• 조명전기설비학회논문지
• /
• 제14권1호
• /
• pp.47-52
• /
• 2000

이중화 PLC 제어시스템은 높은 유용성과 고장허용을 목표로 사용되고 2채널(1-out-of-Z) 구조로 동기화된 마스터, 스탠바이 시스템으로 PLC의 고장허용 제어를 실현함으로써 기계, 플랜트의 연속운전을 실현하며 데이터 링 크는 마스터와 스탠바이 제어기로 연결되어 있다. 고장허용 제어시스템은 전체 제어시스템에서 최소한의 고장으로 손실을 감소시키고 고장발생시 공정의 연속적인 운전과 시스템의 중단없이 수리 및 점검올 가능하게 하여 생산손실을 최소화하며 전체 시스템에 대하여 신뢰도를 향상시키는것이다.

• Journal of Information Processing Systems
• /
• 제11권4호
• /
• pp.509-527
• /
• 2015

Wireless Video Sensor Networks (WVSNs) have become a leading solution in many important applications, such as disaster recovery. By using WVSNs in disaster scenarios, the main goal is achieving a successful immediate response including search, location, and rescue operations. The achievement of such an objective in the presence of obstacles and the risk of sensor damage being caused by disasters is a challenging task. In this paper, we propose a fault tolerance model of WVSN for efficient post-disaster management in order to assist rescue and preparedness operations. To get an overview of the monitored area, we used video sensors with a rotation capability that enables them to switch to the best direction for getting better multimedia coverage of the disaster area, while minimizing the effect of occlusions. By constructing different cover sets based on the field of view redundancy, we can provide a robust fault tolerance to the network. We demonstrate by simulating the benefits of our proposal in terms of reliability and high coverage.

• 대한전자공학회논문지
• /
• 제25권6호
• /
• pp.598-605
• /
• 1988

A kinematic control method for the redundant robot manipulator is proposed, where redundancy is utilized to avoid the limit of joint positions and velocities. For the given tadk, the joint positions are obtained in such a way that each joint is placed as close to its center point as possible by considering the velocity limit. The robot is, therefore, controlled so that the joints move with the acceptable velocities and lie within the reachable ranges. To show the validities of the proposed method, two examples are illustrated by computer simulations for the RHINO-XR robot with sliding base.

• 한국농업기계학회:학술대회논문집
• /
• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
• /
• pp.1063-1072
• /
• 1996

Fruit harvesting robots should have more diversity and flexibility in the working conditions and environments than industrial robots. This paper presents an efficient optimization algorithm for redundant manipulators to avoid obstacles using dynamic performance criteria, while the optimization schemes of the previous studies used the performance criteria using kinematic approach. Feasibility and effectiveness of this algorithm were tested through simulations on a 3-degrees-of-freedom manipulator made for this study. Only the position of the end-effector was controlled , which requires only three degrees of freedom. Remaining joints, except for the wrist roll joint, which does not contribute to the end-effector linear velocity, provide two degrees of redundancy. The algorithm was effective to avoid obstacles in the workspace even through the collision occurred in extended workspace, and it was found be to a useful design tool which gives more flexibility to design conditions nd to find the mechanical constraints for fruit harvesting robots.

• 한국정밀공학회지
• /
• 제10권2호
• /
• pp.170-177
• /
• 1993

In robotic arc welding, the roll (rotation) of the torch about its direction vector does not have any effect on the welding operation. Thus we could use this redundant degree of greedom for the motion control of the robot manipulator. This paper presents an algorithm for the pseudo- inverse kinematic motion control of the 6-axis robot, which utilizes the above mentioned redunancy. The prototype welding operation and the tool path are also graphically simulated. Since the proposed algorithm requires only the position and normal vector of the weldine as an input data, it is useful for the CAD-based off-line programming of the arc welding robot. In addition, it also has the advantages of the redundant manipulator motion control, like singularity avoidance and collision free motion planning, when compared with the other motion control method based on the direct inverse kinematics.

• 전기학회논문지
• /
• 제61권12호
• /
• pp.1911-1919
• /
• 2012

In this paper, we focus on a robotic sealing process in which three robots are used. Each robot can be considered as a 7 axis redundant robot of which the first joint is prismatic and the last 6 joints are revolute. In the factory floor, robot path planning is not a simple problem and is not automated. They need experienced operators who can operate robots by teaching and playing back fashion. However, the robotic sealing process is well organized so the relative positions and orientations of the objects in the floor and robot paths are all pre-determined. Therefore by adopting robotic theory, we can optimally plan robot pathes without using teaching. In this paper, we analyze the sealing robot by using redundant manipulator theory and propose three different methods for path planning. For sealing paths outside of a car body, we propose two methods. The first one is resolving redundancy by using pseudo-inverse of Jacobian and the second one is by using weighted pseudo-inverse of Jacobian. The former is optimal in the sense of energy and the latter is optimal in the sense of manipulability. For sealing paths inside of a car body, we must consider collision avoidance so we propose a performance index for that purpose and a method for optimizing that performance index. We show by simulation that the proposed method can avoid collision with faithfully following the given end effector path.