How to visualize a vector in Simscape Multibody

Hello!

I have been working on a 6-DOF Simscape Multibody simulation for a thrust vectored rocket. The simulation works, but I have been wanting to visualize the thrust vector below the rocket. How should I go about this?

In my searching, I have found that this visualization would likely have to be a geometric solid with no mass, which is okay (I just want an indication of direction and I have modeled a vector solid already). This would be relatively straightforward if the Rigid Transform block could take a dynamic rotation matrix, as that is already what my simulation uses to calculate the thrust vector in the proper global frame, but it seems that it can only take a compile- or run-time rotation matrix.

I have also considered using a spherical joint under the rocket connected to the vector solid, but doing so would require being able to set the position of the spherical joint, and I have not been able to figure out how to do that.

I have even tried making my own Simscape component to act as a Dynamic Transform block, but the Simscape language does not have access to the Multibody Frame class necessary to make this work.

Is visualizing a vector like this possible, and if so, what is the best way to go about it?

[Yifeng Tang]

Simscape language won't help with Multibody :(

The spherical joint + massless solid idea should work fine, as long as you have the direction and know how to apply the rotation to the spherical joint. One frame of the spherical joint can be attached to the massless (or tiny mass) solid and the other frame to your rocket.

I also wonder if a telescoping joint will be even nicer. It's a spherical joint plus a prismatic joint. The prismatic joint can be used to indicate the length of the vector, if desired.

Answer 1

[Supraja]

Hello William,

As far as I understand, you would like to know how to visiualize the underneath thrust for your 6-DOF Simscape multibody.

As Yifen mentioned you might need to use spherical joint with the massless solid. Also, you can try specifying the orientation of your target as mentioned in the documentation link below:

https://in.mathworks.com/help/sm/ref/6dofjoint.html#:~:text=Provided%20by%20Input-,Spherical%20Primitive%20(S),-State%20Targets

This might help you to specify the postion according to your need.

I hope this helps!