Tracking control for hydraulic systems is a key system requirement, as these devices must often follow prescribed motions. Tracking control of hydraulic systems has been approached using both linear and nonlinear control laws. The latter provides improved performance, but at the expense of additional sensors. Further, the control laws often employ hydraulic fluid bulk modulus—a difficult-to-characterize quantity—as a parameter. To overcome these difficulties, we have developed a control design procedure that requires no additional sensors and is robust to variations in the bulk modulus. A dual approach of singular perturbation theory and Lyapunov techniques form the basis for the procedure. For the cases of a small-amplitude sinusoidal input and large-amplitude polynomial input, a candidate system achieved good tracking performance and exhibited outstanding robustness. The ability to accomplish good tracking in a robust manner with no additional sensors provides advantages over other nonlinear tracking algorithms.

1.
Kokotovic´, P. V., and Khalil, H. K., eds., 1986, Singular Perturbations in Systems and Control, IEEE Press, New York, NY.
2.
Kokotovic´, P. V., Khalil, H. K., and Reilly, J. O., 1986, Singular Perturbation Methods in Control: Analysis and Design, Academic Press, New York, NY.
3.
Kokotovic´
,
Petar V.
,
1989
, “
Applications of singular perturbation techniques to control problems
,”
SIAM Rev.
,
26
, No.
4
, pp.
501
550
.
4.
Kim, Eung-Seok, 1996, “Nonlinear indirect adaptive control of a quarter car active suspension,” Proceedings of the 1996 Conference on Control Applications, pp. 61–66, Dearborn, MI, Sept.
5.
Alleyne, Andrew, 1996, “Nonlinear force control of an electro-hydraulic actuator,” Japan-USA Symposium on Flexible Automation, pages 193–200, Boston, MA, June American Society of Mechanical Engineers.
6.
Hahn, H., Piepenbrink, A., and Leimbach, K.-D., 1994, “Input/output linearization control of an electro servo-hydraulic actuator,” Proceedings of the 1994 Conference on Control Applications, pp. 995–1000, Glasgow, UK, Aug.
7.
Sohl
,
Garett A.
, and
Bobrow
,
James E.
,
1999
, “
Experiments and simulations on the nonlinear control of a hydraulic servosystem
,”
IEEE Trans. Control Syst. Technol.
,
7
, No.
2
, pp.
238
247
.
8.
Alleyne, Andrew, and Karl Hedrick, J., 1992, “Nonlinear control of a quarter car active suspension,” Proceedings of the 1992 American Control Conference, pp. 21–25, Chicago, IL, June.
9.
Alleyne
,
Andrew
, and
Karl Hedrick
,
J.
,
1995
, “
Nonlinear adaptive control of active suspensions
,”
IEEE Trans. Control Syst. Technol.
,
3
, No.
1
, pp.
94
101
.
10.
Park, H. J., Cho, H. S., and Hyun, B. S., 1989, “An adaptive control of nonlinear time-varying hydraulic servo systems,” Proceedings of the 1989 American Control Conference, pp. 1894–1898, Pittsburgh, PA, June.
11.
Khalil, Hassan K., 1996, Nonlinear Systems, Prentice-Hall, New Jersey.
12.
Eryilmaz, Bora, and Wilson, Bruce H., 1999, “A unified model of a proportional valve.” Sanjay I. Mistry and Tim McLain, eds, Proceedings of the ASME Fluid Power Systems and Technology Division, Vol. FPST-Vol. 6, pp. 95–102, Nashville, TN, Nov., ASME IMECE Congress.
13.
Merritt, Herbert E., 1967, Hydraulic Control Systems, Wiley, New York, NY.
14.
de Boor, Carl, 1997, Matlab Spline Toolbox, The MathWorks, Natick, MA, Dec.
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