公开(公告)号：US10118636B2

公开(公告)日：2018-11-06

申请号：US15520162

申请日：2015-12-24

Applicant: NSK LTD.

Inventor： Toru Sakaguchi ,  Shoya Maruyama

IPC: B62D5/04 ,  G05B13/04 ,  B62D6/00 ,  B62D1/16

Abstract: A high-performance electric power steering apparatus that includes a control system based on a physical model, includes a model following control that an output (a distance to a rack end) of a controlled object follows-up to a reference model, eliminates or reduces the occurrences of a noisy sound and a shock force at an end hitting without giving any uncomfortable steering feeling to a driver, and reduces the end hitting. The electric power steering apparatus calculates a current command value based on at least a steering torque and performs an assist-control of a steering system by driving a motor based on the current command value, including: a configuration of a model following control including a viscoelastic model as a reference model within a predetermined angle at front of a rack end so as to suppress a rack end hitting.

公开(公告)号：US09604666B2

公开(公告)日：2017-03-28

申请号：US14777547

申请日：2013-03-18

Applicant: NSK LTD.

Inventor： Sachio Nakayama ,  Toru Sakaguchi ,  Yuzuru Hoshi ,  Shinichi Tanaka ,  Masanori Shingou

IPC: B62D5/04

CPC classification number: B62D5/0463 ,  B62D5/0481

Abstract: An electric power steering apparatus that protects Zener diodes without impairing steering performances by time-integrating a loss power of the Zener diodes for protecting FETs and gradually limiting a duty ratio with an increase in an integrating loss. The apparatus includes a loss power calculating section that calculates a loss power when a difference between an ignition voltage and an inverter applying voltage is equal to or more than a predetermined voltage; an integrating loss calculating section to calculate an integrating loss of the loss power; a permissible loss calculating section to calculate a permissible loss based on a temperature; a minimum value selecting section to select a minimum value of a loss difference of the permissible loss and the integrating loss; and a limit value calculating section to calculate a limit value of the PWM-signal based on the minimum value of the loss difference and the permissible loss.