Synchronizing rapid execution

jay_cjay_c Netherlands

I'm wondering if anybody has a suggestion for how I can improve the synchronization of my program, either through rapid or the controller configuration. The process is a additive-printing sequence, where the dispense-rate is varying along the path (such as decreasing around a corner). We've noticed that the dispense-rate is a few Robtargets ahead of the real TCP position, indicating that the process is looking ahead and calculating the upcoming dispense-rate too early. Our paths are usually made up of many smaller segments (2-5mm) and our velocity is usually around 30-120 mm/s. 

I know that using a fine-point zonedata can help with this, but unfortunately for a smooth printing motion it is important to avoid the stop/start motion. Perhaps there is something I'm missing in the motion_planner (MOC.cfg) which can give more precise execution, or in the movement commands within the rapid program.

Some motion planner parameters that may be relevant:
Path resolution = 1
Queue time = 0.2903
Use additional interp. object batch = 1
Prefetch time = 0.1 
Number of Internal Event Objects = 500

Thanks in advance for any help or suggestions!
I am using a IRB6400 with an IRC5 controller, running on RobotWare 6.08. 


  • lemster68lemster68 United States ✭✭✭
    But are you using Dispenseware?
    Lee Justice
  • jay_cjay_c Netherlands
    But are you using Dispenseware?

    No we aren't using the Dispenseware Add-in, does this have some functionality which improves the program synchronization? 
  • lemster68lemster68 United States ✭✭✭
    In my opinion, yes.  It will come with features for gun on, off and you can set up an analog signal for tcp velocity/dispense rate, so to speak.  The controller as you have it will always read ahead in there are not fine points.  I have to ask also, you said something about the calculations are ahead of the motion.  Can you put a sample of that code here for us to see?  Might be able to help some more.  Are you using Trigg instructions already?  Dispenseware is based on that technology.  If you do get the dispenseware and even with the trigg you will want to look at event preset time.  A lot of people don't get that right.
    Lee Justice
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