Vehicle steering device and control method for vehicle steering device

A vehicle steering controller for a vehicle including a steering wheel operable by a driver and having a steering wheel shaft connected thereto, a turning mechanism operable to turn at least one steered wheel to a turning angle in response to operation of the steering wheel, and a selectively engageable clutch positioned between the steering wheel and the turning mechanism and including a first rotary member mechanically connected to the turning mechanism, a second rotary member mechanically connected to the steering wheel shaft, and an engaging piece interposed between the first rotary member and the second rotary member, the clutch having an engaged position when the engaging piece is in wedging engagement between the first rotary member and the second rotary member wherein the steering wheel shaft is mechanically connected to the turning mechanism for turning the at least one steered wheel, and the clutch having a disengaged position when the engaging piece is in intermediate position between the first rotary member and the second rotary member wherein the steering wheel shaft is mechanically separated from the turning mechanism for steer-by-wire control of the at least one steered wheel, the controller comprising:

• means for selectively moving the selectively engageable clutch between the engaged position and the disengaged position in response to operation of the steering wheel;
• and
• means for performing clutch release control by providing a rotational angle of deviation between the steering input shaft and the turning mechanism in a direction of disengagement when moving the clutch means from the engaged position to the disengaged position.

A control method for a vehicle steering device including a steering wheel operable by a driver and having a steering wheel shaft connected thereto, a turning mechanism operable to turn at least one steered wheel to a turning angle in response to operation of the steering wheel, and a selectively engageable clutch positioned between the steering wheel and the turning mechanism and including a first rotary member mechanically connected to the turning mechanism, a second rotary member mechanically connected to the steering wheel shaft, and an engaging piece interposed between the first rotary member and the second rotary member, the clutch having an engaged position when the engaging piece is in wedging engagement between the first rotary member and the second rotary member wherein the steering wheel shaft is mechanically connected to the turning mechanism for turning the at least one steered wheel, and the clutch having a disengaged position when the engaging piece is in intermediate position between the first rotary member and the second rotary member wherein the steering wheel shaft is mechanically separated from the turning mechanism for steer-by-wire control of the at least one steered wheel, the method comprising:

• selectively moving the clutch between the engaged position and the disengaged position in response to the steering wheel;
• and
• performing clutch release control by providing a rotational angle of deviation between the steering wheel shaft and turning mechanism in a direction of disengagement when moving the clutch from the engaged position to the disengaged position.