This article presents the development of a multiple inner-loop control strategy for improving the performance of hydrostatic actuation systems. In these actuators, the presence of nonlinearities associated with pump/motor static friction and backlash, pressure drop in the piping system, and nonlinear friction at the load have a significant effect on the performance and positional accuracy of the system. The effect of nonlinear friction at the pump/motor interface has been overcome by the use of a high gain pump-speed inner-loop control strategy. In this article, the concept of inner-loop control will be extended to target other specific sources of performance degradation. Velocity feedback will be incorporated in this manner to decrease the effects of pump backlash and nonlinear friction at the load. Simulation results supported by theoretical analysis indicate that a considerable improvement in performance can be achieved by the implementation of this control strategy.

References

References
1.
Habibi
,
S.
, and
Goldenberg
,
A.
, 2000, “
Design of A New High-Performance Electrohydraulic Actuator
,”
IEEE/ASME Trans. Mechatron
.
5
(
2
), pp.
158
64
.
2.
Manring
,
N.
, and
Luecke
,
G.
, 1998, “
Modeling and Designing a Hydrostatic Transmission With a Fixed-Displacement Motor
,”
Trans. ASME J. Dyn. Syst. Meas. Control
,
120
(
1
), pp.
45
49
.
3.
Manring
,
N.
, 2000, “
The Discharge Flow Ripple of an Axial-Piston Swash-Plate Type Hydrostatic Pump
,”
Trans. ASME J. Dyn. Syst. Meas. Control
,
122
(
2
), pp.
263
8
.
4.
Watton
,
J.
, 1989,
Fluid Power Systems
, Prentice-Hall Int., Hemel Hempstead.
5.
Tran
,
H. D.
, and
DeBra
,
D. B.
, 1994, “
Design of a Fast Short-Stroke Hydraulic Actuator
,”
CIRP Ann
.
43
(
1
), pp.
469
472
.
6.
Habibi
,
S.
, and
Goldenberg
,
A.
, 1999, “
Design and Analysis of a New Symmetrical Linear Actuator for Hydraulic and Pneumatic Systems
,”
Trans. Canadian Soc. Mech. Eng
.
23
(
3
), pp.
377
396
.
7.
Habibi
,
S.
,
Burton
,
R.
, and
Sampson
,
E.
, 2006, “
High Precision Hydrostatic Actuation Systems for Micro and Nano Manipulation of Heavy Loads
,”
ASME J. Dyn. Syst., Meas., Control
,
128
(
4
), pp.
778
787
.
8.
Van de Vegto
,
J.
, 1994, Feedback Control Systems, 1 ed., Prentice Hall, England Cliffs, NJ.
9.
Joshi
,
S.
, and
Kelkar
,
A.
, 1998, “
Inner Loop Control of Supersonic Aircraft in the Presence of Aeroelastic Modes
,”
IEEE. Trans. Control Sys. Technol.
,
6
(
6
), pp.
730
739
.
10.
Kelly
,
R.
, and
Moreno
,
J.
, 2005, “
Manipulator Motion Control in Operational Space Using Joint Velocity Inner Loops
,”
Automatica
,
41
(
8
), pp.
1423
1432
.
11.
Sampson
,
E. B.
, 2005, “
Fuzzy Control of the Electrohydraulic Actuator
,” Master’s thesis, University of Saskatchewan, Saskatoon, Canada.
12.
Chinniah
,
Y. A.
, 2004, “
Fault Detection in the Electrohaydraulic Actuator Using Extended Kalman Filter
,” Ph.D. thesis, University of Saskatchewan, Saskatoon, Canada.
13.
Slotine
,
J.-J.
, and
Li
,
W.
, 1990,
Applied Nonlinear Control,
1 ed.
, Prentice Hall, United States Ed edition.
14.
Habibi
,
S.
, and
Singh
,
G.
, 2000, “
Derivation of Design Requirements for Optimization of a High Performance Hydrostatic Actuation System
,”
Int. J. Fluid Power
,
1
(
2
), pp.
11
29
.
15.
Habibi
,
S.
,
Roach
,
J.
, and
Luecke
,
G.
, 2008, “
Inner-Loop Control for Electromechanical (ema) Flight Surface Actuation Systems
,”
Trans. ASME J. Dyn. Syst., Meas., Control
,
130
, pp.
051002
–1-
13
.
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