APPARATUS AND METHOD FOR DETECTING ROTATIONAL SPEED OF ENGINE

摘要

PURPOSE: An apparatus and a method for detecting a rotational speed of an engine are provided to reduce the load of ECU by simplifying the program of ECU to discriminate the rotational speed of the engine and to simplify the wiring between the front end components not to have a communication path to transmit the rotational speed of the engine to a plurality of modules. CONSTITUTION: A method for detecting a rotational speed of an engine includes the steps of: inputting(S301) a first signal; inputting(S303) a second signal; calculating(S305) a speed and a gradient from the first and the second signals; inputting(S307) a third signal; calculating(S309) the speed and the gradient; determining(S311) whether the calculated result is equal to that of the previous step or not; correcting(S313) the calculated result if the calculated result is negative; outputting(S315) if the calculated result is affirmative; determining(S317) whether the module is cleared; going(S317) to the step S307 if the determined result is negative; and ending the steps if the determined result is affirmative.