Danfoss pved-cl, Operation Manual, Page: 25 / 116

Diagram
Open-loop mode
Spool displacement
[mm, Xsp]
Flow, Q
[L/min]
Maximum flow (Vcap)
hydraulic deadband
Closed-loop mode
0
R L
Xspl_1000 Xspr_1000
Xspl_0 Xspr_0
(Xspl_0 - XspClosedLoopOffset)
Lspl Lspr
( XspClosedLoopOffset)
0
0
Flow range Flow range
Valve interface parameters
Xspl_0 Left software dead-band in PVED-CL open-loop operation mode.
Lspl Controls the left spool position-to-flow linearity. Use for compensating for non-linearity or to create
non-linear spool characteristics. Default is linear spool characteristic.
Xspl_1000 Left maximum port flow. Port flow at this set-point is equivalent to maximum valve capacity.
Xspr_0 Right software dead-band in PVED-CL open-loop operation mode.
Lspr Controls the right spool position-to-flow linearity. Use for compensating for non-linearity or to
create non-linear spool characteristics. Default is linear spool characteristic.
Xspr_1000 Right maximum port flow. Port flow at this set-point is equivalent to maximum valve
capacity.
Vcap Parameter holding information about the maximum flow capacity of the valve.
ClosedLoopXspOffset Spool position offset which is added to spool position set-point in closed-loop
mode only. The offset ensures that the spool is always operated at a point where the valve outputs a flow.
The offset extends the software open-loop dead-bands to form closed-loop dead-bands as illustrated
above.
Valve interface parameters
Symbol Index Default Value range
Xspl_0 737 -185 -250 to 0 for EH valve
-350 to 0 for EHPS valve
Lspl 702 0 -10 to 10 (max regressive to max progressive)
Xspl_1000 729 -1000 -1000 to -300 for EH valve
-1000 to -400 for EHPS valve
Xspr_0 738 185 0 to 250 for EH valve
0 to 350 for EHPS valve
Lspr 703 0 -10 to 10 (max regressive to max progressive)
Xspr_1000 747 1000 300 to 1000 for EH valve
400 to 1000 for EHPS valve
Vcap 706 25 5 to 120 (5 to 120 L/min)
ClosedLoopXspOffset 748 25 0 to 1000 (0 to ±maximum spool stroke)
ValveType 65121 1 1 - EHPS valve
2 - EH/OSPE valve
Note that the default values may not be suitable for all valve types.
Operation Manual
PVED-CL Controller for Electro-Hydraulic Steering, Version 1.38
Installation
© Danfoss | May 2016 11025583 | AQ00000216en-US0302 | 25