Method for detecting knocking of engine for vehicle

A method of detecting knocking of an engine for a vehicle, the method comprising:

• receiving, by a controller, a knock signal indicating a vibration level in a cylinder of the engine and a crank angle signal indicating a crank angle by which a knocking window and an end of injection of an injector in the engine are expressed;
• determining, by the controller, whether the knocking window and the end of injection of the injector overlap, according to the crank angle signal;
• setting, by the controller, a second reference value for an overlapping range within the knocking window overlapping the end of injection of the injector by reflecting according to a predetermined level on a first reference value for a non-overlapping range within the knocking window non-overlapping the end of injection of the injector, depending on whether the knocking window and the end of injection of the injector overlap;
• integrating, by the controller, the knock signal in the knocking window;
• determining, by the controller, whether an integrated value of the knock signal is greater than the first reference value in the non-overlapping range or the second reference value in the overlapping range;
• and
• retarding, by the controller, an ignition timing of the engine as a knocking avoidance logic depending on whether the integrated value of the knock signal is greater than the first reference value in the non-overlapping range or the second reference value in the overlapping range.