• Journal of Power Electronics
• /
• 제19권4호
• /
• pp.881-893
• /
• 2019

This paper proposes a practical sliding-mode controller design for shaping the impedances of cascaded boost-converter power decoupling circuits for reducing the second order harmonic ripple in photovoltaic (PV) current. The cascaded double-boost converter, when used as power decoupling circuit, has some advantages in terms of a high step-up voltage-ratio, a small number of switches and a better efficiency when compared to conventional topologies. From these features, it can be seen that this topology is suitable for residential (PV) rooftop systems. However, a robust controller design capable of rejecting double frequency inverter ripple from passing to the (PV) source is a challenge. The design constraints are related to the principle of the impedance-shaping technique to maximize the output impedance of the input-side boost converter, to block the double frequency PV current ripple component, and to prevent it from passing to the source without degrading the system dynamic responses. The design has a small recovery time in the presence of transients with a low overshoot or undershoot. Moreover, the proposed controller ensures that the ripple component swings freely within a voltage-gap between the (PV) and the DC-link voltages by the small capacitance of the auxiliary DC-link for electrolytic-capacitor elimination. The second boost controls the main DC-link voltage tightly within a satisfactory ripple range. The inverter controller performs maximum power point tracking (MPPT) for the input voltage source using ripple correlation control (RCC). The robustness of the proposed control was verified by varying system parameters under different load conditions. Finally, the proposed controller was verified by simulation and experimental results.

• 전자공학회논문지SC
• /
• 제39권6호
• /
• pp.9-19
• /
• 2002

로봇 제어에서 로봇 핸드가 환경과 접촉하는 상황에서는 위치제어와 힘 제어를 동시에 필요로 한다. 그것을 구현하는 알고리즘 즉, 순응성 제어, 힘 제어, 하이브리드 힘/위치 제어, 임피던스 제어 등의 많은 제어기들이 발표되어 왔으나, 위치/힘 제어가 통합구조로 구성되어 있는 임피던스 제어기가 최근에 많은 연구들을 통하여 가장 효율적인 알고리즘으로 증명되고 있다. 고유 어드미턴스 제어기는 임피던스 제어기가 단순 변형된 것으로 속도 보상기와 힘 보상기로 구성되어 있으며, 로봇 핸드의 속도와 힘제어를 통합 구조로 수행한다. 어드미턴스 제어 방식은 이미 발표된 여러 논문에서 제어구조상의 장점이 확인된 바 있다. 본 논문에서는 고유 어드미턴스 제어기의 게인 파라미터 값을 시스템의 안정성을 확보하면서 결정하는 게인 튜닝 알고리즘을 설계하고, 그것을 실험용으로 제작한 1축 로봇 시스템에 적용하여 임의의 강성을 갖는 환경과의 접촉시에 발생 할 수 있는, 환경의 반작용 힘에 대해서 제어모터가 성공적으로 상호 작용하는 제어성을 실험한다. 또한, 1축 로봇 시스템에 쿨롱 마찰력을 가하여 로봇제어에 방해요소가 되는 외란의 영향에도 불구하고 고유 어드미턴스 제어기가 강인하게 대처함으로서 제어모터가 원하는 위치나 속도로 제어되는 것을 실험결과를 통하여 확인한다.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 19-21 Oct. 1992
• /
• pp.230-235
• /
• 1992

We propose a method of generating data to train a neural network controller. The data can be prepared directly by an iterative learning technique which repeatedly adjusts the control input to improve the tracking quality of the desired trajectory. Instead of storing control input data in memory as in iterative learning control, the neural network stores the mapping between the control input and the desired output. We apply this concept to the trajectory control of a two link robot manipulator with a feedforward neural network controller and a feedback linear controller. Simulation results show good generalization of the neural network controller.

• 한국전자통신학회논문지
• /
• 제4권3호
• /
• pp.236-242
• /
• 2009

2관절 유연한 로봇 팔는 관절 축을 회전할 때 진동이 발생한다. 본 논문에서는 유연한 로봇팔의 진동 동력학은 bernoulli-Euler의 beam이론과 라그란지 방정식을 이용하여 구하였고, $\dot{D}$-2C가 skew symmetric이다는 사실을 사용하여 계산량을 줄이는 단순한 구조의 새로운 제어기를 제안한다. Lyapunov 안정도 이론은 관절을 조절하기 위한 안정한 확정적인 비선형 제어기를 성취하기 위하여 적용된다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1989년도 하계종합학술대회 논문집
• /
• pp.544-547
• /
• 1989

The introduction of resonant link inverters has allowed the use of much higher switching frequencies in induction motor current regulators. The resonant link inverter,however, requries the use of discrete time switching strategies. This type of controller,while giving the best possible performance, is difficult to implement, since motor parameters must be calculated or measured. The delta modulated current regurator (DMCR) has been introduced as a controller without additional state feedback. A discrete pulse modulated current regulator which controls load current is introduced in the paper.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2001년도 ICCAS
• /
• pp.121.2-121
• /
• 2001

Many of today´s robot are required to perform tasks which demand a high level of accuracy in end-effector positioning. Those rigid robots are very inefficient and slow because its have large and heavy links, In an attempt to solve these problems, a robots using flexible beam were created. But the single-link flexible beam is infinite-dimensional system. Many researchers have proposed controlling such a beam an approximated model consisting of a finite a number of models. In this paper, we start by deriving the analytic model for the dynamics of general single-link beam, and a controller is designed for flexible beam with integral type servo system bases of the linear matrix inequality (LM) technique. To the end, simulation results show that a designed controller guarantees affective vibration control the single-link flexible beam.

• Journal of Power Electronics
• /
• 제11권4호
• /
• pp.561-567
• /
• 2011

This paper presents a high-efficiency power conditioning system (PCS) for grid-connected photovoltaic (PV) modules. The proposed PCS consists of a step-up DC-DC converter and a single-phase DC-AC inverter for the grid-connected PV modules. A soft-switching step-up DC-DC converter is proposed to generate a high DC-link voltage from the low PV module voltage with a high-efficiency. A DC-link voltage controller is presented for constant DC-link voltage regulation. A half-bridge inverter is used for the single-phase DC-AC inverter for grid connection. A grid current controller is suggested to supply PV electrical power to the power grid with a unity power factor. Experimental results are obtained from a 180 W grid-connected PV module system using the proposed PCS. The proposed PCS achieves a high power efficiency of 93.0 % with an unity power factor for a 60 Hz / 120 Vrms AC power grid.

• International Journal of Precision Engineering and Manufacturing
• /
• 제6권2호
• /
• pp.61-71
• /
• 2005

The study reported deals with investigating the feasibility of control strategy for a serial rigid link manipulator that applies impulsive torques at the joints. The strategy is illustrated for a planar three rigid link manipulator. An impulse-based concept which uses successive torque impulses on rigid link as the controller for motion correction was introduced. This control strategy was tested over the entire trajectory to demonstrate that the tracking error could be reduced effectively. The best condition for minimizing the tracking error with the least impulse input at each joint is investigated by considering one design and one operating parameter. The first was the damping in the system, and the second was the sampling time during operation. The results show that this approach can provide useful guidance for the design and control of robot manipulators that require minimum impulse feedback for accurate tracking.

• 융합신호처리학회 학술대회논문집
• /
• 한국신호처리시스템학회 2001년도 하계 학술대회 논문집(KISPS SUMMER CONFERENCE 2001
• /
• pp.97-100
• /
• 2001

본 논문은 2자유도 평행링크 로봇의 고속궤적 추적시 링크간의 간섭을 최소화하고 시스템의 불확실성에도 불구하고 설계사양을 만족하는 제어기 설계방법을 소개한다. 이를 위해 ICD기법으로 평행링크 로봇의 채널을 분리하고 QFT를 이용해서 각 채널의 제어기를 설계한다. 마지막으로 시뮬레이션과 실험을 통해 QFT 제어기의 강인성과 우수성을 확인한다.

• Journal of information and communication convergence engineering
• /
• 제17권4호
• /
• pp.255-260
• /
• 2019

A pendubot is a representative example of an underactuated system that has fewer actuators than the degree of freedom of the system. In this study, the characteristics of the pendubot are first reviewed; each part is then designed using Solidworks by dividing the pendubot into three parts: the base frame, first link frame, and second link frame. These three parts are then imported into the Simulink environment via a STEP file format, which is the standard protocol used in data exchange between CAD applications. A 3D model of the pendubot is then constructed using Simscape, and the usefulness of the 3D model is validated by a comparison with a dynamic equation derived using the Lagrangian formulation. A linearized model around an upright equilibrium position is finally obtained, and a sliding mode controller is designed based on the linear quadratic regulator. Simulation results showed that the designed controller effectively maintained upright balance of the pendubot in the presence of disturbance.