Scalar in terms of multiple variables, Nyquist & Bode Plot

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The discussion focuses on finding a discrete equivalent model for a scalar controlled system with a step time of 0.2 seconds. The user struggles with converting the scalar into a state-space representation, questioning how to derive matrices A, B, C, and D from single values. It is clarified that even for a scalar, these matrices can still be represented as 1x1 matrices. The user anticipates that once the discrete model is established, they can analyze stability using the Nyquist plot and easily generate the Bode plot with MATLAB. The conversation emphasizes the importance of understanding matrix representation in control theory.
YoshiMoshi
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Homework Statement



A scalar is given by

upload_2018-3-3_20-42-37.png


It is controlled by

upload_2018-3-3_20-43-2.png


With step time h = 0.2 s

1. Find the discrete equivalent model
2. Check the stability of closed loop (K = +1)
3. Obtain the
upload_2018-3-3_20-44-11.png
via the Bode plot

Homework Equations

The Attempt at a Solution



So for question 1. This is where I'm struggling.

I know how to discrete a transfer function in terms of matrix A, B, C, and D through MATLAB easily. However how do I do that for a scalar, where I don't have matrix A, B, C, and D but just single values? Also how does the controller effect this?

I tried searching on google a bit, and can't find a solved example that is similar to this problem.

I know that question 2, I can get once I have the answer to question 1 by easily plotting the Nyquist plot.

I know that question 3, is very easy with MATLAB.

THANKS FOR ANY HELP!
 

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YoshiMoshi said:

Homework Statement



A scalar is given by

View attachment 221400

It is controlled by

View attachment 221401

With step time h = 0.2 s

1. Find the discrete equivalent model
2. Check the stability of closed loop (K = +1)
3. Obtain the View attachment 221402 via the Bode plot

Homework Equations

The Attempt at a Solution



So for question 1. This is where I'm struggling.

I know how to discrete a transfer function in terms of matrix A, B, C, and D through MATLAB easily. However how do I do that for a scalar, where I don't have matrix A, B, C, and D but just single values? Also how does the controller effect this?

I tried searching on google a bit, and can't find a solved example that is similar to this problem.

I know that question 2, I can get once I have the answer to question 1 by easily plotting the Nyquist plot.

I know that question 3, is very easy with MATLAB.

THANKS FOR ANY HELP!

You're overthinking it...
you do have an ABCD matrix.

Your A matrix is a 1x1.
Your B matrix is a 1x1.
Your C matrix is a 1x1.
Your d matrix is a 1x1
 

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