A bearing arrangement includes a shaft, at least one contact bearing and at least one non-contact bearing and a controller. The controller is configured to control a magnitude of a restoring force applied to the shaft by the non-contact bearing in accordance with a sensed parameter such that a stiffness of the shaft is modified such that one or more resonance frequencies of the shaft are moved away from one or more external forcing frequencies.

An electrical machine (1) comprises a rotor (20), a stator (10), a rotor power supply (50), at least one sensor (70) and a rotor magnetization control arrangement (60). The rotor has rotor windings (22) for controlling magnetization of rotor magnetic poles (24). The sensor is arranged to measure a parameter associated with a relative force between the stator and the rotor. The rotor magnetization control arrangement is communicationally connected to the sensor for receiving a signal representing the measured parameter. The rotor magnetic poles are divided into at least two groups (23). The rotor magnetization control arrangement is arranged for controlling the magnetization of the groups individually by providing a respective individually controllable rotor current. The rotor magnetization control arrangement is arranged to individually control the rotor currents in dependence of the signal representing the measured parameter. A method for controlling such an electrical machine is also disclosed.

An electrical machine (1) comprises a rotor (20), a stator (10), a rotor power supply (50), at least one sensor (70) and a rotor magnetization control arrangement (60). The rotor has rotor windings (22) for controlling magnetization of rotor magnetic poles (24). The sensor is arranged to measure a parameter associated with a relative force between the stator and the rotor. The rotor magnetization control arrangement is communicationally connected to the sensor for receiving a signal representing the measured parameter. The rotor magnetic poles are divided into at least two groups (23). The rotor magnetization control arrangement is arranged for controlling the magnetization of the groups individually by providing a respective individually controllable rotor current. The rotor magnetization control arrangement is arranged to individually control the rotor currents in dependence of the signal representing the measured parameter. A method for controlling such an electrical machine is also disclosed.

One or more example embodiments provide systems and methods for using impedance separation and impedance shaping.

A vibration suppression device that suppresses vibration of an operation unit in a mechanical system having a natural vibration mode including the operation unit, an actuator unit that operates the operation unit, and an elastic body that couples the operation unit and the actuator unit, the vibration suppression device including a generation means for generating a drive signal for driving the actuator unit, an estimation means for estimating a measurement amount related to the mechanical system, a correction means for correcting the drive signal generated by the generation means on the basis of the measurement amount estimated by the estimation means, and a change means for changing a gain used by the estimation means so that an influence of an increase in a modeling error becomes small in a period in which the modeling error of the mechanical system increases.

A system includes a motor configured to be coupled to a non-rigid load and a control system disposed within, or communicatively coupled to, a drive system configured to control an operation of the motor. The control system includes a processor and a memory accessible by the processor. The memory stores instructions that, when executed by the processor, cause the processor to generate a smooth move input profile to control the operation of the motor based on inputs specifying a desired operation of the motor, apply a notch filter having a notch filter frequency to the smooth move input profile to produce a filtered smooth move input profile, and send a command to the drive system based on the filtered smooth move input profile, wherein the command is configured to adjust the operation of the motor.

A system includes a motor configured to be coupled to a non-rigid load and a control system disposed within, or communicatively coupled to, a drive system configured to control an operation of the motor. The control system includes a processor and a memory accessible by the processor. The memory stores instructions that, when executed by the processor, cause the processor to generate a smooth move input profile to control the operation of the motor based on inputs specifying a desired operation of the motor, apply a notch filter having a notch filter frequency to the smooth move input profile to produce a filtered smooth move input profile, and send a command to the drive system based on the filtered smooth move input profile, wherein the command is configured to adjust the operation of the motor.

Disclosed herein is a drain pump driving apparatus and a laundry treatment machine including the same. The drain pump driving apparatus and the laundry treatment machine including the same according to an embodiment of the present invention include a motor to operate the drain pump, an inverter to convert a direct current (DC) power to an alternating current (AC) power by a switching operation and output the converted AC power to the motor, an output current detector to detect an output current flowing to the motor, and a controller to control the inverter, wherein the controller may calculate a speed ripple of the motor based on the output current and performs a control operation based on the calculated speed ripple of the motor to change a speed of the motor.

Disclosed herein is a drain pump driving apparatus and a laundry treatment machine including the same. The drain pump driving apparatus and the laundry treatment machine including the same according to an embodiment of the present invention include a motor to operate the drain pump, an inverter to convert a direct current (DC) power to an alternating current (AC) power by a switching operation and output the converted AC power to the motor, an output current detector to detect an output current flowing to the motor, and a controller to control the inverter, wherein the controller may calculate a speed ripple of the motor based on the output current and performs a control operation based on the calculated speed ripple of the motor to change a speed of the motor.

A motor control apparatus that calculates duty command values of respective phases for controlling currents of a motor by means of a control calculation, forms PWM-signals in correspondence to the duty command values, drives the motor by means of an inverter based on the PWM-signals, and which is provided a rotation sensor to detect a motor angle of the motor.