Method and apparatus for detecting drift of pilot

Abstract

Method and apparatus for detecting drift of pilot, wherein the method includes: measuring two rotation speeds corresponding to each detection point of at least one detection point when an engine equipped with an injector is in an idle state, wherein the detection point is point(s) of an injection curve measured under the condition that a current injection pressure is applied to the injector when there is no drift of pilot in the injector, energizing time indicated by the point(s) being less than a predefined value, one rotation speed is a rotation speed of the engine during a certain working cycle of a cylinder injected by the injector, the injector being energized for an energizing time indicated by that detection point in a pilot period of the cycle, and another rotation speed is a rotation speed of the engine during an another working cycle of the cylinder, the injector not being energized in the pilot period of the cycle; calculating a current engine rotation speed change corresponding to the detection point; acquiring an indication value corresponding to the detection point; and determining whether there is drift of pilot in the injector, based on the indication value.