Plotting Output Response Curve with Unit Steps: A Matlab Guide

[lukus09]

How do i plot an output response curve when input unit steps are (undamped natural frequency is normalised to 1):

damping ration = 0, 0.1, 0.4,0.6,0.8,0.9 1 and 2

1) how do i plot a 2d plot for all curves on same graph. Time scale 0 - 10, steps of 0.2 seconds.
2) How do i make use of a 'for loop' to generate step response for the damping ratios,
3) How do i produce an m file to obtain response.
4) how can i produce a 3d plot
5)how do i produce a Matlab program to get rise time, peak time, settling time and max overshoot of the 2nd order system [for equation 10/ 2s^2 + 4s +15]

 

[MATLABdude]

From your PM, I'd recommend that you ask your prof for materials / a lecture / lab on MATLAB, especially if you [collectively you, meaning you and your classmates] have never used it before. If learning MATLAB by yourself *is* part of this course, then you should probably read the textbook (if provided) or go through some of the http://www.mathworks.com/academia/student_center/tutorials/launchpad.html" , and/or go through the following thread:
https://www.physicsforums.com/showthread.php?t=296209


1) Assuming you have data for each of the graphs you wish to plot:
http://www.mathworks.com/access/helpdesk/help/techdoc/ref/plot.html


3) An m-file allows you to automate a sequence of commands. Instead of typing out 20 commands each and every time you want to do something, you type out the 20 commands in the m-file, and just type the name of the m-file (assuming it's in the current directory) to execute these commands. You can start a new m-file by going File > New m file (or something similar). Getting started with m scripts:
http://www.mathworks.com/access/helpdesk/help/techdoc/matlab_prog/f7-38085.html#f7-60588


2) The 'for' loop in MATLAB:
http://www.mathworks.com/access/helpdesk/help/techdoc/ref/for.html


4) Producing a (basic) 3d plot:
http://www.mathworks.com/access/helpdesk/help/techdoc/ref/plot3.html

Note that you can generate various 3D surface plots using, for instance, mesh and surf:
http://www.mathworks.com/access/helpdesk/help/techdoc/ref/mesh.html
http://www.mathworks.com/access/helpdesk/help/techdoc/ref/surf.html


5) Take a look at the following Wikibook on using MATLAB for Control Systems:
http://en.wikibooks.org/wiki/Control_Systems/MATLAB

 

[Mene]

1) To plot all the curves on the same graph, you can use the "hold on" command before each plot command. This will allow all the curves to be plotted on the same graph. You can also add a legend to differentiate between the different curves.

2) To use a for loop to generate step response for the different damping ratios, you can define a vector containing the different damping ratios and then use a for loop to iterate through the vector and plot the corresponding response curve for each damping ratio.

3) To produce an m file to obtain the response, you can use the "save" command in Matlab to save your code as an m file. You can also use the "publish" command to automatically generate an m file with your code and results.

4) To produce a 3d plot, you can use the "plot3" command in Matlab. This command allows you to plot a 3d curve by specifying the x, y and z coordinates.

5) To produce a Matlab program to get the rise time, peak time, settling time, and maximum overshoot of the second-order system, you can define a function that takes in the system equation and calculates these parameters using the appropriate formulas. You can then call this function with different input values to get the results for different damping ratios.