| 摘要 |
<p>PURPOSE:To improve restorability by producing returning force without delay when a handle-steering force is loosened, by controlling electric current of a motor combining, as a pair, an assisting force with a returning force which corresponds to a steering angle. CONSTITUTION:When a car is steered to the right, an output torque indicating functional section 20 outputs positive assisting force due to twisting torque from a torque sensor 12. This signal is input to a motor driving section 23 through a plus or minus distinguishing section 22, an absolute value converting section 24, and a duty control section 25. Thereby, the electric motor 7 produces rightward steering force, and assisting force is given to a rack and-pinion mechanism 11. And when steering motion begins, a torque value indicating functional section 21 outputs return signal due to steering angle from a steering angle sensor 13. Accordingly, the electric motor 7 is controlled by values adding assisting signal and return signal. Thereby, when steering motion is released and twisting torque is reduced suddenly, the motor 7 produced leftward steering force and the restoration is performed smoothly.</p> |
