Electric power steering apparatus

申请公布号：

US9387877(B2)

申请号：

US201414759991

申请日期：

2014.01.14

申请公布日期：

2016.07.12

申请人：

NSK Ltd.

发明人：

Tsubaki Takahiro

分类号：

B62D5/04;B62D6/02;B62D6/08;B62D1/28

主分类号：

B62D5/04

代理机构：

Sughrue Mion, PLLC

代理人：

Sughrue Mion, PLLC

地址：

Tokyo JP

摘要：

[Problem];An object of the present invention is to provide an electric power steering apparatus that does not give uncomfortable feeling to a driver by detecting that the driver steers a steering wheel in an automatic steering mode by means of a steering torque from a torque sensor and switching to a manual steering mode by a capacity (an integrated value) corresponding to the occurring torque magnitude.;[Means for solving the problem];The present invention comprises a steering angle control section that calculates a motor current command value 2, a torque integral judging section that outputs a steering torque judging signal by integrating a steering torque, which is compared with a threshold, and a switching section that inputs the motor current command value 1 and the motor current command value 2, and is switched in accordance with a switching signal or the steering torque judging signal; the torque integral judging section comprises a torque value comparing section, an integral calculating section and a switch judging section; and the switching section is switched depending on a switching command of an automatic steering mode and a manual steering mode or the steering torque judging signal.

主权项：

1. An electric power steering apparatus that calculates a motor current command value 1 based on a steering torque and a vehicle speed, drives a motor based on said motor current command value 1 so as to perform an assist control of a steering system, and has a function for switching an automatic steering mode and a manual steering mode, comprising: a steering angle control section that calculates a motor current command value 2 to get an actual steering angle close to a target steering angle; a torque integral judging section that outputs a steering torque judging signal by integrating said steering torque, which is compared with a predetermined threshold; and a switching section that inputs said motor current command value 1 and said motor current command value 2, and is switched in accordance with a switching signal or said steering torque judging signal; wherein said torque integral judging section comprises a torque value comparing section that compares an absolute value of said steering torque with a torque threshold so as to output a predetermined signal, an integral calculating section that integrates said predetermined signal, and a switch judging section that compares an integral value from said integral calculating section with an integral threshold so as to output said steering torque judging signal, and initializes said integral calculating section in case said absolute value of said steering torque is smaller than said torque threshold; and wherein said switching section is switched depending on a switching command of said automatic steering mode and said manual steering mode or said steering torque judging signal.