A vibration measurement system comprises an image capturing apparatus, a distance measuring apparatus, a sensor that outputs a signal according to an inclination of the image capturing apparatus relative to the vertical direction, and a vibration measurement apparatus. The vibration measurement apparatus includes calculating an angle formed by the normal of an image capturing surface of the image capturing apparatus and the normal of the measurement target surface that the image capturing apparatus shoots, based on the signal output by the sensor, converting the image obtained that the image capturing apparatus shoots into an image that would be obtained were the normal of the measurement target surface coincident with the normal of the image capturing surface of the image capturing apparatus, using the calculated angle, and measuring vibration of the structure, using the converted image and the measured distance from the image capturing apparatus to the measurement target surface.

A vibration measurement system comprises an image capturing apparatus, a distance measuring apparatus, a sensor that outputs a signal according to an inclination of the image capturing apparatus relative to the vertical direction, and a vibration measurement apparatus. The vibration measurement apparatus includes calculating an angle formed by the normal of an image capturing surface of the image capturing apparatus and the normal of the measurement target surface that the image capturing apparatus shoots, based on the signal output by the sensor, converting the image obtained that the image capturing apparatus shoots into an image that would be obtained were the normal of the measurement target surface coincident with the normal of the image capturing surface of the image capturing apparatus, using the calculated angle, and measuring vibration of the structure, using the converted image and the measured distance from the image capturing apparatus to the measurement target surface.

A method for calibrating an output of a torsional vibration transducer can include: providing a torsional vibration transducer proximate to a body of a shaft configured to rotate along an axis of rotation, the torsional vibration transducer configured to measure a torsional vibration of the shaft; actuating the shaft to cause rotation of the shaft; while the shaft rotates, acquiring, using the torsional vibration transducer, a plurality of zero-stress measurements of the shaft across a plurality of gaps between the torsional vibration transducer and the shaft; calculating at least one calibration coefficient using the plurality of zero-stress measurements; and calibrating the output of the torsional vibration transducer according to the at least one calibration coefficient to reduce a sensitivity of the torsional vibration transducer to changes in gap between the torsional vibration transducer and the shaft when the torsional vibration of the shaft is measured.

A method of bearing fault detection including measuring a signal of torsional energy transfer from a rotating device to a non-rotating device at a distance away from the rotating device, calculating a health status of the rotating device based on a comparison of the measured signal to a baseline signal, and calculating a remaining useful life of the rotating device.

Methods and systems for the absolute high-resolution measurement of angle of rotation of a shaft, which allow for concurrent measuring of axial displacement and/or encoded identification information, are disclosed. Included is a method for measuring characteristics of a rotating shaft comprising obtaining optical signals by optically probing one or more patterns having a leading edge and a series of symbols disposed at one or more circumferences of the shaft; oversampling the optical signals; measuring time of arrival for the leading edges and determining therefrom an amount of time between arrival of two or more of the leading edges; interpolating and extrapolating the amount of time between arrival of the leading edges; and determining therefrom one or more of shaft twist, angle of rotation and/or axial loading, translation, or displacement. The methods include optically probing a pattern disposed around the circumference of a shaft that comprises a series of wedge-shaped symbols.

Methods and systems for the absolute high-resolution measurement of angle of rotation of a shaft, which allow for concurrent measuring of axial displacement and/or encoded identification information, are disclosed. Included is a method for measuring characteristics of a rotating shaft comprising obtaining optical signals by optically probing one or more patterns having a leading edge and a series of symbols disposed at one or more circumferences of the shaft; oversampling the optical signals; measuring time of arrival for the leading edges and determining therefrom an amount of time between arrival of two or more of the leading edges; interpolating and extrapolating the amount of time between arrival of the leading edges; and determining therefrom one or more of shaft twist, angle of rotation and/or axial loading, translation, or displacement. The methods include optically probing a pattern disposed around the circumference of a shaft that comprises a series of wedge-shaped symbols.

A vibration measurement system comprises an image capturing apparatus, a distance measuring apparatus, a sensor that outputs a signal according to an inclination of the image capturing apparatus relative to the vertical direction, and a vibration measurement apparatus. The vibration measurement apparatus includes calculating an angle formed by the normal of an image capturing surface of the image capturing apparatus and the normal of the measurement target surface that the image capturing apparatus shoots, based on the signal output by the sensor, converting the image obtained that the image capturing apparatus shoots into an image that would be obtained were the normal of the measurement target surface coincident with the normal of the image capturing surface of the image capturing apparatus, using the calculated angle, and measuring vibration of the structure, using the converted image and the measured distance from the image capturing apparatus to the measurement target surface.

A vibration measurement system comprises an image capturing apparatus, a distance measuring apparatus, a sensor that outputs a signal according to an inclination of the image capturing apparatus relative to the vertical direction, and a vibration measurement apparatus. The vibration measurement apparatus includes calculating an angle formed by the normal of an image capturing surface of the image capturing apparatus and the normal of the measurement target surface that the image capturing apparatus shoots, based on the signal output by the sensor, converting the image obtained that the image capturing apparatus shoots into an image that would be obtained were the normal of the measurement target surface coincident with the normal of the image capturing surface of the image capturing apparatus, using the calculated angle, and measuring vibration of the structure, using the converted image and the measured distance from the image capturing apparatus to the measurement target surface.

A method for calibrating an output of a torsional vibration transducer can include: providing a torsional vibration transducer proximate to a body of a shaft configured to rotate along an axis of rotation, the torsional vibration transducer configured to measure a torsional vibration of the shaft; actuating the shaft to cause rotation of the shaft; while the shaft rotates, acquiring, using the torsional vibration transducer, a plurality of zero-stress measurements of the shaft across a plurality of gaps between the torsional vibration transducer and the shaft; calculating at least one calibration coefficient using the plurality of zero-stress measurements; and calibrating the output of the torsional vibration transducer according to the at least one calibration coefficient to reduce a sensitivity of the torsional vibration transducer to changes in gap between the torsional vibration transducer and the shaft when the torsional vibration of the shaft is measured.

A hardened inductive device and systems and methods for protecting the inductive device from impact is provided. The inductive device is hardened with protective coating and/or an armor steel housing. The hardened inductive device is protected from impact by an object such as a bullet and leakage of dielectric fluid is prevented. Acoustic and vibration sensors are provided to detect the presence and impact, respectively, of an object in relation to the inductive device housing. The measurements of the acoustic and vibration sensors are compared to thresholds for sending alarms to the network control center and initiating shut-down and other sequences to protect the active part. The acoustic sensor results are utilized to determine the location of origin of the projectile.