Hi Michele, you are right - at the moment there is no model for static friction in joints. This is a feature that I postponed for a while, and I never had time to implement because it was too low in my priority list.
It is not easy to do because (at least in a context of DVI nonsmooth dynamics) it requires some low level stuff in terms of ChVariable and ChConstraint class hierarchy - even if probably one could just reuse the ChConstraintTwoTuplesFrictionT class that was meant for 3d contact, and put it inside a ChLinkMate-inherited new constraint along with other ChConstrainTwoBodies. But not sure, until I'll have time to play with this. Also, if you need this feature in smooth dynamics (ex ChSystemSMC, not ChSystemNSC) then it will be a different story. It would be a matter of force fields as in Pacejka formulas etc. thanks Alessandro Tasora Il giorno sabato 4 gennaio 2025 alle 15:52:14 UTC+1 [email protected] ha scritto: > Hi all, I'm loking into the documentation of this amazing project to > understand if it is suitable to be used in my case, so I'm definitly a > newbie / beginner and I apologize if the question is trivial. > I'm modelling a serial robot and I'm loking a way to simulate static joint > friction (for a revolute or prismatic joint) but I'm not able to find any > model for that, even a simple static friction model (Coulomb). > > I've seen that the friction physycs could be added through a > ChContactMaterial > <https://api.projectchrono.org/classchrono_1_1_ch_contact_material.html> > and a collision box, which seems a bit overkilling for the specific case. > I've also seen in the forum a proposal to add a ChLinkLock > <https://api.projectchrono.org/classchrono_1_1_ch_link_lock.html> to the > joint, but this do not manage static friction (only constant torque and > viscous damping). > > Am I missing something? > > Thanks a lot for any hints / help! > Michele Bucceri > > > *Confidentiality Notice:** This email and any documents attached to it, > may include information that is confidential and intended only for the use > of the recipient(s) named above. If you believe you have received this > email in error, please notify the sender and delete the message and all > attached documents. Disclosure, copying, distribution or use of > confidential information included in this email or its attachments, by > anyone other than an intended recipient, is strictly prohibited.* -- You received this message because you are subscribed to the Google Groups "ProjectChrono" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/d/msgid/projectchrono/20d9aa89-d322-42e6-84fd-6d939b704b43n%40googlegroups.com.
