Synchronous shift execution for hybrid transmission

Article of manufacture, comprising a computer readable storage medium having a computer program encoded therein for effecting a method to execute a shift in a transmission of a powertrain system, the powertrain system comprising a plurality of torque-generative devices operable to supply motive torque to the transmission device, the transmission device comprising a plurality of gears and a plurality of torque-transfer devices, wherein torque is transmitted between the transmission device and an output shaft through actuation of at least one of the torque-transfer devices, the computer program comprising:

• code for operating the transmission in an initial fixed ratio operation including actuation of a first torque-transfer device and a second torque-transfer device;
• code for reducing reactive torque of the first torque-transfer device;
• code for deactivating the first torque-transfer device when the reactive torque of the first torque-transfer device is less than a predetermined value;
• code for operating the transmission in a mode operation including actuation of the second torque-transfer device;
• code for determining rotational speed of an input shaft to the transmission is substantially synchronized with a rotational speed of a third torque-transfer device when operating the transmission in the mode operation;
• and
• code for actuating the third torque-transfer device when the rotational speed of the input shaft to the transmission is substantially synchronized with the rotational speed of the third torque-transfer device to operate the transmission in a final fixed ratio operation, including actuation of the second torque-transfer device and the third torque-transfer device.