Fanuc Corporation

Franc Ltd.

Shinichi Kono

Hironobu Takahashi

Masaaki Fukukura

Junichi Tezuka

Kosei Nakamura

Shinichi Horikoshi

Katsuo Kohari

Shunsuke Matsubara

Kazuhisa Numai

Mamoru Yaeshima

Takahiro Akiyama

Masami Kimijima

Shigeki Hanyu

Yuuki Morita

Yoshiki Fujioka

Naoto Ota

Yuuichi Yamada

Tatsuo Shinohara

Masahiro Kaku

Hironobu Takahasi

A motor driver capable of detecting the insulation deterioration of a motor easily and inexpensively is disclosed. The voltage supplied from an AC power supply () is rectified by a first rectifying circuit (Dto D) and smoothed by a capacitor (C) in a power supply unit (). The output voltage of the power supply unit () is converted into an AC voltage of a frequency and a motor (M) is driven by a motor drive amplifier (). Elements (RCRC) are connected between at least one of the positive electrode () and the negative electrode () of the output line () of the power supply unit () and the ground (GG). An insulation deterioration circuit () detects at least one of the voltage between the elements and the current flowing through the elements.

Motor driver

A circuit system that includes a sensor circuit for a sensor that detects the state of a motor is provided in an inverter unit for driving the motor. A 0V of the circuit system is connected with a shield braid of a shielded cable that connects the sensor circuit and the sensor. Further, the shield braid of the shielded cable is connected to an earth plate.

Inverter unit grounding method and inverter unit

The present invention is directed to the provision of a servomotor driving apparatus that feeds energy stored in a power storage part connected with a DC link that connects a rectifier circuit with an inverter circuit so that the energy stored in the power storage part can be reduced. A motor driving apparatus () includes: a step-up type DC/DC converter circuit () for boosting voltage appearing at an output of the power storage part (C) connected with a DC link; and a DC/AC conversion circuit () for converting the boosted DC electric power into AC electric power and feeding it to an electric power source.

Motor driving apparatus

A magnetic flux produced by the current of a motor is detected by means of a Hall element, and an infinitesimal current proportional to the actual current of the motor is outputted. The outputted infinitesimal current is run through a resistor, and a potential difference across the resistor is detected by a &#x394;&#x3a3; modulator circuit. The motor is subjected to feedback control based on the potential difference detected by the &#x394;&#x3a3; modulator circuit.

Motor control apparatus

A motor controller capable of obtaining information on offsets, amplitudes and a phase difference of analog feedback signals from encoders without using special measuring device. The analog feedback signals from the encoders are A/D converted and the offsets, the amplitudes and the phase difference of A-phase and B-phase analog feedback signals are obtained based on the converted digital signals by an arithmetic section. The obtained offsets, amplitudes and phase difference are displayed by a display section of the motor controller and/or a display section of a numerical controller as a host controller. Further, the obtained offsets and amplitudes are compared with respective reference values for determining acceptability of the feedback signals from the encoders and the results of the comparison is displayed by the display section and/or the display section of the numerical controller.

Motor controller

A compact, low-cost outage management emergency power supply device with a simple constitution is provided by connecting an auxiliary capacitor and charging battery to a DC link portion. In one embodiment, an auxiliary capacitor is connected in series via a switching circuit to a DC link portion which supplies direct-current voltage of a converter device which converts alternating-current voltage to direct-current voltage, and the input-output of current to the auxiliary capacitor is controlled by the switching circuit, so that the capacity of the additional auxiliary capacitor is not subject to limitations. Further, in another embodiment, a charging battery is connected to a DC link portion via a parallel circuit of a switching circuit or diode, and a resistor.

Outage management emergency power supply device

In the primary frequency control of an induction motor which controls the velocity by changing the supply frequency of the induction motor, the torque component current value is determined from the current value on the primary side of the induction motor, and the excitation frequency command corresponding to the torque component current value is determined by changing the velocity command value by the torque component current value. Based on the excitation frequency command, the voltage command is formed and supplied to the primary side of the induction motor, to drive the induction motor. The acceleration and deceleration of the induction motor is thus performed in which the adjustment of the excitation frequency depends on the change of the load inertia.

Method for controlling acceleration/deceleration of an induction motor

A method and apparatus for controlling a machine in a power failure. The present invention is applicable to such machines that a tool and a workpiece must always be controlled in synchronization with each other, and allows the tool and workpiece to stop without any damage in the power failure situation. If a power failure occurs during a synchronous cutting operation, the present invention disables a power regeneration function, connects a discharge resistor unit to a DC link of a power regeneration circuit, decelerates motors for tool drive and workpiece drive in synchronization with each other, and retracts the tool back to a safe area by driving a motor for tool feed with the power regenerated from the other two motors.

Method and apparatus for control in power failure

Cutter fracture detecting system

Spindle positioning method

A slip frequency control method for induction motors, capable of achieving accurate control and excellent in control response. To effect determination of a slip frequency (fs) and an excitation magnetic flux frequency (.omega.0) by software processing to reduce a control error and a control delay caused if hardware elements are employed for the determination of these parameters, a vector control processor divides, in a speed control routine (101-104), the sum of a slip frequency, obtained by dividing the product of a secondary current command (I2) and a proportional constant (K2) by an excitation magnetic flux command (.PHI.), and a remainder (.alpha.') in the preceding routine by a routine executing frequency (CV), so as to derive a slip amount (A) and a remainder (.alpha.) in the present routine. In a current control routine (201 to 205) executed at intervals of a period shorter than that of the speed control routine, the processor divides the sum of the derived slip amount and the remainder (.beta.') in the preceding routine by the number (n) of execution of the current control, to thereby derive slip distribution data (.omega.s) and a remainder (.beta.) in the present current control routine, and further adds data (.omega.r) indicative of an actual motor speed to the derived slip distribution data, to thereby derive an excitation magnetic flux frequency (.omega.0).

Slip frequency control method for induction motors

A main spindle rotation control method capable of preventing a workpiece from being twisted during the delivery of the workpiece between two main spindles of a machine. When the rotating speeds of first and second main spindles (100, 200) reach a synchronous rotating velocity as a result of a speed loop control executed by velocity control sections (111, 211) of first and second spindle control circuits (110, 210), position loop control is executed by position control sections (112, 212) of these control circuits, and each main spindle is driven to be decelerated in accordance with the rotational phase of each main spindle, and the velocity loop control is then executed again, to bring the main spindles to rotate in the same phase and at the same synchronous rotating speed. When the delivery of the workpiece (300) between the main spindles is started under this condition, integral control in both the velocity control sections is invalidated. Thus, even if a difference is present between the rotating speeds of the two main spindles at the start of the workpiece delivery, due to fluctuations in the main spindle rotating speeds, a difference between torque commands from the velocity control sections, attributable to the difference between the main spindle rotating speeds, never be gradually increased by the integral control, to thereby prevent the workpiece from being twisted.

Growing community of inventors

Oshino, Japan

Shinichi Kono