Hello,

I'm trying to do something really simple, but far more delicate than expected.

Physically, it's a travelator/moving belt (don't know which is the best term in english) on where is spread a layer of textile, which is described by his density.

So, a certain physical quantity (the density) varies with the space and with the time. With the space because the layer is not uniform, and with the time because the travelator is moving.

Moreover, the speed of the travelator can vary.

In openmodelica, if I want to modelize this system in one block, i've got the access to local variables at the input and I must determinate a mean to calculate the density at the output.

On sheets of paper, I tried several things ; including variable delay and seeking differential equation, but I must conceed I'm back to square one.

Would someone have an idea ?

Thank you by advance,