To provide a failure detection method of a torque sensor specifying a normal detection signal, even when a failure in which a detection signal is raised or lowered from a normal value is generated in a torque sensor, and also to provide a power steering device specifying the normal detection signal by the failure detection method.
This failure detection method of the torque sensor is provided, wherein a total voltage Vt of a voltage V1 of a first detection signal and a voltage V2 of a second detection signal changing corresponding to a steering torque becomes a prescribed voltage. The method has steps of: (S411) calculating a characteristic angle θ determined by Atan(V2/V1); (S416) calculating a reference angle θS of the characteristic angle θ; and (S417) calculating an angle error Δθ by subtracting the reference angle θS from the characteristic angle θ. In the method, a normal signal out of the first detection signal and the second detection signal when the total voltage Vt is out of a prescribed voltage is specified based on the angle error θS and the total voltage Vt.
Etsuo Tada
Mitsuharu Oda
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