Danfoss pved-cl, Operation Manual, Page: 73 / 116

Kp
Port flow
limiter
Qm
Yact -
Actuator
position
Xstl -
Pot-
meter
like
device
Q - Port flow
command
Yr, Yl, Lx, Xysat, db
10 ms
10 ms
P005 211E
Tracking
Angle
Setpoint
Select the Control Principle
Cp selects the closed loop control using parameter index 3y02 equal to 255. Y selects the program and
ranges from 0 and 4. The value for y must be consistently used throughout the entire configuration of a
single program.
Acquire the Signals
See
Mapping a Steering Device on page 31 on how to map an analogue or CAN-based high priority closed-
loop steering device and steering wheel angle sensor.
Create the Set Point
A function provides 5 parameters to transform angle information to a steering actuator position set point.
1000
1000 -1000
-1000
750
500 250 -500 -750 -250
-750
-500
-250
250
500
750
St
eer
ing ac
tua
tor
p
osition setp
oin
t
Right steering
actuator end-lock
Left steering
actuator end- lock
saturation
YR
Lx
YL
db
Xysat
Example:
db = 250, Lx = 10
Xysat = 750
YR = -750
YL = 500
Xstl - Input signal: 1
unit = 0.1% of max
activation
Max input signal
for activating the
steering idevice
into the right
direction
Max input signal
for activating the
steering device
into the left
direction
1 unit = 0.1% of
st
eer
ing ac
tua
tor a
t the
righ
t end lo
ck p
osition
1 unit = 0.1% of
st
eer
ing ac
tua
tor a
t the
lef
t end lo
ck p
osition
P005 212E
Defaults:
db = 0, Lx = 0
Xysat = 1000
YR = 1000
YL = -1000
db Sets a dead band about the middle region of the signal. The parameters prevent self-steering, caused
by manufacturing deviations in the signal when the handle is in the middle or released position.
However, db is normally set to zero for pot-meter like steering devices.
The default value is set to serve pot-meter like steering devices
Lx Set the curve linearity. The parameter is set down when the cylinder position is too far (over-steer) for
small steering angles or vice versa.
The optimum value for this parameter is closely related to:
•
The inherent linearity between steering actuator position and signal
•
The inherent linearity between device handle angle and signal
•
The inherent over or under-steer tendency of the vehicle when steering into curves
•
The default value will not effect the resulting relation.
YR, YL The difference between the values of both parameter set the freedom of the steering actuator.
Normally, YR is set equal at the right mechanical end lock. YL is normally set equal to the left mechanical
end lock. This results in steering to the right direction. In case an opposite steering behavior is required,
Operation Manual
PVED-CL Controller for Electro-Hydraulic Steering, Version 1.38
Steering by High Priority Steering Device – Closed Loop
© Danfoss | May 2016 11025583 | AQ00000216en-US0302 | 73