Multi-speed marine propulsion system with improved automatic shifting strategy based soley on engine speed

摘要

A marine propulsion system is provided with a gear shifting apparatus and method that changes a transmission from a low gear to a high gear, and vice versa, based solely on the engine speed. Engine speed is measured and a rate of change of engine speed is determined as a function of the actual change in engine speed over a measured time interval. Several threshold magnitudes are preselected and used to define one or more engine speed ranges. At least one threshold magnitude is used to compare the actual rate of change of engine speed to a preselected value. Both up shifting and down shifting of a transmission are controlled as a function of engine speed and rate of change of engine speed.