scholarly journals In-field failure assessment of tractor hydraulic system operation via pseudospectrum of acoustic measurements

2019 ◽  
Vol 27 (4) ◽  
pp. 2718-2729 ◽  
Author(s):  
Saurabh GUPTA ◽  
Mahdi KHOSRAVY ◽  
Neeraj GUPTA ◽  
Hemant DARBARI
2012 ◽  
Author(s):  
Jesse A. Monn ◽  
Timothy Sullivan Raffio ◽  
Kelly Kissock

2012 ◽  
Vol 619 ◽  
pp. 503-507
Author(s):  
Yu Lan Li ◽  
Xiang Bi An ◽  
Dao Wei Zhu

The reversing valve is a vital servo component in the hydraulic system, which reversing the movement of the execute component by the movement of the valve core to change on-off of the hydraulic channels. The model for a three-position four-way electromagnetic reversing valve used in some hydraulic system was established based on AMESim. The simulation operation results showed that the model had realized the same function with that of the actual valve, and had been consistent with the actual one on dynamic characteristics. The established of the model and the dynamic simulation analysis laid foundation for the hydraulic system operation reliably and effectively.


2013 ◽  
Vol 816-817 ◽  
pp. 851-856
Author(s):  
Qing Xia Qin ◽  
Hong Geng

Study of Hydraulic Power System for development of Maintenance Training Simulator is very important. By analyzing the operational principle of the hydraulic system, presents an aircraft hydraulic system functional simulation model. After the whole hydraulic model has been established, attach to the maintenance training simulation platform. Simulation results show that this model can simulate the normal system operation and indication, and can simulate the impacts of fault disturbances under various conditions, which meets the simulation demand.


2019 ◽  
Vol 1 (1) ◽  
pp. 700-707
Author(s):  
Andrzej Sobczyk ◽  
Janusz Pobędza

AbstractThe subject of the article is concern towards hydraulic systems safety improvement by elimination or/and reduction the possible mistakes which could be the reason of operator accidents and damage of the machine and surroundings. The most typical situation which could be present during hydraulic system operation and maintenance have been analysed and classified to help understand its correlation with safety. Finally each of specified danger situation during system operation and/or maintenance contents rules and warning advice to avoid safety risk.


2020 ◽  
Vol 63 (12) ◽  
pp. 3991-3999
Author(s):  
Benjamin van der Woerd ◽  
Min Wu ◽  
Vijay Parsa ◽  
Philip C. Doyle ◽  
Kevin Fung

Objectives This study aimed to evaluate the fidelity and accuracy of a smartphone microphone and recording environment on acoustic measurements of voice. Method A prospective cohort proof-of-concept study. Two sets of prerecorded samples (a) sustained vowels (/a/) and (b) Rainbow Passage sentence were played for recording via the internal iPhone microphone and the Blue Yeti USB microphone in two recording environments: a sound-treated booth and quiet office setting. Recordings were presented using a calibrated mannequin speaker with a fixed signal intensity (69 dBA), at a fixed distance (15 in.). Each set of recordings (iPhone—audio booth, Blue Yeti—audio booth, iPhone—office, and Blue Yeti—office), was time-windowed to ensure the same signal was evaluated for each condition. Acoustic measures of voice including fundamental frequency ( f o ), jitter, shimmer, harmonic-to-noise ratio (HNR), and cepstral peak prominence (CPP), were generated using a widely used analysis program (Praat Version 6.0.50). The data gathered were compared using a repeated measures analysis of variance. Two separate data sets were used. The set of vowel samples included both pathologic ( n = 10) and normal ( n = 10), male ( n = 5) and female ( n = 15) speakers. The set of sentence stimuli ranged in perceived voice quality from normal to severely disordered with an equal number of male ( n = 12) and female ( n = 12) speakers evaluated. Results The vowel analyses indicated that the jitter, shimmer, HNR, and CPP were significantly different based on microphone choice and shimmer, HNR, and CPP were significantly different based on the recording environment. Analysis of sentences revealed a statistically significant impact of recording environment and microphone type on HNR and CPP. While statistically significant, the differences across the experimental conditions for a subset of the acoustic measures (viz., jitter and CPP) have shown differences that fell within their respective normative ranges. Conclusions Both microphone and recording setting resulted in significant differences across several acoustic measurements. However, a subset of the acoustic measures that were statistically significant across the recording conditions showed small overall differences that are unlikely to have clinical significance in interpretation. For these acoustic measures, the present data suggest that, although a sound-treated setting is ideal for voice sample collection, a smartphone microphone can capture acceptable recordings for acoustic signal analysis.


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