Research on Mechanical Manufacturing with Posture Optimization of Installation of the Bolts in Large Component Assembly

2014 ◽  
Vol 1014 ◽  
pp. 81-85
Author(s):  
Peng Huang
Keyword(s):  
Simulation Experiment ◽  
Measurement Data ◽  
Optimization Method ◽  
Initial Distribution ◽  
Maximum Diameter ◽  
Large Component ◽  
Measuring Device ◽  
Pass Through ◽  
The Stability ◽  
Component Assembly

To improve the assembly efficiency, an optimization model is proposed to achieve the optimal posture of the component of the bolts installation. The component is measured and aligned by an automatic system, which consists of some NC locators and coordinate measuring device. Based on the measurement data of the bolt hole and the end surface, the maximum diameter of the bolt that can pass through the joint hole is obtained by using morphology theory. The particle swarm optimization method is adopted to solve this problem, and the stability and efficiency of the calculated results are improved by controlling the initial distribution of particles. The numerical simulation experiment shows that the proposed method would be helpful to guide the alignment and docking of large components.

Heading Measurement Based on Ultrasonic and Magnetic Compass

2013 ◽  
Vol 341-342 ◽  
pp. 896-900
Author(s):  
Bao Jiang Sun ◽  
Yue Xu
Keyword(s):  
Navigation System ◽  
Simulation Experiment ◽  
Measurement Data ◽  
Magnetic Compass ◽  
Positioning System ◽  
Integrated Navigation ◽  
Adaptive Kalman Filter ◽  
Integrated Navigation System ◽  
Advantages And Disadvantages ◽  
Measurement Principle

Describes briefly ultrasonic positioning system (UPS) and digital magnetic compass (DMC) heading measurement principle,analyzed the advantages and disadvantages of each option. To improve the accuracy of the heading measurement, As the theoretical basis of adaptive Kalman filter, designed a kind of ups and dmc integrated navigation system. Based on both real measurement data, made a simulation experiment and confirmed the feasibility of the navigation system.

scholarly journals Numerical Analyses on the Stability of a Deep Coalmine Roadway Passing through a Fault Zone: A Case Study of the Gugui Coalfield in China

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2114
Author(s):  
Yongshui Kang ◽  
Congcong Hou ◽  
Jingyi Liu ◽  
Zhi Geng ◽  
Jianben Chen ◽  
...  
Keyword(s):  
Fault Zone ◽  
Distinct Element ◽  
Three Dimensional ◽  
Tectonic Stress ◽  
Three Dimensional Model ◽  
Support Strategy ◽  
Failure Theory ◽  
Calculation Results ◽  
Pass Through ◽  
The Stability

Massive deformation often occurs when deep coalmine roadways pass through a fault zone due to the poor integrity of rock mass and high tectonic stress. To study deformation characteristics of the surrounding rock in the fault zone of a coalmine, a roadway passing through the FD1041 fault zone in China’s Gugui coalfield was investigated in this research. The geo-stress characteristics of this fault zone were analyzed based on the Mohr failure theory. Furthermore, a three-dimensional model for the experimental roadway in the FD1041 fault zone was built and calculated by a numerical program based on the distinct element method. Stability conditions of the roadway, using several types of support methods, were calculated and compared. Calculation results indicated that pre-grouting provides favorable conditions for the stability of a roadway in a fault zone. Finally, an optimized support strategy was proposed and implemented in the experimental roadway. Monitored results demonstrated that the optimized support strategy is appropriate for this fault zone.

Transportation-oriented spatial allocation of land use development: a simulation-based optimization method

SIMULATION ◽  
2020 ◽  
Vol 96 (7) ◽  
pp. 583-591
Author(s):  
Hongzhi Lin ◽  
Yongping Zhang
Keyword(s):  
Land Use ◽  
Urban Development ◽  
Simulation Experiment ◽  
Optimization Method ◽  
Transportation System ◽  
Sustainable Urban Development ◽  
Total System ◽  
Simulation Based ◽  
Level Model ◽  
Land Use Development

Urban development usually deteriorates the transportation system. For sustainable urban development, policymakers often face the challenging problem of how to optimally allocate overall land use quotas across a number of residential locations according to the performance of the transportation system. This is a kind of Stackelberg competition, where policymakers make land use decisions and travelers make behavioral responses. A novel bi-level model is formulated to solve this problem. The upper-level model minimizes the total system travel time by land use allocation, while at the lower level are sequential models with feedback for transportation system equilibrium. The Dirichlet allocation algorithm, a simulation-based heuristic algorithm, is designed to solve this bi-level model. A simulation experiment using the Nguyen–Dupuis network is then used to verify the proposed model and algorithm. The results from the simulation experiment demonstrate that not only are the model and algorithm operational but that they also provide an effective tool for policymakers to plan for land use development.

Development of quaternary Fe–B–Y–Nb bulk glassy alloys with high glass-forming ability

2007 ◽  
Vol 22 (2) ◽  
pp. 471-477 ◽  
Author(s):  
Dong Ho Kim ◽  
Jin Man Park ◽  
Do Hyang Kim ◽  
Won Tae Kim
Keyword(s):  
Glass Phase ◽  
Crystallization Behavior ◽  
Alloy System ◽  
Glass Forming Ability ◽  
Maximum Diameter ◽  
Glass Forming ◽  
Glassy Alloys ◽  
The Stability ◽  
Nb Addition ◽  
Compressive Mechanical Property

The effects of niobium (Nb) addition on the glass-forming ability (GFA), crystallization behavior, and compressive mechanical property of iron (Fe)–boron (B)–yttrium (Y) alloys have been investigated. Among the (Fe71.2B24Y4.8)100−xNbx (x = 0, 2, 4, 6, 8) alloys investigated, (Fe71.2B24Y4.8)96Nb4 exhibits the highest GFA, enabling the formation of glassy rods with a maximum diameter of 7 mm, which is the largest among quaternary Fe-based alloys. The comparison of the crystallization behavior of the alloys shows that the formation of metastable Fe23B6 phase during crystallization in the (Fe71.2B24Y4.8)96Nb4 alloy can suppress the formation of other stable crystalline phases such as α-Fe, enhancing the stability of the glass phase. The present results show that the attainment of a significantly high GFA is possible even in a quaternary Fe-based alloy system by properly tailoring the competing crystalline phase by the modification of liquid chemistry.

scholarly journals A fibre-based 2D-slit homogenizer concept for high-precision space-based spectrometer missions

2022 ◽  
Author(s):  
Timon Hummel ◽  
Claude Coatantiec ◽  
Xavier Gnata ◽  
Tobias Lamour ◽  
Rémi Rivière ◽  
...  
Keyword(s):  
Spectral Response ◽  
Measurement Data ◽  
Single Fibre ◽  
Study Phase ◽  
Total Size ◽  
The Earth ◽  
Spectral Sample ◽  
Significant Performance ◽  
The Stability ◽  
High Level

AbstractThe measurement accuracy of recent and future space-based imaging spectrometers with a high spectral and spatial resolution suffer from the inhomogeneity of the radiances of the observed Earth scene. The Instrument Spectral Response Function (ISRF) is distorted due to the inhomogeneous illumination from scene heterogeneity. This gives rise to a pseudo-random error on the measured spectra. In order to assess the spectral stability of the spectrograph, stringent requirements are typically defined on the ISRF such as shape knowledge and the stability of the centroid position of the spectral sample. The high level of spectral accuracy is particularly crucial for missions quantifying small variations in the total column of well-mixed trace gases like $$\hbox {CO}_{2}$$ CO 2 . In the framework of the $$\hbox {CO}_{2}$$ CO 2 Monitoring Mission (CO2M) industrial feasibility study (Phase A/B1 study), we investigated a new slit design called 2D-Slit Homogenizer (2DSH). This new concept aims to reduce the Earth scene contrast entering the instrument. The 2DSH is based on optical fibre waveguides assembled in a bundle, which scramble the light in across-track (ACT) and along-track (ALT) direction. A single fibre core dimension in ALT defines the spectral extent of the slit and the dimension in ACT represents the spatial sample of the instrument. The full swath is given by the total size of the adjoined fibres in ACT direction. In this work, we provide experimental measurement data on the stability of representative rectangular core shaped fibre as well as a preliminary pre-development of a 2DSH fibre bundle. In our study, the slit concept has demonstrated significant performance gains in the stability of the ISRF for several extreme high-contrast Earth scenes, achieving a shape stability of $$<0.5{\%}$$ < 0.5 % and a centroid stability of $$<0.25 \ \text {pm}$$ < 0.25 pm (NIR). Given this unprecedented ISRF stabilization, we conclude that the 2DSH concept efficiently desensitizes the instrument for radiometric and spectral errors with respect to the heterogeneity of the Earth scene radiance.

scholarly journals Overview of Methods for Determining Parameters of Synchronous Generators

2020 ◽  
Vol 20 (4) ◽  
pp. 103-113
Keyword(s):  
Power Systems ◽  
Computational Models ◽  
Meta Analysis ◽  
Measurement Data ◽  
Synchronous Generator ◽  
Adaptive Model ◽  
Operational Control ◽  
Synchronous Generators ◽  
Computing Power ◽  
The Stability

A synchronous generator is one of the key elements of any power system, having a significant impact on the stability and reliability of consumers’ power supply. Nowadays, the power systems emergency and operational control issues are being solved using computational models, the parameters whereof are determined using the reference data, or the data obtained during testing. High dependence of the models’ parameters on various external factors leads to a significant decrease in the accuracy of solving the issues of emergency and operational control. Identification based on the traditional telemetry systems or synchrophasor measurements is used to improve the accuracy of parameters of the power systems’ computational models. The purpose of this research lies in a meta-analysis of the available studies aimed at developing a methodology for determining parameters of a synchronous generator on the basis of measurement data. Russian and foreign studies were analyzed and grouped to achieve this goal. After that, for each group, advantages, disadvantages, and the area of application were identified. As a result, it is shown that the existing methods for determining parameters of synchronous generators based on measurement data cannot adapt to the source dataset and also require significant computing power. As a way to overcome these shortcomings, an adaptive model of a synchronous machine is proposed.

scholarly journals Dynamic torque calibration by means of model parameter identification

ACTA IMEKO ◽  
2015 ◽  
Vol 4 (2) ◽  
pp. 39 ◽  
Author(s):  
Leonard Klaus ◽  
Barbora Arendacká ◽  
Michael Kobusch ◽  
Thomas Bruns
Keyword(s):  
Frequency Response ◽  
Dynamic Behaviour ◽  
Measurement Data ◽  
Model Parameters ◽  
Dynamic Calibration ◽  
Extended Model ◽  
Unknown Parameters ◽  
Measuring Device ◽  
Torque Transducer ◽  
Least Squares Approach

For the dynamic calibration of torque transducers, a model of the transducer and an extended model of the mounted transducer including the measuring device have been developed. The dynamic behaviour of a torque transducer under test is going to be described by its model parameters. This paper describes the models with these known and unknown parameters and how the calibration measurements are going to be carried out. The principle for the identification of the transducer's model parameters from measurement data is described using a least squares approach. The influence of a variation of the transducer's parameters on the frequency response of the expanded model is analysed.

Synthesis of a High-Precision Missile Homing System with an Permissible Stability Margin of the Normal Acceleration Stabilization System

2021 ◽  
Vol 22 (7) ◽  
pp. 365-373
Author(s):  
Quang Thong Do
Keyword(s):  
High Precision ◽  
Parametric Optimization ◽  
Stability Margin ◽  
Optimization Method ◽  
Synthesis Process ◽  
Stabilization System ◽  
Gain Margin ◽  
The Stability ◽  
Automatic Systems ◽  
Normal Acceleration

The proportional guidance method-based missile homing systems (MHS) have been widely used the real-world environments. In these systems, in order to destroy the targets at different altitudes, a normal acceleration stabilization system (NASS) is often utilized. Therefore, the MHS are complex and the synthesis of these systems are a complex task. However, it is necessary to synthesize NASS during the synthesis of the MHS. To simplify the synthesis process, a linear model of the NASS is used. In addition, we make use of the available commands in Control System Toolbox in MATLAB. Because the Toolbox has the commands to describe the transfer function, determine the stability gain margin, and the values of the transient respond of the linear automatic systems. Thus, this article presents two methods for synthesizing the missile homing systems, including (i) a method for synthesizing the MHS while ensuring the permissible stability gain margin of the NASS, and (ii) a method for synthesizing the MHS while ensuring the permissible stability margin of the NASS by overshoot. These techniques are very easy to implement using MATLAB commands. The synthesis of the proposed MHS is carried out by the parametric optimization method. To validate the performance of the proposed techniques, we compare them withthe MHS synthesized by ensuring the stability margin of the NASS bythe oscillation index. The results show that, two our proposed methods and the existing method provide the same results in terms of high-precision. Nevertheless, the proposed methods are simple and faster than the conventional method. The article also investigates the effect of gravity, longitudinal acceleration of the rocket, andblinding of the homing head on the accuracy of the synthesized MHS. The results illustrate that they have a little effect on its accuracy.

Novel robust controller design for load sway reduction in double-pendulum overhead cranes

2018 ◽  
Vol 233 (12) ◽  
pp. 4359-4371 ◽  
Author(s):  
Huimin Ouyang ◽  
Xin Deng ◽  
Huan Xi ◽  
Jinxin Hu ◽  
Guangming Zhang ◽  
...  
Keyword(s):  
Controller Design ◽  
Dynamic Performance ◽  
Optimization Method ◽  
Linear Matrix ◽  
Double Pendulum ◽  
Control Performance ◽  
Mass Property ◽  
Length Changes ◽  
The Stability ◽  
Dynamic Performance Analysis

It is seen that when the hook mass is larger than the load mass or the load has distributed mass property, the load sway of the crane system presents as double-pendulum effect. In this situation, crane system has two different natural frequencies so that the sway characteristic becomes more complex and greatly increases the difficulty of the dynamic performance analysis and controller design. Moreover, the rope length changes significantly affect the stability and control performance of the crane system. In order to solve the aforementioned problems, the linear dynamics of a two-dimensional overhead crane with double-pendulum effect is derived based on a disturbance observer, and is decoupled for controller design by modal analysis. Next, a state feedback controller is presented to achieve robust control performance for a given range of rope length changes. The controller gains are obtained via linear matrix inequality optimization method. Finally, numerical simulations and experimental results validate that the proposed method has superior control performance.

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