US 11,807,316 B2
Power steering apparatus
Ryo Kano, Kariya (JP); Daisuke Kobayashi, Kariya (JP); and Takashi Suzuki, Kariya (JP)
Assigned to DENSO CORPORATION, Kariya (JP)
Filed by DENSO CORPORATION, Kariya (JP)
Filed on Sep. 4, 2019, as Appl. No. 16/559,946.
Claims priority of application No. 2018-167319 (JP), filed on Sep. 6, 2018.
Prior Publication US 2020/0079421 A1, Mar. 12, 2020
Int. Cl. B62D 5/04 (2006.01); B62D 1/20 (2006.01); B62D 15/02 (2006.01); B62D 3/12 (2006.01)
CPC B62D 5/0484 (2013.01) [B62D 1/20 (2013.01); B62D 3/126 (2013.01); B62D 5/0412 (2013.01); B62D 5/0463 (2013.01); B62D 15/0235 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A power steering apparatus providing a total steering assist torque in a steering system that transmits a steering torque of a steering wheel from a steering shaft in a steering column, via an intermediate shaft and a rack gear, to a tire, the power steering apparatus comprising:
a first actuator including a multi-phase rotating electric machine, disposed on a steering column side of the intermediate shaft, and outputting a first steering assist torque;
a second actuator disposed on a rack gear side of the intermediate shaft, and outputting a second steering assist torque;
a first controller controlling a drive of the first actuator and detecting an abnormality of the first actuator; and
a communication bus having a connection to the first controller, wherein
the first controller changes an output of the first actuator based on a notification from the communication bus, and
the first controller performs an initial diagnosis of the first actuator at a vehicle startup time by supplying electric power to the first actuator in a manner that provides at least one of a first diagnosis test and a second diagnosis test,
wherein the first diagnosis test generates:
(i) a nonzero first winding torque in a first set of windings in the first actuator, and
(ii) a nonzero second winding torque in a second set of windings in the first actuator, such that the nonzero first winding torque and the nonzero second winding torque respectively have a positive value and a negative value, which have a same absolute value and are opposite in polarity, and such that the nonzero first winding torque plus the nonzero second winding torque equals zero, and
wherein the second diagnosis test generates:
(i) a nonzero first steering assist torque, and
(ii) a nonzero second steering assist torque, such that the nonzero first steering assist torque and the nonzero second steering assist torque respectively have a positive value and a negative value, which have a same absolute value and are opposite in polarity, and such that the nonzero first steering assist torque plus the nonzero second steering assist torque equals zero.