# What is Simulink: Definition and 115 Discussions

Simulink is a MATLAB-based graphical programming environment for modeling, simulating and analyzing multidomain dynamical systems. Its primary interface is a graphical block diagramming tool and a customizable set of block libraries. It offers tight integration with the rest of the MATLAB environment and can either drive MATLAB or be scripted from it. Simulink is widely used in automatic control and digital signal processing for multidomain simulation and model-based design.

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1. ### (Control) Derivative filter and discrete model

Hi I am back :). I have been doing some Simulink modeling for a project. I modeled it with a discrete system due to the controller rate. I have noticed that for all the discrete system I have tried, adding a derivative filter not only improves the performance (smaller settling time), but it is...
2. ### Engineering Control System mass spring damper

Hello everybody I have a question about my control system, and I've included a diagram for reference. In the diagram below, I've illustrated three different control schemes using Simulink. The first scheme represents a PI controller for a mass-spring-damper system, which I understand well. It...
3. ### Engineering Simulink: How to fix given error for a closed loop model w/ PID controller?

Could I get some input on how to fix this problem please? Thanks in advance! The exercise for which I need the model. The simulink model together + the error that needs to be fixed + Matlab code used: Note: Gain 1 = 1/Ti
4. ### Engineering How to implement a transfer function in Simulink with variable coefficients?

The implementations for the two filters in simulink are as follow: For the first filter: For the second one: The obtained results have values of 10^-12, while the expected results should be between 10^-3 - 10. Since it's the first time when I try t implement a tf with variable coefficients I...
5. ### MATLAB Modelling a Heat Pump with Linear Compressor using MATLAB Simulink

Hello, I am a final year mechanical engineering student designing a heat pump with a linear compressor for an electric vehicle and have decided to model this using Simulink, I would love some help on the governing equations/formulas needed for each component of the heat pump as well as guidance...
6. ### Engineering How do I use Simulink to create a control system with a 2nd order ODE?

Equation: , where matrix D, C, G and F can be represented by I'm supposed to design a control system that looks like this: I am given that the dynamic model = fcn(D,C,G,dq) where the dq is the same as 𝑞̇ and d2q in the diagram is the same 𝑞̈. The default initial value of [𝑞(0), 𝑞̇(0)] is...
7. ### Simulate a Chopper of Class A circuit in MATLAB Simulink

I tried to simulate the circuit but I got unreliable results. Here's what I got when I set the duty cycle to be 20%: Stop Time = 0.02 The efficiency is more than100%. Here's the parameters: Could someone please let me where is my mistake?
8. ### A Solving a differential equation with two unknowns

One thing that is given in paper (attached) is a operating set point for temperature which is given as 20 for day and 16 for night but I do not know whether its initial condition for temperature or not. Can anyone please guide me that what kind of equation is it and how can I solve it with these...
9. ### Problem with PMSM motor model in Simulink

Good afternoon, I have developed a Vector Control for a PMSM motor in Simulink using Simscape Electrical but my motor is not spinning. I have tried applying various speed values but nothing happens. I am applying a step signal from 0 to 300 but the motor speed still doesn't move. My error...
10. ### Mathematical Modeling of an evaporator for evaporating water

I am trying to model an evaporator which evaporates water to steam in Matlab/simulink. Are there any governing equations i need to know and follow when modelling the evaporator mathematically? Please let me know.
11. ### Mathematical modeling of a screw compressor

I am trying to design a compressor in simulink. the mathematical equations has been modeled. but i just need, is there any relation to find the rate of change of volume with respect to time in compressor. Are there any equations or relations to find the rate of change in volume. As its a...

Hello all, I've decided to post my question on here as it seems to be a more active forum over Matlab's one. So what I am after is help when with modelling, now, when I model in Solidworks have assemblies within the main assembly, but the issue with this is that it's not detecting the joint...
13. ### MATLAB Spring mass impact system in Matlab - How to correct it?

I am new to Simulink and I wanted to start practicing using a spring mass damper system. My first tutorial was this: Later, I wanted to model a spring system where a mass moving at a known velocity hits the spring. The governing equation and a similar modeling method given in the previous...
14. ### Find the real power consumed using MATLAB Simulink

My work is attached below. I want to confirm my answer. Any help would be greatly appreciated !
15. ### Simulink: Saturation characteristic of saturable transformer

I'm trying to get saturation characteristic of current transformer in simulink... In simulink, there was an example of a current transformer : https://www.mathworks.com/help/physmod/sps/examples/current-transformer-saturation.html And in this document, it said : the CT is assumed to saturate...
16. ### Open CT Dialog Box in Simulink | Mathworks

I'm reading this Document : https://www.mathworks.com/help/physmod/sps/examples/current-transformer-saturation.html#d117e16073 In this document, it said : "Open the CT dialog box and observe how the CT parameters are specified" How to open CT dialog box in simulink ? Thanks for your help
17. ### Simulate distance protection in simulink

Hi, I'm learning Electrical engineering, and I'm trying to Simulate distance protection, using matlab/simulink I searched google and it has many documents about this problem, but those only show the result, and also i can't find any simulation file So i have many questions : 1. how to calculate...
18. ### Implement a DC current source - simulink

Homework Statement Homework Equations - The Attempt at a Solution Here's my work : When I add the DC current source , it shows a red dotted line and won't connect to other elements . Any help would be greatly appreciated !
19. ### Gas pressure regulator model in Simscape

Hello, I want to develop a pressure regulator model in simscape. The model will be the springloaded direct acting system and the aim is to target outlet pressure, temperature and flow rate by giving input parameters as pressure, temperature, spring stiffness, length and preload, lever(it is...
20. ### Simulink bloc of PMSM (permanent magnet synchronous motor) parameters

greetings. I designed a system on simulink. it is missing a pmsm. I found a block on simpowersystems in simulink nde matlab. I hope that this engine provides a nominal power of 96kw and maximum of 100kw. so how to test it? to verify that this engine can deliver these two powers? cordially. said.
21. ### Step Response Characteristics in Simulink

I have a system that I have built in Simulink with a step input and scope output. I would like to measure the peak overshoot, settling time etc. In Matlab this can be done using the 'step' command and generating the characteristics from the Figure window. Is there a way of getting the same...
22. ### Dynamic modeling of a system and transients of the system

Consider, I have a dynamic system model for air compressor. Which means I have modeled the system by including its physics. Does this means I also included the transients of the system? What I think is, when i modeled any system with equations, I think that includes the transients. Is it...
23. ### Converting Simulink model to C code, integration

Dear Forumers,Given a simulink model: http://www.femm.info/Archives/contrib/images/TransientLoudspeaker/SimulinkOverview.png I would like to implement fast code for it.I have no access to matlib or simulink at all, so I tried to implement the simulation in C code. Code for the block...
24. ### MATLAB Sliding mode observer in Matlab or Simulink

Hi, I have designed a variable-based observer analytically on paper. Now it's time to implement it in Simulink/matlab. Suppose we have followings in a tire model. The EOM says: J\dot{\omega} = T-R_eF_x m\dot{v}_x = F_x where J is the inertia of the wheel, \omega is the angular velocity , m is...
25. ### MATLAB Simulink: designing a 2nd order sliding controller

Hi, I've had obtained a mathematical model for the slip controller issue. As you see I have the diffequation for the slip. and the input that force the system to zero error is provided as well. Now it's time to implement it in simulink or matlab. I took a look at the example provided on...
26. ### Novice trouble modeling a system in Simulink

Greetings, For the past 5 days i have been learning how to use simulink.I decided to try and model a mechanical system described by the equations in the picture below.I provide a second picture with my work so far.A couple of questions that i have are: a)How do i include the first equation? and...
27. ### MATLAB Issues Replicating Simulink Model within MATLAB (2DOF)

Hey all, I've been trying to debug a model I've created of a 4DOF geared system within Simulink by reproducing the results in MATLAB going from a 2DOF upwards to verify the dynamics are acting correctly. At the moment I am purely trying to model the stiffness between two gears, my equations...
28. ### 4DOF Spur Gear System - Eigenvalues not corresponding with the Eqns?

Hi there, I am modelling a four degree of freedom system which is the dynamics of two spur gears in mesh, having two rotational and two translation degrees of freedom, respectively, a diagram exhibiting the system can be seen below. I have derived the equations of motion (EOM) and...
29. ### System of differential equations in MATlab simulink

Hello everyone, I would like if someone could help me with a little excersie here. 1. Homework Statement I am trying to simulate a mechanical system from a differential equations in simulink, but I don't know If I am doing it right. I've made the model as you can see in the 2nd picture...
30. ### Simulink model of a hybrid vehicle (replace battery with fuel cell)

greetings, here I found a Simulink model on mathswork, I want to replace the battery with a fuel cell, so I'm stuck at the level of the energy management block. here is the link of the model: https://www.mathworks.com/matlabcentral/fileexchange/28441-hybrid-electric-vehicle-model-in-simulink...
31. ### Boost converter in Simulink problem

Hi I am trying to simulate a boost converter in Simulink, but I have a problem. When I measure the inductor current it shows as a triangular waveform instead of an exponential waveform like I would expect, does anyone know why? Does simulink do some simplification I am not aware of...
32. ### Generating SPWM using arduino-simulink environment

hi all...am trying to generate sinusoidal pulse width modulation using arduino-simulink for my inverter board...I simulated the SPWM logic in simulink, then installed the required support package for arduino-simulink...but i am facing some problems...I started from basic...like linking arduino...
33. ### Automotive Vehicle and Engine Simulink Model Engine rpm calculation

Hello Everyone, I am designing Simulink model for HIL testing. Basic concept: Input: Throttle angle ----> Injection timing from that I have calculated requested torque (% of max torque)(chekced and correct) Real torque follows requested torque with delay. (long list of conditions depending on...
34. ### Problem with permanent magnet synchronous machine simulink

Hi I would ask someone that is pratical with Simulink in particular of Simscape about a problem which involve my simulation in Matlab-Simulink of a permanent magnet synchronous machine that is connected, by a rectifier, to a DC current source. all the blocks of the simuation are included into...
35. ### The battery equivalent internal impedance equation

Homework Statement Hello, long story short: I need to create a model of Li-Ion battery and I'm stuck on calculating the battery equivalent internal impedance. The thing is, I don't know the equation or even how to make one. However, I have a circuit drawing: Homework Equations Values in...
36. ### How to design an impulse input in Matlab Simulink

Homework Statement I would like to know a way to design an impulse input in a Matlab Simulink model. I know there are step input and ramp input blocks but there is no impulse input block. Homework Equations The Attempt at a Solution If any working is needed please let me know
37. ### Could someone please check my Simulink Diagram

Homework Statement I was asked to draw a Simulink Model for the above (car suspension) system. m = 250kg k, spring constant = 70000N/m c, damping coefficient = 3000N/m/s Homework Equations If any equations are needed please let me know The Attempt at a Solution The question says to draw...
38. ### Bungee jump -> differential equation -> simulink simulation

Hello guys, I found this forum using google because I need help with simulating bungee jump model. I've already done that with zero initial values and it looks good but I want it more realistic : Let's say L is the length of rope so elasticity force starts acting when y=L so logically time...
39. ### Second order differential equation

i am given an equation which i have to solve in simulink. the equation is quite veered to me. some one help me in understanding what kind of equation it is so that i can solve it in MATLAB simulink. (2+x^2)theta'' + (2xx' +1)theta' + 9.8(xcostheta-sinthetha)-x''=T
40. ### Direct synthesis of a controller (plus simulink modeling)

Homework Statement Homework EquationsThe Attempt at a Solution Part (a) Starting with the formula $$g_{c} = \frac {g_{CL}}{g_{p}(1-g_{CL})}$$ The controller transfer function is determined,  g_{c} = \frac { \frac {1}{\lambda s + 1}}{\frac {k_{p}}{(\tau_{p1}s+1)(\tau_{p2}s+1)} - \frac...
41. ### Lead-lag system and model with Simulink

Homework Statement Homework EquationsThe Attempt at a Solution Hello, I am trying to construct the model, but I don't know how to incorporate 3 steps. I tried making 3 step blocks, but the input for the transfer function will only take one line. Then I tried to use one step block and make a...
42. ### Simulink vector space alpha beta transformation

<< Thread moved to the HH forums from the technical engineering forums, so no HH Template is shown >> The model: The goal: 1. Create a three phase voltage 2. Do a alpha-beta transformation 3. Do a Cartesian to Polar transformation 4 Check the output angle The expected result: Since the space...
43. ### Simulink Memory Block: Integration & Inherit Sample Time

Ok,here is the problem. The block holds and delays the input signal for some time but what is a major integration step?Where is the integration?And if we choose inherit sample time,from where does the block inherit sample time?
44. ### MATLAB Matlab Simulink: How to Access SIMSCAPE for Electrical Simulations

hello people, I have MATLAB R2014a installed in my system, i would like to do some electrical simulations. Unfortunately I am unable to find SIMSCAPE in my library. Can anyone suggest me how to get it. thanks in advance.
45. ### How to combine two PID controllers in one system?

I have a model of car, my aim is to make a simple model of adaptive cruise control. The only input to this model is a user set distance (range 2 to 50 meters), this is the distance that our vehicle should maintain between itself and the leading vehicle. I plan to control this using throttle and...
46. ### I need Savonius Model on SIMULINK

Hi there, I'm trying to simulate savonius and Darrieus rotors in simulink. below is brief summary of how much i have done:- 1. I found Darrieus model 2. Darrieus MATLAB code done. 3. the simulation was great and successful but... 1. I couldn't find Savonius model 2. I tried with a difficult one...
47. ### Matlab Simulink: Simulate the height of ball thrown upward

Homework Statement Upthrow simulation Conditions: initial velocity v=10m/s, initial height h=0m when t=0. Gravity acceleration g=10m/s2 . Using Simulink to simulate the variation of height with time when t≥0. Homework Equations I figured that the governing equation should be: Height =...
48. ### Simulink help for getting a frequency I can use as an input

Ok, say I have a sine wave block that has a frequency of 60Hz. What can I do to get that frequency as a number so I can use it as an input to another block? I've tried various things such as a "sign" block that counts when it switches from positive to negative and then a counter that resets...
49. ### Data scrambler in simulink

hi , i am designing a data scrambler block in simulink. it is for wimax system so i have designed one using delay units, XOR gates.i used the specification specified for the initial condition of delay elements and feedback connection according to wimax forum specifications, but i am not able to...
50. ### Simulink Diagram for Solving a Nonlinear Second-Order Differential Equation

< Mentor Note -- thread moved to HH from the technical engineering forums, so no HH Template is shown > \frac{d^2 \theta}{dx^2}=-\frac{x}{10}\cos \theta - \frac{9.8}{10}\sin \theta I'm supposed to draw a simulink diagram for this equation and find the response to a unit step function This is...