• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1482-1487
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• 2003

This paper presents a new family of 4-DoF parallel mechanism with two platforms. The new mechanism is composed of front and rear platforms, and three limbs. Two limbs with 6dof joint (P-P-S-P) are attached to the each platform and are perpendicular to baseplate, while the middle limb with 4-Dof joints (R-R-R-P or R-R-P-P) is attached to the revolute joint that connect front and rear platform. The two-DoF-driving mechanism at the middle limb with two base-fixed prismatic actuators can generate the heaving and roll motions or two translational motions. Therefore, Therefore, the new 4-Dof parallel mechanism (1T-3R) can generate pitch motions at each platforms, roll, and heaving motions, while another type of new 4-Dof parallel mechanism (2T-2R) can generate pitch motions at each platforms, x and z translational motions. For 1T-3R mechanism, kinematic analyses including inverse, forward kinematics, and Jacobian are performed.

• Journal of Institute of Control, Robotics and Systems
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• v.2 no.1
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• pp.45-52
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• 1996

This work deals with the kinematic and dynamic optimal design of a six degree-of-freedom Stewart Platform mechanism, which is actuated by six prismatic cylinfers. Composite design index is employed to deal with multi-criteria based design in a systematic manner, and a sequential design method is suggested, in which the results from the kinematic optimization are employed in the following dynamic optimization.

• The Journal of Korea Robotics Society
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• v.6 no.1
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• pp.78-85
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• 2011

This article investigates kinematic characteristics of a Sch$\ddot{o}$nflies motion generator which represents a mechanism having translational three Degree-of-Freedom (DOF) and rotational one-DOF motion about a fixed axis. The mechanism consists of the base plate and the moving plate, and four identical limbs connecting them. Each limb employs two revolute joints (RR), one parallelogram (Pa), and two revolute joints (RR) from the base plate to the moving plate. The mechanism is driven by four actuators which are placed on the base plate to minimize dynamic loads. It is shown through simulations that the mechanism can be designed to secure large dexterous workspace and thus has very high potential for actual applications such as haptic devices and high-speed requiring tasks such as pick-and-place operations, riveting, screwing tasks, etc.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.965-970
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• 1992

A dynamic modeling and analysis for the Stewart platform type of parallel robot is addressed. The dynamic modeling is performed based on the method of Kinematic Influence Coefficients(KIC) and transfering of the generalized coordinates. The optimum geometric configurations of the system that minimize the actuating forces at the linear actuator are found for several trajectories by using the optimization technique.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.557-560
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• 2000

The Purpose of this study is analysis of kinematic for a modified manipulator and experimental test to certify auto-balancing operation. The test is carried out as follows. First, we solve the inverse kinematics and then do a closed loop control. Second we confirm translation displacement and rotation angle of a manipulator.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.83.2-83
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• 2001

This paper presents a new formulation approach to reduce computational burden of the direct kinematics of 6-dof haptic devices with three sets of a parallel-serial linkage. Their direct kinematics has been formulated through employing the Denavit-Hartenberg notation, which results in complicated formulation procedures and heavy computational burden. For reducing these problems, this paper reconfigures the haptic devices into an equivalent kinematic model of the 3-6 Stewart-Gough Platform that has three connecting joints on the moving platform. Moreover, the direct kinematics of the 3-6 Platform can be effectively formulated by using the proposed Tetrahedron Approach.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.281-286
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• 1993

In this paper, a parallel link typed wrist is developed for robotic precision assembly. The developed wrist can make the corrective motion required for compensating lateral and tilting errors. The mechanism of this wrist is one example of a motion simulator generating 6 DOF motion in space by 6 actuators connected in paralle. To make the wrist more compact, miniature DC motors containing reduction gears and servo system were used. The parallel link architecture enables a high positioning accuracy and high nominal load capacity. In this study, inverse kinematic problem is solved by using a Denavet-Hartenberg method and a simulational result about workspace of the proposed parallel mechanism is obtained.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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• pp.679-684
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• 2000

This paper presents the development of system and program for a Parallel-Typed CNC Machine. The system consists of parallel manipulator, PC (Personal Computer), DMC (DSP Motion Controller), and machining tools. In order to control the manipulator, the program, which is implemented in "c/c++" language, involves inverse/direct kinematics, velocity mapping, Jacobian and etc. A controller computes the kinematic formulation in real-time and generates and motion by the DMC. A monitor, which has access to program and sensory information, displays the status of manipulator.nipulator.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.3
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• pp.1-7
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• 2008

This paper describes the kinematics which is a new type of parallel manipulator, and the neural network is applied to solving the forward kinematics problem. The parallel manipulator called it as a Stewart platform has an easy and unique solution about the inverse kinematics. However, the forward kinematics is difficult to get a solution because of the lack of an efficient algorithm caused by its highly nonlinearity. This paper proposes the neural network scheme of an Newton-Raphson method alternatively. It is found that the neural network can be improved its accuracy by adjusting the offset of the obtained result.

• Journal of the Semiconductor & Display Technology
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• v.10 no.4
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• pp.79-87
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• 2011

In this paper, suggested is a hybrid-type visual alignment system to align mask and panel in 3-D space, where mask and panel are to be controlled independently by two individual positioning mechanisms in order to compensate for spatial misalignments. In the hybrid visual alignment system, the below 4-PPR parallel mechanism provides in-plain motions to pattern mask like the other conventional alignment systems while the above 4-RPS parallel mechanism is to move glass panel to achieve a complete spatial alignment. For the control of the hybrid alignment system, first, inverse kinematic solutions for the parallel mechanisms are given to determine the driving distance of each active joint, and also an efficient way to determine the spatial alignment error is developed by exploiting three in-plane cameras.