| 摘要 |
A rotation detection sensor (30) is disposed so as to oppose an outer peripheral portion (21) of a signal rotor (20) and outputs a detection signal (PDS) corresponding to the position of the outer peripheral portion (21) according to the rotation of the signal rotor (20). Additionally, the rotation detection sensor (30) detects a rotation reference position by detecting, on the basis of the gap between the rotation detection sensor (30) and the signal rotor (20), a change from a protrusion (22) to a toothless portion (23) and outputs a rotation reference position signal (RRPS) indicating position information for the rotation reference position when the transition from the protrusion (22) to the toothless portion (23) is detected. Further, the detection signal (PDS) and rotation reference position signal (RRPS) are input to an ECU (40) from the rotation detection sensor (30), and the ECU (40) acquires the rotation reference position on the basis of the rotation reference position signal (RRPS). |
