• Journal of the Korean Society for Precision Engineering
• /
• v.22 no.7 s.172
• /
• pp.112-121
• /
• 2005

This paper is concerned with smooth trajectory generation of biped robot which has inverted pendulum type balancing weight. Genetic algorithm is used to generate the trajectory of the leg and balancing weight. Balancing trajectory can be determined by solving the second order differential equation under the condition that the reference ZMP (Zero moment point) is settled. Reference ZMP effect on gait pattern absolutely but the problem is how to determine the reference ZMP. Genetic algorithm can find optimal solution under the high order nonlinear situation. Optimal trajectory is generated when use genetic algorithm which has some genes and a fitness function. In this paper, minimization of balancing joints motion is used for the fitness function and set the weight factor of the two balancing joints at the fitness function. Inverted pendulum type balancing weight is very similar with human and this model can be used fur humanoid robot. Simulation results show ZMP trajectory and the walking experiment made on the real biped robot IWR-IV.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.33 no.6C
• /
• pp.498-504
• /
• 2008

In this paper, an efficient hardware platform for the digital signal processing for OFDM Communication systems is presented. The hardware platform consists of a single FPGA, two DSPs with 8000 MIPS of maximum at 1 GHz clock, 2-channel ADC and DAC supporting maximum 125 MHz sampling rate, and flexible data bus architecture, so that a wide variety of baseband signal processing algorithms for practical OFDM communication systems may be implemented and tested. The IEEE 802.16 software modem is also presented in order to verify the effectiveness and usefulness of the designed platform.

• The Journal of the Korea Contents Association
• /
• v.6 no.11
• /
• pp.295-301
• /
• 2006

The scope ID field of IPv6 multicast address indicates the zone of the destination for which a multicast traffic is intended. Without any further examination on the header field, the scope ID enables a router to determine whether the traffic will be forwarded to a subnet or not. For the graceful migration from IPv4 networks to IPv6 networks, various IPv6 applications working through IPv4 networks are indispensable during the migration period. This paper describes development of an interactive remote lecture system providing service integration on voice, image, and data of teaching materials. Access right to the network for dialog among multicast group members is controlled via additional TCP (Transmission Control Protocol) session. A jitter buffer algorithm was implemented to improve the voice communication jitters.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.6 no.4 s.23
• /
• pp.15-20
• /
• 2006

This study developed integration control system that improve efficiency and give flexibility of smoke control system and can improve prevention of disasters performance. The reliable each kind sensor and of integration control system was developed by establishing the specifications, algorithms and constructing engineering data. More correct and reliable control function of optimization can be obtained by the central control from integration control system rather than the existent individual control. This sees to do to impose flexibility to smoke control system. Also, this will provide the basics of integration control system and ability security of smoke control system and can construct smoke control system of performance based.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.34 no.8B
• /
• pp.768-776
• /
• 2009

This paper analyses the message complexity of TDMA ad hoc MAC protocols. Since the network resource of ad hoc networks is limited due to the multiple interferences and the contention-based wireless channel, the scalability issue is one of the main research topics in developing ad hoc algorithms. Simulation demonstrates that SMACS protocol has the lowest message complexity, whereas TMMAC has the highest. In addition, it is found that since the effect of unicast dominates in the message complexity compared to other factors with an increasing number of nodes, Z-MAC tends to have the property of linearity, whereas BMA and TMMAC show exponential increases in their complexities.

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2011.06a
• /
• pp.23-24
• /
• 2011

본 논문에서는 승객 수송수요 반영 단계에서는 역별 승하차인원, 시간대별 재차인원 등 수송수요에 반영할 기준을 설정하여 수송력과 승차인원의 기준을 판단하고, 열차운행계획 수립 단계에서는 운행구간, 선로용량, 선로조건 등 제약조건과 적정수송력에 맞는 운행계획을 수립하고, 마지막 단계에서 경제성, 능률성, 합리성 등을 감안한 운용효율 향상을 위한 열차 DIA를 작성하고자 한다. 또한 통계적 분석절차에 따라 재차인원과 운행횟수를 각각의 독립변수와 종속변수로 산정하여 두 변수간의 상관관계를 확인한 후 회귀분석을 통해 얻은 회귀식을 실제열차운행 횟수와 비교하여 최적의 열차운행횟수를 산정하였으며 회귀식의 유효성 검증을 통해 열차운행 환경변화에 신속하게 대응할 수 있는 유연한 시스템을 구축한 후 서울도시철도공사 실용 Dia에 적용하여 유효성을 검토하였다.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.19 no.1
• /
• pp.103-109
• /
• 2019

The automotive electronic system should provide a method that can be safely performed by loading a number of application programs having time constraints in several electronic control devices. In this paper, we propose a timing protection mechanism for AUTOSAR, which is a real - time operating system specification for automotive field, in order to observe the deadline of each task when scheduling real - time tasks. We propose a dynamic non-preemption algorithm to guarantee a flexible deadline for fixed priority or dynamic priority tasks, and a location where execution time can be monitored for errors, and suggest ways to implement the AUTOSAR time protection mechanism.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.26 no.3
• /
• pp.214-226
• /
• 2023

A transfer alignment is used to initialize, align, and calibrate a SINS(Slave INS) using a MINS(Master INS) in motion. This paper presents an airborne transfer alignment with velocity and azimuth matching to estimate inertial sensor biases under the wing flexure influence. This study also considers the lever arm, time delay and relative orientation between MINS and SINS. The traditional transfer alignment only uses velocity matching. In contrast, this paper utilizes the azimuth matching to prevent divergence of the azimuth when the aircraft is stationary or quasi-stationary since the azimuth is less affected by the wing flexibility. The performance of the proposed Kalman filter is analyzed using two factors; one is the estimation performance of gyroscope and accelerometer bias and the other is comparing aircraft dynamics and attitude covariance. The performance of the proposed filter is verified using a long term flight test. The test results show that the proposed scheme can be effectively applied to various platforms that require airborne transfer alignment.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 1994.10a
• /
• pp.116-120
• /
• 1994

최근 항공우주 및 생산자동화 분야의 급격한 발달에 따라 정밀도와 효율성을 향상시키기 위해 저중량, 고강도 구조물이 요구된다. 그러나 경량화 추세로 인해 수반되는 구조물의 유연성 증가로 외력에 대한 구조응답의 진폭이 커지고 구조물의 피로 수명이 단축되어 매우 위험한 상황에 이를 수 있다. 이런 바람직하지 않은 진동현상을 제어하기 위해 여러 제어이론을 응용한 진동억제시스템의 연구가 활발하며, 신소재인 압전재료의 개발로 새로운 방향이 제시되고 있다. 압전재료는 유연한 구조물에 부착되어 압전재료의 수축, 팽창 운동에 의해 발생된 에너지를 부착된 구조물에서의 제어력으로 사용되어, 진동 혹은 자세 및 형상 제어에 활용되고 있다. 압전재료에 대한 연구로는 Crawley, de Luis3가 보의 표면 혹은 내부에 압전세라믹을 부착하여 액튜에이터로 사용하는 경우 집중모멘트를 가하는 역할을 함을 밝혔고, Hanagud, obal은 압전재료를 센서와 액튜에이터로 사용해 복합재료 보에 대한 최적 진동제어 알고리즘을 개발, 그 성능에 대한 효과를 조사하였고 임의의 위치에 부착된 센서 및 액튜에이터를 고려한 복합재료 보의 운동방정식을 유한요소법을 이용 유도하였으며 변위율 피드백(rate feedback)과 모달피드백(modal feedback) 제어기를 적용하여 진동제어 효과를 고찰하였다. 그리고 Tomas, James, Hubbard는 압전필름을 액튜에이터로 사용해 복합재료 보에 Liapunov 제어기와 변위율 피드백 제어기를 사용하여 능동감쇠기를 설계하였고, Lee, Chaing, Sullivan은 압전필름을 센서와 액튜에이터로 사용해 평판에 변위율 피드백 제어기를 적용한 능동감쇠기를 설계하고 실험적으로 수행하였다. Base가 백색잡음가진을 지속적으로 받을 때 보끝의 움직임이 최소가 되도록 제어하고자 연구를 수행 중인 바 그 결과로소 본 논문에서는 적용시켰고 F-P-K 방정식을 이용해 확률영역으로 변환하여 LQR 제어기와 pole allocation 제어기를 시스템에 적용시켜 우수한 특성을 갖음을 제어 시뮬레이션의 결과를 통해 입증하였다.

• Journal of Advanced Navigation Technology
• /
• v.21 no.6
• /
• pp.521-528
• /
• 2017

Research on AI is essential to build a system with collective intelligence that allows a large number of UAVs to maintain their flight while carrying out various missions. A typical approach of AI includes 'top-down' approach, which is a rule-based logic reasoning method including expert system, and 'bottom-up approach' in which overall behavior is determined through partial interaction between simple objects such as artificial neural network and Flocking Algorithm. In the same study as the existing Flocking Algorithm, individuals can not perform individual tasks. In addition, studies such as UAV formation flight can not flexibly cope with problems caused by partial flight defects. In this paper, we propose organic integration between top - down approach and bottom - up approach through multi - agent system, and suggest a flight flight algorithm which can perform flexible mission through it.