JP2022178671A - Control device of vehicle - Google Patents

Abstract

To suppress or avoid an engine stool and a transmission shaft from reversely rotating even when negative torque as torque on the transmission shaft is excessively required.SOLUTION: A lower limit value of required torque on a transmission shaft that is used in controlling output torque of an engine and output torque of an electric motor is set to a value determined by converting a predetermined lower limit value of torque that the engine can output to torque on a transmission shaft, which can suppress or avoid the torque on the transmission shaft achieved by the output torque of the engine and the output torque of the electric motor from becoming lower than the value determined by converting the lower limit value of the torque that the engine can output to torque on the transmission shaft. This can suppress or avoid an engine stool and the transmission shaft from reversely rotating even negative torque as the torque on the transmission shaft is excessively required.SELECTED DRAWING: Figure 3

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a vehicle equipped with a power transmission device for transmitting output torque of a driving force source including an engine and an electric motor to drive wheels.

BACKGROUND ART A control device for a vehicle is well known that includes a driving force source including an engine and an electric motor, and a power transmission device that transmits the output torque of the driving force source to drive wheels. For example, a hybrid vehicle control device described in Patent Document 1 is one of them. This Patent Literature 1 discloses that each required output shared by the engine and the electric motor is set based on predetermined conditions so that the required output of the hybrid vehicle as a whole is realized.

JP 2008-285096 A

By the way, a vehicle includes a power transmission device having a transmission shaft to which a driving force source including an engine and an electric motor is connected so as to be able to transmit power, and transmitting output torque of the driving force source input to the transmission shaft to drive wheels. is also well known. When the technology described in Patent Document 1 is adopted for this vehicle, it is conceivable to control the output torque of the engine and the output torque of the electric motor so as to realize the required torque value on the transmission shaft, for example. At this time, if an excessive negative torque whose absolute value is larger than the limit value of the negative torque that the engine can output as the torque on the transmission shaft is required, even if the negative torque of the engine is limited by the limit value, the electric motor can realize the excessive negative torque. As a result, engine stall may occur, or reverse rotation of the transmission shaft may occur, in which the rotation of the transmission shaft is opposite to the direction of rotation of the vehicle.

The present invention has been made against the background of the above circumstances, and its object is to prevent engine stall and reverse rotation of the transmission shaft even if excessive negative torque is required as the torque on the transmission shaft. It is an object of the present invention to provide a vehicle control device capable of suppressing or avoiding.

The gist of the first invention is (a) having a driving force source including an engine and an electric motor, and a transmission shaft to which the driving force source is constantly or selectively connected via a clutch so as to be able to transmit power. and a power transmission device for transmitting the output torque of the driving force source input to the transmission shaft to drive wheels, wherein: (b) a torque demand value on the transmission shaft (c) a driving force source control unit that controls the output torque of the engine and the output torque of the electric motor so as to realize the required transmission shaft torque of a required torque arbitration unit for setting a lower limit value of the required transmission shaft torque used for control to a value obtained by converting a predetermined lower limit value of the torque that the engine can output onto the transmission shaft. be.

According to the first aspect, the lower limit value of the required transmission shaft torque used for controlling the output torque of the engine and the output torque of the electric motor is the predetermined lower limit value of the torque that the engine can output. Therefore, the torque on the transmission shaft realized by the output torque of the engine and the output torque of the electric motor is higher than the value obtained by converting the lower limit of the torque that the engine can output on the transmission shaft. Being degraded is suppressed or avoided. Therefore, even if excessive negative torque is required as the torque on the transmission shaft, engine stall and reverse rotation of the transmission shaft can be suppressed or avoided.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram for explaining a schematic configuration of a vehicle to which the present invention is applied, and is a diagram for explaining main parts of a control system and control functions for various controls in the vehicle; FIG. 4 is a block diagram illustrating control for distributing the required system shaft torque to the engine torque and the MG torque; 3 is a flowchart for explaining the main part of the control operation of the electronic control unit, and control for suppressing or avoiding engine stall and reverse rotation of the electric motor connecting shaft even if excessive negative torque is required as the torque on the electric motor connecting shaft. 4 is a flow chart for explaining the operation;

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

FIG. 1 is a diagram for explaining a schematic configuration of a vehicle 10 to which the present invention is applied, and is a diagram for explaining control functions and main parts of a control system for various controls in the vehicle 10. As shown in FIG. In FIG. 1, a vehicle 10 is a hybrid vehicle including an engine 12 and an electric motor MG, which are driving force sources SP for running. The vehicle 10 also includes drive wheels 14 and a power transmission device 16 provided in a power transmission path between the engine 12 and the drive wheels 14 .

The engine 12 is a known internal combustion engine such as a gasoline engine or a diesel engine. An engine control device 50 including a throttle actuator, a fuel injection device, an ignition device, and the like provided in the vehicle 10 is controlled by an electronic control device 90, which will be described later, to control the engine 12. The engine torque Te, which is the output torque of the engine 12, is controlled by the engine 12. is controlled.

The electric motor MG is a rotating electric machine having a function as a motor that generates mechanical power from electric power and a function as a generator that generates power from mechanical power, and is a so-called motor generator. Electric motor MG is connected to a battery 54 provided in vehicle 10 via an inverter 52 provided in vehicle 10 . The battery 54 is a power storage device that transfers electric power to and from the electric motor MG. In the electric motor MG, the MG torque Tm, which is the output torque of the electric motor MG, is controlled by controlling the inverter 52 by the electronic control unit 90, which will be described later. For example, when the rotation direction of the electric motor MG is the same rotation direction as the engine 12 is running, the MG torque Tm is a power running torque when the positive torque is on the acceleration side, and is a regenerative torque when the negative torque is on the deceleration side. be. The electric motor MG, for example, generates power from the power of the engine 12, and the battery 54 charges the electric power from the electric motor MG. Electric power is also synonymous with electrical energy, if not specifically distinguished. The power is also synonymous with torque and force unless otherwise specified.

The power transmission device 16 includes a K0 clutch 20, a torque converter 22, an automatic transmission 24, etc. in a case 18, which is a non-rotating member attached to the vehicle body. K0 clutch 20 is a clutch provided between engine 12 and electric motor MG in a power transmission path between engine 12 and driving wheels 14 . Torque converter 22 is connected to engine 12 via K0 clutch 20 . Automatic transmission 24 is connected to torque converter 22 and is interposed in a power transmission path between torque converter 22 and drive wheels 14 . Automatic transmission 24 is a transmission provided between electric motor MG and drive wheels 14 in a power transmission path between engine 12 and 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 an automatic transmission 24, a differential gear 30 connected to the propeller shaft 28, and a gear 1 connected to the differential gear 30. A pair of drive shafts 32 and the like are provided. The power transmission device 16 also includes an engine connection shaft 34 that connects the engine 12 and the K0 clutch 20, an electric motor connection shaft 36 that connects the K0 clutch 20 and the torque converter 22, and the like.

The electric motor MG is connected to the electric motor connecting shaft 36 within the case 18 so as to be able to transmit power. In other words, the electric motor MG is connected to a power transmission path between the engine 12 and the drive wheels 14, particularly a power transmission path between the K0 clutch 20 and the torque converter 22 so that power can be transmitted. In other words, the electric motor MG is connected to the torque converter 22 and the automatic transmission 24 without the K0 clutch 20 so that power can be transmitted.

The electric motor connecting shaft 36 is a transmission shaft to which the engine 12 is selectively connected via the K0 clutch 20 so as to be able to transmit power, and to which the electric motor MG is always connected so as to be able to transmit power.

The torque converter 22 includes a pump impeller 22 a connected to an electric motor connecting shaft 36 and a turbine impeller 22 b connected to a transmission input shaft 38 which is an input rotating member of the automatic transmission 24 . The torque converter 22 is a hydrodynamic transmission device that transmits the power from the driving force source SP from the electric motor connecting shaft 36 to the transmission input shaft 38 via fluid. The torque converter 22 includes an LU clutch 40 as a direct clutch that connects the pump impeller 22a and the turbine impeller 22b, that is, connects the electric motor connecting shaft 36 and the transmission input shaft 38. The LU clutch 40 is a known lockup clutch.

The automatic transmission 24 is a known planetary gear type automatic transmission including, for example, one or a plurality of sets of planetary gears (not shown) and a plurality of engagement devices CB. The engagement device CB is, for example, a known hydraulic friction engagement device. Each of the engagement devices CB is engaged by changing the CB torque Tcb, which is the torque capacity, by the CB hydraulic pressure PRcb, which is the regulated hydraulic pressure supplied from the hydraulic control circuit 56 provided in the vehicle 10. An operating state or control state such as engaged or disengaged is switched.

In the automatic transmission 24, the gear ratio (also referred to as gear ratio) γat (=AT input rotation speed Ni/AT output rotation speed No) is established by engaging any one of the engagement devices CB. is a stepped transmission in which one of a plurality of gear stages (also referred to as gear stages) is formed. The automatic transmission 24 switches between gear stages according to the driver's accelerator operation, the vehicle speed V, and the like, by an electronic control unit 90, which will be described later. The AT input rotation speed Ni is the rotation speed of the transmission input shaft 38 and the input rotation speed of the automatic transmission 24 . The AT input rotation speed Ni has the same value as the turbine rotation speed Nt, which is the output rotation speed of the torque converter 22 . The AT input rotation speed Ni can be represented by the turbine rotation speed Nt. The AT output rotation speed No is the rotation speed of the transmission output shaft 26 and the output rotation speed of the automatic transmission 24 .

The K0 clutch 20 is a hydraulic friction engagement device composed of, for example, a multi-plate or single-plate clutch. The K0 clutch 20 changes the K0 torque Tk0, which is the torque capacity of the K0 clutch 20, by the K0 hydraulic pressure PRk0, which is the regulated hydraulic pressure supplied from the hydraulic control circuit 56, so that the engaged state and the disengaged state are changed. Control state is switched.

In the vehicle 10, when the K0 clutch 20 is engaged, the engine 12 and the torque converter 22 are connected so as to be able to transmit power. On the other hand, when the K0 clutch 20 is released, power transmission between the engine 12 and the torque converter 22 is cut off. Since the electric motor MG is connected to the torque converter 22, the K0 clutch 20 functions as a clutch that connects and disconnects the engine 12 with the electric motor MG.

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 connection shaft 34 to the K0 clutch 20, the electric motor connection shaft 36, the torque converter 22, the automatic transmission 24, The power is transmitted to the drive wheels 14 through the propeller shaft 28, the differential gear 30, the drive shaft 32, and the like. The power output from the electric motor MG is transmitted from the electric motor connecting shaft 36 to the torque converter 22, the automatic transmission 24, the propeller shaft 28, the differential gear 30, the drive shaft 32, etc. regardless of the control state of the K0 clutch 20. The power is transmitted to the driving wheels 14 through successively. In this manner, the power transmission device 16 transmits the driving force source torque Tsp, which is the output torque of the driving force source SP input to the electric motor connecting shaft 36 , to the drive wheels 14 . The driving force source torque Tsp is the total torque of the engine torque Te and the MG torque Tm.

The vehicle 10 includes a mechanical oil pump MOP 58, an electric oil pump EOP 60, a pump motor 62, and the like. The MOP 58 is connected to the pump impeller 22a, and is driven to rotate by the driving force source SP to discharge hydraulic oil OIL used in the power transmission device 16. As shown in FIG. The pump motor 62 is a motor dedicated to the EOP 60 for rotating the EOP 60 . The EOP 60 is rotationally driven by the pump motor 62 to discharge hydraulic oil OIL. Hydraulic oil OIL discharged from the MOP 58 and the EOP 60 is supplied to the hydraulic control circuit 56 . The hydraulic control circuit 56 supplies the CB hydraulic pressure PRcb, the K0 hydraulic pressure PRk0, etc., each of which is adjusted based on the hydraulic oil OIL discharged from the MOP 58 and/or the EOP 60 .

The vehicle 10 further includes an electronic control unit 90 that includes a control unit for the vehicle 10 . The electronic control unit 90 includes, for example, a so-called microcomputer having a CPU, a RAM, a ROM, and an input/output interface. Various controls of the vehicle 10 are executed by performing signal processing. The electronic control unit 90 includes computers for engine control, electric motor control, hydraulic control, etc., as required.

The electronic control unit 90 includes various sensors provided in the vehicle 10 (for example, the engine rotation speed sensor 70, the turbine rotation speed sensor 72, the output rotation speed sensor 74, the MG rotation speed sensor 76, the accelerator opening sensor 78, the throttle valve Various signals based on detection values by the opening sensor 80, the brake switch 82, the battery sensor 84, the oil temperature sensor 86, etc. (e.g., the engine rotation speed Ne, which is the rotation speed of the engine 12, and the AT input rotation speed Ni) Turbine rotation speed Nt, AT output rotation speed No corresponding to vehicle speed V, MG rotation speed Nm, which is the rotation speed of electric motor MG, and accelerator opening θacc, which is the amount of accelerator operation by the driver representing the magnitude of acceleration operation by the driver. , the throttle valve opening θth which is the opening of the electronic throttle valve, the brake-on signal Bon which is a signal indicating that the brake pedal for operating the wheel brake is being operated by the driver, the battery temperature THbat of the battery 54, and A battery charging/discharging current Ibat, a battery voltage Vbat, a working oil temperature THoil which is the temperature of the working oil OIL in the hydraulic control circuit 56, etc.) are respectively supplied.

From the electronic control device 90, various command signals (for example, engine Control command signal Se, MG control command signal Sm for controlling the electric motor MG, CB hydraulic control command signal Scb for controlling the engagement device CB, K0 hydraulic control command signals Sk0 and LU for controlling the K0 clutch 20 LU oil pressure control command signal Slu for controlling the clutch 40, EOP control command signal Seop for controlling the EOP 60, etc.) are respectively output.

In order to realize various controls in the vehicle 10, the electronic control unit 90 includes driving force source control means, i.e., a driving force source control section 92, operation control means, i.e., an operation control section 94, request torque mediation means, i.e., a request torque mediation portion 96, and shift control means, that is, a shift control section 98 .

The driving force source control unit 92 functions as engine control means, ie, an engine control unit 92a, for controlling the operation of the engine 12, and functions as an electric motor control unit, ie, an electric motor control unit 92b, for controlling the operation of the electric motor MG via the inverter 52. function, and hybrid control means, ie, a hybrid control section, for executing hybrid drive control by the engine 12 and the electric motor MG by means of these control functions.

The driving force source control unit 92 calculates the driver requested driving torque Trdemd as the driving requested amount of the vehicle 10 by the driver, for example, by applying the accelerator opening θacc and the vehicle speed V to the driving requested amount map. The required drive amount map is a relationship that is experimentally or design-experimentally obtained and stored, that is, a predetermined relationship. The required drive amount for the vehicle 10 is, for example, the required drive torque Trdem at the drive wheels 14 . The required driving torque Trdem [Nm] is, in other words, the required driving power Prdem [W] at the vehicle speed V at that time. As the required driving amount, the required driving force Frdem [N] at the driving wheels 14, the required AT output torque at the transmission output shaft 26, and the like can be used. In the calculation of the drive demand amount, the AT output rotation speed No or the like may be used instead of the vehicle speed V. FIG.

The driving force source control unit 92 calculates the driver-requested system shaft torque Tsdemd for realizing the driver-requested driving torque Trdemd, taking into consideration the transmission loss, the auxiliary load, the gear ratio γat of the automatic transmission 24, and the like. The driver requested system shaft torque Tsdemd is the requested system shaft torque Tsdem based on the driver's operation. The required system shaft torque Tsdem is a required value of torque on the electric motor connection shaft 36, that is, a required transmission shaft torque.

The operation control unit 94 performs predetermined control CTf such as vehicle speed control and vehicle stability control. The vehicle speed control is, for example, known cruise control that controls the driving torque Tr so that the vehicle speed V follows a target vehicle speed set by the driver. Alternatively, the vehicle speed control is a known vehicle speed limiter (ASL (Adjustable Speed Limiter)) that controls the drive torque Tr so that the vehicle speed V does not exceed a target vehicle speed set by the driver. The vehicle stability control is a known sideslip suppression control called VSC (Vehicle Stability Control), which controls a drive torque Tr and the like for stabilizing the posture of the vehicle, for example. For example, when the predetermined control CTf is executed, the operation control unit 94 calculates a predetermined control request driving torque Trdemf as the amount of driving demand for the vehicle 10 by the predetermined control CTf. The operation control unit 94 calculates the predetermined control required system shaft torque Tsdemf for realizing the predetermined control required drive torque Trdemf, taking into consideration the gear ratio γat of the automatic transmission 24 and the like. The predetermined control required system shaft torque Tsdemf is the required system shaft torque Tsdem by the predetermined control CTf.

The required torque arbitration unit 96 determines whether or not the predetermined control required system shaft torque Tsdemf has been calculated. When determining that the predetermined control required system shaft torque Tsdemf has not been calculated, the required torque arbitration unit 96 sets the driver required system shaft torque Tsdemd to the required system shaft torque Tsdem. On the other hand, when determining that the predetermined control request system shaft torque Tsdemf has been calculated, the request torque arbitration unit 96 gives priority to which of the driver request system shaft torque Tsdemd and the predetermined control request system shaft torque Tsdemf. Either is selected based on a predetermined arbitration procedure, and the selected one is set as the required system shaft torque Tsdem.

The driving force source control unit 92 outputs an engine control command signal Se for controlling the engine torque Te and an engine control command signal Se for controlling the MG torque Tm so as to realize the required system shaft torque Tsdem set by the required torque arbitration unit 96. MG control command signal Sm is output.

The driving force source control unit 92 sets the running mode to the motor running (=EV running) mode when the required system shaft torque Tsdem can be covered only by the output of the electric motor MG. In the EV traveling mode, the driving force source control unit 92 performs EV traveling in which the vehicle travels by outputting power only from the electric motor MG of the driving force source SP in the disengaged state of the K0 clutch 20 . On the other hand, when the required system shaft torque Tsdem cannot be met without using at least the output of the engine 12, the driving force source control unit 92 sets the running mode to the engine running mode, that is, the hybrid running (=HV running) mode. . In the HV running mode, the driving force source control unit 92 performs engine running, ie, HV running, in which power is output from at least the engine 12 of the driving force source SP to run while the K0 clutch 20 is engaged. On the other hand, even if the required system shaft torque Tsdem can be covered only by the output of the electric motor MG, the driving force source control unit 92 is operated when the battery 54 needs to be charged or when the engine 12 or the like needs to be warmed up. , the HV running mode is established. In this manner, the driving force source control section 92 distributes the required system shaft torque Tsdem set by the required torque arbitration section 96 to the engine torque Te and the MG torque Tm based on a predetermined distribution procedure.

The shift control unit 98 performs shift determination for the automatic transmission 24 using, for example, a shift map having a predetermined relationship, and outputs a CB hydraulic control command signal for executing shift control of the automatic transmission 24 as necessary. Scb is output to the hydraulic control circuit 56 . The shift map is a predetermined relationship having a shift line for judging the shift of the automatic transmission 24 on two-dimensional coordinates having, for example, the vehicle speed V and the driver's requested drive torque Trdemd as variables. In the shift map, AT output rotational speed No may be used instead of vehicle speed V, and accelerator opening θacc or throttle valve opening θth may be used instead of driver required drive torque Trdemd.

Here, in the vehicle speed control, the vehicle stability control, and the like, there are cases where a torque reduction request is made to reduce the predetermined control request system shaft torque Tsdemf. Further, for example, in shift control of the automatic transmission 24 during regenerative control of the electric motor MG, shift control of the automatic transmission 24 during off-upshift, etc., a torque down request is made to reduce the input torque of the automatic transmission 24. may occur. Since the torque down request for reducing the input torque of the automatic transmission 24 is a torque down request for the electric motor coupling shaft 36, it is also one of the torque down requests for reducing the predetermined control required system shaft torque Tsdemf. Therefore, the shift control of the automatic transmission 24 is also one of the predetermined controls CTf.

The requested torque arbitration unit 96 determines whether or not a torque reduction request has been made from the predetermined control CTf in which the predetermined control requested system shaft torque Tsdemf is reduced. When the request torque arbitration unit 96 determines that the predetermined control request system shaft torque Tsdemf has been calculated and determines that the torque reduction request from the predetermined control CTf has been made, the request torque arbitration unit 96 adjusts the predetermined control request system shaft torque, for example. Set Tsdemf to the required system shaft torque Tsdem.

By the way, when the torque reduction request from the predetermined control CTf is excessive negative torque whose absolute value is larger than the lower limit of the torque that the engine 12 can output, the engine 12 can bear the negative torque only up to the lower limit. The electric motor MG can realize the excessive negative torque. As a result, the engine may stall, or the electric motor connecting shaft 36 may rotate in the opposite direction to the direction in which the vehicle travels. If, for example, a drive torque monitoring function is added for engine stalls and reverse rotation of the electric motor connecting shaft 36, there is a risk that the cost will increase, and problems such as drive torque cuts due to erroneous monitoring may occur. The lower limit of the torque that the engine 12 can output is, for example, the engine rotation speed Ne, or the engine lower limit torque Telolim, which is predetermined according to the vehicle speed V, the gear position of the automatic transmission 24, or the like.

Therefore, when a torque reduction request is made to the electric motor connection shaft 36 by the predetermined control CTf, the requested torque arbitration unit 96 limits the driving force source torque Tsp to a level equivalent to the engine lower limit torque Telolim. This does not limit each of the engine torque Te and the MG torque Tm. That is, the required torque arbitration unit 96 sets the lower limit value of the required system shaft torque Tsdem used for controlling the engine torque Te and the MG torque Tm to a value obtained by converting the engine lower limit torque Telolim on the electric motor connection shaft 36 . In the power transmission device 16, the engine 12 is not connected to the electric motor connection shaft 36 via a reducer or a speed increaser, so the lower limit of the required system shaft torque Tsdem is set to the engine lower limit torque Telolim. be.

FIG. 2 is a block diagram illustrating control for distributing the required system shaft torque Tsdem to the engine torque Te and the MG torque Tm. In FIG. 2, in a block B10 (hereinafter, the block is omitted) corresponding to the function of the driving force source control section 92, the driver requested system shaft torque Tsdemd is calculated. In B20 corresponding to the functions of the operation control section 94 and the shift control section 98, a predetermined control required system shaft torque Tsdemf is calculated. At B30 corresponding to the function of the driving force source control section 92, the engine lower limit torque Telolim is estimated based on the engine rotation speed Ne and the like. At B40 corresponding to the function of the required torque arbitration section 96, the required system axial torque Tsdem is set to the driver required system axial torque Tsdemd or the predetermined control required system axial torque Tsdemf which is prioritized. At this time, the lower limit of the required system shaft torque Tsdem is limited by the engine lower limit torque Telolim. At B50 corresponding to the function of the driving force source control section 92, the required system shaft torque Tsdem is distributed to the engine torque Te and the MG torque Tm.

During HV running, when the engine lower limit torque Telolim is -10 [Nm], even if the torque down request from the shift control of the automatic transmission 24, that is, the predetermined control request system shaft torque Tsdemf is -30 [Nm]. , The engine torque Te and the MG torque Tm are set so that the driving force source torque Tsp, which is the total torque of the two, is -10 [Nm] or more, regardless of how the engine torque Te and the MG torque Tm are distributed. . For example, the engine torque Te may be -10 [Nm] and the MG torque Tm may be 0 [Nm], or the engine torque Te may be 20 [Nm] and the MG torque Tm may be -30 [Nm]. . The distribution between the two is set according to, for example, the state of charge of the battery 54, the warm-up state of the engine 12, and the like.

During EV running, if the engine lower limit torque Telolim is −10 [Nm] when it is assumed that HV running is performed with the vehicle speed V and the gear stage of the automatic transmission 24 at that time, the automatic transmission 24 MG torque Tm is set so that MG torque Tm is -10 [Nm] or more even if the torque reduction request from shift control is -30 [Nm].

FIG. 3 is a flowchart for explaining the main part of the control operation of the electronic control unit 90. Even if an excessive negative torque is required as the torque on the electric motor connecting shaft 36, the engine stall and the reverse rotation of the electric motor connecting shaft 36 will not occur. 4 is a flow chart illustrating control operation for suppressing or avoiding , which is executed repeatedly, for example.

In FIG. 3, first, in step S10 corresponding to the function of the required torque arbitration unit 96 (hereinafter, the step is omitted), the driver required system shaft torque Tsdemd is obtained. Next, in S20 corresponding to the function of the required torque arbitration unit 96, it is determined whether or not the predetermined control required system shaft torque Tsdemf has been calculated. If the determination in S20 is negative, the driver requested system shaft torque Tsdemd is set to the requested system shaft torque Tsdem in S30 corresponding to the function of the requested torque arbitration unit 96 . If the determination in S20 is affirmative, in S40 corresponding to the function of the required torque arbitration unit 96, it is determined whether or not a torque reduction request has been made from the predetermined control CTf. If the determination in S40 is negative, in S50 corresponding to the function of the required torque arbitration section 96, whichever of the driver required system shaft torque Tsdemd and the predetermined control required system shaft torque Tsdemf is prioritized is the required system shaft torque. It is set to the torque Tsdem. If the determination in S40 is affirmative, in S60 corresponding to the function of the required torque arbitration unit 96, the predetermined control required system shaft torque Tsdemf is set as the required system shaft torque Tsdem. Next, in S70 corresponding to the function of the required torque adjusting section 96, the engine lower limit torque Telolim is obtained. Next, in S80 corresponding to the function of the required torque arbitration unit 96, the required system shaft torque Tsdem is limited by the engine lower limit torque Telolim. Following S30, S50, or S80, in S90 corresponding to the function of the driving force source control section 92, the required system shaft torque Tsdem is distributed to the engine torque Te and the MG torque Tm.

As described above, according to this embodiment, the lower limit value of the required system shaft torque Tsdem used for controlling the engine torque Te and the MG torque Tm is the value obtained by converting the engine lower limit torque Telolim on the electric motor connection shaft 36. is set, the torque on the electric motor connecting shaft 36 realized by the engine torque Te and the MG torque Tm is suppressed or avoided from being reduced below the value obtained by converting the engine lower limit torque Telolim on the electric motor connecting shaft 36. be done. Therefore, even if excessive negative torque is required as the torque on the electric motor connection shaft 36, engine stall and reverse rotation of the electric motor connection shaft 36 can be suppressed or avoided.

Further, from the perspective of the predetermined control CTf, there is no need to consider the engine lower limit torque Telolim when calculating the predetermined control required system shaft torque Tsdemf, so there is no need to change the design of the predetermined control CTf.

Although the embodiments of the present invention have been described in detail above with reference to the drawings, the present invention is also applicable to other aspects.

For example, in the above embodiment, the power transmission device 16 including the K0 clutch capable of disconnecting the engine 12 from the electric motor connecting shaft 36 was exemplified, but the present invention is not limited to this aspect. For example, the power transmission device 16 may include a clutch capable of disconnecting the electric motor MG from the electric motor connecting shaft 36, and the electric motor MG may be selectively connected to the electric motor connecting shaft 36 via the clutch. . Alternatively, the power transmission device 16 may be configured such that the engine 12 and the electric motor MG are connected to the electric motor connecting shaft 36 so as to always be capable of transmitting power without intervening a clutch.

Further, in the above-described embodiment, the automatic transmission 24 is a planetary gear type automatic transmission, but it is not limited to this aspect. For example, the automatic transmission 24 may be a synchronous mesh parallel twin-shaft automatic transmission including a known DCT (Dual Clutch Transmission), a known belt-type continuously variable transmission, or the like. Alternatively, if the power transmission device 16 has a K0 clutch, the automatic transmission 24 does not necessarily have to be provided. In short, it has a driving force source including an engine and an electric motor, and a transmission shaft to which the driving force source is connected so as to be able to transmit power, and transmits the output torque of the driving force source input to the transmission shaft to the driving wheels. The present invention can be applied to any vehicle provided with a power transmission device.

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

It should be noted that what has been described above is just one embodiment, and the present invention can be implemented in aspects with various modifications and improvements based on the knowledge of those skilled in the art.

10: Vehicle 12: Engine 14: Driving Wheel 16: Power Transmission Device 20: K0 Clutch (Clutch)
36: Electric motor connecting shaft (transmission shaft)
90: Electronic control device (control device)
92: Driving force source control unit 96: Requested torque arbitration unit MG: Electric motor SP: Driving force source

Claims (1)

A driving force source including an engine and an electric motor, and a transmission shaft to which the driving force source is connected to the driving force source constantly or selectively via a clutch so that power can be transmitted, and the output of the driving force source inputted to the transmission shaft. A control device for a vehicle comprising a power transmission device that transmits torque to drive wheels,
a driving force source control unit that controls the output torque of the engine and the output torque of the electric motor so as to achieve a required transmission shaft torque that is a required torque value on the transmission shaft;
The lower limit value of the required transmission shaft torque used for controlling the output torque of the engine and the output torque of the electric motor is a value obtained by converting a predetermined lower limit value of the torque that the engine can output onto the transmission shaft. a request torque arbitration unit set to
A control device for a vehicle, comprising:

Images