Is there a block in Simulink to load equations in state variables ?

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Roberto Carabajal 2021-9-7

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评论： Paul 2021-9-10

I remember having seen some time ago a custom block in Simulink, that allowed to place a system of equations written in the format of state variables (in several lines). I haven't found it again and I don't see it in the repositories. I would be very grateful if someone could tell me about it.

My best regards.

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Answer 1

Paul 2021-9-7

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This one?

State Space

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Paul 2021-9-10

在 MATLAB Online 中打开

One can enter user defined differential equations in a Matlab Function block. The body of the function would look like:

function xdot = pendulum(x)
g = -9.81;
L = 1;
xdot(1) = x(2);
xdot(2) = -g/L*sin(x(1));
end

Mabe this is what you're looking for?

In any case, if you respond to this comment, please don't start a new answer. Instead, just type your response in the area underneath this comment that says in light gray "Comment on this answer ..."

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Answer 2

Roberto Carabajal 2021-9-8

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No, it was something like

x(1)= .........

x(2)= .......

x(3)= ........

where x(n) means derivative of x(n-1)

x(1) means x dot.

Each x() is placed in one line in the box

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Paul 2021-9-9

编辑：Paul 2021-9-9

Now I'm confused about what the equations are that need to be implemented. Can you write a few lines of Matlab code that illustrates an example set of equations?

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