A fundamental part of a digital fluid power (DFP) pump is the actively controlled valves, whereby successful application of these pumps entails a need for control methods. The focus of the current paper is on a flow control method for a DFP pump. The method separates the control task concerning timing of the valve activation and the task concerning the overall flow output control. This enables application of linear control theory in the design process of the DFP pump flow controller. The linearization method is presented in a general framework and an application with a DFP pump model exemplifies the use of the method. The implementation of a discrete time linear controller and comparisons between the nonlinear model and the discrete time linear approximation shows the applicability of the control method.

References

References
1.
Ehsan
,
M.
,
Rampen
,
W. H. S.
, and
Salter
,
S. H.
,
2000
, “
Modeling of Digital-Displacement Pump-Motors and Their Application as Hydraulic Drives for Nonuniform Loads
,”
ASME J. Dyn. Syst. Meas. Control
,
122
(
1
), pp.
210
215
.
2.
Payne
,
G. S.
,
Stein
,
U. B. P.
,
Ehsan
,
M.
,
Caldwell
,
N. J.
, and
Rampen
,
W. H. S.
,
2005
, “
Potential of Digital Displacement Hydraulics for Wave Energy Conversion
,”
Sixth European Wave and Tidal Energy Conference
(
EWTEC
), Glasgow, UK, Aug. 29–Sept. 2, pp. 365–372.https://www.researchgate.net/publication/303313586_POTENTIAL_OF_DIGITAL_DISPLACEMENT_HYDRAULICS_FOR_WAVE_ENERGY_CONVERSION
3.
Rampen
,
W.
,
2010
, “
The Development of Digital Displacement Technology
,” Bath/ASME Symposium on Fluid Power and Motion Control (FPMC), Bath, UK, Sept. 15–17, pp. 11–16.
4.
Song
,
X.
,
2008
, “
Modeling an Active Vehicle Suspension System With Application of Digital Displacement Pump Motor
,”
ASME
Paper No. DETC2008-49035.
5.
Locateli
,
C. C.
,
Teixeira
,
P. L.
,
De Pieri
,
E. R.
,
Krus
,
P.
, and
De Negri
,
V. J.
,
2014
, “
Digital Hydraulic System Using Pumps and On/Off Valves Controlling the Actuator
,”
ASME
Paper No. FPNI2014-7839.
6.
Chapple
,
P.
,
Lindholdt
,
P. N.
, and
Larsen
,
H. B.
,
2014
, “
An Approach to Digital Distributor Valves in Low Speed Pumps and Motors
,”
ASME
Paper No. FPMC2014-7861.
7.
Roemer
,
D. B.
,
Johansen
,
P.
,
Pedersen
,
H. C.
, and
Andersen
,
T. O.
,
2014
, “
Optimum Design of Seat Region in Valves Suitable for Digital Displacement Machines
,”
Int. J. Mechatronics Autom.
,
4
(
2
), pp.
116
126
.
8.
Roemer
,
D. B.
,
Johansen
,
P.
,
Pedersen
,
H. C.
, and
Andersen
,
T. O.
,
2014
, “
Design Method for Fast Switching Seat Valves for Digital Displacement® Machines
,”
ASME
Paper No. FPNI2014-7852.
9.
Roemer
,
D. B.
,
Bech
,
M. M.
,
Johansen
,
P.
, and
Pedersen
,
H. C.
,
2015
, “
Optimum Design of a Moving Coil Actuator for Fast-Switching Valves in Digital Hydraulic Pumps and Motors
,”
IEEE/ASME Trans. Mechatronics
,
20
(
6
), pp.
2761
2770
.
10.
Wilfong
,
G.
,
Batdorff
,
M.
, and
Lumkes
,
J.
,
2010
, “
Design and Dynamic Analysis of High Speed On/Off Poppet Valves for Digital Pump/Motors
,”
6th FPNI-Ph.D. Symposium
, West Lafayette, IN, June 15–19.
11.
Wilfong
,
G.
,
Holland
,
M.
, and
Lumkes
,
J.
,
2011
, “
Design and Analysis of Pilot Operated High Speed On/Off Valves for Digital Pump/Motors
,”
52nd National Conference on Fluid Power
, Las Vegas, NV, Mar. 23–25, pp. 539–545.
12.
Scheidl
,
R.
, and
Manhartsgruber
,
B.
,
2005
, “
State of the Art in Hydraulic Switching Control—Components, Systems, Applications
,”
Ninth Scandinavian International Conference on Fluid Power
(
SICFP
), Linköping, Sweden, June 1–3, pp. 50–62.
13.
Winkler
,
B.
,
2004
, “
Development of a Fast Low-Cost Switching Valve for Big Flow Rates
,”
3rd FPNI Ph.D. Symposium on Fluid Power
, Terrassa, Spain, June 30–July 2, pp. 599–606.
14.
Winkler
,
B.
, and
Scheidl
,
R.
,
2006
, “
Optimization of a Fast Switching Valve for Big Flow Rates
,” Bath Symposium on Power Transmission and Motion Control (PTMC), Bath, UK, Sept. 13–15, pp. 387–399.
15.
Winkler
,
B.
,
Ploeckinger
,
A.
, and
Scheidl
,
R.
,
2008
, “
Components for Digital and Switching Hydraulics
,”
1st Workshop on Digital Fluid Power
, Tampere, Finland, Oct. 3, pp. 53–76.
16.
Holland
,
M. A.
,
Wilfong
,
G. J.
,
Merrill
,
K. J.
, and
Lumkes
,
J. H.
,
2011
, “
Experimental Evaluation of Digital Pump/Motor Operating Strategies With a Single-Piston Pump/Motor
,”
52nd National Conference on Fluid Power
, Las Vegas, NV, Mar. 23–25, pp. 13–21.
17.
Merrill
,
K.
,
Holland
,
M.
, and
Lumkes
,
J.
,
2011
, “
Analysis of Digital Pump/Motor Operating Strategies
,”
52nd National Conference on Fluid Power
, Las Vegas, NV, Mar. 23–25, pp. 1–7.
18.
Merrill
,
K. J.
,
Holland
,
M. A.
, and
Lumkes
,
J. H.
,
2010
, “
Efficiency Analysis of a Digital Pump/Motor as Compared to a Valve Plate Design
,”
7th International Fluid Power Conference: Workshop Proceedings
, Aachen, Germany, Mar. 22–24, pp.
313
324
.
19.
Merrill
,
K.
, and
Lumkes
,
J.
,
2010
, “
Operating Strategies and Valve Requirements for Digital Pump/Motors
,”
Sixth FPNI-PhD Symposium
, Lafayette, IN, June 15–19, pp. 341–352.
20.
Merrill
,
K.
,
Breidi
,
F.
, and
Lumkes
,
J.
,
2013
, “
Simulation Based Design and Optimization of Digital Pump/Motors
,”
ASME
Paper No. FPMC2013-4475.
21.
Nieling
,
M.
,
Fronczak
,
F.
, and
Beachley
,
N.
,
2005
, “
Design of a Virtually Variable Displacement Pump/Motor
,”
50th National Conference on Fluid Power
, Las Vegas, NV, Mar. 16–18, pp. 290–302.
22.
Johansen
,
P.
,
Roemer
,
D. B.
,
Andersen
,
T. O.
, and
Pedersen
,
H. C.
,
2015
, “
Delta-Sigma Modulated Displacement of a Digital Fluid Power Pump
,” 7th Workshop on Digital Fluid Power (
DFP
), Bath, UK, Feb. 26–27, pp. 143–151.http://vbn.aau.dk/en/publications/deltasigma-modulated-displacement-of-a-digital-fluid-power-pump(7ad972d3-522c-47ae-9e38-9c3a9658ce5b).html
23.
Armstrong
,
B. S. R.
, and
Yuan
,
Q.
,
2006
, “
Multi-Level Control of Hydraulic Gerotor Motors and Pumps
,”
American Control Conference
(
ACC
), Minneapolis, MN, June 14–16, pp. 4619–4626.
24.
Heikkilä
,
M.
,
Tammisto
,
J.
,
Huova
,
M.
,
Huhtala
,
K.
, and
Linjama
,
M.
,
2010
, “
Experimental Evaluation of a Piston-Type Digital Pump-Motor-Transformer With Two Independent Outlets
,” ASME/Bath Symposium on Fluidpower and Motion Control (
FPMC
), Bath, UK, Sept. 15–17, pp. 83–99.
25.
Heikkilä
,
M.
, and
Linjama
,
M.
,
2013
, “
Displacement Control of a Mobile Crane Using a Digital Hydraulic Power Management System
,”
Mechatronics
,
23
(
4
), pp.
452
461
.
26.
Sniegucki
,
M.
,
Gottfried
,
M.
, and
Klingauf
,
U.
,
2013
, “
Optimal Control of Digital Hydraulic Drives Using Mixed-Integer Quadratic Programming
,”
9th IFAC Symposium on Nonlinear Control Systems
(
NOLCOS
), Magdeburg, Germany, Sept. 4–6, pp. 827–832.
27.
Pedersen
,
H. C.
,
Johansen
,
P.
,
Yigen
,
C.
,
Andersen
,
T. O.
, and
Roemer
,
D. B.
,
2012
, “
Analysis of Temperature's Influence on a Digital Displacement Pump's Volumetric Efficiency
,”
Appl. Mech. Mater.
,
233
, pp.
24
27
.
28.
Roemer
,
D.
,
Johansen
,
P.
,
Pedersen
,
H. C.
, and
Andersen
,
T. O.
,
2012
, “
Analysis of Dynamic Properties of a Fast Switching On-Off Valve for Digital Displacement Pumps
,”
Bath/ASME Symposium on Fluid Power and Motion Control
(
FPMC
), Bath, UK, Sept. 12–14, pp.
151
164
.http://vbn.aau.dk/en/publications/analysis-of-dynamic-properties-of-a-fast-switching-onoff-valve-for-digital-displacement-pumps(f87a7f5e-40b0-4f93-abd1-a420f865918c).html
29.
Merritt
,
H.
,
1967
,
Hydraulic Control Systems
,
Wiley
, New York.
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