A system for monitoring fruit growth including: a vibration exciter that imparts predetermined vibration to a stem or a branch between a fruit and a stalk growing on a plant; a vibration sensor that detects vibration of the stem or the branch caused by the vibration imparted by the vibration exciter; and a detector that detects a weight or weight change of the fruit based on a frequency of the vibration detected by the vibration sensor.

An inspection device includes an oscillator for generating ultrasonic waves toward a first connector, and a vibration receiver for receiving vibrations generated in the first connector. The inspection device includes a vibration controller for analyzing the vibrations received by the vibration receiver. The vibration controller detects a resonance frequency by converting, by Fourier transform, the vibrations received by the vibration receiver. The vibration controller determines an insertion amount of the first connector into the second connector, based on the detected resonance frequency.

An inspection device includes an oscillator for generating ultrasonic waves toward a first connector, and a vibration receiver for receiving vibrations generated in the first connector. The inspection device includes a vibration controller for analyzing the vibrations received by the vibration receiver. The vibration controller detects a resonance frequency by converting, by Fourier transform, the vibrations received by the vibration receiver. The vibration controller determines an insertion amount of the first connector into the second connector, based on the detected resonance frequency.

For measuring the oscillation amplitude of a scanner mirror in a projection system of a motor vehicle headlight, a laser beam generated by a laser source is directed onto the scanner mirror and reflected by the latter so that the laser beam thus reflected is incident on a detector device (20) that has a plurality of photodetector elements (Q1, Q2, Q3, Q4) and there describes a curve (P) based on the oscillation movement of the scanner mirror. The center point of the curve (P) is offset by an offset value (x.sub.offset, y.sub.offset) from the center of the detector device (20). The time period (t.sub.ON,X, t.sub.ON,Y) in which the curve passes through the specific detector region (R.sub.X, R.sub.Y) that corresponds to a coordinate to be measured is determined; and the oscillation amplitude (x.sub.pp, y.sub.pp) in the direction of the specific coordinate is determined using the ratio of the time period (t.sub.ON,X, t.sub.ON,Y) determined in this manner to the total duration (T) of an oscillation period and the offsets (x.sub.offset, y.sub.offset).

For measuring the oscillation amplitude of a scanner mirror in a projection system of a motor vehicle headlight, a laser beam generated by a laser source is directed onto the scanner mirror and reflected by the latter so that the laser beam thus reflected is incident on a detector device (20) that has a plurality of photodetector elements (Q1, Q2, Q3, Q4) and there describes a curve (P) based on the oscillation movement of the scanner mirror. The center point of the curve (P) is offset by an offset value (x.sub.offset, y.sub.offset) from the center of the detector device (20). The time period (t.sub.ON,X, t.sub.ON,Y) in which the curve passes through the specific detector region (R.sub.X, R.sub.Y) that corresponds to a coordinate to be measured is determined; and the oscillation amplitude (x.sub.pp, y.sub.pp) in the direction of the specific coordinate is determined using the ratio of the time period (t.sub.ON,X, t.sub.ON,Y) determined in this manner to the total duration (T) of an oscillation period and the offsets (x.sub.offset, y.sub.offset).

Creation and use of a digital twin instance (DTI) for a physical instance of the part. The DTI may be created by a model inversion process such that model parameters are iterated until a convergence criterion related to a physical resonance inspection result and a digital resonance inspection result is satisfied. The DTI may then be used in relation to part evaluation including through simulated use of the part. The physical instance of the part may be evaluated by way of the DTI or the DTI may be used to generate maintenance schedules specific to the physical instance of the part.

An observation system includes an information acquiring section configured to acquire sensor information from a sensor section set in a structure and configured to detect vibration of the structure and a processing section configured to calculate information concerning a peak vibration frequency of the vibration on the basis of the sensor information and determine a surface state of the structure on the basis of the information concerning the peak vibration frequency.

An observation system includes an information acquiring section configured to acquire sensor information from a sensor section set in a structure and configured to detect vibration of the structure and a processing section configured to calculate information concerning a peak vibration frequency of the vibration on the basis of the sensor information and determine a surface state of the structure on the basis of the information concerning the peak vibration frequency.

A natural-frequency measurement device for measuring the natural frequency of a belt includes: an acceleration sensor attached to a portion of the belt between an adjacent pair of pulleys to sense acceleration resulting from the vibration of the belt; and a measuring instrument configured to measure the natural frequency of the belt based on the acceleration sensed by the acceleration sensor.

A natural-frequency measurement device for measuring the natural frequency of a belt includes: an acceleration sensor attached to a portion of the belt between an adjacent pair of pulleys to sense acceleration resulting from the vibration of the belt; and a measuring instrument configured to measure the natural frequency of the belt based on the acceleration sensed by the acceleration sensor.