Scilab/C4/Control-systems/English-timed

Time	Narration
00.01	Dear Friends,
00.02	Welcome to the spoken tutorial on “Advanced Control of Continuous Time systems”
00.09	At the end of this tutorial, you will learn how to
00.12	Define a continuous time system: second and higher order
00.17	Plot response to step and sine inputs
00.20	Do a Bode plot
00.22	Study numer and denom Scilab functions
00.26	Plot poles and zeros of a system
00.30	To record this tutorial, I am using
00.33	Ubuntu 12.04 as the operating system with
00.36	Scilab 5.3.3 version
00.40	Before practising this tutorial, a learner should have basic knowledge of Scilab and control systems.
00.48	For Scilab, please refer to the Scilab tutorials available on the Spoken Tutorial website.
00.55	In this tutorial, I will describe how to define second-order linear system.
01.02	So, first we have to define complex domain variable 's'.
01.08	Let us switch to the Scilab console window.
01.11	Here type s equal to poly open paranthesis zero comma open single quote s close single quote close paranthesis , press Enter.
01.25	The output is 's'.
01.27	There is another way to define 's' as continuous time complex variable.
01.32	On the console window, type:
01.35	s equal to percentage s, press Enter.
01.41	Let us study the syslin Scilab command.
01.44	Use the Scilab function ’syslin’ to define the continuous time system.
01.51	G of s is equal to 2 over 9 plus 2 s plus s square
01.58	Use csim with step option, to obtain the step response and then plot the step response.
02.06	Let us switch to the Scilab console window.
02.09	Here type: sys capital G equal to syslin open paranthesis open single quote c close single quote comma two divide by open paranthesis s square plus two asterik s plus nine close paranthesis close paranthesis
02.32	Here c is used as we are defining a continuous time system.
02.38	Press Enter
02.40	The output is linear second order system represented by
02.44	2 over 9 plus 2 s plus s square
02.49	Then type t equal to zero colon zero point one colon ten semicolon
02.57	Press Enter.
02.59	Then type y one is equal to c sim open paranthesis open single quote step close single quote comma t comma sys capital G close the paranthesis semicolon
03.15	Press Enter.
03.17	Then type plot open paranthesis t comma y one close paranthesis semicolon
03.24	Press Enter.
03.26	The output will display the step response of the given second order system.
03.33	Let us study the Second Order system response for sine input.
03.39	Sine inputs can easily be given as inputs to a second order system to a continuous time system.
03.47	Let us switch to the Scilab console window.
03.51	Type U two is equal to sine open paranthesis t close paranthesis semicolon
03.59	Press Enter.
04.01	Then type y two is equal to c sim open paranthesis u two comma t comma sys capital G close the bracket semicolon
04.15	Press Enter
04.17	Here we are using sysG, the continuous time second order system we had defined earlier.
04.25	'Then type plot open paranthesis t comma open square bracket u two semicolon y two close square bracket close paranthesis
04.39	Make sure that you place a semicolon between u2 and y2 because u2 and y2 are row vectors of the same size.
04.50	'Press Enter.
04.52	This plot shows the response of the system to a step input and sine input. It is called the response plot.
05.01	Response Plot plots both the input and the output on the same graph.
05.06	As expected, the output is also a sine wave, and
05.11	there is a phase lag between the input and output
05.15	Amplitude is different for the input and the output, as it is being passed through a transfer function.
05.23	This is a typical under-damped example.
05.26	Let us plot bode plot of 2 over 9 plus 2 s plus s square
05.32	Please note command 'f r e q' is a Scilab command for frequency response.
05.39	Do not use f r e q as a variable !!
05.44	Open the Scilab console and type
05.47	f r is equal to open square bracket zero point zero one colon zero point one colon ten close square bracket semicolon.
06.00	Press Enter.
06.03	The frequency is in Hertz.
06.06	Then type bode open paranthesis sys capital G comma fr close paranthesis
06.15	and press Enter.'
06.17	The bode plot is shown
06.20	Let us define another system.
06.23	We have an over-damped system p equal to s square plus nine s plus nine
06.32	Let us plot step response for this system.
06.36	Switch to Scilab console.
06.38	Type this on your console.
06.40	p is equal to s square plus nine asterik s plus nine
06.47	and then press Enter.
06.49	Then type this on your console.
06.51	sys two is equal to syslin open paranthesis open single quote c close single quote comma nine divided by p close paranthesis
07.04	and press Enter.
07.07	Then type t equal to zero colon zero point one colon ten semicolon
07.14	Press Enter.
07.17	y is equal to c sim open paranthesis open single quote step close single quote comma t comma sys two close the paranthesis semicolon
07.31	Press Enter.
07.33	Then type plot open paranthesis t comma y close paranthesis
07.39	Press Enter.
07.41	The response plot for over damped system is shown.
07.46	To find the roots of p type this on your console -
07.49	Roots of p and press Enter.
07.54	These roots are the poles of the system sys two
07.59	The roots or poles of the system are shown.
08.02	Please plot Step response for this system along similar lines, as for over damped system.
08.11	G of s is equal to 2 over 9 plus 6 s plus s square which is a critically damped system
08.20	Then G of s is equal to two over 9 plus s square which is an undamped system
08.28	G of s is equal to 2 over 9 minus 6 s plus s square which is an unstable system
08.36	Check response to sinusoidal inputs for all the cases and plot bode plot too.
08.45	Switch to Scilab console. ;
08.48	For a general transfer function, the numerator and denominator can be specified separately.
08.55	Let me show you how.
08.57	Type on console
08.59	sys three is equal to syslin open paranthesis open single quote c close single quote comma s plus six comma s square plus six asterik s plus nineteen close paranthesis
09.19	Press Enter
09.21	Another way of defining a system, is to type
09.24	g is equal to open paranthesis s plus six close paranthesis divided by open paranthesis s square plus six asterik s plus nineteen close paranthesis
09.40	Press Enter.
09.42	Then type this on your console
09.44	sys four is equal to syslin open paranthesis open single quote c close single quote comma g close paranthesis
09.55	Press Enter.
09.58	Both ways, we get the same output;
10.01	six plus s over 19 plus six s plus s square
10.07	The variable ’sys’ is of type ’rational’.
10.10	Its numerator and denominator can be extracted by various ways.
10.16	Sys of two , numer of sys or numer of g gives the numerator.
10.22	The denominator can be calculated using sys(3) or denom of sys functions.
10.30	The poles and zeros of the system can be plotted using p l z r function.
10.37	The syntax is p l z r of sys
10.41	The plot shows x for poles and circles for zeros.
10.46	Switch to Scilab console.
10.48	Type this on your Scilab console.
10.50	sys three open paranthesis two close paranthesis
10.55	Press Enter.
10.56	This gives the numerator of the rational function 'sys three' that is 6 + s
11.03	Otherwise, you can type
11.05	numer open paranthesis sys three close paranthesis.
11.11	Press Enter
11.13	The numerator of system three is shown.
11.17	To get the denominator, type
11.19	sys three open paranthesis three close paranthesis. Press Enter.
11.26	The denominator of the function is shown.
11.30	You can also type denom open paranthesis sys three close paranthesis.
11.36	Press Enter.
11.38	Then type p l z r open paranthesis sys three close paranthesis.
11.44	Press Enter.
11.47	The output graph plots the poles and zeros.
11.50	It shows cross and circle' for poles and zeros of the system respectively.
11.58	It is plotted on the complex plane.
12.01	In this tutorial, we have learnt how to:
12.03	Define a system by its transfer function.
12.08	Plot step and sinusoidal responses.
12.11	Extract poles and zeros of a transfer function.
12.15	Watch the video available at the following link
12.19	It summarises the Spoken Tutorial project
12.22	If you do not have good bandwidth, you can download and watch it
12.27	The spoken tutorial project Team
12.29	Conducts workshops using spoken tutorials
12.32	Gives certificates to those who pass an online test
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12.43	Spoken Tutorial Project is a part of the Talk to a Teacher project
12.47	It is supported by the National Mission on Eduction through ICT, MHRD, Government of India.
12.55	More information on this mission is available at spoken-tutorial.org/NMEICT-Intro
13.06	This is Ashwini Patil signing off.
13.08	Thank you for joining Good Bye.

Contributors and Content Editors

Devraj, Gaurav, PoojaMoolya, Sandhya.np14