siconos
joints in the mechanisms toolbox
Hi,
I'm currently working with the mechanisms toolbox, and i'm trying to model Newton's cradle with it. I'm having some trouble finding information about how to use the toolbox as I can't find any documentation online. I only found those examples on Git. Do you have more information about the mechanisms toolbox somewhere ?
I'm currently trying to model the joints of the pendulum, but I don't know how to implement them in the bodydef.py file to make it work. In particular, I don't understand the difference between mbtb.PIVOT_0 and mbtb.PIVOT_1. Also, I'm unsure how to define the position of the joints in the bodydef.py file. Can you help me ?
Regards, Rémy ROUBINET
Dear Remy, Unfortunately, the documentation for the toolbox mechanisms is rather poor. This is mainly due to the fact that we have been considering another implementation for some time now and are concentrating our efforts on it.
The main difference between mbtb.PIVOT_0 and mbtb.PIVOT_1 lies in the number of dynamical systems related to a pivot joint.
If you want to make a pivot on a single boby (only one dynamical system) then use mbtb.PIVOT_0. This is the case when the pivot is written with respect to the fixed frame. In this case, the position of the joint is given in the body frame of the body.
If you want to make a pivot between two bodies, then use mbtb.PIVOT_1. The position of the joint is given in the body frame of the first body.
You can hace a look here to understand how it is taken into account : https://github.com/siconos/siconos/blob/445f102faa029deaeb69a0a0aa13313e1b68be38/mechanisms/src/MBTB/MBTB_PYTHON_API.cpp#L360
Best
