• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2000.11a
• /
• pp.563-567
• /
• 2000

This research is concerned with the dynamic modeling of solar arrays equipped with strain energy hinges(SEH). It is found from experiments that the SEH has nonlinear dynamic characteristics and complex buckling behavior, which is difficult to explain theoretically. In this paper, we use an equivalent one-dimensional nonlinear torsional spring for the SEH. Assuming that solar panels are rigid, we developed the systematic approach for the derivation of the theoretical model for the solar arrays equipped with the multitudes of the SEH. To this end, the kinematic relation of the displacement vector of each body is derived and then applied to the equations of motion. Lagrangian equations of motion are used for the derivations.

• Journal of Korea Water Resources Association
• /
• v.38 no.7 s.156
• /
• pp.555-564
• /
• 2005

In this study, a simple rainfall-runoff model was proposed by using the hydraulic routing model that requires relatively few parameters. The parameters of this model were estimated by the watershed characteristics data, and were applied to the Soyang watershed and Ui stream watershed by using the kinematic wave for overland flow and dynamic wave routing for channel routing. In order to demonstrate validity, the proposed approach was compared to the HEC-1 model for the Soyang watershed. As the results of modeling have shown, the hydraulic model shows reasonable results similar to that of the HEC-1 model. This model also represents good results for the Ui stream watershed. Hence, even if this model is a simple rainfall-runoff model using general methodology, it is competitive to the natural watershed. However, it is still difficult to estimate the roughness coefficient and the catchment width, and therefore this model is in need of such supplements.

• Applied Chemistry for Engineering
• /
• v.28 no.5
• /
• pp.559-564
• /
• 2017

In this study, the optimization process was carried out by using the central composite model of the response surface methodology in waste cooking oil based biodiesel production process. The acid value, reaction time, reaction temperature, methanol/oil molar ratio, and catalyst amount were selected process variables. The response was evaluated by measuring the FAME content (more than 96.5%) and kinematic viscosity (1.9~5.5 cSt). Through basic experiments, the range of optimum operation variables for the central composite model, such as reaction time, reaction temperature and methanol/oil molar ratio, were set as between 45 and 60 min, between 50 and $60^{\circ}C$, and between 8 and 12, respectively. The optimum operation variables, such as biodiesel production reaction time, temperature, and methanol/oil molar ratio deduced from the central composite model were 55.2 min, $57.5^{\circ}C$, and 10, respectively. With those conditions the results deduced from modeling were as followings: the predicted FAME content of the biodiesel and the kinematic viscosity of 97.5% and 2.40 cSt, respectively. We obtained experimental results with deduced operating variables mentioned above as followings: the FAME content and kinematic viscosity of 97.7% and 2.41 cSt, respectively. Error rates for the FAME content and kinematic viscosity were 0.23 and 0.29%, respectively. Therefore, the low error rate could be obtained when the central composite model among surface reaction methods was applied to the optimized production process of waste cooking oil raw material biodiesel.

• Journal of Korea Water Resources Association
• /
• v.32 no.2
• /
• pp.185-195
• /
• 1999

The finite difference method and the method of characteristics are frequently used for the numerical analysis of kinematic wave model. Truncation errors cause the peak discharge dissipated in the solution from the finite difference method. The peak discharge is conserved in the solution from the finite difference method. The peak discharge is conserved in the solution from the method of characteristics, however, the shock may deteriorates the numerical solution. In this paper, distinctive features of each scheme are investigated for the numerical analysis of kinematic wave model, and applicability of shock fitting algorithm such as Propagating Shock Fitting and Approximated Shock Fitting methods are studied. Propagating Shock Fitting method appears to treat shock properly, however, it failed to fit the shock appropriately when applied to a sudden inflow change in a long river. Approximate Shock Sitting method, which uses finer elements, is found to be more proper shock-fitting than the Propagating Shock Fitting method. Comparisons are made between two solution from the kinematic wave theory with shock fitting and full dynamic wave theory, and the results are discussed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2012.05a
• /
• pp.521-523
• /
• 2012

In the field of virtual reality and game production with realistic, real-time character's behavior is frequently used. In this paper, the terrain changes or other actions on the surrounding environment by implementing adaptive any action that is the most natural and can be adapted to analyze real-time character animation is implemented. For this purpose, in order to control the various movements of the character of the human body, by highlighting the major joints Kinematic dummy character animation is to create a way. Changes in terrain height difference of the two stairs that could cause analysis of the behavior in the environment and the other on the surrounding environment by adapting behavior to analyze the behavior of the slope climbing Based on this, the character animation is implemented.

• Journal of Institute of Control, Robotics and Systems
• /
• v.16 no.4
• /
• pp.319-328
• /
• 2010

This paper proposes a robust adaptive fuzzy tracking control scheme for a nonholonomic mobile robot with external disturbances as well as parameter uncertainties in the robot kinematics, the robot dynamics, and the actuator dynamics. In modeling a mobile robot, the actuator dynamics is integrated with the robot kinematics and dynamics so that the actuator input voltages are the control inputs. The presented controller is designed based on a FBFN (Fuzzy Basis Function Network) to approximate an unknown nonlinear dynamic function with the uncertainties, and a robust adaptive input to overcome the uncertainties. When the controller is designed, the different parameters for two actuator models in the actuator dynamics are taken into account. The proposed control scheme does not require the kinematic and dynamic parameters of the robot and actuators accurately. It can also alleviate the input chattering and overcome the unknown friction force. The stability of the closed-loop control system including the kinematic control system is guaranteed by using the Lyapunov stability theory and the presented adaptive laws. The validity and robustness of the proposed control scheme are shown through a computer simulation.

• Journal of Ocean Engineering and Technology
• /
• v.25 no.5
• /
• pp.1-8
• /
• 2011

This paper proposes a controller design for an omnidirectional mobile platform (OMP) with three wheels using backstepping control. A kinematic model and dynamic model of the system are presented. Based on the dynamic modeling, a backstepping controller is designed to stabilize the OMP when following a desired path. The controller is designed based on a backstepping control theory. It includes two steps: first, a virtual state and a stability function are introduced. Second, Lyapunov functions for the system are chosen and an equation for the virtual control that makes the system stabile is obtained. The system stability is guaranteed by the Lyapunov stability theory. The simulation and experimental results are presented to demonstrate the effectiveness of the proposed controller.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.06a
• /
• pp.785-791
• /
• 2005

Reconfigurability of machine tools is one of the critical factors to realize the responsive manufacturing systems to satisfy the mass-customization production. This paper presents the methods to model and simulate the machine tools on Internet in response to change in the machining requirements. Specifically, a set of module combination rules and a modeling method of the structure of machine tools using connectivity graph are developed. In response to the user requirements, kinematic relations and structures of machine tools can be derived using the module combination rules and connectivity graph relationships. Internet-based simulator of machine tools is implemented and presented. The developed machine tool simulator can be used to verify the structure of machine tools derived from the user requirements.

• Journal of the Society of Naval Architects of Korea
• /
• v.61 no.4
• /
• pp.247-257
• /
• 2024

The present study suggests a data-driven multivariate identification method based on principal component analysis and shows an application to ship dynamics modeling in maneuver. A reduced order model of ship dynamics is built by linear combination of three principal components acquired from large angle zigzag maneuver test. For a given kinematic state with three variables, a proper span is found by least square method, therefore accompanying hydrodynamic force and moment is determined. Suggested dynamics model correctly estimates hydrodynamic force and moment, thus it showed good agreement in maneuver simulation with that of conventional ship dynamics model obtained by system identification of captive model tests.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.8 no.4
• /
• pp.19-28
• /
• 1999

In order to control thermal deformation of the machine origin of machine tools a empirical model and a compensation system have been developed, Prior to empirical modeling the volumetric error considering shape errors and joint errors of slides is formulated through the homogeneous transformation matrix (HTM) and kinematic chain. Simulation results of the HTM method show that the thermal error of the machine origin is more critical than position-dependent errors. In order to make a stable and effective software error compensation system the GMDH (Group Method of Data Handling) models are constructed to estimate the thermal deformation of the machine origin by measuring deformation data and temperature data. A test bar and gap sensors are used to measure the deformation data. In order to compensate the estimated error the work origin shift method is developed by implementing a digital I/O interface board between a CNC controller and an IBM PC. The method shifts the work origin as much as the amounts which are calculated by the pre-established thermal error model. The experiment results for a vertical machining center show that the thermal deformation of the machine origin is reduced within $\pm$5$mu extrm{m}$.