Patent ID: 8862350

Claim:
A method for controlling a powertrain system comprising a multi-mode transmission configured to transfer torque among an engine, torque machines, and a driveline, the method comprising: in response to an output torque request: executing, by a processor, a dual closed-loop control scheme including determining an engine-based output torque range employed in a first feedback loop and simultaneously determining a control acceleration-based output torque range employed in a second feedback loop, said control acceleration comprising acceleration of an output member coupled between the transmission and the driveline, and said control acceleration-based output torque range comprising a desired control acceleration range associated with a transition in output torque at the output member during a gear lash event; controlling engine commands responsive to the engine-based output torque range and simultaneously controlling the control acceleration responsive to the control acceleration-based output torque range to achieve an output torque of the powertrain system responsive to the output torque request.