Abstract: The control device (50) operates to: calculate the ignition timing of each cylinder (101) of an engine (100) based on whether or not knocking is occurring; set, as a reference ignition timing, the ignition timing of any of the cylinders (101) for which the ignition timing is on the advanced angle side relative to the most retarded angle ignition timing on the most retarded angle side and on the retarded angle side relative to the most advanced angle ignition timing on the most advanced angle side; set an allowable timing difference range that is a range of an allowable timing difference with reference to the reference ignition timing; and when determining that the ignition timing of a cylinder (101) falls outside the allowable timing difference range, correct the ignition timing so that the timing difference with respect to the reference ignition timing falls within the allowable timing difference range.

Abstract: The control device (50) operates to: calculate the ignition timing of each cylinder (101) of an engine (100) based on whether or not knocking is occurring; set, as a reference ignition timing, the ignition timing of any of the cylinders (101) for which the ignition timing is on the advanced angle side relative to the most retarded angle ignition timing on the most retarded angle side and on the retarded angle side relative to the most advanced angle ignition timing on the most advanced angle side; set an allowable timing difference range that is a range of an allowable timing difference with reference to the reference ignition timing; and when determining that the ignition timing of a cylinder (101) falls outside the allowable timing difference range, correct the ignition timing so that the timing difference with respect to the reference ignition timing falls within the allowable timing difference range.