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Development of Remote Laboratory for Feedback Control System Class
(2021-01-01)
Jitthammapirom, Piya
;
Chayratsami, Pornpimon
;
Somha, Worawit
This research presents a low cost web-based remote laboratory system for a feedback control system class. The system is created by an inexpensive single-board computer (Raspberry Pi 3B+) as laboratory server, an edge of extinct Lego Mindstorms set as a controlled plant, and an IP camera system. The laboratory server based on Ubuntu, which is a free and open-source software and the web application is written with JavaScript based on a MEAN stack platform. The proposed laboratory is used for verifying a design project of the angle control system using Proportional-Integral-Derivative (PID) control.
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Hysteresis Modeling of Lithium-Silicon Half Cells Using Prandtl-Ishlinskii Model
(2020-10-09)
Chayratsami, Pornpimon
;
Plett, Gregory L.
State-of-charge (SOC)-estimation accuracy is critical to battery management in electric-vehicle (EV) applications. SOC-estimation error can arise from unmodeled nonlinear battery hysteresis; so to enhance performance, it is necessary to model hysteresis voltage. This paper presents results from applying three kinds of Prandtl-Ishlinskii (PI) model to a Li//Si half cell: classical PI (CPI), generalized PI (GPI), and modified generalized PI (mGPI). The performance comparison among these models and also comparisons to the Preisach and Krasnosel'skii-Pokrovskii (KP) models are made. It is found that the mGPI provides best performance among all models having the same level of calculation.
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Development of Angle Control System Application Using Python
(2019-11-01)
Phutthanukun, Warinda
;
Chayratsami, Pornpimon
This paper presents an educational tool for feedback control system class. An application is created using Python for simulating the DC motor angle control. The control method used in the application is Proportional-Integral-Derivative (PID) controller. Inputs of the application consist of motor parameters obtained by theoretically modeling the system, the PID control constant gains, and a desired angle. Outputs are the displays of a root locus plot, a step response plot, and an animation of the motor movement. The results of using the application in the feedback control class indicate that the application helps enhancing student's understanding in the PID control concept and also helps students to visualize the system behavior practically.
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Hysteresis Modeling of Lithium-Silicon Half Cells Using Krasnosel'skii-Pokrovskii Model
(2019-08-01)
Chayratsami, Pornpimon
;
Plett, Gregory L.
Unmodeled battery-cell voltage hysteresis can cause state-of-charge (SOC) estimation error in a battery-management system (BMS) of an EV system. To improve BMS performance, hysteresis voltage must be modeled correctly. This paper presents the use of linear least-squares identification of a Krasnosel'skii-Pokrovskii (KP) model to estimate hysteresis for a Li//Si half cell. We find that the KP model provides good estimates and has lower root-mean-squared estimation error than a classical discrete Preisach model with the same degree of discretization.
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The optimum ring ratio of 16-APSK in LTE uplink over nonlinear system
(2014-01-01)
Chayratsami, Pornpimon
;
Thuaykaew, Sorapong
Single Carrier Frequency Division Multiple Access (SC-FDMA) has been selected for use in the Long Term Evolution (LTE) uplink due to its lower Peak-to-Average Power Ratio (PAPR) relative to OFDMA The resultant lower PAPR results in fewer excursions into the amplifier's nonlinear region, where signal distortion can occur and results in degraded bit error rate (BER). The SC-FDMA scheme normally applies 16-ary Quadrature Amplitude Modulation (16-QAM), but amplitude phase shift keying (APSK) modulation has a lower PAPR than does 16-QAM, resulting in improved BER This paper investigates the constellation ring ratio of the 16-APSK modulation scheme and its effects on BER through its effects on the PAPR. Simulation results are used to conclude that a ring ratio that ranges from 2.5 to 3.5 delivers the best results and provides BER and PAPR improvement. © 2014 Global IT Research Institute (GIRI).
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MATLAB GUI for digital communication system with tone jamming
(2013-12-01)
Mathumisaranon, Thanakorn
;
Chayratsami, Pornpimon
This paper presents an educational tool for teaching in the signals and systems and related courses using the MATLAB Graphical User Interface (GUIs). The proposed GUI module is a simulation of the baseband digital communication system. It demonstrates the transmission of the Binary Phase Shift Keying signal over an AWGN channel with a tone jamming interference and the reduction of the jamming effect using a digital notch filter at the receiver. The output response can be selected to illustrate the differences of the signal corresponding to each section of the communication system. These GUls are thoroughly explained in the paper. © 2013 IEEE.
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Supplementary laboratory in digital circuit and logic design course for pre-service vocational teacher in Thailand
(2013-08-07)
Chayratsami, Pornpimon
This paper provides an evaluation of a teaching method using a supplementary laboratory, that utilizes 3 types of laboratory setups to increase the understanding and hands-on skill in a digital circuit and logic design class for pre-service vocational teacher in Thailand. The laboratories include building a digital circuit using logic blocks, doing a computer simulation, and using a programmable logic device (PLD). The effectiveness of the teaching method is evaluated based on students' feedbacks, backgrounds, opinions, and scores. The tools, used in this research, are a set of lab sheets, a computer simulation program called 'Digital Works', and a portable equipment box. After two consecutive years of teaching and using the supplementary laboratory in the digital circuit and logic design class, the students have the same opinions that the laboratory helps them to understand the theories, they will be able to apply the knowledge to the related advance courses, and they agree that all 3 parts of the laboratory are necessary and encourage them to have more hands-on skill. In addition, students' scores show that the students have better grades in average by using the supplementary laboratory. © 2013 IEEE.
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Combined discrete cosine transform and two-piecewise companding transform for PAPR reduction in OFDM signals
(2013-01-01)
Thititummajariya, Wisan
;
Chayratsami, Pornpimon
The high peak-to-average power ratio (PAPR) is one major drawback of orthogonal frequency division multiplexing (OFDM) systems. In this paper, a new companding technique is proposed by using the combination of the discrete cosine transform (DCT) and two-piecewise companding (TPWC) transform. Computer simulation results show that the proposed scheme offers better PAPR reduction and also improve bit error rate (BER) and power spectrum density (PSD) performances compared with the ordinary companding method. © 2013 IEEE.
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Design of combinational logic training system using FPGA
(2010-12-01)
Sothong, Sujittra
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Chayratsami, Pornpimon
This paper describes a design of a training system for a combinational logic design course. The goals of this design are to reduce a cost of the system and to lower the lost and damage of TTL elements used in a digital laboratory currently. The system uses a Field Programmable Gate Array (FPGA) as a processor containing basic logic gates, and uses a microcontroller as a gate selector. The training system consists of a system unit base, 17 basic logic gate models, and 10 lab sheets. The system is evaluated in terms of quality and using suitability of the system by experts and instructors who work with technical schools in Thailand and have been involving and teaching a combinational logic design course for at least 5 years. The results show that the system is rated to have a very good quality and is suitable for being used as a training system in a combinational logic course with inexpensive cost. © 2010 IEEE.

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