BETA LaserMike

BETA LaserMike

Presented by:Les Jenson

Chief EngineerBeta LaserMike

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

ICE USA 2011 Technical Program

Non-Contact Laser Gauge

BETA LaserMike

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

Non-Contact Laser Gauge

BETA LaserMike

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

Non-Contact Laser Gauge

BETA LaserMike

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

Non-Contact Laser Gauge

BETA LaserMike

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%

Non-Contact Laser Gauge

BETA LaserMike

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 ports26.25 X 20.67 X 10.5 cm

2.54 Kilograms

Non-Contact Laser Gauge

BETA LaserMike

System Concept

FPGA- Signal processing PCB

Laser diode assembly with temperature control

Proprietary beams steering optics and receiving optics

Measuring region

Non-Contact Laser Gauge

BETA LaserMike

Non-Contact Gauge Technology

Non-Contact Laser Gauge

BETA LaserMike

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.

Non-Contact Laser Gauge

BETA LaserMike

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

Non-Contact Laser Gauge

BETA LaserMike

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

Non-Contact Laser Gauge

BETA LaserMike

Laser Doppler Velocimetry (LDV) Theory

sin2d

ft

1

fdV *

T vdtL0

t

dv

Fringe direction

Non-Contact Laser Gauge

BETA LaserMike

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

Non-Contact Laser Gauge

BETA LaserMike

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

sin2d

Non-Contact Laser Gauge

BETA LaserMike

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

ft

1

fdV *

t

dv

Non-Contact Laser Gauge

BETA LaserMike

No Calibration Required

Length is achieved by numerically integrating the speed

Permanently calibrated with very high accuracy

T vdtL0

Non-Contact Laser Gauge

BETA LaserMike

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

Non-Contact Laser Gauge

BETA LaserMike

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

Non-Contact Laser Gauge

BETA LaserMike

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

Non-Contact Laser Gauge

BETA LaserMike

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

Non-Contact Laser Gauge

BETA LaserMike

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

Non-Contact Laser Gauge

BETA LaserMike

Roofing Product Application

Premium Quality Organic Mat Saturated with high-grade

asphalt Dried Slit to width Cut to length

Non-Contact Laser Gauge

BETA LaserMike

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

Non-Contact Laser Gauge

BETA LaserMike

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

Non-Contact Laser Gauge

BETA LaserMike

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

Non-Contact Laser Gauge

BETA LaserMike

Sanitary Products Application

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

Slitting and cut-to-length requirements

Non-Contact Laser Gauge

BETA LaserMike

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

Non-Contact Laser Gauge

BETA LaserMike

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

Non-Contact Laser Gauge

BETA LaserMike

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

Non-Contact Laser Gauge

BETA LaserMike

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

Non-Contact Laser Gauge

BETA LaserMike

Thank You -- Questions