A method for operating a drive device for a motor vehicle, which has an internal combustion engine and an electric motor. A drive shaft of the internal combustion engine can be coupled to a motor shaft of the electric motor by a shift clutch. The shift clutch is adjusted to a desired clutch torque over a dragging period for startup of the internal combustion engine. Prior to the startup, a quantity of heat that is expected to accrue in the shift clutch during the startup is predicted and, when the predicted quantity of heat exceeds a limit value, at least one operating parameter of the drive device that influences the startup is chosen in such a way that the quantity of heat expected to accrue is reduced.

A vehicle driving apparatus includes a friction clutch, a lubricating system, and a control system. The friction clutch is disposed in a power transfer path coupling a power source of a vehicle to drive wheels of the vehicle, and controls a torque distribution ratio between the drive wheels. The lubricating system supplies oil to the friction clutch. The control system executes clutch protection control to suppress an occurrence of a slip state of the friction clutch. The control system executes the clutch protection control when a slip amount of the friction clutch becomes larger than a first threshold while the friction clutch is in a first lubricating state, and executes the clutch protection control when the slip amount of the friction clutch becomes larger than a second threshold while the friction clutch is in a second lubricating state.

The invention relates to a method for controlling a drivetrain having an internal combustion engine, a dual-clutch transmission, having a first and second sub-transmission having at least one shiftable gear ratio, a first friction clutch disposed between the internal combustion engine and the first sub-transmission and a second friction clutch disposed between the internal combustion engine and the second sub-transmission to provide a drivetrain torque at a transmission output of the dual-clutch transmission by transferring an engine torque adjusted thereto via the friction clutches. So as to be able to continue operating a friction clutch which may have a previously damaged friction lining, at a first clutch torque transferred via the first friction lining, depending on a friction coefficient and a current temperature of a second friction lining of the second friction clutch, the second friction clutch is engaged at a gear ratio selected in the second sub-transmission and the friction lining is heated to a specified temperature.

A hybrid vehicle includes an engine, an electric machine, a disconnect clutch configured to selectively couple the engine to the electric machine, and a controller. The controller is programmed to, in response to a request to start the engine with the electric machine, command a target pressure to the disconnect clutch that depends on a seal friction derived from a measured line pressure of the disconnect clutch and a rate change of the measured line pressure.

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.

Embodiments of the present invention provide a control system (200) for an electric machine (120) of a vehicle, the control system comprising one or more controllers, the control system comprising input means (230) to receive a torque communication signal (255) indicative of torque communication through a belt (130) associated with the electric machine, processing means (210) arranged to determine a torque limit for the electric machine in dependence on the torque communication signal and a first torque threshold, and output means (240) arranged to output a torque limit signal (245) in dependence on the torque limit to control the torque communicated through the belt associated with the electric machine.