Is there a way to add a graphical only line between two frames in multibody

Is there a way to add a simple line that connects two points or frames that move arbitrarily large distances in space? This is for multibody simulations.

thank you very much

[Sahas]

Hi @Mark,

I am not sure that this property currently exists as an inbuilt function or property, but you can try out and combine the following MathWorks documentation links on Assembly, frames and graphic joints and use it as suitable to you:

• https://www.mathworks.com/help/sm/ug/frames-and-frame-transforms.html
• https://www.mathworks.com/help/sm/ref/graphic.html
• https://www.mathworks.com/help/sm/ug/assembling-multibody-systems.html

I hope this is beneficial!

Answer 1

[Yifeng Tang]

Hi Mark,

I don't think there is a "native" way to do this. I can think of a clunky way of doing this. I don't like it but maybe it's barly sufficient.

The idea is to have a lot of little spheres, say 20 of them, each connected to the world frame via a cartesian joint. The measured positions of the two points can be fed and distributed to these 20 spheres, such that they form a dotted "line" between the two frames. You may be able to use a custom Simcape language block in the PS domain to handle the vectorized algebra. The individual position of the spheres can then be sent to the actuation input of the cartesian joints to move the sphere to the right place to form a dotted line at any moment.

[Mark]

Is there a way to code our own custom blocks/features in simscape multibody? Adding a simple line between two points graphically really sounds like something basic that we ought to be able to code.

[Yifeng Tang]

Multibody, probably no.

One idea just came to me: do you think it's possible to use the pulley and cable in Multibody to create that visual? A spool with negligible inertia at one point, with the other end fixed at the other point. Never tried this. Just a thought.