A sensor device may transform sensor data into spectrum data to be processed by a computer device. In an example, the sensor device may detect acceleration forces caused by a vibration. The sensor device may transform the acceleration forces into sensor data. The sensor device may transform the sensor data into spectrum data. The sensor device may execute a spectrum analysis on the spectrum data. The sensor device may generate a packet that includes a result of the spectrum analysis as a payload of the packet. A format of the packet may be based on a protocol of a communication link between the sensor device and the computer device. The sensor device may send the packet to the computer device through the communication link.

A first determination unit performs a process (first process) of sequentially dividing an intensity value constituting first data by a reference intensity value to calculate an intensity ratio and determining whether the intensity ratio exceeds a first threshold (steps S3 and S4). When a predetermined period has elapsed, a second determination unit calculates an average change rate of the first data in the predetermined period to determine whether the average change rate is within a predetermined range (steps S9 and S10). When it is determined that the average change rate is within the range, the reference intensity value is updated and lowered (step S11). When the reference intensity value is updated, the first determination unit performs the first process by using the updated reference intensity value in the next predetermined period.

A magnetic resonance device comprising a gradient coil assembly having gradient coils is described. The gradient coils are supported by at least one cylindrical coil carrier for generating gradient fields. As part of the gradient coil assembly, at least one vibration sensor is provided for measuring vibrations of the gradient coil assembly at least in a radial direction of oscillation.

One preferable aspect of the present invention is a state detecting system which detects a state of a machine device based on a detection signal from a detecting element provided to the machine device, and is the state detecting system which includes a non-normal time rate detecting unit which detects a rate or a value as a non-normal time rate, the rate being a rate of an integration value of a time during which an amplitude of the detection signal exceeds a predetermined normal amplitude within a predetermined time, and the value being physically equivalent to the rate.

According to one embodiment, a structure evaluation system according to an embodiment includes a plurality of sensors, a position locator, and an evaluator. The plurality of sensors detect elastic waves. The position locator locates positions of elastic wave sources by using the elastic waves among the plurality of elastic waves respectively detected by the plurality of sensors having an amplitude exceeding a threshold value determined according to positions of the sources of the plurality of elastic waves and the positions of the plurality of disposed sensors. The evaluator evaluates a deteriorated state of the structure on the basis of results of the position locating of the elastic wave sources which is performed by the position locator.

A vibration-sensor-integrated vibration exciter 4 has a chassis 21, an excitation unit 22, a magnet 23, a yoke 24, a vibration sensor 25, a fixed plate 26, a moving plate 27, coil springs 28a to 28d, a retaining plate 29, and a crisscross plate 30. Shafts 31a to 31d are fixed to the fixed plate 26. The excitation unit 22 is fixed to the crisscross plate 30. Four vibration-proof rubber members 32a to 32d are installed to the crisscross plate 30 at 90-degree pitches with same radius centering on the excitation axis of the fixed excitation unit 22. The crisscross plate 30 is installed to the retaining plate 29 through the vibration-proof rubber members 32a to 32d. A vibration applied to the chassis 21 is absorbed by the vibration-proof rubber members 32a to 32d, to prevent the yoke 24 from being dislocated in lateral direction due to the vibration.

A vibration-sensor-integrated vibration exciter 4 has a chassis 21, an excitation unit 22, a magnet 23, a yoke 24, a vibration sensor 25, a fixed plate 26, a moving plate 27, coil springs 28a to 28d, a retaining plate 29, and a crisscross plate 30. Shafts 31a to 31d are fixed to the fixed plate 26. The excitation unit 22 is fixed to the crisscross plate 30. Four vibration-proof rubber members 32a to 32d are installed to the crisscross plate 30 at 90-degree pitches with same radius centering on the excitation axis of the fixed excitation unit 22. The crisscross plate 30 is installed to the retaining plate 29 through the vibration-proof rubber members 32a to 32d. A vibration applied to the chassis 21 is absorbed by the vibration-proof rubber members 32a to 32d, to prevent the yoke 24 from being dislocated in lateral direction due to the vibration.

A periodic signal parameter (PSP) indicates periodic patterns in an autocorrelated vibration waveform and potential faults in a monitored machine. The PSP is calculated based on statistical measures derived from an autocorrelation waveform and characteristics of an associated vibration waveform. The PSP provides an indication of periodicity and a generalization of potential fault, whereas characteristics of the associated waveform indicate severity. A periodic information plot (PIP) is derived from a vibration signal processed using two analysis techniques to produce two X-Y graphs of the signal data that share a common X-axis. The PIP is created by correlating the Y-values on the two graphs based on the corresponding X-value. The amplitudes of Y-values in the PIP is derived from the two source graphs by multiplication, taking a ratio, averaging, or keeping the maximum value.

A periodic signal parameter (PSP) indicates periodic patterns in an autocorrelated vibration waveform and potential faults in a monitored machine. The PSP is calculated based on statistical measures derived from an autocorrelation waveform and characteristics of an associated vibration waveform. The PSP provides an indication of periodicity and a generalization of potential fault, whereas characteristics of the associated waveform indicate severity. A periodic information plot (PIP) is derived from a vibration signal processed using two analysis techniques to produce two X-Y graphs of the signal data that share a common X-axis. The PIP is created by correlating the Y-values on the two graphs based on the corresponding X-value. The amplitudes of Y-values in the PIP is derived from the two source graphs by multiplication, taking a ratio, averaging, or keeping the maximum value.

One aspect of the present technology relates to a safety cable vibration monitoring system. The system includes a vibration sensor configured to be coupled to a safety cable. A vibration monitoring computing device is coupled to the vibration sensor. The vibration monitoring computing device includes a processor and a memory coupled to the processor which is configured to execute one or more programmed instructions comprising and stored in the memory to receive data from the vibration sensor. An occurrence of a fall event related to use of the safety cable is determined based on the received data from the vibration sensor. A method of monitoring a safety cable and a safety cable monitoring network are also disclosed.