ABB RAPID - calculating seam length

Question

I have an Arc welding RAPID program with many seams. One of them looks like this:

ArcLStart W007_On, vtoArc, sm01, s_12, fine, R1_tWeld\WObj:=R1_wFix;
ArcL W007_1, vWeld, sm01, s_8, z1, R1_tWeld\WObj:=R1_wFix;
ArcC W007_2, W007_3, Vweld, sm01, s_8, z1, R1_tWeld\WObj:=R1_wFix;
ArcL W007_4, vWeld, sm01, s_8, z10, R1_tWeld\WObj:=R1_wFix;
ArcL W007_5, vWeld, sm01, s_8, z5, R1_tWeld\WObj:=R1_wFix;
ArcLEnd W007_Off, vWeld, sm01, s_8, z1, R1_tWeld\WObj:=R1_wFix;

What I want to do is measure/calculate the seam length programatically. Calculation can take place during normal program execution or in specialised routine (doesn't matter). How can I do that in RAPID?

Answer 1

Can you run something like this, parallel a parallel task (623-1: Multitasking) to the welding process?

VAR iodev Pos_file; 
VAR string FilePath:="TCPPos"; 
VAR string TCP_str; 
FilePath:=FilePath+"_"+CDate()+".log";

Open FilePath, Pos_file\Append;

//Cycle until Welding process is active
  TCP_str:= .. Add current TCP position
  WRITE TCP_str;

Close FilePath

Then you can take the TCPPos_DATE_.log file and post process it on a PC

Answer 2

This is a good robotics question, IMHO. A 3D printer extruding molten plastic has to do this task, so the right amount of plastic is squeezed out (e.g. Marlin, Repetier). The slicer can give the total amount needed for a given object (e.g. Cura by Ultimaker). It is not a trivial thing to calculate, yet very useful to know (so you don't run out of filament before object finishes printing). But all the 3D printers I work with use GCODE as file format. I do not know RAPID, but a pre-processor must be possible to create. Effectively, just need to parse the file, adding up lengths as they occur (and quietly ignoring anything irrelevant). Is there a simulator available (that might already implement the parsing part)?

Answer 3

Thanks everyone for useful suggestions!

I ended up using module with ArcX instruction aliases. It calculates seam length during program execution. Following is a simplified example of implementation:

MODULE ArcEx(NOSTEPIN)
   CONST robtarget ArcEx_pNonePoint := [[0,0,0],[0,0,0,0],[0,0,0,0],[9E9,9E9,9E9,9E9,9E9,9E9]];
   TASK VAR robtarget ArcEx_pRefPoint := ArcEx_pNonePoint; ! Variable for storing previous point
   TASK VAR num ArcEx_nWeldDistance := 0; ! Calculated weld distance

   PROC ArcLStartEx(robtarget ToPoint) ! Arguments ommited for readibility (same as original ArcLStart)
      ArcEx_nWeldDistance := 0;
      ArcEx_pRefPoint := ToPoint;
    
      ArcLStart ToPoint, \ID?ID, Speed, Seam, \AdvData?AdvData, Weld, \Weave?Weave, Zone, Tool, \WObj?WObj, \Corr?Corr, \Track?Track, \SeamName?SeamName, \T1?T1, \T2?T2, \T3?T3, \T4?T4, \T5?T5, \T6?T6, \T7?T7, \TLoad?TLoad;
   ENDPROC

   PROC ArcLEx() ! Arguments ommited for readibility (same as original ArcL)
      ArcEx_nWeldDistance := ArcEx_nWeldDistance + Distance(ArcEx_pRefPoint.trans, ToPoint.trans);
      ArcEx_pRefPoint := ToPoint;
    
      ArcL ToPoint, \ID?ID, Speed, Seam, Weld, \Weave?Weave, Zone, Tool, \WObj?WObj, \Corr?Corr, \Track?Track, \Time?Time, \T1?T1, \T2?T2, \T3?T3, \T4?T4, \T5?T5, \T6?T6, \T7?T7, \TLoad?TLoad;
   ENDPROC

   PROC ArcLEndEx() ! Arguments ommited for readibility (same as original ArcLEnd)
      ArcEx_nWeldDistance := ArcEx_nWeldDistance + Distance(ArcEx_pRefPoint.trans, ToPoint.trans);            
      ArcEx_pRefPoint := ArcEx_pNonePoint;
        
      TPWrite "Seam length: "\num:=ArcEx_nWeldDistance
    
      ArcLEnd ToPoint, \ID?ID, Speed, Seam, Weld, \Weave?Weave, Zone, Tool, \WObj?WObj, \Corr?Corr, \Track?Track, \Time?Time, \T1?T1, \T2?T2, \T3?T3, \T4?T4, \T5?T5, \T6?T6, \T7?T7, \TLoad?TLoad;
   ENDPROC
ENDMODULE

Example usage:

ArcLStartEx W007_On, vtoArc, sm01, s_12, fine, R1_tWeld\WObj:=R1_wFix\SeamName:="W007";
ArcLEx W007_1, vWeld, sm01, s_8, z1, R1_tWeld\WObj:=R1_wFix;
ArcCEx W007_2, W007_3, Vweld, sm01, s_8, z1, R1_tWeld\WObj:=R1_wFix;
ArcLEx W007_4, vWeld, sm01, s_8, z10, R1_tWeld\WObj:=R1_wFix;
ArcLEx W007_5, vWeld, sm01, s_8, z5, R1_tWeld\WObj:=R1_wFix;
ArcLEndEx W007_Off, vWeld, sm01, s_8, z1, R1_tWeld\WObj:=R1_wFix;

This obviously needs a lot of work for handling circular movements, zones etc. That's why I'm not marking this question answered yet.