nondestructive impact and acoustic testing for quality assessment of apples by itzhak shmulevich,...
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Nondestructive Impact and Nondestructive Impact and Acoustic Testing ForAcoustic Testing For Quality Quality
Assessment of ApplesAssessment of Applesby by
Itzhak Shmulevich, Naftali Itzhak Shmulevich, Naftali GaliliGalili
andand
M. Scott Howarth M. Scott Howarth
AAGGEENGNG 2002 2002
Budapest, Hungary June 30-July 4, 2002Budapest, Hungary June 30-July 4, 2002
The Department of The Department of Agricultural Agricultural EngineeringEngineeringTechnion-Israel Institute of TechnologyTechnion-Israel Institute of Technology
Presentation outlinePresentation outline
Introduction - firmness quality nondestructive Introduction - firmness quality nondestructive measurements;measurements;
Impact technique vs. acoustic technique;Impact technique vs. acoustic technique; Experimental report on various fruits;Experimental report on various fruits; Results; Results;
Discussion; Discussion;
Conclusions.Conclusions.
Quality Factors of Quality Factors of Agricultural ProductsAgricultural Products
Appearance - visual Texture - feel Flavor - taste and smell Safety Nutritive Value
TextureTexture
Texture can be defined by subjective Texture can be defined by subjective terms such as:terms such as:
Firmness Firmness Mealiness, Hardness, Softness, Mealiness, Hardness, Softness, Brittleness, Ripeness, Toughness, Brittleness, Ripeness, Toughness, Chewiness, Smoothness, Crispness, Chewiness, Smoothness, Crispness, Oiliness, Springiness, Toughness, Oiliness, Springiness, Toughness, Fibrousness, or Juiciness etc.Fibrousness, or Juiciness etc.
Quality Sensing in Quality Sensing in Commercial SettingsCommercial Settings
RequirementsRequirements
NondestructiveNondestructive
External and internal propertiesExternal and internal properties
AccuracyAccuracy
Speed (5-15 fruits/sec)Speed (5-15 fruits/sec)
Recognize inherent product variabilityRecognize inherent product variability
NondestructiveNondestructive Firmness Firmness
Measurement Measurement TechniquesTechniques Fruit Response to ForceFruit Response to Force
Detection by Impact ForceDetection by Impact Force Forced VibrationsForced Vibrations Mechanical or Sonic ImpulseMechanical or Sonic Impulse Ultrasonic TechniquesUltrasonic Techniques Indirect Firmness MeasurementIndirect Firmness Measurement
Research Research ObjectiveObjective
The motivation of the present work is to develop
a fast nondestructive method for quality firmness
testing of apples.
The general objective of the research is to
compare sensing the fruitfirmness using low
mass impulse excitation to the acoustic response
for quality assessment of apples.
Relationship between turgor Relationship between turgor pressure and tissue rigiditypressure and tissue rigidity
E=3.6 p +2.5 x10E=3.6 p +2.5 x1077 [ [ dynes/cmdynes/cm22]]
Modulus of ElasticityModulus of Elasticity
NondestructiveNondestructive Firmness Firmness MeasurementMeasurement
Impact Force TechniqueImpact Force Technique
IQ FirmnessIQ Firmness
IQ IQ TM TM Firmness Tester Firmness Tester
Sinclair International Sinclair International LTDLTD
NondestructiveNondestructive Firmness Firmness MeasurementMeasurement
Acoustic TechniqueAcoustic Technique
Typical Acoustic Fruit Typical Acoustic Fruit ResponseResponse
Frequency DomainFrequency DomainTime DomainTime Domain
(b)-5
-3
-1
1
3
5
0 5 10 15 20 25TIME (ms)
AM
PL
ITU
DE
(V
)
Sensor-1
Sensor-2
Sensor-3
(d)0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0 400 800 1200 1600FREQUENCY (Hz)
AM
PL
ITU
DE
(V
)
Sensor-1
Sensor-2
Sensor-3
Microphone Based Microphone Based System for Acoustic System for Acoustic
Firmness TestingFirmness Testinghp 35665A
Impact
Microphone Signal conditioner
Source: J. De BaerdemaekerSource: J. De Baerdemaeker
Comparison Between Comparison Between Two Acoustic Test Two Acoustic Test
MethodsMethods
35302520151055
10
15
20
25
30
35
FIRMNES INDEX - METHOD-A
FIR
MN
ES
S I
ND
EX
- B y = 0.00328 + 0.9954x
R^2 = 0.977
BRAEBURN
3025201510500
5
10
15
20
25
30
FIRMNESS INDEX - METHOD-AFI
RM
NE
SS
IN
DE
X -
B
y = -0.30995 + 1.0080x R^2 = 0.989
JONAGOLD
Method-A:Method-A: Microphone Microphone Method-B:Method-B: Piezoelectric-Film Sensor Piezoelectric-Film Sensor
Source: N. Galili & J. De BaerdemaekerSource: N. Galili & J. De Baerdemaeker
22
p
p
T
FC
p
p
T
FC 1
1.5 2 2.5 3 3.5
x 10-3
0
0.1
0.2
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0.5
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0.7
0.8
0.9
1
Time [sec]
Am
plit
ude [
volt]
d
sec
N
Fp
Tp
td
Quality Detection by Impact Quality Detection by Impact ForceForceChen. P (1996), Farabee (1991)
Delwiche (1989 ,1991), Nahir et al. (1986 )
Quality Detection by Quality Detection by ImpactImpact
0 0.5 1 1.5 2 2.5 3 3.5 4
x 10-3
0
10
20
30
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60
Time [sec]
F [N
]
day 1day 2day 3day 4
0 100 200 300 400 500 600 700 800 900
0.2
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1
Frequency [Hz]
Norm
alize
Am
plitu
de
day 1day 2day 3day 4
Source: Shmulevich et. al. Source: Shmulevich et. al. ( 2000 )( 2000 )
The Acoustic The Acoustic Parameters Parameters
of a Fruitof a Fruit Natural frequencies and firmness index - Natural frequencies and firmness index - FIFI
FI = f FI = f 22 m m 2/32/3 {10{104 4 kgkg2/32/3 s s-2-2} }
where: where: f f - first spherical resonant frequency - first spherical resonant frequency
mm - fruit’s mass. - fruit’s mass. Damping ratio - Damping ratio - The centeroid of the frequency response - The centeroid of the frequency response - ffcc
Parameters Parameters extracted from the extracted from the
measurementsmeasurements Low-Mass Impulse parameters: Low-Mass Impulse parameters:
C1 = Fp/Tp; C2 = Fp/Tp2 ; (-20); and fc(in).
IQ , IT
Acoustic parameters:
f1 ; FI ; and fc;
Destructive parameters: E ; MT.
Method and Method and MaterialsMaterials
• Three apples cultivers;Three apples cultivers;
• Shelf life conditions: 20 Shelf life conditions: 20 00C C 50%RH;50%RH;
• 25 fruits were tested daily 25 fruits were tested daily both both nondestructively and nondestructively and destructively;destructively;
• Destructive test - (MT, E’);Destructive test - (MT, E’);
.
Results - Results - Rubber Spheres Rubber Spheres
0
20
40
60
80
100
120
140
160
0 1 2 3 4 5 6 7 8
Displacement (mm)
Fo
rce
(N
)
White
Black
Yellow
Red
Typical input signal in time domain of theLow-Mass Impact system for different
Rubber Spheres
2000
2100
2200
2300
2400
2500
2600
2700
2800
50 100 150 200 250 300 350 400
Time steps
Am
plit
ud
e
White
Black
Yellow
Red
Typical input signal in time domain of theLow-Mass Impact system by Sinclair for
different Rubber Spheres
1800
2000
2200
2400
2600
2800
3000
3200
3400
3600
3800
50 100 150 200 250 300 350 400
Time steps
Am
plit
ud
e
White
Black
Yellow
Red
Results - Results - Rubber Spheres Rubber Spheres
IQ = 3.0396x + 0.2495
R2 = 0.9984
IT = 2.936x - 0.6056
R2 = 0.9975
FI = 1.5694x - 0.8186
R2 = 0.99650
5
10
15
20
25
30
35
40
45
50
0 2 4 6 8 10 12 14 16
E' (MPa)
Fir
mn
ess
FI (mean)
IQ (mean)
IT (mean)
Typical Acoustic Fruit Typical Acoustic Fruit ResponseResponse
Frequency DomainFrequency DomainTime DomainTime Domain
(b)-5
-3
-1
1
3
5
0 5 10 15 20 25TIME (ms)
AM
PL
ITU
DE
(V
)
Sensor-1
Sensor-2
Sensor-3
(d)0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0 400 800 1200 1600FREQUENCY (Hz)
AM
PL
ITU
DE
(V
)
Sensor-1
Sensor-2
Sensor-3
Pearson linear correlation between the Pearson linear correlation between the nondestructive and destructive tests,nondestructive and destructive tests,
n=270 Golden Delicious -Apple, n=270 Golden Delicious -Apple, Correlation is significant at the 0.05 levelCorrelation is significant at the 0.05 level
E' MT FI IQ IT
E' 1 0.542 0.913 0.911 0.923
MT 1 0.520 0.517 0.547
FI 1 0.923 0.927
IQ 1 0.990
IT 1
Results -Golden Results -Golden DeliciousDeliciousGolden Apples (N = 270)
MT = 0.2925x + 2.9894
R2 = 0.2942
FI = 4.0346x - 2.9391
R2 = 0.8339
IQ = 2.1593x + 6.3759
R2 = 0.8292
IT = 4.0464x + 8.1449
R2 = 0.85260
5
10
15
20
25
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50
0 2 4 6 8 10
E' (MPa)
Fir
mn
es
s
MT (mean)
FI (mean)
IQ (mean)
IT (mean)
Results-Golden Results-Golden DeliciousDeliciousGolden Delicious
IT = 0.0456x2 - 1.9376x + 39.995
R2 = 0.9646
IQ = 0.023x2 - 1.0098x + 23.336
R2 = 0.9679
FI = 0.0515x2 - 2.1226x + 29.909
R2 = 0.957
E' = 0.0074x2 - 0.372x + 7.3076
R2 = 0.9592
MT = 0.0009x2 - 0.0956x + 5.224
R2 = 0.93770
5
10
15
20
25
30
35
40
45
0 2 4 6 8 10 12 14 16 18 20 22
Day
Fir
mn
ess
E' (average)
MT(average)
FI (average)
IQ (average)
IT (average)
Pearson linear correlation between the Pearson linear correlation between the nondestructive and destructive tests,nondestructive and destructive tests,
n=270 Starking -Apple, n=270 Starking -Apple, Correlation is significant at the 0.05 levelCorrelation is significant at the 0.05 level
E' MT FI IQ IT
E' 1 0.597 0.947 0.837 0.850
MT 1 0.598 0.532 0.542
FI 1 0.829 0.842
IQ 1 0.990
IT 1
Results-Starking Results-Starking ApplesApples
IT = 2.8958x + 13.914
R2 = 0.7226
IQ = 1.6916x + 8.6502
R2 = 0.7006
FI = 3.003x - 2.5367
R2 = 0.8966
MT = 0.3071x + 3.9389
R2 = 0.3565
0
5
10
15
20
25
30
35
40
45
50
0 2 4 6 8 10
E' (MPa)
Fir
mn
ess
MT (mean)
FI (mean)
IQ (mean)
IT (mean)
Results-Starking Results-Starking ApplesApples
IT= 0.0097x2 - 0.8215x + 37.34R2 = 0.9627
IQ = 0.0065x2 - 0.5113x + 22.477R2 = 0.9302
FI = 0.0113x2 - 0.8938x + 21.854R2 = 0.9966
E' = 0.0028x2 - 0.2475x + 7.694R2 = 0.9888
MT = 0.0007x2 - 0.0751x + 6.3496R2 = 0.9206
0
5
10
15
20
25
30
35
40
0 10 20 30 40 50Day
Fir
mn
ess
E'-average
MT-average
FI-average
IQ-average
IT-average
Pearson linear correlation between the Pearson linear correlation between the nondestructive and destructive tests,nondestructive and destructive tests,
n=270 Granny Smith -Apple, n=270 Granny Smith -Apple, Correlation is significant at the 0.05 levelCorrelation is significant at the 0.05 level
E' MT FI IQ ITE' 1 0.450 0.915 0.820 0.791
MT 1 0.461 0.426 0.406FI 1 0.883 0.885 IQ 1 0.978 IT 1
Results- Granny Results- Granny SmithSmith
MT = 0.155x + 4.9758R2 = 0.2497
FI = 2.5615x + 3.1173R2 = 0.8374
IT = 1.5315x + 18.428R2 = 0.6264
IQ = 0.9198x + 11.384R2 = 0.672
0
5
10
15
20
25
30
35
40
45
0 2 4 6 8 10 12 14
E' (MPa)
Fir
mn
ess
MT (mean)
FI (mean)
IQ (mean)
IT (mean)
Results- Granny SmithResults- Granny Smith
IT = 5.1747x + 19.314R2 = 0.7387
IQ = 4.5916x + 18.456R2 = 0.7055
FI = 2.4549x + 6.924R2 = 0.992
MT = 0.1472x + 5.2212R2 = 0.7301
E' = 0.834x + 2.1082R2 = 0.9198
0
5
10
15
20
25
30
35
40
0 10 20 30 40 50Day
Firm
ness
E' (mean)
MT (mean)
FI (mean)
IQ (mean)
IT (mean)
SummarySummary
•The impact firmness parameter IQ and IT of The impact firmness parameter IQ and IT of
the calibration balls, obtained by the the calibration balls, obtained by the
instrumented instrumented
hammer and the Sinclair sensor, were very closehammer and the Sinclair sensor, were very close
(R-average = 0.992), while the Sinclair sensor (R-average = 0.992), while the Sinclair sensor
predicted slightly better the elastic modulus predicted slightly better the elastic modulus
of the balls (R = 0.9992).of the balls (R = 0.9992).
Summary (Cont,)Summary (Cont,)
•The elastic modulus E’, which is the The elastic modulus E’, which is the physical measurement of firmness, was physical measurement of firmness, was predicted well by the IQ and IT impact predicted well by the IQ and IT impact parameters in Golden Delicious apples (R-parameters in Golden Delicious apples (R-average = 0.917). average = 0.917).
•The acoustic firmness index FI was The acoustic firmness index FI was equivalent to IQ in Golden Delicious, but equivalent to IQ in Golden Delicious, but improved the prediction of E’ in Starking and improved the prediction of E’ in Starking and Granny Smith apples (R-average = 0.931).Granny Smith apples (R-average = 0.931).
Summary (Cont.)Summary (Cont.)
•High correlation was found between the High correlation was found between the
individual readings of IT and IQ in all individual readings of IT and IQ in all
apples (R = 0.9867). Hence, the simple IT apples (R = 0.9867). Hence, the simple IT
algorithm may replace the IQ algorithm, if algorithm may replace the IQ algorithm, if
quick firmness calculation is needed to quick firmness calculation is needed to
increase the present operation speed of the increase the present operation speed of the
low-impact sorter (600 fruit per minute per low-impact sorter (600 fruit per minute per
lane).lane).
Summary (Cont.)Summary (Cont.)
•The changes in the penetration force MT The changes in the penetration force MT
(the yield strength of fruit tissue) during the (the yield strength of fruit tissue) during the
test period were very low, and their test period were very low, and their
correlation with the elastic modulus and correlation with the elastic modulus and
firmness parameters of all apples’ varieties firmness parameters of all apples’ varieties
was poor (R < 0.60).was poor (R < 0.60).
Summary (Cont.)Summary (Cont.)
•These findings in the tested apple varieties These findings in the tested apple varieties
indicate that the acoustic firmness index FI, if indicate that the acoustic firmness index FI, if
successfully applied in a sorting line, may successfully applied in a sorting line, may
improve the sorting capacity of a multi-sensor improve the sorting capacity of a multi-sensor
(FI and IQ) automatic machine.(FI and IQ) automatic machine.