starts to increase, the execution of the backlash eliminating control CTp is prohibited, and the MG rotation speed Nm is controlled to the target rotation speed Nmf at a predetermined increasing gradient. Even in the case of the above-mentioned control, the effect of suppressing the vehicle 10 from sliding down can be obtained by prohibiting the backlash eliminating control CTp.

[0075] In the above embodiment, the case where the shift operation position POSsh is switched from the R position to the D position has been described as one aspect, but the present invention is not limited to the above aspect. For example, the present invention can be applied even when the shift operation position POSsh is switched from the N position or P position, which is a non-driving position (non-driving position), to the D position or R position, which is a driving position (driving position). Similarly, the present invention can be applied even when the shift operation position POSsh is switched from the D position to the R position.

[0076] In the above embodiment, the vehicle 10 is judged to be sliding downhill when the AT output rotation speed No of the automatic transmission 24 becomes equal to or higher than the predetermined rotation speed No1, but the present invention is not necessarily limited to the AT output rotation speed No. For example, the present invention can be applied to any rotation speed that is correlated with the vehicle speed V, such as the wheel speed.

[0077] In addition, in the above-described embodiment, the clearance elimination control CTp is executed when the vehicle 10 slides down while the quick garage control CTgq is being executed. However, the present invention is not limited to being applied while the quick garage control CTgq is being executed, and can also be applied while the normal garage control CTgn is being executed.

[0078] In the above embodiment, the vehicle 10 including the engine 12, the electric motor MG, and the automatic transmission 24 is exemplified as a vehicle to which the present invention is applied, but the present invention is not limited to this embodiment. For example, the present invention can be applied to an electric vehicle that does not include an engine and uses only an electric motor as a driving force source, or a hybrid vehicle that includes an automatic transmission in series at the rear stage of a known electric continuously variable transmission. In addition, when the vehicle is, for example, the electric vehicle, the automatic transmission that transmits the driving force from the electric motor may be replaced with a mechanical transmission device that simply has an engagement device. In short, the present invention can be applied to any vehicle that includes an electric motor and a mechanical transmission device that has a predetermined engagement device and that has a driving position that allows the driving force from the electric motor to be transmitted to the driving wheels as a shift position by engaging the predetermined engagement device.

[0079] 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 embodiment. For example, the automatic transmission 24 may be a known DCT (Dual Clutch Transmission), a known belt type continuously variable transmission, or the like. When the automatic transmission 24 is a DCT, one of the engagement devices connected to the input shafts of each of the two systems corresponds to the predetermined engagement device. When the automatic transmission 24 is a belt type continuously variable transmission, one of the engagement devices, a forward clutch and a reverse brake, of a known forward / reverse switching device provided together with the belt type continuously variable transmission corresponds to the predetermined engagement device.

[0080] In the above embodiment, the torque converter 22 is used as the fluid-type power transmission device, but the present invention is not limited to this. For example, instead of the torque converter 22, other fluid-type power transmission devices such as a fluid coupling that does not amplify torque may be used as the fluid-type power transmission device.

[0081] 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]

[0082] 10: Vehicle 14: Drive wheel 16: Power transmission device (mechanical transmission device) 63: Shift operation device 90: Electronic control device (control device) 92c: Backlash control section 96a: Garage control unit MG: Electric motor CB1: First engagement device (predetermined engagement device) CB2: Second engagement device (predetermined engagement device) POSsh: Shift position (shift position)

Claims

[Claim 1] A control device for a vehicle including an electric motor and a mechanical transmission device provided in a power transmission path between the electric motor and a drive wheel, the mechanical transmission device being provided with a predetermined engagement device that connects and disconnects power transmission in the power transmission path, and the predetermined engagement device being switched to an engaged state when a shift operation position of a shift operation device is operated to a drive position, a garage control unit that, when the shift operation position is switched to the driving position from a state in which another operation position different from the driving position is selected, executes control to engage the predetermined engagement device, and then executes garage control to control the rotation speed of the electric motor to a target rotation speed or higher to generate a creep torque that causes a creep phenomenon; and a backlash eliminating control unit that executes backlash eliminating control for temporarily easing a gradient of change in the rotation speed of the electric motor so as to reduce a shock that occurs when backlash formed on a power transmission path between the electric motor and the drive wheels is eliminated during a transitional period in which the garage control unit increases the rotation speed of the electric motor. When a rotation speed correlated with a vehicle speed becomes equal to or higher than a predetermined rotation speed during execution of garage control, the garage control unit prohibits the backlash elimination control and increases the rotation speed of the electric motor to equal to or higher than the target rotation speed, The garage control unit executes rapid garage control for increasing the command pressure of the predetermined engagement device stepwise when torque is not input to the mechanical transmission device, and gradually increases the command pressure of the predetermined engagement device when the rapid garage control is not executed. A vehicle control device comprising:

Images