To see the other types of publications on this topic, follow the link: Dynamic weighing method.
Journal articles on the topic 'Dynamic weighing method'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Dynamic weighing method.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Yin, Rong Sen, and Jia Qiang Yang. "A Dynamic Voltage Compensation Method for Improving Weighing Accuracy." Applied Mechanics and Materials 333-335 (July 2013): 317–21. http://dx.doi.org/10.4028/www.scientific.net/amm.333-335.317.
Full textAbstract:
In order to eliminate the measurement error caused by working voltage fluctuation of weighing sensor, a dynamic voltage compensation method for improving the weighing accuracy was proposed in the paper. The method takes strain gauge type pressure sensor as the weighing sensor and corrects Wheatstone bridge circuit. By synchronously detecting output voltage signal and working voltage of the weighing sensor, the method dynamically compensates the working voltage fluctuation of the weighing sensor, corrects the measurement error caused by the voltage fluctuation of external source and calculates the weight in real time. A weighing system based on the digital signal processor (DSP) was designed. Results of simulation experiment verify the feasibility of the proposed method.
2
Wang, Yan Xia, Chun Hui Bao, and Chun Ling Fan. "Research of Dynamic Weighing System Based on Multi-Sensor Data Fusion Technology." Advanced Materials Research 721 (July 2013): 479–82. http://dx.doi.org/10.4028/www.scientific.net/amr.721.479.
Full textAbstract:
The multi-sensor data fusion techniques is discussed in dynamic weighing system based on the data measured from ultrasonic sensors, speed sensors, capacitive sensors and load cells. This new method can greatly increase the measure precision of the dynamic weighing systems, at the same time it can effectively reduce noise, vibration, electromagnetic interference and other environmental factors on the influence of dynamic weighing system measurement. Judging from the simulation result, this new method proves to be more accurate and stable than ordinary processing methods.
3
Jiang, Qing, Xiao Qian Shen, Jin Hui Cai, and Yan Yao. "Application of RBF Neural Network in Dynamic Weighing." Advanced Materials Research 383-390 (November 2011): 1495–99. http://dx.doi.org/10.4028/www.scientific.net/amr.383-390.1495.
Full textAbstract:
In order to improve the dynamical respond of the weighing system and to meet the demand of rapid weighing, a new method based on radial basis function neural network (RBFNN) is introduced in this paper. The dynamic system is described as a network and the output values of steady state are predicted by an on-line modeling before the platform has settled to the steady state. The sample weight is calculated according to weighted moving average. The experimental results proved that the neural network method in this paper can be used to effectively reduce the weighing time and to increase the accuracy simultaneously.
4
An, Jianqi, Fayang You, Min Wu, and Jinhua She. "Iterative Learning Control for Nonlinear Weighing and Feeding Process." Mathematical Problems in Engineering 2018 (December 20, 2018): 1–9. http://dx.doi.org/10.1155/2018/9425902.
Full textAbstract:
Due to the nonlinear dynamics in weighing and feeding process, it is difficult to achieve high accuracy with conventional control methods. This paper uses a piecewise linearization method for the nonlinear problem and discusses the application of iterative learning control in weighing and feeding process. First, the nonlinear problem and the repeatability are discussed based on dynamic analysis of weighing and feeding process. Next, a linear state space model is established with a piecewise linearization method. Then, an iterative learning controller is presented by utilizing repetitive characteristics, and the controller parameters are obtained by using a multi-objective optimization method. Finally, simulation results show that the presented control method improves the control performances and the accuracy of feeding.
5
Mao, Xiaohui, Liping Fei, Xianping Shang, Jie Chen, and Zhihao Zhao. "A fuzzy evaluation method of road vehicle automatic weighing instrument in dynamic force metrological performance." International Journal of Applied Electromagnetics and Mechanics 64, no. 1-4 (December 10, 2020): 1365–72. http://dx.doi.org/10.3233/jae-209455.
Full textAbstract:
The measurement performance of road vehicle automatic weighing instrument installed on highways is directly related to the safety of roads and bridges. The fuzzy number indicates that the uncertain quantization problem has obvious advantages. By analyzing the factors affecting the metrological performance of the road vehicle automatic weighing instrument, combined with the fuzzy mathematics theory, the weight evaluation model of the dynamic performance evaluation of the road vehicle automatic weighing instrument is proposed. The factors of measurement performance are summarized and calculated, and the comprehensive evaluation standard of the metering performance of the weighing equipment is obtained, so as to realize the quantifiable analysis and evaluation of the metering performance of the dynamic road vehicle automatic weighing instrument in use, and provide data reference for adopting a more scientific measurement supervision method.
6
Zhang, Wei, Chun-li Li, Xiao-feng Di, Mi Chen, and Sheng Tao. "Research on Automotive Dynamic Weighing Method Based on Piezoelectric Sensor." MATEC Web of Conferences 139 (2017): 00203. http://dx.doi.org/10.1051/matecconf/201713900203.
Full text
7
Paik, J. S., K. W. Lim, and K. B. Lee. "Calibration of Coriolis mass flowmeters using a dynamic weighing method." Flow Measurement and Instrumentation 1, no. 3 (April 1990): 171–75. http://dx.doi.org/10.1016/0955-5986(90)90007-t.
Full text
8
He, Hui-Mei, Pingjie Huang, Dibo Hou, Wen Cai, Zhe Liu, and Guangxin Zhang. "An Intelligent Signal Processing Method for High-Speed Weighing System." International Journal of Food Engineering 9, no. 2 (May 10, 2013): 179–86. http://dx.doi.org/10.1515/ijfe-2012-0019.
Full textAbstract:
AbstractThe dynamic weighing signal processing method in high-speed fruits sorting system directly affects the weighing accuracy. This paper describes a basic modeling method for time series, including modeling, order determining, applicability analysis, and prediction. Considering the structural characteristics of weighing system and the limit of PLC sampling speed, a modified auto-regressive (AR) model for stable value prediction of the high-speed weighing signals is presented. Meanwhile, a simulation base on Matlab platform and an implementation example are used to test the method performance. At last, the impacts of environmental changes, sorting speeds, fruits shapes, and sizes on the method performance are discussed. In experimental conditions, this method can be applied to fruits sorting system with sorting speed up to 18 per second for standard fruit (smooth round surface without defects) and an acceptable weighing accuracy can be obtained.
9
Feng, Ningning, Xi Kang, Haoyuan Han, Gang Liu, Yan’e Zhang, and Shuli Mei. "Research on a Dynamic Algorithm for Cow Weighing Based on an SVM and Empirical Wavelet Transform." Sensors 20, no. 18 (September 18, 2020): 5363. http://dx.doi.org/10.3390/s20185363.
Full textAbstract:
Weight is an important indicator of the growth and development of dairy cows. The traditional static weighing methods require considerable human and financial resources, and the existing dynamic weighing algorithms do not consider the influence of the cow motion state on the weight curve. In this paper, a dynamic weighing algorithm for cows based on a support vector machine (SVM) and empirical wavelet transform (EWT) is proposed for classification and analysis. First, the dynamic weight curve is obtained by using a weighing device placed along a cow travel corridor. Next, the data are preprocessed through valid signal acquisition, feature extraction, and normalization, and the results are divided into three active degrees during motion for low, medium, and high grade using the SVM algorithm. Finally, a mean filtering algorithm, the EWT algorithm, and a combined periodic continuation-EWT algorithm are used to obtain the dynamic weight values. Weight data were collected for 910 cows, and the experimental results displayed a classification accuracy of 98.6928%. The three algorithms were used to calculate the dynamic weight values for comparison with real values, and the average error rates were 0.1838%, 0.6724%, and 0.9462%. This method can be widely used at farms and expand the current knowledgebase regarding the dynamic weighing of cows.
10
Liu, Qin Xian, Wei Lv, and Wei Bing Bao. "The Application of EMD and Genetic Neural Network Algorithm to the Dynamic Weighing System for Loader." Applied Mechanics and Materials 135-136 (October 2011): 1002–6. http://dx.doi.org/10.4028/www.scientific.net/amm.135-136.1002.
Full textAbstract:
The output signal of pressure sensor installed in the dynamic weighing system for loader contains strong vibration, noise, nonlinear signal. The accuracy of the dynamic weighing system is closely related to the pressure signal. An empirical mode decomposition (EMD) algorithm is proposed to preprocessing the signal contaminated. The real weighing signal is filtered out. a new method based on neural network is used to predicate the nonlinear output. in order to solve the problem that it was easily to sink into the partial minimum , the genetic algorithm was put forward .The emulation analysis and the results show that by using the above method, measure precision within 1% can be obtained.
11
Zhao, Li Bo, Jian Qiang Liang, Yu Long Zhao, Jian Zhu Wang, Wei Chen, Yong Li, and Zhuang De Jiang. "Analysis and Research of Piezoelectric Dynamic Weighing Sensor." Key Engineering Materials 483 (June 2011): 643–46. http://dx.doi.org/10.4028/www.scientific.net/kem.483.643.
Full textAbstract:
The Kistler company has invented piezoelectric dynamic weighing sensors which are applied to determine dynamically axle load, speed and gross weight of the vehicle based on piezoelectric effect of quartz crystal. They mainly consist of load-carrying beams and sensitive elements. Focusing on the control of preload in design and fabrication, finite element method (FEM) is applied with ANSYS software to optimize structural sizes. The influence curve of the structural dimensions of load-carrying beam on the preload is analyzed. With the piezoelectric coupling analysis function, the preload influence on the sensor sensitivity is researched. FEM simulation results show that the critical dimensions of load-carrying beam as well as the deformation and wall thickness of cavity have significant impact on the preload. Further studies show that the sensor has the highest sensitivity with the reasonable deformation and wall thickness of the cavity. In this paper, a sensor with range of 150 kN has the highest sensitivity at the wall thickness of 2 mm and the deformation of 0.14 mm.
12
Zhu, Jie Bin, Gao Hua Liao, and De Hui Liu. "Multifunction Intelligent Dynamic Weighing System Based on Embeded Computer." Applied Mechanics and Materials 448-453 (October 2013): 3641–44. http://dx.doi.org/10.4028/www.scientific.net/amm.448-453.3641.
Full textAbstract:
A weighing instrument system embedded multifunctional intelligent has been developped, and a compensation method proposed to improve the measurement accuracy of the system performance. Weighing instrument took embedded computer as the core, used the logic processing of the powerful FPGA, USB interface data communication function connecting to the PC machine to build host/slave system. Dynamically compensate in the series compensation link to solve the system of nonlinear strength, poor dynamic performance of sensor, short the time to reach the steady state for the whole measurement system. Results show that the system is suitable for the requirement of fast measurement, effectively improve the accuracy and reliability.
13
Sarnecki, Rafał, Wojciech Wiśniewski, Wiktor Ślusarski, and Piotr Wiłkojć. "Traceable calibration of automatic weighing instruments operating in dynamic mode." MATEC Web of Conferences 182 (2018): 02005. http://dx.doi.org/10.1051/matecconf/201818202005.
Full textAbstract:
This article describes calibration method of automatic weighing instruments for measuring vehicles in motion. These measuring instruments in future will be widely used to determine the axle loads, if applicable the axle-group and vehicle mass of road vehicles when the vehicles are weighed in motion. For several years, some activities have been carried out on the weight control system that determines the mass of vehicles moving at higher speeds, called HS-WIM. The implementation of such systems will affect both the improvement of road safety and indirectly limit the number of road users moving by overloaded vehicles.
14
Plyaskin, Andrei, Nikolai Belov, Nikolai Yugov, Artem Ryshkov, Aleksei Yugov, and Nina Matskevich. "Research of brick dynamic strength when subjected to shock loading by method of computer modelling." EPJ Web of Conferences 221 (2019): 01041. http://dx.doi.org/10.1051/epjconf/201922101041.
Full textAbstract:
The study represents the mathematical model of distorting and destruction of ordinary brick and masonry when subjected to shock-wave loadings. The research of the impact dynamic strength of the masonry's two fragments to the steel drop-weight of 1-2 m, weighing 197-1000 kg, was conducted by using the method of the computer modelling.
15
Zhu, Jing Fei, Shao Jie Xu, and Yong Wei Li. "The System Design of Granular Bulk Materials Continuous Conveyor Weighing Measurement." Applied Mechanics and Materials 345 (August 2013): 145–49. http://dx.doi.org/10.4028/www.scientific.net/amm.345.145.
Full textAbstract:
For continuous transportation of granular bulk materials measurement and weighing is important link in industrial and agricultural production, warehousing and product flows. Improve said heavy of precision and speed is the key of dynamic measurement, and traditional for the continuous delivery of materials weighing system can not meet the requirements of quickly weighed and measured accurately, while sometimes variable, and nonlinear and random, factors in actual process in the of interference, in order to overcome these factors on continuous conveying material measurement system of effect, this article based on RBF Neural network model for foundation made a dynamic clustering algorithm optimization strategy.By means algorithm calculated the center of the base function, further extended RBF Neural network constants from hidden layer to output layer , then using least-squares method calculates the weight matrix to determine the final network structure and main parameters. This article on measurement of dynamic process has simulation test research, and BP neural network for effect comparison, simulation results indicates that, based on RBF of neural network on continuous conveying bulk material measurement control system is more effective, and weighing accuracy and speed is improved, in order to achieve the continuous delivery of materials weighing process optimization control, and at the same time provides an effective way to solve the existing problems of this type of system.
16
Chen, Yong Xiang, Jin Biao Liu, and Nan Zhang. "Research on Supply Chain Network System Based on Industrial Cluster." Applied Mechanics and Materials 587-589 (July 2014): 1907–11. http://dx.doi.org/10.4028/www.scientific.net/amm.587-589.1907.
Full textAbstract:
The reliability of supply chain network system design and optimization based on the industrial cluster was discussed, that is, the operational platform of multi-objective supply chain network was moved to industrial cluster, so the platform has the effects of both regional radiation and scale of economy. Instead of some static research methods such as former traditional mathematic planning, systematic and dynamic analysis, this paper put forward a coordinative mechenism construction, this mechenism used dynamic simulation method which combined the supply chain system with industrial cluster multi-objective weighing in the region, the mechenism should be cost efficient and satisfy the application in the industrial cluster radiation region, the mechenism should integrate all possible resources in the industrial cluster and consider heterogeneity, layout, nonlinear, limitation and dynamics of the supply chain network system.
17
Mitsuta, Shinji, Kazuto Seto, Hiroyuki Ito, and Akio Nagamatsu. "Vibration and Motion Control of Flexible Structures by Hybrid Dynamic Absorber(Influence of Vibration System with Nonlinear Element)." Journal of Robotics and Mechatronics 6, no. 3 (June 20, 1994): 230–36. http://dx.doi.org/10.20965/jrm.1994.p0230.
Full textAbstract:
Recently, the necessity for making machines weighing less and operating at high speeds has increased. This paper is concerned with vibration and motion control by a control system which combines a servo controller and a hybrid dynamic absorber. In our method, vibration control and motion control are designed independently. First, the dynamics of a tower structure and a servo motor are modeled. Then, it is shown experimentally that although vibration control by the servo controller alone causes instability due to nonlinear elements such as friction or rattle, the hybrid dynamic absorber does not easily cause this sort of instability. On the comparison of vibration control effect and control force, the hybrid dynamic absorber requires less force. Finally, to know the effect of the new method, we evaluated the motions (triangular wave and sine wave) of the flexible structure. The effectiveness of this vibration and motion control method for the flexible structure was demonstrated by simulations and experiments.
18
Tukhvatullin, Rustam Rashidovich, and Alexey Valentinovich Shchelchkov. "Modern trends in the design of modules of national standards for units of volume fluid flow rate (volume) in the range from 10–5 to 103 ml/min." Izmeritel`naya Tekhnika, no. 7 (2021): 32–41. http://dx.doi.org/10.32446/0368-1025it.2021-7-32-41.
Full textAbstract:
In the context of the needs of the leading sectors of the world economy, the current state of metrological support for measuring units of mass and volume of a liquid in a flow, mass and volume flow rates of a liquid in the range of micro-flow rates of 10–5–103 ml/min is considered. Based on the results of the analytical review, the main metrological and operating characteristics of national standards are presented. The basic principles of generating a fluid flow in national gravimetric and volumetric standards when measuring the mass and volume of a fluid by the dynamic weighing method have been determined. Constructive solutions and principles of operation of key modules of national standards are considered. Methods for filling a liquid into a storage tank and designs of storage tanks are determined, taking into account the minimization of the effect of liquid evaporation, the influence of capillary force and buoyancy. The main sources of uncertainty in measuring the mass and volume of a liquid by the dynamic weighing method and methods for minimizing these uncertainties are considered. A modified model of dynamic measurement of liquid mass flow rate is proposed, taking into account the main sources of uncertainty. A comparative assessment of the influence of sources of uncertainty on the metrological characteristics of national standards is presented.
19
Chan, Bin-Da, Kutay Icoz, Wanfeng Huang, Chun-Li Chang, and Cagri A. Savran. "On-demand weighing of single dry biological particles over a 5-order-of-magnitude dynamic range." Lab Chip 14, no. 21 (2014): 4188–96. http://dx.doi.org/10.1039/c4lc00765d.
Full textAbstract:
A method to weigh individually selected biological microparticles over a dynamic range of 30 pg to 2.4 μg. The figure shows a single pollen grain specifically picked and placed on the left-hand cantilever for weighing; on the right-hand cantilever is a bead used as a reference.
20
Zhang, Jianyi, Yibin Ying, Huanyu Jiang, Haijun Wang, Chunwei Yang, Yonghua Yu, and Jianping Wang. "Application of Optimized Digital Filters and Asymmetrically Trimmed Mean to Improve the Accuracy of Dynamic Egg Weighing." Transactions of the ASABE 60, no. 4 (2017): 1099–111. http://dx.doi.org/10.13031/trans.11693.
Full textAbstract:
Abstract. Rolling poultry eggs through a weighing rail is a simple, fast, and efficient way to measure mass. However, disturbances generated primarily by the rolling eggs vary with the rolling state and speed as well as with the egg mass and shape. These disturbances distort the load cell signal in the form of a stochastic strong amplitude fluctuation, and eliminating these fluctuations completely is a difficult task. A piezoelectric accelerometer was used to measure the vibration disturbances. The smoothed pseudo-Wigner-Ville distribution (SPWVD), which is a type of time-frequency analysis, was used to analyze the vibration disturbances using the accelerometer data. The results indicated that the disturbances were non-stationary, and the frequency characteristics were time-varying. Preliminary experiments showed that the commonly used low-pass filtering and subsequent average-based mass estimation method (AME) did not result in a satisfactory weighing accuracy. To meet the requirement of fast and accurate dynamic weighing of eggs, this research proposed a sorting-based mass estimator (SME) that consisted of an optimized digital filter and asymmetrically trimmed mean. The SME regarded the mass measurement as a problem of location estimation of non-Gaussian and heavy-tailed random variables, given the short observation time and the presence of outliers (disturbances). Four types of digital filters in the SME were selected to pre-filter the load cell data. The relevant parameters of the digital filters and asymmetrically trimmed mean in the SME were optimized using a grid search. Experimental results showed that the proposed SME effectively improved the weighing accuracy, and almost all of the egg weighing errors were less than 1 g with a processing speed of up to 5 eggs s-1. Compared with the AME, the overall mean error was reduced by approximately 86% to 93%, and the overall standard deviation of the error (SDE) was reduced by approximately 41% to 50%. Keywords: Asymmetrically trimmed mean, Digital filters, Dynamic weighing, Egg mass, Time-frequency analysis.
21
Wang, Ying, Lingyu Kong, Xinjun Yang, Ya Xu, and Feng Xu. "Research on Key Technologies of Powdery Material Dynamic Buoyancy Weighing System Based on Comparative Compensation Method." Journal of Physics: Conference Series 1213 (June 2019): 052097. http://dx.doi.org/10.1088/1742-6596/1213/5/052097.
Full text
22
Xu, Qian Yu, Yu Qin, Juan Li, Hui Hui Zheng, and Fa Wu Yang. "Weigh-in-Motion Data Fitting Based on Least-Squares Method." Applied Mechanics and Materials 135-136 (October 2011): 1123–28. http://dx.doi.org/10.4028/www.scientific.net/amm.135-136.1123.
Full textAbstract:
The dynamic weighing technology is multi-domain comprehensive technology, including the mechanics of materials, dynamics, the technology of sensor, the technology of electronic information and so on. Vehicle weigh-in-motion system is a detection system which is used to measure the weight of the moving vehicle. With the development of the transport industry output and commercial trade, Vehicle weigh-in-motion technology is playing a more and more important role. At the same time, the accuracy of the weigh-in-motion data has become the centre of attention. In this paper, use the method of least square and polynomial fitting and the MATLAB mathematical software, by studying and analyzing a mass of weigh-in-motion data，the fitting curve of the vehicle weigh in different speeds is obtained. According the variation law of fitting curve, further improvement need to do in certain standard and weigh carefully as to the true quality when the vehicle is in some speed region.
23
Xu, Ming, Hui Qin Zhang, Qian Zhou, and Zhe Sheng. "Research on the Method of Code Migration from JSP to ASP.NETMing." Advanced Materials Research 756-759 (September 2013): 1334–38. http://dx.doi.org/10.4028/www.scientific.net/amr.756-759.1334.
Full textAbstract:
The JSP and ASP.NET are two common dynamic web technology, both can be embedded into HTML. But each of them has advantages and disadvantages in using and has many differences in nature. How to weigh them and searching for the most accurate and rapid migration plan being the focus we should think about seriously. This article puts forward three methods of code migrations from JSP to ASP.NET Entire code transform migration, Reserved migration and Neutral migration. Additionally, that can obtain the best transplantation method by weighing these pros and cons as well as the performances of the program after migration.
24
Sagdeev, D. I., I. M. Abdulagatov, N. K. Nikulin, and V. I. Tyulkin. "MODERNISED DESIGN OF A HYDROSTATIC DENSIMETER FOR MEASURING DENSITY OF HIGHLY VISCOUS OILS." Herald of Dagestan State Technical University. Technical Sciences 46, no. 4 (January 2, 2020): 42–52. http://dx.doi.org/10.21822/2073-6185-2019-46-4-42-52.
Full textAbstract:
Objectives. The aim of this work is to modernise a VT-KHTI densimeter operated by the method of hydrostatic weighing in order to study the density of highly viscous oils and oil products in the temperature range from 293 K to 473 K at atmospheric pressure.Method. Among the many methods for studying density, the following were used in the course of the study: the constant- and variable-volume piezometer method and the method of hydrostatic weighing.Results. The results of the densimetric study of highly viscous oils obtained from the Republic of Tatarstan in the temperature range from 293 K to 473 K at atmospheric pressure. The following grades are presented: Ashalchinskaya oil (super-viscous, SVO); Kuakbash oil (sulphur), Kichuy oil and Devon oil. Following an analysis and selection of methods for measuring density, a technique for error estimation and densimeter calibration is presented. A calculated expression for the hydrostatic weighing method, derived from the modernised hydrostatic densimeter design for measuring the density of highly viscous oils, is presented.Conclusion. The VT-KHTI densimeter for vacuum working fluids has been modernised and calibrated for research work on measuring the dynamic viscosity coefficient of both Newtonian and non-Newtonian liquids.
25
Hao, Tianzhi, Zhengyuan Xie, and Mengsheng Yu. "The identification technology of vehicle weight based on bridge strain time-history curve." Advances in Structural Engineering 22, no. 7 (January 10, 2019): 1606–16. http://dx.doi.org/10.1177/1369433218823487.
Full textAbstract:
It is the basic characteristics of bridge weigh-in-motion technology to directly identify the vehicle weight based on the bridge dynamic response. At present, bridge weigh-in-motion technology tends to be mature in identification of gross vehicle weighing, but there is no breakthrough in identification of single-axle weighing. Therefore, a new axle-weight identification method is proposed using bridge weigh-in-motion technology in this article, in which the idea of bridge weigh-in-motion technology is introduced first. The numerical expression of the single-axle weight and the identification expression of axle space and vehicle speed are presented thereafter. Furthermore, the accuracy of the presented method is further reinforced through a series of practical model experiments of simply supported and continuous beam. The experimental result indicated that the proposed method is feasible in practical application.
26
Sil'chenko, Ol'ga, Marina Siluyanova, and Petr Hopin. "INVESTIGATIONS OF DENSITY AND POROSITY OF COATINGS MADE OF CERAMIC-POLYMERIC OR COMPOSITES WITH QUASI-CRYSTALS OBTAINED WITH GAS-DETONATION METHOD AND METHOD OF GAS-DYNAMIC SPUTTERING." Bulletin of Bryansk state technical university 2020, no. 7 (June 28, 2020): 4–11. http://dx.doi.org/10.30987/1999-8775-2020-7-4-11.
Full textAbstract:
The work purpose consists in the development of the procedure for density and strength definition through the method of hydro-static weighing in relation to titanium carbonitride-based coatings.
The development object – quasi-crystals based titanium carbonitride clad with nickel. Novelty and urgency of this work are based on the creation of polymeric antifriction materials intended for operation in the mode of hydro-dynamic friction. Frictionless and slider bearings with anti-friction coatings are the most efficient structures allowing the considerable increase of capacity and reliability of friction unit operation in machinery.
There are presented microstructure photos of coatings obtained with the method of gas-dynamic sputtering.
As a result of the technology developed it is defined that at the base a coating has the VN20 coarse-grain which has maximum parameters of static strength (bending, tearing and adhesion strength) at the expense of its structure and coarse grain.
As we move forward from the layer adjoining the base to the operation one of the coating we observe the decrease of structure grain (from 100 to 15 mkm) and a gradual change of the composition, micro-hardness increase.
As a result a carrying layer of KNTP35 coating has maximum parameters of long strength at the expense of a fine-grain structure and composition. It is characterized with increased resistance to thermal blow, tacking, spalling and higher impact elasticity and wear-resistance.
In the paper there is offered a method of hydro-static weighing for the determination of density and porosity regarding coatings.
According to the optimum technological mode are made samples and their porosity and density are investigated.
27
Mahmoudi, Mohamadreza, Hannan Amoozad Mahdiraji, Ahmad Jafarnejad, and Hossein Safari. "Dynamic prioritization of equipment and critical failure modes." Kybernetes 48, no. 9 (October 7, 2019): 1913–41. http://dx.doi.org/10.1108/k-08-2018-0417.
Full textAbstract:
Purpose The purpose of this paper is to identify critical equipment by dynamically ranking them in interval-valued intuitionistic fuzzy (IVIF) circumstances. Accordingly, the main drawbacks of the conventional failure mode and effects analysis (FMEA) are eliminated. To this end, the authors have presented the interval-valued intuitionistic fuzzy condition-based dynamic weighing method (IVIF-CBDW). Design/methodology/approach To realize the objective, the authors used the IVIF power weight Heronian aggregation operator to integrate the data extracted from the experts’ opinions. Moreover, the multi-attributive border approximation area comparison (MABAC) method is applied to rank the choices and the IVIF-CBDW method to create dynamic weights appropriate to the conditions of each equipment/failure mode. The authors proposed a robust FMEA model where the main drawbacks of the conventional risk prioritization number were eliminated. Findings To prove its applicability, this model was used in a case study to rank the equipment of a HL5000 crane barge. Finally, the results are compared with the traditional FMEA methods. It is indicated that the proposed model is much more flexible and provides more rational results. Originality/value In this paper, the authors have improved and used the IVIF power weight Heronian aggregation operator to integrate information. Furthermore, to dynamically weigh each equipment (failure mode), they presented the IVIF-CBDW method to determine the weight of each equipment (failure mode) based on its equipment conditions in the O, S and D criteria and provide the basis for the calculation. IVIF-CBDW method is presented in this study for the first time. Moreover, the MABAC method has been performed, to rank the equipment and failure mode. To analyze the information, the authors encoded the model presented in the robust MATLAB software and used it in a real sample of the HL5000 crane barge. Finally, to evaluate the reliability of the model presented in the risk ranking and its rationality, this model was compared with the conventional FMEA, fuzzy TOPSIS method, the method of Liu and the modified method of Liu.
28
WANG, Wei. "Integrative modeling method based on empirical mode decomposition and least square support vector machines about dynamic weighing of loaders." Chinese Journal of Mechanical Engineering 44, no. 02 (2008): 87. http://dx.doi.org/10.3901/jme.2008.02.087.
Full text
29
Haap, Classen, Beringer, Mecheels, and Gutmann. "Microplastic Fibers Released by Textile Laundry: A New Analytical Approach for the Determination of Fibers in Effluents." Water 11, no. 10 (October 7, 2019): 2088. http://dx.doi.org/10.3390/w11102088.
Full textAbstract:
The detection of shedded fibers in effluents from textile washing has attracted much attention due to its reported contribution to microplastic pollution. Commonly used analytical methods for fiber detection in liquids are based on filtration with subsequent microscopic analysis and/or gravimetric weighing. These approaches are time-consuming and prone to errors. In this study, an approach based on dynamic image analysis was applied in order to set up an efficient method to analyze fibers in effluents from washing processes. In an initial validation step, reliable information on the counts of fibers and the morphological characteristics were confirmed. For wastewaters from polyester-cotton blends, the chemical nature of the fiber debris (natural vs. synthetic origin) was determined by combining the dynamic image analysis with a chemical pre-treatment. In this study, dynamic image analysis was revealed as a rapid, non-destructive, precise, and reliable technology for the characterization and quantification of the fiber debris, offering a promising approach for fiber analysis in liquids.
30
Wang, Wei, Zhi Wu Wang, Wan Li Zhong, Tao Song, and Yang Sen Hu. "Oxidation Behavior of a TP304H Stainless Steel in the High Temperature and High Pressure Water Vapor." Advanced Materials Research 652-654 (January 2013): 938–41. http://dx.doi.org/10.4028/www.scientific.net/amr.652-654.938.
Full textAbstract:
The feature, structure and composition of oxide films of a TP304H steel oxidized under 650°C and 25MPa water vapor for 1~50h were analyzed by SEM, EDS and XRD. The oxidizing dynamic curves were measured by discontinuous weighing method. The results indicated that the oxidation kinetics was agreement with the parabolic law. At the beginning of the oxidation, the formation of oxide was Fe2O3, while Fe3O4 and FeCr2O4 were formed with the increasing of oxidation time, without independent Cr2O3.
31
Ka'ka, Simon, and Festo Andre H. "Performance Effects of Shock Absorber and Spiral Springs Against Vertical Vehicle Expenses Weighing the Road Structure." INTEK: Jurnal Penelitian 7, no. 1 (October 20, 2020): 79. http://dx.doi.org/10.31963/intek.v7i1.2298.
Full textAbstract:
This study aims to examine more about the effect of vertical dynamic load of vehicles and changes in dimensional barriers on the road surface in its path. Experimentally this fluctuating load is replaced by a pneumatic force change based on the regulation of air pressure on the regulator. The deviations generated by the varying load work are measured by placing a proximity sensor along the spring movement. The amount of vertical load transformation reaches the road surface is measured by using Load cell. Characteristics of vertical dynamic vibration occurring due to several dimensional barriers, U (cm) obtained using mathematical modeling method with 2 DOF suspension system transfer function. The results showed a condition on the body and wheels of vehicles experienced a brief overshot for 0.14 seconds with deviation of 0.178 m. From the graph shows that the rate of deviation that occurs is large enough that Y2d = 1.03 m / s caused by a sudden shock that occurred on the wheels of the vehicle. This condition does not last long that is only duration t = 0.22 s, because the spring reaction force and shock absorber can absorb 25% vibration against the sprung and un-sprung vertical load of the vehicle.
32
Qin, Tianhao, Mengxiang Lin, Ming Cao, Kaiya Fu, and Rong Ding. "Effects of Sensor Location on Dynamic Load Estimation in Weigh-in-Motion System." Sensors 18, no. 9 (September 12, 2018): 3044. http://dx.doi.org/10.3390/s18093044.
Full textAbstract:
In recent years, weigh-in-motion systems based on embedded sensor networks have received a lot of attention. However, how to improve the accuracy of multi-sensor weigh-in-motion (WIM) systems while keeping costs low remains a challenge. In this paper, a numerical simulation method is presented to analyze the relationship between sensor location and the accuracy of static weight estimation. The finite element model of a WIM system is developed, which consists of three parts: a pavement model, a moving load model and two types of sensor models. Analysis of simulation results shows that the ability of sensing dynamic load is closely related to the installation depth of sensors and pavement material. Moreover, the distance between the moving wheel and sensors has a great impact on estimating performance. Gaussian curve fitting could be used to reduce weighing error within a limited range. Our work suggests that much more attention should be paid to the design of the sensor layout of a WIM system.
33
Stanković, Miomir, Željko Stević, Dillip Kumar Das, Marko Subotić, and Dragan Pamučar. "A New Fuzzy MARCOS Method for Road Traffic Risk Analysis." Mathematics 8, no. 3 (March 24, 2020): 457. http://dx.doi.org/10.3390/math8030457.
Full textAbstract:
In this paper, a new fuzzy multi-criteria decision-making model for traffic risk assessment was developed. A part of a main road network of 7.4 km with a total of 38 Sections was analyzed with the aim of determining the degree of risk on them. For that purpose, a fuzzy Measurement Alternatives and Ranking according to the COmpromise Solution (fuzzy MARCOS) method was developed. In addition, a new fuzzy linguistic scale quantified into triangular fuzzy numbers (TFNs) was developed. The fuzzy PIvot Pairwise RElative Criteria Importance Assessment—fuzzy PIPRECIA method—was used to determine the criteria weights on the basis of which the road network sections were evaluated. The results clearly show that there is a dominant section with the highest risk for all road participants, which requires corrective actions. In order to validate the results, a comprehensive validity test was created consisting of variations in the significance of model input parameters, testing the influence of dynamic factors—of reverse rank, and applying the fuzzy Simple Additive Weighing (fuzzy SAW) method and the fuzzy Technique for Order of Preference by Similarity to Ideal Solution (fuzzy TOPSIS). The validation test show the stability of the results obtained and the justification for the development of the proposed model.
34
CARVALHO NETO, J. A. DE, and L. A. C. M. VELOSO. "Weighing in motion and characterization of the railroad traffic with using the B-WIM technique." Revista IBRACON de Estruturas e Materiais 8, no. 4 (August 2015): 491–506. http://dx.doi.org/10.1590/s1983-41952015000400005.
Full textAbstract:
AbstractThe knowledge on the active moving load of a bridge is crucial for the achievement of the information on the behavior of the structure, and thus foresee maintenance, repairs and better definition of the logistics of its active vehicles. This paper presents the development of the algorithms for the application of the Bridge-Weigh In Motion (B-WIM) method created by Moses for the weighing of trains during motion and also for the characterization of the rail traffic, allowing the obtainment of information like passage's train velocity and number and spacing of axles, eliminating the dynamic effect. There were implemented algorithms for the determination of the data referring to the geometry of the train and its loads, which were evaluated using a theoretical example, in which it was simulated the passage of the train over a bridge and the loads of its axles were determined with one hundred percent of precision. In addition, it was made a numerical example in finite elements of a reinforced concrete viaduct from the Carajás' Railroad, in which the developed system reached great results on the characterization and weighing of the locomotive when the constitutive equation of the Brazilian Standards was substituted by the one proposed by Collins and Mitchell.
35
He, Yinshui, Daize Li, Zengxi Pan, Guohong Ma, Lesheng Yu, Haitao Yuan, and Jian Le. "Dynamic Modeling of Weld Bead Geometry Features in Thick Plate GMAW Based on Machine Vision and Learning." Sensors 20, no. 24 (December 11, 2020): 7104. http://dx.doi.org/10.3390/s20247104.
Full textAbstract:
Weld bead geometry features (WBGFs) such as the bead width, height, area, and center of gravity are the common factors for weighing welding quality control. The effective modeling of these WBGFs contributes to implementing timely decision making of welding process parameters to improve welding quality and enhance automatic levels. In this work, a dynamic modeling method of WBGFs is presented based on machine vision and learning in multipass gas metal arc welding (GMAW) with typical joints. A laser vision sensing system is used to detect weld seam profiles (WSPs) during the GMAW process. A novel WSP extraction method is proposed using scale-invariant feature transform and machine learning. The feature points of the extracted WSP, namely the boundary points of the weld beads, are identified with slope mutation detection and number supervision. In order to stabilize the modeling process, a fault detection and diagnosis method is implemented with cubic exponential smoothing, and the diagnostic accuracy is within 1.50 pixels. A linear interpolation method is presented to implement sub pixel discrimination of the weld bead before modeling WBGFs. With the effective feature points and the extracted WSP, a scheme of modeling the area, center of gravity, and all-position width and height of the weld bead is presented. Experimental results show that the proposed method in this work adapts to the variable features of the weld beads in thick plate GMAW with T-joints and butt/lap joints. This work can provide more evidence to control the weld formation in a thick plate GMAW in real time.
36
Papagiannakis, A. T., K. Senn, and H. Huang. "On-Site Calibration Evaluation Procedures for WIM Systems." Transportation Research Record: Journal of the Transportation Research Board 1536, no. 1 (January 1996): 1–11. http://dx.doi.org/10.1177/0361198196153600101.
Full textAbstract:
The feasibility of two methods for evaluating and calibrating weigh-in-motion (WIM) systems is explored. The first method uses a combination of test trucks and vehicle simulation models. The computer model VESYM was used for the simulations. The models for the test trucks were calibrated using acceleration measurements on board the vehicles. Although, this approach does not allow calculation of the discrete value of the dynamic axle load over WIM sensors, it can be used effectively in establishing the extent of variation at a particular WIM site. This information leads to an effective WIM system calibration method. The second method for calibrating WIM systems compares static and dynamic axle loads of vehicles through automatic vehicle identification (AVI). The AVI facilities developed for the Heavy Vehicle Electronic License Plate project on the I-5 corridor was used for this purpose. The static axle load of AVI-equipped vehicles was obtained from the Oregon Department of Transportation for two sites, Woodburn southbound and Ashland northbound. The WIM load data were obtained from Lockheed IMS for all the AVI-equipped WIM systems on the I-5 corridor. The data were analyzed to match AVI numbers, dates, and times of weighing. Time limits for traveling between sites were established to ensure that trucks could not stop and load or unload cargo between sites. Errors were calculated as the percentage difference between WIM and static loads for individual axles and axle groups. Calibration factors were derived to minimize the residual sum of squares of the errors.
37
Yarullin, Lenar Yu, Farizan R. Gabitov, Lyudmila Y. Sabirova, and Polina V. Antonova. "Determination of concentration equilibrium of the substance being measured in a supercritical solvent with a dynamic research method." Butlerov Communications 64, no. 10 (October 31, 2020): 68–73. http://dx.doi.org/10.37952/roi-jbc-01/20-64-10-68.
Full textAbstract:
At present, there is no universal method for studying the solubility of substances in supercritical fluid media. The expediency of combining certain methods of solution saturation and composition analysis is determined by the object of study, the range of concentrations. In the case of low solubility of solids in the solvent, a flow-through system or dynamic solubility measurement method is usually used to obtain the required amount of precision weighing material. The dynamic method for measuring the solubility of substances in supercritical carbon dioxide is not without its drawbacks, which primarily include the need to strictly control the mass flow rate of supercritical carbon dioxide in the cell with the substance being measured. With an increase in the consumption of supercritical dioxide from zero (static method) to a certain value, the concentration of the measured substance in supercritical carbon dioxide within the acceptable level of uncertainty for measuring the solubility of 4-6% can be considered unchanged. The plateau of the concentration of the measured substance in supercritical carbon dioxide from the flow rate obtained in the diagram corresponds to the saturation state of the solvent, which is carbon dioxide and the solute, which corresponds to the concept of solubility. However, with a further increase in the consumption of carbon dioxide, the concentration begins to decrease and it can no longer be considered equilibrium. This is due to the fact that at significantly high flow rates of carbon dioxide, which is a solvent, coming into contact with the substance being dissolved, it does not have time to saturate it and, accordingly, weakly dissolves it. This concentration does not correspond to the concept of solubility. Thus, the determination of the range of mass flow rate at which the conditional state of saturation of the solvent and the solute is reached is the most important stage in studies to measure the solubility of substances in supercritical fluids. Based on the results of experimental data measuring the solubility of tannin in supercritical carbon dioxide, the dependences of the concentration of tannin in supercritical carbon dioxide on the mass flow rate are presented. It follows from the results that, in the flow rate range of 0-0.6 g/min, the tannin concentration in supercritical carbon dioxide is practically independent of the solvent flow rate, which is evidence of the equilibrium of this concentration and its compliance with the concept of solubility.
38
Richter, Johannes, Arnd Kessler, Thomas Weber, Heinz Heißler, Michaela Gerstenlauer, Matthias Wüst, and Rainer Stamminger. "Developing and testing a new quantitative near infrared spectroscopy online tracking measuring system for soil detection during automatic dishwashing." Journal of Near Infrared Spectroscopy 29, no. 3 (April 13, 2021): 179–87. http://dx.doi.org/10.1177/09670335211006614.
Full textAbstract:
Near infrared (NIR) measurements have been used for several years to examine the processes taking place in the dishwasher during dishwashing. It is possible to differentiate between the soil components butterfat, oatmeal and egg-yolk and to determine their concentration in the dishwashing liquor quantitatively. Consequently, time-consuming dishwashing tests can be avoided by weighing the dishes. However, this method is also based on a small number of NIR measurements which are carried out intrusively during the dishwashing process, i.e. outside the dishwasher. These few NIR measurements make it difficult to investigate the dynamics of a dishwashing process. In this study, the development, testing and usage of a new online tracking measuring system is presented. The latter was used to perform 38 dishwashing processes, each containing 51 NIR spectra, to develop a calibration model using the partial least squares regression method with cross-validation. This new online tracking measuring system, based on the calibration, can determine the concentrations of three different soil components in the dishwashing liquor during automatic dishwashing. By recording the 51 spectra, it is possible to display a tracking curve for each soil component, i.e. the concentration courses of the dishwashing process over time. This results in a significantly better time resolution and it was possible to investigate the first dynamic part of the tracking curve, i.e. the beginning of the dishwashing process. This could lead to the opportunity to change the state of the dishwasher depending on the concentrations detected in the first step and, secondly, to a more environmentally friendly and cost-reducing dishwashing process.
39
Voronkov, A. V., and A. S. Lysenko. "METHOD FOR DETERMINING THE UPPER LIMIT OF CEREBRAL AUTOREGULATION IN RATS." Pharmacy & Pharmacology 6, no. 5 (November 10, 2018): 488–98. http://dx.doi.org/10.19163/2307-9266-2018-6-5-488-498.
Full textAbstract:
The main objective of the phenomenon of cerebral autoregulation is to maintain a constant cerebral blood flow rate with changes in systemic arterial pressure in the range of 50 mmH up to 150 Mmhg. To study this phenomenon, there are two approaches: dynamic and static. The dynamic approach is known to the study autoregulation, can indirectly characterize this phenomenon with the help of calculated indicators, and the described static methods can characterize only the lower limit of autoregulation of cerebral blood flow.The aimof the study was to develop a method for determining the value of pressure at the “breakdown” point of the upper limit of cerebral hemodynamics autoregulation.Materials and methods. The experiment was carried out on male rats of the Wistar line weighing 200–250 g, kept in standard vivarium conditions. The essence of the method of establishing the upper “breakdown” point of the autoregulatory mechanisms of cerebral circulation is pumping blood from the femoral artery to both carotid arteries by means of a peristaltic pump, while controlling the pressure and cerebral blood flow velocity. In order to avoid blood loss as a result of blood flow redistribution, external carotid arteries were ligated. The pressure was measured by the direct method. Since the pressure is created by the resistance of the cerebral vessels, it can be measured at the entrance by specially modeled carotid catheters. Cerebral blood flow velocity was measured by an ultrasound doppler scanner using MDK-Minimax Doppler v .2.1 program. To establish the possibility of using this method in the study of the influence of substances on the autoregulation of cerebral circulation, the effect of nicergoline on this phenomenon was studied. The drug was administered as a suspension intragastrally to rats 1 hour before metering.The results and discussionof the experiment showed that in intact rats the “breakdown” point of the upper limit of autoregulation was recorded at 165.0 ± 3.4 Mmhg (M ± m). Statistical processing of the obtained data indicates the normal distribution of the sample and the validity of the developed method. The introduction of nicergoline led to the increase in pressure at which there was a “breakdown” of the autoregulation mechanisms to 181.7 ± 4.7 Mmhg, which was significantly higher than the values of the intact group.Conclusion. As a result of the experiment on male rats, a valid method was developed for determining the blood pressure value at the highest point of “breakdown” of cerebral hemodynamics autoregulation and it was established that nicergoline shifts the functioning limit of the autoregulation phenomenon to higher values.
40
Kwiecień, Sławomir. "The influence of loading plate diameter on the results of trial load tests of dynamic replacement columns." Transportation Overview - Przeglad Komunikacyjny 2017, no. 5 (May 1, 2017): 1–9. http://dx.doi.org/10.35117/a_eng_17_05_01.
Full textAbstract:
The dynamic replacement method of soil strengthening consists in the constructing columns made of aggregate of various granularity. In order to form them, heavy pounders (weighing from 10 to 20 tonnes) are dropped from the height of 25 m. Considering the specificity of this technique, it is quite important to verify on site the assumptions of the project, such as diameter and length of columns, their compaction or stiffness. For that reason, a number of examinations are performed, including column excavations, various types of probing tests or trial loads. The latter consists in determining the “load-settlement” dependence - usually during initial and secondary loadings phase – and on their basis, indicating the value of deformation modulus. Therefore, a stiff plate is placed on the column head and the loading is realised using actuators leaning on the ballast. The diameter of the loading plate depends on diameter and length of column and on the predicted pressure under the plate. The diameter of the loading plate is often smaller than column's diameter. This paper tries to determine the influence of the diameter of the plate used in test loads on the result of the research presented as “load-settlement” dependence and on the values of deformation modulus determined on their basis. The calculations were performed using FEM on a spatial numerical model calibrated on the basis of column's bearing capacity tests. Two models were applied in calculations: elastic-ideally plastic and isotropic hardening elastoplastic.
41
Jin, Qiang, Lin Zhu, Di Hu, Chunxia He, and Li Li. "Nuclear magnetic resonance analysis of water absorption characteristics and dynamic changes in pore size distribution of wood-plastic composites." BioResources 16, no. 2 (April 23, 2021): 4064–80. http://dx.doi.org/10.15376/biores.16.2.4064-4080.
Full textAbstract:
Low-field nuclear magnetic resonance (NMR) technology was used to perform the experiments of transverse relaxation time (T2), pore size distribution, and water absorption rate for wood-plastic composites (WPC) with different contents of added slag powder, exploring the water movement and the dynamic changes of pore size during the moisture absorption process of the material under immersion condition. The experimental results were as follows: (1) According to the T2 of H proton and its inversion pattern, the measured porosity had a relatively small difference from that of the weighing method. (2) The pore size distribution graph showed the following: (i) when the immersion time of composite materials was different, the changing law of volume of pores with different radius was different.; (ii) when the material’s immersion time was greater than 216 h, the pore radius and its distribution characteristics showed large differences; (iii) slag powder changed the pore structure of the WPC but did not change the water absorption characteristics of the wheat straw. (3) The changes of water absorption and expansion rate showed that the slag powder changed the time for the materials’ pores to absorb water until saturation and reduced the water absorption and expansion rate. The measurement results were consistent with changing trend in the pore size obtained by low-field NMR relaxometry.
42
Shang, Weiyan, Canjun Yang, Yunping Liu, and Junming Wang. "Design on a Composite Mobile System for Exploration Robot." Shock and Vibration 2016 (2016): 1–14. http://dx.doi.org/10.1155/2016/6363071.
Full textAbstract:
In order to accomplish exploration missions in complex environments, a new type of robot has been designed. By analyzing the characteristics of typical moving systems, a new mobile system which is named wheel-tracked moving system (WTMS) has been presented. Then by virtual prototype simulation, the new system’s ability to adapt complex environments has been verified. As the curve of centroid acceleration changes in large amplitude in this simulation, ride performance of this robot has been studied. Firstly, a simplified dynamic model has been established, and then by affecting factors analysis on ride performance, an optimization model for suspension parameters has been presented. Using NSGA-II method, a set of nondominated solutions for suspension parameters has been gotten, and by weighing the importance of the objective function, an optimal solution has been selected to be applied on suspension design. As the wheel-tracked exploration robot has been designed and manufactured, the property test has been conducted. By testing on physical prototype, the robot’s ability to surmount complex terrain has been verified. Design of the wheel-tracked robot will provide a stable platform for field exploration tasks, and in addition, the certain configuration and suspension parameters optimization method will provide reference to other robot designs.
43
Rao, P. V. R. R. Bhogendra, V. S. N. Murthy Arikapalli, Shiladitya Bhowmick, and Ramakalyan Ayyagari. "Missile Longitudinal Dynamics Control Design Using Pole Placement and LQR Methods." Defence Science Journal 71, no. 5 (September 2, 2021): 699–708. http://dx.doi.org/10.14429/dsj.71.16232.
Full textAbstract:
In high-maneuvering missile systems, with severe restrictions on actuator energy requirements, it is desirable to achieve the required performance with least actuation effort. Linear Quadratic Regulator (LQR) has been in literature for long and has proven it’s mettle as an optimal controller in many benign aerospace applications and industrial applications where the response times of the plant, in most cases, are seen to be greater than 10 seconds. It can be observed in the literature that LQR control methodology has not been explored enough in the tactical missile applications where requirement of very fast airframe response times are desired, typically of the order of milliseconds. In the present research, the applicability of LQR method for one such agile missile control has been critically explored. In the present research work, longitudinal dynamic model of an agile missile flying at high angle of attack regime has been established and an optimal LQR control solution has been proposed to bring out the required performance demanding least control actuator energy. A novel scheme has been presented to further optimise the control effort, which is essential in this class of missile systems with space and energy constraints, by iteratively computing optimal magnitude state weighing matrix Q and control cost matrix R. Pole placement design techniques, though extensively used in aerospace industry because of ease of implementation and proven results, do not address optimality of the system performance. Hence, a comparative study has been carried out to verify the results of LQR against pole placement technique based controller. The efficacy of LQR based controller over pole placement design techniques is successfully established with minimum control energy requirement in this paper. Futuristic high maneuvering, agile missile control design with severe space and energy constraints stand to benefit incorporating the controller design scheme proposed in this paper.
44
Grakovski, Alexander, Yuri Krasnitski, Igor Kabashkin, and Victor Truhachov. "Some Approaches to the Rolling Wheels’ Dynamics Modelling in the Weight-in-Motion Problem." Transport and Telecommunication Journal 14, no. 1 (March 1, 2013): 57–78. http://dx.doi.org/10.2478/ttj-2013-0007.
Full textAbstract:
Abstract Some possibilities of fibre-optic sensors (FOS) application for measuring the weight of moving vehicles realized in weightin- motion (WIM) systems are discussed. As the first, the model of small-buried seismic sensor transient response excited by a car tyre interaction with asphalt-concrete road pavement is proposed. It is supposed that a seismic wave received by the sensor is the vertical component of surface Raleigh wave. The model is based on supposition that a tyre footprint is acceptable to consider as some array of point sources of these waves. The proper algorithms permit to vary different parameters of the array excitation, as to footprint dimensions, load distribution, car velocities and others. The set of Matlab codes is worked out for seismic pulses modelling and processing. The second way considered is to simulate the FOS signal in the basis of differential equations describing a deformable wheel behaviour, or wheel oscillations, in order to identify relations with optoelectronic mechanical parameters. An attempt to find the mass of the vehicle is based on minimizing the discrepancy between the actual FOS signal and the solution of the differential equation. The accuracy of the evaluated weight depends on many external factors, the mathematical modelling of them are expressed in the numerical values of the coefficients and external stimuli. The influence of these factors are analysed and tested by simulations and field experiments. One of ideas in dynamic weighing problem solution should consist in evaluation of position of virtual gravity centre of the vehicle in time. The processing algorithm of the data received from the FOS is proposed based on conception of database retaining in some reference system memory. Certain requirements concerning the elements and blocks of the algorithm are defined as well. The reference system is realized as the digital filter with the finite impulse response. The method to estimate the filter coefficients is worked out. Several experiments with this algorithm have been carried out for the vehicle identification with the reference loads adopted from real data. The different factors have an influence on the measurement accuracy of FOS. The roadbed features, temperature, nonlinearities and delay effects in FOS are among them. The results of laboratory and field measurements with FOS responses to different axle’s loadings are presented. Charging and inertial characteristics of FOS under the impact of various external factors (protective cover, temperature, contact area, and installation mode especially) as well as their approximations are investigated. It is found that the final calibration of the FOS has to be done individually and only after it has been installed in the pavement. Certain methods and algorithms of linearization, as well temperature and dynamic errors compensation of FOS data are discussed.
45
Valentina Lungu, Magdalena. "Tungsten-Copper Composites for Arcing Contact Applications." Material Science Research India 17, no. 3 (July 22, 2020): 214–29. http://dx.doi.org/10.13005/msri/170304.
Full textAbstract:
The study presents the research findings on electrical contact materials based on tungsten-copper (W-Cu) composites containing 72 ± 3 wt.% W, rest Cu, and up to 1.5 wt.% Ni. Cylindrical sintered parts with 57 ± 0.5 mm in diameter and 12 ± 0.5 mm in height were manufactured by pressing, sintering, and liquid infiltration route, then were mechanically polished and processed as complex shape protection rings used as arcing contacts in high voltage circuit breakers (HVCBs). The surface elemental composition of the sintered parts was determined by wavelength dispersive X-ray fluorescence spectrometry. The density was determined by hydrostatic weighing in ethanol. The arithmetic mean surface roughness was measured by contact profilometry. The microstructure was studied by scanning electron microscopy. The electrical conductivity was measured by eddy current method. The thermal diffusivity and specific heat were determined by laser flash analysis. Instrumented indentation testing and two computational methods (Oliver & Pharr, and Martens hardness) were employed to study the mechanical properties under quadratic loading and continuous multi cycle (CMC) indentation mode. The functional behavior of the arcing contacts was assessed in terms of static and dynamic contact resistance in operation in minimum oil HVCBs of 110 kV. The properties investigation revealed highly dense contact parts with homogeneous microstructure, Vickers hardness of 260-374, elastic modulus of 185-311 GPa, as well as good electrical and thermal conductivity. The arcing contacts proved a good functional behavior. in service, too. The results endorse the developed sintered contact materials for implementation in practical applications.
46
Власенко, М., M. Vlasenko, К. Трубакова, and K. Trubakova. "Water regime Poaceae family species in the drought conditions." Agrarian Bulletin of the 190, no. 11 (November 14, 2019): 2–8. http://dx.doi.org/10.32417/article_5dcd861e230788.72509133.
Full textAbstract:
Abstract. The purpose of the research is to consider the patterns of water regime of plants in dry conditions, depending on changes in environmental conditions and plant physiology. The objectives of the research included: identifying abilities of Poaceae family herbs (Festuca pratensis, Bromus inermis L., Agropyron cristatum L., Agropyrum Gaertn.) introduced into crops on the vegetation sites of the lysimetric complex of the Federal Science Center of Agroecology of the Russian Academy of Sciences (Volgograd) to sustainability in adverse environmental conditions. Scientific novelty and practical significance. The study contributes to the solution of issues of effective prediction of the productivity of forage grasses, since water-regime patterns of growth and development of vegetation must be taken into account when developing optimal growing methods. Methods. The determination of the water-holding capacity of herbs was carried out according to the Arlanda method and is based on taking into account the water loss by plants. The intensity of transpiration was determined by the method of fast weighing the selected sheet of L. А. Ivanov. A description of the mechanism of water retention by plants with an increase in drought is given. Results. As a result, it has been established that perennial grasses of the family Poaceae have a high potential for resistance to soil and atmospheric drought. The largest water retention capacity is: Bromus inermis L. (87.8%), Agropyrum Gaertn. (87.1 %) and Agropyron cristatum L. (87.0 %). The ability to change water retention capacity can be viewed not only as an adaptive function in changing environmental conditions, but also as a dynamic process that characterizes the natural course of the metabolism of cells and tissues during ontogenesis. Indicators of transpiration intensity in species of the Poaceae family usually reach a maximum up to high midday temperatures. The highest rates were found in Bromus inermis L. and Agropyrum Gaertn., for which in the morning they reached 1.41–1.42 g/dm2-h.
47
Seo, Dong-Hun, and Won-Don Lee. "A New Ensemble System using Dynamic Weighting Method." Journal of the Korean Institute of Information and Communication Engineering 15, no. 6 (June 30, 2011): 1213–20. http://dx.doi.org/10.6109/jkiice.2011.15.6.1213.
Full text
48
GAO, Shesheng, Yi GAO, Yongmin ZHONG, and Wenhui WEI. "Random Weighting Estimation Method for Dynamic Navigation Positioning." Chinese Journal of Aeronautics 24, no. 3 (June 2011): 318–23. http://dx.doi.org/10.1016/s1000-9361(11)60037-x.
Full text
49
Ning, Xizhan. "Mixed Sensitivity-Based Robust H∞ Control Method for Real-Time Hybrid Simulation." Symmetry 13, no. 5 (May 10, 2021): 840. http://dx.doi.org/10.3390/sym13050840.
Full textAbstract:
Real-time hybrid simulation (RTHS), dividing the emulated structure into numerical substructures (NS) and physical substructures (PS), is a powerful technique to obtain responses and then to assess the seismic performance of civil engineering structures. A transfer system, a servo-hydraulic actuator or shaking table, is used to apply boundary conditions between the two substructures. However, the servo-hydraulic actuator is inherently a complex system with nonlinearities and may introduce time delays into the RTHS, which will decrease the accuracy and stability of the RTHS. Moreover, there are various uncertainties in RTHS. An accurate and robust actuator control strategy is necessary to guarantee reliable simulation results. Therefore, a mixed sensitivity-based H∞ control method was proposed for RTHS. In H∞ control, the dynamics and robustness of the closed-loop transfer system are realized by performance weighting functions. A form of weighting function was given considering the requirement in RTHS. The influence of the weighting functions on the dynamics was investigated. Numerical simulations and actual RTHSs were carried out under symmetric and asymmetric dynamic loads, namely sinusoidal and earthquake excitation, respectively. Results indicated that the H∞ control method used for RTHS is feasible, and it exhibits an excellent tracking performance and robustness.
50
Lü, Peitao, Xinmin Huang, Hongmei Li, Jiping Liu, Shenggen He, Daryl C. Joyce, and Zhaoqi Zhang. "Continuous Automatic Measurement of Water Uptake and Water Loss of Cut Flower Stems." HortScience 46, no. 3 (March 2011): 509–12. http://dx.doi.org/10.21273/hortsci.46.3.509.
Full textAbstract:
In studying the postharvest water relations of cut flowers, researchers aim to determine rates of water uptake and water loss along with changes in fresh weight. An automatic apparatus was devised for continuous monitoring of these indices. The novel apparatus consists of two balances automatically recording mass at a relatively high data acquisition rate (min−1), a personal computer, two containers, and plastic tubing. The apparatus is accurate, labor-saving, and real-time. It enabled dynamic synchronous recording of water uptake as well as fresh weight of the cut flower stem, from which precise water uptake loss rates during vase life can be accurately determined. Rates of water uptake and water loss of individual cut rose (Rosa hybrida cv. Movie Star) stems were measured using the apparatus under alternating 12-h light and dark periods. Both water uptake and water loss rates fluctuated with the light to dark shift over 120 h of observation. Stem fresh weight increased rapidly over the first 40 h of vase period and decreased gradually thereafter. Cut lily (Lilium hybrida cv. Yellow Overlord) stems showed similar trends in water uptake and water loss rate to cut rose stems. The accuracy and sensitivity of the new apparatus was validated by comparison with manual weighing using a balance at 2-h intervals under alternating 12-h light and dark periods over 108 h. The apparatus described here constitutes a suitable method for direct measurement of water uptake and fresh weight, including capturing relatively rapid water balance responses to changes in the postharvest environment.