• 전기학회논문지P
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• 제60권4호
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• pp.227-235
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• 2011

This paper describes a PMSM control algorithm for realizing a low-cost motor drive system using a general purpose microcontroller. The proposed sensorless algorithm consists of the current observer and the sensorless scheme based on instantaneous reactive power. Also the control board system is not the high-cost DSP(digital signal processor) system but the general purpose microcontroller and it allows to reduce the unit cost of the motor system. However the clock frequency of the proposed microcontroller is one-fifths for the clock frequency of the DSP. In addition, the switching frequency must be selected as the lower frequency because of complex mathematic modeling of the sensorless algorithm. the low switching frequency augments the noise of the motor and might make accurate speed control impossible. Thus this paper proposes the optimization method to supplement the drawback of the general purpose microcontroller and the usefulness of the proposed method is verified through the experiment.

• International Journal of Advanced Culture Technology
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• 제6권3호
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• pp.129-141
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• 2018

As the scope of social expectations and roles in the design field has expanded, the demand for education to cope with changes in the technology environment is increasing in design education. In response to this trend, microcontroller board-type design-prototyping tools have also been introduced into design education, and much educational content is being developed. However, there is the perception that students who are majoring in design without engineering knowledge are still barred from entry. A variety of educational content and tools have been developed to solve these difficulties, although there are several limitations to their practical application. Especially, in the design education courses in universities, the functional expectation level for prototyping is high, but most of the content developed for solving the difficulties has been developed for the lower education levels, and it could be said that a great deal of learning is necessary to solve the problem. In this study, students were asked about microcontroller board utilization and their satisfaction with their design through questionnaires and with the developed microcontroller board development direction via Focus Group Interviews. Based on this, we tested microcontroller boards that eliminate the coding process and which students can use to create and prototype their work as a suggestion to fulfil demand. After using the board, both the usability and improvement of the product were checked. Confirmation of the usefulness of the free- coding-type microcontroller was obtained through this study along with the possibility of responding to various educational demands by applying the application design related to this product.

• Nuclear Engineering and Technology
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• 제54권12호
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• pp.4422-4430
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• 2022

Studying the effects of gamma radiation on the instrumentation and control (I&C) system of a nuclear power plant is critical to the successful and reliable operation of the plant. In the accidental scenario, the adverse environment of ionizing radiation affects the performance of the I&C system and it leads to inaccurate and incomprehensible results. This paper reports the effects of gamma radiation on the AT89C51RD2, a commercial-off-the-shelf 8-bit high-performance flash microcontroller. The microcontroller, selected for the device under test for this study is used in the remote terminal unit for a nuclear power plant. The custom circuits were made to test the microcontroller under different gamma doses using a ⁶⁰Co gamma source in both ex-situ and in-situ modes. The device was exposed to a maximum dose of 1.5 kGy. Under this hostile environment, the performance of the microcontroller was studied in terms of device current and voltage changes. It was observed that the microcontroller device can operate up to a total absorbed dose of approximately 0.6 kGy without any failure or degradation in its performance.

• International Journal of Contents
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• 제14권3호
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• pp.61-68
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• 2018

Unlike in the past, where the expression of the form was given a priority, with the widening of the scopes of the designs, the proportion of design education institution curricula targeting user experience and the application of technology is continually and gradually increasing. Open source microcontroller boards such as Arduino have initiated attracting attention as a countermeasure against these changes. These prototyping tools have many advantages for the diversification of expression and design verification in the design field and therefore have a high likelihood of being introduced into many design education institutes; however, the tools act as high entry barriers for design students who lack engineering knowledge. Although various educational content and tools have been developed to address the issue of barrier, existing solutions remain insufficient as alternatives for the purpose of activation. In this study, we investigated the present state of related education content and conducted a pilot workshop using a prototype microcontroller board with simplified coding. We intend to use the results of this investigation to develop study material for design education. We started by conducting a survey regarding the pre-university education situation. It was observed that engineering education opportunities are insufficient and the problem of mutual application between educations due to course-based education was not realized. We also analyzed the characteristics of simplified training tools using the microcontroller to establish a direction for educational design and conducted a pilot workshop using the microcontroller toolkit with a simplified coding process based on this content. Students who lack a basic knowledge of engineering technology received instruction, and after completing minimum preliminary training, they proceeded to practical exercises that involved utilizing the toolkit. Through this process, we identified the need for a simple-type microcontroller board with low-complexity for use in educating students majoring in design. We also identified some obstacles that serve as barriers to entry of utilizing microcontroller board. Based on these results, we propose several functional requirements and teaching guidelines for prototyping toolkits for design education.

• 한국군사과학기술학회지
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• 제11권6호
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• pp.148-155
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• 2008

We investigated the damage effects of microcontroller devices under high power electromagnetic(HPEM) wave. HPEM wave was radiated from the open-ended standard rectangular waveguide(WR-340) to free space. The influence of different reset-, clock-, data-, and power supply-line lengths has been tested. The susceptibility of the tested microcontroller devices was in general much influenced by clock-, reset-, and power supply-line length, little influenced by data-line length. Further the line length was increased, the malfunction threshold was decreased as expected, because more energy couples to the devices. The surfaces of the destroyed microcontroller devices were removed and the chip conditions were investigated with microscope. The microscopic analysis of the damaged devices showed component and bondwire destructions such as breakthroughs and melting due to thermal effects.

• 센서학회지
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• 제23권1호
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• pp.24-28
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• 2014

A lock-in amplifier was proposed for capacitive sensor applications. This amplifier was based on a general-purpose microcontroller and had only a charge amplifier as analog circuits. All the other functions of lock-in amplifier except for the charge amplifier were implemented with firmware and the internal resources of the microcontroller. A rectangular signal, generated by the microcontroller, was used in a sensor-driving signal instead of a conventional sinusoidal signal. This makes it possible that the phase comparison circuit in the lockin amplifier is made with analog-to-digital converter, a timer and an interrupt controller. Using the oversampling method and the rectangular driving signal, we can make it easy to implement the peak detection function with software and sample the peak-to-peak signal at charge amplifier output. A charge amplifier was proposed to cancel out the base capacitance existing in capacitive sensors structurally. The experimental results show that the lock-in amplifier operating in the supply voltage of 3.0 V cancels out the base capacitance and has good linearity.

• 전기학회논문지
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• 제58권5호
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• pp.976-981
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• 2009

This paper proposed optimal design and microcontroller driver for driving the thin-type ultrasonic motor. To find the optimal size of the stator, motions of the motor were simulated using ATILA by changing length, width and thickness of the ceramics. Two sinusoidal waves which have 90 degree phase difference were needed for driving the thin-type motor. The thin-type ultrasonic motor driver was composed of microcontroller(Atmega128), push-pull inverter, encoder and AD-converter. Microcontroller generates four square waves which have variable frequency and 25[%] duty ratio in $20{\sim}150$[kHz]. The output signals of microcontroller were converted to sine wave and cosine wave by push-pull inverter and were applied to the thin-type ultrasonic motor. The encoder and AD-converter were used for maintaining speed of the thin-type ultrasonic motor. The AD-converter controlled DC voltage of inverter in accordance with output signal of encoder. Using the driver, characteristics of the motor as speed and torque were measured.

• 한국소프트웨어감정평가학회 논문지
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• 제17권1호
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• pp.93-99
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• 2021

최근 COVID-19 등의 영향으로 온라인 교육에 대한 요구가 급증하고 있다. 공학계열의 온라인 교육에 있어 가장 큰 어려움 중의 하나는 실험관련 교과목을 어떻게 효율적으로 온라인상에서 수행할 수 있느냐는 것이다. 본 연구에서는 전기전자정보통신 분야 교육에서 필수적으로 요구되는 마이크로컨트롤러 응용 학습을 위해 사용할 수 있는 가상실험 시스템 구축을 위해 반드시 필요한 마이크로컨트롤러 기능 모델링에 대해 기술하고, 자바언어로 구현하여 가상 실험에 적용함으로써 그 유용성을 검증하였다.

• 전기학회논문지
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• 제57권12호
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• pp.2263-2268
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• 2008

We investigated the malfunction and destruction characteristics of microcontroller devices under high power electromagnetic(HPEM) wave by magnetron. HPEM was rated at a microwave output of 0 to 1,000 W, at a frequency of 2,450${\pm}$50 MHz and was radiated from the open-ended standard rectangular waveguide(WR-340) to free space. The influence of different reset-, clock-, data-, and power supply-line lengths has been tested. The variation of the line length was done with flat cables. The susceptibility of the tested microcontroller devices was in general much influenced by clock-, reset-, and power supply-line length, little influenced by data-line length. Further the line length was increased, the malfunction threshold was decreased as expected, because more energy couples to the devices. The surfaces of the destroyed microcontroller devices were removed and the chip conditions were investigated with microscope. The microscopic analysis of the damaged devices showed component and bondwire destructions such as breakthroughs and melting due to thermal effects. The obtained results are expected to provide fundamental data for interpreting the combined mechanism of microcontroller devices in an intentional microwave environment.

• 한국산업정보학회논문지
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• 제27권6호
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• pp.51-58
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• 2022

마이크로 컨트로러(MCU)는 Advanced Microcontroller Bus Architecture (AMBA)에 다양한 모듈을 연결시켜 프로그래밍을 통해 각 모듈들을 적절히 활용하도록 설계되어있다. 범용 MCU는 많이 사용되는 모듈들을 미리 설계 및 제작하여 소비자가 적절히 사용하도록 제작되어 판매되고 있다. 하지만, 특정 산업군에서는 MCU를 직접 설계하여 분야에 적합한 모듈 종류 및 수량을 사용자가 희망하는대로 설계하여 활용할 필요가 있다. 하지만, 대부분의 소비자는 MCU를 직접 설계하기에는 상당한 진입장벽이 있다. 본 연구에서는 MCU 교육 및 연구단계에서 손쉽게 MCU를 설계할 수 있는 개발 가이드라인을 제공한다. 먼저, AMBA를 활용하기위해 요구되는 필수 모듈을 소개하고, 해당 모듈이 AMBA 및 인터럽트 동작을 통해 제대로 동작하는지 검증하고, 최종적으로는 온칩으로 설계하여 사용될 수 있도록 방법론을 제공한다.