• Journal of Institute of Control, Robotics and Systems
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• v.7 no.2
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• pp.117-124
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• 2001

In a SRM drive, the on/off angles of each phase switch should be accurately controlled in order to control to torque and speed in a stable way, The accuracy of the switching angles is dependent upon the resolution of the encoder and the sampling period of the microprocessor. However, as the speed increase, the amount of the switching angle deviation from the preset values is also increased by the sampling period of the microprocessor. Therefore, a low cost encoder suitable for a practical and stable SRM drive is proposed and the control algorithm to provide the switching signals using the simple digital logic circuit is also presented in this paper. It is verified from the experiments that the proposed encoder and logic controller can be a powerful candidate a the practical low cost SRM drive.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1984.10a
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• pp.98-100
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• 1984

This paper design the emulator of the 8 bit microprocessor based on the z-80. The system control the debugging relation ship concerning the hardware and the software between the target system and the host system. It is purpose that emulator manufacture low cost.

• Proceedings of the KIPE Conference
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• 2007.07a
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• pp.7-9
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• 2007

If used to drive the minicar, the BLDC Motor has advantages of weightless, efficient, small-size and credibleness. In this paper at first the position detecting method for BLDC was introduced, secondly the simulation of control algorithm was done and at last the prototype controller based one chip processor MEGA48 was fabricated. The controller proposed has characteristic of cheap cost, reliable performance and totally meeting demands of minicar control.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.190-198
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• 2002

In switched reluctance motor(SRM) drive, it is necessary to synchronize the stator phase excitation with the rotor position. Therefore the rotor position information is an essential. Usually optical encoders or resolvers are used to provide the rotor position information. These sensors are expensive and are not suitable for high speed operation. In general, the accuracy of the switching angles is dependent upon the resolution of the encoder and the sampling period of the microprocessor. But the region of high speed, switching angles are fluctuated back and forth from the preset values, witch are cause by the sampling period of the microprocessor. Therefore, the low cost linear encoder suitable for the practical and stable SRM drive is proposed and the control algorithm to provide the switching signals using the simple digital logic circuit is also presented in this paper It is verified from the experiments that the proposed encoder and logic controller can be a powerful candidate for the practical low cost SRM drive.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.63 no.2
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• pp.69-73
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• 2014

In this paper, remote control and surveillance monitoring system of HID street-lamp using low-cost type of Zigbee communication module was developed. A plurality of capacitors with different capacity are attached to magnetic ballast for HID lamps. Changes in the amount of illumination can be adjusted by the changes in capacity so that the electric energy can be reduced. In Zigbee communication module, a ATmega128L microprocessor is used and in main CPU, ARM9 Core is used to construct a low-cost smart system. In surveillance monitoring systems, the system was configured to remote monitoring of presence of error in the lamp abnormalities, the status of leakage current and abnormalities of ballasts and capacitors and the validity of the proposed empirical experiment was confirmed.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.12
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• pp.61-67
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• 2000

In switched reluctance motor(SRM) drive, it is necessary to synchronize the stator phase excitation with the rotor position. Therefore the rotor position information is an essential. Usually optical encoders or resolvers are used to provide the rotor position information. These sensors are expensive and are not suitable for high speed operation. In general, the accuracy of the switching angle is dependent upon the resolution of the encoder and the sampling period of the microprocessor. But the region of high speed, switching angles are fluctuated back and forth from the preset values, which are cause by the sampling period of the microprocessor. Therefore, the low cost linear encoder suitable for the practical and stable SRM drive is proposed and the control algorithm to provide the switching signals using the simple digital logic circuit is also presented in this paper. It is verified from the experiments that the proposed encoder and logic controller can be a powerful candidate for the practical low cost SRM drive.

• International Journal of Aeronautical and Space Sciences
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• v.17 no.2
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• pp.222-231
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• 2016

This paper proposes a new method achieving computationally efficient attitude reference system for low cost strapdown sensors and microprocessor platform. The main idea in this method is to define and compare velocity differential vectors, geometrically computed from INS and GPS data with different update rate, for generating attitude error measurements which is further used for filter construction. A quaternion based Kalman filter configuration is applied for the attitude estimation with the adapted measurement model of differential vector comparison. Linearized model for Extended Kalman Filter and low pass filtered characteristics of measurement greatly extend the affordability of the proposed algorithm to the field of simple low cost embedded systems. For performance verification, experiment are done employing a practical low cost MEMS IMU and GPS receiver specification. Performance comparison with a high grade navigation system demonstrated good estimation result.

• Journal of Sensor Science and Technology
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• v.23 no.1
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• pp.58-65
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• 2014

We developed a low-cost automatic diagnosis system for water quality in cooling towers to measure the concentrations of key ingredients such as $Ca^{2+}$, $Cl^-$, $PO{_4}^{3-}$, and $Fe^{2+}$. $Ca^{2+}$, and $Cl^-$ are the main factors that cause the generation of scale, corrosion, and sludge in water pipes. $PO{_4}^{3-}$ prevents corrosion, sludge and scale by inhibiting the ions (i.e., $Ca^{2+}$, $Cl^-$) from sticking to the pipes. $Fe^{2+}$ is an indicator of pipe corrosion. The proposed system consists of a microprocessor, a specimen container and heater, a precision pump, relays and valves, LED optical sources, and photo detectors. It automatically collects water samples and carries out pretreatment for determining the concentration of each chemical, and then estimates the concentration of each ion using low-cost LED optical sources and detectors. Experimental results showed that the accuracy of the proposed system is sufficiently high for water quality diagnosis and management of cooling towers, demonstrating the possibility of the proposed system's wide usage in real environments.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.7
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• pp.1289-1295
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• 2007

In this paper, we implemented high-performance concurrent control system which manages whole RF systems with digital type and communicates with remote station on both wire and wireless networking. It consists of FPGA (Field Programmable Gate Array) part which controls forward/reverse LPA (Linear Power Amplifier), forward/reverse LNA (Low Noise Amplifier), channel cut wire/wireless TCP/IP, etc, master microprocessor (AVR), which manages the whole control system, Slave microprocessor which communicates SA (Spectrum Analyzer) and observes frequency spectrum of each channel with the resolution of 5KHz, 10 channel card microprocessor which independently observes each channel card and sets frequency synthesizer in channel cut and other peripherals and logics. The whole system is divided to two parts of H/W (hardware) and S/W (software) considering operational efficiency and concurrency, and implementation and cost. H/W consists of FPGA and microprocessor. We expected the optimized operation through H/W and SW co-design and hybrid H/W architecture.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.12
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• pp.1045-1050
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• 2005

This paper describes a design experience of a low-cost 6 DOF spatial tracker system where relative low accuracy and relatively long ranges, wireless communication will be achieved by means of low cost accelerometers and gyros with contemporary microprocessor. However, there are two key problems; one is the bias drift problem and the other is that single or double integration of acceleration signal suffers not only from noise but also from nonlinear effects caused by gravity. To be specific, beginning and stopping of hand motions needs to be accurately detected to initiate and terminate integration process to get position and pose of the hand from accelerometer and gyro signals, since errors due to noise and/or hand-shaking motions accumulated by integration processes. Several experimental results are shown to validate our proposed algorithms.