Hitachi, Ltd.

Hitachi Keiyo Engineering Co., Ltd.

Hitachi Keiyo Eng. Co., Ltd.

Hiroshi Sugai

Sumio Kobayashi

Hisakazu Ninomiya

Hiroyuki Tomita

Kunio Miyashita

Hiroshi Nagase

Yasuyuki Sugiura

Masataka Yahara

Mitsuru Watabe

Shigeki Morinaga

Satoshi Ibori

Nobuyoshi Mutoh

Koichi Sugimoto

Toshihiko Sakai

Kyozo Tachibana

Hisaaki Hirabayashi

Mutsuo Tokashiki

Tadashi Okawa

Sadayuki Igarashi

Rika Oue

Kazuyuki Nakagawa

Yoshiomi Joujima

Goro Urayama

Masaharu Muramatu

Mutuo Tokashiki

Tadashi Ookawa

Kazumasa Sugiyama

A motor driving control apparatus having a function for performing an individual test operation of a servomotor driving control apparatus or an inverter apparatus by generating test operation command in the control apparatus in place of a command from an external controller, whereby both a function check and a performance check can be performed to attain an improvement in reliability and case of operation.

Motor driving control apparatus

Sine wave signals generated from a position detector are used as analog values to detect a fine position of a rotating or moving body, a rise or fall edge of the sine wave signal is used to detect a coarse position of the rotating or moving body, and the position or speed of the rotating or moving body is detected based on a signal indicative of the detected coarse position when the rotating or moving body is at high speed and based on a signal indicative of the detected fine position when the rotating or moving body is at low speed to thereby provide optimal control from high speed to low speed. Especially at extremely low driving, speed detection with superhigh resolution is effected using the analog value to decrease an uneven rotation of the rotating body.

Method and apparatus for detecting positions and/or speed of a moving

Disclosed is a position detecting method and apparatus which are suitable for detecting the position of a moving body on the basis of the output of a position detector for generating two-phase periodic waves having a phase difference of a quarter period, the method comprising the steps of: comparing either one of the two-phase periodic waves with a predetermined reference value having hysteresis to thereby obtain a roughly estimated position for every half period of the one periodic wave; analog-to-digital converting the two-phase periodic waves and a zero-cross value for every sampling period to thereby obtain a finely estimated position; and detecting the position of the moving body on the basis of the roughly estimated position and the finely estimated position while correcting an error due to the hysteresis at the starting point of the roughly estimated position, by use of the relationship between the roughly estimated position and the finely estimated position. According to this method/apparatus, continuity between the roughly estimated position and the finely estimated position can be maintained, so that exact and high-resolution position detection can be performed.

Position/speed detection method and apparatus

A signal whose frequency is proportional to a rotational speed of a rotor and whose rising and falling angles near points crossing zero becomes larger with the rotational speed of the rotor is used to produce a first signal of amplitude corresponding to the rising and falling angles and a second signal of amplitude corresponding to the frequency, a difference between the first and second signals is evaluated, and the first or second signals are corrected with the difference.

Rotating speed measuring apparatus having a corrector for low and high

The present invention relates to a control system for a servomechanism device such as robot, and more particularly to a position correcting control system for a servomechanism device which is well suited to perform high-precision positioning or high-perfomance operations on the basis of a sensor feedback control system such as force detection feedback control. It is characterized in that a plurality of algorithms for correcting a position target value on the basis of a sensor signal are prepared and are switchedly used so as to readily switch functions, depending upon whether the purpose of a sensor control is a high-precision control or any other high-performance control, that the position target value is corrected through a threshold characteristic element or a dead band element so as to make effective the correction of the position target value based on the sensor signal, and that a correcting signal is applied through a response lag element so as to attain stabilization owing to a viscous effect bestowed on the position correcting operation based on the sensor signal.

Position correcting control system for servomechanism device

A permanent magnet rotor wherein a rotary shaft has an orthogonal cross a sectional shape orthogonal in a longitudinal direction of the rotary shaft, a plurality of circular-arc portions which are around the axis of rotation of the rotary shaft, and rectilinear portions which connect the adjacent circular-arc portions with straight lines having no curved portion. Respective permanent magnets, equal in number to the circular-arc portions, are fixed extending over the circular-arc portions and the rectilinear portions. The surface of each permanent magnet remote from the rotary shaft has a cross sectional contour orthogonal to the longitudinal direction of the rotary shaft, forming a circular arc which protrudes outward.

Permanent magnet rotor with sinusoidal flux pattern

A fixed slit plate and a rotary slit plate which is secured to a rotating shaft are provided between two photoconductive elements and a light emitting element, and the two photoconductive elements provide two outputs which have the phase difference .pi. therebetween. These two outputs thus provided are added to extract the dc component, thereafter exerting feedback control over the light emitting element such that this dc component is maintained at a constant level.

Rotational information output device

When driving an AC motor with a PWM inverter, the width of a speed command signal is modulated by a carrier to produce width modulated pulses for controlling main switching elements. The width modulated pulses are liable to be attended with impulses which cause magnetic vibrations in the AC motor, resulting in noises. The generation of these impulses can be suppressed by changing the amplification factor of an amplifier for the speed command signal or the amplitude of the carrier on the basis of the rate of change of the speed command signal. Noises which would be attendant on low speed running of the AC motor can be reduced by changing the amplification factor of the amplifier and the amplitude of the carrier on the basis of detected frequency of the speed command signal or revolution of the AC motor during low speed running.

Control apparatus for AC motors

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Sakura, Japan

Hiroshi Sugai