Abstract: Since an abnormality is judged by executing a square calculating process with respect to sin ? and cos ? for detecting an abnormality in an angular resolver, a processing time is elongated, and a burden to a CPU is great. Since the invention prepares a map which can judge whether the combination of sin ? and cos ? is normal or abnormal, and judges by mapping the combination of the detected sin ? and cos ?, a process can be easily executed, a processing speed is high, and a burden to the CPU can be reduced. Further, an assist can be maintained by controlling a motor by a rectangular wave current by detecting a rotation angle signal at low resolution level, such as Hall sensors arranged around the motor.

Abstract: A system and method for extracting estimated input voltage and input current values of an AC motor based on sensed power inverter output voltage and output current when the AC motor is connected to a front-end EMI filter and the EMI filter is connected to a power inverter. Where the system includes a current estimator portion, and a voltage estimator portion. The estimated input values are used by a feedback controller in the power inverter to control the motor. A second system and method for extracting estimated an input current of an AC motor based on the actual motor input voltage, and the output voltage of the power inverter.

Abstract: A guided stage mechanism suitable for supporting a reticle in a photolithography machine includes a stage movable in the X-Y directions on a base. Laterally surrounding the stage is a rectangular window frame guide which is driven in the X-axis direction on two fixed guides by means of motor coils on the window frame guide cooperating with magnetic tracks fixed on the base. The stage is driven inside the window frame guide in the Y-axis direction by motor coils located on the stage cooperating with magnetic tracks located on the window frame guide. Forces from the drive motors of both the window frame guide and the stage are transmitted through the center of gravity of the stage, thereby eliminating unwanted moments of inertia. Additionally, reaction forces caused by the drive motors are isolated from the projection lens and the alignment portions of the photolithography machine.

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: Systems and methods are presented that cancel the dynamics of a motor and a joint controller in the presence of communication time delays, measurement noise, and controller parameter uncertainties inherent in a robot system. A cancellation system includes feedback of the measured output Ê of a controller block C. A first summing node (?1) subtracts Ê from the desired voltage Ed to determine a voltage error, which is fed into a G(s) block. A second summing node (?2) adds the output of the G(s) block to the desired voltage Ed to generate the signal ?, which is fed into a non-robust controller inversion block C?1. The block C?1 outputs a value ?, which is fed into the block C. The block C outputs the actual voltage E, which is input into a motor block M. Under perfect conditions, the voltage error is zero, in which case the input to block G(s) is zero.

Abstract: Method of controlling a movable member driven by an electric motor by monitoring current circulating through the electric current and ripples therein. The method including detecting current peaks and count the number of current peaks falling within sampling windows such that the number of current peaks falling within the sampling windows are used to determine an angular position of the electric motor for use in facilitating the control thereof.

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: 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: An external force estimation system for estimating an external force acting upon a robot apparatus which includes a machine body which in turn includes a plurality of movable joints is disclosed which includes a distribution type contacting state detection section, an actuator current state measurement section, a motion state measurement section, a motion equation setting section, a known term calculation section, and an external force estimation section.

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 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: An integrated torsional mode damping method for a current source converter, including a rectifier, an inverter, and a DC link inductor coupled between the rectifier and the inverter, includes sensing a signal representative of torque on a shaft coupled to the inverter or rectifier; using the sensed signal for detecting a presence of a torsional vibration on the shaft; and damping the torsional vibration by modulating active power through the respective inverter or rectifier.

Abstract: The invention provides techniques for reducing or altering the magnetic noise of an AC rotary electric machine. A magnetic noise reducing harmonic current of order n, whose frequency is n times the frequency of the fundamental frequency component of a polyphase AC current fed to an armature of a polyphase AC rotary electric machine, is superimposed on the polyphase AC current, thereby reducing or altering a harmonic component having a frequency (n?1) times the frequency of the fundamental frequency component and occurring due to a radial magnetic excitation force acting radially on an iron core of the AC rotary electric machine.

Abstract: A controller for controlling an actuator device which is installed on a vehicle and operated by a motor. The controller includes: a motor control portion operable to control the motor on the basis of a target value; and a target-value determining portion operable to determine the target value on the basis of a wave intensity characteristic. The wave intensity characteristic is represented by a relationship between (A) a propagated wave intensity indicative of an intensity of a wave which is generated as a result of activation of the actuator device and which is propagated to occupant of the vehicle, and (B) an output index indicative of an amount of an output of the motor. Also disclosed is a wave-intensity-characteristic obtainer for obtaining the wave intensity characteristic by measuring the intensity of the wave.

Abstract: A motor drive control apparatus for driving and controlling a linear vibration motor having a mover supported by a spring, with an AC current. The motor drive control apparatus includes a waveform creation unit for creating a comparative current waveform to be a reference of a driving current for the linear vibration motor based on the operating condition of the linear vibration motor, a current detector for detecting the driving current, and a controller for controlling a driving voltage of the linear vibration motor so that a difference between the comparative current waveform and a waveform of the current detected by the current detector becomes zero. The frequency of the driving current is controlled to be close to the resonance frequency of the linear vibration motor, based on the comparative current waveform.

Abstract: Torque pulsations generated in the torque of an engine are obtained from detection signals from a crankshaft angle detection sensor and an engine water temperature detection sensor at the time of an engine starting operation. A control unit controls an MG1 via a drive circuit so that a damping torque of the same phase as the torque pulsations is generated, and ensures that the torque pulsations of the engine are not transmitted to a ring gear from a planetary carrier.

Abstract: Filter network for the reduction of the voltage switching speed between an electrical motor drive and an electrical motor and/or between an electrical distribution network and a motor drive, comprising for each electrical phase a self-damped inductor having a complex impedance determined by a magnitude (Z) and a phase (?), the phase (?) of the complex impedance being comprised between 80 and 90 degrees in the frequency range of the motor's current, and being less than 60 degrees in the frequency range of the overvoltage oscillations. Using the inventive filter network, it is possible to manufacture low cost and small size du/dt-filters generating low voltage overshoot and low losses.

Abstract: Oscillation and other disturbance damping is provided for a system having a load driven by an electric motor, e.g., an electromagnetic actuator. Damping is achieved using feedback in an active mode, where power is supplied in a normal operation mode of the electromagnetic actuator. Feedback may be provided by measured force (or torque) transmitted between the actuator and load mass. A gear train or other mechanical advantage device may be connected between the electromagnetic actuator output and load, this combination forming an electromechanical actuator (EMA). Instead of force or torque, acceleration of the load may be used as a feedback signal. In one embodiment, active mode damping uses the motor's actual current as a feedback signal. In certain or all active damping versions of the invention, a high pass filter is preferably used to receive feedback signals and filter out low frequency feedback. Alternatively, damping is achieved in an inactive (passive) mode of motor operation, e.g.

Abstract: A motor controller system uses a rotary sensor with a plurality of signal conditioning units, coupled to the rotary sensor. Each of these units, which is associated with a particular range of motor output shaft rotation rates, generate a feedback signal indicative of the position of the motor's output shaft. A controller (i) converts a selected motor output shaft rotation rate to a corresponding incremental amount of rotational movement for a selected fixed time period, (ii) selects, at periodic completions of the selected fixed time period, the feedback signal from one of the signal conditioning units for which the particular range of motor output shaft rotation rates associated therewith encompasses the selected motor output shaft rotation rate, and (iii) generates a motor drive signal based on a difference between the incremental amount of rotational movement and the feedback signal from the selected one of the signal conditioning units.

Abstract: A lithographic projection apparatus in which a reaction force is generated between a balance mass and a substrate table. The balance mass is elastically coupled to the base frame with a suspension eigenfrequency of between 0.3 and 10 Hz.

Abstract: A motor controller having a damper that dampens resonance in a motor drive of a common mode filter to prevent it from becoming over excited by operation of the motor drive at a resonant frequency of the common mode filter. The damper is connected to an output feeder line of a motor drive in the motor controller and provides a common mode path to ground for the common mode filter. Thus, even if the motor drive is operating at a resonant frequency of the common mode filter, the resulting resonance in the common mode filter is attenuated by rather than amplified by the common mode filter, thereby preventing the common mode filter from excessive excitation.

Abstract: An automobile servomotor controller includes a master control unit having a master control circuit for transmitting a designation signal and a slave unit having a motor and a control circuit which controls driving of a motor by outputting an operation signal to a driving device depending upon said designation signal. The slave unit is constructed by a same feedback control unit having a non-feedback control unit for inhibiting the operation of the motor until a target is changed by an input of a new designation signal with a target reached state and a feedback control unit for driving the motor to reach a target state by detecting a present position value with a position detecting device, and a control inhibiting signal for inhibiting the feedback control is individually provided to the designation signal transmitted from the master control circuit to the non-feedback control unit.

Abstract: It is a biped (two-footed) walking humanoid robot, which is provided with drive motors (11d, 11e, 18L, 18R-24L, 24R, 28L, 28R-33L, 33R, 35, 36) to pivotally move respective joint portions, and a motion control apparatus (40) to drive-control respective drive motors, and said motion control apparatus (40), together with a detector (45) to detect the robot's current posture and others, compares the robot's detected current posture and others with next motion command input from outside, and if next motion command is within the range of stability limit with respect to the robot's current posture and others, the complementary data with respect to intermediate motion from current posture till initial posture of next motion command and the motion data corresponding to next motion command are generated, each drive motor is drive-controlled based on said complementary and motion data, and thereby various motions are conducted smoothly and continually.

Abstract: A control constant adjusting apparatus in a control apparatus of a robot or a machine tool, etc. is disclosed. This control constant adjusting apparatus includes a speed control part (12), an estimation part (13), an identification part (14) and an adjustment part (15). The identification part (14) makes identification of inertia J obtained from a ratio between a value |SFTr| in which an absolute value |FTr| of a value FTr obtained by passing a torque command Tref of the speed control part (12) through a predetermined high-pass filter is integrated with respect to time at a predetermined interval [a, b] and a value |SFTr?| in which an absolute value |Ftr?| of a value FTr? obtained by passing a model torque command Tref? of the estimation part (13) through a predetermined high-pass filter is integrated with respect to time at the same interval only when a speed Vfb? of a model in the estimation part (13) matches with a motor speed Vfb in the speed control part (12) at a value other than zero.

Abstract: A stepping motor driving system includes: a stepping motor that rotates at a predetermined angle according to a driving pulse signal, a vibration detector that detects vibration to output a vibration signal, and a stepping motor control unit that controls the driving pulse signal, which is applied to the stepping motor, to rotate the stepping motor at the predetermined angle. The driving pulse signal includes a start-up current which is required for rotating the stepping motor at a unit angle and a holding current which maintains a rotational angle of the stepping motor rotated by the start-up current. The stepping motor control unit changes the level of the holding current according to the vibration signal which is outputted from the vibration detector.

Abstract: The invention concerns a method for stabilizing the motion of an articulated chain of a chain block, especially to prevent the formation of resonance oscillation of the chain, in which an articulated chain is led across a polygonal chain wheel with non-uniform pitch, which is driven by an electric motor. In order to create a method to prevent the formation of a resonance oscillation of the articulated chain, it is proposed that a periodic and/or stochastic and dampening actuating variable is superimposed on the velocity of the chain wheel (4) and the dampening actuating variable produces a change in the chain velocity so as to prevent a formation of a resonance oscillation. The chain drive with reduced polygon effect is characterized in that an electronic damper (8) is hooked up in front of the electric motor (2), which produces a control of the electric motor (2) such that a formation of a resonance oscillation of the articulated chain (5) is prevented.

Abstract: A scanning exposure method moves a mask stage in a scanning direction by a driver having a first portion coupled to the mask stage, which includes a reflective portion positioned along the scanning direction. A counter weight having at least one beam extending along the scanning direction, moves in a direction opposite to the mask stage in response to a reaction force generated by movement of the mask stage by the driver. The at least one beam of the counter weight is coupled to a second portion of the driver. The counter weight is movably supported via a first bearing by a base member. The movement of the counter weight is guided in the scanning direction via a second bearing by a guide mounted on the base member and extending along the scanning direction. A length of the guide is longer than a length of the reflective portion.

Abstract: A system and method for reducing torque ripple in a motor controller includes a step (60) of measuring an output voltage at each phase of the motor controller. A next step (61) includes determining a voltage mismatch between the phases. A next step (62) includes phase grounding one phase of the motor. A next step (63) includes calculating a voltage gain for the phases to compensate for voltage mismatches therebetween. The compensating gain can include a gain and/or offset, which are applied as a function of motor angle and is used to generate a PWM signal for driving the motor with reduced torque ripple.

Abstract: An electromagnetic suspension system for a vehicle, comprises an electromagnetic actuator interposed between a sprung mass and an unsprung mass and disposed substantially in parallel with an spring element. An electric motor is provided for driving the electromagnetic actuator. A motor controller is configured to calculate a displacement input applied to the electromagnetic actuator and to control the electric motor in a manner that the electromagnetic actuator generates an optimum damping force corresponding to the displacement input. A motor control circuit is provided for the electric motor, through which the electric motor is connected to the motor controller. Additionally, an electrical damping element is electrically connected to the motor control circuit and in parallel with the electric motor to generate a damping force in a passive manner under a dynamic braking of the electric motor in response to the displacement input to the electromagnetic actuator from the unsprung mass.

Abstract: To appropriately detect overload which may break a motor or deform a body and reduce the overload in the motor. The DC component of a load torque is derived from the sum of absolute values of a torque applied to a link connected to the output shaft of a motor and the generated torque of the motor, and it is determined that overload has been applied when the DC component exceeds a first threshold value for a prescribed period of time or longer. In addition, considering such a characteristic that the variation of energy applied to the output shaft of a motor is in proportion to a product of the torque and the angular velocity of the motor, the AC component of the load torque is detected based on the variation of energy, and it is predicted that overload will be applied when the AC component exceeds a second threshold value.

Abstract: To appropriately detect overload which may break a motor or deform a body and reduce the overload in the motor. The DC component of a load torque is derived from the sum of absolute values of a torque applied to a link connected to the output shaft of a motor and the generated torque of the motor, and it is determined that overload has been applied when the DC component exceeds a first threshold value for a prescribed period of time or longer. In addition, considering such a characteristic that the variation of energy applied to the output shaft of a motor is in proportion to a product of the torque and the angular velocity of the motor, the AC component of the load torque is detected based on the variation of energy, and it is predicted that overload will be applied when the AC component exceeds a second threshold value.

Abstract: To appropriately detect overload which may break a motor or deform a body and reduce the overload in the motor. The DC component of a load torque is derived from the sum of absolute values of a torque applied to a link connected to the output shaft of a motor and the generated torque of the motor, and it is determined that overload has been applied when the DC component exceeds a first threshold value for a prescribed period of time or longer. In addition, considering such a characteristic that the variation of energy applied to the output shaft of a motor is in proportion to a product of the torque and the angular velocity of the motor, the AC component of the load torque is detected based on the variation of energy, and it is predicted that overload will be applied when the AC component exceeds a second threshold value.

Abstract: To appropriately detect overload which may break a motor or deform a body and reduce the overload in the motor. The DC component of a load torque is derived from the sum of absolute values of a torque applied to a link connected to the output shaft of a motor and the generated torque of the motor, and it is determined that overload has been applied when the DC component exceeds a first threshold value for a prescribed period of time or longer. In addition, considering such a characteristic that the variation of energy applied to the output shaft of a motor is in proportion to a product of the torque and the angular velocity of the motor, the AC component of the load torque is detected based on the variation of energy, and it is predicted that overload will be applied when the AC component exceeds a second threshold value.

Abstract: To appropriately detect overload which may break a motor or deform a body and reduce the overload in the motor. The DC component of a load torque is derived from the sum of absolute values of a torque applied to a link connected to the output shaft of a motor and the generated torque of the motor, and it is determined that overload has been applied when the DC component exceeds a first threshold value for a prescribed period of time or longer. In addition, considering such a characteristic that the variation of energy applied to the output shaft of a motor is in proportion to a product of the torque and the angular velocity of the motor, the AC component of the load torque is detected based on the variation of energy, and it is predicted that overload will be applied when the AC component exceeds a second threshold value.

Abstract: A pre-compensator is provided based on a definition of abase vibration model having a motor transfer function 1 for generating motor displacement 12 from an input that is the sum of input torque and a table propelling force 10 multiplied with a reducer and Cartesian-to-polar coordinate transformation constant 14, a table transfer function 14 for multiplying a deviation 11 between an output that is the motor displacement multiplied with a reducer and polar-to-Cartesian coordinate transformation constant 2 and table displacement with a table-displacement-to-force conversion spring constant 3 to generate the table propelling force 10 and to output table displacement 7, and a base driving transfer function 5 for generating base displacement by multiplying base displacement 9 with a base-displacement-to-force conversion spring coefficient 6 and inputting the same with the table propelling force, table displacement 8 being generated from a difference between the table displacement and the base displacement.

Abstract: To appropriately detect overload which may break a motor or deform a body and reduce the overload in the motor. The DC component of a load torque is derived from the sum of absolute values of a torque applied to a link connected to the output shaft of a motor and the generated torque of the motor, and it is determined that overload has been applied when the DC component exceeds a first threshold value for a prescribed period of time or longer. In addition, considering such a characteristic that the variation of energy applied to the output shaft of a motor is in proportion to a product of the torque and the angular velocity of the motor, the AC component of the load torque is detected based on the variation of energy, and it is predicted that overload will be applied when the AC component exceeds a second threshold value.

Abstract: To appropriately detect overload which may break a motor or deform a body and reduce the overload in the motor. The DC component of a load torque is derived from the sum of absolute values of a torque applied to a link connected to the output shaft of a motor and the generated torque of the motor, and it is determined that overload has been applied when the DC component exceeds a first threshold value for a prescribed period of time or longer. In addition, considering such a characteristic that the variation of energy applied to the output shaft of a motor is in proportion to a product of the torque and the angular velocity of the motor, the AC component of the load torque is detected based on the variation of energy, and it is predicted that overload will be applied when the AC component exceeds a second threshold value.

Abstract: To appropriately detect overload which may break a motor or deform a body and reduce the overload in the motor. The DC component of a load torque is derived from the sum of absolute values of a torque applied to a link connected to the output shaft of a motor and the generated torque of the motor, and it is determined that overload has been applied when the DC component exceeds a first threshold value for a prescribed period of time or longer. In addition, considering such a characteristic that the variation of energy applied to the output shaft of a motor is in proportion to a product of the torque and the angular velocity of the motor, the AC component of the load torque is detected based on the variation of energy, and it is predicted that overload will be applied when the AC component exceeds a second threshold value.

Abstract: An apparatus and method for compensating actuator arm oscillation induced by resonance mode excitation during a seek in a disc drive data handling system. The actuator arm supports a head adjacent a recording surface, and a servo loop controls the position of the actuator arm. A frequency of actuator arm oscillation is identified, after which a seek is initiated to move the head from an initial track to a destination track on the recording surface. A position error signal (PES) is generated to indicate position of the head relative to the destination track, and a compensation signal is generated by a filter based on the PES and the frequency of oscillation of the actuator arm. The compensation signal is adapted to remove a component of the PES arising from the actuator arm oscillation, and is applied to the servo loop as the head is settled onto the destination track.

Abstract: A mask having a mask pattern is provided on a mask table. A substrate is provided on a substrate table. The mask is irradiated to project an image of at least a portion of the mask pattern onto a radiation-sensitive layer of the substrate using a projection system. At least one of the mask and substrate tables is positioned using a drive unit having a stationary part coupled to a reaction frame. A position of at least one of the mask and substrate tables is measured using a measuring system having a plurality of measurement sensors that have a stationary part and a movable part. The movable part of one of the sensors is coupled to the one of the mask table and the substrate table whose position is measured, and the stationary parts of the sensors are coupled to a support frame mechanically isolated from the reaction frame.

Abstract: A stage assembly (10) for independently moving and positioning a first device (26A) and a second device (26A) in an operation area (25) is provided herein. The stage assembly (10) includes a stage base (12), a first stage (14), a first mover assembly (15), a second stage (16), and a second mover assembly (18). The first mover assembly (15) moves the first stage (14) and the first device (26A) into the operational area (25) and the second mover assembly (18) moves the second stage (16) and the second device (26B) into the operational area (25). The present stage assembly (10) reduces and minimizes the amount of reaction forces and disturbances that are transferred between the stages (14), (16). This improves the positioning performance of the stage assembly (10). Further, for an exposure apparatus (30), this allows for more accurate positioning of two semiconductor wafers (28) relative to a reticle (32) or some other reference.

Abstract: To eliminate unwanted vibrations caused by synchronous disturbances, such as synchronous disturbances caused by an imbalance, for example, the invention proposes a compensation device for closed loop compensation of a synchronous disturbance in a rotating machine comprising a rotor (64) magnetically suspended by at least one radial magnetic bearing (63) comprising electromagnets (631, 632) driven by amplifiers (61, 62), a radial detector device (633, 634) for sensing the axial position of the rotor, and a closed loop servocontrol circuit connected to said detector device and to said electromagnets and comprising a control circuit (5) for controlling the energization of the electromagnets that supplies a control signal (u) to said amplifiers in response to signals supplied by the detector device to maintain the rotor in a predetermined axial position. The compensation device comprises means (100; 200; 300) for generating a signal for compensating the synchronous disturbance.

Abstract: A closed-loop control system that remotely controls a device over a distributed communications system includes a device that is connected to the distributed communications system and that generates super-media feedback signals. A computer is connected to the distributed communications system and includes a controller that provides super-media feedback. The computer generates and transmits command signals using the controller to the device and outputs the super-media feedback signals to the controller. The closed-loop control system is event-based to ensure stability and synchronization of the closed-loop system.

Abstract: An interface component for a positioning system. The interface component includes a positioning arm having a first end and a second end, the first end being positionable against an object to be positioned and the second end being attachable to an actuator arm of the positioning system, and a damping element operably connected in parallel with the positioning arm.

Abstract: A method for determining at least one time constant of a reference model, which is designed as a 2nd order time-delay element of a machine. The method includes detecting an oscillation frequency of an undamped machine oscillation and determining an optimized value of a time constant of the reference model as a function of the detected oscillation frequency of the undamped machine oscillation.

Abstract: A lithographic projection apparatus in which a reaction force is generated between a balance mass and a substrate table. The balance mass is elastically coupled to the base frame with a suspension eigenfrequency of between 0.3 and 10 Hz.

Abstract: A resonance frequency detector for an electric motor controller in which a resonance frequency can be measured at high speed by a simple calculation and the resonance frequency can be detected by an inexpensive computer is provided. In an electric motor control system including an electric motor (3) for driving a machine, a detecting unit (5) for detecting an amount of operation of the machine (3) and a controller (2) for receiving a control command to drive the electric motor (3), a command generator (1) generates a sweep sine wave signal to input the signal to the electric motor control system, and the frequency information of the sweep sine wave signal outputted by the command generator (1) and the signal of the detecting unit (5) are inputted to output the frequency of the sweep sine wave signal when the absolute value of the signal of the detecting unit (5) becomes maximum as a resonance frequency.

Abstract: A machine model estimating device of an electric motor control apparatus having an electric motor for driving a load machine, a rotation detector for detecting a rotating angle of the electric motor, and a servo control device for controlling the electric motor. The machine has a calculating device for outputting an operation command signal for operating the electric motor to the servo control device, and frequency characteristic equations for a rigid body model and an N-inertia model, N being an integer which is equal to or greater than 2, which are previously input to the calculating device. The calculating device includes a frequency characteristic measuring section, a frequency characteristic peak detecting section, an attenuation estimation value analyzing section, a frequency characteristic error calculating section, and a machine model deciding section.

Abstract: Damping of mechanical oscillation in a shaft that is provided by feedback wherein the output signals of multiple feedback devices are negatively coupled and added to a desired speed signal of a motor speed controller of the driving motor is disclosed. At least one sensor and/or measuring system can be provided for measuring an actual position value. The actual speed of the shaft can be determined by differentiation from the shaft position value measurements or by integration from shaft acceleration measurements. The measured or actual speed of the shaft can be supplied as an input signal to each feedback element. Each feedback element is specifically tuned to an oscillation frequency range of the shaft that is to be damped. The invention provides an easy and cost-effective way of damping mechanical oscillations that have limited frequency ranges.

Abstract: According to the invention, the controller cascades are suitably divided up and the oscillation damped only in the load rotational-speed controller. Here, a motor rotational-speed setpoint value (z) of a quickly regulated motor rotational-speed controller (9) and not the motor torque, is selected as the connection point for a load acceleration (i). In order to achieve a shorter transient response time, according the invention the difference between a setpoint rotational speed (x) and load rotational speed (y) is connected to the motor rotational-speed setpoint value (z). The solution in principle according to the invention which is presented has, in contrast to other known methods, the advantage that the actuation of the corresponding controllers is comparatively simple with very good control results.