ROTATION DETECTION DEVICE, ROTATION ANGLE DETECTION DEVICE, AND ELECTRIC POWER STEERING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a rotation detection device, a rotation angle detection device, and an electric power steering device capable of appropriately detecting the abnormality of a functional part which detects the rotation of a rotary shaft.SOLUTION: A first arithmetic part 51 calculates a rotational direction D1 and a rotational frequency N1 of a rotary shaft 12a on the basis of a change in the combination of the positiveness/negativeness of a first electric signal S1 (first sine signal) and a third electric signal S3(first cosine signal). A second arithmetic part 52 calculates a rotational direction D2 and a rotational frequency N2 of the rotary shaft 12a on the basis of a change in the combination of the positiveness/negativeness of a second electric signal S2 (second sine signal) and a fourth electric signal S4 (second cosine signal). An abnormality determination part 53 determines the abnormality of the first and second arithmetic parts 51 and 52 on the basis of the two rotational directions D1 and D2 calculated by the first and second arithmetic parts 51 and 52.SELECTED DRAWING: Figure 1