• 대한임베디드공학회논문지
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• 제12권2호
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• pp.89-96
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• 2017

We develop an embedded system to measure various sensor data, control multiple motors, and communicate with mobile devices for system managements. Choosing TI AM3359 microprocessor featuring high processing performance, low power consumption, and various I/O device support, we design and build the embedded system hardware so that it supports multiple global positioning system (GPS) and gyro sensor modules to measure precise position; multiple pulse width modulation (PWM) outputs to control multiple direct current (DC) motors; a Bluetooth module to communicate with mobile devices. Then, we port the boot loader and device drivers to the built circuit board and construct the firmware development environment for the application programming. The performance of the designed and implemented embedded system is demonstrated by real motor control test using GPS and gyro sensor data and control parameters configured by a mobile device.

• 전자통신동향분석
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• 제36권2호
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• pp.56-64
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• 2021

Many computer vision algorithms are computationally expensive and require a lot of computing resources. Recently, owing to machine learning technology and high-performance embedded systems, vision processing applications, such as object detection, face recognition, and visual inspection, are widely used. However, on-devices need to use their resources to handle powerful vision works with low power consumption in heterogeneous environments. Consequently, global manufacturers are trying to lock many developers into their ecosystem, providing integrated low-power chips and dedicated vision libraries. Khronos Group-an international standard organization-has released the OpenVX standard for high-performance/low-power vision processing in heterogeneous on-device systems. This paper describes vision libraries for the embedded systems and presents the OpenVX standard along with related trends for on-device vision system.

• Journal of Computing Science and Engineering
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• 제6권2호
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• pp.79-88
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• 2012

Power continues to be a driving force in central processing units (CPU) design. Most of the advanced breakthroughs in power have been in a realm that is applicable to workstation CPUs. Advanced power management systems will manage temperature, dynamic voltage scaling and dynamic frequency scaling in a CPU. The use of power management systems for microcontrollers and embedded CPUs has been modest, and mostly focuses on very large scale integration (VLSI) level optimizations compared to system level optimizations. In this paper, a dynamic frequency controlling (DFC) technique is introduced, to lay the foundation of a system level power management system for commercial microcontrollers. The DFC technique allows a commercial microcontroller to have minor modifications on both the hardware and software side, to allow the clock frequency to change to save power; results in this study show a 10% savings. By adding an additional layer of software abstraction at the interrupt level, the microcontroller can operate without having knowledge of the current clock frequency, and this can be accomplished without having to use an embedded operating system.

• 융합신호처리학회논문지
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• 제12권3호
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• pp.204-211
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• 2011

주변의 환경을 감시하기 위한 요즘의 임베디드 시스템은 고성능의 실시간 데이터 처리능력 및 넓은 통신 대역폭을 요구할 뿐만 아니라 신호처리를 위한 임베디드 시스템의 적은 소비전력소모를 요구하고 있다. 하지만 휴대용의 성격이 있는 임베디드 시스템에 사용되는 배터리의 용량은 이러한 요구조건을 장기간 만족시킬 수 있을 만큼의 기술로는 아직 발전하지 못하였다. 본 논문에서는 이러한 상황을 극복하기 위해 저에너지로 동작하면서도 사건을 정확하게 탐지하기 위한 새로운 접근법을 제안한다. 설계된 방식은 시스템 주변에서 발생하는 사건을 탐지하기 위해 여러 알고리즘이 계층적으로 연결되어 있는 구조를 가지고 있다. 이러한 계층적 사건 탐지기를 구성하는 다양한 사건 탐지 알고리즘들의 정확도에 대한 확률적 특성 변화 따른 에너지 소모의 특성 변화를 보여주고 이들의 관계를 실험을 통하여 분석적으로 설명한다 뿐만 아니라 사건의 정적, 동적 특성에 따라 높은 사건 탐지 정확도를 유지하면서 저에너지로 동작하기 위한 다른 방식들을 기술한다.

• 대한임베디드공학회논문지
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• 제3권1호
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• pp.34-41
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• 2008

There are many researches to build up ubiquitous environment by the Ubiquitous Sensor Network(USN). These applications, such as home network, health care, natural environment and agricultural areas, are implemented by an embedded system. Their fields are gradually spreading. However the power consumption in its implementation plays an important role on the surrounding environment of the wireless network. In this paper, we design low power processor based sensor node platform for agricultural applications. We also compare its some performance with existing products.

• Journal of Electrical Engineering and Technology
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• 제13권6호
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• pp.2268-2275
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• 2018

This paper presents a high-efficiency low-power permanent magnet (PM) generator for the power supply of the generator exciter. In the conventional generator system, the power for the exciter is fed by the generator output power or an emergency battery for the starting. The proposed low-power PM generator can generate the proper power and voltage to excite the exciter field winding. According to the starting of the generator, the designed PM generator can supply the constant voltage to the Automatic Voltage Regulator (AVR), then it can be used to control of exciter field current for the generator. Because of the designed PM generator which is placed inside the conventional generator system, the emergency battery and Potential Transducer(PT) for AVR can be removed. Thus, the total efficiency can be improved. The proposed generator system is tested in the practical system. And the efficiency characteristic is analyzed.

• 한국항행학회논문지
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• 제21권3호
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• pp.300-305
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• 2017

주행중인 차량내의 컴퓨터 시스템과 통신을 효과적으로 연계해서 언제, 어디서나 각종 데이터의 검색이나 수정 등이 가능하고, 제한적인 플랫폼에서 원활한 동작을 하기 위해 장비를 적절히 제어할 수 있도록 주행차량에 맞게 시스템이 구축되어야 한다. 또한 시스템 엔진 정보 추출을 위해 차량 CAN 통신을 이용하고, 이러한 정보 전송을 위해 ZigBee을 이용하여 데이터를 전송한다. 따라서 차량 CAN을 위해 차량에서 자체 제공되는 OBD-II 프로토콜을 사용하여 차량의 각종 센서 정보 및 O2 센서 값을 이용하여 차량 상태 정보와 배기 가스양을 구하고 ZigBee 메인 컨트롤 시스템에 전송한다. 본 연구는 저전력 차량용 임베디드 시스템으로 전력 사용량을 최대로 줄여서 배터리 부하의 데미지를 최대한으로 감소시키고, ZigBee 통신을 통한 차량의 내부 상태 모니터링을 할 수 있는 시스템을 구현하였다.

• 대한임베디드공학회논문지
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• 제17권6호
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• pp.375-382
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• 2022

This paper proposes a multi-core cooperative computing structure considering the heterogeneous features of automotive embedded on-chip software. The automotive embedded software has the heterogeneous execution flow properties for various hardware drives. Software developed with a homogeneous execution flow without considering these properties will incur inefficient overhead due to core latency and load. The proposed method was evaluated on an target board on which a automotive MCU (micro-controller unit) with built-in multi-cores was mounted. We demonstrate an overhead reduction when software including common embedded system tasks, such as ADC sampling, DSP operations, and communication interfaces, are implemented in a heterogeneous execution flow. When we used the proposed method, embedded software was able to take advantage of idle states that occur between heterogeneous tasks to make efficient use of the resources on the board. As a result of the experiments, the power consumption of the board decreased by 42.11% compared to the baseline. Furthermore, the time required to process the same amount of sampling data was reduced by 27.09%. Experimental results validate the efficiency of the proposed multi-core cooperative heterogeneous embedded software execution technique.

• 정보과학회 컴퓨팅의 실제 논문지
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• 제22권10호
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• pp.513-520
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• 2016

IoT 기기가 대중들에게 보급화 됨에 따라서 임베디드 시스템의 성능뿐만 아니라 소모하는 에너지에 관한 문제가 중요하게 대두되고 있다. 이는 특히 휴대용 임베디드 기기에서 더 중요한데, 휴대용 임베디드 기기들은 각 디바이스들이 가지고 있는 배터리를 통하여 전원을 얻기 때문에 얼마나 효율적으로 잘 사용하는지가 곧 시스템의 사용시간으로 귀결되기 때문이다. 본 논문에서는 임베디드 리눅스 시스템에서의 에너지 소모량을 줄이기 위하여 디바이스의 frequency를 조절해주는 주파수 변경 프레임 워크를 통하여 최고의 에너지 효율을 갖는 메모리 frequency를 찾고, 메모리 총 사용량을 통한 새로운 디바이스 주파수 변경 기법을 제안한다. 실험을 통해 본 논문에서 제안하는 정책은 이전의 정책과 비교하여 최악의 경우에도 나쁜 에너지 효율을 보이지 않으며 최대 18%의 에너지 감소율을 보였다.

• 제어로봇시스템학회논문지
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• 제15권4호
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• pp.420-425
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• 2009

In this paper, image detection and recognition algorithms are studied with respect to embedded carrier system. There are many suggested techniques to detect and recognize objects. But they have the propensity to need much calculation for high hit rate. Advanced and modified method needs to study for embedded systems that low power consumption and real time response are requested. The proposed methods were implemented using Intel(R) Open Source Computer Vision Library provided by Intel Corporation. And they run and tested on embedded system using a ARM920T processor by cross-compiling. They showed 1.6sec response time and 95% hit rate and supported the automated moving carrier system smoothly.