Where ThermoMesh meets ThermoNet: A machine learning based sensor for heat source localization and peak temperature estimation

2019 ◽  
Vol 292 ◽  
pp. 30-38 ◽  
Author(s):  
Jingzhou Zhao ◽  
Feng Ye
Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4655
Author(s):  
Dariusz Czerwinski ◽  
Jakub Gęca ◽  
Krzysztof Kolano

In this article, the authors propose two models for BLDC motor winding temperature estimation using machine learning methods. For the purposes of the research, measurements were made for over 160 h of motor operation, and then, they were preprocessed. The algorithms of linear regression, ElasticNet, stochastic gradient descent regressor, support vector machines, decision trees, and AdaBoost were used for predictive modeling. The ability of the models to generalize was achieved by hyperparameter tuning with the use of cross-validation. The conducted research led to promising results of the winding temperature estimation accuracy. In the case of sensorless temperature prediction (model 1), the mean absolute percentage error MAPE was below 4.5% and the coefficient of determination R2 was above 0.909. In addition, the extension of the model with the temperature measurement on the casing (model 2) allowed reducing the error value to about 1% and increasing R2 to 0.990. The results obtained for the first proposed model show that the overheating protection of the motor can be ensured without direct temperature measurement. In addition, the introduction of a simple casing temperature measurement system allows for an estimation with accuracy suitable for compensating the motor output torque changes related to temperature.


Ultrasonics ◽  
2020 ◽  
Vol 106 ◽  
pp. 106144
Author(s):  
Daniel Frank Hesser ◽  
Georg Karl Kocur ◽  
Bernd Markert

Author(s):  
Bing Li ◽  
Casey Jones ◽  
Vikas Tomar

Abstract This work focuses on the use of linear regression analysis-based machine learning for the prediction of the end of discharge of a commercial prismatic lithium (Li)-ion cell. The cell temperature was recorded during the cycling of Li-ion cells and the relation between the open circuit voltage and cell temperature was used in the development of the linear regression-based machine learning algorithm. The peak temperature was selected as the indicator of battery end of discharge. A battery management system using a pyboard microcontroller was constructed to monitor the temperature of the cell under test, and was also used to control a MOSFET that acted as a switch to disconnect the cell from the circuit. The method used an initial 10 charge and discharge cycles at a rate of 1C as the training data, then another charge and discharge cycle for the testing data. During the test cycling, the discharge was continued beyond the cutoff voltage to initiate an overdischarge while the temperature of the cell was continuously monitored. The experiment was performed on 3 different cells, and the overdischarge for each was secured within 0.1 V of the cutoff voltage. The results of these experiments show that a linear regression-based analysis can be implemented to detect an overdischarge condition of a cell based on the anticipated peak temperature during discharge.


2012 ◽  
Vol 152-154 ◽  
pp. 665-671 ◽  
Author(s):  
Bing Gang Zhang ◽  
Guo Qing Chen ◽  
Wei Guo ◽  
Ming Xiao Shi

A composite heat source model composed of Gaussian surface heat source and rotational paraboloidal body heat source have been established to simulate the temperature field of 20mm TA15 titanium alloy. The results show that the simulated peak temperature of molten pool during surface focus welding is 3200°C, while the simulated peak temperature of molten pool during lower focus is 2700°C, and the whole surface temperature of surface focus welding is higher than that of lower focus welding, while the whole inner temperature of surface focus welding is lower than that of lower focus. The simulated temperature gradient in the direction of depth during surface focus welding is large, but the simulated temperature gradient in the direction of depth during lower focus welding is small. The simulated result was verified by the thermocouple and contrast of weld cross section morphology. The simulated thermal cycle curves are well consistent to the results tested by thermocouple, and there is a good consistency between the simulated molten pool morphology and the real weld morphology, they verify the accuracy of finite element model.


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