Preview Control of Slow-active Suspension Systems

Abstract

Preview control is investigated for active suspension systems. Two preview concepts are used: (1) look-ahead preview, where the information relating to roadway disturbances about to be encountered by the moving vehicle is assumed to be sensed, and (2) wheelbase preview, where knowledge of the front wheel states is used to improve performance at the rear of the vehicle. A method based on optimal control theory is presented to find the control laws for a half-car equipped with both fully active and slow-active systems under preview. The random road profile is assumed to be the output of a filtered white-noise process. Human perception of vibration is considered in the design of the active suspension systems. The design of the preview controller is reduced to the classical linear quadratic regulator of the original system and the previewed road inputs. Integral constraints are included in the performance index to achieve better body attitude control. The effect of preview control on vehicle performance characteristics in terms of ride comfort, suspension deflections and road-holding ability is investigated. The results show that the use of wheelbase preview along with look-ahead preview improves all aspects of the suspension performance.

Keywords

Active suspension LQR preview control slow-active system vehicle dynamics

Get full access to this article

View all access options for this article.

References

Abdel-Hady, M.B.A. and Crolla, D.A. , 1989, ‘‘Theoretical analysis of active suspension performance using a four-wheel model,’’ Proceedings of the Institute of Mechanical Engineers 203(D), 125-135.

Athans, M. and Falb, P.L. , 1966, Optimal Control: An Introduction to the Theory and its Applications, McGraw-Hill.

ElMadany, M.M. , Abduljabbar, Z. , and Foda, M. , 2003, ‘‘Optimal preview control of active suspensions with integral constraint,’’ Journal of Vibration and Control 9, 1377-1400.

Fayed, A.A. , 2007, ‘‘Optimal preview control of active suspension systems,’’ MSc thesis, King Saud University , Saudi Arabia.

Godall, R.M. and Kortum, W. , 1983, ‘‘Active control in ground transportation - a review of the state-of-the-art and future potential,’’ Vehicle System Dynamics 12, 205-227.

Hac, A. , 1992, ‘‘Optimal linear preview control of active suspension,’’ Vehicle System Dynamics 21, 167-195.

Hedrick, J.K. and Wormley, D.N. , 1975, ‘‘Active suspension for ground transportation vehicle - a state-of-the-art review,’’ Mechanics of Transportation Systems, AMD 15, 21-40, (ASME ).

Hrovat, V. , 1997, ‘‘Survey of advanced suspension developments and related optimal control applications,’’ Automatica 33(10), 1781-1817.

Huisman, R.G.M. , Veldpaus, F.E. , Voets, H.J.M. , and Kok, J.J. , 1993, ‘‘An optimal continuous time control strategy for active suspensions with preview,’’ Vehicle System Dynamics 22, 43-55.

10.

ISO 7096-82 , 1982, ‘‘Earth Moving Machinery-Operator Seat-Transmitted Vibration,’’ First edition, International Organization for Standardization, Geneva.

11.

ISO 2631-1 , 1997, ‘‘Mechanical Vibration and Shock Evaluation of Human Exposure to Whole-Body Vibration,’’ International Organization for Standardization, Geneva, pp. 1-31.

12.

Karlesson, N. , Dahleh, M. , and Hrovat, D. , 2001, ‘‘Nonlinear active suspension with preview,’’ in Proceedings, American Control Conference, Arlington, VA, June 25-27, Vol. 4, pp. 2640-2645.

13.

Kim, H.-J. , Yang, H.S. , and Park, Y. , 2002, ‘‘Improving the vehicle performance with active suspension using road-sensing algorithm,’’ Computers & Structures 80, 1569-1577.

14.

Louam, N. , Wilson, D.A. , and Sharp, R.S. , 1992, ‘‘Optimization and performance enhancement of active suspensions for automobiles under preview of the road, ’’ Vehicle System Dynamics 21, 39-63.

15.

Matsushita, H. , Dohta, S. , and Noritsugu, T. , 1997, ‘‘Preview control of pneumatic rear suspension using a disturbance observer,’’ Transactions, Japan Society of Mechanical Engineers, Part C, 63(615), 3905-3910.

16.

Mehra, R.K. , Amin, J.N. , Hedrick, K.J. , Osorio, C. , and Gopalasamy, S. , 1997, ‘‘Active suspension using preview information and modal predictive control,’’ in Proceedings, IEEE International Conference on Control Applications , Piscataway, NJ, USA, 97CH36055, pp. 860-865.

17.

Muller, P.C. , Popp, K. , and Schiehlen, W.O. , 1979, ‘‘Covariance analysis of nonlinear stochastic guideway-vehicle-systems,’’ in Proceedings, 6th IAVSD Symposium, Technical University, Berlin, September, pp. 337-351.

18.

Nagai, M. , 1993, ‘‘Recent researches on active suspensions for ground vehicles,’’ JSME International Journal Series C 36(2), 161-170.

19.

Pilbeam, C. and Sharp, R.S. , 1993, ‘‘On the preview control of limited bandwidth vehicle suspension,’’ Proceedings of the Institute of Mechanical Engineers 207, 185-193.

20.

Qarmoush, A.O. , 2004, ‘‘Ride performance of a slow-active suspension system based on a full vehicle model,’’ MSc thesis, King Saud University, Saudi Arabia .

21.

Rotenberg, R.W. , 1972, ‘‘Vehicle suspension,’’ Moskou: Mašinostrojenie (in Russian).

22.

Senthil, S. and Narayanan, S. , 1996, ‘‘Optimal preview control of a two-DOF vehicle model using stochastic optimal control theory,’’ Vehicle System Dynamics 25, 413-430.

23.

Sharp, R.S. and Crolla, D.A. , 1987, ‘‘Road vehicle suspension system design - a review,’’ Vehicle System Dynamics 16, 167-192.

24.

Sharp, R.S. and Hassan, S.S. , 1987, ‘‘Performance and design consideration for dissipative semi-active suspension systems for automobiles, ’’ Proceedings, Institution of Mechanical Engineers Part D, Vol. 201(D2), 1-5.

25.

Sharp, R.S. and Pilbeam, C. , 1993, ‘‘On the ride comfort benefits available from road preview with slow-active car suspensions,’’ in Proceedings, 13th IAVSD Symposium, pp. 437-448.

26.

Thompson, A.G. , Davis, B.R. , and Pearce, C.E. , 1980, ‘‘An optimal linear active suspension with finite preview,’’ Transactions, Society of Automotive Engineers No. 800520.

27.

Yoshimura, T. and Ananthanarayana, N. , 1991, ‘‘Stochastic optimal control of vehicle suspension with preview on an irregular surface,’’ International Journal of System Science 22, 1599-1611.

28.

Yu, F. , Zhang, J.-W. , and Crolla, D.A. , 2000, ‘‘A study of a Kalman filter active vehicle suspension system using correlation of front and rear wheel road inputs,’’ Proceedings of the Institute of Mechanical Engineers 214 Part D, 493-502.