1171results about "Resonant frequency" patented technology

A method for detecting transverse mode vibrations in an ultrasonic hand piece / blade for determining the existence of unwanted vibration in the hand piece / blade. A tracking filter centered at the drive frequency of the generator, is used to monitor the drive frequency of the ultrasonic generator and attenuate the drive signal when it exceeds a predetermined level. The tracking filter has a wide pass band. Alternatively, a tracking filter having a pass band which is divided into several regions is used to avoid other longitudinal resonances, such as a resonance at a second harmonic, or other spectral features that would otherwise detract from the tracking accuracy of the filter.

A method for the detection of analytes using resonant mass sensors or sensor arrays comprises frequency encoding each sensor element, acquiring a time-domain resonance signal from the sensor or sensor array as it is exposed to analyte, detecting change in the frequency or resonant properties of each sensor element using a Fourier transform or other spectral analysis method, and classifying, identifying, and / or quantifying analyte using an appropriate data analysis procedure. Frequency encoded sensors or sensor arrays comprise sensor elements with frequency domain resonance signals that can be uniquely identified under a defined range of operating conditions. Frequency encoding can be realized either by fabricating individual sensor elements with unique resonant frequencies or by tuning or modifying identical resonant devices to unique frequencies by adding or removing mass from individual sensor elements. The array of sensor elements comprises multiple resonant structures that may have identical or unique sensing layers. The sensing layers influence the sensor elements' response to analyte. Time-domain signal is acquired, typically in a single data acquisition channel, and typically using either (1) a pulsed excitation followed by acquisition of the free oscillatory decay of the entire array or (2) a rapid scan acquisition of signal from the entire array in a direct or heterodyne configuration. Spectrum analysis of the time domain data is typically accomplished with Fourier transform analysis. The methods and sensor arrays of the invention enable rapid and sensitive analyte detection, classification and / or identification of complex mixtures and unknown compounds, and quantification of known analytes, using sensor element design and signal detection hardware that are robust, simple and low cost.

A diagnostic device for use in a industrial process includes monitoring electronics or diagnostic circuitry configured to diagnose or identify a condition or other occurrence in the industrial process. The system can be implemented in a process device such as a flowmeter, and in one example an acoustic flowmeter. A transducer can also be used and a frequency response, such as resonant frequency, can be observed.

Methods and apparatus for screening diverse arrays of materials are provided. In one aspect, systems and methods are provided for imaging a library of materials using ultrasonic imaging techniques. The system includes one or more devices for exciting an element of the library such that acoustic waves are propagated through, and from, the element. The acoustic waves propagated from the element are detected and processed to yield a visual image of the library element. The acoustic wave data can also be processed to obtain information about the elastic properties of the library element. In another aspect, systems and methods are provided for generating acoustic waves in a tank filled with a coupling liquid. The library of materials is then placed in the tank and the surface of the coupling liquid is scanned with a laser beam. The structure of the liquid surface disturbed by the acoustic wave is recorded, the recorded disturbance being representative of the physical structure of the library. In another aspect of the invention, a mechanical resonator is used to evaluate various properties (e.g., molecular weight, viscosity, specific weight, elasticity, dielectric constant, conductivity, etc.) of the individual liquid elements of a library of materials. The resonator is designed to ineffectively excite acoustic waves. The frequency response of the resonator is measured for the liquid element under test, preferably as a function of time. By calibrating the resonator to a set of standard liquids with known properties, the properties of the unknown liquid can be determined. An array of library elements can be characterized by a single scanning transducer or by using an array of transducers corresponding to the array of library elements. Alternatively, multiple resonators of differing design may be used to evaluate each element of a library of elements, thus providing improved dynamic range and sensitivity.

A method for determining the quality of an examined weld joint comprising the steps of providing acoustical data from the examined weld joint, and performing a neural network operation on the acoustical data determine the quality of the examined weld joint produced by a friction weld process. The neural network may be trained by the steps of providing acoustical data and observable data from at least one test weld joint, and training the neural network based on the acoustical data and observable data to form a trained neural network so that the trained neural network is capable of determining the quality of a examined weld joint based on acoustical data from the examined weld joint. In addition, an apparatus having a housing, acoustical sensors mounted therein, and means for mounting the housing on a friction weld device so that the acoustical sensors do not contact the weld joint. The apparatus may sample the acoustical data necessary for the neural network to determine the quality of a weld joint.

A method of analysing tachometer and vibration response data from an apparatus having one or more rotary components is provided. The method comprises the steps of: providing vibration response data and corresponding tachometer data from the apparatus for a period over which a rotary component of the apparatus varies in rotational speed, the tachometer data being for that component; repeatedly performing at intervals throughout the period the sub-steps of: determining a forcing frequency of the component from the tachometer data and a corresponding vibration response frequency of the apparatus from the vibration response data, comparing the forcing and vibration response frequencies to determine the relative phase difference between the frequencies, and determining the corresponding amplitude of the vibration response from the vibration response data; and plotting the relative phase differences and vibration amplitudes on a polar diagram. The plot trajectory is characteristic of the behavior of the apparatus over the period.

A method of analysing tachometer and vibration response data from an apparatus having one or more rotary components is provided. The method comprises the steps of: providing vibration response data and corresponding tachometer data from the apparatus for a period over which a rotary component of the apparatus varies in rotational speed, the tachometer data being for that component; repeatedly performing at intervals throughout the period the sub-steps of: determining a forcing frequency of the component from the tachometer data and a corresponding vibration response frequency of the apparatus from the vibration response data, comparing the forcing and vibration response frequencies to determine the relative phase difference between the frequencies, and determining the corresponding amplitude of the vibration response from the vibration response data; and plotting the relative phase differences and vibration amplitudes on a polar diagram. The plot trajectory is characteristic of the behaviour of the apparatus over the period.

Disclosed is a piezoelectric resonator, a process for the fabrication thereof and its use as a sensor element, which implemented in a through-flow cell, is integratable in a measurement system for the determination of the concentration of a substance contained in a liquid and / or for the determination of the physical properties of the liquid. The piezoelectric resonator is designed plane and is provided on its surface with electric contact areas for an electrode and a counter electrode, which is connectable to a signal source as well as to a measurement device. For measuring, the piezoelectric resonator is brought into contact with the to-be-examined liquid on one side, with the resonator responding to the accumulation of the mass of the to-be-detected substance or to a change in the physical properties of the liquid by changing its resonance frequency and / or oscillation amplitude.The present invention is distinguished by the fact that the piezoelectric resonator is provided with contact electrode areas which is contactable from one single side of the resonator. The resonator is the heart piece of a sensor element, which is integrated in a through-flow cell. The through-flow cell us insertable module-like in a measurement arrangement for determining the concentration of a substance contained in a liquid and / or determining the physical properties of the liquid.

Described is an apparatus for detecting and removing deposits from a surface exposed to wellbore fluids. The apparatus can monitor the rate of deposition and subsequently remove the deposited material. The combination of detection apparatus and removal apparatus provides an instrument with self-cleaning operation mode.

A control system is operable to selectably activate shock damping devices associated with a bicycle so as to eliminate bobbing encountered under extreme pedaling conditions. The system includes a crank axle torque detector which operates to detect a level of torque applied to a crank axle and provide a control signal corresponding to the level of torque. A shock damping device is coupled to the frame of the cycle, and functions to absorb and dampen mechanical shocks communicated to the frame. The shock damping device includes an activator for controlling its damping function. The activator is operable to receive the control signal from the crank axle torque detector and control the shock damping device in response thereto. The control signal may be an electrical or a mechanical signal.

The present invention provides systems and methods to use a measured driving-point response of a nonlinear material to determine one or more elastic properties of the material. The present invention takes advantage of the full information represented by the transient component, the steady-state component, the anharmonic components, and the nonlinear response components of a measured driving-point response of a real nonlinear material, without limitation in the use of large-amplitude forces. The elastic properties are determined by forming and solving a time-domain system of linear equations representing a differential equation model of the driving-point motions of the material. Based on a single, short duration, large-amplitude driving point measurement, both linear and nonlinear properties can be determined; both large-amplitude and near-zero amplitude properties can be determined; and elastic-wave speed and elastic moduli and their variation with depth can be determined. The present invention also provides a system and a method to filter an input signal to either attenuate or preserve each of one or more selected harmonic components that are harmonics of a phase reference signal.

A method for measuring a mechanical property of a subject includes using an ultrasonic transducer to apply ultrasonic vibration pulses to a vibration origin in the subject in an on-off time sequence in order to impart a harmonic motion at a prescribed frequency to the subject, and when the vibration pulses are off, using the same transducer to apply ultrasonic detection pulses to a motion detection point and to receive echo signals therefrom in order to sense the harmonic motion on the subject at the motion detection point. From the harmonic signal information, a harmonic signal is detected and a characteristic such as amplitude or phase of the detected harmonic signal is measured. The mechanical property is calculated using the measured characteristic using for example a wave speed dispersion method.

A system and method for detecting structural damage is provided that utilizes a general order perturbation methodology involving multiple perturbation parameters. The perturbation methodology is used iteratively in conjunction with an optimization method to identify the stiffness parameters of structures using natural frequencies and / or mode shape information. The stiffness parameters are then used to determine the location and extent of damage in a structure. A novel stochastic model is developed to model the random impact series produced manually or to generate a random impact series in a random impact device. The random impact series method or the random impact device can be used to excite a structure and generate vibration information used to obtain the stiffness parameters of the structure. The method or the device can also just be used for modal testing purposes. The random impact device is a high energy, random, and high signal-to-noise ratio system.

The present invention provides systems and methods to used a measured driving-point response of a nonlinear material to determined one or more elastic properties of the material. The present invention takes advantage of the full information represented by the transient component, the steady-state component, the anharmonic components, and the nonlinear response components of a measured driving-point response of a real nonlinear material, without limitation in the use of large-amplitude forces. The elastic properties are determined by forming and solving a time-domain system of linear equations representing a differential equation model of the driving-point motions of the material. Based on a single, short duration, large-amplitude driving point measurement, both linear and nonlinear properties can be determined; both large-amplitude and near-zero amplitude properties can be determined; and elastic-wave speed and elastic moduli and their variation with depth can be determined.

A diagnostic device for use in a industrial process includes monitoring electronics or diagnostic circuitry configured to diagnose or identify a condition or other occurrence in the industrial process. The system can be implemented in a process device such as a flowmeter, and in one example an acoustic flowmeter. A transducer can also be used and a frequency response, such as resonant frequency, can be observed.

A mass sensor including: a connecting plate having one or more slit(s) and / or opening portion(s) formed therein and / or having a thin-walled portion and a thick-walled portion formed therein; a diaphragm joined with the connecting plate at respective side surfaces; a piezoelectric element; a sensing plate with the piezoelectric element being provided at least at one part on at least one surface of the sensing plate, which has its side surface joined with a side surface of the connecting plate in the direction perpendicular to the joining direction of the diaphragm and the connecting plate; and a sensor substrate with which at least a part of side surfaces of the connecting plate as well as the sensing plate are joined, and the diaphragm, the connecting plate, the sensing plate, and the piezoelectric element form a resonating portion. The mass sensor can conveniently be used for determining the mass of a substance to be sensed by measuring changes in resonant frequencies caused by changes in the mass of the diaphragm on which a catching substance for catching a substance to be sensed by reacting only with the object of sensing is applied.

Apparatus and methods to form high efficiency and uniform Fresnel lens arrays for ultrasonic liquid manipulation are provided. An ultrasonic transducer array may be fabricated by forming top and bottom electrodes on top and bottom surfaces of a sensor plate. The ultrasonic transducer array may generate ultrasonic energy to manipulate one or more samples. Each of the top and bottom electrodes may be coupled to a radio frequency source and arranged to form one of a solid shape or a pattern. Additional apparatus and methods are disclosed.

An array of piezoelectric resonators used in a sensor device in order to identify chemical and biological agents. The resonators can operate as bulk acoustic wave (BAW), surface acoustic wave (SAW), or Love mode devices. The sensor device integrates gravimetric, calorimetric, thermal gravimetric, voltage gravimetric and optical detection methods into one sensor system, improving the accuracy of identifying hazardous agents. For gravimetric detection, dual-mode resonators provide simultaneous calorimetric and gravimetric data, one type from each mode. Resonators with heaters on the surfaces will provide thermal gravimetric data. An optical detector can be used to analyze the optical signal from the surface of a coated resonator. Additionally, voltage gravimetric measurements can be made with an electric field set up between the resonator and an external electrode. Thermal voltage gravimetric measurements can be made by adding an integrated heater on the resonator with an external electrode. An alarm can be activated upon the identification of a hazardous agent. The sensor device can utilize other valuable information, including traceable time, GPS location, and variables related to temperature, humidity, air speed, and air direction.

A method for measuring a mechanical property of a subject includes using an ultrasonic transducer to apply ultrasonic vibration pulses to a vibration origin in the subject in an on-off time sequence in order to impart a harmonic motion at a prescribed frequency to the subject, and when the vibration pulses are off, using the same transducer to apply ultrasonic detection pulses to a motion detection point and to receive echo signals therefrom in order to sense the harmonic motion on the subject at the motion detection point. From the harmonic signal information, a harmonic signal is detected and a characteristic such as amplitude or phase of the detected harmonic signal is measured. The mechanical property is calculated using the measured characteristic using for example a wave speed dispersion method.

A method of analyzing vibrations of a rolling element bearing installed in a rotating machine includes accessing vibration data corresponding to the bearing to be analyzed, determining a degraded condition factor BD for the bearing, selecting an expected designer-determined mean-time-to-failure MTTF of the bearing operating under a design load in the operating environment of the rotating machine, selecting a forecast time period, calculating a reduced mean-time-to-failure RMTTF of the bearing using the expected designer-determined mean-time-to-failure MTTF and the degraded condition factor BD, calculating a probability of failure of the bearing in the forecast time period using the reduced mean time to failure RMTTF, accessing cost data corresponding to a cost of failure of the bearing in the rotating machine, calculating a financial risk from the calculated probability of failure in the forecast time period and the cost data, and displaying the financial risk for the selected time period.

Apparatus (15, 30) and methods for performing acoustical measurements are provided having some and preferably all of the following features: (A) the system (15, 30) is operated under near-field conditions; (B) the piezoelement (40) or piezoelements (40, 48) used in the system are (i) mechanically (41, 49) and electrically (13, 16) damped and (ii) efficiently electrically coupled to the signal processing components of the system; (C) each piezoelement (40, 48) used in the system includes an acoustical transformer (42, 50) for coupling the element to a gaseous test medium (9); (D) speed of sound is determined from the time difference between two detections of an acoustical pulse (81, 82) at a receiver (40, FIG. 3; 48, FIG. 7); (E) cross-correlation techniques are employed to detect the acoustical pulse at the receiver; (F) forward and inverse Fourier transforms employing fast Fourier transform techniques are used to implement the cross-correlation techniques; in such a mathematical manner that the peak of the cross-correlation function corresponds to the detection of a pulse at the receiver and (G) stray path signals through the body (31) of the acoustic sensor (15, 30) are removed from detected signals prior to signal analysis. Techniques are also provided for performing acoustical measurements on gases whose thermodynamic properties have not been measured and on mixtures of compressible gases. Methods and apparatus (29) for performing feedback control of a gas of interest in a mixture of that gas and a carrier gas are provided in which the controlled variable is the flow of the carrier gas.

In industrial sensing applications at least one parameter of at least one fluid in a pipe 12 is measured using a spatial array of acoustic pressure sensors 14,16,18 placed at predetermined axial locations x1, x2, x3 along the pipe 12. The pressure sensors 14,16,18 provide acoustic pressure signals P1(t), P2(t), P3(t) on lines 20,22,24 which are provided to signal processing logic 60 which determines the speed of sound amix of the fluid (or mixture) in the pipe 12 using acoustic spatial array signal processing techniques with the direction of propagation of the acoustic signals along the longitudinal axis of the pipe 12. Numerous spatial array-processing techniques may be employed to determine the speed of sound amix. The speed of sound amix is provided to logic 48, which calculates the percent composition of the mixture, e.g., water fraction, or any other parameter of the mixture, or fluid, which is related to the sound speed amix. The logic 60 may also determine the Mach number Mx of the fluid. The acoustic pressure signals P1(t), P2(t), P3(t) measured are lower frequency (and longer wavelength) signals than those used for ultrasonic flow meters, and thus is more tolerant to inhomogeneities in the flow. No external source is required and thus may operate using passive listening. The invention will work with arbitrary sensor spacing and with as few as two sensors if certain information is known about the acoustic properties of the system. The sensor may also be combined with an instrument, an opto-electronic converter and a controller in an industrial process control system.

A measurement device is provided that determines fluid properties from vibration frequencies of a sample cavity. In one embodiment, the measurement device includes a sample flow tube, vibration source and detector mounted on the tube, and a measurement module. The sample flow tube receives a flow of sample fluid for characterization. The measurement module employs the vibration sources to generate vibrations in the tube. The measurement module combines the signals from the vibration detector on the tube to determine properties of the sample fluid, such as density, viscosity, compressibility, water fraction, and bubble size. The measurement module may further detect certain flow patterns such as slug flow, for example. To measure the sample fluid density, the measurement module determines the resonant frequency of the sample flow tube. The density can then be calculated according to a formula that compensates for the temperature and pressure of the system.

An apparatus and method for determining the kinematic characteristics of a golf club head are disclosed. The apparatus includes at least one piezoelectric component selectively positioned within or upon a club head. The piezoelectric component is preferably positioned to the rear of the center of gravity, and near the midpoint of the face of the club head. During a golf club swing, the piezoelectric component determines the acceleration and deceleration of the golf club head. When the club head impacts an object such as a golf ball, the piezoelectric component is also operable to determine the velocity of the club head. It may also be desirable for the piezoelectric component to determine the magnitude of vibration during impact. In this manner, the piezoelectric component may function determine the efficiency of a golf club swing.

A defect detection system for thermally imaging a structure that has been energized by a sound energy. The system includes a transducer that couples a sound signal into the structure, where the sound signal causes defects in the structure to heat up. In one embodiment, the sound signal has one or more frequencies that are at or near an eigen-mode of the structure. In another embodiment, an on-linear coupling material is positioned between the transducer and the structure to couple the sound energy from the transducer to the structure. A predetermined force is applied to the transducer and a pulse duration and a pulse frequency of the sound signal are selected so that the sound energy induces acoustic chaos in the structure, thus generating increased thermal energy. A thermal imaging camera images the structure when it is heated by the sound signal.

Described is a downhole apparatus for detecting and removing deposits from a surface exposed to wellbore fluids. The apparatus can monitor the rate of deposition and subsequently remove the deposited material. The combination of detection apparatus and removal apparatus provides a downhole instrument with self-cleaning operation mode.

Acoustic sensing utilizing a cantilever structure coupled about at least one side of said cantilever to a base substrate, wherein said cantilever includes a piezoelectric section and has at least one acoustic wave device on a portion of the cantilever, wherein a flexure of the cantilever produces force-frequency effects measurable by the acoustic wave device. According to one embodiment, the cantilever sensor uses the flexure-frequency effect as measured by an acoustic wave device to sense a target matter. According to one embodiment, a sensing material is disposed on at least a portion of at least one surface of the cantilever.