• The Transactions of the Korean Institute of Power Electronics
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• v.15 no.3
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• pp.188-198
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• 2010

Recently, as the demand of the environmental-friendly energy storage system such as an electric double-layer condenser increases, that of the bidirectional charger/discharger for the systems also increases. However, when charging/discharging mode-change occurs, the charger/discharger employing a bi-directional DC-DC converter with a commercialized analog controller has a complex circuit scheme, and a poor transient response. On the other hand, if a single digital controller is used for the bi-directional mode, the system performances can be improved by application of an advanced power-processing algorithm. In the paper, an environmental-friendly power storage systems including an Electric Double Layer Capacitor(EDLC) banks were developed with a bi-directional buck-boost converter and a digital signal processor (TMS320F28335). A simulation test-bed was realized and tested by MATLAB Simulink, and the hardware experiment was performed which shows that the dynamic response was improved such as the simulation results.

• Journal of the Korean Institute of Intelligent Systems
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• v.12 no.1
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• pp.19-26
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• 2002

There are some difficulties to construct a sensory-motor controller for an autonomous mobile robot such as coordinating the mechanics and control system parts of the robot, and managing interaction with external environments. In previous research, we evolve the CAM-Brain, neural networks based on cellular automata, to control an autonomous mobile robot. In this paper, we propose the method of combining multi-modules evolved to do simple behavior in order to making more sophisticated behaviors because the controller composed of one neural network module is difficult to make complex behaviors. In experimental results, we can get the controller adapting to more complex environments by combining CAM-Brain modules evolved to do simple behavior by rule-based approach.

• The Journal of the Convergence on Culture Technology
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• v.9 no.3
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• pp.677-682
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• 2023

A large number of motors and sensors are used to drive a humanoid robot. In order to solve the wiring problem that occurs when connecting multiple actuators, a controller based on a communication network has been used, and CAN, which is advantageous in terms of cost and a highly reliable communication protocol, was mainly used. In terms of the structure of the controller, a torque control type structure that is easy to implement an advanced algorithm into the upper controller is preferred. In this case, the low communication bandwidth of CAN becomes a problem, and in order to obtain sufficient communication bandwidth, a communication network is configured by separating into a plurality of CAN networks. In this study, a stability analysis on transmission time delay is performed for a multi-motor control system in which high-speed FlexRay and low-speed CAN communication networks are hierarchically connected in order to obtain a high communication bandwidth, and sensor information and driving signals are delivered within the allowed transmission time. The proposed hierarchical network-based control system is expected to improve control performance because it can implement multiple motor control systems with a single network.

• Journal of the Korea Computer Industry Society
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• v.7 no.4
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• pp.321-328
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• 2006

This thesis is focused on the design and implement the remote control and monitoring system for the effective management of communication equipments on the distributed environment. As a result of this paper, RCMS can effective manage communication base stations by the monitoring and transmission.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.3
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• pp.555-562
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• 2008

In this paper we proposed a practical low-power design technique using clock-gating in RTL. An efficient low-power methodology is that a high-level designer analyzes a generic system and designs a controller for clock-gating. Also the desirable flow is to derive clock-gating in normal synthesis process by synthesis tool than to insert directly gate to clock line. If low-power is considered in coding process, clock is gated in coding process. If not considered, after analyzing entire operation. clock is Bated in periods of holding data. After analyzing operation for clock-gating, a controller was designed for it, and then a low-power circuit was generated by synthesis tool. From result, we identified that the consumed power of register decreased from 922mW to 543mW, that is the decrease rate is 42%. In case of synthesizing the test circuit using synthesizer of Power Theater, it decreased from 322mW to 208mW (36.5% decrease).

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.3
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• pp.315-321
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• 2014

This paper presents an integrated chassis control system with fail safety using optimum yaw moment distribution for a vehicle with steer-by-wire and brake-by-wire devices. The proposed system has two-level structure: upper- and lower-level controllers. In the upper-level controller, the control yaw moment is computed with sliding mode control theory. In the lower-level controller, the control yaw moment is distributed into the tire forces of active front steering(AFS) and electronic stability control(ESC) with the weighted pseudo-inverse based control allocation(WPCA) method. By setting the variable weights in WPCA, it is possible to take the sensor/actuator failure into account. In this framework, it is necessary to optimize the variables weights in order to enhance the yaw moment distribution. For this purpose, simulation-based tuning is proposed. To show the effectiveness of the proposed method, simulations are conducted on a vehicle simulation package, CarSim.

• Proceedings of the KIPE Conference
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• 2016.07a
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• pp.525-526
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• 2016

전기자동차 (EV)에서 구동용 모터의 토크 제어를 위한 인버터에는 제어 연산 및 고장 진단 기능을 수행하기 위한 MCU가 있으며, MCU는 상위 제어기 차량 제어 유닛 (VCU)에게 현재 모터 및 인버터의 상태를 주기적으로 전달하고, 현재 차량 주행에 적합한 토크 지령을 받아 토크 제어를 수행하게 된다. 이를 위해 MCU는 전류, 전압 및 위치 센서의 값을 읽어 제어를 수행하게 되며, 제어의 결과 값으로 pulse width modulation (PWM)을 생성하여 이를 통해 모터에 전압을 공급하게 된다. 즉 차량의 구동에 있어 PWM 신호는 가장 중요한 부분이다. 하지만 생산 불량 또는 진동에 의한 납땜 불량 또는 MCU 전원 고장 등으로 MCU에 고장이 발생하게 되면 이상 PWM을 생성하게 되고 정상적인 토크 제어가 불가능해진다. 이때 안전하게 EV를 정지 시키는 알고리즘이 필요하게 되며, 이를 수행 할 supervisor control unit (SCU)가 인버터 컨트롤 보드에 추가되어야 한다. 본 논문에서는 고속으로 주행하던 차량에서 메인 MCU가 고장 날 경우에 안전하게 EV를 정차시키는 방법에 대해 다루었다.

• Proceedings of the KIPE Conference
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• 2020.08a
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• pp.463-464
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• 2020

전세계적으로 신재생에너지 연구가 개발되면서 DC 마이크로 그리드가 빠르게 확산되고 있다. DC 마이크로 그리드에는 ESS가 필수적으로 적용되는데, ESS 충방전을 위해 양방향 및 절연 기능이 포함한 토폴로지가 적용되어야 한다. 최근에는 절연형 양방향 컨버터로 듀얼 액티브 브리지 토폴로지가 제어에 대한 연구와 함께 많이 적용되어지고 있다. DC 마이크로 그리드에는 여러 DC-DC 컨버터로 구성되어 있어 상위 제어기에서 전류지령 값을 통해 전류제어로 운영된다. 본 논문에서는 가상 직접 전력 제어를 이용하여 빠른 응답을 구현하는 전류제어를 제안하였다. 검증 방법으로는 시뮬레이션을 통해 검증 하였다.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.8
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• pp.45-52
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• 2017

This paper presents a high-performance software-hardware dehazing system based on a dedicated hardware accelerator for the haze removal. In the proposed system, the dedicated hardware accelerator performs the dark-channel-prior-based dehazing process, and the software performs the other control processes. For this purpose, the dehazing process is realized as an OpenCL kernel by finding the inherent parallelism in the algorithm and is synthesized into a hardware by employing a high-level-synthesis technique. The proposed system executes the dehazing process much faster than the previous software-only dehazing system: the performance improvement is up to 96.3% in terms of the execution time.

• Journal of KIISE:Computing Practices and Letters
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• v.11 no.1
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• pp.92-99
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• 2005

In this paper, we present a high-level design methodology applied on a network system-on-a-chip(SOC) using SystemC. The main target of our approach is to get optimum performance parameters for high network address translation(NAT) throughput. The Fast Ethernet media access controller(MAC) and its direct memory access(DMA) controller are modeled with SystemC in transaction level. They are calibrated through the cycle-based measurement of the operation of the real Verilog register transfer language(RTL). The NAT throughput of the model is within $\pm$10% error compared to the output of the real evaluation board. Simulation speed of the model is more than 100 times laster than the RTL. The validated models are used for intensive architecture exploration to find the performance bottleneck in the NAT router.