| 摘要 |
PROBLEM TO BE SOLVED: To provide an electric power steering device which can detect an abnormal situation in which deviation occurs in a correspondence relationship between rotational angle information which is detected by a rotation angle detection device and an actual steering angle of a steering wheel.SOLUTION: The electric power steering device comprises a torque sensor 30 which is arranged at a column shaft, and detects steering torque Th, a motor which imparts an assist force to the column shaft, and a rotation angle detection device 44 which detects a rotation angle θe of an output shaft 21a of the motor. The rotation angle detection device 44 comprises a rotation detection part 61 which changes a value of a counter 61a on the basis of the motor rotation angle θe, and an abnormality detection part 62 which detects an abnormality on the basis of the steering torque Th which is detected by the torque sensor 30, and the value of the counter 61a. A microcomputer 40 calculates a steering angle on the basis of the value of the counter 61a. When the abnormality detection part 62 detects a change of the value of the counter 61a, the abnormality detection part detects the abnormality on the basis that the steering torque Th is smaller than a prescribed threshold.SELECTED DRAWING: Figure 3 |
