The present invention is a powertrain for a hybrid vehicle, comprising a driving and receiving machine (20), a thermal engine (10) and engine shaft (12), a speed variation device (14) including an engine epicyclic gear train (24) with a sun gear (34) and a crown (42) which are each connected to the engine shaft (12) by an engine controlled coupling (26, 28) and to a fixed part (40) of the powertrain by a one-way automatic coupling (30, 32). A planet gear carrier (46) and a machine epicyclic gear train (60) are arranged on a shaft (62) substantially parallel to engine shaft (12). The planet gear carrier comprises a sun gear (64), a crown (72), a planet gear carrier (68) and an epicyclic gear train controlled coupling (88). The speed variation device (14) comprises a device (94) for connecting and disconnecting and electrical machine (20) with a machine epicyclic gear train (60).

The present invention relates to a method and apparatus for controlling a transmission of a vehicle and, more particularly, to a method and apparatus for controlling synchronization of a synchronizer included in a transmission. The method includes determining a speed change mode of a vehicle and a target time corresponding to the speed change mode; calculating a difference in speed between an input shaft and an output shaft with respect to a current time; calculating a speed increment or decrement of the output shaft from the current time to the target time; calculating a synchronization torque using the difference in speed and the speed increment or decrement; determining a target displacement of a synchronizer using the synchronization torque; and controlling the synchronizer according to the target displacement and recognizing a sleeve with a clutch gear.

An engine is driven at an operating point with high engine efficiency to improve fuel economy. A vehicle control device according to the present invention controls a transmission ratio before increasing the engine rotation speed, and thereafter, engages the clutch.

A vehicle powertrain includes a propulsion unit having a propulsion unit auxiliary brake, a transmission, driven wheels and a control unit arranged to control at least the transmission, where the propulsion unit is drivingly connected to the driven wheels via a clutch and different engagable gear ratios in the transmission. The control unit is arranged to perform the following steps when upshifting: automatically disengage the clutch in order to disengage the propulsion unit from the transmission; upshift the transmission to a new gear compared to current gear; initiate a synchronization in order to decrease and synchronize rotational speed of the propulsion unit to rotational speed of the new gear to be engaged; if it is determined by the control unit that the synchronization cannot be performed by decreasing rotational speed of the propulsion unit by the control unit controlling the auxiliary brake to brake the rotational speed of the propulsion unit then, automatically initiate a reengagement of the clutch in order to perform the synchronization.

A corresponding method, a computer program, a computer readable medium, and a control unit for controlling the powertrain are also provided.

A gear selection recommendation can be displayed in a vehicle having a transmission to be actuated manually. The gear selection recommendation can be calculated based on a present deceleration setpoint value to be ascertained by a control unit. A gear suitable for generating an engine braking force corresponding to the present deceleration setpoint value is calculated and the calculated gear is displayed as the gear selection recommendation on a display unit included in the vehicle.

An engine control device to be mounted on a vehicle is provided. The control device includes a transmission state determining module for determining a connection between a stepped transmission and an engine, determining that a gear shift has started if the connection is disengaged from a connected state, and determining that the gear shift has finished if the connection is resumed, a gear position estimating module for estimating a gear position when the gear shift is determined to have started, a target engine speed specifying module for specifying a target engine speed based on the estimated gear position, and a speed control module for controlling an engine speed to the target engine speed when the gear shift is determined to have started.

A starting clutch control device for an automatic transmission has a starting clutch controller. The starting control device controls a transmission torque capacity of a starting clutch interposed in a transmission path in which rotation of the power source is transmitted to wheels while shifting is underway by the automatic transmission. The starting clutch controller controls the transmission torque capacity of the starting clutch such that a rotation trajectory of the power source develops as desired in a low rotation speed range in which the transmission torque capacity control of the starting clutch is necessary. The starting clutch controller causes the transmission torque capacity of the starting clutch to change, when a shift of the automatic transmission occurs during the transmission torque capacity control by the starting clutch controller, in a direction in which the change in the rotation trajectory will occur corresponding to the shift.

In a vehicle having a manual transmission, various sensors such as pedal and gearshift position sensors and accelerometers provide data to a control module such as an engine control module. The control module includes a microprocessor which calculates derivatives, i.e., the rate of change (first derivative) or the rate of change of the rate of change (second derivative) of the data from the sensors. Based on these derivatives, the microprocessor classifies the current driving activity into one of two, three or more modes, for example, track, sport and touring. During a shift, from the data from the gearshift sensor, the microprocessor determines whether an upshift or downshift is imminent or in progress and decreases or increases the engine speed to achieve zero or negligible cross clutch speed differential upon clutch engagement, rapidly if in the first (track) mode, less rapidly in the second (sport) mode and less rapidly still in the third (touring) mode.