| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a rotation angle detection device capable of accurately detecting movement of a magnetic pole even when a fixing abnormality (an abnormality that an output signal is fixed to a certain value) occurs in one sinusoidal signal of a plurality of sinusoidal signals. <P>SOLUTION: Three magnetic sensors 21, 22, 23 are disposed about a rotation center axis of a rotor 1 at angle intervals of predetermined angles around the rotor 1. Sinusoidal signals having a predetermined phase difference 120° are output from the magnetic sensors 21, 22, 23. A rotation angle computing device 20 detects movement of a magnetic pole of a first output signal V1 as follows. Specifically, the rotation angle computing device 20 detects the movement of the magnetic pole of the first output signal V1, based on one, of a current value of a second output signal V2 and a current value of a third output signal V3, in which an absolute value of a difference between a previous value thereof and the current value is larger than that of the other, a previous value of the first output signal V1, and a current value of the first output signal V1. <P>COPYRIGHT: (C)2012,JPO&INPIT |
