In this technical brief, a novel hydraulic drive for large forces and power ratings at relatively high operating frequencies combining variable displacement control and hydraulic digital control is introduced. Basic analog motion control is achieved via variable displacement pumps driving a first cylinder stage. Digital control is realized by switching additional hydraulic cylinder stages on and off to support the analog stage if high forces are needed. The control strategy corresponds to this hydraulic concept. It consists of a feed forward control, a switching logic for the digital booster stages and a feed back proportional-integral (PI) control for stabilization. The validity of this concept and of the control strategy are shown by experiments on a highly downscaled test rig.

References

References
1.
Bramah
,
J.
,
1795
, “
Obtaining and Applying Motive Power
,” British Patent No. 2045.
2.
Roelands
,
R.
,
2000
, “
Modeling the Dynamics of Hydraulic Press Brakes
,” Primär-und Sekundärregelung für Pressen Eindhoven University of Technology, Eindhoven, NL,
Technical Report No. 2000.43
.
3.
Schmidt
,
S.
,
1997
, “
Energiesparende Primär-und Sekundärregelung für Pressen
,”
Ölhydraulik Pneum.
,
41
(
10
), pp.
747
751
.
4.
Li
,
W.
,
Sun
,
T.
,
Hu
,
Y.
, and
Li
,
W.
,
2013
, “
Research on Constant Velocity Extruding Press Control for 36,000-Ton Vertical Extrusion Press
,”
ASME J. Dyn. Syst., Meas., Control
,
135
(
4
), p.
041009
.
5.
Luenberger
,
D.
,
1979
,
Introduction to Dynamic Systems: Theory, Models, and Applications
,
Wiley
, Chichester, UK.
6.
Chen
,
C.
,
1998
,
Linear System Theory and Design
,
3rd ed.
,
Oxford University Press
, Oxford, UK.
You do not currently have access to this content.