Patent ID: 8781696

Claim:
A powertrain for a machine, comprising: an engine having an output shaft; a transmission having a first input connected to the output shaft of the engine; a variator that includes a pump connected to the output shaft and a motor connected to a second input of the transmission, said pump having a variable setting that is determinable by a position of a pump actuator that is responsive to a command signal; a controller associated with the engine, transmission and variator, the controller disposed to control operation of the variator, at least in part, by providing the command signal to the pump actuator, said command signal being determined based on an operator command, a compensation term, the compensation term depending on a correlation function that uses a parameter related to a speed ratio between a pump speed and a motor speed, and a scaling factor, the scaling factor depending on a ground speed of the machine as a primary control parameter such that the scaling factor enhances a control response of the variator at low ground speeds to avoid engine underspeed, and is muted at high ground speeds to provide for smooth shifting.