Idea for slowing down robot, when PLC sends trigger signal over ProfiNet.

ChristianLiinHansen · May 12, 2022 at 9:37 PM

Hi out there.

I want to run two interrupts, triggered over ProfiNet at $IN[401]. When signals go TRUE, the robot should ramp down in speed, wherever it is, and stop within like say 2-3 sec. And when signal is FALSE, the robot should ramp up again. My idea was as followed in this test program below, where I declare the interrupts as below:

Code

   INTERRUPT DECL 30 WHEN $IN[401] == TRUE DO ISR_SlowSpeedTestTrue()

   INTERRUPT DECL 31 WHEN $IN[401] == FALSE DO ISR_SlowSpeedTestFalse()

Full test program:

Code: SlowSpeedTest.src

&ACCESS RVP

&REL 16

&PARAM EDITMASK = *

&PARAM TEMPLATE = C:\KRC\Roboter\Template\vorgabe

&PARAM DISKPATH = KRC:\R1\Program\HelperFunctions

DEF SlowSpeedTest( )

   

   $ADVANCE = 1

   INTERRUPT DECL 30 WHEN $IN[401] == TRUE DO ISR_SlowSpeedTestTrue()

   INTERRUPT DECL 31 WHEN $IN[401] == FALSE DO ISR_SlowSpeedTestFalse() 



   LOOP

      

   INTERRUPT ON 30 ; Enable the interrupt

   INTERRUPT ON 31 ; Enable the interrupt

   

;FOLD SPTP P1 CONT Vel=100 % PDAT1 Tool[1]:ForkCenterOfBoxCAD Base[5]:PalletAligned ;%{PE}

;FOLD Parameters ;%{h}

;Params IlfProvider=kukaroboter.basistech.inlineforms.movement.spline; Kuka.IsGlobalPoint=False; Kuka.PointName=P1; Kuka.BlendingEnabled=True; Kuka.MoveDataPtpName=PDAT1; Kuka.VelocityPtp=100; Kuka.VelocityFieldEnabled=True; Kuka.ColDetectFieldEnabled=True; Kuka.CurrentCDSetIndex=0; Kuka.MovementParameterFieldEnabled=True; IlfCommand=SPTP

;ENDFOLD

SPTP XP1 WITH $VEL_AXIS[1] = SVEL_JOINT(100.0), $TOOL = STOOL2(FP1), $BASE = SBASE(FP1.BASE_NO), $IPO_MODE = SIPO_MODE(FP1.IPO_FRAME), $LOAD = SLOAD(FP1.TOOL_NO), $ACC_AXIS[1] = SACC_JOINT(PPDAT1), $APO = SAPO_PTP(PPDAT1), $GEAR_JERK[1] = SGEAR_JERK(PPDAT1), $COLLMON_TOL_PRO[1] = USE_CM_PRO_VALUES(0) C_Spl

;ENDFOLD

;FOLD SPTP P2 CONT Vel=100 % PDAT2 Tool[1]:ForkCenterOfBoxCAD Base[5]:PalletAligned ;%{PE}

;FOLD Parameters ;%{h}

;Params IlfProvider=kukaroboter.basistech.inlineforms.movement.spline; Kuka.IsGlobalPoint=False; Kuka.PointName=P2; Kuka.BlendingEnabled=True; Kuka.MoveDataPtpName=PDAT2; Kuka.VelocityPtp=100; Kuka.VelocityFieldEnabled=True; Kuka.ColDetectFieldEnabled=True; Kuka.CurrentCDSetIndex=0; Kuka.MovementParameterFieldEnabled=True; IlfCommand=SPTP

;ENDFOLD

SPTP XP2 WITH $VEL_AXIS[1] = SVEL_JOINT(100.0), $TOOL = STOOL2(FP2), $BASE = SBASE(FP2.BASE_NO), $IPO_MODE = SIPO_MODE(FP2.IPO_FRAME), $LOAD = SLOAD(FP2.TOOL_NO), $ACC_AXIS[1] = SACC_JOINT(PPDAT2), $APO = SAPO_PTP(PPDAT2), $GEAR_JERK[1] = SGEAR_JERK(PPDAT2), $COLLMON_TOL_PRO[1] = USE_CM_PRO_VALUES(0) C_Spl

;ENDFOLD

;FOLD SPTP P3 CONT Vel=100 % PDAT3 Tool[1]:ForkCenterOfBoxCAD Base[5]:PalletAligned ;%{PE}

;FOLD Parameters ;%{h}

;Params IlfProvider=kukaroboter.basistech.inlineforms.movement.spline; Kuka.IsGlobalPoint=False; Kuka.PointName=P3; Kuka.BlendingEnabled=True; Kuka.MoveDataPtpName=PDAT3; Kuka.VelocityPtp=100; Kuka.VelocityFieldEnabled=True; Kuka.ColDetectFieldEnabled=True; Kuka.CurrentCDSetIndex=0; Kuka.MovementParameterFieldEnabled=True; IlfCommand=SPTP

;ENDFOLD

SPTP XP3 WITH $VEL_AXIS[1] = SVEL_JOINT(100.0), $TOOL = STOOL2(FP3), $BASE = SBASE(FP3.BASE_NO), $IPO_MODE = SIPO_MODE(FP3.IPO_FRAME), $LOAD = SLOAD(FP3.TOOL_NO), $ACC_AXIS[1] = SACC_JOINT(PPDAT3), $APO = SAPO_PTP(PPDAT3), $GEAR_JERK[1] = SGEAR_JERK(PPDAT3), $COLLMON_TOL_PRO[1] = USE_CM_PRO_VALUES(0) C_Spl

;ENDFOLD

;FOLD SPTP P4 CONT Vel=100 % PDAT4 Tool[1]:ForkCenterOfBoxCAD Base[5]:PalletAligned ;%{PE}

;FOLD Parameters ;%{h}

;Params IlfProvider=kukaroboter.basistech.inlineforms.movement.spline; Kuka.IsGlobalPoint=False; Kuka.PointName=P4; Kuka.BlendingEnabled=True; Kuka.MoveDataPtpName=PDAT4; Kuka.VelocityPtp=100; Kuka.VelocityFieldEnabled=True; Kuka.ColDetectFieldEnabled=True; Kuka.CurrentCDSetIndex=0; Kuka.MovementParameterFieldEnabled=True; IlfCommand=SPTP

;ENDFOLD

SPTP XP4 WITH $VEL_AXIS[1] = SVEL_JOINT(100.0), $TOOL = STOOL2(FP4), $BASE = SBASE(FP4.BASE_NO), $IPO_MODE = SIPO_MODE(FP4.IPO_FRAME), $LOAD = SLOAD(FP4.TOOL_NO), $ACC_AXIS[1] = SACC_JOINT(PPDAT4), $APO = SAPO_PTP(PPDAT4), $GEAR_JERK[1] = SGEAR_JERK(PPDAT4), $COLLMON_TOL_PRO[1] = USE_CM_PRO_VALUES(0) C_Spl

;ENDFOLD



   ENDLOOP 

   

END

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ISR for Slowing down the robot.

Code: ISR_SlowSpeedTestTrue.src

&ACCESS RV1
DEF ISR_SlowSpeedTestTrue()
DECL INT count
INTERRUPT OFF 30

; Ramp down
;FOR count = 100 TO 0 STEP 10
;$OV_PRO = count 
;WAIT SEC 0.1
;ENDFOR

;Somehow the for loop did not work, but I will figure this out later... Perhaps because I cant declare INT in an interrupt?

$OV_PRO = 90 
WAIT SEC 0.1

$OV_PRO = 80 
WAIT SEC 0.1

$OV_PRO = 70 
WAIT SEC 0.1

$OV_PRO = 60 
WAIT SEC 0.1

$OV_PRO = 50 
WAIT SEC 0.1

$OV_PRO = 40 
WAIT SEC 0.1

$OV_PRO = 30 
WAIT SEC 0.1

$OV_PRO = 20 
WAIT SEC 0.1

$OV_PRO = 10
WAIT SEC 0.1

$OV_PRO = 0
WAIT SEC 0.1

END

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ISR for speeding up the robot again...

Code: ISR_SlowSpeedTestFalse.src

&ACCESS RV1
DEF ISR_SlowSpeedTestFalse()

DECL INT count

INTERRUPT OFF 31



; Ramp up

;FOR count = 0 TO 100 STEP 10

;$OV_PRO = count 

;WAIT SEC 0.1

;ENDFOR

$OV_PRO = 10 
WAIT SEC 0.1
$OV_PRO = 20 
WAIT SEC 0.1
$OV_PRO = 30 
WAIT SEC 0.1
$OV_PRO = 40 
WAIT SEC 0.1
$OV_PRO = 50 
WAIT SEC 0.1
$OV_PRO = 60 
WAIT SEC 0.1
$OV_PRO = 70 
WAIT SEC 0.1
$OV_PRO = 80 
WAIT SEC 0.1
$OV_PRO = 90 
WAIT SEC 0.1
$OV_PRO = 100 
WAIT SEC 0.1
END

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I was looking into the manual and was thinking, that I should be able to override the acceleration, and I was trying to set

$ACC, $ACC_OV etc, but it complained when I e.g. set

$ACC.CP = 1.

So therefore I went back to the OV_PRO version, and "manually" ramping down using decrementing the value with an wait statement. I think this is a bit ugly, so what is the best practice to do this?

Thanks in advance...

DS186 · May 12, 2022 at 10:11 PM

I would either use an interrupt with a Brake command or the functions ROB_STOP() and ROB_STOP_RELEASE(). Check the manual for details and examples.

**panic mode** · May 12, 2022 at 10:33 PM

when counting down step need to be negative. so change 10 to -10 for the step value and it should be ok.

still... i would not place loop and delays inside an interrupt. this is is better done in submit.

**SkyeFire** · May 13, 2022 at 2:22 PM

I agree with Panic. Generally, you want to get in and out of an ISR as quickly as possible, except in situations where you're actually stopping the robot process (IR_STOPM comes to mind). Ramping $OV_PRO in the SPS is probably the better way to go, here.

Alternatively, using BRAKE or ROB_STOP in your ISR should achieve the same result, unless you really want a slow ramp-down.

hermann · May 13, 2022 at 7:38 PM

One more possibility is to create a second interrupt triggered by a timer flag. In the existing interrupt set the timer to -100, this should trigger the second, in that interrupt set the override and reset the timer again.

**panic mode** · May 13, 2022 at 7:54 PM

i was reluctant to suggest that after seeing what has found its way into ISR

ChristianLiinHansen · May 13, 2022 at 10:18 PM

Quote from SkyeFire

I agree with Panic. Generally, you want to get in and out of an ISR as quickly as possible, except in situations where you're actually stopping the robot process (IR_STOPM comes to mind). Ramping $OV_PRO in the SPS is probably the better way to go, here.
Alternatively, using BRAKE or ROB_STOP in your ISR should achieve the same result, unless you really want a slow ramp-down.

Hi SkyeFire .

So the tool of the robot will carry a relative large load, so yes I really want a slow ramp-down of minimum 3 sec or something. Not stop immediately. but spend minimum like 3-5 sec to ramp slowly down...

**SkyeFire** · May 16, 2022 at 2:12 PM

3-5sec decel is meters of motion, unless your robot is moving very slowly, in which case you hardly need such a long decel ramp. How did you come up with that number? I honestly can't see any application that would need such a long decel ramp, aside perhaps from carrying an open-topped bucket of water and not wanting to spill a drop.

As long as the robot has good $LOAD data, issuing a basic BRAKE command in the ISR should give you a path-maintaining stop that's not very violent, but requires much less time that 3-5sec. Have you tried that approach?

Idea for slowing down robot, when PLC sends trigger signal over ProfiNet.

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