T
(Ve)
saturates
100
200
300
400
500
0
100
200
300
400
500
Tfo
T
(V
e)
-
R
amp do
wn
time in ms
Ve - Vehicle speed: 1 unit = 0.1 km/h
700
800
900
600
1000
P005 218E
min time = 1
max time = 1000
Tfh
Default:
Verm=500
Tfo=350
Tfh=200
V
er
m
T
(Ve)
saturates
100
200
300
400
500
0
100
200
300
400
500
Tro
T
(V
e)
-
R
amp up
time in ms
Ve - Vehicle speed: 1 unit = 0.1 km/h
700
800
900
600
1000
min time = 1
max time = 1000
Trh
V
er
m
Default:
Verm=500
Tro=200
Trh=200
Sr Selects the ramp type. The ramp function can be disabled, fixed or related to vehicle speed. Set Sr to
21 to select vehicle speed dependant ramps.
Lr Sets the linearity of the ramp-up curve.
The default value is a linear ramp.
Lf Sets the linearity of the slow ramp-down curve.
The default value is a linear ramp.
Tro Sets the ramp-up time to open the valve from zero to max port flow when the vehicle speed is 0
kmph. The time applies for both ports.
To gain the best performance, the ramp-up time shall be set larger than the inherent ramp up time of the
main spool. See
on page 22.
Tfo Sets the ramp-down time to close the valve from max to zero port flow when the vehicle speed is 0
kmph. The time applies for both ports. It has most effect when the ramp-up time is set larger than the
inherent ramp down time of the main spool. See
on page 22 for these data.
Trh Sets the ramp-up time to open the valve from zero to max port flow when the vehicle speed is equal
to Verm kmph. The time applies for both ports.
To gain the best performance, the ramp-up time shall be set larger than the inherent ramp up time of the
main spool. See
on page 22 for these ramp times.
Tfh Sets the ramp-down time to close the valve from max to zero port flow when the vehicle speed is
equal to Verm kmph. The time applies for both ports. It has most effect when the ramp-up time is set
larger than the inherent ramp down time of the main spool. See
ramp times.
Verm Sets the region (in kmph) where ramp-up (Trh) and ramp-down (Tfh) time is variable to vehicle
speed.
YsetFr Experience shows that ramping down from maximum flow towards medium flows do not cause
as much jerk as ramping down from medium flows towards no flow (close to the valve dead-bands). In
order to “expedite” the ramping at large flows, a flow range can be set up where the spool can move
faster down to a flow range, where the slow down ramp is active. The overall goal with the parameter is
Operation Manual
PVED-CL Controller for Electro-Hydraulic Steering, Version 1.38
Steering by High Priority Steering Device – Open Loop
©
Danfoss | May 2016
11025583 | AQ00000216en-US0302 | 67