Hitachi, Ltd.

Hitachi Keiyo Engineering Co., Ltd.

Sumio Kobayashi

Hiroshi Sugai

Hiroyuki Tomita

Hiroshi Nagase

Hisakazu Ninomiya

Kunio Miyashita

Nobuyoshi Mutoh

Yasuyuki Sugiura

Mutsuo Tokashiki

Tadashi Okawa

Rika Oue

Kazuyuki Nakagawa

Sadayuki Igarashi

Masataka Yahara

Masaharu Muramatu

Tadashi Ookawa

Mutuo Tokashiki

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

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

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

A control apparatus for an induction motor wherein an inverter is connected between a power source and the induction motor so as to energize the induction motor through the inverter, characterized in that when an input voltage of the inverter has lowered, a magnetizing current component command is decreased, while a torque current component command is increased.

Control apparatus for induction motor

Growing community of inventors

Funabashi, Japan

Sumio Kobayashi