Dynamic Measurement System Research Articles

Development and implementation of a dynamic force measurement system for automatic tool changer system and drawbar mechanism in machining center

Automatic tool changer system (ATCS) and drawbar mechanism (DM) are two of key basic parts for realizing the automatic tool-changing cycle in machining centers. The dynamic force in a tool-changing cycle plays an essential role in condition monitoring, fault diagnosis, and failure warning for the ATCS and DM. However, existing force detection systems have limitations in practical application. In this paper, a novel dynamic force measurement system (DFMS) is developed, which is based on a force sensing element installed on the BT40 tool holder and operating through a wireless network. The force sensing element is used to convert the dynamic force into the electrical signal. Digital measurements are collected from the 24-bit sigma-delta analog-to-digital converter with a programmable gain array, which then are transmitted to the upper computer software via a wireless transceiver. Besides, a Teager energy operator based dual-threshold two sentences endpoint detection method is proposed to recognize the temporal onset and offset of each force event in the dynamic force recording. Experimental results show that the DFMS is reliable and suitable to measure the dynamic force in automatic tool-changing cycles.

Experiments and Simulations of the Secondary Suspension System to Improve the Dynamic Characteristics of HTS Maglev

High temperature superconducting (HTS) magnetic levitation (maglev) has the potential as a high-speed passenger transportation mode owing to its passive stabilization. Our group is constructing a 1500 m-long HTS maglev high speed test line. As a kind of passenger transport, safety and comfort are primary factors for its operation quality. However, the weak damping in HTS maglev system is not enough to suppress the vibration. As a preliminary study of the test line, this article investigates an additional suspension system aiming to improve the dynamic characteristics of HTS maglev through experiments and simulation. We first built an HTS maglev model vehicle composed of a levitation frame and a car body. The dynamic responses were tested based on a dynamic measurement system. Second, a dynamic model of this kind of maglev device was established and the influence of suspension parameters on its vibration performance is analyzed theoretically. Third, this suspension system was applied to an HTS maglev engineering prototype through numerical simulations. Experimental and simulation results manifested that the suspension system can effectively reduce the vibration, especially with high frequencies. This article provides a reference for the design of HTS maglev vehicles.

Development of a new low-cost instrument for dynamic friction coefficient measurement of yarns based on the entanglement method

The surface dynamic and static coefficient of friction of yarns is one of the most important means of characterizing the surface structure of yarns and can provide an important basis for yarn performance evaluation and quality monitoring. The lack of highly stable, high precision and low-cost instruments for measuring the dynamic coefficient of friction of yarns is a major constraint to yarn performance evaluation and performance improvement. The entanglement method calculates the coefficient of friction between yarns by measuring the input and output tensions on both sides of the yarn at its own kink point, which is easy to use and highly accurate. Based on this, a yarn dynamic friction coefficient measurement system was developed based on the kink principle and the measurement error was evaluated using 28tex cotton yarn and 420 D polyester yarn in turn. After five repeatability tests using 28tex cotton yarn, 36tex aramid and 420 D polyester, the coefficient of friction between the three yarns themselves fluctuated by less than 0.01 and the instrument showed good stability and repeatability. In six comparative tests with the CTT constant tension transfer system from Lawson, USA, the inter-group CV of the coefficient of friction between the yarns themselves was only 3.66% after six tests. A final comparison of the data from the entanglement and the Rhodes method tests shows that the coefficients of friction obtained show the same trend. The yarn running speed and pre-tension are adjustable and the system has a timed test function, which allows the input and output tensions of the yarn and the dynamic coefficient of friction between the yarn and the yarn to be measured and displayed in real time. This improves the measurement accuracy, reduces the price of the product and helps to evaluate the surface properties of yarns and improve product quality.

Development of Long Coil Dynamic Magnetic Field Measurement System for Dipole Magnets of HEPS Booster

Development of Long Coil Dynamic Magnetic Field Measurement System for Dipole Magnets of HEPS Booster

An Improved Transmissive Method of Stress Nondestructive Measurement Based on Inverse Magnetostrictive Theory for the Ferromagnetic Material

In order to meet the technical requirements of non-destructive measurement for the internal stress of ferromagnetic materials represented by cold-rolled steel sheets during the rolling control process, the paper presents a novel method for the nondestructive measurement of ferromagnetic materials based on inverse magnetostrictive principle. By improving the traditional U-shaped sensor, a transmissive quadrapole layout is proposed. The corresponding excitation module and fast signal processing system for dynamic measurement were developed and the test system for detecting innerstress of ferromagnetic material was constructed in the laboratory. The relationship between the magnetic flux with the principal stress was found by experimental investigation and the sensitive correlation of the two was verified under the laboratory measurement conditions without strong electromagnetic interference. The influence of measurement results by sensor parameters such as sensor angle, amplitude of excitation current, variation of air gap were discussed in detail and a method was proposed to decrease the power supply instability caused by the change of the airgap. The experimental results show that the transmission quadrupole layout makes the test system exhibit a good linear response to the internal stress in the specimen. The feasibility of the magnetic detection method of internal stresses in ferromagnetic material was verified through the experiment.

An Improved Large-Field Microscopic Speckle Interferometry System for Dynamic Displacement Measurement of MEMS

The traditional microscopic speckle interferometer has limited applications in engineering due to its small field of view. In this paper, we propose a large-field microscopic speckle interferometer which embeds two doublet lens groups in the improved Mach–Zehnder optical path structure to expand its field of view. At the same time, the new system can reduce the coherent noise of reflected light in the optical path. We use this new system to measure the dynamic displacement process of the entire surface of the microchips. The experimental results show that our improved measurement system can achieve large-field, real-time and high-precision dynamic measurement of micro-electromechanical systems (MEMS).

Human resource management (HRM) in the performance measurement and management (PMM) domain: a bibliometric review

PurposeThe literature highlights the key role of human resource management in developing effective organizational performance measurement and management. To understand the state of the art of this role, the paper reviews the literature on human resource management in the performance measurement and management domain.Design/methodology/approachThe paper conducts a bibliometric literature review on 1,252 articles to identify the prevailing research trends and the conceptual structure of human resource management in the performance measurement and management domain.FindingsThe study highlights a growing number of publications and four themes related to human resource management in performance measurement and management. It also underlines the shift from static to the dynamic performance measurement and management systems within organization which is expected to be more suited to current and future contexts.Practical implicationsThe paper highlights the need to manage the identified themes as strategic organizational assets and further develop the strategic dimension of human resource management practices leveraging on project management and information systems.Originality/valueThe paper goes beyond the traditional focus on performance appraisal of human resource management studies and assumes the challenge of connecting two research fields: human resource management and performance measurement and management.

Development and Application of a Wide Dynamic Range and High Resolution Atmospheric Aerosol Water-Based Supersaturation Condensation Growth Measurement System

The supersaturated condensation of atmospheric aerosol is important in the study of mechanisms of cloud condensation and even heavy air pollution. The existing technology cannot realize accurate dynamic control of wide range supersaturation, so it is difficult to study condensation growth characteristics of nanoparticles through different levels of supersaturation. Here, a supersaturated condensation growth measurement system with three-stage microscope pipes was developed. The resolution of supersaturated condensation system is 0.14, within the range of 0.92 to 2.33 after calibration. Stabilization time is only about 80 s for saturation range 0.92–1.01, which helps to control saturation rapidly, and the control deviation of saturation is no more than 0.06. Measurement of different supersaturated condensation growth control conditions showed that, the particle size increased significantly compared with hygroscopic growth at high humidity. For single-component particles, the increase in size increased to a similar size at the same saturation, with a difference within 7.4%. The increase in size for ammonium sulfate (AS) increased by 13.4–30.2% relative to that of glucose. For the mixed-component, the increase in size decreased about 15.9–25.0% with the increase of the glucose. Because the glucose coating on the surface of AS have hindered particle growth. This also shows that atmospheric ultrafine particles, especially inorganic salt particles, will rapidly grow into larger particles under supersaturated conditions such as increased environmental humidity, thus having some impact on environmental pollution and climate change.

Research on Field Application Technology of Dynamic Angle Measurement Based on Fiber Optic Gyroscope and Autocollimator

For the purpose of realizing the dynamic angle measurement and calibration of the inertial equipment (such as rotary table), a dynamic angle measurement system based on the autocollimator and the fiber optic gyroscope (FOG), which can be used as an angle standard device, is designed in this paper. In this system, the scale factor of the FOG can be calibrated in the field application based on the autocollimator with the precision of 1 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">''</sup> in the range of ±0.05°. Furthermore, the angle measurement deviation between the FOG and the rotary table can be limited in ±3 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">''</sup> when the scale factor of the FOG is calibrated by the autocollimator when necessary. This research can guarantee the long-term accuracy of the scale factor of the FOG in the field application and it will greatly promote the applications of the FOG as an angle standard device in the field of dynamic angle measurement.

Evolution of coal flocs during flocculation under different stirring velocities

ABSTRACT A dynamic floc measurement system was developed to analyze flocs during sedimentation and automatically extract floc characteristics without damaging them. An optimized algorithm was proposed to remove fuzzy flocs, and visual inspection verified that this algorithm achieved satisfactory separation performance between well-defined and fuzzy flocs. This program was used to study the development of coal flocs and showed that the flocs grew rapidly at the beginning of flocculation. The floc size at equilibrium at low stirring velocities was larger than those at high stirring velocities. A high stirring velocity can cause irreversible damage to the flocs, and those flocs cannot be restored to their original size by decreasing the stirring velocity. In addition, the fractal dimension decreased with increasing time, indicating that there is an optimal stirring velocity which can be selected to enhance the size and structure of flocs. This research provided an effective way to study the characteristics of flocs, and the change process of the flocs under different stirring velocities was investigated in detail to understand the growth, breakage, and regrowth process.

Development of dynamic moisture content measurement system for wooden members exposed to fire heating

AbstractIn this study, a small sensor for the dynamic measurement of the local moisture content within a wooden member exposed to fire heating is developed. The measurement is based on the unique dependence of the electrical resistance of wood on moisture content and temperature. These relationships are observed experimentally at temperatures between 20°C and 90°C, and moisture content between 6.9% and 232.8%, for Cryptomeria japonica, Larix leptolepis, Pseudotsuga menziesii, and Zelkova serrata. The electrical resistance is represented with the temperature and moisture content for each tree species. The measurement is found to be the most effective within the moisture content of 10%‐30%.

Review of surface transient charge measurement on solid insulating materials via the Pockels technique

Surface charges accumulated on solid insulating materials in electrical apparatuses and electronic devices could distort the initial electric field and severely damage the insulation performance. Accurate transient surface charge measurement is critical to determine the mechanisms of charge transport and flashover occurrence, and estimate surface insulation strength under high voltage. The measurement technique based on the Pockels electro-optic effect is considered as the only approach for 2-D dynamic charge distribution behaviour so far, and it has good capability to avoid original electric field distortion caused by conventional methods featured by metal probes. This paper reviews recent progress of the non-invasive dynamic surface charge measurement systems on the Pockels technique. We focus especially on typical systems with transmitting and reflecting configurations and the frequently used fast inversion algorithms. It can be inferred that higher spatial-temporal resolution, higher signal-to-noise ratio, and better compatibility for both transparent and opaque materials are the future development trends, which greatly depend on multiple technological breakthroughs at impact-resistant electro-optic crystals, advanced high-speed photography and high-performance inversion algorithms. In addition, the recent studies on transient behaviour of surface discharge, together with the present limitation and future prospects are discussed. It is expected that more ideas will be inspired in transient surface charge measurement by the Pockels technique and other relevant electro-optic methods.

Analytical solution of uncertainty with the GUM method for a dynamic stereo vision measurement system.

Directed at the strong correlation among the input parameters and long measurement chain, which are difficult for uncertainty analysis with the guide of the expression of uncertainty in the measurement (GUM) method, a novel dynamic stereo vision measurement system based on the quaternion theory is presented to reduce the orthogonality restrictions of shafting manufacturing and application. According to the quaternion theory in the kinematic model of the cameras and the analytical solution of uncertainty with the GUM method, the complete, detailed, and continuous uncertainty results of the full-scale measurement space can be obtained. Firstly, one-dimensional turntables and rigid connections are utilized to form the motion cores and the automatic control carriers in the system. Secondly, the novel measurement model is used in the measurement process to shorten the calibration and measurement chains. Once the system based on the novel measurement model is set up, the analytical solution of uncertainty is utilized in the accuracy process. During the analysis process, the strong correlation among the extrinsic parameters is decoupled by introducing virtual circles and the measurement strategy with the GUM method. Through analyzing the relationship among the attitude angles, the major factors which influence the uncertainties in each axis and the final uncertainty are clarified. Moreover, the analytical continuous uncertainty maps for the uncertainties along each axis, combined standard uncertainty, and the expanded uncertainty are illustrated and the uncertainty variation tendency is declared. Finally, the analytical solution of uncertainty with the GUM method proposed in this paper predicts the uncertainty in the full-scale space and provides a new idea of the uncertainty analysis for the complicated combined measurement system.

A Dynamic Joint Angle Measurement Device for an Active Hand Rehabilitation System

Traditional methods of measuring a joint angle are neither repeatable nor accurate and cannot instantly display, record, and upload the data onto a cloud drive. These mechanisms require development if they are to be used to evaluate rehabilitation programs. This pilot study aim is to create a simple dynamic joint angle measurement system and develop a hand rehabilitation application for stroke users using small and sensitive 3-axis accelerometers. Using Bluetooth communication technology, an electrogoniometer is developed to measure the free range of motion of lower limb joints and automatically send and save all data on to a cloud drive. The reliability of the proposed device is evaluated by comparison with a commercial electrogoniometer. Five healthy youth subjects and five health elderly subjects are involved in the evaluation process for this pilot study. The accuracy and repeatability of the proposed device are tested using Bland–Altman plots and linear correlation analysis. Measurements that were made by the proposed device and a commercial electrogoniometer are shown to be comparable and repeatable, as confirmed by Bland–Atman plots. There is also a very high degree of linear correlation (R2 &gt; 0.99 for all joint angle measurements) between the lower limb joint angles that are measured using both devices. In conclusion, a portable, highly accurate and repeatable device was designed to be used for clinical assessment and for rehabilitation application that gives increased motivation to the user.

Hot-Probe Characterization of Transparent Conductive Thin Films.

Transparent conductive oxide (TCO) thin films represent a large class of wide-bandgap semiconductors applied in all fields of micro- and optoelectronics. The most widespread material applied for the creation of TCO coatings is indium-tin oxide (ITO). At the same time, there are plurality trends to change the high-cost ITO on other materials, for example, on the ZnO doped by different elements such as Al, Mn, and Sb. These films require mobile and low-cost evaluation methods. The dynamic hot-probe measurement system is one of such techniques that can supplement and sometimes replace existing heavy systems such as the Hall effect measurements or the Haynes–Shockley experiments. The theoretical basis and the method of analysis of the recorded dynamic hot-probe characteristics measured at different temperatures were presented in this work. This method makes it possible to extract the main parameters of thin films. Commercial thin ITO films and new transparent conducting ZnO:Al layers prepared by magnetron co-sputtering were studied by the proposed method. The measured parameters of commercial ITO films are in agreement with the presented and reference data. In addition, the parameters of ZnO:Al thin films such as the majority charge carriers type, concentration, and mobility were extracted from dynamic hot-probe characteristics. This method may be applied also to other wide-bandgap semiconductors.

A Full-Field Non-Contact Thermal Modal Testing Technique Under Ambient Excitation

Temperature has significant effects on modal parameters of a structure. However, it is difficult to do a full-field dynamic measurement and identify modal parameters of the structure under high temperature and working conditions. In this work, three-dimensional digital image correlation combined with Bayesian operational modal analysis is used to yield a full-field non-contact thermal modal testing technique under ambient excitation. Thermal modal verification experiments are carried out on a titanium plate with free boundary conditions under ambient excitation by a low-cost high-temperature dynamic measurement system. Natural frequencies and mode shapes of the plate under different average high temperatures are studied in detail. From the experimental process, it is believed that the thermal modal testing technique proposed in this work is an effective alternative testing technique to traditional contact testing techniques, and after some improvements, one can achieve thermal modal analysis of a structure under high temperature and working conditions.

Dynamic accuracy measurement system for mechanical wristwatch

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.

Company performance measurement systems: History and prospects

Subject. The article considers the most well-known Performance Measurement Systems, i.e. Strategic Measurement Analysis and Reporting Technique (SMART), Balanced Scorecard System (BSC), Integrated Dynamic Performance Measurement System (IDPMS), Performance Prism System (PPS), Dynamic Multi-Dimensional Performance Model (DMP). Objectives. We focus on identifying the specifics of the analyzed systems and determining the direction of their development. Methods. The study employs general scientific methods. The specifics of efficiency measurement systems are described and compared by a single set of parameters (the composition of stakeholders, whose interests are taken into account, practical applicability, dynamic adaptability, the presence of links between strategy and technological operations, innovation, etc.). Results. We analyzed the said efficiency measurement systems, described their strengths and aspects that need to be developed in further research. The findings can be used to create a system to measure the performance of Russian manufacturing and trading companies that produce goods for individual consumers. Conclusions. The systems like SMART, BSC, IDPMS, PPS and DMP are significant developments that help companies achieve their goals. These systems are universal. They serve as a methodological framework for creating a particular system for measuring a company's performance, taking into account its industry-specific requirements. These systems enable to solve some economic and management problems, but do not allow, for example, to determine the optimal business model of the company. It is appropriate to develop efficiency measurement systems by incorporating the value-based management principles.

Comparison of Dry Matter Loss Rates from Static and Dynamic Grain Respiration Measurement Systems for Soybeans at 18% Moisture Content and 30°C

HighlightsDesign, description, and comparison of static (S) and dynamic (D) grain respiration measurement systems (GRMS).No differences were detected between dry matter loss rates (vDML) from S-GRMS and D-GRMS for soybeans at 18% moisture content and 30°C stored for 20 d.Literature reports variable vDML estimates for soybeans stored in S-GRMS and D-GRMS; more studies should be conducted with a wider range of storage conditions before developing maximum allowable safe storage time guidelines.Abstract. Time to reach 0.5% dry matter loss (DML) is the estimated maximum allowable storage time (MAST) for shelled corn and has been suggested for use with other grains. Respiration studies have reported various estimates of this threshold depending on the type of grain respiration measurement system (GRMS) and storage conditions tested. The objectives of this study were (1) to design and evaluate two GRMS in which oxygen needed for respiration was limited in a static system (S-GRMS) or continuously supplied in a dynamic system (D-GRMS) during storage and (2) to compare the effects of GRMS on DML rates (vDML) for 18% moisture content soybeans stored at 30°C for 20 d. In this study, S-GRMS and D-GRMS units were designed to conduct respiration tests. Respired CO2 (mg CO2) was measured over time and used to calculate the specific mass of respired CO2 (mg CO2 kg-1 d.b. beans) and subsequent DML (%) using stoichiometric ratios from the respiration chemical reaction. DML rates, vDML (% d-1), were estimated by least squares linear regression of DML and time data. Four replications of respiration tests were conducted in each GRMS. Average estimates of vDML were 0.0157% d-1 and 0.0189% d-1 for S-GRMS and D-GRMS, respectively. Mean vDML from D-GRMS tests was 1.2 times greater than mean vDML from S-GRMS but not statistically different (p = 0.09). However, the coefficient of variation was 8 times greater for D-GRMS than for S-GRMS. More studies with a wider range of storage conditions should be conducted for development of a safety factor between both systems prior to using data from respiration of soybeans in the literature to estimate MAST. Keywords: Dry matter loss, Grain storage, Respiration, Soybeans.

RFID Dynamic Performance Measurement System Embedded in Multiscale Deep Learning

Multitag sensitivity would be affected by electromagnetic coupling during simultaneous reading. The reading distance of multitag depends on the least sensitivity and operating power of all tags, which is an indicator of reading performance. The main purpose of this article is to optimize the reading performance of multitag by embedding deep learning, while the reading distance of multitag changes with the 3-D geometric structure. Dynamic multitag image deblurring based on multiscale convolutional neural network (MCNN) improves image restoration ability and clarity. Also, tag detection from the estimated image via YOLOv3 improved by feature enhancement (YOLOv3_f) can improve the detection ability of small size targets, and mean average precision (mAP) is increased by 16.4%. Finally, the 3-D coordinates of tags in pixel space are converted into 3-D coordinates of world space by a quaternion. Comparing our system with the positioning method without deblurring, the 3-D coordinate structures are tested in the dynamic measurement system. The experimental results show that the reading performance of the designed RFID system has been greatly improved as the number of tags increases. Our scheme can improve the reading distance of multitag from the physical structure and the anticollision ability of the RFID system.