• International Journal of Naval Architecture and Ocean Engineering
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• v.6 no.3
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• pp.652-669
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• 2014

This paper concerns the kinematic characteristics of a coupling device in a deep-seabed mining system. This coupling device connects the buffer system and the flexible pipe. The motion of the buffer system, flexible pipe and mining robot are affected by the coupling device. So the coupling device should be considered as a major factor when this device is designed. Therefore, we find a stable kinematic device, and apply it to the design coupling device through this study. The kinematic characteristics of the coupling device are analyzed by multi-body dynamics simulation method, and finite element method. The dynamic analysis model was built in the commercial software DAFUL. The Fluid Structure Interaction (FSI) method is applied to build the deep-seabed environment. Hydrodynamic force and moment are applied in the dynamic model for the FSI method. The loads and deformation of flexible pipe are estimated for analysis results of the kinematic characteristics.

• International Journal of Automotive Technology
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• v.6 no.4
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• pp.403-411
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• 2005

The bus is regarded as one of the most frequently used public transportation systems, the research and development on driving stability, safety, and convenience for drivers and passengers has tremendously increased in recent days. This paper investigated the design of the bus door mechanism composed of an actuator (or motor) and linkages. The bus door mechanism is divided into many types according to the coupling of the linkages and the driving system. The mathematical models of all types of door mechanism have been constructed for computer simulation. To design the bus door mechanism, we developed a simulation program, which automates the kinematic and dynamic analysis according to the input parameters of each linkage and the driving system. Using this program, we investigated the design parameters that affect the kinematic and dynamic characteristics of the bus door mechanism under various simulation conditions. In addition, simple examples are examined to validate the developed program.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.6
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• pp.187-193
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• 2002

Since the bus is regarded as the one of the most public transportation systems, research on the safety and facilities of the bus has been increased actively in recent years. In this paper, we concern the design of the bus door mechanism that is composed of many linkages and actuators(or motors). In particular, the folding door mechanism is representative system installed in most of urban buses. To design the folding door mechanism, we construct the kinematic and dynamic analysis model fur computer simulation. Also, the dynamic analysis is accomplished by both direct dynamics and inverse dynamics. Since the folding door mechanism has many design variables, the analysis program is developed to perceive kinematic and dynamic characteristics according to the design variables and simulation conditions.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.101.1-101
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• 2002

Vehicle driving simulator is a virtual reality device which makes a human being feel as if the one drives a vehicle actually. Unlike actual vehicle, the simulator has limited kinematic workspace and bounded dynamic characteristics. So it is difficult to simulate dynamic motions of a multi-body vehicle model fully. In order to overcome these problems, washout algorithm which restricts workspace of the simulator within the kinematic limits is needed, and analysis of dynamic characteristics is required also. However, it is difficult to select the proper cutoff frequency of filters in washout algorithm. This paper introduces the signal compression method as an effective method to analyze the sim...

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.8
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• pp.823-830
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• 2009

For developing automotive parts and telematics devices the real car test often shows limitation because it needs high cost, much time and has the possibility of the accident. Therefore, a Vehicle Driving Simulator (VDS) instead of the real-car test has been used by some automotive manufactures, research centers, and universities. The VDS is a virtual reality device which makes a human being feel as if one drives a vehicle actually. Unlike actual vehicle, the simulator has limited kinematic workspace and bounded dynamic characteristics. So it is difficult to simulate dynamic motions of a multi-body vehicle model fully. In order to overcome these problems, a washout algorithm which restricts workspace of the simulator within the kinematic limits is needed, and analysis of dynamic characteristics is required also. However, a classical washout algorithm contains several problems such as time delay and generation of wrong motion signal caused by characteristics of filters. Specially, the classical washout algorithm has the simulator sickness when driver hardly turns brakes and accelerates the VDS. In this paper, a new washout algorithm is developed to enhance the motion sensitivity and improve the simulator sickness by using the vehicle tilt signal which is generated in the real time vehicle dynamic model.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.378-381
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• 2003

Efficient development of method on a performance evaluation for machine tools has been regarded as the most important work for accuracy and quality enhancement to every user and manufacturer. A evaluation method of accuracy for machine tools has been studied recently according to the rapid increase of interest in precision machine tools. To this point of view, the circular interpolation test of machine tools is recognized as the most useful method to distinguish a dynamic accuracy of NC machine tools by ISO and ANSI/ASME, etc. In this paper, we have studied and developed the form measurement system with grid encoder to analyse the final accuracy of NC machine tools. we have analyzed the servo system error and geometric error of NC machine tools through measuring a dynamic error signal by this system. and then we verified the experimental result and enhanced the reliability by means of comparing the characteristics of the developed system with the kinematic ball-bar system.

• 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.

• Safety and Health at Work
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• v.3 no.1
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• pp.22-30
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• 2012

Objectives: To challenge the problem of slipperiness, various slipmeters have been developed to assess slip hazard. The performance of in-situ slipmeter is, however, still unclear under the various floor conditions. The main objectives of this study were to evaluate the performance of three kinds of slipmeters under real conditions, and to find their dynamic and kinematic characteristics, which were compared with gait test results. Methods: Four common restaurant floor materials were tested under five contaminants. Slipmeters and human gaits were measured by high speed camera and force plate to find and compare their dynamic and kinematic characteristics. Results: The contact pressures and built-up ratio were below those of subjects. The sliding velocity of British Pendulum Tester was above those of subjects, while those of BOT-3000 and English XL were below those of subjects. From the three meters, the English XL showed the highest overall correlation coefficient (r = 0.964) between slip index and $R_a$, while the rest did not show statistical significance with surface roughness parameters ($R_a$, $R_z$). The English XL only showed statistical significance (p < 0.01) between slip index and contaminants. The static coefficient of friction obtained with the BOT-3000 showed good consistency and repeatability (CV < 0.1) as compared to the results for the BPT (CV > 0.2) and English XL (CV < 0.2). Conclusion: It is unclear whether surface roughness can be a reliable and objective indicator of the friction coefficient under real floor conditions, and the viscosity of contaminants can affect the friction coefficient of the same floors. Therefore, to evaluate slipperiness, the performance of the slipmeters needed to improve.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.5 s.122
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• pp.415-426
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• 2007

In a link motion punch press, numerous links are interconnected and each link executes a constrained motion at high speed. As a consequence, dynamic unbalance force and moment are transmitted to the main frame of the press, which results in unwanted vibration. This degrades productivity and precise stamping work of the press. This paper presents an effective method for reducing dynamic unbalance in a link motion punch press based upon kinematic and dynamic analyses. Firstly, the kinematic analysis is carried out in order to understand the fundamental characteristics of the link motion mechanism. Then design variable approach is presented in order to automate the model setup for the mechanism whenever design changes are necessary. To obtain the inertia properties of the links such as mass, mass moment of inertia, and the center of mass, 3-dimensional CAD software was utilized. Dynamic simulations were carried out for various combinations of design changes on some links having significant influences on kinematic and dynamic behavior of the mechanism.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.238-243
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• 2002

This paper presents a design and a control of a biped walking AGO-robot and dynamic walking simulation for this system. The biped walking RGO-robot is distinguished from other one by which has a very light-weight and a new RGO type with servo motors. The gait of a biped walking AGO-robot depends on the constrains of mechanical kinematics and initial posture. The stability of dynamic walking is investigated by ZMP(Zero Moment Point) of the biped walking AGO-robot. It is designed according to a human wear type and is able to accomodate itself to human environments. The joints of each leg are adopted with a good kinematic characteristics. To test of the analysis of joint kinematic properties, we did the strain stress analysis of dynamic PLS and the study of FEM with a dynamic PLS. It will be expect that the spinal cord injury patients are able to train effectively with a biped walking RGO-robot.