Toyoda Koki Kabushiki Kaisha

Jtekt Corporation

Atsuhisa Asada

Jiro Nakano

Yoshihiko Yamada

Toshio Kohno

Shinji Murakami

Akimitsu Kamiya

Yasuhiro Yamashita

Kazunari Ogura

Tetsuro Shibukawa

Tadashi Otani

Katsuhiro Maseki

Kunpei Manabe

Hideki Katou

In an electric power steering apparatus, at least one of a speed reduction gear ratio of the speed reduction gear mechanism and the number of pole pairs of a motor resolver is set in such a manner that a calculated value, which is obtained by multiplying the speed reduction gear ratio of the speed reduction gear mechanism with the number of pole pairs of the motor resolver, represents a non-integer having a numerical value of the decimal place. This electric power steering apparatus includes an absolute rotational position specifying device configured to specify an absolute rotational position of the steering wheel from among plural possible absolute rotational positions that are obtained based on the steering angle and the motor electrical angle. This electric power steering apparatus is hence capable of controlling an electric motor based on the absolute rotational position of the steering wheel.

Electric power steering apparatus

An electric power steering apparatus includes a first resolver whose pole pair number is 'm' and a second resolver whose pole pair 'n'. The electric power steering apparatus further includes a torsion calculating means which calculates the a torsion angle of the torsion bar from a difference between the rotating angle detected by the first resolver and the rotating angle detected by the second resolver. The torsion calculating means compensates the angle difference by a compensation value obtained by a table on the basis of the value obtained by multiplying an electrical angle of the first resolver by &#x2018;n&#x2019; and the value obtained by multiplying an electrical angle of the second resolver by &#x2018;m&#x2019;.

Electric power steering apparatus and angle compensating method therefor

A method for setting a control parameter for an electric power steering device includes process of obtaining a speed ratio between a steering shaft and a motor based on a mechanical angle at the steering shaft obtained from a first steering angle and a second steering angle and a motor electric angle of the motor, and setting the speed ratio as a control parameter used for obtaining the absolute rotational position of the steering wheel from the first steering angle, the second steering angle, and the motor electric angle at the control means.

Setting method for control parameter, setting device for control parameter, and electric power steering device

An electric power steering device according to the embodiment disclosed herein employs, in addition to a motor resolver of an electric motor for assisting the rotational manipulation of a steering shaft, first and second resolvers which are made different in the number of N-S pole pairs from each other each for detecting the rotational position of the steering shaft. The reduction gear ratio of a reduction gear mechanism of a ball screw mechanism driven by the electric motor is set so that a calculated value which is obtained by multiplying the reduction gear ratio with the number of pole pairs of a motor resolver represents a non-integer having a numerical value of the decimal place. Thus, it does not occur that calculated value becomes an integer which does not have any numerical value of the decimal place. As a result, it can be realized that the mechanical angle of the steering wheel which is calculated based on electrical angles of the first and second resolvers can be made not take the same value within any one-rotational range unit as that within another one-rotational range unit of four rotations in total of the steering wheel including two left rotations and two right rotations. Consequently, it becomes possible to detect the absolute rotational position of the steering wheel precisely, so that the motor for assisting the steering manipulation can reliably be controlled in dependence on the absolute rotational position of the steering wheel so precisely detected.

Electric power steering device and method and apparatus for manufacturing the same

A power steering device is provided which is capable of preventing a wrong operation from occurring in a steering control state even when an initial torque of torque detection was not detected normally due to a human error. Upon receipt of a trigger signal, a CPU reads an initial setting program from a program storage area of a ROM and executes the initial setting program in the following order of steps. That is, the CPU detects by torque detection an initial torque which is generated primarily by the cause of the difference between origin positions of a pair of resolverswhich together with a torsion bar constitutes the torque detection. Then, the CPU operates an assist motor to rotate a steering handle from a neutral position a predetermined rotational angle in one direction about the handle axis to stop the steering handle at a first judgment position and detects a first judgment torque value by the torque detection with the steering handle being stopped at the first judgment position. Then, the CPU rotates the steering handle from the neutral position the same angular position in the other direction to stop the steering handle at a second judgment position and detects a second judgment torque value by the torque detection with the steering handle being stopped at the second judgment position. Further, the CPU judges whether the initial torque has been detected normally or not, based on the first and second judgment torque values.

Power steering device

An electrically driven steering apparatus is capable of continuing to detect a steering angle even if a rotation angle sensor is in trouble. The steering angle is acquired using three rotation angle sensors (first resolversecond resolvermotor resolver). Thus, even if any resolver is in trouble, the steering angle can be detected continuously and by maintaining the functions of ABS, VSC and the like, the safety in traveling can be intensified.

Electrically driven steering apparatus

A torque detector that suppresses fluctuation of an output value relative to fluctuation of an input value and that also has the output value accurately follow the input value even when the input value changes suddenly. The torque detector includes a detection element, a converter, and a hysteresis processor. The detection element detects the steering torque applied to a steering shaft when the steering shaft is rotated to generate an analog torque signal corresponding to the steering torque. The converter converts the analog torque signal to a digital torque signal. The hysteresis processor performs hysteresis processing on the digital torque signal to include the value of the digital torque signal in a predetermined range.

Torque detector and electric power steering controller provided with torque detector

An apparatus for setting control parameters of a machining apparatus. The setting apparatus includes a storage unit for storing a set of control parameters for each of a plurality of machining modes; an input device for selecting one of the plurality of machining modes; and a control unit for selecting a set of control parameters corresponding the selected machining mode and setting the set of control parameters as control parameters to be used for controlling the machining apparatus.

Apparatus and method for setting control parameters of machining apparatus

A machining system having a workpiece storage for storing plural workpieces to be machined each of which are machined in plural machining stages. A computer of the system memorizes first information indicating the membership of plural machine tools in plural machine groups suitable for plural different machinings, and second information indicating plural machining stages for machining each of the workpieces and machine groups which can carry out the machinings in respective machining stages. When one of the machine tools becomes empty, the computer finds out what kind of machining is required in the next machining stage of each workpiece so as to find a workpiece which can be machined by a machine group to which the empty machine tool belongs, and the found workpiece is then transferred to the empty machine tool.

Growing community of inventors

Obu, Japan

Atsuhisa Asada