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A vehicle simulation model, CO2MPAS supports the introduction of the new WLTP-based certification system for CO2 emissions in Europe. This paper investigates the possibility to use the underlying simulation methodology to accurately calculate CO2 emissions over real-world trips, thus to extend the use of the methodology beyond vehicle certification. As a reference, the analysis used measurement data obtained from four vehicles over two different routes under real-world driving conditions. The CO2 emissions were measured using portable emissions measurement systems. The formal CO2MPAS methodology and two modified versions of it that require a reduced number of input data were assessed about their capacity to predict the measured CO2 emissions. The analysis focused on the accuracy and uncertainty of the three different methodology configurations. As an additional benchmark, the analysis considered the CO2 emissions estimates obtained from the EMEP/EEA Guidebook methodology used for emissions inventorying in Europe. Results show that the basic CO2MPAS configuration demonstrates good performance in predicting CO2 emissions over on-road tests, reaching a prediction accuracy over an entire test trip of −0,3% and a standard deviation of 3,1%. The modified versions showed slightly higher biases up to 3% and uncertainties (5–7%), but remaining within reasonable limits considering the reduced number of inputs used in each case. Given its ability to predict CO2 emissions accurately on a local base, CO2MPAS could be used for the prediction of instantaneous CO2 emissions in traffic micro-simulation exercises.

Three-dimensional (3D) profile scanning plays a crucial role in the inspection of assembled large aircraft. In this paper, to achieve noncontact automatic measurements of the high-reflective profiles of large-scale curved parts and components, an automated noncontact system and method with high accuracy and high efficiency are presented. First, a hybrid 3D coordinate measurement system based on proximity sensors and cameras is proposed to obtain noncontact measurements while avoiding the influence of high reflection on the measurement accuracy. A hybrid measurement model that combines the one-dimensional distances measured by the proximity sensors and the 3D information obtained by cameras is proposed to determine high-accuracy 3D coordinates of the measured points. Then, a profile-driven 3D automated scanning method and strategy are designed to rapidly scan and reconstruct the profile within the effective range without scratching the profile or exceeding the measurement range of the proposed system. Finally, experiments and accuracy analyses are performed in situ on an assembled tailplane panel (approximately 1760 mm × 460 mm). The automated scanning process is completed in a timeframe of 208 s with an average error of less than 0.121 mm for profile reconstruction. Therefore, the proposed method is promising considering both the high accuracy and high efficiency requirements of profile inspections for large aircraft.

Femtosecond laser processing is a non-thermal process with less heat effect on a target material and is applied to dielectric and difficult-to-machine materials, such as titanium alloy and diamond. Femtosecond laser processing has been used for 3-dimensional shape generation in recent years, and increasing accuracy and productivity are required for such generation by femtosecond lasers. However, a 2.5-dimensional computer-aided manufacturing (CAM) system, which is mainly used in femtosecond laser processing, does not satisfy the requirement for complicated 3-dimensional shape generation. Therefore, there is a need for the development of a 3-dimensional CAM system for high-precision and productive 3-dimensional processing. Furthermore, for the 3-dimensional CAM system, quantitative identification of a 3-dimensional removal shape through ablation is necessary. This study proposes the development of a simulation method to accurately predict the 3-dimensional removal shape through femtosecond laser processing, including the piecewise approximation of the ablation rate and absorptance correction. At the same time, a similar 3-dimensional shape as that found through the experimental results was obtained during the simulation by considering the mechanical errors of the laser processing machine in the simulation model. Furthermore, an on-machine measurement system was developed to efficiently identify the ablation parameters.

Slip status of drill string is system generated binary value computed by comparison of sensor generated real time hook load value with a minimum threshold value of hook load stored in measurement system. This research article describes a novel method of slip status detection by machine vision technology which helps overcome the constraints of slip status detection with legacy measurement method. It also helps improve the real time drilling data quality and optimize and automate drilling operations. A method to detect drill string slip status with high-resolution digital camera installed on mast near rig floor is described along with backend vision processing and communication modules, which generate binary values of slip status. The binary values are transferred in real time to drilling measurement system of rig to compute other drilling parameters like bit depth, hole depth and stand counters. This method includes deploying active optical sensors at the rig floor, obtaining 1-D, 2-D, or 3D image data, and processing it to obtain the status of drill string. Reliable measurement of slip status by machine vision helps reduce non-productive time (NPT) by reliable real time surveillance of drilling operations.

In this study, we developed a neutron time-of-flight (nTOF) measurement system for a 1.7-MV tandem proton accelerator with a target covered with 300-nm-thick lithium (Li) layer. With implementation of beam chopping module after its ion source, the accelerator is configured to operate in pulsed-beam mode with a pulse width

International audience; We have measured the three-dimensional coordinates of retroreflecting glass spheres using a multilateration technique. To this end, the distances between each target and our measurement heads have been determined by an in-house prototype of electro-optical absolute distance meter. The used targets are spheres of glass refractive index n=2 and of diameter 14.2 mm. They offer a much larger aperture than corner cubes and a lower cost, but they present a low reflectivity. However, this paper shows that with a proper collimation of the laser beams it is possible to reach a range of operation of 20 m. The standard uncertainty on such distances is better than 11 µm, including the mechanical errors of the gimbal mechanisms of our aiming systems. This uncertainty has been validated thanks to a comparison with an interferometric bench. In addition, the measurement of the coordinates of 16 glass spheres using a self-calibration multilateration algorithm has also confirmed the performances of the developed system: the standard deviation on the position errors has been estimated to about 10 µm.

Electric thrusters are considered to be the most promising propulsion system of choice for space gravitational wave detection. However, the requirement of high accuracy and drag-free control results in significant challenges in thrust measurements. To better understand the thrust noise characteristics, this work proposes a time-frequency-domain method for thrust noise analysis, i.e., a scalogram method attained through wavelet analysis. Unlike the conventional Fourier transform method, it can provide 3-D relationships for the time-frequency and thrust noise. A free-state thrust measurement experiment identified that the environmental temperature produces the dominant impact in the thrust noise. During a 70,000 s measurement, even without thruster operation, the thrust noise increased from 0.3 μN/Hz1/2 to 19 μN/Hz1/2 as the environmental temperature increased from −1 °C to 3 °C. The corresponding frequency of peak thrust noise for the entire period tends to be the same of 0.1 Hz. Additionally, a Hall thruster thrust measurement experiment was conducted to verify the method's time-varying analysis capability for thrust noise. The complete time-frequency thrust noise variation throughout the entire operating process of a Hall thruster was observed. The results at different stages of thruster operation indicate that thrust noise has the greatest influence 150–300 s after ignition. This is because the thrust stand will take hundreds of seconds to reach thermal equilibrium after ignition. Another finding during the Hall thruster operation is that the 0.1 Hz frequency corresponding to the peak thrust noise is highly consistent with the frequency of peak thrust noise in the free-state thrust experiment. This reveals the fact that the 0.1 Hz frequency should be the dominant frequency for thrust noise caused by temperature drift in our thrust measurement system.

In this study, the ECT system was used to study the temporal and spatial distribution characteristics of bed density in an ADMFB under the influence of superficial gas velocity and static bed height. The results show that, In the axial distribution, the closer to the top of the bed at low gas velocity( 13 cm/s), the lower the density. In the radial distribution, the closer to the central axis, the lower the density. With the decrease of static bed height, the radial uniformity becomes worse. The optimal gas velocity is 12.5 cm/s, under which the bed spatial distribution is the most uniform, and the ecart probable moyen of spherical particles is 0.06. The separation density is smaller than the bed density and is close to the central axis density.

Self-adaptive surface measurements that can reduce data redundancy and improve time efficiency are in high demand in many fields of science and technology. For this purpose, a system implemented with Gaussian process (GP) adaptive sampling is developed. The non-parametric GP model is applied to reconstruct the topography and guide the subsequent sampling position, which is determined from the inference uncertainty estimation. A criterion is proposed to terminate the GP adaptive measurement automatically without any prior model or data of the topography. Experiments on typical surfaces validate the intelligence, adaptability, and high accuracy of the GP method along with the stabilization of the automatic iteration termination. Compared with traditional raster sampling, data redundancy is reduced and the time efficiency is improved without sacrificing the surface reconstruction accuracy. The proposed method can be implemented in other systems with similar measurement principles, thus benefitting surface characterizations.

The evaluation of the volumetric accuracy of a machine tool is an open challenge in the industry, and a wide variety of technical solutions are available in the market and at research level. All solutions have advantages and disadvantages concerning which errors can be measured, the achievable uncertainty, the ease of implementation, possibility of machine integration and automation, the equipment cost and the machine occupation time, and it is not always straightforward which option to choose for each application. The need to ensure accuracy during the whole lifetime of the machine and the availability of monitoring systems developed following the Industry 4.0 trend are pushing the development of measurement systems that can be integrated in the machine to perform semi-automatic verification procedures that can be performed frequently by the machine user to monitor the condition of the machine. Calibrated artefact based calibration and verification solutions have an advantage in this field over laser based solutions in terms of cost and feasibility of machine integration, but they need to be optimized for each machine and customer requirements to achieve the required calibration uncertainty and minimize machine occupation time. This paper introduces a digital twin-based methodology to simulate all relevant effects in an artefact-based machine tool calibration procedure, from the machine itself with its expected error ranges, to the artefact geometry and uncertainty, artefact positions in the workspace, probe uncertainty, compensation model, etc. By parameterizing all relevant variables in the design of the calibration procedure, this simulation methodology can be used to analyse the effect of each design variable on the error mapping uncertainty, which is of great help in adapting the procedure to each specific machine and user requirements. The simulation methodology and the analysis possibilities are illustrated by applying it on a 3-axis milling machine tool.

The accurate measurement of surfaces of large aviation components is vital for the assessment of manufacturing and assembly quality of such components. To satisfy the measurement requirement of large-size components, most current researches pay more attention to combined measurement methods utilizing different measuring instruments, but the related researches on error analysis and optimization methods are not taken enough attention. This paper proposes a combined laser-assisted measurement method with feature enhancement techniques, and it also develops an error propagation model of the main factors affecting the overall measurement error in detail. Firstly, the surface of a large-size component is measured by the measurement system at multiple stations. Secondly, a control point coordinate system is established as a bridge to unify all local measurement data into the global coordinate system. To improve the overall measurement accuracy, the pixel extraction error as a key factor causing the overall measurement error is analyzed in detail. Next, the error propagation model is established, and some optimization strategies of layout for minimizing measurement error and transformation error are researched. Finally, experiments are carried out to verify the effectiveness of the proposed method. The results show that the measurement error of the proposed method reaches 0.073% and 0.14% with a 1D standard ruler and a flat plate, respectively.

Confocal microscopy is high precision and widely used method for topography measurement. The surface height information is obtained by peak extraction of the axial response signal (ARS) which axial tomography of the surface is required. Therefore, when scanning large-diameter surfaces with a confocal coordinate measuring system (CCMS), the relative horizontal scanning trajectory (RHST) between the confocal sensor and surface is repeated and time-consuming step motion, which greatly increases the measurement time. To improve the scanning measurement efficiency of CCMS, we propose a new location tracking scanning (LTS) method based on multi-focus. In the LTS method, the RHST is a continuous linear motion during the process of axial tomography, and the horizontal motional surface is located and tracked through a series of focuses to restore the ARS. A generatrix profile of a spherical surface is measured to verify the effectiveness of the proposed method, and the results show that the scanning measurement time can be reduced by more than 90% without loss of accuracy of the profile measurement.

Vehicle safety and performance can be dramatically improved if force or friction measurement of the tyre-terrain interface is known. Since the tyre-terrain interface is responsible for the majority of forces acting on the vehicle, this region has received a lot of attention in vehicle dynamics. Direct measurement of the tyre-terrain interface is difficult since it is hidden by the tyre and terrain. A lot of research has been conducted on the inside of tyre using accelerometers or strain gauges with research more focussed on passenger car tyres and very little work performed on agricultural tyres with larger lugs. This study performs strain measurements using point measurement, from strain gauges, and full field measurement, using a stereo camera measurement system, of the inside of an agricultural tyre on a drum test rig during vertical and lateral loading. Results show similar trends when compared to results on passenger car tyres, however the mounting of the strain gauge relative to the lug is shown to play a large role in the developed strain. Linear relationships between the applied tyre force and strain were obtained in different direction with R2 values above 0.97.

Summarization: Time is the fundamental measurement in satellite altimetry and the key parameter in building and keeping up a long-term, consistent, and reliable record for monitoring changes in sea level. Over the years, different time scales, although interconnected, have been used in altimetry and also in satellite positioning. This sometimes leads to inexplicit descriptions and ambiguous use of time and orbit coordinates as well as of their transformations between various reference and measuring systems. Altimetry satellites, like Sentinel-3, CryoSat-2, Jason-3, HY-2A/-2B, IceSat-2, etc., observe and practically realize ranges by measuring time differences between the transmission and reception of an electromagnetic wave (either radar or laser at present). Similar principles apply for global navigation satellite systems and for their terrestrial reference systems upon which altimetry is linked and tied together. Yet, the “meter” of any terrestrial reference systems is also defined by time. This work seeks to establish a standard reference system for “time” and “coordinates” in an effort to reach uniform and absolute standardization for satellite altimetry. It describes various errors generated from differences, discontinuities and interactions in time, frequency, range, time tagging, and reference coordinate frames. A new approach, called “fiducial reference measurements for altimetry”, is here given to examine ways to connect errors with metrology standards in order to improve the estimation of uncertainty budgets in ocean and water level observation by altimetry. Finally, the geocentric inertial reference system and the international atomic time are proposed in this paper for satellite altimetry observations and products. Presented on: Advances in Space Research

The time shift of mechanical watches is caused by individual differences (manufacturing error), environmental temperature, magnetism, posture, impact force and dynamic environment. The easiest and clearest method of measuring the accuracy of mechanical watches is to measure the time shift by comparing it with the reference time. The disadvantage of this method is that it can only measure accuracy at a certain time. Another method for measuring the accuracy of mechanical watches uses a watch timing machine that obtains the vibration sound of a watch using a microphone and calculates accuracy in the short term. This method can measure the change in watch accuracy over time. However, it cannot be used to measure accuracy in a dynamic environment because the watch timing machine is large and there is a sound noise. To clarify the accuracy of mechanical watches in dynamic environment, this study developed an accuracy measurement system which can be carried and measure in a dynamic environment. This study monitors the movement of a partly constituted mechanical watch using a photo interrupter and develops a method to calculate the rate and amplitude of a balance wheel from the output value of the photo interrupter. The validity of the developed system is verified by comparing the time shift of the system and radio clock time over the long term. The developed system, can be used in a dynamic environment because it consists of the photo interrupter in the watch case. Moreover, this study conducted measurements under forced vibration using vibration generator and during walking with the system.

Many methods have been applied to monitor fugitive methane gas from landfills. Recently, there have been suggestions to use a framework utilizing an unmanned aerial vehicle (UAV) for landfill gas monitoring, and several field campaigns have proved that a rotary UAV-based measurement has advantages of ease of control and high-resolution concentration mapping on the target planes. However, research on the evaluation of error-inducing factors in the suggested system is limited so far. This study prepared a measurement system with a lightweight methane detector and a rotary UAV to support the applicability of rotary UAV in landfill gas monitoring. Then, the validity of the system was tested experimentally and theoretically. In the detector reliability test, the methane detector had sufficient resolution for field application. The critical UAV velocity required was obtained to ensure the credibility of the proposed measurement system. When spatial interpolators were applied to field data from the measurement system, the empirical Bayesian kriging demonstrated the best prediction of methane concentrations at unmeasured points. With the verifications provided in this study, this proposed method may contribute to reducing uncertainty in estimating fugitive landfill gas emission.

In this paper, a static multi-longitudinal mode laser self-mixing absolute angle measurement system is developed to accurately monitor the deflection angle. The experimental results show that this multi-longitudinal mode laser angle sensor is capable of effectively measuring the deflection angle of the vertical dihedral mirror. The angle-measurement range and resolution of the self-mixing experimental sensing system can be obtained as ±22.0° and 0.008°, respectively. Furthermore, in-depth analysis of the angle-measurement error and related error sources are performed, of which the absolute error is less than 0.37° that demonstrates the good reliability and practicality of the self-mixing angle sensor.

Fine powders are generated in large volumes by industrial activities such as mining, metallurgical processing, energy generation and processing of waste. To meet specifications for further use, powder processing such as comminution and size classification are commonly applied. To optimise the design and operation of air-flow based classification processes, continuous on- line, monitoring of variations in dust particle concentration are an asset. This paper reports on the development of a novel ultrasonic measurement system suitable for robust monitoring of air-borne dust concentration variations during the operation of powder classification installations. The system was tested on a pilot-scale classifier designed for air-borne separation and recovery of ultrafine powders from coal combustion fly ashes. The monitoring method is based on a measurement of ultrasonic wave attenuation by particles suspended in the air-flow of the classifier.

International audience; This work presents a novel technique with fast response for Residence Time Distribution (RTD) measurements in gas-solid unit operations (e.g., fluidized bed reactors). This technique is based on an optical method which eliminates the requirement of knowing the velocity and concentration profiles at the exit section of the system. Experiments were carried out with SiC particles and a phosphorescent pigment used as a tracer. A concentration measurement system was developed to measure the tracer concentration in SiC/pigment mixtures. The corresponding pigment concentrations were evaluated at the bottom of this system using a photomultiplier. The pigment concentration was derived from the integral of the signal intensity received by the photomultiplier. Then, a calibration curve was established which provided the empirical relationship between the integral and pigment concentration. In order to validate this RTD measurement technique, a series of experiments was performed in a bubbling fluidized bed and the effect of the bed height was studied. It was shown that the experimental RTD curves were in good agreement with the theoretical RTD of bubbling fluidized beds. This solids RTD measurement technique can be used to provide a better understanding of the hydrodynamics of complex solids unit operations.

A method is proposed in this paper to correct the position error in radar cross section (RCS) calibration. In radar RCS measurement system, in order to get the accurate information, the amplitude and phase calibration are very important to remove the error influence. The measurement results are influenced by multipath effect, laboratory background, target position, environmental noise and so on. In this paper, the position error correction is under consideration. Firstly, the method of getting target position is derived. Following this, the phase error caused by it can be got rid of to get more accurate data. Finally, we show the extensive simulation results and experiment results of typical cylinder, which all demonstrate the validity of the method.

Verification tests defined in the ISO 10360 series of standards guarantee that coordinate measuring systems (CMS) have consistent performance. The development of these tests is focused on practical industrial applicability. All tests are based on multiple measurements of probing points. This gives the tests a statistical nature. As each measurement is treated separately and must conform to the maximum permissible error, a considerable risk of false acceptance/rejection is present. An approach based on a statistical model of the test is proposed instead. The approach can manage customer and producer risks in a way that is consistent with ISO/IEC GUIDE 98–4.

Using the example of the rotary bending process, 3D-printing technologies are used to integrate sensors and actuators into the working area. This enables to obtain information directly from the working area, which can be used for setting up the process parameters or for predictive maintenance. Especially in terms of maintenance, the aim of research is to find out how the hybrid tools behave in action. Therefore, an optical measurement system is used to detect the strain of the hybrid tool and the forming machine itself.

Speckle images have found multiple applications in image-based measurement techniques, where the objective of measurement is the estimation of speckle displacements between two often consecutive images. Depending on the characteristics of a measurement system and its measurands, the signal-to-noise ratio (SNR) of recorded images may become low and even marginal. One solution to improve the accuracy of speckle displacement estimation in such cases is the use of super-resolution methods. In this article a robust and versatile partial differential equation based resolution enhancement method is presented for the analysis of low SNR speckle displacement signals. The application of the method to synthetic one-dimensional and two-dimensional signals as well as actual particle displacement images indicate that the method is capable of reducing noise effects and partially recovering lost correlation, which in turn makes the selection of smaller interrogation windows and achieving higher resolution and accuracy of displacement estimation possible. The method is applicable to both speckle and particle displacement images.

The uncertainty of measurement (UOM) is an integral part of measurement system. In the competitive era of globalization every testing laboratory is facing the problem of acceptability of its results. The acceptability of testing results depends on the accuracy as well as precision with minimum degree of uncertainty of test result. Many quantitative and qualitative factors influence on test results. The estimation of effects of quantitative parameters are possible using statistical methods such as analytical method, ISO-GUM methods etc. But the exact estimation of effects of qualitative parameters is not possible to control the effect of uncertainty of measurement. The cause and effect diagram, brain storming and questionnaire based data are used for finding the qualitative factors affecting the measurement uncertainty. The multi-decision criteria making tool, analytical hierarchical process (AHP) is most suitable for ranking the effects of various parameters on overall UM. The testing laboratories should apply this method for control the quality of their test results with minimum UM.

Measuring and assessing the basic physical abilities of athletes is an important factor in the search for sporting talent and in training. Traditional methods are mainly based on knowledge of results, such as the time required to complete the given task. Various modern sensors allow us to obtain details of task execution that were previously unavailable, such as the trajectory of movement, thus giving us knowledge of performance. Our motivation is to use MEMS accelerometer to measure and analyze rapid hand movements, such as a standard tapping test, which is one of the most frequently used tests to assess the basic physical abilities. For this purpose, we use a specially designed wireless sensor device including an accelerometer with a dynamic range of ±16 g0 and validate its measurements with the professional optical motion capture system from Qualisys. In addition to the time required to perform the tapping task, we also compare the main characteristics of the hand acceleration, hand velocity and hand displacement signals acquired and derived by both measurement systems: MEMS accelerometer and optical motion capture system. The results show that the accelerometer measures the hand acceleration with sufficient accuracy to derive all other important hand movement parameters. Finally, we conclude that the accelerometer used in our tests, as well as devices with similar characteristics, are suitable for the accurate measurement of the tapping performance variables and can therefore be used in tapping tests.

Aero-engine casing manufacturing requires considerable processing accuracy. In the aero casing turning process, the entire profile needs to be machined in one process to ensure the surface smoothness and control the remained wall thickness. However, the wall thickness error will be affected by tool wear and workpiece deformation in turning. This paper proposed a non-contact ultrasonic measurement system to measure the wall thickness and compensate the wall thickness error. The wall thickness of the aero casing is measured on the lathe after each turning process and compensated in the next path. Experiments validate the effectiveness of the developed method.

Eco-driving is designed to reduce fuel consumption and emissions by the improvement of driving behaviors. The objective of this work is to propose some eco-driving behavior suggestions by analyzing the impact of driving behaviors on vehicle emissions. A Portable Emission Measurement System (PEMS) was used to collect emissions and microscopic driving behavior data. Then the multi-dimensional characteristics of driving behaviors and corresponding link-level emission characteristics were quantified. The results show that the vehicle activities change significantly when the road traffic tends to be saturated or forced. The change of driving behavior and associated vehicle activities leads to the significant increase of emission factor in saturated flow and forced flow. Traditional eco-driving advice advocates using the highest gear as much as possible to reduce fuel consumption. But the results indicate that using the highest gear can achieve a savings in CO2 while at a cost in NOX. If the time percentage of the highest gear increase by 54%, the CO2 emission factors will reduce by 22% while NOX will increase by 14%. Then a total of six factors were extracted to characterize driving behaviors. The statistical analysis shows that not only the driving operational intensity have an impact on the emissions factors but also the durations and frequencies of individual maneuver states will affect emissions. Decision tree algorithm was used to identify eco-driving behaviors. Finally, a model with 97% accuracy was put forward. The conclusions are helpful to improve traditional eco-driving strategies.

The Cos α method has emerges as new technique for measurement of the residual stresses using whole Debye-Scherrer ring recorded on two dimensional imaging plates (IPs) with the help of X-ray residual stress measurement system μ-X360 Ver. 2. 3. 0. 1. Considering with more accountability of the tempering treatment process for decreasing or eliminating the residual stresses, the effect of tempering is monitored experimentally. The main objectives of this paper is to predict the residual stresses distribution, and surface roughness of the machined samples (with and without tempered) on CNC lathe at the same process parameters (speed, feed and depth of cut) using tungsten carbide tool. Surface residual stresses of five turned specimen with and without tempered have been measured. The residual stress graphs, FWHM (full width at half maximum) graphs and Debye –scherrer rings, and surface roughness of all samples have been obtained and critically studied. The residual stress and surface roughness were found minimum in sample tempered at 450°C. The min and max peak values were found as 149 k and 175 k for samples tempered at 450°C and untempered respectively. The average surface roughness (Ra = 2.06, Rq = 10.4 and Rz = 2.45) and(Ra = 3.65,Rq = 16.9 and Rz = 4.27) were seen in sample tempered at 450°C and untempered respectively. The results obtained from the present experiment, literature review and the theoretical study validate the present work and method in strong confirmation and bear a good agreement among them.

An increasing interest in lattice structures is developing in various industrial sectors. These structures, composed of several cavities or voids, are used in a wide range of applications. They allow to lighten workpieces while maintaining good mechanical characteristics. Although these structures offer new design opportunities, they are difficult to manufacture because of their complex geometry and internal surfaces that are difficult to access. The special characteristics of lattice structures almost always require the use of additive manufacturing processes. By using lattice structures, new problems arise in additive manufacturing, such as lattice defects characterization and measurement issues. The objective of this study is to characterize the geometric defects of lattice structures obtained using L-PBF additive manufacturing process. Lattice structures exhibit not only common defects inherent to L-PBF process, but other geometric defects specific to their unit cell that require appropriate measurement systems and new processing techniques. This paper deals with a systematic approach to evaluate geometric defects obtained from Additive Manufacturing simulation software. First, lattice structures are generated using Rhino-Grasshoper visual programming capabilities. Then, virtual parts are built using Ansys Additive software. Registration methods are used thereafter to compare the simulated and the nominal models. The advantage of non-rigid methods such as CPD and BCPD for registration is highlighted. Finally, the obtained data can be used in the future to enhance the predictive modeling of geometric defects in L-PBF.

This article describes the technical principles and clinical applications of dual source CT. A dual source CT (DSCT) is a CT system with two x-ray tubes and two detectors at an angle of approximately 90°. Both measurement systems acquire CT scan data simultaneously at the same anatomical level of the patient (same z-position). DSCT provides temporal resolution of approximately a quarter of the gantry rotation time for cardiac, cardio-thoracic and pediatric imaging. Successful imaging of the heart and the coronary arteries at high and variable heart rates has been demonstrated. DSCT systems can be operated at twice the spiral pitch of single source CT systems (up to pitch 3.2). The resulting high table speed is beneficial for pediatric applications and fast CT angiographic scans, e. g. of the aorta or the extremities. Operating both X-ray tubes at different tube potential (kV) enables the acquisition of dual energy data and the corresponding applications such as monoenergetic imaging and computation of material maps. Spectral separation can be improved by different filtration of the X-ray beams of both X-ray tubes. As a downside, DSCT systems have to cope with some challenges, among them the limited size of the second measurement system, and cross-scattered radiation.

The thermal conductivity of hydrogen and its mixtures is a key parameter for its production, storage, and application; however, thermal conductivities at high temperatures and pressures are rarely measured due to gas leakage. A system based on the short-hot-wire method is developed here to measure the thermal conductivity of H2/CO2 binary mixtures at 323.15–620.05 K and 2.14–9.37 MPa. A double sealing device consisting of a steel tube filled with magnesium oxide powder and a tension nut was designed and used to seal the electrical wires and prevent gas leakage. A relatively low uncertainty of 2.254% for the thermal conductivity was achieved due to the high accuracy of the measurement system. The calculation results from two theoretical models are compared with the measurement results with good consistency.

A new contact-type on-machine measurement system is designed and developed for the evaluation of a micro cutting edge profile. The measurement system is composed of a compact probe unit having a sharp stylus mounted on a flexible beam, an inner displacement sensor for the detection of the stylus displacement, and a two-axis precision positioning system. For the evaluation of tool faces having a steep slope, a new probing procedure with the enhancement of the inner displacement sensor integrated into the probe unit is newly proposed. After the design and development of the probe unit, the feasibilities of the developed measurement system and the proposed probing procedure are demonstrated through some basic experiments. Regarding the out-of-straightness and angular error motion of the two-axis positioning system employed in the developed measurement system, a pair of length gauges is newly employed to reduce the influences of error motions of the stage system. The topographic profile of the micro cutting edge obtained by the measurement system with the modified probe unit is then compared with those obtained by a commercial stylus profiler and a laser confocal microscope. The feasibility and effectiveness of the developed on-machine tool edge profile measurement system are also demonstrated through uncertainty analysis based on the GUM with the Monte-Carlo method.

In cabin-type component alignment, digital measurement technology is usually adopted to provide guidance for assembly. Depending on the system of measurement, the alignment process can be divided into measurement-assisted assembly (MAA) and force-driven assembly. In MAA, relative pose between components is directly measured to guide assembly, while in force-driven assembly, only contact state can be recognized according to measured six-dimensional force and torque (6D F/T) and the process is completed based on preset assembly strategy. Aiming to improve the efficiency of force-driven cabin-type component alignment, this paper proposed a heuristic alignment method based on multi-source data fusion. In this method, measured 6D F/T, pose data and geometric information of components are fused to calculate the relative pose between components and guide the movement of pose adjustment platform. Among these data types, pose data and measured 6D F/T are combined as data set. To collect the data sets needed for data fusion, dynamic gravity compensation method and hybrid motion control method are designed. Then the relative pose calculation method is elaborated, which transforms collected data sets into discrete geometric elements and calculates the relative poses based on the geometric information of components. Finally, experiments are conducted in simulation environment and the results show that the proposed alignment method is feasible and effective.

The traditional process of mechanical cutting of electrotechnical steels, still have many advantages such as: high efficiency, no thermal deformation zone affected by hot ablation, the possibility of shaping products of any length of the cutting line. However, this process introduces a substantial plastic deformation to the sheet metal and causes premature edge fracture during the subsequent forming process. This causes the deterioration of the magnetic properties of material. The paper studies the effects of the technological parameters of shear- slitting process on residual stresses and strains, quality of sheared edge and selected magnetic properties based on ET 122-30 grain oriented electrical steel. For the study, a simulation model ofthe process using mesh-free method (SPH) is developed. To obtain knowledge of the influence of this parameters on quality of cut surface and magnetic properties of material, experimental research was done using vision-based measurement system, confocal and atomic force microscopes and system for testing soft magnetic materials. Finally, an example of graphical optimization is presented and set of acceptable solutions is developed on the plane of controllable variables. Using obtained relationships and results, it is possible to control cutting process to obtain high cut surface quality with minimum deterioration of magnetic properties.

The visual measurement system was established to investigate the fluid flow during high-speed gas metal arc welding. The two-dimensional fluid flow velocity on weld pool surface was measured using the tracer particles. The characteristic parameters of the backward liquid metal flow were extracted, then the speed of the liquid metal flow was compared with different welding speeds. The results showed that the high-speed backward liquid metal flow and the pinching & earlier solidification of the backward liquid metal flow channel caused the humping bead formation. A transverse magnetic field was used to control the fluid flow behavior to prevent the humping bead. Due to the introduction of transverse magnetic field, the thickness of liquid metal layer underneath the arc was increased. The longitudinal velocity of the liquid metal flow was decreased while the transverse velocity was increased so the humping bead can be suppressed.

In order to achieve high accuracy of computer numerical controlled (CNC) machine tools, various error compensation functions are implemented in the CNC control system. However, these error compensations are not designed to track the dynamic change in accuracies, such as thermal distortion or aging deterioration, during a machining process. To compensate for the dynamic change in accuracy, a built-in automatic measurement and compensation system based on dual linear scales was proposed, and its performance requirement was analyzed. Based on the analysis, a physical prototype was developed, and its feasibility was investigated by a series of experiments. The results showed that the measurement with the linear scale system agreed with a conventional measurement method within the uncertainty estimated at the design stage. In a subsequent experiment, the accuracy compensation was performed based on the measurement value. With compensation, the maximum accuracy deterioration was successfully suppressed from 22 to 3 μm.

Amplitude–wavelength (AW) maps or “Stedman diagrams” are often used to provide a graphical representation of the limitations and capabilities of surface measuring instruments. This paper presents an approach for setting the parameter constraints of X-ray computed tomography (CT) in terms of resolution and measuring range for the purpose of representing the performance of industrial CT systems on an AW map. Such AW map will allow instrument users to quickly compare the CT instrument performance to other measuring systems. Examples of the construction of AW maps for different working capabilities of X-ray CT systems, and based on experimental data, are provided. Polypropylene, aluminum, and steel are three workpiece materials considered for determining some of the limitations of measuring capability for the maps developed in this paper. Although the limiting boundaries of the AW plots presented in this paper set a generalized measure of performance for comparisons with other measuring instruments, they may evolve with more comprehensive models of the limiting factors in X-ray CT.

In the ultra-precision manufacturing of large optics, industrial robots have the potential to become an intelligent and economical choice of surface polishing. However, the transport of the workpieces between the polishing platform and the measurement instrument seriously limits the manufacturing efficiency. Therefore, an in-situ measurement system based on the monoscopic deflectometry is developed to determine the form quality of the optical lenses during rough polishing. Stray light reflected from the lower surface of transparent lenses may degrade the measuring quality, thus an effective absolute phase retrieval algorithm is developed to decouple the superposed fringes associated with the upper and lower surfaces. Then, the form of the upper surface under polishing can be reconstructed to guide the subsequent polishing. Experimental results demonstrate that the accuracy of the method is comparable to that of the coordinate measuring machine, consequently the manufacturing efficiency and reliability of large optical workpieces can be greatly improved.

The use of areal characterization of surface texture with high accuracy in a quality control process requires reliability. Therefore, regular inspection of the measurement systems is needed. Important metrological features of a measurement system in dimensional metrology are the amplification factor and linearity. This paper presents a simple method for characterizing the axial scanning system of areal topography measuring instruments with little expense and effort, well suited for industrial routine calibration in the field. The method is based on employing a single material measure with a range of step heights. It is shown that the amplification factor and linearity deviations can be determined and adjusted for large axial measurement ranges.

An image-based measurement system was developed to evaluate the induced local deformations of saturated sand specimens in undrained torsional shear tests. The images of specimens taken by a camera in front of a pressure chamber were noticeably distorted. To correct the errors caused by the curvature of the specimens and by the refraction of rays traveling through water, acrylic resin, and the atmosphere, a coordinate correction method was proposed to convert the apparent coordinates obtained from the distorted specimen image into the real coordinates under planar conditions. This method was verified using a rigid dummy specimen and was illustrated using a sand specimen as an example. The results obtained indicate that the resolution of displacement measurements is approximately 0.01 mm, representing approximately 3.3e-5 of the specimen height. Moreover, high measurement accuracy is obtained even if the dummy specimen has undergone a rotation of up to 26.4°. This measurement system was further extended to directly evaluate the local deformation of sand specimens through a transparent membrane. The direct and indirect evaluations indicate that the direct evaluation is more effective for quantitatively representing specimen deformation than indirect evaluation since membrane wrinkles and vertical slippage between the specimen and membrane occurred during liquefaction.

Morphological parameters of coarse aggregates, including the angularity index (AI), flat and elongated ratio, flatness ratio, and sphericity, strongly affect the performance of asphalt concrete. A device must be developed to efficiently and accurately measure these parameters. Herein, a charge-coupled device camera and a linear profile scanner are combined to evaluate the parameters. The AI is calculated using three methods. The results show that the fitted-ellipse method provides superior results among the three AI measurement methods. Moreover, the use of a linear profile scanner improves the AI measurement accuracy. Therefore, the proposed combination has high measurement efficiency and is suitable for batch inspections.

In this study, a system for measuring small-sized holes with a 17–21 mm diameter and 1000 mm length was constructed. The system comprises a laser interferometer to detect hole accuracy, a probe connected to a measurement bar, and an optical apparatus for detecting the probe attitude (position and inclination). The probe was supported by supporting pads. A steel workpiece with 18 -mm diameter and 800 mm length was used for the performance test. During the experiment, errors were found in terms of hole deviation and roundness profile. Further experiments, using new experimental apparatus and analysis, revealed the causes of errors: electrical noise that increased with time, two periodic stylus swings in the longitudinal direction of the hole per rotation of the measurement unit, and the excessive spring force pushing the tip of the stylus, causing a large frictional force with the hole wall, etc. If these errors are corrected, high accuracy in the measurement of hole deviation and roundness can be achieved.

The reason for the rounding error in a measurement system under the condition of a limited sampling period is analysed, and a three-point method based on the difference algorithm (D3P method) is proposed. The effect of the rounding error is reduced by differential approximation of the roundness error and reconstruction of the transfer function. The generalized three-point method (G3P method), the three-point method based on the first-order difference algorithm (I-D3P method) and the three-point method based on the second-order difference algorithm (II-D3P method) are compared and analysed by simulation. The results show that the accuracy of the D3P method is greatly improved compared with that of the G3P method under the restricted sampling period and that the D3P method retains high precision in the case of failed error separation of the G3P method. An experimental system was constructed to realize error separation, and the experimental results show that the D3P method has higher accuracy than the G3P method over a small sampling period.

Full aperture continuous polishing using pitch lap is a key process of finishing large flat optical workpiece. The friction force of the workpiece and pitch lap interface significantly affects material removal. In this work, the friction force was determined by a measurement system that uses force transducers to support the workpiece. Experimental and theoretical analyses have been carried out to investigate the evolution of friction force with polishing time and its effect on material removal. Our results show that the friction coefficient of the workpiece/lap interface decreases during polishing, which is due to surface smoothing of the viscoelastic pitch lap by loading conditioner. In addition, the spatial average and uniformity of material removal rate (removal coefficient) increases with the increase of friction coefficient, which is due to rough lap surface, provides more sharp asperities to charge the polishing particles.

The presence of an appropriately trained and experienced anaesthetist is arguably one of the key determinants of patient safety during anaesthesia. However, human error is inevitable and there is substantial evidence that superior measurement and monitoring systems reduce the probability of such errors. A good understanding and appropriate use of these devices enable the anaesthetist to provide safe anaesthetic care. The basic components of measurement systems in clinical use include a sensor, transducer, signal processor, display and storage unit. Signal processing is necessary to amplify the desired signal and reduce noise from sources of interference. The performance of measurement systems can be described in terms of their accuracy, precision, and linearity. Hysteresis is a special case of non-linearity. Non-linearity can be adjusted for by calibration. The response of a measurement system can be static or dynamic. Errors can occur due to inherent limitations of the equipment, defective equipment, inappropriate use of equipment, or user interpretation. Interpretation of the data from these devices depends on a thorough knowledge of the clinical and technical aspects of the modality in use. This article discusses the principles and clinical application of some of these measurement and monitoring systems.

Depth from defocus is one technology for depth estimation. We estimate particle depth information from two defocused images captured simultaneously by two coaxial cameras with different imaging distances. The images are processed with the Fourier transform to obtain the characteristic parameter (i.e., the standard deviation of the relative blur kernel of these two defocused images). First, we theoretically analyze the functional relationship between the object depth and the standard deviation or variation of the relative blur kernel. Then, we verify the relationship experimentally. We analyze the influence of particle size, window size and image noise on the calibration curves using both numerical simulations and experiments. We obtain the depth range and accuracy of this measurement system experimentally. For the verification experiments, we use a sample of glass microbeads and the irregularly-shaped dust particles on a microscope slide. Both of these experiments present a suitable depth measurement result. Finally, we apply the measuring system to the depth estimation of drops from a small anti-fogging spray. The results show that our system and image processing algorithm are robust for different types of particles, facilitating the in-line three-dimensional positioning of particles.

The demand for efficient and qualified measurements is high. The measurements of physical parameters in industrial environments usually are automatically executed using process measurement technologies. The close coupling of the measurement system and process equipment enables in-process data acquisition (inline or online). In contrast, compound-oriented measurements for the qualitative identification and quantitative determination of chemical elements and chemical compounds, or the determination of biological behavior, are still challenging in measurement processes. Today, biological assays as well as high-content and high-throughput screening procedures are well automated. It appears quite differently if the efficiency of analytical measurements should be improved. Due to the characteristics of the samples and processes, inline or online coupling is often not possible. Therefore, atline or offline couplings are gaining in importance. In combination with robotic systems, efficient automation of analytical measurements can be reached. The book Automation Solutions for Analytical Measurements: Concepts and Applications presents and discusses suitable automation concepts and a variety of realized robot-based analytical measurement systems. In this commentary, the main findings are highlighted and discussed.

In order to make the concentrating solar power (CSP) more competitive, an accurate prediction of the solar radiation incident on CSP tower plant receivers is necessary. The extinction in the heliostat-receiver pathway plays an important role in the optical loss of the solar field and therefore, in the performance of the plant. In order to correctly operate these kind of plants and to select new potential emplacements, it is necessary to know the on-site levels of extinction. A methodology was developed in another published work, called Extinction AOT method (EAM), with the purpose of finding out the levels of extinction present at a location using AERONET AOT as input data. However, there is no AERONET AOT data available at any potential site of interest for setting up a solar tower plant, so, alternative approaches were necessary. This paper proposes to determine levels of extinction at any location using AOT satellite data instead of AERONET data. These results have been compared with results obtained applying the EAM with AERONET data and using real extinction measurements obtained with the CIEMAT extinction measurement system. The extinction obtained at PSA has been 5% in all cases considering the error rates.

In this paper, modeling and machine learning with experimental data and a novel calibration function for a gas-solid flow sensor fusion are presented. Sensor fusion is the use of software that intelligently combines data from multiple sensors in order to improve overall system performance. This technique can be applied to measurement of mass flow rate of solids in a pipeline with non-intrusive electrostatic techniques. Data fusion from multiple heterogeneous/homogenous sensors can overcome the limitations of an individual sensor and measured variable. It is shown that the output voltage of a ring-shaped electrode is predominantly a function of solids mass flow rate and velocity for a flow of bulk solids in a pipeline, when particle size, properties and ambient conditions remain constant. By incorporating solids flow velocity in a proposed mathematical model (obtained via machine learning), meter output voltage could be predicted with superior accuracy, for wide range of different flow parameters from numerous experiments with a pneumatic conveying system. Transposing the model yields a new calibration function which, when deployed in signal processing software, enables accurate mass flow measurement with velocity compensation. The described method also de-necessitates determination of air solids ratio or solids volumetric concentration, thereby enabling simplification of the overall measurement system whilst yielding higher accuracy than calibration methods from previous studies. Accurate flow measurement facilitates enhanced monitoring and controllability of blast furnaces, power stations, chemical reactors, process plants etc. where there are bulk solids flows in pipelines. Optimization of such highly materially consumptive and energy intensive processes can yield significant reductions in waste and emissions (CO2, NOx) and increased efficiencies in global production of energy and materials.