Hello Joel, thanks for the information, I'll surely do as you suggest, but as this was a short term  project for a student of mine, I built a model on another system that I was more familiar with.

I have no problems with programming part of the solution myself, I just wanted to make sure I was not missing something obvious and reinventing the wheel, since this model, with excitation coming from the movement of the base, is really very common in mechanical engineering for suspension simulation and vibration isolation, also for mechanisms normally we would input the velocity of a link and compute the velocity of other links, in civil engineering it's used to compute the response to earthquakes and so on.

Please understand that I'm not complaining, I fully understand that no one has any obligation to do for free the things that are useful to me, I'm just commenting on a design choice that was very different from what I would have made.

Thanks again for the time you spent on this,

Ramiro.

Hi Joel,

Thanks again for you time,

Of course I don't want it fixed in space. I just used the fixed block to have something I could "move" up and down to show what I needed, I apologize (again
for the confusion.

Animation would not be a problem, but using a force as input is a problem, because the contact force between the tires and the ground is unknown, it depends on the dynamics of the system. It has to be computed by the system.

I *have* the curve "y(t)", and I want to find the displacement of the sprung mass, "x(t)", in the figure. This is certainly possible, because there are vehicle models and road models in OpenModelica, but they are all very complex and I need a simple model for demonstration purposes.

Anyways, thank you the attention,

Ramiro.

Hello, thanks for taking the time to reply. I apologize for not being clear in the first place. I also apologize in advance for the "ms paint" skills that are about to come.

I made a drawing that perhaps would make the situation clear. The simplest model for the study of vehicular suspensions is a single degree of freedom model which is excited by the movement of the base. I made a simple schematic with OMEdit shown below. Please disregard the fact that as it is, the body can move just about everywhere, in a real model there would be constraints that would allow it to move only vertically.



The problem is to compute the displacement of the body given a known displacement (not force, the resultant contact force is one of the things I'd like to compute) of the ground. This has to be something very obvious, so I apologize again

Thanks for the attention,

Hello,

This is very likely a dumb question, but I've really searched the whole day and could not find an answer.

It is possible, and if so, how should I go about to do it, to make a mechanical model where the movement is a result of the displacement of the support?

Every example and component I could find both in the Multibody library and Planar Mechanics are driven by a force, or the inertia of some component. What I need is something similar to the "Position" component of the Translation Library, or someway of connecting it to the Multibody library or planar mechanics library.