THE STUDY OF SLIDER CRANK MECHANISM USING MATLAB AND SCILAB

Transcription

1 THE STUDY OF SLIDER CRANK MECHANISM USING MATLAB AND SCILAB 1 Ioan Sorin Șorlei, 2 Adriana Elena Cernat, 3 Ciprian Ion Rizescu, 4 Dana Rizescu 1,2,3,4 University of POLITEHNNICA Bucharest/ Department of Mechatronics and Precision Engineering Splaiul Independentei 313, postal code 642, Bucharest sorleisorin@gmail.com, ae.cernat@gmail.com, ciprian.rizescu@upb.ro, dana.rizescu@upb.ro Abstract - The study presents a comparison between a graphic simulation of a slider crank mechanism developed both in Matlab and Scilab environments. Also some remarks, concerning the software s efficiency and an economic analysis efficiency-cost of the two software, are presented in this study which have an identical use/purpose. Mainly, the idea of materialization of such a work has come out of necessity of programs usage that imply low purchase costs. From the point the view of acquisition, SCILAB is a free software through the licence CeCIILL (CEA CNRS INRIA Logiciel Libre). Both programs, MATLAB and SCILAB, can achieve certain accounts, can employ matrix and implement utility programs the difference between them are the used functions, because some of them don't match. MATLAB is a broader program from the point of view of functions against SCILAB, but from the point of view of cost software SCILAB is the advantageous solution. Using SCILAB software in achieving performance and make an animation of the sliding crank mechanism, it was noticed that the only differences between this program and MATLAB are certain functions with different syntaxes. In the present study it stands out in particular that both software are similar in terms of programming language and interface. Each environment has advantages and disadvantages and their use is identical in terms of performances compared to results. Considering that SCILAB environment uses a particular programming language MATLAB is much used in industry and academia worldwide. The study of present paper can be enhanced with new researches concerning the description and functionality of the programs as well as the presentation and improvement of the toolbox sites belonging SCILAB program, in order to achieve more complex animation in terms of the movement mechanisms. Keywords: SCILAB, MATLAB, slider crank mechanism, leverage, simulation. 1. Introduction This paper deals with a mechanism simulation: slider crank mechanism using both SCILAB and MATLAB programs. Also, in the frame of the paper, there will be highlighted the main advantages and disadvantages of using SCILAB with respect to MATLAB. In principle, the idea of such work arise from the need to use some programs involving the minimum cost of purchase. From this point of view, SCILAB is a free software. Both of these programs, MATLAB and SCILAB, can perform certain calculations, may use the matrix and deploy algorithms, the difference between them being the functions used because some of them do not match. MATLAB is a much more comprehensive from the point of view of the functions in relation to the SCILAB, but from the point of view of the cost price, the SCILAB solution is advantageous. Using the SCILAB to achieve performance and animate slider crank mechanism, it was noted that the only differences between this program and MATLAB, there are certain functions with different syntax checker. 2. Remarks about programming in MATLAB The MATLAB programming is a graphical representation, numerical calculation, graphic differentiation or data read on the graphs based on certain applications encountered in practice. It should be stressed that the numerous software currently existing in the market, the most appropriate for the analysis of the static and dynamic mechatronics systems is the program MATLAB through the spread of its pronounced in both the academic environment as well as in the industrial uses. The MATLAB programming has several commands for the numerical analysis, for the purpose of calculating the matrix vector and, for generating and processing the signals for the analysis of the control systems and for the integration of the numerical systems linear or nonlinear media. Must be and effective controls for generating the performance of the two-dimensional and three-dimensional, what can easily be customized. Writing models calls the syntax checker and notations very similar to those used to define the analytical models, which makes that the programming itself to be 26 The Romanian Review Precision Mechanics, Optics & Mechatronics, 216, Issue 5

2 quite easy. In the working area of the MATLAB (Workspace) can be executed all controls, can be displayed index, results [1]. - WHO - lists all of the variables listed in the Workspace; - WHOS - much like WHO, but in addition it provides the size of the variable (number of lines or columns belonging to the variable); - WHAT - lists the *.m or *.mat, presented in the current directory; - HELP - provides information on-line" about MATLAB and its functions; - % - a straight line preceded by the % is interpreted as a comment and is not executed; -! - carrying out the orders of the operating system DOS, without leaving MATLAB; - QUIT, EXIT - commands to exit the MATLAB; Comments: MATLAB program makes distinction between uppercase and the small ones (g is not the same as G). All commands will be written using small letters, otherwise it will display error messages that warn that a certain command does not exist. In figure 1 is presented the simulation the slider crank mechanism. In figure 2 is shown the operating of slider crank mechanism from 45 to 45. Figure 1: Simulating non centric slider crank mechanism in MATLAB The Romanian Review Precision Mechanics, Optics & Mechatronics, 216, Issue 5 27

3 Figure 2: Simulating operating of slider crank mechanism in MATLAB Remarks about programming in SCILAB The SCILAB programming is a development environment very easy to use. Can be used for calculation and static analysis, enables the manipulation array, display the functions, implementing the algorithms, the creation of graphical user interfaces (GUI) and can interact with other applications. The mathematics becomes extremely easy with this application. From the point of view of the software, the SCILAB programming uses an interpreted language, i.e. a language that has certain syntax checker prescribed for to be more easily programmed and used. This, in general, allows to obtain a rapid processes of execution, because the operator accesses directly a language, high level with a rich feature-set offered in SCILAB library. Programming language allows the compilation in a dynamic mode and links to other media program such as FORTRAN and C: in this way, external libraries can be used as and when you were part of the inside of the SCILAB. From the scientific point of view, SCILAB comes with many features of which a part are focused on the linear algebraic, but also many areas of the scientific computing. A short list of his capacity is presented in the following: algebra linear array and phased array, polynomial and rational functions, interpolation and approximation, optimization linear and non-linear square, solving ODE (Ordinary Differential Equation) and DAEs (Differential Equations Algebraic), optimization's no trouble (Linear Matrix Inequality), processing the signals, statistics. From the license point of view, SCILAB is a free software in the sense that the user does not paid for him being under license CeCILL (THE INRIA CNRS Logiciel Libre). The software is distributed with the source code so that the user has access to all the functions of the internal affairs of the SCILAB. Most of the time, the user downloads and installs a binary version of the software, whereas SCILAB consortium offers more executable versions on different platforms like: Windows, Linux and Mac OS. Section online 'Help' of the program is offered in a variety of national language. The general aspects of the two programming environments reflect the fact that although they look similar at a first consideration, they differ very much by syntaxes that are used to create the programs and the most representative aspect is by the fact that many functions of the MATLAB have no correspondence in SCILAB, even highlighted in the two programs used to the creation of a mechanism with levers - a slider-crank mechanism, the environment of MATLAB programming being more complex in performing the functions, more powerful, but with certain disadvantage of the cost. In figure 3 is presented the simulation of slider crank mechanism. In figure 4 is shown the operating of slider crank mechanism from 45 to The Romanian Review Precision Mechanics, Optics & Mechatronics, 216, Issue 5

4 Figure 3: Simulating non centric slider crank mechanism in SCILAB Figure 4: Simulating operating of slider crank mechanism in SCILAB The Romanian Review Precision Mechanics, Optics & Mechatronics, 216, Issue 5 29

5 Considering operating simulation from figure 2 and figure 4, one can see that there are no major differences. Both, Matlab and SCILAB are similar, even some commands are different. In figure 5 are represented the stroke, X[mm], versus rotation angle, φ[ ], and geometric speed v/ω versus rotation angle, φ[ ], [2]. 4. Conclusions The work highlights the importance of using SCILAB program from the point of view of the completion of the animations, as well as the side with the levers, four bar mechanisms or other type of animations and opens up new directions regarding the execution of the GUI interfaces or other applications. The similarities between the two environments, MATLAB and SCILAB, are given in the writing of functions, but also of the results of the graphics. The two software does not have as a result important differences, which shows us that both programs can easily perform applications relatively simple. An important aspect to economy mode of approach the two software being at different ends when we discuss about the purchase price of the MATLAB programming having a high cost and the environment of programming SCILAB having a zero cost being a free software by means of the license CeCILL (THE INRIA CNRS Logiciel Libre). Each environment presents the advantages and disadvantages, and their use is the performance of even the same, as well as the comparison of the results but with a certain threshold of the complexity of the programs, complexity is given no more and no less than the SCILAB environment. Therefore, MATLAB environment is much more used in the fields of industrial and academic ones, at the global level. The study of the work can be enhanced with new research relating to the description and functionality of the program as well as the presentation and improve the toolbox sites that belong to the SCILAB program, in order to achieve animations, most complex from the point of view of the machinery movement, [3]. 5. References Figure 5: Stroke x and geometric speed v/ω versus rotation angle, φ[ ] for slider crank mechanism [1] Rizescu D., Miu S., Rizescu C.I., Complemente de mecatronică, București, Printech 2; [2] Prisăcaru,Gh., Bercea,M., Gramescu,B., Ciupe, V., Mecatronica aplicata, Ed. Academiei Oamenilor de Stiinta din Romania, Bucureşti, 211. [3] Charalampides, G., Dontu, O., Gheorghe, Gh. I., Besnea, D., Avarvarei, I., Ciobanu, R., Considerations regarding the integration of CAD/CAM design and manufacturing using CNC processing machines - The Romanian Review Precision Mechanics, Optics & Mechatronics, Nr.38/21; The Romanian Review Precision Mechanics, Optics & Mechatronics, 216, Issue 5