# Tag Info

Accepted

### Root Locus and Routh–Hurwitz stability criterion

Suppose we have a third order polynomial in the form : $$s^3+a_2s^2+a_1s+a_0 = 0$$ There is nice caveat for third order systems which is derived from the Routh-Hurwitz stability criterion. In order ...

### What are the Singular Values of a dynamic system and how are they calculated in the *sigma* function in Matlab?

For a MIMO system $y(s) = G(s)d(s)$, with $m$ inputs and $l$ outputs. Consider a fixed frequency $\omega$ where $G(j\omega)$ is a constant $l \times m$ complex matrix. For the sake of simplicity the ...
Accepted

### Design op-amp circuit from transfer function?

To my knowledge the simplest way to accomplish the transfer function... $$G(s) = \frac{E_o(s)}{E_i(s)} = \frac{0.0364s}{0.0002s + 1} = \frac{KTs}{Ts +1}$$ ...is the following high-pass filter ...
Accepted

### Nyquist plot - what is the meaning of circles with dB values on complex plane

See doc nyquist: The nyquist function has support for M-circles, which are the contours of the constant closed-loop magnitude. M-circles are defined as the ...
• 540
Accepted

### Problem with performances of a control scheme

Your closedloop crossover frequency (when the magnitude of $P(s)\,C(s)$ is equal to one) lies at roughly 1 rad/s. This means that the feedback controller already causes the system to track reference ...
• 1,663

### How to find closed loop transfer function and use it to identify τ and k?

The general form of a transfer function for a first order system is the following: $$T(s) = \frac{K}{\tau s+1}$$ where: $\ K \rightarrow$ DC Gain of the system $\ \tau \rightarrow$ Time ...

• 1,663

### Is Matlab old versions usable with Win 10 on core i3

"Windows 2010" is not a Windows version so i'm guessing that you are referring to Windows 10. In general all software that came out since Windows Vista (2007) also runs fine on newer Windows versions ...
• 203

### Model Reduction - Export matrices from ANSYS to MATLAB

So my first question would be - Should I build my flexible body with deformation model for each part (say it is a table, should I describe every leg of my table and the plate using rigid body and ...
• 12.6k
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### Analizing Vibrations Influence on Dynamic Weighing

So, look at the time history that you added in edit 3. Notice how it is never ever ever below 1. That's very telling. Let us assume that you have a MEMS accelerometer is able to read down to 0 ...
• 2,656

### sinking speed of particle in water

I think I understand where you are stuck - it appears (I don't "speak" Matlab) you're trying to solve u directly, without adressing that u goes into Re. Here's what I'd do: Guess $u$ for the ...
• 4,791

### How can I find deflection in a member that doesn't have a constant area moment of inertia?

There are two aspects to this problem that are each significantly more complicated than what you seem to have tried so far: The angle of 45 degrees by which the cross section is changing dimension is ...
• 1,288

### How do I interpret states in the MATLAB System Identification Toolbox?

Due to the fact that you are mentioning the $A,B,C,D$ matrices I assume that your model is a linear one of the form: $$\dot{x} = Ax + Bu$$ $$y = Cx + Du$$ where $x$ is the state vector and $y$ the ...

### What meaning does the following sine wave have when it comes to amplitude?

It means that there is a positive offset of one. So your signal is $$x(t) = 1 + 2 \cdot \sin(\omega t)$$ where: 1 is the offset 2 is the amplitude of your signal (not 4).
• 24.4k
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### Optimization with GA (genetic algorithm)

Taking the norm of a system is something different that taking the norm of a matrix. Luckily, matlab has you covered: https://nl.mathworks.com/help/control/ref/lti.norm.html This page even shows an ...
• 1,099

### Pole placement with damping ratio and natural frequency

The natural frequency $\omega_n$ and damping ratio $\zeta$ of a system are computed by using the two dominant poles of the system. Dominant poles are the ones that are closer to the imaginary axis (i....
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### Do I need a feedback loop while testing PID controller?

I am having trouble imaging a PID controller without a feedback loop. The reason is that P, I and D controllers each calculate their response based on the error between the target and the current ...
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### Do I need a feedback loop while testing PID controller?

Testing physical controller hardware in "open loop" isn't uncommon, but it would just be part of a test, and the feedback line can be split at a point and treated as both input and output of ...
• 1,362
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### Extraction Flash Calculation - 4 Component and 2 Phase System

For reference, I am drawing from the chapter on isothermal VLE separations in Separation Process Principles by Seader, Henley, and Roper. Consider only the final state. The two starting statements in ...
• 2,981
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### MATLAB allmargin() function return multiple GainMargin, but how to identify them on the Bode plot?

Try right clicking and there should be a menu item along the lines of show->all margins as opposed to show->minimum margin....
• 1,134

### Linear and nonlinear model outputs are different using the same input

What are you missing? You are using two different models, and getting two different results. There should be no surprise in this. When you linearize a nonlinear* system around a point, you are ...
• 2,692
1 vote

### Finding coefficients for a PID controller that minimize the integral of the squared error (ISE)

Mm, I can't show you in matlab, but I can show some basic things with just plain math and a little script in mathematica. If we do a Partial division, we see that: \frac{1}{s^3+6 s^2+5 s} = -\frac{1}...
1 vote

### Finding coefficients for a PID controller that minimize the integral of the squared error (ISE)

In general, the problem of finding a controller that minimizes some objective function falls under an extremely deep field of control theory called “optimal control”. Optimal control theory deals with ...
1 vote

### Temperature not changing in my code for 1-D heat equation: Explicit Scheme

This stackexchange doesn't really seek to solve these homework-like problems directly. However, I can offer some hints on how to proceed. Are you sure the scale of ...
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1 vote
Accepted

### Get results of output for each one value of the input - MATLAB ODE

If you want $u$ to be considered as a smooth continuous function, then you should define it as such since you also have $t$ available as well. So you could use: ...
• 1,663

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