First of all, I will never "reset the the robot automatically" on a collision.
Personally if I see a collision I would like to investigate the reason why and not just send the robot home and start again,
Having said that, I can tell you the following:
We have a robot that pick parts (like 99% of the people)
On the program, we go to the approach point and from there on with the help on system variables we check the torque, the we move toward the pick in 2 mm increments and repeat the check until we get to the pick point.
Obviously, we still going to crash, you can not avoid that, but it's going to be minor. If crashes, the robot will send a fault and that we can reset it with the PLC sending the robot home. We do this acknowledging the fault from a button on the HMI
Hi
I modified the programs a little bit . I deleted lines that they are not important to this example
First you need a background program
/MN
Controls from PLC if you want the check sensitivity. Some of my parts did not need that
1: IF (DI[67:Collision detect ON]=ON) THEN ;
2: R[13:SenseOn]=1 ;
3: ELSE ;
4: R[13:SenseOn]=0 ;
5: ENDIF ;
Go to the variables and monitor the number manually. You can actually see numbers changing if you try to move the robot with your hands. Once you do that, yo have to put that value on R[14]. That will be your "I'm crashing" value
Compare the variable and "I'm crashing" value
6: IF ($SV_INFO[1].$Q_CURRENT[3]>R[14:CurrentLimitSet]) THEN ;
7: R[15:ExceedCurrentLit]=1 ;
8: ELSE ;
9: R[15:ExceedCurrentLit]=0 ;
10: ENDIF ;
/POS
/END
Then you have the pick program
Approach
19:L PR[R[9]] 2000mm/sec CNT5 VOFFSET,VR[1] Tool_Offset,PR[3:Body pick app ] ;
20: !Collision_Sense_for_Pick ;
If collision check is not necessary, jump to label 15,
21: IF R[13:SenseOn]=0,JMP LBL[15] ;
Move to a location above part where it's impossible to have a collision
22: PR[7,3:BodyPickSenseApp]=R[11:Collision height] ;
23: ;
24:L PR[R[9]] 1000mm/sec CNT2 VOFFSET,VR[1] Tool_Offset,PR[7:BodyPickSenseAp] ;
Start coming down on 1.5 mm increments
25: FOR R[60:ForLoopValue]=1 TO 5 ;
26: PR[7,3:BodyPickSenseApp]=PR[7,3:BodyPickSenseApp]+1.5 ;
27:L PR[R[9]] 1000mm/sec CNT0 VOFFSET,VR[1] Tool_Offset,PR[7:BodyPickSenseAp] ;
Check condition from background program
28: IF (R[15:ExceedCurrentLit]=1) THEN ;
29: DO[147:ToolOnGripper]=OFF ;
30: R[41:PartFound A]=0 ;
31: R[46:IndexA]=1 ;
32: PR[7,3:BodyPickSenseApp]=R[11:Collision height] ;
33: ENDIF ;
34: IF (R[15:ExceedCurrentLit]=1),JMP LBL[20] ;
If "crashed" but not really bad the robot should not send a fault and the logic jumps to label 20
If "crashed" was bad, robot send a fault and stop. Initiate recovery from PLC
35: ENDFOR ;
36: PR[7,3:BodyPickSenseApp]=R[11:Collision height] ;
37: LBL[15] ;
38: !Pick point ;
39:L PR[R[9]] 500mm/sec CNT0 VOFFSET,VR[1] ;
40: CALL EOAT_PICK ;
41:R[15:ExceedCurrentLit]=0
44: LBL[20] ;
45: !Pick dep ;
46: R[30:Actual col guard]=R[32:Col guard 100] ;
47: COL GUARD ADJUST R[32] ;
48:L PR[R[9]] 1000mm/sec CNT100 VOFFSET,VR[1] Tool_Offset,PR[4:Body pick dep ] ;
49: R[43:Temp PartFound A]=0 ;
I wonder what sense does it make specifying 1000mm/sec speed when moving in 1.5 increments with complete stops in between?
What robot is it?
Hi
SCARA
Basically it's a pick and place
This is the deal
i told the customer that IF (big IF) nobody touches the robot manually, the robot can recover from all the positions that moves during automatic cycle
The customer did not agree, they don't watch to touch the pendant.
Here is the problem, the operators twice or three times a day they go inside the cell to clean it and they manually push the robots away.
That's why I did this programs, I move axis 3 up all the way and hopefully does not reap anything apart.
I just posted this as an example, it's up to the robot programmer and the application to incorporated on their logic
As far as the speed I was doing it a 200 mm/s but they test with me there and agree to 1000mm (which is ridiculous)
"Customer is always right"
