| 摘要 |
In a rotation angle detecting device, a first magnetic sensor and a second magnetic sensor are disposed at an interval of an electrical angle of 120 degrees around a rotation center axis of a rotor. An output signal of the first magnetic sensor is expressed by V1=sin θ, and an output signal of the second magnetic sensor is expressed by V2=sin(θ+120). A determination device determines whether both the magnetic sensors are normal, or there is a failure in at least one of the magnetic sensors, based on whether an expression of L≦V12+V22+V1·V2−0.75≦U is satisfied, where L is a lower limit and U is an upper limit. |
| 主权项 |
1. A rotation angle detecting device comprising:
a first magnetic sensor that outputs a first sinusoidal signal (V1) in accordance with rotation of a rotating body; and a second magnetic sensor that outputs a second sinusoidal signal (V2) in accordance with the rotation of the rotating body, wherein a phase difference (α) between the first sinusoidal signal (V1) and the second sinusoidal signal (V2) is an electrical angle other than 90 degrees and 180 degrees, 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 (V1) and the second sinusoidal signal (V2), and 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 (V1), the second sinusoidal signal (V2), and the phase difference (α), and 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
L≦X12≦U X12=V12+V22−2[1−2 sin2(α/2)]V1·V2−1+{1−2 sin2(α/2)}2, (a) 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. |
