Patent ID: 7958725

Claim:
A drivetrain system, comprising: a first rotary fluid actuator having variable displacement and being configured to affect an output of the drivetrain system; a second rotary fluid actuator having variable displacement and being configured to affect the output of the drivetrain system; an input device configured to receive a command indicative of a desired output of the drivetrain system; and a controller in communication with the first rotary fluid actuator, the second rotary fluid actuator, and the input device, the controller being configured to: determine a desired change in an effective gear ratio of the drivetrain system based on the received command; determine a total displacement change associated with the first and second rotary fluid actuators that produces the desired change in the effective gear ratio of the drivetrain system; compare the total displacement change to a threshold change level; affect simultaneous displacement changes in the first and second rotary fluid actuators when the total displacement change exceeds the threshold change level; and affect sequential displacement changes in the first and second rotary fluid actuators when the total displacement change is less than the threshold change level.