scholarly journals Investigating the Trackability of Silicon Microprobes in High-Speed Surface Measurements

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1557
Author(s):  
Min Xu ◽  
Zhi Li ◽  
Michael Fahrbach ◽  
Erwin Peiner ◽  
Uwe Brand
Keyword(s):  
Dynamic Model ◽  
High Speed ◽  
High Signal ◽  
Resonant Response ◽  
High Demand ◽  
Surface Measurements ◽  
Tactile Roughness ◽  
Low Mass ◽  
Roughness Measurements

High-speed tactile roughness measurements set high demand on the trackability of the stylus probe. Because of the features of low mass, low probing force, and high signal linearity, the piezoresistive silicon microprobe is a hopeful candidate for high-speed roughness measurements. This paper investigates the trackability of these microprobes through building a theoretical dynamic model, measuring their resonant response, and performing tip-flight experiments on surfaces with sharp variations. Two microprobes are investigated and compared: one with an integrated silicon tip and one with a diamond tip glued to the end of the cantilever. The result indicates that the microprobe with the silicon tip has high trackability for measurements up to traverse speeds of 10 mm/s, while the resonant response of the microprobe with diamond tip needs to be improved for the application in high-speed topography measurements.

Dynamic model for high-speed rotors based on their experimental characterization

2017 ◽  
Vol 2 (4) ◽  
pp. 25
Author(s):  
L. A. Montoya ◽  
E. E. Rodríguez ◽  
H. J. Zúñiga ◽  
I. Mejía
Keyword(s):  
Dynamic Model ◽  
High Speed ◽  
Natural Frequencies ◽  
Mode Shapes ◽  
Experimental Characterization ◽  
Rotating Systems ◽  
Computing Performance ◽  
The Impact ◽  
Stiffness Distribution ◽  
Good Agreement

Rotating systems components such as rotors, have dynamic characteristics that are of great importance to understand because they may cause failure of turbomachinery. Therefore, it is required to study a dynamic model to predict some vibration characteristics, in this case, the natural frequencies and mode shapes (both of free vibration) of a centrifugal compressor shaft. The peculiarity of the dynamic model proposed is that using frequency and displacements values obtained experimentally, it is possible to calculate the mass and stiffness distribution of the shaft, and then use these values to estimate the theoretical modal parameters. The natural frequencies and mode shapes of the shaft were obtained with experimental modal analysis by using the impact test. The results predicted by the model are in good agreement with the experimental test. The model is also flexible with other geometries and has a great time and computing performance, which can be evaluated with respect to other commercial software in the future.

scholarly journals Development of Real-Time Time Gated Digital (TGD) OFDR Method and Its Performance Verification

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4865
Author(s):  
Kinzo Kishida ◽  
Artur Guzik ◽  
Ken’ichi Nishiguchi ◽  
Che-Hsien Li ◽  
Daiji Azuma ◽  
...  
Keyword(s):  
Real Time ◽  
Optical Fibers ◽  
High Speed ◽  
Oil And Gas ◽  
Scattered Light ◽  
Oil And Gas Industry ◽  
High Signal ◽  
Chirp Pulse ◽  
Sound Waves ◽  
Industry Applications

Distributed acoustic sensing (DAS) in optical fibers detect dynamic strains or sound waves by measuring the phase or amplitude changes of the scattered light. This contrasts with other distributed (and more conventional) methods, such as distributed temperature (DTS) or strain (DSS), which measure quasi-static physical quantities, such as intensity spectrum of the scattered light. DAS is attracting considerable attention as it complements the conventional distributed measurements. To implement DAS in commercial applications, it is necessary to ensure a sufficiently high signal-noise ratio (SNR) for scattered light detection, suppress its deterioration along the sensing fiber, achieve lower noise floor for weak signals and, moreover, perform high-speed processing within milliseconds (or sometimes even less). In this paper, we present a new, real-time DAS, realized by using the time gated digital-optical frequency domain reflectometry (TGD-OFDR) method, in which the chirp pulse is divided into overlapping bands and assembled after digital decoding. The developed prototype NBX-S4000 generates a chirp signal with a pulse duration of 2 μs and uses a frequency sweep of 100 MHz at a repeating frequency of up to 5 kHz. It allows one to detect sound waves at an 80 km fiber distance range with spatial resolution better than a theoretically calculated value of 2.8 m in real time. The developed prototype was tested in the field in various applications, from earthquake detection and submarine cable sensing to oil and gas industry applications. All obtained results confirmed effectiveness of the method and performance, surpassing, in conventional SM fiber, other commercially available interrogators.

scholarly journals Spectrum radial velocity analyser (SERVAL)

2017 ◽  
Vol 609 ◽  
pp. A12 ◽  
Author(s):  
M. Zechmeister ◽  
A. Reiners ◽  
P. J. Amado ◽  
M. Azzaro ◽  
F. F. Bauer ◽  
...  
Keyword(s):  
Radial Velocity ◽  
Line Width ◽  
Active Regions ◽  
High Signal ◽  
Chromatic Index ◽  
Visual Channel ◽  
Low Mass Stars ◽  
Differential Line ◽  
Spectral Diagnostics ◽  
Low Mass

Context. The CARMENES survey is a high-precision radial velocity (RV) programme that aims to detect Earth-like planets orbiting low-mass stars. Aims. We develop least-squares fitting algorithms to derive the RVs and additional spectral diagnostics implemented in the SpEctrum Radial Velocity AnaLyser (SERVAL), a publicly available python code. Methods. We measured the RVs using high signal-to-noise templates created by coadding all available spectra of each star. We define the chromatic index as the RV gradient as a function of wavelength with the RVs measured in the echelle orders. Additionally, we computed the differential line width by correlating the fit residuals with the second derivative of the template to track variations in the stellar line width. Results. Using HARPS data, our SERVAL code achieves a RV precision at the level of 1 m/s. Applying the chromatic index to CARMENES data of the active star YZ CMi, we identify apparent RV variations induced by stellar activity. The differential line width is found to be an alternative indicator to the commonly used full width half maximum. Conclusions. We find that at the red optical wavelengths (700–900 nm) obtained by the visual channel of CARMENES, the chromatic index is an excellent tool to investigate stellar active regions and to identify and perhaps even correct for activity-induced RV variations.

High-speed optical 3D roughness measurements

1999 ◽  
Author(s):  
Robert Windecker ◽  
Stefan Franz ◽  
Hans J. Tiziani
Keyword(s):  
High Speed ◽  
Roughness Measurements

scholarly journals High-speed high-resolution laser diode-based photoacoustic microscopy for in vivo microvasculature imaging

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Xiufeng Li ◽  
Victor T C Tsang ◽  
Lei Kang ◽  
Yan Zhang ◽  
Terence T W Wong
Keyword(s):  
High Resolution ◽  
High Speed ◽  
High Performance ◽  
Continuous Wave ◽  
Signal To Noise Ratio ◽  
Cost Effective ◽  
High Signal ◽  
Photoacoustic Microscopy ◽  
Mouse Ear

AbstractLaser diodes (LDs) have been considered as cost-effective and compact excitation sources to overcome the requirement of costly and bulky pulsed laser sources that are commonly used in photoacoustic microscopy (PAM). However, the spatial resolution and/or imaging speed of previously reported LD-based PAM systems have not been optimized simultaneously. In this paper, we developed a high-speed and high-resolution LD-based PAM system using a continuous wave LD, operating at a pulsed mode, with a repetition rate of 30 kHz, as an excitation source. A hybrid scanning mechanism that synchronizes a one-dimensional galvanometer mirror and a two-dimensional motorized stage is applied to achieve a fast imaging capability without signal averaging due to the high signal-to-noise ratio. By optimizing the optical system, a high lateral resolution of 4.8 μm has been achieved. In vivo microvasculature imaging of a mouse ear has been demonstrated to show the high performance of our LD-based PAM system.

Effect of Different Geometrical Inlet Pipes on a High Speed Centrifugal Compressor

2013 ◽  
Author(s):  
Ce Yang ◽  
Ben Zhao ◽  
C. C. Ma ◽  
Dazhong Lao ◽  
Mi Zhou
Keyword(s):  
Centrifugal Compressor ◽  
High Speed ◽  
Pressure Ratio ◽  
Inlet Pipe ◽  
Unsteady Pressure ◽  
Bent Pipe ◽  
Low Mass ◽  
Compressor Performance ◽  
Spectral Frequency ◽  
The One

Two different inlet configurations, including a straight pipe and a bent pipe, were experimentally tested and numerically simulated using a high-speed, low-mass flow centrifugal compressor. The pressure ratios of the compressor with the two inlet configurations were tested and then compared to illustrate the effect of the bent inlet pipe on the compressor. Furthermore, different circumferential positions of the bent inlet pipe relative to the volute are discussed for two purposes. One purpose is to describe the changes in the compressor performance that result from altering the circumferential position of the bent inlet pipe relative to the volute. This change in performance may be the so-called clocking effect, and its mechanism is different from the one in multistage turbomachinery. The other purpose is to investigate the unsteady flow for different matching states of the bent inlet pipe and volute. Thus, the frequency spectrum of unsteady pressure fluctuation was applied to analyze the aerodynamic response. Compared with the straight inlet pipe, the experimental results show that the pressure ratio is modulated and that the choke point is shifted in the bent inlet pipe. Similarly, the pressure ratio can be influenced by altering the circumferential position of the bent inlet pipe relative to the volute, which may have an effect on the unsteady pressure in the rotor section. Therefore, the magnitude of interest spectral frequency is significantly changed by clocking the bent inlet pipe.

Improvement and Lock Calculation of Electric Switch Machine of Railway Turnout

2013 ◽  
Vol 409-410 ◽  
pp. 1496-1501 ◽  
Author(s):  
Jing Mang Xu ◽  
Ping Wang ◽  
Hao Xu
Keyword(s):  
Dynamic Model ◽  
High Speed ◽  
Lateral Stiffness ◽  
High Speed Railway ◽  
Train Speed ◽  
Working Status ◽  
Stress And Deformation ◽  
Railway Turnout

Electric switch machine locks the crossing rail in the working direction and checks the working status of the crossing. With the increase of train speed, the ZD(J)9 electric switch machine cant satisfy the equipment of high speed railway, This paper studied the optimization; in order to study the lock calculation of nose rail after conversion, a dynamic model is established to research the influence of working status of the crossing. It indicates that for the first traction point, the stress and deformation are mainly affected by scant displacement between nose rail and wing rail; for the second traction point, they are affected by the gap between nose rail and spacer; fastener lateral stiffness doesnt influence the stress status, but the lateral fastener stiffness should not be too small.

A fault dynamic model of high-speed angular contact ball bearings

2020 ◽  
Vol 143 ◽  
pp. 103627 ◽  
Author(s):  
Yi Qin ◽  
Chengcheng Li ◽  
Folin Cao ◽  
Haizhou Chen
Keyword(s):  
Dynamic Model ◽  
High Speed ◽  
Ball Bearings

scholarly journals A Study on the Relationship between the Design of Aerotrain and Its Stability Based on a Three-Dimensional Dynamic Model

Robotics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 96
Author(s):  
Quang Huan Luong ◽  
Jeremy Jong ◽  
Yusuke Sugahara ◽  
Daisuke Matsuura ◽  
Yukio Takeda
Keyword(s):  
Dynamic Model ◽  
High Speed ◽  
Three Dimensional ◽  
Vehicle Body ◽  
Directional Stability ◽  
Rigid Body Model ◽  
Body Design ◽  
The Stability ◽  
New Generation ◽  
The Relationship

A new generation electric high-speed train called Aerotrain has levitation wings and levitates under Wing-in-Ground (WIG) effect along a U-shaped guideway. The previous study found that lacking knowledge of the design makes the prototype unable to regain stability when losing control. In this paper, the nonlinear three-dimensional dynamic model of the Aerotrain based on the rigid body model has been developed to investigate the relationship between the vehicle body design and its stability. Based on the dynamic model, this paper considered an Aerotrain with a horizontal tail and a vertical tail. To evaluate the stability, the location and area of these tails were parameterized. The effects of these parameters on the longitudinal and directional stability have been investigated to show that: the horizontal tail gives its best performance if the tail area is a function of the tail location; the larger vertical tail area and (or) the farther vertical tail location will give better directional stability. As for the lateral stability, a dihedral front levitation wing design was investigated. This design did not show its effectiveness, therefore a control system is needed. The obtained results are useful for the optimization studies on Aerotrain design as well as developing experimental prototypes.

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