Post on 12-Jan-2016
transcript
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