The present invention relates to a drive for an electric application such as an electric motor, said drive including at least one microphone for registering noise signals occurring at the drive, wherein the microphone is connectable to a computing device for analysing the registered noise signals. The registered noise signals may be used for a maintenance process of the drive and/or a fine-tuning process of a drive control method of the drive. The present invention also relates to a maintenance process, in particular a predictive maintenance process for a corresponding drive. Furthermore, the present invention relates to a process for fine tuning a drive control method of a corresponding drive.

A vivarium measurement system for deployment in a vivarium environment and corresponding rooms that includes a microphone system, an at least one accelerometer in operational relationship to the microphone system, a data computational device that inputs data from the microphone system and the at least on accelerometer and wherein the data computational device comprises of a spectrum analyzer. The vivarium measurement system is optionally provided with an at least one alarm system that relays an alert when a threshold parameter is exceeded as determined by the spectrum analyzer.

Disclosed are a directional acoustic sensor, a method of adjusting directional characteristics using the directional acoustic sensor, and a method of attenuating an acoustic signal in a specific direction using the directional acoustic sensor. The directional acoustic sensor includes a plurality of resonance units arranged to have different directionalities and a signal processor configured to adjust directional characteristics by calculating at least one of a sum of and a difference between outputs of the resonance units. In this state, the signal processor attenuates an acoustic signal in a specific direction by using a plurality of directional characteristics obtained by calculating at least one of the sum of and the difference between the outputs of the resonance units at a certain ratio.

The present invention relates to a vibration sensor comprising a pressure generating element for generating pressure differences between a first and a second volume in response to vibrations of the vibration sensor, the first and second volumes being acoustically sealed from each other, and a pressure transducer for measuring pressure differences between the first and second volumes. The present invention also relates to an associated method for detecting vibrations.

A method for monitoring chatter in a machining process includes the following steps: collecting an original signal related to chatter in the machining process; for the original signal, obtaining a signal segment for calculation and analysis by updating data points in a sliding window with a set step-length, where the step-length refers to a number of data points updated every time in the sliding window, and is not greater than the size of the sliding window; calculating fractal dimensions of the signal segments in the sliding window by using a fractal algorithm; and comparing the calculated fractal dimension with an identification threshold to determine whether chatter occurs in the machining process. The measured signal does not need to be preprocessed by using the method, which can greatly improve calculation efficiency and can ensure accuracy of chatter identification.

A method is provided for measuring a flow rate of a fluid. The method incudes emitting a periodic signal from a first ultrasonic transductor, where the periodic signal is emitted by the piezoelectric wafer and passes through a liquid media. Unwanted reflections of the periodic signal are delayed so that the first periods of the periodic signal are representatives of the passage measurement. The first periods of the periodic signal are received at a second ultrasonic transductor having a piezoelectric wafer that receives the periodic signal. The flow rate of the fluid is determined by using the first periods of the periodic signal.

A photoacoustic apparatus may include: a ring transducer configured to measure a photoacoustic signal generated from an object, and including a hollow space that is provided as a travel path of light and ultrasonic waves; a mirror part disposed along a light path of the light transmitted from the ring transducer, and configured to reflect the light transmitted from the ring transducer, and the ultrasonic waves generated from the object, and to adjust magnification of the mirror part according to a number of apertures of the photoacoustic apparatus; and a fluid tank including a transparent film that allows the photoacoustic signal to pass through the fluid tank, and accommodating a fluid, the ring transducer, and the mirror part inside the fluid tank.

In order to provide a protection monitoring system that comprises a warning function to which it is not easy to become habituated, and that can call attention at the time when abnormal vibration is sensed even without a cable undergoing failure, the protection monitoring system according to an embodiment of the present invention comprises an optical fiber provided along a long infrastructure element installed in water or on a seabed, an interrogator for acquiring environment information at positions along the long infrastructure element using the optical fiber, an abnormal event detection means for detecting an abnormal event around the positions when the environment information acquired at the positions satisfies an abnormality pattern provided in advance, and a notification means for issuing a notice to a ship positioned in a prescribed range from a position in which the abnormal event is detected.

Disclosed are a directional acoustic sensor, a method of adjusting directional characteristics using the directional acoustic sensor, and a method of attenuating an acoustic signal in a specific direction using the directional acoustic sensor. The directional acoustic sensor includes a plurality of resonance units arranged to have different directionalities and a signal processor configured to adjust directional characteristics by calculating at least one of a sum of and a difference between outputs of the resonance units. In this state, the signal processor attenuates an acoustic signal in a specific direction by using a plurality of directional characteristics obtained by calculating at least one of the sum of and the difference between the outputs of the resonance units at a certain ratio.

A system includes a memory configured to store a first acoustic profile associated with a device. The first acoustic profile includes at least two of the following acoustic characteristics: frequency, amplitude, and time. The system further includes a processor communicatively coupled to the memory and an acoustic sensor. The processor is configured to receive, from the acoustic sensor, an acoustic signal comprising one or more of the frequency and amplitude, compare the received acoustic signal to the first acoustic profile, and determine that the received acoustic signal matches the first acoustic profile based on the comparison of the received acoustic signal to the first acoustic profile.