ELECTRIC POWER STEERING DEVICE

摘要

PROBLEM TO BE SOLVED: To estimate a vehicle speed in an electric power steering device when abnormality occurs in a detection means for detecting vehicle speed. SOLUTION: A MCU 100 for controlling an electric power steering device is equipped with a vehicle speed estimation module 260. Vibrations of a vehicle detected by a torque sensor 41 is processed in a FFT processing part 262 after a vibration level is limited by a level limiter 261 of the vehicle speed estimation module 260. A vehicle speed estimation part 263 estimates vehicle speed on the basis of frequency characteristics of vibration of the vehicle obtained through the FFT processing. COPYRIGHT: (C)2009,JPO&INPIT