A method for operating a transmission device for a motor vehicle. A drive gear is selected from a drive gear set and set on a transmission and upon going above a rotational speed upper limit a drive gear with a larger gearing ratio and upon going below a rotational speed lower limit a drive gear with a smaller gearing ratio is selected from the drive gear set and set on the transmission. In a normal operating mode, the drive gear set corresponds to a normal operation drive gear set having a plurality of different drive gears, and the rotational speed upper limit corresponds to a normal operation rotational speed upper limit and the rotational speed lower limit corresponds to a normal operation rotational speed lower limit. In an alternative operating mode the drive gear set corresponds to an alternative operation drive gear set, having a smaller number of different drive gears than the normal operation drive gear set.

A method for operating a transmission device for a motor vehicle. A drive gear is selected from a drive gear set and set on a transmission and upon going above a rotational speed upper limit a drive gear with a larger gearing ratio and upon going below a rotational speed lower limit a drive gear with a smaller gearing ratio is selected from the drive gear set and set on the transmission. In a normal operating mode, the drive gear set corresponds to a normal operation drive gear set having a plurality of different drive gears, and the rotational speed upper limit corresponds to a normal operation rotational speed upper limit and the rotational speed lower limit corresponds to a normal operation rotational speed lower limit. In an alternative operating mode the drive gear set corresponds to an alternative operation drive gear set, having a smaller number of different drive gears than the normal operation drive gear set.

During a shift from a first driving range to a second driving range in a continuously variable power-split transmission having a continuously variable branch and a mechanical branch, in which during the range shift, the synchronous rotation speed is kept constant, the range shift is discontinued if a predefined threshold of at least one driving requirement is exceeded.

An automatic transmission includes a main transmission and an auxiliary transmission. The auxiliary transmission includes an auxiliary-transmission-side planetary gear mechanism, a first clutch, and a second clutch. The auxiliary-transmission-side planetary gear mechanism is provided between a pair of main-transmission-side planetary gear mechanisms, and a part of the auxiliary-transmission-side planetary gear mechanism is located within the main transmission. The first clutch fixes rotation of a sun gear of the auxiliary-transmission-side planetary gear mechanism. The second clutch connects a ring gear of the auxiliary-transmission-side planetary gear mechanism with the sun gear.

An automatic transmission includes a main transmission and an auxiliary transmission. The auxiliary transmission includes an auxiliary-transmission-side planetary gear mechanism, a first clutch, and a second clutch. The auxiliary-transmission-side planetary gear mechanism is provided between a pair of main-transmission-side planetary gear mechanisms, and a part of the auxiliary-transmission-side planetary gear mechanism is located within the main transmission. The first clutch fixes rotation of a sun gear of the auxiliary-transmission-side planetary gear mechanism. The second clutch connects a ring gear of the auxiliary-transmission-side planetary gear mechanism with the sun gear.

A system and method for minimizing shift cycling for low speed engine operation with a vehicle cruise control. A vehicle control system operating in a cruise control mode determines a deficiency in vehicle speed between a measured vehicle speed and a cruise set speed. The deficiency is determined by comparing the vehicle speed to the cruise set speed, and includes using the compared value to find a cruise speed margin, which is continuously updated. While the cruise control system is active, the control system logic determines the time at which a transmission upshift occurs based on the cruise speed margin. The vehicle speed, at which the upshift is made, is determined as a function of the updated cruise speed margin. An upshift is not made, if a likely drop in vehicle speed would result in the event a downshift would occur once the upshift is made.

A method of adjusting deceleration dependent shift points to maintain a target minimum turbine speed includes calculating a vehicle speed offset based on vehicle acceleration rate a predicted downshift delay for the target minimum turbine speed and converting the target minimum turbine speed to a target vehicle speed based on the deceleration condition. Thereafter, the method continues with determining a target gear based on the vehicle speed offset and the target vehicle speed, and downshifting to the target gear having vehicle speed less than or equal to a vehicle speed corresponding to the current turbine speed. The method ends with maintaining the target gear until a shift delay period is greater than a predetermined delay threshold.

A system and method for minimizing shift cycling for low speed engine operation with a vehicle cruise control. A vehicle control system operating in a cruise control mode determines a deficiency in vehicle speed between a measured vehicle speed and a cruise set speed. The deficiency is determined by comparing the vehicle speed to the cruise set speed, and includes using the compared value to find a cruise speed margin, which is continuously updated. While the cruise control system is active, the control system logic determines the time at which a transmission upshift occurs based on the cruise speed margin. The vehicle speed, at which the upshift is made, is determined as a function of the updated cruise speed margin. An upshift is not made, if a likely drop in vehicle speed would result in the event a downshift would occur once the upshift is made.

A method for controlling a transmission for a vehicle includes: sensing, by a controller, an opening degree of an accelerator pedal; checking, by the controller, a gear stage engaged with an input shaft, with which a Reverse (R) gear and a second gear of a Dual-Clutch Transmission (DCT) are engageable, if the opening degree of the accelerator pedal is less than or equal to a reference value as a result of the sensing; and controlling, by the controller, the vehicle in a parking mode in which disengagement of the R gear is prevented if the R gear is engaged with the input shaft as a result of the checking.

A method for controlling a transmission for a vehicle includes: sensing, by a controller, an opening degree of an accelerator pedal; checking, by the controller, a gear stage engaged with an input shaft, with which a Reverse (R) gear and a second gear of a Dual-Clutch Transmission (DCT) are engageable, if the opening degree of the accelerator pedal is less than or equal to a reference value as a result of the sensing; and controlling, by the controller, the vehicle in a parking mode in which disengagement of the R gear is prevented if the R gear is engaged with the input shaft as a result of the checking.