Patent attributes
One of a controllable load and a fuel flow to a single-spool turboshaft engine is controlled so that a rotational speed of a single-spool turboshaft engine is substantially regulated to a level corresponding to a corrected rotational speed command, and the other of the fuel flow and the controllable load is controlled so that a torque transmitted from the single-spool turboshaft engine to the controllable load is substantially regulated to a level corresponding to a corrected torque command. Under at least one operating condition, the corrected rotational speed command is determined so as to minimize or nearly minimize a measure of fuel consumption by the single-spool turboshaft engine when operated so that the torque transmitted to the controllable load corresponds to the corrected torque command.