Why is “lsim” different than Simulink’s “Linear Analysis Tool”

Hi All,

I have a simple transfer function. I want to analyze its time response to a random input signal. When I use the “lsim” command (or ltiviewer), I can run a simulation. However, when I implement my transfer function in Simulink, and run the same simulation (random input) using the Linear Analysis tool, I get completely different results. Is there a fundamental difference between the two tools? It seems like Simulink and lsim/ltiview are treating my transfer function differently…

ANSWER

Matlabsolutions.com provide latest MatLab Homework Help,MatLab Assignment Help for students, engineers and researchers in Multiple Branches like ECE, EEE, CSE, Mechanical, Civil with 100% output.Matlab Code for B.E, B.Tech,M.E,M.Tech, Ph.D. Scholars with 100% privacy guaranteed. Get MATLAB projects with source code for your learning and research.

Yes, several suggestions/questions.

First of all, your workflow does not quite make sense. Frequency Response Estimation capability in the Linear Analysis tool is designed for computing frequency response of nonlinear Simulink models that cannot be linearized using exact linearization due to discontinuities such as PWM or triggered subsystems. It does not make sense to use it in your case — you can if you want to, but it is meaningless.

Let me explain why. What you have is a linear system — a transfer function. There is no need to linearize Simulink model that consists only of a transfer function — you already have this transfer function to start with! Also, there is no need to use frequency response estimation. What it does is that it injects a signal into the model, logs the output, and computes the FFT of system response from the input and output signals. Again, as you already have your transfer function, there is no need to use frequency response estimation.

In your case, it seems you are trying to simulate a transfer function output to a random signal. You already know how to do it in MATLAB. To do it in Simulink, you just run the simulation, you do not need to linearize the model or use frequency response estimation. Just double check that your Random number block generates the same signal as input signal you designed in MATLAB, replace the outport block with “To workspace” block, and run the simulation.

SEE COMPLETE ANSWER CLICK THE LINK

https://www.matlabsolutions.com/resources/why-is-lsim-different-than-simulink-s-linear-analysis-tool-.php

--

--

--

Simple! That is me, a simple person. I am passionate about knowledge and reading. That’s why I have decided to write and share a bit of my life and thoughts to.

Love podcasts or audiobooks? Learn on the go with our new app.

Recommended from Medium

Fall 2020 CS373: Week of 21 Sep — 27 Sep

Experiencing the power of LINUX and GIT

📈Los mejores scripts para la plataforma de negociación Thinkorswim (TOS)

Github Actions Tutorial | Basic Concepts and Complex workflow | Github Actions Build Matrix

How to create&build a Docker image

WHAT IS THINKIUM?

READ/DOWNLOAD#> Go in Practice: Includes 70 Techniques FULL BOOK PDF & FULL AUDIOBOOK

Serverless is problematic

Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store
Technical Source

Technical Source

Simple! That is me, a simple person. I am passionate about knowledge and reading. That’s why I have decided to write and share a bit of my life and thoughts to.

More from Medium

Beginners guide for Restricted Boltzmann Machine

How to control elevation of geoshow() contour lines

Predicting Parkinsonian Symptom Severity from Voice Recordings

Creating a deep learning application telling which celebrity your voice sounds like