Abstract: A fibrous-web-consolidating appliance which is configured to consolidate fibrous web and includes: at least two drive devices, each of which is configured to drive at least one needling device of the fibrous-web-consolidating appliance. Each needling device is configured to consolidate fibrous web and is driven by one of the at least two drive devices. At least one oscillation-recording device is configured to record oscillation data, the oscillations including oscillations such as those created by the operation of the needling devices. A control device is configured to receive the oscillation data recorded by the oscillation-recording device and to control the operation of the at least two drive devices in response to the received oscillation data. A control device and a method for operating the drive devices of the fibrous-web-consolidating appliance are also provided.

Abstract: A positioning controller includes a position command signal generating unit that generates a position command signal for moving a mechanical load over a set movement distance D by driving a motor; a drive control unit that executes positioning control on the basis of a detected position signal of the mechanical load and the position command signal; a residual vibration information recording unit that stores a plurality of pieces of residual vibration information; and a position command signal parameter determining unit that determines, on the basis of the allowable positioning error and the plurality of pieces of the residual vibration information, a position command signal parameter for generating the position command signal for which the residual vibration amplitude is smaller than or equal to an allowable positioning error.

Abstract: A power controller for an AC power converter connected in series with a load and receiving power from or delivering power to a power source, the power controller comprising: a radial control block controlling a radial component of an electrical parameter of the AC power converter; and a chordal control block controlling a chordal component of the electrical parameter of the AC power converter. Also provided is a power system comprising one or more loads each connected in series to a power converter each controlled by a power controller as described above. There is also provided a method of controlling an AC power converter connected in series with a load and receiving power from a power source, the method comprising: controlling a radial component of an electrical parameter of the AC power converter; and controlling a chordal component of the electrical parameter of the AC power converter.

Abstract: An apparatus for angular positioning of a mirror includes a motor that rotates a mirror, a detector that detects a rotational angle of the mirror, and a controller. The controller supplies current to the motor so that the rotational angle of the mirror reaches a target angle, estimates, based on a model representing a relation between a value of current to be supplied to the motor and an angle of inclination of the mirror, the angle of inclination of the mirror to which current is supplied, and if the estimated angle exceeds a predetermined tolerance, adjusts the supply of current to the motor so that the angle of inclination of the mirror falls within the predetermined tolerance.

Abstract: A computer-implemented method for dialog state tracking employs first and second latent variable models which have been learned by reconstructing a decompositional model generated from annotated training dialogs. The decompositional model includes, for each of a plurality of dialog state transitions corresponding to a respective turn of one of the training dialogs, state descriptors for initial and final states of the transition and a respective representation of the dialog for that turn. The first latent variable model includes embeddings of the plurality of state transitions, and the second latent variable model includes embeddings of features of the state descriptors and embeddings of features of the dialog representations. Data for a new dialog state transition is received, including a state descriptor for the initial time and a respective dialog representation. A state descriptor for the final state of the new dialog state transition is predicted using the learned latent variable models.

Abstract: A method for providing acceleration data with reduced substrate-displacement bias includes receiving in an accelerometer an external acceleration, determining the acceleration data with reduced substrate displacement bias in a compensation portion in response to a first and a second displacement indicators from a MEMS transducer, and, in response to substrate compensation factors from a MEMS compensation portion, outputting the acceleration data with reduced substrate displacement bias, wherein the first displacement indicator and the second displacement indicator are determined by the MEMS transducer relative to a substrate in response to the external acceleration and to a substrate displacement, and wherein the substrate compensation factors are determined by the MEMS compensation portion relative to the substrate in response to the substrate displacement.

Abstract: A battery control device having a battery system having a plurality of cells, a first electronic unit, a second electronic unit having a ground potential operatively connected to a potential of the battery system, a communication link including an electric isolation and a communication line having an electromagnetic shielding at least in sections, the communication link being configured to operatively connect and enable communication between the first electronic unit and the second electronic unit. The electromagnetic shielding is operatively connected to the ground potential of the second electronic unit.

Abstract: A scanning exposure apparatus exposes a plurality of shot regions on a substrate to light while scanning an original and the substrate. The apparatus includes: a stage which holds the substrate and moves; and a controller which controls movement of the stage based on a driving profile that defines the movement of the stage. A portion in the driving profile, which defines the movement of the stage during exposure of at least one shot region, is formed by a sine wave having a frequency lower than a resonance frequency in a stage controller.

Abstract: Methods and systems of processing sensor signals to determine motion of a motor shaft are disclosed. This disclosure relates to the processing of sequences of pulses from a sensor for computing the motion of an electric motor output shaft. Furthermore, this disclosure relates to the processing of two sequences of pulses from sensor outputs, which may be separated by only a few electrical degrees, to compute the motion of an electrical motor output shaft while using a limited bandwidth controller. Motor shaft direction, displacement, speed, phase, and phase offset may be determined from processing the sensor signals.

Abstract: A projector includes: a drive motor adapted to drive a lens unit; a control section adapted to control the drive motor; a storage section adapted to store a target position of the lens unit; and a position detector adapted to detect a present position of the lens unit, wherein if a deviation between the target position stored in the storage section and the present position detected by the position detector is equal to or larger than a predetermined value, the control section performs drive of the drive motor with feedforward control until the present position and the target position are coincident with each other, and performs drive control of the drive motor with a predetermined unit based on a deviation between a stop position by the feedforward control and the target position.

Abstract: A motor control apparatus includes a state quantity detector configured to output a detection signal in correspondence with a state quantity of a motor, a vibration detection unit configured to detect a disturbance vibration component of the motor based on a torque instruction and the detection signal and output a vibrational component signal in correspondence with the detection result, a speed signal generator configured to generate a speed signal based on a result of subtracting the vibration component signal from the detection signal, and a speed controller configured to generate the torque instruction based on a deviation between a speed instruction and the speed signal.

Abstract: A method and device for controlling an electric motor, in particular a machine tool drive, wherein during a sensorless open-loop control mode of operation of the electric motor the speed and the torque are determined from the motor current and the motor voltage, and the moment of inertia of the electric motor torque are determined from the determined motor current and the determined motor voltage, wherefrom then a control torque is determined, which is then associated with an open-loop torque control value and supplied as the torque setpoint value to a control element for setting the motor current and/or the motor voltage in the open-loop mode of operation. As long as the speed is below a minimum speed, the control element receives as input variable a control or pilot control torque generated from a predefined moment of inertia for a sensorless closed-loop control mode of operation of the electric motor.

Abstract: In positioning control of a machine in which residual vibrations are caused due to a low mechanical rigidity, residual vibrations are suppressed within an allowable positioning error, and a positioning time period required for the positioning control is shortened. Based on information of operation conditions and residual vibrations, the amplitude of the residual vibrations of the machine is predicted before execution of positioning, and based on a result of the prediction, a first servo controller (11) which performs positioning control in which suppression of residual vibrations of the machine is not considered or a second servo controller (12) in which suppression of residual vibrations of the machine is considered is automatically selectively used.

Abstract: A control device is for a motor, especially a brushless DC motor. The control device contains a bridge circuit for generating a rotating field for the motor and a sensor system for detecting a position of a rotor of the motor, a control signal for the bridge circuit being derivable from the signal representing the rotor position. The sensor system includes an absolute value transmitter which detects the absolute position of the rotor and which is configured to derive at least one incremental signal from the absolute position and to make it directly available to a control component for controlling the bridge circuit for commuting the motor.

Abstract: A control system of multi-shaft servo motor comprises a position loop module (400) for receiving a position loop given value and a position feedback value of respective shelves and figuring out a velocity loop given value; a velocity loop module (500) for receiving the velocity loop given value and a velocity feedback value of respective shelves and figuring out a current loop given value; a current loop module (200) for receiving the current loop given value and a current feedback value of respective shelves and outputting a current loop output value; a PWM signal generation module (300) for receiving the current loop output value from the current loop module (200) and generating a PWM signal for controlling respective shelves of the servo motor; and a multi-shaft time sequence control module (700).

Abstract: A method processes a motor variable of a DC motor of an actuating device for a motor vehicle. The DC motor is supplied by an on-board system DC voltage, in which the armature current and the motor voltage of the DC motor are detected and the actuating position of an actuating element is determined from a time profile of the armature current by counting the current ripple contained therein. During an initial phase, the armature current which rises over time is replicated by a function which is determined from pairs of values for the motor voltage and the armature current which are detected in a time interval. A current value of the armature current expected at a later point in time is extrapolated. In the event of a discrepancy between the armature current detected at this later point in time and the extrapolated armature current, a ripple count is started.

Abstract: A position control apparatus calculates a position detection value by adding an output of a first-order delay circuit 17 that receives a difference between a driven member position detection value Pl and a motor position detection value Pm to the motor position detection value Pm, and uses the obtained position detection value as a position feedback value. An aging corrector 30 suppresses low frequency vibrations by controlling a time constant Tp of the first-order delay circuit 17 in such a way as to increase the time constant when a vibratory state of the driven member is detected.

Abstract: A dual mode vibrator is disclosed. There are available two vibrating units to enable obtainment of a variety of vibrations. Each lateral portion of the first and second vibrating units respectively supported by the first and second elastic members is supported by the first and second support bars secured at the housing for rotatable installation. Therefore, although the first and second vibrating units may rotate about the first and second support bars, the first and second vibrating units are not allowed to deviated or disengaged from the first and second support bars, whereby the plastic deformation of the first and second elastic members is prevented, and the first and second vibrating units can be positioned at predetermined positions at all times to enhance reliability of product.

Abstract: A hybrid controller for a mechanical system includes an actuator configured to position a load. A vibration attenuation controller produces a vibration attenuation control signal in response to an input signal for the mechanical system. A tracking controller configured produces a tracking control signal in response to the input signal. In response to an output signal from the mechanical system, either the vibration attenuation control signal or the tracking control signal is switched as a control signal for the mechanical system to reduce both vibration in the mechanical system and improve tracking the load.

Abstract: The present invention provides a position sensorless control method of a high performance permanent magnet synchronous motor during emergency operation, which can accurately detect a magnetic pole position of the synchronous motor based on a position sensorless vector control using an adaptive observer configured based on a permanent magnet synchronous motor model.

Abstract: A device and a method for determining the current position of a rotor, particularly the angle of rotation of the rotor, of an electric motor, wherein said device determines the current position of the rotor using the fluctuations of the armature current or the armature voltage of the electric motor. The fluctuations of the armature current or the armature voltage are separated from the fluctuations of the motor current or the motor voltage with the help of an amplifier unit dependent on a controllable offset value. The offset value is changed according to the motor current or the motor voltage. By virtue of the device and the method, the fluctuations of the armature current or the armature voltage can be separated from the fluctuations of the motor current or the motor voltage over the full measurement range of the motor current or the motor voltage.

Abstract: This invention relates to an apparatus and method for deriving speed and position information for an electric motor. Apparatus for and a method of controlling a motor 100 are also disclosed. The apparatus for providing information relating to the operation of an electrical motor 100 comprises a sampler 50, 51 for sampling the instantaneous motor current is and a processor 160 for determining the instantaneous rate of change of the motor current and providing information about the motion or position of said motor based on said instantaneous rate of change of the motor current. In this way speed and position information can be provided, at low speeds, and without using a speed sensor.

Abstract: A system includes a power control module, a period determination module, and a control module. The power control module controls current through stator coils of a motor to rotate a rotor. The period determination module determines a first length of time between a first set of induced stator coil voltages and determines a second length of time between a second set of induced stator coil voltages. The control module determines whether an external disturbance disturbs rotation of the rotor based on a difference between the first and second lengths of time.

Abstract: A method for determining gain of a back-electromotive force amplifier may include setting an electric motor into a tri-state function mode and storing a first quasi steady-state value for back-electromotive force from the difference signal, and forcing a reference current through the electric motor and determining a first value of the gain of the amplifier for equaling a difference signal to the first quasi steady-state value. The method may further include setting the electric motor into a tri-state function mode a second time and storing a second quasi steady-state value for back-electromotive force from the difference signal, and increasing the first value of the gain by an amount proportional to a difference between the second quasi steady-state value and the first quasi steady-state value.

Abstract: A position control apparatus calculates a position detection value by adding an output of a first-order delay circuit 17 that receives a difference between a driven member position detection value Pl and a motor position detection value Pm to the motor position detection value Pm, and uses the obtained position detection value as a position feedback value. An aging corrector 30 suppresses low frequency vibrations by controlling a time constant Tp of the first-order delay circuit 17 in such a way as to increase the time constant when a vibratory state of the driven member is detected.

Abstract: In positioning control of a machine in which residual vibrations are caused due to a low mechanical rigidity, residual vibrations are suppressed within an allowable positioning error, and a positioning time period required for the positioning control is shortened. Based on information of operation conditions and residual vibrations, the amplitude of the residual vibrations of the machine is predicted before execution of positioning, and based on a result of the prediction, a first servo controller (11) which performs positioning control in which suppression of residual vibrations of the machine is not considered or a second servo controller (12) in which suppression of residual vibrations of the machine is considered is automatically selectively used.

Abstract: An integrated brushless DC motor and controller including a brushless DC motor having a rotating shaft with a 2 pole permanent magnet affixed to the shaft for rotation thereby in a plane orthogonal to the axis of rotation of the shaft. An X-Y Hall Effect Sensor is carried by a controller mounted on a circuit board attached to the motor and the Hall Effect Sensor is positioned proximate the magnet with the Hall Effect Sensor producing the Sine and Cosine components of the magnetic field as the magnet is rotated by the motor shaft. The electronic controller includes software for determining the motor angle and commutation logic from the Sine and Cosine components generated by the Hall Effect Sensor response to the rotating magnetic field.

Abstract: A method for estimating a rotor position in an electrical machine is provided. The method is applicable to electrical machines that have magnetic saliency. The method includes extracting the rotor position from a demodulated output signal generated in response to an injected high frequency carrier signal and determining a position error compensation based upon a demodulation delay and a velocity or rotational frequency of the electrical machine. The method also includes estimating the rotor position by applying the position error compensation to the extracted rotor position.

Abstract: Provided is a motor control device which realizes automatic adjustment of control of a motor for driving a mechanical load through a simple operation. The motor control device includes: a follow-up control unit (6) for receiving detection information of a detector (3) to output a torque command signal and output a status of motor control of a motor (1) as a control status amount signal, when a command signal regarding the motor control to be output from an upper-level controller is absent; an oscillation detection unit (9) for receiving the control status amount signal and detecting oscillation of a control status amount to output an oscillation detection signal; and an automatic adjustment unit (10) for receiving the oscillation detection signal to monitor a control status of the motor (1) and adjust a control parameter of the follow-up control unit (6) only when abnormality is detected.

Abstract: A motion control servo loop apparatus, comprising: a feed-forward control module, and a proportional-integral-derivative (PID) control loop and a compensation adder. The feed-forward control module is capable of generating a feed-forward compensation. The PID control loop further comprises: a proportional control module, an integral control module and a derivative control module. The proportional control module is capable of generating a proportional compensation. The derivative control module is capable of generating a derivative compensation. The integral control module uses a digital differential analyzer (DDA) algorithm to perform integration for accumulated errors with respect to each sampling clock at each DDA pulse and thus output an accumulated error, which is then processed to generate an integral compensation.

Abstract: A control device for driving a motor which includes a rotor and a stator is provided. The control device includes a Hall detector and driving circuit. The Hall detector detects magnetic flux variation when the rotor rotates and generates a first detection signal and a second detection signal. The first and second detection signals represent current rotation location when the rotor rotates. The driving circuit generates a driving signal to drive the stator. The driving circuit turns on or off the driving signal according to a control signal and the relationship between the first and second detection signals.

Abstract: A control device, for a servo die cushion, capable of improving a response after overshoot generated by collision of a slide and a die cushion. The control device has a local maximum point judging part which judges a local maximum point based on the detected speed of the servomotor; a speed correction value calculating part which calculates a speed correction value for the servomotor based on the judgment result and the detected speed of the slide; a second force commanding part which generates a second force command value, the second force command value decreasing from an initial value to a first force command value, the initial value being equal to the force detected value when reaching generally the local maximum point. The force command value is switched from the first force command value to the second force command value, when the force detected value reaches the local maximum point.

Abstract: A motor control method includes the steps of: measuring a time period from an output of a drive detection signal to a next output of a drive detection signal; storing the measurement result at each time of output of a drive detection signal as a measured cycle; calculating a driven velocity of the driven object based on the stored measured cycle; calculating an operation amount of the motor such that the calculated driven velocity is equal to a predetermined target velocity. In the motor control method, it is determined, at each calculation timing, whether or not the driven object is in a low velocity state where an actual velocity is lower than the target velocity. When determined affirmative, calculation of the driven velocity of the driven object is performed based on a measured value being currently measured at the calculation timing in place of the stored measured cycle.

Abstract: A motor controller includes: a notch filter arranged inside a control system; an oscillation frequency estimating section which estimates an oscillation frequency component in a motor; and a notch control section which controls a notch filter so as to change a notch frequency and a notch width. The notch control section changes a frequency between an oscillation frequency and a notch frequency set in a notch filter as a new notch frequency, while changing a notch width to a new notch width such that the notch width is larger after the change than before the change.

Abstract: A mechanism for empirically deriving the values of the damping ratio and frequency of the mechanism driven by a servo-controlled control system is disclosed. In accordance with the illustrative embodiment, the values of the damping ratio and frequency are continually re-generated based on empirical data derived from sensor feedback of the maximum-amplitude switch and the linear second-order servo. Because the values of the damping ratio and frequency are generated from empirical data, it is not necessary that they be known, and because the values of the damping ratio and frequency are continually re-generated, variances in their values are continually noticed and compensated for.

Abstract: A control device, for a servo die cushion, capable of improving a response after overshoot generated by collision of a slide and a die cushion. The control device has a local maximum point judging part which judges a local maximum point based on the detected speed of the servomotor; a speed correction value calculating part which calculates a speed correction value for the servomotor based on the judgment result and the detected speed of the slide; a second force commanding part which generates a second force command value, the second force command value decreasing from an initial value to a first force command value, the initial value being equal to the force detected value when reaching generally the local maximum point. The force command value is switched from the first force command value to the second force command value, when the force detected value reaches the local maximum point.

Abstract: A difference between each position command data outputted in a form of a step signal from a high-level controller and its corresponding detected position data of a movable body is integrated by an integral compensator to position the movable body. Assuming, for example, that the movable body is a steerable mirror, digital filters are arranged to compensate the value of an initial state of an angular displacement and the value of an initial state of an angular velocity, respectively, and respective impulse responses of the digital filters as additional input elements are added to an output terminal of the integral compensator. For higher effectiveness, internal state variables of the digital filters can desirably be cleared to zero whenever an angle (position) command data is received.

Abstract: A torque command (Tht) used in the calculation of a voltage command (Vht) of a voltage-up converter is generated by adding an upper limit value (Tc_max) of damping control that can be set by a motor drive device with a target drive torque (Tbt). Accordingly, the torque command (Tht) exhibits a waveform absent of variation, differing from a torque command (Tcmd) that is generated by adding damping torque generated based on revolution count variation component with the target drive torque (Tbt). Therefore, the voltage command (Vht) calculated based on the torque command (Tht) exhibits a waveform absent of variation. Accordingly, increase in current passing through the voltage-up converter caused by variation in the voltage command (Vht) can be suppressed. As a result, power loss at the voltage-up converter is reduced and operation of the motor at high efficiency can be realized. Further, the voltage-up converter can be protected from element fracture.

Abstract: A method for damping vibrations in a stepper motor with micro-stepping control which comprises the steps of identifying the force amplitudes and phase shifts of multiple harmonic detent torques of the stepper motor, such as the first, second and fourth harmonic detent torques, and tuning the stepper motor with different current commands until minimum friction and resistive torque are obtained. Thereafter, a compensating harmonic current derived from said force amplitudes and phase shifts of the said multiple harmonic detent torques is injected into a current command during operation of the stepper motor to compensate for torque ripples.

Abstract: A closed loop control system for controlling an actuator operating on a moveable member, includes a control device controlling operation of the actuator, a sensor responsive to a condition such as loading of the moveable member as it is moved by the actuator and adapted to generate a corresponding feedback control signal SL, and a damping device having a damping effect on the response of the actuator to the feedback control signal, the damping effect being varied in accordance with the movement of the moveable member so as to vary the response of the actuator. The damping effect is increased in the region of stationary states to render the system more stable, and reduced therebetween to make the system more responsive at increased speeds, and thereby more conformal to a required performance profile. The position or velocity of the moveable member can be used to control the damping effect, or a timer can be used to control the damping effect.

Abstract: In electric vehicle control, system voltage stabilization control is executed to reduce the difference between a target value and detected value of a system voltage generated by a voltage boosting converter for an AC motor. Further, conversion power control is executed to reduce the difference between a command value and detected value of the conversion power, which is defined as the output power of the voltage boosting converter. A conversion power correction quantity is computed from an input power operation quantity of the system voltage stabilization control and reflected in the conversion power control to correct the conversion power. Thus, variations in a system voltage caused by an error or the conversion power control can be reduced.

Abstract: Systems and methods for controlling a rotating electromagnetic machine. The rotating machine, such as a permanent magnet motor or hybrid switched reluctance motor, includes a stator having a plurality of phase windings and a rotor that rotates relative to the stator. A drive is connected to the phase windings for energizing the windings. A controller outputs a control signal to the drive in response to an input demand such as a demanded speed or torque. Control methods (which can be implemented separately or in combination) include varying the gain of an estimator as a function of a demanded or estimated speed to position control system poles at desired locations, de-coupling control system currents to achieve a constant torque with motor speed, compensating flux estimates of the estimator for saturation operation of the stator, estimating rotor position using averages of sample values of energization feedback, and calculating a trim adjusted speed error from a plurality of speed estimates.

Abstract: The invention relates to a method and an arrangement for a digital servo system with moving average filter (Amovavf 1, Amovavf 2),which is used as an input filter for a digital signal processor of the servo system to shorten processing delay, which improves the stability of the control loop and/or allow a fast servo signal processing, which improve the overall servo signal control performance. Said input filter provides average values of samples provided from an analog digital converter (ADC) at a frequency corresponding to a sample frequency (fADC) of the analog digital converter (ADC) and has an adjustable filter length (n), which is determined according to a quality of detector signals indicating a deviation from a target of servo means of the servo system. The invention is e.g. applicable for a fast digital servo system in an optical disc drive.

Abstract: The control apparatus 10 of a servo motor of the present invention has a position control unit 11 controlling the position of a servo motor 33, a speed control unit 12 controlling a speed of the servo motor 33, a distributing unit 13 dividing the speed command output by the position control unit 11 into a filtered part Vf which is filtered to suppress vibration and a nonfiltered part Vnf, a filtering unit 14 receiving as input the filtered part Vf and filtering and outputting the filtered part Vf, and an adder unit 15 adding the filtered part Vf filtered by the filtering unit 14 and the nonfiltered part Vnf and outputting the result to the speed control unit 12.

Abstract: A method for damping vibrations in a stepper motor with micro-stepping control which comprises the steps of identifying the force amplitudes and phase shifts of multiple harmonic detent torques of the stepper motor, such as the first, second and fourth harmonic detent torques, and tuning the stepper motor with different current commands until minimum friction and resistive torque are obtained. Thereafter, a compensating harmonic current derived from said force amplitudes and phase shifts of the said multiple harmonic detent torques is injected into a current command during operation of the stepper motor to compensate for torque ripples.

Abstract: Systems and methods for controlling a rotating electromagnetic machine. The rotating machine, such as a permanent magnet motor or hybrid switched reluctance motor, includes a stator having a plurality of phase windings and a rotor that rotates relative to the stator. A drive is connected to the phase windings for energizing the windings. A controller outputs a control signal to the drive in response to an input demand such as a demanded speed or torque. Control methods (which can be implemented separately or in combination) include varying the gain of an estimator as a function of a demanded or estimated speed to position control system poles at desired locations, decoupling control system currents to achieve a constant torque with motor speed, compensating flux estimates of the estimator for saturation operation of the stator, estimating rotor position using averages of sample values of energization feedback, and calculating a trim adjusted speed error from a plurality of speed estimates.

Abstract: A disk drive controller including a differential voice coil motor control function is disclosed. The differential voice coil motor control function includes an on-chip compensation network for the inner control loop, including a resistor formed of one or more MOS transistors connected in series. The gate of the MOS transistors in the compensation network is driven with a bias voltage based on a tuning current, where the tuning current is derived so that it varies with process and temperature variations of the integrated circuit, for example with variations in an on-chip capacitor. The on-chip compensation network can be tuned with sufficient precision to properly compensate the inner control loop to provide the desired frequency response in driving the voice coil motor in the disk drive.

Abstract: A circuit (90) and method are presented to accurately determine a BEMF voltage of a VCM coil (20) after termination of a driving current in a first current direction in the coil (20). The circuit includes a circuit for activating selected VCM coil driver transistors (44–47) to apply a current to the coil (20) in a direction opposite the first current direction to generate a magnetic field to oppose eddy currents established in structures adjacent the coil (20) by the driving current. The time that the eddy current opposing current may be applied may be determined, for example, by determining a magnitude of the original current command, a time that the coil spends in flyback, or a magnitude of the original driving current, and adjusting the time of application of the eddy current opposing current accordingly.

Abstract: A speed control means 7 for outputting a drive command signal for a motor 1 to make the speed of the motor 1 conform to the speed command signal based on a signal indicating the difference between the speed command signal and the detected speed of the motor; a filter 13 inserted in series with the speed control means 7 in the speed control loop, having a high frequency domain, a low frequency domain, and an intermediate frequency domain between the high frequency domain and the low frequency domain, a gain KL in the low frequency domain being larger than a gain KH in the high frequency domain, and having a phase lag characteristic so that the phase in the intermediate frequency domain is delayed; the speed control means 7 having a proportional controller 9 that multiplies input by a proportional gain KP and outputs the result, and the filter 13 being set so that phase lag occurs between a resonance frequency and an anti-resonance frequency of a mechanical system.

Abstract: A control device for controlling the motion of a movable part in a machine while suppressing vibration generated in the movable part. The control device includes a state-variable estimating section for estimating a state variable of a controlled system in the machine and outputting an estimated state variable; a reference model for outputting an ideal controlled variable for the controlled system; a compensator for calculating a compensation value for correcting a control input for the controlled system, based on a difference between the estimated state variable and the ideal controlled variable; and a feedback control section for determining the control input, based on a deviation between a desired command value and one of the estimated state variable and the ideal controlled variable.