Measurement System Research Articles

Low-frequency vibration monitoring system measuring the fringe shift by using linear Fresnel zone plates for shiny surfaces

This paper presents a vibration monitoring system that measures the fringe shift from the Fresnel diffraction pattern for noncontact measurement of translational and angular vibrations. Conventional vibration systems have some major limitations in practical applications. For example, a laser Doppler vibrometer (LDV) fails to accurately measure large-amplitude vibrations of a mirrored object undergoing dynamic tilts or rotations. Additionally, achieving the accuracy required for micro/nanomeasurement in precision machines when measuring low-frequency vibrations (LFV) remains a significant challenge. In this study, the vibration measurement system utilizes a linear Fresnel zone plate with parallel strip lines to create the diffraction pattern. Surface vibrations cause shifts in these lines, and the resulting fringe pattern on the vibrating surface carries information about the local vibrational amplitude and frequency. To achieve this, the linear vibration and displacement of the object are accurately verified using a linear motion platform and a rotation stage, with accuracies of approximately 20 nm and 0.002°, respectively. Rotational vibration measurements utilize tracking beam deflection through the image fringe shift measurement method, while out-of-plane displacement is determined both from this method and from changes in the period density of diffraction patterns, which depend on the position of the patterns and the local spatial frequency. A CCD camera captures sequences of images of the deflected fringes due to vibrating object. The system can detect linear vibrations with frequencies above 251.91 µHz and has a displacement uncertainty of approximately 5.8 µm, achieving an angular resolution of 37.67 µrad. Compared to conventional LDV vibrometers and eddy current sensors, the proposed method offers an effective and accurate technique for measuring LFVs of shiny surfaces. Furthermore, it provides a significantly extended measurement range for both translation and rotational angles of objects in engineering applications.

A high-speed camera-based measurement system for monitoring and controlling the induced jet break-up fabrication of advanced ceramic breeder pebbles

AbstractThe production of lithium-rich ceramic pebbles is crucial for future fusion reactors, as they are one of the most important components of the tritium-breeding blankets. In order to produce high-quality pebbles, a melt-based fabrication process KALOS (KArlsruhe Lithium OrthoSilicate) has been developed at the Karlsruhe Institute of Technology (KIT), which produces pebbles utilising the break-up of a molten laminar jet. Since the production of the pebbles is very precise (with diameters of hundreds of micrometres) and significantly influenced by process parameters, a system that monitors and regulates the fabrication in real-time is essential. This paper elaborates on a high-speed camera-based measurement system for automatically monitoring and controlling the production process. Experimental proof demonstrates that the presented measurement system can provide the real-time sizes, locations and distance distribution of the molten ceramic droplets accurately. In addition, the system is also designed to enable the control of the pebble production by adjusting a production parameter, i.e. the driving frequency, based on the real-time output of the proposed measurement system.

Application of deep learning in wound size measurement using fingernail as the reference

ObjectiveMost current wound size measurement devices or applications require manual wound tracing and reference markers. Chronic wound care usually relies on patients or caregivers who might have difficulties using these devices. Considering a more human-centered design, we propose an automatic wound size measurement system by combining three deep learning (DL) models and using fingernails as a reference.Materials and methodsDL models (Mask R-CNN, Yolov5, U-net) were trained and tested using photographs of chronic wounds and fingernails. Nail width was obtained through using Mask R-CNN, Yolov5 to crop the wound from the background, and U-net to calculate the wound area. The system’s effectiveness and accuracy were evaluated with 248 images, and users’ experience analysis was conducted with 30 participants.ResultsIndividual model training achieved a 0.939 Pearson correlation coefficient (PCC) for nail-width measurement. Yolov5 had the highest mean average precision (0.822) with an Intersection-over-Union threshold of 0.5. U-net achieved a mean pixel accuracy of 0.9523. The proposed system recognized 100% of fingernails and 97.76% of wounds in the test datasets. PCCs for converting nail width to measured and default widths were 0.875 and 0.759, respectively. Most inexperienced caregivers consider convenience is the most important factor when using a size-measuring tool. Our proposed system yielded 90% satisfaction in the convenience aspect as well as the overall evaluation.ConclusionThe proposed system performs fast and easy-to-use wound size measurement with acceptable precision. Its novelty not only allows for conveniences and easy accessibility in homecare settings and for inexperienced caregivers; but also facilitates clinical treatments and documentation, and supports telemedicine.

Breaking Spatial Constraints: A Dimensional Perspective-Based Analysis of the Eco-Efficiency of Cultivated Land Use and Its Spatial Association Network

Global urbanization has caused enormous challenges that seriously threaten ecological security and the food system. Thus, there is a need for finding an optimal solution for the eco-efficiency of cultivated land use (ECLU) that can promote the development of new-type urbanization, while ensuring the sustainable utilization of limited cultivated-land resources. The quantitative system of multi-scale ECLU used in existing studies is inadequate; it is necessary to establish a measurement system from the perspective of geographical spatial relationship that uses evaluation as a key basis for management. In this study, we considered the Changchun Metropolitan Area and a representative urban–rural transition area as the target regions and customized new ECLU evaluation systems for different scales. The super slack-based measure and gravity and social network analyses methods were applied to evaluate the ECLU and explore the structural characteristics of its spatial association network. The average ECLU value for the Changchun Metropolitan Area was 0.974; the results indicated that most of the study area was eco-efficient. The value of ECLU for the urban–rural transition area varied from 0.022 to 1.323; thus, the highly efficient cultivated land was mainly distributed around the urban built-up area. The spatial association network of ECLU revealed that the overall spatial correlations were relatively weak, with a significant “bipolar” division of ECLU; furthermore, the network hierarchy and stability needed improvement. Moreover, we noted distant attraction capacity and siphoning effects outside regional boundaries. In the Changchun Metropolitan Area, it manifested as a monocentric radiation, with Changchun City as the center. In the urban–rural transition area, the cultivated land in proximity to the newly built urban area was more likely to experience spatial spillover. These findings have important implications for strengthening land-use management and advancing sustainable agricultural development for new-type urbanization. Our study can be used by policymakers and stakeholders to design sustainable urban cities, while improving land-use management and optimizing resource use.

Design of a computer vision system for accurate measurement of mango skin defects by surface image slicing

Abstract External features such as color, size, weight, and defect area are among the critical parameters for grading mangoes for export purposes. This paper describes a novel computer vision system (CVS) for the accurate measurement of mango skin defects. A novel algorithm called mango skin image slicing (MSIS) was developed to generate mango slices, each of which includes points of pseudo-equidistance from the camera to accurately calculate the defect area. Based on images captured from 360-degree views, defects on the entire mango surface can be detected. For the first time, a strategy for preventing multiple considerations of the same defects from 360-degree images was introduced based on MSIS. The experimental results revealed that recalculations of the same defects were avoided, and negligible minor defects were excluded, complying with the guidance of the mango exporting firms. The measurement accuracy was evaluated with artificial defects of 100 mm2, yielding a mean error of 6.0 ± 1.4 mm2, which was suitable for defect area measurement considering the mango grading standard. The CVS throughput of approximately 644 mangoes per hour was also a reasonable trade-off for the achieved accuracy and great potential of extending the CVS for more sophisticated classification of non-negligible defects based on the advantages of mango images captured at closer camera–object distances.

Accuracy, precision, and sensitivity of a new contact plate for assessing vertical jump height performance

This study aimed to assess the accuracy, precision, and sensitivity of the Ergonauta contact plate in evaluating jump height performance in countermovement (CMJ) and squat jumps (SJ), compared to two previously validated devices (OptoJump and My Jump). Twenty-six young basketball players participated in the study. The participants positioned themselves on the Ergonauta contact plate along with the My Jump app and OptoJump optical measurement system. Three CMJs and SJs were performed, and jump height was analyzed. Intraclass correlation coefficient (ICC) and typical error (TE) were used as relative and absolute reliability indicators, respectively. The Bland-Altman plot was used to examine agreement between metrics (Ergonauta contact plate, My Jump app, and OptoJump) in CMJ and SJ, with significance set at p < 0.05. Results demonstrated excellent relative reliability for both protocols in the Ergonauta contact plate (ICC = 0.94–0.99, TE = 1.07–1.23). Bland-Altman plots showed good agreement for the Ergonauta contact plate (CMJ and SJ) and devices (close to 0). In conclusion, the Ergonauta contact plate proved reliable and valid for assessing jump height performance, particularly in measuring jump height and mean propulsive velocity metrics.

Roll angle measurement method based on a double-sided optical wedge

The roll angle is an important albeit difficult-to-measure geometric parameter. This study proposes a roll angle measurement method for an entire circle (360°). An elaborately designed double-sided optical wedge (DOW) is employed as a roll angle probe to divide the incident light beam into two beams. Both beams are imaged using a photodetector, and the roll angle of the DOW is obtained through the detection of the motion trajectories of the two images. The measurement principle is comprehensively analyzed, and the experimental results indicate that the accuracy of the constructed measurement system is better than ±7.72arcsec in the range of 360°. The proposed method is confirmed to be effective for large-range roll angle measurements.

Deep Learning-based Segmentation of Cervical Posterior Longitudinal Ligament Ossification in CT Images and Assessment of Spinal Cord Compression: A Two-center Study.

This study aims to develop a fully automated, CT-based deep learning（DL） model to segment ossified lesions of the posterior longitudinal ligament (OPLL) and to measure the thickness of the ossified material and calculate the cervical spinal cord compression factor. A total of 307 patients were enrolled, with 260 patients from Shanghai Changzheng Hospital, And 47 patients from the Traditional Chinese Medicine Hospital of Southwest Medical University. CT images were used to manually segment the OPLL by four experienced radiologists. The DL model employing a 3D U-Net framework was developed to segment the OPLLs. The system also measures the thickness of the ossified material at its thickest point and the diameter of the spinal canal at the corresponding level. Segmentation performance was evaluated using the Dice Similarity Coefficient (DSC), Average Surface Distance (ASD), and Intra-Class Correlation (ICC) between ground truth and segmentation volumes. Concordance between the radiologists' and the DL system's measurements of the ossified material thickness, residual spinal canal diameter at maximum compression, and cervical spinal cord compression coefficient was assessed in a randomly selected subset of 30 cases from the training set using ICCs and Bland-Altman plots. The DL system demonstrated average DSC of 0.81, 0.75, and 0.71 for the training, internal validation, and external test sets, respectively. The mean ASD was 1.30 for the training set, 2.35 for the internal validation set, and 2.63 for the external test set. The intraclass correlation coefficient (ICC) values of 0.958 for the thickness of the ossified material and 0.974 for the residual canal diameter measurement. The proposed DL model effectively detects and separates ossification foci in OPLL on CT images. It exhibits comparable performance to radiologists in quantifying spinal cord compression metrics.

MATHEMATICAL MODELING OF THE DYNAMICS OF THE AEROELASTIC "PIPELINE – PRESSURE SENSOR" SYSTEM

This paper proposes mathematical models of mechanical systems "pipeline - pressure sensor" designed to control the pressure of the working medium in the combustion chambers of engines. In such systems, to mitigate the impact of vibration accelerations and high temperatures, the sensor is connected to the engine using a pipeline and is located at some distance from it. The movement of the working medium is described by linear models of fluid and gas mechanics. To describe the dynamics of an elastic sensitive element, linear models of the mechanics of a solid deformable body are used. Based on linear differential equations with partial derivatives, mathematical formulations of problems are proposed that correspond to three-dimensional models of pressure measurement systems in gas-liquid media for some pipeline cross-sectional shapes, namely, for a pipeline with a rectangular cross-section, with a section in the form of a sector and in the form of a ring. By introducing integral characteristics, the solution of problems is reduced to studying one-dimensional models. Equations have been obtained that make it possible to determine the pressure of the working medium in the combustion chamber at each moment of time by the value of deformation of the sensitive element of the sensor. Analytical and numerical-analytical methods for solving the corresponding initial-boundary value problems for systems of differential equations are proposed. In the analytical approach, the solution of the problem is reduced to solving a differential equation with a deviating argument. The numerical-analytical study of the problem is based on the application of the Galerkin method. Also, a numerical experiment was carried out and examples of calculating the deformation of the sensitive element of the sensor in the case of rigid fastening when specifying specific values of the mechanical parameters of the system are presented, also during setting the law of change in the excess pressure of the working medium in the engine.

Smart Concrete Using Optical Sensors Based on Bragg Gratings Embedded in a Cementitious Mixture: Cure Monitoring and Beam Test

Smart concrete is a structural element that can combine both sensing and structural capabilities. In addition, smart concrete can monitor the curing of concrete, positively impacting design and construction approaches. In concrete, if the curing process is not well developed, the structural element may develop cracks in this early stage due to shrinkage, decreasing structural mechanical strength. In this paper, a system of measurement using fiber Bragg grating (FBG) sensors for monitoring the curing of concrete was developed to evaluate autogenous shrinkage strain, temperature, and relative humidity (RH) in a single system. Furthermore, K-type thermocouples were used as reference temperature sensors. The results presented maximum autogenous shrinkage strains of 213.64 με, 125.44 με, and 173.33 με for FBG4, FBG5, and FBG6, respectively. Regarding humidity, the measured maximum relative humidity was 98.20 %RH, which was reached before 10 h. In this case, the recorded maximum temperature was 63.65 °C and 61.85 °C by FBG2 and the thermocouple, respectively. Subsequently, the concrete specimen with the FBG strain sensor embedded underwent a bend test simulating beam behavior. The measurement system can transform a simple structure like a beam into a smart concrete structure, in which the FBG sensors’ signal was maintained by the entire applied load cycles and compared with FBG strain sensors superficially positioned. In this test, the maximum strain measurements were 85.65 με, 123.71 με, and 56.38 με on FBG7, FBG8, and FBG3, respectively, with FBG3 also monitoring autogenous shrinkage strain. Therefore, the results confirm that the proposed system of measurement can monitor the cited parameters throughout the entire process of curing concrete.

Multispectral Schwarzschild imaging system for the extreme ultraviolet emission measurement of tokamak plasma

Multispectral Schwarzschild imaging system for the extreme ultraviolet emission measurement of tokamak plasma

SF6 Dynamic Capacitance Measurement Methods for Breaks in the Breaking Process of Circuit Breakers

In order to effectively obtain the contact state without disassembling the interrupter chamber of the SF6 circuit breaker, a dynamic capacitance measurement method for the breakout process of the circuit breaker is proposed. The dynamic capacitance measurement is carried out by applying high-frequency excitation at both ends of the interrupter chamber, the dynamic capacitance measurement system that can meet the pF-level variation is designed, and the measurement method for correcting the stray capacitance of the wire is proposed. Based on the fundamental wave component method, a dynamic capacitance calculation method is proposed for the circuit breaker tripping process, and the optimal parameter combination for the dynamic capacitance calculation is determined through simulation analysis. The best combination of computational parameters for dynamic capacitance calculations was determined to be a triangular window, a window length of 480, and an overlap length of 0. The dynamic capacitance-travel curve of SF6 circuit breaker tripping process under different ablation states is obtained in the final test, and the results show that: with the increase in contact ablation, the overall shape of the dynamic capacitance-travel curve is basically unchanged, and the capacitance value at the starting point increases and the travel value decreases, which provides a new idea for the evaluation of circuit breaker interrupter chamber’s electric life. This provides a new idea for the electrical life assessment of circuit breaker interrupters.

Statistical analysis on influence of groove patterns on the mechanical strength of friction-welded SAE1018 steel

This research work focuses on the impact of various groove pattern, groove depth, and their combination on SAE 1018 mild steel rod friction welded mechanical properties. SAE 1018 steel was used, with a modified vertical milling machine with parameters of the Taguchi's L9 Orthogonal array used in the welding process. The groove pattern and groove depth which provides maximum UTS were determined with the help of ‘Minitab 17 software analysis’. The parameters with the best characteristics of measurement system were grooves made on the stationary and rotating specimens, equal to 1.5 mm groove depth, and hash pattern. The initial optimization predicted the UTS to be 542 MPa however the experimental analysis resulted in a value of 564 MPa which is greater than the base material UTS of 436 MPa. It was also observed from ANOVA that the groove on both specimens had the greatest effect on the UTS percent contribution of 58.65% followed by the depth and pattern percent contribution of 20.42% and 13.55% respectively. Hardness analysis pointed to the maximum microhardness value of 300 HV at the weld center and the minimum value of 200 HV at 15 mm from the center. The difference in hardness between the two rotating and the two stationary discs was ascribed to increased frictional and plastic flow on the rotating side. XRD characterization of the samples supported the findings of the presence of both α-Fe and FeO phases for all the samples and MnO was detected primarily in the Z Groove pattern.

Towards an Integrated Performance Management and Measurement System for healthcare organisations: a case study in Montreal

This study proposes an approach for developing or improving performance management and measurement systems (PMMSs) for healthcare organisations. First, data is collected to analyse and understand the current organisation’s performance management system. Second, the SWOT (Strengths, Weaknesses, Opportunities, Threats) method is used to identify the main aspects of the performance management system to be improved. Third, based on the scientific literature and SWOT analysis, BSC principles are integrated to this performance management system to better align the organisation’s performance objectives and indicators with its strategy. Finally, we develop a performance indicator structure and select indicators to be used as well as how these indicators could be integrated and shared with higher hierarchical levels in the organisation by using AHP (Analytic Hierarchy Process). Our approach is applied to the CIUSSS du Centre-Sud-de-l’île-de-Montreal (CCSMTL), a large healthcare network, in the province of Québec, Canada.

Distance Estimation with a Stereo Camera and Accuracy Determination

Distance measurement plays a key role in many fields of science and technology, including robotics, civil engineering, and navigation systems. This paper focuses on analyzing the precision of a measurement system using stereo camera distance measurement technology in the context of measuring two objects of different sizes. The first part of the paper presents key information about stereoscopy, followed by a discussion of the process of building a measuring station. The Mask R-CNN algorithm, which is a deep learning model that combines object detection and instance segmentation, was used to identify objects in the images. In the following section, the calibration process of the system and the distance calculation method are presented. The purpose of the study was to determine the precision of the measurement system and to identify the distance ranges where the measurements are most precise. Measurements were made in the range of 20 to 70 cm. The system demonstrated a relative error of 0.95% for larger objects and 1.46% for smaller objects at optimal distances. A detailed analysis showed that for larger objects, the system exhibited higher precision over a wider range of distances, while for smaller objects, the highest accuracy was achieved over a more limited range. These results provide valuable information on the capabilities and limitations of the measurement system used, while pointing out directions for its further optimization.

Distortion correction algorithm based on absolute phase image in structured light 3D reconstruction

Abstract This paper proposes a distortion correction algorithm based on absolute phase maps for a dual-projector, single-camera structured light 3D shape measurement system. Distortion correction is performed separately for the projector-camera pairs on the left and right. By projecting a ninth-order complementary Gray code combined with the eight-step phase-shifting method onto a white board, absolute phase maps are obtained, solving the impact of radial and tangential lens distortion. A sub-pixel level distortion error lookup table is introduced to address the influence of residual error after distortion correction on measurement accuracy, improving the overall precision by at least 95.7%. Experiments demonstrate that the dual-projector, single-camera structured light 3D shape measurement system expands the system’s measurement range while reducing shadowing issues caused by single-projector illumination. The proposed distortion correction and error compensation algorithms effectively enhance the overall measurement accuracy of the system and significantly improve issues like warping caused by distortion.

A simple and cost-effective sample preparation and storage method for stable isotope analysis of atmospheric CO2 for GasBench II/continuous flow isotope ratio mass spectrometry.

The stable isotope compositions of atmospheric CO2 can provide useful insight into various geochemical processes and carbon cycles on Earth, which is critical for understanding of Earth's changing climate. Here, we present a simple and cost-effective analytical method for the collection and measurement of carbon and oxygen isotope compositions of atmospheric CO2. Air samples of ~150 mL were collected individually or collectively using our simple active air collection system and then extracted on a vacuum purification line to remove noncondensable gases and atmospheric water vapor. The efficiency of removing atmospheric water vapor was tested by using a magnesium perchlorate desiccant trap and a dry ice/ethanol trap. Lastly, a "J-Cut tube sealing/cracking method" was developed to store and transfer purified atmospheric CO2 to the GasBench II and CF-IRMS system for δ13C and δ18O measurements. The collective active air collection method combined with the full sample air extraction method for a 3-min transfer time or "Full 3m TE" yields the best analytical precision of 0.07‰ (δ13C) and 0.04‰ (δ18O). Removing atmospheric water vapor from air samples is not necessary for δ13C, but essential for δ18O measurements. The J-Cut tube sealing/cracking method shows a near 100% effectiveness for the storage and transfer of atmospheric or any CO2. A simple and cost-effect method was developed for the collection, purification, storage, and isotopic analysis of indoor/outdoor atmospheric CO2 samples for general users. This method utilizes a popular headspace gas sample preparation system for CF-IRMS and an easy-to-build vacuum purification line without involving complex and high-cost devices for the preparation of atmospheric CO2.

Barkhausen Noise‐ and Eddy Current‐Based Measurements for Online Detection of Deformation‐Induced Martensite During Flow Forming of Metastable Austenitic Steel AISI 304L

ABSTRACTThis paper deals with micromagnetic measurements for online detection of strain‐induced α′‐martensite during plastic deformation of metastable austenitic steel AISI 304L. The operating principles of the sensors are magnetic Barkhausen noise (MBN) and eddy currents (EC), which are suitable for detection of microstructure evolution due to formation of ferromagnetic phases. The focus of this study was put on the qualification of different micromagnetic techniques and different measurement systems under conditions similar to the real ones during production, which is crucial for implementation of a property‐controlled flow forming process. The investigation was carried out on tubular specimens produced by flow forming, which have different content of α′‐martensite. To characterize the sensitivity of the sensors, different contact conditions between sensors and workpieces were reproduced. MBN sensors are suitable for detecting amount of α′‐martensite, but the measurements are affected by the surface roughness. This entails that the calibration models for MBN sensors must take account of these effects. EC sensors show a closer match with the amount of α′‐martensite without having major affectation by other effects.

Experimental Study of Mechanical Wave Propagation in Solidifying Cement-Based Composites.

In this paper, a new measurement procedure is presented as an experimental study. In this experimental study, a measurement system using the pass-through pulsed ultrasonic method was used. The pilot application of the measurement setup was to monitor mechanical wave changes during the solidification and hardening of fine-grained cement-based composites. The fine-grained composites had different water-cement ratios. The measured results show apparent differences in the recorded mechanical wave parameters. Significant differences were observed in the waveforms of the amplitude increase in the passing mechanical waves. At the same time, the frequency spectra of the five most dominant frequencies are presented, where the frequency lines are clear, indicating the quality of the hydration process. Based on the results, it can be concluded that the new method is usable for fine-grained cement-based materials but is not limited to that. The advantages of this method are its high variability and non-destructive character. The experimental study also outlines the possible future applications of the pulsed passage ultrasonic method.

A System for Simultaneous Measurement of Hysteresis Loops and Barkhausen Noise in Amorphous Ferromagnetic Ribbons

A System for Simultaneous Measurement of Hysteresis Loops and Barkhausen Noise in Amorphous Ferromagnetic Ribbons