Guo, YongxingHu, ZhaoXiong, LiZhou, Xinglin...
8页查看更多>>摘要：Accurate measurement of bolt force condition is essential for safe operation of industrial infrastructures. We propose a novel bolt force sensor based on fiber Bragg grating (FBG) with features of quasi-distributed sensing and anti-torque interference. The sensor consists of three strain measurement units and a temperature compensation unit, and a miniature bearing-based anti-torsion structure is applied to the strain measurement unit to make it immune to torque. The manufactured sensor was embedded into the bolt to obtain a smart bolt with capabilities of strain and temperature sensing, and relevant performance tests were carried out. Experimental results showed that the sensitivities of the sensor are 5.564 pm/KN, 6.405 pm/KN, 6.777 pm/KN in the measurement range of 25 KN, respectively. Moreover, the sensor has good quasi-distributed measurement capability, and performs well in terms of creep and torque resistance. In practice, the number of measurement units can be selected as required.
原文链接:
NSTL
Elsevier
Zhang, LuCheng, XiaoxiangWu, GangWang, Tianyu...
28页查看更多>>摘要：Damage information is important for bridge condition assessment and maintenance. Extensive research has been conducted to extract this information from the responses of bridges (e.g., displacement and strain). However, among these methods, the responses of intact bridges are required for damage identification, which is difficult to acquire for most existing bridges. For such circumstances, a reference-free damage identification method for highway continuous girder bridges is presented in this paper, which takes advantage of long-gauge fibre Bragg grating strain sensors. A 1:10 indoor model experiment is conducted to verify the practicability of the method, which is effective under various damage and vehicle parameters. The extents of damage identification errors can reach 50% because of experimental errors. Furthermore, the number of bridge spans and road surface roughness are proven to have no effect on the method with a bridge-vehicle coupling system, and the extents of damage identification errors are below 10%.
原文链接:- NSTL
- Elsevier
Kanoun, OlfaKallel, Ahmed YahiaFendri, Ahmed
14页查看更多>>摘要：The rising use of capacitive sensors imposes the need of numerous measuring circuits with different characteristics. Stray fields and conductance losses are thereby key influencing factors that must be taken into account. In this paper, we provide an actual overview of capacitance measurement circuits considering well-known and modern measurement methods, such as lock-in amplifier, relaxation methods, and Martin-based oscillators as well as completely novel classes of capacitance measurement circuits converting the capacitance value directly to digital signals via sigma-delta and dual-slope converter circuit architectures. We classify the capacitance measurement circuits into six categories and address their properties and implementation aspects and compare their performance in a wide the capacitance range. The comparison shows that immunity to stray capacitances and conductive losses is not always given. Capacitance-to-Voltage, Auto-Balancing Bridge, and Capacitance-to-Digital show the best performance in this aspect and are therefore relevant for use in dielectric spectroscopy.
原文链接:- NSTL
- Elsevier
Zheng, ShuaikangLi, ZhitianYin, YuanliLiu, Yunfei...
8页查看更多>>摘要：The relative position and orientation estimation is one of the most fundamental components for multi-robot systems, while it still remains an open and challenging research topic in infrastructure-free environments. In this paper, a novel graph optimization and UWB range based relative positioning and orientation estimation framework is proposed, which improves the estimation performance with a sliding window for multi-robot system in anchor-free and GNSS-denied environment. Single shot estimation capability of relative position and orientation benefits from the "single robot - multi tags " structure, which greatly improves the robustness and adaptability of the system. Real-site experiments demonstrates that our system can achieve centimeter-level relative positioning performance, and the influence of distance between nodes and the number of nodes on system performance is fully discussed through simulation, which lays a comprehensive preparation for future practical application.
原文链接:- NSTL
- Elsevier
Wang, GuoweiLu, WenshengYuan, ChengWang, Ying...
13页查看更多>>摘要：Shallow cable is the component of cable-supported glass roof systems, which has been widely used in modern building constructions. In this research, a vision-based method is proposed for estimating tension values of shallow cables subjected to harmonic excitations. To validate the accuracy of the proposed low-cost, easy-tooperate, and multipoint synchronous measurement method, vision-based results are compared with the data obtained from contact sensors, and the error is within 2%. In addition, the data-driven stochastic subspace identification (Data-SSI) is employed to identify the first-order modal shapes of the shallow cable by vision-based data, and the results have a precise match with the computed shape of the numerical analysis. To investigate the practicality of the proposed method, the uncertainty evaluation for shallow cable tensions obtained by visionbased data is conducted based on the Monte Carlo method (MCM). These results demonstrate that the method proposed in this research is effective for capturing vibrational properties and estimating shallow cable tension.
原文链接:- NSTL
- Elsevier
Zhao, HengJu, JianzhongYe, ShuyuanLi, Xuan...
11页查看更多>>摘要：Piezoelectric transducer (PT) is the key component in power ultrasonics. Its vibration amplitude directly reflects the performance of the transducer. The real time measurement of amplitude is seldomly reported and difficult to be realized due to the high frequency and confined space to accommodate a sensor. Currently, there are no viable solutions for monitoring the amplitude when the tool is engaged in the material. We present a real time, low-cost amplitude monitoring strategy of the PT, incorporating voltage, current and resonant frequency. The piezoelectric and wave transmission equation are combined with the displacement and force boundaries. The displacement amplitude of the PT is predicted by the established numerical model based on the voltage, current and resonant frequency. Validating experiments are conducted and experimental results demonstrate that the amplitude measurements have a good agreement with the mathematic simulation, which has confirmed the validity of the proposed technique.
原文链接:- NSTL
- Elsevier
Ahmed, Maznah binti lliyasAdam, AnbiaHatem, NoorMemon, Danish Ali...
14页查看更多>>摘要：Manufacturing Metrology is a vital aspect of the sophisticated industrial 4.0-based manufacturing industry, as practically everything machined with certain metrological systems has to be measured or inspected. The Internet of Things (IoT) is a critical technology for industry 4.0 development. Furthermore, modern industrial devices should communicate via local (edge) and cloud computing servers. The Message Queuing Telemetry Transport (MQTT) protocol intends to increase the performance for sending/receiving roundness holes' data measuring from /to the server-based cloud. An error in its roundness mainly involves the inspection of circular portions. Roundness errors generate assemblies, lubricant distribution, and rotational force creation challenges. This study proposed applying the 3SMVI system and validating the system's by utilising the minimum zone circle tolerance algorithm to provide the precise error value and determine the roundness circle's error between the five circles. Hence, the approach is currently used for measuring the roundness circle error in the camera industry throughout the manufacture of components. The experiment was conducted using the smart system based on interpreted STEP-NC files for machine vision inspection (3SMVI) for non-contact and Coordinate Measuring Machine (CMM) for contact approaches by comparing the results. The Contact Measurement Method (CMM) is one of the most precise and time-consuming ways to inspect a round object for imperfections. The article validates the development of the 3SMVI system based on IoT architecture by utilising image processing technologies to measure errors in the circular roundness that can overcome these difficulties. The findings of both approaches showed a difference between 4.6 mu m and 9.6 mu m. However, Precession can be enhanced by a high-resolution camera with the right light.
原文链接:- NSTL
- Elsevier
Wang, KanWang, Dai-HuaYuan, GangBao, Li-Ping...
17页查看更多>>摘要：Because of small depth of field and field of view of microscopic vision system in microassembly system, the trans scale microparts and microgripper jaws can not be observed and described simultaneously, which limits microassembly of trans-scale microparts. Focusing on simultaneously obtaining global morphologies and local features of trans-scale microparts and microgripper jaws in microassembly space with high precision and realizing digital microassembly, this paper presents a principle of digitalization of microassembly space that can transform the microassembly space containing trans-scale microparts and microgripper jaws into digital microassembly space expressed by 3D point cloud. By using the obtained digital microassembly space, the trans scale microparts and microgripper jaws in microassembly space can be observed and described, their global morphologies and local features can be simultaneously obtained and digitally measured with high accuracy, and their positions and orientations can be estimated for realizing their digital microassembly.
原文链接:- NSTL
- Elsevier
Liang, FulaiLou, HaoZhang, YangLv, Hao...
15页查看更多>>摘要：Radar-based life imaging technology has been widely applied in both civilian and military applications. Wall penetration attenuation degrades the signal-to-clutter-and-noise ratio (SCNR) and radar portability restricts the spatial resolution of the high-dimensional image. In this study, we constructed a portable linear-frequency continuous-wave (LFMCW) multiple-input multiple-output (MIMO) radar system, and we presented a novel high-dimensional imaging framework. We combined the maximum spectrum peak, fourth-order cumulant (FOC) and 3D coherent factor (CF) to enhance vital signs based on attention mechanism. We improve resolution by deconvolution algorithm using the data from a human dummy. Visualization-enhanced 4D point clouds images were created by mapping micro-doppler-frequency to color. We employed a series of experiments to validate the proposed method, including human and beagle imaging in free space, and short-range and long-range (16 m) human imaging through a wall. These high-dimensional imaging results validated the portable radar system's potential in detection, identification, interpretation of human targets.
原文链接:- NSTL
- Elsevier
Davis, Benjamin T.Bryant, Brianna, IFritz, Stacy L.Handlery, Reed...
9页查看更多>>摘要：Measuring gait parameters (e.g. speed, cadence, step duration) accurately is invaluable for evaluation during treatment of older adults who struggle with disability onset, disease progression, balance, and injurious falls. Traditionally stopwatches or timing gates are used to measure gait speed in clinical settings, and these are limited to measuring gait speed. Other wearable and non-wearable technologies offer the ability to measure additional gait parameters though patients are known to walk differently with the devices and even tend to slow down before engaging with a non-wearable such as a floor mat. Floor vibrations are a promising option to measuring gait parameters while not being intrusive and not requiring line-of-sight to the patient for measurements. This paper presents methodology for extracting gait parameters using vibrations with comparisons to APDM Wearable Technologies Mobility Lab sensors and stopwatch measurements. Performance is examined across 97 participants for self-selected speed forward, full speed forward, and backwards walks at three different testing sites for a total of 1039 walks. Gait speed vibrations measurements demonstrated excellent reliability with APDM Mobility Lab (ICC: 0.98; 99% CI: 0.01 +/- 0.01 m/s) and stopwatch (ICC: 0.97; 99% CI: -0.01 +/- 0.01 m/s) measurements. Similar excellent results are reported for cadence, gait cycle duration, step duration, and stride length parameters.
原文链接:- NSTL
- Elsevier
