adaptive welding controls for aerospace applications
TRANSCRIPT
![Page 1: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/1.jpg)
Bob CohenWeldComputer Corporation
Copyright © 2014 WeldComputer CorporationAll Rights Reserved
Adaptive Controls for Aerospace Resistance Welding Applications
![Page 2: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/2.jpg)
Adaptive control is about Recognizing when a process variability exists that would affect
the outcome of a production weld
Identifying the underlying condition responsible for the variability
Taking corrective action to compensate for the variability as the weld is taking place
The end result is to prevent the occurrence of a bad weld in the first place and to increase the consistency of all welds produced
When it’s impossible to correct the problem and make a good weld, notify the operation about the problem
![Page 3: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/3.jpg)
Flattening electrodes
Surface contamination
Poor parts fit-up
Shunt condition and other geometry variations
Workpiece thickness variation
Electrode force variation
Wheel/brush contact resistance variation
Wheel velocity variation
![Page 4: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/4.jpg)
Reduce reliance on destructive testing.
Prevent random problem welds from passing through production undetected.
Automatically take corrective pre-conditioning and compensating actions to prevent out of spec welds from being produced.
Increase consistency of all welds.
Substitute in process monitoring in place of manual surface resistance checks.
Substitute in-process monitoring of the weld machine in place of periodical machine inspection.
![Page 5: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/5.jpg)
4.3.3.3 Contractor may substitute nondestructive evaluation for routine lot tests upon approval of the procurement activity provided he can demonstrate that the evaluation system will identify welds complying with size or strength requirements with a 99.5% reliability.
4.2.6 Control Adjustments: …settings may be varied by ±5% from the established certification values, or by ±10% when only one setting is adjusted.
![Page 6: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/6.jpg)
![Page 7: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/7.jpg)
![Page 8: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/8.jpg)
![Page 9: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/9.jpg)
Data collected with WeldComputer® Adaptive Control
Adaptive Weld Schedule Nominal Current and Thermal Expansion Response
ExpansionCurrent
![Page 10: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/10.jpg)
Data collected with WeldComputer® Adaptive Control
Adaptive schedule detects greater than normal thermal expansion rate and reduces current to prevent expulsion from occurring.
Current Expansion
![Page 11: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/11.jpg)
Data collected with WeldComputer® Adaptive Control
Adaptive control increases heat on cycle 6 by 1% in response to low expansion on cycle 5.
Current Expansion
![Page 12: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/12.jpg)
Data collected with WeldComputer® Adaptive Control
Adaptive control increases heat on cycle 4 by 1% in response to low expansion on cycle 3.
Current Expansion
![Page 13: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/13.jpg)
Data collected with WeldComputer® Adaptive Control
Adaptive control increases heat on cycle 4 by 1% in response to low expansion on cycle 3, and an additional 1% heat increase on cycle 6 in response to low expansion response on cycle 5.
Current Expansion
![Page 14: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/14.jpg)
![Page 15: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/15.jpg)
![Page 16: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/16.jpg)
![Page 17: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/17.jpg)
Side view (left) and front view (right) of displacement sensor mounted on seam welder.
![Page 18: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/18.jpg)
Displacement Monitoring:
No production slow-down
Speeds up production when used in conjunction with adaptive control
More reliable than destructive testing, because destructive testing doesn’t measure the size of any weld except the one that is destroyed.
Ability to meet the 99.5% reliability requirement demanded by the MIL-SPEC has been demonstrated.
![Page 19: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/19.jpg)
X-RAY Testing
Severe impact on productivity.
Can detect porosity, cracks, lack of fusion. Difficult to determine weld penetration.
Ultrasonic Testing
Severe impact on productivity.
Can detect porosity, cracks, lack of fusion. Difficult to determine weld penetration.
Ability to meet the 99.5% reliability requirement demanded by the MIL-SPEC has not been demonstrated.
![Page 20: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/20.jpg)
4.3.3.3 Contractor may substitute nondestructive evaluation for routine lot tests upon approval of the procurement activity provided he can demonstrate that the evaluation system will identify welds complying with size or strength requirements with a 99.5% reliability.
4.2.6 Control Adjustments: …settings may be varied by ±5% from the established certification values, or by ±10% when only one setting is adjusted.
![Page 21: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/21.jpg)
5.2.3 Alternate Testing Requirements As an alternate to the testing requirements of 5.2.2(1) real time nondestructive system may be used when approved by the Engineering Authority. As a minimum the system shall address: part fitup, precleaning, electrode monitoring, and in-process monitoring of critical process parameters. This system of controls shall include but is not limited to, real time adaptive controls or in-process NDT methods. Destructive testing must still be used to establish and verify that the capability of this system will identify welds complying with strength or size requirements with 99.5% reliability.
5.1.5 Control Adjustments. The settings may be varied by ±5% from the established certification values, or by ±10% when only one setting is adjusted.
![Page 22: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/22.jpg)
4.2.2.1 Preconditioning steps to compensate for fitupvariations that involve the controlled application of heat and/or force may be employed.
![Page 23: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/23.jpg)
Current trace (left) & Expansion response trace (right) recorded with WeldView® Monitor.
Current and Expansion Response of Spot Weld Produced with Conventional Control
ExpansionCurrent
Material thermally expands while weld current is applied
Material thermally contracts after weld current stops
![Page 24: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/24.jpg)
Current trace (left) & Expansion response trace (right) recorded with WeldView® Monitor.
Spot Weld Produced with Conventional Control has Slight Fit-Up Problem
Current Expansion
Negative movement documents parts fitting together before material starts to thermally expand
Material has acceptable thermal response despite slight fit-up problem
![Page 25: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/25.jpg)
Current trace (left) & Expansion response trace (right) recorded with WeldView® Monitor.
Severe Fit-Up Problem with Conventional Control Results in Undersized Weld
Weld time is lost squeezing parts together
Not enough weld time remaining after parts fit together results in undersized weld
Current Expansion
![Page 26: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/26.jpg)
Data collected with WeldComputer® Adaptive Control
Adaptive Weld Schedule Nominal Current and Thermal Expansion Response
ExpansionCurrent
Diagnostic/Pre-Conditioning Heat Pulse
![Page 27: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/27.jpg)
Data collected with WeldComputer® Adaptive Control
Adaptive schedule produces pre-conditioning pulses to correct fit-up problem before proceeding to make weld.
Weld heat occurs after 3rd
pre-conditioning pulse succeeds in correcting fit-up problem.
Pre-conditioning pulse didn’t fully correct fit-up problem, so weld heat is inhibited, and a cool down delay applied before repeating process.
Pre-conditioning heat pulse 1
Pre-conditioning heat pulse 2
Pre-conditioning heat pulse 3
![Page 28: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/28.jpg)
5.1.5.1 Control adjustments shall apply from start to finish of the weld nugget formation.
![Page 29: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/29.jpg)
5.1.4.2 Use of in-process weld control monitoring capable of detecting when a micro-ohms shift outside of the specification range occurs may be substituted for the surface resistance checks as deemed appropriate by the Engineering Authority.
![Page 30: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/30.jpg)
Data collected with WeldComputer® Adaptive Control
Substitution of In-Process Micro-Ohm Measurements
Diagnostic/Pre-Conditioning heat pulse measures resistance on every weld
![Page 31: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/31.jpg)
Data collected with WeldComputer® Adaptive Control
Current Expansion
Adaptive schedule responds to expulsion occurrence by instantly terminating weld current to minimize part damage, then automatically performs a repair weld operation.
![Page 32: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/32.jpg)
Instantly cut off heat upon detection of expulsion.
Keep electrodes clamped on part and wait for weld to cool.
Perform re-weld operation.
![Page 33: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/33.jpg)
5.1.5.2 Any control adjustment made beyond the constraints set forth in 5.1.5 taken to minimize part damage during the occurrence of a welding fault shall be excluded as a condition that would require the establishment of a new certified welding procedure.
![Page 34: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/34.jpg)
Control adjustments beyond the constraints set forth in 5.1.5 may be taken in instances when it can be demonstrated that not taking such actions would increase part damage and/or reduce weld consistency.
![Page 35: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/35.jpg)
Current (7" Length Seam)
0
5
10
15
20
25
30
351
45
89
133
177
221
265
309
353
397
441
485
529
573
617
661
705
749
793
837
881
925
969
101
3
ms
KA
mp
Conductance (7" Length Seam)
0
2
4
6
8
10
12
14
16
1
45
89
133
177
221
265
309
353
397
441
485
529
573
617
661
705
749
793
837
881
925
969
101
3
ms
KM
ho
Conductance reveals 3.1 KMho drop after completing 4.45” of welding on seam.
Current is consistently maintained at 29 KA over length of seam.
![Page 36: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/36.jpg)
4.3.4 Maintenance of Equipment. For machine characteristics wherein the behavior of the machine can be monitored, and criteria exists for those monitored parameters that would trigger maintenance when required, such monitoring techniques may be employed in place of periodical machine inspection.
![Page 37: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/37.jpg)
![Page 38: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/38.jpg)
![Page 39: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/39.jpg)
Total RMS Current (for 22 welds)
3000
4000
5000
6000
7000
8000
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
Weld Number
RM
S A
mp
s
Conductance (4.2ms after start of weld)
0
10000
20000
30000
40000
50000
60000
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
Weld Number
Mh
o
![Page 40: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/40.jpg)
![Page 41: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/41.jpg)
![Page 42: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/42.jpg)
4.3.3 Jigs and Fixtures. Where shunting cannot be avoided due to part design, the effects of shunting shall be factored into the production weld schedule and necessary adjustments made to ensure acceptable welds are produced.
![Page 43: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/43.jpg)
I
Use right machine, control, electrodes, force & current to make weld.
![Page 44: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/44.jpg)
I
2nd weld is smaller than 1st because some current shunts through 1st weld.
![Page 45: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/45.jpg)
I
3rd weld is smaller than 2nd because current shunts through 1st & 2nd welds.
![Page 46: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/46.jpg)
I
Subsequent welds are all similarly reduced in size due to current shunting.
![Page 47: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/47.jpg)
I
Shunting makes welds hotter at start of seam.
![Page 48: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/48.jpg)
produce smaller nuggets than they really want throughout the entire length of the seam, in order to avoid having the first few welds on the seam be too hot and possibly expulse material,
or
suffer from having the first few welds be too hot and expulse material, just so the rest of the welds in the seam are the size they want.
![Page 49: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/49.jpg)
Scale heat down for 2nd spot.
Scale head down more for 1st spot.
![Page 50: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/50.jpg)
All welds occurring at same wheel speed
![Page 51: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/51.jpg)
Welding starts at slower speed
Welding stopsat slower speed
![Page 52: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/52.jpg)
Wheel velocity is a major parameter of control, as significant as force and current.
For a given applied force and current.
Lower velocity causes hotter welds.
Higher velocity causes colder welds.
![Page 53: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/53.jpg)
Upslope heat at start of seam.
Downslope heat at end of seam.
Hard to coordinate upslope heat and downslope heat with increasing and decreasing velocity.
Hard to synchronize heat profile with velocity profile.
![Page 54: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/54.jpg)
Program the control to automatically adjust the heat up or down, in relation to instantaneous wheel velocity.
Heat is always coordinated and synchronized with wheel velocity.
Easy to manage because there are no operator settings or proximity switches to constantly adjust.
![Page 55: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/55.jpg)
Dynamically adjusting weld heat to compensate for velocity fluctuations increases weld consistency and reduces leakers.
![Page 56: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/56.jpg)
Constant Speed
Edge to edge adaptive control produces gas tight welds over the entire length of the seam.
![Page 57: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/57.jpg)
Water heaters
55 Gallon drums
Pails
Aerosol Cans
![Page 58: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/58.jpg)
Plot of wheel rolling up on front tank, across tank, & off back of tank.
Wheel starts rolling up on front of part.
Wheel starts rolling off back of part.
Data collected with WeldComputer® Adaptive Control.
![Page 59: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/59.jpg)
![Page 60: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/60.jpg)
Current starting here after wheel is already rolling up on part results in undersized weld on front edge
Wheel starts rolling up on part here
Displacement data (top) and current data (bottom) collected with WeldView® Monitor.
![Page 61: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/61.jpg)
Wheel starts rolling up on part here
Current starting before wheel comes in contact with part overheats front edge of part.
Displacement data (top) and current data (bottom) collected with WeldView® Monitor.
![Page 62: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/62.jpg)
Inability to control welds on front edge
Inability to control welds on back edge
Inability to prevent hot spots
Inability to prevent cold spots
Inability to produce consistent current
![Page 63: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/63.jpg)
Heat envelop is precisely coordinated with front edge of part.
![Page 64: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/64.jpg)
Current
Force
Wheel/Electrode Cooling
Machine Stability
![Page 65: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/65.jpg)
Velocity fluctuations: can be
compensated for with adaptive control.
Force fluctuations: can be compensated
for with adaptive control.
![Page 66: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/66.jpg)
Wheel starts rolling up on front of part.
Wheel starts rolling off back of part.
Wheel overshoots rolling up on front of part.
Wheel bounces when it lands on top of part.
Wheels bounce against each other after rolling off back of part.
![Page 67: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/67.jpg)
Displacement of wheel rolling up on front of part triggers current.
Velocity
Each 5ms duration weld current pulse (below) is adjusted every millisecond to control weld based on displacement, velocity & force.
Data collected and current synthesized with WeldComputer® Adaptive Control.
Wheel bounces when it lands on top of part.Wheel overshoots rolling
up on front of part.
![Page 68: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/68.jpg)
Velocity
Heat automatically reduces itself and shuts off as wheel rolls off part.
Wheels bounce against each other after rolling off back of part.
Wheel starts rolling off back of part.
Data collected and current synthesized with WeldComputer® Adaptive Control.
![Page 69: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/69.jpg)
Apply right heat before hitting front edge of part.
Profile heat envelope rolling up on part.
Compensate for bounce of wheel landing on part.
Compensate for velocity fluctuations.
Profile heat envelope rolling off back of part.
Instantly cut off heat rolling off back edge of part.
Adjust heat for height variations on part.
Use control that delivers accurate repeatable heat.
![Page 70: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/70.jpg)
Part proximity sensors used to synchronize heat with front of part entering machine have too much variability to accurately control welding on the front edge.
Inability to synchronize heat with back of part leaving machine.
Inability to compensate for machine force and velocity variations.
SCR based controls have limitations on current wave shape and regulation.
Traditional MFDC controls, provide ineffective regulation and heat repeatability, in applications requiring short duration high current pulses.
![Page 71: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/71.jpg)
Current trace recorded with WeldView® Monitor.
![Page 72: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/72.jpg)
Process is unregulated when control never reaches programmed current targets.
Seam performance is compromised when high currents persist during cool times.
Current trace recorded with WeldView® Monitor.
Current only decays to 13.5kA at end of programmed cool time.
Current trace recorded with WeldView® Monitor.
![Page 73: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/73.jpg)
Process is unregulated when unstable current overshoots, has oscillations, and never reaches programmed current targets.
Current trace recorded with WeldView® Monitor.
Current overshoot followed by current undershoot represents 73% current fluctuation during each weld.
Undershoot occurring 8 ms after overshoot. Current never decays to zero during
cool time between impulses.
Peak current fluctuates 15% from one impulse to the next.
![Page 74: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/74.jpg)
Current trace recorded with WeldView® Monitor.
0
1
2
3
4
5
6
7
8
9
10
1 6 11
16
21
26
31
36
41
46
51
56
61
66
71
76
81
86
91
96
101
106
111
116
121
126
131
136
141
146
151
156
161
166
171
176
181
186
191
196
201
206
211
K-a
mp
s
Big current fluctuations reduces stability of process
Long current decay during cool time means hotter wheels
Current still rising at end of programmed heat means process is uncontrolled
![Page 75: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/75.jpg)
Current trace recorded with WeldView® Monitor.
Big current fluctuations caused by MFDC reduces stability of process
Long current decay during cool time means hotter wheels
0
5
10
15
20
K-a
mp
s
![Page 76: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/76.jpg)
Big mechanical disturbance from current fluctuations occurs twice per millisecond of applied heat.
Current decay time after each weld diminishes effectiveness of cool time & causes wheels to run hotter.
Magnetizes machine and part.
Causes heat imbalance from Peltier Effect.
Asymmetrical electrode wear.
Limited current adjustment rate.
![Page 77: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/77.jpg)
Current trace recorded with WeldView® Monitor.
0
5
10
15
20
K-a
mp
s
![Page 78: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/78.jpg)
Current trace recorded with WeldView® Monitor.
-15
-10
-5
0
5
10
15
K-a
mp
s
![Page 79: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/79.jpg)
![Page 80: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/80.jpg)
Current trace recorded with WeldView® Monitor.
0
5
10
15
20
K-a
mp
s
![Page 81: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/81.jpg)
Current trace recorded with WeldView® Monitor.
-20
-15
-10
-5
0
5
10
15
20
K-a
mp
s
![Page 82: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/82.jpg)
Current trace recorded with WeldView® Monitor.
![Page 83: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/83.jpg)
0
16000
1
Am
ps
Time
3 ms Weld Produced with 6 Pulses at a 2kHz Switching Frequency
3 ms Weld Produced with 12 Pulses at 4kHz Switching Frequency
0
16000
Time
Am
ps
![Page 84: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/84.jpg)
3 ms Weld Produced with 24 Pulses at 8kHz Switching Frequency
0
16000
Time
Am
ps
3 ms Weld Produced with 48 Pulses at 16kHz Switching Frequency
0
16000
Time
Am
ps
![Page 85: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/85.jpg)
![Page 86: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/86.jpg)
Archive File # Avg. Expansion Avg. Current Avg. Force
983 (sample - left) 5.77 6.77 2.64
982 (part - right) 3.45 6.12 2.88
Sample Actual Part
![Page 87: Adaptive Welding Controls for Aerospace Applications](https://reader034.vdocuments.net/reader034/viewer/2022051521/5a6eb9237f8b9a49648b5ceb/html5/thumbnails/87.jpg)
Bob CohenWeldComputer Corporation
Copyright © 2014 WeldComputer CorporationAll Rights Reserved
Adaptive Controls for Aerospace Resistance Welding Applications