Methods and systems are provided for operating a driveline of a hybrid vehicle that includes an internal combustion engine, an electric machine, and a transmission, where the transmission is downstream of the engine, and where the electric machine is downstream of the transmission. In one example, responsive to a driver-demanded wheel torque that exceeds a capacity of the electric machine, a vehicle acceleration plateau is avoided by transiently connecting a crankshaft of the engine to a low speed input shaft of the transmission while the engine is accelerating to a target speed.

An internal combustion engine and a multi-speed transmission in series, the shift control device comprising: a control portion providing a downshift control input shaft rotation speed of the multi-speed transmission is increased through a torque-up control of the internal combustion engine toward a post-shift input shaft rotation speed in a neutral state where a release-side frictional engagement device during a downshift of the multi-speed transmission is released, an engagement-side frictional engagement device to be engaged after the shift; and a torque setting portion setting a required torque of the internal combustion engine in the torque-up control of the internal combustion engine increasing rate of an actual torque of the internal combustion engine becomes smaller in the case of a shift pattern having a large internal inertia of the multi-speed transmission during the downshift as compared to the case of a shift pattern in which the internal inertia is small.

A method for operating a drive train of a motor vehicle includes closing a frictional-locking shift element that serves as a starting element of a transmission in a slipping manner such that slip at the frictional-locking shift element is reduced by a defined pressure control of the frictional-locking shift element, determining a differential rotational speed at the frictional-locking shift element or a variable dependent on the differential rotational speed while the frictional-locking shift element is closing, and, when the differential rotational speed or the variable dependent on the differential rotational speed is less than a first limit value or reaches the first limit value, changing a rotational speed of the drive unit in such a manner that the differential rotational speed or the variable dependent on the differential rotational speed becomes less than a second limit value or reaches the second limit value within a defined time period.

A control device of a vehicle including a multi-speed transmission having gear positions switched by executing release of a release-side engagement device out of a plurality of engagement devices and engagement of an engagement-side engagement device out of the plurality of engagement devices, and an engine of which a power is transmitted through the multi-speed transmission to drive wheels, the control device performing a shift of the multi-speed transmission by using a predefined shift model for determining control operation amounts of a torque at an input rotating member of the multi-speed transmission, a torque capacity of the release-side engagement device, and a torque capacity of the engagement-side engagement device, the control operation amounts achieving shift target values that are a target value of a torque at an output rotating member of the multi-speed transmission and a target value of angular acceleration of the input rotating member of the multi-speed transmission, the control device comprising: a condition setting portion setting a condition necessary for determining the control operation amounts using the shift model such that during a downshift performed during deceleration running associated with accelerator-off state, an output torque of the engine is raised with the release-side engagement device released so as to increase a rotation speed of the input rotating member of the multi-speed transmission toward a synchronous rotation speed after the downshift and such that the engagement-side engagement device is then engaged; and a shift target value setting portion setting the target value of the torque at the output rotating member of the multi-speed transmission during the downshift such that the torque at the output rotating member of the multi-speed transmission is increased from a value of the torque at the output rotating member before the downshift within a range of zero or less, and when a rotation speed of the input rotating member of the multi-speed transmission approaches the synchronous rotation speed after the downshift, the target value is reduced toward a torque at the output rotating member after the downshift.

A control device that controls a vehicle drive transmission device including a speed change device disposed on a power transmission path connecting an internal combustion engine and wheels, and an engagement device disposed between the internal combustion engine and the speed change device, the control device including an electronic control unit.

A vehicle drive system includes an internal combustion engine, a clutch, an engine rotation speed detector, an output shaft rotation speed detector, and a processor. The internal combustion engine includes cylinders and a crankshaft. The clutch is connected to the crankshaft via a torsion element and includes an output shaft. The engine rotation speed detector detects a crankshaft rotation speed. The output shaft rotation speed detector detects an output shaft rotation speed. The processor is configured to calculate a torque generated in each of the cylinders based on the crankshaft rotation speed. The processor is configured to decrease transmission torque of the clutch so that a difference between the crankshaft rotation speed and the output shaft rotation speed to be a target value when misfiring occurs. The processor is configured to identify a misfiring cylinder among the cylinders based on the torque calculated while the transmission torque is decreased.

A vehicle includes an engine and an electric machine coupled to a gearbox through a torque converter. The vehicle includes a controller programmed to command an engine torque and an electric machine torque to achieve a predetermined positive torque at the input of the torque converter when a driver demand torque at the torque converter input decreases to fall within a range between the predetermined positive torque and a predetermined negative torque.

The present invention relates to a controlling apparatus for a powertrain of an electric vehicle, wherein the electric vehicle comprises a gearbox having an input shaft, a first electric machine and a second electric machine being coupled to the input shaft of the gearbox. The controlling apparatus is configured to control the operation of the first and second electric machines by the steps of: changing the speed of the first and second electric machines to reach a target speed of the input shaft; determining that the speed of the input shaft is within a target range of the target speed; setting one of the first and second electric machines in a first control mode, the first control mode being speed control to adjust for changes so that the target speed of the input shaft can be kept when reached, and setting the other one of the first and second electric machines in a second control mode being different to the first control mode, in response of determining that the speed of the input shaft is within the target range.

Method and system for starting an internal combustion engine that rotates a drive shaft providing torque to a driving wheel via a transmission unit comprising a first clutch connecting the engine to an input shaft of a gearbox connected to a torque converter. The torque converter is connected to a second clutch connected to the driving wheel through a transmission, and the input shaft is connected to an auxiliary drive source in an offset arrangement with a predetermined torque ratio between the input shaft and the auxiliary drive source. Starting the engine comprises disengaging the first clutch, disengaging the second clutch to a predetermined torque level, accelerating the input shaft and the torque converter with the auxiliary drive source to a predetermined rotational speed, and engaging the first clutch to start the engine with the energy stored in the input shaft, the torque converter, and the auxiliary drive source.

A method for learning a touch point of an engine clutch of a hybrid electric vehicle including a motor connected to a transmission and an engine selectively connected to the motor through the engine clutch includes determining whether a learning condition of the touch point of the engine clutch is satisfied, releasing a transmission clutch and controlling a motor speed when the learning condition is satisfied, increasing a coupling pressure of the engine clutch when a change amount of the motor speed is less than a first predetermined value, comparing a change amount of a motor torque according to the increased coupling pressure of the engine clutch with a second predetermined value, and learning the touch point of the engine clutch when the change amount of the motor torque is greater than or equal to the second predetermined value.