How can I simulate a wire actuated soft robot?

Hi,

I have been trying to simulate a wire actuator made of a flexible plastic using Simulink Multibody. Wire goes through holes in the segments of the plastic actuator, and when a motor pulls on the wire, the actuator bends.

It is very similar to this model, simulated using the SOFA framework: https://www.youtube.com/watch?v=uXkxI6NwIIY.

The closest I have come is to attatch cable pulleys to the actuator made by several different 'flexible beams' in simulink. This is extremely slow to simulate and it is also not a correct model of my robot. I have also tried using internal forces in the flexible beam, which is faster but still not correct.

Do you have any suggestions of how i can make wire go through a hole in a flexible object? Or have you seen any similar project being simulated in Simulink Multibody?

I am grateful for any suggestions.

Answer 1

[Steve Miller]

Some suggestions:

1. If you can treat the finger segments as rigid and put joints with spring and damping coefficients at the places where the segments join, the simulation will run faster.
2. To model the cable going through the channels in the finger segments, put very small pulleys at each end of the channels. Make sure the cable wraps around the pulley at least once (or at least enough so that it cannot unrwap fully.

I have seen other users create models like this, so it is definitely possible.

--Steve