Kabushiki Kaisha Yaskawa Denki

Kabushiki Kaisha Yaskawa Denki Seisakusho

Ryuichi Oguro

Souki Kaku

Hideki Honda

Kozo Ide

Nobuhiro Umeda

Masanobu Inazumi

Hidekazu Miyagawa

Shuang-Hui Hao

Shinya Morimoto

Tetsuro Izumi

Kazuhiro Tsuruta

Keisei Inoki

Takehiko Komiya

Masao Ojima

Takeshi Kamei

Shuichi Fujii

Soki Kaku

Masanori Kawatani

Noriaki Sueyoshi

In sensorless vector control performed through use of a rotation speed of a synchronous motor 6 and the position of a rotor, a positive current is caused to flow to a &#x3b3; axis on the assumption that a 'd' axis serving as a true magnetic axis is out of phase with the &#x3b3; axis by only an angle of load &#x3b8;e, whereby torque which is proportional to i&#x3b3; sin &#x3b8;e and directed toward the &#x3b3; axis arises in the magnetic axis. Accordingly, a deviation between a d-q axis serving as a true magnetic axis and a &#x3b3;-&#x3b4; axis serving as a control axis is eliminated. Even if load is exerted on the motor, the &#x3b3; axis serving as a control axis is constantly aligned with the 'd' axis serving as the magnetic axis of the synchronous motor, thereby enabling excellent vector control.

Method of controlling speed of synchronous motor, and method of identifying constant of synchronous motor

A pre-compensator is provided based on a definition of abase vibration model having a motor transfer functionfor generating motor displacementfrom an input that is the sum of input torque and a table propelling forcemultiplied with a reducer and Cartesian-to-polar coordinate transformation constant, a table transfer functionfor multiplying a deviationbetween an output that is the motor displacement multiplied with a reducer and polar-to-Cartesian coordinate transformation constantand table displacement with a table-displacement-to-force conversion spring constantto generate the table propelling forceand to output table displacement, and a base driving transfer functionfor generating base displacement by multiplying base displacementwith a base-displacement-to-force conversion spring coefficientand inputting the same with the table propelling force, table displacementbeing generated from a difference between the table displacement and the base displacement.

Positioning control method

A motor controller, comprising a first simulation control unit () and a second simulation control unit () as a feed forward control means for inputting a command to an actual control unit () performing a feedback control, wherein the control parameter of the first simulation control unit () is set so that the high-speed property of a control response is increased, and the control parameter of the second simulation control unit () is set so that the stability of the control response is increased, whereby an entire feed forward control means can be designed so as to meet the requirements for the high-speed property and high stability of the control response.

Motor controller

Host control sectionis provided with simulation modelfor simulating the signal transmission characteristics of an electric motor control device. Host control sectionperforms an operation on the actual position command signal &#x3b8;ref that is supplied from the host device in accordance with the simulation model, calculates the speed and position of the electric motor corresponding to the actual position command signal &#x3b8;ref, and applies this speed and position as first simulation speed signal &#x3c9;F and first simulation position signal &#x3b8;F, respectively, with each second control sampling period t. Host control sectionfurther generates a linear combination of &#x3b8;ref&#x2212;&#x3b8;F and &#x3c9;F using, as combination coefficients, constants determined by parameters that characterize the simulation model, and supplies this linear combination as feedforward torque signal TFF for each second control sampling period t. In this way, the occurrence of error between the actual position signal and the simulation position signal can be prevented even when the control sampling period of the feedforward operation differs from the control sample cycle of the feedback operation.

Electric motor control device

There are performed converting electric currents Iu, Iv, and Iw flowing through the synchronous motor into a d-axis actual current Idfb and a q-axis actual current Iqfb on rotational coordinate axes which rotate synchronously with a rotor magnetic flux vector, on the basis of an actual position &#x3b8; of the rotor of the synchronous motor; estimating a d-axis simulated current Idob and a q-axis simulated current Iqob on the basis of the d-axis actual current Idfb, the q-axis actual current Iqfb, a d-axis actual voltage command Vdref, and a q-axis actual voltage command Vqref; generating a d-axis actual voltage command Vdref and a q-axis actual voltage command Vqref on the basis of a d-axis current command Idref, a q-axis current command Iqref, a d-axis simulated current Idob, and a q-axis simulated current Iqob; and converting the d-axis actual voltage command Vdref and the q-axis actual voltage command Vqref into actual voltage commands Vuref, Vvref, and Vwref on the basis of the actual position &#x3b8; of a rotor of the synchronous motor. As a result, there can be provided a method and apparatus for controlling an electric current of a synchronous motor, which can provide a superior current response characteristic regardless of the influence of temperature.

Method and device for controlling currents of synchronous motor

A motor controller comprising a machine system ( ) having a load machine ( ), a transmission mechanism ( ) for transmitting power, and a motor for driving the load machine through the transmission mechanism; a simulator unit ( ) having a numeric model ( ) including the machine system, a simulation control section ( ) for giving a torque command to the numeric model by using an observable quantity of state of the numeric model, and an evaluating section ( ) for sending a control parameter to the simulation control section and an actual control unit; and the actual control unit ( ) having an actual control section which receives an observable quantity of state of an actual system and has the same structure as that of the simulator unit and adapted to supply a torque signal to the motor serving as a drive source. Therefore the control gain of a motor controller can be automatically adjusted quickly and optimally.

A electric motor control device is provided for controlling an electric motor which actuates a movable member of a machine through a transmitting mechanism. When a torque command is given as motion command signal ( ) to servo device ( ), servo device ( ) sends input torque signal ( ) corresponding to motion command signal ( ) to electric motor ( ), which is energized. Movable member ( ) is thus moved, producing vibrations. Servo device ( ) outputs input torque signal ( ) equivalent to input torque signal ( ), and input torque signal ( ) and rotational speed signal ( ) are stored in memory device ( ). Analyzing device ( ) analyzes the frequencies of input torque signal ( ) and rotational speed signal ( ) according to an FFT, and outputs analytical result ( ).

A three-phase-to-two-phase converter detects two-phase currents of three-phase stator currents, converts the stator currents into a &ggr;-&dgr; coordinate system to derive a &ggr;-axis current and a &dgr;-axis current. The &ggr;-axis current, the &dgr;-axis current, and voltage command values outputted respectively from a &ggr;-axis current controller and a &dgr;-axis current controller are entered to a stator current and induced electromotive force estimator, which determines estimated values of the stator currents and estimated values of an induced electromotive force in the &ggr;-&dgr; coordinate system.

Method for estimating induced electromotive force and speed of induction motor, method for correcting misalignment of shaft thereof, and induction motor controller

In order to estimate a magnetic pole position of a permanent magnet type brushless motor, the following steps are conducted. A given &ggr; axis and a given &dgr; axis in an advanced from the &ggr; axis by an electrical angle of 90&deg; are set. A closed-loop electric current control system in the &ggr; axis direction is formed while forming an open-loop electric current control system in the &dgr; axis direction. It is calculated an interference current generating in the &dgr; axis direction when a current command in the &ggr; axis direction is given as a stepwise alternating current command. The &ggr; axis is finely advanced by an angle of &Dgr;&thgr; when a sign of a product of an integral value of the interference current and a value of the current command in the &ggr; axis direction is positive. Alternatively, the &ggr; axis is finely delayed by an angle of &Dgr;&thgr; when the sign is negative. Thereby, the &ggr; axis is made accord with either a d axis as a true magnetic axis or with a -d axis advanced by 180&deg; from the true magnetic axis.

Method of estimating initial pole position of permanent magnet brushless motor

Sensorless control method and apparatus of permanent magnet synchronous

Controller of multi-axis robot

A magnetic levitation and transport system has a plate-like moving element (SFT) which is moved by a linear motor disposed in a stator (STT). The moving element is moved vertically by first through fourth electromagnetic devices (MGV.sub.10 -MGV.sub.41), and fifth and sixth electromagnetic devices (MGH.sub.10 -MGH.sub.21) exert forces on the moving element in a horizontal direction perpendicular to the direction in which the moving element is moved. Gaps between the moving element and the electromagnetic devices are detected by gap sensors which produce gap data. In the vertical direction, for example, attractive force commands (f.sub.V1 -f.sub.V2) are produced from the outputs from a circuit for calculating the amount of feedback (10) which is supplied with the gap data (XV.sub.1 -XV.sub.4) and also with the output from a variable gain g.sub.V (l) generator (60) to which the position (l) of the center of gravity of the moving element is supplied. The attractive force commands are then linearized by linearizing circuits (71-74), and linearized outputs are applied to the electromagnetic devices. With this arrangement, the variable gains can be established by an analog circuit, and control gains in the respective control directions can be given independently of each other.

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Fukuoka, Japan

Ryuichi Oguro