scholarly journals Influence of automation on biomechanical exposure of the upper-limbs in an industrial assembly line: a pilot study

2020 ◽  
Vol 4 (2) ◽  
pp. 1-11
Author(s):  
Joana Santos ◽  
Ana Betty Abreu ◽  
Pedro Fonseca ◽  
Carlos Carvalhais ◽  
J. Santos Baptista ◽  
...  
Keyword(s):  
Cross Correlation ◽  
Assembly Line ◽  
Joint Angle ◽  
Correlation Coefficients ◽  
Assembly Lines ◽  
Joint Angles ◽  
Industrial Assembly ◽  
Time Courses ◽  
Experienced Female ◽  
Full Body

Automation of assembly work was originally developed to increase operation efficiency and to reduce workload. However, a considerable number of unanticipated ergonomic problems have been observed such as the interaction between humans and automated systems. The aims of this study were to quantify joint angle positions (shoulder, elbow and wrist) of workers in two assembly lines with different mechanization levels and analyse the performance of an inertial motion capture system. Seven experienced female assemblers participated in this study. The measurements were performed in the workplace with a full-body inertial measurement system (Xsens MVN BIOMECH system). Maximum cross-correlation between angle-time courses was calculated to quantify the waveform similarities. In manual line, there are larger variations of joint angles than in the semi-automatic one. The analysis of cross correlation coefficients revealed that electromagnetic interferences are potential limitations to the use of these systems under field conditions.

Measurement of Patellar Proximodistal Positioning with Limited Joint-Angle Sensitivity

2020 ◽  
Vol 33 (02) ◽  
pp. 096-101
Author(s):  
Clara M. Allberg ◽  
James Miles
Keyword(s):  
Joint Angle ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Reference Intervals ◽  
Joint Angles ◽  
Angle Variation ◽  
Intraclass Correlation Coefficients ◽  
Stifle Joint ◽  
Wide Range ◽  
Coefficients Of Variations

Abstract Objective Patellar luxation can be associated with abnormal proximodistal positioning of the patella. The current gold standard index (Insall–Salvati) for referencing this position is poorly suited to postoperative use, if the tibial tuberosity is moved surgically, but has the advantage of changing minimally with altered joint angles. The aim of this study was to identify an alternative index, which was simple to use, joint-angle insensitive and suitable for postoperative use. Study Design Candidate indices based on the angle between stifle joint landmarks were screened across a wide range of joint angles for insensitivity to joint angle changes using vulpine and canine stifle radiographs. Intraobserver and interobserver agreements were assessed for a single candidate index using canine radiographs. Results An angular index based on the caudal aspect of the femoral and tibial condyles and the apex of the patella was largely insensitive to joint angle variation. Intra- and interobserver agreements appeared suitable for clinical use, with low within-subject standard deviations (<1.3°) and coefficients of variations (<2.2%), and high intraclass correlation coefficients (>0.89). Conclusion Patellar proximodistal position can be acceptably assessed at a variety of caudal joint angles using the described angular index. Further work is required to define reference intervals across a range of canine breeds.

scholarly journals Genome-Wide Association Studies Based on Equine Joint Angle Measurements Reveal New QTL Affecting the Conformation of Horses

Genes ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 370 ◽  
Author(s):  
Annik Imogen Gmel ◽  
Thomas Druml ◽  
Rudolf von Niederhäusern ◽  
Tosso Leeb ◽  
Markus Neuditschko
Keyword(s):  
Joint Angle ◽  
Association Studies ◽  
Genome Wide Association ◽  
Cranial Morphology ◽  
Genome Wide Association Studies ◽  
Joint Angles ◽  
Mineral Density ◽  
Mixed Effect ◽  
Stifle Joint ◽  
Genome Wide

The evaluation of conformation traits is an important part of selection for breeding stallions and mares. Some of these judged conformation traits involve joint angles that are associated with performance, health, and longevity. To improve our understanding of the genetic background of joint angles in horses, we have objectively measured the angles of the poll, elbow, carpal, fetlock (front and hind), hip, stifle, and hock joints based on one photograph of each of the 300 Franches-Montagnes (FM) and 224 Lipizzan (LIP) horses. After quality control, genome-wide association studies (GWASs) for these traits were performed on 495 horses, using 374,070 genome-wide single nucleotide polymorphisms (SNPs) in a mixed-effect model. We identified two significant quantitative trait loci (QTL) for the poll angle on ECA28 (p = 1.36 × 10−7), 50 kb downstream of the ALX1 gene, involved in cranial morphology, and for the elbow joint on ECA29 (p = 1.69 × 10−7), 49 kb downstream of the RSU1 gene, and 75 kb upstream of the PTER gene. Both genes are associated with bone mineral density in humans. Furthermore, we identified other suggestive QTL associated with the stifle joint on ECA8 (p = 3.10 × 10−7); the poll on ECA1 (p = 6.83 × 10−7); the fetlock joint of the hind limb on ECA27 (p = 5.42 × 10−7); and the carpal joint angle on ECA3 (p = 6.24 × 10−7), ECA4 (p = 6.07 × 10−7), and ECA7 (p = 8.83 × 10−7). The application of angular measurements in genetic studies may increase our understanding of the underlying genetic effects of important traits in equine breeding.

scholarly journals Experimental and Numerical Study of Fracture Behavior of Rock-Like Material Specimens with Single Pre-Set Joint under Dynamic Loading

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2690
Author(s):  
Bo Pan ◽  
Xuguang Wang ◽  
Zhenyang Xu ◽  
Lianjun Guo ◽  
Xuesong Wang
Keyword(s):  
Crack Initiation ◽  
Crack Propagation ◽  
Joint Angle ◽  
Simulation Software ◽  
Dissipated Energy ◽  
Energy Structure ◽  
Joint Angles ◽  
Crack Penetration ◽  
Before And After ◽  
The Impact

The Split Hopkinson Pressure Bar (SHPB) is an apparatus for testing the dynamic stress-strain response of the cement mortar specimen with pre-set joints at different angles to explore the influence of joint attitudes of underground rock engineering on the failure characteristics of rock mass structure. The nuclear magnetic resonance (NMR) has also been used to measure the pore distribution and internal cracks of the specimen before and after the testing. In combination with numerical analysis, the paper systematically discusses the influence of joint angles on the failure mode of rock-like materials from three aspects of energy dissipation, microscopic damage, and stress field characteristics. The result indicates that the impact energy structure of the SHPB is greatly affected by the pre-set joint angle of the specimen. With the joint angle increasing, the proportion of reflected energy moves in fluctuation, while the ratio of transmitted energy to dissipated energy varies from one to the other. NMR analysis reveals the structural variation of the pores in those cement specimens before and after the impact. Crack propagation direction is correlated with pre-set joint angles of the specimens. With the increase of the pre-set joint angles, the crack initiation angle decreases gradually. When the joint angles are around 30°–75°, the specimens develop obvious cracks. The crushing process of the specimens is simulated by LS-DYNA software. It is concluded that the stresses at the crack initiation time are concentrated between 20 and 40 MPa. The instantaneous stress curve first increases and then decreases with crack propagation, peaking at different times under various joint angles; but most of them occur when the crack penetration ratio reaches 80–90%. With the increment of joint angles in specimens through the simulation software, the changing trend of peak stress is consistent with the test results.

scholarly journals Insights to enhance the examination of tool marks in human cartilage

2021 ◽  
Author(s):  
Matthias Weber ◽  
Anja Niehoff ◽  
Markus A. Rothschild
Keyword(s):  
Light Microscope ◽  
Cross Correlation ◽  
Costal Cartilage ◽  
Correlation Coefficients ◽  
Human Cartilage ◽  
Cut Marks ◽  
Tool Marks ◽  
The Cross ◽  
Cleaning Methods ◽  
The Individual

AbstractThis work deals with the examination of tool marks in human cartilage. We compared the effectiveness of several cleaning methods on cut marks in porcine cartilage. The method cleaning by multiple casts achieved the significantly highest scores (P = 0.02). Furthermore, we examined the grain-like elevations (dots) located on casts of cut cartilage. The results of this study suggest that the casting material forms these dots when penetrating cartilage cavities, which are areas where the strong collagen fibres leave space for the chondrocytes. We performed fixation experiments to avoid this, without success. In addition, 31 casting materials were compared regarding contrast under light-microscope and 3D tool marks scanner. Under the light-microscope, brown materials achieved significantly higher values than grey (P = 0.02) or black (P = 0.00) whereas under the 3D scanner, black materials reached higher contrast values than grey (P = 0.04) or brown (P = 0.047). To compare the accuracy and reproducibility of 6 test materials for cartilage, we used 10 knives to create cut marks that were subsequently scanned. During the alignment of the individual signals of each mark, the cross-correlation coefficients (Xmax) and lags (LXmax) were calculated. The signals of the marks in agarose were aligned with significantly fewer lags and achieved significantly higher cross-correlation coefficients compared to all tested materials (both P = 0.00). Moreover, we determined the cross-correlation coefficients (XC) for known-matches (KM) per material. Agarose achieved significantly higher values than AccuTrans®, Clear Ballistics™, and gelatine (all P = 0.00). The results of this work provide valuable insights for the forensic investigation of marks in human costal cartilage.

scholarly journals Preliminary Evidence That Taping Does Not Optimize Joint Coupling of the Foot and Ankle Joints in Patients with Chronic Ankle Instability

2021 ◽  
Vol 18 (4) ◽  
pp. 2029
Author(s):  
Charles Deltour ◽  
Bart Dingenen ◽  
Filip Staes ◽  
Kevin Deschamps ◽  
Giovanni A. Matricali
Keyword(s):  
Cross Correlation ◽  
Ankle Instability ◽  
Correlation Coefficients ◽  
Preliminary Evidence ◽  
Chronic Ankle Instability ◽  
Heel Strike ◽  
Segmental Motion ◽  
Barefoot Running ◽  
Ankle Motion ◽  
Joint Coupling

Background: Foot–ankle motion is affected by chronic ankle instability (CAI) in terms of altered kinematics. This study focuses on multisegmental foot–ankle motion and joint coupling in barefoot and taped CAI patients during the three subphases of stance at running. Methods: Foot segmental motion data of 12 controls and 15 CAI participants during running with a heel strike pattern were collected through gait analysis. CAI participants performed running trials in three conditions: barefoot running, and running with high-dye and low-dye taping. Dependent variables were the range of motion (RoM) occurring at the different inter-segment angles as well as the cross-correlation coefficients between predetermined segments. Results: There were no significant RoM differences for barefoot running between CAI patients and controls. In taped conditions, the first two subphases only showed RoM changes at the midfoot without apparent RoM reduction compared to the barefoot CAI condition. In the last subphase there was limited RoM reduction at the mid- and rearfoot. Cross-correlation coefficients highlighted a tendency towards weaker joint coupling in the barefoot CAI condition compared to the controls. Joint coupling within the taped CAI conditions did not show optimization compared to the barefoot CAI condition. Conclusions: RoM was not significantly changed for barefoot running between CAI patients and controls. In taped conditions, there was no distinct tendency towards lower mean RoM values due to the mechanical restraints of taping. Joint coupling in CAI patients was not optimized by taping.

scholarly journals Optimal Control of Industrial Assembly Lines

2020 ◽  
Author(s):  
Francesco Liberati ◽  
Andrea Tortorelli ◽  
Cesar Mazquiaran ◽  
Muhammad Imran ◽  
Martina Panfili
Keyword(s):  
Optimal Control ◽  
Assembly Lines ◽  
Industrial Assembly

Research and Design of SWET Equipment for Engineering Machinery Company

2014 ◽  
Vol 971-973 ◽  
pp. 646-649
Author(s):  
Qing Song Zhao
Keyword(s):  
Control System ◽  
Automatic Control ◽  
Work Environment ◽  
Simulation Training ◽  
Assembly Line ◽  
Training System ◽  
Assembly Lines ◽  
Structural Framework ◽  
Research And Design ◽  
Disassembly Line

The structural framework for the car’s assembly line simulation training system of the SWET(Simulated Work Environment Training) is designed overall, including two automatic car assembly lines and two manually run the disassembly line. The automatic control system of the car’s assembly line simulation training system is designed with the knowledge of electrical and electronic, SCM principles, counts the number of the car, automatically pause and open the line with alarm and automatic recovery control.

scholarly journals RECOGNIZING DIFFERENT TYPES OF STOCHASTIC PROCESSES

2006 ◽  
Vol 06 (01) ◽  
pp. L1-L6
Author(s):  
JONG U. KIM ◽  
LASZLO B. KISH
Keyword(s):  
Image Processing ◽  
Stochastic Processes ◽  
Cross Correlation ◽  
Correlation Method ◽  
Correlation Coefficients ◽  
Power Density Spectrum ◽  
Density Spectrum ◽  
Random Telegraph Signals ◽  
Different Types ◽  
Coefficient Method

We propose a new cross-correlation method that can recognize independent realizations of the same type of stochastic processes and can be used as a new kind of pattern recognition tool in biometrics, sensing, forensic, security and image processing applications. The method, which we call bispectrum correlation coefficient method, makes use of the cross-correlation of the bispectra. Three kinds of cross-correlation coefficients are introduced. To demonstrate the new method, six different random telegraph signals are tested, where four of them have the same power density spectrum. It is shown that the three coefficients can map the different stochastic processes to specific sub-volumes in a cube.

Variation Analysis for Compliant Assembly

2000 ◽  
Author(s):  
S. Jack Hu ◽  
Yufeng Long ◽  
Jaime Camelio
Keyword(s):  
Sheet Metal ◽  
Assembly Line ◽  
Assembly Process ◽  
Variation Analysis ◽  
Assembly Lines ◽  
Compliant Assembly ◽  
Single Station ◽  
Dimensional Variation ◽  
Sheet Metal Assembly

Abstract Assembly processes for compliant non-rigid parts are widely used in manufacturing automobiles, furniture, and electronic appliances. One of the major issues in the sheet metal assembly process is to control the dimensional variation of assemblies throughout the assembly line. This paper provides an overview of the recent development in variation analysis for compliant assembly. First, the unique characteristics of compliant assemblies are discussed. Then, various approaches to variation modeling for compliant assemblies are presented for single station and multi-station assembly lines. Finally, examples are given to demonstrate the applications of compliant assembly variation models.

scholarly journals Bucket Brigades to Increase Productivity in a Luxury Assembly Line

10.5772/56837 ◽  
2013 ◽  
Vol 5 ◽  
pp. 28 ◽  
Author(s):  
Filippo De Carlo ◽  
Orlando Borgia ◽  
Mario Tucci
Keyword(s):  
Assembly Line ◽  
Assembly Line Balancing ◽  
Assembly Lines ◽  
Manual Assembly ◽  
Increase Productivity ◽  
Assembly Line Balancing Problem ◽  
High Level ◽  
Simple Assembly ◽  
A Company ◽  
Bucket Brigades

One of the most challenging issues in manual assembly lines is to achieve the best balance of workloads. There are many analytic approaches to solve this problem, but they are often neglected, since they are time-consuming and require high level engineering skills. Fashion bags packaging lines must comply with a number of different products with low production volumes, while the organization of the line is often under the mere responsibility of the foreman, who balances workloads in an empirical way. The aim of this work is to evaluate the effectiveness of the arrangement of bucket brigades (BBs) for an assembly line of luxury handbags. To do this, it was decided to perform a testing activity in a company producing fashion handbags in order to compare the self-made design with the BBs and with a simple assembly line balancing problem algorithm. The originality of this research lies in the fact that there are no studies in the literature on BBs applied to the packaging of highly variable small batches. The results were excellent, showing the advantages of BBs in terms of flexibility, the reduction of work in the process and the ability to handle small anomalies.

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