Air Impact Drive for Positioning by Pulse and Continuous Air Pressure

1999 ◽  
Vol 11 (4) ◽  
pp. 263-268 ◽  
Author(s):  
Mohammad Hossein Kouklan ◽  
◽  
Yousef Hojjat ◽  
Toshiro Higuchi ◽  
Keyword(s):  
Pulse Pressure ◽  
Air Pressure ◽  
Impulsive Force ◽  
Precise Positioning ◽  
Good Linearity ◽  
Free Body ◽  
The Impact ◽  
Theoretical Results ◽  
Good Agreement

In recent years, the application of impacts to precise positioning has been increased. Previously, the impulsive force or impact was generated by electromagnetic impulsive force or by the sudden deformation of a piezoelement. In this paper, a new actuator named as Air Impact Drive (AID) is introduced, in which the impact is generated by impulsive air pulse pressure. Free body diagrams and equations of this new actuator were drawn and determined. Experimental and theoretical results are in good agreement. The new actuator could displace a 0.2kg object at 0.1 of millimeter per pulse by pulse air pressure. By implementing suitable setup of parameters, the AID could move the object by continuous, constant air pressure with good linearity. This property is unique among other impact drives for positioning. By 0.3Mpa of source air pressure, the new actuator could move the mentioned object at the speed of approximately 13.4mm/s.

Study on Damage Characteristics of Concrete under Impact Load and the Constitutive Model after Damage

2011 ◽  
Vol 48-49 ◽  
pp. 1137-1142
Author(s):  
Bin Jia ◽  
Zheng Liang Li ◽  
Hua Chuan Yao ◽  
Xiao Wei Zhu
Keyword(s):  
Impact Load ◽  
Impact Damage ◽  
Strain Process ◽  
Testing Data ◽  
Freezing Test ◽  
Strain Threshold ◽  
The Impact ◽  
Dynamic Damage ◽  
Theoretical Results ◽  
Good Agreement

The damage ‘freezing’ test of concrete was carried out with the static load and SHPB testing technique, so the relatively loss ultimate bearing capacity could express the damage in macro-level. The result showed that the dynamic damage of the concrete increased with the increasing strain or strain rate and the dynamic damage had a certain strain threshold. Based on the damage evolutive law of concrete whose probability density was distributed Weibul1 distribution, the impact damage factor equation was put forward. Besides, the unified equation which described the whole stress-strain process of the concrete after impact damage were established. Compared with the testing data, it showed that the experiment and theoretical results were in good agreement.

Use of Statical Indentation Laws in the Impact Analysis of Laminated Composite Plates

1985 ◽  
Vol 52 (1) ◽  
pp. 6-12 ◽  
Author(s):  
T. M. Tan ◽  
C. T. Sun
Keyword(s):  
Impact Analysis ◽  
Laminated Composite ◽  
Composite Plates ◽  
Impact Response ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
The Impact ◽  
Theoretical Results ◽  
Theoretical Procedure ◽  
Good Agreement

The low-velocity impact response of graphite/epoxy laminates was investigated theoretically and experimentally. A nine-node isoparametric plate finite element in conjunction with an empirical contact law was used for the theoretical investigation. Theoretical results are in good agreement with strain-gage experimental data. The results of the investigation indicate that the present theoretical procedure describes the impact response of laminate for low-impact velocities.

APPLICATION OF ELASTIC MATERIALS IN PROTECTION FROM STRONG IMPACTS

2004 ◽  
Vol 18 (14) ◽  
pp. 1977-1990
Author(s):  
MASKOVIC D. LJILJANA ◽  
MOHORA EMILIJAN ◽  
TOSIC S. BRATISLAV ◽  
VUJOVIC R. RATKO
Keyword(s):  
Elastic Material ◽  
Short Pulse ◽  
Three Dimensional ◽  
Polymer Materials ◽  
Elastic Materials ◽  
One Dimensional ◽  
Spherical Surfaces ◽  
The Impact ◽  
Theoretical Results ◽  
Good Agreement

The analysis of the behavior of elastic material subject to strong short pulse impact has shown that only one-dimensional structures support the impact without destruction. Compact two- and three-dimensional structures are destroyed during the impact along circular lines and spherical surfaces. For that reason, web-like shields are proposed for the protection of man and equipment. Polymer materials are most suitable for the production of web-like shields since they are made of fibers and highly stress resistant. Theoretical results are experimentally tested and the good agreement with theory was found.

ASSESSING THE ADEQUACY OF MODELING THE IMPACT OF HEAVY CHARGED PARTICLES ON A CHIP

2016 ◽  
Vol 8 (4) ◽  
pp. 10-12 ◽  
Author(s):  
Грошев ◽  
A. Groshev ◽  
Чубур ◽  
K. Chubur ◽  
Яньков ◽  
...  
Keyword(s):  
Charged Particles ◽  
Heavy Charged Particles ◽  
Comparison Of The Results ◽  
The Impact ◽  
Theoretical Results ◽  
Good Agreement

Considered a comparison of experimental and theoretical results is the number of failures at the chip under the influence of heavy charged particles. Comparison of the results showed good agreement.

Movement characteristics analysis of bi-directional friction linear micro-motor driven by a set of micro-actuator

2021 ◽  
pp. 2140013
Author(s):  
Zhenlu Wang ◽  
Jiue Zhang ◽  
Shuxia Ma ◽  
Guangqiao Liu
Keyword(s):  
Driving Frequency ◽  
Dynamics Model ◽  
Motion Direction ◽  
Movement Characteristics ◽  
Theoretical Predictions ◽  
Characteristics Analysis ◽  
Directional Motion ◽  
The Impact ◽  
Theoretical Results ◽  
Good Agreement

In this paper, a bi-directional friction linear micro-motor (BFLM) driven by a set of micro-actuators was introduced and analyzed. The BFLM was fabricated using PolyMUMPs process. The impact dynamics model for the BFLM was established, and its motion equation was also derived that takes into account the friction and contact. The relative motion between the driving head and the slider, as well as forward or backward movement of the slider were analyzed in detail. The forward and backward movement displacement of the slider was measured, and the experimental results were in good agreement with theoretical predictions. The theoretical results show that the motion direction of the slider can be changed by controllable driving frequency to the BFLM. It was feasible to use a set of actuators to drive the slider in bi-directional motion.

Investigating the Nonlinear Optical Response of Pepper Oil under Low Power Irradiation with Continuous Wave Visible Laser Beam

2020 ◽  
pp. 131-138
Keyword(s):  
Refractive Index ◽  
Nonlinear Refractive Index ◽  
Nonlinear Optical ◽  
Continuous Wave ◽  
Diffraction Integral ◽  
Visible Laser ◽  
Limiting Property ◽  
Kirchhoff Diffraction Integral ◽  
Theoretical Results ◽  
Good Agreement

The nonlinear optical properties of pepper oil are studied by diffraction ring patterns and Z-scan techniques with continuous wave beam from solid state laser at 473 nm wavelength. The nonlinear refractive index of the sample is calculated by both techniques. The sample show high nonlinear refractive index. Based on Fresnel-Kirchhoff diffraction integral, the far-field intensity distributions of ring patterns have been calculated. It is found that the experimental results are in good agreement with the theoretical results. Also the optical limiting property of pepper oil is reported. The results obtained in this study prove that the pepper oil has applications in nonlinear optical devices.

Modeling of Tread Block Contact Mechanics Using Linear Viscoelastic Theory3

2008 ◽  
Vol 36 (3) ◽  
pp. 211-226 ◽  
Author(s):  
F. Liu ◽  
M. P. F. Sutcliffe ◽  
W. R. Graham
Keyword(s):  
High Speed ◽  
Slip Rate ◽  
Material Model ◽  
Contact Forces ◽  
Block Modeling ◽  
Rate Dependent ◽  
Linear Viscoelastic Material ◽  
Linear Viscoelastic ◽  
The Impact ◽  
Good Agreement

Abstract In an effort to understand the dynamic hub forces on road vehicles, an advanced free-rolling tire-model is being developed in which the tread blocks and tire belt are modeled separately. This paper presents the interim results for the tread block modeling. The finite element code ABAQUS/Explicit is used to predict the contact forces on the tread blocks based on a linear viscoelastic material model. Special attention is paid to investigating the forces on the tread blocks during the impact and release motions. A pressure and slip-rate-dependent frictional law is applied in the analysis. A simplified numerical model is also proposed where the tread blocks are discretized into linear viscoelastic spring elements. The results from both models are validated via experiments in a high-speed rolling test rig and found to be in good agreement.

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 Measuring Hydrometeors Using a Precipitation Microphysical Characteristics Sensor: Sampling Effect of Different Bin Sizes on Drop Size Distribution Parameters

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Xichuan Liu ◽  
Taichang Gao ◽  
Yuntao Hu ◽  
Xiaojian Shu
Keyword(s):  
Drop Size ◽  
Rain Rate ◽  
Monte Carlo Model ◽  
Rain Gauge ◽  
Sampling Schemes ◽  
Distribution Parameters ◽  
Optimum Sampling ◽  
Simulation Results ◽  
The Impact ◽  
Good Agreement

In order to improve the measurement of precipitation microphysical characteristics sensor (PMCS), the sampling process of raindrops by PMCS based on a particle-by-particle Monte-Carlo model was simulated to discuss the effect of different bin sizes on DSD measurement, and the optimum sampling bin sizes for PMCS were proposed based on the simulation results. The simulation results of five sampling schemes of bin sizes in four rain-rate categories show that the raw capture DSD has a significant fluctuation variation influenced by the capture probability, whereas the appropriate sampling bin size and width can reduce the impact of variation of raindrop number on DSD shape. A field measurement of a PMCS, an OTT PARSIVEL disdrometer, and a tipping bucket rain Gauge shows that the rain-rate and rainfall accumulations have good consistencies between PMCS, OTT, and Gauge; the DSD obtained by PMCS and OTT has a good agreement; the probability of N0, μ, and Λ shows that there is a good agreement between the Gamma parameters of PMCS and OTT; the fitted μ-Λ and Z-R relationship measured by PMCS is close to that measured by OTT, which validates the performance of PMCS on rain-rate, rainfall accumulation, and DSD related parameters.

scholarly journals Robust Filtering Techniques for RTK Positioning in Harsh Propagation Environments

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1250
Author(s):  
Daniel Medina ◽  
Haoqing Li ◽  
Jordi Vilà-Valls ◽  
Pau Closas
Keyword(s):  
Intelligent Transportation Systems ◽  
Robust Statistics ◽  
Real Data ◽  
Transportation Systems ◽  
Global Navigation Satellite Systems ◽  
Mixed Integer ◽  
Robust Filtering ◽  
Precise Positioning ◽  
The Impact ◽  
Filtering Techniques

Global navigation satellite systems (GNSSs) play a key role in intelligent transportation systems such as autonomous driving or unmanned systems navigation. In such applications, it is fundamental to ensure a reliable precise positioning solution able to operate in harsh propagation conditions such as urban environments and under multipath and other disturbances. Exploiting carrier phase observations allows for precise positioning solutions at the complexity cost of resolving integer phase ambiguities, a procedure that is particularly affected by non-nominal conditions. This limits the applicability of conventional filtering techniques in challenging scenarios, and new robust solutions must be accounted for. This contribution deals with real-time kinematic (RTK) positioning and the design of robust filtering solutions for the associated mixed integer- and real-valued estimation problem. Families of Kalman filter (KF) approaches based on robust statistics and variational inference are explored, such as the generalized M-based KF or the variational-based KF, aiming to mitigate the impact of outliers or non-nominal measurement behaviors. The performance assessment under harsh propagation conditions is realized using a simulated scenario and real data from a measurement campaign. The proposed robust filtering solutions are shown to offer excellent resilience against outlying observations, with the variational-based KF showcasing the overall best performance in terms of Gaussian efficiency and robustness.

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