Patent ID: 8118706

Claim:
A method of operating a machine having a power system that includes a prime mover, a multiple-ratio transmission, a propulsion device, and power-system controls, the method comprising: propelling the machine by transmitting power from the prime mover to the propulsion device through the multiple-ratio transmission, while controlling operation of the prime mover and the multiple-ratio transmission with the power-system controls, including: determining with the power-system controls at least one energy-efficiency estimate based at least on energy-efficiency characteristics of the prime mover and energy-efficiency characteristics of the multiple-ratio transmission, wherein determining the at least one energy-efficiency estimate includes determining multiple energy-efficiency estimates associated with alternative combinations of the prime-mover operating speed and the transmission drive ratio, and controlling a prime-mover operating speed of the prime mover and a transmission drive ratio of the multiple-ratio transmission based at least on the at least one energy-efficiency estimate, wherein controlling the prime-mover operating speed and the transmission drive ratio includes: selecting a combination of the prime-mover operating speed and the transmission drive ratio associated with one of the multiple energy-efficiency estimates as a first target for the prime-mover operating speed and the transmission drive ratio; determining a second target for the prime-mover operating speed and the transmission drive ratio, the second target being associated with responsiveness of the power system to increased power demands; and controlling the prime-mover operating speed and the transmission drive ratio based at least on the first target and the second target.