Nsk Corporation

Hideaki Kawada

Shuji Endo

Seiichi Kobayashi

Takahiro Tsubaki

Yusuke Itakura

Yasuhiko Miyaura

Hisayoshi Koiwai

Toru Sakaguchi

Takaaki Sekine

Shigeo Shinohara

Takeshi Senba

Keiji Kashimoto

Tetsuya Kodama

Atsushi Ooshima

Hiroshi Eda

Shigeru Endo

Isamu Chikuma

Shin Kumagai

Hideyuki Kobayashi

Yuho Aoki

Nobuyasu Ando

Atsushi Horikoshi

Tamotsu Oumi

Kenichi Hayakawa

Yasuhiro Shimizu

Yuji Kouzaki

Yoshinori Sugiyama

Naoki Hyoudou

Mitsuo Shimoda

Kei Chin

Hiroyuki Kano

Shozo Sekiya

Hiroyuki Kanoh

Syuji Endo

A motor control apparatus includes a steering column having inserted therein a steering shaft to which steering torque is transmitted, a reduction gear box coupled to the steering shaft, and an electric motor that transmits a steering assisting force to the steering shaft via a reduction mechanism in the reduction gear box. The electric motor and its control unit including a control board mounted with a control circuit, are provided side by side in the reduction gear box. A connection terminal of the electric motor is electrically connected to the control unit directly. This minimizes a connection distance between the control unit and the electric motor.

Electric power steering apparatus and method of assembling the same

To provide an electric power steering apparatus in which it is possible to reduce a size of the entire structure of a control unit while sufficiently showing a heat radiation effect of heat generating members. The electric power steering apparatus includes a steering columnhaving inserted therein a steering shaftto which steering torque is transmitted, a reduction gear boxcoupled to the steering shaft, and an electric motorthat transmits a steering assisting force to the steering shaftvia a reduction mechanism in the reduction gear box. In the reduction gear box, a motor mounting sectionfor mounting the electric motoris formed at an end face in a direction perpendicular to an axis of the steering shaftand a control-unit mounting sectionfor mounting a control unitfor controlling to drive the electric motoris formed near the motor mounting section

Electric power steering apparatus

The present invention includes a control part for controlling switching elements on diagonal lines in the upper and lower stage of an H bridge circuit respectively by different duty ratios based on a steering torque exerted on a steering system, and an electric power supply source for supplying an electric power. When the voltage of the electric power supply source is lower than a prescribed voltage, the control part causes the switching element EETor FETon the upper-stage side to be driven by a pulse width modulation signal PWMor PWM, the switching element FETor FETon the lower-stage side to be turned on, and the frequency of the pulse width modulation signal to be lowered to an audible frequency range.

Electric power steering device

An object of the present invention is to provide a controller for an electric power steering apparatus which has a function capable of detecting abnormality of motor current detection circuits even while a steering operation is being executed and can execute alternate control when a failure is detected. This object is achieved by a controller for an electric power steering apparatus for controlling a motor so that a steeling assist power is applied to a steering mechanism based on a current command value calculated from a steering assist command value calculated based on a steering torque, which is generated in a steering shaft, and from a motor current detection value. The controller has a function for determining a failure of a plurality of motor current detection circuits by detecting a current flowing in the motor by a single current detecting resistor, inputting the detected signal to the of motor current detection circuits in parallel, and comparing outputs from the motor current detection circuits.

Electric power steering device control apparatus

An electric power steering device enabled to surely detect a fault of its motor current detector circuit by avoiding the disturbance by an electrically insulated oxide film formed on the contact surface between the commutator and the brush of the motor. An ignition key is turned on, then the motor applied voltage is increased with time to break the oxide film so that the motor current flows normally. The estimated motor current is then compared with the detected motor current. When the absolute value of the difference between those estimated motor current and detected motor currents is over a predetermined limit value, it is determined that the motor current detection circuit is defective. It is also possible to break the oxide film by integrating each difference between the motor current command value and the detected motor current value, thereby increasing the current control value step by step and increase voltage applied to the motor.

A control apparatus of power steering device having functions of monitoring intermediate troubles such as offset or drift out of signal troubles of torque sensor, and limiting the current for limiting the assist function is presented. In a control apparatus of power steering device for controlling a motor on the basis of a current control value calculated from a steering assist command value calculated by calculating means on the basis of a steering torque generated on a steering shaft, and a current value of a motor for applying a steering assist force to a steering mechanism, wherein the difference of a main torque signal and a sub torque signal of a torque sensor for detecting the steering torque is stored preliminarily, and the difference of the main torque signal and the sub torque signal during operation is compared with the stored value, and at least the current control value is limited when the difference based on the comparison is a condition larger than a first prescribed value and continues for a time longer than a first prescribed time.

Control apparatus of power steering device

There is provided a control unit for an electric power steering apparatus that 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. The control unit has a first controller and a second controller for controlling the motor. Based on a current command value calculated by the second controller, the second controller monitors the first controller that controls the driving of the motor based on the steering assist command value calculated by the first controller. When the first controller is in a status not controlling the steering assist command value, the function of the second controller for monitoring the first controller is limited.

Control unit for electric power steering apparatus

There have been cases wherein the program itself does not operate normally and only continues to output the monitoring pulse so that racing cannot be detected, or due to electromagnetic waves or noise a pulse signal being outputted normally is measured erroneously and a mis-detection is made. In a control apparatus of an electric power steering system for, on the basis of a current command value computed from a current detected value of a motor and a steering assist command value computed on the basis of a steering torque arising in a steering shaft, controlling the motor, which applies a steering assist force to a steering mechanism, a control apparatus of an electric power steering system characterized in that it comprises a first control part and a second control part each inputting at least a torque signal, a vehicle speed signal, the motor current detected value and a motor terminal voltage, and the motor is controlled with the first control part and the second control part.

Control apparatus of electric power steering system

In control devices of electric power steering systems, steering characteristics are improved by control being carried out by means of a signal based on rotor speed or steering angle after failure of a torque sensor is detected. In the present invention, in a control device of an electric power steering system for controlling a motor applying a steering assist force to a steering mechanism on the basis of a current control value computed from a motor current value and a steering assist command value computed on the basis of a steering torque in a steering shaft, two over-current detecting circuits have different detection current values; when an over-current is detected by the circuit having the lower current detection value within the response time of current control, the duty of PWM for driving the motor is restricted, and when an over-current is detected by the circuit having the higher current detection value, motor current output is stopped and a relay is opened and the system is disengaged from the steering mechanism.

Control apparatus for electric power steering system

To provide a controller of an electric power-steering system, capable of improving the steering performance by presuming a motor angular speed .omega. in a range in which the angular speed of a motor is small and moreover very accurately presuming the motor angular speed and thereby, completely showing the functions for compensating the inertia of the motor and controlling the astringency of a vehicle. Because the presumed error of a back electromotive force between a model motor and a motor to be actually mounted is proportional to a motor current, a dead zone of a motor angular speed having a width proportional to a motor current is set to the presumed value of the motor angular speed. When the motor current is small, the width of the dead zone also decreases. Therefore, it is possible to presume an angular speed .omega. even in a region where the motor angular speed is small. Moreover, a motor angular speed is presumed by defining impedance models of motor driving systems in an intermittent mode and a continuous mode.

Controller of electric power-steering system

Control apparatus of electric power steering apparatus

In order to provide an electric power steering apparatus which can be made compact as well as reduced in cost and can be improved in reliability, a control circuit and a drive circuit are provided on a deformable flexible circuit substrate. The circuit substrate is provided on the housing of a reduction gear mechanism while being deformed so as to cover a portion of the outer surface of the housing along the shape of the outer surface.

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Maebashi, Japan

Hideaki Kawada