Applied Sciences

Research

32 pages, 10227 KiB

Open AccessFeature PaperArticle

Instrumental Uncertainty of Conductance Transducers for Maritime Reduced-Scale Models

by Luís Filipe Lages Martins, Álvaro Silva Ribeiro, Alexandre Pinheiro, Ricardo Mendes and Catarina Simões

Appl. Sci. 2021, 11(9), 3772; https://doi.org/10.3390/app11093772 - 22 Apr 2021

Viewed by 1006

Abstract

This paper aims to determine the instrumental measurement uncertainty of conductance transducers for maritime reduced-scale models developed in hydraulic experimental facilities. These transducers are used for the measurements of wave levels and their variations under a dynamic regime (being the measurement principle and [...] Read more.

This paper aims to determine the instrumental measurement uncertainty of conductance transducers for maritime reduced-scale models developed in hydraulic experimental facilities. These transducers are used for the measurements of wave levels and their variations under a dynamic regime (being the measurement principle and method briefly described in the paper). Several metrological characterization methods are also presented, aiming to identify and quantify measurement uncertainty components, namely electrical stability, linearity, reversibility, repeatability, and thermal influence. The obtained results were applied in the evaluation of the transducer instrumental measurement uncertainty. Full article

(This article belongs to the Special Issue Experimental Mechanics, Instrumentation and Metrology)

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27 pages, 9452 KiB

Open AccessArticle

On the Measurement of Particle Contact Curvature and Young’s Modulus Using X-ray μCT

by Li Ge Wang, Zhipeng Li, Lianzhen Zhang, Rongxin Zhou and Xizhong Chen

Appl. Sci. 2021, 11(4), 1752; https://doi.org/10.3390/app11041752 - 16 Feb 2021

Cited by 5 | Viewed by 2653

Abstract

Contact curvature plays a pivotal role in the Young’s modulus determination and mechanical response of a particle. This paper presents the sensitivity analysis of a particle morphology to contact curvature and its influence on the Young’s modulus determination during the elastic deformation of [...] Read more.

Contact curvature plays a pivotal role in the Young’s modulus determination and mechanical response of a particle. This paper presents the sensitivity analysis of a particle morphology to contact curvature and its influence on the Young’s modulus determination during the elastic deformation of a particle. X-ray computed micro-tomography (μCT) was conducted to obtain the prototype of a single particle. The digital information of the scanned particle, including 2D slices and 3D rendering was processed and the variation of contact curvature of the particle was examined using the circular (spherical at 3D) and polynomial fitting methods. The fitting sections of the particle are taken into account. The effect of contact curvature on Young’s modulus determination was investigated and it was found that Young’s modulus changed substantially from global fitting to local fitting. Young’s modulus is highly related to the surface roundness, which exerts a significant influence on the determination of Young’s modulus. Full article

(This article belongs to the Special Issue Experimental Mechanics, Instrumentation and Metrology)

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16 pages, 5178 KiB

Open AccessArticle

Design and Calibration of a Tri-Directional Contact Force Measurement System

by Rizwan Ahmed, Christian Maria Firrone and Stefano Zucca

Appl. Sci. 2021, 11(2), 877; https://doi.org/10.3390/app11020877 - 19 Jan 2021

Cited by 2 | Viewed by 3258

Abstract

In low pressure turbine stages, adjacent blades are coupled to each other at their tip by covers, called shrouds. Three-dimensional periodic contact forces at shrouds strongly affect the blade vibration level as energy is dissipated by friction. To validate contact models developed for [...] Read more.

In low pressure turbine stages, adjacent blades are coupled to each other at their tip by covers, called shrouds. Three-dimensional periodic contact forces at shrouds strongly affect the blade vibration level as energy is dissipated by friction. To validate contact models developed for the prediction of nonlinear forced response of shrouded blades, direct contact force measurement during dynamic tests is mandatory. In case of shrouded blades, the existing unidirectional and bi-directional contact force measurement methods need to be improved and extended to a tri-directional measurement of shroud contact forces for a comprehensive and more reliable validation of the shroud contact models. This demands an accurate and robust measurement solution that is compatible with the nature and orientation of the contact forces at blade shrouds. This study presents a cost effective and adaptable tri-directional force measurement system to measure static and dynamic contact forces simultaneously in three directions at blade shrouds during forced response tests. The system is based on three orthogonal force transducers connected to a reference block that will eventually be put in contact with the blade shroud in the test rig. A calibration process is outlined to define a decoupling matrix and its subsequent validation is demonstrated in order to evaluate the effectiveness of the measurement system to measure the actual contact forces acting on the contact. Full article

(This article belongs to the Special Issue Experimental Mechanics, Instrumentation and Metrology)

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23 pages, 5658 KiB

Open AccessArticle

Numerical Design Method for CVT Supported in Standard Variable Speed Rubber V-Belts

by Ivan Arango and Sebastian Muñoz Alzate

Appl. Sci. 2020, 10(18), 6238; https://doi.org/10.3390/app10186238 - 08 Sep 2020

Cited by 6 | Viewed by 3865

Abstract

The design of a V-belt continuously variable transmission (CVT) system is a complex problem due to the multiple interactions between components during its operation. Literature on CVT system design methods is scarce, and the vast majority of works include implicit equations that hinder [...] Read more.

The design of a V-belt continuously variable transmission (CVT) system is a complex problem due to the multiple interactions between components during its operation. Literature on CVT system design methods is scarce, and the vast majority of works include implicit equations that hinder applications at a basic design level. This research aims to introduce a numerical CVT design method for electric vehicles (EV) and internal combustion engine (ICE) vehicles considering each one of their components and using mechanical centrifugal actuators and a rubber V-belt. This design method is based on user needs, for which there are three main requirements: road specifications, vehicle characteristics, and expected performance. This method is focused on a transmission for a vehicle traveling on the same route constantly, such as public transport vehicles. From three-wheelers to medium cargo vehicles, there is a greatly diverse range of potential applications for using this method for each type of standard rubber V-belt. Full article

(This article belongs to the Special Issue Experimental Mechanics, Instrumentation and Metrology)

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19 pages, 3286 KiB

Open AccessArticle

Development of F-N-C-O Taguchi Method for Robust Measurement System Using a Case Study of T-Peel Test on Adhesion Strength

by Rozzeta Dolah, Mohamad Zaki Hassan, Santhana Krishnan, Faizir Ramlie, Mohd Fadhil Md Din and Khairur Rijal Jamaludin

Appl. Sci. 2020, 10(18), 6203; https://doi.org/10.3390/app10186203 - 07 Sep 2020

Cited by 1 | Viewed by 2375

Abstract

A robust measurement system in the Taguchi Method as a testing method should be explained from the beginning of an experimental design until the application of the optimum condition. Measurement has always been described either by discussing the measurement concepts theoretically or demonstrating [...] Read more.

A robust measurement system in the Taguchi Method as a testing method should be explained from the beginning of an experimental design until the application of the optimum condition. Measurement has always been described either by discussing the measurement concepts theoretically or demonstrating a case study on how the data measurement is being done practically. The distance between theory and practical case study that connects the test method used for measurement is always missing. In this paper, a case of T-peel test on strength measurement is used to reflect the robust measurement system, which includes the theory of experimental design together with methods to achieve the optimum condition. Seven control factors, two noise factors with one signal factor are used with orthogonal array L18. Not only the experiment results, but methodology on choosing the control, noise, and signal factors are described intensively. Therefore, the aims are to provide the procedure on evaluating optimum conditions, to analyze variability and optimization of T-peel test when measuring the strength, and to establish a mainstream flow to achieve high-quality experimental design for a robust measurement system. As a result, a robust measurement system that includes variation elimination is developed, which consists of four elements—F (function), N (noise), C (Control), and O (Optimization). The elements of the F-N-C-O system are connected to one another by the Plan-Do-Study-Act; P-D-S-A cycle. The results affect the existing measurement system by enlightening the black box of parameter design behind optimization results in Taguchi Method. Thus, the measurement is more convergent and obtain higher degree of confidence in parameter design. Full article

(This article belongs to the Special Issue Experimental Mechanics, Instrumentation and Metrology)

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11 pages, 1570 KiB

Open AccessArticle

Compensation Method for Polarization Mixing in the Homodyne Interferometer

by Chaoqun Wang, Qiangxian Huang, Xuemeng Ding, Rongjun Cheng, Liansheng Zhang, Ruijun Li and Hongli Li

Appl. Sci. 2020, 10(17), 6060; https://doi.org/10.3390/app10176060 - 01 Sep 2020

Cited by 5 | Viewed by 2737

Abstract

A homodyne interferometer is one of the most important tools in nanometre measurements. However, its nonlinear error seriously affects measurement accuracy at the sub-nanometre level. As one of the dominant factors that cause nonlinear error in a homodyne interferometer with a quadrature detector [...] Read more.

A homodyne interferometer is one of the most important tools in nanometre measurements. However, its nonlinear error seriously affects measurement accuracy at the sub-nanometre level. As one of the dominant factors that cause nonlinear error in a homodyne interferometer with a quadrature detector system, the imperfection of polarizing beam splitters (PBSs) is investigated in this paper. The nonlinear error caused by the imperfection of PBSs in the detection part can be reduced by adjusting the gains of detectors. Nevertheless, eliminating the nonlinear error caused by the polarization mixing of the PBS in the interferometer part is difficult. In this paper, the nonlinear error caused by the polarization mixing of the PBS in the interferometer part is analyzed, and an optical compensation method is proposed to correct this polarization mixing. Theoretical calculation and simulation analysis show that this method can reduce the effect of inherent polarization mixing on nonlinear error significantly. In comparison with using only gain adjustment, the nonlinear error can be reduced by two orders of magnitude when the proposed method is applied. The nonlinear error can be decreased from approximately 4.5 nm to approximately 0.045 nm using the presented method based on the simulation results. Full article

(This article belongs to the Special Issue Experimental Mechanics, Instrumentation and Metrology)

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9 pages, 3160 KiB

Open AccessArticle

Wavelength-Tuning Common-Path Digital Holographic Microscopy for Quantitative Phase Imaging of Functional Micro-Optics Components

by Bingcai Liu, Dasen Wang, Xueliang Zhu, Hongjun Wang, Ailing Tian and Weiguo Liu

Appl. Sci. 2020, 10(16), 5602; https://doi.org/10.3390/app10165602 - 13 Aug 2020

Cited by 4 | Viewed by 2389

Abstract

This study proposes a novel wavelength-tuning common-path digital holographic microscopy technique for quantitative phase imaging of functional micro-optics components. The proposed technique is immune to vibration and can reduce system error. In the proposed configuration, a parallel glass plate was inserted into the [...] Read more.

This study proposes a novel wavelength-tuning common-path digital holographic microscopy technique for quantitative phase imaging of functional micro-optics components. The proposed technique is immune to vibration and can reduce system error. In the proposed configuration, a parallel glass plate was inserted into the light path to create two identical test beams, which passed through a specially designed window filter. In this process, one beam serves as the object beam, while the other is diffracted to produce an ideal spherical wave front (the reference beam). A wavelength tunable laser was used as the light source to generate phase-shifting digital holograms. Structural information for the functional micro-optics components was then extracted using a classical four-step phase-shift algorithm. The viability of the proposed technique was assessed by measuring a micro-optics array. Full article

(This article belongs to the Special Issue Experimental Mechanics, Instrumentation and Metrology)

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14 pages, 7466 KiB

Open AccessFeature PaperArticle

Experimental and Numerical Simulation Study of the Vibration Properties of Thin Copper Films Bonded to FR4 Composite

by Sufyan A. Azam and Alex Fragoso

Appl. Sci. 2020, 10(15), 5197; https://doi.org/10.3390/app10155197 - 28 Jul 2020

Cited by 5 | Viewed by 2892

Abstract

Printed circuit boards constitute the basis of most electronic devices and are mainly fabricated of thin copper films bounded to fiber epoxy laminates, such as FR4. Vibrational stress can induce device failure, and hence, studies addressing their modal properties have important applications. In [...] Read more.

Printed circuit boards constitute the basis of most electronic devices and are mainly fabricated of thin copper films bounded to fiber epoxy laminates, such as FR4. Vibrational stress can induce device failure, and hence, studies addressing their modal properties have important applications. In this paper, cantilever samples made of bare copper bounded to FR4 have been studied to analyze, for the first time, the vibration behavior of specimens with different aspect ratios, with and without central holes of different diameters. Natural frequencies and damping ratios were determined experimentally and analytically using a finite element method for four groups of samples with a very good correspondence between both methods. The fundamental resonance frequency of all the specimens was found to be less than 40 Hz and the influence of a central hole was not significant to affect the modal properties. Full article

(This article belongs to the Special Issue Experimental Mechanics, Instrumentation and Metrology)

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21 pages, 15629 KiB

Open AccessArticle

Theoretical and Experimental Study on Contact Characteristics of Spiral Bevel Gears under Quasi-Static and Large Loading Conditions

by Yimeng Fu, Yaobing Zhuo, Xiaojun Zhou, Bowen Wan, Haoliang Lv and Zhe Wang

Appl. Sci. 2020, 10(15), 5109; https://doi.org/10.3390/app10155109 - 25 Jul 2020

Cited by 7 | Viewed by 4880

Abstract

The precise mathematical model for the tooth surface and transition surface of spiral bevel gears is derived. Taking a pair of spiral bevel gears of a heavy vehicle as an example of calculation and analysis, a finite element model of spiral bevel gears [...] Read more.

The precise mathematical model for the tooth surface and transition surface of spiral bevel gears is derived. Taking a pair of spiral bevel gears of a heavy vehicle as an example of calculation and analysis, a finite element model of spiral bevel gears transmission system is established. Through the finite element tooth contact analysis under quasi-static loading and high loading condition, the influences of torque on the root stress distribution, contact stress, and transmission error are discussed, and the results are compared with the empirical formula results. Finally, a contact performance test bench of spiral bevel gear pair is developed, then the root bending stress, contact pattern, and transmission error tests are carried out. These experiment results are compared with analyzed ones, which showed a good agreement. Full article

(This article belongs to the Special Issue Experimental Mechanics, Instrumentation and Metrology)

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12 pages, 5374 KiB

Open AccessArticle

Alternative Pedicle Screw Design via Biomechanical Evaluation

by Jiwoon Kwon, Myung Heon Ha and Moon Gu Lee

Appl. Sci. 2020, 10(14), 4746; https://doi.org/10.3390/app10144746 - 09 Jul 2020

Cited by 5 | Viewed by 6486

Abstract

With the recent increase in the elderly population, many people suffer from spinal diseases, and, accordingly, spinal fusion surgery using pedicle screws has been widely applied to treat them. However, most research on pedicle screw design has been focused on the test results [...] Read more.

With the recent increase in the elderly population, many people suffer from spinal diseases, and, accordingly, spinal fusion surgery using pedicle screws has been widely applied to treat them. However, most research on pedicle screw design has been focused on the test results rather than the behavior of the screws and vertebrae. In this study, a design platform with a series of biomechanical tests and analyses were presented for pedicle screw improvement and evaluation. The platform was then applied to an alternative hybrid screw design with quadruple and double threads. An experimental apparatus was developed to investigate the bending strength of the screw, and several tests were performed based on the ASTM F1717 standard. In the experiments, it was confirmed that the alternative pedicle screw has the highest bending strength. To examine the stress distribution of pedicle screws, finite element models were established, through which it was found that the proposed pedicle screw has sufficient mechanical safety to make it acceptable for spinal fusion treatment. Finally, we conclude that the platform has good potential for the design and evaluation of pedicle screws, and the alternative dual screw design is one of the best options for spinal fusion surgery. Full article

(This article belongs to the Special Issue Experimental Mechanics, Instrumentation and Metrology)

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21 pages, 7213 KiB

Open AccessArticle

Mechanism and Compensation of Measurement Error Induced by Thermal Deformation of Digital Camera in Photo Mechanics

by Shichao Zhou, Haibin Zhu, Qinwei Ma and Shaopeng Ma

Appl. Sci. 2020, 10(10), 3422; https://doi.org/10.3390/app10103422 - 15 May 2020

Cited by 3 | Viewed by 2280

Abstract

A thermal-induced measurement error induced by thermal deformation of digital camera in photo mechanics methods that has the same magnitude of the error as that in the resistance strain measurement method reduces the accuracy of high-precision measurement substantially and must, therefore, be compensated. [...] Read more.

A thermal-induced measurement error induced by thermal deformation of digital camera in photo mechanics methods that has the same magnitude of the error as that in the resistance strain measurement method reduces the accuracy of high-precision measurement substantially and must, therefore, be compensated. Starting from the underlying mechanism of a thermal-induced measurement error, we investigated the image error introduced by thermal behaviours of digital cameras widely used in photo mechanics. We experimentally determined the relationships between the thermal behaviours and temperature, derived the relationship between the image error and measurement error of photo mechanics methods, and eventually established a physical model to explain the underlying relationship between the thermal-induced measurement error and temperature. Furthermore, based on the investigation of the underlying mechanism, we introduced three types of temperature compensation methods for photo mechanics, namely the model compensation method, the preheating method, and the compensation specimen method. We experimentally demonstrated the feasibility of these compensation methods. The model compensation method only needs the data regarding the environmental temperature during operation of the digital camera to implement the correction of the measurement results and enhance the measurement accuracy of photo mechanics methods. The preheating method is suitable for indoor photo mechanics measurements wherein the environmental temperature is almost constant, which ensures that the appearance of thermal balance of the digital camera after a period of self-heating. The compensation specimen method reduces the effective resolution of the images and it also requires that the image error forms in the region of tested specimen are the same as that in the region of the compensation specimen. Full article

(This article belongs to the Special Issue Experimental Mechanics, Instrumentation and Metrology)

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16 pages, 5445 KiB

Open AccessArticle

A Space Inertial Sensor Ground Evaluation System for Non-Sensitive Axis Based on Torsion Pendulum

by Shaoxin Wang, Liheng Chen, Yukun Wang, Zhenping Zhou, Keqi Qi and Zhi Wang

Appl. Sci. 2020, 10(9), 3090; https://doi.org/10.3390/app10093090 - 29 Apr 2020

Cited by 4 | Viewed by 2668

Abstract

The inertial sensor is the key measurement payload of the technology verification satellite of China’s space gravitational wave detection mission-Taiji Project, which uses capacitive sensors to sense the acceleration disturbance of the test mass under the influence of non-conservative forces in the frequency [...] Read more.

The inertial sensor is the key measurement payload of the technology verification satellite of China’s space gravitational wave detection mission-Taiji Project, which uses capacitive sensors to sense the acceleration disturbance of the test mass under the influence of non-conservative forces in the frequency range of 10 mHz~1 Hz. It is necessary to perform a ground performance evaluation and estimate the working state of the payload in orbit. However, due to the influence of the earth’s gravity and seismic noise, it is impossible to directly evaluate the resolution level of the non-sensitive axis when testing with high-voltage levitation, which leads to incomplete evaluation of the performance of the inertial sensor. In order to implement this part of the test, the sensitive structure is designed and a torsion pendulum facility for performance testing is developed. The experimental results show that the measurement resolution of the non-sensitive axis of the inertial sensor can reach 9.5 × 10⁻⁷ m/s²/Hz^1/2 under the existing ground environmental conditions and is mainly influenced by the seismic noise during the system measurement. If the inertial sensor enters orbit, the measurement resolution can achieve 3.96 × 10⁻⁹ m/s²/Hz^1/2, which meets the requirements of the technology verification satellite for a non-sensitive axis. This proposed system also provides a reasonable method for the comprehensive evaluation of inertial sensors in the future. Full article

(This article belongs to the Special Issue Experimental Mechanics, Instrumentation and Metrology)

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16 pages, 7853 KiB

Open AccessArticle

A Simple Methodology to Develop Bifilar, Quadrifilar, and Octofilar Calculable Resistors

by Alepth H. Pacheco-Estrada, Felipe L. Hernandez-Marquez, Carlos D. Aviles, Carlos Duarte-Galvan, Juvenal Rodríguez-Reséndiz, Humberto Aguirre-Becerra and Luis M. Contreras-Medina

Appl. Sci. 2020, 10(5), 1595; https://doi.org/10.3390/app10051595 - 28 Feb 2020

Viewed by 2658

Abstract

This paper describes the development of bifilar, quadrifilar, and octofilar Calculable Resistors (CRs). The research involves Evanohm-S and Isaohm wire heat treatment processes to achieve temperature coefficients less than 0.5

μ Ω / Ω

/

^{\circ}

C in the CR’s wire resistance element, [...] Read more.

This paper describes the development of bifilar, quadrifilar, and octofilar Calculable Resistors (CRs). The research involves Evanohm-S and Isaohm wire heat treatment processes to achieve temperature coefficients less than 0.5

μ Ω / Ω

/

^{\circ}

C in the CR’s wire resistance element, tests of different terminal–wire joining techniques, and construction aspects achieving a stability of less than 0.05

μ Ω / Ω

/day. This kind of construction methodology has not been presented in detail in previous CR papers, and it is essential to accomplish the correct parameters of a CR. Without it, the development of a CR can take several months or even years. A comparison between CRs developed in this research and a CR from the Federal Institute of Metrology (METAS) in Switzerland was carried out. Measurement results between the 10 k

Ω

octofilar CR and the METAS 1 k

Ω

coaxial CR show an agreement better than 0.35

μ Ω / Ω

through the audio-frequency range. Therefore, the octofilar CR can be used as an AC resistance reference with traceability to the quantum Hall resistance in DC. Full article

(This article belongs to the Special Issue Experimental Mechanics, Instrumentation and Metrology)

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11 pages, 1367 KiB

Open AccessFeature PaperArticle

An Uncertainties Simulation Model Applied to an Automated Laminar Flowmeter

by António Pedro, Teresa Morgado and Helena Navas

Appl. Sci. 2020, 10(3), 888; https://doi.org/10.3390/app10030888 - 29 Jan 2020

Cited by 2 | Viewed by 2175

Abstract

Aircraft oxygen regulators are a normally used specialized test bench designed to perform tests to the regulators during its work conditions. The tests are performed placing the regulator in the barometric chamber, where low pressure conditions are forced to simulate altitude conditions and [...] Read more.

Aircraft oxygen regulators are a normally used specialized test bench designed to perform tests to the regulators during its work conditions. The tests are performed placing the regulator in the barometric chamber, where low pressure conditions are forced to simulate altitude conditions and then a flow is forced on the output of the regulator to simulate the inhalation of the user. The relevant test flows are measured by laminar flowmeters. These flowmeters are meant to measure the flowrate at pressures correspondent to altitudes between sea level altitude and fifty thousand feet. In this work a way was studied to automate laminar flowmeters used on oxygen regulator test benches. For this purpose, was developed a data acquisition system (DAS) using a microcontroller board and two microelectromechanical systems—MEMSs (a pressure and temperature sensor and a differential pressure sensor). Since these MEMSs did not have factory calibration, they were calibrated in this study. The automated flowmeter was also calibrated. To estimate the error of flow rate measured by this solution, an uncertainties simulation model based on the Monte Carlo method and several calibrations were performed. According to the automated flowmeter calibration, the uncertainty obtained (±0.45% fs) is accepted, but the authors only recommend its use for actual volumetric flowrate measurements. Full article

(This article belongs to the Special Issue Experimental Mechanics, Instrumentation and Metrology)

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23 pages, 6145 KiB

Open AccessFeature PaperArticle

Optical Measurement of Planar Deformations in the Destructive Mechanical Testing of Masonry Specimens

by Luís Filipe Lages Martins, Ana Isabel Marques, Álvaro Silva Ribeiro, Paulo Candeias, Maria do Rosário Veiga and João Gomes Ferreira

Appl. Sci. 2020, 10(1), 371; https://doi.org/10.3390/app10010371 - 03 Jan 2020

Cited by 3 | Viewed by 1718

Abstract

This paper addresses the planar measurement problem in the destructive mechanical testing of masonry specimens, describing the proposed optical measurement solution. The adopted affine geometrical camera model is described as well as its experimental implementation using a digital camera and a measurement referential [...] Read more.

This paper addresses the planar measurement problem in the destructive mechanical testing of masonry specimens, describing the proposed optical measurement solution. The adopted affine geometrical camera model is described as well as its experimental implementation using a digital camera and a measurement referential traceable to the International System of Units (SI). Experimental results from non-destructive tests are presented and discussed, including measurements obtained from the use of classical contact instrumentation. Measurement estimates and uncertainties related to the quantified mechanical properties are also shown. Full article

(This article belongs to the Special Issue Experimental Mechanics, Instrumentation and Metrology)

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14 pages, 2200 KiB

Open AccessArticle

A Random Factorial Design of Experiments Study on the Influence of Key Factors and Their Interactions on the Measurement Uncertainty: A Case Study Using the ZEISS CenterMax

by Michaela Kritikos, Lissette Concepción Maure, Alfredo Alejandro Leyva Céspedes, Daynier Rolando Delgado Sobrino and Róbert Hrušecký

Appl. Sci. 2020, 10(1), 37; https://doi.org/10.3390/app10010037 - 19 Dec 2019

Cited by 9 | Viewed by 3815

Abstract

This paper addresses the uncertainty analysis in the case of a coordinate measuring machine. The main goal was analyzing, quantifying, and drawing conclusions on the influence of key factors and their interactions on the measurements’ uncertainty of the variable’s parallelism, angularity, roundness, diameter, [...] Read more.

This paper addresses the uncertainty analysis in the case of a coordinate measuring machine. The main goal was analyzing, quantifying, and drawing conclusions on the influence of key factors and their interactions on the measurements’ uncertainty of the variable’s parallelism, angularity, roundness, diameter, and distance. In order to achieve this goal, a Random Factorial Design of Experiments was designed and implemented. It focused on the factors Stylus diameter, Step width, and Speed using three random levels each. For the solution of the experiment, an analysis of variance was used. The study was carried out on the coordinate measuring machine (CMM) ZEISS CenterMax. It was concluded that the interaction effects among Stylus diameter, Step width, and Speed were active at a confidence level of 95%. Besides, it was possible to estimate random factors‘ variance and their contribution to the total variation. Among the main effects, the Stylus diameter showed to be the one with the biggest influence. The paper also quantifies the influence in the measurement uncertainty, where the highest value of standard uncertainty belonged to the Stylus diameter in the evaluation of the variable’s angularity and diameter. Besides, the Speed factor was proved to have the biggest influence on the roundness’ measurement and evaluation. Full article

(This article belongs to the Special Issue Experimental Mechanics, Instrumentation and Metrology)

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17 pages, 10356 KiB

Open AccessArticle

Self-Insulating Joint Design for Live-Line Operation Based on the Cable-Driven Parallel-Series Mechanism

by Jiahong He, Weilun Xu and Bingtuan Gao

Appl. Sci. 2020, 10(1), 22; https://doi.org/10.3390/app10010022 - 18 Dec 2019

Cited by 2 | Viewed by 2880

Abstract

This paper proposes a self-insulating joint design based on the cable-driven parallel-series (CDPS) mechanism and electrical insulation analysis. The design provides the motions, mechanic support, and electrical insulation for robotic arms in live-line operation, which can maintain the equipment without manual intervention and [...] Read more.

This paper proposes a self-insulating joint design based on the cable-driven parallel-series (CDPS) mechanism and electrical insulation analysis. The design provides the motions, mechanic support, and electrical insulation for robotic arms in live-line operation, which can maintain the equipment without manual intervention and power interruption. This CDPS mechanism can integrate four degrees of freedom (DOFs) motion in one joint, while the traditional series joint can only realize one DOF independently. The cable forces in the CDPS are calculated by the inverse kinematics to ensure the safe and flexible operation of the mechanism. The self-insulating joint has certain advantages over other designs because the electrical insulation is integrated into the joint instead of the traditional extra insulation layer. This integration reduces the weight of the arm mechanic structure. In addition, the structural complexity and weight are further reduced by separating the actuators and motors from the joint by using CDPS. Electric field distribution near the joint is calculated by the charge simulation method to analyze the insulation performance under the voltage of 35 kV. The cable forces and electric field distribution of the mechanism are measured to validate the simulation models. The inverse kinematics and insulation models of the self-insulating joint can provide detailed information for the mechanic and insulation design of the robotic arms. Full article

(This article belongs to the Special Issue Experimental Mechanics, Instrumentation and Metrology)

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10 pages, 3299 KiB

Open AccessArticle

Measurement of In-Plane Displacement in Two Orthogonal Directions by Digital Speckle Pattern Interferometry

by Peizheng Yan, Xiangwei Liu, Fangyuan Sun, Qihan Zhao, Shimin Zhong and Yonghong Wang

Appl. Sci. 2019, 9(18), 3882; https://doi.org/10.3390/app9183882 - 16 Sep 2019

Cited by 5 | Viewed by 2846

Abstract

The measurement of in-plane displacement in two orthogonal directions is of considerable significance for modern industries. This paper reports on a spatial carrier phase-shift digital speckle pattern interferometry (DSPI) for the simultaneous measurement of in-plane displacement in two orthogonal directions. The object is [...] Read more.

The measurement of in-plane displacement in two orthogonal directions is of considerable significance for modern industries. This paper reports on a spatial carrier phase-shift digital speckle pattern interferometry (DSPI) for the simultaneous measurement of in-plane displacement in two orthogonal directions. The object is illuminated from a single direction and observed from four symmetrical directions simultaneously. One pair of the four observation directions is sensitive to in-plane displacement in one direction, and the other pair is sensitive to in-plane displacement in the perpendicular direction, resulting in the displacement in two directions being measured independently. The polarization property of light is used to avoid cross-interference between the two pairs of beams. Spatial carrier frequencies are generated by aperture misalignment, and the displacement in two directions is modulated onto the same interferogram. With a spatial carrier phase-shift technique, the displacement can be separated in the frequency domain and the phase can be evaluated from a single interferogram in real time. The capability of DSPI is described by theoretical discussions and experiments. Full article

(This article belongs to the Special Issue Experimental Mechanics, Instrumentation and Metrology)

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16 pages, 8154 KiB

Open AccessArticle

A Real-Time Numerical Decoupling Method for Multi-DoF Magnetic Levitation Rotary Table

by Xianze Xu, Chenglin Zheng and Fengqiu Xu

Appl. Sci. 2019, 9(16), 3263; https://doi.org/10.3390/app9163263 - 09 Aug 2019

Cited by 7 | Viewed by 2735

Abstract

Magnetic levitation technology shows promise for realizing multiple degrees of free precision motion for modern manufacturing, as the bearing and guiding parts are not used. However, motion decoupling in a magnetically levitated (maglev) system is difficult because it is hard to derive accurate [...] Read more.

Magnetic levitation technology shows promise for realizing multiple degrees of free precision motion for modern manufacturing, as the bearing and guiding parts are not used. However, motion decoupling in a magnetically levitated (maglev) system is difficult because it is hard to derive accurate magnetic force and a torque model considering the translation and rotation in all axes. In this work, a magnetic levitation rotary table that has the potential to realize unlimited rotation around the vertical axis and a relatively long stroke in the horizontal plane is proposed and analyzed, and the corresponding real-time numerical decoupling method is presented. The numerical magnetic force and torque model solves the current to magnetic force and torque transformation matrix, and the matrix is used to allocate the exact current in each coil phase to produce the required motion in the magnetically levitated (maglev) system. Next, utilizing a high-level synthesis tool and hardware description language, the proposed motion-decoupling module is implemented on a field programmable gate array (FPGA). To realize real-time computation, a pipelined program architecture and finite-state machine with a strict timing sequence are employed for maximum data throughput. In the last decoupling module of the maglev system, the delay for each sampling point is less than

200 μ

s. To illustrate and evaluate real-time solutions, they are presented via the DAC adapter on the oscilloscope and stored in the SD card. The error ratios of the force and torque results solved by the numerical wrench model were less than

5 %

and

10 %

using the solutions from the boundary element method (BEM) program package Radia^TM as a benchmark. Full article

(This article belongs to the Special Issue Experimental Mechanics, Instrumentation and Metrology)

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12 pages, 2633 KiB

Open AccessArticle

Design and Validation of a Self-Driven Joint Model for Articulated Arm Coordinate Measuring Machines

by Yi Hu, Wei Huang, Peng-Hao Hu, Wen-Wen Liu and Bing Ye

Appl. Sci. 2019, 9(15), 3151; https://doi.org/10.3390/app9153151 - 02 Aug 2019

Cited by 6 | Viewed by 3215

Abstract

Articulated arm coordinate measuring machines (AACMMs) have been developed and applied in industrial measurement fields for more than 30 years. Manual operation is typically required during measurement, which introduces uncertain influences, such as fluctuation of measurement force, speed, and acceleration, and leads to [...] Read more.

Articulated arm coordinate measuring machines (AACMMs) have been developed and applied in industrial measurement fields for more than 30 years. Manual operation is typically required during measurement, which introduces uncertain influences, such as fluctuation of measurement force, speed, and acceleration, and leads to poor reliability and reproducibility. In this paper, a novel self-driven joint model is proposed to realize automatic measurement for AACMMs. A self-driven joint is designed by combining the joint of an AACMM with a robotic arm to realize automatic rotation. A self-driven AACMM is designed using three rolling joints and three pitching joints with assigned parameters. A virtual prototype of the self-driven AACMM is established using the Adams software to simulate the driving moment of each joint. The simulation results demonstrate that the designed mechanical structure and selected devices can meet the preset requirements. Additionally, based on the proposed model, a single physical joint is developed and assembled for performance testing. Experimental results demonstrate that the model can achieve a repeatability of 1.39″ (k = 2) when the rotational velocity is less than 1.53 rad/s. Therefore, the proposed design is suitable for use in AACMMs. Full article

(This article belongs to the Special Issue Experimental Mechanics, Instrumentation and Metrology)

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27 pages, 14377 KiB

Open AccessArticle

Research on the Modeling, Control, and Calibration Technology of a Tracked Vehicle Load Simulation Test Bench

by Haoliang Lv, Xiaojun Zhou, Chenglong Yang, Zhe Wang and Yimeng Fu

Appl. Sci. 2019, 9(12), 2557; https://doi.org/10.3390/app9122557 - 22 Jun 2019

Cited by 5 | Viewed by 3467

Abstract

The load simulation test bench plays an important role in tracked vehicle development. The stability and accuracy of the system have a vital impact on the experimental results. To accurately reproduce the power performance of a tracked vehicle on the test platform, this [...] Read more.

The load simulation test bench plays an important role in tracked vehicle development. The stability and accuracy of the system have a vital impact on the experimental results. To accurately reproduce the power performance of a tracked vehicle on the test platform, this paper aims to investigate the model, control, and calibration method of the test bench. Firstly, the dynamic model of a tracked vehicle under complex driving conditions is analyzed and established, which takes driving torque as the input and driving wheel speed as the output. Then, considering the uncertainties and disturbances in the system model, a 2-degree-of-freedom (2-DOF) control method combined with a disturbance observer is proposed to solve the stability problem of the system. Furthermore, in order to investigate the accuracy of the simulation on the test bed, a method of calibrating the system by a flywheel set with standard inertia is proposed. In the calibration process, the influence of the system resistance torque and the original mechanical inertia on the results is considered, and the response time of the inertia simulation is analyzed in both a steady and dynamic state. Finally, the load simulation test is carried out with the corrected system. The test results show that the system has a high load simulation accuracy under various load simulation tests. Full article

(This article belongs to the Special Issue Experimental Mechanics, Instrumentation and Metrology)

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