motor simulation

[Shameer]

Hi,

I am doing my masters project on control systems. In short, the first step of my project is to simulate the effect of different control algorithms for a machining setup. The machine (which was fabricated in my institute) is a 3 axis micro-machining centre, with servo motors on each axis controlling the motion of a tool, with a Newport ESP 300 motion controller.

I wanted to know if it is possible to simulate the whole setup in LabView. As in, I need to plot the output contour traced by the tool for a particular input trajectory, for different control algorithms. (Preferably no hardware at all). I heard about the NI Softmotion Module, and its ability to collaborate with Solidworks. 

Can anyone tell me if its possible in LabView, or should I look for some other software?

Thank you

Shameer

[majoha]

Hi Shameer,

The NI Softmotion Module does give you the ability to simulate motion profiles using a Solidworks Assembly, so I think LabVIEW and NI Softmotion Module can help you simulate your hardware system.  You will need a Solidworks rendering of your machine to do this simulation.  Here is a link to the Getting Started Guide for NI Softmotion for Solidworks.

What control algorithms are you referring to?  Do you mean high level path planning algorithms, or low level control loops (PID, velocity, etc.)?

Regards,

Michael

[Shameer]

Hi Michael,

Thanks a lot. The aim of my project in a nutshell, is to see the effect of different feedforward algorithms on the machining error. 

And as you said, I need to have a complete render of the machine, even including the motor and all? Is there a place where i can look at some examples of these kind anywhere?

Shameer

[majoha]

Shameer,

One concern I have is that you mention the goal of testing different feedfoward algorithms.  The Softmotion for Solidworks feature sends position setpoints to the Solidworks Application.  Softmotion doesn't perform a normal servo control loop when communicating to Solidworks.  It simply generates a trajectory and feeds points to Solidworks, while getting feedback information including the torque required to perform the requested trajectory move.  Unfortunately that means that there is no feedforward functionality being performed in Softmotion in the Solidworks case.  So the Softmotion for Solidworks feature will not be adequate for your specific goal of testing feedforward algorithms.

In answer to your first question: Yes you need a Solidworks Assembly that represents your machine, or atleast the part of it where motion is relevant.  You can add motors within the Solidworks application.  There are examples installed with NI Softmotion Module that you can locate through the Example Finder (or just browse to <Labview>\examples\motion\Solidworks).

Regards,

Michael

[Shameer]

Michael,

Are you sure about feedforward not being possible in Softmotion, because I had found this earlier while searching about the software earlier. http://search.ni.com/nisearch/app/main/p/bot/no/ap/global/lang/en/pg/1/sn/catnav:oh/q/feedforward/fi...

I am still doing my literature review and all, and haven't actually started working on the simulation, so I can't really tell you if this is what I want. 

And did you mean to say that we cannot implement different control algorithms, or just that we can't implement different feedforward algorithms? All I want to do is a normal PID control with velocity and/or acceleration feedforward. Then I might have to tune the gains of these to see the effect of that on the machining error. 

Thank you

Sham

[majoha]

Shameer,

Yes, Softmotion does support PID control with feedforward gains for certain hardware servo axes, such as an axis mapped to a 9514 or 9516 drive interface module.  However, the Solidworks axis does not use these parameters internally since it doesn't perform any closed loop control.  You can set the feedforward gains (and the rest of the PID gains) in the Solidworks Axis configuration dialog, but they will have no effect on the execution of a Solidworks Axis.

The Softmotion for Solidworks feature may still be helpful to you in doing the following:

• Path Planning
• Motor Sizing
• Collision Detection
• Limits & Home Planning using Solidworks Sensors

Regards,

Michael

[kyleshook]

Michael,

Does SoftMotion Standard support PID control or only Premium?

Thanks,

Kyle