| 摘要 |
PROBLEM TO BE SOLVED: To provide an electric power steering device improved in responsivity by bringing an electric current frequency characteristic of an electric current controlling system close to an original motor/driving circuit system property. SOLUTION: In the electric power steering device, deviation between a target electric current value and an actual electric current value is calculated, and a PI controlling portion 15 produces an voltage command value on the basis of the deviation. The PI controlling portion 15 is designed on the basis of an inductance L of the motor, inner resistance R of the motor, and outer resistance R' of wiring and the driving circuit. At that time, a transfer function of the PI controlling portion 15 is made to be G<SB>9</SB>(s)=2<SB>π</SB>f<SB>c</SB>=(R+R')/s. In this expression, f<SB>c</SB>is a PI gain of the PI controlling portion, and s is a Laplace operator. In case of 2<SB>π</SB>f<SB>c</SB>=(R+R')/L, the transfer function of an electric current controlling system comes to have a characteristic same as that of the transfer function of the motor/driving circuit system, so that the responsivity is improved and a required torque frequency characteristic can be obtained. COPYRIGHT: (C)2004,JPO&NCIPI |
