• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.449-454
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• 1994

The Stewart Platform is one example of a motion simulator which generater 6DOF motion in space by six actuators in parallel. The presented control methrol of 6DOF motion simulator is generally classified into two types, one is SISO and the other is MIMO control type. The SISO control can't compensate for external load variation and different dynamic behavior of 6DOF motion, trerefore this type don's control motion precisely. On the other hand, the MIMO control compensates for a interference of 6DOF motion because MIMO controller is designed with 6DOF motion simulator synamics. But MIMO control of motion simulator has a complexity of 6DOF displacement feedback, because in oder to obtain feedback value we must solve the forward kinematics using measurement of cylinder length or design a state estimator, unless measurement of 6DOF displacement is possible. In this paper, a multivariable controller using H .inf. optimal control theory is designed to consider a interference of 6DOF motion and to obtain robust,precise control of system. Also in order to solve the mentioned problem of MIMO control, this paper presents a modified MIMO control model which control 6DOF motion by using feedback of measurement od cylinder length.

• Journal of the Korean Society for Railway
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• v.8 no.1
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• pp.27-33
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• 2005

This paper presents a development of 6DOF motion platform far a tilting train simulator. The tilting train simulator will be used to verify the tilting electronics and tilting control algorithm which are to be applied the Korean 180km/h tilting train. The tilting train simulator is composed of a 6-axis motion platform, a track generation system, a graphic user interface, and a visualization system with 1600mm-diameter dome screen. In this study, the 6DOF motion platform for a tilting train simulator has been designed and manufactured. The motion platform developed is a motion platform of Stewart type. The inverse kinematic analysis has been performed to determine the length of the links of the platform. Furthermore, the specification of the motors have been evaluated by the equation of motion of the platform.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.260-260
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• 2000

In this work, we have developed a 2 degree of freedom(DOF) motion simulator that can generate the sensation of motion in a 6 DOF space. The motion base has the DOF of roll and pitch, and the purpose of the motion base is to create the sensation of riding a vehicle in a 3D space by controlling the motion base. The dynamics of the mechanism was analysed and the optimal design of the motion base mechanism has been reached. The prototype motion base mechanism was developed and tested. The multi-axis motion controller(MMC) was used to control the two ac servo motors that drive the roll and pitch motion.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.736-741
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• 1992

The Stewart platform is one example of a motion simulator which generates 6 DOF motion in space by 6 actuators connected in parallel. The present SISO controllers are designed to track displacement command of each actuator computed from reference 6 DOF motion of platform by Stewart platform inverse kinematics. But this type of control can't cope with external load variation, geometric configuration of motion simulator, and different dynamic behavior of 6 DOF motion. In this paper, a multivariable controller using H- optimal control theory is designed for linerized simulator model with each actuator driving force as control input and platform 6 DOF motion as measured output. Nonlinear simulation result of the H$_{\infty}$ MIMO controller is not satisfied in steady-state characteristics. But the proposed H$_{\infty}$ + PI control scheme shows acceptable performance.e.e.

• Journal of Electrical Engineering and Technology
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• v.7 no.6
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• pp.926-931
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• 2012

Since robot industry growing, the machine that could move with multi-DOF has been studied in many industrial fields. Spherical motor is one of the multi-DOF machine that doesn't need gear for multi-DOF motion. Unlike conventional motor, spherical motor can not only rotate on the shaft axis (rotating motion), but tilt the shaft with 2-DOF motion (positioning motion). In the typical type of spherical motor, one coil took part in positioning motion and rotating motion at the same time. As the result, the control algorithm was complex. To solve this problem, this study proposed a novel type of coil on the stator. The coils were separated for positioning motion and rotating motion. Thus the linkage flux of rotating coil didn't be affected the positioning angle. In this paper, comparing the back-EMF of typical and novel type was conducted and the driving experiment was carried out as the positioning angle. From the experiment result, the performance of proposed spherical motor could be verified.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.13-16
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• 1989

The paper, introduce the real time controller Design method of heavy load 6-DOF motion simulator. And also, introduce the Geometric design of 6-DOF Motion generation, real time control A algorithm and the configuration method of real time controller H/W and S/W.

• Journal of Industrial Technology
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• v.21 no.A
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• pp.81-88
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• 2001

In this work, we have developed a 2 degrees of freedom(DOF) motion simulator that can generate the sensation of motion in a 6 DOF space. The motion base has the DOF of roll and pitch, and the purpose of the motion base is to create the sensation of riding a vehicle in a 3D space by controlling the motion base. The dynamics of the mechanism was analysed and the optimal design of the motion base mechanism has been reached. The prototype motion base mechanism was developed and tested. The multi-axis motion controller(MMC) was used to control the two AC servo meters that drive the roll and pitch motion.

• Journal of Ocean Engineering and Technology
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• v.36 no.1
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• pp.50-60
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• 2022

The deep ocean engineering basin (DOEB) of the Korea Research Institute of Ship and Ocean Engineering (KRISO) is equipped with an extreme-environment reproduction facility that can analyze the motion characteristics of offshore structures and ships. In recent years, there have been requirements for a wide range of six-degree-of-freedom (6-DOF) motion measurements for performing maneuvering tests and free-running tests of target objects (offshore structures or ships). This study introduces the process of developing a wide-area motion measurement technology by incorporating the auto-tracking technology of the towing carriage system to overcome the existing 6-DOF motion measurement limitation. To realize a wide range of motion measurements, the automatic tracking control system of the towing carriage in the DOEB was designed as a speed control method. To verify the control performance, the characteristics of the towing carriage according to the variation in control gain were analyzed. Finally, a wide range of motions was tested using a model test object (a remotely operated vehicle (ROV)), and the wide-area motion measurement technology was implemented using an automatic tracking control system for a towing carriage.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.6
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• pp.169-174
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• 2019

Flexure joints are recently used in the ultra-precision mechanism for a telecommunication mirror stage. Flexure joints have several advantages coming from their monolithic characteristics. They can be used to reduce the size of manipulators or to increase the precision of motion. In our research, 6 dof(degree of freedom) mechanism is suggested for micrometer repeatability using a flexure mechanism. To design the 6-dof motion, the 2-dof planar mechanism are designed and assembled to make the 6-dof motion. To achieve a certain performance, it is necessary to define the performance of mechanism that quantifies the characteristics of flexure joints. This paper addresses the analysis and design of the 6-dof parallel manipulator with a flexure joint using a finite element analysis tool. To obtain experimental result, CCD laser displacement sensor is used for the total displacement and the stiffness for the 6-dof flexure mechanism.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.37.6-37
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• 2002

Omnidirectional mobile robots are capable of arbitrary motion in an arbitrary direction without changing the direction of wheels, because they can perform 3 degree-of-freedom (DOF) motion on a 2-dimensional plane. In this research, a new class of an omnidirectional mobile robot is proposed. Since it has synchronously steerable omnidirectional wheels, it is called an omnidirectional mobile robot with steerable omnidirectional wheels (OMR-SOW). It has 3 DOFs in motion and one DOF in steering. One steering DOF can function as a continuously variable transmission (CVT). CVT of the OMR-SOW increases the range of velocity ratio from the wheel velocities to robot velocity, which may improve...