Simulating a tendon driven robotic finger on Simmechanics

Hello,

I'm trying to simulate a tendon driven robotic finger on Simmechanics but I got stuck on setting the positions of the pulleys on the mechanical system.

The mechanical system I want to simulate on Simmechanics can be summarized by the below figure:

Sorry about the roughness of the figure.

Yellow line represents the tendon and the circles represents the pulleys. The rightmost, the leftmost and the center pulleys are concentric with revolute joints. The others are fixed to the rigid links on the positions just above them.

I prepared a Simulink model with Simmechanics blocks:

The rigid links and revolute joints are imported from a Mechanical CAD tool via an XML file. Then I added pulleys, rotational/translational Simscape interfaces and hard-stop blocks.

My problems about this model are:

- The model lacks the intermediate pulleys between revolute joints. I couldn't figure out how to locate them to the positions fixed to the rigid links.

- I don't know how to position the belt on the correct side of the pulleys.

- I tried to find a way to fix the left end of the belt to the distal phalange (rightmost rigid link), but I'm not sure it is working.

Any help on this issue will be greatly appreciated.

Thanks in advance,

Evren

Answer 1

[Steve Miller]

There are a set of blocks directly in Simscape Multibody that enable you to model systems with cables.

See this documentation page:

https://www.mathworks.com/help/physmod/sm/ref/beltcableproperties.html

--Steve