A method for measuring an axial-force of a bolt fastened to a component to be fastened, includes temporarily fastening the bolt to the component to be fastened with a temporarily-tightening torque, the temporarily-tightening torque being a torque which is determined in advance and by which a depression is formed on a head of the bolt, measuring a first axial force of the temporarily-fastened bolt, regularly fastening the bolt to the component to be fastened with a regularly-tightening torque, the regularly-tightening torque being torque which is determined in advance and larger than the temporarily-tightening torque, measuring a second axial force of the regularly-fastened bolt, and measuring an estimated axial force of the regularly-fastened bolt by using the torque with which the bolt is temporarily fastened, the torque with which the bolt is regularly fastened, and a difference between the first and second axial forces.

A stress estimation method for a machine structure according to an embodiment is provided with a calculation step of calculating a relationship between the stress generated at the evaluation target position and a physical quantity including a sound pressure or vibration generated at a detection position different from the evaluation target position during vibration of the machine structure. The stress estimation method for a machine structure is provided with a detection step of detecting the physical quantity generated at the detection position during operation of the machine structure. The stress estimation method for a machine structure is provided with an estimation step of estimating the stress generated at the evaluation target position during operation of the machine structure on the basis of the relationship calculated in the calculation step and the physical quantity detected in the detection step.

Rotating machine vibration monitoring process for detecting degradations within a rotating machine providing an output axle fitted with magnetic bearings, the magnetic bearings having at least a position sensor and at least a magnetic actuator, the process provides the following steps: 1) defining a set of excitations that does not destabilizes the rotating machine, 2) injecting the set of excitations in the rotating machine through the magnetic actuators and 3) measuring the response of the rotating machine checking whether the response verifies at least one predefined criterium, 4) if it is not the case, adjusting the properties of the set of excitations and resuming the process at the injection step, 5) if the response verifies the at least one criterium, determining at least one condition indicator based on the response measured, 6) determining if an alarm is to be triggered based on the condition indicator determined.

Rotating machine vibration monitoring process for detecting degradations within a rotating machine providing an output axle fitted with magnetic bearings, the magnetic bearings having at least a position sensor and at least a magnetic actuator, the process provides the following steps: 1) defining a set of excitations that does not destabilizes the rotating machine, 2) injecting the set of excitations in the rotating machine through the magnetic actuators and 3) measuring the response of the rotating machine checking whether the response verifies at least one predefined criterium, 4) if it is not the case, adjusting the properties of the set of excitations and resuming the process at the injection step, 5) if the response verifies the at least one criterium, determining at least one condition indicator based on the response measured, 6) determining if an alarm is to be triggered based on the condition indicator determined.

A method for detecting damage to a bearing of an engine using a knocking sensor includes a data storing step, which stores a vibration signal output from the knocking sensor in a data storing unit, a by-frequency amplitude calculating step, which performs Fast Fourier Transform (FFT) for the vibration signal and calculates an amplitude for each frequency, a detection frequency integrating step, which obtains a detection frequency integration value by adding all amplitudes of detection frequencies, a noise determining step, which determines whether the vibration signal is the vibration signal irrelevant to damage to the bearing by determining whether exclusion frequencies correspond to a preset condition, a counter increasing step, which increases a damage counter, when the detection frequency integration value is greater than a preset damage threshold, and a damage confirming step, which confirms damage to the bearing, when the damage counter equals or exceeds a preset confirmation counter.

One embodiment of the present invention provides an apparatus and the like for improving the accuracy of deterioration estimation regarding a monitoring target. An information processing apparatus as one embodiment of the present invention includes a detector, a separator, a calculator, and an estimator. The detector detects a normal waveform pattern included in a waveform of time-series data of a target. The separator separates the waveform of the time-series data into components while removing the normal waveform pattern that is detected. The calculator calculates a feature of the time-series data based on at least one of the components. The estimator estimates deterioration of the target based on the feature.

One embodiment of the present invention provides an apparatus and the like for improving the accuracy of deterioration estimation regarding a monitoring target. An information processing apparatus as one embodiment of the present invention includes a detector, a separator, a calculator, and an estimator. The detector detects a normal waveform pattern included in a waveform of time-series data of a target. The separator separates the waveform of the time-series data into components while removing the normal waveform pattern that is detected. The calculator calculates a feature of the time-series data based on at least one of the components. The estimator estimates deterioration of the target based on the feature.

The disclosure is directed to a method comprising the steps: carrying out multiple measurements on a mechanical object, the measurements each differing by one or more parameters influencing the measurement; determining a spectrogram on the basis of the measurement data of the measurements and depending on a predefined parameter of the mechanical object; determining one or more excitations of the mechanical object; reproducing the excitations in the spectrogram.

The disclosure is directed to a method comprising the steps: carrying out multiple measurements on a mechanical object, the measurements each differing by one or more parameters influencing the measurement; determining a spectrogram on the basis of the measurement data of the measurements and depending on a predefined parameter of the mechanical object; determining one or more excitations of the mechanical object; reproducing the excitations in the spectrogram.

A multi-slice hinge-line actuator includes a plurality of actuator slices mounted around a common axis of rotation and arranged to be rotated around the axis of rotation by a drive means in response to a control signal, the slices spaced axially along the axis of rotation. Each actuator slice has a first attachment means for attachment to a relatively fixed structure and a second attachment means for attachment to a moveable structure to be moved by the actuator in response to the control signal. The actuator also includes means for monitoring a strain pattern in the actuator at a plurality of locations along the axial direction of the actuator.