| 摘要 |
PROBLEM TO BE SOLVED: To provide a motor-driven power steering device capable of reducing vibration transmitted from the steered wheels to a steering shaft via the power steering device without the need for sensing the vibration of the steering shaft. SOLUTION: The arrangement according to the present invention works through such procedures as computing the steering torque Tsp after the phase compensation on the basis of the steering torque Ts and a control constant A (S20 and S30), computing the target assist force Fat on a rack bar 14 on the basis of the steering torque Tsp after the phase compensation (S40 and S50), analyzing the frequency and the phase of the thrust force Fo due to excitation of the rack bar 14 using a frequency/phase analyzing device 32 in the condition that the rack bar 14 is excited by an exciter 28 (S130 and S140), analyzing the frequency and the phase of the target assist force Fat using a frequency/phase analyzing device 32 (S150 and S160), and changing the control constant A in conformity to the predetermined procedures (S170 and S180) until judgement is passed that the phases of the thrust force Fo and the target assist force Fat are opposite to each other (S170). COPYRIGHT: (C)2006,JPO&NCIPI |
