Tagged Questions

Questions on the use of Mathematica to analyze, design, and simulate continuous- and discrete-time control systems.

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1
vote
1answer
70 views

Why does LyapunovSolve solve non-standard form?

LyapunovSolve[A,Q] solves the equation $A P + P A^T = Q$ for $P$ whereas the standard form (wikipedia,lecture notes, p.25, linear control systems) of the Lyapunov ...
3
votes
0answers
53 views

StateSpaceRealization “ControllableCompanion” does not generate ControllableCompanion form from DE

I must be doing something wrong, but do not see it. There is an option in Mathematica control system function StateSpaceModel where one asks it to generate the ...
5
votes
0answers
108 views

How to draw block diagrams as Graph objects?

In the documentation ClosedLoopResponsesWithAPIDController, There is a very nice block diagram. I want to create my own block diagrams similar to this. I clicked on the diagram and pressed ...
1
vote
1answer
61 views

NonlinearStateSpaceModel: Trying to parse the documentation

I am trying to follow the documentation on NonlinearStateSpaceModel here, and the first basic example throws me for a loop. It says it's defining the nonlinear ...
5
votes
2answers
103 views

ToDiscreteTimeModel fails following video

Following the systems-modeling video here at about 15 min, 20 seconds in, the presenter (Bob Sanhedrick, I think) shows a model for an "Asteroids-game"-like 2D spacecraft. The model is trivial: ...
8
votes
1answer
129 views

On using DiracDelta[t] in OutputResposne in version 10. Different result from version 9

I am baffled by this. I was trying to run same example I had working in version 9.01 and found now I get empty plots. The example is here . Here is a simplified version of the above. The same exact ...
5
votes
3answers
142 views

Laplace: from differential equation to transfer function

First at all, this is trictly related to my own question: How to transform transfer functions into differential equations? How can I transfer my differential equation into a transfer function? For ...
0
votes
1answer
78 views

A problem with “RiccatiSolve::ncsol: Cannot compute a stabilizing solution to the matrix equation ”

I have a SSM ( State Space Model ) and I want to calculate its optimum gains unisng LQOutputRegulatorGains[] command. When I run the code, it solves the equations ...
4
votes
1answer
93 views

Why do NDSolve and OutputResponse not evaluate non-analytic functions numerically?

test = OutputResponse[TransferFunctionModel[1/(1 + s), s], Exp[-(1/t)], {t, 0, 10}] does not evaluate. If Exp[-(1/t)] is ...
0
votes
1answer
38 views

Multiplicate in an Integration with time [closed]

I am calculating the area of a step response. I try to use this Integral Criterion for my Calculation. The time t is multiplicated with the control error xd raised to the second power. ...
1
vote
0answers
38 views

Plotting a StateResponse inside a loop for some reason gives an error [closed]

/edit Nevermind i figured it out, i now have: ...
4
votes
2answers
291 views

How to transform transfer functions into differential equations?

is there a way with Mathematica to transform transferfunctions (Laplace) into differential equations? Let's say I have the transfer function $\frac{Y(s)}{U(s)}=\text{Kp} \left(\frac{1}{s ...
3
votes
1answer
80 views

How to apply RootLocusPlot corectly

I have to analyze the complex regions of variable c which is define obtained with InverseLaplace help in the form ...
5
votes
0answers
458 views

Estimate parameters of the state space model

I'm using Mathematica 9 and its Control Systems functionality. I've searched the references extensively but seem not to be able to find any examples of state space model parameters estimation. All ...
1
vote
1answer
264 views

Unit of the frequency axis in BodePlot

I have a simple question: What is the unit of the frequency axis in the BodePlot? I searched the documentation, but only found this: The scaling functions can be specified as ...
1
vote
0answers
118 views

No response from DSolve

Using optimal control theory, I am trying to find the optimal paths of d and k such that they will maximize profit as given by lc: ...
0
votes
1answer
131 views

How to use NyquistPlot without having a transfer function model?

Could anyone tell me how to use NyquistPlot with a first argument that is not a transfer function model? The expression I'd like to pass to ...
8
votes
1answer
464 views

How to calculate the $H_2$ and $H_\infty$ norms of TransferFunctionModels or StateSpaceModels?

Lets assume we have a system model: ...
3
votes
1answer
441 views

How to increase Maximum number of steps in any other functions except NDSolve?

I want to plot an output response from a state space model. I use StateResponse[] to calculate it and then plot it. When I run my code, I face this message: ...
5
votes
2answers
315 views

Adding noise to nonlinear control system using NDSolve

I have a nonlinear control system ...
2
votes
1answer
1k views

How can I draw an asymptotic bode plot?

When I use Mathematica to draw a bode plot, it always gives the precise version, like this: BodePlot[(10 (s + 3))/(s (s + 2) (s^2 + s + 2))] How can I draw the ...
0
votes
1answer
453 views

How to simulate the response of a linear parametric varying system in Mathematica?

Consider the following system \begin{align} \dot{x}(t)&=\sum_{i=1}^{2}\rho_{i}(x(t))\left[A_{i}x(t)+B_{i}u(t)\right]\\ y(t)&=Cx(t) \end{align} with: ...
4
votes
1answer
214 views

Problems with RootLocusPlot

I am having some trouble to understand how the RootLocusPlot works (options, drawing and etc.) Here is an example ...
13
votes
1answer
487 views

Simulating discrete time stochastic dynamic systems

What is the canonical way of simulating discrete time stochastic dynamical systems in Mathematica using the new functionality of Random processes? To take a concrete example, lets consider the ...
4
votes
0answers
439 views

Kalman filter by hand

I am now learning the Kalman filter and wants to implement it by hand to understand it better. To be specific I want to first simulate a sequence of data by $$ \dot x=Ax+Bw\\ y=Cx+Dv,\\ ...
2
votes
2answers
551 views

Using transfer function model to generate state space model

I am trying to generate the state space model for the following system: However, the following code does not generate the state space model I expect: ...
6
votes
1answer
666 views

Does Mathematica solve transfer functions differently to Matlab?

Please note this is an edit to the same question posed a few weeks back: I'm using Mathematica to derive the transfer functions for a three phase AC/DC inverter. Given below is the code for the ...
4
votes
1answer
228 views

Using the LQGRegulator to build a human operator model

I'm trying to build a human operator model using an optimal control model in Mathematica: The vehicle dynamics are given by ...
3
votes
3answers
279 views

Strange behaviour of OutputResponse

I am having some trouble when using OutputResponse. For instance consider the following command ...
3
votes
1answer
253 views

How to adjust the parameters on a Nyquist Plot?

In order to see some details on a Nyquist Diagram I have used the function NyquistPlot that comes with Mathematica v8 and v9. ...
4
votes
3answers
1k views

How to fix BodePlot that comes with Mathematica?

I am using Mathematica to go through the examples and exercises on the book Modern Control Systems, 6th edition by Dorf. On page 605, there is a table (Table 8.5) with the Bode plot for several ...
6
votes
1answer
360 views

How to convert a transfer function model to a zero-pole-gain model?

Mathematica has a function to convert TransferFunctionModels to StateSpaceModels: ...
7
votes
1answer
232 views

How do you use SystemsModelFeedbackConnect?

I'm trying to grasp the new control system functions in Mathematica 8. I'd like to connect a controller model to a model of a plant to simulate the behavior of the system. I define a simple servo ...