A method for operating a drive train of a motor vehicle includes performing a startup operation of the motor vehicle or a stopping operation of the motor vehicle. A starting component (3) is engaged or bridged during the startup operation or the stopping operation of the motor vehicle. The startup operation is driven by a drive source (1). The method also includes comparing an actual value of an output shaft (22) based variable with a target value of the output shaft (22) based variable during the startup operation or the stopping operation and, on reaching or exceeding a specific deviation of the actual value from the target value, moving the starting component (3) into a slipping state. The starting component (3) transmits torque in the slipping state. A related drive train module for a motor vehicle is also provided.

Systems and methods for operating a hybrid driveline that includes an engine, a motor/generator, and a driveline disconnect clutch are described. The systems and methods may improve vehicle efficiency while providing expected vehicle operation and performance. In one example, transmission line pressure is adjusted to match driveline disconnect clutch torque capacity to driver demand torque.

A hybrid rear axle provides a variety of functionality in addition to the functionality of a non-hybrid axle. The axle transmits power from an electric motor to the drive wheels at two selectable speed ratios to propel the vehicle. One of the two ratios is usable to propel the vehicle electrically with the engine stopped. With the drive wheels stationary, the axle transmits power from the driveshaft to the motor to charge a battery or from the motor to the driveshaft to start the engine.

A vehicle includes an engine and electric machine connected to a planetary gear, a one-way clutch, and a controller. The one-way clutch transfers torque from the planetary gear to an overdrive gear. The controller, in response to a condition requiring disengagement of the one-way clutch, increases a torque of the electric machine based on a torque command for the electric machine and the torque transferred from the planetary gear to the overdrive gear.

A control process including the following steps is executed. The control process includes, at the time of switching from series-parallel mode to series mode, a step of reducing an engine torque, a step of releasing a clutch, a step of reducing a reaction torque of a first rotary electric machine and a step of increasing a torque of a second rotary electric machine, and, when synchronization is started and a step of increasing a positive torque of the first MG, a step of starting engagement of a clutch, and, when a rotation speed of the first rotary electric machine and a rotation speed of an engine are synchronous with each other, a step of engaging the clutch.

A device for controlling an engine clutch in an environmentally-friendly vehicle, wherein the engine clutch is disposed between an engine and a driving motor and is configured to selectively connect the engine to the driving motor, includes: a transmission configured to receive a driving force that is transmitted from at least one of the engine and the driving motor by release or engagement of the engine clutch; and a controller configured to control the engine clutch based on a gear of the transmission when the failure of the engine clutch is detected and configured to charge a battery using the engine.

System and methods are provided for improving fuel economy of a hybrid vehicle. A hybrid vehicle may include an EV driving mode, where the motor alone powers the hybrid vehicle. However, use of such a driving mode may be limited to conditions involving low drive force and power requests due to motor and battery power specifications. In some circumstances, the conditions during which the motor can be used to power the hybrid vehicle can be expanded. Such conditions may include instances where the driver only seeks light accelerations for a short period of time. Such an expanded EV mode may be triggered when the hybrid vehicle is travelling a downhill grade.

A hybrid drive including a first drive motor coupled by a clutch to a shaft, and a second drive motor coupled rigidly to the shaft. A method for determining the temperature of the clutch in the hybrid drive includes the steps of: determining a temperature of the clutch; determining a temperature of the clutch housing; determining the temperature difference between the clutch and the clutch housing; determining the heat conductivity between the clutch and the clutch housing, wherein the heat conductivity is determined as a function of the rotational speed of the first drive motor and the rotational speed of the second drive motor; determining the heat flow between the clutch and the clutch housing on the basis of the product of the heat conductivity and the temperature difference; and adjusting the ascertained clutch temperature on the basis of the ascertained heat flow.

A method for starting a combustion engine fitted to a hybrid or dual-mode motor vehicle includes starting an additional motor upon a setpoint torque demanded by a driver of the vehicle, with a view to accelerating the vehicle beyond a threshold speed at which the combustion engine is driven beyond a stalling speed threshold when the combustion engine is mechanically coupled to wheels of the vehicle.

A low-voltage hybrid powertrain system for a vehicle includes an engine that is coupled via an engine disconnect clutch to an input member of the transmission, and a low-voltage electric machine is coupled to the transmission. The powertrain system operates in an electric vehicle (EV) mode with the engine in an OFF state and with the engine disconnect clutch in an open/deactivated state. When an output torque request indicates a command for vehicle acceleration, the electric machine is controlled to generate torque in response to the output torque request and the engine is simultaneously cranked and started. Upon starting, the engine operates in a speed control mode to activate the engine disconnect clutch. The engine and the low-voltage electric machine are controlled to generate torque in response to the output torque request when the engine disconnect clutch is activated.