scholarly journals Motion Analysis of Butterfly-Style Flapping Robot Using CFD Based on 3D-CAD Model and Experimental Flight Data

2021 ◽  
Vol 33 (2) ◽  
pp. 216-222
Author(s):  
Keisuke Sanuki ◽  
◽  
Taro Fujikawa
Keyword(s):  
Flow Field ◽  
Motion Analysis ◽  
The Body ◽  
Cad Model ◽  
Cfd Analysis ◽  
Flight Data ◽  
3D Cad ◽  
Pitch Moment ◽  
The Difference ◽  
Analysis System

In this paper, a computational fluid dynamics (CFD) analysis system based on a 3D-CAD model of a butterfly-style flapping robot using its experimental flight data is proposed. The butterfly-style flapping robot can control its attitude by changing its flapping and lead-lag angles; however, measuring the lift, thrust, and body pitch moment directly during flight is difficult. In the case of the flight motion analysis of insects, the state of flight has been photographed, and numerical analysis has been performed to obtain the flow field around the wings. However, when performing the motion analysis of hardware, it is difficult to reflect the shape of the body accurately using this method. In this study, a CFD analysis system considered the shape of the developed butterfly-style flapping robot as 3D-CAD data and analyzed the flow field around the wings using the experimental flight data of the hardware. The results of motion analysis showed that the attitude during flight differs due to the difference in lifts and body pitch moments in the flight experiment data of the hardware with different neutral angles of the flapping wings.

Differences Among an Expert and a Non Expert in the Behavior for Chucking in the Lathe

2013 ◽  
Author(s):  
Porakoch Sirisuwan ◽  
Tetsushi Koshino ◽  
Chieko Narita ◽  
Takashi Yoshikawa
Keyword(s):  
Motion Analysis ◽  
Sampling Rate ◽  
Arm Movement ◽  
Motion Analysis System ◽  
Video Cameras ◽  
Position Data ◽  
Lathe Machine ◽  
The Difference ◽  
Infrared Cameras ◽  
Analysis System

The expert worker (85 years old) has worked for 70 years and the non expert (16 years old) has worked 1 year of experience for the lathe processing. The subjects were compared the difference in the waist, the shoulder and the fore arm movement between the two worker while they were chucking on the lathe machine. Determination used the same parts and the same type of lathe machine for investigated. There were 4 main categories that related three stances position alignment and two hands position on the key chuck. Using the 6 infrared cameras and 2 video cameras captured the position of each marker. All markers position data which synchronization was taken by a motion analysis system (sampling rate: 100Hz). As a results show the balance movement both the waist and the shoulder during the chucking that had significantly greater in the expert worker than the non expert worker.

scholarly journals Precision and repeatability analysis of a motion analysis system for traction therapy

2018 ◽  
Vol 7 (2.8) ◽  
pp. 156
Author(s):  
Se Jin Park ◽  
Murali Subramaniyam ◽  
Seung Nam Min ◽  
Seoung Eun Kim ◽  
Sikyung Kim
Keyword(s):  
Cervical Spine ◽  
Motion Analysis ◽  
Traction Force ◽  
Cervical Vertebra ◽  
Body Part ◽  
Rehabilitation Medicine ◽  
The Body ◽  
Motion Analysis System ◽  
Analysis System ◽  
Traction System

Neck pain or cervical pain is most common in individuals who are all working in seated postures for prolonged period of time, example computer users. The pain caused by extreme postural positions including forward head postures and extension angle maintained in cervical. The use of cervical vertebra traction therapy has increased as a part of rehabilitation medicine. However, lack of usability standard in this traction therapy i.e., the exact instructions on how to choose the traction force and location are unclear. To fix this issue, first, the cervical spine traction system analysing the change of cervical spine depending on the traction location has been investigated. Motion analysis systems are widely used to measure the changes in the body part movement. However, the precision and repeatability of motion analysis systems are not much studied. In this paper, the precision and repeatability of a three-dimensional (3D) motion analysis system (i.e., NDI’s Optotrak Certus (OC)) is evaluated with developed 3D robot for traction therapy as an application example. The 3D robot quantitated the accuracy and precision of the system regarding angle and distance. Angle and distance among markers showed good agreement between measurements, and comparable measures of precision reported. Experimental results demonstrate a measure of precision and repeatability for the movement of the patients on the cervical traction system; hence the repeatability was satisfactory.

An Automatic Technique for CAE Analysis With a 3D-CAD Model

2002 ◽  
Author(s):  
Norihiko Nonaka ◽  
Ichirou Nishigaki
Keyword(s):  
Computer Aided Design ◽  
Geometric Model ◽  
Three Dimensional ◽  
Analysis Time ◽  
Cad Model ◽  
3D Cad ◽  
Computer Aided ◽  
Cae Analysis ◽  
Analysis System ◽  
Definition Of

A CAE (computer-aided engineering) analysis system, consisting of a 3D-CAD (three-dimensional computer-aided design) modeler, a pre-processor, an analysis solver, and a post-processor, was developed. This system uses automated procedures for solid modeling, definition of analysis models (i.e., defining boundary conditions and material properties, traditionally done manually), mesh generation, numerical simulation, and visualization of results. The CAE analysis system has two key features: it can greatly reduce the analysis time, and it uses a 3D-CAD model as the geometric model for numerical analysis. It was found that the developed automatic system reduces the analysis time by 50% compared with that for manual operation.

scholarly journals Use of Lumbar Point for the Estimation of Potential and Kinetic Mechanical Power in Running

2004 ◽  
Vol 20 (3) ◽  
pp. 324-331 ◽  
Author(s):  
Jean Slawinski ◽  
Véronique Billat ◽  
Jean-Pierre Koralsztein ◽  
Michel Tavernier
Keyword(s):  
Potential Energy ◽  
Constant Velocity ◽  
Mechanical Energy ◽  
Center Of Mass ◽  
Video Camera ◽  
The Body ◽  
Motion Analysis System ◽  
The Difference ◽  
Analysis System ◽  
Significant Underestimation

The purpose of this study was to estimate the difference between potential and kinetic mechanical powers in running (Pke, Ppe) calculated from the center of mass and one anatomic point of the body located on the lower part of the runner's back, the “lumbar point.” Six runners undertook a treadmill run at constant velocity and were filmed individually with a video camera (25 Hz). The 3-D motion analysis system, ANIMAN3D, uses a numerical manikin (MAN3D) which compares a voluminal subject (the athlete) directly to the manikin which possesses the same voluminal properties. This analysis system allows the trajectories of the center of mass and the lumbar point to be calculated. Then, from these trajectories, potential and kinetic mechanical powers in running are calculated. The results show that the utilization of the lumbar point rather than the runner's center of mass leads to a significant overestimation of Pkeand a significant underestimation of Ppe(bothp< 0.05). In spite of these differences, however, both methods of calculating Pkeand Ppeare well correlated: respectively,r= 0.92;p≤ 0.01, andr= 0.68;p≤ 0.05. Taking into account that the trajectory of an anatomic point is experimentally easier to access than that of the center of mass, such a point could be used to estimate the evolution of kinetic or potential energy variation in different cases. However, when the lumbar point rather than the center of mass is used to estimate the mechanical energy produced in running, Pkecould appear to be a discriminating parameter, which it is not.

The Research on Post Rolling of Aerodynamic Characteristics Numerical Simulation of Flow Field

2014 ◽  
Vol 684 ◽  
pp. 30-33
Author(s):  
Qi Wang ◽  
Jing Zhang ◽  
Ming Ming ◽  
Xiao Xu Chen
Keyword(s):  
Flow Field ◽  
Preliminary Analysis ◽  
Aerodynamic Force ◽  
Aerodynamic Characteristics ◽  
Source Model ◽  
Cfd Analysis ◽  
Analysis Method ◽  
Model Flow ◽  
The Difference ◽  
Aerodynamic Torque

In this paper, according on post rolling maneuver and the flow field, we build a CFD analysis method about momentum source model flow field and aerodynamic characteristics. Preliminary analysis of the numerical has be finished to contrast the difference of post rolling maneuver. The changing law of aerodynamic force, aerodynamic torque variation and the focus position have be given.

scholarly journals The use of 3D scanning in reverse engineering

Mechanik ◽  
2019 ◽  
Vol 92 (3) ◽  
pp. 194-196
Author(s):  
Jerzy Bochnia
Keyword(s):  
Reverse Engineering ◽  
3D Scanning ◽  
The Body ◽  
Real Object ◽  
Surface Model ◽  
Cad Model ◽  
Master Cylinder ◽  
3D Cad ◽  
Geometrical Dimensions

The procedure of building a surface model and inspecting its dimensions by scanning a real object is discussed. The body of a two-part master cylinder was scanned. Geometrical dimensions of the obtained surface model were inspected. Based on obtained data, a 3D CAD model of the scanned object was developed.

Study of geometrical defects of free-form surface machined using neural network

2021 ◽  
Vol 13 (11) ◽  
pp. 168781402110609
Author(s):  
Benattia Bloul ◽  
Hélène Chanal ◽  
Benaoumeur Aour ◽  
Nargess Chtioui
Keyword(s):  
Artificial Intelligence ◽  
Three Dimensional ◽  
Free Form ◽  
Cad Model ◽  
3D Cad ◽  
Measuring Machine ◽  
The Difference ◽  
Geometrical Defects ◽  
Free Form Surfaces

The manufacture of total hip arthroplasty (THA) requires the control of the quality of free form surfaces. In fact, the polyethylene insert is deformed to fit the overall geometry of the femoral part, which has an impact on the quality of the contact. In this paper, we propose a method for evaluating the defects of complex forms. The originality of the approach is the use of artificial intelligence to position the cloud of measured points, obtained with a three-dimensional measuring machine equipped with a contactless sensor, with regard to the 3D CAD model of the THA. The artificial intelligence algorithm used is based on neural networks that are trained using a virtual positioning realized with 3D CAD software. Finally, the difference between the positioned point cloud and the CAD model allows us to evaluate the shape defect of the measured THA surface. We found that the error of the proposed method is at the vicinity of micron scale.

CFD Analysis of a Captive Bullet Entry in Calm Water With and Without Turbulence

2019 ◽  
Author(s):  
René Bettencourt Rauffus ◽  
António Maximiano ◽  
Luís Eça ◽  
Guilherme Vaz
Keyword(s):  
Experimental Data ◽  
Turbulent Flow ◽  
Turbulence Model ◽  
Computational Cost ◽  
Longitudinal Force ◽  
The Body ◽  
Test Case ◽  
Vertical Force ◽  
Pitch Moment ◽  
The Difference

Abstract Simulations are carried out for a simplified lifeboat drop test case, which consists of a captive axisymmetric generic lifeboat shape (bullet), that penetrates the water surface at a constant velocity and angle of attack. The quantities of interest are the body fixed longitudinal force FX, vertical force FZ, and pitch moment MYY.This case was previously used in a verification and validation exercise [1]. Here, a step forward in complexity is taken, as the previous numerical model is now supplemented with the eddy-viscosity based turbulence model k–ω SST. Both approaches are then used to simulate two different cases: Case 1 with minimal wake effects; and Case 3 with flow separation and significant wake. The results are compared with the experimental data. The numerical uncertainty is estimated for both models. It is seen that for Case 1 the difference between both models is mostly within the comparison uncertainty, except for the longitudinal force FX, where the turbulent flow predicts a larger force, improving the comparison with the experiments. The loads predicted with turbulent flow stayed mostly within 6 % of the laminar flow. For Case 3 small differences between both models are found during/after the wake collapse stage. However, this difference is often within the comparison uncertainty. A reasonable agreement is found with the experimental data, except for FZ after the bow wake collapse. The turbulent flow improves slightly on the laminar approach regarding the agreement with the experiments, however it can be argued if this difference justifies the increased computational cost of the turbulence model.

APPLYING THE ISF TECHNOLOGY TO PRODUCE THE CAR PART MODELS

2010 ◽  
Vol 13 (4) ◽  
pp. 91-98
Author(s):  
Tuan Dinh Phan ◽  
Binh Thien Nguyen ◽  
Dien Khanh Le ◽  
Phuong Hoang Pham
Keyword(s):  
Rapid Prototyping ◽  
Incremental Sheet Forming ◽  
Cad Model ◽  
Post Processing ◽  
Technological Parameters ◽  
Batch Production ◽  
Complex Products ◽  
3D Cad ◽  
Real Size ◽  
Single Batch

The paper presents an application the research results previously done by group on the influence of technological parameters to the deformation angle and finish surface quality in order to choose technology parameters for the incremental sheet forming (ISF) process to produce products for the purpose of rapid prototyping or single-batch production, including all steps from design and process 3D CAD model, calculate and select the technological parameters, setting up manufacturing and the stage of post-processing. The samples formed successfully showed high applicability of this technology to practical work, the complex products with the real size can be produced in industries: automotive, motorcycle, civil...

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