Piezoelectric sensor controllers may facilitate detection and identification of various potential fault states with parameter measurements. In an illustrative embodiment of a piezoelectric-based sensor having response-parameter-based fault diagnosis, the sensor includes a piezoelectric transducer and a controller. The controller drives the piezoelectric transducer to generate bursts of acoustic energy and, based on a response of the piezoelectric transducer to said driving, identifies a corresponding transducer state from a set of potential states including multiple transducer fault states. An illustrative embodiment of a sensing method having fault diagnosis, the method includes: driving a piezoelectric transducer to generate a burst of acoustic energy; monitoring a response of the piezoelectric transducer to said driving; identifying, based on said response, a corresponding transducer state from a set of potential states including multiple transducer fault states; and if the transducer state is a fault state, reporting that fault state.

Piezoelectric sensor controllers may facilitate detection and identification of various potential fault states with parameter measurements. In an illustrative embodiment of a piezoelectric-based sensor having response-parameter-based fault diagnosis, the sensor includes a piezoelectric transducer and a controller. The controller drives the piezoelectric transducer to generate bursts of acoustic energy and, based on a response of the piezoelectric transducer to said driving, identifies a corresponding transducer state from a set of potential states including multiple transducer fault states. An illustrative embodiment of a sensing method having fault diagnosis, the method includes: driving a piezoelectric transducer to generate a burst of acoustic energy; monitoring a response of the piezoelectric transducer to said driving; identifying, based on said response, a corresponding transducer state from a set of potential states including multiple transducer fault states; and if the transducer state is a fault state, reporting that fault state.

Drill bit vibration data for lateral, axial, and torsional directions of a drill bit is collected for a simulated or deployed drill bit for visualization of 3D coupled vibration. A frequency converter transforms the drill bit vibration data into frequency vibration data. A drill bit analyzer identifies local maxima (“peaks”) in the frequency vibration data in each of the lateral, axial, and torsional directions. Common peaks across all 3 directions with sufficiently high frequency and sufficiently high bit rotation speed are indicated as 3D coupled vibration. A drill bit data visualizer uses the indications of 3D coupled vibration in addition to the vibration data and frequency vibration data to generate visualizations of 3D coupled vibration in the drill bit.

Drill bit vibration data for lateral, axial, and torsional directions of a drill bit is collected for a simulated or deployed drill bit for visualization of 3D coupled vibration. A frequency converter transforms the drill bit vibration data into frequency vibration data. A drill bit analyzer identifies local maxima (“peaks”) in the frequency vibration data in each of the lateral, axial, and torsional directions. Common peaks across all 3 directions with sufficiently high frequency and sufficiently high bit rotation speed are indicated as 3D coupled vibration. A drill bit data visualizer uses the indications of 3D coupled vibration in addition to the vibration data and frequency vibration data to generate visualizations of 3D coupled vibration in the drill bit.

A sensitivity analyzing device and method are disclosed. The device includes a vibration exciter to configure a vibration exciting pattern and apply a physical force to one face of a test object based on the pattern; a first sensor in contact with the one face of the test object to measure a physical force applied to the test object; a second sensor in contact with an opposite face of the test object to collect a vibration of the test object caused by the physical force; and a sensitivity analyzer configured to: control the vibration exciter to configure the vibration exciting pattern; convert the physical force signal measured by the first sensor and the vibration signal collected by the second sensor in responses to the vibration exciting pattern into frequency domain signals to calculate a frequency response function of the test object; and calculate a sensitivity index of the test object.

The fixing force evaluation method of the present embodiment includes the natural frequency measurement step of measuring the natural frequency of the stator in which the tooth portions and the stator coil are fixed by the insulating paper, and the fixing force evaluation step of evaluating that the fixing force of the insulating paper is larger, when the natural frequency of the stator measured in the natural frequency measurement step is equal to more than a predetermined determination frequency, compared to when the natural frequency is lower than the determination frequency. Thus, since the fixing force of the insulating paper is evaluated in the fixing force evaluation step based on the natural frequency of the stator measured in the natural frequency measurement step, the fixing force of the insulating paper can be evaluated by measuring the natural frequency of the stator without destroying the stator.

Disclosed is a method for detecting a value which represents the temperature of a vibrating element of an ultrasonic transducer. The ultrasonic transducer has a resonant frequency (f.sub.r). The method comprises the steps of operating the ultrasonic transducer with an electric measuring signal at a measuring frequency (f.sub.m) which is above the resonant frequency, and of detecting the absolute value of the complex impedance of the ultrasonic transducer at this measuring frequency (f.sub.m) and, building thereon, ascertaining the desired value, which is to represent the temperature of a vibrating element of an ultrasonic transducer, as a function of the detected absolute value of the complex impedance of the ultrasonic transducer at this measuring frequency (f.sub.m).

Aspects of the present disclosure describe distributed fiber optic sensing (DFOS)—distributed acoustic sensing (DAS) based systems, methods, and structures that advantageously enable and/or facilitate the determination of natural frequency(ies) of civil infrastructures.

Systems and Methods for controlling one or more mechanical resonators and determining information from resonant shift of the resonator(s) behavior, including at least one mechanical resonator, an excitation element for driving the resonator(s), a sensor for monitoring the motion of the resonator(s), at least one phase locked loop (PLL) in feedback between the excitation and monitoring elements, wherein each PLL is configured to operate at or near a different resonant mode of the resonator(s), and a processor for determining information from PLL internal signals indicative of a resonator frequency shift.

Systems and Methods for controlling one or more mechanical resonators and determining information from resonant shift of the resonator(s) behavior, including at least one mechanical resonator, an excitation element for driving the resonator(s), a sensor for monitoring the motion of the resonator(s), at least one phase locked loop (PLL) in feedback between the excitation and monitoring elements, wherein each PLL is configured to operate at or near a different resonant mode of the resonator(s), and a processor for determining information from PLL internal signals indicative of a resonator frequency shift.