• Journal of IKEEE
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• v.23 no.3
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• pp.1068-1076
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• 2019

Most of the electronics we use today have built-in microcontrollers, which are called embedded systems. In such a small environment, responsiveness is very important for the microcontroller. In this paper, the basic input/output control, timer/counter interrupt operation principle, and understanding of the microcontroller are described. Program logic is proposed to improve throughput and latency by controlling characteristics of service routine and program execution order. The hardware simulations in this paper were verified using ATmega128 and PIC16F877A from Atmel and Microchip.

• Journal of the Korean Society of Propulsion Engineers
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• v.9 no.4
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• pp.96-103
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• 2005

The main purpose of launch vehicle is to insert satellite into a target orbit safely and correctly. To accomplish the main purpose of launch vehicle, the inserting velocity, inserting angle, and final mass of launch vehicle should be within the allowable range. In general, such requirements are satisfied with applying TCS(Thrust Control System) and TDS(Tank Depletion System), which manage thrust and mixture ratio by controlling propellant flow rate with thrust and mixture ratio control valves. In this study, the control characteristics of thrust and mixture ratio control valve were examined by PID control logic for stable operation of liquid-Propellant rocket engine at on-dosing point. The analysis on the control characteristics of control valves was done with AMESim code and the results from control valve test facility at KARI.

• Journal of KIISE:Software and Applications
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• v.35 no.3
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• pp.149-161
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• 2008

As Programmable Logic Controllers(PLCs) are frequently used to implement real-time safety critical software, testing of PLC software is getting more important. We propose a structural testing technique on Function Block Diagram(FBD) which is one of the PLC programming languages. In order to test FBD networks, we define templates for function blocks including timer function blocks and propose an algorithm based on the templates to transform a unit FBD into a flowgraph. We generate test cases by applying existing testing techniques to the generated flowgraph. While the existing FBD testing technique do not consider infernal structure of FBD to generate test cases and can be applied only to FBD from which the specific intermediate model can be generated, this approach has advantages of systematic test case generation considering infernal structure of FBD and applicability to any FBD without regard to its intermediate format. Especially, the proposed method enables FBD networks including timer function blocks to be tested thoroughly. To demonstrate the effectiveness of the proposed method, we use trip logic of bistable processor of digital nuclear power plant protection systems which is being developed in Korea.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.7 no.3
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• pp.27-33
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• 1993

This paper presents the &tal controller for driving high frequency voltage fed PWM inverter that carrier frequency is over 2OkHz.We analyzed the conventional PWM to select a proper PWM pattern. as the result, obtained PWM pattern of the controller in which asynchronus staircase sinusoidal waveform is used as reference signal, and variable carrier ratio method was used for PWM control. The PWM controller is designed by fully digital method. Especially, Thk proposed controller is consisted of 8 bit one-chip microprocessor and digital logic. the former is for arithmetic and data processing, and the latter is for PWM pattern synthesis. Therefore, The responsibility and controllability is improved. Also, Data processing capability is improved using proper program to output modulation index with 9 bits. Circuits configuration of digital controller are made up of one chip 8051 and EPLD, and its controllability is tested by operating voltage fed inverter. Harmonics and current waveform is evaluated and analyzed for the voltage fed inverter system.

• Proceedings of the KIEE Conference
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• 1997.07c
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• pp.948-950
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• 1997

This paper presents a basic interposing logic program to control nuclear power plant. In this paper we select a target control loop among the whole interposing modules, develop logic algorithm and functional software to compose target control loop. After that we carry out V&V(Verification and Validation) into the developed logic program to improve quality and reliability.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.4
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• pp.1555-1560
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• 2013

The Column type Motor Driven Power Steering(CMDPS) systems are generally equipped among passenger vehicles ensuring better vehicle safety and fuel economy. In general to analyze systems and to develop a controller a full vehicle model from CarSim developed by Mechanical Simulation Incorporation interacting with MDPS control algorithm from Matlab Simulink was concurrently simulated. This paper describes the development of concurrent simulation technique in detail for analyzing Matlab Simulink MDPS control system with a dynamic vehicle system because the specific method has not been revealed in detail. The steering wheel angle input was evaluated and well compared with proving ground experimental data. The comparisons from concurrent simulation show an effective way to develop and validate the control algorithm. This concurrent simulation capability will be efficiently used for CMDPS performance evaluation and logic tuning as well as for vehicle handling performance.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2006.05a
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• pp.119-123
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• 2006

본 논문에서는 마이크로프로세서의 기능을 수행하는 데 필수적이며 사용빈도가 높은 총 64개의 명령어를 정의한 후 이를 처리할 데이터패스를 구성해 스테이트 머쉰으로 제어하는 방식으로 실용적 8비트 마이크로프로세서를 VHDL로 설계를 하고 FPGA로 구현했다. 통상 마이크로프로세서 관련 논문에서는 기능적 시뮬레이션까지만 했거나, 인터럽트 기능이 없든지, 하드웨어로 구현을 하지 않았거나, 또는 개발 관련 내용이 자세히 제시되지 않았었다. 본 논문에서는 데이터 이동, 논리, 가산 연산뿐만 아니라 분기, 점프 연산도 실행할 수 있도록 해 연산 및 제어용도에 적합하도록 하였고, 스택, 외부 인터럽트 기능까지도 지원하도록 해 그 자체로서 완전한 실용적 마이크로프로세서가 되도록 하였다. 또한 프로그램 ROM까지도 칩 안에 넣어 전체 마이크로프로세서를 단일 칩으로 구현하였다. 타이밍 시뮬레이션으로 검증 후 제작 과정을 통해, 설계된 마이크로프로세서가 정상적으로 동작함을 확인하였다. Altera MAX+.PLUS II 통합개발환경 하에서 EP1K50TC144-3 FPGA 칩으로 구현을 하였고 최대 동작주파수는 9.39MHz까지 가능했고 사용한 로직 엘리먼트의 개수는 2813개로서 논리 사용률은 97%이었다.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.5
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• pp.833-840
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• 2022

The precision of automation equipment and motors in factories is required, and global motor market has increased significantly. However, domestic motor technology lags behind foreign technology. In this thesis, the precision stability and efficiency were compared with a linear algorithm by applying a non-linear algorithm to a PLC servo motor and an Arduino step motor in order to improve the technology of the motor. The nonlinear algorithm was able to shorten the same driving reference time because the maximum speed of the motor was faster than the linear algorithm, and it was confirmed that the precision was improved due to the low curvature.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.2
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• pp.166-171
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• 2015

This paper shows the design of operational flight program(OFP) using model-based design(MBD) method which is used in various engineering fields to reduce time and flight risks for development. The verification of OFP for DO-178C guidelines carry out by a model advisor function of simulink. The flight control logic on simulink is converted into C-language by auto code generation tool from, then it is implemented on 32bit digital signal processor(DSP). The verifications of flight control algorithm on various weather conditions are performed by the HILS system with Flight simulator program, X-plane.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.6
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• pp.1295-1302
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• 2021

As the market size of 3D printers increases, the precision of the printout and the speed of operation by the motor are very important issues. In this parer, G-code of each output was generated using a CURA program to compare whether the output of the PLC equipment is the same as that of the Arduino CNC. And after conversion to NC File, a pen was attached to each device to output a result to A4 paper. As a result, the output time was measured to be 1m 39s for PLC equipment and 2m 5s for Arduino CNC. In addition, it was confirmed that the 2D output was equally from the two equipments.