Hitachi, Ltd.

Hitachi Information Control Systems, Inc.

Noboru Azusawa

Hisayoshi Shiraishi

Tadashi Okamoto

Makoto Tachikawa

Tadahiko Hashimoto

Yoshiharu Nagae

Takeshi Katoh

Junichi Hamano

Akihiro Ohhashi

Hitoshi Saitoh

Yasuo Morooka

Kenji Kubo

Toshihiko Matsuda

Toru Ishikawa

Masahiro Tobise

Kunihiko Onuma

Mitsuaki Kobayashi

Kuniyuki Igari

Rached Dhaouadi

Hiromitsu Kikuchi

A process controlling method and apparatus which uses a flowchart language program and ladder programs with an intermediate register accessible using the same name by both the flowchart language program and the ladder programs. Each ladder program defines the operation of a machine, including an interlock condition of the machine operation. The flowchart language program defines an automatic operation flow which sequentially activates the ladder programs using the data in the intermediate register. This arrangement allows the flowchart language program to be separated from the ladder programs improving productivity, serviceability and security of the programs.

Apparatus and method for controlling a system process

A motor controller includes a shaft torsion vibration estimator for estimating a shaft torsion vibration between a motor and a mechanical load and a shaft torque estimator for estimating a shaft torque acting upon a motor shaft, wherein a vibration in a mechanical load driving system is suppressed by utilizing an estimated shaft torsion torque value calculated by the shaft torsion vibration estimator and an estimated shaft torque value calculated by the shaft torque estimator in addition to a detected motor speed value. Using such a system stable speed control having improved response can be achieved since higher order vibration modes can be suppressed without deteriorating its shaft torsion vibration without deteriorating its shaft torsion vibration suppression performance by combining the shaft torsion vibration estimator and the shaft torque estimator.

Motor speed controller for suppressing shaft torsion vibration

A programmable controller for executing a program having mixed instructions. The programmable controller includes a bit operation memory for storing a mixed instruction inclusive of the mixture of bit operation instructions and word operation instructions in order of execution and a word operation memory for storing the word operation instructions in the mixed instruction in order of execution. A bit operation processor is provided in the programmable controller for outputting a start command for a word operation instruction when a word operation instruction read from the bit operation memory subsequently to the execution of the bit operation instruction has been recognized. The programmable controller also provides a microprocessor for receiving the word operation start command to execute the word operation instruction stored in the word operation memory,

Programmable controller and sequence control method

A process controlling method uses a flowchart language program and ladder programs with an intermediate register to be accessible with the same name by both the flowchart language program and the ladder programs. Each ladder program defines the operation of a machine, including an interlock condition or the like of the machine operation. The flowchart language program defines an automatic operation flow which sequentially activates the ladder programs using the data in the intermediate register. This arrangement allows the flowchart language program to be separated from the ladder programs, thereby improving productivity, serviceability and security of the programs.

The liquid crystal is written with a laser beam. The laser beam generated by a laser source is applied through an optical control unit such as galvanometer mirrors to the liquid crystal. To erase a part of the data written in the previous time completely, the liquid crystal is irradiated with the laser beam slightly wider than the portion that was thermally written on the liquid crystal in the previous time.

System for partially erasing thermally written liquid crystal element

A multiplex control system has controllers for delivering control data to at least one common controlled system, and a multiplex mode switching device which is constructed to permit the logic for selecting the control data to be changeably set therein. The mode selection logic of the multiplex mode switching device can be set and changed freely by the user so that a desired logic is obtainable for the selection of the control data from the controllers, whereby the adaptability and utility of the multiplex control system are increased.

Multiplex control system with programmable logic for controlling signal

The liquid crystal is written with a laser beam. The laser beam generated by a laser source is applied through an optical control unit such as galvanometer mirrors to the liquid crystal. The intensity of the laser beam applied to the liquid crystal is controlled by a laser beam intensity varying unit. A writing control unit controls the mechanical displacement caused by the optical axis control unit and controls the laser beam intensity varying unit. The laser beam energy applied to the liquid crystal can be maintained constant, thus enabling a constant written line width even during acceleration and deceleration of the optical axis control unit.

Liquid crystal projection display

Liquid crystal projection display having laser intensity varied

A modulating wave signal whose phase abruptly changes is compared with a carrier signal to generate a pulse width modulation pulse. The carrier signal is a sine wave signal having a frequency n times as high as that of the modulating signal and synchronized with the modulating signal. A phase of the carrier abruptly changes by a factor of n as the phase of the modulating signal abruptly changes. Thus, a pulse with modulation pulse which causes an output voltage of a pulse with modulation inverter to be sinusoidal is generated even if the phase of the modulating wave signal abruptly changes.

Pulse width modulation pulse generator

A control apparatus for a thyristor converter which supplies electric power to a load generating a changeable electromotive force, wherein, in response to a load current being changed from an intermittent load current mode to a continuous load current mode, an actual main circuit constant of the load is calculated on the basis of a pregiven main circuit constant of said load, a predetermined minimum value of a DC average motor current at which a compensation control angle is zero, a DC average load current and a set control angle at a time when the load current just changed from the intermittent load current mode to the continuous load current mode. The compensation control angle is obtained on the basis of the calculated actual main circuit constant and the DC average load current. The calculated compensation control angle is added to the set control angle to thereby apply the added angle to the thyristor converter as a firing control angle.

Apparatus and method for controlling a thyristor converter in response

A synchronous motor having a polyphase armature winding and a field winding is driven by a frequency converter. A position signal associated with the rotational position of the synchronous motor is adapted to be shifted in phase by the maximum of 180.degree. to the advance and lag side by a position control signal, so that a firing pulse for the frequency converter is generated by a combination of a phase-shifted position signal and a reverse signal. Thus the operation modes are switched stably between motoring and regenerative and between forward and reverse operations by changing the magnitude of the phase control signal and reversing the polarity thereof.

Control system for commutatorless motor

A control system for a commutatorless motor comprises a frequency converter which includes two graetz-connected thyristor converters and D.C. lines interconnecting the converters, between an A.C. motor and an A.C. power supply. Motoring operation and regenerating operation are selectively effected between the motor and the power supply. In switching the operation mode, one of the converters which has been operated in a recitifier operation mode is first switched to an inverter operation mode, and after it has been confirmed that a control voltage to determine a firing angle of the one converter has been shifted to an inverter region, the other convertor is switched to the rectifier operation mode.

Growing community of inventors

Katsuta, Japan

Noboru Azusawa