JP7615928B2 - Vehicle control device - Google Patents

Description

The present invention relates to a vehicle control device, and in particular to a vehicle control device that generates regenerative torque by controlling a rotating machine during coasting.

(a) A vehicle control device is provided in 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 a drive wheel, and (b) a coasting regenerative control unit that regeneratively controls the rotating machine so that a larger regenerative torque is generated when the brakes are applied during coasting compared to when the brakes are not applied. The vehicle described in Patent Document 1 is one example, and the regenerative torque is switched depending on whether the brakes are applied (on or off). Patent Document 1 also describes that when the automatic transmission is downshifted during regenerative coasting in which the rotating machine is regeneratively controlled by the coasting regenerative control unit during coasting, if the regenerative torque is reduced with a brake-off operation after the inertia phase of the downshift has started, there is a risk of a shift shock occurring due to the reduction in the regenerative torque, so the rate of change in the regenerative torque is suppressed. In other words, in Patent Document 1, downshifts are performed by engaging the hydraulic friction engagement device, so the hydraulic friction engagement device may suddenly engage due to a decrease in regenerative torque, which can cause a synchronous shock when the gear shift ends. To prevent this, the rate of change of the regenerative torque is reduced.

JP 2011-199958 A

However, if the rate of change of the regenerative torque is suppressed as in Patent Document 1, the change in the regenerative torque in response to the brake-off operation becomes slower, which may result in poor responsiveness to the loss of deceleration, which reduces the vehicle deceleration, and may cause the driver to feel uncomfortable.

The present invention was made against the background of the above circumstances, and its purpose is to suppress shift shock while ensuring responsiveness in deceleration loss when regenerative torque is reduced in accordance with changes in braking operation during downshifts during regenerative coasting.

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.

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.

The 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 the amount of reduction in the regenerative torque from the start of the inertia phase to the time when 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.

The fourth invention is a vehicle control device according to any one of the first to third inventions, characterized in that (a) the automatic transmission forms the multiple gear stages according to the engagement and disengagement states of multiple hydraulic friction engagement devices, and (b) the regenerative coast downshift control unit reduces the engagement transient hydraulic pressure of the hydraulic friction engagement devices that are engaged during the downshift, and performs a pressure reduction correction to lower the engagement transient hydraulic pressure when the regenerative torque is reduced by the coast regenerative control unit after the inertia phase begins.

The fifth invention is a vehicle control device according to any one of the first to fourth inventions, characterized in that 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 torque of the automatic transmission, which is obtained by multiplying the regenerative torque controlled by the coasting regenerative control unit by the gear ratio of the automatic transmission.

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 just before the end of the downshift, suppressing the change in the input rotation speed just before it increases and reaches the synchronous rotation speed after the shift, suppressing the shift shock at the time of synchronization (at the end of the shift). On the other hand, if the regenerative torque is reduced by the coasting regenerative control unit in response to a change in brake operation after the inertia phase of the downshift begins, the regenerative torque down amount during the regenerative torque down control is increased so that the shift shock caused by the reduction in 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 brake operation even during a downshift, and the same responsiveness in deceleration loss as during normal regenerative coasting other than during a shift is obtained.

The second invention is a case where the rotating machine is regeneratively controlled according to 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 according to the amount of decrease in regenerative torque so that the greater the amount of decrease in regenerative torque after the inertia phase begins, the greater the regenerative torque down amount. Since the regenerative torque and the regenerative torque down amount are precisely controlled according to changes in the brake operation amount, the vehicle deceleration is appropriately controlled according to the brake operation amount, and shift shock during downshifting is appropriately suppressed regardless of changes in the regenerative torque.

In the third invention, the amount of correction used to increase the regenerative torque down amount is calculated based on the amount of regenerative torque reduction from the start of the inertia phase and the amount of regenerative torque reduction per unit time, so that shift shock during downshifts can be appropriately suppressed by taking into account long-term and short-term changes in the amount of brake operation during the inertia phase.

The fourth invention is for an automatic transmission equipped with multiple gear stages formed according to the engaged and disengaged states of multiple 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 hydraulic pressure of the engaging hydraulic friction engagement device that raises the input rotation speed is reduced so that this is corrected to be lower, and combined with the increasing correction of the regenerative torque down amount in the regenerative torque down control, it is possible to more appropriately suppress the shift shock at the time of synchronization when the input rotation speed reaches the synchronous rotation speed after shifting.

In the fifth invention, whether the regenerative torque has been reduced is determined based on an estimated value of the output torque of the automatic transmission, so that the regenerative torque reduction amount can be increased by appropriately determining the reduction in the regenerative torque, regardless of the various compensation controls of the input torque that are implemented to ensure smooth downshifting.

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. FIG. 2 is a schematic diagram illustrating an example of an automatic transmission provided in the vehicle of FIG. 1 . 3 is an engagement operation table illustrating the relationship between a plurality of gear stages of the automatic transmission of FIG. 2 and an engagement/disengagement state of a hydraulic friction engagement device. 2 is a diagram illustrating an example of a 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. 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. 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. 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. 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. 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. 8 is an example of a time chart illustrating the change 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 Figure 7 when there is a change in the amount of brake operation during downshifting during regenerative coast driving. 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.

The present invention is preferably applied to a hybrid electric vehicle having an engine (internal combustion engine) in addition to a rotating machine as a driving force source, but can also be applied to an electric vehicle having only a rotating machine as a driving force source for running. The hybrid electric vehicle may be one having an engine and a single rotating machine, or one having two or more rotating machines, and may be applied to various hybrid electric vehicles, such as one having an electric differential unit having a differential mechanism and a rotating machine for differential limiting. The rotating 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 an automatic transmission, for example, a planetary gear type stepped transmission in which multiple gear stages are formed depending on 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 a gear type transmission mechanism and a belt type transmission mechanism provided in parallel to change the speed by switching between them.

The coasting regenerative control unit that generates regenerative torque during coasting is configured to generate regenerative torque when the brake pedal is depressed (brake on), and to generate a smaller regenerative torque when the brake pedal is not depressed (brake off) than when the brake is on, but the regenerative torque may be stopped 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 also be possible to simply generate a constant regenerative torque regardless of the amount of brake operation.

The regenerative torque down control, which increases the regenerative torque just before the end of a downshift, may increase the regenerative torque by a fixed amount that is predetermined for each type of downshift, but may also change the regenerative torque down amount (the amount of increase in regenerative torque) depending on the vehicle state, such as the vehicle deceleration, the amount of brake operation, 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 begins, but the correction amount may be constant or may be changed depending on the amount of reduction in the regenerative torque. 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 to the time 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. However, the correction amount may be determined only by 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. Various embodiments are possible. If the regenerative torque is increased with an increase in the brake operation after the inertia phase starts, it is not necessary to correct the regenerative torque down amount, but it is also possible to correct the regenerative torque down amount by decreasing it. In other words, the regenerative torque down amount may be increased or decreased according to the increase or decrease in the regenerative torque.

When an automatic transmission has multiple gear stages formed according to the engagement and disengagement states of multiple hydraulic friction engagement devices, in addition to the above-mentioned regenerative torque down amount increase correction, it is desirable to reduce or increase the engagement transient oil pressure of the hydraulic friction engagement device that is engaged during a downshift when the regenerative torque is reduced, but it is also possible to simply perform an increase correction of the regenerative torque down amount. When the regenerative torque is increased with an increase in braking operation after the inertia phase begins, it is not necessarily necessary to correct the engagement transient oil pressure of the engaging hydraulic friction engagement device, but it is also possible to increase or increase the engagement transient oil pressure. In other words, the engagement transient oil pressure of the engaging hydraulic friction engagement device may be reduced or increased in response to the decrease or increase in the regenerative torque.

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 compensation controls so that the downshift proceeds appropriately, and may increase or decrease depending on the compensation controls. 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 torque of the automatic transmission, which is obtained by multiplying the regenerative torque by the gear ratio of the automatic transmission.

The following describes in detail the embodiments of the present invention with reference to the drawings. Note that in the following embodiments, the drawings have been simplified or modified as appropriate for the purpose of explanation, and the dimensional ratios and shapes of the various parts are not necessarily drawn accurately.

Figure 1 is a schematic diagram of the drive system of a vehicle 10 to which the present invention is applied, showing the control functions for various controls in the vehicle 10 and the main parts of the control system. In Figure 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 the 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.

The engine 12 is a known internal combustion engine such as a gasoline engine or a diesel engine. The engine 12 has an engine control device 50, which includes a throttle actuator, a fuel injection device, an ignition device, and the like, provided on the vehicle 10, controlled by an electronic control device 90, thereby controlling the engine torque Te, which is the output torque of the engine 12.

The motor generator MG corresponds to a rotating machine, and is a rotating electric machine that has the function of an electric motor that generates mechanical power from electric power, and the function of 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 motor generator MG controls the MG torque Tmg, which is the output torque of the motor generator MG, by controlling the inverter 52 by the electronic control device 90. For example, when the rotation direction of the motor generator MG is the same as the rotation direction when the engine 12 is operating, the MG torque Tmg is a power torque when it is a positive torque on the acceleration side, and 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 driving according to the MG torque Tmg, which is a power torque, by being supplied with electric power from the battery 54 via the inverter 52 instead of or in addition to the engine 12. In addition, the motor generator MG is rotated and driven by the power of the engine 12 and the driven force input from the drive wheels 14 side, and generates electricity according to 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 according to 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 power can be replaced with torque or force.

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, which is a non-rotating member attached to the vehicle body, and a motor generator MG is connected to the 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 drive 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 the torque capacity of the K0 clutch 20, which is the K0 torque Tk0, by the 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.

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 the power transmission path between the engine 12 and the drive wheels 14, particularly to the power transmission path between the K0 clutch 20 and the torque converter 22 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.

The torque converter 22 is a fluid-type 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 the transmission input shaft 38, which 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, which is formed integrally with the turbine shaft that is rotated by the turbine wheel 22b. The torque converter 22 is a fluid-type power transmission device that transmits the driving force from each of the driving force sources, the engine 12 and the motor generator MG, to the transmission input shaft 38 via fluid. The torque converter 22 is equipped with an LU clutch 40 that connects the pump impeller 22a and the turbine impeller 22b. The LU clutch 40 is a direct clutch that connects the input and output rotating members of the torque converter 22, i.e., a known lock-up clutch.

The LU clutch 40 switches between operating and control states by changing the LU clutch torque Tlu, which is the torque capacity of the LU clutch 40, with the regulated LU hydraulic 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 slippage, 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 impeller 22a and the turbine impeller 22b are rotated together.

The automatic transmission 24 is connected to the torque converter 22 and is disposed in the 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, and a pair of drive shafts 32 connected to the differential gear 30.

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 has 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 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 are configured as a Ravigneaux-type planetary gear train in which the carrier and ring gear of both are constructed from common materials, and 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.

The automatic transmission 24 in FIG. 2 is equipped with four clutches C1-C4 and two brakes B1, 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, 1st gear "1st" to 8th gear "8th", and two reverse gears, 1st reverse gear "Rev1" and 2nd 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, and the eighth gear "8th" side is the high gear. As is clear from Fig. 3, when the automatic transmission 24 of this embodiment shifts between successive 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 the engagement device CB is inserted. Each engagement device CB has its torque capacity, CB torque Tcb, changed by the regulated CB hydraulic pressure PRcb supplied from the hydraulic control circuit 56, thereby switching the control state between an engaged state, a released state, etc.

The automatic transmission 24 is controlled by an electronic control device 90 to switch gears in response to the driver's accelerator operation, vehicle speed V, etc., i.e., one of a number of gears is selectively established. 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 the same value as 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.

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 addition, 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., regardless of the control state of the K0 clutch 20.

The vehicle 10 is equipped with a MOP 58 which is a mechanical oil pump, an EOP 60 which is an electric oil pump, a pump motor 62, etc. The MOP 58 is connected to the pump impeller 22a, and is rotated and driven by a driving power source (engine 12, 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 EOP 60 is supplied to the hydraulic control circuit 56. The hydraulic control circuit 56 supplies the CB hydraulic pressure PRcb, K0 hydraulic pressure PRk0, LU hydraulic pressure PRlu, etc., which are adjusted based on the hydraulic oil OIL discharged by the MOP 58 and/or EOP 60, to the engagement devices CB, K0 clutch 20, LU clutch 40, etc.

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.

The electronic control unit 90 receives various signals based on detection values from various sensors provided in the vehicle 10 (e.g., engine rotation speed sensor 70, turbine rotation speed sensor 72, output rotation speed sensor 74, MG rotation speed sensor 76, accelerator opening sensor 78, throttle valve opening sensor 80, air flow meter 82, brake operation amount sensor 84, battery sensor 86, oil temperature sensor 88, etc.) (e.g., engine rotation speed Ne, which is the rotation speed of the engine 12; turbine rotation speed Nt, which is the same value as the AT input rotation speed Ni; AT output rotation speed No, which corresponds to the vehicle speed V; MG rotation speed Nmg, which is the rotation speed of the motor generator MG; accelerator opening θacc, which is the accelerator operation amount (e.g., the amount of depression of the accelerator pedal) that represents the magnitude of the driver's acceleration request; throttle valve opening θth, which is the opening of the electronic throttle valve; intake air volume Qair of the engine 12). , brake operation amount Bon, which is the force of depression of the brake pedal 85 indicating the magnitude of the driver's deceleration request, battery temperature THbat, battery charge/discharge current Ibat, battery voltage Vbat of the battery 54, and a signal indicating the hydraulic oil temperature THoil, which is the temperature of the hydraulic oil OIL in the hydraulic control circuit 56, are supplied. The MG rotation speed Nmg corresponds to the input rotation speed of the torque converter 22, which is a fluid transmission device, and the turbine rotation speed Nt corresponds to the output rotation speed of the torque converter 22, which is a fluid transmission device. The accelerator opening θacc corresponds to the driver's acceleration request, and the brake operation amount Bon corresponds to the driver's deceleration request.

The electronic control device 90 outputs various command signals (e.g., engine control command signal Se for controlling the engine 12, MG control command signal Sm for controlling the motor generator MG, CB hydraulic control command signal Scb for controlling the engagement device CB, K0 hydraulic control command signal Sk0 for controlling the K0 clutch 20, LU hydraulic control command signal Slu for controlling the LU clutch 40, EOP control command signal Seop for controlling the EOP 60, etc.) to each device (e.g., engine control device 50, inverter 52, hydraulic control circuit 56, 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 brake device 64 that generates braking force in the wheel brakes provided on all 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 mechanically changes the braking force according to the brake operation amount Bon.

The electronic control device 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, in order to realize various controls in the vehicle 10.

The hybrid control unit 92 is functionally equipped with 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 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, the required drive torque Trdem at the drive wheels 14. In other words, the required drive torque Trdem [Nm] is the required drive power Prdem [W] at the vehicle speed V at that time. The drive demand amount can also be the required drive force Frdem [N] at the drive wheels 14, the required AT output torque at the transmission output shaft 26, etc. In the calculation of the drive demand amount, the AT output rotation speed No, etc. may be used instead of the vehicle speed V.

The hybrid control unit 92 calculates the required input torque Tindem, which is the input torque of the torque converter 22 required to realize the required driving power Prdem, and outputs an engine control command signal Se to control the engine 12 and an MG control command signal Sm to control the motor generator MG so that the required input torque Tindem is obtained. When the required input torque Tindem can be met only by the output of the motor generator MG, the hybrid control unit 92 sets the driving mode to the BEV (Battery Electric Vehicle) driving mode. In the BEV driving mode, the vehicle runs in a BEV mode, using only the motor generator MG as a driving force source with the K0 clutch 20 in a disengaged state. In addition, when the required input torque Tindem cannot be met without using at least the output of the engine 12, the hybrid control unit 92 sets the driving mode to the engine driving mode, i.e., the HEV (Hybrid Electric Vehicle) driving mode. In the HEV driving mode, the vehicle runs in an engine mode, i.e., the HEV mode, using at least the engine 12 as a driving force source with the K0 clutch 20 in an engaged state. Based on the required input torque Tindem, etc., the hybrid control unit 92 automatically stops the engine 12 during HEV driving, restarts the engine 12 after the engine has stopped, starts the engine 12 during BEV driving, automatically stops the engine 12 while the vehicle is stopped, and starts the engine 12, thereby switching between the BEV driving mode and the HEV driving mode.

The shift control unit 94 uses, for example, a shift map, which is a predetermined relationship, to determine whether the automatic transmission 24 should be shifted, and outputs a CB hydraulic control command signal Scb 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 a predetermined relationship having a shift line for determining whether the automatic transmission 24 should be shifted, for example, on a two-dimensional coordinate system with vehicle speed V and required driving torque Trdem as variables. In the shift map, the AT output rotation speed No may be used instead of the vehicle speed V, and the required driving force Frdem, accelerator opening θacc, throttle valve opening θth, etc. may be used instead of the required driving torque Trdem.

The coasting regeneration control unit 96 executes coasting regeneration control to control the MG torque Tmg so that the motor generator MG generates regenerative torque when 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 the 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 for the generated 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 power Wg obtained. During coasting, the engine 12 is stopped by cutting off fuel, and the K0 clutch 20 is released to stop rotation. In other words, a braking force equivalent to engine braking or a braking force greater than engine braking can be generated by regenerative control of the motor generator MG. It is also possible to perform regenerative control during coasting while rotating the engine 12 with the K0 clutch 20 still connected.

The coasting MG regenerative torque Tmgc is calculated according to a predetermined map or calculation formula so that it increases as the brake operation amount Bon increases, and is changed sequentially 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, in which the coasting MG regenerative torque Tmgc is continuously increased as the brake operation amount Bon increases. In FIG. 4, the torque Tmgc increases linearly, but 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 that is smaller than that during 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, the map and calculation formula for calculating the coasting MG regenerative torque Tmgc are determined for each gear stage of the automatic transmission 24.

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 (in this case, increases) due to the change in gear stage caused by the downshift, i.e., the change (in this case, increase) in the gear ratio γ. 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, taking into account the change in the gear ratio γ, so that the propeller shaft regenerative torque Tprg transmitted to the propeller shaft 28 is maintained approximately 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.

Figure 6 is an example of a time chart that explains the change in the operating state of each part during downshift during regenerative coasting. The release side hydraulic command value PRdra and the engagement side hydraulic command value PRapp are the hydraulic command values of the release side engagement device CBdra that is released during clutch-to-clutch shifting during downshifting, and the engagement side engagement device CBapp that is engaged. Time t1 in Figure 6 is the time when the downshift shift command is output, and the CB hydraulic control command signal Scb for performing the clutch-to-clutch shifting 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 between time t2 and time t3, which correspond to the torque phase, regardless of the change in the gear ratio γ due to the downshift. The propeller shaft regenerative torque Tprg is a calculated value calculated based on the brake operation amount Bon, like the coasting MG regenerative torque Tmgc, and corresponds to the coasting MG regenerative torque Tmgc, but is maintained constant regardless of downshifting 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 or changed according to changes in the gear ratio γ so that the propeller shaft regenerative torque Tprg is maintained constant regardless of downshifting.

In FIG. 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 engaging 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 zero). 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.

The regenerative coast downshift control unit 94a also performs regenerative torque down control to increase the coasting MG regenerative torque Tmgc just before the synchronization, because there is a risk that the engaging side engagement device CBapp will suddenly engage and cause a shift shock when the AT input rotation speed Ni increases to reach the synchronous rotation speed after the shift. This regenerative torque down control increases the coasting MG regenerative torque Tmgc by a predetermined regenerative torque down amount TDmgc from the reference value shown by the dashed line in Figure 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, etc., or may be variably set according to the rate of change of the AT input rotation speed Ni, etc. Also, the remaining time until the AT input rotation speed Ni reaches the synchronous rotation speed after the shift is calculated, and when the remaining time falls below a judgment value, the regenerative torque down control is performed. The regenerative torque down amount TDmgc is calculated according to a map or a formula that is predetermined for each type of downshift, so that the regenerative torque down amount TDmgc increases as the vehicle deceleration (absolute value of dV/dt) increases. FIG. 5 shows an example of the regenerative torque down amount TDmgc set according to the vehicle deceleration, and the regenerative torque down amount TDmgc is continuously increased as the vehicle deceleration increases. In FIG. 5, the regenerative torque down amount TDmgc increases linearly, but it may increase nonlinearly or in stages. The regenerative torque down 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, etc., and various other aspects are possible.

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 increases, so that the AT input rotation speed Ni gradually approaches the synchronous rotation speed after the shift, suppressing the shock at the end of the shift (synchronization) when the engaging device CBapp is fully engaged. Time t4 in Figure 6 is the time when the differential rotation ΔNi becomes equal to or less than the judgment value Nis and regenerative torque down control is started, and time t5 is the end of the shift when the AT input rotation speed Ni reaches the synchronous rotation speed after the shift and the engaging device CBapp is engaged.

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 in 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 increase speed of the AT input rotation speed Ni increases, so that the engaging side engagement device CBapp suddenly engages regardless of the regenerative torque down control immediately before synchronization, which may cause a shift shock. To prevent this, if the change in the coasting MG regenerative torque Tmgc is suppressed as in Patent Document 1, specifically, if the slope of the reference value of the coasting MG regenerative torque Tmgc is made gentle as shown by the dashed line in Figure 11, the slope of the propeller shaft regenerative torque Tprg will also be gentle as shown by the dashed line, which will result in poor response to the deceleration loss that reduces the vehicle deceleration, and the vehicle deceleration will not change regardless of the return operation of the brake pedal 85, which may cause the driver to feel uncomfortable. Times t5 and t6 in Figure 11 correspond to times t4 and t5 in Figure 6, respectively.

In contrast, the regenerative coast downshift control unit 94a of this embodiment executes signal processing according to the flowchart shown in FIG. 7 without performing the gradual change processing (smoothing processing) 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 begun.

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, 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, 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, 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.

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 by which the regenerative torque down amount TDmgc in the regenerative torque down control is increased and corrected, and in this embodiment, it is calculated according to a map or equation, etc., that is predetermined for each type of downshift, using as parameters the amount of decrease ΔTprg of the propeller shaft regenerative torque from the start of the inertia phase and the amount of decrease (dTprg/dt) of the propeller shaft regenerative torque per unit time at the current time point as parameters, as shown in Figure 8. In Figure 8, it is determined that the larger the amount of decrease ΔTprg, the larger the correction amount α becomes, and that the larger the amount of decrease (dTprg/dt), the larger the correction amount α becomes. The engagement transient hydraulic pressure correction amount β is an amount of pressure reduction correction for the hydraulic pressure command value PRapp of the engaging side engaging device CBapp. In this embodiment, as shown in FIG. 9, for example, the amount of decrease in the propeller shaft regenerative torque ΔTprg from the start of the inertia phase 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 it is calculated according to a map or formula that is predetermined for each type of downshift. In FIG. 9, the larger the amount of decrease ΔTprg, the larger the correction amount β becomes, and the larger the amount of decrease (dTprg/dt), the larger the correction amount β becomes. The unit time of the decrease (dTprg/dt) is, for example, the control cycle time of the electronic control device 90, and is, for example, 16 ms.

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 the change is 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 the decrease in the brake operation amount Bon, and specifically, they are the values obtained by multiplying the decrease amounts ΔTmgc and (dTmgc/dt) by the gear ratio γ of the automatic transmission 24.

In the next step S6, the regenerative torque down amount TDmgc is increased by the correction amount α, and the on-coming hydraulic command value PRapp is decreased by the 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 just before the synchronization when the differential rotation ΔNi becomes equal to or less 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. Figure 10 is a time chart corresponding to Figure 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 Figure 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 started 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 regenerative torque down control is appropriately performed to suppress the increase in the AT input rotation speed Ni just before synchronization and suppress sudden engagement of the engaging side engaging device CBapp, regardless of the decrease in the coasting MG regenerative torque Tmgc that accompanies the decrease in the brake operation amount Bon, and the gear shift shock caused by the sudden engagement of the engaging side engaging device CBapp is suppressed.

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. In other words, 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 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 increase, the regenerative torque down amount TDmgc and the on-coming hydraulic command value PRapp are not corrected.

In this way, 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 just before the end of the downshift, so that the change in the AT input rotation speed Ni just before it rises and reaches the synchronous rotation speed after the shift is suppressed, and the 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 regenerative control unit 96 reduces the coasting MG regenerative torque Tmgc in accordance with the decrease in the brake operation amount Bon, and in response to this, when the propeller shaft regenerative torque Tprg is reduced, the regenerative torque down amount TDmgc during the regenerative torque down control is increased so as to suppress the shift shock caused by the decrease in the coasting MG regenerative torque Tmgc. In addition, 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 starts, the coasting MG regenerative torque Tmgc is quickly reduced in accordance with the decrease in the brake operation amount Bon even during a downshift, and the responsiveness of the deceleration loss is the same as during normal regenerative coasting other than when shifting gears, so there is no risk of the driver feeling uncomfortable.

As is clear from FIG. 4, the motor generator MG is regeneratively controlled according to the brake operation amount Bon so that the coasting MG regenerative torque Tmgc increases as the brake operation amount Bon increases, and as shown in FIG. 8, the regenerative torque reduction amount TDmgc is increased and corrected according to the decrease in the propeller shaft regenerative torque Tprg so that the regenerative torque reduction 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. In other words, the coasting MG regenerative torque Tmgc and the regenerative torque reduction amount TDmgc are finely controlled according to the change in the brake operation amount Bon, so that the vehicle deceleration is appropriately controlled according 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.

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

In addition, when the coasting MG regenerative torque Tmgc is reduced by the coasting regenerative control unit 96 after the inertia phase of a downshift during regenerative coasting begins and the propeller shaft regenerative torque Tprg is reduced accordingly, the engagement side hydraulic command value PRapp is reduced so that the engagement transient hydraulic pressure of the engagement side engagement device CBapp that raises the AT input rotation speed Ni is lowered. This, combined with the increase 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.

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 decrease in the coasting MG regenerative torque Tmgc that accompanies the decrease in the brake operation amount Bon, and perform an increase correction of the regenerative torque down amount TDmgc and a decrease correction of the engagement transient hydraulic pressure of the engagement side engagement device CBapp.

The above describes in detail an embodiment of the present invention based on the drawings, but 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.

10: Vehicle 14: Drive wheels 24: Automatic transmission 84: Brake operation amount sensor 90: Electronic control unit (vehicle control unit) 94a: Regenerative coast downshift control unit 96: Coast regenerative control unit MG: Motor generator (rotating machine) C1-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: Amount of decrease from the start of the inertia phase dTprg /dt: Amount of decrease 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 (5)

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
a regenerative coast downshift control unit that, 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, increases and corrects the regenerative torque down amount during the regenerative torque down control. The coasting regenerative control unit controls the rotating machine in a regenerative manner in response to a brake operation amount so that the regenerative torque increases as the brake operation amount increases,
2. The vehicle control device according to claim 1, wherein the regenerative coast downshift control unit increases 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 brake operation amount after the inertia phase starts increases. 3. The vehicle control device according to claim 2, wherein 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 a start of the inertia phase to a 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. 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 vehicle control device according to any one of claims 1 to 3, characterized in that the regenerative coast downshift control unit performs a pressure reduction correction for an engagement transient oil pressure of the hydraulic friction engagement device that is engaged during the downshift so that the engagement transient oil pressure is lowered when the regenerative torque is reduced by the coasting regenerative control unit after the inertia phase starts. The vehicle control device according to any one of claims 1 to 4, characterized in that 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.

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