A motor control device is a motor control device which controls a spindle motor in a machine tool, and includes: a moving average filter which moving averages a torque command value or drive current value of the spindle motor for averaging time and generates averaged load information of the spindle motor; and an averaging time calculation unit which calculates, as the averaging time of the moving average filter, a first time of an integral multiple of a period of one rotation of the spindle driven by the spindle motor, or a second time of an integral multiple of a value arrived at by dividing the period of one rotation of the spindle by the number of cutting tooth of the tool.

A motor control device is a motor control device which controls a spindle motor in a machine tool, and includes: a moving average filter which moving averages a torque command value or drive current value of the spindle motor for averaging time and generates averaged load information of the spindle motor; and an averaging time calculation unit which calculates, as the averaging time of the moving average filter, a first time of an integral multiple of a period of one rotation of the spindle driven by the spindle motor, or a second time of an integral multiple of a value arrived at by dividing the period of one rotation of the spindle by the number of cutting tooth of the tool.

A disclosed motor control device includes: a PI controller which controls a velocity of a motor; an input unit which receives specification information including information of a weight and a center of mass of a tool; a calculation unit which calculates a gravitational torque based on the specification information; a storage which stores the gravitational torque output from the calculation unit and an integral value output from the PI controller, and outputs the gravitational torque and the integral value in response to a break signal; and a selection unit which sets, to the PI controller, the integral value output from the storage, according to a collision sensitivity input from the input unit.

A disclosed motor control device includes: a PI controller which controls a velocity of a motor; an input unit which receives specification information including information of a weight and a center of mass of a tool; a calculation unit which calculates a gravitational torque based on the specification information; a storage which stores the gravitational torque output from the calculation unit and an integral value output from the PI controller, and outputs the gravitational torque and the integral value in response to a break signal; and a selection unit which sets, to the PI controller, the integral value output from the storage, according to a collision sensitivity input from the input unit.

A motorized device capable of moving in a fluid and including one or more locomotor systems, each having at least one drive assembly linked to at least one locomotion member and a motor controlled by a voltage. The frequency of a reciprocating motion of the drive assembly matches the resonant frequency of the locomotion member linked to a non-movable portion by at least one prestrained elastic member. The instantaneous amplitude of the reciprocating motion of the drive assembly is adjusted to control the average position and the maximum amplitude of the reciprocating motion of the locomotion member. The drive assembly includes at least one speed reducer for reducing the speed of rotation of the motor. When the motor is operating at its maximum mechanical power, the speed of rotation transmitted to the at least one locomotion member is reduced to match the resonance frequency.

A motorized device capable of moving in a fluid and including one or more locomotor systems, each having at least one drive assembly linked to at least one locomotion member and a motor controlled by a voltage. The frequency of a reciprocating motion of the drive assembly matches the resonant frequency of the locomotion member linked to a non-movable portion by at least one prestrained elastic member. The instantaneous amplitude of the reciprocating motion of the drive assembly is adjusted to control the average position and the maximum amplitude of the reciprocating motion of the locomotion member. The drive assembly includes at least one speed reducer for reducing the speed of rotation of the motor. When the motor is operating at its maximum mechanical power, the speed of rotation transmitted to the at least one locomotion member is reduced to match the resonance frequency.

An apparatus includes a rotation body, a motor, a drive controller, a rotating speed detector, a rotation error determination circuit, and a filter. The rotation body is provided on an outer peripheral surface of an elongated insertion section and configured to be rotatable around a longitudinal axis. The motor rotates the rotation body. The drive controller controls driving of the motor. The rotating speed detector detects a rotating speed of the motor based on an encoder signal output from an encoder. The rotation error determination circuit determines an error in rotation of the rotation body based on the detected rotating speed. The filter passes, as the encoder signal, only a signal having a frequency, outside a frequency band of a high-frequency signal of a high-frequency treatment instrument, of signals input to the rotating speed detector.

An electric motor control device performing feedback control of a state amount of an electric motor or a load and being capable of changing a control bandwidth of a feedback control system includes: a notch filter arranged in the feedback control system and having a filter coefficient which is changeable; a notch control section which changes a notch frequency as a center frequency of the notch filter to remove an oscillation component attributable to mechanical resonance related to the electric motor; and a control coefficient setting section which changes at least one of the control bandwidth or the filter coefficient of the notch filter in accordance with the control bandwidth and the notch frequency to stabilize the feedback control system.

Subsea power supply assembly supplying electric power to a motor at a second location from a first location. The subseas power supply assembly includes a variable speed drive (VSD) and a step-up transformer connected to it. At a subsea location the assembly includes a first step-down transformer with input and output and an uninterruptible power supply having an input. A step-out cable supplies power from the step-up transformer to the motor. The cable connects to the first step-down transformer. The speed of the electric motor is proportional to the output frequency of the VSD. The power receiving input of the uninterruptible power supply connects to the output of the first stepdown transformer, thereby receiving electrical power with frequency equal to the output frequency of the VSD.

Subsea power supply assembly supplying electric power to a motor at a second location from a first location. The subseas power supply assembly includes a variable speed drive (VSD) and a step-up transformer connected to it. At a subsea location the assembly includes a first step-down transformer with input and output and an uninterruptible power supply having an input. A step-out cable supplies power from the step-up transformer to the motor. The cable connects to the first step-down transformer. The speed of the electric motor is proportional to the output frequency of the VSD. The power receiving input of the uninterruptible power supply connects to the output of the first stepdown transformer, thereby receiving electrical power with frequency equal to the output frequency of the VSD.