A control device that includes an electronic control unit that is programmed such that, when the internal combustion engine is started by the rotary electric machine while output torque from the rotary electric machine is transferred to the wheels in a state in which rotation of the internal combustion engine has been stopped, the electronic control unit: executes second slipping control in which the second engagement device is controlled into a slipping engagement state, executes first slipping control in which the first engagement device which has been in a disengaged state is controlled into a slipping engagement state during execution of the second slipping control, and controls an engagement pressure of the first engagement device so as to lower a rotational speed of the rotary electric machine in the first slipping control.

A method for operating a drivetrain of a motor vehicle, includes, when the motor vehicle is at a standstill and upon demand for a drive torque of the motor vehicle, increasing power (25p) supplied to a separate electric pump drive (25) such that a pressure chamber whose pressurization effects a complete closure or lock-up of a launch element (3) is fast charged with hydraulic pressure from a pump (24). The method also includes performing a launch process of the motor vehicle with the drive source (1) and with a closed or locked-up launch element (3) and reducing the power (25p) supplied to the separate electric pump drive (25) after fast charging the pressure chamber. A related drive train module is also provided.

A control device for a vehicle is provided. The vehicle includes an engine, an accessory, a continuously variable transmission, and a lock-up clutch. The control device includes an electronic control unit. The electronic control unit is configured to: when the load state is less than a predetermined value, control the speed ratio of the continuously variable transmission and the rotational speed of the engine such that the rotational speed of the engine during engagement of the lock-up clutch is kept at a first rotational speed; and when the load state is greater than or equal to the predetermined value, control the speed ratio of the continuously variable transmission and the rotational speed of the engine such that the rotational speed of the engine during engagement of the lockup clutch becomes a second rotational speed higher than the first rotational speed.

Systems and methods for improving operation of a hybrid vehicle driveline are presented. In one example, a margin torque for closing a torque converter clutch is adjusted responsive to a state of engine operation.

A method for operating a drive train of a motor vehicle may include, for a starting process of an internal combustion engine, transferring the separating clutch from a disengaged condition into an engaged condition or a slip state such that the electric machine accelerates the internal combustion engine to a starting speed. The method may further include actuating a torque-transmitting element between the electric machine and the output shaft to enter a slip state. The method may also include increasing the torque of the electric machine to reliably reach and hold the slip state of the torque-transmitting element. Additionally, the method may include operating the electric machine as a generator or as a motor depending on an expected load direction of the drive train during the starting process to reliably reach and hold the torque-transmitting element in the slip state.

A control device for a vehicle including a variable compression ratio mechanism arranged to vary an engine compression ratio of an internal combustion engine, and a torque converter which includes a lock-up mechanism, and which is disposed between the internal combustion engine and a transmission, has a controller configured to switch the engine compression ratio from a high compression ratio to a low compression ratio, and to switch the lock-up mechanism from a lock-up OFF state to a lock-up ON state. When the controller is switching the engine compression ratio from the high compression ratio to the low compression ratio, the controller starts switching the lock-up mechanism to the lock-up ON state when a current engine compression ratio is equal to or smaller than a permissible compression ratio which is between the high compression ratio and the low compression ratio.

A power transmission device of the present invention is a power transmission device for a vehicle, including: a generator configured to be driven by power of an internal combustion engine; a travel motor configured to be driven by electric power generated by the generator and to drive a drive wheels; and the drive wheels configured to be driven by the power of the internal combustion engine or power of the travel motor. The power transmission device includes: a first power transmission path configured to transmit power between the travel motor and the drive wheels; and a first clutch mechanism configured to allow or interrupt power transmission through the first power transmission path.

A transmission gear control apparatus for a vehicle is provided. The vehicle includes an automatic transmission, a torque converter, and an accelerator operation amount sensor. The torque converter is disposed between the engine and the automatic transmission. The transmission gear control apparatus includes an electronic control unit. The electronic control unit is configured to: (i) control switching of a transmission gear stage of the automatic transmission at least on a basis of a change in vehicle speed of the vehicle; (ii) control lockup of a lock-up clutch of the torque converter on a basis of a state of the vehicle; and (iii) control the automatic transmission when the accelerator operation amount is equal to or larger than a specified value such that an upshift of the automatic transmission is performed at a higher vehicle speed as a rotation difference between input and output of the torque converter is reduced.

A controller and a control strategy for a hybrid electric vehicle having a traction motor between an engine and an automatic transmission include maintaining a bypass clutch of a torque converter in an engaged position and applying a motor torque from a traction motor to the torque converter such that slip of the torque converter does not otherwise reach zero while the bypass clutch is maintained in the engaged position.

An electronic control unit starts shift initial oil pressure control after the completion of lockup initial oil pressure control when shift control is performed during the performance of lockup control, the electronic control unit starts shift initial oil pressure control after the completion of lockup initial oil pressure control. Besides, the electronic control unit places priority on the shift control and starts the lockup initial oil pressure control after the completion of the shift initial oil pressure control, when the lockup control is performed during the performance of the shift control. Therefore, the shift initial oil pressure control and the lockup initial oil pressure control are prevented from occurring at the same time when the shift control and the lockup control are performed at the same time.