Method for Operating an Automatic Transmission
AssigneeZF Friedrichshafen AG
InventorRuben Cueppers
Life of this patent
Estimating the term…
Abstract
A method for operating an automatic transmission is provided. The method includes commanding a positive shifting element to actuate to a disengaged configuration or an engaged configuration and opening at least one non-positive shifting element if the positive shifting element does not properly actuate. Opening the at least one non-positive shifting element may terminate power flow from the automatic transmission in order to protect the automatic transmission.
Claims20
A method for operating an automatic transmission, the automatic transmission having a plurality of non-positive shifting elements and at least one positive shifting element, the method comprising:
- commanding a first one of the at least one positive shifting element to actuate from a disengaged configuration to an engaged configuration;
- measuring a speed differential of a first one of the at least one positive shifting element during said step of commanding;
- and
- opening at least one non-positive shifting element of the plurality of non-positive shifting elements if the speed differential exceeds a speed differential limit during said step of measuring.
A method for operating an automatic transmission, the automatic transmission having a plurality of non-positive shifting elements and at least one positive shifting element, the method comprising:
- commanding a first one of the at least one positive shifting element to actuate from an engaged configuration to a disengaged configuration;
- determining a position of the first one of the at least one positive shifting element during said step of commanding;
- and
- opening at least one non-positive shifting element of the plurality of non-positive shifting elements if the position of the first one of the at least one positive shifting element does not reach an open position during said step of determining.
A method for operating an automatic transmission in a start-stop mode, the automatic transmission having a plurality of non-positive shifting elements and at least one positive shifting element, the method comprising:
- deactivating an engine of a vehicle when the vehicle comes to a stop;
- opening at least one non-positive shifting element of the plurality of non-positive shifting elements at said step of deactivating;
- keeping the at least one positive shifting element in an engaged configuration during said step of deactivating;
- activating the engine of the vehicle after said step of deactivating;
- and
- closing the at least one non-positive shifting element of the plurality of non-positive shifting elements at said step of activating.
Dependencies are inferred from the claim text.