Motorcycle engine control system and method for enabling the use of traditional crankshaft

An engine ignition control method for controlling timing of spark for initiating burning in a combustion chamber of a four stroke cycle internal combustion engine, said engine comprising a cylinder, a piston in said cylinder, a crankshaft connected to said piston, said engine ignition control method comprising a computer processor executing a process of crankshaft angular velocity prediction comprising:

• computing a current lapse time, which is time lapsed since time of receipt of a last crankshaft position sensor pickup electrical signal until time of receipt of a current crankshaft position sensor pickup electrical signal, wherein the current crankshaft position sensor pickup electrical signal being the crankshaft position sensor pickup electrical signal most recently received by the computer processor, and the last crankshaft position sensor pickup electrical signal being the crankshaft position sensor pickup electrical signal received by the computer processor prior to the current crankshaft position sensor pickup electrical signal;
• computing difference in lapse time between a last lapse time and the current lapse time, wherein the last lapse time is time lapsed since time of receipt of one prior to the last crankshaft position sensor pickup electrical signal until time of receipt of the last crankshaft position sensor pickup electrical signal;
• computing a predicted next lapse time, wherein the predicted next lapse time being the sum of the current lapse time and the difference in lapse time multiplied by a reasonable weighting factor;
• computing a next capture window of next crankshaft position sensor pickup electrical signal using the predicted next lapse time, wherein the next capture window being a configurable period of time centered around an instance of time that is the predicted next lapse time past the time of receipt of the current crankshaft position sensor pickup electrical signal;
• computing a current crankshaft angular velocity based on the current lapse time;
• determining whether the current crankshaft position sensor pickup signal occurred within a current capture window of the current crankshaft position sensor pickup electrical signal;
• if within the current capture window of the current crankshaft position sensor pickup electrical signal, then repeat the process of crankshaft angular velocity prediction for the receipt of the next crankshaft position sensor pickup electrical signal;
• else
• if not within the current capture window of the current crankshaft position sensor pickup electrical signal, resetting the process of crankshaft angular velocity prediction.

An engine ignition control method for controlling timing of spark for initiating burning in a combustion chamber of a four stroke cycle internal combustion engine, said engine comprising a cylinder, a piston in said cylinder, a crankshaft connected to said piston, said engine ignition control method comprising:

• a crankshaft position sensor detecting the crankshaft rotational movements and generating periodic pickup electrical signals as the crankshaft rotates during a combustion cycle, wherein one crankshaft position sensor pickup electrical signal being generated for each full crankshaft rotation;
• a computer processor executing an engine start initial ignition synchronization process comprising:
• periodically receiving the crankshaft position sensor pickup electrical signals;
• initially generating a spark-triggering electrical signal for each crankshaft position sensor pickup electrical signal;
• computing a crankshaft angular velocity using time lapsed between the receipts of two crankshaft position sensor pickup electrical signals;
• computing a crankshaft angular acceleration based on difference between the computed crankshaft angular velocity and a prior computed crankshaft angular velocity;
• and
• if the crankshaft angular acceleration is positive, then generating a spark-triggering electrical signal for the next crankshaft position sensor pickup electrical signal then for every other crankshaft position sensor pickup electrical signal.