Abstract: A drive signal generating unit generates a drive signal used to alternately deliver a positive current and a negative current to a coil. A driver unit generates the drive current in response to the drive signal generated by the drive signal generating unit and supplies the drive current to the coil. After the drive termination of a linear vibration motor, the drive signal generating unit generates a drive signal whose phase is opposite to the phase of the drive signal generated during the motor running. The driver unit quickens the stop of the linear vibration motor by supplying to the coil the drive current of opposite phase according to the drive signal of opposite phase.

Abstract: A noise reduction device for a starter includes a positive electrode connected to a power supply line via a branch wire, a grounding electrode connected to ground via a motor body of a motor, two capacitors connected in parallel with each other between the positive electrode and the grounding electrode, and a resin package into which the positive electrode and the grounding electrode are inserted and fixed. The package holds the two capacitors. The two capacitors include a capacitor body and two lead terminals extracted from the capacitor body in the same direction with respect to the capacitor body. The two capacitors are arranged in such a direction that the lead terminals of one thereof face the lead terminals of the other thereof across the positive electrode and the grounding electrode. The two lead terminals are joined to the positive electrode and the grounding electrode by welding.

Abstract: An active vibration control apparatus includes a linear actuator and a controller. The linear actuator includes a moving element, a stator and an elastic support. The stator has a plurality of coils surrounding the moving element. The elastic support supports the moving element to be reciprocally movable relative to the stator in an axial direction of the moving element due to elastic deformation of the elastic support. The controller is configured to apply an alternating current to the stator to generate vibration due to relative displacement of the moving element and the stator in the axial direction. The controller is configured to correct a center position of an amplitude of the vibration by additionally applying a predetermined direct current as a biased current to the stator when the linear actuator satisfies a predetermined vibration condition.

Abstract: In a method and module for controlling rotation of a motorized spindle driven by a driving unit, a sensing unit senses vibration of the spindle and generates a voltage signal corresponding to the vibration of the spindle. A processing unit receives the voltage signal from the sensing unit, generates an adjusting ratio equal to a reference voltage corresponding to a predetermined vibration level of the spindle by the voltage signal upon detecting that the voltage signal is greater than the reference voltage and is less than a predetermined threshold voltage that is greater than the reference voltage, and outputs a control signal corresponding to the adjusting ratio to the driving unit such that the driving unit reduces a rotation speed of the spindle by the adjusting ratio in response to the control signal from the processing unit.

Abstract: A method of actuating a system comprising a movable component and an actuator configured to move the movable component comprises providing a control signal representative of a desired motion of the movable component. The control signal is supplied to one or more resonators. Each of the one or more resonators has a mode of oscillation representative of at least one elastic mode of oscillation of the system. The control signal is modified by subtracting from the control signal a signal representative of a response of the one or more resonators to the control signal. The actuator is operated in accordance with the modified control signal. Thus, undesirable elastic oscillations of the system which might occur if the system were operated with the original control system can be reduced.

Abstract: A vibration motor driving apparatus using a serial interface comprises a serial interface part for receiving an effect command (effect digital data or effect generating command digital data) from a main processor upon occurrence of an event, a unit for generating a clock when the effect command is received from the serial interface unit, a vibration motor driving signal generating unit including an effect data generating part for outputting effect data having a resonance frequency of a vibration motor on the basis of the effect command received from the serial interface unit and the clock received from the clock generating unit, and a D/A converting part for converting the effect data into a vibration motor driving signal, and the vibration motor which vibrates in accordance with the vibration motor driving signal to generate a haptic rhythm.

Abstract: An amplitude control unit (40) detects the amplitude of a movable element (12) that reciprocates relative to a stator (11), detects fluctuations in a load over time according to detected fluctuations over time in the amplitude, and detects an abnormality on the basis of the detected fluctuations over time in the load. The amplitude control unit (40) outputs the detected amplitudes to a control output unit (50). The control output unit (50) controls a drive current (Id) for reciprocating the movable element (12) on the basis of the amplitude information supplied from the amplitude control unit (40).

Abstract: The electromagnetic vibration exciter system with an adjustable electro-viscoelastic suspension device comprises an electromagnetic vibration exciter, a power amplifier and an adjustable electro-viscoelastic suspension device, which acts as the suspension device of the electromagnetic vibration exciter. The adjustable electro-viscoelastic suspension device contains a displacement sensor detecting the displacement of the moving component, a first adjustable amplifier and a second adjustable amplifier, a differentiator, an adjustable phase shifter, an adder and a proportioner. The linearity of the stiffness and damping of the exciter system is excellent, which can be adjusted as need through the adjustment of gain of the adjustable amplifier, the proportioner, the adjustable phase shifter. This invention has adjustable and linear parameters and it is also easy to be realized.

Abstract: In a drive control circuit of a linear vibration motor, a differential amplifier circuit includes an operational amplifier in which an P-channel type transistor is used as a transistor that receives an input voltage, and the differential amplifier circuit detects an induced voltage occurring in a coil. Before the H-bridge circuit is controlled to a high impedance state, a drive signal generating unit turns on a first transistor and a second transistor, and delivers a regenerative current through the coil, the first transistor, the second transistor and the power supply potential.

Abstract: A drive signal generating unit generates a drive signal used to alternately deliver a positive current and a negative current to a coil. The drive signal is such that nonconducting periods are set before and after a positive current conducting period and the nonconducting periods are set before and after a negative current conducting period. A driver unit generates the drive current in response to the drive signal generated by the drive signal generating unit and then supplies the drive current to the coil. The drive signal generating unit sets the width of a nonconducting period such that, after the drive start of the linear vibration motor, the width of a nonconducting period to be set before at least the first conducting period of the drive signal is shorter than the width of a nonconducting period to be set before each conducting period during steady operation of the linear vibration motor.

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: A magnetic actuator system which includes a case (10) and a spindle (22) which extends through the case comprising a magnetizable material such as iron. The actuator further includes a pair of permanent magnet assemblies (14, 16) positioned fixedly within the casing with a longitudinal space there between, wherein the permanent magnet assemblies comprise an alternating plurality of north pole/south magnet sections (18) which extend longitudinally or circumferentially of the actuator. The actuator further includes a coil winding (24) which surrounds the spindle, positioned between the two permanent magnet assemblies. Magnetic pole assemblies (28, 30) attached to the spindle are positioned within the volume encompassed by the permanent magnet assemblies, such that an alternating drive signal produces an oscillating action of the spindle of desired frequency and amplitude.

Abstract: A method, computer readable medium, and apparatus for controlling a moveable element includes generating and providing with a control device one or more driving signals to one or more positioning actuators to move the moveable element towards a target position based on a target travel distance and a calibration value. The control device determines when a post-movement position of the moveable element is outside of a tolerance range of the target position. The control device recalibrates the calibration value when the post-movement position is determined to be outside of the tolerance range. The control device repeats the generating, the determining, and the recalibrating as open loop steps until the post-movement position is within the tolerance range or until a limit, if any, on attempts is reached.

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: The instant invention provides a magnetically controlled reciprocating engine having a unique electromagnet control system. The engine is constructed and arranged to operate from a stored power source such as batteries to provide extended run times by controlling the power supplied to the electromagnets in a manner that controls heat generation within the electromagnetic coils, thereby increasing coil life. The control system is also capable of controlling engine speed and/or torque outputs to make the engine versatile for a wide variety of uses. The system is constructed and arranged to be utilized on new or pre-existing engines of various configurations and may be utilized in other industries or devices that benefit from the use of electromagnets.

Abstract: A linear actuator driving device is provided. The linear actuator driving device includes an electromagnetic driving unit which makes a moving element reciprocate in response to a driving command and an offset correcting unit which corrects the driving command to carry out offset energization to make the center of reciprocation of the moving element be moved in the direction in which deviation between the center of reciprocation of the moving element and the center of the movement possible range is eliminated. The offset correcting unit is configured such that the amplitude information is acquired and, with respect to the amplitude value corresponding to the acquired amplitude information, if the movable amplitude is in a movable area insufficient condition, correction of the driving command is performed and, on the other hand, if the movable amplitude is not in the movable area insufficient condition, correction of the driving command is released.

Abstract: The present invention relates to synchronized vibration devices that can provide haptic feedback to a user. A wide variety of actuator types may be employed to provide synchronized vibration, including linear actuators, rotary actuators, rotating eccentric mass actuators, and rocking mass actuators. A controller may send signals to one or more driver circuits for directing operation of the actuators. The controller may provide direction and amplitude control, vibration control, and frequency control to direct the haptic experience. Parameters such as frequency, phase, amplitude, duration, and direction can be programmed or input as different patterns suitable for use in gaming, virtual reality and real-world situations.

Abstract: In a polyphase electric motor, a voltage is sequentially applied to a plurality of windings on a phase-by-phase basis. Then, there is sensed a rotational speed of a rotor, which is rotated by a rotating magnetic field that is generated by sequentially flowing an electric current in the windings on the phase-by-phase basis upon the sequential application of the voltage to the windings. Then, an oscillation frequency of a periodic oscillation, which is generated in the motor at the sensed rotational speed of the rotor, is obtained. Thereafter, it is determined whether the obtained oscillation frequency is a predetermined resonance frequency. Next, the voltage to be applied to the windings is corrected in a manner that reduces a resonance generated in the motor when a result of the determination indicates that the obtained oscillation frequency is the predetermined resonance frequency.

Abstract: An adaptive system for a personal care appliance, such as a power toothbrush, having a workpiece which is driven through an amplitude of motion by a drive mechanism which includes a stator member includes a circuit (13) for measuring average electrical current through the stator member and stored information (19) in the personal care appliance which relates the average current values through the stator during operation of the device to corresponding amplitude of motion of the workpiece. A processor (17) utilizing a stored program adjusts the operating frequency to produce a stator current value which correlates to the desired amplitude of motion of the workpiece.

Abstract: Disclosed herein is a method of controlling a motor in an image reading apparatus. It may be possible to optimize the drive current of the motor for driving the movement of the scanning module by using information associated with, for example, the time it takes for the scanning module to return to a home or rest position after the scanning module is moved from the home position to a predetermined position. Such optimized drive current can result in improvements in the reading performance of an image by the image reading apparatus and reduction of power consumption.

Abstract: Methods and apparatus include improving print quality of a bi-directionally scanning electrophotographic (EP) device, such as a laser printer or copy machine, according to ambient pressure in which operated. A moving galvanometer or oscillator reflects a laser beam to create scan lines of a latent image in opposite directions. A damping of the motion occurs per air density implicated by temperature and pressure, where the pressure changes occurring especially from altitude changes. During use, a drive signal, such as a pulse train, moves the galvanometer or oscillator at or near its resonant frequency. Based on a parameter of the drive signal, such as pulse width, the ambient pressure can be made known. In general, a high-pressure environment requires a relatively longer pulse width to resonate the galvanometer or oscillator in comparison to a shorter pulse width for a low-pressure environment. Corrections to print quality stem from the determined ambient pressure.

Abstract: A method of controlling a moving part of a voice coil motor to move from an first position to a second position, wherein the position of the moving part is controlled by the level of an electrical signal applied to a coil of the voice coil motor, a first level of the electrical signal corresponding to the first position, and a second level of the electrical signal corresponding to the second position, the method including: at a first time, changing the electrical signal from the first level to an intermediate level, the intermediate level being chosen such that a peak overshoot of the moving part corresponds to the second position; and at a second time calculated to correspond to a delay of half an oscillation period of the moving part after the first time, changing the electrical signal to the second level.

Abstract: This vibrating element includes a movable portion driven to vibrate at a prescribed resonance frequency, a driving portion vibrating the movable portion by cyclically supplying a pulse signal and a detecting portion detecting the vibrational state of the movable portion, while the driving portion is so formed as to supply the pulse signal at a first frequency substantially identical to the resonance frequency of the movable portion at least in starting and to cyclically supply the pulse signal at a second frequency smaller than the first frequency in detection of the vibrational state of the movable portion.

Abstract: In a device and method for non-destructive materials testing with at least one ultrasonic transducer, the transducer is able to be moved by a movement system in at least one direction to a workpiece surface. The emission of ultrasonic by the ultrasonic transducer is able to be synchronized with the activation of the movement system so that electrical interference caused by the movement system occurs at times at which no echo is expected for ultrasonic emitted by the transducer. The method and device can be applied to non-destructive materials testing with ultrasound.

Abstract: The current application is directed to various types of linear vibrational modules, including linear-resonant vibration modules, that can be incorporated in a wide variety of appliances, devices, and systems to provide vibrational forces. The vibrational forces are produced by linear oscillation of a weight or member, in turn produced by rapidly alternating the polarity of one or more driving electromagnets. Feedback control is used to maintain the vibrational frequency of linear-resonant vibration module at or near the resonant frequency for the linear-resonant vibration module. Both linear vibration modules and linear-resonant vibration modules can be designed to produce vibrational amplitude/frequency combinations throughout a large region of amplitude/frequency space.

Abstract: The instant invention provides a magnetically controlled reciprocating engine having a unique electromagnet control system. The engine is constructed and arranged to operate from a stored power source such as batteries to provide extended run times by controlling the power supplied to the electromagnets in a manner that controls heat generation within the electromagnetic coils, thereby increasing coil life. The control system is also capable of controlling engine speed and/or torque outputs to make the engine versatile for a wide variety of uses. The system is constructed and arranged to be utilized on new or pre-existing engines of various configurations and may be utilized in other industries or devices that benefit from the use of electromagnets.

Abstract: A method and apparatus of driving a motor in a light scanning arrangement. The method includes the following steps: (1) driving a drive coil with a drive signal to oscillate a scan mirror and a light beam reflected from the scan mirror; (2) generating a feedback signal having zero crossings during oscillation of the scan mirror by a feedback coil in proximity to the drive coil; (3) integrating the feedback signal to generate an integrated feedback signal; and (4) processing the integrated feedback signal to generate a periodic drive signal that has the same time period as the feedback signal.

Abstract: An electromagnetic actuator includes a stator and a movable body. The stator includes a core provided with magnetic poles and a coil wound on at least one of the magnetic poles. The movable body includes a permanent magnet and supported in such a manner as to make reciprocating in a direction perpendicular to a direction in which the permanent magnet opposes the magnetic poles. The movable body is reciprocated upon applying an alternating voltage to the coil. An electromagnetic actuator driving method for driving the electromagnetic actuator includes performing feedback control of the alternating voltage in which the alternating voltage is applied to the coil during a first half of a control period and in which an induced electromotive force generated in the coil during a second half of the control period is used as a control signal.

Abstract: A resonant motor unit that has a resonant motor, a control unit, a measurement unit, and an evaluation unit is described. The control unit drives the resonant motor at a driving frequency, short-circuits the resonant motor during at least a first short-circuiting phase in successive driving cycles and concludes the first short-circuiting phases by switching off the current flow through the resonant motor at least at a predetermined first time instant within the driving cycles. The measurement unit successively measures at least a first voltage signal provided by the resonant motor at the predetermined first time instant, and the evaluation unit for determines whether the first voltage signal has changed between successive measurements.

Abstract: An electrical appliance with a resonant motor for driving a vibratory component is provided that has a control unit for driving the resonant motor with a predetermined driving frequency and for measuring the motion-induced voltage of the resonant motor and for determining whether the measured voltage value coincides with a predetermined target voltage value or whether the measured voltage value has crossed over the predetermined target value. The control unit measures the motion-induced voltage at a predetermined time of measurement (tm) within a driving cycle.

Abstract: Methods, apparatus, and systems are disclosed for identifying force-ripple and/or side-forces in actuators used for moving a multiple-axis stage. The identified force-ripple and/or side-forces can be mapped, and maps of corresponding position-dependent compensation ratios useful for correcting same are obtained. The methods are especially useful for stages providing motion in at least one degree of freedom using multiple (redundant) actuators. In an exemplary method a stage member is displaced, using at least one selected actuator, multiple times over a set distance in the range of motion of the subject actuator(s). Each displacement has a predetermined trajectory and respective starting point in the range. For each displacement, respective section force-command(s) are extracted and normalized to a reference section force-command to define a section compensation-ratio.

Abstract: Method for balancing the motion of the magnetized movable masses of a bilinear electrodynamic motor comprising two movable masses moving in opposite senses parallel to the axis (x-x) of the motor, characterized in that the said method comprises the steps of: providing at least one first magnetic sensor and at least one second magnetic sensor which are able to deliver respectively a first electrical signal (s1(t)) and a second electrical signal (s2(t)) respectively representative of the motion of a first and of a second movable mass, recording an error signal (?s(t)) equal to the difference between the said first (s1(t)) and second (s2(t)) electrical signals and performing a harmonic analysis of the said error signal, applying a sinusoidal excitation signal (e1(t)) at a given frequency f0 to the first movable mass, iteratively applying N successive excitation signals (e2n(t)) to the second movable mass, an excitation signal of rank n (0?n?N?1) being equal to a Fourier series of order n of fundamental freque

Abstract: An active vibration control apparatus includes a linear actuator and a controller. The linear actuator includes a moving element, a stator and an elastic support. The stator has a plurality of coils surrounding the moving element. The elastic support supports the moving element to be reciprocally movable relative to the stator in an axial direction of the moving element due to elastic deformation of the elastic support. The controller is configured to apply an alternating current to the stator to generate vibration due to relative displacement of the moving element and the stator in the axial direction. The controller is configured to correct a center position of an amplitude of the vibration by additionally applying a predetermined direct current as a biased current to the stator when the linear actuator satisfies a predetermined vibration condition.

Abstract: A toothbrush has a removable end cap at its free end area directed away from the bristles, which end cap closes off an inner space of a grip element. The end cap accommodates an electrical control element, in particular a potentiometer, which can be adjusted via an adjustment element arranged rotatably on the end cap. The toothbrush also comprises an electrical power consumption unit, in particular an electric motor, which is designed to set the bristles in vibration. The energy supply from an energy reservoir arranged in the interior to the electrical power consumption unit can be adjusted continuously by means of the control element, as a result of which the vibration intensity of the bristles can be steplessly adjusted.

Abstract: In a drive control circuit of a linear vibration motor, a differential amplifier circuit includes an operational amplifier in which an P-channel type transistor is used as a transistor that receives an input voltage, and the differential amplifier circuit detects an induced voltage occurring in a coil. Before the H-bridge circuit is controlled to a high impedance state, a drive signal generating unit turns on a first transistor and a second transistor, and delivers a regenerative current through the coil, the first transistor, the second transistor and the power supply potential.

Abstract: In a drive control circuit of a linear vibration motor, the drive signal generating unit generates a drive signal whose phase is opposite to that of the drive signal generated during the motor running, after the running of the linear vibration motor has terminated; this drive signal of opposite phase includes a high impedance period during which the driver unit is controlled to a high impedance state. An induced voltage detector detects an induced voltage occurring in the coil. A comparator has a function as a hysteresis comparator in which the output level does not vary in a predetermined dead band, and the comparator outputs a high-level signal or a low-level signal during the high impedance period. When an in-phase signal is consecutively outputted from the comparator during the consecutive high-impedance periods, the drive signal generating unit determines that the linear vibration motor has come to a stop.

Abstract: In a drive control circuit of a linear vibration motor, a drive signal generating unit generates a drive signal used to alternately deliver a positive current and a negative current to a coil. A driver unit generates a drive current in response to the drive signal generated by the drive signal generating unit and supplies the drive current to the coil. An induced voltage detector detects an induced voltage occurring in the coil. After a running of the linear vibration motor has terminated, the drive signal generating unit generates a drive signal whose phase is opposite to that of the drive signal generated during the motor running; this drive signal of opposite phase includes a high impedance period during which the driver unit is controlled to a high impedance state. The induced voltage detector detects the induced voltage occurring in the coil during the high impedance period.

Abstract: A compensating system for compensating a cogging torque of a motor includes a speed measuring apparatus, a moment of inertia measuring apparatus, a rotor position sensor, a processor, a plurality of band-pass filters, and a current control apparatus. The processor receives a speed, a moment of inertia, and a rotor position of the motor, to determine the cogging torque of the motor. Each band-pass filter is arranged with a different frequency to filter different frequencies of waveforms of the cogging torque. The processor determines a Fourier transformation of the cogging torque according to a number of Fourier coefficients from the band-pass filters, a cogging torque at a preset rotor position, and a cogging current according to the Fourier transformation of the cogging torque. The current control apparatus outputs a current opposite to the cogging current, to compensate the cogging torque of the motor.

Abstract: A drive signal generating unit generates a drive signal used to alternately deliver a positive current and a negative current to a coil with a nonconducting period inserted between conducting periods. A driver unit generates a drive current in response to the drive signal generated by the drive signal generating unit and supplies the drive current to a coil. The drive signal generating unit estimates the eigen frequency of a linear vibration motor based on a detected position of the zero cross occurring in the coil during the nonconduting period, and the frequency of the drive signal is brought close to the estimated eigen frequency. The zero-cross detecting unit sets a detection window for avoiding the detection of zero cross of voltages other than the induced voltage. The zero-cross detecting unit enables a zero cross detected within the detection window and disables a zero cross detected outside the detection window.

Abstract: A drive signal generating unit generates a drive signal used to alternately deliver a positive current and a negative current to a coil with a nonconducting period inserted between conducting periods. A driver unit generates a drive current in response to the drive signal generated by the drive signal generating unit and supplies the drive current to a coil. An induced voltage detector detects an induced voltage occurring in the coil during the nonconducting period. A zero-cross detecting unit detects the zero cross of the induced voltage detected by the induced voltage detector. The drive signal generator estimates the eigen frequency of the linear vibration motor based on a detected position of the zero cross, and the frequency of the drive signal is brought close to the estimated eigen frequency.

Abstract: A drive signal generating unit generates a drive signal used to alternately deliver a positive current and a negative current to a coil. A driver unit generates the drive current in response to the drive signal generated by the drive signal generating unit and supplies the drive current to the coil. After the drive termination of a linear vibration motor, the drive signal generating unit generates a drive signal whose phase is opposite to the phase of the drive signal generated during the motor running. The driver unit quickens the stop of the linear vibration motor by supplying to the coil the drive current of opposite phase according to the drive signal of opposite phase.

Abstract: An actuator, includes: a weight part; a supporting part supporting the weight part; a connecting part coupling the weight part rotatable to the supporting part and having an elastic part; a driving member for driving and rotating the weight part; and a semiconductor circuit for driving the weight part. The driving member is operated to torsionally deform the elastic part and rotate the weight part. The elastic part has a first silicon part that is mainly made of silicon and a first resin part that is mainly made of resin and coupled to the first silicon part. The supporting part has at least a second silicon part made mainly of silicon and coupled to the first silicon part of the elastic part. The semiconductor circuit is provided on the second silicon part of the supporting part.

Abstract: The present invention relates to synchronized vibration devices that can provide haptic feedback to a user. A wide variety of actuator types may be employed to provide synchronized vibration, including linear actuators, rotary actuators, rotating eccentric mass actuators, and rocking mass actuators. A controller may send signals to one or more driver circuits for directing operation of the actuators. The controller may provide direction and amplitude control, vibration control, and frequency control to direct the haptic experience. Parameters such as frequency, phase, amplitude, duration, and direction can be programmed or input as different patterns suitable for use in gaming, virtual reality and real-world situations.

Abstract: An active vibration isolation support system includes an electronic control unit which supplies a target electric current to an actuator to periodically drive the actuator in an expansion and contraction manner with a target vibration waveform. The controller sets the target electric current by synthesizing a driving primary electric current waveform corresponding to the target vibration waveform for the actuator with higher-order (driving secondary and/or tertiary) electric current waveforms which eliminate higher-order vibration components of the actuator corresponding to the driving primary electric current waveform. It is possible to alleviate a calculating load in the electronic control unit by ignoring the quaternary and still higher-order vibration components which less affect the target vibration waveform for the actuator.

Abstract: An apparatus and method for identifying the position of a magnetic shaft are provided. N field sensors are adjacently positioned at fixed locations relative to the shaft's periodic field, corresponding to 180/N relative phase shifts. A table provides N>2 predetermined signal models and a pre-identified position associated with each. An interpolator compares a representation of the N measured sensor signals to at least two predetermined models to generate a correction signal that provides another pre-identified position. The correction signal depends on N sensors for every position of the shaft. The correction signal is used to incrementally choose said another pre-identified position from the table as an approximate position of the shaft in an iterative process to find the minimum correction signal and identify the position.

Abstract: A helicopter having a rotor, a fuselage connected to the rotor by connecting means, and a control device for controlling vibration of the fuselage; the control device including generating means for generating signals associated with vibration of the fuselage, and actuating means for producing a force on the fuselage associated with the signals to reduce vibration; and the actuating means being carried by the connecting means.

Abstract: The amplitude of a swing powered by an electric motor is controlled by detecting a peak voltage induced in the motor coil by the swing motion when the motor is not being powered and comparing the detected voltage with a one of a set of pre-measured reference values of peak voltages obtained at corresponding amplitude settings to provide a signal to a motor controller which adjusts the power supplied to the motor to bring the swing amplitude to. The motor controller supplies a PWM signal voltage to power the motor and adjusts the voltage on-time to bring or restore the swing to the selected amplitude.

Abstract: The present invention discloses an apparatus and method for controlling a linear compressor which can actively handle load and efficiently perform an operation, by synchronizing an operation frequency with a natural frequency of a movable member varied by the load.

Abstract: An apparatus and method for identifying the position of a magnetic shaft are provided. N field sensors are adjacently positioned at fixed locations relative to the shaft's periodic field, corresponding to 180/N relative phase shifts. A table provides N>2 predetermined signal models and a pre-identified position associated with each. An interpolator compares a representation of the N measured sensor signals to at least two predetermined models to generate a correction signal that provides another pre-identified position. The correction signal depends on N sensors for every position of the shaft. The correction signal is used to incrementally choose said another pre-identified position from the table as an approximate position of the shaft in an iterative process to find the minimum correction signal and identify the position.

Abstract: Disclosed are a low vibration cryocooler and a method of reducing vibration in a cryocooler. The cryocooler can be a Stirling class cryocooler includes at least one motor that drives a mass, the motor having a main drive winding and a separate trim winding. A motor controller outputs a main drive signal that is coupled to the main drive winding and a separate vibration reducing signal that is coupled to the trim winding.