BETA LaserMike Presented by: Les Jenson Chief Engineer Beta LaserMike Non-Contact, Laser-Based Technology for Accurately Measuring the Length and Speed.

BETA LaserMike

Presented by:Les Jenson

Chief EngineerBeta LaserMike

Non-Contact, Laser-Based Technology for Accurately Measuring the Length and Speed of Product in Web Coating

and Lamination

Presented by: Stuart Manser, Beta LaserMike

2011 AIMCAL Technical Conference

Non-Contact Laser Gauge

Introduction Technology of a Non-Contact Length and Speed

gauge Describe how it works Three applications examples:

Coating and Lamination Control Continuous Length Stretch and Draw


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


Disadvantages Tachometers/Encoders

Error caused by slippage Dependent on friction Wheel pressure 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


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%


System Concept

FPGA- Signal processing PCB

Laser diode assembly with temperature control

Proprietary beams steering optics and receiving optics

Measuring region


Non-Contact Gauge Technology


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 (constructive) and dark (destructive) stripes


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


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


Laser Doppler Velocimetry (LDV) Theory

sin2d

ft

1

fdV *

T vdtL0

t

dv

Fringe direction


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 No moving parts in optics package Crossing angle is permanently fixed

Fringe Spacing ‘d’ is fixed and cannot change

sin2d



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

ft

1

fdV *

t

dv



Length is achieved by numerically integrating the speed

Permanently calibrated with very high accuracy

T vdtL0


Non-Contact Gauge Block Diagram -Dual-Beam Laser Interferometer

Measurement Region

ProductDiode Laser

Optical Beam Splitter

Photo -Detector

Receiving Lens (15mm)

Received Light

Fringe Direction

Acusto-Optical Modulator


Coating and Lamination Control Application Manufactures label products

Depends on accuracy of line’s drive speed and contact encoder to: Apply adhesive and easy release

coatings to backing Apply varnishes to face of label Control speed of two or more materials

during lamination of clear material to printed face stock

Measures product length to apply exact quantity of coatings and lamination


Problem

Inaccurate length and speed measurements 2% error

Slippage due to texture, slick coatings, lubricants, etc.

Contact method relies on wheel circumference and # of rotations

Contact measurement wheel: Rides on product Builds-up debris or wears down Requires recalibration


Scrap Cost Calculation

2% length and speed inaccuracy 20,000 foot roll 400 feet of uncertainty Each roll costs a significant amount in

unnecessary expense Scrap = roll length x material cost/ft x contact

encoder accuracy (2%)


Solution Install non-contact laser gauge

at specific measurement points on the line

Control length and speed of lamination line and coating application

+/- 0.05% speed accuracy Instead of 400 foot per every

20,000 feet of uncertainty Lowers error to a max of 10 ft

on a 20,000 foot roll

Coating Control

Lamination Control


Continuous Length Application

Manufactures diapers, pads, liners and pull-on style disposable underwear

Slitting and cut-to-length requirements


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


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


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


Stretch and Draw Application

Manufacturers require: Draw down of thin sheet to

consistent thickness Draw and drive rollers pull

product down at same speed Draw down to specific

controlled thickness with minimal variance and breakage


Problem

Drive speeds and contact encoders do not provide accurate measurements

Tension problems, product composition, and texture cause slippage errors Slippage error - 1% to 2%

Wheel wear, dirt buildup causes calibration errors Calibration is directly proportional to the

circumference of the wheel Down time for recalibration


Solution Install non-contact laser gauge at each critical

measurement point along the line Non-contact laser gauge directly measures product Slippage is not a problem +/-0.05% accuracy provides reliable, precise stretch

and draw measurements Eliminates any measurement guesswork and

uncertainty


Summary

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%

Non-Contact Laser Gauge Advantages


Summary Continued Complete System

in one small rugged package Sensor Processor I/O Power Supply

24 VDC operation IP67 protection Built-in water

cooling ports26.25 X 20.67 X 10.5 cm

2.54 Kilograms


Thank You -- Questions

BETA LaserMike Presented by: Les Jenson Chief Engineer Beta LaserMike Non-Contact, Laser-Based Technology for Accurately Measuring the Length and Speed.

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