How do I create a Belt-Cable Spool with a variable diameter?

I am attempting to model a belt-cable spool that is spun up to pull in a cable. The physical spool has a semi-conical shape instead of the standard cylinder, which changes both the cable speed and the torque behavior. Is there a way to model a belt-cable spool with a variable diameter?

Alternatively, are there some resources on constructing custom belt-cable multibody blocks?

Answer 1

[Lucas Schloemp]

The solution I followed involved the Driveline library. The rope drum object in that library has its source code available, from which it was easy to create a custom version with the drum radius as an input signal.Then the translational multibody interface (rather, my own version of that block since I'm using 2020b) connected me back into the multibody visualization world.

I still have a strange issue here where I can't use the measured angle of the drum as part of this radius input signal without putting a unit delay on the angle feedback. It raises an error that the initial radius of the drum cannot be zero, even though it is not. I believe this is some kind of issue with the mechanical sensor elements holding everything downstream of their sensor lines low at the simulation build time, but I have not investigated that in depth.

Answer 2

[Dhruv]

Hi Lucas,

Modeling a belt-cable spool with a variable diameter, especially one with a semi-conical shape, would involve several steps.

The approach involves making use of Simscape Multibody for geometries and mechanical systems. The following link offers a comprehensive overview of the topic:

https://www.mathworks.com/help/sm/index.html

To begin, I recommend exploring the following MathWorks documentations. These include useful examples that can guide you through the modelling process:

https://www.mathworks.com/help/sm/ref/beltcablespool.html

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

Hope this helps!