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

Abstract

This study presents a novel fast Fourier transform (FFT)‐based non‐contact vibrational harmonics measurement system using a position sensitive detector (PSD) along with calibration using a piezoelectric accelerometer. Frequency‐domain vibrational analysis is required as the changes in machine dynamics are directly related to its failures and could provide more insight into the vibration signal. In this regard, FFT is used for spectral analysis to detect the harmonics in the vibration signal. The novelty of the applied technique for detecting vibrational harmonics lies in its innate contactless nature where the vibration detection sensor i.e. PSD is placed at a particular distance from the vibrating target. Additionally, the parasitic and external vibrations, which might pose unforeseen errors in the detected vibration data, have been nullified by employing a self‐vibration technique using an ADXL‐345 three‐axis accelerometer. The results obtained through PSD have been calibrated via a standard Brüel & Kjaer (B & K) vibration measurement system which uses a piezoelectric accelerometer (B & K accelerometer). The proposed measurement technique is equipped with NI compact RIO‐9074 that features a real‐time processor and an FPGA. The system was observed to effectively measure the frequency range 5–600 Hz with a maximum relative error of 2% in FFT amplitudes.

Battery-Free and Real-Time Wireless Sensor System on Marine Propulsion Shaft Using a Wireless Power Transfer Module

“…Various attempts have been made to apply battery-free real-time wireless sensor sys-tems to a rotating shaft. These efforts can be largely divided into research on sensors [ 2 , 3 , 4 ] such as non-powered sensors, and research on power sources [ 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 ] such as wireless power transfer (WPT) or energy harvesters. For sensor research, powerless and non-contact sensor technologies are being considered for rotating shaft applications.…”

“…However, since these technologies are affected by ambient noise, such as temperature change or electromagnetic fields, additional devices or circuits are required. Two-dimensional (2-D) position-sensitive detection (PSD) has been used for vibrational harmonics measurements, but complex calibrations such as additional sensors and spectrum analysis are involved [ 4 ]. Until recently, interesting sensor technologies have been devised for continuous real-time measurement, but additional devices and circuits are needed to achieve accurate and reliable measurements.…”

Position sensitive detector based non-contact vibration measurement with laser triangulation method utilizing Gabor Transform for noise reduction

“…However, the primary constraint of the reported work presented time-domain analysis using a sine signal. Later on, a PSD-based non-contact calibrated self-vibration compensated vibrational harmonics measuring technology was developed using fast Fourier transform (FFT) (Das et al, 2020). In this experimental setup, the laser, mirror and PSD were arranged at an angle of 90 degree to each other therefore which demands more space, that making it compatible only for laboratory use and not suitable for commercial purposes.…”

A novel Ethernet based processing system for remote source harmonic detection

“…It can also be utilized to find electrical grid harmonics as shown by Buzachis et al [20]. In addition to the work of Parimala et al [19] and Buzachis et al [20], Das et al [21] used the algorithm to find calibrated non-contact vibrational harmonics.…”