A control system controls a turbo-charged trottled engine. The control system includes a throttle between the compressor and the engine, a wastegate communicated with exhaust upstream and downstream from the turbine, and a control unit for controlling the throttle and the wastegate. The control unit generates a desired air mass value per engine stroke as a function of a desired fuel flow amount and a stored compressor surge characteristic, generates a desired manifold air pressure value as a function of the desired air mass value and sensed engine parameters, and controls the throttle so that actual manifold air pressure matches the desired manifold air pressure. The control unit also generates a desired pressure boost value as a function of the desired manifold pressure value and a stored compressor surge characteristic, and controls the wastegate so that an actual boost pressure matches the desired boost pressure.
William Lyle Hartman; Donald Lee McCaw; Daniel James Podnar; John Thomas Kubesh