Problem with KnC event
Hi,
I've created a model that works well for simulating dynamical events. However, when I switch to a kinematic simulation, it becomes very slow and doesn't simulate correctly. I’m not receiving any errors or warnings, so I’m unsure what the issue might be.
Thank you in advance for your help.
Have a great day!
Best regards
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Hi,
Yes, I understand that it is slower than dynamic events, but it took 6 hours to complete. In contrast, when I use a basic model, it only takes 5 minutes.
I already checked the animation, and nothing appears to be moving, even though the event ran completely. Additionally, the data logger doesn't show any output, nor does the debug file.
This is why I’m reaching out for help. I added the file again this one should have the kinematic event in it.
Have a nice day.
Altair EmployeeHello @MBURE,
after checking your model quickly I noticed the following issues. There is a chassis body and a vehicle body. In KnC the chassis body is selected as vehicle body in your case. But automatically Joint 0 is selected in constrain 1 (Optional). By default you should have there the PERP Clamp. This led to the below odd behavior
Please update the joint there with Body Clamp PERP.
and try simulate. I would suggest to first run with SDF output unchecked so that it runs faster. Check the visualization. Here is what I've got.
Hope this helps!
Best regards,
Orestes
Hi @MBURE,
There are several reasons why the KnC event may take longer than a DLC, for example, such as the event runtime (90 seconds vs. ~5 seconds). Additionally, if the KnC stroke lengths are not set to the size of your vehicle, it may be trying to compress or extend your suspension far beyond what is possible and causing integration issues. Roughly, how long are these models taking to solve?
Please check to see if the KnC settings are appropriate for your vehicle. Also, I would review the animation to find clues as to why your model is having difficultly solving. Lastly, if you enable the DEBUG settings in the Global Simulation Settings, it will show which entity is contributing most to the integration error at each timestep. This usually points to what is causing the slowdown.
Your model archive does not contain your KnC event, so it is difficult to gauge what you may be doing incorrectly in the settings from the file you attached.
Hope this helps!
Adam Reid