A wireless vibrometer employs an antenna array to significantly boost the signal-to-noise ratio of faint received signals twin small objects vibrating at acoustic frequencies. This technique may be used to provide an improved physiological monitor (such as a pulse detector) or for long-range eavesdropping using the emitted power from a cell phone or the like.

A wireless vibrometer employs an antenna array to significantly boost the signal-to-noise ratio of faint received signals twin small objects vibrating at acoustic frequencies. This technique may be used to provide an improved physiological monitor (such as a pulse detector) or for long-range eavesdropping using the emitted power from a cell phone or the like.

A building management system includes building equipment operable to affect a variable state or condition of a building and a controller including a processing circuit. The processing circuit is configured to obtain a vibration data set related to vibrations of the building equipment and analyze the vibration data set by one or more machine learning models to generate a set of probabilities. The set of probabilities is related to a probability that the vibration data set is abnormal. The processing circuit is configured to identify the vibration data set as normal or abnormal based on the set of probabilities and initiate a corrective action responsive to identifying the vibration data set as abnormal.

A building management system includes building equipment operable to affect a variable state or condition of a building and a controller including a processing circuit. The processing circuit is configured to obtain a vibration data set related to vibrations of the building equipment and analyze the vibration data set by one or more machine learning models to generate a set of probabilities. The set of probabilities is related to a probability that the vibration data set is abnormal. The processing circuit is configured to identify the vibration data set as normal or abnormal based on the set of probabilities and initiate a corrective action responsive to identifying the vibration data set as abnormal.

Example implementations relate to receiving vibration notifications from vibration sensors. In example implementations, a subset of a plurality of vibration sensors from which vibration notifications are expected may be identified based on a position of a train along a track. The plurality of vibration sensors may be arranged in a predetermined order on the track. Whether vibration notifications have not been received from consecutive, with respect to the predetermined order, vibration sensors in the subset may be determined.

Example implementations relate to receiving vibration notifications from vibration sensors. In example implementations, a subset of a plurality of vibration sensors from which vibration notifications are expected may be identified based on a position of a train along a track. The plurality of vibration sensors may be arranged in a predetermined order on the track. Whether vibration notifications have not been received from consecutive, with respect to the predetermined order, vibration sensors in the subset may be determined.

A membrane hydrophone for analyzing high frequency ultrasound transducers has a piezoelectric membrane with electrode patterns created on the surface of the membrane. In one embodiment, the electrode patterns are doubled on each side of the membrane except for an active area of the hydrophone. In one embodiment, the electrodes are formed by removing a conductive coating on the membrane with laser pulses. The laser is set to remove the conductive coating from the piezoelectric membrane from the same side of the membrane in order to accurately align the electrodes in the active area. In one embodiment, the active area of the hydrophone has an area in a range of 900-10,000 square microns.

A device is provided as part of a system, the device being for capturing vibrations produced by an object such as a musical instrument. Via a fixation element, the device is fixed to a drum. The device has a sensor spaced apart from a surface of the drum, located relative to the drum, and a magnet adjacent the sensor. The fixation element transmits vibrations from its fixation point on the drum to the magnet. Vibrations from the surface of the drum and from the magnet are transmitted to the sensor. A method may further be provided for interpreting an audio input, such as the output of the sensors within the system, the method comprising identifying an audio event or grouping of audio events within audio data, generating a model of the audio event that includes a representation of a timbre characteristic, and comparing that representation to expected representations.

A device is provided as part of a system, the device being for capturing vibrations produced by an object such as a musical instrument. Via a fixation element, the device is fixed to a drum. The device has a sensor spaced apart from a surface of the drum, located relative to the drum, and a magnet adjacent the sensor. The fixation element transmits vibrations from its fixation point on the drum to the magnet. Vibrations from the surface of the drum and from the magnet are transmitted to the sensor. A method may further be provided for interpreting an audio input, such as the output of the sensors within the system, the method comprising identifying an audio event or grouping of audio events within audio data, generating a model of the audio event that includes a representation of a timbre characteristic, and comparing that representation to expected representations.

An environmental condition may be measured with a sensor (10) including a wire (20) having an ultrasonic signal transmission characteristic that varies in response to the environmental condition by sensing ultrasonic energy propagated through the wire using multiple types of propagation, and separating an effect of temperature on the wire from an effect of strain on the wire using the sensed ultrasonic energy propagated through the wire using the multiple types of propagation. A positive feedback loop may be used to excite the wire such that strain in the wire is based upon a sensed resonant frequency, while a square wave with a controlled duty cycle may be used to excite the wire at multiple excitation frequencies. A phase matched cone (200, 210) may be used to couple ultrasonic energy between a waveguide wire (202, 212) and a transducer (204, 214).