The Obstacle-Surmounting Process Simulation of Arm-Swing Wheeled Robot Based on MATLAB

2011 ◽  
Vol 199-200 ◽  
pp. 1244-1248
Author(s):  
Li Gong ◽  
Yu Feng Ding ◽  
Bu Yun Sheng ◽  
Dong Dong Che
Keyword(s):  
Simulation Analysis ◽  
Mathematic Model ◽  
Test Results ◽  
Complex Environment ◽  
Arm Swing ◽  
Wheeled Robot ◽  
Resistance Moment ◽  
Physical Prototype ◽  
Three Stages ◽  
The Stability

Considering complex environment of disaster site, an Arm-swing Wheeled Robot (AWR) with auxiliary obstacle-surmounting mechanism was developed. The obstacle-surmounting process is simplified into three stages, and the mathematic model of kinematic for each stage has been established. The simulation for each stage of obstacle-surmounting has been carried out in MATLAB. The stability of obstacle-surmounting is analyzed and the trend of resistance moment is obtained. Finally, the effectiveness of simulation analysis is verified by comparing with the test results of physical prototype.

Simulation and Optimization Research of Multi-Stud Tensioning Machine Controlled by Servo Valve

2013 ◽  
Vol 664 ◽  
pp. 871-877
Author(s):  
Xiao Dong Tan ◽  
Wei Ji ◽  
Zhi Bo Luan
Keyword(s):  
Dynamic Characteristics ◽  
Pid Controller ◽  
Simulation Analysis ◽  
Mathematic Model ◽  
Hydraulic Cylinder ◽  
Simulation And Optimization ◽  
Hydraulic Cylinders ◽  
Hydraulic Servo ◽  
Hydraulic Servo System ◽  
The Stability

In this paper, we base on the simulation analysis of the electro-hydraulic servo system about dual hydraulic cylinders parallel driving Multi-Stud Tensioning Machine, focus on the dynamic characteristics of a single hydraulic cylinder (asymmetric hydraulic cylinder), make use of Matlab Simulink module to carry on to imitate, and design a PID controller to correct the system. The results of simulation prove correctness of the system mathematic model, and the stability of the system is obviously improved.

scholarly journals Analytical and Experimental Investigation of the Stability of the Rotor-Bearing System of a New Small Turbocharger

1987 ◽  
Author(s):  
H. R. Born
Keyword(s):  
Experimental Investigation ◽  
Dynamic Stability ◽  
Squeeze Film ◽  
Test Results ◽  
Flow Capacity ◽  
Squeeze Film Dampers ◽  
Rotor Bearing ◽  
The Stability ◽  
Turbine Design ◽  
Bearing System

This paper presents an overview of the development of a reliable bearing system for a new line of small turbochargers where the bearing system has to be compatible with a new compressor and turbine design. The first part demonstrates how the increased weight of the turbine, due to a 40 % increase in flow capacity, influences the dynamic stability of the rotor-bearing system. The second part shows how stability can be improved by optimizing important floating ring parameters and by applying different bearing designs, such as profiled bore bearings supported on squeeze film dampers. Test results and stability analyses are included as well as the criteria which led to the decision to choose a squeeze film backed symmetrical 3-lobe bearing for this new turbocharger design.

Durability of BFRP and Hybrid FRP Sheets under Freeze-Thaw Cycling

2010 ◽  
Vol 163-167 ◽  
pp. 3297-3300 ◽  
Author(s):  
Jia Wei Shi ◽  
Hong Zhu ◽  
Zhi Shen Wu ◽  
Gang Wu
Keyword(s):  
Mechanical Properties ◽  
Test Data ◽  
Mechanical Characteristics ◽  
Test Results ◽  
Freeze Thaw ◽  
Frp Composites ◽  
Test Parameters ◽  
The Stability ◽  
Better Than

Coupon tests were conducted to investigate the mechanical characteristics of basalt FRP (BFRP) sheet, basalt-carbon hybrid FRP sheets and the corresponding epoxy rein under the effect of freeze-thaw cycling. FRP sheets and epoxy rein coupons were subjected to up to 200 and 250 freeze-thaw cycles respectively. Test parameters included the number of freeze-thaw cycles and the types of FRP composites. Test results show that (1) BFRP sheet perform better than CFRP or GFRP sheets under high freeze-thaw cycles; (2) exposed hybrid FRP sheets not only show very little loss in mechanical properties, but also contribute to the stability of test data; (3) mechanical properties of rein epoxy decrease significantly with increasing freeze-thaw cycles.

scholarly journals Numerical Simulation on Large Deformation of Weak Rock Mass Tunnel Under High Geostress

2018 ◽  
Vol 175 ◽  
pp. 03025
Author(s):  
Feng Zhou ◽  
Hongjian Jiang ◽  
Xiaorui Wang
Keyword(s):  
Rock Mass ◽  
Large Deformation ◽  
Lateral Pressure ◽  
Simulation Analysis ◽  
Pressure Coefficient ◽  
Surrounding Rock ◽  
Analog Simulation ◽  
Lateral Pressure Coefficient ◽  
High Geostress ◽  
The Stability

The problem about the stability of tunnel surrounding rock is always an important research object of geotechnical engineering, and the right or wrong of the result from stability analysis on surrounding rock is related to success or failure of an underground project. In order to study the deformation rules of weak surrounding rock along with lateral pressure coefficient and burying depth varying under high geostress and discuss the dynamic variation trend of surrounding rock, the paper based on the application of finite difference software of FLAC3D, which can describe large deformation character of rock mass, analog simulation analysis of surrounding rock typical section of the class II was proceeded. Some conclusions were drawn as follows: (1) when burying depth is invariable, the displacements of tunnel surrounding rock have a trend of increasing first and then decreasing along with increasing of lateral pressure coefficient. The floor heave is the most sensitive to change of lateral pressure coefficient. The horizontal convergence takes second place. The vault subsidence is feeblish to change of lateral pressure coefficient. (2) The displacements of tunnel surrounding rock have some extend increase along with increasing of burying depth. The research conclusions are very effective in analyzing the stability of surrounding rock of Yunling tunnel. These are going to be a reference to tunnel supporting design and construction.

scholarly journals Rise and Decay of the COVID-19 Epidemics in the USA and the State of New York in the First Half of 2020: A Nonlinear Physics Perspective Yielding Novel Insights

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Till D. Frank
Keyword(s):  
New York ◽  
Human Life ◽  
Compartment Model ◽  
The State ◽  
Stability Parameters ◽  
Intervention Measures ◽  
Infection Dynamics ◽  
The Usa ◽  
Three Stages ◽  
The Stability

As of December 2020, since the beginning of the year 2020, the COVID-19 pandemic has claimed worldwide more than 1 million lives and has changed human life in unprecedented ways. Despite the fact that the pandemic is far from over, several countries managed at least temporarily to make their first-wave COVID-19 epidemics to subside to relatively low levels. Combining an epidemiological compartment model and a stability analysis as used in nonlinear physics and synergetics, it is shown how the first-wave epidemics in the state of New York and nationwide in the USA developed through three stages during the first half of the year 2020. These three stages are the outbreak stage, the linear stage, and the subsiding stage. Evidence is given that the COVID-19 outbreaks in these two regions were due to instabilities of the COVID-19 free states of the corresponding infection dynamical systems. It is shown that from stage 1 to stage 3, these instabilities were removed, presumably due to intervention measures, in the sense that the COVID-19 free states were stabilized in the months of May and June in both regions. In this context, stability parameters and key directions are identified that characterize the infection dynamics in the outbreak and subsiding stages. Importantly, it is shown that the directions in combination with the sign-switching of the stability parameters can explain the observed rise and decay of the epidemics in the state of New York and the USA. The nonlinear physics perspective provides a framework to obtain insights into the nature of the COVID-19 dynamics during outbreak and subsiding stages and allows to discuss possible impacts of intervention measures. For example, the directions can be used to determine how different populations (e.g., exposed versus symptomatic individuals) vary in size relative to each other during the course of an epidemic. Moreover, the timeline of the computationally obtained stages can be compared with the history of the implementation of intervention measures to discuss the effectivity of such measures.

scholarly journals Analysis and Calculation of Stability Coefficients of Cross-Laminated Timber Axial Compression Member

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4267
Author(s):  
Qi Ye ◽  
Yingchun Gong ◽  
Haiqing Ren ◽  
Cheng Guan ◽  
Guofang Wu ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Axial Compression ◽  
Calculation Method ◽  
National Standards ◽  
Test Results ◽  
Average Deviation ◽  
Stability Coefficient ◽  
Cross Laminated Timber ◽  
Stability Bearing Capacity ◽  
The Stability

Cross-laminated timber (CLT) elements are becoming increasingly popular in multi-storey timber-based structures, which have long been built in many different countries. Various challenges are connected with constructions of this type. One such challenge is that of stabilizing the structure against vertical loads. However, the calculations of the stability bearing capacity of the CLT members in axial compression in the structural design remains unsolved in China. This study aims to determine the stability bearing capacity of the CLT members in axial compression and to propose the calculation method of the stability coefficient. First, the stability coefficient calculation theories in different national standards were analyzed, and then the stability bearing capacity of CLT elements with four slenderness ratios was investigated. Finally, based on the stability coefficient calculation formulae in the GB 50005-2017 standard and the regression method, the calculation method of the stability coefficient for CLT elements was proposed, and the values of the material parameters were determined. The result shows that the average deviation between fitting curve and calculated results of European and American standard is 5.43% and 3.73%, respectively, and the average deviation between the fitting curve and the actual test results was 8.15%. The stability coefficients calculation formulae could be used to predict the stability coefficients of CLT specimens with different slenderness ratios well.

scholarly journals Stability and Emission Characteristics of Diesel-Ethanol-Coconut Methyl Ester Blends for the Diesel Engines

2015 ◽  
Vol 14 (2) ◽  
pp. 1
Author(s):  
Tanti Ardiyati ◽  
Nathaniel P. Dugos ◽  
Susan A. Roces ◽  
Masaaki Suzuki ◽  
Kusnanto Kusnanto
Keyword(s):  
Methyl Ester ◽  
Diesel Engines ◽  
Emission Characteristics ◽  
Test Results ◽  
Fuel Blends ◽  
Fuel Consumption Rate ◽  
Efficient Combustion ◽  
Smoke Opacity ◽  
The Stability ◽  
Blended Fuels

The stability and emission characteristics of diesel-ethanol-coconut methyl ester (CME) blends were studied to determine the most suitable fuel blends to be applied in diesel engines. This is done in order to assess the potential of the blends as a substitute for commercially available diesel fuel used in diesel engine. The stability results of the blends using 100% and 99.5% ethanol purity showed that the fuel blends containing ethanol up to 10% and CME of 5% and greater exhibited high mutual solubility at any temperature range and were resistant to microbial growths after 3 months storage. Engine operations at low speed especially at idle-no load and using a bigger size engine lead to a minimum ignition delay and result in lower fuel consumption rate. The emission test results with the new- blended fuels showed a reduction in CO2 and increasing percentage by volume of CO2 compared to commercially available diesel. The blends could deliver an efficient combustion and could run efficiently since production of the CO2 gases is higher than that of CO. The blends of 80% diesel, 5% ethanol, 10% CME; and 80% diesel, 10% ethanol, 10% CME could reduce the smoke opacity compared to commercially available diesel.

Simulation Analysis of the Working Process of the Corn Seed Metering Device with Combination Inner-Cell

2012 ◽  
Vol 215-216 ◽  
pp. 160-167 ◽  
Author(s):  
Qing Long Li ◽  
Ji Yang Yu ◽  
Qiang Qiang Zhang ◽  
Jian Qun Yu ◽  
Hong Fu
Keyword(s):  
Simulation Analysis ◽  
Three Dimensional ◽  
Bench Test ◽  
Particle Model ◽  
Test Results ◽  
Working Process ◽  
Corn Seed ◽  
3D Cad ◽  
Novel Method ◽  
Seed Metering Device

A three-dimensional discrete element method analytic model of the corn seed metering device with combination inner-cell was established based on its 3D CAD model, and the three-dimensional particle model of corn seeds was built by using the method of combination spherical particle. The working process of the corn seed metering device was simulated and analyzed by self-developed three-dimensional CAE software. It was observed that the simulative results of the seeding performance, clearing angles and dropping angles of the corn seeds well agreed with the bench test results. A novel method for studying and designing of the corn seed metering device was put forward.

Analysis of Climbing Obstacle Capability and its Influential Factors of Omni-Directional Wheeled Robot

2012 ◽  
Vol 591-593 ◽  
pp. 717-721 ◽  
Author(s):  
Ai Cheng Li ◽  
Huo Hong Tang ◽  
Bao Lin Feng ◽  
Lu Li
Keyword(s):  
Theoretical Foundation ◽  
Simulation Analysis ◽  
Influential Factors ◽  
Mechanics Model ◽  
Wheeled Robot ◽  
Obstacle Height

The perpendicular climbing obstacle capability of omni-directional wheeled robot was studied, based on simplified mechanics model. The relation between influential factors and perpendicular climbing obstacle height was given under two conditions: simultaneously climbing obstacle by two front wheels and simultaneously climbing obstacle by two rear wheels. Then maximum perpendicular climbing obstacle height of this omni-directional wheeled robot was calculated. Simulation analysis to the result by MATLAB was done. The simulation analysis gave theoretical foundation to the climbing obstacle capability of omni-directional wheeled robot.

scholarly journals Lyapunov Based Estimation of Flight Stability Boundary under Icing Conditions

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Binbin Pei ◽  
Haojun Xu ◽  
Yuan Xue
Keyword(s):  
Equilibrium Point ◽  
External Disturbance ◽  
Stability Boundary ◽  
Wind Tunnel Test ◽  
Test Results ◽  
Theoretical Support ◽  
Effect Model ◽  
Short Period ◽  
The Stability ◽  
Period Model

Current fight boundary of the envelope protection in icing conditions is usually defined by the critical values of state parameters; however, such method does not take the interrelationship of each parameter and the effect of the external disturbance into consideration. This paper proposes constructing the stability boundary of the aircraft in icing conditions through analyzing the region of attraction (ROA) around the equilibrium point. Nonlinear icing effect model is proposed according to existing wind tunnel test results. On this basis, the iced polynomial short period model can be deduced further to obtain the stability boundary under icing conditions using ROA analysis. Simulation results for a series of icing severity demonstrate that, regardless of the icing severity, the boundary of the calculated ROA can be treated as an estimation of the stability boundary around an equilibrium point. The proposed methodology is believed to be a promising way for ROA analysis and stability boundary construction of the aircraft in icing conditions, and it will provide theoretical support for multiple boundary protection of icing tolerant flight.

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