Method and Control Unit for Operating a Power-Shift Transmission

A method for operating a power shiftable transmission (G) of a motor vehicle, the transmission (G) including a control unit (ECU), an input shaft (GW1), an output shaft (GW2), a gear set (GRS), and multiple shift elements, the multiple shift elements interacting with the gear set (GRS) for providing various gear ratios between the input shaft (GW1) and the output shaft (GW2), the method comprising:

• transmitting, with the control unit (ECU), a request for a reduction of a drive torque (ME) acting on the input shaft (GW1) for carrying out an upshift;
• determining, with the control unit (ECU), whether the reduction of the drive torque (ME) acting on the input shaft (GW1) is completely possible, partially possible, or impossible based on a signal indicative of whether the reduction of the drive torque (ME) acting on the input shaft (GW1) is completely possible, partially possible, or impossible;
• controlling, with the control unit (ECU), a torque transmission rate of a shift element of the multiple shift elements to be engaged during the upshift according to a first way when it is determined that the reduction of the drive torque (ME) acting on the input shaft (GW1) is completely possible;
• and
• controlling, with the control unit (ECU), the torque transmission rate of the shift element of the multiple shift elements to be engaged during the upshift according to a second way when it is determined that the reduction of the drive torque (ME) acting on the input shaft (GW1) is partially possible or impossible, the second way differing from the first way,
• wherein the control unit (ECU) controls the torque transmission rate of the shift element of the multiple shift elements by an open-loop system or a closed-loop system.

A control unit (ECU) for open-loop control of functions of a power shiftable transmission (G) for a motor vehicle, the transmission (G) including an input shaft (GW1), an output shaft (GW2), a gear set (GRS), and multiple shift elements, the multiple shift elements interacting with the gear set (GRS) for providing various gear ratios between the input shaft (GW1) and the output shaft (GW2), wherein the control unit (ECU) is configured to:

• transmit a request for a reduction of a drive torque (ME) acting on the input shaft (GW1) for carrying out an upshift;
• determine whether the reduction of the drive torque (ME) acting on the input shaft (GW1) is completely possible, partially possible, or impossible based on a signal indicative of whether the reduction of the drive torque (ME) acting on the input shaft (GW1) is completely possible, partially possible, or impossible;
• control a torque transmission rate of a shift element of the multiple shift elements to be engaged during the upshift according to a first way when it is determined that the reduction of the drive torque (ME) acting on the input shaft (GW1) is completely possible;
• and
• control the torque transmission rate of the shift element of the multiple shift elements to be engaged during the upshift according to a second way when it is determined that the reduction of the drive torque (ME) acting on the input shaft (GW1) is partially possible or impossible, the second way differing from the first way.