MEASUREMENTS OF REMISSION FROM PALLETS & ALUMINIUM
FOIL & POLYETHYLENE BY IR RANGEFINDER
1. Devices and Equipment. Goals and Methodology of experiment.
1.1 Goals of the experiments.
- To check the applicability of Al foil marks on pallets for pallet recognition,
using the remission channels of IR rangefinder.
- To investigate the remission features of different materials in relative
values of the remission channels of IR rangefinder.
1.2 Devices, Equipment, Materials and Software.
- IR Rangefinder SICK\LMS-111.
- Camera MatrixVision\mvBlueFox.
- Cables (for power supply +12V & Ethernet to Rangefinder).
- 2 europallets.
- Aluminium foil (Al foil), Metal plates, polyethylene, dark scotch tape.
- PC with SOPAS ET, MATLAB R2010, Windows, “uRDEsm.exe” utility.
1.3 Methodology of experiment.
1.3.1 Switch on and adjust the Rangefinder and Camera, set the Al foil on
the pallets (and also metal plates, polyethylene, and dark scotch tape) in
the positions of interest (see Appendix 5.1).
1.3.2 Take the photos from the Camera and Rawdata from the Rangefinder
in the mode: 4 channels rawdata, 0.25° resolution, 16-bit remission, 25 Hz.
1.3.3 Preprocess the Rangefinder Rawdata by the “uRDEsm.exe” utility (to
extract the information on the Distance & Remission for 2 channels).
1.3.4 Process the Distance & Remission data by MATLAB with purpose to
obtain the information about the Rangefinder environment (contour of
pallets, room & other objects with remission values).
Subject: Measurements of remission from pallets & aluminium foil & polyethylene by IR rangefinder Date: 2016-02-09
Project: LASER-CAMERA SYSTEMS
Author: Afanasyev Ilya
E-mail: ilya.afanasyev@gmail.com
Copyright © Trento University, 2010. Duplication and disclosure to third party is forbidden without approval from Trento University.
1
Measurements of remission from pallets & aluminium foil & polyethylene by
IR rangefinder
2. Summary
2.1. The frontal IR remission from Al foil surfaces is higher than from
wooden. The remission values of Al foil lay in the range of 630-840 digits,
whereas for wooden blocks are 480-550 digits, see Figure 1, left. However,
for case with the rotated pallets, most of IR remission points from Al foil
surfaces are lower than from wooden. Actually, the remission values of Al
foil lay in the range of 450-495 digits for pallet structures 1 and 2 (and 520600 digits for pallet structure 3, which has folds and shines, see Figure 1,
right), whereas for the same structures of wooden blocks are 495-550
digits, see Figure 1 (right). The conclusion: as far as remission values of Al
foil depend on the angle of observation, it is difficult to use Al foil for reliable
detection of pallets.
Figure 1. Photo of pallets with/without Al foils (top), which are in direct
position (left) and rotated (right) in respect to rangefinder. The rangefinder
remission data for such pallet configurations (bottom).
2.2. Measurements with pallets with Al-foil+1-layer polyethylene and
without (see, Figure 2). For case with Al-foil and polyethylene shown in
Figure 2, structures 1, 2, and 3 have remission values in ranges 590-725,
670-825, and 600-675 digits, whereas the structures 4, 5, and 6 have
remission values of 500-545, 500-560 and 490-530 digits resp. Layers of
Subject: Measurements of remission from pallets & aluminium foil & polyethylene by IR rangefinder Date: 2016-02-09
Project: LASER-CAMERA SYSTEMS
Author: Afanasyev Ilya
E-mail: ilya.afanasyev@gmail.com
Copyright © Trento University, 2010. Duplication and disclosure to third party is forbidden without approval from Trento University.
2
Measurements of remission from pallets & aluminium foil & polyethylene by
IR rangefinder
polyethylene between the pallets give 430-455 digits of remission. So, it
can be difficult to recognize the 1-layer polyethylene, both on Al foil and
wooden surfaces.
Figure 2. Photo of the front-side of pallets (left), which conclude blocks with
Al-foil+1-layer polyethylene and without, and Rangefinder remission data
for selected pallets (right).
2.3. Measurements with different reflecting materials on pallet blocks (see,
Figure 3), where figures mean the surfaces: 1 – multilayer polyethylene +
Al foil; 2, 3 – Al foils; 4 – dark scotch tape; 5 – pure wooden pallet block; 6
– metal. The structures 1, 2, and 3 have remission values of 500-660, 690790, and 640-700 digits, whereas the structures 4, 5, and 6 have remission
values of 510-540, 520-550 and 435-445 digits resp.
The conclusions:
- The multilayer polyethylene significantly decrease the remission of Al foil,
but it cannot be usable for polyethylene detection because the dependence
of remission values of Al foil on the angle of observation (see, chapter 2.1).
- The IR reflection from the metal surface is much lower than from Al foil
and lower than wooden pallet. It can be explained both reflection features
of a covering on the metal surface and the remission dependence from
angle of observation.
- The dark scotch tape gives slightly lower remission than wooden block of
pallet.
Subject: Measurements of remission from pallets & aluminium foil & polyethylene by IR rangefinder Date: 2016-02-09
Project: LASER-CAMERA SYSTEMS
Author: Afanasyev Ilya
E-mail: ilya.afanasyev@gmail.com
Copyright © Trento University, 2010. Duplication and disclosure to third party is forbidden without approval from Trento University.
3
Measurements of remission from pallets & aluminium foil & polyethylene by
IR rangefinder
Figure 3. Photo of the front-side of pallets (left), which conclude blocks with
different reflecting materials (1- Al-foil + multilayer polyethylene; 2, 3 – Al
foils; 4 – dark scotch tape; 5 – pure wooden pallet block; 6 – metal), and
Rangefinder remission data for selected pallet structures (right).
Subject: Measurements of remission from pallets & aluminium foil & polyethylene by IR rangefinder Date: 2016-02-09
Project: LASER-CAMERA SYSTEMS
Author: Afanasyev Ilya
E-mail: ilya.afanasyev@gmail.com
Copyright © Trento University, 2010. Duplication and disclosure to third party is forbidden without approval from Trento University.
4
Measurements of remission from pallets & aluminium foil & polyethylene by
IR rangefinder
3. Conclusions.
3.1. As far as remission values of Al foil depend on the angle of
observation, it is difficult to use Al foil marks for reliable detection of pallets.
For pallet recognition task can be used another material with good IR
reflectivity and dead surface (with Lambert reflection property).
3.2. It can be difficult to recognize the 1-layer polyethylene, both on Al foil
and wooden surfaces.
3.3. The multilayer polyethylene significantly decrease the remission of Al
foil, but it cannot be usable for polyethylene detection because the
dependence of remission values of Al foil on the angle of observation (see,
conclusion 3.1).
3.4. The IR reflection from the metal surface is much lower than from Al foil
and lower than wooden pallet. It can be explained both reflection features
of a covering on the metal surface and the remission dependence from
angle of observation (see, conclusion 3.1).
3.5. The dark scotch tape gives slightly lower remission than wooden block
of pallet.
4. Acknowledgments.
Acknowledgments to the supervisor of the Project: Assoc. Prof. Mariolino
De Cecco and the group of Mechatronics (Mechanical and Structural
Engineering Dep., University of Trento): Luca Baglivo (for the problem
definition), Nicolo Biasi (for rawdata capturing), and Mattia Tavernini (for
MATLAB processing).
Subject: Measurements of remission from pallets & aluminium foil & polyethylene by IR rangefinder Date: 2016-02-09
Project: LASER-CAMERA SYSTEMS
Author: Afanasyev Ilya
E-mail: ilya.afanasyev@gmail.com
Copyright © Trento University, 2010. Duplication and disclosure to third party is forbidden without approval from Trento University.
5
Measurements of remission from pallets & aluminium foil & polyethylene by IR rangefinder
5. Appendixes.
5.1 Photos and Rangefinder remission data on experiments with Pallets & Al foils & Polyethylene.
Subject: Measurements of remission from pallets & aluminium foil & polyethylene by IR rangefinder Date: 2016-02-09
Project: LASER-CAMERA SYSTEMS
Author: Afanasyev Ilya
E-mail: ilya.afanasyev@gmail.com
Copyright © Trento University, 2010. Duplication and disclosure to third party is forbidden without approval from Trento University.
6
Measurements of remission from pallets & aluminium foil & polyethylene by IR rangefinder
Surfaces: 1 – polyethylene + Al foil; 2, 3 – Al foils; 4 – dark scotch tape; 5 – pure wooden pallet block; 6 – metal.
Subject: Measurements of remission from pallets & aluminium foil & polyethylene by IR rangefinder Date: 2016-02-09
Project: LASER-CAMERA SYSTEMS
Author: Afanasyev Ilya
E-mail: ilya.afanasyev@gmail.com
Copyright © Trento University, 2010. Duplication and disclosure to third party is forbidden without approval from Trento University.
7
Measurements of remission from pallets & aluminium foil & polyethylene by
IR rangefinder
5.2 MATLAB code for Rangefinder data processing
clear all
close all
clc
Dist1
Dist2
RSSI1
RSSI2
=
=
=
=
load('DIST1.txt');
load('DIST2.txt');
load('RSSI1.txt');
load('RSSI2.txt');
theta = deg2rad( (225:-0.25:-45) );
st = 475;
ed = 615;
for i=1%1:1:1%size(Dist1,1)
maxrsssi = max (RSSI1(i,st:ed));
minrsssi = min (RSSI1(i,st:ed));
range = maxrsssi-minrsssi+1
a = jet(range);
[X1,Y1] =
[X2,Y2] =
[X1r,Y1r]
[X2r,Y2r]
pol2cart( theta ,
pol2cart( theta ,
= pol2cart( theta
= pol2cart( theta
Dist1(i,:) );
Dist2(i,:) );
, RSSI1(i,:) );
, RSSI2(i,:) );
figure(2)
title('Cartesian Coordinate DIST1')
clf, axis equal, grid on , hold on
for j=st:1:ed
text( X1(j) , Y1(j) , num2str(RSSI1(i,j)))
plot( X1(j) , Y1(j) , 'x' , 'color' , a( RSSI1(i,j)+1-minrsssi,:) ,
'markersize' , 4 , 'linewidth' , 4 )
end
plot( 0 , 0 , 'xb' ,'markersize' , 10 , 'linewidth' , 2 )
xlabel('x [mm]')
ylabel('y [mm]')
figure(4)
title('Cartesian Coordinate DIST1 + DIST2')
clf, axis equal, grid on , hold on
for j=1:1:length( X1 )
plot( X1(j) , Y1(j) , '.b' )
plot( X2(j) , Y2(j) , 'xr' )
if norm( [X2(j) , Y2(j)] )~0
line( [X1(j),X2(j)],[Y1(j),Y2(j)],'color','g');
end
plot( 0 , 0 , 'xb' ,'markersize' , 10 , 'linewidth' , 2 )
end
xlabel('x [mm]')
ylabel('y [mm]')
%
end
pause( 0.1 )
Subject: Measurements of remission from pallets & aluminium foil & polyethylene by IR rangefinder Date: 2016-02-09
Project: LASER-CAMERA SYSTEMS
Author: Afanasyev Ilya
E-mail: ilya.afanasyev@gmail.com
Copyright © Trento University, 2010. Duplication and disclosure to third party is forbidden without approval from Trento University.
8