A motor controller according to the present invention includes a position command unit for commanding the position of a driven unit, a compensation filter unit for compensating a position command, and a servo control unit for controlling the operation of a servomotor based on a compensated position command. The compensation filter unit includes an inverse characteristic filter for approximating an inverse characteristic of a transfer characteristic from a motor position to a mechanical position, and a high frequency cutoff filter for reducing a high frequency component of the position command. The inverse characteristic filter is a filter for reducing a gain at a mechanical resonance frequency ω.sub.0. The high frequency cutoff filter has a constant “a” times high frequency cutoff frequency aω.sub.0 using a constant “a” of 1 or more, with respect to the mechanical resonance frequency ω.sub.0 determined in the inverse characteristic filter.

A servomotor control device includes a connection mechanism configured to connect a servomotor and a driven body, and transmit power of the servomotor to the driven body, a position command generation unit configured to generate a position command value for the driven body, a motor control unit configured to control the servomotor using the position command value, a force estimation part configured to estimate drive force acting on the driven body at a connecting part with the connection mechanism, a switching part configured to switch between a first force estimated value estimated by the force estimation part and a second force estimated value that is a fixed value, and a compensation amount generation part configured to generate a compensation amount for compensating the position command value generated by the position command generation part, based on the first or second force estimated value that was switched to by the switching part.

A servomotor control device includes a connection mechanism configured to connect a servomotor and a driven body, and transmit power of the servomotor to the driven body, a position command generation unit configured to generate a position command value for the driven body, a motor control unit configured to control the servomotor using the position command value, a force estimation part configured to estimate drive force acting on the driven body at a connecting part with the connection mechanism, a switching part configured to switch between a first force estimated value estimated by the force estimation part and a second force estimated value that is a fixed value, and a compensation amount generation part configured to generate a compensation amount for compensating the position command value generated by the position command generation part, based on the first or second force estimated value that was switched to by the switching part.

A motor control device includes a control unit and a generation-method changer. The control unit generates a driving signal for driving a motor in accordance with a command signal and an encoder signal and outputs the generated driving signal to the motor, the command signal being a signal for setting the position of a moving part connected to the motor to a target position, the encoder signal indicating the position of the motor detected by an encoder. The generation-method changer changes a method used by the control unit to generate the driving signal in accordance with a position sensor signal indicating a detected target position that is the target position detected by a position sensor mounted on the moving part.

A portable fan configured with a high-speed three-phase motor is provided, the portable fan includes: a control module, a drive module, and the high-speed three-phase motor. The high-speed three-phase motor has an operating voltage of 2V to 18 V and an operating current of 0.1 to 10 A, and/or has a rated operating power of 0.5 to 100 W. The control module is configured to control, via the drive module and based on the operating voltage, the operating current, and/or the rated operating power, a rated operating rotation speed of the high-speed three-phase motor to reduce noise generated due to a high rotation speed of the high-speed three-phase motor and to control an air speed to be within a preset air speed range.