Simscape Multibody *** Model not assembled: position violation ***

Hi, I'm currently trying to simlulate the movement of an RRRP linkage in Simscape Multibody but I am running into an assembly error when running. I Have determined which joint the issue is and have followed this tutorials steps ( https://www.mathworks.com/help/physmod/sm/ug/find-and-fix-aiming-mechanism-assembly-errors.html ) to attempt to fix the problem. According to this I had to allign the axis of the frames to be parellel to each other and I have done so as seen in the picture below.

With the frames rotated like so I am still recieveing the "*** Model not assembled: position violation *** Resolve this issue in order to simulate the model." error when running the simulation. Would anybody know where I went wrong with attempting to fix this?

Answer 1

[Juan Sagarduy]

Hi Garett Do you have the chance to share the model? It must be a detail in there that needs sorting out. Br Juan

[G Mcc]

Hi, Thank you so much for helping! I've attached a picture of the model below, forgive me if its messy I'm new to this.

[Juan Sagarduy]

Hi Garett

This mechanism is more compex that what one would think. I remember using it for my first Simscape workshop. I guess that there are different approaches and you need to find the one you prefer.

As an attachment, I had the model I've built using local frames for the rods and simualting motion in the x-Y plane (gravity along -Y). Since the mechanism is a kinematic closed path, you need to be able to access the end point from origin through the prismatic joint and slider, and from the path created by the rods. If you do carefully, it works out well.

I am sure that in your case, you did not succeed in reaching the end point transform consistently, and hence the model assembly violation error. Until the model is correctly assembled, it is better not to prescribe any motion as it can complicate the process.

Check this out & Good Luck.

Cheers Juan