Patent ID: 7086495
Filing Date: 2006-08-08
Classification: B62D,H02H

Abstract:
1. A transmission-ratio-varying steering apparatus comprising: an input shaft connected to a steering wheel; an output shaft connected to steered wheels; an electric motor for varying a rotation angle of the output shaft with respect to a rotation angle of the input shaft; a relative-angle detection means for detecting a relative angle between the input and output shafts; a rotation-angle computation means for computing an absolute angle based on a relative angle detected by the relative-angle detection means; a non-volatile storage means for holding an absolute angle computed by the rotation-angle computation means; a control unit having a storage supplementary means for an absolute angle into the non-volatile storage means, wherein the control unit controls an operation to drive the electric motor in order to change the rotation angle of the output shaft; and a power-providing means, which is used for adjusting a voltage generated by a power supply and a generator for supplementing power supplied by the power supply to a voltage not exceeding a first predetermined voltage and supplying the adjusted voltage to the control unit when the voltage generated by the power supply and the generator is normal, and is used for discontinuing an operation to supply power to the control unit when the voltage generated by the power supply and the generator is at least equal to a second predetermined voltage wherein voltages not exceeding the first predetermined voltage are voltages in an operating range of the control unit and the second predetermined voltage is an abnormal voltage, wherein: