System Modeller, Modellica : Prosthetics joints and electronics


Please see:

The models are based upon Modelica language:

You need mix electronics with mechanical parts, you need to have a SIMULATOR to make sure your designs work prior to any fabrication to reduce cost dev time.

We have also purchase the license for System Modeller, which we could share on our server for programmers and designs dealing with Prosthetics’ system modelling.

I have not program in these yet, but the interface is graphical:


Hey @dara, did you try these tools? could be useful to simulate the joint fingers of new fable


yes, they are useful for both mechanical and electronic part.

The tools also solve differential equations of movement.

However it requires serious study and training, it is not a trivial tool


Why don’t you spec out a project that is realistic and you can build it in reasonable amount of time, and we develop code against the specs.


This is a sample paper:

See section IV.

You need to develop a some equations namely differential equations that model the movement of your fingers. Solution to these equations become the input signals to your hand and then it does something systematic and predictable.

People do not build these systems at first, what they do is they write a simulator first to simulate the hand and fingers , then compute the said solutions and finally see if the solutions actually work.

Once they have some success with simulation then they build the electro-mechanical controls.

You should know that human fingers are one the most sophisticate controlled dynamical systems in the universe!

If I were to contribute, this is kinda what I plan:

  1. Single finger simulation software
  2. Single finger dynamical solutions for very specific movements e.g. pointing, scratching
  3. Then I will learn from the above and code a simulator for the 5 fingers and wrist

Assumption being that there is a huge computer attached to the hand to compute the solutions it needs e.g. 10times a second.

Good design and the hardest part of a design is the genius to find a simple system at first to simulate.


all of this is surely really interesting because it’s a big and hard challenge, I know well the problem and my friends here in Italy are working hard in their lab on it.
Anyway, i think is a little off topic for OBM, because we aren’t a research center and unfortunately we don’t have equipment and time to do these kinds of works.

We can try to do a simple biomechanical simulation with the 3d model that we have (joint with 1 DOF) to improve the motion find the best position amoung fingers and hand and to find the stress spot to improve the 3d model.

i think this is more easy and useful for us, what do you think?


Sure we could discuss and plan the simpler simulation.

I suggest that you ask your Italian friends on the research papers in the mathematical modelling of the parameter space of the fingers and hand.

These are like the phase spaces in physics, you do not need to worry about them but I need them to model in software. Roughly they are matrix groups which model composite rotations of the joints, you then have space to navigate to find the shortest paths which translate to the most efficient angles sequences to rotate.

I give you the control code in this format:

You can then make a lab setup and use the CDF to control the fingers and collect data from the movement.

Meanwhile I do my own search. I also will find the robotics guy at Wolfram who modelled their robot arm.