US 9,809,246 B2
Electric power steering apparatus
Takahiro Tsubaki, Maebashi (JP); and Tamotsu Oumi, Maebashi (JP)
Assigned to NSK LTD., Tokyo (JP)
Appl. No. 14/786,410
Filed by NSK LTD., Tokyo (JP)
PCT Filed Apr. 7, 2014, PCT No. PCT/JP2014/060093
§ 371(c)(1), (2) Date Oct. 22, 2015,
PCT Pub. No. WO2014/175052, PCT Pub. Date Oct. 30, 2014.
Claims priority of application No. 2013-090650 (JP), filed on Apr. 23, 2013; and application No. 2014-075257 (JP), filed on Apr. 1, 2014.
Prior Publication US 2016/0059885 A1, Mar. 3, 2016
Int. Cl. B62D 5/04 (2006.01)
CPC B62D 5/0472 (2013.01) 14 Claims
OG exemplary drawing
 
1. An electric power steering apparatus that assist-controls a steering by driving a motor with a current command value calculated based on at least a steering torque, comprising:
a vibration-damping compensating section that calculates a vibration-damping compensation command value for suppressing a vibration of a handle based on a motor velocity of said motor,
wherein said vibration-damping compensating section comprises a motor velocity-sensitive table 1 for converting said motor velocity into a trapezoidal-wave type vibration-damping compensation value 1 and a band pass filer (BPF) to output a vibration-damping compensation value 2 by BPF-filtering said vibration-damping compensation value 1,
wherein a zero-cross point of said vibration-damping compensation value 1 is coincident with a zero-cross point of said motor velocity,
wherein a zero-cross point of said vibration-damping compensation value 2 is prior to said zero-cross point of said motor velocity,
wherein said current command value is corrected by said vibration-damping compensation command value obtained at least in part from the vibration-damping compensation value 2, and
wherein vibration amplitude of said motor near said zero-cross point of said motor velocity is suppressed.