• 한국정밀공학회지
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• 제14권12호
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• pp.95-104
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• 1997

We consider controller design problem to enhance shift quality for automatic transmission. A dynamic modeling related to shifting (mainly 2-3 up-shift) is constructed and nonlinear robust controllers are designed to reduce output torque during shifting. Suggesting a new hydraulic circuit enabling the direct clutch drive, the control activity is extended and more implementable than the conventional design. The designed robust controllers overcome the unmodeled dynamics and the uncertainty embending in the system. Moreover, the dynamic effect between the clutch pressure and the PWM valve duty is considered via singular perturbation technique.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1991년도 추계학술대회 논문집
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• pp.171-179
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• 1991

This paper refers to the results of a study on the usefulness of simulation techniques based on both modeling and experiments of KICK DOWN pressure control circuit using an duty solenoid valve controlled by pulse width modulation for an automatic transmission. In this study, dynamic characteristics of solenoid valve plunger and first pressure are verified. Besides, this paper shows the design data for improvement of feeling in changing of gear by means of simulation according to varying the size of jet orifice and temperature of automatic transmission fluid, which are the important variables of the first pressure.

• 한국자동차공학회논문집
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• 제7권6호
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• pp.91-105
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• 1999

Dynamic simulation techniques are developed to analyze the shift characteristics of vehicle powertraisn with automatic transmission. In this study, the mathematical modeling of powertrain components such as engine , clutch system, planetary gear system and road load , is presented for the simulation. The clutch engagement condition, which determines the degree of freedom for the system, is also proposed .By using a detailed nonlinear model of torque converter, it is possibile to accurately analyze the extremely transient state such as the shift. Dynamo-based experiments are carried out to prove the validity of the proposed simulation techniques. Using the developed simulation program, the effects of the dynamic design variables and the control conditions , focused on the shift, are evaluated to improve the driving comforability.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2003년도 학술발표논문집
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• pp.327-330
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• 2003

The objectives of this study are to develope the automatic design programs to offer the data when constructing a small scale vinyl-house by region. This program consists of four subroutines. The first is an automatic greenhouse modeling program, the second is a calculating design load program by region, the third is a structural analysis program and the last is a optimum shape design program. The structural analysis can be conducted by simple date input and considering the design load of the install regions into account. The shape of input data is very simple, and the program reflects the design load by region. The output data can be obtained from the automatical calculation processing after structural analysis. The program was verified by compared with outputs of a common use structural analysis program and the results are the same. It was concluded that the developed program could be used efficiently in optimum design of small scale vinyl house.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1994년도 Proceedings of the Korea Automatic Control Conference, 9th (KACC) ; Taejeon, Korea; 17-20 Oct. 1994
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• pp.71-75
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• 1994

This paper presents a method of optimal design of an automatic transfer system which is controlled by the electro-pneumatic servo scheme. The electro-pneumatic automatic transfer system can move parts to desired points or displace defective parts. The dynamic performance of the system can be examined by observing the behavior of the output. The output of the servo control system is the motion of the cylinder, pneumatic actuator. The dynamic performance of the cylinder is governed by the parameters of the components of the entire system. The optimal design can be accomplished by selecting of the parameters such that the desired dynamic performance of the cylinder is obtained. The optimal set of parameters might be obtained through the repeated simulations. Repeated simulations, however, is not effective to determine the optimal set of parameters since the set of parameters is large. This paper presents modeling, application of an optimization method, and the numerical results. The optimization algorithm utilizes the concept of the conjugate gradient method. The results show that the suggested optimization scheme can render faster convergence of iteration compared to other method based on an algebraic optimization method and can reduce the design efforts.

• 한국공작기계학회논문집
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• 제11권1호
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• pp.91-96
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• 2002

Recently industry has moved towards automated operations with the goal of achieving better product quality greater productivity and reliability The pump design in characterized by extensive utilization of the related database which contains performance data. The inputs to the system are through interactive dialogue sessions and the basic input consist of flow rate, head, of fluid efficiency and the customer special requirements. These basic inputs along with the numerous rules in the knowledge bases and the mathematical modeling enable the effective design of the pump industry This paper represents the development of an automatic pump design system that was composed of a main program the data input module the drawing module the drawing edit module and was programed by the AutoLISP language under the Auto CAD program The developed system ultimately generates the design for a pump through the AutoCAD language.

• 한국정밀공학회지
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• 제18권9호
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• pp.53-60
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• 2001

This paper presents a position control of a platform at the seaport cargo handling system. After brief description of the operating principles of the cargo handling system, the governing equation of the moving platform is derived. The equation is described in the state space model, and a robust H$_{\infty}$ controller to achieve position tracking of the moving platform. which can carry 200ton of containers, is formulated. In the synthesis of the controller, the weight of the container is treated as uncertain parameter. Both regulating and tracking control responses are analyzed for the loading and unloading procedures of the proposed automatic cargo handling system.

• 한국정밀공학회지
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• 제20권10호
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• pp.98-104
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• 2003

Model structure of solenoid valve in the automatic transmission is determined as 5th order system by the signal error test. For determining parameter of the solenoid valve, parameters in time discrete model are searched by the least square method. By bilinear transform, we have found the model of solenoid valve in s domain. Afterward, experimental output data is compared with simulated output data by MATLAB having identified parameter. As the result, experimental data is agreed with simulated data very well.

• Journal of Mechanical Science and Technology
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• 제19권spc1호
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• pp.395-402
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• 2005

This paper deals with modeling and computer simulation of a full multibody vehicle model for a driving simulator. The multibody vehicle model is based on the recursive formulation and a corresponding simulation code is generated automatically from AUTOCODE, which is a symbolic computation package developed by the authors using MAPLE. The paper describes a procedure for automatically generating a highly efficient simulation code for the full vehicle model, while incorporating realistically modeled components. The following issues have been accounted for in the procedure, including software design for representing a mechanical system in symbolic form as a set of computer data objects, a multibody formulation for systems with various types of connections between bodies, automatic manipulation of symbolic expressions in the multibody formulation, interface design for allowing users to describe unconventional force-and torque-producing components, and a method for accommodating external computer subroutines that may have already been developed. The effectiveness and efficiency of the proposed method have been demonstrated by the simulation code developed and implemented for driving simulation.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제4권2호
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• pp.193-198
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• 2004

This paper describes an automatic finite element (FE) mesh generation for three-dimensional structures consisting of tree-form surfaces. This mesh generation process consists of three subprocesses: (a) definition of geometric model, (b) generation of nodes, and (c) generation of elements. One of commercial solid modelers is employed for three-dimensional solid structures. Node is generated if its distance from existing node points is similar to the node spacing function at the point. The node spacing function is well controlled by the fuzzy knowledge processing. The Voronoi diagram method is introduced as a basic tool for element generation. Automatic generation of FE meshes for three-dimensional solid structures holds great benefits for analyses. Practical performances of the present system are demonstrated through several mesh generations for three-dimensional complex geometry.