Rotation angle detection device and electric power steering system
AssigneeDenso Corporation
InventorsTakafumi SATOU, Takashi Suzuki, Yasuhiko Mukai, Nobuhiko Uryu
Life of this patent
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Abstract
Bridge circuits have half bridges formed of sensor elements, which vary respective impedances in accordance with a rotating magnetic field generated by a rotary object. A control unit acquires output signals produced from intermediate points of the half bridges, and calculates a rotation angle of the rotary object based on the output signals. The control unit determines that the output signal is abnormal, if a calculation value of the output signal calculated based on at least four output signals is outside a predetermined range. The control unit thus determines which one of the output signals has become abnormal due to failure or the like.
Claims15
A rotation angle detection device comprising:
- a plurality of bridge circuits including a plurality of half bridges, each of the half bridges including a sensor element varying an impedance thereof in response to rotating magnetic field generated by rotation of a reference part and the half bridges generating output signals from intermediated points, respectively;
- and
- a control unit including a signal acquisition section for acquiring the output signals of the bridge circuits, a rotation angle calculation section for calculating a rotation angle of the reference part based on the output signals acquired by the signal acquisition section, and an abnormality determination section for determining an abnormal signal, which is one of the output signals having abnormality,
- wherein the abnormality determination section calculates calculation values by using at least four signals of the output signals and determines the abnormal signal among the output signals, the abnormal signal causing the calculation value to be outside a predetermined range.
Dependencies are inferred from the claim text.