Lab. Manual. Practical Special Topics (Matlab Programming) (EngE416) Prepared By Dr. Emad Saeid

Transcription

1 KINGDOM OF SAUDI ARABIA JAZAN UNIVERSTY College of Engineering Electrical Engineering Department المملكة العربية السعودية وزارة التعليم العالي جامعة جازان كلية الھندسة قسم الھندسة الكھربائية Lab. Manual Practical Special Topics (Matlab Programming) (EngE416) Prepared By Dr. Emad Saeid 1

2 Table of Contents General Introduction...3 The Purpose of This Manual..4 Lab Instructions..4 Part One M-Files & Function Files Lab. No Lab. No Lab. No Lab. No Lab. No Lab. No Part Two Simulink Introduction...26 Starting Simulink st Model.28 Running Simulations.30 2 nd Model rd Model.32 4 th Model.33 5 th Model.34 2

3 General Introduction MATLAB is a powerful language for technical computing. The name MATLAB stands for MATrix LABoratory, because its basic data element is a matrix (array). MATLAB can be used for math computations, modeling and simulations, data analysis and processing, visualization and graphics, and algorithm development. MATLAB is widely used in universities and colleges in introductory and advanced courses in mathematics, science, and especially in engineering. In industry the software is used in research, development and design. The standard MATLAB program has tools (functions) that can be used to solve common problems. In addition, MATLAB has optional toolboxes that are collections of specialized programs designed to solve specific types of problems. Examples include toolboxes for signal processing, symbolic calculations, and control systems. Until recently, most of the users of MATLAB have been people who had previous knowledge of programming languages such as FORTRAN or C, and switched to MATLAB as the software became popular. Consequently, the majority of the literature that has been written about MATLAB assumes that the reader has knowledge of computer programming. 3

4 The Purpose of This Manual This manual is intended for students who are using MATLAB for the first time and have little or no experience in computer programming. Lab Instructions When you attend to the lab you must follow the following instructions: 1. Attend at your time, not before not after; 2. Try to use the same computer every time you attend the lab; 3. Open your computer and run the Matlab program; 4. Make a folder with your name and save the programs you perform at this folder, (this important for your evaluation). 4

5 Part One Lab. No Explain the main windows in matlab desktop? 5

6 1. Command Window This window is used to enter variables and run functions and M- files. For more information, click the Help button. 6

7 2. Command History In this window, we can view previously used functions, and copy and execute selected lines. 7

8 3. Launch Pad MATLAB s Launch Pad provides easy access to tools, demos, and documentation. 8

9 4. Help browser The Help browser is used to search and view documentation for all your Math Works products. To open the Help browser, click the help button in the toolbar, or Type helpbrowser in the Command Window. 9

10 5. MATLAB Workspace The MATLAB workspace consists of the set of variables built up during a MATLAB session and stored in memory. 10

11 6. Current Directory Browser MATLAB file operations use the current directory and the search path as reference points. Any file you want to run must either be in the current directory or on the search path. 11

12 2. Enter the following matrix, A = (a) Get the matrix size (b) Get the matrix transpose 3. We have the following two matrices B = [2 2 3; 4 0 6; 8 1 5] C = [1 1 2; 6 3 5; 1 9 1] Calculate: (a) D = B - C (b) E = B + C (c) F= E+2 (d) G=B*C (e) H= B.*C 4. If V 1 = 5v, V 2 = 6v, Z 11 =2, Z 12 =1, Z 21 =3 Z 22 =4, get the value of I 1 and I 2? 5. If A1 = [ ] and B1 = [ ], get (a) C1 = A1.*B1 (b) D1 = A1./B1 6. If r1 = [ 7 3 5] and s1 = [ 2 4 3], get (a) q1 = r1.^s1 (b) q2 = r1.^2 7. state if the following statements are true or false, (a) If a MATLAB statement ends with a semicolon (;) MATLAB evaluates the statement but suppresses the display of the results. (b) The end of each row in entering a matrix, is indicated by a semicolon (;) (c) MATLAB is case sensitive in naming variables only. 12

13 Lab. No Enter the following matrix, A = (a) Get the diagonal of the matrix A (b) Get the sum of each column in the matrix A (c) Get the sum of each row in the matrix A (d) Get the sum of all elements in the matrix A (e) Add 2 to the element in the 2 nd row and 3 rd column 2. Enter the following complex number, z = 2-j3 then (a) Get the real and the imaginary parts of z (b) Get the magnitude and the phase angle of z (c) If y = 3+j5, calculate the following: y+z, y-z, y z 3. If w = [1+j 5-2*j; 3+2*j 4+3*j] (a) Get the conjugate transpose (b) Get the point transpose (c) Type the elements of 2 nd row only 4. If R = 10 Ohms and the current is increased from 0 to 10 A with increments of 2A, write a MATLAB m-file program to generate a table of current, voltage and power dissipation. 13

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19 Lab No. 4 Function File 1. Write a function file (name it chp6one) for the function The input to the function is x and the output is f(x). Use the function to calculate: a) f(x) for x = 6. b) f(x) for x = 1, 3, 5, 7, 9, and Write a function file to solve the equivalent resistance of series connected resistors, R1, R2, R3,, Rn. Use the function to calculate: the series equivalent resistance of 10, 20, 15, 16 and 5 ohms. 19

20 3. plot, xlabel, ylabel, title, and axis commands; 4. The difference between plot, semilogy, semilogx, logog commands 20

21 5. bar plot command 6. pie plot 21

22 7. Write an m-file to give the following figure? 1 figure no. 1 1 figure no. 2 y = sin(x) 0 z = cos(x) x-axis 1 figure no x-axis m = exp(-x) x-axis 22

23 8. Write an m-file to give the following figure? 1 figure no. 1 y = sin(x) figure no. 2 x-axis figure no z = cos(x) 0 m = exp(-x) x-axis x-axis 23

24 Lab No. 5 Q1. What is meant by relational and logical operators, give examples? Q.2 The following were the daily maximum temperatures (in F): Use relational and logical operations to determine the following: a) The number of days the temperature was above 75. b) The number of days the temperature was between 65 and 80. c) The days of the month that the temperature was between 50 and 60. Q.3 Q.4 A 3-bit A/D converter, with an analog input x and digital output y, is represented by the equation: y = 0 x < -2.5 = x < -1.5 = x < -0.5 = x < 0.5 = x < 1.5 = x < 2.5 = x < 3.5 = 7 x 3.5 (a) Write a MATLAB program to convert analog signal x to digital signal y. (b) Test the program by using an analog signal with the following amplitudes: -1.25, 2.57 and

25 Lab No. 6 Q.1 Determine the number of consecutive integer numbers which when added together will give a value equal to or just less than Q.2 C) The roots of the polynomial f(x) Q.3 If we have the following roots of the polynomial, r = find the polynomial? Q.4 we have Find a) f 1 (x) + f 2 (x) b) f 1 (x) * f 2 (x) Q.5 Divide a) b) by 25

26 Introduction Part Two Simulink Simulink is a graphical extension to MATLAB for the modeling and simulation of systems. In Simulink, systems are drawn on screen as block diagrams. Many elements of block diagrams are available (such as transfer functions, summing junctions, etc.), as well as virtual input devices (such as function generators) and output devices (such as oscilloscopes). Simulink is integrated with MATLAB and data can be easily transferred between the programs. In this part, we will introduce the basics of using Simulink to model and simulate a system. Simulink is supported on Unix, Macintosh, and Windows environments, and it is included in the student version of MATLAB for personal computers. 26

27 Starting Simulink Simulink is started from the MATLAB command prompt by entering the following command: >> Simulink Alternatively, you can click on the "Simulink Library Browser" button at the top of the MATLAB. 27

28 The Simulink Library Browser window should now appear on the screen. Most of the blocks needed for modeling basic systems can be found in the subfolders of the main "Simulink" folder (opened by clicking on the "+" in front of "Simulink"). Once the "Simulink" folder has been opened, the Library Browser window should look like: 1. 1 st Model Building a System To demonstrate how a system is represented using Simulink, we will build the block diagram for a simple model consisting of a sinusoidal input multiplied by a constant gain, which is shown below: 28

29 This model will consist of three blocks: Sine Wave, Gain, and Scope. The Sine Wave is a Source Block from which a sinusoidal input signal originates. This signal is transferred through a line in the direction indicated by the arrow to the Gain Math Block. The Gain block modifies its input signal (multiplies it by a constant value) and outputs a new signal through a line to the Scope block. The Scope is a Sink Block used to display a signal (much like an oscilloscope). 29

30 Running Simulations Now that our model has been constructed, we are ready to simulate the system. To do this, go to the Simulation menu and click on Start, or just click on the "Start/Pause Simulation" button in the model window toolbar (looks like the "Play" button on a VCR). Because our example is a relatively simple model, its simulation runs almost instantaneously. With more complicated systems, however, you will be able to see the progress of the simulation by observing its running time in the the lower box of the model window. Double-click the Scope block to view the output of the Gain block for the simulation as a function of time. Once the Scope window appears, click the "Autoscale" button in its toolbar (looks like a pair of binoculars) to scale the graph to better fit the window. Having done this, you should see the following: 30

31 2. 2 nd Model Signal Routing Draw the output of each scope? 31

32 3. 3 rd Model Transfer Functions 32

33 4. 4 th Model Closed Loop Control System Here is an example of a closed-loop system with an on-off controller. Notice the oscillations in the response. 33

34 5. 5 th Model Integrators and Derivatives 34