L. Olmos & L. Álvarez-lcaza

Instituto de Ingeniería, Universidad Nacional Autónoma de México. 04510, Coyoacán DF, México. LOlmosG@iingen.unam.mx alvar@pumas.iingen.unam.mx

Received: January 20^th 2003.
Accepted: March 30^th 2005.

A dynamic friction model for the tire-road interface is used in an optimal control scheme for emergency braking of vehicles. The controller sets a target relative velocity curve that the vehicle must track in order to achieve braking in minimum time. It is shown that this curve corresponds to the solution of a minimum time optimal control problem. The final goal of the control is to improve the safety levels in highway transportation.

Keywords: Optimal control, Vehicular control, Dynamic friction model.

Resumen

Se utiliza un modelo dinámico de fricción para la interfase llanta-pavimento en el diseño de un esquema de control óptimo para el frenado de emergencia de vehículos. El controlador establece una curva de referencia para la velocidad relativa que el vehículo debe seguir para poder alcanzar el frenado en tiempo mínimo. Se muestra que esta curva corresponde con la solución de un problema de control óptimo. El objetivo final de este esquema de control es aumentar los niveles de seguridad en autopistas.

DESCARGAR ARTÍCULO EN FORMATO PDF

Acknowledgments

Reference

[1] Lygeros, J. D., Godbole, N., and Broucke, M. E. "A fault tolerant control architecture for automated highway systems," IEEE Transactions on Control Systems Technology, vol. 8, pp. 205-219, 2000.         [ Links ]

[2] L. Alvarez and R. Horowitz, "Safe platooning in AHS. Part I: safety regions design, "Vehicle System Dynamics, vol. 32, no. 1,pp. 23-56, 1999.         [ Links ]

[3] J. Yi, L. Alvarez, X. Claeys, R. Horowitz, C. Canudas, and L. Olmos," Adaptive emergency braking control with observer-base dynamic tire/road friction model and underestimation of friction coefficient." Proceedings of the IFAC'02 World Congress, Paper #2252, T-ThA02, 2002.         [ Links ]

[4] U. Kiencke and A. Daiss, "Estimation of tyre friction for enhanced ABS-systems," in Proceedings of the AVEG'94, 1994.         [ Links ]

[5] U. Kiencke, "Realtime estimation of adhesion characteristic between tyres and road," in Proceedings of the FFAC World Congress, vol. 1, pp. 15-22, 1993.         [ Links ]

[6] Y. Liu and J. Sun,"Target slip tracking using gain scheduling for anti-lock braking systems," in Proceedings of the 1995 American Control Conference, pp. 1178-1182, 1995.         [ Links ]

[7] T. Gillespie, Fundamentals of Vehicle Dynamics. Warrendale, PA: Society of Automotive Engineers, Inc., 1992.         [ Links ]

[8] E. Bakker, L. Nyborg and H. Pacejka, "Tyre modelling for use in vehicle dynamic studies." Society of Automotive Engineers Paper # 870421, 1987.         [ Links ]

[9] M. Burckhardt, Fahrwerktechnik: Radschlupfregelsysteme. Germany: Vogel-Verlag, 1993.         [ Links ]

[10 ] C. Canudas de Wit, H. Olsson, K. J. "Astrom, and P. Lischinsky, "A new model for control of systems with friction," IEEE Transactions on Automatic Control, vol. 40, no. 3, pp. 419-425, 1995.         [ Links ]

[11] C. Canudas and R. Horowitz, "Observers for tire/road contact friction using only whell angular velocity information," in Proceedings of the 1999 Conference on Decision and Control, pp. 3932-3937, 1999.         [ Links ]

[12] L. Olmos, "Control de frenado de emergencia con base en modelos de fricción llanta pavimento," Master's thesis, Programa de Maestría y Doctorado en Ingeniería, Universidad Nacional Autónoma de México, 2001.         [ Links ]

[13] H. K. Khalil, Nonlinear Systems. USA: Prentice-Hall, second ed., 1996.         [ Links ]

[14] A. E. Bryson and Y.-C. Ho, Applied Optimal Control. USA: Blaisdell Publishing Company, first ed., 1969.         [ Links ]

[15] P. Tsiotras and C. Canudas, "On the optimal braking of wheeled vehicles," in Proceedings of the 2000 American Control Conference, pp. 569-573, 2000.         [ Links ]

[16] C. Canudas and P. Tsiotras, "Dynamic tire friction models for vehicle traction control," in Proceedings of the 1999 Conference on Decision and Control, pp. 3746-3751, 1999.         [ Links ]