Loading...

Current Issue

Dec. 2012, Volume 19 Issue 6 Previous Issue    Next Issue
Reliability and its sensitivity analyses for the folding support locking mechanism using extreme learning machine
YIN Kai, LAI Xiong-Ming, WU Zheng-Hui
Chinese Journal of Engineering Design, 2012, 19(6): 417-421.  
Abstract( 930 )   HTML( 0 )     PDF(809KB)( 956 )
For the most reliability problems with implicit limit state function in engineering mechanism, a new method based on extreme learning machine(ELM) that regress approximation of the limit state equation for reliability and reliability sensitivity analysis was presented. Using the fast learning capacity of extreme learning machine, implicit limit state function was approximated to explicit limit state function by combining the extreme learning machine with Monte Carlo method. The failure probability of mechanism was calculated using Monte Carlo method, and then explicit limit state function could be employed to analyze the sensitivity of each parameter. The method using single hidden layer feedforward neural network learning algorithm, thus in fitting the nonlinear limit state equation performed superior and has a high accuracy and efficiency. Finally, the reliability and sensitivity analysis of the folding support lock mechanism in a type of landing gear were carried out using the presented method. The results show that the presented method has virtues of high accuracy and efficiency. Thus, it is valuable for the engineering application.
Improved bacterial foraging algorithm and its application to design of frame structures
ZHANG Can, LIU Feng, LI Li-Juan
Chinese Journal of Engineering Design, 2012, 19(6): 422-427.  
Abstract( 1005 )   HTML( 1 )     PDF(740KB)( 953 )
Based on the basic principles of bacterial foraging algorithm(BFA), an improved bacterial foraging algorithm(IBFA) was proposed, which combined with heuristic algorithm, and was applied to optimal design of frame structures. The weight optimization design of discrete variable was carried out on a onebay eightfloor frame structure and a twobay fivefloor frame structure using this algorithm.The calculation results were compared with those of BFA. The optimal results show that the improved bacterial foraging algorithm has better convergence velocity and accuracy, and can be applied to optimal design of engineering structures.
Hybrid magnetic suspension platform control design and implementation based on model design methodology
LIU Lin, TANG Meng
Chinese Journal of Engineering Design, 2012, 19(6): 428-433.  
Abstract( 1017 )   HTML( 0 )     PDF(680KB)( 1149 )
We applied modelbased design method to hybrid magnetic suspension system combing with Matlab/Simulink simulation of floatingpoint PID control and fixedpoint controller DSP2812.Based on the method and architecture, we established the control system quickly, the system model/design/simulation, as well as hardware implementation can be seamlessly integrated. Firstly, we built system model and control design for hybrid magnetic suspension system in matlab/simulink environment, and processed it by using its own fixedpoint processing on the digital controller. Simulink code model was transforred  with a digital averaging filter. Secondly, we done Oncircuit debugging and verification of the algorithm via RTDX functions,and then obtained the optimization code model. Finally, downloaded the automatically generated C code into the DSP platform for controlling the hybrid magnetic suspension system. The real experiment system was developed and the control result showed that the modelbased method can integrate and unify from model design and simulation to system implementation.
Energetic parameter test on disc shear of plate and establishment of the best blade clearance mathematical model
MA Li-Feng, HUANG Qing-Xue, HUANG Zhi-Quan, CHU Zhi-Bing, HAN He-Yong
Chinese Journal of Engineering Design, 2012, 19(6): 434-439.  
Abstract( 1479 )   HTML( 4 )     PDF(807KB)( 1010 )
According to the problem of poor quality of plate of disc shear cutting and the larger deviation value obtained from shear stress theory, we carried out the production test, data acquisition and regression fitting. There is an error of -9.56%~+56.5% between the existing theoretical calculation results and measured results. The nonlinear changes of shear resistance and shearing area with the increasing of the film thickness were not considered in theoretical formulas, so the shear stress accuracy was substantially reduced. These theoretical formulas are suitable for thin plate calculation, however if these theoretical formulas are used in the thickness plate calculation of shearing force, there will need some further improvement.  At the same time, this paper established a shear blade gap adjustment model which considering plate thickness, material properties, cumulative shear area of the disc, and also the cutter device in the shear deformation in the process of cutting clearance effect. Therefore, in view of the different disc shear equipment, the knife shaft load deformation value influence was considered in this model, to modify the model to be perfect, the clearance adjusting process parameters can be obtained.
Variation of aerodynamic load engineering analysis during wind turbine run
GUAN Xin, SUN Zhi-Li, BI Xiao-Guo, WEI Yun-Gang, LIU Xu-Dong
Chinese Journal of Engineering Design, 2012, 19(6): 440-444.  
Abstract( 747 )   HTML( 0 )     PDF(607KB)( 1057 )
To improve design reliability of wind turbine, it needs the calculating method of aerodynamic load during wind turbine run. NACA special airfoil of wind turbine was analyzed based on the project. Combined with thin theory, airfoil angle of attack variation was deduced, meanwhile wind turbine actual force was calculated in each blade location point when blade of wind turbine was running based on wind shear theory and tower shadow effect. According to actual condition calculation method was engineering simplified, aerodynamic load calculation method of wind turbine blade was obtained. By this method aerodynamic load which was calculated match with experiment result, it fits better.
The establishment and simulation of the parallel mechanism virtual prototype
YANG Hui, ZHAO Heng-Hua, FU Hong-Shuan
Chinese Journal of Engineering Design, 2012, 19(6): 445-448.  
Abstract( 869 )   HTML( 1 )     PDF(496KB)( 884 )
By using 3-TPT parallel mechanism for the study, the positive solutions and negative solutions of the kinematics equations were established. And then the negative solutions of the kinematics were simulated by using LabVIEW and MATLAB software and the theoretical curves of rod length could be got. The parallel mechanism virtual prototype was established and its movement was simulated in ADAMS/View environment. From the results, the curves of rod length could be got. By comparing with the theoretical curves, the negative solutions of the kinematics equations are proved to be right. And it also indicates that the stationarity is well when the mechanism moves in space. In addition, complex mathematical modeling and derivation could be avoided by using virtual prototyping technology to study the parallel machine tool kinematics. Thus the workload of the kinematic analysis is reduced greatly.
Design and optimization of oscillating roller follower cam
HUANG Shang-Bing, JIN Guang, AN Yuan, WANG Dong
Chinese Journal of Engineering Design, 2012, 19(6): 449-453.  
Abstract( 2126 )   HTML( 0 )     PDF(572KB)( 1458 )
The design of oscillating roller follower cam and integrated optimization of contact stress and body size were researched for an optical system. Based on design requirements, analytical method gave profile curve of cam through Matlab. Stress analysis was done on the basis of Hertz formula, and established mathematical model of optimization of contact stress and body size. By optimization contact stress declines from 198 MPa to 176 MPa (11%), and body size declines 50%. The optimization makes cam better meeting the application requirements and miniaturization requirements.
Elevation design method of intersection based on hybrid digital elevation model
YANG Liu, ZHENG Jian-Long
Chinese Journal of Engineering Design, 2012, 19(6): 454-459.  
Abstract( 733 )   HTML( 1 )     PDF(797KB)( 975 )
In the CAD methods of elevation design method for intersection, the traditional twodimensional method cannot conduct threedimensional visual design and spatial analysis. In addition, the surface fitting method does not have a unified application standard and is difficult to obtain an analytical solution. Using the premise of the method of CAD and grid square to design contour, the general geometric model and design procedure for intersections were proposed. The advantages and feasibility of describing the threedimensional design surface with a hybrid digital elevation model incorporating irregular grid and triangulated irregular network were analyzed. The mechanism and procedure of modeling were discussed. The methods of creating contour and querying elevation,gradient, and exposure using the digital elevation model were clarified. The program function was implemented with.net advanced development techniques and managed C++ language programming based on the AutoCAD platform. The experimental results show that this method can process the design of intersections of various forms accurately and efficiently.
The rapid reverse design of excavator bucket teeth with both complex inner cavity and outer shapes
WANG Chun-Xiang, MENG Fan-Juan
Chinese Journal of Engineering Design, 2012, 19(6): 460-464.  
Abstract( 629 )   HTML( 1 )     PDF(674KB)( 776 )
To obtain physical models and CAD drawings of the point cloud reverse modeling of a bucket tooth of a certain excavator, quickly materialized method of the bucket tooth point cloud was studied. Reverse design approach which based on the “surface reconstructionmaterializeddrawings” was adopted, reverse strategy include using Imageware software to complete surface reconstruction of the cavity and pin hole area which have high precision, and using Geomagic Studio software to complete surface reconstruction of the general shape of the bucket tooth, and using Pro/E software to complete the surface merger and materialization was proposed. The main processes and methods included tooth point cloud data segmentation, surface reconstruction and consolidation, as well as materialization and the access to get engineering drawing was described. The results show that: for bucket teeth with many and complicated molded surfaces, the selection of the tools of reverse the surface and the data methods to segment the point cloud determine the efficiency of reconstruction of the surface and entity and if its success or failure. It will significantly improve the efficiency of the reverse design if we select appropriate strategies and tools to reverse, simplify rational point cloud segmentation, and surface reconstruction and consolidation, and the process of building physical models.
Electrical control and application of 3D motion system based on PLC
QIAO Dong-Kai, YANG Xiang-Yu, LI Duo-Min, LI Li-Bo
Chinese Journal of Engineering Design, 2012, 19(6): 465-468.  
Abstract( 996 )   HTML( 0 )     PDF(638KB)( 974 )
As for the phenomenon of lots of 3D motion control used in industrial productive process, this movement control adopt relay contact device control frequently, the method is low in stability and reliability, it will consume a lot of human and financial resources. So character of such movement was summed up, and the universal control goal of system was established. The method of 3D motion control based on PLC studied was suitable for all the 3D motion. In the specific application, this method can be used if only the parameters were changed. Good results were achieved when the design was used in 3D control of the movable hood filter.
Research on miniaturization of dynamic parameter recorder based on SoC
CHEN Chang-Xin, JIN Hong, MA Tie-Hua, ZU Jing
Chinese Journal of Engineering Design, 2012, 19(6): 469-472.  
Abstract( 659 )   HTML( 0 )     PDF(529KB)( 966 )
The main characteristics of storage measurement is that measurement instrument can be embedded into the body of measured object or be placed in the measured environment to gain dynamic parameter in real time. In order to reduce the influence of measurement instrument on the object, we need to reduce the volume of test instrument and realize miniaturization of the test instrument. As for the miniaturization requirement of storage measurement instrument, a method was put forward in which the analogtodigital conversion unit, control unit, storage unit, interface unit of digital circuit were integrated into the special SoC chip. At the same time, test circuit was divided into three types of circuit,namely,analog circuit unit,SoC digital circuit unit,battery unit,and threedimensionally sealed them into mechanical shell.thus, a microdynamic parameter recorder which realized the miniaturization was design. The volume of the recorder is about 10 cm3 and the recorder can obtain dynamic parameters realtime, which can be embedded inside the measured body or placed in the measured environment. The experiment show that the recorder can be used for strain and other dynamic parameters measurement, such as penetration acceleration, the pressure in the gun,et al.
Design and simulation research on tester of perforator cavity pressure
HU Ming-Xiang, ZU Jing, CUI Chun-Sheng, MA Tie-Hua
Chinese Journal of Engineering Design, 2012, 19(6): 473-478.  
Abstract( 799 )   HTML( 0 )     PDF(855KB)( 909 )
The outer pressure of perforation could not directly reflect the perforation process. To better optimize the process of wells perforated and assess the power of perforator, we developed a perforating gun cavity tester. Due to the special circumstances of the perforating gun cavity, the size and shape of the pressure measurement instruments made strict requirements. In view of the summary of the tests in the XXX perforating base of the Karamay Oilfield, the deformation of the instrument shell that directly affect the instrument internal test circuit. The “bomb” structure of the test instrument shell further research on the basis of plastic mechanics. The results show that the “bombtype” thickwalled shell structure has a good energyabsorbing role in resolving the problem of shell shock resistance.
Analysis of the key factors for the identification probability in embedded RFID system
LIU Ya-Li, HU Sheng-Bo, YAN Fu-Yu
Chinese Journal of Engineering Design, 2012, 19(6): 479-484.  
Abstract( 831 )   HTML( 0 )     PDF(746KB)( 1069 )
To improve the identification probability of RFID systems, optimize and design RFID systems, identifying the key factors that affected the identification probability of RFID systems is needed. Based on the model of key process input variables and key process output variables process, we proposed designing of experiment method to analyze the key factors which affected the identification probability of RFID systems, and then identified the key factors which included the plane angle of the tag and reader, reader antenna number as well as the distance between tag and reader. By testing under the conditions of tag embedded in automobile tires un-vulcanized and vulcanized, we further determined the key factors which affected the identification probability in embedded RFID system. Finally, we adopted binomial logistic regression method to analyze each key factor's contribution to the identification probability by using MINITAB software. The statistical analysis results are beneficial to optimize the design of RFID systems and to improve the identification probability of RFID systems simultaneously.
Improved evidence theory and its application in fault diagnosis of power system
LI Ling-Ling, JING Li-Ting, MA Dong-Juan, LI Zhi-Gang
Chinese Journal of Engineering Design, 2012, 19(6): 485-488.  
Abstract( 747 )   HTML( 1 )     PDF(512KB)( 739 )
A new Dempster-Shafer evidence combination rule based on the Hamming distance was proposed aiming at solving the fusion problem of highly conflicting evidence. At first, we judged the evidence conflict degree according to the size of the conflict coefficient, the Hamming distance was used to determine the similarity to distinguish each of evidence, and the weight was given to the evidence. Then the original basic probability distribution function was redistributed, finally the more reasonable the syncretic result was obtained. At last, the data fusion method was applied to power system fault diagnosis example, the calculation result indicated that the method was effective and reasonable, and the conclusion was more actual.
Startup behavior research of coaxial cylinder magnetic coupler
ZHANG Hong-Jun, BAO Li, LI Xu-Yan
Chinese Journal of Engineering Design, 2012, 19(6): 489-493.  
Abstract( 1137 )   HTML( 0 )     PDF(589KB)( 923 )
Magnetic coupler is a kind of transmission mechanism which is widely used in vacuum, chemical industry. When the load suddenly increases to overload, the phenomenon that torque transmission is over due to slippage will happen. In order to solve the problem, the transmission mathematical model which is about starting up process of the magnetic coupler was established after the theoretical derivation and calculating the determinant condition of simple starting decoupling. We applied MATLAB to simulating the process of the magnetic coupler start-up and decoupling. Furthermore, we made the experiment based on the torque and angle deviation tester, verified the determinant conditions of the simple starting decoupling. The paper presents a time delay activated method to solve the problem of decoupling when it starts. It has significance for popularizing magnetic couplers.
Research on onboard electronic system distributed architecture of civil aircraft
XU Ke-Hua, CHEN Mou, XU Yang, WU Qing-Xian
Chinese Journal of Engineering Design, 2012, 19(6): 494-498.  
Abstract( 1444 )   HTML( 0 )     PDF(698KB)( 772 )
In order to solve the resource conflict and systematic coupling problem that the integration of onboard process system platform brings, the integration of mechanical and electronical system was promoted, distributed integration modular avionics system(DIMA) was used, the process modular was distributed near to signal source, the big cabinet of integrated avionics system was replaced using distributed small cabinet of DIMA, these small cabinets were connected using high speed data bus, the avionics full duplex switched ethernet(AFDX), timetrigger ethernet (TTE network) and ethernet passive optical network(EPON) were selectively analyzed in the application of DIMA system, and theirs technology characteristic were compared, its advantage and characteristic based on AIRBUS DIMA system were analyzed based on the architecture of DIMA. By using the architecture of DIMA, the resource conflict and systematic coupling problem can be resolved, at same time, the structure of back board of process cabinet can be simplified,can be widely used in civil aircraft.
16 articles