China Mechanical Engineering

Information State and Information Measurement for Modeling Design Based on TBS

GAN Ge, CHEN Luo-Luo, ZHANG Xue-Mei

2013, 24(16): 2131-2135.

Asbtract ( )

PDF (485KB) ( )

References | Related Articles | Metrics

Three kinds of information states of the product information transfer process were introduced,which came from TBS to sub-basic skeleton or parts layer-by-layer.In the process,the product had TBS,sub-basic skeleton,parts three information states and the structures of the process were of series and parallel.And in terms of the structures of information transfer and variant designs,the information distance between the product information states was measured by calculation transition probability.This method provides the basis of manufacturing informatics for design.

Duplex Route Planning for Automatic Parallel Parking System with Multi-constraints

LI Gong-1, GUO Kong-Hui-1, 2, SONG Xiao-Lin-1

2013, 24(16): 2135-2140.

Asbtract ( )

PDF (539KB) ( )

References | Related Articles | Metrics

Duplex route was used for strait parking set which was not big enough for car reverse into safely.Potential collision points were analyzed and variables were selected for parking trajectory and constraint equations were established respectively according to the characteristics of different parking paths.Parking set length minimization function was presented to realize the minimal parking set length and radius maximization function was presented to realize the parking trajectory with the restrictions mentioned above respectively.The two approaches were used in a same parking condition,and the trajectory functions were solved in MATLAB.The simulation results show that the two approaches can park car into parking set safely,but parking set needed for the second method is smaller than that of the fist method and the second method parks the car into the same parking set more easily than the first method does.

Feature Extraction of AC Square Wave SAW Arc Characteristics Based on Wavelet Packet Denoising and LMD

HE Kuan-Fang, XIAO Sai-Wen, WU Ji-Gang

2013, 24(16): 2141-2146.

Asbtract ( )

PDF (628KB) ( )

References | Related Articles | Metrics

In order to extract the arc feature information associated with welding quality in alternating current square wave submerged arc welding(AC square wave SAW),a LMD method combining with the wavelet packet transform was put forward.After performing wavelet packet denoising,the LMD was used to decompose the collected current signals into a number of product functions(PFs),and then the PFs were selected for the Hilbert transform and energy entropy calculation.Application of wavelet denoising and LMD can
get the vaild waveform distortion of different frequency components effectively and the amplitude variation characteristics in the time scale.On the basis of that,the Hilbert transform and energy entropy calculation can be used to extracte arc characteristics effectively.Experimental results show the effectiveness of this approach to extract the arc physical information related to welding quality. 

Microstructure of Al-Ti Intermetallic Compound Particle Reinforced Aluminum Matrix Composite In-situ Synthesized by Friction Stir Processing 

CHEN Yu-Hua, GE Jun-Wei, HUANG Chun-Beng, HUANG Ke-Hui, KE Li-Meng

2013, 24(16): 2146-2149.

Asbtract ( )

PDF (483KB) ( )

References | Related Articles | Metrics

Al-Ti intermetallic compound(IMC) particle reinforced aluminum matrix composite was in-situ synthesized by friction stir processing,the microstructure and fine structure of aluminum matrix composite were
studied.The results show that TiAl3 IMC particle reinforced aluminum
matrix composite can be fabricated by friction stir processing method with pure Ti powder and aluminum plate as raw materials.In addition to the generated TiAl3 intermetallic compound,there are also a number of pure Ti particles and solid solution of aluminum matrix on the aluminum base metal.The grains of pure aluminum can be refined by rotational extrusion alloying,and the size of aluminum are about 200nm.The size of a TiAl3 particle is about 200nm to 300nm.

Research on Wind Turbine Tower Structure Parameter Optimization in Extreme Service Environment

DAI Ju-Chuan-1, LIU Xuan-1, YANG Shu-Yi-1, WEN Ze-Jun-1, CHEN Xiang-Bing-2

2013, 24(16): 2150-2156.

Asbtract ( )

PDF (584KB) ( )

References | Related Articles | Metrics

Structure parameter optimization of wind turbine tower in extreme service environment was carried out herein.A segmented linear change structure
was employed to describe the tower
wall thickness,and the tower load analysis method was introduced based on blade element momentum(BEM) theory.The related characteristics of tower structure parameters and stress under extreme loads and that of
tower structure parameters and natural frequency were analyzed by using the finite element simulation method.
The SVM method was used to build a rapid calculation model of tower structure
parameters and stress,and that of tower structure parameters and natural frequency.
Then,the minimum tower mass was selected to be as the optimization goal;the strength,natural frequency and the boundary conditions were selected to be as the constraint conditions;the GA was employed to be as the optimization algorithm.Based on the above proposed optimization method,a 2MW wind turbine tower was optimized and the optimization results show that the tower mass is reduced by 3.5% and the stress curve is smoother.

Mechanical Fault Diagnosis Model Based on IABC Algorithm Optimized Multiple LSSVM Classifier Group

LI Xin-Bin, CHEN Yun-Jiang, ZHANG Chu-Qing

2013, 24(16): 2157-2164.

Asbtract ( )

PDF (800KB) ( )

References | Related Articles | Metrics

In order to improve the fault diagnosis accuracy,the paper presented a fault diagnosis model based on IABC optimized multiple LSSVM classifier group.It used multiple feature extraction methods to get the complete time-frequency domain features.Then IABC was utilized to optimize LSSVM parameters,because it had strong searching ability and fast convergence to improve classification efficiency.And in the diagnostic decisions stage,the criterion matrix was utilized to make the decision of the multiple classifiers.Through the comparison with the traditional methods,the results show that it can obtain complete features information,and can get LSSVM parameters more quickly and effectively.The fusion decision based on criterion matrix fully considering the differences of sub-classifiers performance,and it ensures the higher accuracy of diagnostic decisions.Finally,the various simulation results show that the algorithm can be used in mechanical fault diagnosis well. 

Motion Compatibleness Analysis and Optimization of Double Front Axle Steering Mechanism and Suspension System

LIU Zhen-Qing-1, DIAO Liang-1, 2

2013, 24(16): 2164-2167.

Asbtract ( )

PDF (463KB) ( )

References | Related Articles | Metrics

According to the tires' serious wear phenomenon and running deviation of a four axle heavy vehicle with double front axle steering mechanism reported by one enterprise,a mathematical model of vehicle's steering and suspension system was established,the motion interference between suspension and steering system was researched, and then the double swing arm's movement rules was
analyzed.Finally,this paper took an optimization design of the incompatibility of the
movement between suspension and steering linkage,and the trend of tires' non-pure rolling, to reduce the tires' wear and improve the moving compatibility between suspension and steering system,making the road performance of this vehicle much better than before.

FEA and Mode Experiment of Intelligent 4WD Transfer Case Box

CHEN Li-Qing-1, 2, CHEN Mo-Wei-1, WANG Yu-Meng-1, 4, HU Fang-1, HUANG Min-Feng-3

2013, 24(16): 2168-2172,2194.

Asbtract ( )

PDF (708KB) ( )

References | Related Articles | Metrics

In connection with the design of transfer case,a design method was proposed combined FEA with modal experiment for transfer case herein.Firstly,the modal experiments of transfer case was done by combing the modal experiment with FEA,and the accuracy of the model was verified;secondly,according to the established model of transfer case,the force rolled in transfer case's bearing in different working conditions were analyzed by using Romax software,thus the boundary conditions became more accurate,and then the statics and fatigue analysis were analyzed accurately.The case study shows that:in extreme conditions the maximum stress is as 196.8MPa;it is beyond the allowable stress of the material.So the transfer was improved,through comparative analysis,and the stress and displacements of modal are reduced significantly after improvement,and it meets the design requirements. 

Neural-network Compensation Control for Exoskeleton Robot Based on Computed Torque Control

FENG Chi-Guo

2013, 24(16): 2173-2179.

Asbtract ( )

PDF (608KB) ( )

References | Related Articles | Metrics

Based on the dynamics model of an exoskeleton robot walking on the treadmill for gait rehabilitation in robot-in-charge mode,the computed torque controller with a neural-compensator and portion-differential feedback was designed.According to the Lyapunov function,the stability and the convergence of the control system were proved.The simulation on the virtual prototype were carried out in a conllaborative simulation platform.The results indicate that the proposed method can remove uncertain factors of the dynamic model effectively and increase the ability of the trajectory tracking.

Dynamics Characteristics Analysis of Lifting Platform for a Top-speed Dispensing System

LIU Xiang-Quan, ZUO Yun-Bei

2013, 24(16): 2179-2184.

Asbtract ( )

PDF (557KB) ( )

References | Related Articles | Metrics

Based on the analysis of the dynamics characteristics for transmission system of lifting platform in a top-speed dispensing system,9-DOF dynamics model of transmission system on the vertical direction were established and the dynamics equation was derived.The stimulation matrix was inversely solved according to the running speed of lifting platform.Then MATLAB was used to solve the dynamics equations accurately,the varying regularity of dynamic response was analyzed and compared.The natural frequency was solved and how did the natural frequency vary with different positions of lifting platform and load was studied.

Research on Torque Response Characteristics of Transmission System Based on Vector Control(VC) and Direct Torque Control(DTC) Strategies

DAN Xiao-Hui-1, HU Chuan-He-1, SHI Quan-1, JU Chi-Gong-1, TU Yong-2

2013, 24(16): 2185-2188.

Asbtract ( )

PDF (454KB) ( )

References | Related Articles | Metrics

Aiming at the torque response characteristics of transmission system based on VC and DTC strategies,through a torque non-closed-loop experimental platform of transmission system,a step signal was given,the torque response was tested by using different speeds,the testing results were analysed and
evaluated in the terms of control theory.The results show that the VC strategy can get a quick torque response of transmission system at the low-speed,50% torque load conditions,but overshoot obviously;the DTC strategy can get a quick torque response at the low-speed condition,
no overshoot.Under the same conditions,torque response of DTC strategy is faster
than that of VC strategy,but less stable at low speeds.

Scheduling of Flexible Job Systems on “Manpower-Multiple Single Machine” Based on Genetic Algorithm

LIU Hong-Wei, LIU Zhi-Hui

2013, 24(16): 2189-2194.

Asbtract ( )

PDF (537KB) ( )

References | Related Articles | Metrics

A class of scheduling problem with paralleled multiple single machine model was studied.Taking into account the factors of personnel to operate the machine,in the number of operators and its operating speed difference constraints,how to arrange staff work and machine operation sequence was studied.
Genetic algorithm was used to solve this problem and gave a new hybrid coding method of genetic algorithm based on the staff and machine operation to avoid the production of illegitimate solution in the
genetic manipulation process.Programming by MATLAB an instance was solved,and the efficient results were obtained.Comparing with the single machine model without the consideration of manpower the efficiency of new system was confirmed.

Self-adaptively Rescheduling Flexible Job Shop with Double Genetic Coding

LI Beng-1, 2, TANG Qiu-Hua-1, JIA Xu-Hui-1, CHEN Beng-He-3

2013, 24(16): 2195-2201.

Asbtract ( )

PDF (777KB) ( )

References | Related Articles | Metrics

Aiming at three kinds of uncertain disturbances appearing
frequently within flexible Job Shop,i. e. order changes,operation delays and machine breakdown,a novel rescheduling approach was designed.First,a self-adaptive rescheduling framework was constructed after setting up a set of system parameters including
optional machines and operation times,and formulating strategies about updating systematical parameters under single or multiple
disturbances.Second,codes for depicting job sequence and machine assignment
were combined together in double genetic chromosomes to encode the above system
parameters so as to execute self-adaptive rescheduling.Third,through genetic
algorithm,better solutions were inherited by selection operators and the population of
each generation was expanded gradually via crossover and mutation operators,
and hence global optimization was achieved effectively.Experimental studies with 400
cases from small to large scale verify that near-optimal reschedule can be obtained
under controllable computational times and thus can be applicable in practice. 

#br# Manufacturing Services Matching Based on Dynamic Description Logic in Cloud Manufacturing Environment

YANG Nan, LI Dong-Bei, TONG Yi-Fei

2013, 24(16): 2202-2207.

Asbtract ( )

PDF (605KB) ( )

References | Related Articles | Metrics

To solve the heterogeneous and dynamic manufacturing services matching problems in cloud manufacturing environment,an approach to manufacturing services matching was proposed based on dynamic description logic.The action theory based on DDL was established which contained the principles of
complex action description,disassembly and assembly.On the basis of action theory,a strategy of “five-level-three-phase” service matching was put forward.Firstly,a model with six components was proposed based on DDL,which can describe the input/control/output of manufacturing services accurately and support the semantic description of services matching.Then,the rules and the matching algorithm of cloud manufacturing
services matching were built.Finally,through the cloud transform of a existing forging
manage system,the feasibility and validity of the proposed matching strategy were confirmed.

#br# Analysis of Influence Parameters on Gear's Contact Strength Based on Fractal Contact Model

CHEN Ai, HUANG Kang, ZHANG Pan, SUN Gao

2013, 24(16): 2208-2211.

Asbtract ( )

PDF (464KB) ( )

References | Related Articles | Metrics

According to the gear contact strength theory based on fractal contact
model,several parameters which influence the gear's contact strength were discussed
herein.These parameters included roughness amplitude parameters,material property
parameters,fractal dimension,and the surface roughness.Results show that reducing
the roughness amplitude parameters and improving the material parameters can improve the gear's contact strength.Fractal dimension and surface roughness don't
meet the linear relationship with contact strength,and exist an optimal value when
the contact strength gets a minimum value. 

Key Technologies for Image Display Performance under Vibration Environment

HOU Yang-1, DIAO Xin-Bei-1, MA Zhong-1, CHEN Min-Hua-2

2013, 24(16): 2212-2215,2222.

Asbtract ( )

PDF (556KB) ( )

References | Related Articles | Metrics

Based on computer vision technology,the key technologies
were presented for an automatic detection and analysis of the display performance of
image display device under
the vibration environment.Firstly,we emphasized on the design of the
bracket for image acquisition under vibration environment.After that,
we focused on key algorithm of video motion compensation to reduce image blur and
offset when capturing an image under camera-moved conditions.At last,we detected
and extracted the straight line with sub-pixel accuracy.The experimental results show that
the system can reduce the impact of vibration on the capture images,after video motion
compensation operation,we can detect and analyze image with sub-pixel precision,
and based on the results of the detection we can achieve objective analysis for
image display performance.

Research on Geometric Error Modeling and Parameter Identification Technology Theory of Automotive Camshaft Grinding Based on Multi-body System Theory

FAN Jin-Wei-1, MEI Qin-1, BANG Gao-2, JIN Ai-Hui-1, NING Kun-1, LI Hai-Chong-1

2013, 24(16): 2216-2222.

Asbtract ( )

PDF (554KB) ( )

References | Related Articles | Metrics

This paper focused on the grinding accuracy of an automotive camshaft and executed related research in order to improve the geometric accuracy of MKS8332A CNC camshaft grinder and improved the camshaft grinding accuracy and processing efficiency. A geometric error model of this grinder was analyzed and established by the utilization of multi-body system theory, and the motion constraint equation of precision machining was given. Combining the geometric error parameter identification model based on multi-body system theory with a double ball bar the identification methods were
put forward and could identify the geometric error parameters of the grinder well.
On the basis of above,the calculation methods for precision NC instructions and inverse
contour of cam,ideal NC instructions,grinding errors were all discussed in detail.At last,
a fitting method of the cam-shaped curve and the calculation method of the tool path were all given. 

An Approach to Determine Importance Degree of Targets in Customer Collaborative Products Innovation

MA Jia-Ji-1, YANG Yo-1, LI Fei-1, XIE Jian-Zhong-1, 2

2013, 24(16): 2223-2231.

Asbtract ( )

PDF (742KB) ( )

References | Related Articles | Metrics

In order to solve the problem that importance of targets
was hard to be quantified accurately in customer collaborative products innovation(CCI),an approach to determine the important degree of innovation goals was
proposed.Firstly,a basic structure for target system of CCI was established to certify
integration and system of target.Then,based on combining subjective and objective
methods including AHP and entropy value method,
multi-granularity non-equilibrium semantic treatment method,
a three-stage quantified approach was proposed to calculate and revise the importance
of targets.Finally,the feasibility and effectiveness were verified by a cellphone customer
collaborative innovation example.

Research and Development of Communication between Master Computer and Slave Computer in CNC System

TUN Dong-Dong, ZHOU Xiang-Dong

2013, 24(16): 2231-2234.

Asbtract ( )

PDF (510KB) ( )

References | Related Articles | Metrics

With regard to the application of Ethernet communication,
serial communication and bus communication between the master computer and the
slave computer in CNC system,the paper analyzed the functional requirements,
poposed a reasonable communication mode and communication hierarchy.The
communication mode was client/server mode.Both of client and server contained
communication engine layer,communication abstraction layer,communication interface layer/
communication service layer.Through the analysis to variable service,command
service,alarm service and file service of communication service layer,this paper put forward the
design of every kind of service.Finally,the results of the communication module
test indicate that communication model can communicate through different communication media,and communicate between different platforms.

Dynamic Group Decision-making Fault Diagnosis Method Based on Bayesian Network and TOPSIS

TAO Cheng-Yu-1, CHEN Dong-Ning-2, 3, FENG Zhong-Kuai-1, LV Shi-Jun-2, 3

2013, 24(16): 2235-2241.

Asbtract ( )

PDF (598KB) ( )

References | Related Articles | Metrics

To utilize multi-attribute information and previous results of fault search,a fault diagnosis method of dynamic group decision-making based on Bayesian network and TOPSIS was proposed.Hydraulic system of a concrete pump
distribution valve was given for illustration, the Bayesian network was established to calculate the root nodes' posterior probabilities and criticality importance.According to the information that the current diagnosis result was correct or not and the
influences on the next optimal search decision-making,a heuristic function was defined to obtain the value of heuristic information.
The root nodes' posterior probabilities,criticality importance and heuristic information values were considered comprehensively,and the group's ideal solution and
contrary ideal solution of search schemes were obtained by TOPSIS on the basis of
entropy weight,then the best fault search scheme was obtained.The previous fault
search results' influence on the current search scheme was considered,
then the best solution sequence of the fault search was obtained finally.
The limitations of single-attribute decision making and group decision-making are overcome,and the feasibility and efficiency of fault diagnosis are improved.

Technology of Eliminating Early Failures for NC Machine Tools

FAN Xiu-Jun-1, HU Jing-Lin-2, ZHANG Gen-Bao-1, HU Zhi-1

2013, 24(16): 2241-2247.

Asbtract ( )

PDF (786KB) ( )

References | Related Articles | Metrics

The problem of poor reliability of domestic NC machine tool was studied herein. Starting with modeling and analyzing the failure rate bathtub curve of NC machine tool,the zone of early failures was quantified.Based on in-deep analyzing the causes of early failures and systematically elaborating the mechanism of early fault elimination technology which combined with reliability test technology, early fault elimination technology systems were established and their ideas,methods and contents were elaborated respectively in the stage of failure collection,fault analysis,reliability test and fault elimination.Finally, according to the application of this technology to a NC machine tool manufacturing enterprise in China, the case demonstrates its effectiveness to improve the product reliability.

Study on Dislocation Density Change during Cold Roll-beating of 40Cr

WANG Xiao-Jiang-1, CUI Feng-Kui-1, YAN Gen-Feng-1, LI Yu-Xi-2

2013, 24(16): 2248-2252,2256.

Asbtract ( )

PDF (672KB) ( )

References | Related Articles | Metrics

In order to discover the forming mechanism of 40Cr in
a cold roll-beating process,the 40Cr macro stress was combined with the
dislocation density change mechanism and the 40Cr dislocation density curves
were obtained.Based on the evolution model of micro structure about dislocation density,a change model of the 40Cr was established and the accuracy of the model was
verified.XRD was applied to measure spectrums in the different deformation conditions,combined with
the Dunn formula obtained from 40Cr various crystal surfaces and the
crystal surface as a whole dislocation density
changes under different deformation conditions.By the model validation and test
analysis,the change rules of 40Cr will be further explained from the microscopic view.

Microstructure and Wear Resistance of In-situ Synthesis of TiC/Al3Ti Composite Coating of Gray Cast Iron

RUAN Hong-Yan-1, CHEN Qi-1, SONG Zhen-Da-2

2013, 24(16): 2253-2256.

Asbtract ( )

PDF (517KB) ( )

References | Related Articles | Metrics

A TiC/Al3Ti composite coating on the gray cast iron was fabricated by the reaction
synthesis in melt.The microstructure,interface,micro-hardness and wear resistance were investigated.
The results show that the composite is formed on gray cast iron compactly with a metallurgical bonding interface.TiC presented a strip form as the content of TiC is 20%;with increase of TiC,its shape changes from the strip form to a granular form with decreased size.The hardness of the coating are substantially higher than that of the iron matrix and slightly increases with increasing TiC content.It is found that the composite coatings are more effective in improving wear resistance,greatly enhanced the
surface hardness and the wearing resistance of the gray cast iron.

FEM Simulation Analysis and Estimation on Wet-road Braking Distance of Complex-patterned Tire

CANG Meng-Tan-1, DUAN Fu-Yao-1, ZHOU Chao-2, XU Shan-Hu-1

2013, 24(16): 2257-2261.

Asbtract ( )

PDF (561KB) ( )

References | Related Articles | Metrics

For 205/55R16 radial tire, a numerical investigation of wet-road breaking distance for the vehicles equipped with ABS system was presented. Based on a discrete analysis method, the braking process of tires with different complex pattern and different tread materials on the wet-road with 1.5 mm depth in a series of discrete speeds were studied by using the commercial FEM codes-ABAQUS. According to the results of the simulation, the braking distance was obtained via correlated analysis method. The consistence of the simulation with the corresponding test validates the effectiveness of the method. 

Research on Optimum Design of Hydraulic Flat Transporter Frame Based on Response Surface Method

WANG Xin-Pan-1, GE Tu-Li-1, GUI Tian-2, ZHANG Qing-Wen-1, WANG Qi-1

2013, 24(16): 2261-2265.

Asbtract ( )

PDF (523KB) ( )

References | Related Articles | Metrics

The traditional mechanical design based on stress intensity could not always get the best optimum solution.By the method of stress field test and FE-software ANSYS analysis,the weak parts were obtained.The
stress was concentrated obviously on the chamfer of web's hole between the crossbeams.
Therefore,the hole's length,width and pour circle radius were selected for the
design variables.Based on orthogonal regression design theory and parameterization
FE model of hydraulic's frame,the function of maximum stress was obtained.
The frame's reliability index was obtained using MATLAB mathematics tool case.
The optimum design of the off-road vehicle frame was finally completed based on the
reliability index.Results show that the optimized frame is reliable and lighter.

#br# Study on Sedan Frontal Styling Features Based on Pedestrian Protection

CAO Li-Bei, LONG Teng-Jiao, ZHANG Guan-Jun, LIU Kuo

2013, 24(16): 2266-2271.

Asbtract ( )

PDF (518KB) ( )

References | Related Articles | Metrics

Car styling features were taken for study herein.The front styling features of a compact sedan were extracted for statistical analysis and parametric study.Sedan styling feature parameter description model was created by the styling feature and feature line,to give the styling feature of crash safety properties.Then a multi-rigid body model of the sedan-to-pedestrian crashes was developed for simulation tests.According to the simulation results,quadratic regression equation for pedestrian protection was constructed to analysis the affection of the sedan front styling features to pedestrian injury,and parameter optimization was done.Simulation results show that sedan front styling with leniency and low bumpers,high and steep leading edge of the hood and moderate length of the hood are conducive to pedestrian protection.

Table of Content