Detection of chewing from piezoelectric film sensor signals using ensemble classifiers

2016 ◽  
Author(s):  
Muhammad Farooq ◽  
Edward Sazonov
Keyword(s):  
Piezoelectric Film ◽  
Ensemble Classifiers ◽  
Film Sensor ◽  
Sensor Signals

Localization of Flow Separation and Transition Over a Pitching NACA0012 Airfoil at Transitional Reynolds Numbers Using Hot-Films

2015 ◽  
Vol 137 (12) ◽  
Author(s):  
Allison Poels ◽  
Daniel Rudmin ◽  
Azemi Benaissa ◽  
Dominique Poirel
Keyword(s):  
Reynolds Numbers ◽  
Correlation Technique ◽  
Film Sensor ◽  
Pitching Airfoil ◽  
Eddy Simulation ◽  
Naca0012 Airfoil ◽  
Large Eddy ◽  
Sensor Signals ◽  
Hot Film ◽  
Hot Film Sensor

Separation and transition of flow over a pitching airfoil at transitional Reynolds Number are analyzed experimentally. The method is based on a windowed correlation between hot-film sensor signals taken simultaneously or synchronized based on the airfoil pitch angle. A comparison with large eddy simulation (LES) simulation obtained in the same conditions is presented and discussed. Our results agree very well with the LES data for the separation location during the pitch-up. For the pitch-down, the results show differences with the LES. However, when the LES data are analyzed with the same correlation technique, the results are in a better agreement.

AN INVESTIGATION ON LIGHT STRUCTURE MODAL PARAMETER BY USING EXPERIMENTAL MODAL ANALYSIS METHOD VIA PIEZOFILM SENSOR

2017 ◽  
Vol 79 (6) ◽  
Author(s):  
Mohd Irman Ramli ◽  
Mohd. Zaki Nuawi ◽  
Shahrum Abdullah ◽  
Mohammad Rasidi Mohammad Rasani ◽  
Muhamad Arif Fadli Ahmad ◽  
...  
Keyword(s):  
Modal Analysis ◽  
Natural Frequency ◽  
Experimental Work ◽  
Mode Shapes ◽  
Piezoelectric Film ◽  
Modal Parameter ◽  
Film Sensor ◽  
Work Outcome ◽  
The Status ◽  
Experimental Approaches

This study is conducted to determine the modal parameters namely natural frequencies and mode shapes of aluminum 6061 (Al6061). The parameters are done by conducting a free dynamic vibration analysis. Modal analysis study was conducted by both simulation and experimental approaches. The simulation was conducted via ANSYS software while the experimental work was performed through impact hammer testing to determine the vibration parameter. Two sensors i.e. piezoelectric film and accelerometer were used. The result obtained were ya = 302.02x – 52.51 (accelerometer) and yp = 295.78x - 41.73 (piezofilm). ya (accelerometer) and yp (piezofilm) is linear equation of the data plotted according to the reading from mode shape versus natural frequency. The relation between natural frequency from accelerometer and piezofilm for the rectangular-shaped specimen was ya = 1.02yp – 9.90 and can be concluded that the regression ratio of 1.02 was approximately 1.0 which agreed with the status of piezoelectric film sensor that can be used as an alternative sensor for accelerometer. There was a good results agreement between simulation and experimental work outcome.

Measurement system of swallowing motion by using a piezoelectric film sensor

2020 ◽  
Vol 64 (1-4) ◽  
pp. 1173-1182
Author(s):  
Yusuke Kurishima ◽  
Hirokazu Hashimoto ◽  
Takeshi Okuyama ◽  
Mami Tanaka
Keyword(s):  
Spectral Density ◽  
Measurement System ◽  
Surface Deformation ◽  
The Body ◽  
Digastric Muscle ◽  
Piezoelectric Film ◽  
Sensitive Material ◽  
Film Sensor ◽  
Skin Deformation ◽  
Frequency Components

In this paper, a measurement system of swallowing motion is developed. A piezoelectric film is used as sensitive material of the sensor to measure the body surface deformation due to swallowing. We focused on laryngeal prominence and digastric muscle which are active during swallowing and developed sensors to attach to skin above laryngeal prominence and digastric muscle. As a result of experiments, it was confirmed that output fluctuation occurred at the swallowing. Next, by comparing the frequency spectral density distribution of sensor outputs during swallowing and resting, it was found that the output waveform during swallowing is mainly composed of larger frequency components below 20 [Hz] than that during resting. From the results, it was suggested that the developed measurement system is available to detect the swallowing from skin deformation without obstructing the motion.

NOVEL TECHNIQUE OF MODAL ANALYSIS FOR LIGHT STRUCTURE VIA PIEZOFILM SENSOR: A COMPARISON STUDY

2017 ◽  
Vol 79 (5-2) ◽  
Author(s):  
Mohd Irman Ramli ◽  
Mohd. Zaki Nuawi ◽  
Shahrum Abdullah ◽  
Mohammad Rasidi Mohammad Rasani ◽  
Kho Ko Seng ◽  
...  
Keyword(s):  
Natural Frequency ◽  
Mode Shapes ◽  
Piezoelectric Film ◽  
Comparison Study ◽  
Structural Failure ◽  
Film Sensor ◽  
Work Outcome ◽  
The Status ◽  
Automotive Parts ◽  
Small Structure

This study is conducted to determine the modal parameters namely natural frequencies and mode shapes of aluminum 6061 (Al6061). A light and small structure made from Al6061 is chosen as the experimental specimen mainly because of its wide application in industries such as automotive parts or accessories and robotic, mainly in manufacturing of automobile frames. If a component vibrates with a frequency that is coherent with the component’s natural frequency, resonance frequency will occur and structural failure might emerge. Two sensors i.e. piezoelectric film and accelerometer were used. The result obtained were ya = 329.60x – 142.27 (accelerometer) and yp = 304.98x + 15.18 (piezofilm). The relation between natural frequency of accelerometer and piezofilm for the triangle-shape specimen was ya = 1.08yp – 158.67 and can be concluded that the regression ratio of 1.08 was approximately 1.0 which agreed with the status of piezoelectric film sensor that can be used as an alternative sensor for accelerometer. There was a good results agreement between simulation and experimental work outcome. 

Research on the Unsteady Flow in an Axial Flow Compressor Rotor Based on PVDF Piezoelectric-Film Sensor Array

2017 ◽  
Author(s):  
Jiqing Cong ◽  
Jianping Jing
Keyword(s):  
Unsteady Flow ◽  
Sensor Array ◽  
Pressure Field ◽  
Axial Flow ◽  
Acoustic Resonance ◽  
Piezoelectric Film ◽  
Film Sensor ◽  
Compressor Rotor ◽  
Blade Tip ◽  
Flow Compressor

The unsteady flow in an axial flow compressor rotor is responsible for noise generation and unexpected excitation of blade vibration; therefore, compressors may suffer from fatigue failure of blades and eventually become unable to operate. At present, a set of Kulite pressure transducers mounted on the casing wall is widely used to acquire the pressure field of unsteady flow. However, it will affect the compressor structure and it is physically impossible to mount at a small spacing to capture the variation of casing wall pressure precisely because of the size of transducers. For the requirement of measurement, a self-developed PVDF (polyvinylidene fluoride) piezoelectric-film sensor array measurement system was applied to measure and capture the pressure field distribution over the compressor rotor blade tip clearance. In this system, a multi-measuring points PVDF array, in which 40 measuring points was contained in a 70mm by 40mm rectangle area, was attached on the casing wall of the rotor blade tip. This new technique has great advantages over traditional measurement technique, such as wide frequency response, high space resolution, less impact on the compressor, easy installation and so on. Based on a multistage axial compressor rig test, the unsteady flow pattern on the casing wall was well captured by the PVDF array. And it is revealed in all measuring points that the resonance occurs all over the compressor is under one single frequency, and the pressure level of the acoustic resonance exceeds the level of the usually dominated blade passing frequency when close to the stability limit. At the same time, the acoustic resonance will be modulated with the blade passing frequency.

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