Getting zero Output as Total Force and Torque in simscape multibody simulation

The scenario is to move in a constant radius Circle

My model is behaving as expected it is moving in a constant radius circle it has the right accelrations velocites from the transform sensor

But for some reason it is always giving me Output as zero for all 3 torques and force componets

I tried adding an inertia block to the world frame thinking it might be because Force excerted on zero mass body might be zero but it didnt fix the issue

[Tharun Kumar]

Also i forgot to mention there is a Magic Formular Tire Force and Torque block could that be the reason i am geeting zero force and torque?

I thought the Toruqe Sensing would give Force required to move the object connected betwwen the 2 frames

Answer 1

[Umeshraja]

Hi @Tharun Kumar.

I understand that your model outputs zero force and torque, which can potentially be caused by incorrect tire parameters. While the issue might not seem to originate from the block itself, it could be due to an invalid combination of parameters in the TIR file.

You can refer to the documentation for a list of all required parameters for the Magic Formula Tire Force and Torque block:

https://www.mathworks.com/help/sm/ref/magicformulatireforceandtorque.html#mw_8edcefad-4c58-475e-b205-725241a0b3da

Although each parameter might be valid on its own, when used together in the Magic Formula equations, they can sometimes lead to singularities or domain errors. When such invalid conditions are detected, the block outputs zero force and torque as a safeguard.

All equations used by the Magic Formula Tire Force and Torque block are derived from the references listed in the documentation:

https://www.mathworks.com/help/sm/ref/magicformulatireforceandtorque.html#References

Specifically, they are based on:

Pacejka, Hans B., and Igo Besselink. Tire and Vehicle Dynamics. 3rd. Engineering Automotive Engineering. Amsterdam: Elsevier/Butterworth-Heinemann, 2012

I hope this helps!