US 12,280,842 B2
Control device, electric power steering device, and control method
Shuji Endo, Kyoto (JP); Sohei Miyake, Kyoto (JP); Masaya Ishikawa, Kyoto (JP); and Daisuke Notsu, Kyoto (JP)
Assigned to NIDEC CORPORATION, Kyoto (JP)
Filed by Nidec Corporation, Kyoto (JP)
Filed on Dec. 21, 2022, as Appl. No. 18/086,323.
Claims priority of application No. 2021-214885 (JP), filed on Dec. 28, 2021.
Prior Publication US 2023/0202560 A1, Jun. 29, 2023
Int. Cl. B62D 6/00 (2006.01); B62D 5/04 (2006.01)
CPC B62D 6/008 (2013.01) [B62D 5/0463 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A control device that controls, as a control target, at least a portion including a motor in a steering mechanism including an input shaft to which a steering wheel steered by a steering person is connected, an output shaft connected to the input shaft via a torsion bar, and the motor connected to the output shaft, the control device comprising:
a reaction force controller to generate an input torque input to the control target based on a torsion bar torque generated in the torsion bar and control a reaction force transmitted from the steering wheel to the steering person;
an assist controller to generate a correction torque to correct the input torque based on an output of the control target and a nominal model; and
a state feedback circuit to feed back a state compensation value to the input torque based on the output of the control target; wherein
the assist controller is configured or programmed such that a transfer function of the control target is constrained by a transfer function of the nominal model in a frequency band where a gain in a gain characteristic of a complementary sensitivity function with respect to a modeling error between the control target and the nominal model is approximately 1; and
the state feedback circuit is operable to feed back the state compensation value so that an apparent transfer function of the control target approaches a transfer function of the nominal model based on the output of the control target.