| 摘要 |
PROBLEM TO BE SOLVED: To provide an electric power steering device controlling so as not to rapidly change impressed voltage to an electric motor, regardless of output voltage from a booster circuit. SOLUTION: Detected values of various sensors are input to a microcomputer (S12, S14, S16), a target current value It to be supplied to the motor (S18) is calculated, a deviation value between the target current value It and a detected current value Is is calculated to generate a command value V for feedback control (S20), a calculation duty ratio Dc is calculated based on the command value V (S22), and when the calculation duty ratio Dc exceeds a threshold value D0 such as 100%, the booster circuit 30 is started (S26) to calculate an output duty ratio Dp (=Dc×Voff/Von) (S28). When the calculation duty ratio Dc is not more than the threshold value D0, the booster circuit 30 is stopped (S30) and the calculation duty ratio Dc is used as the output duty ratio Dp (S32). The calculated output duty ratio Dp is provided to a PWM signal generating circuit (S34). COPYRIGHT: (C)2003,JPO |
