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: An inverter supply voltage generator comprises an inverter supply voltage computing unit 10, a voltage converter 11 and a battery 12. The inverter supply voltage generator varies inverter supply voltage Vdc in synchronization with motor-application voltages Vu_pwm, Vv_pwm, and Vw_pwm. Thus, the degree of freedom of the switching operation of a PWM inverter 13 is increased, an inverter loss and the size of the PWM inverter 13 can be reduced, and its efficiency can be enhanced without deteriorating the driving efficiency of an IPM motor 14.

Abstract: The present invention relates to apparatus achieving improvement in operation characteristics in the operation of stopping or reversing the direction of or decelerating movement of a vibrating wave actuator constructed to apply an alternating voltage to an electro-mechanical energy conversion element to vibrate a vibration member to obtain a driving force. In the operation of stopping the vibrating wave actuator, it is necessary to cancel the vibration to stop the actuator, in order to stop the actuator in good response. The present invention has achieved the above object by applying an excitation signal, which excites vibration in a direction to cancel free vibration in the vibration member, to the electro-mechanical energy conversion element in the stop operation or the like.

Abstract: A vibration generator system is capable of generating vibrations of a frequency that can be bodily sensed by humans, notwithstanding a small size, and making setting of a configuration of vibrations easy. When a drive signal composed of a set of an accumulation signal and a damping signal is given as a natural frequency of a movable body, a vibrational waveform of the movable body makes an envelope. Since a frequency of the envelope is in a lower frequency band than the natural frequency of the movable body, humans can surely sense vibrations. When the number of and a current quantity of excitation signals and reverse excitation signals included in the accumulation signal are changed and the number of and a current quantity of inhibition signals and reverse inhibition signals included in the damping signal are changed, the envelope can be changed in frequency and amplitude, so that it becomes possible to generate a variety of vibrations.

Abstract: An apparatus for driving a linear vibration motor that employs a proper motor thrust constant value corresponding to each linear vibration motor at position calculation for obtaining the position of the mover of the linear vibration motor, thereby increasing the accuracy of the position calculation. This motor driving apparatus includes a motor driver for applying a DC voltage to the linear vibration motor, and a thrust detection unit for detecting a thrust of the mover, which is generated by the application of the DC voltage to the linear vibration motor, and calculates the thrust constant of the linear vibration motor according to an arithmetic operation of dividing the mover thrust detected by the thrust detection unit, by a value of a DC current that is supplied to the linear vibration motor due to the application of the DC voltage to the linear vibration motor.

Abstract: This disclosure relates to a technique for smoothly carrying out an acceleration operation and a deceleration operation for a vibration type actuator to prevent a situation where in starting the vibration type actuator, a drive frequency is reduced to become lower than a resonance frequency to stop the vibration type actuator. A first counter performs up-count from a first value to a second value larger than the first value at predetermined time intervals in accelerating the vibration type actuator. A rate multiplier outputs a clock signal having a frequency corresponding to the count value. A second counter measures a period of a pulse signal, the period being adapted to change in correspondence to a drive speed of the vibration type actuator, by counting the clock pulses. The drive speed of the vibration type actuator is controlled such that the measured pulse period becomes a predetermined target value.

Abstract: A method and system for reducing the stepping disturbances generated by a stepping mechanism is disclosed. The method is to select a desired stepping rate to step the stepping mechanism. The method further selects two desired disturbance stepping rates, one fast stepping rate and one slow stepping rate to alternate stepping of the mechanism with the two stepping rates to generate an average stepping rate that is required for the mechanism, and thereby the stepping mechanism will not significantly excite the spacecraft structural mode, and the stepping disturbance is significantly reduced while the mechanism still perform nominally its desired stepping maneuvers.

Abstract: Load cycle oscillations in the drive train of a motor vehicle are reduced by detecting a change in available torque in the drive train, determining the period of a load cycle oscillation, and, at the commencement of the available torque change, applying at least one additional torque pulse, which causes an oscillation in phase opposition to the load cycle oscillation and which lasts half the period of the load cycle oscillation.

Abstract: In order to remove vibration or improve a vibration control effect, and achieve device size reduction, an adjusting device is provided in which a weight of a support target object is supported by a pressure of an internal gas of a first chamber gas via a holding member and which adjusts a position in a gravity direction of the holding member by driving a movable member which changes an internal volume of the first gas chamber by changing an internal volume of a second gas chamber based on a state change of at least one of first and second gas chambers. Because of this, when the holding member is displaced in the gravity direction because of the vibration or the like, as the movable member is driven by the adjusting device, the holding member is maintained at an original position.

Abstract: The present invention provides an improved design of linear motor as well as an improved control strategy. The design allows for a shorted stator, where the armature magnets are controlled to reciprocate to a greater maximum displacement that for a equivalent conventional linear motor. The control strategy is such that a minimum of external sensors are required. The linear motor is driven at its resonant frequency ensuring optionally efficient operation. A determination of the maximum current is made based on a relationship with the resonant frequency and the evaporating temperature/pressure of the vapor entering the compressor. The current is then limited to control the maximum displacement to avoid damage.

Abstract: In order to quickly stop vibration of a vibrator of a vibrator controlling circuit, according to the present invention, an intermittent signal is generated by a spring vibration control integrated circuit, a switching element is turned on/off based on the intermittent signal from the spring vibration control integrated circuit, an intermittent electric current is supplied to a spring vibrator by switching of the switching circuit and the spring vibrator is vibrated. When vibration of the spring vibrator is stopped, a signal opposite to that when the spring vibrator is vibrated is applied from the spring vibration control integrated circuit to the switching element so as to cause the spring vibrator to generate a force to attenuate vibration and to stop the vibrator from vibrating.

Abstract: A brushless motor-driving circuit is disclosed which includes an initializing element setting an initial rotating speed, an oscillating element for generating a frequency corresponding to the initial rotating speed set by the initializing element, a frequency-controlling element for causing the frequency generated by the oscillating element to change from the frequency corresponding to the initial rotating speed to a frequency corresponding to a constant rotating speed, a driving-signal-generating element for generating driving signals having a plurality of phases based on the generated frequency of the oscillating element, and a driving element for driving coils having a plurality of phases based on the driving signals having the plurality of phases generated by the driving-signal-generating element.

Abstract: A non-reciprocal circuit element and a method for manufacturing the same are provided to controls a magnetic flux density between first and second yokes and reduce variation in resonant frequency. The non-reciprocal circuit element includes a first yoke for covering a magnetic, and a second yoke which is disposed below the ferrite member and forms a closed magnetic circuit together with the first yoke. A gap capable of controlling the magnetic flux is provided between the first and second yokes, making it possible to change the gap width of the gap G, thereby adjusting the magnetic flux between the first and second yokes.

Abstract: An antivibration apparatus for a rotary element, including an active mass vibration absorber actuated by a controller which generates a control signal by extracting harmonics of a rotation frequency of the rotary element. The controller determines a phase shift and an amplification as predetermined functions of the rotation frequency, and applies the phase shift and amplification to the harmonics of the input signal for obtaining the control signal.

Abstract: The invention relates to a linear motor with a control system for the translator which is provided with a function-approximator for approximating a function related to the movement of the translator for the purpose of determining the control signal. The function-approximator operates in accordance with the “Support Vector Machine” principle.

Abstract: Disclosed are a magnetic bearing device with a vibration restraining function, a magnetic bearing device with a vibration estimating function, and a pump device with the magnetic bearing devices mounted thereto, in which it is possible to realize a reduction in vibration in the apparatus system as a whole inclusive of the equipment associated with the vacuum pump without newly providing a vibration sensor. In a vibration detector, a multiplication result obtained by multiplying the Laplace transformation of a displacement of a rotor by a predetermined transfer function is added to a multiplication result obtained by multiplying the Laplace transformation of a variation in an unbalance force acting on the rotor by the reciprocal of the mass of the rotor. The result of this calculation is reversed in polarity and is added to the output of a compensator by an adder.

Abstract: An apparatus for driving a linear vibration motor that employs a proper motor thrust constant value corresponding to each linear vibration motor at position calculation for obtaining the position of the mover of the linear vibration motor, thereby increasing the accuracy of the position calculation. This motor driving apparatus includes a motor driver for applying a DC voltage to the linear vibration motor, and a thrust detection unit for detecting a thrust of the mover, which is generated by the application of the DC voltage to the linear vibration motor, and calculates the thrust constant of the linear vibration motor according to an arithmetic operation of dividing the mover thrust detected by the thrust detection unit, by a value of a DC current that is supplied to the linear vibration motor due to the application of the DC voltage to the linear vibration motor.

Abstract: A motor driving apparatus for driving a linear vibration motor is provided with an order output determining unit for determining a motor output required of the linear vibration motor, and a driving frequency determining unit for determining a driving frequency of the linear vibration motor on the basis of the determined motor output, and an amplitude-fixed AC voltage having a frequency equal to the determined driving frequency is applied to the linear vibration motor, whereby the output of the linear vibration motor can be controlled without changing the amplitude value of the driving voltage applied to the linear vibration motor.

Abstract: A system and method are used to levitate and translate a stage within a chamber using a motor assembly coupled to a balance mass assembly. The balance mass assembly is positioned adjacent the chamber. The motor assembly includes a stator and a coil. One of the stator and the coil are coupled to the stage on a first side of a wall of the chamber. The other of the stator and the coil are coupled to the balance mass assembly on a second side of the wall of the chamber. A magnetic assembly coupled to the stage allows the stage to levitate within the chamber. Once levitated, the stage is translated based on the interaction of the magnets and an energized coil.

Abstract: A vibrating linear actuator includes a mover having a permanent magnet, a stator having coils, a base on which the stator is mounted, a cover, and lands electrically coupled to the coils. The lands are provided on the surface of one of the base or the cover.

Abstract: The present invention discloses a control apparatus for a vibration type actuator that can perform the drive of a driven member in a short time. The control apparatus for a vibration type actuator that excites vibration in a vibration body by applying a frequency signal to an electro-mechanical energy converting element and relativity moves the vibration body and a contact body contacting to this vibration body includes a determination unit determining the drive direction of the vibration type actuator, and a frequency setting unit modifying a frequency of the frequency signal according to whether the drive direction of the vibration type actuator determined by the determination unit is the same as or reverse to the last drive direction at the startup of the vibration type actuator.

Abstract: A high-speed precision positioning apparatus has a stage supported by a platen. The stage is driven by a plurality of drive motors that are co-planar with the stage and arranged symmetrically around the stage. The drive motors apply drive forces directly to the stage without any mechanical contact to the stage. The drive forces impart planar motion to the stage in at least three degrees of freedom of motion. In the remaining three degrees of freedom the motion is constrained by a plurality of fluid bearings that operate between the stage and the platen. The drive motors are configured as magnets, attached to the stage, moving in a gap formed in-between top and bottom stationary coils. Integral force cancellation is implemented by a force cancellation system that applies cancellation forces to the stage. The cancellation forces, which are co-planar with a center of gravity of the stage and any components that move with the stage, cancel forces generated by planar motion of the stage.

Abstract: An impact tool control method and apparatus and an impact tool using the same. Pulses of torque applied to a fastener by the impact tool are measured. The duration and magnitude of the torque pulse are subtracted from a torque signal and the resulting difference is integrated over time to obtain a fastener angular velocity signal. The angular velocity signal is integrated over time to obtain a displacement signal which can be converted to a torque signal. The impact tool can be controlled based on the value of the torque signal.

Abstract: In order to quickly stop vibration of a vibrator of a vibrator controlling circuit, according to the present invention, an intermittent signal is generated by a spring vibration control integrated circuit, a switching element is turned on/off based on the intermittent signal from the spring vibration control integrated circuit, an intermittent electric current is supplied to a spring vibrator by switching of the switching circuit and the spring vibrator is vibrated. When vibration of the spring vibrator is stopped, a signal opposite to that when the spring vibrator is vibrated is applied from the spring vibration control integrated circuit to the switching element so as to cause the spring vibrator to generate a force to attenuate vibration and to stop the vibrator from vibrating.

Abstract: The present invention discloses a system for non-contact measurement of vibrational motion in a vibratory compacting machine. The system includes a vibrating element such as a roller drum adapted for vibrational motion and a non-contact sensor positioned a distance from the vibrating element and adapted for sensing the vibrational motion of the vibrating element. The present invention also discloses a method for non-contact measurement of vibrational motion of a vibrating element in a vibrating element that includes sensing position information of the roller drum with a non-contact sensor positioned a distance from the vibrating element and determining at least one vibration characteristic based on the position information sensed with the non-contact sensor.

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, comprises: a waveform creation unit for creating a comparative current waveform to be a reference of a driving current for the linear vibration motor on the basis of 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; wherein the frequency of the driving current is controlled to be close to the resonance frequency of the linear vibration motor, on the basis of the comparative current waveform. Thereby, the driving frequency of the linear vibration motor can always be brought to the resonance frequency without using a sensor for detecting such as displacement, speed, or acceleration of the mover.

Abstract: The present invention relates to a vibration type actuator apparatus, and is aimed to provide an apparatus capable of determining a phase with which a driving voltage is applied to a piezo-electric member particularly relative to a phase of vibration displacement of a vibration member, shifting to a high-speed driving state in a short time, and abruptly stopping.

Abstract: In the present method for damping the torque oscillations of the drive train of an electrically driven road vehicle, the torque or a torque estimated value and the rotational speed of the electric motor which drives the road vehicle as well as the rotational speed of a wheel or the mean value of the rotational speeds of all the driven wheels of the road vehicle are detected as input variables, an observer estimating, from the input variables, the torque which is transmitted to the wheels by the gear mechanism, a regulating block which is connected downstream of the observer determining a compensation torque from the estimated torque, and the compensation torque being added to the setpoint torque of the electric motor, as a result of which a regulating circuit is obtained. By means of these measures, a travel characteristic which is significantly improved for the driver is achieved and the material loading in the drive train is reduced.

Abstract: The invention concerns a device where creation of mechanical vibration is made with a system (1) of two or more rotating eccentrics (10). Each eccentric (10) is rotated by an individually controlled motor (11) and the angle position of each eccentric (10) is read by an angle sensor (12). With a control and monitoring system (5), the rotation frequency, direction of rotation and phase position of each eccentric (10) can be controlled. By choosing a number of eccentrics, mass of the eccentrics, rotation frequency, direction of rotation and phase position, a force vector diagram of suitable form, in space and time, can be generated. The invention is intended primarily for use in appliances for dynamic compaction of various materials.

Abstract: The invention relates to an electronic frequency converter (1) which is used with a high frequency immersion vibrator in order to compact concrete. Said frequency converter comprises a cooling circuit (4) containing a cooling medium; a first heat exchanger (3) which is integrated into said cooling circuit (4) and is used to transmit heat generated in the housing (2) of the frequency converter to the cooling medium; and a second heat exchanger (11) which is integrated into the cooling circuit (4) and is used to outwardly transmit heat absorbed by the cooling medium. The second heat exchanger (11) is received in a vibrator housing (6) of the high frequency immersion vibrator. If the vibrator housing (6) is immersed in concrete (12), the heat produced in the converter housing (2) can be conducted away to the concrete (12).

Abstract: A linear actuator includes a casing and a retractable member driven by a motor is movably received in the casing and a contact member is connected to the retractable member. A first position switch connected to the motor, a plurality of travel switches and a final position switch connected with a diode are connected to the actuator. These switches are connected in series by normal-close switches. Normal-open switches of the travel switches located between the first position switch and the final position switch are connected to a circuit of the control device. The motor is stopped when the final position switch touches the contact member of the retractable member, the motor is activated when a reverse electromotive is applied to the diode.

Abstract: A pressure wave generator comprises an acoustic tube 1, and a driving device 3 connected to one end of the tube for generating acoustic waves toward the interior of the tube 1. A plurality of Helmholtz resonators 2 each having a channel through which the cavity is connected with the interior of the acoustic tube 1 are arranged on the tubular wall of the acoustic tube 1 with suitable axial spacing. Each of the Helmholtz resonators 2 comprises a throat 21 having a narrower in diameter than the acoustic tube 1 and joined at a base end thereof to the tubular wall of the acoustic tube 1, and a cavity 22 joined at the one end of the throat 21 and having a suitable volume. The generator suppresses the generation of shock waves, and generates shock-free larger pressure amplitude than the ones conventionally achieved.

Abstract: An electric power steering apparatus for assisting steering by conferring torque generated by an electric motor to a steering mechanism. The apparatus includes: a correction table created based on a result of actual measurement of torque ripple occurring when a predetermined reference current is supplied to the electric motor; a basic command value setting portion for setting a basic command value according to a steering manipulation of a driver; a current command value setting portion for setting a current command value by correcting the basic command value set by the basic command value setting portion with reference to the correction table; and a motor current control portion for controlling a current to be supplied to the electric motor based on the current command value set by the current command value setting portion.

Abstract: In order to remove vibration or improve a vibration control effect, and achieve device size reduction, an adjusting device is provided in which a weight of a support target object is supported by a pressure of an internal gas of a first chamber gas via a holding member and which adjusts a position in a gravity direction of the holding member by driving a movable member which changes an internal volume of the first gas chamber by changing an internal volume of a second gas chamber based on a state change of at least one of first and second gas chambers. Because of this, when the holding member is displaced in the gravity direction because of the vibration or the like, as the movable member is driven by the adjusting device, the holding member is maintained at an original position.

Abstract: A phase angle monitoring apparatus for phase monitoring a vibratory system includes a controller that produces a phase angle control signal representative of the lead or lag between the vibratory movement of two vibrating masses. The phase angle control signal is coupled to at least one of the vibrating masses to adjust the vibration of the mass to produce a desired phase angle, for example one-hundred eighty degrees (180°).

Abstract: A vibration motor obtains a FAST signal when r.p.m. of the motor is faster than reference speed, whereby an output-driving circuit is controlled by the FAST signal to omit parts of the powering periods of respective phases. The motor thus controls the r.p.m. and increases torque ripple generated from the motor. As a result, vibration magnitude increases and insufficient vibration due to downsizing of the motor can be compensated by the control system.

Abstract: An apparatus for controlling an electromagnetic parts feeder comprises a vibrating unit provided with an electromagnet that vibrates at a predetermined frequency, a bowl adapted to discharge parts accommodated therein by means of the vibrating unit, a driving circuit for driving the electromagnet, and a control unit for outputting a driving signal to the driving circuit to cause a predetermined driving. The control is performed by idling the driving of the electromagnet temporarily at every predetermined driving cycles thereof and controlling the vibration of the electromagnet based on a signal obtained from a coil of the electromagnet by its electromagnetic induction during the idling period, for instance, based on a phase difference between a waveform of this signal and the driving signal of the driving circuit.

Abstract: A DC brushless vibration motor is disclosed to comprise of a stator, a rotor, a drive circuit and a casing. The stator has an upper magnetic pole piece, a lower magnetic pole piece and a stator field winding. The stator field winding is contained inside a ring-shaped space formed by the upper and lower magnetic pole pieces. The internal rotor has a center of mass offset from the center axis of rotation and comprises a ring magnet and an eccentric weight. The eccentric weight has a structural configuration of a ring body, and the ring magnet is securely fixed to the external peripheral surface of the eccentric weight. The drive circuit has a drive integrated circuit for controlling the rotation of the rotor by receiving an externally-supplied electric power. The casing securely encloses the stator and rotor while maintaining an air gap therebetween for generating mechanical vibration when the rotor is propelled to rotate by the stator.

Abstract: A system and method for reducing reaction forces induced in a machine frame by an oscillating tool employs a counterforce assembly which is driven to move along linear slides mounted to the machine frame. The counterforce assembly is driven with a drive signal derived from two signals: a first signal which is proportional to the acceleration of the tool, and a second signal which is directly proportional to the velocity of the oscillating tool. By properly-adjusting the acceleration and velocity components of the drive signal, the magnitude of the reaction forces induced in the machine frame by the oscillating tool can be substantially reduced. The counterforce assembly preferably includes a centering means which prevents it from moving to either end of the slide. An accelerometer is preferably mounted to the machine frame to sense its vibration, with the accelerometer output used to adjust the counterforce assembly's drive electronics to reduce vibration to a minimum.

Abstract: The invention relates to a circuit arrangement for the dynamic control of ceramic solid-state actuators, such as piezotranslators with energy recovery by means of magnetic intermediate stores and/or storage capacitors as well as by clocked switches. For achieving a predetermined linear voltage characteristic at the piezotranslator, according to the invention, a single inductive intermediate store is arranged in the secondary circuit, which is connected in series with the piezotranslator, and the secondary circuit is designed as a half-bridge. The switches provided in the respective half-bridge are controlled at a high cycle or switching frequency by an external controller, with the series connection of piezotranslator and inductive intermediate store furthermore carrying a superimposed bridge direct current in order to ensure the desired charging of the capacitance of the piezotranslator, on the one hand, and to optimize the energy recovery, on the other hand.

Abstract: A driving apparatus is provided for a vibration type motor which obtains a driving force by applying a periodic signal to an electro-mechanical energy conversion element portion of the vibration type motor. When the driven amount of the vibration type motor is small, the vibration type motor is driven by a high voltage in a frequency range with a high lower limit as compared with a case wherein the driven amount is not small, thereby making it possible to realize high-speed focusing and suppress electric power consumption.

Abstract: The present invention relates to a vibration wave motor which is configured to prevent abnormal noise from being produced at a start time or a stop time and, more particularly, to a control device for a vibration wave motor which obtains a driving force by applying a periodic voltage to an electro-mechanical energy conversion element so as to generate in a vibration member thereof a plurality of standing waves having a phase difference therebetween, the plurality of standing waves being synthesized to generate a driving vibration in the vibration member.

Abstract: A driving device for an oscillatory actuator in which a FLL (Frequency Locked Loop) is employed for detecting an electromotive force generated in a driving coil resulting from mechanical oscillation during a period in which no driving current is supplied to the oscillatory actuator, and for controlling an oscillation frequency on the basis of a relative time ratio between positive and negative polarities of the electromotive force to thereby pull a driving frequency into a neighborhood of a self-resonance frequency of the oscillatory actuator.

Abstract: A vibration control device 1 in accordance with the present invention is provided with a liquid lever mechanism 4 which has an action member 5, a liquid chamber 6 and a driving plate 7, and is used for enlarging a displacement, a piezo-actuator 2 which can be displaced in a direction so as to change the volume of the liquid chamber 6, and a rubber vibration isolator 3 which is placed between the liquid lever mechanism 4 and the piezo-actuator 2 in series therewith. This vibration control device 1 has a low natural frequency so that it has a superior passive vibration-blocking performance at high-frequency bands, while maintaining a superior active vibration-blocking performance at low-frequency bands, and also makes it possible to achieve a small size.

Abstract: A method for controlling and positioning a two-dimensional electric motor in six degrees of freedom is disclosed. The electric motor has a coil array and a magnet array. The method controls the motor in six degrees of freedom. The method includes: determining currents for generating the desired forces in a first, second and third direction, the first and second directions being defined in a plane in which the magnets are disposed and the third direction being generally orthogonal to the first and second directions, determining a resultant torque about the first, second, and third directions that would be generated from applying the determined currents, determining current adjustments to compensate for the resultant torque, and applying a current equal to the sum of the determined currents and the current adjustments to the coils to interact with the magnetic fields of the magnet array.

Abstract: A dual sided self-oscillation circuit for driving an oscillatory actuator with high efficiency and high response speed. The actuator has a winding to receive a periodical supply current from a power source and oscillates in a predetermined resonant frequency. The self-oscillation circuit includes a bandpass filter for receiving a back electromotive force voltage (Vbemf) developed across the winding and producing a sine wave output signal, a comparator for comparing the sine wave output signal with a threshold voltage and producing two drive pulses per cycle of the resonant frequency, and a switch connected in series with the winding to connect or disconnect the power source to the winding in response to the drive pulses, thereby flowing electric current in two directions at each cycle.

Abstract: In the present method for damping the torque oscillations of the drive train of an electrically driven road vehicle, the torque or a torque estimated value and the rotational speed of the electric motor which drives the road vehicle as well as the rotational speed of a wheel or the mean value of the rotational speeds of all the driven wheels of the road vehicle are detected as input variables, an observer estimating, from the input variables, the torque which is transmitted to the wheels by the gear mechanism, a regulating block which is connected downstream of the observer determining a compensation torque from the estimated torque, and the compensation torque being added to the setpoint torque of the electric motor, as a result of which a regulating circuit is obtained. By means of these measures, a travel characteristic which is significantly improved for the driver is achieved and the material loading in the drive train is reduced.

Abstract: The invention relates to a method of, and system for, linear speed control for an electric motor, in which a digital to analog converter means is used for converting an 8-bit digital signal to an analog voltage for setting voltage across a motor, a digital state machine means is used for converting the duty cycle of an input signal for output to the digital to analog converter means, and a closed loop feedback loop means is used for monitoring and setting the voltage across the motor. An over-current sense circuit can be used for monitoring the current across the electric motor. An over/under voltage sense circuit can be used for monitoring voltage of the electric motor. The resulting 8-bit digital control signal is converted to an analog voltage for the electric motor. Such methods and systems find particular use in automotive applications.

Abstract: A method and apparatus for controlling acoustic noise generated by a seek operation in a disc drive by using a feedback control system to control the seek operation. The feedback control system is excited by a feed-forward signal during execution of the seek operation. An acoustic factor, which defines a seek operation noise level, is selected. The feed-forward signal is generated based, at least in part, upon the selected acoustic factor. The feed-forward signal has a first derivative having a maximum value. The selected acoustic factor is used to select the maximum value of the first derivative of the feed-forward signal.

Abstract: An adaptive shunt system for controlling vibrations of a frequency-varying structure, the system comprising: a detector for detecting vibrations generated from a predetermined structure and generating vibration signals corresponding to the vibrations; a computer for inputting the vibrations signals from the detector; a signal processing unit for processing the vibration signals from the computer and generating a voltage command in real-time; and an adaptive shunt device for adaptively controlling the vibrations of the structure of which natural frequency varies at every moment according to the voltage command.