Click here to load reader
Upload
vuongmien
View
212
Download
0
Embed Size (px)
Citation preview
Machine vision based monitoring system for milling using ANFIS
1John Stephen R,
2Palani S,
3Alagu sundara pandian,
4Paul Linga Prakash R and
5Vijayakumar
D
1,2,34,5Department of Mechanical Engineering, VEL TECH MULTITECH, Avadi, Chenna-62, India
Corresponding Author E-mail ID: [email protected]
Abstract
The surface roughness of machined work
pieces are the important discussion since the
fitness of the product mainly related to the
roughness of the machined surface. In our
research work deals with the rough
monitoring by machine vision technique on
the machined surface. Here, the machined
surface images are captured by vision
system. A novel adaptive neuro fuzzy
inference system (ANFIS) model is used to
correlate the prediction values with
experimental value of the input and the
response parameters in the end milling
operation. The ANFIS results shows error
while extraction of image values feed as
ANFIS training process. Correlation
accuracy encouraging us for suitable
monitoring technique of the proposed ANFIS
model with image extraction technique with
image processing method and it is very
suitable for online monitoring in the
automated production industries.
Keyword. Milling, machine vision, Non
contact, surface roughness;
ANFIS
1. Intriduction
In the modern manufacturing era, end
milling process is essential one as well as
regularly utilizing for machining of the
metal. Recently, manufacturing components
quality as main concern in the competitive
industrial sectors and needed to online
monitoring methods [1]. The work piece
surface roughness could be measured
through two ways such as contact as well as
non-contact methods. In the method of
contact sensor probe has touch on the
machined surface lead to form scratches on
it. In order to avoid physical touch during
measurement the on line image processing
technique as well as machine vision methods
are introducing in this research work [2].
In computerized manufacturing scenario,
computer machine vision method is a main
play role for fast monitoring [3]. The regular
research has been followed through
computer machine vision method into the
modern manufacturing sector., The non-
contact online monitoring methods very
suitable for machined surface roughness
measurement without affecting the already
machined surface.[4].
Recent day’s machine vision based
techniques eliminated disadvantages of the
conventional probe measuring methods.
Galante et al stated that the vision approach
International Journal of Pure and Applied MathematicsVolume 119 No. 15 2018, 1083-1090ISSN: 1314-3395 (on-line version)url: http://www.acadpubl.eu/hub/Special Issue http://www.acadpubl.eu/hub/
1083
in the process of turning for prediction [5].
Benardos used taquchi's optimization design
method for prediction in the process of face
milling [6]. Lee constructed a model to
measure the roughness through online
monitoring for the operation of turning [7].
In our research work we used neuro fuzzy
logic for correlating actual as well as
predicted roughness values on the work
piece with various condition of machining.
In our research work firstly explain machined surface image extraction and then ANFIS method has been introduced. After that shows the ANFIS prediction results for the different machining conditions with the results of the correlating values with the percentage error. Finally our research work take part of result as well as discussion with model output and conclude the work for possible experimental approaches with accurate dimensions for optimizing the machining time on end milling process.
2. Measurement of roughness of the
work piece
In 1960 the image processing method
was introducing especially for the
investigation of space for generating graph
of earth. Now a day, it improved for
computer aided manufacturing as well as all
sector of developed industrial area for
monitoring by machine vision [8]. The
purpose of vision technique for online
monitoring investigated through the
literature [9]. Bradly [10] developed a novel
online measurement and monitoring model
for roughness through image processing
method.
In our research work, image and vision
method has been used for predicting
roughness of the surface in end milling as
shown in Figure 1. First sources of light has
been focus on job next image of the
machined surface has been accrued through
vision system then directed to work station
with personal computer through frame
grabber. WE use a Surf coder for measuring
the machined surface roughness of work
material with the dimension of 8 mm long
and the speed is 0.5 mm/s. The mean of
arithmetic roughness of the machined
surface Ra has been measured through the
formulae below:
(1)
Where Yi is the height of roughness from its
mean
n is the experimental date number Ga is the average gray value of the
image of work piece machined surface.
International Journal of Pure and Applied Mathematics Special Issue
1084
Figure 1. Rapid I of Computer vision
model
V: 28 m/min V: 28
m/min
F: 0.002 mm/rev F: 0.0466
mm/rev.
D: 0.6 mm D: 0.8
mm
R: 0.6371 µm R: 0.8517 µm
G: 109.563 G: 153.845
Figure 2. Captured work piece Images
The expression of the gray value in
arithmetic average is shown in equation 2:
(2)
Where Gi is the average gray value of the
image of the surface
3. ANFIS Model for surface rough
Problem has been generating through
fuzzy rules with membership function.
These difficulties are overcome with ANFIS
through explicit adaptive knowledge of
fuzzy with implicit learning capacity of
neural networks [11]. The Artificial neural
network (ANN) gives experts neurons to
generate fuzzy control if then rules including
membership for obtaining suitable
formulations methods [12].
The advantages of both traditionally
fuzzy expert and the neural networks
combined with the practice of computer to
obtain computational performance by layer
of hidden neurons as well as the learning
capacity. The model structure of ANFIS is
shown in Figure 3.
Figure 3: Model structure of ANFIS
4. Experimental discussion
The practical status of CNC milling
process is shown in Figure 4
International Journal of Pure and Applied Mathematics Special Issue
1085
Figure 4: Machining status of the CNC
milling
Experimental Results
Table 1: End milling process experiment
values
Sl.
No
V
m/min
F
mm/rev
D
mm Ga
Ra
microns
1 28 0.002 0.6 0.6607 0.6371
2 28 0.002 0.8 0.8498 0.5705
3 28 0.002 1.0 0.7506 0.5039
4 28 0.0333 0.6 0.8420 0.777
5 28 0.0333 0.8 0.6621 0.67
6 28 0.0333 1.0 0.6679 0.644
7 28 0.0466 0.6 1.0000 0.9183
8 28 0.0466 0.8 0.9278 0.8517
9 28 0.0466 1.0 0.7445 0.687
10 38 0.002 0.6 0.8651 0.37
11 38 0.002 0.8 0.7073 0.3025
12 38 0.002 1.0 0.8339 0.2359
13 38 0.0333 0.6 0.7592 0.5097
14 38 0.0333 0.8 0.9069 0.4431
15 38 0.0333 1.0 0.8803 0.3765
16 38 0.0466 0.6 0.6744 0.6503
17 38 0.0466 0.8 0.8694 0.5837
18 38 0.0466 1.0 0.8743 0.587
19 47 0.002 0.6 0.8097 0.0827
20 47 0.002 0.8 0.1574 0.0469
21 47 0.002 1.0 0.1460 0.0321
22 47 0.0333 0.6 0 .8543 0.2417
23 47 0.0333 0.8 0.8342 0.236
24 47 0.0333 1.0 0.4935 0.01321
25 47 0.0466 0.6 0.8938 0.3823
26 47 0.0466 0.8 0.7381 0.3157
27 47 0.0466 1.0 0.7754 0.286
The experimental values are tabulated in
Table 1. 27 experiments through different
milling conditions have been obtained to
train the ANFIS for monitoring roughness of
the work piece surface. The experimental
values were tabulated in Table 1.
5. Prediction of Machined surface
Input data Normalisation
Normalization technique has been utilized
for obtaining test values from -1 to +1. The
normalization process mainly used for
training the parameter values uniformly as
well as to meet equal gap to the training
parameters to increase performance of
ANFIS method at the same time reducing
International Journal of Pure and Applied Mathematics Special Issue
1086
the computation time. Figure 5 shows the
ANFIS training.
Figure 5: ANFIS training
For training ANFIS first proper topology
has been chosen through trial-error method.
Then various topologies have been tried and
4-4-1 topology network has been selected
for training the ANFIS. Figure 5 shows the
created ANFIS.
Finally, trained ANFIS has been
simulated through new input for testing to
predict roughness of the machined surface.
Input data for valitation
Five new sets of data have been taken to
validate proposed ANFIS model. Table 2
shows the values for input as well as output
variables. The % of error in the predicted as
well as experimental value have been
obtained through following formula.
Predicted Value - Experimental value
% of Error = ------------------------------------------
×100
Experimental value
Table 2: Validation between predicted with
experimental values
Sl.
No
V
m/m
in
F
mm/
rev
D
mm Ga
Ra in microns Error
%
Experi Predic.
1 1 0.0429 0.6 0.809
7 0.0511 0.0493 3.523
2 1 0.0429 1.0 0.146 0.0349 0.0311 10.888
3 1 0.7146 1.0 0.493
5 0.0132 0.0130 1.665
4 1 0.0429 0.6 0.809
7 0.0901 0.0832 7.658
5 1 0.7146 0.6 0.854
4 0.2632 0.2599 1.253
Average Absolute Error = 4.997 %
The output of the validation is shown in
Figure 6.
Figure 6: Output of the validation by
ANFIS
International Journal of Pure and Applied Mathematics Special Issue
1087
6. Result and discussion
Proposed model has been developed
through ANFIS. With twenty seven various
machining parameters are as shown in Table
1 used to predict the roughness of the
machined surface in the end milling. The
validation of the predicted values with
experimental values is shown in Figure 7.
Figure 7: Validation of experimental with
ANFIS predicted data
The mean error of percentage of the
proposed model with ANFIS is 4.997% and
accuracy is 95.003%.
7. Conclusion
The results shows that an on line
measuring as well as monitoring method by
machine vision method for investigating
machined surface of the roughness of work
piece by ANFIS. Through this results this
proposed ANFIS model as well as image
processing technique is best suited for
monitoring methods. The outputs of
experiment are comparing through results of
the proposed method shows the proposed
model could be produced very accurate
result.
REFERENCES
[1] G.A. A1. Kindi, R.M., K.F. Gill, “An
Application of machine vision in the
automated inspection of engineering
surfaces” International Journal of
Production Research Vol.30,
No.2,pp,241-253,1992.
[2] M.B. Kiran, B, Ramamoorthy,
B.Radhakrishnan, “ Evaluation of
surface roughness by vision system “,
International Journal roughness by
vision system”, International Journal of
machine Tools & Manufacture Vol.38,
No 5-6, pp 685-690, 1998
[3] M.Gupta, S. Raman, “Machine vision
assisted characterization of machined
surfaces”, International Journal of
Production Research Vol.39,No pp.759-
784,2001.
[4] K. Venkata Ramana, B. Ramamoorthy,
“Statistical methods of compare the
texture features of machine surfaces”,
Pattern Recognition. Vol29, No9 pp,
1447-1459, 1996
[5] Galant G, piacentini M. Ruisi VF.
Surface roughness detection by tool
image processing Wear 1991;148:211-
20.
International Journal of Pure and Applied Mathematics Special Issue
1088
[6] P.G.Benardos, G.C. Vosniakos,
Prediction of surface roughness in CNC
face milling using neural networks and
Taguchi’s design of experiments,
Robotics and Computer Integrated
manufacturing 18 (5-6) (2002) 343-354
[7] B.Y.Lee, S.F.Yu, H.Juan “The model of
surface roughness inspection by
machine vision system in turning,
Mechatronics 14 (2004) 129-141.
[8] Dudas I and Varga G 2001 Metrological
use of CCD Camera microCAD 2001
Int. Scientific Conference March 1-2
Univ. of Miskole, Hungary 35-40
[9] Kurada S Bradley C (1997) A review of
machine vision sensors for tool condition
monitoring, Comput Ind 34(1)55-72
[10] Bradly C Wong YS (2001) surface
tecture indicators of tool wear – a
machine vision approach. Int. J Adv
Manuf Technol 17(6):435-443
[11] Stamotios V. Kartalopoulos, (1996)
“Understanding Network and Fuzzy
Logic” Prentice-Hall of India Ltd, New
Delhi
[12] Jang, J.S. Sun, C.T. Mezuzah,E. (1997)
“Neuro Fuzzy Logic and Soft
Computing”. Prentice-Hall Englewood
cliffs
International Journal of Pure and Applied Mathematics Special Issue
1089
1090