11 Replies Latest reply on Feb 2, 2011 8:59 PM by Gustavo Farias

    Can I do this simulation with the SoftMotion module from labVIEW?

    Cor Jansen

      Hi

       

      I'm searching for a CAD tool suitable for my mechatronics projects.
      Currently the tools I want to choose from are:

       

      SolidWorks
      Autodesk Inventor
      Pro Engineer (Creo Elements)

       

      I will not ask which one is better. That question has been asked many times and there is no clear answer possible. I have a requirements and wish list and I'm checking all the points on the list with each tool. I can find information about most of my requiremetns and wishes on websites and forums. There is however one wish for which I can not find any information.

       

      I would like to design motorized machines (e.g. robotics). I will use the CAD tool to design the mechanics. I will be able to simulate the motion by simulating motor rotation and or forces etc. But what I really would like to do is to simulate the motion including (servo) motor and the motor control loop (e.g. PID loop).

       

      Now I did read something about the SoftMotion module of labVIEW. I understand that you can control your motors inside Solidworks. But is it also possible to simulate a complete motor control loop using this module? So can I use labVIEW to calculate a motor driving force, aply this force in the Solidworks model, making the model to move some parts and can I use some position feedback as input in labVIEW to recalculate the motor force. This way I could write a labVIEW progam that simulates the motor control loop, including PID filter.

       

      So my question is: Is this possible? If so, then I think my choice has been made.

      And if possible, which Solidworks version would I need for that?

       

      Thanks.

        • Re: Can I do this simulation with the SoftMotion module from labVIEW?
          John Sutherland

          I have not looked at LabView, but I can advise that SW Motion Analysis is a Batch, not Interactive process.  The calculated results are presented at the end of the process, not on the fly.  It cannot even render the screen adequately on the fly, or write captured video frames to disk on the fly.  It holds everything in RAM with the consequence that an abend loses many hours of work.  The grass outside my window grows faster than integration proceeds.

           

          It is hard to imagine a PID loop in this software.

          • Re: Can I do this simulation with the SoftMotion module from labVIEW?
            Joe Galliera

            This can be accomplished with LabView NI SoftMotion for SolidWorks, and yes feedback and control is in real-time.  There is a good deal of information available by googling something like "solidworks mechatronics NI softmotion."

             

            Video from SWW 2010 by my good friend Ian Hogg: http://www.solidworks.com/includes/swworld/presentations_/proceedings_display.cfm?sid=20851%C2%A0

            Mechatronics white paper: http://files.solidworks.com/campaigns_global/2009/SWPrem_Mechatronics_WP.pdf

             

            Virtual Prototyping on NI website: http://www.ni.com/virtualprototyping/

             

            Desktop Engineering article: http://www.deskeng.com/articles/aaattg.htm

             

            YouTube: http://www.youtube.com/watch?v=0384hrc0B1Q

            • Re: Can I do this simulation with the SoftMotion module from labVIEW?
              John Sutherland

              Well I have read up on SoftMotion.

               

              I am wondering how much you have thought through your project.

               

              As I see it, if you merely want to visualise a pre programmed motorised motion, e.g. a picking robot, then I can't see why you would need feedback.

               

              My understanding of feedback is in the context of a pump which must deliver a constant output from an unpredictable input.  Feedback tells the pump motor to speed up or slow down as the measured input varies.

               

              You spoke of controlling motor torque without telling us what you plan to measure.

               

              There are some aspects of Motion Analysis I have not used, and it may be that you don't need LabView, but I cannot check now because my simulation has another 24 hours to run (I did say it was slow).

                • Re: Can I do this simulation with the SoftMotion module from labVIEW?
                  Cor Jansen

                  @John:

                   

                  I want to simulate a motor control loop.

                   

                  So I want to be able to control the torque or force on some part in SolidWorks by LabVIEW.

                  This would result in a motion.

                  Then I would like to have position feedback from SolidWorks to LabVIEW (e.g. robot arm position or motor encoder output).

                  This feedback I want to use to (re)calculate the torque or force.

                   

                  This motor control loop will include some kind of PID filter.

                  Because I have very complex movements with multiple axis that influence each other, I would like to simulate the control loops so that

                  I can work on the needed PID (or alike) before building the system.

                   

                  I know you can get some feedback to indicate if some part reaches a predefined position. Like a boolean telling if you reached some point.

                  But I need the feedback of a position as a variable.

                   

                  So basically I need two things:

                  1: A way to make LabView controlling a torque or force in SolidWork (I guess this is possible)

                  2: A way to get position feedback from SolidWorks to LabView.

                   

                  I would be glad if it is possible, even if this is very slow.

                    • Re: Can I do this simulation with the SoftMotion module from labVIEW?
                      John Sutherland

                      My motion integration spontaneously aborted, as it does, so I pulled up this SW Motion Analysis Torque/Force property manager.

                       

                      It promises that Torque can be a function of a measured result.

                       

                      I have seen alluring promises like this in other property managers, and found that they could not be realised, I suspect because the necessary code had not been written.  In other words, the hooks are there but there is nothing hanging on them.  There was an intention to add that code but SW went to press without it.

                       

                       

                      The SoftMotion docs show a screenshot suggesting that SoftMotion can display measured results during SW motion integration, wheras SW shows them only at the end of integration.  This would require SM to pull data from SW memory space.  If it can do this then I suppose it can put data back in.

                       

                       

                      I understand what you want and still think you have not fully thought it through; but I did not fully think through my motion project before I started.  How can you when neither SolidWorks nor LabView give clear statements of what they can achieve.  You have to have faith in the marketing blurb.  I have lost faith.

                       

                      I suppose you are aware of the prices of SW Premium and the various LabView modules required for PID.

                       

                      Perhaps you could try it out on the cloud without paying the upfront cost of all this software?  (that was a cheap and facetious shot at the marketing people)

                       

                      How else can I be of help?

                        • Re: Can I do this simulation with the SoftMotion module from labVIEW?
                          Cor Jansen

                          With version 2011, I managed to use measured results for the calculation of a motor velocity. Controlling a torque seems possible too.

                          So this promise seems valid.

                          However, for a PID control loop I also need the differentiated and integrated versions of the measured results. This is a problem.

                          If you are measuring a position of some object for the feedback, then you can use the velocity of the same object as the differentiated version.

                          But there is no integrated version of the signal that can be used. And there is no way to integrate yourself as far as I know.

                           

                          There seem to be a lot of functions that can be used for the function expression. But no integration function.

                          If the engineers would have added it, a PID loop simulation would have been possible. That would have been a real advantage over Inventor or

                          Pro Engineer.

                           

                          It is not clear to me if it can be done with LabView. If all measured signals are available in LabView including the simulation time, then I guess it is

                          possible to program some integrator. It is a pitty that they choose for LabView. I hate using a graphical programming language like Labview. Typing in an

                          expression and algoritme is so much easier.

                    • Re: Can I do this simulation with the SoftMotion module from labVIEW?
                      Gustavo Farias

                      Hi all,

                       

                      I have some problems with NI softmotion, i use labview 2009 and solidworks 2010 premium version.

                      I'm from Brazil, i'll try to explain the best that i can.

                      I use velocity method of straight line move to connect a rotary motor axis of a wind turbine assembly in solidworks. I have success to connect the softmotion and the motion analysis function correctly, but when i increase the speed in the velocity control palette of my VI, after a few seconds the process stop working and send a message that the solver revealed an error to converger the results.

                      Someone can help me with this.