• The Transactions of the Korean Institute of Electrical Engineers D
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• v.52 no.3
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• pp.134-141
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• 2003

PID controllers with constant gains have been widely used in various control systems due to its powerful performance and easy implementation. But it is difficult to have uniformly good control performance in all operating conditions. In this paper, we propose a nonlinear variable PR controller with immune feedback mechanism. An immune feedback mechanism is based on the functioning of biological T-cells, they include both an active term, which controls response speed. and an inhibitive term, which controls stabilization effect. Therefore, the proposed nonlinear PID controller is based on immune responses of biological. immune feedback mechanism which is the cell mediated immunity and In order to choose the optimal nonlinear PID controller games, we also propose the tuning algorithm of nonlinear function parameter in immune feedback mechanism. To verify performance of the proposed algorithm, the speed control of nonlinear DC motor are performed. Front the simulation results, we have found that the proposed algorithm is more superior to the conventional constant fain PID controller.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.11
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• pp.76-82
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• 1998

In this study, the Ball screw and Servo motor Mechanism is considered as a High Speed Tool Feed System for the machining of a piston of a reciprocating engine. For the machining of a piston, that shapes oval, high speed servo mechanism is needed as a positioning of a cutting tool, and the stroke of tool is 0.1 mm ~ 1 mm. Ball screw and servo motor Mechanism is available very much because this mechanism is used widely in general machine. This Mechanism has been designed with the use of the decrease in mass and partial wear of the ball screw for high speed positioning of tool. Also the periodic learning control method with the inverse transfer function compensation has been applied to the positioning control for the high accuracy positioning of tool. These applications lead the achievement of the machining of a piston with an accuracy of 5${\mu}{\textrm}{m}$ at 2500 rpm in CNC turning.

• Current Applied Physics
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• v.18 no.11
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• pp.1388-1392
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• 2018

Metal thin films are used widely to solve the vibration problem. However, damping mechanism is still not clear, which limits the further improvement of the damping properties for film and the development of multi-functional damping coating. In this paper, Damping microscopic mechanism of porous metal films was investigated at both macroscopically and microscopically mixed levels. Molecular dynamics simulation method was used to model and simulate the loading-unloading numerical experiment on the micro-pore and vacancy model to get the stress-strain curve and the microstructure diagram of different defects. And damping factor was calculated by the stress-strain curve. The results show that dislocations and new vacancies appear in the micro-pores when metal film is stretched. The energetic consumption from the motion of dislocation is the main reason for the damping properties of materials. Micro-mechanism of damping properties is discussed with the results of in-situ experiment.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.741-743
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• 2004

In this paper, we describe a Control Element Drive Mechanism(CEDM) operation test using a Power Controller. By testing, we can catch the mechanical and electrical characteristics of CEDM and obtain the information about the improvement of CEDM and the design of CEDM power cabinet. The power controller for CEDM introduced in this paper can input firing angles directly into gate drive circuits of thyristors so that this method can be used to derive the maximum and minimum values of firing angles within available limits for a 3-phase half-wave rectifier. Angle inputs help us understand each coil's response characteristics. Since this power controller generates a serial sequence for CEDM insertion and withdrawal operations, we may judge whether CEDM works correctly as expected or not in each phase of a step movement.

• The Journal of Korea Robotics Society
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• v.14 no.4
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• pp.264-269
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• 2019

This paper presents mechanical design and control of a bio-inspired legged robot. To achieve a fast legged running mechanism, a novel linkage leg structure is designed based on hind legs of domestic cats. The skeletomuscular system and parallel leg movement of a cat are analyzed and applied to determine the link parameters. The hierarchical control architecture is designed according to the biological data to generate and modulate desired gaits. The effectiveness of the leg mechanism design and control is verified experimentally. The legged robot runs at a speed of 46 km/h, which is comparatively higher speed than other existing legged robots.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.12
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• pp.37-47
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• 1998

This study discusses the feed dog feeding mechanism of an industrial lock stitch sewing machine, which is a good example to study a machine kinematics. The feed dog feeding mechanism makes the fabrics directly be fed by an elliptic motion of the feed dog that is moved by a rotation of the top shaft and controlled by the feeding control mechanism. This study makes mathematical expressions of machine's motion in the feed dog feeding mechanism. Thus, the motions of this mechanism are characterized, namely how an elliptic motion of the feed dog is affected by the feeding control mechanism. Therefore, the above mathematical expressions may be a basis for the new design of the feed dog feeding mechanism and may be adapted to analysis. Development of the similar feed dog feeding mechanism can be applied to other type sewing machine.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.05a
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• pp.467-470
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• 2004

MANPro-based control is a novel control paradigm aimed at intelligent manufacturing systems on the basis of mobile agent-based negotiation process (MANPro). MANPro is a negotiation mechanism based on the agent-based control architecture and, especially, it adapts a mobile agent system called N-agent for the negotiation process. N-agent travels around the network of distributed manufacturing systems to acquire information, and it makes a decision for system control according to the obtained information. MANPro includes communication architecture and information architecture for intelligent shop floor control. MANPro also considers the following issues: (1) negotiation mechanism, (2) single-agent internal strategic policies, and (3) information model. Communication architecture concerns the first issue of the negotiation mechanism. It provides information exchanging mechanism with functional modules. In specific, N-agent is equipped with an intelligent reasoning engine with a built-in knowledge base. This reasoning engine is closely related to the single-agent internal strategic policies of the second issue. Finally, ontology-based information architecture addresses information models and provides a framework for information modeling on negotiation. In this paper, these three issues are addressed in detail and a framework of MANPro-based control is also proposed.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.11
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• pp.1108-1114
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• 2009

Mobility is one of the most important features for a guard robot since it should be operated in rough places. A wheel-based mobile robot capable of jumping is an appropriate structure for a guard robot because it can easily satisfy the requirements for small guard robots. The jumping robot can reach a higher place more rapidly than other locomotion methods. This research proposes a small robot equipped with the jumping mechanism based on the conical spring with the variable length endtip. The variable length endtip enables the independent control of the jump force and jump angle which are related to the jump height and jump distance, respectively. Various experiments demonstrated that the proposed jumping mechanism can provide the independent control of jump force and jump angle, and improve the mobility of a small robot to overcome an obstacle. Furthermore, a combination of the jumping mechanism and the PSD sensor to measure the distance to the step enable the jumping robot to autonomously climb stairs.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.10B
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• pp.613-620
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• 2007

Recently, due to the developing of broadband convergence networks, the high quality multimedia services which are converged with communication and broadcasting can be provided. These high quality communication and broadcasting convergence service needs reliable multicasting mechanism in IP networks. However, multicasting mechanism recently deployed is difficult to guarantee the end-to-end QoS. For the reliable high quality If multimedia IPTV service, the QoS guaranteed multicasting mechanism should be provided. Therefore, we proposed a probing packet based multicasting admission control mechanism using centralized multicasting control management block in this paper. And for the performance evaluation of the proposed mechanism, we used ns-2 simulator.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.7
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• pp.711-719
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• 2008

Although non-real time simulation and pilot based evaluations are available for the development of flight control computer prior to real flight tests, there are still many risky factors. The control law designed for prototype aircraft often leads to degraded performance from the initial design objectives, therefore, the proper evaluation methods should be applied such that flight control law designed can be verified in real flight environment. The one proposed in this paper is IFS(In-Flight Simulator). Currently, this system has been implemented into the F-18 HARV(High Angle of Attack Research Vehicle), SU-27 and F-16 VISTA(Variable stability. In flight Simulation Test Aircraft) programs. This paper addresses the concept of switching mechanism for FLCC(Flight Control Computer)-SWMC(Switching Mechanism Computer) using 1553B communication based on flight control law of advanced supersonic trainer. And, the fader logic of TFS(Transient Free Switch) and stand-by mode of reset '0' type are designed to reduce abrupt transient and minimize the integrator effect in pitch axis control law. It hans been turned out from the pilot evaluation in real time that the aircraft is controllable during the inter-conversion process through the flight control computer, and level 1 handling qualities are guaranteed. In addition, flight safety is maintained with an acceptable transient response during aggressive maneuver performed in severe flight conditions.