• Journal of Institute of Control, Robotics and Systems
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• v.10 no.10
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• pp.869-877
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• 2004

This paper deals with motion planning algorithm for kinematically redundant manipulators that are not fixed to the ground. Differently from usual redundant manipulators fixed to the ground, the stability issue should be taken into account to prevent the robot from falling down. The typical ZMP equation, which is employed in human walking, will be employed to evaluate the stability. This work proposes a feed forward ZMP planning algorithm. The algorithm embeds the 'ZMP equations' indirectly into the kinematics of the kinematic model of a manipulator via a ZMP stability index The kinematic self motion of the redundant manipulator drives the system in such a way to keep or plan the ZHP at the desired position of the footprint. A sequential redundancy resolution algorithm exploiting the remaining kinematic redundancy is also proposed to enhance the performances of joint limit index and manipulability. In addition, the case exerted by external forces is taken into account. Through simulation for a 5 DOF redundant robot model, feasibility of the proposed algorithms is verified. Lastly, usual applications of the proposed kinematic model are discussed.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1660_1661
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• 2009

The excitation system for nuclear emergency diesel generator has been developed and is commercially operating now. The characteristics are triple modular redundant controllers, double redundant rectifiers and digital system, comparing the existing(and removed) system.

• Journal of the Ergonomics Society of Korea
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• v.1 no.2
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• pp.11-15
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• 1982

There is the possibility that human error during testing and maintenance brings about the failure of the system, the reliability of which depends on mechanical failure and human error. This paper deals with the calculation of the reliability of the redundant system with the dependent hunman error through Karnaugh Map. Two cases are considered. One is the reli- ability of the system neglecting the test interval of each component and the other is that considering the test interval of each component.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.301-303
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• 2018

This paper describes a robot control system and control method of a human arm type redundant manipulator. The control of a redundant manipulator suffer from computational complexity and singularity problem because of numerical inverse kinematics. To deal with such problems, analytical methods for a redundant robot arm have been researched to enhance the performance of inverse kinematics. In this research, we propose a numerical control method and weighted pseudo inverse kinematics algorithm. Using this algorithm, it is possible to generate a trajectory passing through the singular points and intuitively move the elbow without regard to the end-effector pose. Performance of the proposed algorithm was verified by various simulations. It is shown that the trajectory planning and using this algorithm provides correct results near the singular points and can utilize redundancy intuitively. We proved this system's validity through field test.

• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.168-172
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• 2003

This paper presents a non-electrical isolated Prototype of N+X redundant UPS with two-quadrant converter. Proposed topology has multi-functions of battery charge and discharge regulation, operates with a near unity input power factor, compensates unbalanced voltage on U bus capacitors, and regenerates the circulating active power among the inverters into battery or grid. And furthermore, this system adopts a novel wireless parallel operation algorithm of N+X redundant UPS system with no control interconnections. Simulation and experiment results are provided in this paper to prove the validity of proposed topology and wireless control algorithm.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.3
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• pp.292-301
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• 2014

This paper describes development of distributed type independent electro-hydraulic ballast valve remote control system with diagnostic function based on fuzzy inference using redundant Modbus communication and ethernet Modbus TCP/IP. Diagnostic function estimate degradation of system components and diagnose system faults, which results in shortage of fault maintenance time and improvement of system safety. Slave devices which control each valve and master device which command, monitor and diagnose slave system are developed. Slave devices are connected to master device with redundant Modbus networks and master device is connected to ship's integrated control system with Modbus TCP/IP. Also this paper describes development of simulator to test and confirm whether developed system can be integrated with ship's integrated control and monitoring system.

• Nuclear Engineering and Technology
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• v.49 no.5
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• pp.989-995
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• 2017

Distributed Control System (DCS) communication networks, which use Fast Ethernet with redundant networks for the transmission of information, have been installed in digitalized nuclear power plants. Normally, failover tests are performed to verify the reliability of redundant networks during design and manufacturing phases; however, systematic integrity tests of DCS networks cannot be fully performed during these phases because all relevant equipment is not installed completely during these two phases. In additions, practical verification tests are insufficient, and there is a need to test the actual failover function of DCS redundant networks in the target environment. The purpose of this study is to verify that the failover functions works correctly in certain abnormal conditions during installation and commissioning phase and identify the influence of network failover on the entire DCS. To quantify the effects of network failover in the DCS, the packets (Protocol Data Units) must be collected and resource usage of the system has to be monitored and analyzed. This study introduces the use of a new methodology for verification of DCS network failover during the installation and commissioning phases. This study is expected to provide insight into verification methodology and the failover effects from DCS redundant networks. It also provides test results of network performance from DCS network failover in digitalized domestic nuclear power plants (NPPs).

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.845-848
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• 2003

There are many researches on using human neuro-biological signals for various problems such as controlling a mechanical object and/or interfacing human with the computer. It is one of very interesting topics that human can use various instruments without learning specific knowledge if the instruments can be controlled as human intends. In this paper, we proposed an intelligent motion planner for a redundant manipulator, which is controlled by humans neuro-biological signals, especially, EOG (Electrooculogram). We found the optimal motion planner for the redundant manipulator that can move to the desired point. We used neural networks to find the inverse kinematics solution of the manipulator. We also showed the performance of the proposed motion planner with several simulations.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.2
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• pp.218-224
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• 2009

This paper proposes an effective SLAM based on redundant extended Kalman filter for robot navigation in an irregular surface to enhance the accuracy of robot's pose. To establish an accurate model of a caterpillar type robot is very difficult due to the mechanical complexity of the system which results in highly nonlinear behavior. In addition, for robot navigation on an irregular surface, its control suffers from the uncertain pose of the robot heading closely related to the condition of the floor. We show how this problem can be overcome by the proposed approach based on redundant extended Kalman filter through some computer simulation results.

• Journal of Ocean Engineering and Technology
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• v.32 no.1
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• pp.68-75
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• 2018

This study deals with the heading angle and depth keeping control technique for an ROV with multiple horizontal and vertical thrusters by thrust allocation. The light work class ROV URI-L, which is under development at KRISO, is a redundant actuating system with multiple thrusters that are larger than the ROV's degree of freedom. In the redundant actuating system, there are several solutions for a specific ROV motion to be performed. Therefore, a thrust allocation algorithm that considers the entire propulsion system should be regarded as important. First, this paper describes the propulsion system of the ROV and introduces the thrust allocation method of each motion controller. In addition, the performance of the controller is examined using a heading angle and depth keeping control test in a stationary state.