Laser Beam Position-Dependent PSD-Based Calibrated Self-Vibration Compensated Noncontact Vibration Measurement System

Calibrated non‐contact vibrational harmonics measurement based on self‐vibration compensated 2D‐PSD with MEMS accelerometer using FFT analysis

“…The erroneous vibration in the X direction of the PSD due to the introduction of the hand jitter is highlighted and recorded and also corrected self‐vibration compensated amplitude of the PSD platform for the same amount of jitter is shown in literature [22 ]. After the self‐vibration compensation, the time‐domain vibration data is converted into the frequency‐domain data using appropriate signal processing.…”

“…2 shows the data flow and various steps that are involved in signal processing using LabVIEW software. The signal processing for time‐domain displacement data analysis is explained in detail in [22 ].…”

“…2 shows the data flow and various steps that are involved in signal processing using LabVIEW software. The signal processing for time-domain displacement data analysis is explained in detail in [22]. After performing the FFT analysis of the self-vibration compensated time-domain displacement data, the result has been displayed on the graphical user interface (GUI).…”

“…Some of the necessities of this measurement technique are somewhat fulfilled using the timedomain vibration measurement as presented in [16] but this work suffers from the limitation of system calibration. Das and Saha [22] used the PSD-based noncontact calibrated self-vibration compensated vibration measurement technique with a resolution <2.07 μm in peak-to-peak displacement, but the limitation is only time-domain analysis using the sinusoidal signal is presented for the measurement of lower vibrational frequency ranges with a minimum frequency of 20 Hz. By using time-domain signals it is difficult to determine the vibration fault in a mechanical structure, so the frequency-domain analysis is a more attractive solution [23][24][25][26].…”

Viaxl: A Solution of a Low-Cost Real-Time Visual Accelerometer Based on Laser Speckle Optical Flow Detection

“…Although these accelerometers have seen successful adoption in various applications, the real-time acceleration measurement based on the strapped-down method limits the applications that require non-contact or nondestructive measurement in some special or extreme scenarios, because the classic accelerometer is difficult to apply in conditions of high temperatures or high pressure, or when the structure of the measured object is easily affected by the added mass, such as medical electronic applications such as laser heartbeat detectors [ 1 ], vibration monitoring of mechanics or infrastructure such as the tip-timing vibration measurement of aero engines, and so on [ 2 , 3 , 4 ]. This problem motivates the search for novel acceleration measurement methods, and particularly optical methods, such as full field laser interferometry based on an image acquisition system [ 5 , 6 , 7 , 8 ], and laser Doppler vibrometry based on a photodetector [ 9 , 10 , 11 ]. Remarkably, the non-contact accelerometer based on laser interferometry [ 5 ] can even realize real-time vibration detection with up to 30 kHz with 1 nm axial resolution, which proves that the comprehensive performance and technical maturity of these classic laser-based optical measurement methods have reached a dramatically high level.…”