Vehicle control device

Abstract

To secure responsiveness to an interruption of deceleration and suppress shift shock when regenerative torque is decreased in accompany with change of brake operation at the time of down-shift during regenerative coast travelling.SOLUTION: A vehicle controller is given in which: after an inertial phase of the down-shift starts, when MG regenerative torque Tmgc at the time of coast is decreased in accompany with change of brake operation amount Bon and propeller shaft regenerative torque Tprg is decreased according thereto, regenerative torque down amount TDmgc of the regenerative torque down control executed just before synchronization of the down-shift is increasingly corrected to suppress shift shock caused by decrease of the MG regenerative torque Tmgc at the time of coast; and since limitation of the decreasing change of the MG regenerative torque Tmgc at the time of coast in accompany with the decreasing change of the brake operation amount Bon is not necessary, the MG regenerative torque Tmgc at the time of coast is rapidly decreased in accompany with change of the brake operation amount Bon even during the down-shift to obtain ordinary responsiveness to an interruption of deceleration.SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] The present invention relates to a vehicle control device, and more particularly to a vehicle control device that generates regenerative torque by controlling a rotary machine to regenerate during coasting. [Background technology]

[0002] There is known a control device for a vehicle, which is (a) provided in a vehicle provided with an automatic transmission having a plurality of gear stages with different gear ratios in a power transmission path between a rotary machine and a drive wheel, and (b) has a coasting regenerative control unit that regeneratively controls the rotary machine so that a larger regenerative torque is generated when a brake operation is performed during coasting compared to when a brake operation is not performed. The vehicle described in Patent Document 1 is an example of such a vehicle, and the regenerative torque is switched depending on the presence or absence (on / off) of a brake operation. Patent Document 1 also describes that when the automatic transmission is downshifted during regenerative coasting during the coasting in which the rotary machine is regeneratively controlled by the coasting regenerative control unit, if the regenerative torque is reduced with a brake-off operation after the inertia phase of the downshift has started, a gear shift shock may occur due to the reduction in the regenerative torque, and therefore the change rate of the regenerative torque is suppressed. In other words, in Patent Document 1, downshifting is performed by engaging the hydraulic friction engagement device, so that a decrease in regenerative torque can cause the hydraulic friction engagement device to be suddenly engaged, potentially resulting in a synchronous shock at the end of the shift; to prevent this, the rate of change of the regenerative torque is reduced. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-199958 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, suppressing the rate of change of the regenerative torque as in Patent Document 1 above slows down the change in the regenerative torque in response to the brake-off operation, which results in poor responsiveness to the loss of deceleration when the vehicle deceleration decreases, and this may cause the driver to feel uncomfortable.

[0005] The present invention has been made against the background of the above circumstances, and its purpose is to suppress gear shift shock while ensuring responsiveness in terms of deceleration loss when regenerative torque is reduced in accordance with changes in brake operation during downshifting during regenerative coasting. [Means for solving the problem]

[0006] In order to achieve this object, the first invention is a control device for a vehicle that (a) is provided on a vehicle in which an automatic transmission having a plurality of gear stages with different gear ratios is provided in a power transmission path between a rotating machine and drive wheels, and (b) has a coasting regenerative control unit that regeneratively controls the rotating machine so that a larger regenerative torque is generated when a brake operation is performed during coasting compared to when no brake operation is performed, (c) the control device is provided with a regenerative coast downshift control unit that performs regenerative torque down control to increase the regenerative torque of the rotating machine just before the end of the downshift when the automatic transmission is downshifted during regenerative coasting in which the rotating machine is regeneratively controlled by the coasting regenerative control unit during the coasting, and (d) the regenerative coast downshift control unit performs an increasing correction so that the amount of regenerative torque down during the regenerative torque down control is larger when the regenerative torque is reduced by the coasting regenerative control unit in conjunction with a change in the brake operation after the inertia phase of the downshift has started. The coasting state is a state in which the accelerator opening, which indicates the driver's required amount of acceleration or drive force, is zero and the vehicle coasts by inertia.

[0007] A second invention is characterized in that, in the vehicle control device of the first invention, (a) the coasting regenerative control unit regeneratively controls the rotating machine in accordance with the brake operation amount so that the regenerative torque increases as the brake operation amount increases, and (b) the regenerative coast downshift control unit increases the regenerative torque down amount in accordance with the amount of decrease in regenerative torque so that the regenerative torque down amount increases as the amount of decrease in regenerative torque due to the change in the brake operation amount after the inertia phase starts. The brake operation amount corresponds to the driver's required deceleration amount, that is, the required braking amount, and is, for example, the force with which the brake pedal is depressed.

[0008] A third invention is characterized in that, in the vehicle control device of the second invention, the regenerative coast downshift control unit calculates a correction amount for increasing the regenerative torque down amount based on an amount of decrease in the regenerative torque from the start of the inertia phase to the time when the regenerative torque down control is performed and an amount of decrease in the regenerative torque per unit time when the regenerative torque down control is performed.

[0009] A fourth invention is a control device for a vehicle of any of the first to third inventions, wherein (a) the automatic transmission has a plurality of gear stages formed according to the engagement and disengagement states of a plurality of hydraulic friction engagement devices, and (b) the regenerative coast downshift control unit reduces and corrects the engagement transient oil pressure of the hydraulic friction engagement devices that are engaged during the downshift when the regenerative torque is reduced by the coasting regenerative control unit after the start of the inertia phase so that the engagement transient oil pressure is lowered.

[0010] A fifth invention is characterized in that, in the vehicle control device of any of the first to fourth inventions, the regenerative coast downshift control unit determines whether the regenerative torque has been reduced by the coasting regenerative control unit based on an estimated value of the output side torque of the automatic transmission obtained by multiplying the regenerative torque controlled by the coasting regenerative control unit by the gear ratio of the automatic transmission. Effect of the Invention

[0011] In such a vehicle control device, when the automatic transmission is downshifted during regenerative coasting, regenerative torque down control is performed to increase the regenerative torque immediately before the end of the downshift, so that the change in the input rotation speed immediately before the input rotation speed increases and reaches the synchronous rotation speed after the shift is suppressed, and shift shock at the time of synchronization (at the end of the shift) is suppressed. On the other hand, when the regenerative torque is reduced by the coasting regenerative control unit in response to a change in the brake operation after the inertia phase of the downshift has started, the regenerative torque down amount during the regenerative torque down control is increased and corrected so that the shift shock caused by the reduction in the regenerative torque is suppressed. In addition, since there is no need to limit the control of the regenerative torque by the coasting regenerative control unit until the regenerative torque down control is started, the regenerative torque is quickly reduced in response to a change in the brake operation even during the downshift, and the same responsiveness in deceleration loss as during normal regenerative coasting other than during the shift is obtained.

[0012] The second invention is a case in which the rotating machine is regeneratively controlled in accordance with the brake operation amount so that the greater the brake operation amount, the greater the regenerative torque, and the regenerative torque down amount is increased in accordance with the amount of decrease in regenerative torque so that the greater the amount of decrease in regenerative torque after the start of the inertia phase, the greater the regenerative torque down amount.Since the regenerative torque and the regenerative torque down amount are finely controlled in accordance with changes in the brake operation amount, vehicle deceleration is appropriately controlled in accordance with the brake operation amount, and gear shift shock during downshifting is appropriately suppressed regardless of changes in the regenerative torque.

[0013] In the third invention, the correction amount for increasing the regenerative torque down amount is calculated based on the amount of decrease in regenerative torque from the start of the inertia phase and the amount of decrease in regenerative torque per unit time. This makes it possible to appropriately suppress gear shift shock during downshifts by taking into account long-term and short-term changes in the amount of brake operation during the inertia phase.

[0014] The fourth invention is directed to a case where an automatic transmission is provided in which a plurality of gear stages are formed according to the engagement and disengagement states of a plurality of hydraulic friction engagement devices, and when the regenerative torque is reduced by the coasting regenerative control unit after the start of the inertia phase of a downshift during regenerative coasting, the engagement transient oil pressure of the engaging hydraulic friction engagement device that raises the input rotational speed is reduced so as to be corrected lower. This, combined with the increasing correction of the regenerative torque down amount in the regenerative torque down control, makes it possible to more appropriately suppress the shift shock at the time of synchronization when the input rotational speed reaches the synchronous rotational speed after the shift.

[0015] In the fifth aspect of the present invention, whether or not the regenerative torque has been reduced is determined based on an estimated value of the output side torque of the automatic transmission. Therefore, regardless of various types of compensation controls of the input torque that are implemented to ensure smooth downshifting, the decreasing change in the regenerative torque can be appropriately determined and an increasing correction can be made to the regenerative torque down amount. [Brief description of the drawings]

[0016] [Figure 1] 1 is a schematic diagram illustrating a drive system of a vehicle having a control device according to an embodiment of the present invention, the diagram showing control functions for various controls and essential parts of the control system. [Diagram 2] 2 is a schematic diagram illustrating an example of an automatic transmission provided in the vehicle of FIG. 1. [Diagram 3] 3 is an engagement operation table illustrating the relationship between a plurality of gear stages of the automatic transmission in FIG. 2 and the engaged and released states of the hydraulic friction engagement devices. [Figure 4] 2 is a diagram illustrating an example of the relationship between a coasting regenerative torque control unit, which is functionally included in the electronic control device in FIG. 1, and a coasting regenerative torque control unit that controls a coasting regenerative torque in response to a brake operation amount. FIG. [Diagram 5] 2 is a diagram illustrating an example of the relationship between the regenerative coast downshift control unit, which is functionally included in the electronic control device in FIG. 1, and the regenerative torque down amount in response to vehicle deceleration. FIG. [Figure 6]11 is an example of a time chart illustrating changes in the operating state of each part when regenerative torque down control is performed by a regenerative coast downshift control unit without a change in the amount of brake operation during a downshift during regenerative coast driving. [Figure 7] 10 is a flowchart illustrating a process for correcting a regenerative torque down amount and an engagement transient hydraulic pressure when downshift control is performed by a regenerative coast downshift control unit. [Figure 8] FIG. 8 is a diagram illustrating an example of a map used when calculating a regenerative torque down correction amount α based on a decreasing change in propeller shaft regenerative torque in step S5 of FIG. 7. [Figure 9] FIG. 8 is a diagram illustrating an example of a map used when calculating an engagement transient hydraulic pressure correction amount β based on a decreasing change in the propeller shaft regenerative torque in step S5 of FIG. 7. [Figure 10] FIG. 8 is an example of a time chart illustrating changes in the operating state of each part when a correction process is performed by the regenerative coast downshift control unit according to the flowchart of FIG. 7 when there is a change in the amount of brake operation during downshifting during regenerative coast driving. [Figure 11] 8 is an example of a time chart illustrating changes in the operating state of each part when the brake operation amount changes and the correction process according to the flowchart of FIG. 7 is not performed during a downshift during regenerative coasting. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] The present invention is preferably applied to a hybrid electric vehicle having an engine (internal combustion engine) in addition to a rotary machine as a driving force source, but can also be applied to an electric vehicle having only a rotary machine as a driving force source for traveling. The hybrid electric vehicle may be one having an engine and a single rotary machine, or one having two or more rotary machines, and may be applied to various hybrid electric vehicles, such as one having an electric differential unit having a differential mechanism and a rotary machine for differential limiting. The rotary machine is a rotating electric machine that can be selectively used as an electric motor and a generator, and is a so-called motor generator. As the automatic transmission, for example, a planetary gear type stepped transmission in which multiple gear stages are formed according to the engagement and release states of multiple hydraulic friction engagement devices is preferably used, but a constant mesh type stepped transmission such as a parallel two-shaft type can also be used, and various embodiments are possible, such as one that changes speed by switching between a gear type transmission mechanism and a belt type transmission mechanism provided in parallel.

[0018] The coasting regenerative control unit that generates regenerative torque during coasting is configured to generate regenerative torque when the brake pedal is depressed and brake-on, and to generate a smaller regenerative torque when the brake pedal is not depressed and brake-off, but may also stop the regenerative torque when the brake is off. Also, when the brake is on, it is desirable to change the regenerative torque according to the amount of brake operation, but it may simply generate a constant regenerative torque regardless of the amount of brake operation.

[0019] The regenerative torque down control, which increases the regenerative torque immediately before the end of a downshift, may increase the regenerative torque by a constant amount that is predetermined for each type of downshift, for example, or may vary the regenerative torque down amount (the amount of increase in the regenerative torque) depending on vehicle conditions such as vehicle deceleration, brake operation amount, and the rate of change of the input rotation speed. This regenerative torque down amount is increased and corrected when the regenerative torque is reduced after the inertia phase starts, but the correction amount may be constant or may be changed depending on the amount of reduction in the regenerative torque, etc. For example, it is desirable to determine the correction amount based on both the amount of reduction in the regenerative torque from the start of the inertia phase until the regenerative torque down control is performed and the amount of reduction in the regenerative torque per unit time when the regenerative torque down control is performed, but the correction amount may be determined based only on the amount of reduction from the start of the inertia phase, or the correction amount may be determined using other parameters related to the reduction in the regenerative torque, and various other modes are possible. When the regenerative torque is increased with an increase in the brake operation after the inertia phase starts, the regenerative torque down amount does not necessarily have to be corrected, but it is also possible to correct the regenerative torque down amount by decreasing it. That is, the regenerative torque down amount may be increased or decreased according to the decrease or increase in the regenerative torque.

[0020] In the case of an automatic transmission in which a plurality of gear stages are formed according to the engagement and disengagement states of a plurality of hydraulic friction engagement devices, in addition to the above-mentioned correction for increasing the regenerative torque down amount, it is desirable to correct the engagement transient oil pressure of the hydraulic friction engagement device that is engaged during a downshift by reducing the pressure when the regenerative torque is reduced, but it is also possible to simply correct the regenerative torque down amount. When the regenerative torque is increased with an increase in the brake operation after the start of the inertia phase, it is not necessarily necessary to correct the engagement transient oil pressure of the engagement side hydraulic friction engagement device, but it is also possible to correct the engagement transient oil pressure by increasing the pressure. In other words, the engagement transient oil pressure of the engagement side hydraulic friction engagement device may be corrected by reducing or increasing the pressure in response to the decrease or increase in the regenerative torque.

[0021] Whether or not the regenerative torque of the rotating machine has been reduced by the coasting regenerative control unit can be determined based on that regenerative torque, but the regenerative torque input to the automatic transmission is subjected to various types of compensation control etc. so that the downshift proceeds appropriately, and may increase or decrease due to the compensation control etc. For this reason, it is desirable to determine whether or not the regenerative torque has been reduced by the coasting regenerative control unit based on an estimated value of the output side torque of the automatic transmission obtained by multiplying the regenerative torque by the gear ratio of the automatic transmission. EXAMPLES

[0022] 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 for the purpose of explanation, and the dimensional ratios and shapes of the various parts are not necessarily drawn accurately.

[0023] Fig. 1 is a schematic diagram of a drive system of a vehicle 10 to which the present invention is applied, showing control functions for various controls in the vehicle 10 and main parts of the control system. In Fig. 1, the vehicle 10 is a hybrid electric vehicle equipped with an engine 12 and a motor generator MG as a driving force source for traveling. The vehicle 10 also has a power transmission device 16 provided in a power transmission path between the engine 12 and the motor generator MG and drive wheels 14. The drive wheels 14 are, for example, the left and right rear wheels of the vehicle 10. The vehicle 10 is a four-wheeled vehicle equipped with left and right front wheels (not shown) in addition to the left and right rear wheels that are the drive wheels 14.

[0024] The engine 12 is a known internal combustion engine such as a gasoline engine, a diesel engine, etc. An electronic control device 90 controls an engine control device 50 including a throttle actuator, a fuel injection device, an ignition device, etc., provided in the vehicle 10, thereby controlling an engine torque Te, which is an output torque of the engine 12.

[0025] The motor generator MG corresponds to a rotating machine, and is a rotating electric machine having a function as an electric motor that generates mechanical power from electric power, and a function as a generator that generates electric power from mechanical power. The motor generator MG is connected to a battery 54 provided in the vehicle 10 via an inverter 52 provided in the vehicle 10. The inverter 52 of the motor generator MG is controlled by an electronic control device 90, whereby the MG torque Tmg, which is the output torque of the motor generator MG, is controlled. For example, when the rotation direction of the motor generator MG is a positive rotation that is the same as the rotation direction when the engine 12 is operating, the MG torque Tmg is a power running torque when it is a positive torque on the acceleration side, and is a regenerative torque (also called a power generation torque) when it is a negative torque on the deceleration side. Specifically, the motor generator MG generates power for traveling according to the MG torque Tmg, which is a power running torque, by being supplied with electric power from the battery 54 via the inverter 52 instead of or in addition to the engine 12. Furthermore, the motor generator MG is rotated and driven by the power of the engine 12 or the driven force input from the drive wheels 14 side, thereby generating electricity in accordance with the MG torque Tmg, which is a regenerative torque. When connected to the drive wheels 14, a braking force is applied to the vehicle 10 in accordance with the MG torque Tmg. The electric power generated by the motor generator MG is stored in the battery 54 via the inverter 52. The battery 54 is an electricity storage device that supplies and receives electric power to the motor generator MG. The electric power can be replaced with electric energy, and the motive power can be replaced with torque or force.

[0026] The power transmission device 16 includes a K0 clutch 20, a torque converter 22, and an automatic transmission 24 in series from the engine 12 side in a case 18 that is a non-rotating member attached to the vehicle body, and a motor generator MG is connected to a power transmission path between the K0 clutch 20 and the torque converter 22. The K0 clutch 20 is a clutch provided between the engine 12 and the motor generator MG in the power transmission path between the engine 12 and the driving wheels 14, and is an engine disconnecting device that connects and disconnects the motor generator MG and the engine 12. The K0 clutch 20 switches between control states such as an engaged state and a released state by changing a K0 torque Tk0 that is a torque capacity of the K0 clutch 20 by a regulated K0 oil pressure PRk0 supplied from a hydraulic control circuit 56 provided in the vehicle 10. The power transmission device 16 includes an engine connecting shaft 34 that connects the engine 12 and the K0 clutch 20, and an MG connecting shaft 36 that connects the K0 clutch 20 and the torque converter 22.

[0027] The motor generator MG is connected to the MG connecting shaft 36 in the case 18 so as to be capable of transmitting power. The motor generator 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 so as to be capable of transmitting power. In other words, the motor generator 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. In other words, the torque converter 22 and the automatic transmission 24 each constitute a part of the power transmission path between the motor generator MG and the drive wheels 14. The torque converter 22 and the automatic transmission 24 transmit the driving force from the driving force sources of the engine 12 and the motor generator MG to the drive wheels 14, respectively.

[0028] The torque converter 22 is a fluid-type power transmission device provided between the motor generator MG and the automatic transmission 24, and is connected to the engine 12 via the K0 clutch 20. The torque converter 22 includes a pump wheel 22a connected to the MG 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 pump wheel 22a is connected to the engine 12 via the K0 clutch 20, and is also directly connected to the motor generator MG. The pump wheel 22a is an input member of the torque converter 22, and the turbine wheel 22b is an output member of the torque converter 22. The MG connecting shaft 36 is also an input rotating member of the torque converter 22. The transmission input shaft 38 is also an output rotating member of the torque converter 22 that is formed integrally with a turbine shaft that is rotationally driven by the turbine wheel 22b. The torque converter 22 is a fluid type power transmission that transmits driving force from each of the engine 12 and the motor generator MG, which are driving force sources, to the transmission input shaft 38 via fluid. The torque converter 22 is equipped with an LU clutch 40 that connects the pump wheel 22a and the turbine wheel 22b. The LU clutch 40 is a direct clutch that connects input and output rotating members of the torque converter 22, that is, a well-known lock-up clutch.

[0029] The LU clutch 40 switches between operating states, i.e., control states, by changing the LU clutch torque Tlu, which is the torque capacity of the LU clutch 40, with the regulated LU oil pressure PRlu supplied from the hydraulic control circuit 56. The control states of the LU clutch 40 include a fully released state in which the LU clutch 40 is released, a slip state in which the LU clutch 40 is engaged with slipping, and a fully engaged state in which the LU clutch 40 is engaged. When the LU clutch 40 is in the fully released state, the torque converter 22 is in a torque converter state in which a torque amplification effect is obtained. When the LU clutch 40 is in the fully engaged state, the torque converter 22 is in a lock-up state in which the pump wheel 22a and the turbine wheel 22b are rotated together.

[0030] The automatic transmission 24 is connected to the torque converter 22, and is disposed in a power transmission path between the torque converter 22 and the drive wheels 14. The power transmission device 16 includes a propeller shaft 28 connected to a transmission output shaft 26 which is an output rotating member of the automatic transmission 24, a differential gear 30 connected to the propeller shaft 28, a pair of drive shafts 32 connected to the differential gear 30, and the like.

[0031] Fig. 2 is a schematic diagram specifically illustrating an example of an automatic transmission 24. This automatic transmission 24 is a planetary gear type stepped transmission, and is configured approximately symmetrically with respect to the axis, so the lower half is omitted in the schematic diagram of Fig. 2. The automatic transmission 24 shown in Fig. 2 includes a first transmission section 43 mainly composed of a double pinion type first planetary gear device 42, and a second transmission section 47 mainly composed of a single pinion type second planetary gear device 44 and a double pinion type third planetary gear device 46, which are located on a common axis, and changes the speed of the rotation of the transmission input shaft 38 and outputs it from the transmission output shaft 26. The second planetary gear set 44 and the third planetary gear set 46 have their carriers and ring gears constructed from common parts, and are configured as a Ravigneaux type planetary gear train in which the pinion gear of the second planetary gear set 44 also serves as the second pinion gear (outer pinion gear) of the third planetary gear set 46.

[0032] The automatic transmission 24 in FIG. 2 is equipped with four clutches C1 to C4 and two brakes B1 and B2 (hereinafter, simply referred to as engagement devices CB) as hydraulic friction engagement devices. As shown in the engagement operation table in FIG. 3, this automatic transmission 24 establishes eight forward gears from a first gear "1st" to an eighth gear "8th" and two reverse gears from a first reverse gear "Rev1" and a second reverse gear "Rev2" by engaging any two of the engagement devices CB, and enters N (neutral) in which power transmission is interrupted by disengaging all of the engagement devices CB. The first gear "1st" is the low gear with the largest gear ratio γ (=AT input rotation speed Ni / AT output rotation speed No), and the eighth gear "8th" is the high gear with the smallest gear ratio γ. That is, the first gear "1st" side is the low gear side, and the eighth gear "8th" side is the high gear side. As is clear from FIG. 3, when the automatic transmission 24 of this embodiment shifts between consecutive forward gears, such as between the second gear "2nd" and the third gear "3rd", a clutch-to-clutch shift is performed in which one of the engagement devices CB is released and the other engagement device CB is engaged. The engagement device CB is, for example, a wet-type multi-plate type in which a plurality of overlapping friction plates are pressed by a hydraulic actuator, or a band brake in which one end of one or two bands wrapped around the outer circumferential surface of a rotating drum is tightened by a hydraulic actuator, and is a device for selectively connecting members on both sides between which it is inserted. The engagement devices CB are each switched between a control state such as an engaged state or a released state by changing the CB torque Tcb, which is the torque capacity of each of the engagement devices CB, by the CB hydraulic pressure PRcb adjusted by the hydraulic control circuit 56.

[0033] The automatic transmission 24 has its gear shifted by the electronic control device 90 in response to the accelerator operation by the driver, the vehicle speed V, etc., i.e., one of a plurality of gears is selectively formed. 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 also the rotation speed of the output rotating member of the torque converter 22, and is equal to the turbine rotation speed Nt, which is the output rotation speed of the torque converter 22. 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. The AT output rotation speed No corresponds to the vehicle speed V.

[0034] In the power transmission device 16, when the K0 clutch 20 is engaged, the power output from the engine 12 is transmitted from the engine connecting shaft 34 to the drive wheels 14 via the K0 clutch 20, MG connecting shaft 36, torque converter 22, automatic transmission 24, propeller shaft 28, differential gear 30, drive shaft 32, etc. in this order. Moreover, the power output from the motor generator MG is transmitted from the MG connecting shaft 36 to the drive wheels 14 via the torque converter 22, automatic transmission 24, propeller shaft 28, differential gear 30, drive shaft 32, etc. in this order, regardless of the control state of the K0 clutch 20.

[0035] 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 and driven by a driving force source (the engine 12, the motor generator MG) 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 and driving the EOP 60. The EOP 60 is rotated and driven 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 CB hydraulic pressure PRcb, the K0 hydraulic pressure PRk0, the LU hydraulic pressure PRlu, and the like, which are adjusted based on the hydraulic oil OIL discharged by the MOP 58 and / or the EOP 60, to the engagement devices CB, the K0 clutch 20, the LU clutch 40, and the like.

[0036] The vehicle 10 is equipped with an electronic control device 90. The electronic control device 90 is configured to include a so-called microcomputer equipped with, for example, a CPU, RAM, ROM, an input / output interface, etc., and the CPU executes various controls of the vehicle 10 by performing signal processing according to a program previously stored in the ROM while utilizing the temporary storage function of the RAM. In other words, the electronic control device 90 is a control device that executes various controls of the vehicle 10. The electronic control device 90 is configured to include computers for engine control, MG control, hydraulic control, etc. as necessary.

[0037] 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, an air flow meter 82, a brake operation amount sensor 84, a battery sensor 86, an oil temperature 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 corresponding to the vehicle speed V, an MG rotation speed Nmg which is the rotation speed of the motor generator MG, an accelerator opening θacc which is an accelerator operation amount (for example, an accelerator pedal depression operation amount) which represents the magnitude of an acceleration request by the driver, a throttle valve opening θth which is the opening of the electronic throttle valve, an intake air amount Qair of the engine 12, a brake operation amount Bon which is a depression operation force of a brake pedal 85 which represents the magnitude of a deceleration request by the driver, a battery temperature THbat of the battery 54 and a battery charge / discharge current Ibat The hydraulic control circuit 56 is supplied with signals representing various parameters, such as a signal representing the hydraulic pressure, a battery voltage Vbat, and a hydraulic oil temperature THoil, which is the temperature of the hydraulic oil OIL in the hydraulic control circuit 56. The MG rotation speed Nmg corresponds to the input rotation speed of the torque converter 22, which is a fluid type power transmission, and the turbine rotation speed Nt corresponds to the output rotation speed of the torque converter 22, which is also a fluid type power transmission. The accelerator opening θacc corresponds to the amount of acceleration required by the driver, and the brake operation amount Bon corresponds to the amount of deceleration required by the driver.

[0038] 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 motor generator 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. The electronic control device 90 also outputs a brake control command signal Sb for controlling the braking force of the wheel brakes to the wheel brakes provided on all the wheels including the drive wheels 14. This brake control command signal Sb is mainly controlled based on the brake operation amount Bon. In addition, a wheel brake device may be provided that is mechanically connected to the brake pedal 85 and whose braking force is mechanically changed according to the brake operation amount Bon.

[0039] In order to realize various controls in the vehicle 10, the electronic control unit 90 includes a hybrid control means, i.e., a hybrid control unit 92, a shift control means, i.e., a shift control unit 94, and a coasting regenerative control means, i.e., a coasting regenerative control unit 96.

[0040] The hybrid control unit 92 functionally includes an engine control unit 92a that controls the operation of the engine 12, and an MG control unit 92b that controls the operation of the motor generator MG via the inverter 52, and executes hybrid drive control by the engine 12 and the motor generator MG by using these control functions. The hybrid control unit 92 calculates the drive demand amount for the vehicle 10 by the driver, for example, by applying the accelerator opening θacc and the vehicle speed V to a drive demand amount map. The drive demand amount map is a relationship that is experimentally or design-wise obtained and stored in advance, that is, a predetermined relationship. The drive demand amount is, for example, a required drive torque Trdem at the drive wheels 14. In other words, the required drive torque Trdem [Nm] is a required drive power Prdem [W] at the vehicle speed V at that time. The drive demand amount can also be a required drive force Frdem [N] at the drive wheels 14, a required AT output torque at the transmission output shaft 26, or the like. In calculating the drive demand amount, an AT output rotation speed No or the like can be used instead of the vehicle speed V.

[0041] The hybrid control unit 92 obtains a required input torque Tindem, which is an input torque of the torque converter 22 required to realize the required driving power Prdem, for example, and outputs an engine control command signal Se for controlling the engine 12 and an MG control command signal Sm for controlling the motor generator MG so that the required input torque Tindem can be obtained. When the required input torque Tindem can be satisfied only by the output of the motor generator MG, the hybrid control unit 92 sets the traveling mode to a BEV (Battery Electric Vehicle) traveling mode. In the BEV traveling mode, the vehicle travels in a BEV mode using only the motor generator MG as a driving force source with the K0 clutch 20 in a disengaged state. When the required input torque Tindem cannot be satisfied without using at least the output of the engine 12, the hybrid control unit 92 sets the traveling mode to an engine traveling mode, i.e., an HEV (Hybrid Electric Vehicle) traveling mode. In the HEV traveling mode, the vehicle travels in an engine mode using at least the engine 12 as a driving force source with the K0 clutch 20 in an engaged state, i.e., an HEV mode. The hybrid control unit 92 switches between the BEV driving mode and the HEV driving mode by automatically stopping the engine 12 during HEV driving, restarting the engine 12 after the engine has been stopped, starting the engine 12 during BEV driving, automatically stopping the engine 12 while the vehicle is stopped, or starting the engine 12, based on the required input torque Tindem and the like.

[0042] The shift control unit 94 judges whether or not to shift the automatic transmission 24 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 shift condition, and is, for example, a predetermined relationship having a shift line for judging whether or not to shift the automatic transmission 24 on a two-dimensional coordinate system having the vehicle speed V and the required driving torque Trdem as variables. In the shift map, the AT output rotation speed No or the like 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 coasting regeneration control unit 96 executes coasting regeneration control for controlling the MG torque Tmg so that the motor generator MG generates a regenerative torque during coasting in which the accelerator opening θacc is 0 and the vehicle 10 is coasting forward by inertia. Hereinafter, the MG torque Tmg at this time is referred to as coasting MG regenerative torque Tmgc. The coasting regeneration control unit 96 outputs an MG control command signal Sm for generating the coasting MG regenerative torque Tmgc, specifically, a command value of the generated electric power Wg of the motor generator MG, to the inverter 52. This coasting MG regenerative torque Tmgc is transmitted to the drive wheels 14 via the automatic transmission 24, so that a braking force according to the coasting MG regenerative torque Tmgc is applied to the vehicle 10, and the battery 54 is charged by the generated electric power Wg obtained. During coasting, the engine 12 is cut off from fuel and stopped, and the K0 clutch 20 is released and stopped from rotating. In other words, a braking force equivalent to or greater than the engine brake can be generated by the regenerative control of the motor generator MG. Note that it is also possible to perform the regenerative control during coasting while rotating the engine 12 with the K0 clutch 20 connected.

[0044] The coasting MG regenerative torque Tmgc is calculated according to a predetermined map or calculation formula so that the larger the brake operation amount Bon is, the larger the coasting MG regenerative torque Tmgc is, and is changed successively according to the change in the brake operation amount Bon. FIG. 4 shows an example of the coasting MG regenerative torque Tmgc set according to the brake operation amount Bon, and the coasting MG regenerative torque Tmgc is continuously increased as the brake operation amount Bon increases. Although the coasting MG regenerative torque Tmgc increases linearly in FIG. 4, it may be increased nonlinearly or in stages. In this embodiment, even when the brake operation amount Bon=0, that is, when the brake operation is not performed, regenerative control is performed with a predetermined coasting MG regenerative torque Tmgc smaller than that during the brake operation. However, when the brake operation amount Bon=0, the coasting MG regenerative torque Tmgc=0 may be set so that the coasting regenerative control is not performed. The braking force due to the coasting MG regenerative torque Tmgc is transmitted to the drive wheels 14 via the automatic transmission 24, and since the braking force varies depending on the gear stage of the automatic transmission 24, a map or an arithmetic formula for calculating the coasting MG regenerative torque Tmgc is determined for each gear stage of the automatic transmission 24.

[0045] On the other hand, during regenerative coasting in which the motor generator MG is regeneratively controlled by the coasting regenerative control unit 96, for example, when the automatic transmission 24 is automatically downshifted as the vehicle speed V decreases, the braking force applied to the vehicle 10 by the coasting MG regenerative torque Tmgc changes (increases in this case) due to the change in gear stage caused by the downshift, i.e., the change in the gear ratio γ (increase in this case). The gear shift control unit 94 is functionally provided with a regenerative coast downshift control unit 94a that executes the downshift during this regenerative coasting. In order to suppress the change in braking force when downshifting during regenerative coasting, the regenerative coast downshift control unit 94a reduces (changes closer to 0) the coasting MG regenerative torque Tmgc during the downshift process in consideration of the change in the gear ratio γ so that, for example, the propeller shaft regenerative torque Tprg transmitted to the propeller shaft 28 is maintained substantially constant. This decrease in the coasting MG regenerative torque Tmgc can be performed via the coasting regenerative control unit 96, but the regenerative coast downshift control unit 94a may also control the coasting MG regenerative torque Tmgc in priority to the regenerative control by the coasting regenerative control unit 96.

[0046] FIG. 6 is an example of a time chart explaining the change in the operating state of each part during downshift during the regenerative coasting. The release side hydraulic command value PRdra and the engagement side hydraulic command value PRapp are the hydraulic command value of the release side engagement device CBdra that is released during the clutch-to-clutch shift during the downshift, and the hydraulic command value of the engagement side engagement device CBapp that is engaged. Time t1 in FIG. 6 is the time when the downshift shift command is output, and the CB hydraulic control command signal Sbc for performing the clutch-to-clutch shift is output, and the release side hydraulic command value PRdra and the engagement side hydraulic command value PRapp are each changed according to a predetermined change pattern. Time t2 is the start time of the torque phase, and time t3 is the start time of the inertia phase. The coasting MG regenerative torque Tmgc is decreased and changed so that the propeller shaft regenerative torque Tprg is maintained approximately constant regardless of the change in the gear ratio γ due to the downshift between time t2 and time t3 corresponding to the torque phase. The propeller shaft regenerative torque Tprg is a calculated value calculated based on the brake operation amount Bon, similar to the coasting MG regenerative torque Tmgc, and corresponds to the coasting MG regenerative torque Tmgc, but is maintained constant regardless of a downshift if there is no change in the brake operation amount Bon. In other words, the propeller shaft regenerative torque Tprg is an estimated value of the output side torque of the automatic transmission 24 calculated by multiplying the coasting MG regenerative torque Tmgc by the gear ratio γ, and the coasting MG regenerative torque Tmgc is decreased in accordance with changes in the gear ratio γ so that the propeller shaft regenerative torque Tprg is maintained constant regardless of a downshift.

[0047] In Figure 6, after time t3, which is after the start of the inertia phase, if there is no change in the brake operation amount Bon, the propeller shaft regenerative torque Tprg is maintained constant, and the coasting MG regenerative torque Tmgc is also basically maintained constant as shown by the dashed line. In this case, when the engagement torque of the engagement-side engagement device CBapp causes the AT input rotation speed Ni to rise away from the synchronous rotation speed before shifting, the propeller shaft regenerative torque Tprg increases due to inertia, so in order to suppress this, inertia phase compensation control is performed to reduce the coasting MG regenerative torque Tmgc (bring it closer to 0). This suppresses the increase in the propeller shaft regenerative torque Tprg caused by inertia when the AT input rotation speed Ni rises, that is, the change that temporarily increases the vehicle deceleration.

[0048] The regenerative coast downshift control unit 94a also performs regenerative torque down control to increase the coasting MG regenerative torque Tmgc immediately before the synchronization, because there is a risk that the engaging side engagement device CBapp will suddenly engage when the AT input rotation speed Ni increases to reach the synchronous rotation speed after the shift, causing a shift shock. This regenerative torque down control increases the coasting MG regenerative torque Tmgc by a predetermined regenerative torque down amount TDmgc from a reference value shown by a broken line in FIG. 6 when the differential rotation ΔNi between the synchronous rotation speed after the shift and the AT input rotation speed Ni becomes equal to or less than a predetermined judgment value Nis. The judgment value Nis may be a fixed value determined according to the type of shift, or may be variably set according to the rate of change of the AT input rotation speed Ni. Various modes are possible, such as calculating the remaining time until the AT input rotation speed Ni reaches the synchronous rotation speed after the shift, and performing the regenerative torque down control when the remaining time becomes equal to or less than the judgment value. The regenerative torque reduction amount TDmgc is calculated according to a map or a calculation formula that is predetermined for each type of downshift, so that the regenerative torque reduction amount TDmgc increases as the vehicle deceleration (absolute value of dV / dt) increases. FIG. 5 shows an example of the regenerative torque reduction amount TDmgc that is set according to the vehicle deceleration, and the regenerative torque reduction amount TDmgc is continuously increased as the vehicle deceleration increases. Although the regenerative torque reduction amount TDmgc increases linearly in FIG. 5, it may increase nonlinearly or in stages. The regenerative torque reduction amount TDmgc may be determined based on other vehicle conditions such as the rate of change of the AT input rotation speed Ni, or a fixed value may be determined according to the type of shift, and various other aspects are possible.

[0049] When the coasting MG regenerative torque Tmgc is increased just before synchronization in this way, the rotational resistance of the AT input rotation speed Ni becomes large, so that the AT input rotation speed Ni gradually approaches the synchronous rotation speed after the shift, and the shock at the end of the shift (synchronization) when the engagement side engagement device CBapp is fully engaged is suppressed. Time t4 in Figure 6 is the time when the differential rotation ΔNi becomes equal to or less than the judgment value Nis and the regenerative torque down control is started, and time t5 is the time when the shift is completed when the AT input rotation speed Ni reaches the synchronous rotation speed after the shift and the engagement side engagement device CBapp is engaged.

[0050] Here, during the shift transition of the downshift, specifically in the inertia phase in which the AT input rotation speed Ni moves away from the synchronous rotation speed before the shift and toward the synchronous rotation speed after the shift, if the brake pedal 85 is released and the brake operation amount Bon decreases, the coasting MG regenerative torque Tmgc decreases with the decrease in the brake operation amount Bon. The time chart of FIG. 11 shows a case in which the brake pedal 85 is released at time t4 during the inertia phase in this way, and the coasting MG regenerative torque Tmgc decreases with the decrease in the brake operation amount Bon. When the coasting MG regenerative torque Tmgc is reduced in this way, the rotational resistance of the AT input rotation speed Ni decreases and the rate at which the AT input rotation speed Ni increases increases, so that regardless of the regenerative torque down control performed immediately before synchronization, the engaging-side engagement device CBapp may suddenly engage, causing a shift shock. To prevent this, if the change in coasting MG regenerative torque Tmgc is suppressed as in Patent Document 1, specifically, if the slope of the reference value of coasting MG regenerative torque Tmgc is made gentle as shown by the dashed line in Fig. 11, the slope of the propeller shaft regenerative torque Tprg will also become gentle as shown by the dashed line, resulting in poor responsiveness in the deceleration drop-out where the vehicle deceleration decreases, and the vehicle deceleration will not change regardless of the release operation of the brake pedal 85, which may cause the driver to feel uncomfortable. Times t5 and t6 in Fig. 11 correspond to times t4 and t5 in Fig. 6, respectively.

[0051] In contrast, the regenerative coast downshift control unit 94a of this embodiment executes signal processing in accordance with the flowchart shown in FIG. 7 without performing the gradual change processing (smoothing processing) as described in Patent Document 1, even when the coasting MG regenerative torque Tmgc is reduced by the coasting regenerative control unit 96 after the inertia phase of the downshift has started.

[0052] In step S1 of Fig. 7, it is determined whether or not the vehicle is in regenerative coasting, in which the coasting MG regenerative torque Tmgc is controlled by the coasting regenerative control unit 96 in response to the brake operation amount Bon. If the vehicle is not in regenerative coasting, the process ends as is, and if the vehicle is in regenerative coasting, step S2 is executed. In step S2, it is determined whether or not the vehicle is in downshift control, and if the vehicle is in downshift control, the process ends as is, and if the vehicle is in downshift control, step S3 is executed. In step S3, it is determined whether or not the inertia phase has started, and if the inertia phase has started, the process ends as is, and if the inertia phase has started, step S4 is executed. Whether or not the inertia phase has started can be determined by whether or not the AT input rotation speed Ni has deviated from the synchronous rotation speed before shifting and started to rise.

[0053] In step S4, it is determined whether the coasting MG regenerative torque Tmgc has been reduced by the coasting regenerative control unit 96 after the inertia phase has started. Since the coasting MG regenerative torque Tmgc can also be changed by the inertia phase compensation control, in this embodiment, it is determined whether the propeller shaft regenerative torque Tprg, which is not affected by the inertia phase compensation control, has been reduced. If the propeller shaft regenerative torque Tprg has been reduced, step S5 is executed to calculate the regenerative torque down correction amount α and the engagement transient hydraulic pressure correction amount β. The regenerative torque down correction amount α is an amount for increasing and correcting the regenerative torque down amount TDmgc in the regenerative torque down control, and in this embodiment, it is calculated according to a map or an arithmetic expression, etc., that are predetermined for each type of downshift, using the amount of reduction in the propeller shaft regenerative torque ΔTprg from the start of the inertia phase and the amount of reduction in the propeller shaft regenerative torque per unit time at the current time (dTprg / dt) as parameters, as shown in FIG. 8, for example. In FIG. 8, the larger the decrease amount ΔTprg, the larger the correction amount α, and the larger the decrease amount (dTprg / dt), the larger the correction amount α. The engagement transient hydraulic pressure correction amount β is an amount for reducing and correcting the hydraulic pressure command value PRapp of the engagement side engagement device CBapp, and in this embodiment, as shown in FIG. 9, for example, the amount of decrease in the propeller shaft regenerative torque from the start of the inertia phase ΔTprg and the amount of decrease in the propeller shaft regenerative torque per unit time at the current time (dTprg / dt) are used as parameters, and are calculated according to a map, an arithmetic expression, or the like, that is predetermined for each type of downshift. In FIG. 9, the larger the decrease amount ΔTprg, the larger the correction amount β, and the larger the decrease amount (dTprg / dt), the larger the correction amount β. The unit time of the decrease amount (dTprg / dt) is, for example, 16 ms, such as the control cycle time of the electronic control device 90.

[0054] Here, the decrease amount ΔTprg and the decrease amount (dTprg / dt) of the propeller shaft regenerative torque are both in the direction in which the propeller shaft regenerative torque Tprg approaches 0, i.e., toward the upper side in the time charts of Figures 10 and 11, and the magnitude of this change represents the magnitude of the decrease amount ΔTprg and the decrease amount (dTprg / dt). Also, the decrease amount ΔTprg and the decrease amount (dTprg / dt) of the propeller shaft regenerative torque correspond to the decrease amount ΔTmgc and the decrease amount (dTmgc / dt) of the coasting MG regenerative torque Tmgc that accompanies a decrease in the brake operation amount Bon, and specifically, are values ​​obtained by multiplying these decrease amounts ΔTmgc, (dTmgc / dt) by the gear ratio γ of the automatic transmission 24.

[0055] In the next step S6, the regenerative torque down amount TDmgc is increased by a correction amount α, and the on-coming hydraulic command value PRapp is decreased by a correction amount β. In this case, the correction of the regenerative torque down amount TDmgc is performed when the regenerative torque down control is started immediately before the synchronization when the differential rotation speed ΔNi becomes equal to or smaller than the judgment value Nis. In other words, the calculation of the regenerative torque down correction amount α in step S5 may be performed after the regenerative torque down control is started. On the other hand, the correction of the on-coming hydraulic command value PRapp is performed immediately when the propeller shaft regenerative torque Tprg is decreased in the inertia phase. Fig. 10 is a time chart corresponding to Fig. 11, and after time t4 when the propeller shaft regenerative torque Tprg and the coasting MG regenerative torque Tmgc are changed and decreased in accordance with the decrease in the brake operation amount Bon, the on-coming hydraulic command value PRapp is reduced and corrected by the correction amount β, so that sudden engagement of the on-coming engagement device CBapp is suppressed regardless of the decrease in the coasting MG regenerative torque Tmgc. The dashed dotted line in the on-coming hydraulic command value PRapp column in Fig. 10 is the standard value before correction, which is the case when there is no change in the brake operation amount Bon, and is maintained approximately constant in the inertia phase, but various embodiments are possible, such as increasing at a predetermined gradient or feedback control, and it is sufficient to reduce the standard value by the correction amount β. In addition, when regenerative torque down control is initiated at time t5 when the differential rotation ΔNi becomes equal to or less than the judgment value Nis, the regenerative torque down amount TDmgc is increased by the correction amount α, so that regardless of the decrease in coasting MG regenerative torque Tmgc accompanying the decrease in brake operation amount Bon, regenerative torque down control is appropriately performed to suppress the increase in AT input rotation speed Ni immediately before synchronization and suppress sudden engagement of the engaging side engagement device CBapp, thereby suppressing gear shift shock caused by sudden engagement of the engaging side engagement device CBapp.

[0056] If the determination in step S4 is NO (negative), that is, if the propeller shaft regenerative torque Tprg has not decreased, but has not changed or has increased, step S7 is executed. In step S7, the correction amount α of the regenerative torque down amount TDmgc and the correction amount β of the on-coming hydraulic command value PRapp are maintained at their current values ​​without being changed. That is, if the brake operation amount Bon decreases during a downshift, the propeller shaft regenerative torque Tprg and the coasting MG regenerative torque Tmgc are decreased according to the amount of decrease, and the regenerative torque down amount TDmgc and the on-coming hydraulic command value PRapp are corrected to suppress a shift shock. However, even if the brake operation amount Bon increases and the propeller shaft regenerative torque Tprg and the coasting MG regenerative torque Tmgc are increased, the regenerative torque down amount TDmgc and the on-coming hydraulic command value PRapp are not corrected.

[0057] In this manner, in the electronic control device 90 of the vehicle 10 of this embodiment, when the automatic transmission 24 is downshifted during regenerative coasting, regenerative torque down control is performed to increase the regenerative torque immediately before the end of the downshift, so that the change in the AT input rotation speed Ni immediately before the AT input rotation speed Ni rises and reaches the synchronous rotation speed after the shift is suppressed, and shift shock at the time of synchronization (at the end of the shift) is suppressed. On the other hand, after the inertia phase of the downshift begins, the coasting MG regenerative torque Tmgc is reduced by the coasting regenerative control unit 96 in accordance with the decreasing change in the brake operation amount Bon, and the propeller shaft regenerative torque Tprg is reduced accordingly, so that the regenerative torque down amount TDmgc during the regenerative torque down control is increased and corrected to be larger, thereby suppressing shift shock caused by the reduction in the coasting MG regenerative torque Tmgc. Furthermore, since there is no need to limit the control of the coasting MG regenerative torque Tmgc by the coasting regenerative control unit 96 until the regenerative torque down control begins, the coasting MG regenerative torque Tmgc is quickly reduced in accordance with the decreasing change in the brake operation amount Bon even during a downshift, and the same responsiveness in deceleration loss as during normal regenerative coasting other than when changing gears can be obtained, and there is no risk of the driver feeling uncomfortable.

[0058] As is clear from Fig. 4, the motor generator MG is regeneratively controlled in response to the brake operation amount Bon so that the coasting MG regenerative torque Tmgc increases as the brake operation amount Bon increases, and the regenerative torque down amount TDmgc is increased and corrected in response to the decrease in the propeller shaft regenerative torque Tprg so that the regenerative torque down amount TDmgc increases as the decrease in the coasting MG regenerative torque Tmgc after the inertia phase starts, i.e., the decrease in the propeller shaft regenerative torque ΔTmgc and the decrease per unit time (dTprg / dt) increase, as shown in Fig. 8. In other words, since the coasting MG regenerative torque Tmgc and the regenerative torque down amount TDmgc are precisely controlled in response to changes in the brake operation amount Bon, the vehicle deceleration is appropriately controlled in response to the brake operation amount Bon, and the shift shock during downshifting is appropriately suppressed regardless of the decrease in the coasting MG regenerative torque Tmgc.

[0059] In addition, the correction amount α for increasing the regenerative torque down amount TDmgc is calculated based on the amount of decrease ΔTmgc in the propeller shaft regenerative torque from the start of the inertia phase and the amount of decrease per unit time (dTprg / dt) of the propeller shaft regenerative torque Tprg, so that gear shift shock during downshifting can be appropriately suppressed by taking into account the long-term and short-term changes in the brake operation amount Bon during the inertia phase.

[0060] In addition, when the coasting MG regenerative torque Tmgc is reduced by the coasting regenerative control unit 96 after the start of the inertia phase of a downshift during regenerative coasting, and the propeller shaft regenerative torque Tprg is reduced accordingly, the engagement side oil pressure command value PRapp is reduced so that the engagement transient oil pressure of the engagement side engagement device CBapp that raises the AT input rotation speed Ni is lowered. This, combined with the increasing correction of the regenerative torque down amount TDmgc in the regenerative torque down control, makes it possible to more appropriately suppress the shift shock at the time of synchronization when the AT input rotation speed Ni reaches the synchronous rotation speed after the shift.

[0061] In addition, since it is determined whether the coasting MG regenerative torque Tmgc has been reduced based on the propeller shaft regenerative torque Tprg, which is an estimated value of the output side torque of the automatic transmission 24, regardless of inertia phase compensation control that reduces the coasting MG regenerative torque Tmgc in the inertia phase so that downshifts are performed smoothly, it is possible to appropriately determine the decreasing change in the coasting MG regenerative torque Tmgc that accompanies the decreasing change in the brake operation amount Bon, and perform an increasing correction of the regenerative torque down amount TDmgc or a reducing correction of the engagement transient hydraulic pressure of the engaging side engagement device CBapp.

[0062] Although the embodiment of the present invention has been described in detail above with reference to the drawings, this is merely one embodiment, and the present invention can be implemented in various forms with various modifications and improvements based on the knowledge of those skilled in the art. [Explanation of symbols]

[0063] 10: vehicle 14: drive wheels 24: automatic transmission 84: brake operation amount sensor 90: electronic control device (vehicle control device) 94a: regenerative coast downshift control unit 96: regenerative control unit during coasting MG: motor generator (rotating machine) C1 to C4: clutch (hydraulic friction engagement device) B1, B2: brake (hydraulic friction engagement device) Bon: brake operation amount Ni: AT input rotation speed (input rotation speed) Tmgc: MG regenerative torque during coasting (regenerative torque) TDmgc: regenerative torque down amount Tprg: propeller shaft regenerative torque (estimated value of output side torque) ΔTprg: decrease amount from start of inertia phase dTprg / dt: decrease amount per unit time PRapp: engagement side hydraulic pressure command value (engagement transient hydraulic pressure) α: regenerative torque down correction amount β: engagement transient hydraulic pressure correction amount

Claims

1. The vehicle is provided with an automatic transmission having a plurality of gears with different gear ratios in a power transmission path between a rotary machine and drive wheels, A control device for a vehicle having a coasting regenerative control unit that controls the rotating machine to generate a larger regenerative torque when a brake operation is performed during coasting compared to when a brake operation is not performed, The control device includes a regenerative coast downshift control unit that, when downshifting the automatic transmission during regenerative coasting in which the rotating machine is regeneratively controlled by the coast regenerative control unit during the coasting, performs regenerative torque down control to increase the regenerative torque of the rotating machine immediately before the end of the downshift, and The regenerative coast downshift control unit, when the regenerative torque is reduced by the coasting regenerative control unit in accordance with a change in the brake operation after the inertia phase of the downshift has started, performs an increasing correction so that the regenerative torque down amount during the regenerative torque down control becomes large. A vehicle control device comprising:

2. The coasting regenerative control unit controls the rotating machine in a regenerative manner in response to an amount of braking operation so that the regenerative torque increases as the amount of braking operation increases, The regenerative coast downshift control unit increases and corrects the regenerative torque down amount in accordance with an amount of decrease in the regenerative torque such that the regenerative torque down amount increases as an amount of decrease in the regenerative torque associated with a change in the amount of brake operation after the inertia phase starts increases.

2. The vehicle control device according to claim 1.

3. The regenerative coast downshift control unit calculates a correction amount for increasing and correcting the regenerative torque down amount based on an amount of decrease in the regenerative torque from the start of the inertia phase until the regenerative torque down control is performed and an amount of decrease in the regenerative torque per unit time when the regenerative torque down control is performed.

3. The vehicle control device according to claim 2.

4. The automatic transmission forms the plurality of gear stages according to the engagement and disengagement states of a plurality of hydraulic friction engagement devices, The regenerative coast downshift control unit performs a pressure reduction correction for the engagement transient hydraulic pressure of the hydraulic friction engagement device that is engaged during the downshift, so that the engagement transient hydraulic pressure is lowered when the regenerative torque is reduced by the coasting regenerative control unit after the inertia phase starts.

4. The vehicle control device according to claim 1, wherein the vehicle control device is a vehicle control device.

5. The regenerative coast downshift control unit determines whether the regenerative torque has been reduced by the coasting regenerative control unit based on an estimated value of an output side torque of the automatic transmission obtained by multiplying the regenerative torque controlled by the coasting regenerative control unit by a gear ratio of the automatic transmission.

5. The vehicle control device according to claim 1, wherein the vehicle control device is a vehicle control device.

Images