Hi Sherm, Thank you very much for the reply, and apologies for my late reply as well. (b) I'm not yet confident about extending Simbody, but please if anyone reading interested in this feature wants to submit a PR, it would certainly come in handy. (a) Clay's approach is indeed very interesting! Whi...

Hi, I have two questions about the integration of the EOM: a) The system under study implements a force F=-A*sign(v), where A is a constant and v is the speed of the point where the force acts. The actual implementation smoothes the sign() function to avoid integration issues. The problem of the lat...

Hi Sherm,

I am connecting the dots now, many thanks for your valuable help!

Best regards,
Simone

Hi Sherm, Yes, I will apply it as body forces! The mobilizers are actually following a unit speed trajectory, so the equivalent body force should be along the tangent to the trajectory, with the same magnitude as the mobility force. Moreover, I noticed (for example in a system with 1 slider along th...

Hi Sherm, Thank you, with the documentation and the example I could create a minimal system that allocates an auto-update variable. Now I am still trying to find a way to compute the needed reactions. Let me explain it again with the following basic system: diagram.PNG The system consists of two sli...

Hi Sherm, Regarding the reaction force, where should I be setting the allocated auto-update discrete variables? And by auto-update does it mean that, no matter when I set the value, it will be updated only after a step finishes? As for the actual friction force calculation, it does not directly depe...

Hi Sherm, I still have not found a convenient solution for the problem I am trying to solve, I would appreciate if you could shed more light upon it. Let me state the problem with a simpler equivalent system. The system has two mobilized bodies, each one of the same type, with one generalized coordi...

Hi Sherm, I think I understand it now. I falsely assumed the mobilizer reaction forces only included the mobility forces when directly specifying a motion, but it turns out it also applies for constraints acting directly on the generalized coordinates. That means, for example, that SimTK::Constraint...

Hi Sherm, Thank you for the prompt response. Indeed, both options could work. I would opt for the second one, given that I have many SimTK::Force components and just one SimTK::Constraint::CoordinateCoupler acting on each mobilized body. For the mobilizer reactions, I can use for instance findMobili...

Hello! Is there any function in Simbody that calculates the "net internal wrench" applied to a MobilizedBody? By that I mean the following: if a MobilizedBody is subject to a series of constraints, then this net force would be the sum of both the mobilizer force and the constraint forces, both obvio...