QUALITY IMPROVEMENT FOR BRAKE JUDDER USING DESIGN FOR SIX SIGMA WITH RESPONSE SURFACE METHOD AND SIGMA BASED ROBUST DESIGN |
H. S. KIM1, C. B. KIM2, H. J. YIM1 |
1Kookmin University 2Inha University |
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ABSTRACT |
The problem of brake judder is typically caused by quality defects in manufacturing. DFSS(Design for six sigma) is a design process for quality improvement. DFSS will result in more improved but less expensive quality products. This paper presents an implementation of DFSS for quality improvement of the brake judder of heavy-duty trucks. Carrying out 5 steps of DFSS, the major reasons for quality defects are found. And the numerical approximation of the brake system is derived by means of the response surface method. Its quality for brake judder is improved by use of the sigma based robust design methodology. Results between the conventional deterministic optimal design and the proposed sigma based robust design are compared. The proposed one shows that manufacturing cost may increase as the quality level increase. The proposed one, however, is more economical in aspect of overall cost, because the probability of failure dramatically goes down. |
Key Words:
Brake judder, Design for six sigma(DFSS), Response surface method, sigma based robust design, Brake torque variation (BTV), Deterministic optimization, Probabilistic optimization |
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