Aplicação de um modelo paramétrico multivariado para o controle da temperatura de fornos de túnel
Souza, Adriano Mendonça; Samohyl, Robert Wayne; Malavé, Cesar O.
Abstract
O principal objetivo desta pesquisa é implementar um ajuste multivariado proporcional, em relação ao último erro, das variáveis que estão fora do alvo desejado. Para a realização do ajuste multivariado proporcional, utilizou-se um forno de túnel para a queima de azulejo. Dessa forma, foi possível analisar todas as etapas do processo produtivo, para efetivar a equação de controle proposta. As etapas seguidas foram: a aplicação da estatística de médias móveis ponderadas exponencialmente, que determinará o comportamento dos distúrbios; os valores futuros das variáveis serão estimados por regressões aparentemente não correlacionadas, pois existe relação entre as variáveis e entre os erros das equações estimadas; e aplicação da equação de controle proposta. Dessa forma, um ajuste de realimentação multivariado pode ser alcançado de modo científico, controlando, assim, a temperatura do forno.
Keywords
References
ASTROM, K.J, and WITTENMARK, B. Adaptative Control. Addison Wesley, Reading, MA. 1989.
APARISI, F. (1997). Sampling plans for the multivariate T2 control chart. Quality Engineering, v.10. n.1, p.141-147.
BOX, G.E.P. (1991). Feedback control by manual adjustment. Quality Engineering, 4(1), p. 143-151.
BOX, G.E.P. and JENKINS, G.M. Time series analysis - Forecasting and control. Oakland, CA: Holden-Day, 1970.
BOX, G.E.P; HUNTER, W.G. and HUNTER, J.S. Statistics for experiments. An introduction to design, data analysis and model building. John Wiley & Sons, Inc. NY. 1978.
BOX, G.E.P.; JENKINS, G.M. and Mac GREGOR, J.F. (1974). Some recent advances in forecasting and control. Applied Statistics, v. 23, p. 158-179.
BOX, G.E.P; JENKINS G.M and REINSEL G.C. Time series analysis: forecasting and control. 3 ed. Prentice Hall Inc. Englewood Cliffs, NJ, 1994.
BOX, G.E.P. and KRAMER, T. (1992). Statistical process control and automated process control - A discussion. Technometrics, August, v. 34, p. 251-267.
BOX, G.E.P. and LUCEÑO, A. (1997). Discrete proportional-integral adjustment and statistical process control. Journal of Quality Technology, July, v. 29, n. 3.
______. Statistical control by monitoring and feedback adjustment. John Wiley & Sons, Inc. NY, 1997.
CHARENZA, W.W. and DEADMAN, D. New directions in econometric practice general to specific modelling, cointegration and vector autoregression. 2 ed. Edward Elgar Publishier Limited, Cheltenham, UK, 1997.
COCHRANE, J.H. Time series for macroeconomics and finance. University of Chicago, Chicago, IL. Spring 1997.
CROWDER, S.V. (1989). Average runs lengths of exponentially weighted moving average control charts. Journal Quality Technology, v. 19, p. 161-164.
CROWDER, S.V. and HAMILTON, M.D. (1992). An EWMA for monitoring a process standard deviation. Journal of Quality Technology, January, v. 24 n. 1, p. 12-21.
DEL CASTILLO, E. (1996). A multivariate self-tuning controller for run-to-run process control under shift and trend disturbances. IIE transactions, v. 28, p. 1011-1021.
ENDERS, W. Applied econometric time series. Wiley series in probability and mathematical statistics. John Wiley and Sons, Inc., New York. N.Y. 1995.
FRANKLIN, F.G.; POWELL, D.J. and EMAMI-NAEINI, A. Feedback control of dynamic systems. 3 ed. Addison-Wesley Publishing Company, Inc. New York. N.Y. 1994.
HAMILTON, J.D. Time Series analysis. Princeton University Press, Princeton - New Jersey, N.J. 1994.
HILL, C.; GRIFFITHS, W.; JUDGE, G. Econometria. São Paulo. Editora Saraiva, 1999.
HUNTER, J. S. (1986). The exponentially weighted moving average. Journal of Quality Technology, v. 18, p. 203-210.
JACKSON, J.E. (1956).Quality control methods for two related variables. Industrial Quality Control, January. p. 4-8.
KEATING, J.W. (1990). Identifying VAR models under rational expectations. Journal of Monetary Economics, v. 25, p. 453-476.
KHURI A.I. & CONLON M. (1981). Simultaneous optimization of multiple responses represented by polynomial regression functions. Technometrics, November. v. 23, n. 4.
LUCAS, M.J. and SACCUCCI, M.S. (1990). Exponentially weighted moving average control schemes: Properties and enhancements. Technometrics, February. v. 32. n. 1, p.1-12.
______. (1990). Exponentially weighted moving average control schemes: Properties and enhancements. Technometrics, v. 20, p. 85-93.
LÜTKEPOHL, H. Introduction to multiple time series analysis. 2. ed. Springer-Verlag Berlin - Germany, 1991.
Mac GREGOR, J.F. (1987). Interface between process control and on-line statistical process control. Computational System Technology Division Communication, v. 10, p. 9-20.
MADDALA, G.S. Introduction to econometrics. 2. ed. Prentice-Hall Inc. Englewood Cliffs, New Jersey, 1992.
MONTGOMERY, D.C. and MASTRANGELO, C.M. (1991). Some statistical process control methods for autocorrelated data. Journal of Quality Technology, July, v. 23, n. 3, p.179-204.
MONTGOMERY, D.C; KEATS, J.B.; RUNGER, G.C. and MESSINA, W.S. (1994). Integrating statistical process control and engineering process control. Journal of Quality Technology, April, v. 26, n. 2, p. 79-87.
RAMIREZ, W.F. (1994). Process control and identification. Academic Press, Inc. San Diego, C.A.
REINSEL, G. C. Elements of multivariate time series analysis. Springer-Verlag, New York, 1993.
SACHS, E.; HU, A. and INGOLFSSON, A. (1995). Run by run process control: Combining SPC and feedback control. IEEE Transaction on Semiconductor Manufacturing, February, v. 8, n. 1, p. 26-43.
SIMS, C.A. (1980). Macroeconomicas and reality. Econometrica 48, p. 1-48.
SHINSKEY, F.G. Feedback controlers for the process industries. Mc Graw Hill, Inc., New York. N.Y. 1994.
TUCKER, W.T; FALTIN, F.W and VANDER WIEL, S.A.V. (1993). Algorithmic statistical process control: An elaboration. Technometrics, November, v. 35. n. 4.
VANDER WIEL, S.A. (1996). Monitoring process that wander using integrated moving average models. Technometrics, May, v. 38, n. 2.
ZELLNER, A. (1962). An efficient method of estimating seemingly unrelated regressions and tests for aggregation bias. American Statistical Association Journal, June, p. 348- 368.
ZELLNER, A. and THEIL, H. (1962). Three-stage least squares: Simultaneous estimation of simultaneous equations. Econometrica, January, v. 30, n. 1.