• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2005년도 ICCAS
• /
• pp.308-313
• /
• 2005

For a real-time quadruped robot running control, there are many important objectives to consider. In this paper, the running control architecture based on global states, which describe the cyclic target motion, and central pattern is proposed. The main goal of the controller is how the robot can have robustness to an unpredictable environment with reducing calculation burden to generate control inputs. Additional goal is construction of a single framework controller to avoid discontinuities during transition between multi-framework controllers and of a training-free controller. The global state dependent neuron network induces adaptation ability to an environment and makes the training-free controller. The central pattern based approach makes the controller have a single framework, and calculation burden is resolved by extracting dynamic equations from the control loop. In our approach, the model of the quadruped robot is designed using anatomical information of a cat, and simulated in 3D dynamic environment. The simulation results show the proposed single framework controller is robustly performed in an unpredictable sloped terrain without training.

• 전기학회논문지
• /
• 제62권3호
• /
• pp.322-331
• /
• 2013

This paper describes the development of the pilot plant of distributed intelligent management system for a microgrid. For optimal control and management of microgrids, intelligent agents area applied to the microgrid management system. Each agent includes intelligent algorithms to make decisions on behalf of the corresponding microgrid entity such as distributed generators, local loads, and so on. To this end, each agent has its own resources to evaluate the system conditions by collecting local information and also communicating with other agents. This paper presents key features of the data communication and management of the developed pilot plant such as the construction of mesh network using local wireless communication techniques, the autonomous agent coordination schemes using plug-and-play functions of agents and contract net protocol (CNP) for decision-making. The performance of the pilot plant and developed algorithms are verified via real-time microgrid test bench based on hardware-in-the-loop simulation systems.

• 대한전자공학회논문지TC
• /
• 제40권7호
• /
• pp.282-292
• /
• 2003

본 논문에서는 폐루프 고속 전력 제어를 수행하여 WCDMA(Wideband Code Division Multiple Access) 역방향 링크 수신기 시스템의 성능을 분석하였다. 고속 전력 제어를 수행하기 위해서는 기지국에서 SIR(Signal to Interference power Ratio)이 정확히 측정되어야 한다. 이를 위해 본 논문에서는 간단한 구조를 갖는 SIR 측정 알고리즘을 제안하였다. 제안한 구조는 미사용 OVSF(Orthogonal Variable Spreading Factor) 부호를 이용하여 간섭 전력을 측정하는 새로운 방식이다. 본 논문에서 제안된 SIR 측정 알고리즘과 참고 문헌 ［1］에 제시된 기존외 SIR 측정 알고리즘을 폐루프 고속 전력 제어에 적용하여 성능을 비교하였다. 동기 데이터 복조를 수행하기 위한 채널 추정 알고리즘으로는 Κ=2인 WMSA (Weighted Multi-Slot Averaging) 채밀 추정 필터를 적용하였다. 모의 실험 결과를 통해 제안한 SIR 측정 방식이 평균 BER 10/sup -3/관점에서 수신 Ε/sub b//Ι/sub 0/를 최대 0.9㏈ 감소시킬 수 있으며 다중 경로 수가 증가할수록 그리고 페이딩 속도가 더 빨라질수록 성능 차이는 더욱 커진다는 것을 제시하였다.

• 한국주거학회논문집
• /
• 제19권6호
• /
• pp.33-44
• /
• 2008

The street system in multi-family housing is an important design element to control the circulation of vehicles and pedestrians, and to form the spatial organization of the projects. In particular, in the case of high-rise apartments, the street patterns have an influence on the safety, amenity, and convenience of facilities. Until now, however, the design of street patterns in most high-rise multi-family housing projects has diminished the quality of residential environments because priority of design consideration has primarily been given to planning road ways and parking areas. Nevertheless, the design competitions introduced for the first time in the 1980s have played a significant role in developing fresh ideas and concepts in housing design. Because street patterns have been respectably modified as a result of the generalizing of design competitions, it is important to review the ideas that have been proposed in competitions over the recent past. In this context, this study classified the types of street patterns and analyzed their design characteristics for the proposals of housing design competitions since the 1990s. As a result of this analysis, the road patterns are classified into 4 types: 1) serial type, 2) isolated type, 3) mixed type, and 4) not a road pattern due to the system of connection. In addition, these were further divided into 8 types: 1) loop, 2) ring, 3) penetration, 4) tree, 5) direct entry, 6) ring and penetration, 7) loop and penetration, 8) not a road pattern due to appearance and the collector.

• 전기전자학회논문지
• /
• 제15권1호
• /
• pp.23-28
• /
• 2011

본 논문에서는 CMOS 회로를 이용한 스프레드 스펙트럼 클록 발생기(SSCG)를 제안하고 구현하였다. 지연고정루프(DLL)의 저역통과필터(LPF)에 스프레드 스펙트럼 클럭 변조 로직에 의해 조절되는 전하펌프를 연결하여 전압 제어지연로직(VCDL)에 가해지는 제어전압을 조절함으로써 주파수의 변화를 유도하는 방법을 사용하였다. 이와 같은 구조에서는 변조 비율을 조절하기 위한 부가적인 회로가 필요없기 때문에 레이아웃 면적이 작아지게 되고 전력소모가 작아지는 장점을 갖는다. 스프레드 스펙트럼 클록 발생기는 UMC 0.25um 공정을 이용하여 시뮬레이션 및 레이아웃을 수행하였으며 전체 면적은 290um${\times}$120um^2 이다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제3권5호
• /
• pp.423-443
• /
• 2009

We present the design and implementation of a unique sensing and actuation application -- the Illuminator: a sensor network-based intelligent light control system for entertainment and media production. Unlike most sensor network applications, which focus on sensing alone, a distinctive aspect of the Illuminator is that it closes the loop from light sensing to lighting control. We describe the Illuminator's design requirements, system architecture, algorithms, implementation and experimental results. The system uses the Illumimote, a multi-modal and high fidelity light sensor module well-suited for wireless sensor networks, to satisfy the high-performance light sensing requirements of entertainment and media production applications. The Illuminator system is a toolset to characterize the illumination profile of a deployed set of fixed position lights, generate desired lighting effects for moving targets (actors, scenic elements, etc.) based on user constraints expressed in a formal language, and to assist in the set up of lights to achieve the same illumination profile in multiple venues. After characterizing deployed lights, the Illuminator computes optimal light settings at run-time to achieve a user-specified actuation profile, using an optimization framework based on a genetic algorithm. Uniquely, it can use deployed sensors to incorporate changing ambient lighting conditions and moving targets into actuation. Experimental results demonstrate that the Illuminator handles various high-level user requirements and generates an optimal light actuation profile. These results suggest that the Illuminator system supports entertainment and media production applications.

• Journal of Electrical Engineering and Technology
• /
• 제12권5호
• /
• pp.1821-1834
• /
• 2017

Medium voltage control applications due to obtain better output voltage and reduced electro-magnetic interference multi level inverter is used. In closed loop control with inverter, the PI controller does not operate satisfactorily when the operating point changes. This paper presents the performance of Co-Efficient diagram PI controller based indirect vector controlled induction motor drive fed from three-level inverter under different operating conditions (dynamic and steady state). The proposed Co-Efficient diagram PI controller based three level inverter significantly reduces the torque ripple compared to that of conventional PI controller. The performance of the indirect vector controlled induction motor drive has been simulated at different operating conditions. For three-level inverter control, a simplified space vector modulation technique is implemented, which reduces the coordinate transformations complications in the algorithms. The performance parameters, torque ripple contents and THD of induction motor drive with three-level inverter is compared under different operating conditions using CDM-PI and conventional PI controllers.

• 대한기계학회논문집A
• /
• 제27권8호
• /
• pp.1353-1362
• /
• 2003

This paper considers a simultaneous optimization problem of structure and control systems. The problem is generally formulated as a non-convex optimization problem for the design parameters of mechanical structure and controller. Therefore, it is not easy to obtain the global solutions for practical problems. In this paper, we parameterize all design parameters of the mechanical structure such that the parameters work in the control system as decentralized static output feedback gains. Using this parameterization, we have formulated a simultaneous optimization problem in which the design specification is defined by the Η$_2$and Η$\_$$\infty$/ norms of the closed loop transfer function. So as to lead to a convex problem we approximate the nonlinear terms of design parameters to the linear terms. Then, we propose a convex optimization method that is based on linear matrix inequality (LMI). Using this method, we can surely obtain suboptimal solution for the design specification. A numerical example is given to illustrate the effectiveness of the proposed method.

• Journal of Mechanical Science and Technology
• /
• 제20권11호
• /
• pp.1993-2001
• /
• 2006

The piezoelectric bimorph film, which, as an actuator, can generate more effective displacement than the usual PVDF film, is used to control the turbulent boundary-layer flow. The change of wall pressures inside the turbulent boundary layer is observed by using the multi-channel microphone array flush-mounted on the surface when actuation at the non-dimensional frequency $f_b^+$:=0.008 and 0.028 is applied to the turbulent boundary layer. The wall pressure characteristics by the actuation to produce local displacement are more dominantly influenced by the size of the actuator module than the actuation frequency. The movement of large-scale turbulent structures to the upper layer is found to be the main mechanism of the reduction in the wall- pressure energy spectrum when the 700$700{\nu}/u_{\tau}$-long bimorph film is periodically actuated at the non- dimensional frequency $f_b^+$:=0.008 and 0.028. The biomorph actuator is triggered with the time delay for the active forcing at a single frequency when a 1/8' pressure-type, pin-holed microphone sensor detects the large-amplitude pressure event by the turbulent spot. The wall-pressure energy in the late-transitional boundary layer is partially reduced near the convection wavenumber by the open-loop control based on the large amplitude event.

• 한국정밀공학회지
• /
• 제12권5호
• /
• pp.57-68
• /
• 1995

A general procedure for the numerical solution of coupled, nonlinear, differential two-point boundary-value problems, solutions of which are crucial to the controller design, has been developed and demonstrated. A fixed-end-points, free-terminal-time, optimal-control problem, which is derived from Pontryagin's Maximum Principle, is solved by an extension of Davidenko's method, a differential form of Newton's method, for algebraic root finding. By a discretization process like finite differences, the differential equations are converted to a nonlinear algebraic system. Davidenko's method reconverts this into a pseudo-time-dependent set of implicitly coupled ODEs suitable for solution by modern, high-performance solvers. Another important advantage of Davidenko's method related to the time-optimal problem is that the terminal time can be computed by treating this unkown as an additional variable and sup- plying the Hamiltonian at the terminal time as an additional equation. Davidenko's method uas used to produce optimal trajectories of a single-degree-of-freedom problem. This numerical method provides switching times for open-loop control, minimized terminal time and optimal input torque sequences. This numerical technique could easily be adapted to the multi-point boundary-value problems.