Questions tagged [matlab]

Use of Matlab to solve engineering problems.

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6
votes
1answer
572 views

mass calculation from transfer function or bodeplot

I have a double mass rotary model. The two masses are connected by an axis which together acts as a spring damper system of the fourth order. The system is actuated by a motor and the angle of ...
6
votes
1answer
191 views

Programmable parameter change of Pro/E simulation by using Excel VBA , Matlab, Labview or Pro/E own function

Now, I've been conducting beam simulation by using Pro/E. I would like to change payload(force) of beam step by step, and then plot the relation between deflection and payload(load range : 50kg to ...
5
votes
1answer
129 views

dSPACE compiler linker error -- fscanf undefined

I'm dealing with a somewhat intractable problem. We're running dSPACE 7.4 (RTI 1006) on MATLAB 2011a, which I understand uses the dSPACE DS1006 C Compiler v. 2.2. When I try to compile one of our ...
4
votes
2answers
144 views

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

The problem The problem is to find the coefficients for the P, I and D terms of a PID controller used to regulate the object that minimize the the integral of the squared error (ISE): $$Q = \int_0^\...
4
votes
1answer
122 views

How to design the right input to obtain a desired output for a linear system?

If I have a state-space model, so that matrices $A$, $B$, $C$ and $D$ are known, how can I design the right input $u$, so that $y$ is a desired signal, say, a sine wave with constant amplitude? $$\...
4
votes
1answer
624 views

Is it normal to get different solutions with different ODE methods in MATLAB simulink?

I made a block diagram using simulink. When I solve it with ode45 and ode23 it gives me different graphs. Is it normal? Should I use the proper one? ...
4
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0answers
266 views

3 DOF SISO state space control

As part of a control systems course I have to implement control for a 3 DOF SISO mass spring damper model of a robotic cutter arm. The arm is to follow a 5Hz triangle wave reference which is ...
4
votes
1answer
121 views

Convolution with RTD laminar flow

I have laminar flow in a tube. Consider the tube to be 0.2 m long and with an average velocity of 0.05 m/s. The analytical expression for my transfer function is: $E(t)= \frac{\tau^2}{2*t^3}$ for $t$>=...
3
votes
1answer
63 views

Problem with performances of a control scheme

I am trying to prove with Matlab that if I have an improper system and I place poles at higher and higher frequencies the performances of the system improves. In particular I am considering the ...
3
votes
1answer
525 views

How do I create a graph of the phase angle and response of a harmonic excitation in Matlab?

In my course of dynamics of structures, I am struggling with some basic principles. As a practice, I am plotting (or attempting to plot) the curves that are shown in the course book, with the help of ...
3
votes
1answer
3k views

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

According to Matlab documentation: sigma plots the singular values of the frequency response of a dynamic system. bode creates a Bode plot of the frequency response of a dynamic system. I am ...
3
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0answers
47 views

Mathematical transformation of a heading angle to a roll angle

I'm trying to understand a function in a SIMULINK example of a path following UAV simulation. The gist is that, the UAV Waypoint Follower block provides a required heading from a list of waypoints and ...
3
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0answers
62 views

LQR Implementation in MATLAB

I am trying to implement a simple LQR controller in MATLAB for a purely deterministic system. The code is shown below: ...
3
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0answers
63 views

How to solve LMIs with equality constraints using MATLAB?

I would like to find n by n matrices P and Q that minimize J = norm(P) + w*norm(Q), where w is a given weight, subject to P>=0, Q>=0, and f(P,Q)=0, where f(P,Q)=0 is a given function of P and R. I ...
2
votes
1answer
1k views

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

Let's start with arbitrary transfer function as an example, such as: obj = tf([1 2],[1 0 2 5]); nyquist(obj); grid on; axis([-2 2 -2 2]); axis equal As far as I ...
2
votes
1answer
747 views

Design op-amp circuit from transfer function? [closed]

What is the best way to design a circuit based on the following transfer function: (0.0364*s)/(0.0002*s + 1) ? I am trying to design the derivative stage of a PIDF controller using op-amps EDIT: This ...
2
votes
1answer
1k views

How to import a CATIA assembly into SimMechanics

I need to import an assembly from CATIA into SimMechanics but in CATIA, the .stl file format is available only for part files and not for assembly files. How can I do this? Is it possible to convert ...
2
votes
1answer
949 views

Question on sketching nyquist plot of transfer function with poles on imaginary axis

I have encountered some issues with sketching the nyquist plot for the following loop transfer function: $L(s) = \frac{25K}{S^2+25}$ I know that you first take: $L(\omega=0) = K$ $L(\omega = ...
2
votes
1answer
191 views

Active suspension with accelerometers and displacement observer/estimator problem

I faced a logical dilemma, while designing and simulating Active suspension system. This is what I have planned: My system will be controlling actuators of a vehicle, using PI. It is 2nd order ...
2
votes
1answer
660 views

How to use lsim in matlab for a closed loop system

I have designed a system using a minimum realization. I have the A, B, C matrices and I have assigned closed loop poles for the system. I used the place command to find my K matrix. I am wondering ...
2
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0answers
64 views

Maintaining constant speed of a CVT engine during a slope

I am not sure if this question is related to this community. But nevertheless. I work on CVT engines, I had a new idea of modifying my controller during a slope or a gradient on the road so that the ...
2
votes
0answers
37 views

Discretise this transport equation

I am trying to discretise the PDE: $$\phi \frac{\partial c}{\partial t}+\frac{\partial j}{\partial x}=0$$ where $c$ is a function of $x$ and $t$, and $j=qc-D(q)\frac{\partial c}{\partial x}$, $q$ is ...
2
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0answers
64 views

calculate output $y(t)$ from $Y(z)$ having discrete closed loop model with sine input - residue method

I have closed loop - discrete model. This is how it looks in matlab: I need to compute analitically output $y(t)$ (same as in the Matlab's scope) having $Y(z)$. Where $Y(z)=U(z)*G(z)$ Input is sine ...
2
votes
0answers
532 views

Export simulink sdi dataset from MATLAB 2015b

I have used the Simulation Data Inspector in Simulink to log a dataset of two time varying signals. The only option I see concerning exporting is to .mat or to workspace, which basically produce the ...
1
vote
2answers
71 views

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

I am using the MATLAB System Identification Toolbox to estimate a 3rd order state space plant model. More precisely, the plant is a car with an Arduino mounted on it. The car takes in a PWM duty cycle ...
1
vote
1answer
274 views

Root Locus and Routh–Hurwitz stability criterion

A satellite launcher has a unit feedback system, whose TF global open loop is given by: $$G_c(s)G(s) = \frac{K(s^2-4s+18)(s+2)}{(s^2-2)(s+12)} $$ a) Draw the root locus for this function b) ...
1
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2answers
1k views

Calculating a derivative in a loop?

I am not sure where else to post this, so here goes. I have a velocity profile ($v_{\phi}$) for a radial distance ($r$). From this velocity profile I am trying calculate the shear rate ($y$) which ...
1
vote
2answers
68 views

Fault Recovery of a UAV using MATLAB

I'm currently investigating fault recovery in a UAV using MATLAB. I've been given several variables: phi = the roll angle psi = the yaw/heading angle beta = the side slip p = roll rate r = yaw/...
1
vote
2answers
100 views

Analizing Vibrations Influence on Dynamic Weighing

I have a very sensitive scale used for dynamic weighing (by dynamic I mean that the scale and load cells are actually beneath a belt conveyor that actively weight product when it´s being transported ...
1
vote
1answer
1k views

Closed loop response of a discrete system

I have trasfer functions of a plant and a controller in laplace domain. I checked for the closed loop response by applying a step response. The system is found to be stable. I checked the response ...
1
vote
1answer
122 views

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

I am simulating a mass - damper - system in Matlab and I have the following vector (1x100) as input to my system: ...
1
vote
2answers
2k views

How to generate a NACA 6-Series Airfoil analytically?

I asked this question over at Aviation.stackexchange but after that I figured it might be better to place it here. Especially since there were really good answers on the NACA 5-digit-Series airfoil ...
1
vote
1answer
78 views

Unachievable motions because of singular Jacobian

This is the Jacobian of a robot arm (IBB IRB 120) with already specified joint angles (0,0,0,0,0,0). This Jacobian is singular for this configuration. ...
1
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0answers
67 views

Errors obtained in the numerical solution of the 1D convection-diffusion equation

I have been trying to solve the 1D convection-diffusion equation In implementing the above, I have tried to follow closely the method described here: https://uk.mathworks.com/support/search.html/...
1
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0answers
27 views

Slow integration of system ODE under specific conditions in adsorption problem

I am trying to solve the system of ODEs below. I am applying the finite differences to z, so I get a system of ODE that I can solve with a solver like ode45. The problem is that under the conditions ...
1
vote
1answer
212 views

How to calculate initial concentration of first-order reaction in CSTR?

(This question comes from a Chemical Engineering background, but basic Math and Programming knowledge is also required. I hope it still falls in the scope of engineering.stackexchange.com If not, ...
1
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0answers
9 views

how to implement an encoder in matlab

How can I encode a quantized vector in matlab ? This is a part of a problem where I am asked to implement a communication block using matlab.
1
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0answers
16 views

Unexpected Closed-Loop System Response of Longitudinal Aircraft Dynamics

I have a closed-loop system that represents the longitudinal dynamics of an aircraft with states x velocity, z velocity, pitch rate, pitch, and x and z inertial positions. The outputs of the system (...
1
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0answers
31 views

How can I measure the impact of noise on a FFT?

Please, I have to solve a problem and I really need some help. I have to give an efficient method to consider a maximum amplitude as a starting point to consider as noise the whole spectrum below ...
1
vote
1answer
114 views

Stabilization of telescope on gimbal using data from encoders and gyroscope

I'm designing a control system for a balloon-borne telescope experiment. As the balloon is constantly moving and the gondola is rotating, I want to stabilize the telescope which can be controlled in 3 ...
1
vote
0answers
148 views

Designing a PID Controller for Satellite Control

As an Aerospace Engineering Student, I have been trying to make a project of a PID Controller to control the attitude response of a satellite using the parameters from a project called Kufasat. The ...
1
vote
0answers
84 views

How can I do engineering projects for money at home? [closed]

I am a M.Sc. graduate in mechanical engineering and I have experience with engineering software, like MATLAB, CATIA, and ABAQUS. I want to know how I can find industrial projects like finite element ...
1
vote
1answer
112 views

Simulating a mass - spring - damper system

I have a mass - spring - damper system with external force and I am trying to simulate it using Matlab. I want to have a linearly parameterized form and use the least squares method to find the ...
1
vote
0answers
125 views

Method to simulate a dipole antenna in salt water?

I am looking to simulate the radiation pattern of a 2.7Ghz half-wavelength dipole antenna immersed in salt water. I've been using Altair FEKO software to try and accomplish this. I've tried two ...
1
vote
1answer
567 views

Model Reduction - Export matrices from ANSYS to MATLAB

I am trying to reduce my model in ANSYS using Craig-Bampton Method. My ultimate goal is to read system matrices, stiffness, damping and mass matrix with MATLAB. The size of stiffness matrix that I ...
1
vote
1answer
51 views

classify ECG signal using neural network

I am looking to classify ECG signal using with neural network. I have never done signal analysis before. From the samples of data I have, I have noramlised, transformed using the FFT , get the pics, ...
1
vote
1answer
116 views

simulation of an attitude optimal Backstepping controller based quaternion for a UAV in MATLAB

I'am trying to implement this open access research article Attitude Optimal Backstepping Controller Based Quaternion for a UAV I did not find the same result in this paper Can anyone tell me where my ...
1
vote
0answers
68 views

Temperature distribution

First of all I am just a starter in Matlab, so the program is not optimized. For now I just want to get it running. This is a 3D heat problem with boundary conditions. Fixed temperature from the north,...
1
vote
0answers
41 views

Simulink analysis of data parallel to generation

I would like to simulate the following scenario with Simulink/Matlab(/Stateflow): A random number generator is running. Every 10 seconds the numbers that were generated during the last 10 seconds are ...
1
vote
0answers
25 views

Linear Guidance law into X-Y axis

Im currently writing a model for a guidance law named Maintaining Guidance law. The law looks as following: $$ a_{M} = [K_1,K_2]*[\dot{\lambda_T} ,\dot{\lambda_D}]'$$ Since im using a linear model I ...