Nsk Corporation

Nsk Steering Systems Co., Ltd.

Nsk Steering Co., Ltd.

Takeshi Hara

Shuji Endo

Sakae Nejo

Toru Sakaguchi

Hideyuki Kobayashi

Toshiyuki Onizuka

Yong Wei

Tohru Sakaguchi

Hideaki Okazaki

Takeshi Ishikawa

An electric power steering apparatus including a steering angle detection part that detects a steering angle of a steering wheel and outputs a steering angle signal, a steering control unit that controls a motor to give an assist torque to the steering wheel, an abnormality detection part that determines an abnormality of the steering angle detection part, and a motor angle detection part that detects a rotational angle of the motor. The steering control unit calculates a steering angle information based on at least the steering angle signal, and includes a signal storage part that stores the steering angle information. The steering control unit runs the motor continuously when the abnormality detection part detects the abnormality of the steering angle detection part until a vehicle stops or until the abnormality detection part determines that the steering angle signal returns to a normal state from the occurrence of the abnormality.

Control apparatus for electric power steering

An electric power steering device changes the discontinuous non-linear characteristics in the duty ratio of the PWM signal versus motor current generated during steering wheel handle return into linear characteristics to suppress noise and provides a smooth and natural feeling steering. The electric control circuit () provided a current reference value calculator (A) to calculate I, a current controller (B) to obtain V, a compensation adder () to obtain a duty D, and a current discontinuity compensator () in order to obtain a duty D. A motor drive circuit () including an H bridge circuit whose upper stage FET () is driven by the duty D, and whose lower stage FED () paired with the upper stage FET (), is driven by the duty Dto allow forming a continuous linear characteristic in the duty ratio of the PWM signal versus the motor current.

Electric power steering device

It is an object of the present invention to provide a control unit for an electric power steering apparatus for accurately detecting an abnormality of a steering angle sensor without forming the steering angle sensor as a double system or using an expensive position detection sensor. The object is achieved by calculating a relative steering angle by using inexpensive position detection sensors disposed at a motor of the electric power steering apparatus to output binary values and comparing a change amount of an absolute steering angle detected by the steering angle sensor and a change amount of the calculated relative steering angle with each other to thereby detect the abnormality of the steering angle sensor.

Control unit for electric power steering apparatus

A steering angle sensor detects a rotational angle of a steering system whose steering is assisted by driving of an electric motor via a reduction mechanism so as to calculate a steering angle of a steering wheel. The steering angle sensor includes: a sensor wheel operating simultaneously with rotation of a steering shaft; and an absolute angle calculating unit for calculating an absolute steering angle based on a steering angle signal from the sensor wheel. The sensor wheel includes a GMR element and a magnetizing portion which is arranged around the GMR element, and the rotational angle is detected by making two turns of the steering shaft as one cycle of the steering angle signal based on a change in resistance value of the GMR element obtained by changing a magnetic field direction according to a rotation of the magnetizing portion.

Steering angle sensor

The present invention provides a steering angle estimating apparatus for vehicle that can accurately determine a steady state at all the steering angles, and can estimate the steering angle as much as possible even in a non-steady state. In the steering angle estimating apparatus for vehicle that has wheel rotational velocity sensors for four wheels, respectively, and estimates the steering angle of the vehicle based on wheel rotational velocities from the wheel rotational velocity sensors, relationships in the wheel rotational velocities between respective combinations of two wheels of the front and rear wheels on right and left sides are compared so that slip of the four wheels is detected.

Steering angle estimating apparatus for vehicle

Provides a control unit for an electric power steering apparatus with improved steering performance by recognizing a turn and a return of a steering wheel in a steering wheel return control, and by employing information on a steering angular velocity in calculating a current. This control unit controls a motor for giving steering assist force to a steering mechanism based on a current control value calculated from a steering assist command value calculated based on the steering torque generated in the steering shaft, and a current value of the motor. A steering wheel return controller for applying a steering wheel return control signal to the steering assist command value is provided, thereby to execute the steering wheel return control only when the steering wheel returns.

Growing community of inventors

Gunma, Japan

Takeshi Hara