Suppliers who write dynamical specification inside their data sheet?

Question

I am a beginner in control system for hydraulic servo systems. The reason why I haven't started yet to do simulations of hydraulic servo system is because I have no information about the components I want to use.

For exampe. To do a simulation of a hydraulic system, you need to know the dynamical characteristics of the components you are using.

If you look at this document, you sure know what I'm talking about.

Let's a assume that you are building a system like that and you want to simulate it in MATLAB.

Well, OK. First you need to know what components you want to have. That's easy, just follow the picture. Then when you have found all the components you need, you also need to know the dynamics such as gain factors, damping, leackage etc.

The problem that all suppliers I have visit, don't show their specification inside the data sheet of the products they are selling.

Example, if you want to do a transfer function of a hydraulic pump and you go to Bosch Rexroth to buy a hydraulic pump. All they going to give you are static equations e.g formulas.

So that led me to the question: If I want to have dynamical information of hydraulic pump, hydraulic cylinders, electrical motors. What supplier should I visit then?

Answer 1

The dynamics you’re looking for are largely governed by how you connect the different components in your design. Although the hydraulic pump you select is important, the equations provided in the supplier catalog should (at least) be sufficient for an initial design analysis (i.e. make an assumption with respect to pump’s efficiency by using the provided charts or google for typical/sane values). Depending on the required detail level of the model (which is determined by the design specifications) additional details might or might not have to be included in the model.

With respect to your last question; in my experience the level of detail you’re looking for is generally not available in supplier catalogs. Mainly because it is not needed for sizing a pump, motor, etc. However, if you know what additional information you need, try giving the supplier a call. They might be willing/able to help ...