22888results about "Non-rotating vibration suppression" patented technology

An electromagnetic linear generator and regenerative electromagnetic shock absorber is disclosed which converts variable frequency, repetitive intermittent linear displacement motion to useful electrical power. The innovative device provides for superposition of radial components of the magnetic flux density from a plurality of adjacent magnets to produce a maximum average radial magnetic flux density within a coil winding array. Due to the vector superposition of the magnetic fields and magnetic flux from a plurality of magnets, a nearly four-fold increase in magnetic flux density is achieved over conventional electromagnetic generator designs with a potential sixteen-fold increase in power generating capacity. As a regenerative shock absorber, the disclosed device is capable of converting parasitic displacement motion and vibrations encountered under normal urban driving conditions to a useful electrical energy for powering vehicles and accessories or charging batteries in electric and fossil fuel powered vehicles. The disclosed device is capable of high power generation capacity and energy conversion efficiency with minimal weight penalty for improved fuel efficiency.

The present invention relates to a variable-torque magnetorheologically actuated prosthetic knee which utilizes a plurality of interspersed and alternating rotors and stators to shear magnetorheological fluid in gaps formed therebetween. Advantageously, by operating in the "shear mode" there is substantially no or negligible fluid pressure buildup or change. Moreover, the multiple MR fluid gaps or flux interfaces desirably allow for the production of a large torque at low speed-eliminating the need for a transmission-and also for a wide dynamic torque range. One embodiment of the invention allows the rotors and / or stators to close the gaps therebetween to create a frictional torque component, thereby forming a "hybrid" braking system which provides a total torque or damping which is a combination of viscous torque and frictional torque.

A damper including a valve movable between an open position and a closed position to selectively alter the compression damping rate of the shock absorber. The valve may include a self-centering feature that operates to keep the valve body centered about the valve shaft. The damper may also include a timer feature, which retains the valve in an open position for a predetermined period of time after it is initially opened.

A regenerative shock absorber that include a housing and a piston that moves at least partially through the housing when the shock is compressed or extended from a rest position. When the piston moves, hydraulic fluid is pressurized and drives a hydraulic motor. The hydraulic motor, in turn, drives an electric generator that produced electric energy. The electric energy may be provided to a vehicle, among other things. The regenerative shock absorber may also provide ride performance that comparable to or exceeds that of conventional shock absorbers.

The present invention relates to a variable-torque magnetorheologically actuated prosthetic knee which utilizes a plurality of interspersed and alternating rotors and stators to shear magnetorheological fluid in gaps formed therebetween. Advantageously, by operating in the "shear mode" there is substantially no or negligible fluid pressure buildup or change. Moreover, the multiple MR fluid gaps or flux interfaces desirably allow for the production of a large torque at low speed-eliminating the need for a transmission-and also for a wide dynamic torque range. One embodiment of the invention allows the rotors and / or stators to close the gaps therebetween to create a frictional torque component, thereby forming a "hybrid" braking system which provides a total torque or damping which is a combination of viscous torque and frictional torque.

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.

An improved damping apparatus that utilizes a fluid having a viscosity that may be varied by the application of an electromagnetic field, such as a magnetorheological fluid or an electrorheological fluid, to provide the damping response. The damping apparatus includes a linear to rotary conversion mechanism which comprises a translatable member that is adapted for linear translation in a forward and a reverse direction and a rotatable member comprising a rotatable shaft that is rotatably coupled to the translatable member; wherein translation of the translatable member in one of the forward or the reverse directions produces a forward or a reverse rotation of the rotatable member and shaft, respectively. The damping apparatus also includes a damping mechanism which comprises a hub that is fixed to the shaft, a means for generating a variable electromagnetic field in response to an applied electrical signal that may be continuously varied in response to an input signal that is representative of a desired damping force and a fluid having a viscosity that may be continuously varied by application of the electromagnetic field that is in touching contact with the hub. Application of the variable electromagnetic field to the fluid produces changes in the viscosity of the fluid that in turn provides variable resistance to rotation of the hub and resistance to translation of the translatable member, thereby providing a damping apparatus with a continuously variable damping response.

A supporting device for supporting in a lithographic projection apparatus a supported part relative to a supporting part, is presented. The supporting device includes a first part that engages the supporting part of the lithographic projection apparatus; a second part that engages the supported part of the lithographic projection apparatus; a supporting spring system disposed between the first part and the second part; and a position control system configured to control a position of the supported part. The position control system comprises at least one reference object that is movable relative to the supporting part; a reference support device that supports the reference object relative to the first part, wherein the reference object and the reference support device form a reference mass-spring system; at least one position sensor that detects at least one attribute of the position of the second part relative to at least one of the reference objects, the position sensor including a sensor output for outputting a position signal representing at least one of the attributes; and an actuator, communicatively coupled to the position sensor, that is configured to adjust the position of the second part relative to the first part, in response to the position signal.

A control system for a resilient support mechanism such as a suspension mechanism of a wheeled vehicle including a damper disposed between an unsprung mass member and a sprung mass member of the vehicle, wherein a damping coefficient of the damper is divided into a linear portion and a nonlinear portion, and wherein the nonlinear portion of the damping coefficient is defined as a control input u and applied with a frequency weight Wu(s), while a vertical velocity of the sprung mass member, a relative velocity of the sprung mass member to the unsprung mass member and a vertical acceleration of the sprung mass member are defined as an evaluation output zp and applied with a frequency weight Ws(s). In the control system, a nonlinear Hinfin control theory is applied to a generalized plant to obtain a positive definite symmetric solution P and to calculate a target damping force based on the positive definite symmetric solution P and a state amount such as the vertical velocity of the sprung mass member, a relative displacement of the sprung mass member to the unsprung mass member or the like.

A guideless stage for aligning a wafer in a microlithography system is disclosed, and a reaction frame is disclosed which isolates both external vibrations as well as vibrations caused by reaction forces from an object stage. In the guideless stage an object stage is disclosed for movement in at least two directions and two separate and independently movable followers move and follow the object stage and cooperating linear force actuators are mounted on the object stage and the followers for positioning the object stage in the first and second directions. The reaction frame is mounted on a base structure independent of the base for the object stage so that the object stage is supported in space independent of the reaction frame. At least one follower is disclosed having a pair of arms which are respectively movable in a pair of parallel planes with the center of gravity of the object stage therebetween. The linear positioning forces of the actuator drive means are mounted and controlled so that the vector sum of the moments of force at the center of gravity of the object stage due to the positioning forces of the drive means is substantially equal to zero. The actuator mounting means can include at least two thin flexible members mounted in series with the primary direction of flex of the members being orthogonal to one another.

Due to variations arising during manufacturing, axial fans often are slightly imbalanced, resulting in noise during operation, which is undesirable in many contexts, for example when the fan is used for ventilation purposes in a motor vehicle. A fan with improved vibration and noise damping can be achieved by elastically suspending the fan wheel within a first ring formed of a hard plastic, the first ring having a tubular extension formed of a softer plastic, and serving to mechanically connect the first ring to a surrounding annular carrier part. Optionally, the first ring and extension unit can include a spring element. Preferably, the first ring and tubular extension are produced by a multi-component forming technology such as two-plastic technology. The fan is preferably driven by an electronically commutated motor (ECM).

Electro-rheological fluid brake or actuator devices provide controllable resistance with or without inclusion of active torque output in either direction of rotation under manual or computer control. The brake and actuator devices are suitable for use in an orthotic device for a joint, such as the knee or elbow.

A hybrid vehicle drive for a motor vehicle includes an internal combustion engine and an electric machine which is selectively coupled with the internal combustion engine. The electric machine can be operated as a generator and as a motor. Regulation device which responds to a reference signal predetermined by a reference signal preset device are provided for the active damping of vibrations, especially torsional vibrations in the torque transmission path between the internal combustion engine and wheels of the motor vehicle driven by the latter. The regulation device also respond to sensing device which deliver an actual-value vibration signal containing vibration information about a rotating structural component of the motor vehicle and control the load torque exerted on the internal combustion engine by the electric machine for reducing or eliminating the vibrations of the structural component. An analysis device for determining a frequency spectrum of the actual-value vibration signal is associated with the regulation device. The reference signal preset device establishes a reference signal with predetermined frequency spectrum. The regulation device control the frequency spectrum of the load torque exerted on the internal combustion engine by the electric machine such that excessive spectral vibrations of the actual-value vibration signal are reduced or eliminated.

A regenerative damper and method for regenerative damping are disclosed. The regenerative damper uses the kinetic energy of undesirable vehicle motion to generate electrical current in a circuit. The electricity is generated by a power screw that operates like an alternator. Vehicle energy efficiency is increased by using the electrical current to charge a battery. The regenerative damper can be semi-active or passive. The semi-active embodiment is able to adapt to operating conditions to improve vehicle ride and handling, whereas the passive embodiment has a fixed response, regardless of operating conditions.

An object of the present invention is to execute an optimum control of vibrations due to a driver's operation of an accelerator pedal, steering wheel and brake pedal. The operation instructions are inputted into a vibration calculating means (kinetic model) comprising a vehicle body model, suspension model and tire model. Conventional kinetic model controlled the suspension in order to suppress the vehicle body vibration. However, in the kinetic model of the present invention, the tire vibration due to a change in the engine output is first absorbed by the suspension, whereby a residual vibration which was not be absorbed yet by the suspension is transferred to the vehicle body. The operation inputs are compensated by the three feed-back loops between the outputs of the above-mentioned three portions and input of the tire portion, giving the highest priority on the vehicle body model.

The invention relates to an automated speed-adaptive and patient-adaptive control scheme and system for a knee prosthesis. The control scheme and system utilizes sensory information measured local to the prosthesis to automatically adjust stance and swing phase knee resistances to a particular wearer under a wide variety of locomotory activities. Advantageously, no patient-specific information needs to be pre-programmed into the prosthetic knee by a prosthetist or the patient. The system is able to adapt to various types of disturbances once the patient leaves the prosthetist's facility because it is patient-adaptive and speed-adaptive.

Methods and apparatus for regulating the function of a suspension system are disclosed herein. Suspension characteristics often contribute to the efficiency of a suspended system. Depending on the desired operating parameters of the suspended system, it may be desirable to alter the functional characteristics of the suspension from time to time in order to maintain or increase efficiency. The suspension hereof may be selectively locked into a substantially rigid configuration, and the damping fluid may be phase separated and / or cooled to increase damping rate during use (or offset rate degradation). The suspension hereof may generate power usable to achieve any or all of the foregoing or to be stored for use elsewhere in the suspended system or beyond.

An electromagnetic shock absorber including: (a) a wheel-side member; (b) a body-side member movable relative to the wheel-side member; and (c) a damping force generator with an electromagnetic motor including stationary and movable elements movable relative to each other. The damping force generator can generate, based on a force generated by the motor, a damping force acting against a relative movement of the wheel-side member and the body-side member. The motor has an axis extending in a both-members-relative-movement direction as a direction of the above-described relative movement. The stationary element is supported by the wheel-side member via an elastic body, to be movable relative to the wheel-side member in the both-members-relative-movement direction. The electromagnetic motor allows relative movement of the stationary element and the movable element upon movement of the stationary element relative to the wheel-side member.

A system and method for controlling a damping system. The system has at least two dampers for damping between sprung and unsprung masses in the compression and rebound directions. Sensors generate signals based on position and other parameters of motion representative of the displacement between the sprung and unsprung masses. The process determines the appropriate compression and rebound forces to be applied at the wheels. A regulator responds to at least one of the independent compression and rebound control signals for adjusting, respectively, at least one of compression and rebound resisting forces of the dampers between the masses. Compliance for the dampers is emulated with software to produce the desired compliance forces. The distributed controller includes a processor that is responsive to signals representative of the position signals for forming the compression and rebound control signals for the regulator as a function of motion between the masses or a motion of a vehicle in which the dampers are located. The system has the capability of locking the suspension when parked.

The invention relates to an automated speed-adaptive and patient-adaptive control scheme and system for a knee prosthesis. The control scheme and system utilizes sensory information measured local to the prosthesis to automatically adjust stance and swing phase knee resistances to a particular wearer under a wide variety of locomotory activities. Advantageously, no patient-specific information needs to be pre-programmed into the prosthetic knee by a prosthetist or the patient. The system is able to adapt to various types of disturbances once the patient leaves the prosthetist's facility because it is patient-adaptive and speed-adaptive.

The invention discloses a six-degree-of-freedom vibration isolation platform based on a Stewart parallel mechanism. Through the combination of active vibration isolation technology, passive vibration isolation technology, the optimized design of the spatial six-degree-of-freedom parallel movement mechanism, the design of flexible mechanisms and the like, designed is the six-degree-of-freedom vibration isolation platform which is capable of rigidly transmitting low-frequency attitude control signals and attenuating high-frequency jamming signals and which is resonance free. A control moment gyro group is integrated in the platform; multi-degree-of-freedom disturbance produced by the control moment gyro group is converted into six independent unidirectional linear vibrations. Telescopic bars are exactly the same in structural design and all provided with an active vibration isolation unit and a passive vibration isolation unit, which are used to isolate the six independent linear vibrations respectively.

A magnetically actuated motion control device includes a housing defining a cavity and including a slot therethrough. A movable member is located within the cavity and is movable relative to the housing. A magnetic field generator located on either the housing or the movable member causes the housing to press against the movable member to develop a friction force.

Electro-rheological fluid brake or actuator devices provide controllable resistance with or without inclusion of active torque output in either direction of rotation under manual or computer control. The brake and actuator devices are suitable for use in an orthotic device for a joint, such as the knee or elbow.

Systems and methods for providing a haptic device are described. In one described system, a first brake surface of a first element contacts a second brake surface of a second element. At least one actuator is configured to exert a force on at least one of the first and second elements. A flexure is coupled to at least one of the first element, the second element, a housing, a manipulandum, and a shaft coupled to the manipulandum. The flexure provides a degree of rotational flexibility to the manipulandum when the at least one actuator exerts the force. The described system may include a processor in communication with the at least one actuator for providing the haptic effects.

An apparatus of a damper (46) for a bicycle comprising a housing defining a chamber, and a piston, movable in the chamber along a first direction. The apparatus further comprises a controllable means to vary the resistance to movement of the piston in the chamber, a sensor (62), and a controller (58) including a timer. Said sensor measures at least one dynamic quantity and produces an output signal based thereon. Said output signal is received by the controller, and said controller controls said controllable means based on said dynamic quantity as a function of time to control the level of damping. The invention further provides means for manually adjusting the level of rebound damping.

A spring carrier for mounting a spring strut to a vehicle body includes a vibration damper having a cylinder and a piston rod which is axially guided in the cylinder, first and second spring collars, and a spring located between the spring collars. An actuator includes a nut and a threaded spindle surrounding the piston rod, the actuator being driven to change the relative axial position of the spring collars. A guide tube extends coaxially between the piston rod and the threaded spindle, the guide tube being fixed to the vehicle body by a first resilient mount, the piston rod being fixed to the guide tube by a second resilient mount, whereby the piston rod can move relative to the first resilient mount.

A strut (12) is configured for an active suspension system (142) which provides electronic control for both the force applied by the strut (12) and the dampening characteristics of the strut (12). A compressible fluid (18) is used within the strut (12), and preferably includes a compressible base fluid and electromagnetic field responsive particles (132) which are suspended in the compressible base fluid. The electromagnetic field responsive particles (132) are preferably closely matched in density and modulas of elasticity to that of the compressible base fluid to prevent sedimentation of the particles (132) and to maintain the elasticity of the compressible fluid (18). The amount compressible fluid (18) within the strut (12) is electronically controlled to determine the force applied by the strut (12) and a field strength applied to the compressible fluid in a fluid flow passage is electronically controlled to determine the dampening characteristics of the strut (12).

A spring carrier for mounting a spring strut to a vehicle body includes a vibration damper having a cylinder and a piston rod which is axially guided in the cylinder, first and second spring collars, and a spring located between the spring collars. An actuator includes a nut and a threaded spindle surrounding the piston rod, the actuator being driven to change the relative axial position of the spring collars. A guide tube extends coaxially between the piston rod and the threaded spindle, the guide tube being fixed to the vehicle body by a first resilient mount, the piston rod being fixed to the guide tube by a second resilient mount, whereby the piston rod can move relative to the first resilient mount.