US 12,459,560 B2
Steer-by-wire steering system
Takahito Ishino, Numazu (JP); Masaharu Yamashita, Toyota (JP); Kenji Shibata, Nagoya (JP); Yosuke Yamashita, Nagoya (JP); Shintaro Takayama, Toyota (JP); Kazuaki Iida, Toyota (JP); Ryo Yamazaki, Okazaki (JP); Yuuta Kajisawa, Okazaki (JP); Kenichi Abe, Okazaki (JP); Toyohiro Hayashi, Kariya (JP); Nobuyori Nakajima, Kariya (JP); Hiroyasu Otake, Kariya (JP); Kurumi Tazuke, Kariya (JP); and Hiroki Tomizawa, Kariya (JP)
Assigned to TOYOTA JIDOSHA KABUSHIKI KAISHA, Toyota (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 Dec. 16, 2022, as Appl. No. 18/067,487.
Claims priority of application No. 2022-001538 (JP), filed on Jan. 7, 2022.
Prior Publication US 2023/0219618 A1, Jul. 13, 2023
Int. Cl. B62D 5/04 (2006.01); H02P 23/14 (2006.01); H02P 29/68 (2016.01)
CPC B62D 5/0496 (2013.01) [B62D 5/046 (2013.01); H02P 23/14 (2013.01); H02P 29/68 (2016.02)] 12 Claims
OG exemplary drawing
 
1. A steer-by-wire steering system, comprising:
a steering device including a steering motor and configured to steer one or more wheels mechanically independently of an operation force of an operating member; and
a controller configured to supply a steering current to the steering motor based on a steering request to control the steering motor,
wherein the controller includes:
a plurality of microcomputers communicably connected to each other, each of the plurality of microcomputers being configured to calculate a current value of the steering current based on the steering request;
a plurality of drive circuits respectively corresponding to the plurality of microcomputers, each of the plurality of drive circuits being configured to supply the steering current to the steering motor based on control of a corresponding one of the plurality of microcomputers; and
a plurality of temperature sensors respectively corresponding to the plurality of microcomputers, each of the plurality of temperature sensors being configured to detect a temperature of a corresponding one of the plurality of microcomputers,
wherein, when a detection temperature difference that is a difference between detection temperatures of any two of the plurality of temperature sensors is greater than a predetermined threshold, each of the plurality of microcomputers executes an independent calculation control to independently calculate and set a current limit value, which is an upper limit value of the steering current, based on a detection temperature of one of the plurality of temperature sensors corresponding to itself, irrespective of detection temperatures of one or more of the plurality of temperature sensors other than the one of the plurality of temperature sensors corresponding to itself.