Double transition shift control in an automatic powershifting transmission

A method for controlling a double transition downshift in an automatic transmission of a vehicle powertrain, comprising:

• performing closed loop control of an intermediate shaft speed using a primary on-coming clutch in a primary gear section of the automatic transmission to achieve pull-up of the intermediate shaft, the primary gear section connected to an output shaft and the intermediate shaft, the intermediate shaft connected between the primary gear section and a secondary gear section of the automatic transmission;
• while the intermediate shaft is being pulled up, performing closed loop control of an input shaft speed using a secondary off-going clutch in the secondary gear section to achieve partial pull-up of the input shaft, the input shaft connected between the secondary gear section and a power generation unit of the vehicle;
• and
• releasing the secondary off-going clutch and performing closed loop control of the input shaft speed using a secondary on-coming clutch in the secondary gear section to complete the pull-up of the input shaft.

A system for controlling a double transition upshift in an automatic transmission of a vehicle powertrain, comprising:

• a primary gear section of the automatic transmission, the primary gear section connected to an output shaft;
• a secondary gear section of the automatic transmission;
• an intermediate shaft connected between the primary gear section and secondary gear section;
• an input shaft connected between the secondary gear section and a power generation unit of the vehicle;
• and
• a processor-based controller in operative communication with the primary and secondary gear sections;
• wherein the controller is configured to perform closed loop control of the intermediate shaft speed during the double transition upshift using a primary on-coming clutch in the primary gear section to achieve pull-down of the intermediate shaft;
• wherein the controller is further configured to perform closed loop control of the input shaft speed using a secondary off-going clutch in the secondary gear section to achieve partial pull-down of the input shaft while the intermediate shaft is being pulled down;
• and
• wherein the controller is further configured to release the secondary off-going clutch and perform closed loop control of the input shaft speed using a secondary on-coming clutch in the secondary gear section to complete the pull-down of the input shaft.

A system for controlling a double transition downshift in an automatic transmission of a vehicle powertrain, comprising:

• a primary gear section of the automatic transmission, the primary gear section connected to an output shaft;
• a secondary gear section of the automatic transmission;
• an intermediate shaft connected between the primary gear section and secondary gear section;
• an input shaft connected between the secondary gear section and an a power generation unit of the vehicle;
• and
• a processor-based controller in operative communication with the primary and secondary gear sections;
• wherein the controller is configured to perform closed loop control of the intermediate shaft speed during the double transition downshift using a primary on-coming clutch in the primary gear section to achieve pull-up of the intermediate shaft;
• wherein the controller is further configured to perform closed loop control of the input shaft speed using a secondary off-going clutch in the secondary gear section to achieve partial pull-up of the input shaft while the intermediate shaft is being pulled up;
• and
• wherein the controller is further configured to release the secondary off-going clutch and perform closed loop control of the input shaft speed using a secondary on-coming clutch in the secondary gear section to complete the pull-up of the input shaft.