Fanuc Corporation

Tsutomu Shikagawa

Sou Saito

Kiichi Inaba

Sou Saitou

Taku Sasaki

Yasuyuki Matsumoto

Shinichi Horikoshi

Naoyuki Suzuki

Minoru Kobayashi

Shouta Fujii

Hitoshi Ishida

A motor drive device includes: a converter converting an AC voltage supplied from an AC power supply into a DC voltage; a smoothing capacitor smoothing the DC voltage output from the converter; an inverter converting the DC voltage smoothed by the smoothing capacitor into an AC voltage to drive a motor; a regenerative circuit that is disposed between the smoothing capacitor and the inverter, includes a first resistor and a first switch, and short-circuits the ends of the smoothing capacitor through the first resistor by turning on the first switch; and a control unit keeping the first switch in the OFF state during an emergency stop.

Motor drive device

A motor driving device includes: a rectifier circuit for rectifying an AC input voltage supplied from an AC power supply to a DC voltage; a smoothing capacitor for smoothing the rectified DC voltage; a relay that outputs a contact signal when the input voltage is input to the rectifier circuit from the AC power supply; an input voltage detector for detecting the input voltage; a capacitor voltage detector for detecting the capacitor voltage; a volatile first storage; a nonvolatile second storage; and a backup start determiner for determining whether or not to start a backup operation of transferring the information stored in the first storage to the second storage, based on at least one of the contact signal, the input voltage and the capacitor voltage.

Motor driving device and determination method

A motor drive apparatus includes a converter configured to convert AC power from an AC power supply into DC power and then output the DC power to a DC link, a capacitor provided in the DC link, an inverter configured to convert DC power in the DC link into AC power for motor drive, a discharge circuit which is provided in parallel with the capacitor in the DC link, and is selectively switched between a discharge operation of discharging DC power in the DC link by electrically connecting the discharge circuit and the capacitor to each other, and a non-discharge operation of cutting electric connection between the discharge circuit and the capacitor, and a discharge circuit drive unit configured to perform switch drive of the discharge operation and the non-discharge operation of the discharge circuit by using DC power of the DC link as drive power for the switch drive.

Motor drive apparatus equipped with discharge circuit of capacitor of DC link

A motor drive device includes an inverter configured to convert a DC voltage to an AC voltage by switching power devices, a current detector configured to detect a current output from the inverter, a current controller configured to generate a voltage command, a control signal generator configured to control switching of the power devices, a dynamic brake circuit provided with relays and configured to short-circuit an output side terminal of the inverter via resistances, a storage configured to store an initial current value and a first threshold value, and a failure determiner configured to compare a current value and an initial current value after a predetermined time has elapsed since detection of the initial current value, and determine presence or absence of a failure based on a result of comparing a change rate of the current value from the initial current value with the first threshold value.

Motor drive device having failure detection function

A brake control system includes: a plurality of motors each provided with a brake device and a position detecting section; and a brake control device that controls a plurality of the brake devices using one brake-oriented power source. The position detecting section includes a position detecting circuit section and a communication circuit section. The brake device includes: a current detecting section that detects a brake current flowing through a brake coil of an electromagnetic brake; and an insulating circuit section that electrically insulates the current detecting section and the communication circuit section. The communication circuit section transmits to the brake control device the brake current acquired via the insulating circuit section. The brake control device includes a fault specifying section that specifies the faulty brake device based on a plurality of detection signals detected by a plurality of the current detecting sections.

Brake control system and method of fault detection

A motor driving device controls braking of multiple motors each having a braking device by using a single brake power supply. The braking device includes: an electromagnetic brake that releases braking of a rotary shaft of the motor by energizing a brake coil; a conductive disk configured to rotate together with the rotary shaft and connected in series with the brake coil; and a plurality of resistors provided on a surface of the disk so as to be periodically connected in series with the brake coil as the disk rotates. The motor driving device identifies a failed braking device of the braking devices, based on the current value of the current flowing from the brake power supply and the rotational positions of the rotary shafts of the multiple motors.

Motor driving device and failure detecting method

A conduction path structure of a robot in which a conduction path has a simplified structure is provided. A conduction path structure of a robot includes: a structural mechanism which functions as a support and has a conductor portion; an actuator that operates the structural mechanism; and a conduction path through which driving power and/or a control signal is supplied to the actuator, wherein the conduction path also serves as the conductor portion of the structural mechanism.

Conduction path structure of robot

An apparatus with a motor drive device is provided with a support plate including an opening part for supporting the motor drive device. The support plate includes a first edge part around the opening part and a second edge part on the opposite side of the first edge part. The motor drive device includes a first recessed part formed on one end part in a predetermined direction, and a second recessed part formed on the other end part on the opposite side of the one end part. The first edge part is inserted into the first recessed part, and the second edge part is inserted to the second recessed part.

Apparatus with motor drive device, to which motor drive device can be easily attached

A robot includes a motor drive power source for converting a voltage supplied from a power source to a motor drive unit-grade voltage and outputting it, a motor drive unit for converting a motor drive unit-grade voltage output from the motor drive power source to a motor drive voltage and outputting it, a motor driven to be rotated by a motor drive voltage output by the motor drive unit, a robot arm on which the motor drive unit and the motor are arranged, and a robot controller which is provided independently of the robot arm and on which the motor drive power source is arranged.

Robot with daisy-chainable robot arm

A machine learning apparatus includes: a state observation unit that observes a state variable including an error between a position command and an actual position of a rotor, temperature of a motor driving apparatus and the motor, and voltage of each part of the motor driving apparatus; and a learning unit that learns a current feedback offset correction value for correcting an offset in the current feedback value, an inter-current-feedback-phase unbalance correction value for correcting an unbalance between phases in the current feedback value, and a current command correction value for a dead zone for correcting a current command in order to compensate a decreased amount of current due to a dead zone by which switching elements of upper and lower arms in the same phase of an inverter for motor power supply are not simultaneously turned on, in accordance with a training data set defined by the state variable.

Machine learning apparatus and method for learning correction value in motor current control, correction value computation apparatus including machine learning apparatus and motor driving apparatus

A motor driving device includes, a DB current calculation unit which calculates a DB current flowing through a DB circuit, based on the motor rotational speed and intrinsic parameters for a motor and the DB circuit, a Joule heat calculation unit which calculates a Joule heat resulting from a DB current, based on the DB current, a storage unit which stores a table defining the relationship between the DB current at the start of DB and the Joule heat resulting from an arc generated in a relay depending on the DB current, an integration unit which integrates the Joule heat resulting from an arc at the start of DB, the Joule heat resulting from a DB current, or the sum of these Joule heats, every time DB is performed, and a comparison unit which outputs the comparison result between the resultant integration value and a predetermined reference value.

Motor driving device including dynamic braking circuit

A motor drive apparatus includes: a motor current detection unit; a brake release determination unit that determines that the brake is not released when the motor current detected when the motor is operated under a predetermined load by application of a voltage to a brake coil is larger than a current for when the brake is normally released; a brake coil voltage change unit that changes a voltage applied to the brake coil when it is determined that the brake is not released to a larger value; a change history storage unit that stores the voltage after being changed and change date and time; and a life prediction unit that calculates a predicted life of the brake apparatus based on the voltage after being changed and the change date and time and the previously stored failure-time brake coil voltage.

Motor drive apparatus equipped with life prediction function for motor brake

A motor drive according to the present invention has a dynamic braking circuit. The motor drive includes a motor drive control circuit for applying a voltage to windings of a synchronous motor and the dynamic braking circuit for a predetermined time by switching power transistors connected to a direct current power supply, a current detection circuit for detecting a current value outputted from the power transistor, and a failure determination circuit for determining the presence or absence of a failure in the dynamic braking circuit from the current value detected by the current detection circuit and a predetermined threshold value. When the presence or absence of a failure in the dynamic braking circuit is detected, the resistance of the dynamic braking circuit is changed.

Motor drive having function of detecting failure in dynamic braking circuit

A first switching element is connected to one end of a brake and switches from the off state to the on state when a switch command is input to cause a brake drive current to flow through the brake. A second switching element is connected to the other end of the brake and switches from the off state to the on state when the switch command is input to cause a brake drive current to flow through the brake. A voltage detection unit detects a brake voltage being applied to the brake. A switch command delay unit delays the switch command input to the first switching element. A short circuit determination unit determines whether or not a short circuit has occurred in the first switching element based on the brake voltage and the switch command delayed by the switch command delay unit.

Growing community of inventors

Yamanashi, Japan

Tsutomu Shikagawa