New Non-Contact Laser Gauge for Length and Speed Measurement

1. ICE USA 2011 Technical Program The Development of a New Non-Contact Laser Gauge That Can Measure the Length and Speed of Moving Product with High Accuracy Les Jensen, Beta LaserMike Presented by: Les Jenson Chief Engineer Beta LaserMike BETA LaserMike

2. Introduction • Technology of a Non-Contact Length and Speed gauge • Describe how it works • Three applications examples: • Corrugated Box application • Roofing Products application • Sanitary Products application

3. Traditional Length & Speed Measurements • Accomplished by using a roller that contacts the material being measured • The material turns the roller as the material moves • An encoder or tachometer is attached to the roller • Generates pulses as the wheel or roller rotates • Relies on friction between the material and roller

4. Disadvantages Tachometers/Encoders • Error caused by slippage • Dependent on tension • Product surface • Lubricant on surface • Recalibration • Diameter change because of wear • Diameter change because of build-up • Maintenance • Bearings and other mechanical parts wear out

5. LaserSpeed History • LaserSpeed technology was developed in 1984 • Aluminum/Steel Mills • Small integrated gauge developed in 2001 • Smaller • Cheaper • Easy to Install • High Accuracy – 0.05%

6. Non-Contact Laser Gauge • Compete System in one small rugged package • Sensor • Processor • I/O • Power Supply • 24 VDC operation • IP67 protection • Built-in water cooling ports 26.25 X 20.67 X 10.5 cm 2.54 Kilograms

7. System Concept FPGA- Signal processing PCB Laser diode assembly with temperature control Proprietary beams steering optics and receiving optics Measuring region

8. Non-Contact Gauge Technology

9. Non-Contact Gauge Technology Two laser beams cross at an angle 2K. K bisects the two laser beams Constructive and Destructive Interference cause a Fringe Pattern The Fringe Pattern consists of light and dark stripes.

10. Fringe Pattern Expanded • Constructive Interference occurs when two laser beams are in phase and add together to equal the original laser density - light stripe • Destructive Interference occurs when two laser beams are out of phase and the two laser beams cancel each other out - dark stripe

11. Fringe Pattern Generation • Fringe Pattern looks like an elongated football • Measuring region (Depth of Field) is where the fringe pattern exist • Project this fringe pattern on the surface of the product to be measured

12. Laser Doppler Velocimetry (LDV) Theory Fringe direction

13. Non-Contact Gauge Block Diagram -Dual-Beam Laser Interferometer DiodeLaser Acusto-Optical Modulator Product Optical Beam Splitter Photo -Detector Received Light Receiving Lens (15mm) Fringe Direction Measurement Region

14. No Calibration Required • Wave length of the laser is fixed and constant • Laser diode based system • Laser diode is temperature controlled • Crossing angle is created optically • All optics are glued in place • Crossing angle is permanently fixed • Fringe Spacing ‘d’ is fixed and cannot change

15. No Calibration Required • Frequency measurement uses an all Digital Signal Processor • Autocorrelation algorithm • High measurement rate • High measurement accuracy • High measurement repeatability • Signal processor is all digital and has no drift or measurement error

16. No Calibration Required • Length is achieved by numerically integrating the speed • Permanently calibrated with very high accuracy

17. Corugated Box Application • Drawing Paperboard through a gear-like cylinder • Makes the web into waves • Glue applied to tips • Pressed against a liner • Continuous process • Needs to be cut into precise lengths

18. Problem • There are frequent product change-overs • Requires the corrugated board to be sheered 90 feet before the cutter • Knives are used to cut the corrugated board into the target lengths • Cut signal was controlled from and encoder attached to a roller • Roller had slippage especially when during the change-over

19. Problem cont. • Slippage error during change-over caused the cut length to be out of specification • Roller had excessive slippage because of high speed changes during change-over • 90 feet of corrugated board had to be scraped each time a change-over occurred

20. Scrap Cost Calculation • Scrap 90 foot for each change-over • Average 25 change-over/day • Cost of corrugated board/foot = $0.25 • Scrap cost 90 X 25 X 0.25 X 30 = $16.875/month or $202,500/year

21. Solution • Installed non-contact laser gauge just upstream of the cutting knives • Non-contact gauge has no slippage errors • Were able to cut the corrugated board to target length even during a change-over • Potential saving of $202,500/Year • Reduced maintenance costs • No recalibration • No moving parts to wear out

22. Roofing Product Application • Premium Quality Organic Mat • Saturated with high-grade asphalt • Dried • Slit to width • Cut to length

23. Problem • Tension problems cause slippage errors • Slippage error - 1% to 2% • Wheel wear caused calibration errors • Calibration is directly proportional to the circumference of the wheel • The circumference wears because of the abrasive property of the roofing material • Down time for recalibration • Wear of the bearings caused maintenance problems

24. Scrap Cost Calculation • Average slippage error – 1.5% • Average line speed 210 Ft/min • Operation 22 hours/day, 355 days/year • Product cost – $0.06/ft • Scrap cost 0.015 X 210 X 60 X 22 X 355 X $0.06 = $88,500/year

25. Solution • Non-contact laser gauge was installed just Upstream of the cutter • Non-contact gauge has no slippage errors • Potential saving of $88,500/Year • Reduced maintenance costs • No recalibration • No moving parts to wear out

26. Sanitary Products Application • Manufactures adult diapers, pads, liners and pull-on style disposable underwear • Slitting and cut-to-length requirements

27. Problem • Lubricants caused slippage errors – 2.5% • Slippage errors always make the product length long • 2.5% slippage error on a 1000 foot makes the actual length 1025 foot • Give away 25 foot for every 1000 foot produced

28. Scrap Cost Calculation • Manufacture produces between $2 to $4M of product on this line per year • Over length error of 2.0% cost between $40,000 and $80,000/year/machine

29. Solution • Non-contact laser gauge was installed on in-feed side of parent roll • Non-contact gauge has no slippage errors • Potential saving of $40,000 to 80,000/Year • Reduced maintenance costs • No recalibration • No moving parts to wear out

30. Summary Non-Contact Laser Gauge Advantages • No slippage error - optical system and does not contact the product • Permanently calibrated – Laser Interferometer Optical system • No moving parts to wear out • Accuracy: +/-0.05% • Repeatability: +/-0.02%

31. Thank You -- Questions