A method for operating a hybrid drive assembly for a motor vehicle, which has an internal combustion engine and an electric engine. A separating clutch arranged in drive terms between the internal combustion engine and the electric engine is set to a target clutch torque by at least partially engaging during an attempt to start the internal combustion engine. An actual clutch torque actually transmitted via the separating clutch and a speed of the internal combustion engine are determined during the attempt to start, and if a characteristic value dependent on the actual clutch torque exceeds a threshold value and if an integral of the speed over time continuously falls below a limit value during the attempt to start, the attempt to start is aborted.

A method for operating a hybrid drive train of a motor vehicle includes: starting the motor vehicle solely with the aid of an electric machine; engaging a torque converter lockup clutch for rotationally fixing an impeller of a torque converter to a turbine wheel of the torque converter, wherein the turbine wheel is rotationally fixed to the electric machine; and engaging a clutch in order to drivingly connect the impeller to a motor vehicle drive unit, in order to start the motor vehicle drive unit.

A vehicle control apparatus includes an overlapping-prediction determination portion configured to determine whether or not it is predicted that, during execution of a synchronous control for placing a clutch, which is provided between an engine and an electric motor, into an engaged state, a synchronization-completion time point of the clutch overlaps with an inertia phase period in process of a shift control of a transmission, and a torque limitation portion configured, when the overlapping-prediction determination portion determines that it is predicted that the synchronization-completion time point overlaps with the inertia phase period, to execute a torque limitation by which at least one of a torque capacity of the clutch and an output torque of the engine is made smaller than when the overlapping-prediction determination portion determines that it is not predicted that the synchronization-completion time point overlaps with the inertia phase period.

A method for estimating cardan shaft moments in a vehicle includes performing a state space modelling of a physical model for force transmission in at least one drive train The at least one drive train is formed with at least one drive machine, at least one axle and at least two axle shafts each with a respective wheel. The method further includes selecting the physical model as a torsional oscillator chain in which a respective drive machine inertia moment is assigned to the respective drive train and a respective wheel inertia moment is assigned to the respective wheel. The respective drive machine inertia moment is connected by a respective spring-damper element to the respective wheel inertia moment of the respective wheel which is connected to the respective axle shaft. A vehicle mass is connected by a respective spring-damper element to the respective wheel inertia moment of the respective wheel.

The method includes, based on a torque variation of a drive shaft after an engagement timing of an engine clutch 21 and before a release timing of a motor clutch 19 when switching a power transmission path from a first power transmission path 24 to a second power transmission path 25, increasing a slope of a torque increase of a power generation motor 4 in an absolute value with respect to a slope of a torque decrease of a traveling motor 2 in at least a part of a period from a timing T12 to a timing T14, and increasing a slope of a torque decrease of the power generation motor 4 in the absolute value with respect to a slope of a torque increase of the traveling motor 2 in at least a part of a period from the timing T14 to a timing T16.

Systems and methods for starting an engine that may be started via an electric machine and a driveline disconnect clutch are described. In one example, the method estimates a maximum motor propulsive torque during engine starting. The maximum motor propulsive torque may be based on an estimated speed that a torque converter impeller speed will be when an engine cranking period ends.

A vehicle control apparatus includes an overlapping-prediction determination portion configured to determine whether or not it is predicted that, during execution of a synchronous control for placing a clutch, which is provided between an engine and an electric motor, into an engaged state, a synchronization-completion time point of the clutch overlaps with an inertia phase period in process of a shift control of a transmission, and a torque limitation portion configured, when the overlapping-prediction determination portion determines that it is predicted that the synchronization-completion time point overlaps with the inertia phase period, to execute a torque limitation by which at least one of a torque capacity of the clutch and an output torque of the engine is made smaller than when the overlapping-prediction determination portion determines that it is not predicted that the synchronization-completion time point overlaps with the inertia phase period.

A method and device for operating a powertrain of a motor vehicle are provided, wherein the powertrain includes an internal combustion engine, a transmission and a friction clutch arranged there between in order to control a power flow between the internal combustion engine and the transmission. The method includes the steps of detecting clutch judder, analysing clutch judder, and determining a type of clutch judder. Based on determined type of clutch judder the method further includes selecting a udder countermeasure from a number of predetermined judder countermeasures and executing selected judder countermeasure. Detected clutch judder can be taken care of in an efficient way and future clutch judder may be prevented.

A transmission includes an input shaft coupled to a prime mover, a countershaft, main shaft, and an output shaft, with gears between the countershaft and the main shaft. The shift actuator is mounted on an exterior wall of a housing including the countershaft and the main shaft. A shift control circuit operates a shift actuator using a first opposing pulse command and a first actuating pulse command, and releases pressure with shift actuating and opposing volumes of the shift actuator upon determining a shift completion event.

A transmission includes an input shaft coupled to a prime mover, a countershaft, main shaft, and an output shaft, with gears between the countershaft and the main shaft. A shift actuator selectively couples the input shaft to the main shaft by rotatably coupling gears between the countershaft and the main shaft. The shift actuator is mounted on an exterior wall of a housing including the countershaft and the main shaft. A controller controls the shift actuator utilizing an actuating pulse and an opposing pulse.