Mitsubishi Denki Kabushiki Kaisha

Tsutomu Kazama

Mitsuyasu Kachi

Takao Mizutani

Hirokazu Sakuma

Yukio Aoki

Toshiyuki Kaitani

Tetsuaki Nagano

Masanori Ozaki

Chihiro Morita

Satoshi Kondo

Kimio Saito

Fumio Kumazaki

Yuusuke Ushio

Tadakatsu Yokoi

There is provided a serial transmitting section for serially transmitting a command frame which is sent from a host controller to a positioning type servo amplifier and a command follow-up type servo amplifier . In the command frame , an information section, into which information to be transmitted is inputted, has discrimination data for showing a selection between the positioning type servo amplifier and the command follow-up type servo amplifier . In the positioning type servo amplifier and the command follow-up type servo amplifier , there is provided information reading section for reading the content of an information section after the discrimination data of the command frame by the discrimination data of the command frame

Servo control system

There is provided a controlling device for an AC motor having a structure in which a current of a three phase brushless DC motor is detected and then converted to a rotor coordinate system, to separately control a torque split current (q axis) and an exciting split current (d axis), wherein an offset is estimated with a DC component of a multiplied value of the values corresponding to a d axis voltage command which is an output of an exciting split current controller and an electrical angle, and the detected current is compensated for, so that an offset of a current detector may be estimated and compensated for during its operation without stopping its rotation and the motor can rotate smoothly without a torque ripple, even in the case in which the current detector has an offset error or in the case in which an offset changes due to a temperature drift.

Controller for AC motor

An absolute position detection apparatus which comprises sine and cosine wave generators for generating one or more sets of sine and cosine waves within a cycle, analog-to-digital converters for converting the incoming sine and cosine waves generated by the sine and cosine wave generators into digital values. An arithmetic unit is used for calculating a compensation for errors including offset, amplitude and phase errors on the basis of the digital values from the analog-to-digital converters. In the apparatus, the arithmetic unit operates on a phase angle from phase angles found by the arithmetic performed prior to or during said error compensations and the digital values from the analog-to-digital converters, whereby a low-priced, highly reliable absolute position detection apparatus can be achieved without the addition of compensation circuits to the hardware.

Absolute position detection apparatus and error compensation methods

A position control system for feeding back position information detected by position detection means for detecting the position of a machine movable part, is disclosed. The system includes a second order system position control loop formed by providing an internal second control loop. By adequately setting the internal control loop gain, a high response and stable control loop and also smooth response waveform can be obtained, thus ensuring vibration-free operation of the machine.

Position control system and position control method thereof

A motor control unit having a first semiconductor module circuit for converting an alternating current into a direct current, a second semiconductor module circuit consisting of switching elements for converting the direct current into an alternating current of optional voltage and frequency, and a control circuit for controlling the semiconductor module circuits. The unit has a case that is substantially rectangular in cross section, vertically high and laterally thin with respect to a perpendicular installation surface. Two heat sinks are disposed at the outside of the unit case at the back thereof and are thermally connected to a laminar heat plate that is disposed within the case and in contact with the heat dissipating installation surfaces of the semiconductor modules inside the unit case.

Motor control unit with thermal structure

The position of a machine tool or the like is accurately obtained by an absolute value encoder. Light emission elements emit light which passes through scales containing optical patterns and is detected by light receiving elements. First, a signal detected by the light receiving elements while the light emission elements are extinguished is stored in memory. Then, the light emission elements are lighted and the signal detected by the light receiving elements is corrected by the previously stored signal.

Growing community of inventors

Aichi, Japan

Tsutomu Kazama