A power-split transmission device for a vehicle, which connects a drive engine to a drive output, having a hydrostatic unit for continuous adjustment of the transmission ratio at a transmission unit, and two range clutches that alternately operate for respectively associated driving ranges with different transmission ratios. A control unit, during regular vehicle deceleration, implements the driving range change from a first range, with higher transmission ratios, to a second range, with lower transmission ratios, by switching from the first to the second range clutch in accordance with a synchronous point dependent deceleration control logic. In the special case of an unexpected increase of the deceleration dynamic at the beginning of an already initiated driving range change from the first to the second driving range, the control unit immediately forces the change by bypassing the synchronous point dependent deceleration control logic when other boundary conditions are fulfilled.

A power-split transmission which is designed to be operated with either first or second deceleration logics. The second deceleration logic has a higher deceleration dynamic than the first deceleration logic, and is designed to disengage an engaged range clutch immediately so as to reduce the transmission ratio by way of a hydrostatic unit with a maximum dynamic. A method of operating the transmission includes: monitoring various vehicle parameters while the vehicle is operated with the first deceleration logic; detecting that at least one set limit value has been exceeded while the vehicle operated with the first deceleration logic; activating the second deceleration logic, to immediately disengage an engaged range clutch; reducing a transmission ratio to a maximum using the hydrostatic unit, the hydrostatic unit being displaced with a maximum dynamic; and engaging the range clutch and activating the first deceleration logic.

A transmission includes an input shaft, an output shaft, a variable-ratio unit, and a plurality of torque transmitting mechanisms. The plurality of torque transmitting mechanisms include a first clutch, a second clutch, a third clutch, and a fourth clutch. The transmission is operable to (i) engage the first clutch and the second clutch in a first operating mode and (ii) engage the first clutch and the third clutch in a second operating mode. The transmission is further operable to (i) engage the fourth clutch and disengage the second clutch during a first period of time and (ii) engage the third clutch and disengage the fourth clutch during a second period of time following the first period of time to transition from the first operating mode to the second operating mode.

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.

A work vehicle including a transmission that transmits power of an engine to wheels at a plurality of different transmission gear ratios, the work vehicle traveling while maintaining a targeted speed by controlling a degree of opening of an accelerator, brakes, and the transmission, wherein the work vehicle includes a controller which inhibits change in the transmission gear ratio of the transmission when the transmission shifts up before lapse of a first predetermined time after the transmission shifts down while the vehicle is running downhill and then before a second predetermined time elapses, the transmission shifts down while the vehicle is running downhill.