Mechanism's Custom Loads

[gfraulini]

Hi all,

do anyone know how creating a Custom Load into Mechanism?

I've read what the PTC help says (link) but I'm not very practice of C-programming and anyway the procedure remains to me not clear.

I wonder if it is possible using this method to create a feedback loop linking proE with an external software that analyze datas in output and resends in input tothe motor force/momentum within pro/mechanism.

The purpose is to obtain something like you can have with LMS AMEsim or Maplesim.

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[jwu-2]

Hello,

PTC custom load interface is not easy for application engineer, you need to know how to do programming and you need to purchase TOOLKIT license too. I don't think that is a good solution.

if you want to simulation feedback loop hydraulic and mechanism system in AMEsim, now I used AMEsim planar mechanical module, it also can see mechanism action and force.

if you still want to see situation in Creo. firstly you can simulation all force or pressure from AMEsim, and then input these dataes to Creo by servo motor, you can active the Creo mechanism.

otherwise, you showed the model that only is involved hydraulic open loop system, only included simple driver and torque load, it can simulate in AMesim, don't need Creo

-Jason.

[gfraulini]

Hi Jason,

you're right in talking about the right way to simulate a feedback loop, namely using amesim rather than Pro/mechanism.

But in another post Boris Kirzhner told that you could use alo an external software in bundle with proE/Creo.

If this is not possible, or if you want to use an external simulation software together with Creo mechanism simulation, you should use Custom Load. Custom Loads functionality allows you to bundle external simulation application with the mechanism simulation. Your code will be called at every step of the mechanism simulation thus allowing simultaneous integration of mechanism's equations of motion with hydraulics equations.

So I'm a little bit confused.

Which are the real possibilities of ProE/Creo Mechanism? (Custom Load)

And it would be nice to see a real example of the use of this "Costom Load" function. On the forum and on the net I've not found anything, a part the PTC Help which, however, it's not a real example and, in my opinion, it's not veri clear.

[bzarkhine]

Custom Load functionality is devoted to situation when you should perform a co-simulation. That is to say if you have additional differential equation(s), and you want to integrate them together with the Mechanism ones using the same integrator. Such task often arises when you deal with Mechatronics having electrical/magnetic differential equation in addition to the Mechanism ones.

If you do not have additional differential equations, using Custom Loads is an overkill. If you additional load can be represented as a function of positions, velocities, accelerations and even other forces, you should simply use User Defined profile in Force Motors or Forces/Torques as needed. No matter how complex is this function, the functionality will process it as needed.