Machine powertrain and method

A method for reducing power variation in a powertrain during a shift from a converter-drive mode to a direct-drive mode, the powertrain including an engine connected to a transmission through a torque converter, the torque converter being configured to operate in an unlocked state during the converter-drive mode and in a locked state during the direct-drive mode, the transmission having one or more selectable forward and reverse gear ratios, the engine being controlled by an electronic controller, the method comprising:

• providing a locking signal indicative of a locked or unlocked condition of the torque converter;
• providing a throttle signal indicative of an engine throttle command;
• receiving the locking and throttle signals in the electronic controller;
• controlling operation of the engine with the electronic controller at least partially based on the locking and throttle signals by, at least partially:
• determining whether a locked or unlocked condition of the torque converter is present based on the locking signal;
• determining whether a part throttle operating condition or a full throttle operating condition is present based on the throttle signal;
• and
• selecting a load-control power curve for the part throttle operating condition when the torque converter switches from the unlocked to the locked condition.

A method for reducing power variation in a powertrain during a locking of a torque converter, the powertrain including an engine connected to a transmission through the torque converter, the transmission having one or more selectable forward and reverse gear ratios, the engine being controlled by an electronic controller, the method comprising:

• operably arranging a processor with a data storage device and a communication channel;
• providing a locking signal indicative of a locked or unlocked condition of the torque converter over the communication channel;
• providing a throttle signal indicative of an engine throttle command over the communication channel;
• employing the processor executing computer executable instructions stored on a tangible computer-readable medium to implement processes including:
• determining whether a locked or unlocked condition of the torque converter is present based on the locking signal;
• determining whether a part throttle operating condition or a full throttle operating condition is present based on the throttle signal;
• and
• selecting a load-control power curve for the part throttle operating condition when the torque converter switches from the unlocked to the locked condition.