Abstract: A movable member is moved in a preset direction in a linear motor. A characteristic-change position-detecting unit detects a position where the magnetic characteristic of the magnets has abruptly changed. The position detected is used as an origin-setting reference position. A reference position for the absolute position of the magnetic linear encoder is set based on the reference position.

Abstract: A device for supplying energy to a long stator winding having multiple winding sections. The device includes an energy source, a supply line connected to the energy source, section switches that are connected to the supply line and that each have a connection for connecting the switch to one winding section each. The device is configured to enable reactive (idle) power compensation independently of the closed-loop control of the energy source. The device for the reactive power compensation is configured to adjust the impedance of the device.

Abstract: The aim of the invention is to improve the precision of measuring leakage field sensitive sensors on electric machines. According to the invention, the electric machine comprises a sensor device (4) which is sensitive to magnetic leakage fields mounted on one of the two active parts (1) or in a defined relative position in relation to the active parts. A magnetic screening device is arranged between the sensor device (4) and one of the two active parts (1). Also, the magnetic leakage fields no longer have an influence on the sensor device such that measuring precision is increased.

Abstract: Connected to a 3-phase linear motor of a submersible oil pump of a crude oil production system, a linear motor automatic control circuit assembly is disclosed to include a linear motor power supply circuit, a CPU, an insulated gate bipolar transistor driving circuit, a current detection circuit, a temperature sensor, a fluid depth sensor, a function setting and status display circuit, and a circuit assembly power supply circuit for controlling the operation speed of the linear motor subject to the submergence depth of the linear motor in the oil well.

Abstract: Flight control systems and methods for rotorcraft are provided. The flight control system includes a user input device and a motor in operable communication with the user input device. The motor includes a plurality of winding sets and an armature coupled to the plurality of winding sets. The armature includes multiple magnets. The winding sets and the armature are configured such that when one or more of the plurality of winding sets are selectively energized, the armature moves relative to the one or more of the plurality of winding sets.

Abstract: A position-data converter and a motor-drive control device are connected. The position-data converter receives two-phase, sine-wave analog signals da and db from two first magnetic detectors, respectively, and converts these signals da and db to position data. On receiving a positioning instruction, the motor-drive control device calculates the value of current, from the current position signal generated by the position-data converter. The permanent magnets incorporated in a linear motor are used as components of a linear scale, as well.

Abstract: A linear motor includes a primary part arranged as a guideway stator and at least one secondary part that is movable with respect to the primary part, the at least one secondary part having device(s) for controlling the generation of a magnetic field, causing its motion, in the primary part. It is possible to avoid costly control devices for the application of current to the stator.

Abstract: A path module for a linear motor system includes a controller coupled to one or more amplifiers that are operative to control associated windings in the module. The controller receives control information via a communications link. The controller controls the amplifier based on the received control information so as to selectively energize the associated windings in the module. In one aspect, a plurality of such modules may be connected together to form a path along which one or more stages are moveable according to energization of the windings in the path.

Abstract: A micropositioner is provided, which contains an outer magnetic pole-piece and an inner magnetic pole-piece located within the outer magnetic pole piece. At least one permanent magnet is located between the inner magnetic pole piece and the outer magnetic pole-piece. At least one coil is located between the inner magnetic pole-piece and the outer magnetic pole-piece, wherein the at least one coil is capable of directing magnetic flux between the inner magnetic pole-piece and the outer magnetic pole-piece. An outer movable shell is also movably connected to the outer magnetic pole-piece.

Abstract: The start timing of the pole position inference process of the linear motor installed vertically is delayed by a predetermined time after instruction of brake release. For example, from (1) increasing of the thrust instruction value of an ASR control system up to a predetermined value, (2) the movement (falling) distance of the moving part, or (3) the moving (falling) speed of the moving part, the release condition of the brake is detected and moreover after a predetermined time, the inference process of the pole position is started. The inference process of the pole position of a synchronous motor is fit to the release timing of a brake and a malfunction of the inference process and a runaway (falling in the vertical drive) of a moving part are prevented.

Abstract: The invention provides a driving circuit for a voice coil motor. In one embodiment, the driving circuit includes a logic circuit, a digital-to-analog converter, and an output circuit. The logic circuit generates a series of samples of a digital output signal according to a digital input signal, wherein the samples of the digital output signal sequentially alter from a first input value of the digital input value to a second input value of the digital input signal according to an alteration pattern determined by a mode selection signal. The digital-to-analog converter converts the digital output signal to an analog output signal. The output circuit generates a driving current signal according to the analog output signal for driving the voice coil motor.

Abstract: A mover (344) moving a stage (238) along a first axis and about a second axis includes a magnetic component (454), and a conductor component (456). The magnetic component (454) includes one or more magnets (454D) that are surrounded by a magnetic field. The conductor component (456) is positioned near the magnetic component (454) in the magnetic field. Further, the conductor component (456) interacts with the magnetic component (454) when current is directed to the conductor component (456) to generate a controlled force along the first axis, and a controlled moment about the second axis. Additionally, the conductor component (456) interacts with the magnetic component (454) to generate a controlled force along a third axis that is perpendicular to the first axis and the second axis when current is directed to the conductor component (456).

Abstract: A quiet retraction method for regulating constant velocity while parking an arm within a disk drive is described. The method comprises the steps of: driving a motor for the arm using a first drive current for a first period; floating the motor; sampling a back electromotive force (bemf) for a first sampled voltage, while floating the motor; driving the motor with a second drive current during a second period in response to sampling the bemf; determining whether the second drive current exceeds a current limit; estimating the bemf using the first sampled voltage when the second drive current exceeds the current limit; driving the motor with a third current during a third period in response to estimating the bemf; wherein driving the motor with the first, second, and third currents quietly parks the arm, while regulating the constant velocity.

Abstract: At least one exemplary embodiment is directed to an alignment apparatus which includes a moving member, a structural object arranged on the moving member, and an electromagnetic actuator which moves the structural object relative to the moving member. The electromagnetic actuator includes a plurality of linear motor units, which apply forces in the horizontal direction and the vertical direction to the structural object. The plurality of linear motor units apply, to the structural object, forces in the rotation direction about each of two axes orthogonal to each other in the horizontal plane and the rotation direction about the axis in the vertical direction.

Abstract: An apparatus for measuring linear velocity of a movable element relative to a stationary element includes a magnetic element fixed in relation to the stationary element. A soft-magnetic yoke is fixed in relation to the movable element to move with the movable element and is in non-contact relation with the magnetic element. A yoke pole is positioned proximate to the magnetic element and spaced therefrom by an air gap. The pole is magnetically coupled to the magnetic element so that a magnetic flux is generated in the air gap substantially orthogonal to the axis of motion. A conductive coil is coiled around a coil axis and is fixed in relation to the stationary element with the coil axis substantially parallel to the axis of movement. The coil is in non-contact relation with the yoke and resides between the magnetic element and the pole of the yoke in the magnetic flux.

Abstract: Circuits and methods to read out capacitive sensors for distance measurement used by a position control system having a high accuracy and low noise have been disclosed. The ratio or difference of the capacitances of two sensor capacitors is used to determine the distance of an object from a target position. A sense amplifier is using auto-zero methods to achieve a long term stability. A sample-and-hold circuit using double correlated sampling methods minimizes noise. Low cost capacitors can be used with the sample-and-hold circuit because not the absolute value of capacitances but only the ratio of capacitances are relevant. A high resolution is ensured also by significant over-sampling of the control loop.

Abstract: A linear electric motor has a fixed primary comprising a stator that is divided into a number of sections, a translating secondary that has an operative length that is longer than any two adjacent sections of the stator in the form of a reaction plate, and a connecting means for connecting only those sections of the stator that are covered, either fully or partially, by the reaction plate. The stator sections are categorised in three groups—two groups of representative sections and an ordinary group of sections. The first and second representative sections alternate with ordinary sections between them. The position of the reaction plate relative to the stator is determined by monitoring current in the active representative sections. The length of the reaction plate is equal to the distance from the beginning of the first representative stator section to the end of the ordinary stator section immediately following the next second representative stator section.

Abstract: Provided is a method for controlling a plurality of AC linear motors of identical specifications which are connected each other and operated synchronously so that they appear to operate as a single linear motor having desired power. The method for controlling, as an AC linear motor set, a plurality of AC linear motors of identical specifications which are connected to each other, includes the steps of firmly connecting the AC linear motors in such a manner that pole pitches of movers of the AC linear motors and pole intervals of adjacent movers are identical; and setting any one of the AC linear motors to be a master AC linear motor and using a command signal generated based on a feedback signal of the master AC linear motor and current difference information obtained by comparing phase current of the master AC linear motor with phase current of another AC linear motor to control the AC linear motor set.

Abstract: The invention relates to a method for absorbing the displacement, under the influence of an external force, of at least one plunger (10,20) in a linear electrodynamic motor comprising a least an induction coil (11, 21) magnetically coupled with the plunger. Said method comprises the steps of: detecting in said induction coil a current induced (I?ind) amplified relative to the induced current. The invention can be applied to cryogenic machines on board space ships.

Abstract: Self-sensing feedback functionality for electromechanical actuators/motors is provided for use in operation and/or as a redundant safety mechanism to attain safety certification without adding extra bulk or wiring to the motor. An actuator can be manufactured having one or more saliencies that cause a spatial variance of inductance. A high frequency signal can be injected into the actuator and sampled to determine a current, voltage, or other electrical parameter. The parameter can be evaluated against the known saliencies of the actuator to determine a position of the actuator and/or an associated rotor. Additionally, the position can be evaluated as a function of time to determine a velocity. This can provide an alternative method for operating the electromechanical actuator according to the position/velocity provided. Additionally, this can provide a redundant feedback channel for safety certification without requiring additional actuator parts.

Abstract: The aim of the invention is the equipping of a synchronous linear motor with a non-permanently-magnetic secondary part with a simple positional measuring system. Said aim is achieved, whereby the tooth structure of the toothed rack-shaped non-permanently-magnetic secondary part (S) varies with position in the direction of movement (B). Furthermore, the synchronous linear motor can be provided with absolute and incremental positional measuring systems, such that the coarse resolution of the absolute measuring system can be supplemented by the fine resolution of the incremental system.

Abstract: Disclosed are a high-damping and high-thrust cylindrical linear motor and a motor-driven power steering device. A stator includes three-phase stator and a stator core. A slider includes a slider core and permanent magnets. The stator core includes stator-core salient poles, two auxiliary poles and yoke units with a small poles on its surface of the side of the slider, the auxiliary poles being deployed at both ends of the stator-core salient poles, the yoke units configuring a magnetic circuit in cooperation with the stator core and the auxiliary poles. The magnetic circuit is shared among the three phases. Polarities of magnets of the slider become an identical polarity, each of the plurality of permanent magnets being positioned at a position which is opposed to each of the plurality of small poles included in one stator-core salient pole out of the plurality of stator-core salient poles.

Abstract: A sensorless method and apparatus for detecting piston collisions in a free piston linear compressor motor. The waveform of the back EMF induced in the motor stator windings is analysed for slope discontinuities and other aberrations in a time window centred on the back EMF zero-crossings. Waveform slope artefacts are indicative of piston collisions and cause the motor power to be decremented in response.

Abstract: Magnetically latching and releasing a voice coil actuator for controlling electrical switchgear. The voice coil actuator includes a voice coil magnet disposed on a common longitudinal axis with respect to a voice coil assembly. A coil of the voice coil assembly exerts a magnetic force on the voice coil assembly, thrusting the voice coil assembly towards the voice coil magnet. At least one pair of latching members mounted to the voice coil assembly creates a permanent magnet circuit between the latching members and the voice coil magnet. The permanent magnet circuit maintains the position of the voice coil assembly relative to the voice coil magnet, even when power to the coil is removed. This latch can be released by applying a current in the coil or by applying an external, physical force to a member coupled to the voice coil assembly.

Abstract: An improved linear motor which compensates for manufacturing or assembly errors in the positioning of the magnetic field detectors. The linear motor synthesizes a correction signal which can be simply combined (for example added) to the output of one of the magnetic field detectors so as to ensure that the magnetic field detector outputs have the correct phase relationship. This in turn ensures that accurate positioning of the rotor relative to the stator can be achieved. In a preferred embodiment, a deliberate error is introduced into the positioning of the magnetic field detectors and this error, plus any error due to manufacturing or assembly tolerances, is corrected using the correction signal. This allows a simplified correction circuit which only corrects for phase offset errors in one direction to be used.

Abstract: A servo control apparatus for a linear motor comprises a position feedback device, a driver and a position compensating device that are connected with one another. The servo control apparatus is electrically connected to the linear motor. By such arrangements, it can not only improve the precision of the displacement of the linear motor, but also make the movement of the linear motor relatively smooth.

Abstract: A control circuit for a full-bridge-stage to drive an electric load includes PWM generation circuitry for generating first and second PWM signals so that a difference between duty-cycles of the PWM signals represents an amplitude of a drive current. A logic XOR gate is input with the first and second PWM signals and generates a logic XOR signal. A logic sampling circuit generates a logic driving command of a half-bridge of the full-bridge stage, a logic value of which corresponds to a sign of the drive current, by sampling one of the first and second PWM signals based upon active switching edges of the logic XOR signal. A second XOR gate is input with the logic XOR signal and the logic driving command and generates a third PWM driving signal of the other half-bridge of the full-bridge stage, a duty-cycle of which corresponds to the amplitude of the drive current.

Abstract: A reversing linear drive which comprises a field coil and a magnetic armature that is excited by the magnetic field of the field coil to perform a linear, axially oscillating movement. In order to detect the armature position, the drive is provided with a stripe pattern element with an alternating arrangement of transparent and opaque stripes or of light-reflecting stripes and non-light-reflecting stripes which extends at least across the entire axial armature stroke, and with a light barrier with elements that emit and receive light in a direction perpendicular to the axial direction.

Abstract: A linear portable actuator including a direct current electric motor (2) rotationally driving a screw with the aid of a reduction element, wherein the motor (2) is controlled by an electronic module (5) comprising means (12) for the acquisition of instantaneous intensity of a supply current for the motor. Further, the electronic module (5) also comprises means (13) for calculating the differential coefficient in relation to supply-current intensity time, which are connected to means (14) for comparing the differential coefficient to a first predetermined value, and a comparing means controlling means (15) for switching off the supply current it the differential coefficient is greater than the first predetermined value.

Abstract: A linear motor includes a stator having teeth symmetrically formed on upper and lower surfaces thereof at regular pitch; a movable member including upper cores disposed above the stator, lower cores disposed below the stator in symmetrical with the upper cores, and yoke parts connecting the upper and the lower cores around the stator, wherein the upper and lower cores have upper and lower coils wound therearound, respectively; at least one gap sensor to detect the gap between the stator and the upper or lower core and the inclination of the movable member; a controller performing the levitation control by adjusting the amplitudes of currents applied to the upper and lower coils, based on the gap variation, and driving the linear motion by changing the current phases; and a multichannel voltage-to-current power amplifier of which each channel is connected to each coil of the upper and lower cores.

Abstract: The present invention relates to an alternating current electrical motor having a first element with magnets of alternating polarities, and a second element with electrical conductor coils, the first and the second elements being mounted for relative motion to one another. A controller for the electrical motor comprising: a current source for energizing the coils with an alternating current to produce a movement of the first and the second elements relative to one another; a sensor for sensing a phase shift between the magnets and the current in the coils; and a current source controller for varying an amplitude of the current to substantially regulate the phase shift to an optimum phase shift value, thereby providing a minimum power consumption for proper operation of the electrical motor.

Abstract: A production machine includes an electrical positioning drive having a stator and a moveable member displaceable relative to the stator in at least one travel direction. The moveable member is mounted, in relation to the stator, in a contactless manner by a magnetic field in at least one of the supporting directions differing from the travel direction. A sensor device is associated with the positioning drive to shift the moveable member relative to the stator in the supporting direction to be detected. A control device is also associated with the positioning drive, and the shift of the moveable member is detected by the sensor device and can be supplied in the supporting direction. A control signal for a positioning magnet system can be determined by the control device, on the basis of the shift of the moveable member in the supporting direction and a nominal positioning of the moveable member.

Abstract: A linear motor system that can extend the stroke of a linear motor, with power saving and at a low cost, is provided. In a linear motor system, constituted by a linear motor 100, a controller 7 for supplying a variable voltage, a winding switching device 6, for opening and closing phase windings 5 of individual phases that form a plurality of winding groups 4 that are separated in a stroke direction, the winding switching device 6 is constituted by a three-phase rectifying member, a semiconductor switch, which is located at both ends on the direct-current output side of the three-phase rectifying member, and a resistor and a capacitor, connected in parallel to the semiconductor switch. For each of the phase windings, which form the plurality of winding groups 4, separated in the stroke direction, one end is connected to the output end of the controller 7 and the other end is connected to an alternating-current input side of the three-phase rectifying member of the winding switching device 6.

Abstract: A high voltage, low current electric motor. The motor comprises a drive shaft turned by a sprocket that is driven by an assembly of electromagnets. A carrier supporting permanent magnets travels in a tubular track formed into an endless loop around the sprocket. The carrier preferably comprises a chain formed of interconnected links, each link housing a magnet. The tubular track is non-ferrous and forms a core for a plurality of coils spaced around the tube. A sequencing circuit in the motor sequentially energizes the coils to cause the carrier to circulate around the tube by repelling and attracting the magnets. Teeth on the sprocket engage the chain so that as the chain travels through the tube the sprocket is rotated. Preferably, the coils are double-wound so that a direction control circuit may be included to selectively reverse the direction of the carrier's travel. Speed control also may be included.

Abstract: A flat surface tilting device including a selectably positionable flat surface element assembly defining a flat surface element having a flat surface and a pivot location portion, the pivot location portion being generally centered with respect to the flat surface, a pivot support element pivotably engaging the pivot location portion, an electromagnet, fixed with respect to the pivot support element and arranged for application of magnetic force in a direction generally perpendicular to the flat surface thereby to pivot the flat surface element about the pivot support element, a sensor for sensing the position of the flat surface element and feedback circuitry operative in response to an output of the sensor to govern operation of the electromagnet.

Abstract: Embodiments of the invention are directed to a method of controlling a mover device The method includes generating a moving force from a moving force generating unit to move a processing base with respect to a movable base, thereby moving the processing base with respect to a fixed base as a result of the movement of the processing base with respect to the movable base; moving the movable base on the fixed base in the opposite direction to the moving direction of the processing base by virtue of a reaction force caused by the moving force generated from the moving force generating unit to move the processing base, so that the movable base moves in the opposite direction to the moving direction of the processing base on the fixed base. The method further includes controlling the moving velocity of the processing base with respect to the fixed base.

Abstract: A position sensing system for positioning a linear motor that includes a stator and an armature having magnets, the armature moving relative to the stator along a path. A sensor determines a position of the armature based on measurements of a magnetic field generated by the magnets of the armature.

Abstract: A positioning device configured to position a first and a second movable object in a substantially common operation area is presented. The positioning device includes a first coil assembly arranged next to the operation area, a second coil assembly arranged at an opposite side of the operation area, one or more first magnets arranged on the first movable object and configured to cooperate with the first coil assembly, and one or more second magnets arranged on the second movable object and configured to cooperate with the second coil assembly.

Abstract: A system implementing a controller for linear motors is disclosed having a plurality of switches, a reorganization switch control detecting available hot spot sensors, encoder failures, and current sensor failures, and a storage storing a decision matrix having controller reorganization conditions. Upon detecting available hot spot sensors, encoder failures and recoveries, and current sensor failures and recoveries, the reorganization switch control reorganizes itself via configuring at least one of the switches based on information in said decision matrix to operate without available sensors and using available sensors.

Abstract: Connected to a 3-phase linear motor of a submersible oil pump of a crude oil production system, a linear motor automatic control circuit assembly is disclosed to include a linear motor power supply circuit, a CPU, an insulated gate bipolar transistor driving circuit, a current detection circuit, a temperature sensor, a fluid depth sensor, a function setting and status display circuit, and a circuit assembly power supply circuit for controlling the operation speed of the linear motor subject to the submergence depth of the linear motor in the oil well.

Abstract: A driving apparatus which electrically drives a component built in an industrial instrument, comprises a housing including a supply inlet and an exhaust outlet, a fan configured to form an air current so that air is taken into the housing through the supply inlet and exhausted from inside the housing through the exhaust outlet, a driving circuit block which is accommodated in the housing so as to be cooled by the air current, and configured to electrically drive the component, and a cooling unit configured to regulate a temperature of the air exhausted from inside the housing through the exhaust outlet so as to decrease a temperature difference between the air taken into the housing through the supply inlet and the air exhausted from inside the housing through the exhaust outlet.

Abstract: Methods and systems are provided for driving one or more force coils. A system for driving force coils is provided including a PWM drive coupled to a first coil and a linear drive coupled to a second coil. The PWM drive efficiently drives the first coil to apply a first force. The linear drive drives the second coil to apply a second force that is substantially noise-free. The first force is greater than the second force.

Abstract: A position feedback device for a linear motor comprises three linearly-arranged Hall sensors. The three Hall sensors are connected to a mover, respectively. The direction in which the Hall sensor in the middle of the three Hall sensors is reverse to the direction in which the other two Hall sensors of the three Hall sensors are connected, so that the arrangement distance of the three Hall sensors can be reduced, and the size of the position feedback device can be reduced.

Abstract: A control system and method for ensuring proper closure of a dual swing gate. The control system employs position sensors for monitoring the position of each gate arm. A “differential position” is maintained between the arms during closing to ensure proper sequencing. The control system regulates the speed of the master arm and the slave arm to ensure that the differential position is maintained throughout the closure process.

Abstract: A circuit device is disclosed which is used to increase useable motor voltage in a long stator drive. Further, suitable methods for operating a magnetically levitated vehicle provided with the circuit device are also disclosed. In one embodiment of the present invention, the stator section of the long stator drive is connected to the energy supply line on two connection points by way of a first and a second switch. A third switch is located between both connection points arranged on the energy supply line. Both of the stator section connections are connected to the ground potential by way of a fourth and a fifth switch. In one embodiment, in order to accelerate the magnetically levitated vehicle, the first and the second switches are closed and all other switches are opened. The stator section is cross-flown in a direct manner by current in the energy supply line.

Abstract: In order to provide a driving device that is capable of eliminating sticking of a movable member due to nonuse, the driving device includes a drive shaft that reciprocates in axial directions with expansion and contraction of an electromechanical transducer element, a movable member that frictionally engages with the drive shaft, and a drive circuit that inputs drive voltage into the electromechanical transducer element, the drive circuit outputting drive operation pattern voltage having a frequency (fd1?) lower than a resonance frequency (fr) of the electromechanical transducer element and lower than a frequency (fd1) that maximizes moving velocity of the movable member and sticking elimination pattern voltage having a frequency lower than the frequency (fd1?) of the drive operation pattern voltage and in vicinity of a frequency (fd2) that maximizes thrust acting on the movable member.

Abstract: An elevator door mover device (40) includes a threaded ferromagnetic shaft (42). Magnetic movers (48) associated with doors (26) generate magnetic fields that cause the doors to move responsive to rotation of the shaft (42). In one example, a controller (46) controls a speed of a motor (44) that drives the shaft (42). The controller (46) in some examples also selectively controls the strength of the magnetic fields of the movers, which provides more customizable door performance.

Abstract: A rotating stage assembly performs high precision rotational angle and position error correction by continuous sensing and correcting motor stage assembly errors. It performs these corrections, to adjust for motor environmental and operational errors by sensing and correcting using five sensors placed to measure the adjustments of five corresponding actuators, which adjust the entire motor rotating stage and rotary motor assembly relative to a reference frame.

Abstract: The present invention relates to a linear traversing carriage for use in the papermaking industry and the like, which incorporates an air gap inductive motivator and eliminates all mechanical devices between the electrical power supply and the traversing mechanism. Specifically, the present invention relates to a linear traversing device comprising an inductor type linear motor comprising an electrical stator winding, a conductive platen extending over an entire traverse length of the device, a ferromagnetic material affixed to said conductive platen, a support means for supporting the device and maintaining an air-gap between the stator winding and the conductive platen, a user selected feed forward velocity map for driving the device, a controller that controls a movement of the device according to the user selected feed forward velocity map.

Abstract: A control system for a linear actuator having an electric motor drawing a variable current level during operation. The control system includes a current level sensor for determining an operational current level of the linear actuator and a controller for generating a drive signal and a force request signal representative of a desired current level of the linear actuator. The drive signal remains constant during a predetermined time interval of the controller. The control system further includes a current limiting component for receiving the force request signal, the current level of the linear actuator and the drive signal. The current limiting component minimizes the current level of the electric motor in response to a comparison between the force request signal and the desired current level within a time interval substantially smaller than the predetermined time interval of the controller.