Abstract: Device and process for oscillation insulation in a transmission path. The device includes a first body structured and arranged to undergo an oscillation movement, at least one rigid connection element, a second body connected to the first body via the at least one rigid connection element, and an actuator device attached to the at least one connection element. A sensor unit is arranged in an interface area of the at least one connection element, and a regulator unit, connected to the sensor unit, is arranged to control the actuator device to perform an elastic deformation equivalent to an oscillation movement of the first body. The instant abstract is neither intended to define the invention disclosed in this specification nor intended to limit the scope of the invention in any way.

Abstract: A vibration reduction system is provided for use in conjunction with a rotational device including a stationary body, a rotating body, and a first bearing assembly disposed between the stationary body and the rotating body. The vibration reduction system includes a first plurality of bearing mount actuators residing between the stationary body and the first bearing assembly. The first plurality of bearing mount actuators is configured to adjust the radial position of the first bearing assembly. The vibration reduction system further includes a vibration sensor, which is coupled to the stationary body, and a controller, which is coupled to the vibration sensor and to the first plurality of bearing mount actuators. The controller is configured to reduce vibrations sensed by the vibration sensor by selectively adjusting the radial position of the first bearing assembly utilizing the first plurality of bearing mount actuators.

Abstract: A method for actively suspending a real plant in a vehicle includes modifying a control signal on the basis of a difference between a property of the real plant, as indicated by the response of the real plant to the control signal, and a property of a nominal plant.

Abstract: An anti-vibration support system for an engine, comprising an active anti-vibration supporting device including an elastic member adapted to receive a vibration of the engine; a liquid chamber, wherein at least a portion of a wall surface of said liquid chamber is defined by said elastic member; a movable member adapted to change a volume of said liquid chamber; and an actuator that uses an electromagnetic force to drive said movable member, wherein the vibration of the engine is prevented from being transmitted to a vehicle body frame by controlling a supply of electric current to said actuator, and wherein operation of said active anti-vibration supporting device is prohibited when an abnormality in an operational state of the engine is detected.

Abstract: A method of designing a magnetorheological (MR) fluid energy absorbing damper is provided that uses hydromechanical analysis with lumped parameters to allow a determination as to whether a potential damper design will provide predetermined characteristics, such as a desired dynamic force range and maximum piston velocity, with a selected MR fluid and yield stress and preferably meeting predetermined geometric limitations.

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 vibration absorber provided on an optical disk drive module of a disk drive for suppressing vibration produced by the optical disk drive module at various speeds. The vibration absorber at least has a body, dampers, elastic members, an actuator and a controller. The body is secured on the optical disk drive module. The dampers elastically and vertically shift on the body. The elastic members are provided on the body for providing elasticity in shifting of the damper. The actuator is provided on the body and coupled to the damper for providing a driving force for the vertical shifting of the damper. The controller controls the driving force outputted by the actuator based on the change in rotational speed of the optical disk drive module, so as to change the elasticity in vertical shifting of the damper to reduce the shifting and corresponding vibration of the optical disk drive module.

Abstract: In order to control vibrations of two parts of a piece of machinery, a variable force may be generated to oppose the vibrations, with the variable force being generated under control of a controller on the basis of an iterative relationship, the iterative relationship being such as to generate the force of one iteration using a controller output signal in frequency domain vector form derived from the controller output signal of the immediately previous iteration in frequency domain vector form plus a frequency domain vector quantity derived from the resultant vibration of more than one previous iteration. Where these two parts are connected by multiple (f) mounting devices, the controller output signals a previous iterations are taken into account, and the frequency domain vector quantity derived from the controller output signals and more than f previous iterations.

Abstract: An electromagnetic actuator having: a stator and a movable member disposed in a central hole of a coil member of the stator movable in an axial direction; a coupling rod fixed to the movable member; and an elastic stopper having a ring shaped sealing unit at its outer periphery part, a first stopper unit at its center part, a coupling unit that mutually couples the sealing unit and the first stopper unit, and second stopper units located radially between the sealing unit and the first stopper unit at respective circumferential positions. The sealing unit is compressed between the bottom wall of a housing and a lid member to form a sealing mechanism that fluid-tightly close an opening of an adjustment hole. The first stopper unit axially faces the coupling rod bottom with a first separation distance, and the second stopper units axially face the movable member bottom with a second separation distance greater than the first.

Abstract: A damping apparatus for an automobile is provided, capable of ensuring a high level of reliability while obtaining excellent damping effect with simple configuration. The damping apparatus for an automobile that reduces vibrations of an automobile body may include an actuator that is attached to the automobile body and drives an auxiliary mass; a current detector that detects a current flowing through an armature of the actuator; a section that detects a terminal voltage applied to the actuator; a calculation circuit that calculates an induced voltage of the actuator, and further calculates at least one of the relative velocity, relative displacement, and relative acceleration of the actuator, based on a current detected by the current detector and the terminal voltage; and a control circuit that drive-controls the actuator based on at least one of the relative velocity, relative displacement, and relative acceleration of the actuator calculated by the calculation circuit.

Abstract: A system for mounting an assembly, such as a motor vehicle engine, on a supporting structure such as a vehicle body. Disposed between the assembly and the supporting structure is a soft mount and/or a soft rubber spring featuring a damping and/or spring excursion along which the soft mount damps and/or adapts the load acting on the assembly. Also, disposed between the supporting structure and the assembly is an actuator which communicates an adaptive reaction force. A displacement of the assembly caused by the load along the damping or spring excursion of the soft mount or of the rubber spring can be cancelled out by a counter motion of the assembly prompted by the actuator.

Abstract: An active engine mount assembly for counteracting resultant forces in active fuel management systems, wherein resultant forces are transmitted to a frame of a motorized vehicle generated by the deactivation of at least one cylinder in an internal combustion engine. The active engine mount assembly is fluidly connected to a hydraulic circuit. The hydraulic circuit is operatively connected to an engine crankshaft and operable to actively generate pressure pulses having frequencies self-synchronized with the rotational speed of the crankshaft.

Abstract: A portable electronic includes a main body defining a plurality of mounting holes at corners; a plurality of mounting modules; a plurality of resilient members compressed and mounted in mounting holes of the main body by the corresponding mounting modules; and a control module. The control module includes a MCU; an acceleration transducer connected to the MCU to sample a real-time acceleration value, and a memory connected to the MCU to store a critical acceleration value. The control module controls the mounting modules to release the compressed resilient members so as to eject out the resilient members from the main body, when the real-time acceleration value is larger than the critical acceleration value.

Abstract: A component vibration control system is disclosed. The vibration control system includes a first physical end stop, a second physical end stop, a damper assembly, a position sensor configured to determine a component position, and a processor in communication with the position sensor and the damper assembly. The processor is configured to set a first virtual end stop position, regulate a damping force of the damper assembly as the component moves toward the first virtual end stop position, and determine a second virtual end stop position based on a first distance of the component from a set position.

Abstract: Interfaces for damping mechanical vibrations are used, for example, for damping vibrations in the automotive or aerospace industry. The interfaces have a base connection element, a load connection element and a support element, with the support element being connected to the base connection element via a pretensioning device. A first energy converter system extends between engagement points on the base connection element and engagement points on the load connection element. A second energy converter system extends between engagement points on the support element and engagement points on the load connection element.

Abstract: A vehicle engine mount system comprises a housing and an inertia track assembly that forms a first fluid chamber with an upper compliant member and a second fluid chamber with the second end of the housing. The inertia track assembly has first and second passageways therethrough for conducting fluid between the first and second fluid chambers. The first passageway has a substantially greater flow resistance than the second. First and second switches are coupled to the first and second passageways, respectively, for selectively enabling the first and second switches to control fluid displacement between the first fluid chamber and the second fluid chamber.

Abstract: A suspension system for a seat of a vehicle comprises a base, a linkage, and a seat attached to the base via the linkage. A pneumatic shock absorber provides a respective resistance level against movement of the seat with respect to the base based on a corresponding pressure level of air or gas within the pneumatic shock absorber. A set of cylindrical members are spaced apart beneath the seat. A tension member is arranged to engage the cylindrical members. The tension member is attached to the seat via a bracket. An electric motor is capable of driving one of the cylindrical members. A first sensor is arranged to detect first sensor data associated with an instantaneous position of the seat versus time. A controller generates a first control signal for the electric motor to change a height of the seat in opposition to a change in the instantaneous position of the seat and a second control signal to change the pressure level.

Abstract: A suspension system for a seat assembly of a machine includes an upper support member and a lower support member. An array of fluid chambers is operatively connected to the upper and lower support members. Each of the fluid chambers includes an electronically controlled valve for controlling an amount of fluid within the fluid chambers. An elastomer is coupled between the upper support member and the lower support member. An electronic controller is in communication with each of the electronically controlled valves and is configured to actuate the valves in response to a movement of the machine.

Abstract: An elastomer bearing with hydraulic damping is disclosed which includes a housing (1, 2), a connecting element (3), an elastomer body (4) which couples the housing (1, 2) and the connecting element (3) with one another for damping oscillations, two chambers (5, 6) filled with a magneto-rheological fluid, at least one flow channel (8) connecting the chambers (5, 6) with one another for fluid conduction, as well as an actuator (11) associated with the flow channel and attached on the outside of the housing (1, 2) for generating a magnetic field. According to the invention, a field return element (10) with interacts with the actuator is arranged on or in the flow channel (8).

Abstract: An aircraft flight control surface has an actuator that employs a magneto-rheological (MR) fluid for dynamically adjusting the responsiveness of the control surface. The MR fluid may be used as a primary or secondary control in the event that a primary control actuator fails. In the event of system failures associated with the primary control, an alternate level of performance may be provided by the secondary control and communicated to the overall flight control system. This permits the control surface actuator to reactively and proactively respond to changes associated with the flight control system. If the design fails, it also permits a safe mode of operation should the ability to dynamically adjust the viscosity of the MR fluid be negatively impacted. The safe mode of operation may involve a reduced level of performance.

Abstract: When switching between L3 cylinder cut-off running in which a bank on one side of a V6 engine is cut off and V4 cylinder cut-off running in which one cylinder in each of the two banks is cut off, V6 all-cylinder running to operate all the cylinders is interposed therebetween. Therefore, a transitional period is provided between L3 cylinder cut-off running and V6 all-cylinder running and between V6 all-cylinder running and V4 cylinder cut-off running, and no transitional period is present between L3 cylinder cut-off running and V4 cylinder cut-off running. Thus, it is possible to simplify control of an active vibration isolation support system during the transitional period and to avoid deterioration of a vibrational state during the transitional period.

Abstract: An active engine mount assembly for counteracting resultant forces in active fuel management systems, wherein resultant forces are transmitted to a frame of a motorized vehicle generated by the deactivation of at least one cylinder in an internal combustion engine. The active engine mount assembly is fluidly connected to a hydraulic circuit. The hydraulic circuit is operatively connected to an engine crankshaft and operable to actively generate pressure pulses having frequencies self-synchronized with the rotational speed of the crankshaft.

Abstract: When driving an actuator 41 of an active vibration isolating support apparatus M to extend and contract on a predetermined cycle so as to suppress the transmission of vibrations of an engine, since a combined target current ICMDT is calculated by combining a primary target current which cancels a primary vibration of the engine with a secondary target current which cancels a secondary vibration of the engine and furthermore, the actuator 41 is driven with a target driving current ICMD in which a minimum value of the combined target current ICMDT is offset to 0, can the primary vibration and the secondary vibration of the engine be cancelled so as to enhance a vibration isolating function and the inclusion of a direct current component into the target driving current ICMD can be prevented so as to suppress a wasteful heat release of the actuator 41 to a minimum level.

Abstract: An active vibration damping device wherein first and second mounting members are linked by a main rubber elastic body, a pressure receiving chamber having a non-compressible fluid sealed therein is defined by the main rubber elastic body at one part and by an oscillation member in the other part. A solenoid actuator designed with a movable element positioned inserted into a guide hole of a stator having a yoke member is attached about a coil to form a stator-side magnetic path with the guide hole lying on its center axis, so that current passed through the coil creates actuating force in the axial direction between the stator and the movable element. The stator of the solenoid actuator is affixed to the second mounting portion and the movable element is attached to the oscillation member. A bias urging assembly is disposed for urging the movable element in one axis-perpendicular direction to the stator.

Abstract: The invention describes a device as well as a method for eliminating vibrations of a mechanical structure with at least one electromechanical converter material that is actively connected to the mechanical structure and connected to an electric circuit arrangement with at least one electrical impedance. The invention is characterized in that the electric circuit is connected to an interface, via which the at least one electrical impedance can be variably adjusted by means of wireless or wired communication with a control unit that is separated from the electronic circuit arrangement, and in that the electrical impedance features at least one ohmic resistor and/or one inductive resistor and/or one capacitor that are respectively realized variably.

Abstract: A vibration reduction system is provided for use in conjunction with a rotational device including a stationary body, a rotating body, and a first bearing assembly disposed between the stationary body and the rotating body. The vibration reduction system includes a first plurality of bearing mount actuators residing between the stationary body and the first bearing assembly. The first plurality of bearing mount actuators is configured to adjust the radial position of the first bearing assembly. The vibration reduction system further includes a vibration sensor, which is coupled to the stationary body, and a controller, which is coupled to the vibration sensor and to the first plurality of bearing mount actuators. The controller is configured to reduce vibrations sensed by the vibration sensor by selectively adjusting the radial position of the first bearing assembly utilizing the first plurality of bearing mount actuators.

Abstract: An active torque cancellation system is provided. The system includes a generator set having a combustion engine and mounted to an application structure. The system also includes an active power management module coupled to the engine which actively reduces vibrations in the application structure.

Abstract: An engine mount system includes multiple liquid-filled engine mounts switchable to provide different mount characteristics by selectively introducing negative pressure or atmospheric pressure. On one of pipelines connected to the respective engine mounts for introducing the negative or atmospheric pressure into the respective engine mounts, a check valve and an orifice portion are provided in parallel. The orifice portion restricts an amount of air flowing therethrough, so that the mount characteristic of the engine mount connected to the one pipeline equipped with the check valve and the orifice portion does not undergo an abrupt change when the pressure introduced in the engine mount is switched from the negative pressure to the atmospheric pressure.

Abstract: A fluid-filled type vibration damping device including: a primary fluid chamber partially constituted by a main rubber elastic body connecting a first and second mounting member; an equilibrium chamber partially constituted by a flexible film; a partition member supported by the second mounting member; and a partition rubber film is superimposed against the partition member and secured interlocking with an annular interlocking projection projecting from the partition member. A first seal rubber is compressed between the interlocking projection and the tubular fitting member and extending about the entire circumference, thereby forming a working air chamber therebetween. A gap is furnished between and a second seal rubber is compressed between the tubular fitting member and the orifice member, and extending about the entire circumference.

Abstract: The natural vibration frequency of a roll resonance which does not occur since the engine rotation number is high in a normal operation range of an engine is detected at the time of engine start or stop when the engine rotation number is lower than the normal operation range, and thus the natural vibration frequency of the roil resonance can be detected with a good accuracy.

Abstract: In order to control vibrations of two parts of a piece of machinery, a variable force may be generated to oppose the vibrations, with the variable force being generated under control of a controller on the basis of an iterative relationship, the iterative relationship being such as to generate the force of one iteration using a controller output signal in frequency domain vector form derived from the controller output signal of the immediately previous iteration in frequency domain vector form plus a frequency domain vector quantity derived from the resultant vibration of more than one previous iteration. Where these two parts are connected by multiple (f) mounting devices, the controller output signals a previous iterations are taken into account, and the frequency domain vector quantity derived from the controller output signals and more than f previous iterations.

Abstract: A vibration control mount apparatus capable of absorbing an initial pushing-up load based on a shock and capable of promptly damping a residual vibration generated after the shock. The vibration control mount apparatus includes a case body mounted on a turning frame, a mount rubber is mounted on the case body. A magnetic viscous fluid of which viscosity is changed by a magnetic filed is sealed in a sealing chamber in the case body. A movable body supported by the mount rubber has a damper plate which moves while receiving resistance from the magnetic viscous fluid in the sealing chamber. Viscosity variable controlling device forms the magnetic field in accordance with vibration acceleration detected by the acceleration detecting device to change the viscosity of the magnetic viscous fluid.

Abstract: A vibration isolation device which damps vibration of an object includes a vibration isolation unit which can be activated in a plurality of vibration isolation modes, an acquisition unit which acquires estimate information associated with vibration of a floor, and a control unit which selects a vibration isolation mode from the plurality of vibration isolation modes in accordance with the estimate information acquired by the acquisition unit, and activates the vibration isolation unit in the selected vibration isolation mode.

Abstract: A releasable fastener system comprises a loop portion and a hook portion. The loop portion includes a support and a loop material disposed on one side thereof whereas the hook portion includes a support and a plurality of closely spaced upstanding hook elements extending from one side thereof. When the hook portion and loop portion are pressed together they interlock to form a releasable engagement. The resulting joint created by the engagement is relatively resistant to shear and pull forces and weak in peel strength forces. The hook elements are formed of a magnetorheological elastomer that provides a change in shape orientation and/or flexural modulus of the hook elements. In this manner, the shape orientation and/or flexural modulus of the hook elements can be remotely changed to provide a reduction or magnification in the shear and/or pull-off forces in addition to providing variable damping capabilities to the fastener system.

Abstract: A damper/strut that can provide variable damping and spring energy storage and dissipation. One embodiment includes an adjustable magnetorheological damper and a mechanically adjustable fluid spring in association with an internal accumulator. A combination of internal and external electromagnets generate the magnetic fields required to activate internally maintained magnetorheological material so that its apparent viscosity undergoes the desired change for a given disturbance. By controlling the strength of the magnetic fields generated in the device, the damping capacity and energy storage of the compressible liquid spring can be affected to provide a semi-active damper that can both dissipate and store energy. The proposed devices can be coupled with a sensor feedback and a control system to provide fast and accurate response force for a variety of engineering applications.

Abstract: A fluid-filled engine mount, including: an elastic body connecting a first and a second mounting member; a pressure receiving chamber partially defined by the rubber elastic body; an equilibrium chamber partially defined by a flexible layer, a first orifice passage connecting between the pressure receiving and equilibrium chambers and tuned to a low frequency range, a second orifice passage connecting the both chambers and tuned to a medium frequency range; a valve member for opening/closing the second orifice passage and operated by a pneumatic actuator; a movable partition member including a rigid center movable plate portion and a readily deformable outer peripheral rubber film portion supported fluid-tightly by the second mount portion; and an intermediate equilibrium chamber formed opposing to the pressure receiving chamber with the movable partition member interposed therebetween.

Abstract: A fluid-filled type vibration-damping device having: an elastic body connecting first and a second mounting members; a pressure-receiving chamber formed axially below the main rubber elastic body and partially defined by the main rubber elastic body; an equilibrium chamber formed between the main rubber elastic body and a flexible film by disposing the flexible film so as to cover an outside face of the main rubber elastic body; and an orifice passage through which both chambers communicate with each other. An equilibrium-chamber-side opening of the orifice passage is situated in proximity to an axial lower end of the outside face of the elastic body. A guide groove extending axially upward is formed in proximity to the equilibrium-chamber-side opening. A projecting rib projects from the flexible film towards the guide groove is formed extending along the guide groove.

Abstract: Linkage system between a first part and a second part capable of movement relative to each other, incorporating a link capable of transmitting forces between the first and second parts and a frequency control loop for said link incorporating means of measuring a distance separating the first and second parts, a frequency filter for said measurements in a given frequency band and means for comparing these filtered values with a set point, said control loop controlling the link such that it transmits forces only in the given frequency band, the frequency control loop being a position control loop, a speed control loop being incorporated in the position control loop, and a force control loop being incorporated in the speed control loop.

Abstract: An adaptive energy absorption system for a vehicle seat is disclosed, utilizing an adaptive energy absorber or variable profile energy absorber (VPEA) for mitigating occupant injury due to extreme vehicle movement (e.g., during a vehicle shock event), and/or for mitigating vibration experienced by an occupant of the vehicle seat during normal vehicle operating conditions. Various configurations of dual-goal energy absorption apparatuses using both VPEA and fixed load energy absorbers (FLEAs) that enable both shock mitigation and vibration isolation are disclosed. A semi-active control absorption system, comprising a VPEA and FPEA configured to work in series, is also disclosed.

Abstract: An anti-vibration apparatus includes a first magnet unit arranged on a support target and including a first permanent magnet, and a second magnet unit including a pair of second permanent magnets. The pair of second permanent magnets is arranged to interpose the first permanent magnet without contact such that the same magnetic poles of the first and second permanent magnets oppose each other. Sizes of the first and second magnet units are set such that a force acting between the first and second magnet units in a direction perpendicular to a direction in which the first magnet unit supports the support target is zero in a relative positional range between the first and second magnet units.

Abstract: A bushing assembly adapted for application in vehicle suspension systems includes an outer, generally cylindrical bushing member, an inner generally cylindrical bushing member arranged concentrically within the outer member. The two bushing members are interconnected by an elastomeric member disposed there between and bonded thereto to permit limited rotational displacement between the external and internal bushing members. An angular position sensor is at least partially embedded within the elastomeric member and operative to produce an output signal indicative of the relative angular position of the external and internal bushing members. The sensor includes a stator assembly including a permanent magnet, a galvanomagnetic sensing element and a flux guide defining at least one pole face, and a rotor including a flux guide defining a second pole face. An air gap between the two pole faces varies dimensionally as a function of the relative angular position of the stator assembly and rotor.

Abstract: An active vibration reduction system for a vehicle for suppressing a vibration from a vibration source includes a vibration suppression signal generating unit for generating a vibration suppression signal having a frequency being synchronous with the vibration from the vibration source, a sensible signal generating unit for generating a sensible signal having a frequency being asynchronous with the vibration from the vibration source, a magnetic pole forming magnetic flux, a coil provided in a manner that intersects the magnetic flux, and a coil driving circuit relatively vibrating the magnetic pole and the coil by controlling an energized state of the coil based on the vibration suppression signal and the sensible signal.

Abstract: Embodiments of the present invention may provide a storage panel guiding device, which is configured to dampen movement of a storage panel movement using magnetic attractive force to thereby reduce damper friction. The storage panel guiding device of the present invention comprises the following: a magnetic damper including a first magnetic body, a second magnetic body and a thin plate interposed therebetween; a storage panel to which the first magnetic body is attached; a guide panel to which the second magnetic body is attached; a slide rail having a slot in which the guide panel can move; and a storage case accommodating the magnetic damper, the storage panel and the guide panel.

Abstract: A fluid-filled type vibration-damping device having an elastic rubber film partially defining a primary fluid chamber at one surface and partially defining a pressure action chamber. The pressure action chamber varies its pressure under control so that the elastic rubber film changes its elasticity to change damping characteristics of the device. To give sufficient recovery force for the elastic rubber film, the elastic rubber film includes a plurality of thick reinforcing ribs circumferentially spaced apart from one another and extending in a radial direction from an outside peripheral edge over a length not reaching a center so that areas situated between pairs of adjacent reinforcing ribs constitutes thin portions formed by a thin rubber elastic body, while the center portion of the elastic rubber film situated between distal ends constitutes a bowed center portion thinner than the reinforcing ribs and convex towards the pressure action chamber.

Abstract: A damping method for a hybrid vehicle in which a power unit consisting of an engine and a motor is supported in a vehicle body frame via an active vibration isolation support system includes: a step of firstly damping vibration of the power unit by the active vibration isolation support system; and a subsequent step of controlling operation of the motor to damp vibration that has not been eliminated by the active vibration isolation support system. Therefore, it is possible to prevent the damping effect from being degraded by interference between the damping control by the active vibration isolation support system and the damping control by the motor, and to reduce the total power consumption by preferentially operating the active vibration isolation support system which has low power consumption, and secondarily operating the motor which has high power consumption.

Abstract: The invention relates to a switchable assembly bearing that comprises at least one working chamber and one compensation chamber which are separated by a dividing wall. The working chamber and compensation chamber are hydraulically interconnected by means of a damping channel, in addition to at least one other damping channel which can be closed by means of the sealed arrangement of a shut-off body which can be displaced along a displacement path. The other damping channel is formed and arranged in relation to the axis of symmetry of the bearing in such a way that the forces acting on the shut-off body by means of the hydraulic fluid counterbalance each other.

Abstract: An actuator of an active engine vibration isolation support system is driven based on the first, second, third . . . duty groups calculated corresponding to the vibration periods t1, t2, t3 . . . of the engine. When the engine rotational speed varies in the increasing direction and the vibration periods t1, t2, t3 . . . become gradually shorter, parts of the first, second, third . . . duty groups overlap each other, and therefore an electrical current which is supplied to the actuator does not become 0 at the end of the duty groups, leading to a possibility that a peak value of the electrical current gradually increases so that not only the active vibration isolation support system cannot exhibit an effective vibration isolation function, but also the actuator generates heat. Therefore, for example, when the overlapping amount of the first and the second duty groups exceeds a threshold value, a duty ratio of the second duty group is made 0 to stop application of the electrical current to the actuator.

Abstract: An active damping apparatus for damping vibration due to driving of a stage and/or counter-mass mounted on an isolation table in an exposure device for the manufacture of semiconductor devices has a setting unit for selecting the stage and/or the counter-mass to drive and setting a control mode according to what is to be driven. The apparatus further has a control input switch that sets up a control loop for inputting control target values for driving the stage and/or the counter-mass to an isolation table controller so as to offset the drive reaction torque generated by the movement of the stage and/or counter-mass.

Abstract: A fluid-filled active damping apparatus having a pressure receiving chamber partially defined by a rubber elastic body connecting a first and second mounting member; an oscillation plate defining a part of the pressure receiving chamber, and supported in a displaceable fashion; an electromagnetic actuator disposed on one side of the oscillation plate remote from the pressure receiving chamber, with its output member connected to the oscillation plate; an equilibrium chamber partially defined by a flexible diaphragm; and an orifice passage connecting the pressure receiving chamber and equilibrium chamber. A rigid annular guide member is disposed about the oscillation plate with a slight gap therebetween, such that these members are mutually displaceable in the axial direction. The guide member is elastically supported by and connected to the second mounting member via an elastic support member.

Abstract: A constrained layer damping assembly for a rigid base member having a substantially planar surface comprises a gas impervious damping layer disposed on the substantially planar surface of the base member, and a load element disposed on the damping layer. The damping layer defines at least one void region extending between the planar surface and the load element, and the load element defines at least one channel for coupling a low pressure to the void region relative to the pressure external to the constrained layer damping assembly to establish a pressure differential between the inside of the void region and the outside of the constrained layer damping assembly. The pressure differential keeps the damping layer under compression and secures the load element and the damping layer onto the base member.