Thermal Error Modeling of Precision Positioning Stage

2013 ◽  
Vol 694-697 ◽  
pp. 767-770
Author(s):  
Jing Shu Wang ◽  
Ming Chi Feng

As the thermal deformation significantly impacts the accuracy of precision positioning stage, it is necessary to realize the thermal error. The thermal deformation of the positioning stage is simulated by the finite element analysis. The relationship between the temperature variation and thermal error is fitted third-order polynomial function whose parameters are determined by genetic algorithm neural network (GANN). The operators of the GANN are optimized through a parametric study. The results show that the model can describe the relationship between the temperature and thermal deformation well.

2007 ◽  
Vol 359-360 ◽  
pp. 219-223
Author(s):  
Li Ming Xu ◽  
Lun Shi ◽  
Xiao Ming Zhao ◽  
De Jin Hu

Spindle thermal deformation is the main error source of many precision profile grinders. In this paper, the relationship between spindle temperature and either radial or axial thermal deformation is studied based on experiments. The placement and amount of temperature sensors are optimized. Then a kind of thermal error modeling method based on support vector machine is presented and applied in the modeling of thermal error of profile grinding. The result shows the model is robust and the on-line accurate prediction of grinding thermal error is realized based on monitoring of temperature rise of spindle. Finally, the error compensation strategy is discussed for further application of thermal error modeling.


Author(s):  
Weimin Cui ◽  
Wei Guo ◽  
Zhongchao Sun ◽  
Tianxiang Yu

In order to analyze the reason of failure and improve the reliability of the idler shaft, this paper studies the reliability and sensitivity for the idler shaft based on Kriging model and Variance Methods respectively. The finite element analysis (FEA) of idler shaft is studied in ABAQUS firstly. Then, combining the performance function and various random variables, the Kriging model of idler shaft is established and verified. Based on Kriging model which has been established, the relationship between random variables and the response value is studied, and the function reliability is calculated which explains why the failure of the idler shaft occurred frequently in service. Finally, the variance-based sensitivity method is used for sensitivity analysis of influence factors, the result shows that the reliability of idler shaft is sensitive to the inner diameter of body A and inner diameter of body B, which could contribute for the analysis and further improvement of idler shaft.


2011 ◽  
Vol 58-60 ◽  
pp. 198-204
Author(s):  
Feng Shou Zhang ◽  
Don Gyan Wang ◽  
Jian Ting Liu ◽  
Feng Kui Cui

Friction between the guideway and the bench of large-type CNC lathe will cause thermal deformation of the guideway, which causes processing error of the lathe,thereby reduces machining precision of the workpiece. The authors establish the mathematical model of temperature field and thermal deformation of the guideway in the work process, numerically simulate the guideway thermal characteristics by ANSYS finite element analysis software, and obtain the distribution regularities of temperature field and thermal deformation and their major influencing factors, which provide a theoretical basis for optimizing design and thermal error compensation design of the lathe guideway.


Author(s):  
Bowen Zhong ◽  
Liguo Chen ◽  
Zhenhua Wang ◽  
Lining Sun

This article focuses on developing a novel trans-scale precision positioning stage based on the stick-slip effect. The stick-slip effect is introduced and the rigid kinematics model of the stick-slip driving is established. The forward and return displacement equations of each step of the stick-slip driving are deduced. The relationship of return displacement and the acceleration produced by friction are obtained according to displacement equations. Combining with LuGre friction model, the flexible dynamics model of the stick-slip driving is established and simulated by using Simulink software. Simulation results show that the backward displacement will reduce with the acceleration of the slider produced by dynamic friction force, the rigid kinematics model is also verified by simulation results which are explained in further detail in the article.


2010 ◽  
Vol 129-131 ◽  
pp. 556-560 ◽  
Author(s):  
Chun Li Lei ◽  
Zhi Yuan Rui

In a lot of factors, thermal deformation of motorized high-speed spindle is a key factor affecting the manufacturing accuracy of machine tool. In order to reduce the thermal errors, the reasons and influence factors are analyzed. A thermal error model, that considers the effect of thermodynamics and speed on the thermal deformation, is proposed by using genetic algorithm-based radial basis function neural network. The improved neural network has been trained and tested, then a thermal error compensation system based on this model is established to compensate thermal deformation. The experiment results show that there is a 79% decrease in motorized spindle errors and this model has high accuracy.


2014 ◽  
Vol 989-994 ◽  
pp. 425-428
Author(s):  
Jin Hong Ma ◽  
Bin Tao ◽  
Xiao Han Yao

Applying the research result of the whole corrugated web H-beam to rail structure, a new kind of rail structure, the corrugated web rail was generated. The special structure rail was successfully rolled in the Research Mill Institute of Yanshan University. Based on the finite element analysis software DEFORM-3D, the rolling process of corrugated waist rail is simulated. The miscrostructure evolution of rolling corrugated waist rail is analysed. The relationship between miscrostructure evolution and deformation are also analysed.


Author(s):  
Qiang Zeng ◽  
Kornel F. Ehmann

The parallel wedge precision positioning stage (PW-PPS) presents a novel configuration of a parallel mechanism for precision positioning applications. Based on its specific parallel configuration, the corresponding inverse and forward kinematic models were developed and used to formulate the volumetric error model of the mechanism. The error model that considers the influence of manufacturing errors is built in two steps. In the first, the structural parameter-induced errors associated with the PW-PPS's structural parameters and input variables were considered, while in the second, the joint clearance-induced errors produced by joint clearances were taken into account. The structural parameter-induced errors were modeled based on complete differential-coefficient theory, while the joint clearance-induced errors due to joint clearances were modeled based on the virtual work and deterministic method. In the latter case, the kinetostatic model and joint error contact modes were analyzed to build a joint clearance-induced error model. The relationship between the different error sources and the output pose error of the mechanism's moving platform was obtained. Finally, considering practical values for the mechanism's parameters and errors, the error distribution in the PW-PPS's workspace was evaluated to determine the distributive rules of the various error components.


2014 ◽  
Vol 1056 ◽  
pp. 149-153
Author(s):  
Xiao Long Zhang ◽  
Zhi Wei Lu ◽  
Bo Liu ◽  
Jun An Zhang

In order to reach the requirements of the newest generation of wire bonder, gas bearing positioning stage directly driven by voice coil actuators is designed.In the stage,an air decoupling mechanism is used. And the finite element analysis software ANSYS was used to analyze the static and dynamic characterizes of the stage so that the structure meets the requirement of stiffness,and at the same time,the moving parts are as light as possible. The simulated results show that the maximum deformation of work platform is in the work surface and the deformation is in request scope.,the deformation of decoupling mechanism is in the main driving rod contact, but this has a little influence on the stage.


2008 ◽  
Vol 400-402 ◽  
pp. 551-557 ◽  
Author(s):  
Bao Zhu Cao ◽  
Yao Chun Zhang ◽  
Yue Ming Zhao

Experimental research on square and octagonal concrete filled thin-walled steel tube long columns of 6 specimens in axial compression and 8 specimens in eccentric compression is undertaken. The relationship of global buckling bearing capacity of the columns and local buckling of the steel tubes is obtained. The test indicates that local buckling occurs in steel tube of each column before it reaches ultimate capacity, and has little effect on global buckling performance. The ultimate load decreases obviously with the increase of slender ratio and eccentricity. The ductility of columns increases with the increase of steel ratio in composite sections. Composite beam element of ANSYS is adopted in the finite element analysis. The theoretical results are agreed well with test..


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