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Why velocity and acceleration values can not be measured when sending inputs from Simulink?

Why velocity and acceleration values can not be measured when sending inputs from Simulink?

Why velocity and acceleration values can not be measured when sending inputs from Simulink?

(OP)
Hello,

I modeled a simply pendulum mechanism in MSC Adams/View environment. I give the input angle values to the joint motion from matlab/simulink by using VARVAL(.MODEL_1.angle) command. I defined state variables and my outputs are torque, displacement and velocity x and y and accelereration. I readed this results from Simulink. My question is why it is not showing velocity and acceleration measurements in Simulink? It is showing displacements and torque values. Velocity measurement is done by VX(marker2) command.

I give the inputs in Adams environment instead of giving from Simulink. It gave me all measurement.

Why it is not giving velocity and acceleration values when i sent inputs from SİMULİNK.

Thank you for your consideration.

My file:
https://files.engineering.com/getfile.aspx?folder=...

RE: Why velocity and acceleration values can not be measured when sending inputs from Simulink?

(OP)
If it has problem about output channels, why it is giving displacement and torque values?

I believe that it could be about solver issues. If it gives displacement, velocity and acceleration are just the differantiation of displacement.

I download the file again.

Thanks for your message.

RE: Why velocity and acceleration values can not be measured when sending inputs from Simulink?

It's still a rar file, and frankly it wouldn't be much use to me, I don't have adams or simulink on my own pc, and I don't download anything onto the work pc.

You have to patch each signal across.

Cheers

Greg Locock


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RE: Why velocity and acceleration values can not be measured when sending inputs from Simulink?

It's been years since I last used ADAMS and I havr no accessto it today. But...

If you are imposing motion on a system, the solver isn't solving for it and would have no need to estimate its derivatives unless they are being used elsewhere for other boundary conditions. Maybe those values don't exist in the solution?

Steve

RE: Why velocity and acceleration values can not be measured when sending inputs from Simulink?

(OP)
I try to change the solver parameters from Simulink/Model configuration parameters, fixed step size and solver types, somehow it gave something but i am not really sure it is true or not. The graphic is so wavy for the first time steps.
Why it is so wavy for the first time steps? Should i give initial conditions?

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