High-precision Measurement System Research Articles

Design and Verification of Human Metabolic Measurement System Based on STM32

A high-precision human metabolic measurement system is designed. The system uses STM32F103 as the main control chip to acquire oxygen, carbon dioxide and flow signals to calculate four quantitative indicators: oxygen consumption(VO2), carbon dioxide production(VCO2), respiratory entropy(RQ) and resting energy metabolism(REE), and finally uses an upper computer to display the calculation results.In this paper, the signal acquisition circuit design was carried out for the oxygen sensor, carbon dioxide sensor and flow sensor, and the validity of the device was verified with the American machine MGCDiagnositcs using Bland-Altman analysis method, and the results showed that the four parameters of VO2,VCO2, RQ and REE of both devices fell in the agreement interval of more than 95%. The device thus provides accurate metabolic measurements and offers an effective tool for the field of general health and clinical nutrition support in China.

Increase in the Intracellular Bulk Water Content in the Early Phase of Cell Death of Keratinocytes, Corneoptosis, as Revealed by 65 GHz Near-Field CMOS Dielectric Sensor.

While bulk water and hydration water coexist in cells to support the expression of biological macromolecules, how the dynamics of water molecules, which have long been only a minor role in molecular biology research, relate to changes in cellular states such as cell death has hardly been explored so far due to the lack of evaluation techniques. In this study, we developed a high-precision measurement system that can discriminate bulk water content changes of ±0.02% (0.2 mg/cm3) with single-cell-level spatial resolution based on a near-field CMOS dielectric sensor operating at 65 GHz. We applied this system to evaluate the temporal changes in the bulk water content during the cell death process of keratinocytes, called corneoptosis, using isolated SG1 (first layer of stratum granulosum) cells in vitro. A significant irreversible increase in the bulk water content was observed approximately 1 h before membrane disruption during corneoptosis, which starts with cytoplasmic high Ca2+ signal. These findings suggest that the calcium flux may have a role in triggering the increase in the bulk water content in SG1 cells. Thus, our near-field CMOS dielectric sensor provides a valuable tool to dissect the involvement of water molecules in the various events that occur in the cell.

Rolling force and length of strip head and tail sections under unsteady deformation conditions

This paper describes the results of an experimental study that looked at the distribution of strains and rolling forces along the length of brass (L63), bronze (BrOF6,5-0,23) and copper (M3, M0) strips in a 150×235 twin rolling mill equipped with a microcontroller-based high-precision roll load measurement system. 2 and 3 mm thick workpieces with the widths of 10, 20 and 30 mm and the length of about 200 mm taken from the commercial batches of rolled copper, brass and bronze were used for the study. The workpieces were rolled at the Kolchugino and Kirov Non-Ferrous Metals Processing Plants. The reduction rate was varied within the range of 4 to 45%. The paper contains graphs showing the distribution of rolling forces along the strip length. The graphs indicate that the length of the strip head and tail sections, which experience unsteady rolling conditions, is dictated by the reduction degree, mechanical properties and dimensions of the strip. It was found that the length of the strip head and tail sections undergoing unsteady deformation tends to increase as the reduction rate increases. It was established that the initial mechanical properties of the strips had a significant effect on the unstable rolling duration and the length of the strip head and tail sections deviating from the given dimensions of the proper strip. Regression equations were obtained that can help predict the duration of unsteady rolling conditions with regard to copper strips as a function of their initial rigidity and reduction. The results of the study can be useful when finetuning rolling mills, as well as automatic gauge control systems, to ensure strips are rolled to precision along their entire length.

Modeling and Calibration of Active Thermal-Infrared Visual System for Industrial HMI

In the industrial application of the human-machine interface (HMI), thermal-infrared cameras can detect objects that are limited by visible-spectrum cameras. It can receive the energy radiated by a target through an infrared detector and obtain the thermal image corresponding to the heat distribution field on the target surface. Because of its special imaging principle, a thermal-infrared camera is not affected by the light source when imaging. Compared to visible-spectrum cameras, thermal imaging cameras can better detect defects with poor contrast but temperature differences or internal defects in products. Therefore, it can be used in many specific industrial inspection applications. However, thermal-infrared imaging has the phenomenon of thermal diffusion, which leads to noisy thermal infrared images and limits its applications in high precision industrial environments. In this paper, we proposed a high precision measurement system for industrial HMI based on thermal-infrared vision. The accurate measurement model of the system was established to deal with the problems caused by imaging noise. The experiments conducted suggest that the proposed model and calibration method is valid for the active thermal-infrared visual system and achieves high precision measurements.

High-precision inductance measurement system based on double-excitation auto-balancing bridge

High-precision inductance measurement system based on double-excitation auto-balancing bridge

High-Precision BRDF Measurement System in Near Infrared Band

High-Precision BRDF Measurement System in Near Infrared Band

A high precision stereo-vision robotic system for large-sized object measurement and grasping in non-structured environment

Handling and loading of large-sized objects represent a challenging task in industrial environments, especially when the object is a metal object with reflective surface features. Active stereo vision technology is not good for measuring the posture of reflective metal object, a high-precision pose measurement system based on passive stereo vision is proposed to automatic measurement, handling and loading of large objects by industrial robots in industrial environments. The system adopts advanced coarse and fine stereo vision positioning strategy, and realises the high-precision positioning of the measured target for the premise of ensuring stability. For coarse positioning, an improved multi-models template matching method based on machine learning is proposed to robust recognition of the multiple objects in complex background. A RANSAC-based method for the ellipse fitting and multi-points plane fitting is proposed for the 6-DOF pose of object accurately obtained in fine positioning step. Compared with the classical CAD-views method, experiments show that the method proposed in this paper has better performance in positioning accuracy and recognition robustness.

Experimental investigation on all-target electromagnetic scattering characteristics of hypervelocity HTV2-like flight model

According to the requirements for target detection and recognition of hypervelocity vehicles in near space, the simulation and measurement of corresponding electromagnetic scattering characteristics of non-uniform plasma generated by hypervelocity targets are conducted. A numerical calculation method with dynamic plasma parameters is developed and hypervelocity HTV2-like models launched by the ballistic ranges are used to simulate complex shape target flying at a hypervelocity velocity. The high-precision shadow imaging systems and radar measurement systems of the ballistic range are used to measure the model postures, the electromagnetic scattering characteristics of the whole targets and their flow fields in both C band and X band. The experimental measurement results of the radar cross section (RCS) of the models and their flow fields under different experimental conditions are obtained. The results show that the numerical simulation methods of unsteady high-temperature ionized air flow can be used to simulate the unsteady thermal chemical flow fields around the head and body of the simplified hypervelocity HTV2-like flight models. The electromagnetic scattering characteristics of the models and their plasma sheath differ by more than one order of magnitude under different experimental conditions. The total RCS of the model’s wake in the C band is much smaller than that of the model, and the total RCS of the model’s wake in the X band is significantly enhanced. The attitude angles of the models have great influence on their electromagnetic scattering characteristics and their RCSs with different attitude angles can differ by one order of magnitude. The electromagnetic scattering energy of the model in the C band is distributed mainly around the targets and their flow fields surrounding them. The X band electromagnetic scattering energy of the model is distributed mainly in the regions around the targets, surrounding flow fields and the wake flow fields. According to the experimental conditions of the ballistic range, the numerical simulation analyses of the electromagnetic scattering characteristics of the models and flow fields around them are carried out, and the maximum error between simulation and experimental results is less than 4 dB, verifying the effectiveness of the modeling methods of simulating electromagnetic scattering characteristics of non-uniform plasma coated targets.

Flatness on-machine measurement system of chemical mechanical polishing process for large-caliber tin plates

In planar optics machining, surface flatness is a critical requirement for making high-quality optical devices. Chemical mechanical polishing (CMP) is an important process of smoothing surfaces for hard and brittle planar optics. Thus, there are growing interests in developing high-precision flatness on-machine measurement system for tin plate CMP process. However, the traditional evaluation measurement cannot meet the measurement accuracy requirement of approximate 2 μm. In this study, we propose an effective on-machine measuring system for the large-caliber optical tin plate, which consists of linear guideway, rotary table, and measuring sensor. In the system, the straightness error of the guideway and the axial runout error of the rotary table are compensated using a spiral method and the Keyence LK-G5000 measuring sensor. First, the spiral measuring path is formed by the movement of the line guideway and rotary table, which can prevent from multiple calibration. Then, the 3D flatness error of the dressing process is measured by linear movement of the LK-G5000 and the rotation of the tin plate. After the primary measurement process, the obtained 3D flatness error is compensated for straightness and axial runout error in sequence. To verify the accuracy of the flatness measurement, the tin plate is dressed by the natural diamond tool according to the measured 3D flatness error. After the dressing process, the peak-valley value of the remeasured flatness error can achieve 2.12 μm through a single-step dressing. The experimental results provide the accuracy and reliability of the high-precision on-machine flatness measurement system for the large-caliber tin plate.

A methodology for industrial robot calibration based on measurement sub-regions

This paper proposes a methodology for calibration of industrial robots that uses a concept of measurement sub-regions, allowing low-cost solutions and easy implementation to meet the robot accuracy requirements in industrial applications. The solutions to increasing the accuracy of robots today have high-cost implementation, making calibration throughout the workplace in industry a difficult and unlikely task. Thus, reducing the time spent and the measured workspace volume of the robot end-effector are the main benefits of the implementation of the sub-region concept, ensuring sufficient flexibility in the measurement step of robot calibration procedures. The main contribution of this article is the proposal and discussion of a methodology to calibrate robots using several small measurement sub-regions and gathering the measurement data in a way equivalent to the measurements made in large volume regions, making feasible the use of high-precision measurement systems but limited to small volumes, such as vision-based measurement systems. The robot calibration procedures were simulated according to the literature, such that results from simulation are free from errors due to experimental setups as to isolate the benefits of the measurement proposal methodology. In addition, a method to validate the analytical off-line kinematic model of industrial robots is proposed using the nominal model of the robot supplier incorporated into its controller.

Probe method to measure the electromagnetic field in a plasma by Poynting vector conversion

In this paper, a high-precision electromagnetic measurement system suitable for a high-temperature and high-speed plasma is built to provide a platform for scientific research on the interaction mechanism of the electromagnetic fields and a plasma. This paper presents a method to measure the electromagnetic field inside a plasma by using a probe and Poynting vector conversion, which is a new and completely different method from the traditional method of measuring the electromagnetic field inside plasma. In addition, for this system and method, this work designs a microstrip antenna probe that can suppress multipath effects. This method is confirmed to be valid and usable after closed-loop verification by the CST software.

High precise time division multiplex UV pulse waveform measurement system for high power laser facility

In high power laser facility, the waveform measurement of UV pulse injected to target is very important for power balanced control and experiment result analysis. A time division multiplex UV frequency modulation pulse waveform measurement system based on fiber bundle and lens array is built for a high precise measurement result as well as low construction and maintaining cost. The system can remarkably improve coupling efficiency inject to fiber contribution to the aperture splicing sampling technology and a 50μm multi-mode UV fiber specially developed with 9.2GHz bandwidth@60m transmission. A “four-in-one” time division multiplex measurement system is built for laser facility and the practical experiment indicated that the system can realize precise waveform measurement within good economy and anti-interference performance.

Study on the accuracy of photoacoustic spectroscopy system based on multiple linear regression correction algorithm

Photoacoustic spectroscopy technology is an important method to detect the concentration of trace gases, so it is of great significance to improve the detection accuracy of the photoacoustic spectroscopy system (PAS). In this paper, a multiple linear regression algorithm was proposed to correct the accuracy of the PAS based on the high-precision cavity ring-down spectroscopy measurement system. The results showed that the correlation coefficient R2 between the corrected values of the multiple linear regression model and the reference true values was 0.903. It can be seen that the algorithm can effectively improve the detection accuracy of the PAS. A comparative experiment was carried out with the long optical path differential absorption spectroscopy system (LP-DOAS) for measuring the NO2 concentration in an ambient atmosphere. The experimental results showed that the corrected PAS and the LP-DOAS had a good correlation in measuring the NO2 concentration, the slope of linear fitting was 1.012 ± 0.040, and the correlation coefficient was 0.948.

A Novel Sensor Foil to Measure Ski Deflections: Development and Validation of a Curvature Model.

The ski deflection with the associated temporal and segmental curvature variation can be considered as a performance-relevant factor in alpine skiing. Although some work on recording ski deflection is available, the segmental curvature among the ski and temporal aspects have not yet been made an object of observation. Therefore, the goal of this study was to develop a novel ski demonstrator and to conceptualize and validate an empirical curvature model. Twenty-four PyzoFlex® technology-based sensor foils were attached to the upper surface of an alpine ski. A self-developed instrument simultaneously measuring sixteen sensors was used as a data acquisition device. After calibration with a standardized bending test, using an empirical curvature model, the sensors were applied to analyze the segmental curvature characteristic (m−1) of the ski in a quasi-static bending situation at five different load levels between 100 N and 230 N. The derived curvature data were compared with values obtained from a high-precision laser measurement system. For the reliability assessment, successive pairs of trials were evaluated at different load levels by calculating the change in mean (CIM), the coefficient of variation (CV) and the intraclass correlation coefficient (ICC 3.1) with a 95% confidence interval. A high reliability of CIM −1.41–0.50%, max CV 1.45%, and ICC 3.1 > 0.961 was found for the different load levels. Additionally, the criterion validity based on the Pearson correlation coefficient was R2 = 0.993 and the limits of agreement, expressed by the accuracy (systematic bias) and the precision (SD), was between +9.45 × 10−3 m−1 and −6.78 × 10−3 m−1 for all load levels. The new measuring system offers both good accuracy (1.33 × 10−3 m−1) and high precision (4.14 × 10−3 m−1). However, the results are based on quasi-static ski deformations, which means that a transfer into the field is only allowed to a limited extent since the scope of the curvature model has not yet been definitely determined. The high laboratory-related reliability and validity of our novel ski prototype featuring PyzoFlex® technology make it a potential candidate for on-snow application such as smart skiing equipment.

Comparative Study of the Influence of Bio-Resin Color on the Dimension, Flatness and Straightness of the Part in the 3D Printing Process

This paper aims to determine whether the color of based-plant resin called, by the manufacturer, eco-resin has an influence on the dimensions and geometric accuracy of the 3D-printed part. The analysis of flatness, straightness and dimensions deviations was carried out with high-precision measurement systems, and according to current standards regarding linear dimensions and geometrical tolerances. A coordinate measuring machine with contact probes was used to measure the printed part’s physical characteristics, and analysis of variance and response surface design methods were used for the data analysis. The printing experiment was carried out for each color. After that, the measurement of the printed parts and the study of the data were performed. The first finding is that for black and clear eco-resin, there are problems with the printing of the supports. Based on standard data for the range of nominal lengths of the part for linear dimensions, flatness and straightness, the measurement results can be included in different tolerance classes within standard value limits. The best value of the printed structure was obtained for clear eco-resin. The paper demonstrates that the impact of the color of the eco-resin is more important than the supports density for all the studied features. Based on 3D measurements, the optimal values for each of the eco-resin colors regarding the flatness, straightness and linear dimensions deviations of the 3D printed part were also determined.

Development and verification of a high-precision laser measurement system for straightness and parallelism measurement

Development and verification of a high-precision laser measurement system for straightness and parallelism measurement

Design of High Precision Image Measurement System for Small Workpiece

At present, there are many problems in the measurement of small machined parts (size ⩽ 70mm, such as micro circuit board, small non-standard parts, etc.), such as the difficulty and low efficiency of detection, the large data of sizes to be detected, and mainly rely on manual work. A high-precision image measurement system based on machine vision is designed in this paper, and the systematic error and random error of the machine vision measurement system are improved from hardware and software. Experiments show that size measurement of small workpiece with high efficiency and high accuracy can be realized by the system successfully. The measurement accuracy reaches micron level, which fully meets the testing requirements of production line, and has great value of industrialization promotion.

A high-precision unmanned aerial vehicle positioning system based on ultra-wideband technology

With the help of artificial intelligence technology, the unmanned aerial vehicle (UAV) industry is booming. In the civilian field, a series of fully functional UAV products have emerged one after another, giving birth to a huge industrial chain. To strengthen the UAV market supervision, many countries have introduced a series of standards to regulate UAV products, but they have not yet developed a high-precision positioning system for UAV quality inspection. In this paper, we proposed a high-precision UAV positioning method based on ultra-wideband (UWB) technology. We analyzed the algorithm, base station layout, and clock synchronization to improve the accuracy of the UWB positioning system and established a high-precision UAV trajectory tracking and measurement system based on UWB technology, realizing real-time high-precision positioning of UAVs. Based on the Chan algorithm, we analyzed the base station layout method in combination with the system construction site and proposed a new delay calibration method between positioning base stations. Experimental results show that we have achieved a horizontal accuracy of under 0.1 m and a vertical accuracy of under 0.15 m in a space of 120 m × 60 m × 40 m.

Research on High Precision Angle Measurement and Compensation Technology Based on Circular Grating

In this paper, the angle measurement method of high-precision circular grating is studied. The principle analysis of circular grating angle measurement, the principle analysis of multi reading head, and the design of rotary servo control system are carried out. After analyzing the error model of circular grating angle measurement, the research based on harmonic compensation model is carried out respectively. Aiming at the problem of zero crossing oscillation of compensation algorithm, the piecewise compensation strategy is designed, which fully demonstrates the application value of circular grating angle measurement method in high-precision angle measurement system.

High-precision multi-reference ratiometric temperature measurement system

High-precision multi-reference ratiometric temperature measurement system