US 12,116,063 B2
Steering system
Masaharu Yamashita, Toyota (JP); Masataka Okuda, Toyota (JP); Yosuke Yamashita, Nagoya (JP); Yuji Fujita, Okazaki (JP); Yuuta Kajisawa, Okazaki (JP); Kenichi Abe, Okazaki (JP); Hiroki Tomizawa, Kariya (JP); and Nobuyori Nakajima, Kariya (JP)
Assigned to TOYOTA JIDOSHA KABUSHIKI KAISHA, Toytoa (JP); JTEKT CORPORATION, Kariya (JP); and DENSO CORPORATION, Kariya (JP)
Filed by TOYOTA JIDOSHA KABUSHIKI KAISHA, Toyota (JP); JTEKT Corporation, Kariya (JP); and DENSO CORPORATION, Kariya (JP)
Filed on Apr. 5, 2022, as Appl. No. 17/713,403.
Claims priority of application No. 2021-068667 (JP), filed on Apr. 14, 2021.
Prior Publication US 2022/0332368 A1, Oct. 20, 2022
Int. Cl. B62D 6/02 (2006.01); B62D 5/04 (2006.01); B62D 6/00 (2006.01)
CPC B62D 6/02 (2013.01) [B62D 5/0484 (2013.01); B62D 5/0496 (2013.01); B62D 6/008 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A steer-by-wire steering system for a vehicle, comprising:
an operating member operable by a driver;
a steering device including an electric motor and configured to steer a wheel by a force generated by the electric motor;
a controller configured to control the steering device,
wherein the controller enables the wheel to be steered in accordance with an operation of the operating member while imposing limitation on a supply current to the electric motor,
wherein the limitation imposed on the supply current to the electric motor is made smaller when a running speed of the vehicle is lower than a set speed and a steering motion of the wheel is a motion in a direction to decrease a steering amount than i) when the running speed of the vehicle is not lower than the set speed and ii) when the steering motion of the wheel is a motion in a direction to increase the steering amount, and
wherein, when the running speed of the vehicle is lower than the set speed and the steering motion of the wheel is the motion in the direction to decrease the steering amount, the limitation imposed on the supply current to the electric motor is decreased to such a degree that the supply current is not limited at all.
 
7. The steer-by-wire steering system according to claim 1, wherein, when a degree of the limitation imposed on the supply current to the electric motor is changed, the degree is continuously changed.