• 대한기계학회논문집
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• 제18권11호
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• pp.2825-2836
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• 1994

The engineering optimization has been developed for the automatic design of engineering systems. Since the conventional optimum is determined without considering noise factors, applications to practical problems can be limited. Current design practice tends to account for these noises by the specification of closer tolerances or the use of safety factors. However, these approaches may be very expensive. Thus the consideration on the noises of design variables is needed for optimal design. A method is presented to find robust solutions for unconstrained optimization problems. The method is applied to discrete and continuous variables. The orthogonal array is utilized based on the Taguchi concept. Through mathematical proofs and numerical examples, it is verified that solutions from the suggested method are more insensitive than the conventional optimum within the range of variations for design variables.

• 한국소음진동공학회논문집
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• 제15권6호
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• pp.680-686
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• 2005

This paper introduces the robust design of an intake system using transmission loss and the frequency weighting function. First, transmission loss is measured to evaluate the performance of the noise reduction for the intake system. The robust design parameters of the intake system are extracted by adapting a cost function with the Taguchi method. Subsequently, the frequency weighting function is developed by the subjective evaluation in which 6 special engineers were participated. Finally, the comparison between the proposed frequency weighted optimal design and unweighted optimal design for the transmission loss as the part is performed. Here, the overall levels of the transmission loss according to the methods are presented to validate the effectiveness of the proposed methodology.

• 한국자동차공학회논문집
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• 제22권1호
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• pp.8-19
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• 2014

In this paper, a robust design of the back-plate of the brake pad to decrease the uneven wear of the pad was studied. A finite element analysis was performed to analyze the pressure distributions on the contact surfaces. Optimized back-plate shape of the brake pad was determined using the Taguchi method. The effectiveness of the robust design was clarified by the wear tests with a dynamometer.

• 대한기계학회논문집A
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• 제21권5호
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• pp.859-869
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• 1997

In this paper, the robust design and tolerancing of the stabilized mirror is performed to increase its stabilization performance under vehicle vibration. Based on the sensitivity analysis, the seven important control factors are first identified, and then the optimal as well as robust values in the sense of Taguchi method are obtained. Finally, the tolerances associated with each design variables are determined based on a successive sensitivity analysis of the simulated system response so that the deviation in the response from the target value meets the specification requirements. The proposed tolerancing method features that it is a robust but conservative design method and that the computational effort is much less than the Monte Carlo simulation method.

• 한국정밀공학회지
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• 제13권10호
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• pp.56-61
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• 1996

In this study a method for a robust design of mechanisms is proposed. The method used in the experimental analysis and quality engineering is applied for mechanisms design. A mathematical model for a mechanism is estimated by the response surface analysis and the estimated model is used in minimization of the variance. Using this result, robust design can be carried out. The method can be applied for general mechansims. Furthermore because the method can be used in the design stage using the computer model, improved quality and lower cost of the product is achieved even in the design stage.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.110-113
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• 2006

This paper describes the development process of body and full vehicle for reduced idle vibration through the data level of frequency and sensitivity. The vibration mode map is used to separate body structure modes from resonance of engine idle nm and steering system. This paper describes the analysis approach process to reduce the variation of uncertainties for idle vibration performance at initial design stage. The robust design method is performed to increase the stabilization performance under vehicle vibration. It is used to predict the effects of the stiffness deviation according to the spot welding condition of the body structure. The tolerance associated with hood over slam bumper is analyzed for the quality deviation of the moving system in full vehicle. And the glass sealant stiffness and weight difference is considered for the deviation characteristic. The design guideline is suggested considering sensitivity about body and full vehicle by using mother car at initial design stage. It makes possible to design the good NVH performance and save vehicles to be used in tests. These improvements can lead to shortening the time needed to develop better vehicles.

• 한국기계가공학회지
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• 제7권2호
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• pp.8-15
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• 2008

Current trend of design technologies shows engineers to objectify or automate the given decision-making process. The numerical optimization is an example of such technologies. However, in numerical optimization, the uncertainties are uncontrollable to efficiently objectify or automate the process. To better manage these uncertainties, Taguchi method, reliability-based optimization and robust optimization are being used. Based on the independence axiom of axiomatic design theory that illustrates the relationship between desired specifications and design parameters, the designs can be classified into three types: uncoupled, decoupled and coupled. To best approach the target performance with the maximum robustness is one of the main functional requirements of a mechanical system. Most engineering designs are pertaining to either coupled or decoupled ones, but these designs cannot currently accomplish a real robustness thus a trade-off between performance and robustness has to be made. In this research, the game theory will be applied to optimize the trade-off.

• 대한기계학회논문집
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• 제18권2호
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• pp.278-291
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• 1994

A computer-aided robust design (CARD) technique is developed to search for the design variables, optimal as well as robust in the sense of Taguchi method. The CARD technique can effectively handle inequality problems by employing the variable penalty method, and dynamic problems with many design variables and/or with mixed discrete and continuous variables. It is also capable of providing contributions of each design variables to the object funtion and information for future designs. As the illustrative examples, two dynamic systems, engine mounting system and in-line feeder, are treated.

• 한국공작기계학회논문집
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• 제15권4호
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• pp.8-14
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• 2006

The important function of Ball-Stop part is to operate power shift using suitable pneumatic force for vehicle with more than 5 ton when a driver changes gear. In this paper, we have applied the concept of the DFSS(Design for Six Sigma) to robust design of Ball-Stop part. First, we have found the control factors which could mainly influence the performance of the Ball-Stop part. The simulations of contact between head and detent pin was performed to evaluate effect of control factors according to DOE(Design of experiment) by using $ADAMS^{(R)}$. Finally, we have obtained optimal levels of each factors using $MINITAB^{(R)}$. Through the comparison of the result of optimized design with one of inintial design, we have verified the usefulness of DFSS method which can be applied to robust design of mechanical systems.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 I
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• pp.419-426
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• 2001

Industrial products determined by fixed size posses definite limits variety by manufacture tolerance in existence. The optimum value solved by deterministic approaches do not account of tolerance bands of design variables and material properties. If we examine optimum value considering tolerance bands of design variables and material properties, it might be useless, owing to exist infeasible region. We have two ways to prevent being useless value. The one is to minimize tolerance band, the other is to consider tolerance band in optimum design. The former needed more accuracy during manufacturing process require higher production cost, the letter is more appropriate to consider tolerance band. In this research, we consider the tolerance bands of all variables, which might have the tolerance bands used in the problem, based on optimum value of deterministic approaches. Orthogonal arrays are used to minimize the number of trial. Tolerance bands are supposed discretionary according to design variable. Appropriateness suggested by this research is examined through two examples. Mathematical problem is investigated only in terms of tolerance bands of design variables, and cantilever beam problem is explained through tolerance bands of design variable, material properties and loading conditions. It is proved that values from the presented method are satisfactory for tolerance bands of variables.