scholarly journals An Online Gravity Modeling Method Applied for High Precision Free-INS

Sensors ◽  
2016 ◽  
Vol 16 (10) ◽  
pp. 1541 ◽  
Author(s):  
Jing Wang ◽  
Gongliu Yang ◽  
Jing Li ◽  
Xiao Zhou
Keyword(s):  
High Precision ◽  
Modeling Method ◽  
Gravity Modeling

The performance comparison of typical notched flexure hinges

2019 ◽  
Vol 234 (9) ◽  
pp. 1859-1867
Author(s):  
Wei Ma ◽  
Rongqi Wang ◽  
Xiaoqin Zhou ◽  
Guangwei Meng
Keyword(s):  
High Resolution ◽  
High Precision ◽  
Compliant Mechanisms ◽  
Performance Comparison ◽  
Modeling Method ◽  
Stress Concentrations ◽  
High Demand ◽  
Flexure Hinges ◽  
Matrix Modeling ◽  
Practical Guidelines

Flexure hinges, which serve as the crucial joints in a large number of compliant mechanisms, have been widely applied in a variety of significant fields where there is high demand for the micro/nano motions with high resolution and high precision. Currently, an increasing number of notched flexure hinges with different structures and performances have been rapidly developed, but the existing performance comparisons on different notched flexure hinges were only conducted on seldom typical structures and are far from the comprehensiveness and fairness due to the different comparative conditions and discrepant evaluating indexes. Therefore, the finite beam-based matrix modeling method and nondimension precision factors will be employed in comprehensive comparing and ranking of 13 types of frequently-used notched flexure hinges in terms of their main compliances, motion accuracies, and stress concentrations, further providing useful practical guidelines to develop the compliant mechanisms with excellent overall performances.

3D Stress Field Modeling for Wellbore Stability Analysis

2021 ◽  
Author(s):  
Shaoxuan Li ◽  
Lei Liu ◽  
Zhilei Han ◽  
Rui Wu ◽  
Naichuan Guo
Keyword(s):  
Stability Analysis ◽  
Stress Field ◽  
High Precision ◽  
Seismic Data ◽  
Large Scale ◽  
Seismic Inversion ◽  
Modeling Method ◽  
Wellbore Stability ◽  
Bohai Bay ◽  
Oilfield Development

Abstract Borehole collapse is one of the difficult problems in offshore oilfield drilling, which is directly related to regional geostress field. Seismic inversion is widely used to construct 3D stress field, and the accuracy of seismic inversion results depends heavily on the quality of seismic data. Therefore, in the development oilfield with poor seismic data quality, we use attribute modeling method to construct high-precision 3D geostress field to help analyze the wellbore stability of oilfield development wells. First, 3D structural model is created by using seismic interpretation horizon and fault. Then, the 3D stress body is constructed by filling the vertical and horizontal attributes according to certain constraints by using the known geostress values at the wellbore of the drilled development wells. P oilfield is a large Neogene oilfield located in Bohai Bay. The serious expansion of the wellbore in the shallow unconsolidated sandstone in the oilfield area leads to high engineering risks. Moreover, due to the influence of large-scale gas cloud area, the effective wave energy on seismic profile is submerged. Through the above attribute modeling method, the high-precision 3D geostress field of P oilfield is successfully constructed. Practical application shows this method is suitable for the evaluation of geostress and wellbore stability analysis in areas with high well control in the middle and late stages of oilfield development. Especially in the area where the seismic data is not reliable enough, the 3D modeling results of this method has higher accuracy than the seismic inversion results.

scholarly journals High-Precision Kriging Modeling Method Based on Hybrid Sampling Criteria

Mathematics ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 536
Author(s):  
Junjun Shi ◽  
Jingfang Shen ◽  
Yaohui Li
Keyword(s):  
Correlation Function ◽  
High Precision ◽  
Screening Method ◽  
Kriging Model ◽  
Modeling Method ◽  
Evaluation Point ◽  
Sampling Points ◽  
Close Distance ◽  
Candidate Point ◽  
Hybrid Sampling

Finding new valuable sampling points and making these points better distributed in the design space is the key to determining the approximate effect of Kriging. To this end, a high-precision Kriging modeling method based on hybrid sampling criteria (HKM-HS) is proposed to solve this problem. In the HKM-HS method, two infilling sampling strategies based on MSE (Mean Square Error) are optimized to obtain new candidate points. By maximizing MSE (MMSE) of Kriging model, it can generate the first candidate point that is likely to appear in a sparse area. To avoid the ill-conditioned correlation matrix caused by the too close distance between any two sampling points, the MC (MSE and Correlation function) criterion formed by combining the MSE and the correlation function through multiplication and division is minimized to generate the second candidate point. Furthermore, a new screening method is used to select the final expensive evaluation point from the two candidate points. Finally, the test results of sixteen benchmark functions and a house heating case show that the HKM-HS method can effectively enhance the modeling accuracy and stability of Kriging in contrast with other approximate modeling methods.

A Combined Modeling Method Based on Multiple-Sensor Integrated Measuring System for Reverse Engineering

2011 ◽  
Vol 418-420 ◽  
pp. 2036-2039
Author(s):  
Peng Xin Liu ◽  
Xuan Liu ◽  
Min Li
Keyword(s):  
High Precision ◽  
Modeling Method ◽  
Measuring System ◽  
Software Environment ◽  
Precision Data ◽  
Optical Scanning ◽  
Data Merging ◽  
Common Coordinate System ◽  
Multiple Sensor ◽  
Touch Probe

In this paper a combined modeling method using digitized points measured by multiple-sensor integrated measuring system with a touch probe and a optical scanning probe is presented. The optical scanning data in the form of triangulated mesh and the high precision data captured by a touch probe on an integrated measuring system are transformed into a common coordinate system by the worktable for registration and improved ICP algorithm. A data merging method is used to keep the high precision of feature surfaces.The merging data is unified into a precise 3D model in CAD software environment based on the strategy for optimization reconstruction. Experimental results demonstrate the efficiency of the proposed method, which enhances the flexibility of digitizing while maintaining the accuracy of feature surfaces.

scholarly journals Simulation of VSP data based on DSI data and estimation of shear wave velocity and elastic Moduli for a well case study

2019 ◽  
Vol 4 (4) ◽  
pp. 138-145
Author(s):  
Babak Sayad Noghretab ◽  
Mohammad Kamal Ghassem-Alaskari
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
High Precision ◽  
Shear Wave Velocity ◽  
Elastic Moduli ◽  
Modeling Method ◽  
Gas Field ◽  
Data Set ◽  
Survey Report ◽  
Vsp Data

The purpose of this article was to generate and compare seismic modeling results with real vertical seismic profiling data (VSP data) based on Dipole Shear Imager (DSI) data in the reservoir zone (Kangan and upper Dalan Formations) of a well in South Pars gas field. Estimation of shear wave velocity (Vs) and density for layers above the reservoir zone, for which; DSI data did not exist, was also done by the applied modeling method to estimate elastic parameters of the layers. In this method, modeling for X-component of the VSP survey was run by utilizing the DSI data set of reservoir zone and the VSP survey report of the studied well with high precision. Computed results for the proposed modeling method led to achieving highly accurate, close to the reality of VSP model around the studied well. According to compression wave velocity (VP) attained from VSP survey reports of the well and Vp/Vs ratio obtained from Dipole Shear Imager (DSI), modeling was done. Afterward, shear wave velocity (Vs) for upper layers of reservoir zone estimated with high precision, then density and elastic moduli for the above layers and the reservoir zone were calculated.

scholarly journals A Simplified FE Modeling Strategy for the Drop Process Simulation Analysis of Light and Small Drone

Aerospace ◽  
2021 ◽  
Vol 8 (12) ◽  
pp. 387
Author(s):  
Yongjie Zhang ◽  
Yingjie Huang ◽  
Zhiwen Li ◽  
Liang Ke ◽  
Kang Cao ◽  
...  
Keyword(s):  
High Precision ◽  
Process Simulation ◽  
Modeling Method ◽  
Dynamics Simulation ◽  
Impact Dynamics ◽  
Simplified Models ◽  
Full Size ◽  
Modeling Methods ◽  
Modeling Strategy ◽  
Simplified Modeling

The numerical accuracy of drop process simulation and collision response for drones is primarily determined by the finite element modeling method and simplified method of drone airframe structure. For light and small drones exhibiting diverse shapes and configurations, mixed materials and structures, deformation and complex destruction behaviors, the way of developing a reasonable and easily achieved high-precision simplified modeling method by ensuring the calculation accuracy and saving the calculation cost has aroused increasing concern in impact dynamics simulation. In the present study, the full-size modeling and simplified modeling methods that are specific to different components of a relatively popular light and small drone were analyzed in an LS-DYNA software environment. First, a full-size high-precision model of the drone was built, and the model accuracy was verified by performing the drop tests at the component level as well as the whole machine level. Subsequently, based on the full-size high-precision model, the property characteristics of the main components of the light and small drone and their common simplification methods were classified, a series of simplified modeling methods for different components were developed, several single simplified models and combined simplified models were built, and a method to assess the calculation error of the peak impact load in the simplified models was proposed. Lastly, by comparing and analyzing the calculation accuracy of various simplified models, the high-precision simplified modeling strategy was formulated, and the suggestions were proposed for the impact dynamics simulation of the light and small drone falling. Given the analysis of the calculation scale and solution time of the simplified model, the high-precision simplified modeling method developed here is capable of noticeably reducing the modeling difficulty, the solution scale and the calculation time while ensuring the calculation accuracy. Moreover, it shows promising applications in several fields (e.g., structure design, strength analysis and impact process simulation of drone).

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