A vehicle steering device and control method for use in steer-by-wire
steering systems. A steering instrument is operable to receive input from
a driver and a turning device is operable to turn at least one wheel. A
selectively engageable backup clutch is positioned between the steering
instrument and the turning device. Engagement of the backup clutch
results in a mechanical connection between the steering instrument and
the turning device for assisting control of the at least one wheel, and
release of the backup clutch results in a separation of the steering
instrument and the turning device for steer-by-wire control of the at
least one wheel. A controller is operable to switch from the
steer-by-wire control to the assisting control when the backup clutch
engages during operation of the steer-by-wire control.