Hello Cristian and hello to everyone
Some thesis from the Italian geniuses, go to 20 something pages:
Simple 3-joint model:
Springer matrix model, go to (2.28) equations on p25:
For your finger we need a model like these. They look horrific, but they are much easier to understand and code if proper training provided. I can for now model them given a good understanding of your finger.
In 2D/3D you understand how to model motion, any high school student these days understands this:
r: t->(x(t), y(t), z(t))
Then you define equations using r and taking derivatives.
In the case of your finger, r is a matrix space map
r:t->(matrix1(t), matrix2(t), ...)
Somehow the matrix() define the orientation of the joints. You solve some differential equations and you are able control the finger (simpler said than done).
I use Mathematica to solve the matrix differential equations, numerically at that, so we can simulate the joint model.
People in the labs make big deal of it for job security, but it is much more manageable if people are honest.