Patent ID: 9605974
Date: 2017-03-28
CPC Classifications: G01D

Claim:
1. A rotation angle detecting device comprising: a first magnetic sensor that outputs a first sinusoidal signal (V a second magnetic sensor that outputs a second sinusoidal signal (V wherein a phase difference (α) between the first sinusoidal signal (V wherein the rotation angle detecting device further includes a device that computes a rotation angle (θ) of the rotating body based on the first sinusoidal signal (V a determination device that determines whether both the first and second magnetic sensors are operating normally, or there is a failure in at least one of the first and second magnetic sensors, based on the first sinusoidal signal (V wherein the determination device is configured to determine that both the first and second magnetic sensors are operating normally when an expression (a) is satisfied, and to determine that there is the failure in at least one of the first and second magnetic sensors when the expression (a) is not satisfied, the expression (a) being where L is a lower limit that is set in advance and that is smaller than 0, and U is an upper limit set in advance and that is larger than 0.