Adaptive sliding control of non-autonomous active suspension systems with time-varying loadings

An adaptive sliding controller is proposed in this paper for controlling a non-autonomous quarter-car suspension system with time-varying loadings. The bound of the car-body loading is assumed to be available. Then, the reference coordinate is placed at the static position under the nominal loading so that the system dynamic equation is derived. Due to spring nonlinearities, the system property becomes asymmetric after coordinate transformation. Besides, in practical cases, system parameters are not easy to be obtained precisely for controller design. Therefore, in this paper, system uncertainties are lumped into two unknown time-varying functions. Since the variation bound of one of the unknown functions is not available, conventional adaptive schemes and robust designs are not applicable. To deal with this problem, the function approximation technique is employed to represent the unknown function as a finite combination of basis functions. The Lyapunov direct method can thus be used to find adaptive laws for updating coefficients in the approximating series and to prove stability of the closed-loop system. Since the position and velocity measurements of the unsprung mass are lumped into the unknown function, there is no need to install sensors on the axle and wheel assembly in the actual implementation. Simulation results are presented to show the performance of the proposed strategy.

[1]  D. Hrovat,et al.  A suboptimal nonlinear active suspension , 2000, Proceedings of the 2000 American Control Conference. ACC (IEEE Cat. No.00CH36334).

[2]  Huei Peng,et al.  Adaptive robust control for active suspensions , 1999, Proceedings of the 1999 American Control Conference (Cat. No. 99CH36251).

[3]  Toshio Yoshimura,et al.  CONSTRUCTION OF AN ACTIVE SUSPENSION SYSTEM OF A QUARTER CAR MODEL USING THE CONCEPT OF SLIDING MODE CONTROL , 2001 .

[4]  An-Chyau Huang,et al.  Adaptive sliding control for single-link flexible-joint robot with mismatched uncertainties , 2004, IEEE Trans. Control. Syst. Technol..

[5]  Pierre Apkarian,et al.  Nonlinear H∞ control for an integrated suspension system via parameterized linear matrix inequality characterizations , 2001, IEEE Trans. Control. Syst. Technol..

[6]  Eung-Seok Kim.  Nonlinear indirect adaptive control of a quarter car active suspension , 1996, Proceeding of the 1996 IEEE International Conference on Control Applications IEEE International Conference on Control Applications held together with IEEE International Symposium on Intelligent Contro.

[7]  Kevin M. Passino,et al.  Stable Adaptive Control and Estimation for Nonlinear Systems , 2001 .

[8]  W. Rudin.  Principles of mathematical analysis , 1964 .

[9]  Weiping Li,et al.  Applied Nonlinear Control , 1991 .

[10]  An-Chyau Huang,et al.  Sliding control of non-linear systems containing time-varying uncertainties with unknown bounds , 2001 .

[11]  Andrew G. Alleyne,et al.  Nonlinear adaptive control of active suspensions , 1995, IEEE Trans. Control. Syst. Technol..

[12]  Paul I. Ro,et al.  A sliding mode controller for vehicle active suspension systems with non-linearities , 1998 .

[13]  Davorin David Hrovat,et al.  Nonlinear H/sub /spl infin// control of active suspensions , 2001, Proceedings of the 2001 American Control Conference. (Cat. No.01CH37148).

[14]  Anuradha M. Annaswamy,et al.  Stable Adaptive Systems , 1989 .

[15]  Norihiko Adachi,et al.  Nonlinear and H/sub /spl infin// control of active suspension systems with hydraulic actuators , 1999, Proceedings of the 38th IEEE Conference on Decision and Control (Cat. No.99CH36304).

[16]  D. Hrovat,et al.  Survey of Advanced Suspension Developments and Related Optimal Control Applications, , 1997, Autom..

[17]  Ka C. Cheok,et al.  Model reference adaptive control for vehicle active suspension systems , 1991 .

[18]  Niklas Karlsson,et al.  Nonlinear H, control of active suspensions , 2001 .

[19]  An-Chyau Huang,et al.  Adaptive sliding control of active suspension systems with uncertain hydraulic actuator dynamics , 2003 .