Patent ID: 8374766

Claim:
A method for managing power in a hydrostatically driven vehicle, the vehicle including an engine operating at least one variable displacement pump, at least one implement motor, and at least one propel motor, each receiving a flow of compressed fluid at a pressure, a first sensor disposed to measure the displacement of the at least one variable displacement pump and to provide a first sensing signal, a second sensor disposed to measure the pressure of the compressed fluid and to provide a second sensing signal, and an electronic controller disposed to receive the first sensing signal, the second sensing signal, and to monitor at least one operating parameter of the engine, the controller further disposed to provide an output signal to control the at least one operating parameter of the engine, the method comprising: calculating a power consumption of the vehicle by the electronic controller based on the pressure of the compressed fluid and the displacement of the variable displacement pump; calculating a power output of the engine in the electronic controller based on the at least one engine operating parameter monitored by the controller; subtracting the power consumption of the vehicle from the power output of the engine to provide a power difference; and using the power difference as a primary control parameter to optimize an efficiency of the vehicle by adjusting the output signal such that the power output of the engine is adjusted to minimize the power difference.