International Journal of Engineering Insights: (2024) Vol. 2, Nro. 1, Regular Paper
https://doi.org/10.61961/injei.v2i1.18
Early Fault Detection in Paper Machine Motors Using
Machine Learning
Cristian P. Chuchico · Oscar Acosta Agudelo
Received: 18 Feb 2024 / Accepted: 02 May 2024 / Published: 16 May 2024
Abstract: This research addresses the application of
a neural network as a tool for early fault detection in
the motors of a paper machine under a simulated en-
vironment. It proposes the analysis of variables from
a torque control loop. The data for training and vali-
dating the model is obtained through the simulation of
Direct Torque Control (DTC) of an AC motor in Sim-
scape within Simulink. Both normal and faulty operat-
ing modes are considered. Under these two scenarios,
various speed setpoints are configured, and the neces-
sary data for training the developed model is collected.
Keywords Machine Learning · Predictive Mainte-
nance · Paper Machine · DTC · Simscape
1 Introduction
In the industrial sector, especially in areas like paper
manufacturing where operational efficiency and pro-
cess continuity are paramount, equipment maintenance
plays a crucial role in the success and profitability of op-
erations. Maintenance management is sometimes con-
ducted traditionally with manual records and data en-
try in spreadsheets, methodologies that have yielded
good results for industrial production [1]. However, this
approach involves several issues, such as human errors
in data collection and record entry, the frequency of
maintenance plan execution, among others. Therefore,
the ability to effectively prevent unexpected motor fail-
ures remains a significant challenge [2][3].
Cristian P. Chuchico
Escuela de Ingenier´ıa y Tecnolog´ıa
International University of La Rioja
La Rioja, Spain
Tel.: +593 992842517
E-mail: cristianpaul.chuchico050@comunidadunir.net
Oscar Acosta Agudelo
Escuela de Ingenier´ıa y Tecnolog´ıa
International University of La Rioja
La Rioja, Spain
E-mail: oscaresneider.acosta-externo@unir.net
Moreover, artificial intelligence has seen broad evo-
lution across diverse fields, including service sectors,
healthcare [4], robotics [5], and the industrial domain.
In this context, predictive maintenance, supported by
advances in technologies such as machine learning, could
emerge as a strategy to ensure the availability and re-
liability of industrial assets and processes [6][7]. For
instance, [8] shows the application of neural network
classifiers is proposed for detecting anomalies such as
specks and various types of diffraction in a laser beam.
The research achieves an accuracy of around 99% with
very short processing times, aiming to reduce reliance
on an expert for beam evaluation. Moreover, a review
of ML technologies related to predictive maintenance
of conveyor belts is conducted in [9], summarizing the
results and challenges of various methodologies used in
these systems. In addition, [10] shows a multihead neu-
ral network developed under the variability of individ-
ual machine degradations to derive machine-level prog-
nostics. This network learns degradation features and
updates remaining useful lifetime (RUL) distributions
from diverse distribution ensembles. Even though these
articles are closely related to the paper manufacturing
sector, a comprehensive analysis using artificial intelli-
gence to extend the useful life of engines might still be
unresolved.
In this work, a machine learning algorithm is in-
corporated into the predictive maintenance of the drive
motors of a paper machine. The aim is to provide a tool
that facilitates the early diagnosis of anomalies in mo-
tor operation, thereby preventing mechanical damage
to couplings, crosses, and cardan shafts in the system.
With the incorporation of this tool, the information
from operating variables such as speed reference, speed
feedback, motor current, torque reference, and motor
torque (calculated based on motor voltage and current)
is analyzed. This analysis helps determine whether the
machine’s operation is adequate or if there is a need
to plan activities to address out-of-standard conditions,
thereby avoiding unplanned production stoppages [11][12].
The document presents the result of a direct torque
2 2 NEURAL NETWORK CONFIGURATION AND TRAINING
Fig. 1 Direct Torque Control (DTC) system.
control (DTC) simulation of a three-phase motor using
Simscape in MATLAB [13], from which the parameters
for training the neural network are obtained [14]. The
main contribution of this work is the incorporation of
a neural network for anomaly detection in motors in
the paper industry. By validating the contribution of
this neural network, it is possible to integrate the algo-
rithm into a real production environment and connect
it to the SCADA system via an OPC server, simplify-
ing signal interpretation and contributing to industrial
maintenance management.
2 Neural Network Configuration and Training
2.1 Simulation Scenario Setup
For the implementation of the simulation environment,
Simscape Electrical blocks are used, starting with one
of the direct torque control (DTC) exercises available
on the official MathWorks website [15]. The main blocks
within the simulated environment are: the direct torque
controller, the noise signal activation, and the elements
that emulate the physical system: power supply, recti-
fier block, inverter, and motor. Fig. 1 shows the cited
setup and its connections.
2.2 Data Generation for Training
As described in Table 1, during the model simulations,
different combinations of speed and torque are applied
by using step signals at specific time intervals at the
controller inputs, see Figure 2.
Once the controller’s operation has been verified, a
simulation is run with the same speed and torque set-
points, incorporating random noise in the system feed-
back to emulate abnormal system behavior. The results
shown in Figure 3 indicate that the controller exhibits
highly oscillatory behavior.
The simulation behavior aligns with mechanical issues
encountered in a real system, as shown in Figure 4. The
figure displays the torque of four motors: motors a and
b are operating normally, while motors c and d exhibit
signals from systems with mechanical problems.
The data for the analysis are obtained from several sim-
ulations, which include different scenarios such as ac-
celeration, deceleration, and steady state. The training
of the algorithm is based on identifying the behavior of
the torque control loop variables. For this purpose, 6
variables are considered, from which a total of 533310
samples are obtained. The analyzed variables are:
Set Point or speed reference in RPM.
Motor speed feedback.
Set point or torque reference.
Torque control signal (controller output).
Motor torque.
Motor current.
2.3 Neural Network Training
The process is divided into several trials to define the
best parameters for the neural network, with the con-
figurations shown in Table 2. After the training pro-
cess, the model’s performance is evaluated using con-
fusion matrices for each trial, allowing us to visual-
ize the model’s ability to correctly classify normal and
2.3 Neural Network Training 3
Table 1 Example of applied speed and torque combinations.
step Operation State Torque Ref Torque Motor Speed Ref
T1 Null Null Null Null
T2 Acceleration Null Over Reference 0 to 1200 RPM
T3 Stable 600 and 100 Nm According with reference 1200 RPM
T4 Deceleration 100 Nm Under refernce 1200 to 500 RPM
T5 Stable 100 Nm According with reference 500 RPM
T6 Acceleration & Stable 100 Nm Over and according with reference 500 to 700 RPM
Fig. 2 Direct Torque Control loop response, normal operating conditions.
Fig. 3 Direct Torque Control loop response, operating conditions with noise.
4 3 METRICS CALCULATION
Fig. 4 Torque trends of 4 motors: a) and b) normal operation, c) and d) with mechanical issues.
faulty operating states of the system. The results of
each trial conducted are presented below: In the first
trial, the confusion matrix (Figure 5) shows that the
model achieved a 70.3% accuracy. In the second trial,
whose results are presented in the confusion matrix in
Figure 6, the model’s consistency was confirmed, and a
72.7% accuracy was achieved. Subsequently, in Trial 3,
an increase in the input data was made, and three previ-
ous samples were considered for analysis. That is, to de-
termine the system’s performance at time t
0
, the values
corresponding to t
3
, t
2
, t
1
, and t
0
were taken into
account. Therefore, if the same variables are considered
for each moment in time, the number of neurons in the
input layer will be 24. With the changes considered, a
73.9% accuracy was achieved, and the model’s ability to
distinguish between normal and faulty states improved
(Figure 7). In Trial 4, the algorithm’s robustness and its
ability to generalize from the training data were demon-
strated, achieving the best performance (Figure 8). For
Trial 5, an adjustment was made to the data alloca-
tion as follows: 70% for training and 30% for testing, in
order to evaluate whether the algorithm maintains its
performance and to rule out overfitting of the network
(Figure 9).
3 Metrics Calculation
Based on the developed trials, precision, accuracy, and
recall are calculated, considering the values of true pos-
itives (TP), false positives (FP), false negatives (FN),
and true negatives (TN) shown in each of the confusion
matrices from the previous section. Accuracy indicates
the proportion of correct predictions and is defined as
(1):
Fig. 5 Confusion matrix, Trial 1
accuracy =
T P + T N
T P + T N + F P + F N
(1)
Precision shows the proportion of correct positive pre-
dictions. (2):
precision =
T P
T P + F P
(2)
Recall indicates the proportion of actual positives that
have been correctly predicted. (3):
5
Table 2 Configuration of the conducted trials.
Trial Input layer size Hidden layer size Output layer size Training-validation sample split
Trial 1 6 2 2 90 - 10
Trial 2 6 5 2 90 - 10
Trial 3 24 1 2 90 - 10
Trial 4 24 3 2 90 - 10
Trial 5 24 3 2 70 - 30
Fig. 6 Confusion matrix, Trial 2.
Fig. 7 Confusion matrix, Trial 3.
Fig. 8 Confusion matrix, Trial 4.
Fig. 9 Confusion matrix, Trial 5.
6 4 CONCLUSIONS
Fig. 10 Metrics calculated for each trial conducted.
recall =
T P
T P + F N
(3)
Using the values obtained in (see Sect. 2.3) and ac-
cording to (1), (2), and (3), the metrics for each of the
trials are obtained (Fig. 10). The best performance of
the neural network is achieved with the structure pro-
posed in Trial 4. Finally, in Trial 5, this structure is
maintained, but the percentage of samples assigned for
training is set to 70% and for validation to 30%. Un-
der these conditions, precision reaches 98.7%, accuracy
99.1%, and recall 99.5%, indicating that the algorithm
performs well under the proposed scenario and condi-
tions
4 Conclusions
The main contribution of this work is the application of
a neural network for the early detection of faults based
on the analysis of variables from a direct torque con-
trol (DTC) system. Using Simscape in MATLAB, the
simulation environment was configured, and the nec-
essary data for model training was generated. It has
been demonstrated that the developed system can sat-
isfactorily identify normal and fault conditions with an
accuracy exceeding 99%, confirming the effectiveness of
the adopted approach and highlighting the potential of
machine learning to enhance predictive maintenance in
industrial environments.
As shown in the development of this proposal, it is
possible to design a machine learning algorithm that
continuously analyzes motor operation variables with-
out interfering with daily production activities, provid-
ing a basis for future research and practical applications
related to optimizing control systems and reducing op-
erational costs through early fault detection.
Conflict of interest
The authors declare that they have no conflict of inter-
est.
References
1. G. M. M. Fernandez Cabanas Man´es, ecnicas para el
mantenimiento y diagn´ostico de aquinas el´ectricas ro-
tativas. Gran via de les Corts Catalanes, 594 08007
Barcelona: Marcombo, 1998.
2. J. L. Zhe Li, Qian He, “A survey of deep learning-
driven architecture for predictive maintenance,” Engi-
neering Applications of Artificial Intelligence, vol. 133,
2024.
3. M. J. Gupta Suraj, Kumar Akhilesh, “A critical review
on system architecture, techniques, trends and challenges
in intelligent predictive maintenance,” Saftey Science,
vol. 177, 2024.
4. J. Buele, F. A. Chicaiza, M. Le´on, and A. P. anchez,
“Virtual rehabilitation system for fine motor skills us-
ing artificial neural networks,” in IOP Conference Series:
Materials Science and Engineering, vol. 1070, no. 1. IOP
Publishing, 2021, p. 012054.
5. E. Slawi˜nski, F. Rossomando, F. A. Chicaiza, J. Moreno-
Valenzuela, and V. Mut, “Lstm network in bilateral tele-
operation of a skid-steering robot,” Neurocomputing, p.
128248, 2024.
6. R. Dagner, “Machine learning para mejorar la gesti´on de
mantenimiento de aquinas industriales,” Universidad
Cesar Vallejo, 2021.
7. Y. U. Muhammed Fatih Pek¸sen, Ula¸s Yurtsever, “En-
hancing electrical panel anomaly detection for predictive
maintenance with machine learning and iot,” Alexandria
Engineering Journal, vol. 96, pp. 112–123, 2024.
8. G. P. Mostowski Daniel, Jakubczak Krzusztof, “Auto-
mated laser beam characterization using artificial intelli-
gence (ai) for the predictive maintenance of lasers,” Op-
tics and Laser Technology, 2024.
9. k. R. Santoshi Anusha, “Digital transformation technolo-
gies for conveyor belts predictive maintenance: a review,”
Indonesian Journal of Electrical Engineering and Com-
puter Science, pp. 639–646, 2024.
10. Y. D. Tangbin Xia, Yimin Jiang, “Intelligent main-
tenance framework for reconfigurable manufacturing
with deep-learning-based prognostics,” IEEE Internet of
Things Journal, vol. 11, 2024.
11. B. Patrik, “Smart condition monitoring using machine
learning,” SPE Middle East Intelligent Oil and Gas Sym-
posium, 2017.
12. L. R. J. R. C. R. A. Guerrero Cano Manuel, Luque
Sendra Amalia, “Predictive maintence using machine
learning techniques,” Alexandria Engineering Journal,
vol. 96, pp. 112–123, 2024.
13. Mathworks
®
, “Simscape,” la.mathworks.com/
products/simscape.html, 2024, accedido en junio
de 2024.
14. L. S. J. Alfonso, “Deep learning: teor´ıa y aplicaciones,”
Alpha Editorial, vol. 1, pp. 93–95, 2021.
15. Mathworks
®
, “Direct torque control of an induction
motor drive,” https://la.mathworks.com/help/sps/ug/
power-motordrive-IM-DTC-HYST.html, 2024, accedido
en junio de 2024.
7
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Agudelo.
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