A Two-Stage Vibration Isolation System Featuring an Electrorheological Damper via the Semi-Active Static Output Feedback Variable Structure Control Method

Abstract

In this paper, we present a semi-active static output feedback variable structure control (VSC) strategy for vibration isolation. The control concept is based on the fact that, for a practical vibration isolation system subject to external disturbances, all state variables are hard to measure on-line and variations of system parameters frequently exist. A bypass electrorheological (ER) damper is designed and manufactured by incorporating a Bingham model of ER fluids. After the voltage-dependent damping characteristics of the ER damper are evaluated, the dynamic model of a two-stage vibration isolation system with one ER damper is derived. Using only the measured information from sensors installed at strategic locations, continuous output feedback VSC controllers are presented, which do not have possible chattering effects. The continuous control law is decoupled from external disturbances by combining controller design under a meeting sliding mode reachable condition with the choice of sliding surface gradient parameters under a guarantee of the Routh-Hurwitz stability of reduced-order sliding mode dynamics. The saturation of the actuator is also incorporated into the controller, showing no adverse effect. The self-adaptability of the vibration isolation system with respect to external disturbances, the robustness of the control method with respect to parameter variations and the effectiveness of vibration isolation are demonstrated by numerical simulation results in the frequency and time domains. It is illustrated that the performance of the presented semi-active static output feedback VSC system is superior to those of optimally passive damping and maximum damping variety even if system parameter uncertainties exist.

Keywords

ER damper semi-active control static output feedback variable structure control

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References

Choi, S. B. , Choi, Y. T. , Chang, E. G. , Han, S. J. , and Kim, C. S. , 1998a, “Control characteristic of a continuously variable damper,” Mechatronics 8, 143-161.

Choi, S. B. , Park, Y. K. , Cheong, C. C. , and Lee, H. G. , 1998b, “A semi-active suspension using ER fluids for a commercial vehicle seat,” Journal of Intelligent Material Systems and Structures 9, 601-606.

Choi, S. B. , Choi, Y. T. , and Park, D. W. , 2000, “A sliding mode control of a full car electrorheological suspension system via hardware in-the-loop simulation,” ASME Journal of Dynamic Systems, Measurements, and Control 122, 115-121.

Choi, S. B. , Lee, H. K. , and Chang, E. G. , 2001, “Field test results of a semi-active ER suspension system associated with skyhook controller,” Mechatronics 11, 345-353.

Davison, E. L. and Wang, S. H. , 1975, “On pole assignment in linear multivariable systems using output feedback,” IEEE Transactions on Automatic Control 20, 516-518.

Elbeheiry, E. M. , 2000, “Effects of small travel speed variations on active vibration control in modern vehicles,” Journal of Sound and Vibration 232(5), 857-875.

Gavin, H. P. , Hanson, R. D. , and Filisko, F. E. , 1996, “Electrorheological dampers, part I: Analysis and design,” ASME Journal of Applied Mechanics 63, 669-675.

Gordaninejad, F. , Ray, A. , and Wang, H. , 1997, “Control of forced vibration using multi-electrode electro-rheological fluid dampers,” ASME Journal of Vibration and Acoustics 119(4), 527-531.

Heck, B. S. and Ferri, A. A. , 1989, “Application of output feedback to variable structure systems,” AIAA Journal of Guidance, Control, and Dynamics 12(6), 932-935.

10.

Hsu, K. C. , 1998, “Sliding mode controllers for uncertain systems with input nonlinearities,” AIAA Journal of Guidance, Control, and Dynamics 21(4), 666-669.

11.

Karnopp, D. C. , Crosby, M. J. , and Harword, R. , 1974, “Vibration control using semi-active force generators,” ASME Journal of Engineering for Industry 96(2), 619-626.

12.

Kim, Y.S. , Wang, K. W. , and Lee, H. S. , 1992, “Feedback control of ER-fluid-based structures for vibration suppression,” Smart Materials and Structures 1(2), 139-145.

13.

Nakano, M. , 1995, “A novel semi-active control of automotive suspension using an electrorheological shock absorber,” in Proceedings of the 5th International Conference on ER Fluid, MR Suspensions and Associated Technology, Sheffield, UK, July 10-14, pp. 527-531.

14.

Petek, N. K. , 1992, “An electronically controlled shock absorber using electro-rheological fluid,” SAE Technical Paper 920275.

15.

Petek, N. K. , Romstadt, D. L. , Lizell, M. B. , and Weyenberg, T. R. , 1995, “Demonstration of an automotive semi-active suspension using electrorheological fluid,” SAE Technical Paper 950586.

16.

Rakheja, S. , Afework, Y. , and Sankar, S. , 1994, “Analytical and experimental investigation of the driver-seat-suspension system,” Vehicle System Dynamics 22(7), 501-524.

17.

Stanway, R. , Sproston, J. L. , and El-Wahed, A. K , 1996, “Application of electro-rheological fluids in vibration control: a survey,” Smart Materials and Structures 5, 464-482.

18.

Utkin, V.I. , 1977, “Variable structure systems with sliding modes,” IEEE Transactions on Automatic Control 22, 212-222.

19.

Wang, K. W. , Kim, Y. S. , and Shea, D. B. , 1994, “Structural vibration control via electrorheological-fluid-based actuators with adaptive viscous and frictional damping,” Journal of Sound and Vibration 177(2), 227-237.

20.

Zhou, F. and Fisher, D. G. , 1992, “Continuous sliding mode control,” International Journal of Control 55(2), 313-327.