Abstract: A flow controlled sound generation system is disclosed that includes one or more fluid pumps to control air flow through a sound channel. The air flow is modulated through one or more valves to produce audible frequency pressure waves.

Abstract: A flow controlled sound generation system is disclosed that includes one or more fluid pumps to control air flow through a sound channel. The air flow is modulated through one or more valves to produce audible frequency pressure waves.

Abstract: An adaptable seismic source system that includes a first seismic source having at least one moving plate and a second seismic source also having at least one moving plate. Each of the moving plates of the first and second seismic sources creating a pressure wave. Each seismic source is comprised of a fixed center plate having opposed sides and a pair of movable plates that are arranged at respective opposed sides of the center plate; a coupling member that is disposed between the first and second seismic sources for enabling a sliding action between the first and second seismic sources and a controller coupled with the first and second seismic sources for exciting the seismic sources to provide a combined output with a lower frequency spectrum.

Abstract: A flow controlled sound generation system is disclosed that includes one or more fluid pumps to control air flow through a sound channel. The air flow is modulated through one or more valves to produce audible frequency pressure waves.

Abstract: A seismic shaker for exercising an excitation force on the ground has a base plate and a reaction mass connected to the base plate via a resilient structure and an actuator parallel thereto. A first comparison unit sends a difference signal which is the difference between a displacement measured by a displacement sensor and a set value of the displacement. A control unit calculates a correction value as a function of this difference signal, and sends it to a second comparison unit, which adds the correction value to a value of the excitation force to be exerted set in the second comparison unit. This second comparison unit is connected to a controller unit which controls the actuator. At Low frequency this position control will track the ground force through the position set-point. The position feedback loop will be able to suppress the interfering force of the spring and any hysteresis.

Abstract: A flow controlled sound generation system is disclosed that includes one or more fluid pumps to control air flow through a sound channel. The air flow is modulated through one or more valves to produce audible frequency pressure waves.

Abstract: The present technology is directed to apparatuses, systems, and methods for improving the performance of non-contact vibrometers in the presence of platform motion and speckle noise. In addition, systems and methods are described that allow intentional frequency displacement of heterodyne and/or homodyne vibrometer returns to enable disambiguation of the sign of the vibration direction in the presence or absence of platform motion.

Abstract: A system for passing electrical signals through a living body has a transmitter on one side of a body for feeding thereto a predetermined electrical signal on at least two separate channels on respective different frequencies and a receiver on the other side of the body for receiving the signal on each of the channels. An evaluating unit connected to the receiver evaluates the received signals and selecting from them one signal for further processing.

Abstract: A technique includes determining at least one parameter that characterizes a seismic survey in which multiple interfering seismic sources are fired and seismic sensors sense energy that is produced by the seismic sources. The determination of the parameter(s) includes optimizing the seismic survey for separation of the sensed energy according to the seismic sources.

Abstract: Systems, sensors, and methods for high-speed image monitoring of baseplate movement in a vibrator. The systems can include a baseplate defined by an area, disposable at a ground surface to direct a seismic force into the ground surface. The system can include a reaction mass coupled to and positioned above the baseplate to generate the seismic force at the baseplate. The system can include an actuator assembly coupled to the reaction mass to vibrate the reaction mass, as well as high-speed image units directed at the area of the baseplate. The high-speed image units can include photo detectors to sense a distribution of acceleration across the area of the baseplate, and a light source emit light to be sensed by the photo detectors. The system can also include a controller coupled to the actuator assembly, that drives the actuator assembly.

Abstract: A technique includes modeling a fundamental component of a vibroseis sweep that is injected into the earth based on a ground force measurement and a reference sweep. The technique includes determining an operator to compensate seismic data acquired in response to the injected vibroseis sweep based at least in part on the reference sweep and the fundamental component, and the technique includes applying the operator to the seismic data.

Abstract: An explosion-proof system for generating acoustic energy. An exemplary embodiment of the system includes a main housing defining an open housing space and an opening. A cover structure is configured for removable attachment to the main housing structure to cover the opening and provide an explosion-proof housing structure. The cover structure includes an integral head mass. An acoustic energy emitting assembly includes the head mass, and an excitation assembly disposed within the explosion-proof housing structure. An electronic circuit is disposed within the explosion-proof housing structure to generate a drive signal for driving the excitation assembly to cause the acoustic energy emitting assembly to resonate and generate acoustic energy. In one embodiment the acoustic energy is a beam of ultrasonic energy useful for testing ultrasonic gas detectors. A method is also described for testing ultrasonic gas leak detectors using an ultrasonic source.

Abstract: The infrasound generating device based on a displacement-feedback type vibration exciter comprises a displacement-feedback type vibration exciter system, an infrasound generating chamber (3) and a laser vibrometer (1); the displacement feedback mechanism is adopted in the vibration exciter (2). The piston (31) is driven by the vibration exciter to move in a sinusoidal manner in the cavity (35) of the airtight infrasound generating chamber (3) and the standard infrasonic pressure signal with low harmonic distortion can be achieved. The displacement of the moving part (22) of the vibration exciter (2) can be measured by the laser vibrometer (1) through the measurement beam (15) injecting into the vibration exciter (2) through the optical channel running through the vibration exciter and the standard infrasonic pressure can also be obtained. The value of the standard sound pressure produced by the infrasound generating chamber is calculated.

Abstract: To reproduce sound in an extremely compact size, fluid injectors are used that can generate fluid flow sufficient to create a desired acoustic pressure wave, but which fluid flow operates in a manner that is decoupled from the desired acoustic pressure wave. Fluid flow within the fluid injectors needed to generate the desired acoustic pressure wave need not be directly proportional to the frequencies of the desired acoustic pressure wave. The fluid injector has a control input capable of altering fluid flow relative to a received control signal, which is generated by a controller in response to an electrical signal. The fluid injector produces fluid flow outward and inward in response to the control signal, thereby creating an acoustic wave proportional to the electrical signal. The devices herein may employ valves or not. Synthetic jets may also be used.

Abstract: In one embodiment of the invention a method includes (a) operating a combustion engine at a first activity level corresponding to a first noise level; (b) charging an accumulator with a first pressure input; (c) lowering engine activity level of the engine to a second activity level corresponding to a second noise level that is lower than the first noise level; and (d) seismic sweeping with the vibrator based on the first pressure input and lowering engine noise from the first noise level to the second noise level.

Abstract: The invention is an electric sweep type seismic vibrator source of the type used in seismic prospecting for hydrocarbons. The source uses an engine and generator combination to create electric power for all systems on the source such as driving a frame of linear electric motors that direct a rod or piston to contact the ground in a recurring fashion along with driving the source from location to location through a survey area. The seismic source includes systems for driving the acoustic energy systems using electric energy concurrently from both the generator and an electric energy accumulator such as a capacitor or battery, systems for adjusting the weight on the acoustic energy delivery system by raising and lowering wheels individually and an active energy isolation to isolate the chocks and impulses of the acoustic energy delivery system from the remainder of the seismic source.

Abstract: A seismic survey method including determining an expected time when an actuation step will be performed by a seismic source device, transmitting a signal from the seismic source device to a source control system thereby alerting the source control system of the expected time when the actuation step will be performed by the seismic source device; and in response to the signal from the seismic source device, providing a communication from the source control system to the seismic source device.

Abstract: A bender bar is presented. The bender bar includes at least two pairs of piezoelectric elements arranged on an inert element to adjust the response frequency of the bender bar. In some embodiments, the piezoelectric elements can be stacked on the inert element. In some embodiments, the piezoelectric elements are symmetrically arranged with respect to the bender bar such that a gap is formed between piezoelectric elements arranged on the inert element.

Abstract: A method for manufacturing a condenser microphone includes forming a diaphragm module using microelectromechanical system (MEMS) techniques. The diaphragm module includes a diaphragm that is deformable by energy of sound waves, and a diaphragm spacer that extends from one side of the diaphragm and controls a tension of the diaphragm. The method further includes providing a backplate with vent holes, aligning the vent holes of the backplate with a central region of the diaphragm, and connecting the backplate to the diaphragm spacer to construct a transducer unit. The diaphragm spacer, the diaphragm and the backplate cooperate to form an air chamber in fluid communication with an environment external to the condenser microphone. The backplate and the diaphragm cooperate to form a condenser. The method further includes enclosing the transducer unit in a housing that includes a shell and a circuit board to form the condenser microphone.

Abstract: The invention relates to maintaining constant holddown force on the vibrator baseplate during actuation. The invention described measures the weight on the point of locomotion verses the baseplate and dynamically adjusts the forces required to keep the holddown force on the baseplate constant.

Abstract: Systems and methods for adapting the performance of an acoustic communication link with an implantable medical device (IMD) are disclosed. An illustrative method includes initiating an acoustic link with the IMD, measuring an initial performance of the acoustic link, determining whether the initial performance of the acoustic link is adequate, adjusting an operating parameter related to the acoustic link in the event the initial performance of the acoustic link is inadequate, measuring a performance of the acoustic link in response to the adjusted operating parameter, and setting the operating parameter to a prior setting if the measured performance of the acoustic link does not improve in response to the adjusted operating parameter.

Abstract: A seismic source signal generator having feed-forward control uses pressure, current, and/or valve position sensors to detect system component parameters. Initial and operating parameters are processed during source operation to remove, partially or wholly, harmonic distortions from the seismic source signal.

Abstract: A seismic source signal generator includes a mass, a primary accumulator and a secondary accumulator, the secondary accumulator having an internal volume smaller than an internal volume of the primary accumulator. A method for generating a signal using a seismic vibrator includes operating the seismic vibrator using hydraulic fluid, damping hydraulic pressure deviations in the hydraulic fluid using a first accumulator in hydraulic communication with the hydraulic fluid, and damping pressure deviations in the hydraulic fluid using a second accumulator in hydraulic communication with the hydraulic fluid, the second accumulator having an internal volume smaller than an internal volume of the first accumulator.

Abstract: A seismic source signal generator having feed-forward control uses pressure, current, and/or valve position sensors to detect system component parameters. Initial and operating parameters are processed during source operation to remove, partially or wholly, harmonic distortions from the seismic source signal.

Abstract: A method for controlling output of a marine seismic vibrator includes operating the vibrator using a predetermined driver signal. A vibrator output signal is measured at at least two different places on the vibrator. The at least two measured vibrator output signals are used to determine a corrected driver signal, wherein the corrected driver signal results in fewer harmonics of fundamental frequencies in the vibrator output. The vibrator is operated using the corrected driver signal.

Abstract: A technique includes operating a seismic vibrator, including driving the seismic vibrator at different frequencies and driving forces. The technique includes monitoring a parameter affected by the operation of the seismic vibrator during the frequency sweep and based at least in part on the monitored parameter, determining a maximum driving force profile for the seismic vibrator.

Abstract: A seismic source signal generator having feed-forward control having pressure, current and/or valve position sensors that detect system component parameters. Initial and operating parameters are processed during source operation to remove, partially or wholly, harmonic distortions from the seismic source signal.

Abstract: A method for the simultaneous operation of multiple seismic vibrators using unique modified pseudorandom sweeps and recovery of the transmission path response from each vibrator is disclosed. The vibrator sweeps are derived from pseudorandom binary sequences modified to be weakly correlated over a time window of interest, spectrally shaped and amplitude level compressed. Cross-correlation with each pilot signal is used to perform an initial separation of the composite received signal data set. Recordings of the motion of each vibrator are also cross-correlated with each pilot, windowed, and transformed to form a source cross-spectral density matrix in the frequency domain useful for source signature removal and for additional crosstalk-suppression between the separated records. After source signature removal in the frequency domain an inverse transform is applied to produce an estimate of each source-to-receiver earth response in the time domain.

Abstract: One example of a seismic vibrator system includes a baseplate having a bottom surface and a coupling mechanism, the coupling mechanism being operable to a deployed position; a hold-down mass connected to the baseplate; a lifting mechanism in operational connection with the hold-down mass and the baseplate to apply a selected hold-down weight to the baseplate; and a driving mechanism functionally connected to the baseplate to transmit seismic energy through the baseplate into a ground surface to which the baseplate is coupled, wherein the coupling mechanism is urged outward from the bottom surface and into physical contact with the ground surface when operated to the deployed position.

Abstract: This invention relates to an improvement in systems, methods and apparati for handling and processing information, energy and matter by making use of potentials of new technologies, science and industrial art, principally in cymatics, quantum field theory and psychoenergetic science. It comprises a system of methods and apparati for handling information, energy and material using multimodal cymatic (standing wave patterning, whether stationary or moving) generation, and manipulation, principally of material and energy in vorticoid including concatenated and grouped vorticoid forms, to concentrate, cleanse, separate, transform, produce etc., materials and energy, including without limitation the production of clean water and manufactures materials, the production of net usable energy by effects such as Schauberger and vacuum potential-related, the collection, processing and communication of information by nonlocal quantum coherence (entrainment) of dynamic systems, initially cymatic, viz.

Abstract: A seismic source signal generator includes a mass, a primary accumulator and a secondary accumulator, the secondary accumulator having an internal volume smaller than an internal volume of the primary accumulator. A method for generating a signal using a seismic vibrator includes operating the seismic vibrator using hydraulic fluid, damping hydraulic pressure deviations in the hydraulic fluid using a first accumulator in hydraulic communication with the hydraulic fluid, and damping pressure deviations in the hydraulic fluid using a second accumulator in hydraulic communication with the hydraulic fluid, the second accumulator having an internal volume smaller than an internal volume of the first accumulator.

Abstract: The force exerted by a reciprocating actuator is estimated as a weighted sum of three quantities: a reaction-mass acceleration, a baseplate acceleration, and a relative acceleration of the reaction-mass relative to the baseplate. In one embodiment, acceleration sensors measure the reaction-mass acceleration and the baseplate acceleration; and a displacement transducer measures a relative displacement of the reaction-mass relative to the baseplate. A double-differentiator generates the value of the relative acceleration from the second derivative of the relative displacement. In the sum, the relative acceleration is weighted by factor representative of the ratio of the difference between the masses of the reaction-mass and the baseplate to the sum of the masses of the reaction-mass and the baseplate.

Abstract: The present invention relates to a polymer electrolyte membrane fuel cell with a water removing structure capable of improving a performance of the fuel cell itself due to water removing efficiency higher than that of a conventional fuel cell. It is an object of the present invention to provide a vibration generator removing water using vibration and sound unlike the prior arts to activate an electrochemical reaction and a polymer electrolyte membrane fuel cell having a more compact and efficient water removing structure by comprising the vibration generator.

Abstract: The method for exploring desired characteristics of a subsurface sector, having at least one resonant frequency, is based on selectively transmitting suitable narrowband energy waves into the subsurface sector, thereby producing narrowband signals reflected off the subsurface sector. The transmitted narrowband energy waves can be selectively and optimally adjusted in real time so as to provide optimum illumination of the desired characteristics from the explored sector.

Abstract: The invention relates to an apparatus and method for imparting a precise amount of impulse energy to be delivered to the ground. The apparatus includes an anvil for operative deployment against the earth a hammer operatively connected to the anvil for striking the anvil; and a control system operatively connected to the hammer for controlling the impulse energy of the hammer striking the anvil. The control system includes a linear feedback system for measuring the linear position of the hammer with respect to the anvil during a force stroke and a processor for receiving linear position data from the linear feedback system for controlling the relative speed of the hammer with respect to the anvil during a force stroke through an actuation system.

Abstract: An adaptive controller is used to adaptively generate vibration cancellation signals driving a controlled device which effects an associated vibration and noise-producing plant. The adaptive controller has multiple control paths to generate the control signal. In a vibration attenuation control path(s), an adaptive control signal is generated by plant compensation and adaptive filtering techniques to cancel vibrations. In a position control, saturation prevention path, the available operational extents of the controlled device are monitored and compensation signals are generated which direct the movement of the controlled device in such a manner as to prevent the controlled device from reaching the extents of control. The control signals from the multiple paths are then combined and transmitted to the controlled device which alters in some fashion the noise and vibration being generated or transmitted by the associated vibrating plant.

Abstract: A multivibrator waveform monitoring system uses a plurality of seismic energy sources for giving vibrations to strata and a prospector, connected to a geophone, for measuring reflected vibrations. Each of the plurality of seismic energy sources includes a vibrator, a communication unit and a control unit for controlling the starting of the vibrator based on phase difference cancellation information and an operation starting instruction from the prospector. The prospector includes a communication unit and a synchronization control unit for controlling the synchronization of each of the seismic energy sources.

Abstract: A method for cascading or linking seismic vibrator sweeps to form a cascaded sweep sequence. According to the method, a first cascaded sweep sequence is generated containing N sweep segments linked end-to-end. The N sweep segments are substantially identical, except that the initial phase angle of each sweep segment within the sweep sequence is progressively rotated by a constant phase increment of about 360/N degrees. A second cascaded sweep sequence is generated consisting of (i) N consecutive sweep segments linked end-to-end which correspond to said first cascaded sweep sequence and (ii) an additional sweep segment linked to the N consecutive sweep segments which is positioned and phased so as to substantially suppress harmonic ghosts during correlation. One of these cascaded sweep sequences is used for the vibrator sweep sequence and the other is used for the correlation reference sequence.

Abstract: A method for processing seismic vibrator data. The method utilizes a deterministic signature deconvolution of the vibrator data to compress the impulse response of the data resulting in sharper, clearer seismic images than are possible using cross-correlation techniques. The method may be used in place of or in addition to cross-correlation. Further, the method may be implemented in either the time domain or the frequency domain.

Abstract: A sweep frequency vibrator is set forth. It has an elongate cylindrical housing closed at the top and bottom ends. On the interior, there is a reactionary mass fixed to identical upper and lower piston ends. They are received in seal isolated chambers, one being formed in a moveable plug. The plug is moved to thereby vary the spacing of the chambers. As the frequency is changed, plug is moved to assure sufficient clearance from the excursion of the reactionary mass. Hydraulic oil under pressure is delivered to control valves, one for each piston end. The two control valves and piston ends have very short flow lines. Moreover the excursion permitted for the plug assures operation without bottoming out.

Abstract: A multivibrator waveform monitoring system uses a plurality of seismic energy sources for giving vibrations to strata and a prospector, connected to a geophone, for measuring reflected vibrations. Each of the plurality of seismic energy sources includes a vibrator, a communication unit and a control unit for controlling the starting of the vibrator based on phase difference cancellation information and an operation starting instruction from the prospector. The prospector includes a communication unit and a synchronization control unit for controlling the synchronization of each of the seismic energy sources.

Abstract: An apparatus for reducing harmonic distortion and causing a more linear response in a hydraulic vibrator apparatus which generates a seismic signal into the surface of the earth is disclosed. The force developed in the actuator of a hydraulic vibrator is directly related to pressure applied to the hydraulic piston. Conventional vibrators use flow control type servovalves to develop this pressure. Changes in loading due to earth surface conditions reflect back as changes in pressure across the hydraulic piston. Pressure can be better controlled in the actuator such that it varies only as a function of the input signal, and the natural response of a vibrator can be made more linear, and the harmonic distortion can be reduced by using a pressure control type servovalve.

Abstract: Vibrations in borehole equipment are controlled by defining the energy flow through the equipment as the product of an "across" variable and a "through" variable, wherein fluctuations in one variable are measured and the energy flow is controlled by adjusting the other variable in response to the measured fluctuations in said one variable. Suitable variables for defining the energy flow are voltage times current of an electrical drive, pressure times flow rate of a hydraulic drive, or torque times angular velocity of any rotary drive.

Abstract: An apparatus and method for maximizing the shear wave energy imparted into the soil upon the impacting of a base plate by an impact mass from a seismic generator. A seismic generator is disposed at an angle relative to a line generally perpendicular to the surface to the ground. The angle varies with soil conditions and the angle is determined by locating an accelerometer on the base plate of the generator and observing the horizontal acceleration rate as indicated by the accelerometer. If the acceleration rate exceeds a predetermined value, the anguular disposition of the generator s changed to decrease the angle either manually or automatically until the acceleration rate no longer exceeds a predetermined value.

Abstract: Air wave noise caused by a vibrating baseplate on a seismic vibrator is reduced or eliminated through active cancellation of sound. In active cancellation, the detection of acceleration of the baseplate is used to form a counterpart wave which is equal in amplitude but opposite in phase; a speaker produces an opposite air wave to cancel the baseplate air wave.

Abstract: The disclosure relates to a seismic vibrator having an airbag isolator, a transducer for monitoring the instantaneous air pressure within the airbags, a summer to add the pressures within each air bag and a calibrated weighting network to convert the composite pressure for display as holdown weight on a meter and for comparing the measured holdown against a preset threshold that is used to enable or disable sweep generation or operation of an inducer. The system also includes structure for comparing the measured holdown against a preset threshold that is used as a feedback signal to the lift system and for providing a signal proportional to holdown weight to the sweep generator for use as a feedback signal to modify the amplitude of the force generated by the actuator.

Abstract: An electromagnetic vibrator for seismic and civil-engineering applications is provided with a supporting structure fitted with a coupling element, and a reaction mass, which is to be caused to vibrate, with an electromagnetic drive associated therewith and provided at least with electromagnetic coils. The reaction mass is magnetically suspended on the supporting structure by means of one or more magnets with the associated electromagnetic coils and is at the same time caused to vibrate by the electromagnetic drive. The vibration force is exerted on the pole surface of the one or more magnets and the reaction mass is accelerated to at most the acceleration due to gravity.

Abstract: A hydraulic vibrator having an adjustable piston rod and a fixed piston rod to vary the cylinder volume for operation at different vibration frequencies. The adjustable piston rod is in threaded engagement with the fixed piston rod and has a piston head adjacent a piston head on the fixed piston rod. Rotation of the adjustable piston rod displaces the two piston heads, thereby varying the cylinder volume of the hydraulic vibrator.

Abstract: A field quality control system and real-time method for evaluating the performance of swept frequency vibrators is provided. The system includes independent sensing means adapted to be mounted with the swept frequency vibrators for developing signals representative of reaction mass accelerations and baseplate accelerations, and means for monitoring the swept frequency vibrator's pilot signal. The system also includes a signal calculating means for determining vibrator operating characteristics from the pilot sweep signal, reaction mass acceleration signal, and baseplate acceleration signal and processing means for processing the vibrator operating characteristics to obtain analysis characteristics for evaluating and adjusting the performance of the swept frequency vibrator. In operation, the present invention provides a method for analysis characteristics to analyze and adjust the performance of swept frequency vibrators in real-time on location.

Abstract: A differential transformer is used as a feedback sensor for generating an error signal sensed at the face of an element of a sonar transducing array. This error signal is used to correct the excitation signal to the transducer to correct both phase and amplitude errors in the vibration of the radiating surface of the transducer. In this way, the transmitting beam pattern for the sonar array is improved. The differential transformer is capable of sensing the mechanical motion of the transducer radiating surface without being affected by a strong electric or magnetic field. By using a separate differential transformer sensor and processing circuit for each transducer in the array, electrical cross-talk between the individual elements of the array is eliminated.