Patent ID: 7917283

Claim:
An engine control unit for a boat propulsion system comprising: a predicted boat speed value generator adapted to provide predicted boat speed values by receiving and processing signals related to an engine speed, an intake pressure taken at a downstream side of a throttle valve, a lever position, a shift position, and a throttle position; a control signal generator adapted to receive the predicted boat speed values from the predicted boat speed value generator to determine an injection amount, an amount of air, and an ignition timing based on the predicted boat speed values to provide a fuel injection control signal, an air adjustment control signal, and an ignition timing control signal, respectively; wherein the predicted boat speed value generator is adapted to perform a predicted boat speed mapped value extraction process to search through a predicted boat speed value map during a constant speed operation and an acceleration, based on the engine speed and the intake pressure, to extract and provide a predicted boat speed mapped value; and wherein the predicted boat speed value generator is further adapted to perform a predicted decelerating boat speed value output process to initially receive the last predicted boat speed mapped value at a time of deceleration, establish an initial predicted boat speed value by multiplying attenuation coefficients that vary according to the shift positions by the predicted boat speed mapped value obtained at an end of the deceleration, perform a similar computation in each following cycle using the last predicted boat speed mapped value, and provide an attenuated predicted boat speed value in every cycle.