A reaction compensation device includes a drive mechanism driving a first movable part with respect to a base, a reaction mass drive mechanism driving a second movable part with respect to the base; and a first relative position sensor measuring a relative position between the first movable part and the base. There is also a second relative position sensor measuring a relative position between the second movable part and the base, a first control system controlling the drive mechanism by taking in a signal outputted from the first relative position sensor as a feedback signal in response to a command value, and a second control system correcting the command value using a correction parameter for adjusting a difference between mass properties of the drive mechanism and reaction mass drive mechanism and for controlling the reaction mass drive mechanism.

A wireless and cellular vibration monitoring device (2) comprising a connection structure (6) suitable for attaching the monitoring device (2) to equipment to be monitored is disclosed. The monitoring device (2) comprises a temperature sensor (8) and a vibration sensor (10) configured to remotely monitor vibration and temperature transferred to the monitoring device (2) via the connection structure (6). The device comprises an integrated satellite-based radio-navigation system for location detection. The monitoring device (2) comprises a metal base (4) comprising a body portion (56) comprising a threaded portion (6) constituting the connection structure (6). The threaded portion (6) comprises male threads and protrudes from the body portion (56) of the base (4). The temperature sensor (8) is thermally connected to the body portion (56) of the base (4).

A wireless and cellular vibration monitoring device (2) comprising a connection structure (6) suitable for attaching the monitoring device (2) to equipment to be monitored is disclosed. The monitoring device (2) comprises a temperature sensor (8) and a vibration sensor (10) configured to remotely monitor vibration and temperature transferred to the monitoring device (2) via the connection structure (6). The device comprises an integrated satellite-based radio-navigation system for location detection. The monitoring device (2) comprises a metal base (4) comprising a body portion (56) comprising a threaded portion (6) constituting the connection structure (6). The threaded portion (6) comprises male threads and protrudes from the body portion (56) of the base (4). The temperature sensor (8) is thermally connected to the body portion (56) of the base (4).

Embodiments herein provide a system (100) to estimate the amplitude of oscillations in a turbulent flow system (102) that exhibits oscillatory instabilities. The system (100) comprises of a sensor (102A) mounted on the turbulent flow system (102) to detect an oscillatory variable in the system obtaining a signal, a signal conditioner (104) that conditions the signal from the sensor, an amplitude estimator (110) that estimates the amplitude of the limit cycle oscillations, and also predict the proximity of the system to the oscillatory instability, a processor (108) connected to the amplitude estimator (110) to compare the predicted oscillation amplitude with a threshold value. The amplitude is estimated by estimating the spectral measure of the time series signal obtained from the system.

Embodiments herein provide a system (100) to estimate the amplitude of oscillations in a turbulent flow system (102) that exhibits oscillatory instabilities. The system (100) comprises of a sensor (102A) mounted on the turbulent flow system (102) to detect an oscillatory variable in the system obtaining a signal, a signal conditioner (104) that conditions the signal from the sensor, an amplitude estimator (110) that estimates the amplitude of the limit cycle oscillations, and also predict the proximity of the system to the oscillatory instability, a processor (108) connected to the amplitude estimator (110) to compare the predicted oscillation amplitude with a threshold value. The amplitude is estimated by estimating the spectral measure of the time series signal obtained from the system.

A method for detecting defects in a rotational element of a machine based on changes in measured vibration energy includes: (a) collecting vibration data over an extended period of time using vibration sensors attached to the machine; (b) processing the vibration data to generate a time waveform comprising processed vibration values sampled during sequential sampling time intervals within the extended period of time; (c) detecting multiple time blocks within the extended period of time during which the processed vibration values exhibit sustained increases at progressively increasing rates; and (d) generating alerts based on detection of the multiple time blocks during which the processed vibration values exhibit sustained increases at progressively increasing rates. The multiple time blocks may include a first time block during which the processed vibration values increase at a first rate, and a second time block occurring after the first time block during which the processed vibration values increase at a second rate that is greater than the first rate.

A method for detecting defects in a rotational element of a machine based on changes in measured vibration energy includes: (a) collecting vibration data over an extended period of time using vibration sensors attached to the machine; (b) processing the vibration data to generate a time waveform comprising processed vibration values sampled during sequential sampling time intervals within the extended period of time; (c) detecting multiple time blocks within the extended period of time during which the processed vibration values exhibit sustained increases at progressively increasing rates; and (d) generating alerts based on detection of the multiple time blocks during which the processed vibration values exhibit sustained increases at progressively increasing rates. The multiple time blocks may include a first time block during which the processed vibration values increase at a first rate, and a second time block occurring after the first time block during which the processed vibration values increase at a second rate that is greater than the first rate.

A system for dynamically mitigating resonance in a transport refrigeration unit (TRU) during a mission, having: a TRU controller configured for operating a TRU engine during the mission according to an operational baseline, and while operating the TRU engine, contemporaneously performing steps including: obtaining a first set of data that comprises real time measurements from one or more accelerometers installed in the TRU; converting the real measurements to a second set of data that comprises real time shock and vibration data; processing the second set of data in a control loop to determine an updated operational baseline that avoids resonance detected in the first set of data; and operating the TRU engine according to the updated operational baseline.

A system for dynamically mitigating resonance in a transport refrigeration unit (TRU) during a mission, having: a TRU controller configured for operating a TRU engine during the mission according to an operational baseline, and while operating the TRU engine, contemporaneously performing steps including: obtaining a first set of data that comprises real time measurements from one or more accelerometers installed in the TRU; converting the real measurements to a second set of data that comprises real time shock and vibration data; processing the second set of data in a control loop to determine an updated operational baseline that avoids resonance detected in the first set of data; and operating the TRU engine according to the updated operational baseline.

A vibration control element includes a nanovoided polymer layer having a first damping coefficient and a first resonance frequency in a first state and a second damping coefficient and a second resonance frequency in a second state, where the first damping coefficient is different from the second damping coefficient and the first resonance frequency is different from the second resonance frequency.