Abstract: An angular velocity detected by an angular velocity sensor (10) is integrated by a small angle matrix calculator (12) and a matrix adding calculator (14), and then restored as a posture angle (angular velocity posture angle) by a matrix posture angle calculator (16). A posture matrix is calculated by a tilt angle calculator (22) and an acceleration matrix calculator (24) and an acceleration detected by an acceleration sensor (20) is restored as a posture angle (acceleration posture angle) by a matrix posture angle calculator (26). Low pass filters (18, 28) each extract a low range component, the difference between the two is calculated by a differencer (30), and only the drift amount is extracted. A subtracter (32) removes the drift amount from the angular velocity posture angle and the result is output from an output device (34). In addition, a posture angle matrix calculator (36) converts the result to a posture matrix, which it feeds back to the matrix adding calculator (14).

Abstract: Stabilization of a stage in a movable stage apparatus is enhanced, and increasing in size of the movable stage apparatus is suppressed. A reaction force cancel system is provided in the movable stage apparatus where a stage moves on a surface plate installed on a floor via a vibration-isolating spring, and cancels a reaction force generated on the surface plate upon movement of the stage. The reaction force cancel system includes a reaction force canceling actuator for applying a counter-thrust that is a force for reducing the reaction force to the surface plate. The reaction force canceling actuator is arranged at a lower position than a top surface of the surface plate so that the surface plate hangs over the reaction force canceling actuator.

Abstract: This invention provides a device for preventing sway of a suspended load, which does not require complex calculation for eliminating frictional resistance components. The device is equipped with a speed control device (14) for outputting a torque command based on a speed command, a torque command filter (16), and a load torque observer (4) for estimating the load torque, and configured to output a value obtained by adding a load torque estimation signal to an output of the torque command filter (16). The device is further equipped with a high-pass filter (32) for outputting a signal TRFLHPF in which a frictional resistance component is eliminated from the load torque estimation signal and a sway angle calculator (33) for outputting a sway angle estimation calculated value ?e obtained by multiplying a sway angle calculator factor by the output signal TRFLHPF.

Abstract: A control circuit for an active engine mount is provided, including an electrical bridge circuit, and a pulse-width modulation (‘PWM’) circuit. The PWM circuit receives an input signal from a controller, and generates first and second PWM output signals. The first PWM signal, derived from the input signal, controls first and third switches of the electrical bridge circuit. The second PWM signal comprises a digitally inverted signal of the first PWM signal, and controls second and fourth switches of the electrical bridge circuit. First and second outputs of the bridge circuit are connectable to first and second terminals of the mount device. The controller receives an input signal from crank and cam sensors, as part of the control scheme.

Abstract: A multi-drive printed product processing device is provided that includes a processing component and a motor driving the processing component. A motor control controls the motor. An encoder measures a position of the motor and sends an encoder feedback signal indicating the position. The motor control receives the encoder feedback signal. An encoder feedback signal verification circuit verifies the integrity of the feedback signal.

Abstract: A method and a device with a control apparatus (50) for starting an electric machine (10) with a rotor (20), particularly the spinning cup of an open-end spinning machine, magnetically mounted by a bearing having permanent magnets (31, 32, 33, 34). An actuator system controls the position in the axial direction (35, 36) and two limitation bearings (41, 42), determine the axial end positions of the rotor. The actuator system brings about a lifting from the first axial end position, and a system variable during such lifting is compared with a reference value, and the rotor (20) is moved into the second end position, and the actuator system brings about a lifting from the second axial end position, and a system variable on lifting from the second end position is compared with a reference value.

Abstract: A servo system is provided for controlling movement of a flexible structure having multiple masses and elements. Each element couples a respective two of the masses and functions as a spring when the flexible structure is subject to a linear or rotational input at or above a frequency at which the respective element exhibits flexure. The servo system includes multiple sensors, where each sensor is disposed relative to a respective one of the masses to sense a respective acceleration. A motor having a torque input may operatively be configured to output one of a linear or rotational force on the first mass based on a torque signal present on the torque input. A servo controller that receives each sensed acceleration from each sensor may generate a compensation feedback signal based on a sum of sensed accelerations. The torque signal may be output to the motor based on the compensation feedback signal.

Abstract: An accurate load position control is made possible even when rigidity of a load drive system using a motor is relatively low. Load position signal xl is a present-position measurement value of a load, and after compensation in response to a phase delay thereof has been performed by a stability compensation circuit, the high-frequency portion thereof is taken as a control-target position signal xfb by replacing, in a position-signal combination circuit, a motor position signal xm as a present-position measurement value of a motor, and then the control-target position signal xfb is fed back to a position control circuit. Thereby, a torque command signal indicating a torque target value for driving the load is outputted.

Abstract: An active human-machine interface system includes a user interface, one or more motors, one or more motor controllers, one or more electrically controllable dampers, and one or more damper controllers. The motors are coupled to the user interface and are configured, upon being energized, to supply a haptic feedback force to the user interface. The motor controllers are coupled to, and configured to selectively energize, the motors. The electrically controllable dampers are coupled to the user interface and are configured, upon being energized, to supply a damping force to the user interface. The damper controllers are in operable communication with the motor controllers and are coupled to, and configured to selectively energize, the electrically controllable dampers.

Abstract: In order to simultaneously realize an improvement in disturbance suppression force of an electric motor control apparatus and vibration suppression of a load machine, a velocity control circuit receives a velocity command signal as a target value of velocity of an electric motor and a corrected velocity signal, obtained by correcting a velocity signal with a velocity correction signal, and outputs a torque command signal specifying target torque of the electric motor driving the load machine. A vibration suppression circuit outputs a velocity correction signal, based on an acceleration signal, indicating acceleration of the load machine. A transfer function from the acceleration signal to the torque command signal is obtained by multiplying a transfer function from a position signal, indicating position of the electric motor to the torque command signal, by a proportion characteristic having a specified gain and integration characteristic.

Abstract: A method of obtaining improved feedforward data for a feedforward control system to move a component through a setpoint profile is presented. The setpoint profile includes a plurality of target states of the component each to be substantially attained at one of a corresponding sequence of target times. The method includes moving the component with the feedforward control system according to the setpoint profile using a first set of feedforward data; measuring a state of the component at a plurality of times during the movement; comparing the measured states with corresponding target states defined by the setpoint profile to obtain a set of errors; filtering the set of errors with a non-linear filter; generating improved feedforward data based on the filtered errors, the improved feedforward data being usable by the feedforward control system to move the component more accurately through the setpoint profile.

Abstract: A control apparatus of the present invention comprising a control unit outputting a control signal controlling a servo motor and suppressing natural vibration of a controlled object including a motor and a machine driven by the motor while controlling the controlled object, comprising a frequency analysis unit analyzing a frequency component included in a torque command, an analysis control unit controlling the start or stopping of the frequency analysis unit, a detection unit detecting a natural frequency of the controlled object from an analysis result of the frequency analysis unit, a-band rejection filter receiving as input the torque command, stripping the command of the natural frequency component, and outputting the resultant command to the motor through a current control unit and servo amplifier, and a filter characteristic setting unit setting the frequency to be stripped at the filter based on the natural frequency detected by the detection unit.

Abstract: A method for reducing audible motor noise in a motor drive, wherein the motor drive includes a motor controller driving a PWM space vector modulator providing gating pulses to an inverter providing phase currents to the phase windings of the motor, and wherein phase currents of the motor are determined by taking samples of the DC link current in a DC link powering the inverter. The method comprises determining the speed of the motor and comparing the speed to a preset threshold, the preset threshold defining a speed at which audible noise is generated by the motor due to a minimum pulse constraint being imposed on the motor phase currents in order to reliably sample the DC link current to measure the phase current. If the speed is below the threshold, the DC link current in the DC link is sampled using a reduced number of current samples for a PWM cycle of the PWM space vector modulator to reduce audible motor noise.

Abstract: A gripping device for a manipulation system, particularly a robot, for receiving workpieces and feeding them from a readied stack of the workpieces to a manufacturing plant such as a metal sheet folding machine, punching press, welding plant, etc. The device has a gripper head fitted with gripping means such as suction cups, magnets, tongs, etc., and a detection system for detecting characteristics of the workpiece gripped by the gripping means. A pulse emitter excites vibrations in the workpiece and the vibration spectrum of the workpiece is compared to reference vibration data to determine characteristics of the gripped workpiece, such as whether two or more workpieces are stuck together, or whether the workpiece is the correct workpiece.

Abstract: Presented is a harmonic regulator that regulates a plurality of individual harmonics in a system having periodic torque disturbances to commanded values, including zero. For each harmonic being regulated, a feedback signal having at least one harmonic component due to the harmonic being regulated is transformed from a source reference frame to a harmonic reference frame of the harmonic being regulated to form a qd feedback signal. The qd feedback signal is subtracted from the commanded value to form a qd signal and regulated. The regulated qd signal is transformed to a destination reference frame to form a compensation signal and the compensation signal is added to a control signal to form a qd control signal that drives each harmonic being regulated towards the commanded value.

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: The invention relates to a method of managing a steering control for a steerable portion of an aircraft undercarriage, the method comprising implementing servo-control to servo-control an electromechanical steering actuator on an angular position setpoint, wherein, according to the invention, the servo-control implements a control relationship H? type, the position and speed information being delivered by means of a fieldbus of deterministic type to a computer that implements the servo-control.

Abstract: An active human-machine interface system is implemented without a force sensor. The system includes a user interface that is configured to receive user input and, upon receipt thereof, to move to a position. A position sensor is coupled to the user interface and is operable to sense user interface position and supply a position signal representative thereof. A motor is coupled to the user interface and to receive motor current. In response to the motor current the motor supplies a feedback force to the user interface at a magnitude proportional to the motor current. A control circuit is coupled to receive at least the position signal and a signal representative of the motor current and controls the motor current supplied to the motor.

Abstract: Systems and methods for improved Variable Speed Drives having active inverters include an input filter for filtering common mode and differential mode currents. A three-phase inductor has three windings, each winding of the three-phase inductor having a center tap dividing each winding into a pair of inductor sections; and a three-phase input capacitor bank connected in a wye configuration to the three center taps at one end, and to a common point at the opposite end. The three-phase input capacitor bank provides a short circuit for frequencies above a predetermined fundamental frequency for shunting such frequencies through the three phase capacitor bank, while passing the predetermined fundamental frequency to an input AC power source.

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: An optical image stabilizer includes an optical system including at least one image shake counteracting optical element movable in a plane orthogonal to an optical axis; at least one stepping motor for moving the image shake counteracting optical element in the plane; at least one shake velocity sensor which senses the speed of shake applied to the optical system; and a controller which calculates the number of driving pulses for the stepping motor based on shake speed information output from the shake velocity sensor, and drives the stepping motor so that the image shake counteracting optical element moves in the plane to counteract image shake on an imaging surface of the optical system. The controller changes power supplied to the stepping motor in accordance with the shake speed information when driving the stepping motor.

Abstract: The aim of the invention is to provide a speed control method for reducing current ripple and speed ripple at constant dynamics behavior while reducing the hardware required to a minimum. For this purpose, a control signal, especially a speed deviation (ev) is divided up into at least two signal portions (evhi and evlo). Every one of the at least two signal portions (evhi and evlo) is processed in a different manner. The low-order portion (evlo) can be smoothed by means of a low-pass filter (F). In an adder (Sum6) mounted downstream thereof the differently processed signal portions are then added up for further control.

Abstract: Suppression of vibration of a load machine without reducing the responsiveness of the load machine to an operation command is achieved by a method and an apparatus for controlling an inertial system intended to control an inertial system that has a motive power generator and a load machine that are coupled to each other via a torque transmission element. Acceleration command information that designates the acceleration of the load machine is multiplied by a predetermined gain to produce a vibration suppression control variable. The vibration suppression control variable is added to the position command to form a vibration suppression control command, and the inertial system is controlled according to the vibration suppression control command.

Abstract: A system for replicating the behavior of a target robotic manipulator with respect to a payload and worksite, has a real-time simulator capturing the dynamics of the target robot manipulator; a mock-up of the payload and worksite; and an emulating robotic manipulator for interacting with said payload and worksite. The emulating robotic manipulator is controlled by the real-time simulator in a control loop to replicate the dynamical behavior of said target robotic manipulator in its environment by matching the impedance of the emulating robotic manipulator with that of the target robotic manipulator.

Abstract: In accordance with the invention, an inverse filter is used to improve scanned images from a scanning probe microscope by removing the effect of the scanning system dynamics from the image data. This may be done in-line or as a post-processing operation.

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: A motor control system suppresses vibration of a machine base and achieves high-speed positioning without using a special sensor but using a model control system. A first feedback section outputs a first feedback command generated based on model machine base position information and containing at least position information on the machine base. A second feedback section outputs a second feedback command containing a filtered model torque command. A differential between the sum of the first feedback command and the second feedback command obtained by a second addition section and the model torque command is calculated to give the differential to an input portion of a model torque command low-pass filter and an input portion of a torque command low-pass filter.

Abstract: Systems and methods that determine resonant frequencies of a motor system via employing an output of a velocity regulator. The velocity regulator enables the motor drive to command the rotation of the motor at predetermined rotations, by setting rotational speeds of the motor. The output of the velocity regulator can then be stored as a function of time, and a Fast Fourier Transform performed on such time data to obtain a frequency data and a signal power spectrum.

Abstract: This invention is aimed to provide a control system for a lifting device that can lift a load that enables the operator to have a good judgment for handling the load, so that an operator can simultaneously hold and control the load. The control system of the lifting device of this invention controls the rotation of a servo motor 1 so that an operator can move a load in a direction and at a speed that he or she desires by applying a force for controlling to the load. The load is hoisted up or down or maintains its position by means of a rope 2. The rope is wound up or down by the rotation of the servo motor in the forward or the reverse direction. The system comprises a means 3 for measuring a force, a first controller means, a second controller means, and a switching means. The means for measuring measures the total force that is applied at the lower part of the rope caused by a force for controlling of the operator, the mass of the load, and the acceleration of the load.

Abstract: A damping apparatus is provided for a positioning stage that is operative to move and position an object along a motion axis. The damping apparatus comprises a motion transformation device operative to rotate the positioning stage about a rotary axis that is substantially perpendicular to the motion axis, in response to forces generated to the positioning stage during acceleration or deceleration thereof. Resilient elements connected to the positioning stage serve to reduce transmission of vibration generated from the positioning stage.

Abstract: Method and device for detecting oscillatory faults relating to an aircraft airfoil slaving chain. The device (1) comprises means for carrying out a counting of all the overshoots of a threshold value by the current value of a quantity related to the positional slaving of an airfoil (3), and for detecting an oscillatory fault as soon as the number resulting from said counting becomes greater than a predetermined number.

Abstract: In a motor-assisted hybrid vehicle, an active vibration control system suppresses torque fluctuations of an engine without detriment to the response of a static torque. An adaptive notch filter outputs a control signal depending on a harmonic basic signal generated by a basic signal generator from a rotational frequency of a crankshaft. A combiner combines the control signal with a drive signal for the generator motor and supplies the combined signal through a power controller to the generator motor. The basic signal is supplied to corrective filters having the transfer function of the generator motor to output a reference signal. The filter coefficient of an adaptive notch filter is successively updated so that an error signal representative of a rotational speed fluctuation of the crankshaft will be minimized.

Abstract: A metrology tool is arranged to measure a parameter of a substrate that has been provided with a pattern in a lithographic apparatus. The metrology tool includes a base frame, a substrate table, a sensor, a displacement system, a balance mass, and a bearing. The substrate table is constructed and arranged to hold the substrate. The sensor is constructed and arranged to measure a parameter of the substrate. The displacement system is configured to displace the substrate table or the sensor with respect to the other in a first direction. The bearing is configured to movably support the first balance mass so as to be substantially free to translate in a direction opposite of the first direction in order to counteract a displacement of the substrate table or sensor in the first direction.

Abstract: Stabilization of a stage in a movable stage apparatus is enhanced, and increasing in size of the movable stage apparatus is suppressed. A reaction force cancel system is provided in the movable stage apparatus where a stage moves on a surface plate installed on a floor via a vibration-isolating spring, and cancels a reaction force generated on the surface plate upon movement of the stage. The reaction force cancel system includes a reaction force canceling actuator for applying a counter-thrust that is a force for reducing the reaction force to the surface plate. The reaction force canceling actuator is arranged at a lower position than a top surface of the surface plate so that the surface plate hangs over the reaction force canceling actuator.

Abstract: A velocity control loop of a motor control apparatus including a notch filter. The notch filter attenuates a signal component at a central frequency from a motor driving command, and outputs the attenuated motor driving command. The driving of a motor is controlled based on the attenuated motor driving command. The central frequency of the notch filter is set equal to a frequency at which a phase of open loop frequency characteristics of the velocity control loop that does not include a notch filter is a value obtained by subtracting 180 degrees from a preset phase margin. An attenuation factor of the notch filter by which the signal component at the central frequency is attenuated is set so that a gradient of a phase diagram of the open loop frequency characteristics of the velocity control loop including the notch filter is substantially zero.

Abstract: A metrology tool is arranged to measure a parameter of a substrate that has been provided with a pattern in a lithographic apparatus. The metrology tool includes a base frame, a substrate table constructed and arranged to hold the substrate, a sensor constructed and arranged to measure a parameter of the substrate, a displacement system configured to displace the substrate table or the sensor with respect to the other in a first direction, a balance mass, and a bearing configured to movably support the first balance mass so as to be substantially free to translate in a direction opposite of the first direction in order to counteract a displacement of the substrate table or sensor in the first direction.

Abstract: A brushless motor controller for use in a fuel pump detects a rotor phase based on an induced voltage in each phase coil of a brushless motor, and controls energization of the each phase coil based on the detected rotor phase. A control circuit of the controller is arranged to check the induced voltage by using three reference voltages as judgment values, convert a result of the check into a logic signal, and detect the rotor phase based on a prescribed change of the logic signal.

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: A image stabilization control circuit for an image capturing device, wherein a gyro-equalizer (24) integrates an angular velocity signal from a gyro-sensor (12) in an integration circuit (46). The integration circuit (46) is composed of a low-boost filter (LBF), and a phase delay in a target compensation region is set to a value appropriate for an integration process. Furthermore, a characteristic whereby the LBF reduces the phase delay at higher frequencies is used, compensation is applied to the excess phase delay of the angular signal in the high-frequency region brought about by the effect of the phase delay generated in the high-frequency region by the output signal of the gyro-sensor (12), and the phase delay in the high-frequency region is brought nearer to 90 degrees. This allows the accuracy of the process for determining the required displacement magnitude of a lens to be increased.

Abstract: A method for controlling a steering system, including, receiving a first signal representative of a torque applied to a steering wheel, receiving a second signal representative of a motor velocity of a motor operatively linked to the steering wheel, multiplying the first signal with the second signal resulting in a product signal, applying a backlash function to the product signal, wherein the backlash function imparts a defined hysteresis in the system, multiplying a defined first-third quadrant scaling factor with an active damping signal, and sending a resultant motor command signal to the motor responsive to determining that the product signal is a positive signal, and multiplying a defined second-fourth quadrant scaling factor with the active damping signal, and sending the resultant motor command signal to the motor responsive to determining that the product signal is a negative signal.

Abstract: Presented is a harmonic regulator that regulates a plurality of individual harmonics in a system having periodic torque disturbances to commanded values, including zero. For each harmonic being regulated, a feedback signal having at least one harmonic component due to the harmonic being regulated is transformed from a source reference frame to a harmonic reference frame of the harmonic being regulated to form a qd feedback signal. The qd feedback signal is subtracted from the commanded value to form a qd signal and regulated. The regulated qd signal is transformed to a destination reference frame to form a compensation signal and the compensation signal is added to a control signal to form a qd control signal that drives each harmonic being regulated towards the commanded value.

Abstract: In a method of automatically setting the vibration suppression filter, when a vibration detection portion detects a vibration A2, a state variable frequency analysis portion analyzes the frequencies of data from a state variable trace portion to calculate a vibration frequency A3, and the frequency characteristics of the vibration suppression filter is set based on vibration frequency A5. A vibration level store portion stores the vibration level before the automatic setting of the vibration suppression filter, a filter setting selection portion compares the vibration level after the automatic setting with the vibration level before the automatic setting A6. When the vibration level after the automatic setting is larger than the vibration level before the automatic setting, restoring of the setting of the vibration suppression filter to the state before the automatic setting A7 and/or reducing the gain of a servo control portion.

Abstract: A metrology tool is arranged to measure a parameter of a substrate that has been provided with a pattern in a lithographic apparatus. The metrology tool includes a base frame, a substrate table constructed and arranged to hold the substrate, at least one sensor constructed and arranged to measure a parameter of the substrate, a displacement system to displace one of the substrate table and sensor with respect to the other one of the substrate table and sensor in at least a first direction, a first balance mass, and a first bearing which movably supports the first balance mass so as to be substantially free to translate in the opposite direction of the first direction in order to counteract a displacement of the one of the substrate table and sensor in the first direction.

Abstract: In order to simultaneously realize an improvement in disturbance suppression force of an electric motor control apparatus and vibration suppression of a load machine, a velocity control circuit receives a velocity command signal as a target value of velocity of an electric motor and a corrected velocity signal, obtained by correcting a velocity signal with a velocity correction signal, and outputs a torque command signal specifying target torque of the electric motor driving the load machine. A vibration suppression circuit outputs a velocity correction signal, based on an acceleration signal, indicating acceleration of the load machine. A transfer function from the acceleration signal to the torque command signal is obtained by multiplying a transfer function from a position signal, indicating position of the electric motor to the torque command signal, by a proportion characteristic having a specified gain and integration characteristic.

Abstract: A control unit of a motor driver performs feedback control to supply current to a linear motor based on a detection value of a linear encoder. An anomaly detection unit monitors the supply current to the linear motor, and the anomaly detection unit detects anomaly of a linear motion apparatus based on a waveform of the supply current. In the case where the anomaly is detected, a user is notified of warning by means of a lamp, a buzzer, an e-mail, and the like. Therefore, the anomaly of the linear motion apparatus can be detected early and accurately.

Abstract: In a method for increasing the control dynamics of a load driven by a direct drive via a driveshaft, a first transducer provides a first output signal indicating a first rotation speed, and a second transducer provides a second output signal indicating a second rotation speed. The direct drive is located between the first transducer and second transducer, with the second transducer being located in close proximity of the load. A mixed rotation speed is computed from a linear combination of the two rotation speed values, which is used as an actual control value of a controller of the direct drive. This method provides a very simple approach for increasing the control dynamics of a load driven by direct drive via a driveshaft.

Abstract: The present invention provides a control apparatus of a electric power steering apparatus which can suppress a vibration and a noise of a motor caused by a torque ripple which is generated at a tie of applying a field-weakening control to the motor or on the basis of a motor circulating current. Accordingly, the control apparatus actually measures a relation between a basic correcting current and a rotor position which can suppress the torque ripple generated at a time of applying the field-weakening control or the torque ripple based on the motor circulating current, previously, and adds a correcting current which is regulated by taking into consideration a magnitude of a weak field current of a correcting current, a magnitude of an angular velocity of the rotor or an electrical angle of the circulating current with respect to the basic correcting current, to an original current command value.

Abstract: A damping apparatus is provided for a positioning stage that is operative to move and position an object along a motion axis. The damping apparatus comprises a motion transformation device operative to rotate the positioning stage about a rotary axis that is substantially perpendicular to the motion axis, in response to forces generated to the positioning stage during acceleration or deceleration thereof. Resilient elements connected to the positioning stage serve to reduce transmission of vibration generated from the positioning stage.

Abstract: The present invention provides a circuit for monitoring harmonic distortion in the power supply of a synchronous electrical machine with permanent magnet excitation that comprises a rotor without a damper cage, a stator with first, second, and third windings, a frequency converter, and control circuits for controlling the frequency converter.

Abstract: It is an object of the present invention to provide a method for extracting a maximum gain of a servo controller in which while a machine is vibrated by raising a control gain, the vibration is rapidly detected so that the machine does not greatly vibrate or noise is not generated. In a method for extracting a maximum gain of a servo controller for driving a servo motor, a simulated disturbance torque is applied to a torque command by a vibrating unit while a control gain is raised and the vibration of a control system is detected by a vibration detecting unit (1). A process for applying the simulated disturbance torque is repeated while the control gain is raised until the vibration of a prescribed level is detected. The control gain when the vibration detecting unit (1) detects the vibration exceeding the prescribed level is set as a maximum gain.