公开(公告)号：US20180170422A1

公开(公告)日：2018-06-21

申请号：US15127232

申请日：2015-11-05

Applicant: NSK LTD.

Inventor： Keita YOSHIDA ,  Yousuke IMAMURA ,  Masahiro MAEDA

IPC: B62D5/04 ,  B62D6/00 ,  B62D6/10

CPC classification number: B62D5/0472 ,  B62D5/04 ,  B62D5/046 ,  B62D5/0463 ,  B62D6/008 ,  B62D6/10

Abstract: An electric power steering apparatus that reduces an uncomfortable feeling due to a noise at a steering holding and a low-speed steering time, and can smoothly steers so as to prevent a phase-lag at a high-speed steering time. The apparatus has a torque control section to calculate a current command value based on at least a steering torque, and assist-controls a steering system by driving a motor using a current control system based on the current command value. A motor angular velocity calculating section calculates a motor angular velocity from a motor rotational angle; a motor angular acceleration calculating section calculates a motor angular acceleration from the motor angular velocity; and a stability compensating section calculates a steering torque for compensation and a current command value for compensation based on the motor angular velocity and the motor angular acceleration. The steering torque compensates the steering torque, and the current command value compensates the current command value.

公开(公告)号：US20190084613A1

公开(公告)日：2019-03-21

申请号：US15565774

申请日：2017-03-17

Applicant: NSK LTD.

Inventor： Takahiro TSUBAKI ,  Tetsuya KITAZUME ,  Keita YOSHIDA

IPC: B62D5/04 ,  B62D6/00 ,  H02P6/28

Abstract: [Problem]An object of the present invention is to provide an electric power steering apparatus that gradual-changes a steering angle control command value, an assist control command value and also a steering angle speed command value, suppresses an excessive accumulation of an integral value in a speed control by being provided a steering speed command value with a limiter, and does not give the driver an uncomfortable feeling.[Means for solving the problem]The present invention is the electric power steering apparatus that has a function to switch between an assist control mode and a steering angle control mode, wherein the steering angle control section comprises a position control section that inputs a target steering angle and an actual steering angle and outputs a first steering angle speed command value; a gradual-changing limiting section that limits an upper limiting value and a lower limiting value by gradual-changing a first steering angle speed command value corresponding to a steering angle control gradual-changing gain; a speed control section that processes a second steering angle speed command value, which is outputted from the gradual-changing limiting section, based on an actual steering angle speed and a steering angle control gradual-changing gain; and a first gradual-changing section that gradual-changes the first steering angle control command value, which is outputted from the speed control section, corresponding to a steering angle control gradual-changing gain and outputs a second steering angle control command value, further comprises a second gradual-changing section that gradual-changes a first assist control command value, which is outputted from an assist control section, with an assist control gradual-changing gain and outputs a second assist control command value, wherein a steering angle control section, and a motor current command value is generated based on the second steering angle control command value and the second assist control command value.

公开(公告)号：US20180273090A1

公开(公告)日：2018-09-27

申请号：US15559123

申请日：2016-04-05

Applicant: NSK Ltd.

Inventor： Keita YOSHIDA ,  Yousuke IMAMURA

IPC: B62D6/00 ,  H02P21/22 ,  B62D5/04

CPC classification number: B62D6/008 ,  B62D5/0463 ,  B62D5/0481 ,  B62D6/10 ,  H02P21/22

Abstract: [Problem]An object of the present invention is to provide a motor control unit that achieves desired performance more simply with higher accuracy by setting a frequency characteristic according to a state of the control unit and automatically adjusting a control gain by the set value, and to provide an electric power steering apparatus equipped with the same.[Means for Solving the Problem]A motor control unit that comprises a current command value calculating section that calculates a current command value of a motor applying a steering assist torque to a steering system of a vehicle, and a feedback section that controls a motor current flowing to the motor through a feedback mechanism based on the current command value comprises: a control unit state detecting section that detects at least one state of the motor control unit, and outputs the state as a control unit state; and a characteristic changing section that changes a setting of a closed loop response characteristic of the feedback section in real time depending on the control unit state.