An electric apparatus for controlling movement of a target object by performing first and second feedback controls, based on a detection signal obtained from detecting the movement of the target object, generates an operation quantity on the target object based on first and second operation quantities for the second feedback control if one of a predetermined target value and an estimated first state quantity of the target object is higher than a first threshold value, and generates the operation quantity on the target object using only the first operation quantity from among the first and the second operation quantities if one of the target value and the first state quantity of the target object is lower than the first threshold value.

A system for reducing a resonant oscillation on a direct current bus is disclosed. The system includes a battery, a first capacitor connected in parallel with the battery, and an inductor connected in series with the first capacitor. The system also includes a first element connected in series with the inductor, a second element connected in parallel with the inductor and the first element, and a second capacitor connected in series with the first element. The system also includes an electric machine connected to the second capacitor. During a re-generation mode for charging the battery, a re-generation current flows from the electric machine to the battery, passing through the first element and the inductor and bypassing the second element. Additionally, during a motor mode, a motor current flows from the battery to the electric machine, passing through the second element and bypassing the first element and the inductor.

A system for reducing a resonant oscillation on a direct current bus is disclosed. The system includes a battery, a first capacitor connected in parallel with the battery, and an inductor connected in series with the first capacitor. The system also includes a first element connected in series with the inductor, a second element connected in parallel with the inductor and the first element, and a second capacitor connected in series with the first element. The system also includes an electric machine connected to the second capacitor. During a re-generation mode for charging the battery, a re-generation current flows from the electric machine to the battery, passing through the first element and the inductor and bypassing the second element. Additionally, during a motor mode, a motor current flows from the battery to the electric machine, passing through the second element and bypassing the first element and the inductor.

According to an aspect of the present disclosure, a motor drive control device driving a motor using position information detected by one sensor includes: a current detection unit detecting a magnitude of a coil current flowing through a coil of the motor; a rotation position detection unit detecting a rotation position of the motor based on the position information; and a hunting determination unit determining, based on the magnitude of the coil current, the rotation position of the motor, and a driving command for driving the motor, whether or not the motor is in a hunting condition.

According to an aspect of the present disclosure, a motor drive control device driving a motor using position information detected by one sensor includes: a current detection unit detecting a magnitude of a coil current flowing through a coil of the motor; a rotation position detection unit detecting a rotation position of the motor based on the position information; and a hunting determination unit determining, based on the magnitude of the coil current, the rotation position of the motor, and a driving command for driving the motor, whether or not the motor is in a hunting condition.

A motor drive device includes: a position command generator which generates a position command; a damping filter unit which includes one or more stages of damping filters which reduce vibration of a device including a load and a motor, applies, to a position command, a damping filter determined based on a model parameter corresponding to a model of the device, and outputs a filtered position command to which the damping filter has been applied; a servo controller which gives a torque command to the motor based on the filtered position command; a low-pass filter unit; a parameter estimation unit which estimates the model parameter from the rotational speed and the torque command of the motor which have passed through the low-pass filter unit; and a vibration determination unit which determines presence or absence of vibration in the model.

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 torsional mode damping controller in which the controller modifies electrical power to an electrical motor to provide active damping control of torsional vibration in rotating masses. The controller receives a measurement of a rotational speed of the rotating masses .sub.m and an estimate or a measurement of a torque transmitted between the rotating masses T.sub.sh; based on the received transmitted torque T.sub.sh, generate a compensating torque to suppress vibration T.sub.com; based on the received rotational speed .sub.m and the compensating torque T.sub.com, generate an electromagnetic torque modification signal T.sub.modi; and modify the electrical power provided to the electrical motor on the basis of the electromagnetic torque modification signal T.sub.modi. The controller is further configured to generate compensating torque T.sub.com by applying a filter to the received transmitted torque T.sub.sh, based on plural tunable parameters including a tuning gain K, a cut-off frequency .sub.n and a resonant damping ratio .

A torsional mode damping controller in which the controller modifies electrical power to an electrical motor to provide active damping control of torsional vibration in rotating masses. The controller receives a measurement of a rotational speed of the rotating masses .sub.m and an estimate or a measurement of a torque transmitted between the rotating masses T.sub.sh; based on the received transmitted torque T.sub.sh, generate a compensating torque to suppress vibration T.sub.com; based on the received rotational speed .sub.m and the compensating torque T.sub.com, generate an electromagnetic torque modification signal T.sub.modi; and modify the electrical power provided to the electrical motor on the basis of the electromagnetic torque modification signal T.sub.modi. The controller is further configured to generate compensating torque T.sub.com by applying a filter to the received transmitted torque T.sub.sh, based on plural tunable parameters including a tuning gain K, a cut-off frequency .sub.n and a resonant damping ratio .

A control device includes: an angular velocity detection unit that detects an angular velocity of a motor; a vibration component removal unit that removes a vibration component in a predetermined band from the angular velocity detected by the angular velocity detection unit by filtering; and a current command calculation unit that calculates a current command value of a drive current for driving the motor according to a torque command value and the angular velocity from which the vibration component has been removed by the vibration component removal unit.